KR20200041961A - Systems and methods for purging chiller systems - Google Patents

Abstract

The present disclosure relates to a heating, ventilation, air conditioning, and refrigeration (HVAC & R) system 14, wherein the HVAC & R system is a purge system 80 configured to purge the HVAC & R system against non-condensing gases ) And refrigerant loops. The purge system comprises a liquid pump 84 configured to draw a first refrigerant flow from the evaporator 38, a controllable expansion valve 86 configured to receive the first refrigerant flow from the liquid pump and reduce the temperature of the first refrigerant flow. And a purge heat exchanger 88 comprising a purge coil 108. The purge coil is configured to receive a first refrigerant flow from the controllable expansion valve, the chamber of the purge heat exchanger is configured to draw a mixture of second refrigerant flow and non-condensable gases from the condenser 34, the purge heat exchanger It is configured to separate non-condensable gases from the first refrigerant flow by utilizing the second refrigerant flow.

Description

Systems and methods for purging chiller systems

This application relates generally to purge systems for air conditioning and cooling applications.

Cooler systems or vapor compression systems use working fluids, such as refrigerants, that change the phase between vapor, liquid, and combinations thereof as exposed to different temperatures and pressures associated with the operation of the vapor compression system. In low pressure cooler systems, some components of the low pressure cooler system operate at lower pressures than the ambient atmosphere. Due to the pressure differential, non-condensable gas (NCG), such as ambient air, can move to these low pressure components, causing inefficiencies in low pressure cooler systems. Therefore, the low pressure cooler system can be operated more effectively by purging against the NCG. However, existing purge systems used for NCG removal are expensive, require excessive maintenance, and can be inefficient.

In one embodiment of the present disclosure, the heating, ventilation, air conditioning, and refrigeration (HVAC & R) system comprises a refrigerant loop, a compressor disposed along the refrigerant loop, an evaporator disposed along the refrigerant loop, and And a condenser disposed along the refrigerant loop. The compressor is configured to circulate the refrigerant through the refrigerant loop, the evaporator is configured to place the refrigerant in heat exchange relationship with the first cooling fluid, and the condenser is configured to place the refrigerant in heat exchange relationship with the second cooling fluid. The HVAC & R system also includes a purge system configured to purge the HVAC & R system for non-condensing gases (NCG). The purge system includes a liquid pump configured to draw the first refrigerant flow from the evaporator, a controllable expansion valve configured to receive the first refrigerant flow from the liquid pump and lower the temperature of the first refrigerant flow, and a purge heat exchanger. The purge heat exchanger includes a purge coil. The purge coil is configured to receive the first refrigerant flow from the controllable expansion valve, and the chamber of the purge heat exchanger is configured to draw a mixture comprising the second refrigerant flow and non-condensing gases from the condenser into the purge heat exchanger It is configured to utilize the first refrigerant flow to separate non-condensable gases of the mixture from the second refrigerant flow of the mixture.

In another embodiment of the present disclosure, the HVAC & R system includes a refrigerant loop, a compressor disposed along the refrigerant loop, an evaporator disposed along the refrigerant loop, and a condenser disposed along the refrigerant loop. The compressor is configured to circulate the refrigerant through the refrigerant loop, the evaporator is configured to place the refrigerant in heat exchange relationship with the first cooling fluid, and the condenser is configured to place the refrigerant in heat exchange relationship with the second cooling fluid. The HVAC & R system also includes a purge system configured to purge the HVAC & R system for non-condensing gases (NCG). The purge system includes a purge heat exchanger configured to separate the incoming mixture from the condenser by utilizing a first refrigerant flow of refrigerant drawn from the evaporator. The mixture comprises a second refrigerant flow of refrigerant from the condenser and NCG. Separating the mixture includes separating the NCG from the second refrigerant flow. The purge system also includes one or more thermoelectric assemblies configured to remove thermal energy from the second refrigerant flow.

In another embodiment of the present disclosure, the HVAC & R system includes a refrigerant loop, a compressor disposed along the refrigerant loop, an evaporator disposed along the refrigerant loop, and a condenser disposed along the refrigerant loop. The compressor is configured to circulate the refrigerant through the refrigerant loop, the evaporator is configured to place the refrigerant in heat exchange relationship with the first cooling fluid, and the condenser is configured to place the refrigerant in heat exchange relationship with the second cooling fluid. The HVAC & R system also includes a purge system configured to purge the HVAC & R system for non-condensing gases (NCG). The purge system includes one or more adsorption chambers configured to receive a mixture comprising NCG and refrigerant from the condenser and configured to separate refrigerant from the NCG. The purge system also includes a pump configured to draw the mixture from the condenser.

In a further embodiment of the present disclosure, the HVAC & R system includes a purge system configured to purge the vapor compression system for non-condensing gases (NCG). The purge system includes a pump configured to draw a mixture of NCG and vapor refrigerant from the compressor of the vapor compression system. The purge system further includes a purge heat exchanger configured to receive the mixture from the pump and place the mixture in heat exchange relationship with refrigerant flow drawn from the vapor compression system to condense the vapor refrigerant of the mixture and separate the NCG of the mixture from the vapor refrigerant. The pump is configured to increase the pressure of the mixture to induce the flow of NCG from the purge heat exchanger to the atmosphere through the pressure difference between the NCG and the atmosphere.

1 is a perspective view of an embodiment of a building that can utilize heating, ventilation, air conditioning, and air conditioning (HVAC & R) systems in commercial installations, in accordance with aspects of the present disclosure;
2 is a perspective view of an embodiment of an HVAC & R system, in accordance with aspects of the present disclosure;
3 is a schematic diagram of an embodiment of the HVAC & R system of FIG. 2, according to aspects of the present disclosure;
4 is a schematic diagram of an embodiment of the HVAC & R system of FIG. 2, according to aspects of the present disclosure;
5 is a schematic diagram of one embodiment of the HVAC & R system of FIG. 2 in accordance with aspects of the present disclosure.
6 is a schematic diagram of one embodiment of the HVAC & R system of FIG. 2 in accordance with aspects of the present disclosure.
7 is a schematic diagram of one embodiment of the HVAC & R system of FIG. 2 in accordance with aspects of the present disclosure.
8 is a schematic diagram of one embodiment of the HVAC & R system of FIG. 2 in accordance with aspects of the present disclosure.
9 is a schematic diagram of one embodiment of the HVAC & R system of FIG. 2 in accordance with aspects of the present disclosure.

Embodiments of the present disclosure include a purge system that can improve purging efficiency in heating, ventilation, air conditioning, and refrigeration (HVAC & R) systems. For example, in a constant low pressure HVAC & R system, the evaporator can draw non-condensable gases (NCG) from the atmosphere into the interior due to the pressure difference between the evaporator and the atmosphere. NCG can be passed through the HVAC & R system and ultimately collected in a condenser. NCG should be eliminated as it can harm the overall performance of the HVAC & R system. Accordingly, the disclosed embodiments can efficiently purge HVAC & R for NCG. To this end, the HVAC & R system directs the first refrigerant flow from the evaporator to the additional heat exchanger, and then condenses the second refrigerant flow to separate the NCG from the second refrigerant flow, thereby allowing the second refrigerant in the HVAC & R system to accumulate in the condenser. And a purge system utilizing a first refrigerant flow to separate the NCG from the flow. Thereafter, the NCG can be pumped out or released into the atmosphere. Additionally or alternatively, the purge system can utilize one or more other systems as well as additional heat exchangers to purge the HVAC & R system for NCG. For example, the purge system may also utilize one or more thermoelectric assemblies and / or adsorption chambers. Specifically, one or more thermoelectric assemblies can help reduce the temperature of the refrigerant directed from the evaporator to aid the heat exchange process in the additional heat exchanger. In addition, one or more adsorption chambers can filter the refrigerant from the NCG by using an adsorbent material having electrochemical affinity to the refrigerant, which will adsorb the refrigerant and cause the NCG to flow out of the HVAC & R system. Further, in certain embodiments, the purge system may use a steam pump to draw NCG and second refrigerant flow from the condenser and deliver the NCG and second refrigerant flow to an additional heat exchanger. That is, as the second refrigerant flow and NCG are transferred to the additional heat exchanger, the steam pump can increase their pressure. Due to the higher pressure, the second refrigerant flow can condense to a higher temperature in the additional heat exchanger, thereby reducing the load on the purge system.

Referring now to the drawings, FIG. 1 is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and air conditioning (HVAC & R) system 10 in a building 12 of a typical commercial facility. The HVAC & R system 10 may include a vapor compression system 14 that supplies chilled liquid that can be used for cooling the building 12. The HVAC & R system 10 may also include a boiler 16 that supplies warm liquid to heat the building 12 and an air distribution system that circulates air through the building 12. Further, the air distribution system may include an air return duct 18, an air supply duct 20, and / or an air handler 22. In some embodiments, air handler 22 may include a heat exchanger connected by conduit 24 to boiler 16 and vapor compression system 14. The heat exchanger in the air handler 22 can receive warm water from the boiler 16 or cold water from the vapor compression system 14, depending on the operating mode of the HVAC & R system 10. The HVAC & R system 10 is shown as having a separate air handler on each floor of the building 12, but in other embodiments, the HVAC & R system 10 is air that can be shared between two floors or between multiple floors. Handler 22 and / or other components.

2 and 3 are embodiments of a vapor compression system 14 that can be used in the HVAC & R system 10. The vapor compression system 14 can circulate refrigerant through a circuit starting with the compressor 32. The circuit may also include a condenser 34, expansion valve (s) or device (s) 36, and a liquid chiller or evaporator 38. The vapor compression system 14 is 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 (ie , A controller).

Some examples of fluids that can be used as refrigerant in the vapor compression system 14 are hydrocarbon fluoride (HFC) based refrigerants, such as R-410A, R-407, R-134a, fluorocarbon (HFO), ammonia ( "Natural" refrigerants such as NH ₃ ), R-717, carbon dioxide (CO ₂ ), R-744, or hydrocarbon-based refrigerants, water vapor, refrigerants with a low global warming potential (GWP), or any other suitable refrigerant. In some embodiments, the vapor compression system 14 has a normal boiling point of at least about 0 degrees Celsius or 32 degrees Fahrenheit at 1 atmosphere, also referred to as a low pressure refrigerant compared to a medium pressure refrigerant such as R-134a or a high pressure refrigerant such as R-410A. It may be configured to efficiently utilize the refrigerant having a. As used herein, "normal boiling point" may mean a boiling point temperature measured at a pressure of 1 atmosphere.

In some embodiments, the vapor compression system 14 is a variable speed drive (VSD) 52, motor 50, compressor 32, condenser 34, expansion valve or device 36, and / or evaporator ( 38). The motor 50 can drive the compressor 32 and can be supplied with power by a variable speed drive (VSD) 52. In certain embodiments, compressor 32 may utilize a magnetic bearing. The VSD 52 receives AC power having a specific fixed line voltage and a fixed line frequency from an AC (AC) power supply, and supplies power having a variable voltage and frequency to the motor 50. In another embodiment, the motor 50 may be powered directly from an AC or direct current (DC) power source. The motor 50 can be powered by VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electromagnetic rectifying permanent magnet motor, or other suitable motor. Any type of electric motor.

The compressor 32 compresses the refrigerant vapor and delivers the vapor to the condenser 34 through the discharge passage. In some embodiments, compressor 32 may be a centrifugal compressor. The refrigerant vapor delivered to the condenser 34 by the compressor 32 can transfer heat to a cooling fluid (eg, water or air) in the condenser 34. The refrigerant vapor can condense into refrigerant liquid in the condenser 34 as a result of heat transfer with the cooling fluid. Refrigerant liquid from the condenser 34 can flow through the expansion device 36 to the evaporator 38. In the exemplary embodiment of FIG. 3, the condenser 34 is a water-cooled condenser and includes a tube bundle 54 connected to a cooling tower 56 that supplies cooling fluid to the condenser.

The refrigerant liquid delivered to the evaporator 38 can absorb heat from other cooling fluid, which may or may not be the same cooling fluid used in the condenser 34. The refrigerant liquid in the evaporator 38 may undergo a phase change from refrigerant liquid to refrigerant vapor. As shown in the exemplary embodiment of FIG. 3, the evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to the cooling load 62. The cooling fluid of the evaporator 38 (eg, water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 through the return line 60R and through the supply line 60S. It flows out from the evaporator 38. The evaporator 38 may lower the temperature of the cooling fluid in the tube bundle 58 through heat transfer with the refrigerant. The tube bundle 58 in the evaporator 38 can include multiple tubes and / or multiple tube bundles. In any case, the refrigerant liquid flows out of the evaporator 38 and refluxes to the compressor 32 by the suction line to complete the cycle.

4 is a schematic diagram of a vapor compression system 14 with an intermediate circuit 64 integrated between the condenser 34 and the expansion device 36. The intermediate circuit 64 can have an inlet line 68 that is fluidly connected directly to the condenser 34. In other embodiments, the inlet line 68 may be indirectly coupled fluidly to the condenser 34. As shown in the exemplary embodiment of FIG. 4, the inlet line 68 includes a first expansion device 66 located upstream of the intermediate vessel 70. In some embodiments, intermediate container 70 may be a flash tank (eg, flash intercooler). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or "surface economizer." In the exemplary embodiment of FIG. 4, the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is used to lower the pressure of the refrigerant liquid supplied from the condenser 34 (eg, to expand it). It is composed. During the expansion process, a portion of the liquid may evaporate, so that the intermediate container 70 can be used to separate vapor from the liquid supplied from the first expansion device 66. Additionally, the intermediate vessel 70 may be exposed to the refrigerant liquid due to the pressure drop experienced when the refrigerant liquid enters the intermediate vessel 70 (eg, due to the rapid increase in volume experienced when entering the intermediate vessel 70). It may provide additional expansion. Steam in the intermediate vessel 70 can be sucked by the compressor 32 through the suction line 74 of the compressor 32. In other embodiments, the vapor in the intermediate vessel may be sucked into the intermediate stage of the compressor 32 (eg, not the suction stage). The liquid collected in the intermediate vessel 70 may have a lower enthalpy than the refrigerant liquid exiting the condenser 34 due to expansion in the expansion device 66 and / or the intermediate vessel 70. Thereafter, the liquid from the intermediate vessel 70 can flow from the line 72 through the second expansion device 36 to the evaporator 38.

In some embodiments, when vapor compression system 14 is in operation, evaporator 38 may function at a pressure lower than ambient pressure. Accordingly, the NCG can be drawn into the evaporator 38 and can pass through the compressor 32 and collect in the condenser 34. These NCGs can cause the vapor compression system 14 to operate inefficiently. Thus, the vapor compression system 14 may include features for purging the vapor compression system 14 against the NCG.

For example, as shown in FIG. 5, steam compressor system 14 may include purge system 80. The purge system 80 is configured to remove NCG, such as ambient air, from the steam compressor system 14 by utilizing refrigerant from the steam compressor system 14. To this end, in certain embodiments, purge system 80 includes flash tank 82, liquid pump 84, controllable expansion device 86, purge heat exchanger 88, pump 90 For example, it may include one or more stop valves 96, such as vacuum pumps and / or steam pumps), ejectors 94, solenoid valves.

First, it should be noted that in the following description, the refrigerant may be referred to as having low temperature, medium temperature and / or high temperature, and / or low pressure, medium pressure, and / or high pressure. Indeed, the low pressure / low temperature, medium pressure / medium temperature and high pressure / high temperature of the refrigerant refer to the relative pressure / temperature values of the same refrigerant in the vapor compression system 14 and / or purge system 80. In other words, the vapor compression system can use a single refrigerant type that can have different pressure values throughout the vapor compression system 14 and / or purge system 80.

In some embodiments, vapor compression system 14 may utilize controller 81 to control certain aspects of the operation of purge system 80. The controller 81 can be any device that employs a processor 83 (which may represent one or more processors), such as an application-specific processor. The controller 81 can also include a memory device 85 for storing instructions executable by the processor 83 to perform the control actions and methods described herein for the fuzzy system 80. The processor 83 may include one or more processing devices, and the memory 85 may include one or more types of non-transitory machine-readable media. For example, such machine-readable media may be in the form of RAM, ROM, EPROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage or other magnetic storage device, or machine-executable instructions or data structures. It can include any other medium that can be used to carry or store the desired program code and can be accessed by the processor 83 or any general purpose or special computer equipped with a processor or other machine.

To this end, the controller 81 can be communicatively coupled to one or more components of the purge system 80 via the communication system 87. In some embodiments, communication system 87 may communicate over a wireless network (eg, a wireless local area network (WLAN), a wireless wide area network (WWAN), a near field communication (NFC)). In some embodiments, communication system 87 may communicate over a wired network (eg, a local area network (LAN), a wide area network (WAN)). For example, as shown in FIGS. 5 and 6, the controller 81 can communicate with multiple components of the purge system 80 such as pumps, valves, expansion devices, and other components. In some embodiments, the functions of controller 81 and control panel 40 as described herein (FIGS. 3 and 4) can be controlled through a single controller. In some embodiments, a single controller can be control panel 40 or controller 81.

As shown in FIG. 5, the liquid pump 84 may draw refrigerant (eg, a first refrigerant flow) from the evaporator 38 through a conduit 98. The refrigerant drawn from the evaporator 38 may have a medium pressure (eg, approximately 5 pounds per square inch (psia)) and a medium temperature (eg, approximately 40 degrees Fahrenheit). In some embodiments, the refrigerant may be a two-phase mixture comprising a refrigerant liquid, mostly with a portion of the refrigerant vapor. Thus, in some embodiments, the refrigerant may first flow to the flash tank 82 to separate the two-phase mixture before flowing to the liquid pump 84. Indeed, in some embodiments, purge system 80 may not utilize flash tank 82. In the flash tank 82, the two-phase mixture can be separated into refrigerant liquid accumulated at the bottom of the flash tank 82 and refrigerant vapor collected at the top of the flash tank 82 due to the density difference. Thereafter, the liquid pump 84 can pull the refrigerant liquid from the bottom of the flash tank 82 through the conduit 100. As the refrigerant moves from the flash tank 82 to the pump 84, the refrigerant may have medium temperature (eg, approximately 40 degrees Fahrenheit) and medium pressure (eg, approximately 5 psia). The accumulated refrigerant vapor in flash tank 82 may be drawn through conduit 102 to evaporator 38. Specifically, refrigerant vapor from the flash tank 82 may flow to the low pressure side or the exhaust side of the evaporator 38. For example, the pressure difference between the flash tank 82 and the low pressure side of the evaporator 38 may introduce refrigerant vapor from the flash tank 82 to the intake side of the evaporator 38. Indeed, conduit 102 may be designed to maintain a high enough pressure for refrigerant flowing through conduit 102 to flow into evaporator 38 (eg, size, shape, texture, etc.). When refrigerant vapor flows from flash tank 82 to evaporator 38, the refrigerant vapor may have medium temperature (eg, approximately 40 degrees Fahrenheit) and medium pressure (eg, approximately 5 psia).

Pump 84 may forcibly transfer refrigerant liquid through conduit 104 to controllable expansion device 86. When the refrigerant liquid moves from the liquid pump 84 to the controllable expansion device 86, the refrigerant liquid may have medium temperature (eg, approximately 45 degrees Fahrenheit) and high pressure (eg, approximately 16 psia). Indeed, the refrigerant liquid flowing out of the liquid pump 84 may have a higher pressure and temperature than the refrigerant flowing into the liquid pump 84. In addition, the controller 81 can send one or more liquid pump signals to the liquid pump 84 to control the mass flow rate of refrigerant through the liquid pump 84.

As the refrigerant passes through the controllable expansion device 86, the controllable expansion device 86 can reduce the pressure of the refrigerant, thereby reducing the temperature. In some embodiments, the controllable expansion device 86 can be disposed vertically over the purge heat exchanger 88. After the refrigerant flows out of the controllable expansion device 86, the purge heat exchanger 88 through the conduit 106 is at least partially due to the height difference between the controllable expansion valve 86 and the purge heat exchanger 88. It can be moved to the purge coil (purge coil; 108). As the refrigerant moves from the controllable expansion device 86 to the purge heat exchanger 88, the refrigerant may have a low temperature (eg, approximately 6 degrees Fahrenheit) and low pressure (eg, approximately 3.5 psia). . Also, in some embodiments, a portion of the refrigerant may be evaporated and lost as refrigerant vapor as the controllable expansion device 86 reduces the pressure of the refrigerant.

As will be discussed in more detail below, when refrigerant passes through the purge coil 108 of the purge heat exchanger 88, the refrigerant can be towed from the condenser 34 or from other parts of the system, such as NCG and refrigerant vapor (eg For example, heat may be exchanged with a mixture of the second refrigerant flow). As previously mentioned, due to the low pressure of the vapor compression system 14 against ambient pressure during operation, NCG can be drawn into the evaporator 38 and passed through the vapor compression system 14 to accumulate in the condenser 34. . Specifically, NCG may accumulate in a portion of the condenser 34. Thus, the mixture of NCG and refrigerant vapor can be towed from such a portion of condenser 34. Generally, during normal operation, the area where NCG accumulates is substantially below the discharge baffle, near the middle of condenser 34, near the exhaust port of condenser 34, and near the top of condenser 34. , Or any combination thereof.

In some embodiments, NCG accumulated in condenser 34 may be mixed with refrigerant vapor. The NCG-refrigerant vapor mixture can be introduced into a purge heat exchanger 88, such as a chamber of the purge heat exchanger 88, via conduit 114. The NCG-refrigerant vapor mixture may be introduced into the purge heat exchanger 88 due to the pressure difference between the condenser 34 and the purge heat exchanger 88. Further, in certain embodiments, the NCG-steam mixture may be introduced into the purge heat exchanger 88 due to the partial vacuum of the purge heat exchanger 88 caused by condensation in the purge heat exchanger 88.

As the NCG-refrigerant vapor mixture contacts the cold surface of the purge coil 108, the refrigerant vapor will condense into a refrigerant liquid, creating a partial vacuum in the purge heat exchanger 88, which results in more NCG-refrigerant vapor mixture. Is drawn into the inside from the condenser 34 through the conduit 114. Further, as the NCG-refrigerant vapor mixture enters the purge heat exchanger 88 and the refrigerant vapor condenses into the refrigerant liquid, the refrigerant liquid may collect at the bottom of the purge heat exchanger 88. In practice, due at least in part to the density difference between the condensed refrigerant liquid and the NCG, the NCG will be collected by doing the top of the purge heat exchanger 88, and the condensed refrigerant liquid is collected at the bottom of the purge heat exchanger 88 Will be. Thus, the liquid level of the refrigerant liquid in the purge heat exchanger 88 will rise as a large amount of refrigerant vapor in the NCG-refrigerant vapor mixture condenses within the purge heat exchanger 88.

As will be described in more detail below, once the liquid level of the refrigerant liquid has reached a predetermined threshold in the purge heat exchanger 88, the refrigerant liquid passes through conduit 115 to condenser 34, evaporator 38, or both. And the NCG will be pumped out of the purge heat exchanger 88 by pump 90 through conduit 116. In some embodiments, purge heat exchanger 88 may be disposed vertically over condenser 34 and evaporator 38. In this way, the refrigerant liquid can flow to the condenser 34, evaporator 38, or both due at least in part to the height difference of the purge heat exchanger 88 to the condenser 34 and evaporator 38. have. In some embodiments, the condenser 34 can be placed vertically over the evaporator 38, whereby the refrigerant liquid can flow more easily from the purge heat exchanger 88 to the evaporator 38 compared to the condenser 34. . In addition, the pump 90 may forcibly discharge the NCG to the atmosphere as shown by arrow 117.

In some embodiments, purge heat exchanger 88 may include one or more sensors 119 that may include one or more temperature sensors, pressure sensors, load sensors, liquid level sensors, ultrasonic sensors, or any combination thereof. have. For example, one of the one or more sensors 119 can measure the liquid level of the refrigerant liquid in the purge heat exchanger 88, and send data about the liquid level to the controller 81. have. When the liquid level approaches, matches and / or exceeds a predetermined liquid level threshold, the controller 81 causes the refrigerant liquid to drain to the condenser 34, evaporator 38, or both, as described above. In order to send a signal to one or more of the stop valve (96). Similarly, the controller 81 can send a signal to the pump 90 and / or one or more of the stop valves 96 to release NCG to the atmosphere through the pump 90.

In some embodiments, the controller 81 may have a significant amount inside the condenser 34 before the NCG-refrigerant vapor mixture is introduced into the purge heat exchanger 88, for example by activating one or more of the stop valves 96, or It may be determined whether or not a predetermined amount of NCG is present. In order to determine whether a significant amount or a predetermined amount of NCG is present inside the condenser 34, the other of the one or more sensors 119 has one or more parameters related to the performance of the vapor compression system 14 And data representing one or more such parameters can be sent to the controller 81 for analysis and processing. Specifically, the controller 81 can determine the performance of the vapor compression system 14 based on one or more parameters. If the controller 81 determines that the performance of the vapor compression system 14 is below a predetermined threshold, the controller 81 opens an appropriate stop valve so that the mixture of NCG and refrigerant vapor is purged from the condenser 34 to the heat exchanger 88 ) To allow condenser 34 to purge as described above. In some embodiments, the controller 81 may purge the condenser 34 as described above based on a predetermined schedule.

Additionally or alternatively, one of the sensors 119 can measure the saturation temperature and actual temperature in the condenser 34 and send data indicative of the saturation temperature and actual temperature to the controller 81 for analysis and processing. Thereafter, the controller 81 can determine whether the saturation temperature substantially matches the actual temperature. If the saturation temperature does not substantially match the actual temperature, the controller 81 opens the appropriate stop valve 96 to allow a mixture of NCG and refrigerant vapor to flow from the condenser 34 to the purge heat exchanger 88. The condenser 34 can be purged as described.

In addition, as described above, the refrigerant passing through the purge coil 108 of the purge heat exchanger 88 can exchange heat with a mixture of refrigerant vapor and NCG that has been towed from the condenser 34. More specifically, refrigerant passing through the purge coil 108 absorbs thermal energy from a mixture of refrigerant vapor and NCG, undergoes a phase change from liquid to vapor and exits the purge coil 108 through conduit 118 It can be moved to the ejector 94. In practice, the refrigerant exiting the purge coil 108 may be superheated steam having medium temperature (eg, approximately 30 degrees Fahrenheit) and low pressure (eg, approximately 3.5 psia).

To condense the refrigerant vapor drawn from the condenser 34, the refrigerant flowing into the purge coil 108 may be at a moderately low temperature. To this end, the other sensor 119 of the one or more sensors 119 measures the temperature of the refrigerant flowing out of the purge coil 108, and the controller 81 for analyzing and processing data representing the temperature of the refrigerant Can be transferred to. In this way, the controller 81 controls the controllable expansion device 86 (eg, additional opening and / or closing) to achieve a moderately low temperature by adjusting the temperature of the refrigerant flowing into the purge coil 108. can do.

Refrigerant vapor may be drawn into the ejector 94 due to a pressure difference to the refrigerant vapor stream that may flow from the condenser 34 through the conduit 120 to the ejector 94 after it has flowed out of the purge coil 108. have. Ejector 94 may also help to draw refrigerant through expansion device 86 and purge coil 108. More specifically, the high pressure refrigerant vapor from the condenser 34 may be introduced into the ejector 94 through the nozzle 122, and the flow rate may increase and the pressure may decrease as it flows through the nozzle 122. In this way, the low pressure refrigerant vapor flowing out of the nozzle 122 can draw refrigerant vapor from the purge coil 108, whereby the high pressure refrigerant vapor from the condenser 32 and the purge coil 108 in the ejector 94 Coolant vapor from) can be mixed. Refrigerant vapors will pass through the ejector 94 as it mixes within the ejector 94 and will exit the diffuser cone 124 of the ejector 94. In addition, refrigerant vapors will be mixed as they pass through the ejector 94, which can result in reduced speed and increased pressure. As the refrigerant vapor passes through the diffuser cone 124, the diffuser cone 124 will further reduce the flow rate and further increase the pressure of the refrigerant vapor exiting the ejector 94. Thereafter, refrigerant vapor exiting the ejector 94 may be routed through the conduit 126 to the low pressure side of the evaporator 38. More specifically, the refrigerant vapor flowing out from the ejector 94 is introduced into the evaporator 38 due to the pressure difference for the low pressure refrigerant in the evaporator 38. In particular, the refrigerant flowing from the ejector 94 to the evaporator 38 may be at medium temperature (eg, approximately 40 degrees Fahrenheit) and medium pressure (eg, approximately 5 psia).

As previously mentioned, the embodiments described with respect to FIG. 5 can be utilized when the vapor compression system 14 is in operation. Indeed, during operation, the low pressure in the vapor compression system 14 can introduce ambient air and / or other non-condensing gases into it. However, while the vapor compression system 14 is not operating, the vapor compression system 14 may still contain a certain amount of residual NCG, particularly on top of the condenser 34. However, while the vapor compression system 14 is not operating, the ejector 94 may not be able to draw the high pressure refrigerant from the condenser 34 inward to draw the refrigerant from the purge coil 108, which is This is because the pressure levels of the refrigerant in the vapor compression system 14 do not fluctuate while 14) is not operating (level out). Thus, as shown in FIG. 6, the purge system 80 can utilize the thermoelectric assemblies 150 and / or adsorption chambers 152 to purge the vapor compression system 14 against residual NCG.

For example, as shown in FIG. 6, when the vapor compression system 14 is not operating, the liquid pump 84 may draw refrigerant from the evaporator 38 through the conduit 100 into the inside. The liquid pump 84 can then pump refrigerant through the conduit 104 through the controllable expansion valve 86 to the purge coil 108 of the purge heat exchanger 88. As the refrigerant moves from the liquid pump 84 to the purge coil 108, the temperature may decrease as the thermoelectric assemblies 150 absorb heat from the refrigerant and release heat to the surrounding atmosphere. Specifically, thermoelectric assemblies 150 may utilize a power source 154 to induce a power gradient within thermoelectric assemblies 150. Power source 154 can be any suitable power source, including, but not limited to, a power grid, battery, solar panel, generator, gas engine, vapor compression system 14, or any combination thereof. have. The thermoelectric assemblies 150 may convert a power gradient into a thermal gradient through a thermoelectric effect or a Peltier-Seebeck effect. In particular, thermoelectric assemblies 150 may utilize a thermal gradient to absorb heat from refrigerant flowing from liquid pump 84 to purge coil 108.

In this embodiment, thermoelectric assemblies 150 are disposed on conduit 104 between liquid pump 84 and controllable expansion valve 86, and draw heat therefrom as refrigerant flows through conduit 104. It is configured to absorb. However, in some embodiments, thermoelectric assemblies 150 may be disposed on conduit 106 between controllable expansion valve 106 and purge coil 108, and refrigerant may flow through conduit 106. When it can be configured to absorb heat from it. In some embodiments, conduits 104 and / or 106 may be insulated. Specifically, among the thermoelectric assemblies 150, the thermoelectric assembly 150a or the thermoelectric module may include a thermal paste 156, a thermoelectric device 158, a heat sink 160, and a fan 162. . For example, the thermoelectric assembly 150a is coupled to a conduit such as a conduit 104 and / or a conduit 106 using a thermal paste 156, the thermal paste 156 being the first of the thermoelectric devices 158. Can be coupled to the side. The second side of thermoelectric device 158 is coupled to heat sink 160, which in turn is coupled to fan 162. The thermoelectric assemblies 150 can include any suitable number of individual thermoelectric assemblies 150a or thermoelectric modules. For example, in some embodiments, purge system 80 may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or any other suitable number of thermoelectrics Assembly 150a. In some embodiments, a conduit such as conduit 104 and / or conduit 106 to which thermoelectric assemblies 150 are coupled may include inner fins 161 to facilitate heat transfer to thermoelectric assemblies 150. You can.

The refrigerant may be supercooled as the thermoelectric assemblies 150 absorb heat from the refrigerant. Thus, the controllable expansion valve 86 may be completely or substantially (e.g., so that the refrigerant does not lose evaporation or only a minimum amount evaporates) before reaching the purge coil 108 (e.g., the refrigerant remains supercooled). For example, it can be opened (as indicated by controller 81). As the supercooled refrigerant passes through the purge coil 108, the supercooled refrigerant heat exchanges with a mixture of NCG and refrigerant vapor that could have been introduced from the condenser 34 into the purge heat exchanger 88 as described above with reference to FIG. can do. However, unlike the embodiments described above in FIG. 5, in some embodiments, the supercooled refrigerant moving through the purge coil 108 moves through the purge coil 108 to absorb heat from the mixture of NCG and refrigerant vapor. It should be noted that, if not completely, it can be sufficiently supercooled to remain substantially liquid. In some embodiments, the liquid pump 84 absorbs the supercooled refrigerant such that the supercooled refrigerant passes through the purge coil 108 and absorbs heat from the mixture of NCG and refrigerant vapor, otherwise remaining substantially liquid (eg, For example, it can be forced through the purge coil 108 at this high flow rate (as indicated by the controller 81). In some embodiments, to ensure that the refrigerant remains liquid as it passes through the purge coil 108, the controller 81 pumps the liquid so that the thermoelectric assemblies 150 are in heat exchange relationship with the refrigerant for an extended period of time. Signals may be sent to one or more of 84 and stop valve 96, thereby lowering the temperature of the refrigerant prior to flowing into the purge coil 108.

Due at least in part to the liquid state of the refrigerant in the purge coil 108, head pressure and / or gravity can cause the refrigerant to flow back through the conduit 163 to the evaporator 38. In addition, as described above, the refrigerant vapor of the mixture of NCG and refrigerant vapor drawn from the condenser 34 may be condensed and collected at the bottom of the purge heat exchanger 88, once the refrigerant fluid level is purged heat exchanger 88 Once a predetermined threshold has been reached within, the refrigerant vapor may eventually flow back to condenser 34 and / or evaporator 38.

Also, as shown in FIG. 6, in some embodiments, purge system 80 utilizes adsorption chambers 152 to purge vapor compression system 14 against ambient air or other non-condensing gases. You can. For example, in some embodiments, the NCG gas / refrigerant vapor drawn by the pump 90 from the purge heat exchanger 88 may contain a portion of the refrigerant vapor along with the NCG. Accordingly, the adsorption chambers 152 can remove a portion of the refrigerant vapor introduced into the interior by the pump 90 before forcing the NCG to be discharged into the atmosphere. For illustration, pump 90 may pump a mixture or “mixture” of NCG and refrigerant vapor through one or more of adsorption chambers 152 through conduit 164. As the mixture traverses the adsorption chamber 152 of any of the adsorption chambers 152, the mixture can pass through the reforming material 166 of the adsorption chamber 152, the refrigerant vapor being the refrigerant vapor and the reforming material ( Due to the properties of 166, it can be adsorbed or aspirated into or over the modified material 166. For example, electrochemical properties aid adsorption as described herein. Further, as the mixture traverses through the adsorption chamber 152, the NCG may not be adsorbed to the modified material 166 due at least in part to the nature of the NCG and the modified material 166. Thus, the NCG can be forced through the reforming material 162 and continue to pass through the exhaust valve 168, as shown by arrow 170, into the atmosphere.

As the reforming material 166 adsorbs the refrigerant, the reforming material 166 may eventually saturate with the refrigerant, and may no longer efficiently adsorb additional refrigerant. Thus, heaters 169, such as an immersion heater, external cable heater, or band heater, can be activated to provide thermal energy to the reforming material 166. The modified material 166 transfers heat energy to the refrigerant. Over time, the thermal energy imparted to the refrigerant will cause the combination of the reforming material 166 and the refrigerant to be overcome so that the reforming material 166 releases the refrigerant in a vapor state. The refrigerant vapor, once released from the reforming material 166, may have a high pressure relative to the pressure in the evaporator 38 to flow through the conduit 170 to the evaporator 38. In some embodiments, the adsorption chamber 152 may utilize a vacuum pump to generate traction at the exhaust ports of the adsorption chamber 152. The traction force may be stronger than the electrochemical coupling of the reforming material 166 and the refrigerant so that the refrigerant is towed from the reforming material 166.

In some embodiments, intake valve 166 may allow the mixture to flow only to constant adsorption chambers 152 at a time. In this way, the adsorption chambers 152 can continuously receive and filter the mixture as described above. For example, controller 81 may control stop valves 96 to allow the mixture to be filtered by one or more specific adsorption chambers 152 of adsorption chambers 152. Once the specific adsorption chamber 152 is saturated with refrigerant, the controller 81 can stop flowing the mixture to the specific adsorption chamber 152 and allow the mixture to flow to a different adsorption chamber 152. Once the controller 81 stops flowing to the specific adsorption chamber 152, the controller turns on the heater 169 associated with the specific adsorption chamber 152 to allow refrigerant vapor to flow to the evaporator 38, as described above. Can be activated. Indeed, while a particular adsorption chamber 152 is being heated, the different adsorption chambers 152 can continue to filter the mixture. Once the specific adsorption chamber 152 is not sufficiently saturated with refrigerant, the controller 81 can once again activate one or more of the stop valves 96 to allow the mixture to flow to the specific adsorption chamber 152. have. To this end, purge system 80 may include 1, 2, 3, 4, 5, 6, or any other suitable number of separate adsorption chambers 152 to enable continuous filtration of the mixture. In addition, embodiments discussed herein with respect to FIG. 6, specifically embodiments for utilizing thermoelectric assemblies 150 and / or adsorption chambers 152, may be used when vapor compression system 14 is in operation or It should be noted that the vapor compression system 14 can be utilized when it is not in operation.

In certain embodiments, as shown in FIG. 7, a purge system 80 is disposed upstream of the purge heat exchanger 88 to increase the pressure of the mixture before entering the purge heat exchanger 88. It is also possible to utilize a pump 202, such as a reciprocal / diaphragm oil-free vapor pump, which is configured to allow. In this way, the temperature at which the vapor refrigerant of the mixture condenses in the purge heat exchanger 88 is increased, thereby reducing the load on the purge system 80. Further, the purge system 80 may include a solenoid valve 204, an ejector 206 such as an ejector 94, a purge heat exchanger 88, which may be a shell and tube heat exchanger, and one or more. It may include a stop valve (96).

Generally, purge system 80 may utilize refrigerant from vapor compression system 14 to purge vapor compression system 14 for NCG. In other words, the refrigerant from the vapor compression system 14 can be used as a cooling source for condensing the refrigerant-NCG mixture in the purge system 80. For example, purge system 80 may draw a mixture of NCG and vapor refrigerant from condenser 34. Thereafter, the mixture is pumped to a purge heat exchanger 88 where the vapor refrigerant condenses to separate the refrigerant of the mixture from the NCG of the mixture. In particular, in order to condense the vapor refrigerant, the mixture is in heat exchange relationship with the refrigerant drawn from downstream of the expansion device 36 of the vapor compression system 14. Thereafter, the condensing refrigerant is discharged to the condenser 34 and the NCG is discharged into the atmosphere.

To further illustrate, pump 202 may draw a mixture of vapor refrigerant and NCG from condenser 34 through conduit 203. In certain embodiments, the mixture drawn from condenser 34 is approximately 94 ° F. and can be 26 psi. The pump 202 can increase the pressure of the mixture by pumping the mixture from the condenser 34 and passing the mixture through the conduit 205 to the purge heat exchanger 88. In certain embodiments, the pump 202 can raise the pressure of the mixture by approximately 50 psi. For example, after passing through the pump 202, the mixture can be approximately 160 ° F. and 76 psi, and become superheated steam with a flow rate of approximately 10 lbm / hr (pound-mass per hour). Due to the increased pressure, as mentioned above, the refrigerant vapor in the mixture will condense within the purge heat exchanger 88 to a higher heat exchange temperature. That is, as the pump 202 raises the pressure of the mixture, the condensation temperature of the vapor refrigerant will rise, thereby causing the vapor refrigerant to utilize less cooling for condensation. In certain embodiments, the pump 202 can increase the pressure of the mixture so that the vapor refrigerant can condense to approximately 43 ° F. in the purge heat exchanger 88. In certain embodiments, the pump 202 can include two pumps 199 arranged in series with each other. In this way, the load is distributed or split between the two pumps 199, resulting in less stress induced on the individual pumps 199, thereby reducing maintenance for the pumps 199.

As the purge heat exchanger 88 condenses the vapor refrigerant into a liquid refrigerant, the liquid refrigerant can collect at the base of the purge heat exchanger 88. As previously discussed, once the liquid refrigerant has reached a critical volume within the purge heat exchanger 88, the controller 81 operates stop valves 96 to purge the heat exchanger 88 through conduit 207. The liquid refrigerant can be discharged from the condenser 34. In certain embodiments, liquid refrigerant may be continuously discharged to the condenser 34. In certain embodiments, the liquid refrigerant discharged from purge heat exchanger 88 may be a supercooled liquid at approximately 160 ° F. and 76 psi.

In addition, as the refrigerant and NCG are separated in the purge heat exchanger 88, the NCG can be released into the atmosphere via a solenoid valve 204 via conduit 209. For example, the pump 202 may increase the pressure of the mixture flowing into the purge heat exchanger 88 so that the pressure of the NCG separated from the refrigerant in the mixture is greater than atmospheric pressure. Thus, the pressure difference between the NCG and the atmosphere in the purge heat exchanger 88 can drive the flow of NCG into the atmosphere through the solenoid valve 204. In some embodiments, the controller 81 can activate the solenoid valve 204 to release NCG into the atmosphere once the fluid level in the purge heat exchanger 88 reaches a threshold. In certain embodiments, the controller 81 may purge the mixture prior to discharging the NCG through the solenoid valve 204, for example by activating one or more stop valves 96 and / or deactivating pump 202. It can block the entry into the heat exchanger (88). In this way, purge system 80 can ensure that virtually all vapor refrigerant of the mixture in purge heat exchanger 88 is condensed, thereby blocking the release of vapor refrigerant through solenoid valve 204.

As previously discussed, as the vapor refrigerant condenses into a liquid refrigerant, the vapor refrigerant of the mixture and the NCG can be separated in the purge heat exchanger 88. In particular, in order to condense the vapor refrigerant, the mixture may be in a heat exchange relationship with the liquid refrigerant drawn from the vapor compression system 14. More specifically, liquid refrigerant may be drawn from the vapor compression system 14 refrigerant loop downstream of expansion device 36 through conduit 211. As discussed herein, a refrigerant drawn from the refrigerant loop of the vapor compression system 14 at a location downstream of the expansion device 36 and used to condense the vapor refrigerant of the mixture may be referred to as an “expansion refrigerant”. The expansion refrigerant may be substantially liquid and / or contain some flash gas.

To condense the vapor refrigerant of the mixture within the purge heat exchanger 88, the expanded refrigerant can be routed through the tubes 210 of the purge heat exchanger 88. As the expansion refrigerant passes through the tubes 210 of the purge heat exchanger 88, the expansion refrigerant can exchange heat with the mixture. In particular, the expanding refrigerant can absorb heat from the mixture. Thus, when the expanding refrigerant flows out of the tubes 210 of the purge heat exchanger 88, it may be superheated steam. For example, the expansion refrigerant can exit the purge heat exchanger 88 at approximately 43 ° F. and 9 psi at a flow rate of approximately 8.5 lbm / hr.

To draw the expansion refrigerant through the tubes 210 of the purge heat exchanger 88, the purge system 80 can utilize the ejector 206. The ejector 206 can function similarly to the ejector 94 as described above. For example, the ejector 206 can utilize a pressure differential to draw the expanding refrigerant through the tubes 210 of the purge heat exchanger 88 and through the conduit 212. Specifically, the ejector 206 is a conduit fluidly coupled to a location along the refrigerant loop of the vapor compression system 14 just downstream of the compressor 32, such as between the compressor 32 and the condenser 34 ( 213) may utilize the refrigerant introduced. Ejector 206 may function with increased performance due at least in part to the low pressure differential between the expansion refrigerant flowing through tubes 210 and the refrigerant drawn from the refrigerant loop downstream of compressor 32. For example, the pressure of the expansion refrigerant drawn from the tubes 210 may be between approximately 8 psi and 9 psi, and the pressure of the refrigerant drawn from downstream of the compressor 32 may be approximately 26 psi. Thereafter, the ejector 206 may flow the combined refrigerant through the conduit 215 to the evaporator 38. In addition, the liquid refrigerant may flow from the purge heat exchanger 88 to the evaporator 38 at least partially due to the height difference between the purge heat exchanger 88 and the evaporator 38. Additionally or alternatively, the liquid refrigerant can flow from the purge heat exchanger 88 to the condenser 34 at least partially due to the height difference between the purge heat exchanger 88 and the condenser 34.

Also, in certain embodiments, such as the embodiment shown in FIG. 8, the purge system 80 draws refrigerant from the evaporator 38 to condense the vapor refrigerant of the mixture within the purge heat exchanger 88 to pump the liquid. A liquid pump 222 such as 84 can be utilized. In addition, the purge system 80 purge can be a pump 202, such as a reciprocating / diaphragm oil-free steam pump, solenoid valve 204, direct contact heat exchanger to purge the vapor compression system 14 against the NCG. Heat exchanger 88, pump 202, liquid pump 222, and one or more stop valves 96 may be utilized.

In general, purge system 80 may utilize refrigerant drawn from vapor compression system 14 to purge vapor compression system 14 against the NCG. For example, the purge system 80 can draw NCG that can be mixed with the vapor refrigerant from the condenser 34. Thereafter, the mixture of NCG and vapor refrigerant is pumped to a purge heat exchanger 88, where the vapor refrigerant condenses to separate the refrigerant of the mixture from the mixture's NCG. In particular, in order to condense the vapor refrigerant, the mixture is in heat exchange with a refrigerant that may be drawn upstream of the expansion device 36 or from a location along the refrigerant loop of the vapor compression system 14 or from the evaporator 38. Thereafter, the condensing refrigerant in the purge heat exchanger 88 is discharged to the evaporator 38 and / or condenser 34 and the NCG is released into the atmosphere.

To further illustrate, pump 202 may draw a mixture of vapor refrigerant and NCG from condenser 34 through conduit 203. In certain embodiments, the mixture drawn from condenser 34 is approximately 94 ° F. and can be 26 psi. The pump 202 can increase the pressure of the mixture by pumping the mixture from the condenser and passing the mixture through the conduit 205 to the purge heat exchanger 88. In certain embodiments, the pump 202 can raise the pressure of the mixture by approximately 50 psi. In particular, the mixture can become superheated steam after passing through the pump 202. For example, the mixture has a flow rate of approximately 10 lbm / hr (pound-mass per hour), approximately 160 ° F. and can be 76 psi. In this way, refrigerant vapor will condense within the purge heat exchanger 88 to a high heat exchange temperature. That is, as the pump 202 increases the pressure of the mixture, the condensation temperature of the refrigerant rises, thus utilizing less cooling for condensation.

Once the mixture is pumped to the purge heat exchanger 88, the mixture can exchange heat with refrigerant drawn upstream of the expansion device 36 and / or from the evaporator 38. More specifically, the liquid pump 222 draws liquid refrigerant through the conduit 223 from the bottom or submerged section of the evaporator 38, raises the pressure of the liquid refrigerant, purges the liquid refrigerant through the conduit 225 It can be transferred to a heat exchanger 88 to exchange heat with the mixture. The liquid refrigerant drawn from the evaporator 38 can be approximately 43 ° F. and 9 psi, and can be a supercooled liquid. The liquid pump 222 can, for example, increase the pressure of the liquid refrigerant to approximately 76 psi, and deliver the supercooled liquid refrigerant to the purge heat exchanger 88 at approximately 30 lbm / hr. It should also be noted that the output pressure of the mixture through the pump 202 can substantially match the output pressure of the liquid refrigerant flowing out of the liquid pump 222. Indeed, the pump 202 can deliver the mixture to the purge heat exchanger 88 at approximately 160 ° F. and 76 psi at a flow rate of approximately 10 lbm / hr.

In some embodiments, the liquid pump 222 may draw liquid refrigerant from upstream of the expansion valve 36 as discussed above. In these embodiments, the liquid pump 222 may function with increased efficiency due to a reduced pressure difference. For example, the liquid refrigerant upstream of the expansion device 36 may be at a higher pressure than the liquid refrigerant of the evaporator 38. Therefore, to match the pressure output of the pump 202, the liquid pump 222 may have to operate less if the liquid pump 222 pumps liquid refrigerant drawn from upstream of the expansion device 36.

Liquid refrigerant drawn from the evaporator 38 and / or upstream of the expansion device 36 can be supplied to the purge heat exchanger 88 through the spray system 224, where the spray system 224 is a purge heat exchanger ( And a sprayer rack and spray nozzles configured to disperse the liquid refrigerant throughout the interior volume of 88). As the liquid refrigerant mixes with the mixture of vapor refrigerant and NCG, the vapor refrigerant of the mixture can be condensed into the liquid refrigerant, and then a liquid refrigerant pool can be formed at the bottom of the purge heat exchanger 88. Thereafter, the liquid refrigerant may be discharged through conduit 226 to evaporator 38, as shown. For example, as discussed above, once the liquid refrigerant has reached a critical volume within the purge heat exchanger 88, the controller 81 operates stop valves 96 to transfer the liquid refrigerant to the evaporator 38. Can be discharged. In certain embodiments, liquid refrigerant may be continuously discharged to evaporator 38 and / or condenser 34. In certain embodiments, the liquid refrigerant discharged from purge heat exchanger 88 may be a supercooled liquid at approximately 132 ° F. and 76 psi.

In addition, as the refrigerant of the mixture and NCG are separated in the purge heat exchanger 88, the NCG can be released into the atmosphere through the solenoid valve 204. For example, the pump 202 can raise the pressure of the vapor refrigerant-NCG mixture such that the pressure of the NCG in the purge heat exchanger 88 is greater than atmospheric pressure. Thus, the pressure difference between the NCG and the atmosphere in the purge heat exchanger 88 can drive the flow of NCG to the atmosphere through the solenoid valve 204. In some embodiments, the controller 81 can activate the solenoid valve 204 to release NCG into the atmosphere once the fluid level in the purge heat exchanger 88 reaches a threshold. In certain embodiments, the controller 81 may cause the mixture to purge the heat exchanger (e.g., by activating one or more stop valves and / or deactivating the pump 202) prior to releasing the NCG through the solenoid valve 204. 88) can be blocked. In this way, purge system 80 can ensure that virtually all vapor refrigerant of the mixture in purge heat exchanger 88 is condensed, thereby blocking the release of vapor refrigerant through solenoid valve 204. In addition, the liquid refrigerant may flow from the purge heat exchanger 88 to the evaporator 38 at least partially due to the height difference between the purge heat exchanger 88 and the evaporator 38. Additionally or alternatively, the liquid refrigerant can flow from the purge heat exchanger 88 to the condenser 34 at least partially due to the height difference between the purge heat exchanger 88 and the condenser 34.

As discussed above, in certain embodiments, the pump 202 can include two pumps 199 arranged in series. In this way, the load is distributed between the two pumps 199, resulting in less stress induced in each individual pump 199, thereby reducing maintenance for the pumps 199. Similarly, in certain embodiments, the liquid pump 222 may include two liquid pumps 227 arranged in series. In this way, the load is distributed between the two liquid pumps 227, resulting in less stress induced in each individual liquid pump 227, thereby reducing maintenance for the liquid pumps 227. .

Additionally, the embodiments discussed above with reference to FIG. 8 can be utilized while the vapor compression system 14 is off. Indeed, as discussed with reference to the embodiments of FIG. 8, purge system 80 may not necessarily utilize the conditions calculated by vapor compression system 14 during operation. That is, the pump 202 and the liquid pump 222 can induce the pressure utilized by the functions of the purge system 80 to purge the vapor compression system 14 against the NCG.

Also, in certain embodiments, as shown in FIG. 9, the purge system 80 draws refrigerant from the refrigerant loop of the vapor compression system 14 upstream of the expansion device 36 to condense the vapor refrigerant of the mixture. You can enter. In particular, the purge system 80 expands the refrigerant to an intermediate pressure between the pressures of the condenser 34 and the evaporator 38 so that the pressure difference drives the flow of refrigerant through the tubes 210 of the purge heat exchanger 88. In order to do so, the second expansion device 230 may be utilized. In addition, the purge system 80 has a purge heat exchanger 88 such as a pump 202, a shell-tube heat exchanger, solenoid valve 204 to remove NCG that may accumulate in the condenser 34 as described above. , And a three-way valve 228 may be utilized.

In general, purge system 80 may utilize refrigerant drawn from vapor compression system 14 to purge vapor compression system 14 against the NCG. For example, purge system 80 may draw NCG that may be placed in a mixture with vapor refrigerant from condenser 34. Thereafter, the mixture is pumped to a purge heat exchanger 88 where the vapor refrigerant condenses to separate the refrigerant of the mixture from the NCG of the mixture. For example, to condense the vapor refrigerant, the mixture is in heat exchange relationship with the refrigerant drawn upstream of the expansion device 36. Thereafter, the condensing refrigerant is discharged to the condenser 34 and the NCG is discharged into the atmosphere.

To further illustrate, pump 202 may draw a mixture of vapor refrigerant and NCG from condenser 34 through conduit 203. In certain embodiments, the mixture drawn from condenser 34 is approximately 94 ° F. and can be 26 psi. The pump 202 can increase the pressure of the mixture by pumping the mixture from the condenser 34 and passing the mixture through the conduit 205 to the purge heat exchanger 88. In certain embodiments, the pump 202 can raise the pressure of the mixture by approximately 50 psi. For example, after passing through the pump 202, the mixture can be approximately 160 ° F. and 76 psi and become superheated steam with a flow rate of approximately 10 lbm / hr (pounds-mass per hour). In this way, refrigerant vapor in the mixture can more easily condense within the purge heat exchanger 88. That is, as the pump 202 increases the pressure of the mixture, the condensation temperature of the refrigerant rises, thus utilizing less cooling for condensation.

As the purge heat exchanger 88 condenses the vapor refrigerant into a liquid refrigerant, the liquid refrigerant can collect at the base of the purge heat exchanger 88. As previously discussed, once the liquid refrigerant has reached a critical volume within the purge heat exchanger 88, the controller 81 operates stop valves 96 to deliver the liquid refrigerant through conduit 207 to condenser 34 ). In certain embodiments, liquid refrigerant may be continuously discharged to the condenser 34. In certain embodiments, the liquid refrigerant discharged from purge heat exchanger 88 may be a supercooled liquid at approximately 160 ° F. and 76 psi.

In addition, as the vapor refrigerant of the mixture and the NCG are separated in the purge heat exchanger 88, the NCG can be released into the atmosphere via a solenoid valve 204 via conduit 209. For example, the pump 202 can raise the pressure of the NCG-vapor refrigerant mixture such that the pressure of the NCG in the purge heat exchanger 88 is greater than atmospheric pressure. Thus, the pressure difference between the NCG and the atmosphere in the purge heat exchanger 88 can drive the flow of NCG to the atmosphere through the solenoid valve 204. In some embodiments, the controller 81 may activate the solenoid valve 204 to release NCG into the atmosphere once the internal pressure of the purge heat exchanger 88 reaches a threshold. In certain embodiments, the controller 81 may cause the mixture to purge the heat exchanger (e.g., by activating one or more stop valves 96 and / or deactivating pump 202) prior to releasing the NCG through the solenoid valve. 88) can be blocked. In this way, purge system 80 can ensure that virtually all vapor refrigerant of the mixture in purge heat exchanger 88 is condensed, thereby blocking the release of vapor refrigerant through solenoid valve 204.

To condense the vapor refrigerant of the mixture, purge system 80 may place the mixture in a heat exchange relationship with the liquid refrigerant in purge heat exchanger 88. The liquid refrigerant may be drawn from the refrigerant loop of the vapor compression system 14 through the three-way valve 228 at a position upstream of the expansion device 36. The liquid refrigerant drawn from the refrigerant loop may expand to a medium pressure through the second expansion device 230 before entering the purge heat exchanger 88. In particular, the intermediate pressure may be higher than that of the evaporator 38 and lower than that of the condenser 34. For example, the intermediate pressure can be between approximately 9 psi and 26 psi. As another example, the intermediate pressure can be approximately 10 psi to 12 psi, while the pressure of the evaporator 38 can be approximately 9 psi. Therefore, the liquid refrigerant flows through the tubes 210 of the purge heat exchanger 88, evaporates, and evaporator through the conduit 238 at least partially due to the pressure difference between the vapor refrigerant and the evaporator 38. It can flow to (38). For example, the vapor refrigerant may be approximately 52 ° F. and 11 psi after exiting the purge heat exchanger 88, while the refrigerant in the evaporator 38 may be approximately 9 psi. In addition, the vapor refrigerant may flow from the purge heat exchanger 88 to the evaporator 38 at least partially due to the height difference between the purge heat exchanger 88 and the evaporator 38. Additionally or alternatively, the vapor refrigerant may flow from the purge heat exchanger 88 to the condenser 34 at least in part due to the height difference between the purge heat exchanger 88 and the condenser 34.

Also, as shown in Figures 5-9, in some embodiments, pumps such as liquid pump 84, pump 90, pump 202, and / or liquid pump 222 may be any suitable motor. Power may be supplied by one or more motors 180, which may be. In some embodiments, controller 81 may control pumps through one or more communicating with motor 180. In some embodiments, one or more motors 180 may receive power from a power source 154, which power source 154 is used to power the thermoelectric assemblies 150. It may be similar.

Accordingly, the present disclosure relates to systems and methods for purging a low pressure HVAC & R system (eg, chiller system, vapor compression system) against NCG that may enter the HVAC & R system during operation. Specifically, the purge system can purge the HVAC & R system for the NCG by utilizing the refrigerant drawn from the HVAC & R system. In other words, by utilizing the second refrigerant flow of the HVAC & R system as a cooling source, the first refrigerant flow of the HVAC & R system mixed with the NCG is purged against the NCG to condense the first refrigerant flow and separate the first refrigerant flow from the NCG. have. The disclosed embodiments are cost effective compared to existing purging methods and enable the HVAC & R system to be purged to the NCG without using additional refrigerant loops with additional refrigerant.

While only certain features and embodiments have been illustrated and described, those skilled in the art can make various modifications and changes (eg, size, dimension, structure of various elements) without substantially departing from the novel teachings and advantages of the claimed subject matter in the claims. , Shape and ratio, and parameter values (eg, temperature, pressure, etc.), mounting arrangement, material usage, color, orientation, etc. changes will be possible. The order or sequence of any process or method steps may be altered or rearranged according to alternative embodiments. Accordingly, it is to be understood that the appended claims are within the true spirit of the invention and are intended to cover all such modifications and variations. Also, in an effort to provide a concise description of exemplary embodiments, not all features of an actual implementation may have been described (i.e., those not related to the best mode currently contemplated for carrying out the invention, or claims) Things that have nothing to do with making the invention possible). It should be understood that, as in any engineering project or design project, in the development of any such actual implementation, multiple implementation specific decisions can be made. This development effort can be complex and time consuming, but nevertheless, without undue experimentation, it will be a regular task of design, fabrication, and manufacturing for those skilled in the art to take advantage of the present disclosure.

Claims (32)

As a heating, ventilation, air conditioning, and refrigeration (HVAC & R) system,
Refrigerant loop;
A compressor disposed along the refrigerant loop and configured to circulate the refrigerant through the refrigerant loop;
An evaporator disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a first cooling fluid;
A condenser disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a second cooling fluid; And
And a purge system configured to purge the HVAC & R system for non-condensing gases,
The purge system,
A liquid pump configured to draw a first refrigerant flow from the evaporator;
A controllable expansion valve configured to receive the first refrigerant flow from the liquid pump and reduce the temperature of the first refrigerant flow; And
A purge heat exchanger comprising a purge coil configured to receive the first refrigerant flow from the controllable expansion valve,
The chamber of the purge heat exchanger is configured to draw a mixture comprising the second refrigerant flow and the non-condensing gases from the condenser, wherein the purge heat exchanger utilizes the first refrigerant flow from the second refrigerant flow of the mixture. And configured to separate non-condensable gases of the mixture. According to claim 1,
And an ejector configured to receive the first refrigerant flow from the purge coil, wherein the ejector is configured to increase the pressure of the first refrigerant flow by utilizing the second refrigerant flow from the condenser. system. According to claim 2,
The evaporator is configured to receive the first refrigerant flow and the second refrigerant flow discharged from the ejector, HVAC & R system. According to claim 1,
The purge system further comprises a pump configured to remove non-condensable gases of the mixture from the purge heat exchanger. According to claim 1,
The purge system further comprises a conduit configured to flow the first refrigerant flow from the liquid pump to the controllable expansion valve, wherein the first refrigerant flows through the conduit with one or more thermoelectric assemblies coupled to the conduit An HVAC & R system, configured to remove thermal energy from the flow. The method of claim 5,
Each thermoelectric assembly of the one or more thermoelectric assemblies is configured to remove thermal energy of the first refrigerant flow by converting a power gradient to a thermal gradient. According to claim 1,
The purge system further comprises one or more adsorption chambers configured to receive the mixture from the purge heat exchanger, each adsorption chamber of the one or more adsorption chambers receiving non-condensing gases of the mixture from a second refrigerant flow of the mixture. HVAC & R system, configured to separate. The method of claim 7,
Wherein the one or more adsorption chambers are configured to forcibly release non-condensable gases of the mixture into the atmosphere and flow a second refrigerant flow of the mixture to the evaporator. According to claim 1,
The liquid pump is configured to draw the first refrigerant flow from the evaporator through a flash tank, and the first refrigerant flow drawn from the evaporator includes refrigerant liquid and refrigerant vapor, and the flash tank comprises the refrigerant vapor from the refrigerant vapor. An HVAC & R system, configured to separate refrigerant liquid. The method of claim 9,
The flash tank is configured to flow the refrigerant liquid to the liquid pump and flow the refrigerant vapor to the evaporator. The HVAC & R system of claim 1, wherein the purge heat exchanger is configured to flow a second refrigerant flow of the mixture to the condenser, the evaporator, or both the condenser and the evaporator. As a heating, ventilation, air conditioning, and refrigeration (HVAC & R) system,
Refrigerant loop;
A compressor disposed along the refrigerant loop and configured to circulate the refrigerant through the refrigerant loop;
An evaporator disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a first cooling fluid;
A condenser disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a second cooling fluid; And
And a purge system configured to purge the HVAC & R system for non-condensing gases (NCG),
The purge system,
Configured to separate the mixture drawn from the condenser by utilizing the first refrigerant flow of the refrigerant drawn from the evaporator, the mixture comprising a second refrigerant flow of the refrigerant from the condenser and the NCG, and the mixture Separating comprises separating the NCG from the second refrigerant flow, a purge heat exchanger; And
And one or more thermoelectric assemblies configured to remove thermal energy from the second refrigerant flow. The method of claim 12,
The purge system further comprises a liquid pump configured to draw the first refrigerant flow from the evaporator and push the first refrigerant flow through the one or more thermoelectric assemblies to the purge heat exchanger. The method of claim 13,
The purge system further comprises a conduit configured to flow the first refrigerant flow from the liquid pump to the purge heat exchanger, wherein the one or more thermoelectric assemblies are coupled to the conduit. The method of claim 14,
Each thermoelectric assembly of the one or more thermoelectric assemblies,
A thermal paste configured to couple the thermoelectric assembly to the conduit;
A thermoelectric assembly coupled to the thermal paste and configured to remove thermal energy from the first refrigerant flow by converting a power gradient to a thermal gradient;
A heat sink coupled to the thermoelectric assembly; And
A HVAC & R system comprising a fan coupled to the heat sink. The method of claim 12,
The purge heat exchanger comprises a purge coil configured to receive the first refrigerant flow, HVAC & R system. 13. The HVAC & R system of claim 12, wherein the purge system further comprises a pump configured to remove the NCG from the purge heat exchanger. The method of claim 12,
The purge heat exchanger is configured to flow the second refrigerant flow through the condenser, the evaporator, or both the condenser and the evaporator. The method of claim 12,
The purge system further comprises one or more adsorption chambers configured to receive at least a portion of the mixture from the purge heat exchanger, the one or more adsorption chambers absorbing the second refrigerant flow to thereby absorb the second refrigerant flow from the NCG. HVAC & R system, configured to separate. As a heating, ventilation, air conditioning, and refrigeration (HVAC & R) system,
Refrigerant loop;
A compressor disposed along the refrigerant loop and configured to circulate the refrigerant through the refrigerant loop;
An evaporator disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a first cooling fluid;
A condenser disposed along the refrigerant loop and configured to place the refrigerant in a heat exchange relationship with a second cooling fluid; And
And a purge system configured to purge the HVAC & R system for non-condensing gases (NCG),
The purge system,
Configured to separate the mixture drawn from the condenser by utilizing the first refrigerant flow of the refrigerant drawn from the evaporator, the mixture comprising a second refrigerant flow of the refrigerant from the condenser and the NCG, and the mixture Separating comprises separating the NCG from the second refrigerant flow, a purge heat exchanger; And
And one or more adsorption chambers configured to receive the NCG from the purge heat exchanger and configured to separate the NCG from residual refrigerant. The method of claim 20,
Each of the one or more adsorption chambers comprises a modified material configured to adsorb the residual refrigerant and allow the NCG to pass through the one or more chambers. The method of claim 21,
Each of the one or more adsorption chambers includes a heater configured to heat the reforming material and forcibly discharge the residual refrigerant from the reforming material. The method of claim 20,
And the evaporator is configured to receive the residual refrigerant from the one or more adsorption chambers. The method of claim 20,
The one or more adsorption chambers are configured to forcibly discharge the NCG into the atmosphere, an HVAC & R system. The method of claim 20,
The purge system,
A pump configured to draw the NCG from the purge heat exchanger, wherein the one or more adsorption chambers are configured to receive the NCG from the pump;
A liquid pump configured to draw the first refrigerant flow from the evaporator;
A controllable expansion valve configured to receive the first refrigerant flow from the liquid pump and reduce the pressure of the first refrigerant flow; And
A purge coil of a purge heat exchanger configured to receive the first refrigerant flow from the controllable expansion valve, wherein a chamber of the purge heat exchanger within the purge coil causes the mixture to exchange heat with the first refrigerant flow. The HVAC & R system further comprising the purge coil. The method of claim 25,
The purge system further comprises one or more thermoelectric assemblies configured to remove thermal energy from the first refrigerant flow exiting the liquid pump by converting a power gradient to a thermal gradient. As a heating, ventilation, air conditioning, and refrigeration (HVAC & R) system,
A purge system configured to purge the vapor compression system for non-condensing gases (NCG),
The purge system,
A pump configured to draw a mixture comprising the NCG and vapor refrigerant from the condenser of the vapor compression system; And
A purge heat exchanger configured to receive the mixture from the pump and place the mixture in heat exchange relationship with refrigerant flow drawn from the vapor compression system to condense the vapor refrigerant of the mixture and separate the NCG of the mixture from the vapor refrigerant Including,
Wherein the pump is configured to increase the pressure of the mixture to direct the flow of the NCG from the purge heat exchanger to the atmosphere through a pressure difference between the NCG and the atmosphere. The method of claim 27,
And a liquid pump configured to draw the refrigerant flow from the vapor compression system and provide the refrigerant flow to the purge heat exchanger. The method of claim 28,
The purge heat exchanger is a direct contact heat exchanger, HVAC & R system. The method of claim 27,
And an expansion device disposed along a conduit extending from the refrigerant loop of the vapor compression system to the purge heat exchanger, wherein the conduit and the expansion device are configured to supply the refrigerant flow to the purge heat exchanger. The method of claim 30,
The expansion device is configured to lower the pressure of the refrigerant flow to induce a flow of refrigerant countercurrent through the purge heat exchanger through a second pressure difference between the refrigerant flow and the evaporator of the vapor compression system. Constructed, HVAC & R system. The method of claim 27,
And an ejector configured to draw the refrigerant flow from the purge heat exchanger and direct the refrigerant flow to the evaporator of the vapor compression system.

Images