Freeze protection system for HVAC&r system

Abstract

A heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system (30) includes a chiller system having a first working fluid circuit (34) configured to circulate a first working fluid. The first working fluid circuit (34) includes a first compressor (36), a condenser (38), and an evaporator (42) configured to transfer heat from a conditioning fluid to the first working fluid, and the chiller system is configured to supply the conditioning fluid to a load (104). The HVAC&R system (30) also includes a second working fluid circuit (202) configured to circulate a second working fluid, where the second working fluid circuit (202) includes a second compressor (204) and a first heat exchanger (206) configured to establish a heat exchange relationship between the second working fluid and the conditioning fluid. The HVAC&R system (30) further includes a freeze protection circuit (108) configured to circulate the conditioning fluid between the evaporator (42) and the first heat exchanger (206) in a freeze protection mode of the HVAC&R system (30).

Description

XLR-23-8052-WO (JCCH1161PCT)FREEZE PROTECTION SYSTEM FOR HVAC&R SYSTEMCROSS-REFERENCE TO RELATED APPLICATIONS[00011 This application claims priority from and the benefit of U.S. Provisional Patent Application No. 63 / 719,530, entitled “FREEZE PROTECTION SYSTEM FOR HVAC&R SYSTEM,” filed November 12, 2024, which is hereby incorporated by reference in its entirety for all purposes.BACKGROUND[0002| This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure and are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be noted that these statements are to be read in this light, and not as admissions of prior art.

[0003] Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, such as chiller systems or vapor compression systems, utilize a working fluid (e.g., a refrigerant) that changes phases between vapor, liquid, and combinations thereof, in response to exposure to different temperatures and pressures within components of the HVAC&R system. The HVAC&R system may place the working fluid in a heat exchange relationship with a conditioning fluid and may deliver the conditioning fluid to conditioning equipment and / or an environment serviced by the HVAC&R system. In general, HVAC&R systems include a first heat exchanger configured to transfer heat from the conditioning fluid to the working fluid and thereby cool the conditioning fluid. The HVAC&R system may also include a second heat exchanger configured to condense the working fluid from gaseous or vapor phase to a liquid phase and / or a liquid / gas phase. In some cases, the second heat exchanger may place the working fluid in a heat exchange relationship with an ambient air flow to enable heat transfer from the working fluid to the ambient air flow. However, in some instances, an ambient temperature and / or a temperature of the ambient air flow may decrease to a level at which the HVAC&R system is vulnerable to performance, operational, and / or structural degradation. For example, at some ambient temperatures, the conditioning fluidXLR-23-8052-WO (JCCH:1161PCT)within the first heat exchanger may be susceptible to freezing, which may adversely impact the HVAC&R system.SUMMARY

[0004] A summary of certain embodiments disclosed herein is set forth below. It should be noted that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.[0005J In one embodiment, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes a chiller system having a first working fluid circuit, where the first working fluid circuit is configured to circulate a first working fluid. The first working fluid circuit includes a first compressor, a condenser, and an evaporator, where the evaporator is configured to transfer heat from a conditioning fluid to the first working fluid, and the chiller system is configured to supply the conditioning fluid to a load. The HVAC&R system also includes a second working fluid circuit configured to circulate a second working fluid, where the second working fluid circuit includes a second compressor and a first heat exchanger, and the first heat exchanger is configured to establish a heat exchange relationship between the second working fluid and the conditioning fluid. The HVAC&R system further includes a freeze protection circuit extending between the evaporator and the first heat exchanger, where the freeze protection circuit is configured to circulate the conditioning fluid between the evaporator and the first heat exchanger in a freeze protection mode of the HVAC&R system.

[0006] In an additional embodiment, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes a chiller system having a compressor, a condenser, an evaporator, and an additional heat exchanger disposed along a first working fluid circuit configured to circulate a first working fluid, where the evaporator is configured to transfer heat from the first working fluid to a conditioning fluid, and the condenser is configured to transfer heat from ambient air to the first working fluid. The HVAC&R system also includes a heat pump having a first heat exchanger and a second heat exchanger disposed along a second working fluid circuit configured to circulate a second working fluid, where the second heat exchanger is configured to transfer heat between the second working fluid and ambient air. The HVAC&RXLR-23-8052-WO (JCCH:1161PCT)system also includes a freeze protection circuit extending between the evaporator and the first heat exchanger, where the freeze protection circuit is configured to circulate the conditioning fluid between the evaporator and the first heat exchanger. The HVAC&R system also includes a supplemental cooling circuit extending between the additional heat exchanger and the first heat exchanger, where the supplemental cooling circuit is configured to circulate the conditioning fluid between the additional heat exchanger and the first heat exchanger.[0007[ In another embodiment, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes a chiller system including a first working fluid circuit, where the first working fluid circuit includes an evaporator, a condenser, and an additional heat exchanger disposed between the evaporator and the condenser and downstream of the condenser relative to flow of a first working fluid along the first working fluid circuit, and where the evaporator is configured to transfer heat from a conditioning fluid to the first working fluid. The HVAC&R system also includes a freeze protection system connected to the chiller system, where the freeze protection system is configured to receive the conditioning fluid from the evaporator, heat the conditioning fluid, and direct heated conditioning fluid to the evaporator, where the freeze protection system includes a second working fluid circuit configured to circulate a second working fluid, a first heat exchanger disposed along the second working fluid circuit, where the first heat exchanger is configured to transfer heat from the second working fluid to the conditioning fluid, and a second heat exchanger disposed along the second working fluid circuit, where the second heat exchanger is configured to transfer heat from ambient air to the second working fluid. The HVAC&R system further includes a controller configured to operate the freeze protection system to direct the conditioning fluid from the evaporator to the first heat exchanger and to direct the heated conditioning fluid from the first heat exchanger to the evaporator in response a determination that a temperature associated with the chiller system is below a threshold value.BRIEF DESCRIPTION OF THE DRAWINGS[OO(I8| Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:XLR-23-8052-WO (JCCH:1161PCT)

[0009] FIG. 1 is a perspective view of a building that may utilize an embodiment of a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system in a commercial setting, in accordance with an aspect of the present disclosure;

[0010] FIG. 2 is a schematic of an embodiment of an HVAC&R system, in accordance with an aspect of the present disclosure;

[0011] FIG. 3 is a schematic of an embodiment of an HVAC&R system including a chiller system, a freeze protection circuit, and a heat pump, in accordance with an aspect of the present disclosure;

[0012] FIG. 4 is a schematic of an embodiment of an HVAC&R system including a chiller system, a supplemental cooling circuit, and a heat pump, in accordance with an aspect of the present disclosure;

[0013] FIG. 5 is a schematic of an embodiment of an HVAC&R system including a chiller system, a freeze protection circuit, a supplemental cooling circuit, and a heat pump with a reversing valve in a first configuration, in accordance with an aspect of the present disclosure;

[0014] FIG. 6 is a schematic of an embodiment of an HVAC&R system including a chiller system, a freeze protection circuit, a supplemental cooling circuit, and a heat pump with a reversing valve in a second configuration, in accordance with an aspect of the present disclosure; and

[0015] FIG. 7 is a schematic of an embodiment of an HVAC&R system including a chiller system, a freeze protection circuit, and a heating system, in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION

[0016] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-XLR-23-8052-WO (JCCH1161PCT)related and business-related constraints, which may vary from one implementation to another. Moreover, it should be noted that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.[0017J When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be noted that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.[0018| Embodiments of the present disclosure are directed toward a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system having a chiller system and a freeze protection system configured to block, mitigate, or otherwise avert freezing of one or more fluids within the chiller system. The chiller system may include a working fluid circuit configured to circulate a working fluid, and the working fluid circuit may include one or more heat exchangers. For example, the chiller system may include a first heat exchanger (e.g., an evaporator) configured to establish a heat exchange relationship between the working fluid (e g., refrigerant) and a conditioning fluid, such as water. The first heat exchanger may be configured to transfer heat from the conditioning fluid to the working fluid to enable cooling of the conditioning fluid. The conditioning fluid may then be directed to other conditioning equipment of the HVAC&R system to provide cooling to an environment, conditioned space (e.g., a building), and / or a system or component (e.g., computer system, computer chip, data server). The working fluid circuit may also include a second heat exchanger (e.g., a condenser) configured to establish a heat exchange relationship between the working fluid and a cooling fluid to enable transfer of thermal energy from the working fluid to the cooling fluid. In some applications, the chiller system may include an air-cooled chiller configured to utilize ambient air as the cooling fluid to enable cooling (e.g., condensing) of the working fluid via the second heat exchanger.XLR-23-8052-WO (JCCH:1161PCT)

[0019] As will be appreciated, one or more components of an air-cooled chiller system may be installed in an outdoor location and may be exposed to an ambient environment. In some instances, a temperature of the ambient environment may fall to a level (e.g., threshold temperature) that may cause freezing of one or more fluids within the chiller system. For example, one or more fluids (eg., water) circulated through the chiller system may be particularly susceptible to freezing in some ambient conditions. In some instances, certain fluids within the chiller system may be more susceptible to freezing when the chiller system is not operating (e.g., not powered) and not circulating fluids therethrough. Accordingly, embodiments of the present disclosure are directed to a freeze protection system configured to block, mitigate, or otherwise avert freezing of one or more fluids within the chiller system. The freeze protection system may include a heat pump (e.g., air-source heat pump) and / or an additional heat exchanger (e.g., third heat exchanger, tankless fluid heater) incorporated and / or integrated with the working fluid circuit of the chiller system. The freeze protection system may be configured to heat a fluid within the chiller system. For example, the freeze protection system may operate to heat a fluid of the chiller system during instances in which the chiller system is not operating to actively circulate the fluid through the chiller system. In some implementations, the freeze protection system may be operated to heat a conditioning fluid (e.g., water) that is cooled by the chiller system during operation of the chiller system but not circulated through chiller system when the chiller system is not operating to supply the conditioning fluid to a conditioned space and / or other equipment. As such, the freeze protection system may heat conditioning fluid received from the chiller system, and the heated condition fluid may be directed through components of the chiller system to mitigate freezing of stagnant (e.g. static) conditioning fluid within the chiller system. In this way, present embodiments mitigate freezing of fluids of the chiller system, such as during instances in which an ambient temperature may otherwise cause one or more fluids within the chiller system to freeze.

[0020] Further, in some embodiments of the present disclosure, the freeze protection system be configured to operating in additional operating modes to enable improved operation of the chiller system. For example, the freeze protection system may be operated concurrently with the working fluid circuit of the chiller system to provide additional cooling (e.g., of the conditioning fluid, of the working fluid). The freeze protection system may include a heat pump and / or an additional heat exchanger (e.g., a brazed plate heat exchanger) fluidly coupled to the working fluidXLR-23-8052-WO (JCCH:1161PCT)circuit and configured to provide additional cooling of the working fluid circulated through the chiller system. For example, an additional heat exchanger of the freeze protection system (e.g., heat pump) may be disposed along the working fluid circuit of the chiller system, downstream (e.g., relative to flow of the working fluid along the working fluid circuit) of a heat exchanger (e g., condenser) of the chiller system that is configured to cool the working fluid. The working fluid cooled by the heat exchanger may be directed from the heat exchanger and through the additional heat exchanger, which is configured to place the working fluid in a heat exchange relationship with a separate fluid (e.g., conditioning fluid) that is cooled via operation of the heat pump. To this end, the heat pump may be operated in a cooling mode to enable cooling of the separate fluid to further cool (e.g., subcool, further subcool) the working fluid circulated through the working fluid circuit of the chiller system. The temperature of the working fluid exiting the additional heat exchanger may therefore by further reduced, which enables an increased cooling capacity of the chiller system. In this way, the freeze protection system may be configured to operate in a first mode to mitigate freezing of a fluid within the chiller system (e.g., when ambient temperatures are below a threshold level, during non-operation of the chiller system) and to operate in a second mode to increase a cooling capacity of the chiller system during operation of the chiller system (e.g., provide additional cooling of the working fluid, during periods of increased cooling demand, when ambient temperatures are above a threshold level).[00211 Turning now to the drawings, FIG. 1 is a perspective view of an embodiment of an application for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system. Such systems, in general, may be applied in a range of settings, both within the HVAC field and outside of that field. The HVAC systems may provide cooling to data centers, electrical devices, freezers, coolers, or other environments through vapor-compression refrigeration, absorption refrigeration, or thermoelectric cooling. In presently contemplated applications, HVAC&R systems may be used in residential, commercial, light industrial, industrial, and / or in any other application. In particular, the present techniques may be implemented with HVAC&R systems that generate and supply a chilled liquid, which may be used to cool a building and / or components within the building (e.g., electronic components, computer systems) and that reject heat to an ambient (e.g., outdoor) environment.XLR-23-8052-WO (JCCH1161PCT)

[0022] The illustrated embodiment includes an HVAC&R system configured to condition (e.g., cool) a building 10 and / or components within the building 10. The HVAC&R system includes a chiller system 12 (e.g., HVAC&R system, air-cooled chiller system) and a boiler 14. As shown, the chiller system 12 is disposed on the roof of the building 10, and the boiler 14 is located in a basement of the building 10; however, the chiller system 12 and the boiler 14 may be located in other equipment rooms or areas next to the building 10. The chiller system 12 may be an air-cooled or water-cooled system that implements a refrigeration cycle to cool water or other conditioning fluid. The chiller system 12 is housed within a structure that includes a working fluid circuit and associated equipment such as pumps, valves, and piping. For example, the chiller system 12 may be single package rooftop unit. The boiler 14 may be a closed vessel in which conditioning fluid is heated. The conditioning fluid from the chiller system 12 and / or the boiler 14 is circulated through the building 10 by conditioning fluid conduits 16. The conditioning fluid conduits 16 are routed to air handlers 18 located on individual floors and within sections of the building 10.[00231 The air handlers 18 are coupled to ductwork 20 that is adapted to distribute air between the air handlers 18 and may receive air from an outside air intake. The air handlers 18 include heat exchangers that circulate cold conditioning fluid from the chiller system 12 and hot conditioning fluid from the boiler 14 to provide heated or cooled air to conditioned spaces within the building 10. Fans within the air handlers 18 draw air through the heat exchangers and direct the conditioned air to environments within building 10, such as rooms, apartments, or offices, to maintain the environments at a designated temperature. A control device 22, shown in the illustrated embodiment as including a thermostat, may be used to designate the temperature of the conditioned air. The control device 22 also may be used to control the flow of air through and from the air handlers 18. Other devices may be included in the system, such as control valves that regulate the flow of fluids (e.g., water) and pressure and / or temperature transducers or switches that sense the temperatures and pressures of fluids, air, and so forth. Moreover, control devices 22 may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10.[0024| FIG. 2 is a schematic of an embodiment of an HVAC&R system 30, in accordance with the present techniques. For example, the HVAC&R system 30 may be an air-cooled chiller system.XLR-23-8052-WO (JCCH:1161PCT)However, it should be appreciated that the disclosed techniques may be incorporated with a variety of other types of HVAC&R systems, such as water-cooled chiller systems, heat pumps, another type of HVAC&R system, or any combination thereof.

[0025] The HVAC&R system 30 includes a working fluid circuit 34 (e.g., vapor compression system, chiller system, air-cooled chiller system) configured to circulate a working fluid, such as a refrigerant, therethrough with a compressor 36 (e.g., screw compressor) disposed along the working fluid circuit 34. The working fluid circuit 34 also includes a flash tank 32 (e.g., economizer), a condenser 38 (e.g., first heat exchanger), expansion valves or devices 40, and an evaporator 42 (e.g., second heat exchanger). The components of the working fluid circuit 34 enable heat transfer between the working fluid and other fluids (e.g., conditioning fluid, air, water, etc.) in order to provide cooling and / or heating to a load, such as an interior of the building 10, one or more components within the building 10 (e.g., electronic equipment, computer system), or another load.

[0026] Some examples of fluids that may be used as working fluids (e g., refrigerants) in the HVAC&R system 30 are hydrofluorocarbon (HFC) based working fluids, for example, R-410A, R-407, R-134a, hydrofluoro-olefin (HFO), “natural” working fluids like ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon based working fluids, water vapor, working fluids with low global warming potential (GWP), or any other suitable working fluid. Other possible working fluids that may be circulated through the working fluid circuit 34 include R-123, R-514A, R-1224yd, R-1233zd, R-134a, R-1234ze, R-1234yf, R-1311, and R-32. In some embodiments, the HVAC&R system 30 may be configured to efficiently utilize working fluids having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit or less) at one atmosphere of pressure, also referred to as low pressure working fluids, versus a medium pressure working fluid, such as R-134a. As used herein, “normal boiling point” may refer to a boiling point temperature measured at one atmosphere of pressure.[0027| The HVAC&R system 30 may further include a control panel 44 (e.g., controller, control system) that has an analog to digital (A / D) converter 46, a microprocessor 48 (e.g., processing circuitry), a non-volatile memory 50 (e.g., non-transitory, computer-readable medium), and / or an interface board 52. In some embodiments, the HVAC&R system 30 may use one orXLR-23-8052-WO (JCCH:1161PCT)more of a variable speed drive (VSDs) 54 and a motor 56. The motor 56 may drive the compressor 36 and may be powered by the VSD 54. The VSD 54 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 56. In other embodiments, the motor 56 may be powered directly from an AC or direct current (DC) power source. The motor 56 may include any type of electric motor that can be powered by the VSD 54 or directly from 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.

[0028] The compressor 36 compresses a working fluid vapor and may deliver the vapor to an oil separator 58 that separates oil from the working fluid vapor. The working fluid vapor is then directed toward the condenser 38, and the oil is returned to the compressor 36. The working fluid vapor delivered to the condenser 38 may transfer heat to a cooling fluid at the condenser 38. For example, the cooling fluid may be ambient air 60 forced across heat exchanger coils of the condenser 38 by condenser fans 62. The working fluid vapor may condense to a working fluid liquid in the condenser 38 as a result of thermal heat transfer with the cooling fluid (e.g., the ambient air 60).[002*91 The liquid working fluid exits the condenser 38 and then flows through a first expansion device 64 (e g., expansion device 40, electronic expansion valve). The first expansion device 64 may be a flash tank feed valve configured to control flow of the liquid working fluid to the flash tank 32. The first expansion device 64 is also configured to lower the pressure of (e.g., expand) the liquid working fluid received from the condenser 38. During the expansion process, a portion of the liquid may vaporize, and thus, the flash tank 32 may be used to separate the vapor from the liquid received from the first expansion device 64. Additionally, the flash tank 32 may provide for further expansion of the liquid working fluid due to a pressure drop experienced by the liquid working fluid when entering the flash tank 32 (e.g., due to a rapid increase in volume experienced when entering the flash tank 32).[O03O[ The vapor working fluid in the flash tank 32 may exit and flow to the compressor 36. For example, the vapor working fluid may be drawn to an intermediate stage or discharge stage of the compressor 36 (e.g., not the suction stage). A valve 66 (e.g., economizer valve, solenoid valve,XLR-23-8052-WO (JCCH1161PCT)expansion valve) may be included in the working fluid circuit 34 to control flow of the vapor working fluid from the flash tank 32 to the compressor 36. In some embodiments, when the valve 66 is open (e.g., fully open) additional liquid working fluid within the flash tank 32 may vaporize and provide additional subcooling of the liquid working fluid within the flash tank 32. The liquid working fluid that collects in the flash tank 32 may be at a lower enthalpy than the liquid working fluid exiting the condenser 38 due to the expansion caused via the first expansion device 64 and / or the flash tank 32. The liquid working fluid may flow from the flash tank 32, through a second expansion device 68 (e.g., expansion device 40, an orifice), and to the evaporator 42. In some embodiments, the working fluid circuit 34 may also include a valve 70 (e.g., drain valve) configured to regulate flow of liquid working fluid from the flash tank 32 to the evaporator 42. For example, the valve 70 may be controlled (e.g., via the control panel 44) based on an amount of suction superheat of the working fluid.|0031] The liquid working fluid delivered to the evaporator 42 may absorb heat from a conditioning fluid and / or another cooling fluid, which may or may not be the same cooling fluid used in the condenser 38. The liquid working fluid in the evaporator 42 may undergo a phase change to become vapor working fluid. For example, the evaporator 42 may include a tube bundle fluidly coupled to a supply line 72 and a return line 74 that are connected to a load (e.g., cooling load). The conditioning fluid of the evaporator 42 (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 42 via the return line 74 and exits the evaporator 42 the via supply line 72. The evaporator 42 may reduce the temperature of the conditioning fluid in the tube bundle via thermal heat transfer with the working fluid so that the conditioning fluid may be utilized to provide cooling for a conditioned environment. The tube bundle in the evaporator 42 can include a plurality of tubes and / or a plurality of tube bundles. In any case, the working fluid vapor exits the evaporator 42 and returns to the compressor 36 by a suction line to complete the vapor compression cycle.

[0032] FIG. 3 is a schematic of an embodiment of the HVAC&R system 30, in accordance with the present techniques. The HVAC&R system 30 includes an embodiment of the working fluid circuit 34 (e.g., chiller system, air-cooled chiller system) described above, as well as a freeze protection system 100 implemented with the working fluid circuit 34. The working fluid circuit 34 (e.g., chiller system) include certain elements and element numbers similar to those describedXLR-23-8052-WO (JCCH:1161PCT)above with reference to FIG. 2. For example, the HVAC&R system 30 may be an air-cooled chiller having the working fluid circuit 34 configured to transfer heat between a working fluid and the ambient air 60 via the condenser 38.

[0033] As shown in the illustrated embodiment of FIG. 3, the evaporator 42 includes a tube bundle 102 (e.g., plurality of tubes) that is fluidly coupled to the supply line 72 (e.g., load fluid supply conduit, building supply conduit, fluid supply conduit) and the return line 74 (e.g., load fluid return conduit, building return conduit, fluid return conduit), as similarly described above. The supply line 72 and the return line 74 are fluidly connected to a load 104 (e.g., building 10, electronic equipment). Accordingly, a conditioning fluid (e.g., water) may be circulated between the load 104 and the evaporator 42 to facilitate thermal management of the load 104, such as rooms and / or equipment disposed within the building 10. The conditioning fluid may be received by the evaporator 42 (e.g., via return line 74), the evaporator 42 may condition (e.g., cool) the conditioning fluid (e.g., via heat transfer with the working fluid in the evaporator 42), and the conditioning fluid may then be supplied to the load 104 (e.g., via supply line 72). The conditioning fluid may be any suitable fluid, such as water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid.

[0034] As the HVAC&R system 30 may be configured as an air-cooled chiller system, the HVAC&R system 30 and / or one or more components thereof may be positioned within an ambient environment 106. In some instances, conditions within the ambient environment 106 may render one or more fluids within the HVAC&R system 30 susceptible to freezing. For example, a temperature of the ambient environment 106 may fall to a level that may induce or cause freezing of one or more fluids of the HVAC&R system 30. In some applications, the conditioning fluid (e.g., water) within and / or circulated through the evaporator 42 (e.g., within the tube bundle 102) may be susceptible to freezing. Additionally or alternatively, the conditioning fluid within the tube bundle 102 may be susceptible to freezing during non-operation of the HVAC&R system 30 (e.g., the working fluid circuit 34), such as instances in which the compressor 36 is not operated to circulate working fluid through the working fluid circuit 34. Additionally or alternatively, the conditioning fluid and / or another fluid of the HVAC&R system 30 may be susceptible to freezing in other conditions or instances, such as during operation of the working fluid circuit 34, during periods in which the conditioning fluid is not circulated through the tube bundle 102 (e.g., to andXLR-23-8052-WO (JCCH:1161PCT)from the load 104), and / or instances in which the conditioning fluid remains stagnant within the tube bundle 102. The HVAC&R system 30 therefore includes the freeze protection system 100, in accordance the present techniques, to block, mitigate, and / or otherwise avert undesired freezing of one or more fluids of the HVAC&R system 30.[0035 j In the illustrated embodiment, the freeze protection system 100 includes a heat pump 200 (e.g., air source heat pump) incorporated with the HVAC&R system 30 (e.g., working fluid circuit 34). Specifically, the heat pump 200 is fluidly coupled to the evaporator 42 via a freeze protection circuit 108 (e.g., heating circuit, freeze mitigation circuit). As shown, the heat pump 200 may include a working fluid circuit 202 (e.g., second working fluid circuit, heat pump working fluid circuit) having a compressor 204 (e.g., second compressor), a first heat exchanger 206 (e.g., second condenser), a second heat exchanger 208 (e g., second evaporator), and an expansion device 210 (e.g., electronic expansion valve). The heat pump 200 may include additional and / or alternative components, in some embodiments. For example, the heat pump 200 may include a reversing valve configured to adjust a flow direction of working fluid through the working fluid circuit 202 to enable adjustment of an operating mode (e.g., heating mode, cooling mode) of the heat pump 200.

[0036] In accordance with the present techniques, the heat pump 200 is configured to heat a fluid (e.g., freeze protection fluid, conditioning fluid, water), and the freeze protection circuit 108 is configured to provide heating to one or more components of the working fluid circuit 34 (e.g., evaporator 42) to mitigate or block freezing of one or more fluids of the HVAC&R system 30. For example, the heat pump 200 may be configured to heat a flow of freeze protection fluid that may be supplied to one or more one or more components of the working fluid circuit 34, such as the evaporator 42. The first heat exchanger 206 (e.g., plate heat exchanger, shell and tube heat exchanger) of the heat pump 200 may be configured to place a flow of the freeze protection fluid directed through the freeze protection circuit 108 in a heat exchange relationship with the working fluid circulated through the working fluid circuit 202 of the heat pump 200. In a heating mode of the heat pump 200, as shown in the illustrated embodiment, the working fluid circuit 202 may direct heated working fluid vapor from the compressor 204 to the first heat exchanger 206, and the first heat exchanger 206 may cause transfer of heat from the working fluid to the flow of freeze protection fluid directed through the first heat exchanger 206 via the freeze protection circuit 108.XLR-23-8052-WO (JCCH1161PCT)Thereafter, the heated freeze protection fluid may be directed from the heat pump 200 to one or more components of the working fluid circuit 34 via the freeze protection circuit 108, as described in further detail below.

[0037] The heated freeze protection fluid may be directed to and / or through any suitable components of the working fluid circuit 34 to mitigate freezing of one or more fluids of the HVAC&R system 30. In some embodiments, the freeze protection fluid may be the same fluid as the conditioning fluid circulated between the evaporator 42 and the load 104. For example, the heated freeze protection fluid may be directed through the tube bundle 102 of the evaporator 42 to mitigate freezing of fluid within the tube bundle 102. While the freeze protection fluid circulated by the freeze protection system 100 may be conditioning fluid (e.g., a portion of conditioning fluid) circulated between the evaporator 42 and the load 104 (e g., water) during operation of the HVAC&R system 30 to provide cooling to the load 104, it may be desirable to avoid concurrent flows of freeze protection fluid (e.g., a first flow of conditioning fluid heated by, and received from, the heat pump 200) and conditioning fluid (e.g., a second flow of conditioning fluid received from the load 104) through the tube bundle 102 in order to enable desired operation of the HVAC&R system 30 to condition the load 104. Thus, during operation of the freeze protection system 100 to provide heating and / or freeze mitigation to the HVAC&R system 30, flow of conditioning fluid between evaporator 42 and the load 104 may be interrupted and / or suspended. To this end, the HVAC&R system 30 may include a conditioning fluid supply valve 114 (e.g., supply valve, load supply valve) disposed along the supply line 72 and a conditioning fluid return valve 116 (e.g., return valve, load return valve) disposed along the return line 74. The valves 114 and 116 may be controlled to regulate flow of conditioning fluid to and from the load 104. In some instances, the valves 114 and 116 may be closed during instances in which the working fluid circuit 34 is not operated to condition the conditioning fluid for supply to the load 104.[0038| It should be appreciated that, when the valves 114 and 116 are in respective closed positions, an amount of the conditioning fluid may nevertheless remain within the tube bundle 102 of the evaporator 42. Indeed, the conditioning fluid remaining within the tube bundle 102 may be stagnant and, in some circumstances, may be susceptible to freezing. Certain conditions of the ambient environment 106 may render conditioning fluid within the tube bundle 102 susceptible to freezing. For example, a temperature of the ambient environment 106 may fall to and / or below aXLR-23-8052-WO (JCCH:1161PCT)particular level or threshold that may induce and / or cause freezing of the conditioning fluid within the tube bundle 102. Additionally or alternatively, other parameters may be indicative of potential freezing of the conditioning fluid. It will be appreciated that freezing of conditioning fluid within the tube bundle 102 may adversely impact the tube bundle 102 and / or the evaporator 42 generally. In some instances, conditioning fluid within the tube bundle 102 may be susceptible to freezing during operation of the working fluid circuit 34. Accordingly, operation of the HVAC&R system 30 may be adjusted to enable freeze protection operations via the freeze protection system 100. For example, the valves 114 and 116 may be closed to block circulation of the conditioning fluid between the evaporator 42 and the load 104, and the freeze protection system 100 may be operated to circulate freeze protection fluid (e.g., heated water) to the evaporator 42 in the manner described below. In some implementations, the valves 114 and 116 may be closed (e.g., via a controller) prior to operation of the freeze protection system 100 (e.g., via a controller).|0039] To enable circulation of freeze protection fluid (e.g., heated conditioning fluid) through one or more components of the working fluid circuit 34, the freeze protection circuit 108 is fluidly coupled to one or more components of the working fluid circuit 34. In this way, the freeze protection system 100 is fluidly coupled to one or more components of the working fluid circuit 34, and freeze protection fluid generated by the freeze protection system 100 (e.g., heat pump 200) may be supplied to one or more components of the working fluid circuit 34 via the freeze protection circuit 108. For example, the freeze protection circuit 108 may be fluidly coupled to a conditioning fluid inlet 115 (e.g., fluid inlet) of the evaporator 42 and a conditioning fluid outlet 117 (e.g., fluid outlet) of the evaporator 42. In an embodiment, the conditioning fluid inlet 115 may also be fluidly coupled to the return line 74, and the conditioning fluid outlet 117 may be fluidly coupled to the supply line 72. As shown in the illustrated embodiment, the freeze protection circuit 108 may include a freeze protection fluid supply conduit 124 (e.g., first conduit) extending from the first heat exchanger 206 of the heat pump 200 to the return line 74 and / or to the conditioning fluid inlet 115 of the evaporator 42. Similarly, the freeze protection circuit 108 may include a freeze protection fluid return conduit 126 (e.g., second conduit) extending from the supply line 72 and / or the conditioning fluid outlet 117 of the evaporator 42 to the first heat exchanger 206. In some embodiments, the freeze protection fluid supply conduit 124 may be connected to the return line 74 at a location between the conditioning fluid inlet 115 and the conditioning fluid return valve 116, and the freeze protection fluid return conduit 126 may be connected to the supply line 72 at aXLR-23-8052-WO (JCCH1161PCT)location between the conditioning fluid outlet 117 and the conditioning fluid supply valve 114. As a result, the freeze protection system 100 (e.g., freeze protection circuit 108) may be implemented with the working fluid circuit 34 (e.g., chiller system) with reduced impact and / or modification to piping, conduits, and / or other system architecture of the load 104. In some instances, the arrangements and configurations of the freeze protection system 100 may be implemented as a retrofit kit with embodiments of the working fluid circuit 34 previously installed or implemented at a location of the load 104.

[0040] In some embodiments, the freeze protection fluid return conduit 126 may include a pump 110 configured to force or drive flow of the freeze protection fluid through the freeze protection circuit 108. In some embodiments, the pump 110 may be positioned along the freeze protection fluid supply conduit 124. In other embodiments, the pump 110 may not be included, and the heat pump 200 may be configured to force or drive flow the freeze protection fluid (e.g., via a generated pressure or head). The freeze protection fluid supply conduit 124 may include a supply valve 118, and freeze protection fluid return conduit 126 may include a return valve 120. The supply valve 118 and the return valve 120 are configured to regulate flow of the freeze protection fluid through the freeze protection circuit 108 (e.g., between the tube bundle 102 and the first heat exchanger 206 of the heat pump 200).

[0041] During a freeze protection operating mode of the HVAC&R system 30, the supply valve 118 and the return valve 120 may be adjusted toward respective open positions to enable flow of freeze protection fluid (e.g., water, heated water, heated conditioning fluid) through the freeze protection circuit 108. Additionally, as noted above, the valves 114 and 116 may be adjusted to respective closed positions. In this way, evaporator 42 (e.g., tube bundle 102) may be fluidly disconnected from the load 104 and may be fluidly connected to the freeze protection circuit 108 (e.g., heat pump 200, first heat exchanger 206). To enable adjustable operation of the HVAC&R system 30 (e.g., between the freeze protection operating mode and a regular and / or cooling operating mode), the HVAC&R system 30 may include a controller 150 (e.g., control panel 44, control system, control circuitry) that is communicatively coupled to one or more components of the HVAC&R system 30 (e.g., compressor 36, supply valve 118, return valve 120, conditioning fluid supply valve 114, conditioning fluid return valve 116, compressor 204, pump 110). The controller 150 is also configured to monitor, adjust, and / or otherwise control operationXLR-23-8052-WO (JCCH1161PCT)of the components of the HVAC&R system 30. For example, one or more control transfer devices, such as wires, cables, wireless communication devices, and the like, may communicatively couple the components of the HVAC&R system 30 (e.g., components of the working fluid circuit 34, components of the freeze protection system 100, components of the heat pump 200) to the controller 150. That is, one or more components of the working fluid circuit 34, one or more components of the freeze protection system 100, and / or one or more components of the heat pump 200 may each have one or more communication components that facilitate wired or wireless (e.g., via a network) communication with the controller 150. In some embodiments, the communication components may include a network interface that enables the components of the HVAC&R system 30 to communicate via various protocols such as EtherNet / IP, ControlNet, DeviceNet, or any other communication network protocol. Alternatively, the communication components may enable the components of the HVAC&R system 30 to communicate via mobile telecommunications technology, Bluetooth®, near-field communications technology, and the like. As such, one or more components of the working fluid circuit 34, one or more components of the freeze protection system 100, and / or one or more components of the heat pump 200 may wirelessly communicate data between each other. In other embodiments, operational control of certain components of the HVAC&R system 30 may be regulated by one or more relays or switches (e.g., a 24 volt alternating current [VAC] relay).[0042| In some embodiments, the controller 150 may be a component of or may include the control panel 44. In other embodiments, the controller 150 may be a standalone controller, a dedicated controller, or another suitable controller included in the HVAC&R system 30. In any case, the controller 150 is configured to control components of the HVAC&R system 30 in accordance with the techniques discussed herein. The controller 150 includes processing circuitry 152, such as a microprocessor, which may execute software (e.g., executable instructions, code) for controlling the components of the HVAC&R system 30. The processing circuitry 152 may include multiple microprocessors, one or more “general-purpose” microprocessors, one or more special-purpose microprocessors, and / or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the processing circuitry 152 may include one or more reduced instruction set (RISC) processors.XLR-23-8052-WO (JCCH:1161PCT)

[0043] The controller 150 also include a memory device 154 (eg., a memory, non-transitory, computer readable medium) that may store information, such as instructions, control software, look up tables, code, executable instructions, configuration data, etc. The memory device 154 may include a volatile memory, such as random access memory (RAM), and / or a nonvolatile memory, such as read-only memory (ROM). The memory device 154 may store a variety of information and may be used for various purposes. For example, the memory device 154 may store processorexecutable instructions including firmware or software for the processing circuitry 152 to execute, such as instructions for controlling components of the HVAC&R system 30. In some embodiments, the memory device 154 is a tangible, non-transitory, machine-readable-medium that may store machine-readable instructions for the processing circuitry 152 to execute. The memory device 154 may include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The memory device 154 may store data, instructions, and any other suitable data.[0044J Furthermore, the controller 150 may be configured to control operation of the freeze protection system 100 based on and / or in response to data and / or feedback received by the controller 150. For example, the controller 150 may be configured to enable operation of the freeze protection system 100 in response to feedback (e.g., data) received from one or more sensors 156 (e.g., communicatively coupled to the processing circuitry 152). The one or more sensors 156 may be incorporated with the controller 150 as components of a control system of the HVAC&R system 30. In some embodiments, the one or more sensors 156 may include a temperature sensor (e.g., ambient temperature sensor) configured to detect a temperature associated with operation of the HVAC&R system 30. For example, one of the sensors 156 may be configured to detect a temperature of the ambient environment 106. In response to feedback received from one of the sensors 156 indicative of the temperature of the ambient environment 106 falling to and / or below a threshold value (e.g., a freezing temperature of the conditioning fluid, a temperature above the freezing temperature of the condition fluid, a first threshold value), the controller 150 may adjust operation of the HVAC&R system 30. For example, the controller 150 may control one or more components of the HVAC&R system 30 to transition operation of the HVAC&R system 30 and / or the freeze protection system 100 to a freeze protection operating mode. However, it should be appreciated that operation of the HVAC&R system 30 in the freeze protection operating mode may be initiated in response to additional or alternative data, feedback, and / or input received byXLR-23-8052-WO (JCCH1161PCT)the controller 150, such as data indicative of a temperature of the conditioning fluid circulated through the evaporator 42, an indication of an operating mode of the HVAC&R system 30 (e.g., compressor 36), and / or other suitable input.

[0045] The controller 150 may be configured to transition the valves 114 and 116 toward respective closed positions to fluidly disconnect the evaporator 42 from the load 104 and to enable operation of the HVAC&R system 30 in the freeze protection mode. As will be appreciated, with the valves 114 and 116 in respective closed positions, circulation of conditioning fluid between the evaporator 42 and the load 104 may be blocked. In some embodiments, operation of the compressor 36 may be suspended (e.g., powered off) during operation of the HVAC&R system 30 in the freeze protection operating mode. However, as mentioned above, while the valves 114 and 116 may be adjusted to respective closed positions, an amount of conditioning fluid may nevertheless remain within the evaporator 42 (e.g., within the tube bundle 102) and may be susceptible to freezing in some conditions. To mitigate and / or avoid freezing of the conditioning fluid within the tube bundle 102, the freeze protection system 100 may be operated to provide heating to the evaporator 42 and / or the tube bundle 102. For example, the freeze protection system 100 may operate to circulate conditioning fluid from the tube bundle 102 to first heat exchanger 206 of the heat pump 200 via the freeze protection circuit 108. The heat pump 200 may operate to heat the conditioning fluid within the first heat exchanger 206, and the heated conditioning fluid may be directed back to the tube bundle 102, thereby increasing a temperature (e.g., of conditioning fluid) within the tube bundle 102 and avoiding freezing of fluid therein.[0046| During operation in the freeze protection operating mode, the supply valve 118 and the return valve 120 may be adjusted toward respective open positions to enable flow of freeze protection fluid through the freeze protection circuit 108 and therefore through the tube bundle 102. During operation in the freeze protection operating mode, the pump 110 of the freeze protection circuit 108 may also be operated (e.g., via the controller 150) to cause flow of the freeze protection fluid (e.g., conditioning fluid, water) through the freeze protection circuit 108. Furthermore, the compressor 204 of the heat pump 200 may be operated (e.g., via the controller 150) to enable heating of the freeze protection fluid within the first heat exchanger 206. The first heat exchanger 206 of the heat pump 200 may function as a condenser in the freeze protection operating mode and may transfer heat from a working fluid circulated through he working fluidXLR-23-8052-WO (JCCH1161PCT)circuit 202 of the heat pump 200 to the freeze protection fluid (e.g., water, conditioning fluid) to produce heated freeze protection fluid that may be directed through the tube bundle 102 of the evaporator 42 via the freeze protection circuit 108.

[0047] The second heat exchanger 208 of the heat pump 200 may operate as an evaporator in the freeze protection operating mode. For example, a fan 212 associated with the second heat exchanger 208 may be operated (e.g., via the controller 150) to force an air flow 214 (e.g., ambient airflow) across the second heat exchanger 208 to transfer heat from the air flow 214 to the working fluid within the second heat exchanger 208. The freeze protection fluid circulated through the tube bundle 102 may be returned to the first heat exchanger 206 via the freeze protection fluid return conduit 126 and may be reheated for supply to the tube bundle 102. As the heated freeze protection fluid is circulated through the tube bundle 102, a temperature within the tube bundle 102 may increase, which may mitigate freezing of fluid (e.g., conditioning fluid, freeze protection fluid, water) within the tube bundle 102.

[0048] Operation of the HVAC&R system 30 in the freeze protection operating mode may be suspended (e.g., via the controller 150) based on and / or in response to any suitable data, feedback, input, and / or other parameter. For example, in response to a determination that a temperature of the ambient environment 106 is above a threshold value (e.g., indicated by data and / or feedback received from one of the sensors 156, a second threshold value greater than a first threshold value associated with operation in the freeze protection mode), the controller 150 may suspend operation of the HVAC&R system 30 in the freeze protection operating mode. To suspend operation of the HVAC&R system 30 in the freeze protection operating mode, the controller 150 may adjust the supply valve 118 and the return valve 120 toward respective closed positions to block flow of the freeze protection fluid through the freeze protection circuit 108. With the supply valve 118 and the return valve 120 adjusted to respective closed positions, the tube bundle 102 may be fluidly disconnected from the freeze protection circuit 108 and the first heat exchanger 206 of the heat pump 200. The controller 150 may also suspend operation of the pump 110 to suspend operation of the HVAC&R system 30 in the freeze protection operating mode.

[0049] In some instances, after operation of the HVAC&R system 30 in the freeze protection operating mode is suspended, the controller 150 may adjust the valves 114 and 116 towardXLR-23-8052-WO (JCCH1161PCT)respective open positions to enable circulation of conditioning fluid between the evaporator 42 and the load 104. Additionally or alternatively, the controller 150 may adjust the valves 114 and 116 toward respective open positions to enable resumption of a normal operating mode (e.g., cooling operating mode) of the working fluid circuit 34 to provide cooling to the load 104. After operation of the HVAC&R system 30 in the freeze protection operating mode and after the supply valve 118 and the return valve 120 are closed, a portion of the freeze protection fluid may remain within the tube bundle 102. However, as the freeze protection fluid and the conditioning fluid may both be water, the freeze protection fluid remaining within the tube bundle 102 may be readily circulated between the evaporator 42 and the load 104 as the conditioning fluid during normal operation (e.g., cooling operating mode) of the HVAC&R system 30. In some instances, operation of the heat pump 200 (e.g., compressor 204) may also be suspended subsequent to operation of the HVAC&R system 30 in the freeze protection operating mode.|0050] FIG. 4 is a schematic of an embodiment of the HVAC&R system 30 including an embodiment of the heat pump 200 incorporated with the working fluid circuit 34 as a supplemental cooling system 298. The working fluid circuit 34 and the heat pump 200 include certain elements and element numbers similar to those described above with reference to FIG. 3. In the illustrated embodiment, the heat pump 200 is incorporated to provide additional cooling of the working fluid circulated through the working fluid circuit 34. To this end, the HVAC&R system 30 includes an additional heat exchanger 300 (e.g., supplemental cooling heat exchanger, subcooling heat exchanger) disposed along the working fluid circuit 34. In particular, the additional heat exchanger 300 is disposed along the working fluid circuit 34 downstream of the condenser 38 and upstream of the expansion device 40, relative to a flow direction of the working fluid along the working fluid circuit 34. In some embodiments, the additional heat exchanger 300 may be a brazed plate heat exchanger. The additional heat exchanger 300 is also fluidly coupled to the heat pump 200 via a supplemental cooling circuit 302. Specifically, the supplemental cooling circuit 302 extends from the additional heat exchanger 300 of the working fluid circuit 34 to the first heat exchanger 206 of the heat pump 200 and is configured to circulate a cooling fluid (e.g., water, supplemental cooling fluid, glycol) therethrough. In some embodiments, the cooling fluid may be the same fluid as the conditioning fluid and / or the freeze protection fluid described above.XLR-23-8052-WO (JCCH:1161PCT)

[0051] In the illustrated embodiment, the heat pump 200 is configured for operation in a cooling mode. Accordingly, the compressor 204 of the heat pump 200 operates to direct working fluid to the second heat exchanger 208, which operates as a condenser in the cooling mode. The first heat exchanger 206 operates as an evaporator in the cooling mode. The first heat exchanger 206 is configured to enable heat transfer between the working fluid of the heat pump 200 and the cooling fluid circulated through the supplemental cooling circuit 302. As the first heat exchanger 206 operates as an evaporator in the cooling mode of the heat pump 200, the first heat exchanger 206 is configured to transfer heat from the cooling fluid to the working fluid. Thus, the cooling fluid may be cooled via the first heat exchanger 206 during operation of the heat pump 200.[00521 The cooling fluid cooled via the first heat exchanger 206 may be supplied to the additional heat exchanger 300 of the working fluid circuit 34 to enable supplemental cooling of the working fluid within the working fluid circuit 34. To this end, the supplemental cooling circuit 302 includes a cooling fluid supply conduit 314 extending from the first heat exchanger 206 to the additional heat exchanger 300. The supplemental cooling circuit 302 also includes a cooling fluid return conduit 316 extending from the additional heat exchanger 300 to the first heat exchanger 206. Accordingly, the supplemental cooling circuit 302 may circulate cooling fluid between the first heat exchanger 206 and the additional heat exchanger 300. As will be appreciated, the additional heat exchanger 300 is configured to place the cooling fluid in a heat exchange relationship with the working fluid received from the condenser 38 of the working fluid circuit 34 to enable additional cooling of the working fluid. For example, operation of the supplemental cooling system 298 may enable subcooling or further subcooling of the working fluid before the working fluid is directed to the expansion device 40. In this way, a cooling capacity of the HVAC&R system 30 (e g., to satisfy a demand of the load 104) may be increased via operation of the supplemental cooling system 298. In some embodiments, operation of the supplemental cooling system 298 may be initiated based on certain operating parameters and / or conditions of the HVAC&R system 30, as described in further detail below.

[0053] The cooling fluid supply conduit 314 may include a pump 112 configured to drive flow of the cooling fluid through the supplemental cooling circuit 302. The pump 112 may be positioned along the cooling fluid return conduit 16 or the cooling fluid supply conduit 14. In some embodiments, and respective embodiment of the pump 112 may be disposed along theXLR-23-8052-WO (JCCH:1161PCT)cooling fluid return conduit 316 and the cooling fluid supply conduit 314. In other embodiments, the pump 112 may not be included, and the heat pump 200 may be configured to force or drive flow the cooling fluid, such as via a generated pressure or head. The cooling fluid supply conduit 314 may include a supply valve 318 (e.g., supplemental cooling fluid supply valve), and the cooling fluid return conduit 316 may include a return valve 320 (e.g., supplemental cooling fluid return valve). The supply valve 318 and the return valve 320 are configured to regulate flow of the cooling fluid along the supplemental cooling circuit 302 (e.g., between the first heat exchanger 206 and the additional heat exchanger 300). Control of the pump 112, the supply valve 318, and the return valve 320 may be regulated via the controller 150 to regulate flow of cooling fluid. For example, as similarly described above, the controller 150 may adjust operation of the pump 112, the supply valve 318, and / or the return valve 320 based on data, feedback (e.g., from one or more sensors 156), a user input, another suitable parameter, and / or any combination thereof.|0054] For example, the controller 150 may be configured to operate the HVAC&R system 30 in a supplemental cooling mode. During operation of the HVAC&R system 30 in the supplemental cooling mode, the working fluid circuit 34 (e.g., compressor 36) may be concurrently operated in a normal and / or cooling mode to enable cooling of the conditioning fluid via the evaporator 42. In the supplemental cooling mode, the controller 150 may operate the heat pump 200 in the cooling mode, operate the pump 112, and adjust the supply valve 318 and the return valve 320 toward respective open positions in response to a determination that a temperature of the ambient environment 106 is greater than a threshold value. As will be appreciated, at certain ambient temperatures (e.g., temperatures of the ambient environment 106 above a threshold value), the ambient air 60 may be insufficient to absorb a desired amount of heat from the working fluid within the condenser 38, and the working fluid within the condenser 38 may not be cooled and / or subcooled by a desired amount (e.g., an amount adequate to meet a demand of the load 104). Accordingly, the supplemental cooling system 298 may be operated concurrently with the working fluid circuit 34 (e.g., the compressor 36, in a normal operating mode, in a cooling mode, combined operation of the normal operating mode and supplemental cooling mode) to enable desired cooling and / or subcooling of the working fluid circulated through the working fluid circuit 34 and thereby enable desired cooling of the conditioning fluid supplied to the load 104.XLR-23-8052-WO (JCCH1161PCT)

[0055] Operation of the HVAC&R system 30 (e.g., heat pump 200) in the supplemental cooling mode may be initiated based on a determination that the working fluid circuit 34 (e.g., compressor 36) is operating to satisfy a demand of the load 104. In some embodiments, operation of the heat pump 200 in the supplemental cooling mode may be initiated and / or controlled (e.g., via the controller 150) based on other parameters, data, and / or feedback (e.g., received via one or more of the sensors 156). For example, operation of the heat pump 200 in the supplemental cooling mode may be initiated and / or controlled based on a demand (e.g., magnitude, amount, cooling demand) of the load 104, a temperature of conditioning fluid (e.g., received by the evaporator 42 via the return line 74, at the conditioning fluid inlet 115, at the conditioning fluid outlet 117), a temperature of the load 104, another suitable operating parameter, or any combination thereof. The additional cooling of the working fluid enabled via the supplemental cooling circuit 302 and the cooling fluid circulated therethrough may therefore enable more efficient and / or otherwise improved operation of the HVAC&R system 30 to satisfy a demand of the load 104.[0056J Operation of the HVAC&R system 30 in the supplemental cooling mode may be suspended based on any suitable data, feedback, input, and / or other parameter. For example, in response to a determination that a temperature of the ambient environment 106 is below a threshold value, operation of the HVAC&R system 30 in the supplemental cooling mode may be suspended. Additionally or alternatively, operation of the HVAC&R system 30 in the supplemental cooling mode based on a demand of the load 104 (e.g., satisfaction of a demand of the load 104), a temperature of conditioning fluid cooled via the evaporator 42, a temperature of the load 104, a temperature of the working fluid 34 (e.g., exiting the condenser 38), another suitable operating parameter, or any combination thereof. To suspend operation of the HVAC&R system 30 in the supplemental cooling mode, the controller 150 may suspend operation of the pump 112 and adjust the supply valve 318 and the return valve 320 toward respective closed positions to block flow of the cooling fluid through the supplemental cooling circuit 302. The controller 150 may also suspend operation of the heat pump 200 (e.g., compressor 204). During non-operation of the heat pump 200, working fluid may nevertheless flow through the additional heat exchanger 300 of the working fluid circuit 34. In other embodiments, flow of the working fluid may be directed to bypass the additional heat exchanger 300, such as via a bypass line 324 and one or more valves 326 (e.g., bypass valve, three-way valve) of the bypass line 324 and / or the working fluid circuit 34.XLR-23-8052-WO (JCCH:1161PCT)

[0057] In some embodiments, as mentioned above, the additional heat exchanger 300 may include a brazed plate heat exchanger. The additional heat exchanger 300 (e.g., brazed plate heat exchanger) may have a working fluid inlet 328, a working fluid outlet 330, a cooling fluid inlet 332, and a cooling fluid outlet 334. An embodiment of the additional heat exchanger 300 configured as a brazed plate heat exchanger may include a plurality of plates that are assembled to each other (e.g., in abutment with one another) to define cavities or flow paths (e.g., alternating flow paths) through the brazed plate heat exchanger. In some embodiments, the working fluid may enter the brazed plate heat exchanger and may be circulated through a first plurality alternating flow paths defined by the plurality of plates. Similarly, the cooling fluid may enter the brazed plate heat exchanger and may be circulated through a second plurality of alternating flow paths, separate from the first plurality of alternating flow paths. The first plurality of alternating flow paths and the second plurality of alternating flow paths may be fluidly separate from one another via the plurality of plates, and the plurality of plates may enable transfer of heat from the working fluid to the cooling fluid. In some embodiments, the working fluid inlet 328, the working fluid outlet 330, the cooling fluid inlet 332, and the cooling fluid outlet 334 may be arranged (e.g., as shown in the illustrated embodiment) to enable flow of the working fluid and the cooling fluid through the additional heat exchanger 300 in a counterflow heat transfer arrangement.[0058J Some embodiments of the supplemental cooling system 298 may include a heating system 336 (e.g., one or more heaters) disposed along the supplemental cooling circuit 298 to mitigate potential freezing of the cooling fluid (e.g., supplemental cooling fluid). In some embodiments, the heating system 336 may include one or more heat traces 338 (e.g., electric heat trace, heat tape, surface heater) applied to the cooling fluid supply conduit 314, the cooling fluid return conduit 316, or both. The heating system 336 may be controlled and / or operated via the controller 150. In some embodiments, the heating system 336 may be operated based on data and / or feedback (e.g., received from one or more sensors 156), such as a temperature of the cooling fluid circulated through the supplemental cooling circuit 302, a temperature of the ambient environment 106, another suitable parameter, or any combination thereof. In this way, freezing (e.g., of the cooling fluid) within the first heat exchanger 206, the additional heat exchanger 300, or both, may be avoided, thereby enabling more reliable operation of the supplemental cooling system 298.XLR-23-8052-WO (JCCH1161PCT)

[0059] FIGS. 5 and 6 are schematics of an embodiment of the HVAC&R system 30 including the working fluid circuit 34 and the heat pump 200 incorporated with the working fluid circuit 34, in accordance with techniques described herein. In particular, the heat pump 200 is incorporated with the working fluid circuit 34 to provide both the freeze protection system 100 and the supplemental cooling system 298 described above. The illustrated embodiments include certain elements and element numbers similar to those described above with reference to FIGS. 3 and 4. FIGS. 5 and 6 are discussed concurrently below.

[0060] The heat pump 200 may be operated in a heating mode to enable operation of the HVAC&R system 30 in the freeze protection operating mode, and the heat pump 200 may be operated in a cooling mode to enable operation of the HVAC&R system 30 in the supplemental cooling mode. To this end, the heat pump 200 includes a reversing valve 408 disposed along a working fluid circuit 406 of the heat pump 200. In the illustrated embodiment, the reversing valve 408 includes a first port 416 fluidly coupled to a suction conduit 424 (e.g., of the compressor 204), a second port 420 fluidly coupled to a discharge conduit 426 (e.g., of the compressor 204), a third port 418 fluidly coupled to a first conduit portion 428 of the working fluid circuit 406 extending to the first heat exchanger 206, and a fourth port 422 fluidly coupled to a second conduit portion 430 of the working fluid circuit 406 extending to the second heat exchanger 208.1’0061] The reversing valve 408 is configured to transition between a first configuration 432, as shown in FIG. 5, and a second configuration 434, as shown in FIG. 6. In the first configuration 432, the reversing valve 408 fluidly couples the first port 416 and the fourth port 422 and fluidly couples the second port 420 and the third port 418. In the second configuration 434, the reversing valve 408 fluidly couples the first port 416 and the third port 418 and fluidly couples the second port 420 and the fourth port 422. Accordingly, in the first configuration 432, the reversing valve 408 enables flow of working fluid (e.g., a second working fluid, different from the working fluid circulated through the working fluid circuit 34) from the second heat exchanger 208 to the compressor 204 and from the compressor 204 to the first heat exchanger 206. In this way, the reversing valve 408 in the first configuration 432 enables operation of the heat pump 200 in a heating mode, whereby the first heat exchanger 206 operates as a condenser and the second heat exchanger 208 operates as an evaporator. Operation of the heat pump 200 in the heating mode correspondingly enables operation of the HVAC&R system 30 (e.g., freeze protection system 100)XLR-23-8052-WO (JCCH:1161PCT)in the freeze protection operating mode described above. In particular, the first heat exchanger 206 operating as a condenser in the heating mode of the heat pump 200 may transfer heat from the working fluid of the working fluid circuit 406 to a freeze protection fluid (e.g., conditioning fluid, water) that is supplied to one or more components the working fluid circuit 34 (e.g., evaporator 42, tube bundle 102) via the freeze protection circuit 108, as described above.[00621 Conversely, in the second configuration 434, the reversing valve 408 enables flow of working fluid from the first heat exchanger 206 to the compressor 204 and from the compressor 204 to the second heat exchanger 208. In this way, the reversing valve 408 in the second configuration 434 enables operation of the heat pump 200 in a cooling mode, whereby the first heat exchanger 206 operates as an evaporator and the second heat exchanger 208 operates as a condenser. Operation of the heat pump 200 in the cooling mode correspondingly enables operation of the HVAC&R system 30 (e.g., supplemental cooling system 298) in the supplemental cooling operating mode described above. In particular, the first heat exchanger 206 operating as an evaporator in the cooling mode of the heat pump 200 may transfer heat from the working fluid of the working fluid circuit 406 to a cooling fluid (e.g., supplemental cooling fluid, water, glycol) that is supplied to one or more components the working fluid circuit 34 (e.g., additional heat exchanger 300, brazed plate heat exchanger, subcooling heat exchanger) via the supplemental cooling circuit 302, as described above.

[0063] As shown in the illustrated embodiments of FIGS. 5 and 6, the freeze protection circuit 108 and the supplemental cooling circuit 302 may be at least partially integrated with one another (e.g., coupled to one another, connected to one another) to provide a supplemental fluid circuit 440 (e.g., combined supplemental fluid circuit) of the HVAC&R system 30. The supplemental fluid circuit 440 may include a first valve 450 and a second valve 452 (e.g., switching valves, three-way valves, first supplemental fluid valve and second supplemental fluid valve) configured to adjust and / or control flow of fluid (e.g., freeze protection fluid, cooling fluid, water, glycol, conditioning fluid) through the freeze protection circuit 108 and / or the supplemental cooling circuit 302. As shown, the valves 450, 452 are fluidly connected to each of the freeze protection circuit 108 and / or the supplemental cooling circuit 302, and the valves 450, 452 may be actuated (e.g., actuate upon receipt of one or more control signals from the controller 150) to enable flow of fluid (e.g., a portion of the conditioning fluid, water) through one circuit (e.g., freeze protection circuit 108 orXLR-23-8052-WO (JCCH:1161PCT)supplemental cooling circuit 302) while simultaneously blocking flow of fluid in the other circuit (e.g., freeze protection circuit 108 or supplemental cooling circuit 302).[0064J For example, to enable operation of the HVAC&R system 30 in the freeze protection operating mode (e.g., to circulate freeze protection fluid, such as heated conditioning fluid and / or heated water, through the tube bundle 102 of the evaporator 42), the controller 150 may actuate the valves 450, 452 to respective first positions (e.g., freeze protection positions, heating positions) to fluidly couple the evaporator 42 (e.g., tube bundle 102) and the first heat exchanger 206 and enable fluid flow through the freeze protection circuit 108. In the respective first positions, the valves 450, 452 may also block fluid flow through the supplemental cooling circuit 302 (e.g., fluidly disconnect the first heat exchanger 206 from the additional heat exchanger 300). In particular, the first valve 450 may be adjusted (e.g., to the first position) to enable flow of fluid (e g., conditioning fluid, freeze protection fluid) from the evaporator 42 (e.g., tube bundle 102, conditioning fluid outlet 117) to the first heat exchanger 206 via the freeze protection fluid return conduit 126 and to block flow of fluid between the additional heat exchanger 300 and the first heat exchanger 206. Similarly, the second valve 452 may be adjusted (e.g., to the first position) to enable flow of fluid from the first heat exchanger 206 to the evaporator 42 (e.g., tube bundle 102, conditioning fluid inlet 115) via the freeze protection fluid supply conduit 124 and to block flow of fluid between the first heat exchanger 206 to the additional heat exchanger 300. The controller 150 may also control operation of other components to enable operation of the HVAC&R system 30 in the freeze protection operating mode. For example, the controller 150 may adjust the conditioning fluid supply valve 114 and the conditioning fluid return valve 116 to respective closed positions and / or adjust the supply valve 118 and the return valve 120 to respective open positions, as discussed in detail above. Additionally, the controller 150 may adjust the reversing valve 408 to the first configuration 432, initiate operation of the compressor 204, or both, to enable operation of the heat pump 200 in the heating mode. In this way, the HVAC&R system 30 may operate in the freeze protection operating mode, whereby the first heat exchanger 206 operates to transfer heat from the working fluid of the heat pump 200 to a freeze protection fluid (e.g., conditioning fluid, water) that may be supplied to the evaporator 42 (e.g., tube bundle 102, via the freeze protection circuit 108) to mitigate freezing of fluids within the HVAC&R system 30 (e.g., evaporator 42).XLR-23-8052-WO (JCCH1161PCT)

[0065] To enable operation of the HVAC&R system in the supplemental cooling mode (e.g., to circulate cooling fluid, such as cooled water, conditioning fluid, or glycol, through the additional heat exchanger 300), the controller 150 may actuate the valves 450, 452 to respective second positions (e.g., supplemental cooling positions, cooling positions) to fluidly couple the additional heat exchanger 300 and the first heat exchanger 206 and enable fluid flow through the supplemental cooling circuit 302. In the respective second positions, the valves 450, 452 may also block fluid flow through the freeze protection circuit 108 (e.g., fluidly disconnect the first heat exchanger 206 from the evaporator 42 and / or tube bundle 102). In particular, the first valve 450 may be adjusted (e.g., to the second position) to enable flow of fluid (e.g., conditioning fluid, cooling fluid, subcooling fluid, water, glycol) from the additional heat exchanger 300 to the first heat exchanger 206 via the cooling fluid return conduit 316 and to block flow of fluid between the evaporator 42 and the first heat exchanger 206. Similarly, the second valve 452 may be adjusted (e.g., to the second position) to enable flow of fluid from the first heat exchanger 206 to the additional heat exchanger 300 via the cooling fluid supply conduit 314 and to block flow of fluid between the first heat exchanger 206 to the evaporator 42. The controller 150 may also control operation of other components to enable operation of the HVAC&R system 30 in the supplemental cooling operating mode. For example, the controller 150 may adjust the reversing valve 408 to the second configuration 434, initiate operation of the compressor 204, or both, to enable operation of the heat pump 200 in the cooling mode. In some instances, the controller 150 may also adjust the conditioning fluid supply valve 114 and the conditioning fluid return valve 116 to respective open positions (e.g., to enable flow of conditioning fluid between the evaporator 42 and the load 104) and / or adjust the supply valve 118 and the return valve 120 to respective closed positions. In this way, the HVAC&R system 30 may operate in the supplemental cooling operating mode, whereby the first heat exchanger 206 may operate to transfer heat from a cooling fluid (e.g., conditioning fluid, water, glycol) to the working fluid of the heat pump 200, and the cooling fluid may be supplied to the additional heat exchanger 300 (e.g., via the supplemental cooling circuit 302) to provide supplemental cooling of the working fluid circulated through the working fluid circuit 34.[0066| As described above, the HVAC&R system 30 may operate in the freeze protection operating mode during instances in which operation of the working fluid circuit in a normal or conditioning (e.g., cooling) mode is suspended or idle (e.g., compressor 36 is not powered). OnXLR-23-8052-WO (JCCH:1161PCT)the other hand, the HVAC&R system 30 may operate in the supplemental cooling mode during instances in which the working fluid circuit 34 is operating in a normal or conditioning (e.g., cooling) mode (e.g., to satisfy a demand of the load 104). Control of components of the heat pump 200, the freeze protection system 100, and / or the supplemental cooling system 298 may be coordinated based on and / or in response to an operating status of one or more components of the working fluid circuit 34, data and / or feedback received from one or more of the sensors 156, a user input, another suitable parameter, or any combination thereof.

[0067] In further embodiments, a single embodiment of the heat pump 200 may be fluidly connected to multiple working fluid circuits 34 (e.g., multiple evaporators 42, multiple additional heat exchangers 300). That is, a single embodiment of the heat pump 200 may be implemented with multiple working fluid circuits 34 and may be configured to enable the freeze protection and supplemental cooling operating for each of the multiple working fluid circuits 34 (e.g., via corresponding freeze protection circuits 108 and supplemental cooling circuits 302). For example, in an embodiment of the HVAC&R system 30 having multiple working fluid circuits 34 with a single embodiment of the heat pump 200, one of the multiple working fluid circuits 34 may be operating to provide cooling to a corresponding load, while operation of another of the multiple working fluid circuits 34 may be suspended. In such a circumstance, the heat pump 200 may operate to provide a heated freeze protection fluid to the corresponding evaporator 42 of the working fluid circuit 34 that is not operating. Additionally or alternatively, the heat pump 200 may operate to provide a supplemental cooling fluid to the corresponding additional heat exchanger 300 of the working fluid circuit 34 that is operating.

[0068] FIG. 7 is a schematic of an embodiment of the HVAC&R system 30 including an embodiment of the freeze protection system 100, in accordance with the present techniques. The HVAC&R system 30 includes the working fluid circuit 34, and the freeze protection system 100 includes the freeze protection circuit 108. The working fluid circuit 34 and the freeze protection circuit 108 each include certain elements and element numbers similar to those described above with reference to FIG. 3. The freeze protection system 100 also includes a heating system 500 configured to heat a freeze protection fluid (e.g., conditioning fluid, water) to enable the freeze protection operations described herein. In the illustrated embodiment, the heating system 500XLR-23-8052-WO (JCCH1161PCT)includes a tankless water heater 502. The tankless water heater 502 may be configured to operate in and withstand conditions of the ambient environment 106.[0069J As shown, the tankless water heater 502 (e.g., tankless fluid heater) includes a housing 504 and a heat exchanger 506 disposed within the housing 504. The heat exchanger 506 may include one or more conduits, pipes, channels, flow paths, and / or passages configured to route a freeze protection fluid, such as conditioning fluid received from the tube bundle 102 of the evaporator 42, therethrough. The heat exchanger 506 also includes heating elements 508 configured to transfer heat to the freeze protection fluid directed through the heat exchanger 506. For example, the heating elements 508 may be disposed along a flow path of the freeze protection fluid through the heat exchanger 506 (e.g., internal to the heat exchanger 506). In other embodiments, the heating elements 508 may be coupled to the heat exchanger 506 in another suitable manner.

[0070] In accordance with the present techniques, the heating elements 508 are configured to convert electrical energy to thermal energy (e.g., heat) and to transfer the thermal energy to the freeze protection fluid. Accordingly, the heating elements 508 are configured to receive electrical energy (e.g., power, current) from a power source 510. The power source 510 may include a utility grid, a generator, a battery, a solar panel, another suitable electrical energy source, or any combination thereof. In some embodiments, the controller 150 may be configured to control operation of the tankless water heater 502 to provide a desired amount of heating to the freeze protection to mitigate freezing of fluids within the HVAC&R system 30. Additionally or alternatively, the tankless water heater 502 may include a dedicated controller configured to regulate operation of one or more components of the tankless water heater 502, in accordance with the present techniques. It should be appreciated that the tankless water heater 502 may be incorporated with embodiments of the freeze protection system 100 and in combination with any one or more of the components described herein.[00711 As set forth above, embodiments of the present disclosure may provide HVAC&R system configurations useful for enabling operation of a chiller system while also providing freeze protection operations and / or supplemental cooling operations for the chiller system. For example, a chiller system may be implemented with a heat pump system (e.g., air-source heat pump,XLR-23-8052-WO (JCCH:1161PCT)reversible heat pump) configured to generate and supply a heated freeze protection fluid to one or more components of the chiller system in order to mitigate freezing of fluids within the chiller system. Additionally or alternatively, the heat pump system may be configured to generate and supply a supplemental cooling fluid to the chiller system in order to enable supplemental cooling of a working fluid circulated through the chiller system. Indeed, implementation of the disclosed techniques with one or more of the systems, components, control schemes, and sequences described herein enable freeze protection of a chiller system, such as instances when ambient conditions may cause freezing of a fluid within the chiller system. Further, the disclosed techniques enable supply of additional cooling to the chiller system when additional cooling is demanded by a load and / or when operating conditions of the chiller system (e.g., high ambient temperatures) demand increased cooling. It should be understood that the technical effects and technical problems in the specification are examples and are not limiting. Indeed, it should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems.[0072 | While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, such as temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth, without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.

[0073] Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode, or those unrelated to enablement. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking ofXLR-23-8052-WO (JCCH1161PCT)design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0074] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function]...” or “step for [perform]ing [a function]...”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

Claims

XLR-23-8052-WO (JCCH1161PCT)CLAIMS:

1. A heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system, comprising:a chiller system comprising a first working fluid circuit, wherein the first working fluid circuit is configured to circulate a first working fluid, the first working fluid circuit comprises a first compressor, a condenser, and an evaporator, the evaporator is configured to transfer heat from a conditioning fluid to the first working fluid, and the chiller system is configured to supply the conditioning fluid to a load;a second working fluid circuit configured to circulate a second working fluid, wherein the second working fluid circuit comprises a second compressor and a first heat exchanger, and the first heat exchanger is configured to establish a heat exchange relationship between the second working fluid and the conditioning fluid; anda freeze protection circuit extending between the evaporator and the first heat exchanger, wherein the freeze protection circuit is configured to circulate the conditioning fluid between the evaporator and the first heat exchanger in a freeze protection mode of the HVAC&R system.

2. The HVAC&R system of claim 1, wherein:the first working fluid circuit comprises the condenser configured to transfer heat from the first working fluid to ambient air; andthe second working fluid circuit comprises a second heat exchanger configured to transfer heat between the second working fluid and ambient air.

3. The HVAC&R system of claim 1, wherein:the evaporator comprises a shell and a tube bundle disposed within the shell,the shell is configured to direct the first working fluid through the evaporator,the tube bundle is configured to direct the conditioning fluid through the evaporator, and the freeze protection circuit is configured to direct the conditioning fluid from a conditioning fluid outlet of the tube bundle to the first heat exchanger and from the first heat exchanger to a conditioning fluid inlet of the tube bundle.XLR-23-8052-WO (JCCH1161PCT)4. The HVAC&R system of claim 1, comprising a controller configured to regulate operation of the chiller system, the second working fluid circuit, or both, wherein the controller is configured to operate the HVAC&R system in the freeze protection mode during a suspended operation of the first compressor.

5. The HVAC&R system of claim 1, comprising a controller configured to regulate operation of the chiller system, the second working fluid circuit, or both, and the controller is configured to:receive, via a sensor, data indicative of a temperature associated with operation of the chiller system; andin response to a determination that the temperature is below a threshold temperature value, initiate operation of the HVAC&R system in the freeze protection mode.

6. The HVAC&R system of claim 5, wherein the temperature associated with operation of the chiller system is an ambient temperature or a temperature of the conditioning fluid.

7. The HVAC&R system of claim 1, comprising:a supply conduit extending from the evaporator and configured to direct the conditioning fluid from the evaporator toward the load;a supply valve disposed along the supply conduit;a return conduit extending from the evaporator and configured to direct the conditioning fluid into the evaporator;a return valve disposed along the return conduit; anda controller communicatively coupled to the supply valve and the return valve, wherein the controller is configured to transition the supply valve and the return valve to respective closed positions in the freeze protection mode of the HVAC&R system.

8. The HVAC&R system of claim 1, comprising a heat pump, wherein the heat pump comprises the second working fluid circuit, and the second working fluid circuit comprises a reversing valve configured to adjust a flow direction of the second working fluid along the second working fluid circuit.XLR-23-8052-WO (JCCH:1161PCT)9. The HVAC&R system of claim 8, wherein:the first working fluid circuit comprises an expansion valve and an additional heat exchanger disposed downstream of the condenser and upstream of the expansion valve, relative to a flow direction of the first working fluid along the first working fluid circuit, andthe HVAC&R system comprises a supplemental cooling circuit extending between the additional heat exchanger and the first heat exchanger, wherein the supplemental cooling circuit is configured to circulate a cooling fluid between the additional heat exchanger and the first heat exchanger in a supplemental cooling mode of the HVAC&R system.

10. The HVAC&R system of claim 9, comprising a controller communicatively coupled to the reversing valve, wherein the controller is configured to:adjust the reversing valve to a first configuration to enable operation of the HVAC&R system in the freeze protection mode, wherein the reversing valve is configured to direct the second working fluid from the second compressor to the first heat exchanger in the first configuration; andadjust the reversing valve to a second configuration to enable operation of the HVAC&R system in the supplemental cooling mode, wherein the reversing valve is configured to direct the second working fluid from the first heat exchanger to the second compressor in the second configuration.

11. The HVAC&R system of claim 9, wherein the freeze protection circuit and the supplemental cooling circuit are at least partially integrated with one another to define a supplemental fluid circuit, and the HVAC&R system comprises:a first switching valve disposed along the supplemental fluid circuit;a second switching valve disposed along the supplemental fluid circuit; anda controller communicatively coupled to the first switching valve and the second switching valve, wherein the controller is configured to:adjust the first switching valve and the second switching valve to respective first positions to enable operation of the HVAC&R system in the freeze protection mode, wherein the first switching valve and the second switching valve fluidly connect the evaporator and the firstXLR-23-8052-WO (JCCH:1161PCT)heat exchanger and fluidly disconnect the additional heat exchanger and the first heat exchanger in the respective first positions; andadjust the first switching valve and the second switching valve to respective second positions to enable operation of the HVAC&R system in the supplemental cooling mode, wherein the first switching valve and the second switching valve fluidly connect the additional heat exchanger and the first heat exchanger and fluidly disconnect the evaporator and the first heat exchanger in the respective second positions.

12. A heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system, comprising:a chiller system comprising a compressor, a condenser, an evaporator, and an additional heat exchanger disposed along a first working fluid circuit configured to circulate a first working fluid, wherein the evaporator is configured to transfer heat from the first working fluid to a conditioning fluid, and the condenser is configured to transfer heat from ambient air to the first working fluid;a heat pump comprising a first heat exchanger and a second heat exchanger disposed along a second working fluid circuit configured to circulate a second working fluid, wherein the second heat exchanger is configured to transfer heat between the second working fluid and ambient air;a freeze protection circuit extending between the evaporator and the first heat exchanger, wherein the freeze protection circuit is configured to circulate the conditioning fluid between the evaporator and the first heat exchanger; anda supplemental cooling circuit extending between the additional heat exchanger and the first heat exchanger, wherein the supplemental cooling circuit is configured to circulate the conditioning fluid between the additional heat exchanger and the first heat exchanger.

13. The HVAC&R system of claim 12, comprising a control system comprising a memory and processing circuitry, wherein the control system is configured to regulate operation of the chiller system, the heat pump, the freeze protection circuit, and the supplemental cooling circuit, wherein the control system is configured to selectively operate the HVAC&R system in a freeze protection mode and a supplemental cooling mode, and wherein:XLR-23-8052-WO (JCCH1161PCT)in the freeze protection mode, the control system is configured to suspend operation of the compressor and operate the HVAC&R system to circulate the conditioning fluid between the evaporator and the first heat exchanger and block circulation of the conditioning fluid between the additional heat exchanger and the first heat exchanger; andin the supplemental cooling mode, the control system is configured to operate the compressor to circulate the first working fluid through the first working fluid circuit and operate the HVAC&R system to circulate the conditioning fluid between the additional heat exchanger and the first heat exchanger and block circulation of the conditioning fluid between the evaporator and the first heat exchanger.

14. The HVAC&R system of claim 13, comprising a first switching valve and a second switching valve, wherein each of the first switching valve and the second switching valve is fluidly connected to the freeze protection circuit and the supplemental cooling circuit, and the control system is configured to:actuate the first switching valve and the second switching valve to fluidly connect the evaporator and the first heat exchanger and fluidly disconnect the additional heat exchanger and the first heat exchanger in the freeze protection mode; andactuate the first switching valve and the second switching valve to fluidly disconnect the evaporator and the first heat exchanger and fluidly connect the additional heat exchanger and the first heat exchanger in the supplemental cooling mode.

15. The HVAC&R system of claim 13, wherein the heat pump comprises a second compressor and a reversing valve disposed along the second working fluid circuit, wherein the control system is configured to:adjust the reversing valve to a first configuration to direct the second working fluid from the second compressor to the first heat exchanger in the freeze protection mode; andadjust the reversing valve to a second configuration to direct the second working fluid from the second compressor to the second heat exchanger in the supplemental cooling mode, wherein the first heat exchanger is configured to transfer heat from the second working fluid to the conditioning fluid in the freeze protection mode, and the first heat exchanger isXLR-23-8052-WO (JCCH:1161PCT)configured to transfer heat from the conditioning fluid to the second working fluid in the supplemental cooling mode.

16. The HVAC&R system of claim 13, wherein the control system comprises a sensor communicatively coupled to the processing circuitry, the sensor is configured to detect a temperature associated with the HVAC&R system, and the control system is configured to operate the HVAC&R system in the freeze protection mode, the supplemental cooling mode, or both, based on the temperature associated with the HVAC&R system received via the sensor.

17. The HVAC&R system of claim 16, wherein the temperature associated with the HVAC&R system is an ambient temperature, and the control system is configured to:operate the HVAC&R system in the freeze protection mode in response to a determination that the ambient temperature is below a first threshold value; andoperate the HVAC&R system in the supplemental cooling mode in response to a determination that the ambient temperature is above a second threshold value, greater than the first threshold value.

18. A heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system, comprising:a chiller system comprising a first working fluid circuit, wherein the first working fluid circuit comprises an evaporator, a condenser, and an additional heat exchanger disposed between the evaporator and the condenser and downstream of the condenser relative to flow of a first working fluid along the first working fluid circuit, and wherein the evaporator is configured to transfer heat from a conditioning fluid to the first working fluid;a freeze protection system connected to the chiller system, wherein the freeze protection system is configured to receive the conditioning fluid from the evaporator, heat the conditioning fluid, and direct heated conditioning fluid to the evaporator, wherein the freeze protection system comprises:a second working fluid circuit configured to circulate a second working fluid;XLR-23-8052-WO (JCCH1161PCT)a first heat exchanger disposed along the second working fluid circuit, wherein the first heat exchanger is configured to transfer heat from the second working fluid to the conditioning fluid; anda second heat exchanger disposed along the second working fluid circuit, wherein the second heat exchanger is configured to transfer heat from ambient air to the second working fluid; anda controller configured to operate the freeze protection system to direct the conditioning fluid from the evaporator to the first heat exchanger and to direct the heated conditioning fluid from the first heat exchanger to the evaporator in response a determination that a temperature associated with the chiller system is below a threshold value.

19. The HVAC&R system of claim 18, comprising:a fluid supply conduit extending from the evaporator and configured to direct the conditioning fluid from the evaporator to a load of the HVAC&R system, wherein the fluid supply conduit comprises a load supply valve configured to control flow of the conditioning fluid from the evaporator to the load; anda fluid return conduit extending from the evaporator and configured to direct the conditioning fluid from the load of the HVAC&R system to the evaporator, wherein the fluid return conduit comprises a load return valve configured to control flow of the conditioning fluid from the load to the evaporator,wherein the controller is communicatively coupled to the load supply valve and the load return valve, and the controller is configured to adjust the load supply valve and the load return valve to respective closed positions prior to operation of the freeze protection system.

20. The HVAC&R system of claim 19, wherein the freeze protection system comprises a freeze protection circuit extending between the evaporator and the first heat exchanger, and the freeze protection circuit comprises:a freeze protection fluid return conduit configured to direct the conditioning fluid from the evaporator to the first heat exchanger, wherein the freeze protection fluid return conduit extends from the fluid supply conduit at a first location between the load supply valve and a conditioning fluid outlet of the evaporator; andXLR-23-8052-WO (JCCH:1161PCT)a freeze protection fluid supply conduit configured to direct the heated conditioning fluid from the first heat exchanger to the evaporator, wherein the freeze protection fluid supply conduit extends from the fluid return conduit at a second location between the load return valve and a conditioning fluid inlet of the evaporator.

Images