ADIABATIC COOLER WITH CONTROL SYSTEM FOR WATER AND ENERGY USE REDUCTION

TECHNICAL FIELD

The present disclosure generally describes an adiabatic cooler with a control system and methods relating to water and energy conservation.

BACKGROUND

Heat rejection equipment is commonly used in industrial, commercial, and residential settings to provide cooling. One common type of heat rejection equipment is adiabatic coolers. Adiabatic cooling systems can cool the temperature of air below the ambient air's dry-bulb temperature by increasing the relative humidity of the air by pulling warm air through a wetted pad. Thus, adiabatic systems can be well suited for hot and dry environments because adiabatic cooling systems can consume less water than other types of evaporative heat rejection systems. Moreover, adiabatic systems can provide a similar cooling capacity to traditional dry cooler or condenser systems but do so in a smaller footprint and/or with less energy.

The performance of adiabatic systems can be measured by the saturation efficiency of the pad, heat rejection, water use, and energy use. The saturation efficiency, heat rejection, water use, and energy use can depend on the psychrometric properties of the local environment in which the system is located. Psychrometric properties can include, for example, the dry-bulb temperature, the wet-bulb temperature, the saturated vapor pressure, the relative humidity (RH), the specific humidity, the dew point temperature, and the enthalpy or total heat of the ambient air.

Some adiabatic systems utilize a relative humidity (RH) sensor to measure the incoming air's RH. However, RH sensors can be prone to failure and can be costly to maintain. Thus, without accurate and reliable psychrometric measurements and/or calculations, it can be difficult to operate the adiabatic cooling system in the most energy-efficient manner.

Therefore, there is a need for an adiabatic cooler, including a control system, for reliably measuring one or more psychrometric properties so that the adiabatic system can be operated to conserve water and energy.

SUMMARY

In accordance with some instances of the present disclosure, systems and methods for controlling an adiabatic cooling system are provided. The system and method of the system provide the ability to conserve water and/or energy and, in particular, to overcome the shortcomings related to traditional adiabatic cooling systems.

An adiabatic heat transfer system for cooling a process fluid is disclosed. The system comprises an adiabatic cooler having at least one media pad, at least one heat exchanger containing the process fluid, where the at least one heat exchanger is downstream of the at least one media pad. The cooler further includes a fluid distribution system designed to wet the at least one media pad by distributing cooling water over the at least one media pad. A fluid collection system including a basin for collecting the cooling water from the at least one media pad is also disclosed, and a recirculation conduit is in fluid communication with the basin and the fluid distribution system. A sensor is designed to sense a temperature of the cooling water of the at least one media pad. The system further includes a control system designed to adjust one or more operational parameters of the adiabatic heat transfer system based on the sensed temperature.

In some instances, the system further comprises a cooling water make-up conduit in fluid communication with the basin and a water make-up source. The system can include a first valve designed to control a flow of cooling water make-up through the cooling water make-up conduit, a second valve designed to control a flow of the cooling water to the fluid distribution system, a third valve designed to control a flow of the cooling water through a bleed conduit in fluid communication with the basin, and a fourth valve designed to control a flow of the cooling water through a fluid outlet conduit in fluid communication with the basin.

The control system is further designed to determine a mode of operation of the adiabatic heat transfer system when a sensed process fluid temperature is above a process fluid temperature threshold value, where the mode of operation includes at least one of a water conservation mode and/or an energy conservation mode. The one or more operational parameters of the adiabatic heat transfer system are adjusted based on the determined mode of operation and include opening at least one of the third valve and/or the fourth valve to remove the cooling water from the adiabatic heat transfer system and/or opening the first valve to add the cooling water make-up to the adiabatic heat transfer system.

In some aspects, the system further includes a second sensor designed to sense at least one environmental condition of ambient air. In some implementations, the control system is designed to determine an evaporation rate of the heat transfer system using the cooling water temperature and the sensed at least one environmental condition of the ambient air. In yet another instance, the system further includes a cooling water make-up conduit in fluid communication with the basin and a freshwater make-up source. The control system can be designed to open or close a make-up valve based on the determined evaporation rate and bleed rate of the heat transfer system.

Further provided is an adiabatic heat transfer system for cooling a process fluid. The system comprises an adiabatic cooler including at least one media pad and at least one heat exchanger containing the process fluid, where the at least one heat exchanger is downstream of the at least one media pad. A fluid distribution system is designed to wet the at least one media pad by distributing cooling water over the at least one media pad. A fluid collection system is designed to collect the cooling water from the at least one media pad or the fluid distribution system. A fluid outlet conduit is in fluid communication with the fluid collection system. A valve is designed to control a flow rate of the cooling water through the fluid outlet conduit, and a first sensor is designed to sense one or more water quality parameters of the cooling water leaving the at least one media pad. The system comprises a second sensor designed to sense at least one environmental condition of ambient air. A control system is provided and is designed to determine an approximate wet-bulb temperature of the adiabatic heat transfer system based on the sensed one or more water quality parameters of the cooling water of the at least one media pad, determine a cycles of concentration threshold value using the approximate wet-bulb temperature and the sensed at least one environmental condition of the ambient air, determine an operating cycles of concentration value based on the sensed one or more water quality parameters, and open the valve to drain the cooling water in the fluid collection system when the operating cycles of concentration value is higher than the determined cycles of concentration threshold value.

In some instances, the system further comprises a cooling water make-up conduit designed to deliver freshwater to the fluid collection system. A second valve is designed to control the flow of the freshwater to the fluid collection system. A bleed conduit is designed to deliver at least a portion of the cooling water to a wastewater system, and a third valve is designed to control the flow of the cooling water through the bleed conduit. In some implementations, the bleed conduit is provided downstream of a recirculation basin of the fluid collection system and upstream of the at least one media pad. In other implementations, the bleed conduit is downstream of the at least one media pad and upstream of a recirculation basin of the fluid collection system. In some instances, the control system is designed to open at least one of the second valve and/or the third valve in response to determining that the operating cycles of concentration value is higher than the cycles of concentration threshold value.

Still further provided is an adiabatic heat transfer system for cooling a process fluid. The system comprises an adiabatic cooler having at least one media pad and at least one heat exchanger containing the process fluid, where the at least one heat exchanger is downstream of the at least one media pad, a fluid distribution system designed to wet the at least one media pad by distributing cooling water over the at least one media pad, an air movement device designed to induce a flow of ambient air through the at least one media pad and the at least one heat exchanger, and a sensor designed to sense a temperature of the cooling water leaving the at least one media pad. The system further comprises a control system designed to determine a mode of operation of the adiabatic heat transfer system when a sensed process fluid temperature is above a process fluid temperature threshold value, where the mode of operation includes at least one of a water conservation mode and an energy conservation mode, and adjust one or more operational parameters of the adiabatic heat transfer system based on the mode of operation.

In some instances, in the energy conservation mode, the control system is designed to determine whether the air movement device is operating above a threshold speed setting prior to adjusting the one or operational parameters of the adiabatic heat transfer system. In some aspects, the system further comprises a fluid collection system designed to collect the cooling water that runs off of the at least one media pad, a fluid outlet conduit in fluid communication with the fluid collection system, and an outlet valve designed to control a flow of the cooling water through the fluid outlet conduit, and where adjusting the one or more operational parameters of the adiabatic heat transfer system includes opening the outlet valve to discharge some of the cooling water from the fluid collection system to a wastewater system if the air movement device is operating above the threshold speed setting. In some implementations, the control system is designed to determine whether the sensed process fluid temperature is above a second process fluid temperature threshold value in response to determining the air movement device is not operating above the threshold speed setting. In some instances, adjusting the one or more operational parameters of the adiabatic heat transfer system includes increasing a speed of the air movement device in response to determining the sensed process fluid temperature is greater than the second process fluid temperature threshold value, and determining whether the air movement device is operating at a minimum threshold speed setting in response to determining the sensed process fluid temperature is less than the second process fluid temperature threshold value.

In some instances, in the water conservation mode, the control system is designed to determine whether the sensed process fluid temperature is above a second process fluid temperature threshold value prior to adjusting the one or more operational parameters of the adiabatic heat transfer system. In some cases, the control system is designed to determine whether the air movement device is operating above a minimum threshold speed setting in response to determining the sensed process fluid temperature is less than the second process fluid temperature threshold value and determine whether the air movement device is operating below a maximum threshold speed setting in response to determining the sensed temperature is greater than the second process fluid temperature threshold value. In some aspects, adjusting the one or more operational parameters of the adiabatic heat transfer system includes at least one of adjusting a speed of the air movement device and opening the outlet valve so that at least some of the cooling water in the outlet conduit is discharged from the adiabatic heat transfer system.

A method of operating a heat transfer system is also disclosed. The method comprises the steps of determining an approximate ambient wet-bulb temperature based on a measured temperature of a cooling water stream leaving an adiabatic pad, determining if a measured temperature of a process fluid stream is above a first process fluid temperature setpoint, determining if the heat transfer system is being operated in a water conservation mode of operation or an energy savings mode of operation, and adjusting one or more operational parameters based on the mode of operation.

A method of operating an adiabatic cooling system is also provided. The method includes measuring a cooling water temperature at an outlet stream of a pad of the adiabatic cooling system, determining if a measured temperature of the process fluid is above a first process fluid temperature setpoint, determining if an air movement device is on, determining if the adiabatic cooling system is in a water conservation mode of operation or an energy savings mode of operation in response to determining the air movement device is on, and adjusting one or more operational parameters based on the mode of operation. In one instance, the mode of operation is defined by the water conservation mode.

In some aspects, the method also comprises determining if the process fluid temperature is greater than a second process fluid temperature setpoint in the water conservation mode.

The method can also include a step of determining if an air movement device is operating at its lowest operational setting in response to determining the process fluid temperature is less than a second process fluid temperature setpoint. In some aspects, the method further includes the step of determining if a recirculating pump is on in response to determining that the air movement device is not operating at its lowest operational setting. In yet another instance, the method comprises adjusting the air movement device operational setting to a lower setting as compared to a current setting in response to determining the recirculation pump is off.

The method can further include a step of determining if an ambient dry-bulb temperature is greater than a switchover dry-bulb temperature in response to determining whether the recirculation pump is on. If the system (e.g., unit) is operating adiabatically and the air movement device speed is below a defined percentage of full speed and the process fluid temperature is below the process fluid temperature set point, then the adiabatic operation can be turned off (e.g., the pump is turned off), allowing the system (e.g., unit) to operate in a dry cooling mode.

A recirculating system may be provided and can measure the water temperature on the discharge side of the recirculation pump in order to approximate the wet-bulb temperature. If the recirculation basin is very large, after reaching equilibrium, the accuracy of the approximated wet-bulb temperature can be substantially close to the temperature of the water leaving the adiabatic pad, even though the make-up flow is on.

A Resistant Temperature Detector (RTD) temperature probe can be inserted at a set distance (e.g., about 12 inches) above the bottom of where the water is leaving the pad. The RTD probe can measure or determine the water temperature and is capable of approximating the entering air wet-bulb temperature.

In some instances, the method comprises the step of turning off a recirculation pump in response to determining if the ambient dry-bulb temperature is less than a switchover dry-bulb temperature. If the system (e.g., unit) is operating adiabatically and the air movement device speed is below a defined percentage of full speed and the process fluid temperature is below the process fluid point, then the adiabatic operation can be turned off (e.g., the pump is turned off), allowing the system (e.g., unit) to operate in a dry cooling mode. In some implementations, the method comprises adjusting the air movement device operational setting to a higher setting as compared to the current setting in response to determining if the ambient dry-bulb temperature is less than a switchover dry-bulb temperature.

The method can include a step of determining if a difference between the process fluid temperature and at least one of the first and/or the second process fluid temperature setpoint is greater than a threshold in response to determining that the air movement device is operating at its lowest operational setting. In one instance, the air movement device is turned off in response to determining the difference between at least one of the first process fluid temperature setpoint, the second process fluid temperature setpoint, and/or the process fluid temperature is greater than the threshold temperature value.

In some aspects, the method comprises determining if the air movement device is operating at a maximum operational setting in response to determining that the process fluid temperature is greater than a second process fluid temperature setpoint. The method can include a step of adjusting the air movement device's operational setting to a higher setting as compared to a current setting in response to determining the air movement device is not operating at a maximum operational setting.

In still further examples, the method comprises the step of determining if the recirculation pump is on in response to determining the air movement device is operating at a maximum operational setting. The recirculation pump can be turned on in response to determining the recirculation pump is off.

In another instance, the method comprises the step of determining a bleed conduit valve position in response to determining the recirculation pump is on. The bleed conduit valve position can be adjusted.

In some cases, the method comprises the step of determining the cycles of concentration of the system and determining if the cycles of concentration are greater than a maximum cycles of concentration threshold value. In some examples, the method comprises the step of performing a blowdown or drain process in response to determining the cycles of concentration is greater than the allowed cycles of concentration threshold value.

In one instance, the mode of operation is defined by the energy conservation mode.

The method can include the step of determining if the air movement device is operating at an operational setting less than a maximum set point in the energy conservation mode. In some instances, the method includes the step of adjusting the air movement device's operational setting to a higher setting in response to determining the air movement device is operating at an operational setting less than the maximum set point.

In some implementations, the method comprises the step of determining if the recirculation pump is on in response to determining the air movement device is operating at an operational setting greater than the maximum set point. The recirculation pump can be turned on in response to determining that the recirculation pump is off.

In another aspect, the method comprises the step of determining a bleed conduit valve position in response to determining that the recirculation pump is on. The bleed conduit valve position can be adjusted.

In still another instance, the method comprises the step of determining the cycles of concentration of the system, and determining if the cycles of concentration are greater than a maximum cycles of concentration threshold value. The method can include a step of performing a blowdown or drain process in response to determining the cycles of concentration is greater than the allowed cycles of concentration threshold value.

In yet another instance, the method comprises the step of determining if the temperature of the process fluid is less than a third process fluid temperature setpoint in response to determining the cycles of concentration is less than the allowed cycles of concentration threshold value. In one instance, the method comprises adjusting the air movement device's operational setting to a higher setting in response to determining the temperature of the process fluid is greater than the third process fluid temperature setpoint.

In some aspects, the method of operating an adiabatic cooling system comprises the step(s) of removing and/or draining a concentrated liquid from the pad prior to the liquid entering a recirculation basin.

Further provided is an adiabatic heat transfer system for cooling a process fluid. The system comprises an adiabatic cooler including at least one media pad and at least one heat exchanger containing the process fluid, wherein the least one heat exchanger is downstream of the at least one media pad. A fluid distribution system is designed to wet the at least one media pad by distributing cooling water over the at least one media pad. The system comprises a fluid outlet conduit designed to direct the cooling water from the at least one media pad to a waste system. The fluid outlet conduit comprises a first sensor designed to sense one or more water quality parameters of the cooling water leaving the at least one media pad. The system comprises a second sensor designed to sense at least one environmental condition of ambient air. A control system is provided and is designed to determine an approximate wet-bulb temperature of the adiabatic heat transfer system based on the sensed one or more water quality parameters of the cooling water of the at least one media pad, determine a cycles of concentration threshold value using the approximate wet-bulb temperature and the sensed at least one environmental condition of the ambient air.

In some instances, the system further comprises a cooling water make-up conduit in fluid communication with the basin and a water make-up source. The system can include a first valve designed to control a flow of cooling water make-up through the cooling water make-up conduit and a second valve designed to control a flow of the cooling water to the fluid distribution system. The control system is designed to control the flow of the cooling water through the fluid outlet conduit by adjusting at least one of the first valve and the second valve.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples are described with reference to the following drawing figures. The same numbers are used throughout the figures to reference features and components.

FIG. 1 is a schematic diagram depicting an adiabatic heat rejection system having an adiabatic cooler and a control system in communication therewith;

FIG. 2 is a schematic diagram depicting the adiabatic cooler of FIG. 1 and a frame supporting the cooler;

FIG. 3A is a top left isometric view of a bottom portion of the frame of the adiabatic cooler of FIG. 2;

FIG. 3B is a top left isometric view of the frame of FIG. 3A with a heat exchanger installed on the frame;

FIG. 3C is a partial top right isometric view of a water collection basin of the adiabatic cooler of FIG. 2;

FIG. 3D is an enlarged view of the water collection basin of FIG. 3C;

FIG. 4 is a top right isometric view of an adiabatic cooler with multiple air movement device banks;

FIG. 5 is a schematic diagram depicting an adiabatic heat rejection system including two adiabatic coolers;

FIG. 6 is a flow chart illustrating a method of operation for an adiabatic heat rejection system such as those disclosed herein;

FIG. 7 is a schematic block diagram of a once-through adiabatic cooling system;

FIG. 8 is a schematic block diagram of an adiabatic cooling system having a recirculation system;

FIG. 9 is a schematic block diagram of an adiabatic cooling system having a recirculation system with a bleed conduit disposed at a first location;

FIG. 10 is a graph illustrating a water consumption amount compared to a bleed percent value for the system of FIG. 9;

FIG. 11 is a schematic block diagram of an adiabatic cooling system having a recirculation system with a bleed conduit disposed at a second location;

FIG. 12 is a graph illustrating a water consumption amount compared to a bleed percent value for the system of FIG. 11;

FIG. 13 is a graph illustrating a comparison of a water consumption trend for the adiabatic systems of FIGS. 7, 8, 9, and 11;

FIG. 14A is a flow chart illustrating a first portion of a method of operating an adiabatic cooler with a control system in a water conservation mode where the method includes a step of sensing a water temperature of the cooling water exiting a media pad of the adiabatic heat rejection system;

FIG. 14B is a flow chart illustrating a second portion of the method of FIG. 14A;

FIG. 15A is a flow chart illustrating a first portion of a method of operating an adiabatic cooler with a control system in a water conservation mode where the method includes analyzing a dry-bulb temperature of the adiabatic heat rejection system;

FIG. 15B is a flow chart illustrating a second portion of the method of FIG. 15A;

FIG. 16A is a flow chart illustrating a first portion of a method of operating an adiabatic cooler with a control system in a water conservation mode where the method includes adjusting a speed of an air movement device;

FIG. 16B is a flow chart illustrating a second portion of the method of FIG. 16A;

FIG. 17A is a flow chart illustrating a first portion of a method of operating an adiabatic cooling system in an energy conservation mode; and

FIG. 17B is a flow chart illustrating a second portion of the method of FIG. 17A.

DETAILED DESCRIPTION

Before any instances of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The system is capable of other instances and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” “controlled,” “coupled,” and “communicated” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, controls, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings and can also include electrically and communicatively coupled configurations in addition to other forms of connections or couplings.

The following discussion is presented to enable a person skilled in the art to make and use instances of the system. Various modifications to the illustrated instances will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other instances and applications without departing from instances of the system. Thus, instances of the invention are not intended to be limited to instances shown but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected instances and are not intended to limit the scope of instances of the system. Skilled artisans will recognize the examples provided herein as having many useful alternatives and falling within the scope of instances of the invention.

The present disclosure provides an adiabatic heat rejection system, including a temperature sensor designed to measure the temperature of water exiting a wetted media pad. The adiabatic heat rejection system further includes a controller designed to determine an approximate ambient wet-bulb temperature of the adiabatic heat rejection system based on the measured temperature of the water exiting the media pad. Using the approximate wet-bulb temperature, a controller is designed to adjust one or more operating parameters of the heat rejection system to reduce water and/or energy costs.

Referring to FIG. 1, a schematic of an adiabatic heat transfer system 100 is depicted. The system 100 is provided in the form of at least one adiabatic cooler 110 designed to cool a process fluid and a central controller or control system 120 designed to be in electronic communication with and/or control one or more components of the adiabatic cooler 110. In one instance, the heat transfer system 100 can include a plurality of adiabatic coolers designed to be in fluid communication and/or communicatively coupled with one another.

The control system 120 can be communicatively coupled to the system 100 to control, receive, and/or store data from the system 100. For example, the control system 120 can be in wireless communication or wired communication with a network 140 to directly or indirectly communicate and/or operate at least one or more of the adiabatic cooler 110, fluid distribution system, sump, pump, valve, sensor, air movement device, and/or other system components within the system 100, as discussed herein.

Specifically, the control system 120 can intelligently manage the fluid flow within and/or into and out of the system 100. The control system 120 can be provided in the form of a data-processing device configured to transmit and receive data from the system 100. For example, the control system 120 can receive information at a receiver (not shown). A processor (not shown) included in the control system 120 can analyze the received data and determine instructions to be sent back to the system 100. A transmitter (not shown) of the control system 120 can send the instructions from the processor to one or more components of the system 100. The control system 120 can further include a memory (not shown). The memory can be configured to store data received from the system 100. The memory can be implemented as a stand-alone memory unit and/or as part of a processor included in the control system 120. Further, in some instances, the network 140 can be coupled to the memory, which can include program instructions that are stored in the memory and executable by the processor to perform one or more of the methods described herein.

The network 140 can be provided in the form of a network interface, a local network, or other communication connection and is not limited to the plurality of communication connections. One skilled in the art will recognize that a communication connection can transmit and receive data using a plurality of communication protocols, including but not limited to wired, wireless, Bluetooth, cellular, satellite, GPS, RS-485, RF, MODBUS, CAN, CANBUS, DeviceNet, ControlNet, Ethernet TCP/IP, RS-232, Universal Serial Bus (USB), Firewire, Thread, proprietary protocol(s), or other communication protocol(s) as applicable. In some instances, the network 140 is located proximate to one or more components of the system 100. The network 140 can include the Internet, intranets, extranets, wide area networks (“WANs”), local area networks (“LANs”), wired networks, wireless networks, cloud networks, or other suitable networks, or any combination of two or more networks, Ethernet networks, and other types of networks. The network 140 can be configured to communicate directly or indirectly with the system 100 and/or a user device 130 provided in the form of a personal computer, tablet, cell phone, display, or other similar electronic device (e.g., that can have an application) that allows a user to interface with the control system 120.

Although FIG. 1 depicts the control system 120 in communication with the user device 130 and the network 140, it should be noted that various communication methodologies and connections can be implemented to work in conjunction with, or independent from, one or more local controllers associated with one or more individual components associated with the system 100 as discussed herein.

Turning to FIG. 2, a schematic of a cooler 200 in accordance with the teachings of the present disclosure is shown. The cooler 200 can be the cooler 110 of FIG. 1. The cooler 200 includes at least one heat exchanger 202 designed to cool a process fluid. In some implementations, the cooler 200 is provided in the form of an adiabatic cooler. Accordingly, in some instances, the at least one heat exchanger 202 is an indirect heat exchanger that includes a conduit bundle designed to contain the process fluid therein. In other instances, the at least one heat exchanger 202 can be a direct heat exchanger or another suitable heat exchanger. The process fluid within the at least one heat exchanger 202 is cooled by passing pre-cooled air over the at least one heat exchanger 202. In some aspects, the at least one heat exchanger 202 includes a first heat exchanger conduit bundle 202a positioned on a first side of the cooler 200 and a second heat exchanger conduit bundle 202b positioned on a second side of the cooler 200 opposite the first side. In some instances, each of the first heat exchanger conduit bundle 202a and the second heat exchanger conduit bundle 202b can be arranged in a “V-shaped” configuration. In this configuration, the hot process fluid enters the at least one heat exchanger 202 through a process fluid inlet 204. The cooled process fluid exits the at least one heat exchanger 202 through a process fluid outlet 206.

To pre-cool the air, at least one air movement device 210 is positioned in an upper portion 211 of the cooler 200. In some instances, the at least one air movement device 210 is provided in the form of a fan. Non-limiting examples of fans include an axial fan and a centrifugal blower. The at least one air movement device 210 can be designed to pull ambient air into the cooler 200 via at least one air inlet 212 and through one or more media pads 220 designed to increase the relative humidity of the ambient air, thereby lowering the entering air's dry-bulb temperature. The media pads 220 are designed to be wetted with cooling water via a fluid distribution system 230 (e.g., positioned above or near the top of the media pads 220). The media pads 220 can be supported by a frame 240 extending between the upper portion 211 and an opposing lower portion 213 at or near a basin 260, discussed herein. As shown, the media pads 220 can be provided in the form of a first pad 220a positioned on a first side of the cooler 200 and a second pad 220b positioned on a second side of the cooler 200 opposite the first side. The first pad 220a can be positioned substantially adjacent to the first heat exchanger conduit bundle 202a, and the second pad 220b can be positioned substantially adjacent to the second heat exchanger conduit bundle 202b. In some aspects, each of the first pad 220a and the second pad 220b can be provided in the form of more than one pad. For example, more than one pad can be arranged adjacent to or abut one another, such that they form a larger pad area that defines the first pad 220a or the second pad 220b.

The media pads 220 can be provided in the form of a plurality of impregnated cellulose paper sheets. The plurality of cellulose paper sheets can be connected, attached, or arranged together to form a media pad. In some instances, each sheet is formed into a corrugated or sinusoidal shape pattern designed to increase the surface area per cubic volume of the sheet. In some instances, the sheets can be arranged such that the pattern of the sheet (e.g., the corrugated and sinusoidal shaped patterns) is opposite an adjacent sheet. In other words, the patterns of adjacent sheets can be opposite each other. In some aspects, each sheet of the plurality of sheets are spaced apart about 3 to 6 sheets per inch. The air travel (e.g., depth) of the media pads 220 can be between about 2 inches to about 4 inches. In some instances, the air travel of the media pads 220 is between about 3 inches to about 6 inches.

The fluid distribution system 230 can include at least one inlet for fluid to enter the fluid distribution system 230 and at least one outlet for fluid to exit the fluid distribution system 230, and a plurality of nozzles therebetween. The fluid distribution system 230 further includes a first portion 230a designed to wet the first pad 220a and a second portion 230b designed to wet the second pad 220b. Each of the first portion 230a, and the second portion 230b, can include one or more nozzles of the plurality of nozzles designed to spray cooling water over the media pads 220. In some instances, the first portion 230a and the second portion 230b of the fluid distribution system 230 can be operated independently (e.g., one portion can be “on” and spray cooling water on its associated pad, and the other portion can be “off” and not spray cooling water on its associated pad). In other instances, each of the first portion 230a and the second portion 230b of the fluid distribution system 230 is operated as a single system. For example, each of the first portion 230a, and the second portion 230b, are controlled as a single unit. In other instances, the system 100 can include a plurality of fluid distribution systems 230 designed to be in fluid communication with one another.

During operation, as discussed further herein, the ambient air is pulled through the at least one air inlet 212, adiabatically the air transfers moisture from the pads 220 lowering the air dry-bulb temperature, and then flows across the at least one heat exchanger 202, thereby cooling the process fluid contained within the at least one heat exchanger 202. Thus, the heat from the at least one heat exchanger 202 is transferred to the air. The heated air is then discharged from the cooler 200 via an air outlet 250 positioned in the upper portion 211 of the cooler 200 at or near the at least one air movement device 210.

As discussed herein, the cooling water sprayed over the media pads 220 (e.g., via the fluid distribution system 230) can be collected in a fluid collection system, including the basin 260. The basin 260 can include one or more sensors 262 designed to sense one or more water quality parameters or characteristics of the cooling water in the basin 260. The one or more sensors 262 can be provided in the form of one or more of a temperature sensor, a level sensor, a conductivity sensor, a turbidity sensor, and/or other known sensors in the art. Non-limiting examples of the level sensor include a float switch, an ultrasonic level sensor, a capacitive level sensor, a hydrostatic level sensor, and other known sensors in the art.

As discussed in more detail herein, the cooling water in the basin 260 can be recycled through the cooler 200 (e.g., used to wet the media pads 220 again). Thus, the basin 260 can include and/or be in fluid communication with a pump 270. For example, the pump 270 can be positioned within and/or in communication with the basin 260. The pump 270 is also in fluid communication with a recycle conduit 280, which is in fluid communication with the fluid distribution system 230. The pump 270 provides the driving force to deliver the cooling water from the basin 260 through the recycle conduit 280 to the fluid distribution system 230. In some instances, the recycle conduit 280 includes an optional recycle valve 282 designed to control a flow of the cooling water through the recycle conduit 280. In other instances, the recycle valve 282 may be omitted from the recycle conduit 280, or omitted altogether.

The cooler 200 can include at least one drain valve 283 and/or a cooling water outlet conduit 284 designed to direct some or all of the cooling water collected in the basin 260 to a waste system or a recirculation or storage tank. As discussed herein, the basin 260 can be in fluid communication with one or more flumes designed to direct cooling water run-off from the media pads 220. Accordingly, in some instances, the cooling water outlet conduit 284 can be in fluid communication with one or more flumes as discussed herein. Further discussed in more detail herein, recycling a portion of the cooling water through the cooler 200 can be beneficial. However, it can also be beneficial to discharge some or all of the cooling water to a waste system to limit contaminants in the cooler 200. Too many contaminants can foul the media pads 220 and/or other components of the system 100. Further, some cooling water can evaporate from the cooler 200. Accordingly, the cooler 200 includes a cooling water make-up conduit 286 designed to deliver fresh cooling water (e.g., additional cooling water) to the cooler 200 to replace the discharged and/or evaporated cooling water and/or to dilute contaminants in cooling water being circulated through the cooler 200. In some instances, the cooling water make-up conduit 286 is in fluid communication with the basin 260. Thus, in one instance, the make-up water mixes with the recycled cooling water in the basin 260 before the cooling water is delivered to the fluid distribution system 230. In some instances, the cooling water make-up conduit 286 is in fluid communication with the fluid distribution system 230 (e.g., the cooling water make-up conduit 286 ties into the cooler 200 downstream of the basin 260).

The cooler 200 further includes a controller and/or control system 290. In one instance, the control system 290 can be the control system 120 of FIG. 1. Alternatively, the control system 290 can be a local controller communicatively coupled to the control system 120. The control system 290 is designed to control one or more components of the cooler 200 (e.g., the at least one air movement device 210, the fluid distribution system 230, the pump 270, the optional recycle valve 282 and/or other components, such as sensors, of the cooler 200).

FIGS. 3A-3D illustrate various views of components of an adiabatic cooler 300 in accordance with the teachings of the present disclosure. The adiabatic cooler 300 can be the cooler 110 of FIG. 1 and/or the cooler 200 of FIG. 2. FIG. 3A is a bottom portion of a frame 310 of the cooler 300. The frame 310 can have a base 315 and can include a plurality of supports 320 designed to support the media pads 220 and/or the heat exchanger conduit bundles 202a, 202b discussed in reference to FIG. 2 (e.g., the at least one heat exchanger 202 and the media pads 220).

In some instances, the base 315 of the frame 310 can include one or more flumes 330 in fluid communication with a basin 332, such that a first flume 341 can be positioned on a first side 351 (e.g., substantially underneath at least one (e.g., first) adiabatic pad) and a second flume 342 can be positioned on a second side 352 (e.g., substantially underneath at least one (e.g., second) adiabatic pad) opposite the first side 351. The basin 332 can be the basin 260 of FIG. 2. The one or more flumes 330 are designed to collect the run-off cooling water from the media pads 220 and direct the run-off cooling water toward the basin 332. In some instances, the basin 332 can include a weir or overflow outlet 331 designed to prevent the basin 332 form overflowing. The basin 332 and the one or more flumes 330 can be collectively referred to as a fluid collection system 360.

FIG. 3B illustrates the cooler 300 with a heat exchanger 370 installed on the frame 310. The heat exchanger 370 can be the at least one heat exchanger 202 of FIG. 2.

FIGS. 3C and 3D depict a portion of the basin 332, a pump 380, and a recycle conduit 390. The pump 380 can be the pump 270 of FIG. 2, and the recycle conduit 390 can be the recycle conduit 280 of FIG. 2. As discussed above, the adiabatic cooler described herein can include an optional recycle valve (e.g., the valve 282) on the recycle conduit. However, as shown in FIGS. 5A and 5B, the cooler 300 omits the optional recycle valve 282 discussed with respect to FIG. 2. The pump 380 can be in communication with a controller and/or control system (e.g., the control system 120 of FIG. 1 and/or the control system 290 of FIG. 2).

FIG. 4 illustrates a cooler 400 in accordance with the teachings of the present disclosure. The cooler 400 can be the cooler 110 of FIG. 1. The cooler 400 is similar to the cooler 200 of FIG. However, the cooler 400 can include additional components designed to increase the cooling capacity of the cooler 400.

In some instances, the cooler 400 includes a plurality of heat exchangers 402. The plurality of heat exchangers includes a first heat exchanger conduit bundle 403 positioned on a first side of the cooler 400 and a second heat exchanger conduit bundle 405 positioned on a second side of the cooler 400 opposite the first side. In some instances, each of the first heat exchanger conduit bundle 403 and the second heat exchanger conduit bundle 405 can be arranged in a “V-shaped” configuration.

In some instances, the first heat exchanger conduit bundle 403 includes a first heat exchanger conduit bundle 403a positioned near a lower portion 407 of the cooler 400, and a second heat exchanger conduit bundle 403b positioned above the first heat exchanger conduit bundle 403a, near a top portion 409 of the cooler 400. Similarly, the second heat exchanger conduit bundle 405 can include a third heat exchanger 405a positioned near the lower portion 407 of the cooler 400, and a fourth heat exchanger 405b positioned above the third heat exchanger 405a, near the top portion 409 of the cooler 400. In other words, each of the first heat exchanger conduit bundle 403 and the second heat exchanger conduit bundle 405 can be provided in the form of multiple heat exchanger conduit bundles that can be stacked or arranged vertically to increase the height of the cooler 400. Further, it may be easier to install multiple heat exchangers at the field location of the cooler 400, rather than transporting and arranging one single large heat exchanger.

In some instances, the first heat exchanger conduit bundle 403 and the second heat exchanger conduit bundle 403b are arranged in a parallel configuration. Similarly, the third heat exchanger 405a and the fourth heat exchanger 405b can be arranged in a parallel configuration. Thus, each heat exchanger includes a hot process fluid inlet and a cooled process fluid outlet. A benefit of arranging the heat exchangers in a parallel configuration is that a larger volume of process fluid can be cooled.

In other instances, the first heat exchanger conduit bundle 403 and the second heat exchanger conduit bundle 403b are serially arranged. Similarly, the third heat exchanger 405a and the fourth heat exchanger 405b can be serially arranged. In a serial arrangement, the cooled process fluid from one heat exchanger (e.g., the process fluid outlet) is provided as the hot process fluid (e.g., the process fluid inlet) to the “downstream” heat exchanger. A benefit of arranging the heat exchangers in a serial configuration is that the process fluid can have more time to be cooled.

As discussed herein, pre-cooled air is pulled over the plurality of heat exchangers 402. The cooler 400 includes a plurality of air movement device banks 410, including a plurality of air movement devices positioned in the top portion 409 of the cooler. The plurality of air movement devices are designed to pull the pre-cooled air through the cooler 400. The plurality of air movement device banks 410 can include a first bank 410a arranged on a first side of the cooler (e.g., the same side of the cooler 400 including the first heat exchanger conduit bundle 403) and a second bank 410b positioned on a second side of the cooler 400, opposite the first side (e.g., the same side of the cooler 400 including the second heat exchanger conduit bundle 405).

Each of the first bank 410a and the second bank 410b can include a plurality of air movement devices. In some instances, the plurality of air movement devices are provided in the form of a plurality of fans. As depicted, in some instances, each of the first bank 410a and the second bank 410b may include five air movement devices 410, or another number of air movement devices may be provided. In some instances, the plurality of air movement devices in each of the first bank 410a and the second bank 410b are controlled as a single unit. In other words, a control system can be designed to maintain a power or speed setting of each air movement device of the plurality of air movement devices at an approximately equal setting.

As discussed herein, the plurality of air movement devices are designed to pull ambient air into the cooler 400 and through a plurality of media pads 420. The plurality of media pads 420 can include a first set of media pads 421 positioned on a first side of the cooler 400 (e.g., the same side of the cooler 400 including the first heat exchanger conduit bundle 403) and a second set of media pads 423 positioned on a second side of the cooler 400 opposite the first side of the cooler 400 (e.g., the same side of the cooler 400 including the second heat exchanger conduit bundle 405).

The first set of media pads 421 can include a first media pad 421a positioned near the lower portion 407 of the cooler 400, and a second set of media pad 421b positioned above the first set of media pads 421a, near the top portion 409 of the cooler 400. Similarly, the second set of media pads 423 can include a third media pad 423a positioned near the lower portion 407 of the cooler 400, and a fourth media pad 423b positioned above the third media pad 423a, near the top portion 409 of the cooler 400. In other words, each of the first set of media pads 421 and the second set of media pads 423 can be provided in the form of multiple media pads that can be stacked or arranged vertically to increase the height of the cooler 400. Further, it may be easier to install multiple media pads at the field location of the cooler 400, rather than transporting and arranging one single large media pad.

FIG. 5 is a schematic of a cooler system 500, including a first cooler 501a and a second cooler 501b arranged in a serial configuration. The cooler system 500 can be the cooler 110 of FIG. 1. The first cooler 501a and the second cooler 501b can each independently be provided in the form of the cooler 300 of FIG. 3 or the cooler 400 of FIG. 4. As discussed herein, hot process fluid enters the first cooler 501a via the process fluid inlet 204. However, instead of sending the cooled process fluid to a system to be cooled (e.g., a data center and/or an HVAC system), the cooled process fluid is directed to another cooler (e.g., the second cooler 501b) for further cooling. Thus, the process fluid outlet 206 of the first cooler 501a is in fluid communication with a second process fluid inlet 502 of the second cooler 501b. The process fluid is then further cooled in the second cooler 501b. The cooled process fluid from the second cooler 501b is then sent to the system to be cooled via a second process fluid outlet 506. A benefit of the cooler system 500 is that the process fluid may be able to be cooled to a lower temperature as compared to a single cooler system.

FIG. 6 is a flow chart illustrating a method 600 of operation for an adiabatic cooler. At a first step 610, an adiabatic cooler, such as the cooler 110 of FIG. 1, the cooler 200 of FIG. 2, and/or the cooler 300 of FIGS. 3-5B, can operate in a wet cooling mode or a dry cooling mode. A controller, such as the control system 120 of FIG. 1 and/or the control system 290 of FIG. 2, can control a fluid distribution system (e.g., the fluid distribution system 230 of FIG. 2) to wet a media pad (e.g., the media pads 220 of FIG. 2) of the cooler with cooling water. As discussed herein, during the wet cooling mode, the fluid distribution system distributes cooling water onto one or more of the adiabatic pads. The cooling water then passes over the pad(s) and can be collected in a fluid collection system (e.g., the fluid collection system 360 of FIGS. 3, 4, and 5A-5B). As discussed herein, the cooling water can be recycled through the cooler and/or removed (e.g., drained from a basin or bled from a bleed conduit) from the system 100. During the dry cooling mode, the fluid distribution system does not distribute cooling water onto one or more of the adiabatic pads.

At step 620, the controller can activate or turn on an air movement device, such as the at least one air movement device 210 of FIG. 2, to induce a flow of ambient air through the (e.g., wetted) pads. As warm ambient air is pulled through the (e.g., wetted) pads, the ambient air's relative humidity is increased, thereby reducing the entering ambient air's dry-bulb temperature.

At step 630, the cooled air is pulled across the at least one heat exchanger 202 to cool the process fluid contained therein. The heat from the process fluid is transferred to the air, thereby cooling the process fluid. The cooled process fluid can be used for cooling purposes, such as cooling a data center or an HVAC system.

At step 640, the now heated air is discharged through a top portion of the cooler due to the induced draft created by the air movement device.

A benefit of adiabatic coolers is that they can use less water and energy than traditional evaporative cooling towers. However, it can still be beneficial to adjust one or more operating parameters of the adiabatic cooler system to conserve water and/or energy use based on the cooling needs of the system 100 and/or based on the environment (e.g., geographical location and/or weather) of the heat transfer system 100. The one or more operating parameters can include, for example, the flow rate of the cooling water make-up, the rate of waste cooling water removed from the system, and/or the speed or power of the air movement device. As such, it is beneficial to know the evaporation rate of the system so that the water and energy costs can be minimized.

Some of the psychometric properties of the system and environment are used to determine the evaporation rate. In some known methods to determine or calculate at least one psychrometric property, a measurement such as the atmospheric pressure and at least two other parameters or properties can be used. For example, a combination of psychrometric properties, such as atmospheric pressure, ambient dry-bulb temperature and/or approximate wet-bulb temperature can be used to calculate one or more other psychrometric properties. In another example, a combination of psychrometric properties, such as an atmospheric pressure, a vapor pressure, and/or a specific volume, can be used to calculate one or more other psychrometric properties.

In some instances, knowing the wet-bulb temperature can allow for the determination of the evaporation rate using known or derived methods and/or other known psychrometric measurements. When the evaporation rate is known, and the maximum allowable COC (Cycles of Concentration) is known, the amount of water that should be supplied to the pad to maintain a desired cooling rate can be determined according to Formula I.

$Supply Water to Pad (flow rate) = \frac{Evaporation Rate}{Maximum Cycles of Concentration - 1} + Evaporation rate$

Formula I

It can be advantageous to regulate the flow rate of the cooling water supplied to the pad to maximize the allowable COC of the water leaving the pad. Extra water supplied to the pad can result in higher water usage and, consequently, higher operation costs. Conversely, in cases where less water is supplied to the pad, the COC of water leaving the pad will be higher, and the pad will tend to accumulate mineral deposits or contaminants at a higher rate.

However, determining the wet-bulb temperature can be difficult. Some adiabatic systems employ a relative humidity (RH) sensor to gauge the RH of the incoming air, but RH sensors can be susceptible to malfunction and can incur high maintenance costs. Consequently, without precise and dependable psychrometric measurements and/or calculations, achieving optimal energy efficiency in the operation of adiabatic cooling systems can be challenging.

Therefore, the heat transfer system 100, including the adiabatic cooler 110 disclosed herein, can include systems and methods for determining the approximate wet bulb temperature of the ambient air without using an RH sensor. During operation, as the adiabatic cooling process approaches a steady state, the temperature of the cooling water in the pad can approach the ambient wet bulb temperature. As such, the temperature of the cooling water coming off the pad can be used as the approximate wet bulb temperature. Moreover, unlike RH sensors, temperature sensors can be more reliable and cost-effective. Accordingly, the heat transfer system 100, including the adiabatic cooler 110, 200, and/or 300, includes a plurality of sensors, including at least one temperature sensor, to provide a reliable and affordable method for determining one of the psychometric properties of the system. Thus, the temperature of the cooling water coming off of the pad can be used to determine the evaporation rate of the system 100. Furthermore, the systems and methods disclosed herein can be applied to various adiabatic system configurations. For example, the following figures illustrate exemplary adiabatic cooling systems designed to operate as once-through systems and/or recirculating systems and include various fluid flow arrangements. The systems and methods described herein can be used in conjunction with these adiabatic systems.

Turning to FIG. 7, a block diagram of a portion of a once-through adiabatic heat transfer system 700 is shown. In the system 700, the cooling water delivered to the system 100 is used to wet at least one adiabatic pad, and the water used to wet the pad is not recycled through the system 700. The system 700 can include at least one media (e.g., adiabatic) pad 710 and a cooling water make-up conduit 720 designed to deliver cooling water to the pad 710. The system 700 can be included in, or part of, the cooler 110 of FIG. 1, the cooler 200 of FIG. 2, and/or the cooler 300 of FIGS. 3-5B. Accordingly, the media pad 710 can be the media pads 220 of FIG. 2. The cooling water make-up conduit 720 can be the cooling water make-up conduit 286 of FIG. 2. Furthermore, the system 700 can include one or more components, such as a pump (e.g., the pump 270 of FIG. 2 and/or the pump 380 of FIGS. 5A and 5B) and/or one or more valves 722, for controlling the flow of the incoming cooling water. The cooling water make-up conduit 720 can also include one or more sensors 724 for monitoring one or more parameters (e.g., related to the quality and/or chemical or physical properties, such as temperature, conductivity, turbidity, pH value, and the like) of the incoming cooling water.

The cooling water supplied through the cooling water make-up conduit 720 can be provided from a number of sources, including a municipal water supply, water from a tank, river, lake, canal, or other known water supply. Further, in some instances, the make-up water can be pre-treated prior to entering the system 700. The cooling water make-up conduit 720 can further include a system or be in fluid communication with a system for spraying or otherwise distributing the cooling water over the pad 710 (e.g., the fluid distribution system 230 of FIG. 2). The cooling water that runs off of the pad 710 can be removed from the system 700 as wastewater through a waste conduit 730. In some instances, the waste conduit 730 is the cooling water outlet conduit 284 of FIG. 2. Accordingly, the system 700 can include a fluid collection system 732 designed to collect the cooling water used to wet the at least one pad before the cooling water is removed (e.g., drained) from the system. The fluid collection system 732 can be, or include part of, the fluid collection system 360 of FIG. 3A. The waste conduit 730 can include one or more valves 734 for controlling the flow of the waste cooling water leaving the fluid collection system 732. The waste conduit 730 can further include one or more sensors 736 for monitoring one or more water quality parameters of the waste cooling water. As shown, in some instances, the one or more sensors 736 can be positioned downstream of the pad 710 and upstream of the fluid collection system 732. In some aspects, the one or more sensors 736 can be positioned downstream of the fluid collection system 732. The one or more sensors 736 can be provided in the form of one or more of a temperature sensor, a level sensor, a turbidity sensor, and/or other known sensors designed to sense one or more water quality parameters in the art.

The one or more sensors 724, 736 for monitoring the water quality parameters of the incoming and/or waste cooling water can be provided in the form of a total dissolved solids (TDS) sensor, a flow sensor, a temperature sensor, a conductivity sensor, a pH sensor, and/or any other sensor designed to measure a chemical, physical, or other property of the cooling water. The one or more water quality parameters can be used to determine a desired flow rate of the incoming cooling water in the cooling water make-up conduit 720.

During the operation of system 700, ambient air 740 is provided to the system and pulled across the (e.g., wetted) pad 710 by an air movement device, such as a fan (e.g., the at least one air movement device 210 of FIG. 2) included in or in communication with the system 700. As the air 740 travels across the wetted pad 710, the relative humidity of the air increases, and the air's dry bulb temperature decreases. However, during this cooling process, some of the water sprayed over the pad 710 can evaporate, as shown by the arrow 750, representing the evaporation rate of the cooling water in the system 700. Thus, to ensure that the pad 710 remains wetted and can provide the desired cooling capacity, one or more operating parameters of the system 700 can be adjusted. Thus, in one instance, the one or more sensors 736 include a temperature sensor designed to sense the temperature of the cooling water leaving the pad 710. The temperature sensor can be provided in the form of a Resistant Temperature Detector (RTD), a thermistor, a thermocouple, a semiconductor-based integrated circuit, or any other suitable temperature sensor. To ensure that the measured temperature is close to the wet bulb temperature, placing the temperature sensor proximate to or adjacent to the pad 710 (e.g., at or near the water leaving pad) can be beneficial.

The system 700 further includes a sensor 759 designed to sense one or more environmental conditions near or around the cooler included in the system (e.g., the cooler 110 of FIG. 1, the cooler 200 of FIG. 2, and/or the cooler 300 of FIGS. 3-5B). The one or more environmental conditions can include the dry-bulb temperature, the saturated vapor pressure, the relative humidity (RH), the specific humidity, the dew point temperature, and the enthalpy or total heat of the ambient air near or around the pad 710. In some instances, the sensor 759 is attached to an outer housing of the heat rejection system. For example, the sensor 759 can be mounted on a side wall of the heat rejection system. In some instances, the sensor 759 is positioned near the heat rejection system. It can be beneficial to position the sensor 769 in an area where it is shaded and not exposed to rain so that heat from the sun or the rain may not affect the readings of the sensor 759.

The system also includes a control system 760 designed to receive, process, analyze, and/or store information from the one or more sensors 724, 736, and 759 and control one or more operating parameters and/or components of the system 700 (e.g., the flow rate of the cooling water make-up via the valve 722 and/or the flow rate of the waste cooling water via the valve 734). The control system 760 can be, or be in communication with, the control system 120 of FIG. 1 and/or the control system 290 of FIG. 2.

Furthermore, it is to be understood that the system 700 can include one or more additional components not shown in FIG. 7. For example, the system 700 can include one or more heat exchangers downstream of the pad 710, one or more valves, one or more sensors, a housing, one or more means of moving air, and/or other known components of adiabatic cooling and heat rejection systems. Accordingly, the control system 760 can be designed to control other components included in the system 700.

As discussed herein, the temperature of the cooling water leaving the pad 710, sensed by the one or more sensors 736, can be used as the approximate wet-bulb temperature of the system 700 and can be used to determine the evaporation rate of the system to minimize water and energy costs. Thus, the flow rate of the cooling water make-up in the cooling water make-up conduit 720 can be controlled to ensure enough cooling water is supplied to the pad 710 and/or the system 700 to replace the evaporated and discharged cooling water. In particular, the amount of make-up water supplied in the system 700 can be controlled by adjusting the flow of the make-up water through the cooling water make-up conduit 720 via the valve 722. A criterion that may impact the saturation efficiency of the pad is the water loading rate, which is defined as the supply flow rate of water sprayed onto the pads divided by the pad area upon which the water is sprayed. To minimize water usage, once-through systems may be operated at low water loading rates, which in turn can be detrimental to the performance and operating life of the wetted pad media. However, the amount of fresh cooling water make-up needed can be reduced by recycling some or all of the cooling water run-off from the pad 710. In recirculating systems, periodic bleeding of the recirculating water (e.g., blowdown) can be carried out to preserve water quality in system.

Accordingly, FIG. 8 is a block diagram of a portion of an adiabatic heat transfer system 800, including a recirculation basin 815 designed to retain the cooling water run-off from the pad 710. The system 800 is similar to the system 700 of FIG. 8, wherein the system 800 further includes the recirculation basin 815. The system 800 can further include a cooling water make-up conduit 820, a recirculating cooling water inlet conduit 825, a recirculating cooling water recycle conduit or return conduit 830, and a drain conduit 835 (e.g., a drain line). The system 800 can be included in, or part of, the cooler 110 of FIG. 1, the cooler 200 of FIG. 2, and/or the cooler 300 of FIGS. 3-5B. Accordingly, the media pad 710 can be the media pads 220 of FIG. 2, the cooling water make-up conduit 820 can be the cooling water make-up conduit 286 of FIG. 2, the basin or recirculation basin 815 can be the basin 260 of FIG. 2, and the drain conduit 835 can be the cooling water outlet conduit 284 of FIG. 2.

In some instances, FIG. 8 can be a system 800 (e.g., a recirculating system), including a single drain conduit 835 designed to drain cooling water from the system 800. As shown, the drain conduit 835 is provided as an outlet of the recirculation basin 815. Thus, the cooling water collected in the recirculation basin 815 can be dumped or drained out via the drain conduit 835 when the system 800 reaches a threshold COC. Further, the cooling water make-up conduit 820, the recirculating cooling water inlet conduit 825, the return conduit 830, and/or the drain conduit 835 can be in fluid communication with the recirculation basin 815.

The recirculating cooling water inlet conduit 825 provides incoming recirculating cooling water to the pad 710, which is supplied from the recirculation basin 815, which contains a mixture of fresh make-up water from the cooling water make-up conduit 820 and the recycled cooling water from the return conduit 830. The recirculating cooling water inlet conduit 825 can include a valve 826 for controlling a flow rate of the recycled cooling water. At least some of the recirculating cooling water that passes through the pad 710 is returned to the recirculation basin 815 via the return conduit 830. Thus, similar to the waste conduit 730 of FIG. 7, the return conduit 830 can include at least one (e.g., temperature) sensor 840 for detecting at least one parameter, such as the temperature of the outlet cooling water from the pad 710. In some instances, the system 900 can include both the at least one sensor 827 and the at least one sensor 840. In some instances, the system 900 may only include one of the at least one sensor 827 and the at least one sensor 840. In some instances, the waste conduit 730 can include a valve 842 for controlling the flow of the cooling water to the recirculation basin 815. In some instances, the return conduit 830 does not include the valve 842. As discussed herein, the outlet cooling water temperature is approximately equal to the wet-bulb temperature. Thus, knowing the approximate wet-bulb temperature of the system 800 can allow for the calculation of other psychometric properties.

During the cooling process, some of the cooling water supplied by the recirculating cooling water inlet conduit 825 will evaporate, as shown by the arrow 750, representing the evaporation rate of the system 800. Thus, the amount of cooling water returned to the recirculation basin 815 through the return conduit 830 is less than the amount of incoming cooling water supplied through the recirculating cooling water inlet conduit 825. Moreover, as the cooling water is recycled through the system 800, the COC in the recirculation basin 815 can increase, where the COC can be defined as a ratio of the dissolved solids (e.g., minerals, salts, and other impurities) concentration of the cooling water in the system 800 to the dissolved solids concentration of the make-up water being introduced into the system via the cooling water make-up conduit 820. In one instance, the COC can be defined as the ratio of water conductivity in the system to the ratio of the water conductivity in the make-up water.

Ideally, to conserve water, the cooling water can be recirculated multiple times throughout the system 800. However, the COC can reach an upper threshold value or limit over time. Thus, some of the water in the recirculation basin 815 can be considered contaminated water, which can be removed through the drain conduit 835 during a draining process. In some instance, the drain conduit 835 can be provided in the form of a gravity drain. The drain conduit 835 can include a valve 836 designed to control the discharged waste cooling water flow. In one instance, the valve 836 is an open/close valve, such that the valve 836 can have an open position to enable water to exit the recirculation basin 815 and a closed position that substantially prevents water from exiting the recirculation basin 815. In some instances, the flow through the drain conduit 835 is controlled via a pump. In some instances, the flow through the drain conduit 835 is controlled via a weir system where waste cooling water is drained when it overflows a weir.

Additionally, the system 800 can include one or more sensors 850 for measuring the water quality in the recirculation basin 815 and one or more sensors 860 for measuring the quality of the make-up water of the cooling water make-up conduit 820. The sensors can help determine when and/or how much water to remove from the recirculation basin 815. Thus, to maintain the desired level of water in the recirculation basin 815 and/or COC in the system 800, the flow rate of the make-up water in the cooling water make-up conduit 820 can be about equal to the evaporation rate 750 plus the drain rate. Accordingly, the cooling water make-up conduit 820 can include a valve 870 designed to control a flow rate of the cooling water make-up through the cooling water make-up conduit 820.

In some instances, the evaporation rate of the system 800 can be determined based on a difference between a flow rate of the cooling water in the cooling water make-up conduit 820 and the flow rate of the waste cooling water discharged from the system through the drain conduit 835. Measuring the flow rate of the cooling water make-up can be more straightforward than determining the flow rate of the discharged cooling water because measuring a drain flow rate can present a challenge due to the flow being gravity drained from the system 800. Accordingly, it can be beneficial to use the water temperature of the cooling water leaving the pad 710 as the basis for determining the evaporation rate because it can be easier to determine the water temperature. A benefit of the system 800 is that it can use less water than the once-through system described in FIG. 7. However, it can be beneficial to include additional and/or alternative drain/bleed conduits in the system to control the build-up of contaminants in the system.

Accordingly, FIG. 9 illustrates a block diagram of a portion of an adiabatic heat transfer system 900, including a bleed conduit 910 upstream of the pad 710 and downstream of the recirculation basin 815. The system 900 is similar to the system 800 of FIG. 8. However, in FIG. 9, the recirculating cooling water inlet conduit 825 includes the bleed conduit 910. Thus, the system 900 includes two conduits (e.g., the drain conduit 835 and the bleed conduit 910) for removing cooling water from the system 900. In one instance, the bleed conduit 910 is a pressurized bleed conduit.

A portion of the incoming cooling water in the recirculating cooling water inlet conduit 825 is removed via the bleed conduit 910 and sent to a waste system. In some aspects, the bleed conduit 910 is in fluid communication with the same waste system that the drain conduit 835 is in fluid communication with. The make-up rate of the cooling water supplied by the cooling water make-up conduit 820 can be about equal to the amount of cooling water removed from the system 900 via the bleed conduit 910, the drain conduit 835, and the evaporation rate 750.

However, by bleeding off a portion of the recycled cooling water from the recirculating cooling water inlet conduit 825, the frequency and/or volume within the system 900 can change, which is depicted in FIG. 10. The water from the bleed conduit 910 is a mixture of water have a relatively high concentration of contaminants and fresh make-up water from the cooling water make-up conduit 820. The bleed conduit 910 can include one or more valves 920 for controlling the flow rate through the bleed conduit 910 and/or one or more sensors 930 for measuring one or more water quality parameters and the flow rate of the bleed water. During operation, the cooling water contained within the system can increase in COC until reaching a threshold COC. When the threshold COC is reached, the drain conduit 835 can be opened to allow some or all of the cooling water in the recirculation basin to drain. The water removed from the recirculation basin 815 can be replaced with cooling water from the cooling water make-up conduit 820.

As shown in FIG. 10, the amount of water used in the system 900 can be adjusted based on a bleed percentage (i.e., the percentage of the incoming cooling water removed from the recirculating cooling water inlet conduit 825 through the bleed conduit 910). The bleed percentage can be controlled by a bleed conduit valve (e.g., the valve 920), where a valve position of the bleed conduit valve can be adjusted based on the needs of the system. The simulation results in FIG. 10 were based on an adiabatic cooling system with the same configuration as the system 900. During the simulation, the system included a 30-gallon recirculation basin operating at 2 COC based on the TDS of the water in the pad, such as the media pad 710. As shown, at about a 5% bleed rate, the water consumption of the system is provided at about 1650 gpd (gallons per day) of water surface area of a wetted media pad (gallons per day per square foot of top pad surface area) and at about a 0.5% bleed rate, the water consumption is at about 1650 gpd of one square foot.

Now, turning to FIG. 11, a block diagram of a portion of an adiabatic system 1100, including a bleed conduit 1110 downstream of the pad 710, is shown. The system 1100 is similar to the system 900 of FIG. 9. However, in the system 1100, the return conduit 830 includes a bleed conduit 1110. The bleed conduit can include one or more sensors 1120 for measuring the quality of the cooling water leaving the system 1100 through the bleed conduit 1110. The sensors can help determine when and/or how much water to remove from the system 1100. The bleed conduit 1110 can include a valve 1130 designed to control a flow rate of the cooling water through the bleed conduit 1110.

Similar to the system 900 of FIG. 9, the rate of the make-up water being provided is about equal to the amount of water removed from the system 1100 via the bleed conduit 1110, the drain conduit 835, and the evaporation rate 750. By including the bleed conduit 1110 on the return conduit 830, the cooling water with the highest concentration of contaminants can be removed from the system 1100. Thus, the system 1100 can have a higher reduction in water use than the system 900 of FIG. 9 because the system 1100 removes water having a higher COC before it mixes with fresh make-up water versus the system 900, which removes water having a mixture of fresh make-up water and higher COC water. Therefore, in the system 1100, the frequency and/or volume of the blowdown or drain processes can be decreased, as shown in the graph depicted in FIG. 12.

As shown in FIG. 12, the amount of water used in the system 1100 can be adjusted based on the bleed rate. The simulation results in FIG. 12 were based on an adiabatic cooling system with the same configuration as the system 1100. The system included a 30-gallon recirculation basin operating at 2 COC based on the TDS of the water in the pad. As shown, at about 25% to about 30% bleed rate, the water consumption of the system 1100 is utilized at about 1330 gpd of water surface area of a media pad.

Comparing the results in FIG. 10 to FIG. 12, it can be seen that more water can be conserved in the system 1100 of FIG. 11 as compared to the system 900 of FIG. 9. The system 1100 can have a lower water consumption because, as discussed above, the bleed conduit 1110 can be placed to remove the highest level of contaminants in the system 1100. As such, the level of contaminants in the recirculation basin 815 of the system 1100 may not concentrate as quickly as compared to the recirculation basin 815 of the system 900. Thus, the system 1100 can be drained less often than the system 900 while maintaining approximately the same COC. Moreover, as shown in FIG. 12, the system 1100 of FIG. 11 can conserve more water than a recirculation system without a bleed conduit, such as the system 800 of FIG. 8. If a once-through system, such as the system 700 of FIG. 7, varies the supply water flow (e.g., make-up water flow) over the pads, then the once-thru system's water usage would be approximately the same as the system 1100. However, if the once-thru system has a fixed water flow rate, the water usage of the once-through system will be higher than a recirculation system (e.g., the recirculation system 1100). A drawback of varying the supply water flow rate over the pads is the pad saturation efficiency can decline as the water flow rate is reduced.

FIG. 13 depicts a graph comparing the performance of several exemplary adiabatic systems. The systems included a once-through system, such as the system 700 of FIG. 7, a system with a recirculation basin but no bleed conduit, such as the system 800 of FIG. 8, a system with a recirculation basin and a bleed conduit positioned downstream of the recirculation basin, such as the system 900 of FIG. 9, and a system with a recirculation basin and a bleed conduit positioned upstream of the recirculation basin, such as the system 1100 of FIG. 11. The performance of each system was measured based on the water consumption, measured in gpd, gallons per day, of varying pad water flow rate in gpm/sqft. For systems with recirculation basins, each system included a 30-gallon recirculation basin operating at about 2 COC. The evaporation rate of each system was about 0.4 gpm/sqft of pad surface area.

In some instances, once-through systems, such as the system 700, can operate at low pad water flow rates (i.e., at about 0.3 gpm/sqft). Also, in some instances, operating the water flow rate between about 1.5 gpm/sqft to about 2 gpm/sqft is recommended for improved pad life and performance. Additionally, for the pads to be fully wet (as desired for high pad saturation efficiency), the pad water flow rate can be at least about 0.9 gpm/sqft. At this recommended pad water flow rate range, of about 1.5 gpm/sqft to about 2 gpm/sqft, the system 1100 can perform the best when the system includes a recirculation basin and/or a bleed or drain conduit positioned upstream of the recirculation basin. For example, in one instance, the system 1100 can operate between about 1.5 gpm/sqft to about 2 gpm/sqft to operate or perform best, while in comparison, the system 700 can operate or perform best between about 0.09 to about 0.9 gpm/sqft. However, the system 700 may have a reduced saturation efficiency as the flow rate decreases.

Additionally, from about 1 gpm/sqft to about 2.6 gpm/sqft of minimum outlet water flow rate, the system 1100 can perform equal to or better than all other system configurations (i.e., the system 800 or the system 900). Although the system with a recirculation basin without a bleed conduit (i.e., the system 800 of FIG. 8) performed slightly better than the system having a bleed conduit upstream of the recirculation basin (i.e., system 1100 of FIG. 11) at high pad flow rates (i.e., greater than about 2.6 gpm), the system 1100 can still have higher overall water savings because the pad flow rate can be adjusted to account for changes in operating conditions.

It is to be understood that the simulation results discussed in reference to FIGS. 10, 11, and 13 are merely provided as exemplary comparisons. Similar results for each of the system configurations discussed herein (e.g., the system 700 of FIG. 7, system 800 of FIG. 8, system 900 of FIG. 9, and system 11 of FIG. 11) can exhibit similar trends (e.g., recirculation systems generally conserve more water and energy than once-through systems and systems including a bleed conduit upstream of the recirculation basin (i.e., system 1100 of FIG. 11) can provide more flexibility in operation and conserve water) at different flow rates and system sizes. The performance and operational parameters of each of the systems disclosed herein can be adjusted for water and energy savings.

FIGS. 14A-17B illustrate methods for adjusting one or more system parameters to improve and/or minimize water and energy use in the one or more of the systems 700, 800, 900 and/or 1100.

Turning now to FIGS. 14A and 14B, a method 1400 for operating an adiabatic heat transfer system in a water conservation mode, is shown. The method 1400 can be implemented in the systems 700, 800, 900, and 1100 of FIGS. 7, 8, 9, and 11, respectively.

As discussed herein, each of the systems 700, 800, 900, and 1100 can include a control system 760 communicatively coupled to one or more components of the systems. The control system 760 can include a receiver configured to receive information from the system, a processor configured to interpret the information and determine an action to be taken, and a transmitter configured to send instructions to the system. Thus, the control system 760 can be configured to receive, store, measure, monitor, and/or calculate various operating parameters of the system such as the temperature of the process fluid, recirculating cooling water temperature, the dry-bulb temperature of the ambient air, the speed of an air movement device, the operational status of a recirculation pump, a percent open of a bleed valve, the COC, a level in a recirculation basin, flow rates throughout the system, and any other operational parameter disclosed herein.

At block 1402, one or more sensors can be configured to measure the ambient dry-bulb temperature and/or the process fluid temperature of the system. The dry-bulb temperature can be measured with a thermometer or other temperature-measuring device that is near the system and exposed to the ambient air but shielded away from moisture given off by the system (e.g., the one or more sensors 759 of FIGS. 7-9 and 11). The temperature of the process fluid of the system can be measured at a return conduit, such as the return conduit 206 and/or 506 of FIGS. 2 and 5.

At block 1404, the control system can be configured to perform a check to determine if the process fluid temperature value is greater than a minimum process fluid (PF) temperature setpoint value. The minimum process fluid temperature setpoint value can be predetermined based on the specific application or operational conditions of the system. If the process fluid temperature is less than the minimum process fluid temperature setpoint, then at block 1406, no further action is taken, and the method returns to block 1402, where the control system continues to monitor the process fluid temperature. However, if the process fluid temperature is greater than the process fluid minimum temperature, the method proceeds to block 1408.

At block 1408, the control system can be configured to perform a check to determine if the air movement device, such as a fan, included in the system is on. If the air movement device is off, then at block 1410, the speed or power setting of the air movement device is turned on. However, if the air movement device is on, then at block 1412, the control system determines the system's mode of operation (e.g., is the system operating in water conservation mode or energy conservation mode). The mode of operation can be determined by a system operator and/or preset based on the needs of the system. The mode of operation can depend on factors such as the ambient air temperature, the cooling capacity, electricity cost, water cost, and other operational parameters. Here, the system operates in a water conservation mode, so the method continues to block 1416, which is the beginning of the water conservation mode method.

At block 1418, the control system can be configured to determine if the process fluid temperature value is greater than a second process fluid temperature setpoint value. The second process fluid temperature setpoint can be a predetermined value or range of values set by a system operator or based on the needs of the system. If the process fluid temperature is less than the second process fluid temperature setpoint, then the method proceeds to block 1420.

At block 1420, the control system can be configured to perform a check to determine if the air movement device is set at its lowest speed or power setting. In some instances, the lowest speed or power setting can be set by the air movement device manufacturer. If the air movement device is not set at its lowest speed or power setting, then at block 1422, the control system can be configured to perform a check to determine if a recirculation pump is on. The recirculation pump can be included in systems with a recirculation basin, such as systems 800, 900, and 1100 of FIGS. 7, 8, 9, and 11, respectively. The recirculation pump can be located near or within the recirculation basin 815 or coupled to the side of the recirculation basin 815 (e.g., the pump 270 of FIG. 2 and/or the pump 380 of FIGS. 5A and 5B). In one instance, the systems 700, 800, 900, and 1100 can further include a remote sump where the water from recirculation basin 815 drains to a remote basin, tank, or recirculation basin, and a pump connected to the tank supplies the recirculation water to the adiabatic or media pad 710.

If the recirculation pump is turned off, then the method proceeds to block 1424. At block 1424, the speed or power of the air movement device is reduced. The air movement device speed or power can be automatically reduced by a predetermined amount, manually adjusted by a system operator, and/or set to the lowest possible speed or power setting. Once the air movement device speed or power has been reduced, the method returns to block 1418.

If, at block 1422, the control system determines that the recirculation pump is on, the method proceeds to block 1426. However, prior to proceeding to block 1426, at block 1422 the control system can be designed to determine a bleed valve position (e.g., determine a percent opening of the valve). In some instances, the control system can adjust the bleed valve position (e.g., the bleed flow rate) prior to proceeding to block 1426. In some instances, the control system can determine the COC of the system prior to proceeding to block 1426.

In one instance, at block 1426, the control system can be configured to perform another check. At block 1426, the control system can be configured to perform a check to determine if a difference between the minimum process fluid temperature setpoint and the process fluid temperature is less than a maximum threshold value. It is to be understood that although the maximum threshold value or maximum threshold temperature is shown to be 3° F., the maximum threshold value can be any value. Thus, the maximum threshold value can be set by a system operator and/or based on the needs of the system. In one instance, block 1426 can be substantially similar to block 1434 (described herein).

At block 1426, if the difference between the minimum process fluid temperature setpoint and the process fluid temperature is greater than the maximum threshold value, then the method moves to block 1427, and the control system can be configured to perform a check to determine if the air movement device is operating above or below a maximum set point. As shown, the maximum set point is equal to about 70% of the maximum speed of the air movement device. However, the set point can be any value. Further, the set point can be manually set by a process operator and/or can be determined by the needs of the system. If the air movement device is operating above the maximum set point, then the method proceeds to block 1428, where the power or speed of the air movement device is reduced. The method then returns to block 1418.

However, if at block 1427, the control system determines the air movement device speed is less than the maximum set point, the method proceeds to block 1430.

At block 1430, the control system can be configured to send instructions to the system to turn off the recirculation pump and then at block 1432 to increase the speed of the air movement device, potentially to a full speed setting of the air movement device, or to increase a power setting of the air movement device and to operate the adiabatic system dry. The method then returns to block 1418.

At block 1426, if the difference between the minimum process fluid temperature setpoint and the process fluid temperature is less than the maximum threshold value, then the method proceeds to block 1427, and no operational changes are made to the air movement device. The method then returns to block 1418.

It is to be understood that in systems that do not include a recirculation basin, such as the system 700 of FIG. 7, block 1422, can be omitted in the method. In another instance, in systems without a recirculation basin, block 1422 can be changed to determine whether water is being delivered to the adiabatic pad. Thus, for the system 700, in some instances, at block 1420, the control system determines the air movement device is not set at its lowest speed or power, then the method proceeds to block 1424. In some instances, for the system 700, the control system determines whether water is being delivered to the adiabatic pad by checking a valve status (e.g., the valve 722) to determine whether water is being delivered to the pads.

Referring back to block 1420, if the control system determines that the air movement device is already set at its lowest speed or power, then the method proceeds to block 1434. At block 1434, the control system can be configured to perform a check to determine if a difference between the minimum process fluid temperature setpoint and the process fluid temperature is less than a maximum threshold value. If the difference is less than the maximum threshold value, then at block 1436, no operational changes are made to the air movement device, and the method can return to block 1418. However, if the control system determines the difference between the minimum process fluid temperature setpoint and the process fluid temperature is greater than the maximum threshold value, then at block 1438, the air movement device is turned off. The method then returns to block 1402.

It is to be understood that although the maximum threshold value is shown to be 3° F., the maximum threshold value can be any value. Thus, the maximum threshold value can be set by a system operator and/or based on the needs of the system.

Referring back to block 1418, if the control system determines the process fluid temperature is greater than a process fluid temperature setpoint, then the method proceeds to block 1440. At block 1440, the control system can be configured to perform a check to determine if the air movement device is operating at its maximum speed or power. If the air movement device is not at a maximum speed or power, then at block 1442, the air movement device's speed or power is increased to provide additional cooling. The air movement device speed or power can be automatically increased by a predetermined amount, manually adjusted by a system operator, and/or set to a highest possible speed or power setting. The method then returns to block 1418.

Alternatively, if at block 1440, the control system determines the air movement device is at its maximum speed or power setting, and the system does not include a recirculation basin, such as the once-through system 700 illustrated in FIG. 1, then a flow of water can be turned on. Also, in the absence of the recirculating tank, the water can be sprayed over the pad 710.

If at block 1440, the control system determines the air movement device is at its maximum speed or power setting, and the system has a recirculation basin, such as the systems 800, 900, and/or 1100, then the method proceeds to block 1444 (i.e., block 1440 is connected to block 1444 by line “B”) as shown in FIG. 3D. At block 1444, the control system can be configured to perform a check to determine if the recirculation pump is on. If the recirculation pump is not on, then the method proceeds to block 1446. At block 1446, the recirculation pump is started so that cooling water is delivered to the pad. At block 1448, after the pad has been allowed to become fully wetted, the method returns to block 1418 (i.e., block 1448 is connected to block 1418 by line “C”). The time it takes for the pad to become fully wetted can be a predetermined time period or can be manually controlled by a system operator.

Referring back to block 1450, if the system does not include a bleed conduit, such as the system 800 of FIG. 8, then the method proceeds directly to block 1454. However, if the system includes a bleed conduit, such as systems 900 and 1100 of FIGS. 9 and 11, respectively, and at block 1450, the control system determines that the recirculation pump is on, and then the method proceeds to block 1454.

At block 1450, the control system can be configured to determine an optimal bleed conduit flow rate. The bleed conduit flow rate can be controlled by setting a bleed conduit valve to a particular percent open. Thus, the bleed conduit valve setting can be a function of the evaporation rate of the system, a target COC, and/or the make-up water flow rate. If the bleed conduit valve is not at a desired setting, then at block 1452, the bleed valve setting is adjusted.

At block 1454, the control system can be designed to determine the current COC value of the system using data acquired from one or more sensors. In some instances, the control system can determine the COC by first determining a current bleed flow rate. The bleed flow rate can be a function of a water depth in a collection basin (e.g., the basin 260 of FIG. 2, the basin 332 of FIGS. 3A-3D, and/or the recirculation basin 815 of FIGS. 8, 9, 10, and 11), the bleed valve % open value or setting (e.g., the valve 836 of FIGS. 8, 9, 10, and 11, the valve 920 of FIG. 9, and/or the valve 1130 of FIG. 11), and a valve flow coefficient of the associated bleed valve(s). The valve flow coefficient can be a value provided by the valve manufacturer. The COC can be a function of the evaporation rate and the determined bleed flow rate. The evaporation rate can be determined from one or more psychometric properties and an air movement device airflow rate. The COC can be determined by a mass balance.

The control system can be further configured to perform a check to determine if the current COC value is greater than a maximum COC value. The maximum COC value can be a predetermined value based on the needs of the system and/or can be manually set by a system operator. If the current COC value is less than the maximum COC value, then at block 1458, the system continues to operate without additional changes. Thus, the method returns to block 1418 (i.e., block 1458 is connected to block 1418 by conduit “A”). However, if at block 1456, the control system determines the current COC value is greater than the maximum COC value, the method proceeds to block 1460.

In another instance, at block 1454, the control system can be designed to determine the current total dissolved solids (TDS) level of the system using data acquired from one or more sensors. The control system can be further configured to perform a check to determine if the current TDS level is greater than a maximum TDS level. The maximum TDS level can be a predetermined value based on the needs of the system and/or can be manually set by a system operator. If the current TDS level is less than the maximum TDS level, then at block 1458, the system continues to operate without additional changes. Thus, the method returns to block 1418 (i.e., block 1458 is connected to block 1418 by line “A”). However, if at block 1456, the control system determines the current TDS level is greater than the maximum TDS level, the method proceeds to block 1460.

At block 1460, the recirculation pump is turned off, and the make-up water supply is blocked in preparation for a draining process. Thus, at block 1462, during the draining process, the drain conduit of the recirculation basin is opened to remove at least a portion of the highly contaminated water from the system (i.e., the recycled cooling water with high TDS). The basin can be drained for a predetermined amount of time and/or manually drained by a system operator. After the draining process is complete at block 1464, the make-up water supply is reestablished so that the water level in the recirculation basin can be refilled. Thus, the fresh make-up water also helps dilute the remaining water in the recirculation basin, thereby lowering the COC. Finally, at block 1466, the recirculation pump is turned on so that cooling water is once again supplied to the pad. The method then returns to block 1418 (i.e., block 1466 is connected to block 1418 by line “A”).

Now, turning to FIGS. 15A and 15B, a method 1500 is disclosed. The method 1500 can be implemented in the systems 700, 800, 900, and 1100 of FIGS. 7, 8, 9, and 11, respectively. The method 1500 is similar to the method 1400 of FIGS. 14A and 14B. However, the method 1500 differs at block 1422. In the method 1500, at block 1422, if the control system determines that the recirculation pump is on, the method proceeds to block 1526.

At block 1526, the control system determines if the ambient dry-bulb temperature is less than or greater than a dry-bulb switch-over temperature. The dry-bulb switch-over temperature can be a function of the operational status of the heat rejection system (e.g., wet or dry operation), the speed of the air movement device, the temperature of the process fluid, and/or the ambient dry-bulb temperature. If the control system determines the ambient dry-bulb temperature is greater than the dry-bulb switch-over temperature, the method proceeds to block 1528. At block 1528, the control system reduces the speed of the air movement device. The method then returns to block 1418.

However, if at block 1526, the control system determines the ambient dry-bulb temperature is less than the dry-bulb switch-over temperature, the method proceeds to block 1530. At block 1530, the control system can be configured to send instructions to the system to turn off the recirculation pump and then at block 1532 to increase the speed of the air movement device, potentially to a full speed setting of the air movement device, or to increase a power setting of the air movement device and to operate the adiabatic system dry. The method then returns to block 1418.

The remainder of the method 1500 is the same as the method 1400 of FIG. 14.

Now, turning to FIGS. 16A and 16B, a method 1600 of operating an adiabatic cooling system in a water conservation mode, is shown. The method 1600 can be implemented in the systems 700, 800, 900, and/or 1100 of FIGS. 7, 8, 9, and 11, respectively. The method 1600 is similar to the method 1400 of FIGS. 14A and 14B. However, the method 1600 differs at block 1422. In the method 1600, at block 1422, if the control system determines that the recirculation pump is on, the method proceeds to block 1602.

At block 1602, the control system determines if the air movement device is operating above or below a threshold value. As shown, the threshold value is equal to about 70% of a maximum speed of the air movement device. However, the set point can be any value. Further, the set point can be manually set by a process operator and/or can be determined by the needs of the system. If the air movement device is operating below the threshold value, then the method proceeds to block 1430, where a recirculation pump of the system is turned off.

However, if at block 1602, the control system determines the air movement device speed is greater than the threshold value, the method proceeds to block 1428, where the speed of the air movement device is reduced.

The remainder of the method 1600 is the same as the method 1400 of FIG. 14.

Now, turning to FIGS. 17A and 17B, a method 1700 of operating an adiabatic cooling system in an energy conservation mode, is shown. The method 1700 can be implemented in the systems 700, 800, 900, and/or 1100 of FIGS. 7, 8, 9, and 10, respectively. The method 1700 is similar to the method 1400. However, at block 1412, the system is operated in a way to utilize less energy. Thus, at block 1414, the method proceeds to block 1702.

At block 1702, the control system can be configured to perform a check to determine if the air movement device is operating above a maximum set point value. As shown, the maximum set point value is equal to about 75% of the maximum speed of the air movement device. However, the set point can be any value. Further, the set point can be manually set by a process operator and/or can be determined by the needs of the system. If the air movement device is operating below the maximum set point value, then the method proceeds to block 1704.

At block 1704, the control system can be configured to determine if the process fluid temperature value is greater than a second process fluid temperature setpoint. The second process fluid temperature setpoint can be a predetermined value set by a system operator or based on the needs of the system. If the process fluid temperature is less than the second process fluid temperature setpoint, then the method proceeds to block 1706.

At block 1706, the control system can be configured to perform a check to determine if the air movement device is set at its lowest power or speed setting. If the air movement device is not set at its lowest setting, then at block 1708, the control system can be configured to perform a check to determine if the recirculation pump is on. If the recirculation pump is not on, then at block 1710, the air movement device speed or power is reduced, and the method returns to block 1702.

However, if, at block 1708, the control system determines that the recirculation pump is on, then the method proceeds to block 1712. At block 1712, the control system can be configured to perform a check to determine if the air movement device is operating below a minimum set point. As shown, the minimum set point is equal to about 60% of the maximum speed of the air movement device. However, the set point can be any value. Further, the set point can be manually set by a process operator and/or can be determined by the needs of the system. If the air movement device is operating above the minimum set point, then the method proceeds to block 1714, where the power or speed of the air movement device is reduced. The method then returns to block 1702.

However, if at block 1712, the control system determines the air movement device is operating below the minimum set point, then at block 1716, the recirculation pump is turned off. The air movement device speed is also increased at block 1718. The method then returns to block 1702.

Referring back to block 1706, if the control system determines the air movement device is operating at its lowest power or speed setting, then the method proceeds to block 1720. At block 1720, the control system can be configured to perform a check to determine if a difference between the minimum process fluid temperature setpoint and the process fluid temperature is less than about 3° F. If the difference is not greater than about 3° F., then at block 1722, no changes are made to the operation of the air movement device. However, if the control system determines the difference between the minimum process fluid temperature setpoint and the process fluid temperature is greater than about 3° F., then at block 1724, the air movement device is turned off. The method then returns to block 1702.

Referring back to block 1704, if the control system determines the process fluid temperature is greater than a process fluid temperature setpoint, then the method proceeds to block 1726. At block 1726, the speed or power of the air movement device is increased. The method then returns to block 1702.

Referring back to block 1702, if the control system determines the air movement device is operating above the maximum set point, then the method proceeds to block 1728 (i.e., block 1702 is connected to block 1728 by line “B”). At block 1728, the control system can be configured to determine if the recirculation pump is on. If the recirculation pump is not on, then the method proceeds to block 1730. At block 1730, the recirculation pump is started so that cooling water is delivered to the pad. At block 1732, after the pad has been allowed to become fully wetted, the method returns to block 1728. The time it takes for the pad to become fully wetted can be a predetermined time period and/or can be manually controlled by a system operator.

At block 1728, if the control system determines the recirculation pump is on, then the method proceeds to block 1734. At block 1734, the control system can be configured to determine an optimal bleed or drain conduit flow rate. The bleed conduit flow rate can be controlled by setting a bleed conduit or a drain conduit valve to a particular percent open. Thus, the bleed conduit valve setting can be a function of the evaporation rate of the system, a target COC, and/or the make-up water flow rate. If the bleed conduit valve is not at a desired setting, then at block 1736, the bleed valve setting is adjusted.

However, if the system does not contain a bleed valve, such as the system 800 of FIG. 8, then the method proceeds directly from block 1734 to block 1738.

At block 1738, the control system can be configured to determine the current COC of the system. The control system can be further configured to perform a check to determine if the current COC is greater than a maximum COC. The maximum COC can be a predetermined value based on the needs of the system or can be manually set by a system operator. If the current COC is less than the maximum COC, then at block 1742, the system continues to operate in an adiabatic cooling mode.

At block 1744, the control system can be configured to perform a check to determine if the process fluid temperature is greater than a cooling water set point. The cooling water set point can be a value set by a process operator or can be determined based on the needs of the system. If the temperature of the process fluid is less than the cooling water set point, then the method returns to block 1702 (i.e., block 1744 is connected to block 1702 by line “A”). However, if the temperature of the process fluid is greater than the cooling water set point, then at block 1746, the air movement device speed or power is increased. The method then returns to block 1702 (i.e., block 1746 is connected to block 1702 by line “A”).

Referring back to block 1740, if the control system determines the current COC is greater than the maximum COC, the method proceeds to block 1748. At block 1748, the recirculation pump is turned off, and the make-up water supply is blocked in preparation for a blowdown or drain process. Thus, at block 1750, during a draining process, the drain conduit of the recirculation basin is opened to remove some of the highly contaminated water from the system. After the draining process is complete, at block 1752, the make-up water supply is reestablished so that the water level in the recirculation basin can be refilled. Thus, the fresh make-up water also helps dilute the remaining water in the recirculation basin, thereby lowering the COC. Finally, at block 1754, the recirculation pump is turned on so that cooling water is once again supplied to the pad. The method then returns to block 1702 (i.e., block 1754 is connected to block 1702 by line “A”).

It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular instances and examples, the invention is not necessarily so limited and that numerous other instances, examples, uses, modifications, and departures from the instances, examples, and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference as if each such patent or publication were individually incorporated by reference herein. Various features and advantages of the invention are set forth in the following claims.

ADIABATIC COOLER WITH CONTROL SYSTEM FOR WATER AND ENERGY USE REDUCTION

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

International Classifications

Abstract

Description

Claims

CROSS-REFERENCE TO RELATED APPLICATIONS

Provisional Applications (1)