The technology of the disclosure relates generally to evaporative cooling systems and, more particularly, controlling water supply to evaporative cooling systems based on environmental conditions.
An evaporative cooler or cooling system is a system that cools air through the evaporation of water. Evaporative cooling differs from typical air conditioning systems, which use vapor-compression or absorption refrigeration cycles. Evaporative cooling works by exploiting water's large enthalpy of vaporization. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation). This can cool air using much less energy than refrigeration. In extremely dry climates, evaporative cooling of air has the added benefit of conditioning the air with more moisture for the comfort of building occupants.
Evaporative cooling systems can be particularly effective for cooling livestock to reduce heat stress and reduce production loss. Evaporative cooling is an indirect cooling method that utilizes air entering or inside a barn. The barn may be outfitted with evaporative cooling pads that work by pulling air through a media that is saturated with water. As the water is evaporated, it cools and humidifies the air entering the barn. This cool and humid air then increases convective heat loss from the animals in the barn compared to utilizing air at ambient conditions. Although requiring more equipment and management than a simple tunnel ventilation system, cooling pads offer the opportunity to both reduce heat stress on animals during the hot portion of the day and to cool the barn down quickly in the evening to allow for maximum recovery time for the animals.
Thus, evaporative cooling systems include a water supply to provide water to saturate the evaporative cooling pads. A water trough or tank may be employed to store water that is then pumped by a water pump(s) to the evaporative cooling pads for saturation. The water pumps require power to operate. Thus, energy is consumed each time the pumps are turned on to pump water to the evaporative cooling pads. Purchasing power from power companies to power such pumps adds to the overhead of such agricultural operations. It should be appreciated that such agricultural operations appreciate cost-saving opportunities.
Aspects disclosed herein include evaporative cooling control systems for controlling water supply to evaporative cooling systems. An evaporative cooling system may be employed in barns or other facilities that house animals to provide cooling and to reduce production loss. The evaporative cooling control system may include a microprocessor, microcontroller, or other circuitry designed to control pumping of water with a supply pump to a water storage facility used to supply water to evaporative cooling pads based on data received on inputs for controlling equipment and devices in the evaporative cooling system. In exemplary aspects disclosed herein, the evaporative cooling control system includes a control circuit configured to determine whether or not evaporative cooling would be effective and operates pumps to supply water for the evaporative cooling system at times when that determination is positive and refrains from operating the pumps when that determination is negative.
In a first exemplary aspect, the evaporative cooling control system includes a control circuit configured to receive relative humidity information from a relative humidity sensor in the evaporative cooling control system indicating the relative humidity of the environment of the evaporative cooling system. If the relative humidity is less than a defined relative humidity set point (e.g., 70%), at which it is decided that evaporative cooling would be effective, the control circuit turns on the pump to pump water from a water storage facility to the evaporative cooling pads. When the relative humidity is greater than the defined relative humidity set point (e.g., 70%), where it has been decided that evaporative cooling would not be effective, the control circuit turns off the pump to discontinue pumping water from the water storage facility to the evaporative cooling pads. This conserves power and avoids overfilling the water storage facility when evaporative cooling would not be effective. Turning off the pump in this fashion can also reduce the saturation cycles of the evaporative cooling pads to extend their lives. It should be appreciated that temperature may also be considered when evaluating whether to operate the pump. For example, cooling may be effective but inappropriate at temperatures below approximately 75° F.
In another aspect, the evaporative cooling control system also includes one or more pH sensors in contact with the water supply in the water storage facility of the evaporative cooling system. The control circuit is configured to receive pH information regarding the pH level of the water supply for the evaporative cooling system. If evaporative cooling would not be effective, the control circuit may also determine the pH level of the water supply in the water storage facility for the evaporative cooling system, which can be an indication of contaminants in the water supply in the water storage facility. If the pH level of the water supply for the evaporative cooling system indicates an undesired level of contamination in the water supply, the control circuit can open a flush solenoid valve (“flush solenoid”) to allow water to drain from the water storage facility. The control circuit keeps open a fill solenoid valve (“fill solenoid”) to allow water from a primary water supply or primary water source to be supplied to the water storage facility, but the water in the water storage facility is drained through the flush solenoid. In this regard, in one aspect, the control circuit first turns on the supply pump to pre-pressurize the water storage facility in a flush operation. Then, the control circuit opens the flush solenoid to drain the water from the water storage facility such that the water does not reach the evaporative cooling pads. Once the pH level of the water supply for the evaporative cooling system does not indicate an undesired level of contamination in the water storage facility, the control circuit can close the flush solenoid to discontinue draining of water from the water storage facility.
As an alternative to the pH sensor, a flush may be done periodically without reference to a specific contamination level. The period may be set below an empirically derived timeframe in which contamination is likely to occur or by other means as needed or desired.
In this manner, when evaporative cooling is not effective, the control circuit turns off the pump to avoid the need to consume power to pump water to the evaporative cooling pads, which can also extend the lives of the evaporative cooling pads. If evaporative cooling is deemed not effective, the control circuit can ensure that the water supply in the water storage facility is maintained at a desired contaminant level and flush the water supply if above a desired contaminant level. In one example, flushing of the water supply is performed when evaporative cooling is not effective, so that the flushing operation does not affect supplying water to the evaporative cooling pads when such would be needed to maintain cooling, such as for animals.
One embodiment is a control circuit for controlling an evaporative cooling system. The control circuit is configured to receive an input signal indicating a relative humidity of ambient air of an environment associated with the evaporative cooling system as measured by a relative humidity sensor. The control circuit is also configured to compare the relative humidity as measured by the relative humidity sensor to a defined humidity threshold from a humidity threshold setting. When the relative humidity as measured by the relative humidity sensor is below the defined humidity threshold, the control circuit is configured to generate an output signal to cause a pump to pump water from a water storage facility to evaporative cooling pads in the evaporative cooling system.
A further embodiment includes a method for controlling an evaporative cooling system. The method includes receiving an input signal at a control circuit, the input signal indicating a relative humidity of ambient air of an environment associated with the evaporative cooling system as measured by a relative humidity sensor. The method also includes comparing, with the control circuit, the relative humidity as measured by the relative humidity sensor to a defined humidity threshold from a humidity setting. The method also includes, when the relative humidity as measured by the relative humidity sensor is below the defined humidity threshold, generating an output signal from the control circuit to cause a pump to pump water from a water storage facility to evaporative cooling pads in the evaporative cooling system.
A further embodiment includes a method for controlling an evaporative cooling system. The method includes receiving an input signal at a control circuit, the input signal indicating an amount of light within an environment associated with the evaporative cooling system as measured by a photocell. The method also includes comparing, with the control circuit, the amount of light as measured by the photocell to a defined threshold. The method also includes, when the amount of light as measured by the photocell is indicative of daytime, generating an output signal from the control circuit to cause a pump to pump water from a water storage facility to evaporative cooling pads in the evaporative cooling system.
A further embodiment includes an evaporative cooling system. The evaporative cooling system includes a sensor including at least one of a photocell or a relative humidity sensor. The evaporative cooling system also includes a water pump configured to pump water from a water storage facility to evaporative cooling pads. The evaporative cooling system also includes a control circuit coupled to the sensor and the water pump. The control circuit is configured to receive an input signal from the sensor. Based on the input signal from the sensor, the control circuit is configured to determine if a sensor threshold is met. When the sensor threshold is met, the control circuit is configured to generate an output signal to cause the water pump to pump water from the water storage facility to the evaporative cooling pads.
Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments.
With reference now to the drawing figures, several exemplary aspects of the present disclosure are described. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.
Aspects disclosed herein include evaporative cooling control systems for controlling water supply to evaporative cooling systems. An evaporative cooling system may be employed in barns or other facilities that house animals to provide cooling and to reduce production loss. The evaporative cooling control system may include a microprocessor, microcontroller or other circuitry designed to control pumping of water with a supply pump to a water storage facility used to supply water to evaporative cooling pads based on data received on inputs for controlling equipment and devices in the evaporative cooling system. In exemplary aspects disclosed herein, the evaporative cooling control system includes a control circuit configured to determine whether or not evaporative cooling would be effective and operates pumps to supply water for the evaporative cooling system at times when that determination is positive and refrains from operating the pumps when that determination is negative.
In a first exemplary aspect, the evaporative cooling control system includes a control circuit configured to receive relative humidity information from a relative humidity sensor in the evaporative cooling control system indicating the relative humidity of the environment of the evaporative cooling system. If the relative humidity is less than a defined relative humidity set point (e.g., 70%), at which it is decided that evaporative cooling would be effective, the control circuit turns on the pump to pump water from a water storage facility to the evaporative cooling pads. When the relative humidity is greater than the defined relative humidity set point (e.g., 70%), where it has been decided that evaporative cooling would not be effective, the control circuit turns off the pump to discontinue pumping water from the water storage facility to the evaporative cooling pads. This conserves power and avoids overfilling the water storage facility when evaporative cooling would not be effective. Turning off the pump in this fashion can also reduce the saturation cycles of the evaporative cooling pads to extend their lives.
In another aspect, the evaporative cooling control system also includes one or more pH sensors in contact with the water supply in the water storage facility of the evaporative cooling system. The control circuit is configured to receive pH information regarding the pH level of the water supply for the evaporative cooling system. If evaporative cooling would not be effective, the control circuit may also determine the pH level of the water supply in the water storage facility for the evaporative cooling system, which can be an indication of contaminants in the water supply in the water storage facility. If the pH level of the water supply for the evaporative cooling system indicates an undesired level of contamination in the water supply, the control circuit can open a flush solenoid valve (“flush solenoid”) to allow water to drain from the water storage facility. The control circuit keeps open a fill solenoid valve (“fill solenoid”) to allow water from a primary water supply or primary water source to be supplied to the water storage facility, but the water in the water storage facility is drained through the flush solenoid. In this regard, in one aspect, the control circuit first turns on the supply pump to pre-pressurize the water storage facility in a flush operation. Then, the control circuit opens the flush solenoid to drain the water from the water storage facility such that the water does not reach the evaporative cooling pads. Once the pH level of the water supply for the evaporative cooling system does not indicate an undesired level of contamination in the water storage facility, the control circuit can close the flush solenoid to discontinue draining of water from the water storage facility.
In this manner, when evaporative cooling is not effective, the control circuit turns off the pump to avoid the need to consume power to pump water to the evaporative cooling pads, which can also extend the lives of the evaporative cooling pads. If evaporative cooling is deemed not effective, the control circuit can ensure that the water supply is maintained at a desired contaminant level and flush the water supply in the water storage facility if above a desired contaminant level. In one example, flushing of the water supply is performed when evaporative cooling is not effective, so that the flushing operation does not affect supplying water to the evaporative cooling pads when such would be needed to maintain cooling, such as for animals.
In this regard,
With reference to
With continuing reference to
Note that a flush indicator and fill indicator, such as LED lights, may also be associated with the flush solenoid 148 and the fill solenoid 142, so that a visual indicator is provided when the flush and fill operation cycles are active and inactive.
While the evaporative cooling system 100 is adequate for many installations, there may be reasons where a pH sensor is impractical to sense contamination of the water storage facility. A timer may be used to flush the water storage facility periodically to prevent contamination levels from rising too high. Likewise, it may be appropriate to add a temperature sensor or accommodate a temperature sensor when determining if evaporative cooling would be effective. For example, it may be inappropriate to cool an environment if the ambient temperature is below 50° F. Likewise, while evaporative cooling may be effective below 75° F., it may still be unnecessary to provide cooling at those temperatures.
In this regard,
In addition to the temperature sensor 184, the main control circuit 102A may include a timer 186 which controls the fill and flush cycles as better explained below with reference to
Note that the main control circuit 102 of
If, however, the answer to block 204 is no, evaporative cooling would not be effective, then the main control circuit 102 may turn the pump 138 off or leave the pump 138 off (block 208). While the pump 138 is off, the process 200 may further test for contamination of the water storage facility (block 210). Such test may be performed with a contamination sensor such as the pH sensor 114. Based on the results of the test at block 208, the main control circuit 102 may determine if the water in the water storage facility is contaminated (block 212). If the answer is no, then the process 200 returns and monitors at block 202. If, however, the answer to block 212 is yes, the water is contaminated, then the main control circuit 102 may initiate a flush (block 214) and refill of the water storage facility (block 216) before returning to monitoring at block 202.
If the answer to block 252 is yes, the temperature is above the predefined threshold, there may be an initial signal to turn on the pump 138. However, this signal may be gated by the remainder of the process 250. That is, the process 250 continues by using a sensor to take a measurement (block 202). This sensor may be the relative humidity sensor 110, a daylight sensor such as photocell 510 (
If, however, the answer to block 204 is no, evaporative cooling would not be effective, then the main control circuit 102 may turn the pump 138 off or leave the pump 138 off (block 208).
Instead of testing for contamination, the main control circuit 102A may turn on a timer 186 (block 254) (or leave it on if the timer is already on) and test to see if the timer 186 has expired (block 256). If the answer to block 256 is no, then the process 250 returns and monitors at block 252. If, however, the answer to block 256 is yes, the timer 186 has expired, then the main control circuit 102A may initiate a flush (block 214) and refill of the water storage facility (block 216) before returning to monitoring at block 252. Note that the flushing based on the timer 186 may operate independently of the temperature and/or relative humidity or the flushing may be integrated as illustrated in
With continuing reference to
With continuing reference to
If the relative humidity sensor 110 or pH sensor 114 fails, the system may include a fail safe operation mode wherein the main control circuit 102 continues to operate the water pump 138. Such continued operation causes water to continue to be pumped to the evaporative cooling pads so that the evaporative cooling continues.
With reference back to
Thus, the water pump 138 is on at 404 when either relative humidity is less than the set point AND the on/off timer (OFT) is ON (i.e., evaporative cooling is effective and the timer has not expired) OR relative humidity is greater than the set point AND the pH level is greater than the set point (i.e., there is no cooling and the water needs to be flushed).
The water supply storage is being filled by having the fill solenoid 142 ON at 406 when relative humidity is less than the set point AND the high float sensor 120 is OFF (i.e., the tank is low and it needs water to run the evaporative cooling) OR relative humidity is greater than the set point AND the pH level is greater than the set point AND the low float sensor 126 is OFF (i.e., evaporative cooling is not effective, the water is contaminated and the water level is low).
The flush is activated at 408 when relative humidity is above the set point AND the pH level is above the set point AND, the low float sensor 126 is ON (i.e., evaporative cooling is not effective, the water is contaminated, and the water level is high enough to support a flush).
The alarm is activated at 410 when the high float sensor 120 is OFF AND the low float sensor 126 is OFF AND, the counter is above the set point (i.e., the water level is fine, but the counter has expired).
The flush is also activated at 412 when the high float sensor 120 is OFF AND the low float sensor is OFF AND, the counter is above the set point (i.e., the water level is fine, but the counter has expired (e.g., the water is just stale)).
It should be appreciated that generically, a sensor input (e.g., the input from the relative humidity sensor 110 or the photocell 510) is compared to a sensor threshold to see if the evaporative cooling would be effective. Likewise, water contamination is tested through a pH measurement, and if a threshold is exceeded, the water in the water storage facility is flushed. Flushing and filling of the water storage facility is controlled by the flush/fill solenoids and monitored by water level sensors. If a flush or fill does not operate in a desired manner, an alarm may be generated.
Those of skill in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithms described in connection with the aspects disclosed herein may be implemented as electronic hardware, instructions stored in memory or in another computer readable medium and executed by a processor or other processing device, or combinations of both. The master and slave devices described herein may be employed in any circuit, hardware component, integrated circuit (IC), or IC chip, as examples. Memory disclosed herein may be any type and size of memory and may be configured to store any type of information desired. To clearly illustrate this interchangeability, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. How such functionality is implemented depends upon the particular application, design choices, and/or design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.
The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).
The aspects disclosed herein may be embodied in hardware and in instructions that are stored in hardware, and may reside, for example, in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of computer readable medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a remote station. In the alternative, the processor and the storage medium may reside as discrete components in a remote station, base station, or server.
It is also noted that the operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. The operations described may be performed in numerous different sequences other than the illustrated sequences. Furthermore, operations described in a single operational step may actually be performed in a number of different steps. Additionally, one or more operational steps discussed in the exemplary aspects may be combined. It is to be understood that the operational steps illustrated in the flowchart diagrams may be subject to numerous different modifications as will be readily apparent to one of skill in the art. Those of skill in the art will also understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This application claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 62/702,640 filed Jul. 24, 2018, entitled “HUMIDITY AND PH SENSOR,” the content of which is relied upon and incorporated herein by reference in its entirety.
Number | Date | Country | |
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62702640 | Jul 2018 | US |