System and method for controlling operation of hvacr system

Abstract

Disclosed is a heating, ventilation, air conditioning and cooling (HVACamp; a system (10, R) includes a working fluid circuit configured to circulate a working fluid through the working fluid circuit, and a compressor disposed along the working fluid circuit and configured to pressurize the working fluid. The compressor includes a housing having an impeller cavity configured to direct the working fluid through the impeller cavity and a first flow path fluidly coupled to the impeller cavity and an ambient environment surrounding the compressor. The HVACamp; the R system also includes a control system configured to: operate the compressor in a standby mode wherein there is no presence of the HVACamp in the standby mode; the HVACamp is operated in a standby mode, R is the need for regulation of the system, and in the standby mode, the HVACamp is operated; r system to increase the pressure of the working fluid to meet or exceed a threshold pressure value.

Description

[0001] describe Cross-reference to related applications This application claims priority and benefit to U.S. Provisional Patent Application No. 63 / 531,513, filed August 8, 2023, entitled “SYSTEMS AND METHODS FORCONTROLLING OPERATION OF AN HVAC&R SYSTEM”, which is incorporated herein by reference in its entirety for all purposes. Background Technology

[0002] This section is intended to introduce the reader to various aspects of the technology that may be associated with the aspects of this disclosure described below. It is believed that this discussion will help provide the reader with background information to facilitate a better understanding of the aspects of this invention disclosure. Therefore, it should be understood that these statements should be read in this light, and not as an endorsement of prior art.

[0003] Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems or vapor compression systems (e.g., heat pump systems) utilize a working fluid (e.g., a refrigerant) that changes the phase between vapor, liquid, and combinations thereof in response to varying temperatures and pressures within components exposed to the HVAC&R system. HVAC&R systems can allow the working fluid to exchange heat with a conditioning fluid (e.g., water) and can deliver the conditioning fluid to conditioned equipment and / or conditioned environments served by the HVAC&R system. Furthermore, the conditioning fluid can be directed through downstream devices, such as air handlers, to regulate other fluids, such as air within a building.

[0004] Generally, HVAC&R systems, or vapor compression systems, may include compressors configured to circulate working fluid through the system. The compressor may be operated by an electric motor. In many applications, the compressor motor is cooled by a cooling system. For example, cooling fluid may be directed through the motor to dissipate the heat generated by the motor during compressor operation. Unfortunately, existing cooling systems for compressor motors can be susceptible to various inefficiencies, which can lead to inefficient operation of the HVAC&R system. Summary of the Invention

[0005] The following provides an overview of certain embodiments disclosed herein. It should be understood that these aspects are presented merely to provide the reader with a brief overview of these particular embodiments, and are not intended to limit the scope of this disclosure. In fact, this disclosure may cover various aspects that may not be set forth below.

[0006] In one embodiment, a heating, ventilation, air conditioning, and cooling (HVAC&R) system includes: a working fluid circuit configured to circulate working fluid through the working fluid circuit; and a compressor disposed along the working fluid circuit and configured to pressurize the working fluid. The compressor includes a housing having an impeller chamber and a first flow path, the impeller chamber being configured to guide the working fluid through the impeller chamber, the first flow path being fluidly coupled to the impeller chamber and the surrounding environment surrounding the compressor. The HVAC&R system also includes a control system configured to: operate the compressor in a standby mode, wherein there is no need for regulation by the HVAC&R system in the standby mode, and in the standby mode, operate the HVAC&R system to increase the pressure of the working fluid to meet or exceed a threshold pressure value.

[0007] In another embodiment, the heating, ventilation, air conditioning, and cooling (HVAC&R) system includes: a compressor having an impeller chamber and an impeller disposed within the impeller chamber, wherein the compressor is configured to pressurize a working fluid within the impeller chamber; and a motor coupled to the compressor, wherein the motor is configured to drive rotation of the impeller to pressurize the working fluid, and the motor includes a motor chamber configured to circulate cooling fluid through which. The HVAC&R system also includes a first flow path extending between the impeller chamber and the surrounding environment of the HVAC&R system, and a second flow path extending between the motor chamber and the surrounding environment of the HVAC&R system. The HVAC&R system further includes a control system configured to: operate the HVAC&R system in a normal operating mode in response to heating or cooling needs, and operate the HVAC&R system in a standby mode when there is no heating or cooling need, wherein the control system is configured to operate the HVAC&R system in standby mode to increase the pressure of the working fluid.

[0008] In another embodiment, the control system of the heating, ventilation, air conditioning, and cooling (HVAC&R) system is configured to: determine that there is no heating or cooling demand for the HVAC&R system; operate the HVAC&R system in standby mode based on the determination that there is no heating or cooling demand for the HVAC&R system; receive data indicating the detected parameter value of the working fluid of the HVAC&R system in standby mode; determine that the detected parameter value in standby mode is below a threshold, wherein the threshold is based on the pressure of the surrounding environment of the HVAC&R system; and operate the HVAC&R system in standby mode to increase the detected parameter value of the working fluid in response to determining that the detected parameter value is below the threshold. Attached Figure Description

[0009] A better understanding of the various aspects of this disclosure can be achieved by reading the following detailed description and referring to the figures, in which: Figure 1 This is a perspective view of an embodiment of a building in a commercial environment that can utilize heating, ventilation, air conditioning and / or cooling (HVAC&R) systems, according to one aspect of this disclosure; Figure 2 This is a perspective view of an embodiment of a vapor compression system according to one aspect of the present disclosure; Figure 3 This is a schematic diagram of an embodiment of a vapor compression system according to one aspect of the present disclosure; Figure 4 This is a schematic diagram of an embodiment of a vapor compression system according to one aspect of the present disclosure; Figure 5 This is a cross-sectional side view as part of an embodiment of a compressor in an HVAC&R system according to one aspect of this disclosure; Figure 6 This is a cross-sectional side view of an embodiment of the sealing system of a compressor in an HVAC&R system according to one aspect of this disclosure; Figure 7 This is a schematic diagram of an embodiment of an HVAC&R system including a heat pump system and a heating system according to one aspect of this disclosure; and Figure 8 This is a flowchart of an embodiment of a method for standby operation of an HVAC&R system according to one aspect of this disclosure. Detailed Implementation

[0010] One or more specific embodiments of this disclosure will be described below. These described embodiments are examples of the technology currently disclosed. Additionally, in the process of providing a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints that may vary between implementations. Furthermore, it should be understood that such development work may be complex and time-consuming, but is merely a routine task of design, manufacture, and production for those skilled in the art who benefit from this disclosure.

[0011] When describing elements of various embodiments of this disclosure, the articles “a” and “the” are intended to mean the presence of one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that additional elements may be present in addition to those listed. Furthermore, it should be understood that references to “one embodiment” or “embodiment” in this disclosure are not intended to exclude the existence of additional embodiments further incorporated into the described features.

[0012] As briefly discussed above, heating, ventilation, air conditioning, and / or cooling (HVAC&R) systems can be used to thermally condition spaces within buildings, residences, or other suitable structures. For example, an HVAC&R system may include a vapor compression system (e.g., a cooler system, a vapor compression loop, a heat pump system) that transfers heat between a working fluid (e.g., a refrigerant, a heat transfer fluid, water) and a fluid to be conditioned (e.g., air, water, brine). The vapor compression system may include a condenser (e.g., a first heat exchanger) and an evaporator (e.g., a second heat exchanger) fluidly connected to each other via one or more conduits (e.g., a vapor compression loop, a working fluid loop, a refrigerant loop). A compressor may be included in the vapor compression system to pressurize the working fluid and circulate it through one or more conduits of the vapor compression system, thus enabling the transfer of heat between the working fluid and the fluid to be conditioned, such as via the condenser and / or evaporator.

[0013] Compressors (e.g., centrifugal compressors, direct-drive compressors, open-type compressors, open-design compressors, non-hermetic compressors) can be designed for certain operating conditions, which may depend on one or more characteristics or parameters of the working fluid (e.g., refrigerant, water). For example, compressor operation (e.g., operating parameters, operating speed, rotational speed, target speed, threshold speed) can be determined, utilized, and / or selected based on such characteristics or parameters of the working fluid (e.g., refrigerant, water). Compressors can be designed and / or selected for implementation in HVAC&R systems based on working fluid flow rate, working fluid temperature and / or pressure, cooling and / or heating loads of the HVAC&R system, conditions during compressor operation (such as conditions at the compressor inlet and / or outlet), or any combination thereof. In some applications, HVAC&R systems can be configured to utilize water as the working fluid. In particular, HVAC&R systems may include compressors configured to circulate water through the working fluid loops and components of the HVAC&R system.

[0014] As described above, the operation of the compressor can be driven by the compressor's motor. The compressor and / or HVAC&R system may include a cooling system designed to dissipate the heat generated by the motor during compressor operation. In some applications, a cooling fluid (such as water, air, or other fluid) may circulate through the motor housing to provide cooling. The cooling fluid may absorb the heat generated by the motor to remove heat from the motor. For example, air may be circulated and / or ventilated through the compressor's motor (e.g., the motor housing) and may be discharged into the environment surrounding the compressor.

[0015] According to this technology, a compressor may include a sealing system (e.g., a labyrinth seal system, a discharge system) configured to separate the working fluid circulated by the compressor through a vapor compression system from the cooling fluid circulated by the compressor's motor. In some embodiments, the sealing system may also enable the discharge (e.g., venting) of the working fluid (e.g., water, steam) from the compressor and the discharge (e.g., venting) of the cooling fluid from the compressor's motor. For example, the sealing system may enable the simultaneous discharge of the working fluid from the compressor's impeller chamber (e.g., the working fluid portion) and the discharge of the cooling fluid from the motor chamber (e.g., the cooling fluid portion).

[0016] As will be understood, compressor operation can be adjusted based on various heating and / or cooling requirements of the HVAC&R system. For example, the operating capacity of the HVAC&R system can be reduced, and the operating speed of the compressor can therefore be reduced. In some cases, compressor operation can be suspended, such as when the heating and / or cooling requirements of the HVAC&R system are met and / or do not exist (e.g., nonexistent). As described herein, an operating phase or mode of the HVAC&R system in which the HVAC&R system (e.g., the compressor) is not operated to meet the load (e.g., heating requirements, cooling requirements) of the HVAC&R system can be referred to as a standby mode. In such operating phases, when compressor operation is reduced or suspended, the saturation temperature of the working fluid (e.g., impeller chamber, working fluid section) within the compressor may decrease. For example, in an HVAC&R system using water as the working fluid, the saturation temperature of the water may decrease due to, for example, heat loss (e.g., below 100°C). As a result, the pressure within the compressor (e.g., impeller chamber, working fluid pressure) may decrease (e.g., below 1 bar, below 1.1 bar). When the pressure of the working fluid within the compressor impeller chamber and / or vapor compression system decreases, cooling fluid within the compressor motor (e.g., motor chamber, motor housing) can migrate toward the impeller chamber (e.g., across the sealing system). For example, a pressure difference between the impeller chamber and the motor chamber may cause cooling fluid (e.g., air, non-condensable air) within the motor chamber to flow from the motor chamber to the compressor impeller chamber. In some cases, the pressure of the working fluid within the impeller chamber may additionally or alternatively be lower than the pressure of the environment surrounding the compressor (e.g., atmospheric pressure), which can similarly cause atmospheric or ambient air (e.g., non-condensable air) to migrate into the compressor impeller chamber. Introducing cooling fluid and / or ambient air into the compressor impeller chamber can lead to inefficiencies in the HVAC&R system. For example, non-condensable air introduced into the impeller chamber (such as during compressor reduction, suspension, or inactivity) should be purged before the compressor resumes and / or increases operation. Purging non-condensable air from the compressor impeller chamber may delay the compressor startup process. Therefore, there is a need for improved HVAC&R systems that enable more efficient operation control of the compressor (e.g., reduction or suspension operation control, standby mode control, start-up process control), such as during and / or after reducing and / or suspending compressor operation.

[0017] Therefore, this embodiment relates to an HVAC&R system configured to reduce, mitigate, and / or prevent the migration of cooling fluid and / or ambient air (e.g., air, non-condensable air, motor cooling fluid) from the compressor motor (e.g., motor cavity, cooling fluid section) to the compressor's working fluid section (e.g., impeller cavity). According to this technology, the HVAC&R system is also configured to reduce, mitigate, and / or prevent the migration of working fluid from the compressor's working fluid section to the compressor motor. For example, this embodiment includes systems and methods for operating the HVAC&R system and / or the compressor of the HVAC&R system to prevent undesired migration of working fluid, cooling fluid, ambient air, or any combination thereof within the compressor and / or across components of the compressor. In some embodiments, the HVAC&R system (e.g., the compressor) is configured to operate in a standby mode to be able to heat the working fluid within the compressor. The HVAC&R system can operate in standby mode when it is not operating to meet loads or demands on the HVAC&R system. In some embodiments, operation in standby mode may include operating the compressor at a relatively low speed to increase and / or maintain the pressure of the working fluid within the compressor (e.g., the impeller chamber). In some embodiments, the compressor may be a multi-stage compressor comprising multiple stages (e.g., compressor stages, stages arranged in series), and therefore operation in standby mode may include operating and / or maintaining the operation of a reduced number of compressor stages to increase and / or maintain the pressure of the working fluid within the compressor. Thus, operating the compressor in standby mode may include a smaller number of operating compressor stages (e.g., one, two), such as operating a single compressor stage, compared to multiple operating compressor stages (e.g., two, three, four) operating during normal operation of the compressor (e.g., to meet the load on the HVAC&R system). In additional or alternative embodiments, the HVAC&R system may include a heating system configured to heat the working fluid during compressor inactivity and / or during the compressor's standby mode. In this way, the pressure of the working fluid can be maintained at a level equal to or greater than the pressure of the cooling fluid within the compressor's motor (e.g., atmospheric pressure) and / or ambient air pressure. This prevents fluid migration (e.g., air, ambient air, cooling fluid, motor cooling fluid, non-condensable air) into the compressor (e.g., the impeller chamber). Therefore, the frequency of purging operations to remove such fluids from the compressor's impeller chamber, such as before starting the compressor to meet the needs of the HVAC&R system, can be reduced, allowing the HVAC&R system to operate more efficiently.

[0018] Now turning diagram, Figure 1This is a perspective view of an embodiment of a heating, ventilation, air conditioning, and cooling (HVAC&R) system 10 in a typical commercial building 12. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a heat pump system) that supplies chilled liquid for cooling the building 12. The HVAC&R system 10 may also include a boiler 16 for supplying warm liquid to heat the building 12 and an air distribution system for circulating air through the building 12. The air distribution system may also include an air return duct 18, an air supply duct 20, and / or an air handler 22. In some embodiments, the air handler 22 may include a heat exchanger connected to the boiler 16 and the vapor compression system 14 via a conduit 24. Depending on the operating mode of the HVAC&R system 10, the heat exchanger in the air handler 22 may receive heated liquid from the boiler 16 or chilled liquid from the vapor compression system 14. HVAC&R system 10 is shown as having a separate air processor on each floor of building 12, but in other embodiments, HVAC&R system 10 may include air processor 22 and / or other components that may be shared between floors.

[0019] Figure 2 and Figure 3 An embodiment of a vapor compression system 14 that can be used in an HVAC&R system 10 is illustrated. The vapor compression system 14 can circulate working fluid through a working fluid loop that begins with a compressor 32 (e.g., a centrifugal compressor, single-stage compressor, multi-stage compressor, direct-drive compressor, open-type compressor, non-hermetic compressor). The working fluid loop may also include a condenser 34, an expansion valve or device 36, and a liquid cooler or evaporator 38. The vapor compression system 14 may further include a control panel 40 having an analog-to-digital (A / D) converter 42, a microprocessor 44, non-volatile memory 46, and / or an interface board 48.

[0020] Some examples of fluids that can be used as working fluids in vapor compression system 14 are: hydrofluorocarbon (HFC) based working fluids (e.g., refrigerants), such as R-410A, R-407, R-134a, hydrofluoroolefins (HFO); “natural” working fluids, such as ammonia (NH3), R-717, carbon dioxide (CO2), R-744; or hydrocarbon-based working fluids, water (e.g., water vapor, steam), or any other suitable working fluid. In some embodiments, vapor compression system 14 may be configured to effectively utilize working fluids with a standard boiling point of about 100 degrees Celsius (66 degrees Fahrenheit) at one atmosphere, also referred to as low-pressure working fluids relative to medium-pressure working fluids (such as R-134a). As used herein, “standard boiling point” may refer to the boiling point temperature measured at one atmosphere.

[0021] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or device 36, and / or an evaporator 38. The motor 50 may drive the compressor 32 and may be powered by the VSD 52. The VSD 52 receives AC power with a specific fixed line voltage and fixed line frequency from an alternating current (AC) power source and supplies power with a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be directly powered by an AC or direct current (DC) power source. The motor 50 may include any type of motor that can be powered by a VSD or directly by an AC or DC power source, such as a switched reluctance motor, a direct drive motor, an induction motor, an electronically rectified permanent magnet motor, or another suitable motor.

[0022] Compressor 32 compresses or pressurizes the working fluid vapor and delivers it to condenser 34 via a discharge passage. In some embodiments, compressor 32 may be a centrifugal compressor. Alternatively, compressor 32 may be a direct-drive compressor. In some embodiments, compressor 32 may be a direct-drive compressor with an open or hermetically unsealed design, such that one or more internal components or chambers of compressor 32 may be exposed to the external environment. The working fluid vapor delivered by compressor 32 to condenser 34 can transfer heat to the cooling fluid (e.g., water or air) in condenser 34. The working fluid vapor can condense into a working fluid liquid in condenser 34 due to heat transfer with the cooling fluid. The liquid working fluid from condenser 34 can flow to evaporator 38 via expansion device 36. Figure 3 In the illustrated embodiment, the condenser 34 is water-cooled and includes a tube bundle 54 connected to a cooling tower 56, which supplies cooling fluid to the condenser 34.

[0023] The liquid working fluid delivered to evaporator 38 can absorb heat from the regulating fluid, which may or may not be the same cooling fluid used in condenser 34. The liquid working fluid in evaporator 38 can undergo a phase change from liquid working fluid to working fluid vapor. For example... Figure 3As shown in the illustrated embodiment, the evaporator 38 may include a tube bundle 58 having a supply line 60S connected to a cooling load 62 and a return line 60R. Cooling fluid (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 via the return line 60R and exits the evaporator 38 via the supply line 60S. The evaporator 38 can reduce the temperature of the conditioning fluid in the tube bundle 58 through heat transfer with the working fluid. The tube bundle 58 in the evaporator 38 may include multiple tubes and / or multiple tube bundles. In any case, the vapor working fluid exits the evaporator 38 and returns to the compressor 32 via the suction line to complete the cycle.

[0024] Figure 4 This is a schematic diagram of an embodiment of a vapor compression system 14 having an intermediate loop 64 incorporated between the condenser 34 and the expansion unit 36. The intermediate loop 64 may have an inlet line 68 directly fluidly connected to the condenser 34. In other embodiments, the inlet line 68 may be indirectly fluidly connected to the condenser 34. Figure 4 As shown in the illustrated embodiment, inlet line 68 includes a first expansion device 66 upstream of intermediate container 70. In some embodiments, intermediate container 70 may be a flash tank (e.g., a flash intermediate freezer, economizer, etc.). In other embodiments, intermediate container 70 may be configured as a heat exchanger or a "surface economizer". Figure 4 In the illustrated embodiment, the intermediate container 70 serves as a flash tank, and the first expansion device 66 is configured to reduce the pressure of the liquid working fluid received from the condenser 34 (e.g., to expand the liquid working fluid). During the expansion process, a portion of the liquid may vaporize, and therefore, the intermediate container 70 can be used to separate the vapor from the liquid received from the first expansion device 66.

[0025] Additionally, the intermediate container 70 provides further expansion of the liquid working fluid due to the pressure drop it experiences upon entering the intermediate container 70 (e.g., due to the rapid increase in volume experienced upon entering the intermediate container 70). The compressor 32 can draw vapor from the intermediate container 70 via its suction line 74. In other embodiments, the vapor in the intermediate container 70 may be drawn into an intermediate stage of the compressor 32 (e.g., not the suction stage). The enthalpy of the liquid collected in the intermediate container 70 may be lower than that of the liquid working fluid leaving the condenser 34 due to expansion in the expansion device 66 and / or the intermediate container 70. The liquid from the intermediate container 70 can then flow to the evaporator 38 via the second expansion device 36 in line 72.

[0026] It should be understood that any of the HVAC&R systems described above can be utilized according to this technology. For example, this technology can be combined with embodiments of the HVAC&R system 10, vapor compression system 14, boiler 16, cooler, heat pump, and / or other HVAC&R equipment described herein. As briefly discussed above, this embodiment relates to embodiments of the HVAC&R system 10, such as embodiments configured to use water as the working fluid. In some embodiments, the HVAC&R system 10 may be a heat pump, which may be configured to operate in both heating and cooling modes. In particular, the following discussion describes the technology in combination with embodiments of a heat pump system including a compressor 32 configured to circulate water as the working fluid through the HVAC&R system 10. Furthermore, the compressor 32 includes embodiments of a motor 50 configured to circulate a cooling fluid (such as air (e.g., ambient air, pressurized air)) therethrough to enable cooling of the motor 50. The motor 50 may be configured to allow the cooling fluid to be discharged or vented to the environment surrounding the compressor 32 (e.g., around the HVAC&R system 10). The compressor 32 may include a sealing system (e.g., a labyrinth system, a discharge system) configured to allow working fluid to be discharged from the working fluid portion (e.g., the impeller chamber) of the compressor 32 and to allow cooling fluid to be discharged from the cooling fluid portion (e.g., the motor chamber) of the motor 50 of the compressor 32. In some embodiments, the sealing system may enable simultaneous discharge of cooling fluid from the motor chamber and working fluid from the impeller chamber of the compressor 32. However, it should be understood that the techniques described herein can be combined with other embodiments of the compressor 32, the vapor compression system 14, and the HVAC&R system 10.

[0027] Considering the foregoing, Figure 5 This is a cross-sectional side view of an embodiment of a compressor 32 (e.g., a non-hermetic compressor) according to one aspect of this disclosure, which can be integrated with a heat pump system 100 of an HVAC&R system 10. As discussed herein, compressor 32 can be a single-stage or multi-stage centrifugal compressor. Alternatively or concurrently, compressor 32 can be a direct-drive compressor. Similar to what has been described above, compressor 32 can be positioned along a working fluid circuit (e.g., vapor compression system 14) and can be configured to circulate the working fluid through the working fluid circuit. For example, compressor 32 can be configured to circulate water (e.g., water vapor, steam) as the working fluid. Compressor 32 can be configured to operate at an operating speed (e.g., operating speed range, operating revolutions per minute [RPM], up to 40,000 RPM, greater than 40,000 RPM) that allows for more efficient use of water (e.g., water vapor, steam) as the working fluid within the heat pump system 100. For this purpose, compressor 32 may include embodiments of a motor 50 to drive compressor 32 to rotate at the desired operating speed.

[0028] Additionally, compressor 32 includes a sealing system 102 (e.g., a labyrinth seal system, a discharge system) comprising one or more seals 104 (e.g., labyrinth seals). Seals 104 are configured to restrict fluid flow within compressor 32 in a desired manner. For example, seals 104 may allow working fluid to be discharged from compressor 32 and / or cooling fluid (e.g., motor cooling fluid) to be discharged from compressor 32 (e.g., from motor 50 of compressor 32). One or more seals 104 may also block one or more fluid flows between operating chambers (e.g., spaces, areas) of compressor 32, as further described below. Furthermore, compressor 32 may include a housing 106 (e.g., compressor housing, compressor system housing) and a shaft 108 extending through housing 106. Shaft 108 may be configured to rotate via actuation of motor 50. Additionally, motor 50 may be housed within a motor cavity 110 of motor housing 112 of compressor 32 (e.g., housing, part of housing 106). Motor housing 112 may be considered part of housing 106 of compressor 32. In some embodiments, compressor 32 may include a single compressor stage. In other embodiments, compressor 32 may include two or more compressor stages. The shaft 108 of compressor 32 is configured to rotate about axis 114 (e.g., a rotational axis, a central axis) of compressor 32 to allow a working fluid (e.g., water) to flow through compressor 32. For ease of discussion below, compressor 32 and its components may be described with reference to longitudinal axis 116, vertical axis 118 oriented relative to the direction of gravity, and transverse axis 120 (e.g., a radial axis). However, it should be understood that compressor 32 may be mounted and / or operated in any suitable location (e.g., vertical, horizontal, at any suitable operating angle), and therefore axis 114 may extend at any suitable angle relative to longitudinal axis 116, vertical axis 118, transverse axis 120, or any combination thereof.

[0029] In the illustrated embodiment, compressor 32 includes an inlet 124 (e.g., a suction port) configured to receive a flow of working fluid (e.g., water, water vapor) and an impeller 126 positioned within an impeller chamber 128 (e.g., fluidly connected to the inlet 124) of the housing 106 of compressor 32. The impeller 126 can be coupled (e.g., attached, secured) to shaft 108 via fasteners 130 (e.g., rods, bolts, nuts, mechanical fasteners). Compressor 32 also includes a diffuser passage 132 and a volute 134 formed within the housing 106. It should be understood that, although... Figure 5Compressor 32 is shown as a single stage, but in some embodiments, compressor 32 may be a multi-stage centrifugal compressor (e.g., two-stage, three-stage, four-stage, etc.). In such embodiments, each compressor stage may include a corresponding inlet, impeller, and diffuser passage.

[0030] During operation of compressor 32, shaft 108 is rotatable (e.g., via operation of motor 50) and causes impeller 126 to rotate. Rotation of impeller 126 draws working fluid (e.g., water, water vapor) into housing 106 via inlet 124 and toward impeller 126. Specifically, rotation of impeller 126 can drive working fluid (e.g., from evaporator 38 and / or from intermediate container 70 of vapor compression system 14) along working fluid flow path 136 through compressor 32. Impeller 126 can transfer mechanical energy to the working fluid and can direct the working fluid toward diffuser passage 132. The working fluid can be directed through diffuser passage 132 to volute 134 of compressor 32, and from volute 134 to another component of heat pump system 100 having compressor 32, such as a condenser (e.g., condenser 34), for heat exchange with a fluid (such as a cooling fluid).

[0031] Components of the heat pump system 100 (e.g., compressor 32) can be controlled via the control system 150 of the HVAC&R system 10 (e.g., controller, automation controller). In some embodiments, the control system 150 may correspond to the above reference. Figure 3 and Figure 4 The control panel 40 is described. For example, the control system 150 may include an interface board 152 (e.g., a user interface), a processing circuitry system 154 (e.g., one or more microprocessors), a memory 156, and an analog-to-digital (A / D) converter 158. For example, the memory 156 may include volatile memory (such as random access memory (RAM)) and / or non-volatile memory (such as read-only memory (ROM), optical disc drives, hard disk drives, solid-state drives, or any other non-transitory computer-readable medium storing instructions that, when executed, control the operation of the compressor 32 and / or the HVAC&R system 10. The processing circuitry system 154 may be configured to execute such instructions. In some embodiments, the processing circuitry 154 may include one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), one or more general-purpose processors, or any combination thereof.

[0032] The control system 150 can be configured to control the operation of the HVAC&R system 10 (e.g., one or more components of the heat pump system 100, compressor 32, motor 50, etc.) (e.g., transmit commands to control operation) to enable the HVAC&R system 10 to operate more efficiently. As discussed in more detail below, the control system 150 can be configured to operate the HVAC&R system 10 (e.g., heat pump system 100, compressor 32, and / or one or more components of the HVAC&R system 10) in a standby mode that prevents working fluid from flowing from the impeller chamber 128 to the motor chamber 110 and / or prevents cooling fluid (e.g., motor cooling fluid) from flowing from the motor chamber 110 to the impeller chamber 128. The control system 150 can operate the HVAC&R system 10 in standby mode during periods in which the HVAC&R system 10 does not operate in response to the heating and / or cooling demands of the load (e.g., non-operational, reduction, and / or stop phases of the HVAC&R system 10). In other words, the control system 150 can operate the HVAC&R system in standby mode when there is no regulation requirement. In response to the heating and / or cooling requirements of the HVAC&R system 10, the control system 150 can be configured to operate the HVAC&R system 10 (e.g., heat pump system 100, compressor 32, and / or one or more components of the HVAC&R system 10) in a standard operating mode (e.g., normal operating mode) to meet the heating and / or cooling requirements of the load of the HVAC&R system 10 (e.g., providing heating and / or cooling of regulating fluids).

[0033] Continuing with step 5, the control system 150 can be configured to control the operation of the heat pump system 100 (e.g., compressor 32) based on feedback received from one or more sensors 160 of the heat pump system 100 and / or compressor 32. The sensors 160 can be configured to detect one or more operating conditions of the heat pump system 100 (e.g., operating parameters, operating parameter values) as sensor data and provide sensor data (e.g., feedback) indicating the operating conditions to the control system 150. The sensors 160 can be communicatively coupled to the control system 150 and can include any suitable sensors configured to detect operating parameters of the vapor compression system 100 and / or compressor system 32, such as pressure sensors, temperature sensors, position sensors, voltage sensors, current sensors, flow rate sensors, speed sensors, etc.

[0034] Furthermore, during normal operation of the heat pump system 100 (e.g., standard operating mode) (e.g., operation of compressor 32 to meet the needs of heating and / or cooling loads), the temperature of the working fluid may rise (e.g., to or above a threshold temperature value), and therefore the pressure of the working fluid within impeller cavity 128 may rise (e.g., to or above a threshold pressure value). A pressure greater than the threshold pressure value (e.g., atmospheric pressure) within impeller cavity 128 can prevent fluid (e.g., motor cooling fluid, ambient air, non-condensable air) from the motor cavity 110 and / or from the environment surrounding compressor 32 into impeller cavity 128 (e.g., preventing fluid flow through sealing system 102). For example, during normal operation of compressor 32, the temperature of the working fluid (e.g., water, steam) may be at and / or above 100°C, which can result in a water pressure within impeller cavity 128 equal to or greater than approximately 1 bar (e.g., 1.1 bar, at and / or above 1 bar). Additionally, in some embodiments, the air or other cooling fluid within the motor cavity 110 may be maintained at a target pressure of approximately 1 bar (e.g., 1.1 bar, equal to and / or higher than 1 bar) (e.g., via pressurized air, air pump) to allow air to circulate through the motor cavity 110 and provide cooling to the motor 50. In any case, during normal operation of the compressor 32, a first pressure (e.g., working fluid pressure) within the impeller cavity 128 may be greater than a second pressure (e.g., cooling fluid pressure) within the motor cavity 110, and the flow of fluid (e.g., ambient air, motor cooling fluid) through the sealing system 102 and into the impeller cavity 128 may be blocked.

[0035] As discussed in more detail below, the sealing system 102 (e.g., a labyrinth seal system, a discharge system, one or more seals 104) is configured to ventilate the impeller chamber 128 and / or the motor chamber 110 (e.g., into the environment surrounding the compressor 32). The sealing system 102 may be disposed within the housing 106 of the compressor 32 and may be configured to discharge working fluid (e.g., steam) from the impeller chamber 128. The sealing system 102 may also be configured to discharge cooling fluid (e.g., air) from the motor chamber 110. The structure (e.g., design, construction, components, arrangement) of the sealing system 102 may also prevent cooling fluid (e.g., air) from flowing from the motor chamber 110 into the impeller chamber 128. For example, the sealing system 102 may prevent cooling fluid from flowing from the motor chamber 110 into the impeller chamber 128 during operation of the compressor 32 (e.g., normal operation, operation to meet the heating and / or cooling requirements of the load) (e.g., when the working fluid pressure is above a corresponding threshold, or the cooling fluid pressure is above a corresponding threshold). Similarly, the sealing system 102 can prevent working fluids (e.g., water) from flowing from the impeller chamber 128 into the motor chamber 110, such as during operation of the compressor 32 (e.g., normal operation, operation to meet the heating and / or cooling requirements of the load) (e.g., when the working fluid pressure is above a corresponding threshold, or the cooling fluid pressure is above a corresponding threshold). In some embodiments, the sealing system 102 may additionally or alternatively be configured to prevent ambient air from flowing from the environment surrounding the compressor 32 into the impeller chamber 128 of the compressor 32 during operation of the compressor 32 (e.g., normal operation, operation to meet the heating and / or cooling requirements of the load).

[0036] In some cases, such as in response to changes in heating and / or cooling demand of the heat pump system 100 (e.g., no heating and / or cooling demand for the load of the heat pump system 100, reduced heating and / or cooling demand, or inactive heating and / or cooling demand), the operation of compressor 32 can be limited, reduced, or suspended. For example, the operating speed of compressor 32 (e.g., impeller 126) can be reduced and / or the rotation of impeller 126 can be suspended. In such cases, compressor 32 may not operate to pressurize the working fluid, increase the temperature of the working fluid, and / or drive the working fluid through the heat pump system 100. As a result, the temperature (e.g., saturation temperature) of the working fluid (e.g., water, steam) within the impeller chamber 128 of compressor 32 can be reduced (e.g., below 100°C, below a threshold). Similarly, the pressure of the working fluid within the impeller chamber 128 can be reduced (e.g., below 1 bar, below 1.1 bar, below a threshold). However, in some cases, the pressure of the cooling fluid (e.g., air) within the motor cavity 110 may not decrease and / or may remain at a pressure level higher than that of the working fluid (e.g., above a threshold).

[0037] When the pressure of the working fluid in impeller cavity 128 is below a threshold (e.g., below the pressure of the cooling fluid in motor cavity 110, i.e., a predetermined threshold), a pressure difference may occur between impeller cavity 128 and motor cavity 110. Specifically, the pressure in impeller cavity 128 may drop below the pressure in motor cavity 110. As a result, cooling fluid (e.g., air, non-condensable air) in motor cavity 110 may migrate toward impeller cavity 128 of compressor 32 (e.g., due to pressure gradients and / or pressure differences). In some embodiments, the pressure of the working fluid in impeller cavity 128 may additionally or alternatively be less than the pressure of the environment surrounding compressor 32 (e.g., atmospheric pressure), which may similarly cause atmospheric or ambient air (e.g., non-condensable air) to migrate into impeller cavity 128. Introducing cooling fluid and / or ambient air into impeller cavity 128 may result in inefficiency of heat pump system 100. Furthermore, the presence and / or possibility of cooling fluid (such as air and / or ambient air) within the impeller cavity 128 can facilitate purging operations and / or procedures to remove non-condensable air and / or cooling fluid from the impeller cavity 128 before the compressor 32 is operable to meet the heating and / or cooling requirements of the load on the heat pump system 100. In other words, the resumption of operation of the compressor 32 can be delayed while performing the purging of cooling fluid and / or ambient air from the compressor 32 (e.g., the working fluid side of the compressor).

[0038] Considering the foregoing, Figure 6This is a cross-sectional side view of an embodiment of a compressor 32 (e.g., a non-hermetic compressor) according to one aspect of the present disclosure, illustrating an embodiment of a sealing system 102 (e.g., a labyrinth seal system, a discharge system). Specifically, the sealing system 102 may include one or more seals 104 (e.g., labyrinth seals, vents) disposed within the housing 106 of the compressor 32 and / or the motor housing 112. In some embodiments, the sealing system 102 may include a plurality of seals 104 interconnected with each other (e.g., as a single unit or component). Alternatively, some embodiments of the sealing system 102 may include a plurality of seals 104 disposed separately within the housing 106 and / or the motor housing 112. Seals 104 may be disposed along one or more channels 162 (e.g., pipes, tubes, channels, flow paths, cavities formed in housing 106 and / or motor housing 112) extending between impeller cavity 128 and the environment surrounding compressor 32, between motor cavity 110 and the environment surrounding compressor 32, and / or between impeller cavity 128 and motor cavity 110. In some embodiments, seals 104 may be disposed as a single unit along a portion (e.g., length, dimension, cross-section) of one or more channels 162 (e.g., disposed within that portion). In some embodiments, seals 104 may be disposed along individual portions of one or more channels 162. For example, one or more seals of seals 104 may extend along or be disposed within a first portion of one or more channels 162, and one or more additional seals 104 may extend along or be disposed within a second portion of one or more channels 162 and / or may extend along or be disposed within another channel 162 of one or more channels 162. In some embodiments, the seal 104 may extend along the entire dimension (e.g., length, width, cross-section) of one or more channels 162. Alternatively, each of the one or more channels 162 may include one seal of the seal 104 disposed therein. One or more seals 104 may occupy a portion of the cross-sectional area of ​​one channel of the channel 162 (e.g., relative to fluid flow through it) and / or one or more seals 104 may occupy the entire cross-sectional area of ​​one channel of the channel 162.

[0039] For example, Figure 6A first passage 180 (e.g., a first flow path) is shown extending from impeller cavity 128 and fluidly exposing (e.g., fluidly coupled) the impeller cavity to an environment surrounding compressor 32 (e.g., the environment outside compressor housing 106). The first passage 180 can be configured to direct a flow (e.g., a portion) of working fluid (e.g., water, steam) from impeller cavity 128 to the environment surrounding compressor 32. Additionally, compressor 32 includes a second passage 182 (e.g., a second flow path) extending from motor cavity 110 and fluidly exposing (e.g., fluidly coupled) the motor cavity 110 to the environment surrounding compressor 32. The second passage 182 can be configured to direct a flow of motor cooling fluid (e.g., water, air) from motor cavity 110 to the environment surrounding compressor 32. In some embodiments, the first passage 180 and the second passage 182 may be fluidly coupled to a third passage 184 (e.g., a third flow path). The third passage 184 is configured to fluidly expose (e.g., fluidly coupled) both the first passage 180 and the second passage 182 to the environment surrounding compressor 32. In other words, the third channel 184 can extend from the first channel 180, the second channel 182, or both to the environment surrounding the compressor 32 to fluidly connect the first channel 180 and the second channel 182 to the environment surrounding the compressor 32.

[0040] During operation of compressor 32 (e.g., circulating working fluid through heat pump system 100 to meet loads on heat pump system 100), a portion of the working fluid guided from impeller cavity 128 through first channel 180 and / or the motor cooling fluid flow guided from motor cavity 110 through second channel 182 may flow into third channel 184 before being discharged from compressor 32. Third channel 184 may be fluidly coupled to outlet 186 of housing 106 (e.g., exhaust vent, exhaust port, air outlet). A portion of the working fluid and / or motor cooling fluid flow may flow from third channel 184 into the environment surrounding compressor 32 via outlet 186. Thus, during normal operation of compressor 32 (e.g., to meet heating and / or cooling loads), working fluid flow may be guided from impeller cavity 128 along first channel 180, along third channel 184, and discharged from compressor 32 to the environment surrounding compressor 32 via outlet 186. Alternatively, during normal operation of the compressor 32, the motor cooling fluid flow can be guided from the motor cavity 110 along the second channel 182, along the third channel 184, and discharged from the compressor 32 (e.g., the motor 50) to the environment surrounding the compressor 32 via the discharge port 186.

[0041] It should be understood that, despite Figure 6The diagram illustrates that both the first channel 180 and the second channel 182 are fluidly coupled to the third channel 184, such that the working fluid flow and the motor cooling fluid flow can mix within the third channel 184 before being discharged from the compressor 32 (e.g., via outlet 186, via a common outlet). In some embodiments, the first channel 180 is fluidly coupled to the impeller cavity 128, and the second channel 182, fluidly coupled to the motor cavity 110, can be fluidly coupled to the environment surrounding the compressor 32 via a separate outlet. That is, the first channel 180 can extend from the impeller cavity 128 to a first outlet, which is different from (e.g., separate from) the second outlet, which fluidly couples the second channel 182 to the motor cavity 110. Thus, the working fluid flow can be guided from the impeller cavity 128 and discharged from the compressor 32 along the first channel 180 via the first outlet, and the motor cooling fluid flow can be guided from the motor cavity 110 and discharged from the compressor 32 (e.g., the motor 50) along the second channel 182 via the second outlet (e.g., a separate outlet from the first outlet).

[0042] In the manner described above, sealing system 102 can allow working fluid (e.g., steam) to be discharged from impeller chamber 128 to the environment surrounding compressor 32, and sealing system 102 can allow motor cooling fluid (e.g., air, compressed air) to be discharged (e.g., circulated) from motor chamber 110 to the environment surrounding compressor 32, or both. Sealing system 102 can also prevent the flow of working fluid from impeller chamber 128 to motor chamber 110. Similarly, sealing system 102 can prevent the flow of motor cooling fluid from motor chamber 110 to impeller chamber 128. Figure 6 As shown, the sealing system 102 includes a first seal 164 (e.g., a first labyrinth seal) disposed along a portion of the first channel 180. Therefore, the first seal 164 can be fluidly exposed to the impeller cavity 128. The first seal 164 can be disposed along a flow path 170 (e.g., a first flow path, a working fluid flow path) extending from the impeller cavity 128 to the outlet 186 of the compressor housing 106. The sealing system 102 also includes a second seal 166 (e.g., a second labyrinth seal) disposed along an additional portion of the first channel 180. The second seal 166 is also disposed along the flow path 170.

[0043] The first passage 180 further includes an intermediate cavity 168 disposed between a portion of the first passage 180 including a first seal 164 and an additional portion of the first passage 180 including a second seal 166. The intermediate cavity 168 may be a gap (e.g., a space) formed within the housing 106 of the compressor 32 between the portion of the first passage 180 including the first seal 164 and the additional portion of the first passage 180 including the second seal 166. In some operations, a portion of the working fluid (e.g., steam) within the impeller cavity 128 may flow along a flow path 170 to a discharge port 186 and may be discharged from the housing 106 of the compressor 32. That is, a portion of the working fluid within the impeller cavity 128 may flow along the flow path 170, through the first seal 164, into the intermediate cavity 168, through the second seal 166, and out of the housing 106 via the discharge port 186. The pressure of the working fluid within the intermediate cavity 168 may be different from (e.g., higher, lower) or substantially similar to the pressure of the working fluid within the impeller cavity 128. Additionally, the pressure of the working fluid within the intermediate cavity 168 may be different from (e.g., higher or lower) or substantially similar to the pressure of the environment surrounding the compressor 32 (e.g., the pressure of the outlet or opening of the discharge port 186 exposed to the housing 106).

[0044] It should be understood that the pressure difference between impeller chamber 128 and intermediate chamber 168 and / or between intermediate chamber 168 and the environment surrounding compressor 32 can vary, such as based on operating parameters of compressor 32, operating conditions of compressor 32, environmental conditions in the environment surrounding compressor 32, other factors or variables, or any combination thereof. During operation of compressor 32 to meet the heating and / or cooling requirements of the load of heat pump system 100 (e.g., during normal operating speed of compressor 32), a portion of the working fluid (e.g., steam) within impeller chamber 128 may travel from impeller chamber 128 and along flow path 170, through first passage 180, through first seal 164, into intermediate chamber 168, through second seal 166, through third passage 184, and exit compressor 32 into the environment via discharge port 186. In such cases, the first pressure within impeller chamber 128 may be greater than the second pressure within intermediate chamber 168, and the second pressure within intermediate chamber 168 may be greater than the third pressure in the environment surrounding compressor 32.

[0045] In some embodiments, the sealing system 102 may further include a third seal 188 (e.g., a third labyrinth seal) disposed along a portion of the second channel 182. Thus, the third seal 188 may be fluidly exposed to the motor cavity 110. The third seal 188 may be disposed along an additional flow path 174 (e.g., a second flow path, a motor cooling fluid flow path) extending from the motor cavity 128 to an outlet 186 of the housing 106 of the compressor 32 (e.g., motor 50). In some operations, a portion of the motor cooling fluid (e.g., air) within the motor cavity 110 may flow along the additional flow path 174 to the outlet 186 and may be discharged from the housing 106 of the compressor 32. That is, at least a portion of the motor cooling fluid may flow through the third seal 188 and out of the housing 106 via the outlet 186. The pressure of the motor cooling fluid within the motor cavity 110 may be different from (e.g., higher, lower) or substantially similar to the pressure of the environment surrounding the compressor 32 (e.g., the pressure of the outlet or opening of the outlet 186 exposed to the housing 106). It should be understood that the pressure difference between the motor cavity 110 and the intermediate cavity 168 and / or between the intermediate cavity 168 and the environment surrounding the compressor 32 can vary, such as based on the operating parameters of the compressor 32, the operating conditions of the compressor 32, the operating conditions of the motor 110, the operating parameters of the cooling system of the motor 110, the environmental conditions surrounding the compressor 32, other factors or variables, or any combination thereof. During operation of the compressor 32 to meet the heating and / or cooling requirements of the load (e.g., regulating load, heating load, cooling load) of the heat pump system 100 (e.g., during normal operating speed of the compressor 32), motor cooling fluid (e.g., air) can travel from the motor cavity 110 and along an additional flow path 174, through a second channel 180, through a third seal 188, through a third channel 184, and exit the compressor 32 into the environment via an outlet 186.

[0046] It should be understood that, despite Figure 6 The sealing system 102 is shown as including a first channel 180, a second channel 182 and a third channel 184, a first seal 164, a second seal 166, a third seal 188, an intermediate cavity 168 and an outlet 186. In some embodiments, the sealing system 102 of the compressor 32 may include other suitable corresponding numbers of channels, seals, cavities, outlets or any combination thereof, such as enabling ventilation of the impeller cavity 128 and / or the motor cavity 110 during operation of the compressor 32 (e.g., into the environment surrounding the compressor 32).

[0047] Continue to combine Figure 6During operation of compressor 32 to meet the heating and / or cooling requirements of the heat pump system 100 load (e.g., during normal operating speed of compressor 32), the working fluid can be pressurized within impeller chamber 128 (e.g., via the rotation of impeller 126). In some cases, the pressure within intermediate chamber 168 (e.g., the pressure of the working fluid) can be lower than the pressure within impeller chamber 128 (e.g., the pressure of the working fluid), and the pressure of the environment surrounding compressor 32 (e.g., atmospheric pressure) can be lower than the pressure of the working fluid within intermediate chamber 168. As a result, a portion of the working fluid from impeller chamber 128 can be directed along flow path 170 (e.g., via pressure differential) toward the environment surrounding compressor 32.

[0048] Additionally, during operation of the compressor 32 to meet the heating and / or cooling requirements of the heat pump system 100 load (e.g., during normal operating speed of the compressor 32), motor cooling fluid (e.g., ambient air, pressurized air) can circulate through the motor housing 112 to cool the motor 50. Part or all of the motor cooling fluid (e.g., air) can be discharged from the motor housing 112 via the aforementioned discharge port 186 of the compressor 32. In other words, discharge port 186 can be configured to discharge working fluid received from the impeller cavity 128 via flow path 170, and discharge port 186 can be configured to discharge motor cooling fluid received from the motor cavity 110 via flow path 174 (e.g., an additional flow path, a second flow path, a motor cooling fluid flow path). Flow path 170 extending from the impeller cavity 128 to discharge port 186 and additional flow path 174 extending from the motor cavity 110 to discharge port 186 can also be fluidly connected to each other (e.g., via a third channel 184 upstream of discharge port 186). During operation of the compressor 32, the pressure of the motor cooling fluid (e.g., air) within the motor cavity 110 can be lower than the pressure of the working fluid along flow path 170 (e.g., within intermediate cavity 168). Thus, the pressure of the working fluid along flow path 170 can prevent the motor cooling fluid (e.g., air) from flowing from the motor cavity 110 into the impeller cavity 128 (e.g., via flow path 170). Therefore, during normal operation of the compressor 32, the motor cooling fluid may not flow into the working fluid circuit of the heat pump system 100. Alternatively, the motor cooling fluid can circulate through the motor cavity 110 at an elevated pressure (e.g., greater than atmospheric pressure). In this way, the motor cooling fluid can flow through the motor cavity 110 and out of the outlet 186 (e.g., along an additional flow path 174), which makes it possible to prevent the working fluid from flowing from flow path 170 and into the motor cavity 110 via the additional flow path 174.

[0049] In some applications of the heat pump system 100, the operation of the compressor 32 can be reduced or suspended. In other words, the compressor 32 can be operated at a reduced capacity (e.g., reduced speed, reduced number of operating compressor stages) and / or the compressor 32 can be shut down. For example, the operation of the compressor 32 can be suspended during periods when there is no heating and / or cooling demand for the heat pump system 100 (e.g., no or inactive demand for regulation and / or no or inactive heating or cooling demand) or after the heat pump system 100 has met its heating and / or cooling demand. During reduced and / or suspended operation of the compressor 32, the temperature (e.g., saturation temperature) of the working fluid within the impeller chamber 128 may decrease (e.g., below 100°C). As a result, the pressure of the working fluid within the impeller chamber 128 may decrease (e.g., below 1 bar, below 1.1 bar). When the pressure of the working fluid within the impeller chamber 128 decreases, the pressure (e.g., working fluid pressure) within the intermediate chamber 168 may also decrease. Therefore, the motor cooling fluid (e.g., air, non-condensable air) within the motor cavity 110 may readily migrate (e.g., due to pressure gradients) from the motor cavity 110 toward the impeller cavity 128 of the compressor 32. For example, during periods when the pressure in the intermediate cavity 168 and / or the impeller cavity 128 drops below the pressure of the motor cooling fluid within the motor cavity 110, this can cause the motor cooling fluid to migrate from the motor cavity 110 along the additional flow path 174 and along the flow path 170 into the impeller cavity 128. In some cases (e.g., during shutdown or pause operation of the compressor 32), the pressure within the impeller cavity 128 (e.g., the pressure of the working fluid) may additionally or alternatively be less than the pressure of the environment surrounding the compressor 32 (e.g., atmospheric pressure), which can similarly cause atmospheric or ambient air to migrate into the impeller cavity 128 via the outlet 186 and the flow path 170. Introducing air (e.g., motor cooling fluid, ambient air) into the impeller cavity 128 (e.g., mixing with the working fluid) can lead to inefficiency of the heat pump system 100. In practice, the non-condensable air present in the impeller chamber 128 can prompt the purging of the compressor 32 and / or the working fluid circuit before the compressor 32 can resume operation (e.g., to meet heating and / or cooling loads). Therefore, the restart of the compressor 32 may be delayed, and consequently, the operation of the heat pump system 100 to meet subsequent heating or cooling needs may be delayed.

[0050] According to this technology, components of the heat pump system 100 (e.g., compressor 32) can be controlled via a control system 150 (e.g., controller, automation controller), as referenced above. Figure 5As described. For example, control system 150 may be configured to control the operation of compressor 32 (e.g., one or more components of compressor 32, motor 50, etc.) to enable compressor 32 to operate more efficiently, and thus enable heat pump system 100 to operate more efficiently. Control system 150 may be configured to control the operation of compressor 32 and / or other components of heat pump system 100 to prevent undesired or unintended fluid migration between impeller chamber 128 and motor chamber 110, such as during periods when heat pump system 100 is not operating to meet cooling and / or heating demands. In particular, as discussed in more detail below, control system 150 may be configured to operate heat pump system 100 (e.g., compressor 32) in standby mode during periods when compressor 32 is not otherwise operated (e.g., to meet heating and / or cooling demands of a load on heat pump system 100 operating at a rate above a threshold operating speed). In other words, during periods when compressor 32 is operating in standby mode, there may be no requirement to regulate heat pump system 100 and / or load demand on heat pump system 100. Alternatively, the control system 150 may be configured to control the operation of the heat pump system 100 (e.g., compressor 32) based on feedback received from one or more sensors 160 of the heat pump system 100, as referenced above. Figure 5 As described. Figure 6 As shown, one or more sensors in sensor 160 may be located (e.g., situated) within impeller cavity 128, along the suction inlet of compressor 32, along the discharge outlet of compressor 32, intermediate cavity 168, the environment surrounding compressor 32, motor cavity 110, another suitable location, or any combination thereof. For example, one or more sensors in sensor 160 may be configured to detect pressure (e.g., working fluid pressure, motor cooling fluid pressure, ambient pressure, working fluid suction pressure, working fluid discharge pressure) within the corresponding location of sensor 160 and provide data indicating the detected pressure to control system 150 (e.g., controller). In some embodiments, one or more sensors 160 may be configured to detect operating parameters of compressor 32 and / or motor 50, such as operating speed (e.g., rotational speed), temperature, operating mode, operating capacity, another suitable operating parameter, or any combination thereof.

[0051] In standby mode, control system 150 can operate heat pump system 100 (e.g., compressor 32) to increase and / or maintain the temperature and / or pressure of the working fluid, such as above a threshold level (e.g., threshold pressure level, pressure value greater than ambient pressure). For example, control system 150 can operate compressor 32 (e.g., motor 50) in standby mode to maintain the temperature and / or pressure of the working fluid (e.g., water or steam within impeller chamber 128, along flow path 170) at and / or above a corresponding threshold level. In other words, control system 150 can operate compressor 32 at a rate (e.g., low speed, lower limit speed, minimum permissible speed) that achieves or causes the working fluid (e.g., within impeller chamber 128) to have a desired temperature and / or desired pressure. In some embodiments, compressor 32 may be a multi-stage compressor comprising multiple stages (e.g., compressor stages arranged in series, operating stages). Control system 150 can operate compressor 32 in standby mode by operating and / or maintaining the operation of a reduced number of compressor stages to increase and / or maintain the temperature and / or pressure of the working fluid within compressor 32 above a threshold level. Therefore, in some embodiments, compared to multiple operating compressor stages (e.g., 2, 3, 4) operated and / or maintained by the control system 150 during normal operation of the compressor 32, the control system 150 can operate the compressor 32 in standby mode by operating and / or maintaining the operation of a smaller number of operating compressor stages (e.g., 1, 2), such as operating a single compressor stage.

[0052] In some embodiments, the control system 150 may be configured to select a specific operating speed, control the compressor 32 to operate at a specific operating speed, and / or control multiple operating compressor stages of the compressor 32 based on feedback from one or more sensors in the sensor 160, to maintain the working fluid within the compressor 32 at a pressure equal to or greater than a threshold. For example, one of the sensors in the sensor 160 may include a pressure sensor configured to detect the pressure of the working fluid within the impeller chamber 128 and / or along the flow path 170. In some embodiments, the threshold (e.g., threshold pressure) may correspond to (e.g., may be based on) a pressure substantially equal to or greater than the ambient pressure (e.g., detected by one of the sensors in the sensor 160), the pressure of the motor cooling fluid circulating through the motor chamber 110 (e.g., detected by one of the sensors in the sensor 160), the temperature of the working fluid, the ambient temperature, or other suitable values. In some embodiments, the threshold (e.g., working fluid pressure threshold) may be dynamic (e.g., adjusted), for example, based on feedback from one of the sensors in the sensor 160. For example, the control system 150 may be configured to increase the working fluid threshold based on feedback indicating an increase in the pressure of the motor cooling fluid and / or an increase in the pressure of the surrounding environment around the compressor 32. Similarly, the control system 150 can be configured to reduce a threshold of the working fluid based on feedback indicating a decrease in the pressure of the motor cooling fluid and / or a decrease in the pressure of the surrounding environment around the compressor 32. In other embodiments, the threshold may be a predetermined value, such as a predetermined value associated with an upper limit of the expected cooling fluid pressure and / or an upper limit of the expected ambient air pressure.

[0053] The control system 150 may be further configured to operate the compressor 32 (e.g., the motor 50) to achieve and / or maintain a pressure of the working fluid within the impeller chamber 128 equal to or greater than a threshold. In some embodiments, the memory 156 of the control system 150 may store multiple thresholds (e.g., working fluid pressure values) and corresponding operating parameter values ​​(e.g., operating speed, operating stage, operating capacity) of the compressor 32 that achieve a working fluid pressure equal to or greater than the associated threshold. Alternatively or additionally, the control system 150 may be configured to dynamically adjust the operation of the compressor 32 based on data received from one or more sensors 160 to achieve and / or maintain the working fluid within the impeller chamber 128 and / or other portions of the heat pump system 100 at or above a threshold (e.g., which may correspond to and / or be greater than the ambient pressure and / or motor cooling fluid pressure detected by one or more of the sensors 160). When the control system 150 operates the compressor 32 in standby mode (e.g., at a speed and / or capacity associated with a threshold), the pressure of the working fluid can be increased to the threshold, allowing a portion of the working fluid to flow through the sealing system 102 (e.g., along flow path 170) and out of the compressor 32 housing 106 via the discharge port 186. In this way, air (e.g., motor cooling fluid, ambient air) migrating into the impeller chamber 128 can be prevented by the flow of a portion of the working fluid through the sealing system 102.

[0054] In addition to or instead of operation of compressor 32 in standby mode, HVAC&R system 10 (e.g., via control system 150) may be operated to supply heat to the working fluid within heat pump system 100 (e.g., working fluid circuit, compressor 32) during non-operation, standby, and / or shutdown of compressor 32. For example, HVAC&R system 10 may include one or more components that can be operated to apply and / or transfer heat to the working fluid within heat pump system 100. In this way, the temperature and / or pressure of the working fluid may be maintained at or above a threshold level, which may prevent air (e.g., motor cooling fluid, ambient air) from migrating into the impeller chamber 128 of compressor 32 (e.g., via flow path 170, from motor chamber 110, from the surrounding environment).

[0055] Considering the foregoing, Figure 7 This is a schematic diagram of an embodiment of an HVAC&R system 10 according to one aspect of this disclosure, illustrating an embodiment of a heat pump system 100 including a heating system 200. The heat pump system 100 can be compared with the above-referenced... Figure 3 and Figure 4The described vapor compression system 14 is similar to and / or may include similar components. For example, the heat pump system 100 may include a first heat exchanger 202 (e.g., evaporator 38), a second heat exchanger 204 (e.g., condenser), a compressor 206 (e.g., compressor 32), and an expansion valve 208 (e.g., expansion valve 36) arranged along the working fluid circuit 210. In fact, the compressor 206 of the illustrated embodiment may include the components referenced above. Figure 5 and Figure 6 One or more components are discussed, such as motor 50 and sealing system 102. Components of heat pump system 100 may be arranged along working fluid circuit 210 via pipes, tubes, conduits, pipes, etc. Working fluid circuit 210 enables heat pump system 100 (e.g., vapor compression system 14) to circulate working fluid (e.g., water, steam) through components of heat pump system 100 to cool and / or heat one or more conditioning or cooling fluids (e.g., air, water, brine, ethylene glycol, etc.). In particular, as discussed similarly above, first heat exchanger 202 and second heat exchanger 204 may each be configured to receive working fluid guided along working fluid circuit 210 to receive a corresponding conditioning or cooling fluid flow and to place the working fluid and conditioning or cooling fluid flow in a heat exchange relationship.

[0056] Additionally, the HVAC&R system 10 may include a heating system 200 configured to supply heat to the heat pump system 100 (e.g., to the working fluid of the heat pump system 100). One or more heating systems in the heating system 200 may be located in any suitable location associated with the heat pump system 100 to enable heating of the working fluid via operation of the heating system 200. For example, in some embodiments, the heating system 200 may include an electric heater, a ceramic heater, a resistance heater, a heating blanket, a heating element, a gas heater, a heat exchanger configured to circulate the heating fluid, an infrared heater, another suitable type of heater, or any combination thereof. Additionally or alternatively, in some embodiments, the heating system 200 may include a circulation pump associated with a first heat exchanger 202, a second heat exchanger 204, a working fluid loop 210, or other parts of the heat pump system 100. For example, the operation of the circulating pump can generate heat (e.g., via the motor of the circulating pump) and can supply heat to the working fluid within the first heat exchanger 202, the second heat exchanger, and / or the working fluid circuit 210 (e.g., within the corresponding process piping of the first heat exchanger 202, the second heat exchanger, and / or the working fluid circuit 210). In some applications, according to this technology, the heating system 200 can be implemented and operated in a standby mode (e.g., instead of compressor 206) to reduce or limit short-cycle operation of compressor 206.

[0057] like Figure 7As shown, the heating system 200 may be located at or associated with a first heat exchanger 202 (e.g., evaporator 38), at or associated with a portion (e.g., a pipe) of the working fluid circuit 210 fluidly connected to the first heat exchanger 202 to the compressor 206, at or associated with a portion (e.g., a pipe) of the working fluid circuit 210 fluidly connected to the expansion valve 208 to the first heat exchanger 202, at or associated with a second heat exchanger 204 (e.g., condenser 34), at or associated with a portion (e.g., a pipe) of the working fluid circuit 210 fluidly connected to the expansion valve 208, at or associated with a portion (e.g., a pipe) of the working fluid circuit 210 fluidly connected to the compressor 206 to the second heat exchanger 204, or at or associated with any combination thereof. In some embodiments, the heating system 200 may be configured to transfer heat to the compressor 206 to enable heating of the working fluid within the working fluid circuit 210. For example, heating system 200 may include a heating element (e.g., an electric heating element) coupled (e.g., attached, fixed, fastened) to one or more components of working fluid circuit 210, a conduit of working fluid circuit 210 (e.g., upstream of compressor 206), housing 106 of compressor 206, or any combination thereof.

[0058] The operation of the heating system 200 can also be controlled via the control system 150. Specifically, in some embodiments, the heating system 200 can be configured to provide heat (e.g., compressors 32, 206), another suitable input, or any combination thereof to the heat pump system 100 based on feedback from one or more sensors 160 indicating operating parameters of the heat pump system 100 (e.g., operating parameter values) (e.g., ambient pressure, working fluid pressure, motor cooling fluid pressure), feedback indicating the operating status of the heat pump system, and / or data. According to this technology, the control system 150 can operate the heating system 200 to transfer heat to the working fluid within the working fluid loop 210 (e.g., compressor 206) during non-operation, off, and / or standby operation of the compressor 206. As discussed above, during reduced and / or suspended operation of the compressor 206 (e.g., when there is no load or demand on the heat pump system 100), the temperature and / or pressure of the working fluid circulating through the working fluid loop 210 can drop below a threshold level or threshold (e.g., corresponding to the pressure of the motor cooling fluid and / or the ambient pressure). In such cases, compressor 206 may be susceptible to the ingress of fluids (such as air (e.g., non-condensable air, ambient air, motor cooling fluid)) via sealing system 102. Similarly discussed above, during periods when compressor 206 is not in operation (e.g., to meet the heating and / or cooling demands of the heat pump system 100 load), control system 150 may operate heating system 200 (e.g., activate heating elements) to apply or transfer heat to the working fluid and increase its temperature and / or pressure to maintain it above a threshold level (e.g., atmospheric pressure, motor coolant pressure). When the working fluid pressure is at or above the threshold level, a portion of the working fluid may flow through sealing system 102 (e.g., along flow path 170) and exit compressor 32 housing 106 via outlet 186. In this way, air (e.g., motor cooling fluid, ambient air) migrating into impeller chamber 128 may be blocked by the flow of working fluid at or above the threshold level (e.g., threshold pressure) through sealing system 102.

[0059] Figure 8A flowchart illustrating an embodiment of a method 300 (e.g., control logic, control scheme) for operating an HVAC&R system 10 in a standby mode (e.g., standby operation mode) according to one aspect of this disclosure is shown. Method 300 can be used during periods (e.g., phases, periods) when the operation of compressors 32, 206 is paused, the speed of compressors 32, 206 is reduced, and / or the number of operating compressor stages is reduced. A subset and / or all of the steps of method 300 described below can be implemented and / or executed by control system 150 of heat pump system 100 and / or by another control system. In other words, control system 150 (e.g., a single control system, processing circuitry system 154) can be configured to implement and / or execute method 300 to control various components of heat pump system 100 (e.g., vapor compression system 14, compressors 32, 206) and / or heating system 200. In other embodiments, method 300 can be implemented by another control system (e.g., a dedicated control system for compressors 32, 206), more than one control system, or other suitable control system. In some embodiments, method 300 can be used to control the operation of an embodiment of compressor 32 (e.g., compressor system) having two or more stages (e.g., operating stage, compression stage). It should also be noted that additional steps may be performed with respect to method 300. Furthermore, certain steps of the described method 300 may be omitted, modified, and / or performed in a different order.

[0060] As described above, method 300 can be implemented (e.g., via control system 150) to control components of the HVAC&R system 10 (e.g., heat pump system 100 and / or heating system 200) during periods when compressors 32, 206 are not in operation (e.g., not powered) and / or operating at reduced capacity. More specifically, method 300 can be performed during periods when compressors 32, 206 are readily accessible to fluids (e.g., air, non-condensable air) (such as motor cooling fluid or ambient air) via sealing system 102 (e.g., flow path 170). In some applications, method 300 can be performed based on indications of the operating state of the heat pump system 100 (e.g., compressors 32, 206) (e.g., indications that compressor 32 is not in operation (e.g., no load heating or cooling demand) and / or indications that compressor 32 is operating at reduced capacity or speed) (e.g., speed or capacity below a threshold level). Alternatively, method 300 may be implemented in response to the detected pressure and / or temperature of the working fluid (e.g., within compressor 32, within heat pump system 100) being lower than a target or threshold pressure and / or target or threshold temperature (e.g., a threshold pressure range or value, a threshold temperature range or value) of the working fluid within heat pump system 100. In some embodiments, the threshold pressure value may correspond to the pressure of ambient air and / or the pressure of the motor cooling fluid (e.g., air, compressed air) circulating through motor cavity 110 (e.g., detected by one or more sensors 160).

[0061] Similar to the description above, execution of method 300 may initiate the operation of compressor 32 and / or heating system 200 to increase the pressure and / or temperature of the working fluid within heat pump system 100, thereby achieving and / or maintaining the pressure and / or temperature of the working fluid at threshold pressure and / or threshold temperature levels. In this way, execution of method 300 may reduce and / or prevent the flow of motor cooling fluid (e.g., air, non-condensable air) from motor cavity 110 of motor 50 into impeller cavity 128 of compressor 32, 206 (e.g., thereby preventing the mixing of motor cooling fluid with the working fluid within heat pump system 100) (e.g., via sealing system 102). Similarly, execution of method 300 may reduce and / or prevent the flow of ambient air into impeller cavity 128 via outlet 186 and sealing system 102. Therefore, method 300 can enable the HVAC&R system 10 (e.g., heat pump system 100) to operate more efficiently during changing conditions, phases and / or phases of compressor 32 and / or heat pump system 100 (e.g., compressor 32 pause operation, compressor 32 reduction operation, compressor 32 initial start-up).

[0062] Although method 300 is shown as a series of steps, it should be understood that method 300 and its steps can be executed or implemented as a continuous or sequential control loop (e.g., a proportional-integral-derivative [PID] control loop) based on any suitable input, data, or feedback (e.g., feedback from sensor 160). That is, the steps of method 300 can be repeated (e.g., sequentially, or simultaneously) to enable HVAC&R system 10 to operate in standby or normal mode (e.g., the normal operating speed of compressors 32, 206 during operation to meet the heating and / or cooling requirements of the load of heat pump system 100). In practice, method 300 can be continuously or sequentially executed to dynamically control the components of HVAC&R system 10 in real time (e.g., based on feedback provided by one or more sensors 160) to more reliably prevent, reduce, and / or mitigate unwanted fluid migration to and / or from compressor 32 and motor 50.

[0063] In the illustrated embodiment, method 300 begins with the HVAC&R system 10 (e.g., control system 150) receiving an indication of the operating conditions of the HVAC&R system 10, as shown in block 302. In some embodiments, this indication may be associated with detected operating parameter values ​​of the HVAC&R system 10, such as pressure and / or temperature values ​​of the working fluid (e.g., within compressor 32, upstream of compressor 32, along the working fluid loop of heat pump system 100). In some embodiments, the step at block 302 may include comparing the detected operating parameter values ​​with threshold operating parameter values ​​or value ranges (e.g., lower limits). For example, control system 150 may receive data from sensor 160 indicating detected pressure and / or detected temperature values ​​of the working fluid within heat pump system 100. Control system 150 may compare the detected pressure and / or detected temperature values ​​with corresponding threshold pressure and / or threshold temperature values ​​(e.g., values ​​associated with motor cooling fluid and / or ambient atmosphere) to determine the operating conditions of the HVAC&R system 10. Alternatively or concurrently, operating conditions may indicate the operating status of heat pump system 100 and / or components of heat pump system 100, such as compressor 32. For example, operating conditions may indicate the shutdown of compressor 32 and / or the non-operation of compressor 32 (e.g., paused operation) to allow working fluid to circulate in order to meet the heating and / or cooling loads on HVAC&R system 10.

[0064] In some embodiments, the operating conditions of the HVAC&R system 10 may indicate that the heat pump system 100 (e.g., compressors 32, 206) is operating under normal operating conditions (e.g., compressor 32 is operating at a rate above a threshold, compressor 32 is operating in response to heating and / or cooling demands). For example, the control system 150 may determine that the detected pressure value and / or detected temperature value of the working fluid is within a threshold pressure range and / or a threshold temperature range (e.g., at or above a threshold pressure value and / or threshold temperature value). Based on such determination, method 300 may proceed to block 304, whereby the control system 150 may continue to operate the HVAC&R system 10 in a normal operating mode (e.g., under normal operating conditions) based on this indication. Alternatively, in some embodiments, the indication of the operating conditions of the HVAC&R system 10 may be based on feedback from one or more sensors 160 of the HVAC&R system 10, such as feedback from speed sensors associated with compressors 32, 206 indicating their speed, feedback from one or more flow rate sensors associated with heat pump system 100 indicating the flow rate of the working fluid, indications of heating or cooling demand received by the HVAC&R system 10, etc. In some embodiments, the indication of the operating conditions of the HVAC&R system 10 may be based on inputs (e.g., user input) received via interface 152 of control system 150 and / or operating control logic stored in memory 156 of control system 150 and executed by processing circuitry system 154.

[0065] Furthermore, in some embodiments, the operating conditions of the HVAC&R system 10 may instruct the heat pump system 100 (e.g., compressors 32, 206) to operate at low or reduced capacity (e.g., compressor 32's speed is reduced below a threshold speed associated with normal operating conditions), to pause operation of the heat pump system 100 (e.g., operation of compressors 32, 206 is paused), and / or to operate compressor 32 with a reduced number of operating compressor stages (e.g., compared to the number of operating compressor stages associated with normal operation of the heat pump system 100). In such cases, the operating conditions may be associated with periods in which the heat pump system 100 is not operating to meet loads or demands on the heat pump system 100. For example, the control system 150 may determine that a detected pressure value and / or a detected temperature value of the working fluid is outside a threshold pressure range and / or a threshold temperature range (e.g., the detected value is equal to or below a threshold). Alternatively, in some embodiments, indications that the heat pump system 100 (e.g., compressors 32, 206) is operating at reduced capacity (e.g., compressor 32 is operating at a low speed, below a threshold, and / or compressor 32 is operating at a reduced number of operating compressor-level speeds) and / or the operation of the heat pump system 100 is suspended (e.g., compressors 32, 206 are not operating) can be based on feedback from other sensors 160 of the HVAC&R system 10. For this purpose, one or more sensors 160 may be configured to transmit feedback indicating the detected speed of compressors 32, 206, the detected flow rate of the working fluid, control signals provided to motor 50 (e.g., via control system 150), etc., to control system 150. In some cases, control system 150 may be configured to compare the feedback (e.g., operating parameter values) with corresponding thresholds. In some embodiments, indications that the heat pump system 100 (e.g., compressors 32, 206) is operating at low speed, low capacity, and / or not operating can be based on inputs (e.g., user inputs) received via interface 152 of the control system 150 and / or operational control logic stored in the memory 156 of the control system 150 and implemented by the processing circuitry system 154. For example, this input may be associated with an operational level / stage of the heat pump system 100, where the speed or capacity of compressors 32, 206 is reduced and / or operation of compressors 32, 206 is suspended.

[0066] Based on this determination, method 300 can proceed to block 306. At block 306, control system 150 can operate HVAC&R system 10 in standby mode based on this indication. Specifically, control system 150 can operate one or more components of heat pump system 100 and / or heating system 200 to achieve and / or maintain the temperature and / or pressure of the working fluid (e.g., within impeller chamber 128, along the working fluid loop of heat pump system 100) above a corresponding threshold. According to the present technology, method 300 can be performed to maintain a target pressure and / or target pressure gradient or difference (e.g., between the pressure of the working fluid and the pressure of the motor cooling fluid, between the pressure of the working fluid and the ambient pressure) on sealing system 102. In this way, the flow of motor cooling fluid (e.g., air) from motor chamber 110 to impeller chamber 128 (e.g., through sealing system 102) may be blocked by a portion of the working fluid flowing through sealing system 102 (e.g., towards outlet 186) and / or by the pressure of the working fluid within impeller chamber 128 (which is greater than the pressure of the motor cooling fluid). Additionally, the flow of ambient air from the environment surrounding the compressor 32 to the impeller chamber 128 (e.g., via the outlet 186 and the sealing system 102) can be blocked by the working fluid flowing through the sealing system 102 (e.g., towards the outlet 186) and / or by the pressure of the working fluid within the impeller chamber 128 (which is greater than the pressure of the ambient air).

[0067] In some embodiments, the control system 150 may operate compressors 32, 206 (e.g., at low speed, at a selected speed, having multiple operating stages, controlled via motor 50) to maintain the pressure of the working fluid above a threshold pressure level (e.g., a threshold pressure value), thereby maintaining a desired pressure gradient or pressure difference on the sealing system 102. The control system 150 may control motor 50 to increase the speed of compressors 32, 206 to a specific speed that causes the working fluid pressure to meet and / or exceed the threshold pressure level. In embodiments of compressor 32 configured as a multi-stage compressor and / or a multi-compressor system, the control system 150 may operate a selected number of stages and / or multiple compressors (e.g., a subset of the total) to cause the working fluid pressure to meet and / or exceed the threshold pressure level. For example, the control system 150 may operate a single stage of a multi-stage compressor (e.g., maintain its operation) to cause the working fluid pressure to meet and / or exceed the threshold pressure level. Energy consumption can be reduced by decreasing the speed of compressors 32, 206 and / or reducing the number of stages of operating compressors 32, 206, while still providing heat to the heat pump system 100 (e.g., the working fluid) to maintain the pressure of the working fluid at or above the threshold pressure level.

[0068] Alternatively or concurrently, method 300 may include operation of heating system 200 in standby mode of HVAC&R system 10 (e.g., block 306). In some embodiments, in addition to operating compressor 32 in standby mode of HVAC&R system 10 as described herein (e.g., at low speed, at reduced capacity), or instead of operating compressor 32, control system 150 may also operate heating system 200. As described above, control system 150 may operate heating system 200 to provide heat to the working fluid within heat pump system 100. Applying heat (e.g., saturation temperature) to the working fluid via heating system 200 may increase the pressure of the working fluid, and thus increase the pressure of the working fluid within compressors 32, 206. In this way, a pressure gradient or pressure difference (e.g., working fluid pressure greater than ambient air pressure and / or working fluid pressure greater than motor cooling fluid pressure) may be maintained across sealing system 102, which may enable the blocking of fluid flow (e.g., airflow) into impeller chamber 128 (e.g., from motor chamber 110, from the surrounding environment). Heating system 200 may include an electric heater, resistance heater, heating blanket, heating belt, and / or other suitable type of heater or heating system operatively coupled to (e.g., attached to) compressor 32, the working fluid circuit (e.g., conduit) of heat pump system 100, and / or another component of cap pump system 100 to which the working fluid is exposed. Additionally or alternatively, in some embodiments, heating system 200 may include a circulation pump for first heat exchanger 202, second heat exchanger 204, and / or working fluid circuit 210. For example, operation of the circulation pump may generate heat energy (e.g., via the motor of the circulation pump) and may supply heat to the working fluid within first heat exchanger 202, second heat exchanger, and / or working fluid circuit 210 (e.g., within the corresponding process piping of first heat exchanger 202, second heat exchanger, or both).

[0069] At block 308, the control system 150 may receive indications of operating parameters (e.g., operating parameter values) of the heat pump system 100. For example, the control system 150 may be communicatively coupled to one or more sensors 160 and may be configured to receive data from the sensors 160 indicating one or more operating parameter values. In some embodiments, the control system 150 may receive data indicating detected pressure and / or detected temperature values ​​of the working fluid (e.g., from one or more sensors 160 associated with compressors 32, 206). For example, the control system 150 may receive detected pressure and / or detected temperature values ​​of the working fluid within the impeller chamber 128 and / or intermediate chamber 168 of compressors 32, 206. At block 310, the control system 150 may compare the received operating parameter values ​​with threshold operating parameter values ​​to determine whether the operating parameter values ​​are equal to or greater than the threshold operating parameter values. For example, the control system 150 may compare the detected pressure and / or detected temperature values ​​of the working fluid in the impeller chamber 128 and / or intermediate chamber 168 with target pressure and / or target temperature values ​​(e.g., target pressure range, target temperature range, threshold pressure value) of the working fluid in the impeller chamber 128 and / or intermediate chamber 168. In some embodiments, the control system 150 may compare the detected pressure and / or detected temperature values ​​of the working fluid in the impeller chamber 128 with the detected values ​​of the ambient pressure and / or the pressure of the motor cooling fluid in the motor chamber 110.

[0070] In response to determining that the operating parameter value meets or exceeds a threshold operating parameter value, method 300 may return to block 302 and continue method 300 as described above. In some embodiments, in response to the detected operating parameter value meeting or exceeding a target operating parameter value, control system 150 may suspend the operation of HVAC&R system 10 in standby mode. Alternatively, control system 150 may maintain the operation of HVAC&R system 10 in standby mode to maintain the pressure of the working fluid at or above a threshold. Furthermore, in response to determining that the operating parameter value does not meet the target operating parameter value, method 300 may return to block 306 and continue method 300 as described above. Thus, control system 150 may maintain the operation of HVAC&R system 10 in standby mode and continue executing blocks 308 and 310 until the detected operating parameter value meets or exceeds the target operating parameter value.

[0071] This disclosure can provide one or more technical effects useful in the operation of HVAC&R systems. For example, an HVAC&R system may include a heat pump system configured to operate in a standby mode to reduce and / or prevent undesired fluid migration between the working fluid circuit (e.g., impeller chamber) and the motor cooling chamber of a motor configured to drive a compressor of the heat pump system. For example, the heat pump system may be configured to operate in a standby mode to prevent external fluids (e.g., air, non-condensable air, ambient air, motor cooling fluid) from entering the working fluid circuit of the heat pump system. During standby mode operation, the working fluid may be heated by the HVAC&R system (e.g., compressor, heating system) to cause an increase in the pressure of the working fluid within the working fluid circuit within the compressor. This allows a portion of the working fluid to flow through the compressor's sealing system and prevents external fluids from flowing into the compressor (e.g., into the compressor's impeller chamber). As described above, embodiments of this disclosure may include a compressor having a motor and / or an open-type motor design (e.g., an open compressor, a non-hermetic compressor motor) configured to circulate air as the motor cooling fluid. The disclosed standby mode allows the compressor to operate more efficiently during different phases or time periods, such as during compressor pauses, during compressor operation at reduced capacity, and so on. By preventing external fluids from flowing into the compressor, the standby mode of the HVAC&R system can improve the efficiency of the compressor and / or heat pump system, such as by reducing the downtime of the heat pump system associated with purging of non-condensable air within the system.

[0072] While only certain features and embodiments are shown and described, many modifications and alterations will occur to those skilled in the art without substantially departing from the novel teachings and advantages of the subject matter set forth in the claims, such as variations in the size, dimensions, structure, shape and proportions of various elements, parameter values ​​(such as temperature and pressure), installation arrangements, use of materials, color, orientation, etc. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations that fall within the true spirit of this disclosure.

[0073] Furthermore, in an effort to provide a concise description of exemplary embodiments, not all features of actual implementations may be described, such as those not relevant to the currently anticipated optimal mode or those unrelated to activation. It should be understood that, as in any engineering or design project, many implementation-specific decisions can be made in the development of such actual implementations. Such development work may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, these are routine tasks of design, fabrication, and production without requiring excessive experimentation.

[0074] The techniques proposed and claimed herein are referenced and applied to practical objects and specific instances of a material nature that demonstrably improve the art, and are therefore not abstract, intangible, or purely theoretical. Furthermore, if any claim appended to this specification contains one or more elements expressed as "means for [performing] [function]..." or "steps for [performing] [function]...", it is intended that such elements be interpreted in accordance with 35 USC 112(f). However, for any claim containing elements specified in any other manner, it is intended that such elements not be interpreted in accordance with 35 USC 112(f).

Claims

1. A heating, ventilation, air conditioning and cooling (HVAC&R) system, comprising: - A working fluid circuit, which is configured to circulate working fluid through the working fluid circuit; - A compressor disposed along the working fluid circuit and configured to pressurize the working fluid, wherein the compressor includes a housing, the housing including an impeller cavity and a first flow path, the impeller cavity being configured to guide the working fluid through the impeller cavity, the first flow path being fluidly coupled to the impeller cavity and the surrounding environment of the compressor; and -Control system, which is configured as follows: - Operate the compressor in standby mode, wherein there is no need for adjustment by the HVAC&R system in the standby mode; as well as - In the standby mode, the HVAC&R system is operated to increase the pressure of the working fluid to meet or exceed a threshold pressure value.

2. The HVAC&R system according to claim 1, The control system is configured to operate the compressor in the standby mode to increase the pressure of the working fluid.

3. The HVAC&R system according to claim 1 or 2, The threshold pressure value is based on the pressure of the surrounding environment.

4. The HVAC&R system according to claim 3, The threshold pressure value is greater than the pressure of the surrounding environment.

5. The HVAC&R system according to any one of claims 1 to 4, The compressor mentioned above includes: - An impeller disposed within the impeller cavity; as well as - An electric motor configured to drive the rotation of the impeller, wherein the electric motor includes a motor cavity and a second flow path, the motor cavity being configured to guide cooling fluid through the motor cavity, and the second flow path being fluidly connected to the motor cavity and the surrounding environment surrounding the compressor.

6. The HVAC&R system according to claim 5, The first flow path and the second flow path are fluidly connected to each other within the housing.

7. The HVAC&R system according to claim 6, The housing includes: - The outlet exposed to the surrounding environment surrounding the compressor; as well as - A third flow path extending from the first flow path and the second flow path to the discharge outlet. The first flow path and the third flow path are configured to guide a portion of the working fluid from the impeller cavity to the surrounding environment around the compressor during operation in the standby mode.

8. The HVAC&R system according to any one of claims 5 to 7, The motor is configured to receive an airflow as the cooling fluid and to guide the airflow through the motor cavity and the second flow path.

9. The HVAC&R system according to claim 7, The compressor includes a sealing system, and the sealing system includes: -A first labyrinth seal disposed along the first flow path; as well as - A second labyrinth seal is provided along the second flow path.

10. The HVAC&R system according to any one of claims 1 to 9, It includes a heating system coupled to the working fluid circuit and communicatively coupled to the control system, wherein the control system is configured to operate the heating system in the standby mode to increase the pressure of the working fluid to meet or exceed the threshold pressure value.

11. The HVAC&R system according to claim 10, The heating system mentioned above includes an electric heater.

12. The HVAC&R system according to any one of claims 1 to 11, It includes a sensor communicatively coupled to the control system and configured to detect operating parameters of the working fluid, wherein the control system is configured to operate the HVAC&R system in the standby mode to increase the pressure of the working fluid in response to determining that the operating parameters have dropped below a threshold.

13. The HVAC&R system according to any one of claims 1 to 12, The compressor is configured to circulate water as the working fluid through the working fluid circuit.

14. A heating, ventilation, air conditioning and cooling (HVAC&R) system, comprising: - A compressor including an impeller chamber and an impeller disposed within the impeller chamber, wherein the compressor is configured to pressurize a working fluid within the impeller chamber; - An electric motor coupled to the compressor, wherein the motor is configured to drive the rotation of the impeller to pressurize the working fluid, and the motor includes a motor cavity configured to allow cooling fluid to circulate through the motor cavity; - A first flow path that extends between the impeller cavity and the surrounding environment around the HVAC&R system; - A second flow path that extends between the motor cavity and the surrounding environment surrounding the HVAC&R system; and -Control system, which is configured as follows: - Operate the HVAC&R system in normal operating mode in response to heating or cooling needs; and - Operate the HVAC&R system in standby mode when there is no need for heating or cooling, wherein the control system is configured to operate the HVAC&R system to increase the pressure of the working fluid in the standby mode.

15. The HVAC&R system according to claim 14, The first flow path and the second flow path each extend at least partially through the housing of the compressor, the first flow path and the second flow path are fluidly connected to each other within the housing, and the HVAC&R system includes a labyrinth seal system disposed along the first flow path, the second flow path, or both.

16. The HVAC&R system according to claim 14 or 15, The control system is configured to operate the motor in the standby mode to drive the rotation of the impeller to increase the pressure of the working fluid.

17. The HVAC&R system according to any one of claims 14 to 16, It includes an electric heater connected to the compressor, the heat exchanger of the HVAC&R system, the working fluid circuit of the HVAC&R system, or a combination thereof, wherein the control system is configured to operate the electric heater in the standby mode to increase the pressure of the working fluid.

18. The HVAC&R system according to any one of claims 14 to 17, The control system is configured to operate the HVAC&R system in the standby mode to increase the pressure of the working fluid to meet or exceed a threshold pressure value, wherein the threshold pressure value is based on the pressure of the surrounding environment around the HVAC&R system, the pressure of the cooling fluid, or both.

19. A control system for a heating, ventilation, air conditioning and cooling (HVAC&R) system, wherein the control system is configured to: - Determine that there is no heating or cooling requirement for the HVAC&R system; - Operate the HVAC&R system in standby mode based on the determination that there is no heating or cooling requirement for the HVAC&R system; - Receive data indicating the detected parameter values ​​of the working fluid of the HVAC&R system in the standby mode; - Determining that the detected parameter value is below a threshold in the standby mode, wherein the threshold is based on the pressure of the ambient environment surrounding the HVAC&R system; and - In response to determining that the detected parameter value is below the threshold, the HVAC&R system is operated in the standby mode to increase the detected parameter value of the working fluid.

20. The control system according to claim 18, The detected parameter value is either the detected temperature value or the detected pressure value of the working fluid, and the control system is configured to: operate the compressor of the HVAC&R system in the standby mode to increase the detected parameter value of the working fluid, start the heating system of the HVAC&R system in the standby mode to increase the detected parameter value of the working fluid, or both.

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