Patent Application
20240280304
The present disclosure relates generally to refrigeration systems. More particularly, the present disclosure relates to techniques for improving the coefficient of performance of a refrigeration system.
One implementation of the present disclosure is a refrigeration system, according to some embodiments. In some embodiments, the refrigeration system includes a condenser unit including a condensing coil, an indirect evaporative heat exchanger, a fan, multiple louvres, and a controller. In some embodiments, the condenser unit is configured to receive warm refrigerant, condense and cool the warm refrigerant, and provide cooled refrigerant as an output. In some embodiments, the condensing coil is configured to receive the warm refrigerant and output the cooled refrigerant as the output. In some embodiments, the indirect evaporative heat exchanger is configured to receive air from ambient, and discharge cooled air to the condensing coil. In some embodiments, the indirect evaporative heat exchanger includes multiple dry channels configured to deliver outlet air to an intermediate volume, and multiple wetted channels configured to recirculate a portion of the outlet air and discharge exhaust air into an exhaust space. In some embodiments, the fan is positioned above a vent. In some embodiments, the fan is configured to draw an airflow of the portion of the outlet air through the intermediate volume, across the condensing coil, into a central inner volume, and out of the condenser unit as condenser exhaust air. In some embodiments, the multiple louvres are adjustable between an at least partially open position and a closed position. In some embodiments, the louvres define a boundary between the exhaust space and the central inner volume. In some embodiments, the controller is configured to operate the louvres to transition between the at least partially open position and the closed position based on a temperature reading of the ambient. In some embodiments, the controller is configured to modulate the louvres between the at least partially open position and a fully open position to control cooling of the refrigerant that passes through the condensing coil.
In some embodiments, when the louvres are in the at least partially open position, the fan draws the exhaust air from the exhaust space, between the louvres, and discharges the exhaust air as a portion of the condenser exhaust air out of the condenser unit. In some embodiments, operation of the fan is configured to drive the recirculation of the portion of the outlet air through the wetted channels and into the exhaust space to induce indirect evaporative cooling of the air received from the ambient that travels through the dry channels. In some embodiments, the louvres are infinitely variable between the fully open position and the closed position.
In some embodiments, the controller is configured to compare a temperature of the ambient to a threshold temperature. In some embodiments, responsive to the temperature of the ambient exceeding the threshold temperature, the controller is configured to operate a water tank to provide moisture to the wetted channels, and operate an actuator to transition the louvres into the fully open position. In some embodiments, responsive to the temperature of the ambient being less than the threshold temperature, the controller is configured to operate the water tank to stop providing the moisture to the plurality of wetted channels and operate the actuator to transition the louvres into the closed position.
In some embodiments, the controller is configured to obtain a temperature of the ambient and a humidity of the ambient, and determine a dew point temperature of the ambient based on the temperature and the humidity of the ambient. In some embodiments, the controller is configured to determine an ambient dew point depression based on a difference between the dew point temperature and the temperature of the ambient. In some embodiments, the controller is configured to compare the ambient dew point depression to a threshold dew point depression, and responsive to the ambient dew point depression exceeding the threshold dew point depression, operate a water tank to provide moisture to the wetted channels, and operate an actuator to transition the louvres into the fully open position. In some embodiments, responsive to the ambient dew point depression being less than the threshold dew point depression, the controller is configured to operate the water tank to stop providing the moisture to the wetted channels and operate the actuator to transition the louvres into the closed position.
In some embodiments, the controller is configured to obtain a temperature of the ambient and a humidity of the ambient. In some embodiments, the controller is configured to determine a dew point temperature of the ambient based on the temperature and the humidity of the ambient. In some embodiments, the controller is configured to determine an ambient dew point depression based on a difference between the dew point temperature and the temperature of the ambient. In some embodiments, the controller is configured to compare the ambient dew point depression to a threshold dew point depression, and compare the temperature of the ambient to a threshold temperature. In some embodiments, the controller is configured to operate a water tank to provide moisture to the wetted channels and operate an actuator to adjust the louvres between the fully open position and the at least partially open position responsive to either (i) the ambient dew point depression exceeding the threshold dew point depression or (ii) the temperature of the ambient exceeding the threshold temperature. In some embodiments, the controller is configured to operate the water tank to stop providing the moisture to the plurality of wetted channels and operate the actuator to transition the louvres into the closed position responsive to both (i) the ambient dew point depression being less than the threshold dew point depression and (ii) the temperature of the ambient being less than the threshold temperature.
In some embodiments, operating the actuator to adjust the louvres between the fully open position and the at least partially open position comprises includes obtaining an entering air temperature of the outlet air in the intermediate volume prior to the outlet air being provided to the condensing coil, and modulating the actuator to continuously adjust a position of the plurality of louvres between the fully open position and the at least partially open position to maintain the entering air temperature at a desired temperature value to control the cooling of the refrigerant that passes through the condensing coil. In some embodiments, the desired temperature value is a sum of the dew point temperature and an offset temperature amount.
Another implementation of the present disclosure is a control system for a condenser, according to some embodiments. In some embodiments, the control system includes an actuator and processing circuitry. In some embodiments, the actuator is configured to adjust a position of a louvre that is continuously adjustable between a fully closed position and a fully open position to adjust an amount of airflow that is recirculated through an indirect evaporative heat exchanger. In some embodiments, the indirect evaporative heat exchanger is positioned along a flow path between an external area and a cooling coil of the condenser. In some embodiments, the indirect evaporative heat exchanger is configured to discharge a first airflow of cooled air to the cooling coil, and a second airflow of exhaust air to the vent. In some embodiments, the processing circuitry is configured to obtain a temperature of air in the external area, and responsive to the temperature of the air in the external area being greater than a threshold temperature, operate a water tank to provide moisture to multiple wetted channels of the indirect evaporative heat exchanger, and operate the actuator to transition the vent into the fully open position.
In some embodiments, the processing circuitry is configured to, in response to the temperature of the external area being less than the threshold temperature, operate the water tank to stop providing the moisture to the plurality of wetted channels, and operate the actuator to transition the vent into the fully closed position.
In some embodiments, the processing circuitry is configured to obtain a relative humidity of the air in the external area, and obtain a dew point temperature of the air in the external area based on the relative humidity and the temperature of the air in the external area. In some embodiments, the processing circuitry is configured to determine an ambient dew point depression based on the temperature of the air in the external area and the dew point temperature, and responsive to the ambient dew point depression exceeding a threshold dew point depression, operate the water tank to provide the moisture to the plurality of wetted channels of the indirect evaporative heat exchanger and operate the actuator to transition the vent into the fully open position.
In some embodiments, in response to either (a) the temperature of the air in the external area being greater than the threshold temperature, or (b) the ambient dew point depression exceeding the threshold dew point depression, the processing circuitry is configured to operate the water tank to provide the moisture to the wetted channels of the indirect evaporative heat exchanger, and operate the actuator to transition the vent into the fully open position.
In some embodiments, the processing circuitry is further configured to obtain a temperature of the first airflow before the first airflow is provided to the cooling coil, and modulate operation of the actuator to continuously adjust the vent between different open positions to maintain the temperature of the first airflow at a desired temperature. In some embodiments, the desired temperature is a temperature that achieves a desired coefficient of performance of a refrigeration system of the condenser. In some embodiments, the desired temperature includes a dew point temperature of the air in the external area offset by a predetermined amount such that the first airflow is maintained the predetermined amount above the dew point temperature.
Another implementation of the present disclosure is a method for controlling a condenser unit that includes an indirect evaporative heat exchanger for pre-cooling air from ambient before the air is provided to a condenser coil, according to some embodiments. In some embodiments, the method includes, responsive to a determination that the indirect evaporative heat exchanger should be activated, obtaining a temperature of the pre-cooled air that exits the indirect evaporative heat exchanger for cooling the condenser coil. In some embodiments, the method further includes modulating a vent that controls a portion of the pre-cooled air that is recirculated through the indirect evaporative heat exchanger through multiple wet channels such that the temperature of the pre-cooled air is maintained at least a predetermined amount above a dew point temperature.
In some embodiments, the determination that the indirect evaporative heat exchanger should be activated includes determining at least one of (a) that a temperature of ambient air exceeds a threshold temperature, or (b) that a dew point depression exceeds a threshold dew point depression. In some embodiments, the dew point temperature is a current dew point temperature of ambient air. In some embodiments, the method further includes, responsive to the determination that the indirect evaporative heat exchanger should be activated, activating a water tank to provide moisture to the wetted channels. In some embodiments, the recirculation of the pre-cooled air through the wetted channels induces indirect evaporative cooling of air travelling through multiple dry channels of the indirect evaporative heat exchanger. In some embodiments, modulating the vent includes performing a closed loop control scheme to maintain the temperature of the pre-cooled air at least the predetermined amount above the dew point temperature.
This summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements.
The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:
Before turning to the Figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
Referring generally to the FIGURES, a refrigeration unit or system includes a condenser that is configured to receive warm or hot refrigerant (e.g., coolant) and condense/cool the refrigerant. In some embodiments, the condenser includes condenser coils through which the refrigerant is configured to flow to thereby condense and cool the refrigerant. The cooled refrigerant can be passed through an expansion valve and used in an evaporator to cool a space (e.g., to absorb heat from the space). In some embodiments, the condenser includes an indirect evaporative heat exchanger that is positioned downstream of an inlet to ambient or outdoor air, and upstream of the condenser coils. In some embodiments, the indirect evaporative heat exchanger is controlled to pre-cool or pre-condition the air that is drawn from ambient before the air is provided over the condenser coils. In some embodiments, the indirect evaporative heat exchanger includes dry passages through which air that is provided to the condenser coils flows. The indirect evaporative heat exchanger can also include wet passages such that a portion of air that exits the dry passages is recirculated into the wet passages and facilitates indirect evaporative cooling of the air travelling through the dry passages. Advantageously, the indirect evaporative heat exchanger facilitates improved pre-cooling of the air before the air is used to condense the refrigerant passing through the refrigeration coils, which in turn improves efficiency of the condenser, and improves the coefficient of performance (COP) of the refrigeration unit.
Referring particularly to
The refrigeration system 100 also includes a pressure sensor 112 positioned on a suction side of the compressor 104. The pressure sensor 112 is configured to provide measurements of pressure of the refrigerant as the refrigerant enters the compressor 104. The refrigeration system 100 also includes a temperature sensor 114 that is positioned along the piping 110 before an inlet of the evaporator 102. The temperature sensor 114 can be the temperature sensor 114. In some embodiments, the temperature sensor 114 is configured to provide a temperature of the refrigerant prior to entry of the evaporator 102 to the controller 150. In some embodiments, the refrigeration system 100 includes a flow rate sensor 116 that is configured to measure a flow rate (e.g., volumetric flow rate, velocity, mass flow rate, etc.) (e.g., downstream of the expansion valve 108) and provide the flow rate (shown as Q) to the controller 150.
It should be understood that the refrigerant may be any type of refrigerant such as R32, 410A, R22, CO2, propane, etc., and the systems and methods described herein can apply to any refrigeration system or multiple refrigeration systems that use the same or different refrigerants.
The controller 150 can be configured to generate control signals for the compressor 104 and operate the compressor 104 based on any of the temperature, pressure, or flow rates obtained from the temperature sensor 114, the pressure sensor 112, or the flow rate sensor 116. In some embodiments, the controller 150 is configured to operate the compressor 104 using a closed loop control scheme (e.g., PID control, PI control, etc.). For example, the controller 150 can be configured to perform various control algorithms.
Referring to
The pressure-enthalpy graph 200 includes a vapor dome 202 that includes a critical point 204. An area within the vapor dome 202 illustrates a liquid-vapor region of the refrigerant, shown as liquid-vapor region 214. An area outside of the vapor dome 202 and to the right of the critical point 204 illustrates a superheated vapor region, shown as superheated vapor region 212. An area outside of the vapor dome 202 and to the left of the critical point 204 illustrates a subcooled region, shown as subcooled region 210. Points along the vapor dome 202 to the left of the critical point 204 are saturated liquid points. Points along the vapor dome 202 to the right of the critical point 204 are saturated vapor points.
A first point 216, which is shown on the vapor dome 202 (e.g., along a saturated vapor portion of the vapor dome 202) illustrates the thermodynamic state of the refrigerant as the refrigerant enters the compressor 104. As the refrigerant is pressurized by the compressor 104, the pressure and enthalpy of the refrigerant increases. A second point 218 of the path 206 illustrates a thermodynamic state of the refrigerant as the refrigerant exits the compressor 104 after being pressurized. As shown in
When the refrigerant enters the condenser 106, the refrigerant is at or substantially at the point 218. As the refrigerant passes through the condenser 106, enthalpy of the refrigerant decreases, while pressure of the refrigerant remains substantially constant. Temperature of the refrigerant also decreases as the refrigerant passes through the condenser 106. The refrigerant transitions into a subcooled liquid state (e.g., the subcooled region 210) as the refrigerant exits the condenser 106, shown as point 220.
When the refrigerant enters the expansion valve 108, the refrigerant is at or substantially at the point 220. As the refrigerant passes through the expansion valve 108, the refrigerant expands (e.g., the pressure decreases while the enthalpy remains substantially the same), thereby causing further cooling and transitioning the refrigerant into a vapor liquid mixture, as represented by a point 222. Once the refrigerant achieves the thermodynamic state shown at point 222, the refrigerant can be used to cool the space (e.g., by being transferred through the evaporator 102).
As the refrigerant passes through the evaporator 102, the refrigerant cools the space (e.g., heat transfer from the air of the space to the refrigerant) and thereby increases in temperature. As the refrigerant increases in temperature, the refrigerant also increases in enthalpy while the pressure of the refrigerant remains substantially the same. The refrigerant increases in temperature and enthalpy until the refrigerant achieves the thermodynamic state as shown at point 216 (e.g., as the refrigerant exits the evaporator 102). The point 216 is the starting point of the process illustrated by path 206.
Referring to
The condenser 106 can also include indirect evaporative heat exchangers 312 that are positioned along a flow path of the air between the ambient 314 and the exhaust 334. In some embodiments, the condenser 106 includes multiple evaporative heat exchangers 312 positioned downstream of inlets 326 at which the air is drawn from the ambient 314 into the condenser 106 (e.g., into the inner volume 310 of the housing 302). The evaporative heat exchangers 312 are configured to pre-cool the air in a manner such that the air remains at low humidity in order to facilitate improved cooling and condensation of the refrigerant as the refrigerant travels through the coils 306.
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In some embodiments, a portion of the air that exits the passages 902 is recirculated into the wet passages through inlets 910 (e.g., openings, holes, windows, apertures, etc.) of the wet inlet passages 908. The recirculated air may be drawn back through the wet inlet passages 908 due to operation of the fans 332 and the louvres 342 being in the opened position. In some embodiments, the position or the degree of openness of the louvres 342 (e.g., a cross-sectional flow area defined by the louvres 342) and/or a speed of the fans 332 results in different proportions of the air that exits the dry passages 902 being drawn back into the wet outlet passages 914. For example, when the louvres 342 are in the closed position, none of the air that exits the dry passages 902 into the intermediate volumes 316 is recirculated into the wet outlet passages 914. Similarly, when the louvres 342 are fully opened, a highest amount or rate of air is recirculated through the wet inlet passages 908.
In some embodiments, the dry passages 902 are fluidly separate from the wet passages (e.g., the wet inlet passages 908, the wet medial passages 912, and the wet outlet passages 914). In some embodiments, the water tank 336 is configured to provide liquid or moisture (e.g., droplets, a spray of water, a spray of mist, etc.) to the wet medial passages 912 through pipes 338 and discharge devices 350 (e.g., openings, inlets, misters, etc.). In some embodiments, the moisture provided by the water tank 336 coats or forms droplets on the exterior of an exterior or outer surface of the dry passages 902 such that the air passing through the dry passages 902 undergoes indirect evaporative cooling. The air that is recirculated through the wet inlet passages 908, the wet medial passages 912, and the wet outlet passages 914 may absorb moisture, and provide an airflow over the dry passages 902 (or sidewalls of the dry passages 902) to thereby provide cooling of the air that passes through the dry passages 902. In some embodiments, the tank 336 is configured to discharge the water or moisture into the wet passages by operation of a pump 352 and opening of the valve 340.
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Memory 808 can include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory 808 can include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and/or computer instructions. Memory 808 can include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Memory 808 can be communicably connected to processor 806 via processing circuitry 804 and can include computer code for executing (e.g., by processor 806) one or more processes described herein.
The controller 802 is configured to receive the ambient temperature reading, the ambient humidity reading, and the entering air temperature reading and perform a control process to generate the control signals for the actuators 810 (e.g., to control position of the louvres 342 and to turn on or turn off the water supply from the water tank 336 by actuating the valve 340). In some embodiments, the valve 340 is a pneumatic or electrically operable valve that can be controlled to transition between an open position and a closed position. In some embodiments, the controller 802 is configured to compare the ambient temperature reading (e.g., Tamb) to a threshold temperature (e.g., Tthresh) (e.g., 80 degrees Fahrenheit) and, in response to the ambient temperature reading exceeding the threshold temperature (e.g., Tamb>Tthresh), determining that the louvres 342 should be transitioned into a fully open position and turning on the water supply from the water tank 336 so that the wet inlet passages 908, the wet medial passages 912, and the wet outlet passages 914 are provided with water or moisture to facilitate evaporative cooling of the air that passes through the dry passages 902.
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The process 500 includes providing a refrigerant unit or system including a gas cooler having an indirect evaporative heat exchanger positioned upstream of a condenser and configured to pre-cool air from an ambient environment before being provided over one or more condenser coils (step 502), according to some embodiments. In some embodiments, step 502 includes providing the refrigeration system 100 as a packaged unit, including the condenser 106 as shown and described in greater detail above with reference to
The process 500 includes obtaining an outdoor ambient temperature, Tamb, from a temperature sensor (step 504), according to some embodiments. In some embodiments, step 504 include obtaining a temperature reading from a temperature sensor (e.g., the temperature sensor 812) positioned in the ambient 314. In some embodiments, the ambient 314 is an outdoor environment (e.g., exterior to the unit or the condenser 106) from which fresh air is drawn.
The process 500 also includes comparing the outdoor ambient temperature, Tamb, to a threshold amount, Tthresh (step 506), according to some embodiments. In some embodiments, in response to the outdoor ambient temperature, Tamb, exceeding the threshold amount Tthresh (e.g., Tamb>Tthresh), process 500 proceeds to step 508. In some embodiments, in response to the outdoor ambient temperature, Tamb, being less than (or less than or equal to) the threshold amount Tthresh (e.g., Tamb<Tthresh), process 500 proceeds to step 512. In some embodiments, steps 504 and 506 are performed by the controller 802.
The process 500 includes turning on a water supply to the indirect evaporative heat exchanger and opening exhaust dampers (step 508), according to some embodiments. In some embodiments, step 508 is performed by the controller 802 by generating control signals for a valve of the water supply (e.g., the valve 340 or a pump of the water tank 336) and control signals for an electric motor or actuator of a louvre (e.g., the actuators 810 of the louvres 342). In some embodiments, step 508 includes controlling the water supply to an on position such that one or more wet passages are provided with water or moisture, and controlling the dampers or louvres so that the dampers or louvres are at a fully opened position. In some embodiments, opening the exhaust dampers (e.g., the louvres 342) results in re-circulatory airflow of air exiting the indirect evaporative heat exchangers such that a portion of air exiting the indirect evaporative heat exchangers through one or more dry passages is re-introduced to the indirect evaporative heat exchangers through one or more wet passages to thereby cause indirect evaporative cooling of the air travelling through the dry passages.
The process 500 includes operating the indirect evaporative heat exchanger to pre-cool the ambient air (step 510), according to some embodiments. In some embodiments, step 510 includes continuing to operate exhaust fans of the condenser 106 (e.g., the fans 332) with the louvres 342 being continually held in the fully open position. In some embodiments, step 510 also includes operating the refrigeration system 100 (e.g., by operating the compressor 104 to drive the refrigerant through the piping).
The process 500 includes turning off the water supply to the indirect evaporative heat exchanger and closing the exhaust dampers (step 512), according to some embodiments. In some embodiments, step 512 is performed similarly to step 508, but to close the valve for the water supply, and to transition the exhaust dampers (e.g., the louvres 342) into the fully closed position. When the exhaust dampers are in the fully closed position and the valve of the water supply is shut (e.g., turned off), the airflow through the indirect evaporative heat exchanger occurs without pre-cooling of the air that travels through the dry passages.
The process 500 includes operating the condenser without indirect evaporative heat exchanger (step 514), according to some embodiments. In some embodiments, step 514 includes operating the compressor 104 to discharge the refrigerant through the piping 110. In some embodiments, operating the condenser without the indirect evaporative heat exchanger being active results in the condenser using the outdoor air for cooling the refrigeration coils.
Referring to
The process 600 includes the step 502 of process 500 (e.g., providing the condenser 106 including the indirect evaporative heat exchanger 312) and also includes obtaining outdoor ambient temperature, Tamb, from a temperature sensor and obtaining outdoor humidity (e.g., relative humidity) RHamb, from a humidity sensor (step 602), according to some embodiments. In some embodiments, step 602 is similar to step 504 of process 500, but also includes obtaining the outdoor humidity RHamb from the humidity sensor. In some embodiments, the humidity sensor is positioned proximate the temperature sensor. For example, the humidity sensor may be positioned in the ambient 314. In some embodiments, step 602 is performed by the controller 802.
The process 600 includes obtaining a dew point temperature, Tdp (step 604), according to some embodiments. In some embodiments, step 604 the dew point temperature Tdp is calculated based on the outdoor ambient temperature Tamb and the outdoor humidity RHamb by the controller 802. In some embodiments, the dew point temperature Tdp is determined based on the outdoor ambient temperature Tamb and the outdoor humidity RHamb using a look up table, a regression model, a function, an equation, a graph or chart, etc. The dew point temperature indicates a temperature that air in the ambient (e.g., outside of the condenser 106) should be cooled to (e.g., at a constant pressure) in order to achieve RHamb=100%.
The process 600 includes determining an ambient dew point depression, Tdep, based on the ambient temperature Tamb and the dew point temperature Tdp (step 606), according to some embodiments. In some embodiments, step 606 is performed by the controller 802. In some embodiments, step 606 includes determining a difference between the ambient temperature Tamb and the dew point temperature Tdp (e.g., Tdep=Tamb−Tdp).
The process 600 includes determining if the ambient dew point depression Tdep is greater than a threshold amount, Tthresh,dep (step 608), according to some embodiments. In some embodiments, step 608 is performed by the controller 802. Step 608 may include comparing the ambient dew point depression Tdep to the threshold amount Tthresh,dep and, in response to the ambient dew point depression Tdep being greater than the threshold amount Tthresh, dep (step 608, “YES”), process 600 proceeds to step 508. In response to the ambient dew point depression Tdep being less than the threshold amount Tthresh, dep (step 608, “NO”), process 600 proceeds to step 512. In some embodiments, the threshold amount Tthresh,dep is a fixed amount such as 10 degrees Fahrenheit. In some embodiments, the threshold amount Tthresh,dep is an adjustable amount that can be set by the user (e.g., by providing a user input to the controller 802), or is adjusted given a selected mode of operation.
The process 600 includes steps 508-810 which are performed responsive to the ambient dew point depression Tdep being greater than the threshold amount Tthresh, dep (step 608, “YES”), and steps 512-514 which are performed responsive to the ambient dew point depression Tdep being less than the threshold amount Tthresh, dep (step 608, “NO”). In some embodiments, steps 508 and 510 are performed continuously until the condition Tdep>Tthresh,dep is no longer met. Similarly, steps 512 and 514 can be performed continuously until the condition Tdep≥Tthresh,dep is no longer met.
Referring to
The process 700 includes step 502 of process 500, and steps 602-606 of process 600. In some embodiments, the process 700 includes performing the step 502 of process 500, and steps 602-606 of process 600. The process 700 also includes determining if either (a) the ambient temperature exceeds a threshold (Tamb>Tthresh) or (b) the ambient dew point depression Tdep is greater than a threshold amount Tthresh,dep (Tdep>Tthresh,dep) (step 702), according to some embodiments. If either (a) Tamb>Tthresh or (b) Tdep>Tthresh,dep, process 700 proceeds to step 508. If both (i) Tamb≤ Tthresh and (ii) Tdep≤ Tthresh,dep, process 700 proceeds to step 512.
The process 700 includes performing step 508 (e.g., turning on water supply to the indirect evaporative heat exchanger, etc.) and obtaining entering air temperature Tenter (step 704) in response to either (a) Tamb>Tthresh or (b) Tdep>Tthresh,dep (step 702, “YES”), according to some embodiments. In some embodiments, step 704 includes obtaining a temperature reading from a sensor that is positioned at an outlet of the indirect evaporative heat exchanger 312, within a space between the outlet of the indirect evaporative heat exchanger 312 and the refrigeration coils 306, or at the refrigeration coils 306. In some embodiments, the entering air temperature Tenter is obtained from the temperature sensor 816 that is positioned within the intermediate volume 316.
The process 700 includes modulating the exhaust dampers to maintain the entering air temperature Tenter at a desired value (step 706), according to some embodiments. In some embodiments, step 706 is performed by the controller 802 using a closed loop control scheme. For example, the controller 802 may adjust operation of the actuators 810 to adjust positions of the louvres 342 between 0% open (e.g., closed) to 100% open. In some embodiments, the desired value of the entering air temperature Tenter indicates an amount of cooling required for the air entering the indirect evaporative heat exchanger 312. In some embodiments, the desired value of the entering air temperature Tenter is the dew point temperature Tdp plus a threshold amount (e.g., Tdp+2° F.). In some embodiments, the controller 802 is configured to adjust the control of the actuators 810 to thereby adjust the position of the louvres 342. Adjusting the position of the louvres 342 adjusts or changes an amount of recirculatory air through the wet passages of the indirect evaporative heat exchanger 312 (e.g., the wet inlet passages 908, the wet medial passages 912, and the wet outlet passages 914), which in turn adjusts an amount of cooling provided to the air that travels through the dry passages 902 of the indirect evaporative heat exchanger 312. In some embodiments, step 706 includes obtaining a power drawn by the compressor 104, or a total power consumption of the refrigeration system 100, and determining a target entering air temperature that is predicted to achieve or result in a desired COP of the refrigeration system 100.
As utilized herein, the terms “approximately”, “about”, “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claim.
It should be noted that the terms “exemplary” and “example” as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).
The terms “coupled,” “connected,” and the like, as used herein, mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent, etc.) or moveable (e.g., removable, releasable, etc.). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.
References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” “between,” etc.) are merely used to describe the orientation of various elements in the figures. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.
Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z to each be present, unless otherwise indicated.
It is important to note that the construction and arrangement of the systems as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present disclosure have been described in detail, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements. It should be noted that the elements and/or assemblies of the components described herein may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present inventions. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the preferred and other exemplary embodiments without departing from scope of the present disclosure or from the spirit of the appended claim.
This application claims the benefit and priority to U.S. Provisional Application No. 63/446,138, filed on Feb. 16, 2023, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63446138 | Feb 2023 | US |
