Heat pump for HVACR system

Abstract

Embodiments of the present disclosure relate to heating, ventilation, air conditioning and refrigeration (HVACamp; r) system. The vapor compression system includes: a compressor configured to circulate a refrigerant through the vapor compression system; an evaporator configured to place the refrigerant in thermal communication with a low temperature heat source; and a condenser configured to place the refrigerant in thermal communication with the intermediate fluid loop. The absorption heat pump includes: an absorption evaporator configured to place a working fluid in thermal communication with an intermediate fluid loop; an absorber configured to mix the working fluid in an absorbent to form a mixture; a generator configured to heat the mixture and separate the working fluid from the absorbent; and an absorbent condenser configured to place the working fluid in thermal communication with a heating fluid.

Description

[0001] This application is a divisional application of the Chinese invention patent application with an international application date of October 5, 2017, an international application number of PCT / US2017 / 055344, a national application number of 2017800620186, and an invention name of “Heat pump for HVAC&R system”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to and the benefit of U.S. Provisional Application Serial No. 62 / 404,634, filed on October 5, 2016, entitled “CENTRIFUGAL / ABSORPTION HIGH LIFTHEAT PUMP,” which is incorporated herein by reference in its entirety for all purposes. Background Art

[0004] The present disclosure relates generally to heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, and more particularly to combined HVAC&R systems.

[0005] HVAC&R systems are used in residential, commercial, and industrial environments to control environmental characteristics such as temperature and humidity for occupants of the corresponding environments. In some cases, the HVAC&R system may include a vapor compression system that circulates a refrigerant along a refrigerant circuit. The refrigerant is configured to change phases between vapor, liquid, and combinations thereof in response to being subjected to different temperatures and pressures associated with the operation of the vapor compression system. In some cases, the HVAC&R system may include an absorption heat pump in addition to the vapor compression system. Existing combined systems utilize one or more cooling towers to provide cooling fluid to the condenser of the vapor compression system and / or the condenser of the absorption heat pump. Unfortunately, cooling towers consume relatively large amounts of water, thereby increasing the operating costs of combined systems utilizing a vapor compression system and an absorption heat pump. Summary of the invention

[0006] In one embodiment, a heating, ventilation, air conditioning and refrigeration (HVAC&R) system includes a vapor compression system and an absorption heat pump. The vapor compression system includes a compressor configured to circulate a refrigerant through the vapor compression system; an evaporator configured to place the refrigerant in thermal communication with a low temperature heat source; and a condenser configured to place the refrigerant in thermal communication with an intermediate fluid loop. The absorption heat pump includes an absorption evaporator configured to place a working fluid in thermal communication with an intermediate fluid loop; an absorber configured to mix the working fluid in an absorbent to form a mixture; a generator configured to heat the mixture and separate the working fluid from the absorbent; and an absorbent condenser configured to place the working fluid in thermal communication with a heating fluid.

[0007] In another embodiment, a system includes a vapor compression system and an absorption heat pump. The vapor compression system includes: a compressor, the compressor is configured to circulate a refrigerant through the vapor compression system; an evaporator, the evaporator is configured to place the refrigerant in thermal communication with a low-temperature heat source and a condenser. The absorption heat pump includes: an absorption evaporator, the absorption evaporator is configured to place a working fluid in thermal communication with the refrigerant of the vapor compression system; an absorber, the absorber is configured to mix the working fluid in an absorbent to form a mixture; a generator, the generator is configured to heat the mixture and separate the working fluid from the absorbent; and an absorbent condenser, the absorbent condenser is configured to place the working fluid in thermal communication with a heating fluid.

[0008] In another embodiment, a method includes placing a refrigerant of a vapor compression system in a first heat exchange relationship with an intermediate fluid of an intermediate fluid loop, wherein the vapor compression system is in thermal communication with a low-temperature heat source, placing the intermediate fluid of the intermediate fluid loop in a second heat exchange relationship with a working fluid of an absorption heat pump, circulating the working fluid of the absorption heat pump through an absorber, a pump and a generator of the absorption heat pump to transfer thermal energy to the working fluid, and placing the working fluid in a third heat exchange relationship with a heating fluid. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0012] Figure 4 According to one aspect of this 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 combined HVAC&R system having a vapor compression system and an absorption heat pump according to an aspect of the present disclosure;

[0014] Figure 6 is a schematic diagram of an embodiment of a combined HVAC&R system having a vapor compression system and an absorption heat pump according to an aspect of the present disclosure; and

[0015] Figure 7 According to one aspect of the present disclosure, Figure 5 and Figure 6 A block diagram of a flow chart of the combined HVAC&R system operation. DETAILED DESCRIPTION

[0016] One or more specific embodiments will be described below. In order to provide a concise description of these embodiments, not all features of the actual embodiments are described in the specification. It should be understood that in the development of any such actual embodiment (as in any engineering or design scheme), a large number of embodiment-specific decisions must be made to achieve the developer's specific goals (such as compliance with system-related and business-related constraints), which may vary from one embodiment to another. In addition, it should be understood that such development work may be complex and time-consuming, but for ordinary technicians who benefit from the present disclosure, this is still a routine design, production and manufacturing work.

[0017] In some cases, it may be difficult to extract useful energy from a low temperature heat source (e.g., municipal treated sewage and / or water) using a conventional vapor compression system (e.g., a centrifugal system). For example, the energy associated with the fluid from the low temperature heat source may not be sufficient to heat water or another fluid to a sufficient temperature (e.g., about 65.5°C or higher) that would enable the water or another fluid to be used as a residential or commercial hot fluid supply. Embodiments of the present disclosure relate to a system, for example, that utilizes a combination of a vapor compression system and an absorption heat pump to efficiently utilize energy from a low temperature heat source and generate, for example, a high temperature that can produce a hot fluid supply for a residential or commercial purpose. Existing systems that combine a vapor compression system with an absorption heat pump utilize one or more cooling towers to provide cooling for a condenser of the vapor compression system and / or a condenser of the absorption heat pump. Cooling towers consume relatively large amounts of water, thereby increasing the operating cost of the system. Therefore, embodiments of the present disclosure relate to a combined system having a vapor compression system and an absorption heat pump, but may not include a cooling tower. In this way, the combined system of the present disclosure reduces operating costs while enabling the combined system to utilize energy from a low temperature heat source to produce a heating fluid for a structure.

[0018] In some embodiments, the absorption heat pump can be in thermal communication with the vapor compression system via an intermediate fluid loop, and the intermediate fluid loop guides the intermediate fluid between the condenser of the vapor compression system and the absorption evaporator of the absorption heat pump. For example, the intermediate fluid can absorb the thermal energy (for example, heat) of the refrigerant in the condenser of the vapor compression system, and transfer the thermal energy to the working fluid in the absorption evaporator of the absorption heat pump. When mixed with an absorbent (for example, water or lithium bromide), the working fluid can further receive and / or generate thermal energy in the absorber. The mixture of working fluid and absorbent can absorb additional thermal energy in the generator, so that the working fluid can be separated from the absorbent and the temperature of the mixture can be increased simultaneously. The absorbent can then be guided to the absorbent condenser, which is in thermal communication with the heating fluid (for example, guided to a residential or commercial fluid). Using the vapor compression system to provide thermal energy (for example, heat) to the absorption evaporator enables the combined system to generate a large amount of thermal energy with relatively low thermal energy input, thereby improving the efficiency (for example, coefficient of performance) of the combined system. In some embodiments, the absorption heat pump can be a low-concentration single-effect absorption heat pump. In other embodiments, the absorption heat pump may be another suitable absorption heat pump.

[0019] Now turning to the attached figure, Figure 11 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 that supplies a chilled liquid that may be used to cool 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. 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 by duct 24. The heat exchanger in the air handler 22 may receive heated liquid from the boiler 16 or chilled liquid from the vapor compression system 14, depending on the operating mode of the HVAC&R system 10. 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 two or more floors.

[0020] Figure 2 and Figure 3 3 is an embodiment of a vapor compression system 14 that may be used with the HVAC&R system 10. The vapor compression system 14 may circulate a refrigerant through a circuit beginning with a compressor 32. The circuit may also include a condenser 34, expansion valve(s) or device(s) 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.

[0021] Some examples of fluids that can be used as refrigerants in the vapor compression system 14 are hydrofluorocarbon (HFC) based refrigerants (e.g., R-410A, R-407, R-134a, hydrofluoroolefins (HFO)), "natural" refrigerants (like 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 refrigerant having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere of pressure, also referred to as a low-pressure refrigerant relative to a medium-pressure refrigerant (such as R-134a). As used herein, "normal boiling point" can refer to the boiling point temperature measured at one atmosphere of pressure.

[0022] In some embodiments, the vapor compression system 14 may use one or more of the following: a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or expansion 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 power source or a direct current (DC) power source. The motor 50 may include any type of electric 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. In other embodiments, the compressor 32 is not driven by the motor 50, but by another power source, such as a steam turbine.

[0023] The compressor 32 compresses the refrigerant vapor and delivers the vapor to the condenser 34 through a discharge passage. In some embodiments, the compressor 32 may be a centrifugal compressor. The refrigerant vapor delivered to the condenser 34 by the compressor 32 may transfer heat to a cooling fluid (e.g., water or air) in the condenser 34. As a result of the heat transfer with the cooling fluid, the refrigerant vapor may condense into a refrigerant liquid in the condenser 34. The liquid refrigerant from the condenser 34 may flow through the expansion device 36 to the evaporator 38. Figure 3 In the illustrated embodiment, 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.

[0024] The liquid refrigerant 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 refrigerant in the evaporator 38 may undergo a phase change from liquid refrigerant to refrigerant vapor. Figure 3 As shown in the illustrated embodiment, 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 of the evaporator 38 (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 via the return line 60R and leaves 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 the refrigerant. The tube bundle 58 in the evaporator 38 may include multiple tubes and / or multiple tube bundles. In any case, the vapor refrigerant leaves the evaporator 38 and returns to the compressor 32 through the suction line to complete the cycle.

[0025] Figure 4is a schematic diagram of a vapor compression system 14 having an intermediate loop 64 coupled between the condenser 34 and the expansion device 36. The intermediate loop 64 may have an inlet line 68 that is directly fluidly connected to the condenser 34. In other embodiments, the inlet line 68 may be indirectly fluidly connected to the condenser 34. Figure 4 As shown 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, the intermediate container 70 is used as a flash tank, and the first expansion device 66 is configured to reduce the pressure of the liquid refrigerant received from the condenser 34 (e.g., expand the liquid refrigerant). During the expansion process, a portion of the liquid may vaporize, and therefore the intermediate container 70 can be used to separate the vapor from the liquid received from the first expansion device 66. In addition, since the liquid refrigerant experiences a pressure drop when entering the intermediate container 70 (e.g., due to a rapid increase in volume when entering the intermediate container 70), the intermediate container 70 can further expand the liquid refrigerant. The vapor in the intermediate container 70 can be extracted by the compressor 32 through the suction line 74 of the compressor 32. In other embodiments, the vapor in the intermediate container can be sucked into the middle section (e.g., not the suction section) 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 the pipeline 72 to the evaporator 38.

[0026] As described above, the vapor compression system 14 can be combined with an absorption heat pump to extract a large amount of thermal energy from a low-temperature heat source. In some embodiments, the vapor compression system 14 and the absorption heat pump can be in thermal communication via an intermediate fluid loop, which can circulate an intermediate fluid (e.g., water) between the condenser 54 of the vapor compression system 14 and the absorption evaporator of the absorption heat pump. In other embodiments, the common heat exchanger between the vapor compression system 14 and the absorption heat pump can be used as both a condenser of the vapor compression system 14 and an absorption evaporator of the absorption heat pump. In any case, the working fluid (e.g., ammonia and / or water) in the absorption heat pump can include a relatively low boiling point so that a relatively small amount of thermal energy can cause the working fluid to evaporate (e.g., from a liquid state to a vapor state). In addition, the absorber and generator of the absorption heat pump can be configured to generate and / or transfer a relatively large amount of thermal energy to the working fluid so that the heating fluid directed toward the building can be fully heated to a predetermined temperature (e.g., approximately 93.3°C) in the absorption condenser of the absorption heat pump.

[0027] For example, Figure 5 is a block diagram of an embodiment of a combined vapor compression and absorption heat pump system 100. Figure 5 As shown in the illustrated embodiment, the evaporator 38 of the vapor compression system 14 can receive a fluid (e.g., water) from a low temperature heat source 102 (e.g., a municipal wastewater treatment plant) to place the fluid in a heat exchange relationship with a refrigerant (e.g., water or R134a) of the vapor compression system 14. Thus, heat from the fluid can be transferred to the refrigerant, causing at least a portion of the refrigerant to evaporate (e.g., from a refrigerant liquid to a refrigerant vapor). The refrigerant vapor can then be directed to the compressor 32, which is powered by the steam turbine 104. In other embodiments, the compressor 32 is driven by another suitable power source (e.g., a motor 50), such as Figure 6 In some embodiments, steam turbine 104 may receive exhaust steam from plant 105 (e.g., a power plant) or other suitable source. In any case, compressor 32 may increase the pressure of the refrigerant vapor before directing the refrigerant vapor to condenser 34.

[0028] The condenser 34 can place the refrigerant vapor in a heat exchange relationship with the intermediate fluid loop 106, which is configured to circulate an intermediate fluid (e.g., water). The intermediate fluid can circulate between the vapor compression system 14 and the absorption heat pump 108 of the system 100. For example, the intermediate fluid can be directed from the condenser 34 of the vapor compression system 14 to the absorption evaporator 110 of the absorption heat pump 108. Therefore, thermal energy can be transferred from the refrigerant vapor in the condenser 34 of the vapor compression system 14 to the intermediate fluid, thereby condensing the refrigerant vapor into a refrigerant liquid. The refrigerant liquid can then be directed to an expansion device 36 (e.g., a throttle valve), where the pressure of the refrigerant liquid is reduced, thereby further reducing the temperature of the refrigerant liquid. The refrigerant liquid is then directed back to the evaporator 38 to complete the cycle of the vapor compression system 14.

[0029] As described above, the intermediate fluid circulates between the condenser 34 of the vapor compression system 14 and the absorption evaporator 110 of the absorption heat pump 108. In some embodiments, a pump 111 is provided in the intermediate fluid loop 106 to direct the intermediate fluid through the condenser 34 of the vapor compression system 14 and the absorption evaporator 110 of the absorption heat pump 108. In this way, the intermediate fluid can absorb thermal energy (e.g., heat) in the condenser 34 and then transfer the thermal energy to the working fluid (e.g., ammonia or water) in the absorption evaporator 110. In some cases, the intermediate fluid can be directed to the heat exchanger 112 (e.g., a dump tower) and thus bypass the absorption evaporator 110. For example, the valve 114 can be adjusted to enable at least a portion of the intermediate fluid to bypass the absorption evaporator 110 during the startup of the system 100. During startup, the absorption evaporator 110 may not absorb enough heat from the intermediate fluid so that the intermediate fluid is not at a sufficiently low temperature to condense the refrigerant in the condenser 34. Thus, the intermediate fluid may be directed by valve 114 to heat exchanger 112 to place the intermediate fluid in heat exchange relationship with supplemental cooling fluid 115 that provides supplemental cooling of the intermediate fluid upon startup of system 100 .

[0030] Once the system 100 reaches a steady state, substantially all of the intermediate fluid can be directed to the absorption evaporator 110 via valve 114. The intermediate fluid can transfer heat energy to the working fluid to evaporate the working fluid (e.g., from a liquid working fluid to a vapor working fluid). Therefore, the vapor working fluid can be directed to the absorber 116. In the absorber 116, the vapor working fluid can be mixed (e.g., dissolved) with an absorbent (e.g., water or lithium bromide), which can generate thermal energy (e.g., heat). In some embodiments, the mixture can be in a liquid state so that the pump 117 can drive the working fluid and the absorbent to circulate through the absorption heat pump 108. In other embodiments, the mixture can include both vapor and liquid. In any case, the mixture can be directed to the generator 118 via the pump 117, whereby the working fluid and the absorbent (e.g., the absorption fluid evaporates from the absorber) are separated due to the thermal energy applied to the mixture in the generator 118. In some embodiments, steam from the steam turbine 104 used to power the compressor 32 of the vapor compression system 14 can supply thermal energy to the generator 118. Thus, the steam exiting the generator 118 may be condensed into liquid condensate and returned to the plant, for example, as a cooling fluid. The vapor working fluid exiting the generator 118 is at a relatively high pressure when entering the absorption condenser 120 .

[0031] In addition, the absorbent separated from the working fluid in the generator 118 can be recycled to the absorber 116 via a pump 121, which directs the absorbent through a recirculation flow path 122. In other embodiments, the pressure difference between the generator 118 and the absorber 116 can direct the absorbent from the generator 118 to the absorber 116 without using the pump 121. In such embodiments, the pump 121 is not included in the absorption heat pump 108. In some embodiments, the absorption heat pump 108 may include a heat exchanger 123 (e.g., a solution heat exchanger) that can place a mixture of absorbent and the working fluid flowing from the absorber 116 to the generator 118 in a heat exchange relationship with the recycled absorbent flowing through the recirculation flow path 122. In this way, the mixture of absorbent and working fluid can absorb thermal energy from the recycled absorbent and be preheated before entering the generator 118. In other embodiments, the heat exchanger 123 may place the mixture of absorbent and working fluid flowing from the absorber 116 to the generator 118 in heat exchange relationship with the exhaust fluid leaving the generator 118 (see, e.g., Figure 6 ). In this way, the mixture of absorbent and working fluid is preheated before entering the generator 118, and additional heat energy is extracted from the exhaust fluid leaving the generator 118. In yet other embodiments, a separate heating fluid may be used to preheat the mixture of absorbent and working fluid flowing through the heat exchanger 123 before the mixture flows through the generator 118. In any case, using the heat exchanger 123 to preheat the mixture of absorbent and working fluid can improve the efficiency of the absorption heat pump 123, and therefore improve the efficiency of the combined system 100. It should be understood that the absorption heat pump 123 may include more than Figure 5 and Figure 6 The embodiments shown may have fewer components or include additional components, depending on the absorbent and working fluid used in the absorption heat pump.

[0032] The heating fluid supplied to the absorption condenser 120 can absorb heat energy from the vapor working fluid, thereby condensing the vapor working fluid into a liquid working fluid. In some embodiments, the heating fluid can be water that is ultimately used as a hot water supply for the building 12. Figure 5As shown in the illustrated embodiment, the heating fluid can be directed from the absorber 116 to the absorption condenser 120 in a series arrangement, as shown by line 125. In this way, the heating fluid absorbs thermal energy in the absorber 116 when the working fluid mixes with the absorbent, and then absorbs thermal energy from the vapor working fluid in the absorption condenser 120. In other embodiments, the heating fluid can be directed from the absorption condenser 120 to the absorber 116 in a series arrangement before being directed to the building 12. In yet another embodiment, the heating fluid can be directed through the absorption condenser 120 and the absorber 116 in a parallel arrangement before being combined into a single stream that is ultimately delivered to the building 12. In any case, the liquid working fluid can be directed from the absorption condenser 120 to an absorption expansion device 124 (e.g., a throttling valve) that reduces the pressure of the working fluid. From the absorption expansion device 124, the liquid working fluid can be directed back to the absorption evaporator 110 to complete the cycle of the absorption heat pump 108.

[0033] Compared with the operating temperature of the vapor compression system 14 of the system 100, the operating temperature of the absorption heat pump 108 of the system 100 can be relatively high. Therefore, the temperature of the heating fluid leaving the absorption condenser 120 can be sufficient as a hot water supply for the building 12. In addition, in some cases, the fluid (e.g., from the low-temperature heat source 102) used to evaporate the refrigerant in the evaporator 38 of the vapor compression system 14 can be cooled due to the transfer of heat energy to the refrigerant. Therefore, the system 100 can provide both heating and cooling without using a cooling tower (e.g., an air cooling tower). In some cases, the lift of the system 100 (e.g., the temperature difference between the heat source (low-temperature heat source 102) and the temperature adjustment destination (building 12)) can be increased by using the vapor compression system 14 and the absorption heat pump 108 in combination with each other. Therefore, the performance coefficient of the system can be improved. It should be understood that the performance coefficient can be the ratio between the heating and / or cooling output of the system and the work or energy input to the system. In some embodiments, the coefficient of performance of system 100 may be between 1 and 5, between 1.5 and 4, or between 2 and 3.

[0034] As described above, in some embodiments, the compressor 32 is driven by the motor 50 rather than the steam turbine 104. For example, Figure 61 is a schematic diagram of an embodiment of a combined system 100, which includes a motor 50 for driving a compressor 32 and a heat source 140 that can provide thermal energy to a generator 118. In some embodiments, the heat source 140 supplies a heating fluid of sufficient temperature to the generator 118 to separate the absorbent from the working fluid of the absorption heat pump 108. For example, the heat source 140 can include exhaust gas from an internal combustion engine, exhaust gas from a reactor, exhaust gas from a gas turbine, waste steam from a boiler (another suitable heat source), or any combination thereof. In any case, the heat source 140 is configured to provide sufficient thermal energy to separate the absorbent from the working fluid in the generator 118.

[0035] Figure 7 1 is a block diagram of an embodiment of a process 150 for providing both heating and cooling to, for example, a building 12 using the system 100. As shown in block 152, the refrigerant of the vapor compression system 14 is placed in a heat exchange relationship with the intermediate fluid of the intermediate fluid loop 106 via the condenser 34. For example, thermal energy (e.g., heat) can be transferred from the refrigerant in the vapor compression system 14 to the intermediate fluid of the intermediate fluid loop 102 to condense the refrigerant in the condenser 34. As described above, the evaporator 38 of the vapor compression system 14 can be in thermal communication with the low-temperature heat source 102 (e.g., municipal treated sewage and / or water). Then, the combined system 100 having the vapor compression system 14 and the absorption heat pump 108 can use the low-temperature heat source 102 to increase the temperature of the heating fluid that is ultimately directed to the building 12. For example, in some embodiments, the temperature of the low-temperature heat source 102 can be between 5°C and 30°C, between 7°C and 15°C, or between 9°C and 13°C. Additionally, the temperature of the heating fluid directed to the building 12 may include a temperature between 75°C and 95°C, between 82°C and 93°C, or between 85°C and 90°C.

[0036] In any case, at box 154, the intermediate fluid of the intermediate fluid loop 102 can also be in heat exchange relationship with the working fluid of the absorption heat pump 108 via the absorption evaporator 110. The intermediate fluid can transfer thermal energy (e.g., heat) to the working fluid of the absorption heat pump 108, which can cause the working fluid to change from a liquid state to a vapor state (e.g., evaporator or vaporization). In this way, the vapor working fluid of the absorption heat pump 108 is directed through the absorber 116, pump 117 and generator 118 of the absorption heat pump 108, as shown in box 156. As described above, the vapor working fluid can be dissolved in the absorbent (e.g., water or lithium bromide) in the absorber 116, which can form a mixture with an elevated temperature (e.g., dissolving the working fluid in the absorbent increases the temperature of both the working fluid and the absorbent). Thus, the mixture may be directed via pump 117 to generator 118 where thermal energy (eg, heat) is applied to the mixture (eg, steam from steam turbine 104) to separate the working fluid from the absorbent and even further increase the temperature of the working fluid.

[0037] At box 158, the working fluid flows from the generator 118 to the absorption condenser 120, which can place the working fluid in heat exchange relationship with the heating fluid directed to the building 12. In some embodiments, the heating fluid entering the absorption condenser 120 can include a temperature between 50°C and 75°C, between 55°C and 70°C, or between 60°C and 65°C. As described above, the working fluid can increase the temperature of the heating fluid so that the temperature of the heating fluid introduced into the ducts and / or air handlers of the building 12 is between 80°C and 95°C, between 82°C and 93°C, or between 85°C and 90°C. In this way, the building 12 can receive a water flow that includes a temperature that is substantially higher than the temperature received from the low temperature heat source 102. Therefore, despite the absence of a cooling tower, the coefficient of performance ("COP") of the combined system 100 can be between 1 and 5, between 1.5 and 4, or between 2 and 3.

[0038] As described above, the present disclosure can provide one or more technical effects useful in HVAC&R systems. Embodiments of the present disclosure relate to a combined HVAC&R system including a vapor compression system and an absorption heat pump. The vapor compression system and the absorption heat pump can be thermally connected to each other via an intermediate fluid loop. In any case, a low-temperature heat source can provide thermal energy (e.g., heat) to the evaporator of the vapor compression system. The condenser of the vapor compression system can ultimately transfer the thermal energy to the absorption evaporator of the absorption heat pump (e.g., via an intermediate fluid loop). Then, the working fluid of the absorption heat pump is directed to the absorber, pump, and generator of the absorption heat pump, which can significantly increase the temperature of the working fluid. The high-temperature working fluid can transfer thermal energy (e.g., heat) to a heating fluid, which can be directed to a building or other suitable structure. Therefore, the combined HVAC&R system can have an improved coefficient of performance without including a separate cooling tower. The technical effects and technical problems in this specification are examples and not limiting. It should be noted that the embodiments described in this specification can have other technical effects and can solve other technical problems.

[0039] Although only certain features and embodiments are shown and described, many modifications and changes (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientations, etc.) may be conceived by those skilled in the art without substantially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequencing of any process or method steps may be changed or reordered according to alternative embodiments. Therefore, it should be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the present disclosure. In addition, in order to provide a brief description of the exemplary embodiments, all features of the actual implementation (i.e., those features that are not related to the best mode currently expected to implement the present disclosure or those features that are not related to the disclosure protected by the implementation) may not be described. It should be understood that in the development of any such actual implementation (such as in any engineering or design project), a large number of implementation-specific decisions must be made. Such development work may be complex and time-consuming, but for ordinary technicians who benefit from the present disclosure, this is still a routine design, production and manufacturing work without excessive experimentation.

Claims

1. A heating, ventilation, air conditioning and refrigeration (HVAC&R) system comprising: A vapor compression system, the vapor compression system comprising: a compressor configured to circulate a refrigerant through the vapor compression system; an evaporator configured to place the refrigerant in thermal communication with a first fluid from a low temperature heat source; and a condenser configured to place the refrigerant in thermal communication with an intermediate fluid loop; An absorption heat pump, the absorption heat pump comprising: an absorption evaporator configured to place a working fluid in thermal communication with the intermediate fluid loop; an absorber configured to mix the working fluid with an absorbent to form a mixture; a generator configured to heat the mixture and separate the working fluid from the absorbent; and an absorbent condenser configured to place the working fluid in thermal communication with a heating fluid; The intermediate fluid loop, wherein the intermediate fluid loop comprises a valve and a heat exchanger, and the valve is configured to: During operation of the absorption heat pump in a startup mode, directing an intermediate fluid along the intermediate fluid loop from the condenser to the heat exchanger and bypassing the absorption evaporator; and After the start-up mode of the absorption heat pump, once the absorption heat pump reaches a steady state, directing the intermediate fluid along the intermediate fluid loop from the condenser to the absorption evaporator; and The turbine is configured to receive a second fluid and use the second fluid to power the compressor, Wherein the generator is configured to receive the second fluid from the turbine and transfer heat from the second fluid to the mixture.

2. The heating, ventilation, air conditioning and refrigeration (HVAC&R) system of claim 1, wherein: The HVAC&R system does not include a cooling tower.

3. The heating, ventilation, air conditioning, and refrigeration (HVAC&R) system of claim 1, wherein: The evaporator is configured to receive sewage as the first fluid.

4. The heating, ventilation, air conditioning, and refrigeration (HVAC&R) system of claim 1, wherein: The HVAC&R system includes a coefficient of performance of 2.

5.

5. The heating, ventilation, air conditioning, and refrigeration (HVAC&R) system of claim 1, wherein: The working fluid comprises ammonia and the absorbent comprises water, or Wherein, the working fluid comprises water, and the absorbent comprises lithium bromide.

6. The heating, ventilation, air conditioning, and refrigeration (HVAC&R) system of claim 1, wherein: The absorption heat pump includes a pump disposed between the absorber and the generator.

7. The heating, ventilation, air conditioning, and refrigeration (HVAC&R) system of claim 1, wherein: The turbine is a steam turbine, the second fluid comprises steam, and the steam turbine is configured to receive the steam from an industrial facility.

8. The heating, ventilation, air conditioning and refrigeration (HVAC&R) system of claim 7, wherein: The generator is configured to condense the steam into liquid condensate by transferring heat to the mixture, and the generator is configured to direct the liquid condensate to the industrial facility.

9. A system comprising: A vapor compression system, the vapor compression system comprising: a compressor configured to circulate a refrigerant through the vapor compression system; an evaporator configured to place the refrigerant in thermal communication with a fluid received from a low temperature heat source; and a condenser configured to place the refrigerant in thermal communication with an intermediate fluid; A steam turbine. The steam turbine is configured to receive a steam flow, wherein the steam turbine is configured to power the compressor of the vapor compression system; An absorption heat pump, the absorption heat pump comprising: an absorption evaporator configured to place a working fluid in thermal communication with an intermediate fluid; an absorber configured to mix the working fluid in an absorbent to form a mixture; a generator configured to receive a steam flow from the steam turbine, wherein the generator is configured to transfer heat from the steam flow to the mixture to separate the working fluid from the absorbent and to condense the steam flow into a liquid condensate; and an absorbent condenser configured to place the working fluid in thermal communication with a heating fluid; and An intermediate fluid loop, the intermediate fluid loop comprising a valve, wherein the valve is configured to: In operation of a startup mode of the system, directing the intermediate fluid along the intermediate fluid loop from the condenser to a heat exchanger and bypassing the absorption evaporator; and After the startup mode of operation of the system, in steady state operation of the system, the intermediate fluid is directed from the condenser to an absorption evaporator.

10. The system of claim 9, wherein: The system does not include a cooling tower.

11. The system of claim 9, wherein: The system includes a coefficient of performance of 2.

5.

12. The system of claim 9, wherein: The working fluid comprises ammonia and the absorbent comprises water, or Wherein, the working fluid comprises water, and the absorbent comprises lithium bromide.

13. The system of claim 9, wherein: The evaporator is configured to receive wastewater from a municipal treatment facility as the fluid from the low temperature heat source.

14. The system of claim 9, wherein: The steam turbine is configured to receive a steam flow from an industrial facility, and the generator is configured to direct the liquid condensate to the industrial facility.

15. A method comprising: placing a refrigerant of a vapor compression system in a first heat exchange relationship with an intermediate fluid of an intermediate fluid loop, wherein the vapor compression system is in thermal communication with a low temperature heat source; placing the intermediate fluid of the intermediate fluid loop in a second heat exchange relationship with a working fluid of an absorption heat pump; directing the intermediate fluid through a valve to bypass the absorption heat pump in a startup mode of the absorption heat pump; circulating the working fluid of the absorption heat pump through an absorber, a pump, a heat exchanger, and a generator of the absorption heat pump to transfer thermal energy to the working fluid; placing the working fluid in a third heat exchange relationship with a heating fluid via the generator; directing the heating fluid from the generator to the heat exchanger, wherein the heat exchanger is located upstream of the generator relative to the flow of the working fluid through the absorption heat pump; and The working fluid is placed in a fourth heat exchange relationship with the heating fluid via the heat exchanger.

16. The method of claim 15, comprising receiving exhaust gas as a heating fluid through the generator.

17. The method of claim 15, comprising directing cryogenic fluid from the cryogenic heat source to an evaporator of the vapor compression system, wherein: The first temperature of the cryogenic fluid is between 9°C and 13°C.

18. The method of claim 17, comprising: placing the working fluid in a fifth heat exchange relationship with a water stream through an absorbent condenser of the absorption heat pump; as well as The water flow is directed to a building to provide heat to the building, wherein the second temperature of the water flow is between 75°C and 95°C.

19. A system, comprising any one or any combination of the technical features described in claims 1-8.

20. A system comprising any one or any combination of the technical features described in claims 9-14.

21. A method comprising any one or any combination of the technical features described in claims 15-18.

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