Cooler purge system and method

Abstract

The present disclosure relates to a heat exchanger for heating, ventilation, air conditioning and refrigeration (HVACamp; a purge system (100) for a vapor compression system (10) includes a purge tank (110) configured to receive a fluid mixture from a vapor compression system (14). The fluid mixture includes a heat transfer fluid (224), a non-condensable gas (106), and a condensable fluid (108). The purge system (100) includes a valve system (198) fluidly coupled to the purge canister (110) and a controller (202) communicatively coupled to the valve system (198). The controller (202) is configured to adjust the valve system (198) based on feedback (240, 242, 244) to selectively discharge the heat transfer fluid (224) from the purge canister (110), to selectively discharge the non-condensable gas (106) from the purge canister (110), and to selectively discharge the condensable fluid (108) from the purge canister (110).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 349,916, filed on June 7, 2022, entitled “CHILLER PURGE SYSTEMS AND METHODS,” which is incorporated herein by reference in its entirety for all purposes. Background Art

[0003] This section is intended to introduce the reader to various aspects of the technology that may be related to various aspects of the present disclosure described below. It is believed that this discussion helps to provide the reader with background information to promote a better understanding of various aspects of the present disclosure. Therefore, it should be understood that these statements should be read in this light, rather than as an admission of the prior art.

[0004] Chiller systems for use in residential, commercial, or industrial heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) systems typically include a compressor for circulating a working fluid (e.g., a refrigerant) through a heat exchanger of the HVAC&R system. The heat exchanger facilitates the transfer of thermal energy between the working fluid and a space to be conditioned, such as a room or area within a building or other structure served by the HVAC&R system. The compressor and heat exchanger form part of a vapor compression system of the HVAC&R system. In certain circumstances (e.g., when a low-pressure refrigerant is used), non-condensable gases (e.g., air, nitrogen) and / or condensable fluids (e.g., water) may accumulate in the vapor compression system and mix with the refrigerant. Unfortunately, the accumulation of such impurities in the vapor compression system may reduce the overall operating efficiency of the HVAC&R system. Summary of the invention

[0005] The present disclosure relates to a purification system for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system. The purification system includes a purification tank configured to receive a fluid mixture from a vapor compression system. The fluid mixture includes a heat transfer fluid, a non-condensable gas, and a condensable fluid. The purification system includes a valve system fluidly coupled to the purification tank and a controller communicatively coupled to the valve system. The controller is configured to adjust the valve system based on feedback to selectively discharge the heat transfer fluid from the purification tank, selectively discharge the non-condensable gas from the purification tank, and selectively discharge the condensable fluid from the purification tank.

[0006] The present disclosure also relates to a float system for a purge tank of a heating, ventilation, air conditioning and refrigeration (HVAC&R) system. The float system includes a plurality of switches and a plurality of floats configured to move relative to the plurality of switches. The plurality of switches and the plurality of floats are configured to be disposed within the purge tank. The plurality of floats are configured to selectively engage one or more of the plurality of switches based on a first amount of condensable fluid within the purge tank and a second amount of heat transfer fluid within the purge tank to generate one or more signals indicating the first amount and the second amount.

[0007] The present disclosure also relates to a purification system for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system. The purification system includes a float system configured to be disposed within a purification tank. The float system includes a plurality of switches and a plurality of floats, the plurality of floats being configured to selectively engage one or more of the plurality of switches to generate one or more signals based on a first amount of condensable fluid within the purification tank and a second amount of heat transfer fluid within the purification tank. The purification system also includes a controller configured to receive the one or more signals and analyze the one or more signals to determine the first amount of condensable fluid within the purification tank, the second amount of heat transfer fluid within the purification tank, or both. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various aspects of the present disclosure may be better understood after reading the following detailed description and referring to the drawings, in which:

[0009] Figure 1 is a perspective view of an embodiment of a building utilizing a heating, ventilation, air conditioning and / or refrigeration (HVAC&R) system in a commercial environment according to an aspect of the present disclosure;

[0010] Figure 2 is a perspective view of an embodiment of a vapor compression system according to an aspect of the present disclosure;

[0011] Figure 3 According to one aspect of the present disclosure Figure 2 A schematic diagram of an embodiment of a vapor compression system;

[0012] Figure 4 According to one aspect of the present disclosure Figure 2 A schematic diagram of an embodiment of a vapor compression system;

[0013] Figure 5 is a schematic diagram of an embodiment of a vapor compression system with a purification system according to an aspect of the present disclosure;

[0014] Figure 6 is a schematic diagram of an embodiment of a portion of a purification tank of a purification system according to an aspect of the present disclosure;

[0015] Figure 7 is a schematic diagram of an embodiment of a portion of a purification tank of a purification system according to an aspect of the present disclosure;

[0016] Figure 8 is a schematic diagram of an embodiment of a portion of a purification tank of a purification system according to an aspect of the present disclosure;

[0017] Fig. 9 is a schematic diagram of an embodiment of a portion of a purification tank of a purification system according to an aspect of the present disclosure;

[0018] Fig.10 is a cross-sectional schematic side view of an embodiment of a condenser of a vapor compression system according to an aspect of the present disclosure; and

[0019] Fig.11 is a cross-sectional schematic axial view of an embodiment of an evaporator of a vapor compression system according to an aspect of the present disclosure. DETAILED DESCRIPTION

[0020] One or more specific embodiments of the present disclosure will be described below. These described embodiments are examples of the currently disclosed technology. In addition, in the process of striving to provide a concise description of these embodiments, all features of the actual implementation scheme may not be described in the specification. It should be understood that in the development of any such actual implementation scheme, as in any engineering or design project, numerous implementation-specific decisions can be made to achieve the specific goals of the developer, such as complying with system-related and business-related constraints, which may vary from one implementation scheme to another. In addition, it should be understood that such development work may be complex and time-consuming, but it is nothing more than a routine task of design, manufacture and production for ordinary technicians who benefit from the present disclosure.

[0021] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," and "the" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements in addition to the listed elements. Further, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that are further incorporated into the recited features.

[0022] As used herein, the terms "approximately," "substantially," and "substantially," etc., are intended to convey that the value of a property being described may be within a relatively small range of the value of the property, as understood by a person skilled in the art. For example, when a property value is described as being "approximately" equal to (or, for example, "substantially similar to") a given value, this is intended to mean that the property value may be within + / -5%, within + / -4%, within + / -3%, within + / -2%, within + / -1%, or even closer of the given value. Similarly, when a given feature is described as being "substantially parallel" to another feature, "substantially perpendicular" to another feature, etc., this is intended to mean that the given feature has the described property within + / -5%, within + / -4%, within + / -3%, within + / -2%, within + / -1%, or even closer, such as being parallel to another feature, perpendicular to another feature, etc. Additionally, it should be understood that mathematical terms such as "flat," "inclined," "perpendicular," "parallel," and the like are intended to encompass features of surfaces or elements as understood by one of ordinary skill in the relevant art, and should not be interpreted as strictly as would be understood in the mathematical arts. For example, a "flat" surface is intended to encompass a surface that is machined, molded, or otherwise formed to be substantially flat or smooth (within relevant tolerances) using techniques and tools available to one of ordinary skill in the art. Similarly, a surface having a "slope" is intended to encompass a surface that is machined, molded, or otherwise formed to be oriented at an angle (e.g., inclined) relative to a reference point using techniques and tools available to one of ordinary skill in the art.

[0023] As briefly discussed above, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system can be used to thermally condition a space within a building, residence, or other suitable structure. For example, an HVAC&R system can include a vapor compression system (e.g., a chiller system) that transfers thermal energy between a heat transfer fluid (e.g., a working fluid) such as a refrigerant and a fluid to be conditioned (e.g., air, water, or brine). The vapor compression system can include a condenser and an evaporator that are fluidly coupled to each other via one or more conduits. A compressor can be used to circulate a heat transfer fluid through the conduits, and thereby achieve thermal energy transfer between the heat transfer fluid and the fluid to be conditioned via the condenser and / or the evaporator.

[0024] In certain circumstances, the operation of an HVAC&R system may cause non-condensable gases (e.g., air, nitrogen) and / or condensable fluids (e.g., water) to accumulate within components (e.g., heat exchangers, conduits) of the vapor compression system. For example, during operation of the HVAC&R system, the pressure within certain components of the HVAC&R system may drop below zero PSIG (pounds per square inch gauge). That is, under the operating conditions of these components, the pressure within the components may be less than the surrounding atmospheric pressure. Over time, this pressure differential may introduce (e.g., force) impurities (e.g., non-condensable gases, condensable fluids) from the atmosphere into the components of the vapor compression system. As a result, such impurities may mix with the heat transfer fluid within the vapor compression system. Unfortunately, the mixing of non-condensable gases and / or water with the heat transfer fluid of the vapor compression system may reduce the overall operating efficiency of the vapor compression system.

[0025] Therefore, embodiments of the present disclosure relate to a purification system configured to facilitate the removal (e.g., purification) of non-condensable gases and condensable fluids (e.g., water) from a vapor compression system to improve the purity of a heat transfer fluid within the vapor compression system and improve the overall operating efficiency of the HVAC&R system. The purification system may include a purification tank that is fluidly coupled to a condenser and / or an evaporator via corresponding conduits. The purification tank may be configured to selectively receive a mixture (e.g., a fluid mixture) of a heat transfer fluid (e.g., a refrigerant) and non-condensable gases from the condenser. The purification tank may include a purification coil configured to reduce the temperature within the purification tank. In this way, the purification coil may enable the heat transfer fluid (e.g., a gaseous heat transfer fluid) entering the purification tank (e.g., from the condenser) to condense into a liquid phase or liquid state, while the non-condensable gases received from the condenser may remain in a gas phase or gaseous state. The condensed heat transfer fluid within the purification tank may flow to a collection basin of the purification tank, which may be vertically positioned below at least a portion of the purification coil (e.g., relative to the direction of gravity). The exhaust port of the purge system can enable the non-condensable gases to be discharged from the purge tank to the surrounding environment, such as the atmosphere. The drain of the purge system can enable the heat transfer fluid to be discharged from the collection basin back to the components of the vapor compression system (e.g., the evaporator). In this way, the purge tank helps to purge (e.g., remove) non-condensable gases from the heat transfer fluid of the vapor compression system.

[0026] The purification tank can also be configured to selectively receive a mixture (e.g., a fluid mixture) of a heat transfer fluid (e.g., a refrigerant) and a condensable fluid (e.g., moisture, water vapor) from the evaporator (and / or from another component of the vapor compression system). The purification coil facilitates condensation of the heat transfer fluid and the condensable fluid within the purification tank. Thus, the operation of the purification coil enables the liquid heat transfer fluid and the condensable fluid (e.g., liquid water) to accumulate in the collection basin. The density of the condensable fluid in the collection basin can be less than the density of the liquid heat transfer fluid in the collection basin. Therefore, the condensable fluid and the liquid heat transfer fluid can be stratified in the collection basin. That is, the condensable fluid can accumulate above the liquid heat transfer fluid accumulated in the collection basin relative to the direction of gravity. The purification system can include a float assembly that is configured to provide feedback (e.g., data) indicating the amount of heat transfer fluid in the purification tank, the amount of condensable fluid in the purification tank, or both. A controller of the purification system can receive feedback and be configured to operate components of the purification system (e.g., one or more valves) based on the feedback to selectively drain the heat transfer fluid, the condensable fluid, or both from the collection basin of the purification tank. To this end, the purification tank helps to purify (e.g., remove) the condensable fluid from the heat transfer fluid of the vapor compression system. These and other features will be described in detail below with reference to the drawings.

[0027] Turning now to the accompanying drawings, Figure 1 1 is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 in a building 12 for a typical commercial environment. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller system) that supplies a cooling liquid that may be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 for supplying warm liquid to heat the building 12 and an air distribution system that circulates air through the building 12. The air distribution system may also include an air return duct 18, an air supply duct 20, and / or an air handler 22. In some embodiments, the air handler 22 may include a heat exchanger that is connected to the boiler 16 and the vapor compression system 14 via ducts 24. Depending on the operating mode of the HVAC&R system 10, the heat exchanger in the air handler 22 may receive heated liquid from the boiler 16 or cooled liquid from the vapor compression system 14. The HVAC&R system 10 is shown with separate air handlers on each floor of the building 12, but in other embodiments, the HVAC&R system 10 may include air handlers 22 and / or other components that may be shared between floors.

[0028] Figure 2 and 3is an embodiment of a vapor compression system 14 that may be used in the HVAC&R system 10. The vapor compression system 14 may circulate a heat transfer fluid through a loop starting from a compressor 32. The loop may also include a condenser 34, an expansion valve or device 36, and a liquid cooler or evaporator 38. The vapor compression system 14 may further include a control panel 40 having an analog-to-digital (A / D) converter 42, a microprocessor 44, a non-volatile memory 46, and / or an interface board 48.

[0029] Some examples of fluids that can be used as heat transfer fluids (e.g., refrigerants) in the vapor compression system 14 are hydrofluorocarbon (HFC)-based refrigerants, such as R-410A, R-407, R-134a, hydrofluoroolefins (HFO), "natural" refrigerants such as ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon-based refrigerants, water vapor, or any other suitable refrigerant. In some embodiments, the vapor compression system 14 can be configured to efficiently utilize a heat transfer fluid having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere, also known as a low-pressure refrigerant, rather than a medium-pressure refrigerant, such as R-134a. For example, the vapor compression system 14 can utilize R1233zd as a heat transfer fluid. As used herein, "standard boiling point" can refer to a boiling point temperature measured at one atmosphere.

[0030] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or device 36, and / or an evaporator 38. The motor 50 may drive the compressor 32 and may be powered by the variable speed drive (VSD) 52. The VSD 52 receives AC power having a specific fixed line voltage and a fixed line frequency from an alternating current (AC) power source and provides power having a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be powered directly by an AC or direct current (DC) power source. The motor 50 may include any type of motor that may be powered by a VSD or directly by an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

[0031] Compressor 32 compresses the heat transfer fluid vapor and delivers the vapor to condenser 34 through a discharge passage. In some embodiments, compressor 32 may be a centrifugal compressor. The heat transfer fluid vapor delivered to condenser 34 by compressor 32 may transfer heat to a cooling fluid (e.g., water or air) in condenser 34. As a result of the heat transfer with the cooling fluid, the heat transfer fluid vapor may condense into heat transfer fluid liquid in condenser 34. The liquid heat transfer fluid from condenser 34 may flow to evaporator 38 through expansion device 36. In Figure 3 In the illustrated embodiment of , the condenser 34 is water-cooled and includes a tube bundle 54 connected to a cooling tower 56 that supplies cooling fluid to the condenser 34 .

[0032] The liquid heat transfer fluid delivered to the evaporator 38 may absorb heat from another cooling fluid, which may or may not be the same cooling fluid used in the condenser 34. The liquid heat transfer fluid in the evaporator 38 may undergo a phase change from a liquid heat transfer fluid to a heat transfer fluid vapor. Figure 3 As shown in the illustrated embodiment of FIG. 5 , the evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to a cooling load 62. The cooling fluid (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) of the evaporator 38 enters the evaporator 38 via the return line 60R and exits the evaporator 38 via the supply line 60S. The evaporator 38 may reduce the temperature of the cooling fluid in the tube bundle 58 via heat transfer with a heat transfer fluid. The tube bundle 58 in the evaporator 38 may include multiple tubes and / or multiple tube bundles. In any case, the vapor heat transfer fluid exits the evaporator 38 and returns to the compressor 32 through the suction line to complete the cycle.

[0033] Figure 4 is a schematic diagram of vapor compression system 14 in which intermediate loop 64 is coupled between condenser 34 and expansion device 36. Intermediate loop 64 may have an inlet line 68 directly fluidly connected to condenser 34. In other embodiments, inlet line 68 may be indirectly fluidly coupled to condenser 34. Figure 4 In the illustrated embodiment, the inlet line 68 includes a first expansion device 66 positioned upstream of an intermediate vessel 70. In some embodiments, the intermediate vessel 70 may be a flash tank (e.g., a flash intercooler). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or a "surface economizer." Figure 4 In the illustrated embodiment of , the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is configured to reduce (e.g., expand) the pressure of the liquid heat transfer fluid received from the condenser 34. During the expansion process, a portion of the liquid may evaporate, and thus the intermediate vessel 70 may be used to separate the vapor from the liquid received from the first expansion device 66.

[0034] In addition, the intermediate container 70 can provide further expansion of the liquid heat transfer fluid due to the pressure drop experienced by the liquid heat transfer fluid when entering the intermediate container 70 (e.g., due to the rapid increase in volume experienced when entering the intermediate container 70). The vapor in the intermediate container 70 can be drawn by the compressor 32 through the suction line 74 of the compressor 32. In other embodiments, the vapor in the intermediate container can be drawn to an intermediate stage (e.g., a non-suction stage) of the compressor 32. Due to the expansion in the expansion device 66 and / or the intermediate container 70, the liquid collected in the intermediate container 70 can have a lower enthalpy than the liquid refrigerant leaving the condenser 34. The liquid from the intermediate container 70 can then flow through the second expansion device 36 in line 72 to the evaporator 38.

[0035] Considering the foregoing, Figure 5 Schematic diagram of an embodiment of a portion of an HVAC&R system 10 that includes a purification system 100 configured to purify impurities (e.g., non-condensable gases, condensable fluids) from a heat transfer fluid (e.g., R1233zd) of a vapor compression system 14. The vapor compression system 14 includes a plurality of conduits configured to fluidly couple components of the vapor compression system 14 (e.g., evaporator 38, condenser 34, compressor 32, expansion device 36) to one another to form a heat transfer fluid loop 104 (e.g., a working fluid loop). In some embodiments, operation of the HVAC&R system 10 may cause the pressure within at least a portion of the heat transfer fluid loop 104 (e.g., evaporator 38) to decrease below ambient atmospheric pressure (e.g., less than 14.7 pounds per square inch [PSI]; less than zero PSIG). As a result, a pressure differential may be generated between the heat transfer fluid loop 104 (e.g., components of the refrigerant loop 104) and the surrounding environment (e.g., the environment surrounding the vapor compression system 14). In some embodiments, the pressure differential may cause non-condensable gases 106 (e.g., air, nitrogen) from the surrounding environment to enter components of the vapor compression system 14 (e.g., conduits, heat exchangers) and mix with the heat transfer fluid within the heat transfer fluid loop 104. The non-condensable gases 106 may include any gas (e.g., air, nitrogen) that is non-condensable at the operating temperature of the vapor compression system 14 (e.g., normal operating temperature of the vapor compression system 14 that is not reached in a laboratory environment). The non-condensable gases 106 may circulate through the heat transfer fluid loop 104 via the compressor 32 and may accumulate in the condenser 34, which may ultimately reduce the operating efficiency of the vapor compression system 14, the compressor 32, the condenser 34, the evaporator 38, other components of the HVAC&R system 10, or any combination thereof.

[0036] In certain embodiments, pressure differentials between certain components of the vapor compression system 14 (e.g., the evaporator 38) and the surrounding environment may also cause condensable fluid 108 (e.g., water, moisture, water vapor) to enter the heat transfer fluid loop 104 (e.g., components of the heat transfer fluid loop 104) from the surrounding environment. For example, in certain cases, air entering the heat transfer fluid loop 104 may include moisture (e.g., water vapor) suspended therein, which may ultimately condense within and may accumulate within one or more components of the heat transfer fluid loop 104 (e.g., the evaporator 38). The accumulation of water within the heat transfer fluid loop 104 may reduce the operating efficiency of the vapor compression system 14, the compressor 32, the condenser 34, the evaporator 38, other components of the HVAC&R system 10, or any combination thereof, and may also increase the likelihood of corrosion or wear within the heat transfer fluid loop 104.

[0037] The purification system 100 can be configured to remove and / or separate non-condensable gases 106 and condensable fluids 108 from the heat transfer fluid within the vapor compression system 14. In the illustrated embodiment, the purification system 100 includes a purification tank 110 fluidly coupled to the condenser 34 and the evaporator 38. For example, a first flow path 112 (e.g., one or more conduits) can fluidly couple the purification tank 110 to a first port 114 (e.g., one or more ports) of the condenser 34. The first port 114 can be located near an upper portion of the condenser 34 relative to the direction of gravity, and can enable the heat transfer fluid and non-condensable gases 106 to flow into the first flow path 112 and flow to the purification tank 110. During certain operating cycles or modes of the HVAC&R system 10, the pressure within the condenser 34 can be higher than the pressure within the purification tank 110. As such, the pressure differential between the condenser 34 and the purification tank 110 can be sufficient to enable the heat transfer fluid and non-condensable gases 106 (e.g., a fluid mixture) to flow from the first port 114 to the purification tank 110 without utilizing, for example, a pump. In other embodiments, a pump may be fluidly coupled to the first flow path 112 and configured to direct the flow of the heat transfer fluid and the non-condensable gas 106 from the condenser 34 to the purge tank 110 .

[0038] In certain embodiments, a first control valve 116 may be disposed along (e.g., fluidly coupled to) the first flow path 112 and configured to regulate (e.g., throttle) the flow of the heat transfer fluid and the non-condensable gas 106 from the condenser 34 to the purge tank 110. A first check valve 118 may be disposed along the first flow path 112 and configured to inhibit (e.g., block) the flow of fluid from the purge tank 110 to the condenser 34 via the first flow path 112.

[0039] In some embodiments, a second flow path 120 (e.g., one or more conduits) may fluidly couple the purge tank 110 to a second port 122 (e.g., one or more ports) of the evaporator 38. The second port 122 may be located near a lower portion of the evaporator 38 relative to the direction of gravity, and may enable the heat transfer fluid and the condensable fluid 108 (e.g., a fluid mixture) to flow into the second flow path 120 and toward the purge tank 110. In some embodiments, a pump 124 (e.g., a control valve) may be disposed along the second flow path 120 and configured to direct the flow of the heat transfer fluid and the condensable fluid 108 from the evaporator 38 to the purge tank 110. A second check valve 126 may be disposed along the second flow path 120 and configured to inhibit (e.g., block) the flow of fluid from the purge tank 110 to the evaporator 38 via the second flow path 120. In some embodiments, a liquid tank 128 may be disposed along the second flow path 120 and configured to accumulate liquid (e.g., condensable fluid 108) that may be received from the second port 122 of the evaporator 38. In certain embodiments, the pump 124 may be disposed within or otherwise integrated with the liquid tank 128 .

[0040] In some embodiments, the purge tank 110 may include a purge coil 130 configured to reduce the temperature within the purge tank 110 so as to facilitate condensation of the heat transfer fluid and the condensable fluid 108 within the purge tank 110. As discussed in detail herein, condensation of the heat transfer fluid within the purge tank 110 may facilitate separation of the heat transfer fluid from the non-condensable gases 106 and condensable fluids 108 within the purge tank 110 that are mixed with the heat transfer fluid upon entering the purge tank 110. In some embodiments, the purge coil 130 may be coupled to an auxiliary cooling system configured to provide cooled purge heat transfer fluid (e.g., refrigerant) or other cooled fluid to the purge coil 130. In this way, the fluid circulating through the purge coil 130 may absorb thermal energy from the fluid within the purge tank 110 (e.g., a fluid mixture of heat transfer fluid, non-condensable gases 106, and / or condensable fluid 108). In some embodiments, the fluid circulating through the purge coil 130 may be separated (e.g., isolated) from the fluid circulating through the heat transfer fluid loop 104. In other embodiments, the fluid circulated through the purge coil 130 may include heat transfer fluid received from a portion of the heat transfer fluid loop 104 (eg, heat transfer fluid received from the expansion device 36 ).

[0041] In any case, the gaseous mixture of the heat transfer fluid and the non-condensable gas 106 may flow from the condenser 34 of the vapor compression system 14 to the purge tank 110 via the first flow path 112. In some embodiments, the mixture of the heat transfer fluid and the non-condensable gas 106 may flow into the purge tank 110 via a thermosyphon. Additionally or alternatively, a partial vacuum may be created within the purge tank 110 (e.g., when the incoming heat transfer fluid condenses in the purge tank 110) and facilitate the flow of the fluid through the first flow path 112 into the purge tank 110. In certain embodiments, the pump 124 may direct the heat transfer fluid and the condensable fluid 108 from the evaporator 38 into the purge tank 110. In some embodiments, the pump 124 may include or be replaced by a control valve configured to regulate (e.g., throttle) the flow of the fluid from the evaporator 38 to the purge tank 110 along the second flow path 120. That is, such a control valve may rely on the pressure difference between the evaporator 38 and the purge tank 110 to regulate the flow of fluid from the evaporator 38 to the purge tank 110 without using the pump 124 (e.g., such as when the pressure within the pressure evaporator 38 is greater than the pressure within the purge tank 110). Thus, in some embodiments, the pump 124 may be omitted from the second flow path 120.

[0042] In some embodiments, the first control valve 116 may enable the heat transfer fluid and the non-condensable gases 106 to flow from the condenser 34 to the purge tank 110 at a first time, and the pump 124 may be operated at a second time (e.g., a different time than the first time) to direct the heat transfer fluid and the condensable fluid 108 from the evaporator 38 into the purge tank 110. In any case, the purge coil 130 may absorb heat (e.g., thermal energy) from the mixture of the heat transfer fluid, the non-condensable gases 106, and the condensable fluid 108 that may be within the purge tank 110. In this way, the heat transfer fluid and the condensable fluid 108 within the purge tank 110 may condense into a liquid state, and the non-condensable gases 106 may remain in a gaseous state.

[0043] In some embodiments, at least a portion of the purge coil 130 may be immersed in the mixture of the heat transfer fluid and the condensable fluid 108. The immersed portion of the purge coil 130 may facilitate subcooling of the heat transfer fluid and the condensable fluid 108, and may thereby reduce or substantially inhibit flashing of the heat transfer fluid within the purge tank 110. Further, subcooling of the mixture of the heat transfer fluid and the condensable fluid 108 in the purge tank 110 may reduce the solubility of water in the heat transfer fluid in the purge tank 110, which may facilitate separation (e.g., stratification) of the heat transfer fluid and the condensable fluid 108 in the purge tank 110. The exposed portion of the purge coil 130 (e.g., the portion of the purge coil 130 that may not be immersed in the mixture of the heat transfer fluid and the condensable fluid 108) may facilitate separation of the condensable gases from the non-condensable gases 106 in the purge tank 110.

[0044] The non-condensable gas 106 in the purge tank 110 may be discharged from the purge tank 110 via a first outlet 140 of the purge tank 110 (e.g., to the surrounding environment, to a discharge tank of the purge system 100). A first outlet valve 142 (e.g., a solenoid valve) may be coupled to the first outlet port 140 and configured to regulate the flow of the non-condensable gas 106 from the purge tank 110 to the surrounding environment. A controller of the purge system 100 may operate the first outlet valve 142 (e.g., based on sensor feedback and / or control instructions) to selectively discharge the non-condensable gas 106 from the purge tank 110 to the surrounding environment (e.g., via the first outlet port 140). In some embodiments, the purge tank 110 may include a heating element 144 that may be selectively activated to heat the interior of the purge tank 110, which may increase the pressure in the purge tank 110. The increase in pressure in the purge tank 110 may facilitate the flow of the non-condensable gas 106 through the first outlet port 140 and into the surrounding environment.

[0045] In some embodiments, the purification system 100 may include an auxiliary flow path 150 that fluidly couples the evaporator 38 (or another component of the vapor compression system 14) to the purification tank 110. For example, an auxiliary control valve 152 and an auxiliary check valve 153 may be disposed along the auxiliary flow path 150 and configured to adjust a pressure differential between the purification tank 110 and the evaporator 38. In this way, the auxiliary control valve 152 and / or the auxiliary check valve 153 may ensure that the pressure within the purification tank 110 is generally maintained within a target operating range. In some embodiments, such as when the pressure within the purification tank 110 is less than the pressure within the evaporator 38, the auxiliary check valve 153 may inhibit (e.g., prevent) fluid flow from the evaporator 38 to the purification tank 110.

[0046] The liquid heat transfer fluid and the condensable fluid 108 within the purification tank 110 may accumulate within a collection basin 156 of the purification tank 110. The collection basin 156 may be positioned below (e.g., relative to the direction of gravity) a remaining portion 158 (e.g., an upper portion) of the purification tank 110. The density of the heat transfer fluid within the collection basin 156 may be greater than the density of the condensable fluid 108 within the collection basin 156. In this way, the liquid heat transfer fluid in the collection basin 156 may accumulate below (e.g., relative to the direction of gravity) any condensable fluid 108 that may accumulate within the collection basin 156. In some embodiments, a first diameter 157 or cross-sectional area of ​​the collection basin 156 may be smaller than a second diameter 159 or cross-sectional area of ​​the remaining portion 158 of the purification tank 110. An axial dimension or axis of the collection basin 156, an axial dimension or axis of the remaining portion 158, or both may extend generally along the direction of gravity. The relatively smaller first diameter 157 of the collection basin 156 (e.g., compared to the second diameter 159 of the remaining portion 158) can facilitate accumulation of a column of liquid extending within the collection basin 156, which can facilitate stratification (e.g., gravity-based stratification) of the liquid heat-transfer fluid and the condensable fluid 108 within the collection basin 156. As discussed below, stratification of the liquid heat-transfer fluid and the condensable fluid 108 within the collection basin 156 can facilitate selective (e.g., independent) removal of the liquid heat-transfer fluid or the condensable fluid 108 from the collection basin 156.

[0047] The liquid heat transfer fluid may be discharged from the collection basin 156 to the evaporator 38 via a second outlet 160 of the purification tank 110. The second outlet port 160 may be fluidly coupled to the evaporator 38 via a third flow path 162 (e.g., one or more conduits). In some embodiments, the pressure differential between the evaporator 38 and the purification tank 110 may be sufficient to cause the flow of the liquid heat transfer fluid from the collection basin 156 to the evaporator 38 along the third flow path 162. In other embodiments, a pump may be disposed along the third flow path 162 and configured to direct the liquid heat transfer fluid from the collection basin 156 to the evaporator 38. The liquid heat transfer fluid received at the evaporator 38 via the third flow path 162 may be directed to the plurality of tubes 170 of the evaporator 38 via a heat transfer fluid distributor 172. In some embodiments, a second outlet valve 174 may be disposed along the third flow path 162 and configured to regulate (e.g., throttle) the flow of the heat transfer fluid from the collection basin 156 to the evaporator 38. The third check valve 176 may be disposed along the third flow path 162 and configured to inhibit (eg, prevent) fluid flow from the evaporator 38 to the purge canister 110 via the third flow path 162 .

[0048] The condensable fluid 108 can be discharged from the collection basin 156 to the environment 178 (e.g., a tank, a surrounding environment) via a third outlet port 180 of the purge tank 110. The third outlet port 180 can be vertically positioned above the second outlet port 160 (e.g., relative to the direction of gravity). The third outlet port 180 can be fluidly coupled to the environment 178 via a fourth flow path 182. In some embodiments, the pressure differential between the purge tank 110 and the environment 178 can be sufficient to cause the condensable fluid 108 to flow from the collection basin 156 to the environment 178 along the fourth flow path 182. In other embodiments, a pump can be disposed along the fourth flow path 182 and configured to direct the condensable fluid 108 from the collection basin 156 to the environment 178. In some embodiments, a third outlet valve 188 can be disposed along the fourth flow path 182 and configured to regulate (e.g., throttle) the flow of the condensable fluid 108 from the collection basin 156 to the environment 178. A fourth check valve 190 may be disposed along the fourth flow path 182 and configured to inhibit (e.g., block) fluid flow from the environment 178 to the purification tank 110 via the fourth flow path 182. The valves 116, 142, 152, 174, and / or 188 and / or the pump 124 (e.g., control valves) may form at least a portion 100 of a control valve system 198 (e.g., a valve system) of the purification system.

[0049] In some embodiments, the rate at which the heat transfer fluid accumulates within the collection basin 156 over time may be greater than the rate at which the condensable fluid 108 accumulates within the collection basin 156. Thus, based on the respective amounts of heat transfer fluid and condensable fluid 108 that may be within the collection basin 156, it may be desirable to determine the amounts of heat transfer fluid and condensable fluid 108 within the collection basin 156 and selectively discharge the heat transfer fluid to the evaporator 38, to selectively discharge the condensable fluid 108 to the environment 178, or both. Accordingly, the purge tank 110 includes a float system 200 that enables a controller 202 of the purge system 100 to determine the amount of heat transfer fluid within the collection basin 156, to determine the amount of condensable fluid 108 in the collection basin 156, or both, as discussed in detail herein.

[0050] The controller 202 (e.g., a control system, a control panel, an automation controller) may be communicatively coupled to one or more components of the HVAC&R system 10 and configured to monitor, regulate, and / or otherwise control the operation of the components of the HVAC&R system 10. For example, one or more control transmission devices (e.g., communication devices, data transmission devices), such as wires, cables, wireless communication devices, etc., may communicatively couple the compressor 32, the expansion device 36, the pump 124 (e.g., a control valve), the valves 116, 152, 174, 188, the float system 200, and / or any other suitable component 10 of the HVAC&R system to the controller 202. That is, the compressor 32, the expansion device 36, the pump 124, the valves 116, 152, 174, 188, and / or the float system 200 may each have a communication component that facilitates wired or wireless (e.g., via a network) communication with the controller 202. In some embodiments, the communication components may include a network interface that enables the components of the HVAC&R system 10 to communicate via various protocols such as EtherNet / IP, ControlNet, DeviceNet, or any other communication network protocol. Alternatively, the communication components may enable the components of the HVAC&R system 10 to communicate via mobile telecommunication technologies, In this way, the compressor 32, the expansion device 36, the pump 124, the valves 116, 152, 174, 188 and / or the float system 200 can wirelessly transmit data between each other.

[0051] In some embodiments, controller 202 may include a portion or all of control panel 82, or may be another suitable controller included in HVAC&R system 10. In any case, controller 202 may be configured to control components of HVAC&R system 10 according to the techniques discussed herein. Controller 202 includes processing circuitry 204, such as one or more microprocessors, which may execute software for controlling components of HVAC&R system 10. Processing circuitry 204 may include multiple microprocessors, one or more “general purpose” microprocessors, one or more special purpose microprocessors, and / or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, processing circuitry 204 may include one or more reduced instruction set (RISC) processors.

[0052] The controller 202 may also include a memory device 206 (e.g., memory) that may store information such as instructions, control software, lookup tables, configuration data, and the like. The memory device 206 may include volatile memory, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM). The memory device 206 may store a variety of information and may be used for a variety of purposes. For example, the memory device 206 may store processor-executable instructions including firmware or software for execution by the processing circuit system 204, such as instructions for controlling components of the HVAC&R system 10. In some embodiments, the memory device 206 is a tangible, non-transitory machine-readable medium that may store machine-readable instructions for execution by the processing circuit system 204. The memory device 206 may include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The memory device 206 may store data, instructions, and any other suitable data.

[0053] Figure 6 Schematic diagram of an embodiment of a portion of a purge tank 110 showing a collection basin 156 and a float system 200. In the illustrated embodiment, the float system 200 includes a first float 220 and a second float 222. The first float 220 can have a density or weight that is less than the density or weight of the second float 222. Specifically, the density of the first float 220 can be less than the density of a heat transfer fluid 224 that may be in the collection basin 156, and less than the density of a condensable fluid 108 (e.g., water) that may be in the collection basin 156. The density of the second float 222 can be less than the density of the heat transfer fluid 224, and greater than the density of the condensable fluid 108. Thus, the first float 220 can float on (e.g., be suspended by) both the heat transfer fluid 224 and the condensable fluid 108, while the second float 222 can float on (e.g., be suspended by) the heat transfer fluid 224 but sink into (e.g., not be suspended by) the condensable fluid 108. For the sake of clarity, it should be understood that both the first float 220 and the second float 222 cannot be suspended in the non-condensable gas 106 (eg, may sink therein).

[0054] In other embodiments, the first float 220 and the second float 222 can be configured in any other suitable manner to achieve the floating characteristics discussed above. For example, in some embodiments, the first float 220 and the second float 222 can be made of the same type of material (e.g., a material having a substantially similar density). An additional piece of material (e.g., a weight ring) can be coupled to the second float 222 to increase the mass of the second float 222 relative to the first float 220. In this manner, the first float 220 can float on (e.g., be suspended by) both the heat transfer fluid 224 and the condensable fluid 108, while the second float 222 (e.g., with a weight ring) can float on (e.g., be suspended by) the heat transfer fluid 224 but sink into (e.g., not be suspended by) the condensable fluid 108.

[0055] In the illustrated embodiment, the float system 200 includes a shaft 226 that can be configured to guide movement of the first float 220 and the second float 222 along an axis 230 (e.g., a vertical axis relative to gravity) of the shaft 226. For example, in certain embodiments, the shaft 226 can extend through corresponding openings (e.g., holes 227) formed in the first float 220 and the second float 222 to enable movement of the first float 220 and the second float 222 along the axis 230 while preventing movement of the first float 220 and the second float 222 in a direction extending crosswise to the axis 230. In other embodiments, the float system 200 can include any other suitable mechanism, device, or structure configured to guide movement of the first float 220 and the second float 222 within the collection basin 156 in addition to or in lieu of the shaft 226.

[0056] In any case, the float system 200 may include a first switch 232, a second switch 234, and a third switch 236 (collectively referred to as switches 238) that can be engaged (e.g., switched between an open configuration and a closed configuration) by the first float 220 and the second float 222. For example, in some embodiments, the switch 238 may include a reed switch that can be actuated via respective magnets disposed within and / or otherwise coupled to the first float 220 and the second float 222. That is, the switch 238 can be actuated (e.g., closed) when the corresponding float 220 or 222 is within a threshold distance of the corresponding switch 238, which threshold distance is sufficient to engage (e.g., close) the magnet within the float 220 or 222.

[0057] In some embodiments, one or more stop plates 246 can be disposed along the shaft 226 and provide a physical barrier that limits the movement of the first float 220 and the second float 222 along a particular section of the shaft 226. For example, the first stop plate 247 and the second stop plate 248 can limit the movement of the first float 220 along the first section 250 of the shaft 226, while the second stop plate 248 and the third stop plate 249 can limit the movement of the second float 222 along the second section 252 of the shaft 226. In some embodiments, the stop plates 246 can be positioned along the shaft 226 so that the first float 220 can engage the first switch 232 and the second switch 234, but not the third switch 236. Further, the stop plates 246 can be positioned along the shaft 226 so that the second float 222 can engage the third switch 236, but not the first switch 232 or the second switch 234.

[0058] For example, the first float 220 may be configured to engage the first switch 232 when the first float 220 is a threshold distance from the first switch 232 (e.g., when the first float 220 reaches or contacts the first stop plate 247). The first float 220 may be configured to engage the second switch 234 when the first float 220 is a threshold distance from the second switch 234 (e.g., when the first float 220 reaches or contacts the second stop plate 248). The second float 222 may be configured to engage the third switch 236 when the second float 222 is a threshold distance from the third switch 236 (e.g., when the second float 222 reaches or contacts the third stop plate 249). In some embodiments, the second stop plate 248 may be positioned so that the second float 222 does not engage (e.g., close) the second switch 234 even when the second float 222 contacts the second stop plate 248. In some embodiments, switch 238 may include any other suitable switch configured to enable operation of float system 200 according to the techniques discussed herein in addition to or in lieu of a reed switch. In some embodiments, one or more of switches 238 may be coupled to shaft 226 and / or disposed within the shaft.

[0059] The switches 238 may each be communicatively coupled to the controller 202. Specifically, the first float 220 may be configured to engage (e.g., activate) the first switch 232 and the second switch 234, and the second float 222 may be configured to engage (e.g., activate) the third switch 236. That is, the first switch 232 may send a first signal 240 to the controller 202 when engaged with the first float 220, the second switch 234 may send a second signal 242 to the controller 202 when engaged with the first float 220, and the third switch 236 may send a third signal 244 to the controller 202 when engaged with the second float 222. As used herein, engagement of either of the floats 220, 222 with either of the switches 238 may refer to the float 220 or 222 entering within a threshold distance of a corresponding one of the switches 238.

[0060] In some embodiments, the controller 202 can utilize feedback (e.g., data) from the switch 238 to determine the amount of the heat transfer fluid 224 within the collection basin 156, to determine the amount of the condensable fluid 108 within the collection basin 156, or both. The controller 202 can operate the purification system 100 (e.g., the control valve system 198 of the purification system 100) based on the received feedback to selectively discharge the heat transfer fluid 224 from the collection basin 156, to selectively discharge the condensable fluid 108 from the collection basin 156, or both. Additionally, as discussed above, the controller 202 can operate the first outlet valve 142 of the control valve system 198 (e.g., based on sensor feedback and / or control instructions) to selectively discharge the non-condensable gas 106 from the purification tank 110 to the surrounding environment (e.g., via the first outlet port 140). As such, it should be understood that the controller 202 can adjust the control valve system 198 to selectively discharge heat transfer fluid from the purge tank 110, adjust the control valve system 198 to selectively discharge non-condensable gases 106 from the purge tank 110, adjust the control valve system 198 to selectively discharge condensable fluids 108 from the purge tank 110, or a combination thereof based on sensor feedback and / or control instructions.

[0061] For example, in Figure 6In the illustrated embodiment of FIG. 1 , the collection basin 156 may include a certain amount of heat transfer fluid 224 sufficient to cause the first float 220 to engage (e.g., close) the first switch 232. In this way, the first switch 232 may transmit a first signal 240 to the controller 202, while the second switch 234 and the third switch 236 do not transmit corresponding signals 242, 244 to the controller 202. Upon receiving the first signal 240 from the first switch 232 and not detecting corresponding signals from the second switch 234 and the third switch 236, the controller 202 may determine that the amount of heat transfer fluid 224 within the collection basin 156 is relatively high and / or it is desired to drain the heat transfer fluid from the collection basin 156. In other words, upon receiving the first signal 240 from the first switch 232 and not detecting corresponding signals from the second switch 234 and the third switch 236, the controller 202 may determine that the amount of heat transfer fluid within the purification tank 110 reaches or exceeds the upper threshold level. In this way, the controller 202 may initiate a heat transfer fluid drain procedure to drain the heat transfer fluid 224 from the collection basin 156. To initiate the heat transfer fluid discharge procedure, the controller 202 may instruct the second outlet valve 174 to transition to an open or partially open position. In this manner, the heat transfer fluid 224 may flow from the collection basin 156 through the third flow path 162 and to the evaporator 38 .

[0062] In some embodiments, the controller 202 may instruct the first control valve 116 to open (e.g., at least partially) to allow pressurized gas (e.g., heat transfer fluid) from the condenser 34 to enter the purge tank 110 during the heat transfer fluid discharge procedure, so that the pressurized gas can force the heat transfer fluid to enter and pass through the third flow path 162. The controller 202 may (e.g., via control of the first control valve 116) adjust the rate at which the heat transfer fluid is discharged from the purge tank 110 to be relatively low to inhibit remixing (e.g., vortexing) of the stratified heat transfer fluid and the condensable fluid 108 in the purge tank 110. In some embodiments, such as when the compressor 32 of the vapor compression system 14 is idle, the controller 202 may activate the heating element 144 to increase the pressure within the purge tank 110, thereby enabling the heat transfer fluid to flow into the third flow path 162.

[0063] Execution of the heat transfer fluid drain procedure may cause the level of the heat transfer fluid 224 in the collection basin 156 to decrease over time. Thus, the first float 220 may gradually move along the axis 230 in a first direction 260 (e.g., in the direction of gravity) until the first float 220 engages (e.g., closes) the second switch 234. For example, to better illustrate the engagement between the first float 220 and the second switch 234, Figure 7 is a schematic diagram of an embodiment of a portion of a purification tank 110, wherein the first float 220 is engaged with the second switch 234. Figure 7 In the illustrated embodiment of FIG. 1 , the collection basin 156 may include an amount of the heat transfer fluid 224 sufficient to cause the first float 220 to move away from the first switch 232 (e.g., disengage or open the first switch 232) and toward and engage the second switch 234. In this way, the second switch 234 may transmit a second signal 242 to the controller 202, while the first switch 232 and the third switch 236 do not transmit corresponding signals 240, 244 to the controller 202. Upon receiving the second signal 242 from the second switch 234 and not detecting corresponding signals from the first switch 232 and the third switch 236, the controller 202 may determine that the amount of the heat transfer fluid 224 within the collection basin 156 is moderate and / or that further draining of the heat transfer fluid from the collection basin 156 is desired. In other words, upon receiving the second signal 242 from the second switch 234 and not detecting corresponding signals from the first switch 232 and the third switch 236, the controller 202 may determine that the amount 110 of the heat transfer fluid 224 within the purification tank has reached an intermediate threshold level. Therefore, the controller 202 may continue to execute the heat transfer fluid drain routine to drain additional heat transfer fluid 224 from the collection basin 156 .

[0064] In some embodiments, the controller 202 may continue to execute the heat transfer fluid discharge procedure until a third signal 244 is received from the third switch 236, which may indicate that the level of the heat transfer fluid in the collection basin 156 has dropped sufficiently to enable the second float 222 to engage the third switch 236 (e.g., indicating that the amount of heat transfer fluid in the purification tank 110 has reached a lower threshold level). In other words, the controller 202 may continue to execute the heat transfer fluid discharge procedure until the controller 202 receives a second signal 242 indicating that the first float 220 has engaged (e.g., closed) the second switch 234 and receives a third signal 244 indicating that the second float 222 has engaged (e.g., closed) the third switch 236. To pause the heat transfer fluid discharge procedure (e.g., upon receiving the second signal 242 and the third signal 244), the controller 202 may instruct the second outlet valve 174 to switch to a closed position to prevent the heat transfer fluid 224 from flowing out of the collection basin 156.

[0065] Figure 8A schematic diagram of an embodiment of a portion of the purge tank 110 showing the condensable fluid 108 within the collection basin 156. As discussed above, in response to receiving the first signal 240 and not detecting the second signal 242 and the third signal 244, the controller 202 may initiate a heat transfer fluid drain procedure to extract the heat transfer fluid 224 from the collection basin 156. In the event that the collection basin 156 includes a large amount of condensable fluid 108, executing the heat transfer fluid drain procedure may cause the second float 222 to move toward and engage the third switch 236 while the first float 220 remains engaged with the first switch 232. Thus, the controller 202 may receive the first signal 240 from the first switch 232 and the third signal 244 from the third switch 236. In response to receiving the first signal 240 and the third signal 244, the controller 202 may determine that the amount of the heat transfer fluid 224 in the collection basin 156 is relatively low while the amount of the condensable fluid 108 in the collection basin 156 is relatively high (e.g., indicating that draining the condensable fluid 108 is desired or warranted). That is, in response to receiving the first signal 240 and the third signal 244, the controller 202 may determine that the amount of the heat transfer fluid 224 in the purification tank 110 meets or is below the lower threshold level, while the amount of the condensable fluid 108 in the purification tank 110 meets or exceeds the upper threshold level. Therefore, the controller 202 may suspend execution of the heat transfer fluid discharge procedure (e.g., close the second outlet valve 174) and may initiate the condensable fluid discharge procedure.

[0066] To initiate the condensable fluid drain procedure, the controller 202 may instruct the third outlet valve 188 to transition to an open position or a partially open position to enable the condensable fluid 108 to flow out of the collection basin 156 to the environment 178. That is, by instructing the third outlet valve 188 to transition to an open or partially open position, the controller 202 may enable the condensable fluid 108 to flow from the collection basin 156 through the fourth flow path 182 and to the environment 178. In some embodiments, the controller 202 may instruct the first control valve 116 to open (e.g., at least partially open) to allow pressurized gas (e.g., heat transfer fluid) from the condenser 34 to enter the purge tank 110 during the condensable fluid drain procedure so that the pressurized gas can force the condensable fluid 108 to enter and pass through the fourth flow path 182. The controller 202 may (e.g., via control of the first control valve 116) adjust the rate at which the condensable fluid 108 is discharged from the purge tank 110 to be relatively slow to inhibit remixing (e.g., vortexing) of the stratified heat transfer fluid and the condensable fluid 108 in the purge tank 110. In some embodiments, such as when the compressor 32 of the vapor compression system 14 is idle, the controller 202 may activate the heating element 144 to increase the pressure within the purge tank 110 to enable the condensable fluid 108 to flow into the fourth flow path 182. In some cases, the controller 202 may maintain the pressure within the purge tank 110 slightly greater than atmospheric pressure during the condensable fluid discharge procedure to inhibit air from flowing back into the purge tank 110 from the surrounding environment. Execution of the condensable fluid discharge procedure may cause the first float 220 to move toward and engage (e.g., close) the second switch 234 (e.g., while the second float 222 remains engaged with the third switch 236).

[0067] For example, to better illustrate the engagement between the first float 220 and the second switch 234, Fig. 924 is a schematic diagram of an embodiment of a portion of the collection basin 156 in which the level of the condensable fluid 108 is relatively low. In response to receiving the second signal 242 and the third signal 244, the controller 202 can determine that the amount of the condensable fluid 108 in the collection basin 156 and the amount of the heat transfer fluid 224 in the collection basin 156 are each relatively low and / or that the discharge of the heat transfer fluid and the condensable fluid 108 is not desired or warranted. That is, in response to receiving the second signal 242 and the third signal 244, the controller 202 can determine that the amount of the condensable fluid 108 in the purge tank 110 has reached an intermediate threshold level (e.g., approaching the second stop plate 248), and the amount of the heat transfer fluid in the purge tank 110 has reached a lower threshold level (e.g., approaching the third stop plate 249). Therefore, the controller 202 suspends execution of the condensable fluid discharge procedure (e.g., via transmitting an instruction to close the third outlet valve 188) to prevent further outflow of the condensable fluid 108 from the collection basin 156. In some embodiments, it may be desirable to retain a residual amount of the condensable fluid 108 in the collection basin 156 to inhibit the heat transfer fluid 224 from flowing through the third outlet port 180. As such, the second switch 234 and / or the second stop plate 248 may be positioned such that when the first float 222 engages the second switch 234 (e.g., and the second float 222 engages the third switch 236), the third outlet port 180 is positioned a distance 282 (e.g., a target distance) above an upper level 280 of the heat transfer fluid 224 within the collection basin 156 (e.g., relative to the direction of gravity).

[0068] Fig.10 2 is a cross-sectional schematic side view of an embodiment of the condenser 34. In some embodiments, the first port 114 may include a collecting conduit 290 that may extend along at least a portion of a length 292 of the condenser 34. The collecting conduit 290 may include a plurality of holes 294 formed therein. The holes 294 are configured to enable the heat transfer fluid 224 and the non-condensable gas 106 to flow into the collecting conduit 290 and toward the first port 114. In this manner, the collecting conduit 290 may help to more evenly draw fluid along the length 292 of the condenser 34.

[0069] Fig.11is a cross-sectional schematic axial view of an embodiment of the evaporator 38. In some embodiments, the second port 122 can be fluidly coupled to a liquid funnel 298 (e.g., a guide) and a liquid collector 300 that can be disposed within the interior of the evaporator 38. The liquid funnel 298 and the liquid collector 300 can be configured (e.g., shaped, oriented) to direct the flow of liquid (e.g., condensable fluid 108) toward and into the second port 122. In this way, the liquid funnel 298 and the liquid collector 300 can cooperate to facilitate the collection of the condensable fluid 108 that may be in the evaporator 28 and facilitate the transfer of the condensable fluid 108 to the purification tank 110.

[0070] As described above, embodiments of the present disclosure can provide one or more technical effects useful for removing (e.g., purifying) non-condensable gases and condensable fluids from a vapor compression system via a purification system. Thus, the purification system can improve the purity of the heat transfer fluid within the vapor compression system and, thus, improve the overall operating efficiency of the HVAC&R system. In addition, the purification system can improve the reliability of the HVAC&R system (e.g., reducing wear on motor components due to exposure to water) and can reduce or substantially eliminate corrosion inside components of the system (e.g., valves, conduits, pumps). The technical effects and technical problems in the specification are examples and are not restrictive. It should be noted that the embodiments described in the specification can have other technical effects and can solve other technical problems.

[0071] Although only certain features and embodiments are shown and described, many modifications and changes may occur to those skilled in the art without materially departing from the novel teachings and advantages of the subject matter recited in the claims, such as changes in size, dimensions, structure, shape and proportion of various elements, parameter values ​​(such as temperature and pressure), mounting arrangements, use of materials, color, orientation, etc. The order or sequence of any process or method steps may be changed or re-sequenced according to alternative embodiments. Therefore, it should be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the present disclosure.

[0072] It is important to note that the construction and arrangement of the purification system as shown in the various exemplary embodiments is illustrative only. In addition, in an effort to provide a concise description of the exemplary embodiments, all features of the actual implementation may not be described, such as those features that are not relevant to the currently anticipated best mode or those features that are not relevant to enablement. It should be understood that in the development of such actual implementations, as in any engineering or design project, numerous implementation-specific decisions can be made. Such development work may be complex and time-consuming, but for ordinary technicians who benefit from this disclosure, these are routine tasks of design, manufacture, and production without undue experimentation.

[0073] The techniques presented and claimed herein refer to and apply to substantial objects and specific examples of a practical nature that improve the technical field of the invention in a demonstrable manner and are therefore not abstract, intangible, or purely theoretical. In addition, if any claim appended to the end of this specification contains one or more elements expressed as "means for [performing] [the function] ..." or "steps for [performing] [the function] ...", it is expected that such elements will be interpreted in accordance with 35 U.S.C. 112(f). However, for any claim containing elements specified in any other manner, it is intended that such elements will not be interpreted in accordance with 35 U.S.C. 112(f).

Claims

1. A purification system for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system, the purification system comprising: a purge tank configured to receive a fluid mixture from a vapor compression system, wherein the fluid mixture comprises a heat transfer fluid, a noncondensable gas, and a condensable fluid; a valve system fluidly coupled to the purge tank; and a controller communicatively coupled to the valve system, wherein the controller is configured to regulate the valve system based on feedback to selectively discharge the heat transfer fluid from the purge tank, selectively discharge the noncondensable gas from the purge tank, and selectively discharge the condensable fluid from the purge tank.

2. The purification system of claim 1, comprising a float system disposed within the purification tank and configured to provide at least a portion of the feedback.

3. The purification system according to claim 2, wherein the float system comprises: a plurality of switches communicatively coupled to the controller; and a plurality of floats configured to selectively engage one or more of the plurality of switches to generate one or more signals, wherein the controller is configured to analyze the one or more signals to determine a first amount of the condensable fluid within the purge tank, determine a second amount of the heat transfer fluid within the purge tank, or both.

4. The purification system of claim 3, wherein in response to determining that the first amount of the condensable fluid within the purification tank reaches an upper threshold level and the second amount of the heat transfer fluid within the purification tank is below a lower threshold level, the controller is configured to operate the valve system to discharge the condensable fluid from the purification tank according to a condensable fluid discharge procedure.

5. The purification system of claim 4 , wherein in response to determining that the first amount of the condensable fluid within the purification tank decreases to an intermediate threshold level that is less than the upper threshold level, the controller is configured to suspend the condensable fluid discharge procedure to prevent the condensable fluid from flowing from the purification tank.

6. The purification system of claim 3, wherein in response to determining that the second amount of the heat transfer fluid within the purification tank reaches an upper threshold level, the controller is configured to operate the valve system to discharge the heat transfer fluid from the purification tank according to a heat transfer fluid discharge procedure.

7. The purification system of claim 6, wherein in response to determining that the second amount of the heat transfer fluid within the purification tank decreases to a lower threshold level, the controller is configured to suspend the heat transfer fluid discharge procedure to prevent the heat transfer fluid from flowing from the purification tank.

8. The purification system of claim 1, wherein the controller is configured to regulate the valve system to direct pressurized heat transfer fluid from a condenser into the purification tank, thereby pressurizing the purification tank to force the heat transfer fluid to flow from the purification tank to the evaporator.

9. The purification system of claim 1, wherein the purification tank includes a purification coil disposed therein, wherein the purification coil is configured to absorb thermal energy from the heat transfer fluid in the purification tank, the non-condensable gas in the purification tank, the condensable fluid in the purification tank, or a combination thereof.

10. The purification system according to claim 1, wherein: The purification tank includes a collection basin and an upper portion vertically positioned above the collection basin relative to a gravity direction, wherein the upper portion includes a first diameter and the collection basin includes a second diameter that is smaller than the first diameter, And the purification system is disposed within the purification tank and is configured as a float system providing at least a portion of the feedback, wherein the float system is disposed within the collection basin.

11. A float system for a purification tank of a heating, ventilation, air conditioning and refrigeration (HVAC&R) system, the float system comprising: Multiple switches; and a plurality of floats configured to move relative to the plurality of switches, wherein the plurality of switches and the plurality of floats are configured to be disposed within the purge tank, and wherein the plurality of floats are configured to selectively engage one or more of the plurality of switches based on a first amount of condensable fluid within the purge tank and a second amount of heat transfer fluid within the purge tank to generate one or more signals indicative of the first amount and the second amount.

12. The float system of claim 11, wherein the plurality of floats comprises a first float and a second float, wherein the first float is configured to be suspended within the purification tank by the heat transfer fluid and the condensable fluid, and the second float is configured to be suspended within the purification tank by the heat transfer fluid and to sink into the condensable fluid.

13. The float system of claim 11, wherein the float system comprises a shaft configured to extend through the plurality of floats and guide movement of the plurality of floats relative to the plurality of switches.

14. The float system of claim 13, wherein each of the plurality of floats includes a hole formed therein, wherein the shaft is configured to extend through the hole of each float to guide movement of the plurality of floats along an axis of the shaft and to resist movement of the plurality of floats crosswise to the axis.

15. The float system of claim 11, wherein each switch of the plurality of switches is configured to be actuated in response to a corresponding float of the plurality of floats being positioned within a threshold distance of the switch.

16. A purification system for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system, the purification system comprising: A float system configured to be disposed within a purification tank, wherein the float system comprises: Multiple switches; and a plurality of floats configured to selectively engage one or more of the plurality of switches to generate one or more signals based on a first amount of condensable fluid within the purge tank and a second amount of heat transfer fluid within the purge tank; and A controller configured to receive the one or more signals and analyze the one or more signals to determine the first amount of the condensable fluid within the purge tank, the second amount of the heat transfer fluid within the purge tank, or both.

17. The purification system of claim 16, comprising a valve system configured to control discharge of the condensable fluid and the heat transfer fluid from the purification tank, wherein the controller is communicatively coupled to the valve system and is configured to adjust the valve system based on the one or more signals.

18. The purification system of claim 17, wherein the controller is configured to operate the valve system to discharge the condensable fluid from the purification tank according to a condensable fluid discharge procedure in response to determining that the first amount of the condensable fluid within the purification tank is at or above an upper threshold level.

19. The purification system of claim 17, wherein the controller is configured to operate the valve system to discharge the heat transfer fluid from the purification tank according to a heat transfer fluid discharge procedure in response to determining that the second amount of the heat transfer fluid within the purification tank is at or above an upper threshold level.

20. The purification system of claim 16, wherein the plurality of floats comprises: a first float configured to float within the heat transfer fluid and within the condensable fluid; and A second float is configured to float within the heat transfer fluid and configured to sink within the condensable fluid.

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