Compressor sensor and diagnostics system and method

Abstract

A heating, ventilation, and / or air conditioning (HVAC) system includes a vapor compression cycle having a compressor. The HVAC system also includes a first sensor configured to detect a discharge pressure of a refrigerant leaving the compressor, a second sensor configured to detect a suction pressure of the refrigerant entering the compressor, and processing circuitry. The processing circuitry is configured to receive, from the first sensor and the second sensor, sensor feedback indicative of the discharge pressure and the suction pressure, respectively. The processing circuitry is also configured to determine, based at least in part on the discharge pressure and the suction pressure, a suction mass flow rate of the refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, or any combination thereof.

Description

BACKGROUND

[0001] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0002] The present disclosure relates generally to heating, ventilation, and / or air conditioning (HVAC) systems. A wide range of applications exist for HVAC systems. For example, residential, light commercial, commercial, and industrial systems are used to control temperatures and air quality in residences and buildings. Such systems may perform heating and / or cooling functions. Very generally, these systems operate by implementing a thermal cycle, also referred to as a vapor compression circuit or vapor compression cycle in the present disclosure, in which fluids are subjected to various temperatures and / or pressures to deliver, for example, an air flow with a desired temperature to a controlled space, such as a space within a residence or building. For example, a heat exchanger may include a coil, such as an indoor coil, configured to receive and place a fluid, such as a refrigerant, in a heat exchange relationship with an air flow to enable heat transfer between the fluid and the air flow in order to condition the air flow prior to delivery of the air flow to the controlled space. A compressor of the HVAC system may be configured to bias the fluid, such as the refrigerant, to and from the heat exchanger. Additional or alternate componentry of the HVAC system, such as an additional heat exchanger and an expansion valve, is also possible depending on the application.

[0003] In traditional configurations employing the compressor, it may be expensive (e.g., prohibitively expensive) to directly and accurately detect certain operating characteristics, such as suction mass flow rate of a refrigerant entering the compressor, an input power of the compressor, and the like, important for determining system diagnostics and / or controls of the vapor compression cycle. Accordingly, it is now recognized that improved systems and methods are desired.SUMMARY

[0004] A summary of an embodiment disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of the embodiment and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0005] In an embodiment, a heating, ventilation, and / or air conditioning (HVAC) system includes a vapor compression cycle having a compressor. The HVAC system also includes a first sensor configured to detect a discharge pressure of a refrigerant leaving the compressor, a second sensor configured to detect a suction pressure of the refrigerant entering the compressor, and processing circuitry. The processing circuitry is configured to receive, from the first sensor and the second sensor, sensor feedback indicative of the discharge pressure and the suction pressure, respectively. The processing circuitry is also configured to determine, based at least in part on the discharge pressure and the suction pressure, a suction mass flow rate of the refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, or any combination thereof.

[0006] In another embodiment, one or more tangible, non-transitory, computer readable media store instructions thereon that, when executed by processing circuitry, are configured to cause the processing circuitry to perform various operations. The operations include receiving first data indicative of a first known operating condition of a compressor and receiving second data indicative of a second known operating condition of the compressor. The operations also include determining, based at least in part on the first known operating condition and the second known operating condition, a suction mass flow rate of a refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, a pressure ratio of the refrigerant leaving and entering the compressor, or any combination thereof.

[0007] In another embodiment, a heating, ventilation, and / or air conditioning (HVAC) system includes a vapor compression cycle comprising a compressor, a first sensor configured to detect a first discharge or suction condition of a refrigerant, a second sensor configured to detect a second discharge or suction condition of the refrigerant, and processing circuitry. The processing circuitry is configured to receive, from the first sensor and the second sensor, sensor feedback indicative of the first discharge or suction condition and the second discharge or suction condition, respectively, Further, the processing circuitry is configured to determine, based at least in part on the first discharge or suction condition and the second discharge or suction condition, a suction mass flow rate of the refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, or any combination thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0009] FIG. 1 is a perspective view of an embodiment of a heating, ventilation, and / or air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units, in accordance with aspects of the present disclosure;

[0010] FIG. 2 is a perspective view of an embodiment of an HVAC unit of the HVAC system of FIG. 1, in accordance with aspects of the present disclosure;

[0011] FIG. 3 is a perspective view of an embodiment of a residential split heating and cooling system, in accordance with aspects of the present disclosure;

[0012] FIG. 4 is a schematic view of an embodiment of a vapor compression system that may be used in an HVAC system, in accordance with aspects of the present disclosure;

[0013] FIG. 5 is a schematic illustration of an embodiment of a vapor compression cycle having a compressor, in accordance with aspects of the present disclosure;

[0014] FIG. 6 is a schematic illustration of an embodiment of the compressor of FIG. 5 and various conditions (e.g., temperature and pressure conditions) associated with the compressor and / or a refrigerant flowing therethrough, in accordance with aspects of the present disclosure;

[0015] FIG. 7 is a schematic illustration of an embodiment of a processing system (e.g., a control system) corresponding to the vapor compression cycle of FIG. 5 and / or the compressor thereof illustrated in FIG. 6, in accordance with aspects of the present disclosure; and

[0016] FIG. 8 is a process flow diagram illustrating an embodiment of a method of determining (e.g., via the processing system of FIG. 7) various operating characteristics (e.g., a suction mass flow rate, an input power, system diagnostic characteristics, etc.) of the vapor compression cycle of FIG. 5 and / or the compressor thereof illustrated in FIG. 6, in accordance with aspects of the present disclosure.DETAILED DESCRIPTION

[0017] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0018] When introducing elements of various embodiments of the present disclosure, the articles “a,”“an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be noted that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0019] As used herein, the terms “approximately,”“generally,”“substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to convey that the property value may be within + / −5%, within + / −4%, within + / −3%, within + / −2%, within + / −1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to convey that the given feature is within + / −5%, within + / −4%, within + / −3%, within + / −2%, within + / −1%, or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Mathematical terms, such as “parallel” and “perpendicular,” should not be rigidly interpreted in a strict mathematical sense, but should instead be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that two lines that are substantially parallel to each other are parallel to a substantial degree, but may have minor deviation from exactly parallel.

[0020] The present disclosure is generally directed to determining certain operating characteristics (e.g., inferred or estimated operating characteristics), including system diagnostics characteristics, of a vapor compression cycle and / or a compressor thereof based on certain operating conditions (e.g., detected or otherwise known operating conditions) of the compressor. More specifically, the present disclosure is directed to determining a suction mass flow rate of a refrigerant entering the compressor, an input power of the compressor, a cooling capacity of the vapor compression cycle, and / or a cooling coefficient of performance (COP) of the vapor compression cycle based at least in part on sensor feedback from relatively reliable and relatively inexpensive sensors. In one example, sensor feedback from a first sensor configured to detect a first discharge or suction condition (e.g., a first detected discharge or suction condition) of a refrigerant and a second sensor configured to detect a second discharge or suction condition (e.g., a second detected discharge or suction condition) of the refrigerant may be employed to determine the suction mass flow rate, the input power, or both, from which the cooling capacity and / or the cooling COP may be derived (e.g., inferred or estimated). The detected discharge or suction conditions may include, for example, a detected discharge or suction temperature of the refrigerant and / or a detected discharge or suction pressure of the refrigerant. “Discharge” as used herein refers to the refrigerant leaving the compressor and “suction” as used herein refers to the refrigerant entering the compressor.

[0021] As a more specific example, the first sensor may be configured to detect a discharge pressure of the refrigerant leaving the compressor and the second sensor configured to detect a suction pressure of the refrigerant entering the compressor. Sensor feedback indicative of the discharge pressure and the suction pressure, along with other information, may be employed to determine the suction mass flow rate of the refrigerant entering the compressor, the input power to the compressor, or both. Further, the suction mass flow rate may be employed to determine the cooling capacity of the vapor compression cycle. Further still, the cooling capacity of the vapor compression cycle and the input power may be employed to determine the cooling COP of the vapor compression cycle. The cooling capacity of the vapor compression cycle and the cooling COP may be referred to as “system diagnostics characteristics” herein, which may be a sub-set of the operating characteristics.

[0022] Other sensors and corresponding sensor feedback, such as a third sensor configured to detect a temperature of the refrigerant (e.g., a discharge temperature or a suction temperature), may also be employed to determine certain operating characteristics of the vapor compression cycle and / or the compressor thereof. As an example, a discharge temperature may be determined based on sensor feedback indicative of a suction temperature, the discharge pressure, and the suction pressure, among other possible information. Alternatively, the suction temperature may be determined based on sensor feedback indicative of the discharge temperature, the discharge pressure, and the suction pressure, among other possible information. In some embodiments, a ratio between discharge pressure and suction pressure (referred to herein as a “pressure ratio”) may be determined based on sensor feedback indicative of discharge temperature and suction temperature, among other possible information, where the pressure ratio may be employed, along with other possible information, to determine the suction mass flow rate, the input power, or both. Additionally or alternatively, the pressure ratio may be determined based on sensor feedback indicative of the suction pressure, a rotational frequency of the compressor, and / or the input power of the compressor, where the rotational frequency and the input power are either detected via one or more sensors or otherwise known (e.g., by a variable frequency drive of the compressor).

[0023] While certain of the above-described operating characteristics (e.g., inferred or estimated operating characteristics) are determined based at least in part on sensor feedback, as described above, other information may also be employed to determine the operating characteristics. For example, the rotational frequency of the compressor (which may be known or detected by an additional sensor, as described above), the input power of the compressor (which may be known or detected by an additional sensor, as described above), a density characteristic (e.g., a refrigerant density), a specific volume characteristic (e.g., a refrigerant specific volume), one or more fitting coefficients derived for a particular type of compressor via experimental testing, etc., may also be employed to determine certain of the operating characteristics (e.g., inferred or estimated operating characteristics) of the vapor compression cycle and / or the compressor thereof. These and other aspects of the present disclosure are described in greater detail below with reference to various equations (e.g., operating characteristic equations), also referred to as models, and the drawings.

[0024] In traditional configurations, sensor technologies employed to detect (e.g., directly detect) certain operating characteristics of the vapor compression cycle and / or the compressor thereof, such as the suction mass flow rate and / or the input power described above, may be expensive (e.g., prohibitively expensive) and / or prone to errors or inaccuracies. In accordance with the present disclosure, sensor feedback from relatively reliable and relatively inexpensive sensors, such as pressure sensors and / or temperature sensors, is instead employed (e.g., along with other information) to determine the suction mass flow rate and / or the input power. For example, processing circuitry may be configured to determine the suction mass flow rate, the input power, the cooling capacity of the vapor compression cycle, the cooling COP of the vapor compression cycle, etc. based at least in part on sensor feedback from the pressure and / or temperature sensors in certain embodiments. Additionally or alternatively, the processing circuitry may perform at least one action based at least in part on an analysis of one or more of the operating characteristics, such as transmitting a notification to another device and / or outputting the notification to a display, controlling an operating aspect (e.g., a rotational frequency or speed) of the compressor, controlling a component (e.g., a valve) of the vapor compression cycle other than the compressor, or any combination thereof. The processing circuitry may perform certain of the one or more actions based at least in part on, for example, an operating characteristic deviating from an expected or reference operating characteristic, an operating characteristic meeting a pre-defined relationship with a threshold operating characteristic, or the like. These and other aspects of the present disclosure, including examples of detailed equations (also referred to as models) corresponding to the above-described operating characteristics, are described in greater detail below with reference to the drawings.

[0025] Turning now to the drawings, FIG. 1 illustrates an embodiment of a heating, ventilation, and / or air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units. The HVAC system of FIG. 1 may also employ present embodiments to limit overflow of condensate into ductwork. In the illustrated embodiment, a building 10 is air conditioned by a system that includes an HVAC unit 12. The building 10 may be a commercial structure or a residential structure. As shown, the HVAC unit 12 is disposed on the roof of the building 10; however, the HVAC unit 12 may be located in other equipment rooms or areas adjacent the building 10. The HVAC unit 12 may be a single package HVAC unit containing other equipment, such as a blower, integrated air handler, and / or auxiliary heating unit. In other embodiments, the HVAC unit 12 may be part of a split HVAC system, such as the system shown in FIG. 3, which includes an outdoor HVAC unit 58 and an indoor HVAC unit 56.

[0026] The HVAC unit 12 is an air-cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. Specifically, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and / or a return air flow from the building 10. After the HVAC unit 12 conditions the air, the air is supplied to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or other sections of the building 10. In certain embodiments, the HVAC unit 12 may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream. A heat exchanger of the HVAC unit 12, such as one in a refrigeration circuit, may cause generation of condensate that is collected and removed in accordance with embodiments of the presently disclosed drain system and shield.

[0027] A control device 16, one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device 16 also may be used to control the flow of air through the ductwork 14. For example, the control device 16 may be used to regulate operation of one or more components of the HVAC unit 12 or other components, such as dampers and fans, within the building 10 that may control flow of air through and / or from the ductwork 14. In some embodiments, other devices may be included in the system, such as pressure and / or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and so forth. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10.

[0028] FIG. 2 is a perspective view of an embodiment of the HVAC unit 12. In the illustrated embodiment, the HVAC unit 12 is a single package HVAC unit that may include one or more independent refrigeration circuits and components that are tested, charged, wired, piped, and ready for installation. The HVAC unit 12 may provide a variety of heating and / or cooling functions, such as cooling only, heating only, cooling with electric heat, cooling with dehumidification, cooling with gas heat, or cooling with a heat pump. As described above, the HVAC unit 12 may directly cool and / or heat an air stream provided to the building 10 to condition a space in the building 10.

[0029] As shown in the illustrated embodiment of FIG. 2, a cabinet 24 encloses the HVAC unit 12 and provides structural support and protection to the internal components from environmental and other contaminants. In some embodiments, the cabinet 24 may be constructed of galvanized steel and insulated with aluminum foil faced insulation. Rails 26 may be joined to the bottom perimeter of the cabinet 24 and provide a foundation for the HVAC unit 12. In certain embodiments, the rails 26 may provide access for a forklift and / or overhead rigging to facilitate installation and / or removal of the HVAC unit 12. In some embodiments, the rails 26 may fit into “curbs” on the roof to enable the HVAC unit 12 to provide air to the ductwork 14 from the bottom of the HVAC unit 12 while blocking elements such as rain from leaking into the building 10.

[0030] The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Such heat exchangers may cause accumulation of condensate from environmental air that is addressed by embodiments of the presently disclosed drainage system. Tubes within the heat exchangers 28 and 30 may circulate a working fluid, such as R-410A, through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, microchannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the working fluid undergoes phase changes and / or temperature changes as it flows through the heat exchangers 28 and 30 to produce heated and / or cooled air. For example, the heat exchanger 28 may function as a condenser where heat is released from the working fluid to ambient air, and the heat exchanger 30 may function as an evaporator where the working fluid absorbs heat to cool an air stream. In other embodiments, the HVAC unit 12 may operate in a heat pump mode where the roles of the heat exchangers 28 and 30 may be reversed. That is, the heat exchanger 28 may function as an evaporator and the heat exchanger 30 may function as a condenser. In further embodiments, the HVAC unit 12 may include a furnace for heating the air stream that is supplied to the building 10. While the illustrated embodiment of FIG. 2 shows the HVAC unit 12 having two of the heat exchangers 28 and 30, in other embodiments, the HVAC unit 12 may include one heat exchanger or more than two heat exchangers.

[0031] The heat exchanger 30 is located within a compartment 31 that separates the heat exchanger 30 from the heat exchanger 28. Fans 32 draw air from the environment through the heat exchanger 28. Air may be heated and / or cooled as the air flows through the heat exchanger 28 before being released back to the environment surrounding the rooftop unit 12. A blower assembly 34, powered by a motor 36, draws air through the heat exchanger 30 to heat or cool the air. The heated or cooled air may be directed to the building 10 by the ductwork 14, which may be connected to the HVAC unit 12. Before flowing through the heat exchanger 30, the conditioned air flows through one or more filters 38 that may remove particulates and contaminants from the air. In certain embodiments, the filters 38 may be disposed on the air intake side of the heat exchanger 30 to prevent contaminants from contacting the heat exchanger 30.

[0032] The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 increase the pressure and temperature of the working fluid before the working fluid enters the heat exchanger 28. The compressors 42 may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors 42 may include a pair of hermetic direct drive compressors arranged in a dual stage configuration 44. However, in other embodiments, any number of the compressors 42 may be provided to achieve various stages of heating and / or cooling. As may be appreciated, additional equipment and devices may be included in the HVAC unit 12, such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things.

[0033] The HVAC unit 12 may receive power through a terminal block 46. For example, a high voltage power source may be connected to the terminal block 46 to power the equipment. The operation of the HVAC unit 12 may be governed or regulated by a control board 48. The control board 48 may include control circuitry connected to a thermostat, sensors, and alarms. One or more of these components may be referred to herein separately or collectively as the control device 16. The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring 49 may connect the control board 48 and the terminal block 46 to the equipment of the HVAC unit 12.

[0034] FIG. 3 illustrates an embodiment of a residential heating and cooling system 50, also in accordance with present techniques. The residential heating and cooling system 50 may provide heated and cooled air to a residential structure, as well as provide outside air for ventilation and provide improved indoor air quality (IAQ) through devices such as ultraviolet lights and air filters. In the illustrated embodiment, the residential heating and cooling system 50 is a split HVAC system. In general, a residence 52 conditioned by a split HVAC system may include working fluid conduits 54 that operatively couple the indoor unit 56 to the outdoor unit 58. The indoor unit 56 may be positioned in a utility room, an attic, a basement, and so forth. The outdoor unit 58 is typically situated adjacent to a side of residence 52 and is covered by a shroud to protect the system components and to prevent leaves and other debris or contaminants from entering the unit. The working fluid conduits 54 transfer working fluid between the indoor unit 56 and the outdoor unit 58, typically transferring primarily liquid working fluid in one direction and primarily vaporized working fluid in an opposite direction.

[0035] When the system shown in FIG. 3 is operating as an air conditioner, a heat exchanger 60 in the outdoor unit 58 serves as a condenser for re-condensing vaporized working fluid flowing from the indoor unit 56 to the outdoor unit 58 via one of the working fluid conduits 54. In these applications, a heat exchanger 62 of the indoor unit functions as an evaporator. Specifically, the heat exchanger 62 receives liquid working fluid, which may be expanded by an expansion device, and evaporates the working fluid before returning it to the outdoor unit 58.

[0036] The outdoor unit 58 draws environmental air through the heat exchanger 60 using a fan 64 and expels the air above the outdoor unit 58. When operating as an air conditioner, the air is heated by the heat exchanger 60 within the outdoor unit 58 and exits the unit at a temperature higher than it entered. The indoor unit 56 includes a blower or fan 66 that directs air through or across the indoor heat exchanger 62, where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork 68 that directs the air to the residence 52. In accordance with present embodiments, the indoor unit 56 includes a drain system in accordance with the present disclosure to limit or block condensate generated by cooling of atmospheric air, for example, from entering the ductwork 68. The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the set point on the thermostat, or the set point plus a small amount, the residential heating and cooling system 50 may become operative to refrigerate additional air for circulation through the residence 52. When the temperature reaches the set point, or the set point minus a small amount, the residential heating and cooling system 50 may stop the refrigeration cycle temporarily.

[0037] The residential heating and cooling system 50 may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers 60 and 62 are reversed. That is, the heat exchanger 60 of the outdoor unit 58 will serve as an evaporator to evaporate working fluid and thereby cool air entering the outdoor unit 58 as the air passes over outdoor the heat exchanger 60. The indoor heat exchanger 62 will receive a stream of air blown over it and will heat the air by condensing the working fluid.

[0038] In some embodiments, the indoor unit 56 may include a furnace system 70. For example, the indoor unit 56 may include the furnace system 70 when the residential heating and cooling system 50 is not configured to operate as a heat pump. The furnace system 70 may include a burner assembly and heat exchanger, among other components, inside the indoor unit 56. Fuel is provided to the burner assembly of the furnace 70 where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger 62, such that air directed by the blower 66 passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system 70 to the ductwork 68 for heating the residence 52.

[0039] FIG. 4 is an embodiment of a vapor compression system 72 that can be used in any of the systems described above and incorporates one or more drainage system in accordance with present embodiments. The vapor compression system 72 may circulate a working fluid through a circuit starting with a compressor 74. The circuit may also include a condenser 76, an expansion valve(s) or device(s) 78, and an evaporator 80. The vapor compression system 72 may further include a control panel 82 that has an analog to digital (A / D) converter 84, a microprocessor 86, a non-volatile memory 88, and / or an interface board 90. The control panel 82 and its components may function to regulate operation of the vapor compression system 72 based on feedback from an operator, from sensors of the vapor compression system 72 that detect operating conditions, and so forth.

[0040] In some embodiments, the vapor compression system 72 may use one or more of a variable speed drive (VSDs) 92, a motor 94, the compressor 74, the condenser 76, the expansion valve or device 78, and / or the evaporator 80. The motor 94 may drive the compressor 74 and may be powered by the variable speed drive (VSD) 92. The VSD 92 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 94. In other embodiments, the motor 94 may be powered directly from an AC or direct current (DC) power source. The motor 94 may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

[0041] The compressor 74 compresses a working fluid vapor and delivers the vapor to the condenser 76 through a discharge passage. In some embodiments, the compressor 74 may be a centrifugal compressor. The working fluid vapor delivered by the compressor 74 to the condenser 76 may transfer heat to a fluid passing across the condenser 76, such as ambient or environmental air 96. The working fluid vapor may condense to a working fluid liquid in the condenser 76 as a result of thermal heat transfer with the environmental air 96. The liquid working fluid from the condenser 76 may flow through the expansion device 78 to the evaporator 80.

[0042] The liquid working fluid delivered to the evaporator 80 may absorb heat from another air stream, such as a supply air stream 98 provided to the building 10 or the residence 52. For example, the supply air stream 98 may include ambient or environmental air, return air from a building, or a combination of the two. The liquid working fluid in the evaporator 80 may undergo a phase change from the liquid working fluid to a working fluid vapor. In this manner, the evaporator 80 may reduce the temperature of the supply air stream 98 via thermal heat transfer with the working fluid. Thereafter, the vapor working fluid exits the evaporator 80 and returns to the compressor 74 by a suction line to complete the cycle.

[0043] In some embodiments, the vapor compression system 72 may further include a reheat coil in addition to the evaporator 80. For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream 98 and may reheat the supply air stream 98 when the supply air stream 98 is overcooled to remove humidity from the supply air stream 98 before the supply air stream 98 is directed to the building 10 or the residence 52.

[0044] It should be appreciated that any of the features described herein may be incorporated with the HVAC unit 12, the residential heating and cooling system 50, or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications.

[0045] In any of the systems / units outlined above with respect to FIGS. 1-4, processing circuitry may determine various operating characteristics of a vapor compression cycle (also referred to as a vapor compression circuit) and / or a compressor thereof based at least in part on sensor feedback from relatively reliable and relatively inexpensive sensor technologies, such as one or more pressure sensors (e.g., one or more discharge pressure sensors, one or more suction pressure sensors, or a combination thereof), one or more temperature sensors (e.g., one or more discharge temperature sensors, one or more suction temperature sensors, or a combination thereof), other types of sensors, or a combination thereof. Other information, such as a rotational frequency of the compressor (which may be known or detected by an additional sensor), a density characteristic (e.g., a refrigerant density), a specific volume characteristic (e.g., a refrigerant specific volume), and / or one or more fitting coefficients derived from experimental testing of a compressor type at issue, may also be employed in determining certain operating characteristics of the vapor compression cycle and / or compressor thereof. The operating characteristics may include, for example, a suction mass flow rate of the refrigerant entering the compressor, an input power of the compressor, a particular temperature (e.g., a discharge temperature or a suction temperature) of the refrigerant, various system diagnostics characteristics (e.g., a cooling capacity of the vapor compression cycle, a cooling coefficient of performance or COP of the vapor compression cycle, etc.), or any combination thereof. In some embodiments, the processing circuitry performs at least one action based at least in part on an analysis of one or more of the operating characteristics, such as transmitting a notification (e.g., to a separate device) or otherwise outputting the notification on a display, controlling an operating aspect (e.g., a rotational frequency or speed) of the compressor, controlling an operating aspect of another component (e.g., a valve) of the vapor compression cycle besides the compressor, etc. These and other aspects of the present disclosure are described in detail below with reference to various equations (also referred to as models) and FIGS. 5-8.

[0046] With the preceding in mind, FIG. 5 is a schematic illustration of an embodiment a vapor compression cycle 100 (also referred to as a vapor compression circuit) having a compressor 102. The compressor 102 may be, for example, a positive displacement compressor (e.g., non-injected), although other types or sub-types of the compressor 102 (e.g., a scroll compressor, a screw compressor, a rotary compressor, a reciprocating compressor, a centrifugal compressor, etc.) may also be possible in accordance with the present disclosure. In the illustrated embodiment, the compressor 102 includes an inlet 104 (e.g., a suction side) configured to receive a refrigerant 106, an outlet 108 (e.g., a discharge side) configured to output the refrigerant 106, and a compression mechanism110 (e.g., a positive displacement compression mechanism, such as a piston, a crankshaft, a crosshead, and / or a connecting rod, although other compression mechanisms may also be possible in accordance with the present disclosure, such as an impeller and / or a rotor,). In general, the compression mechanism 110 is configured to compress the refrigerant 106 received via the inlet 104 prior to outputting the refrigerant 106 via the outlet 108. In effect, the compressor 102 may operate to increase a pressure of the refrigerant 106, for example, to bias the refrigerant 106 through the vapor compression cycle 100 and various components thereof, such as an outdoor heat exchanger 112 downstream (e.g., immediately downstream or otherwise adjacent to) the compressor 102 relative to a flow of the refrigerant 106, an expansion valve 114 downstream (e.g., immediately downstream or otherwise adjacent to) the outdoor heat exchanger 112 relative to the flow of the refrigerant 106, and an indoor heat exchanger 116 downstream (e.g., immediately downstream or otherwise adjacent to) the expansion valve 114 relative to the flow of the refrigerant 106.

[0047] In the illustrated embodiment, a first sensor 118 (e.g., a discharge pressure sensor) is configured to detect a discharge pressure of a portion of the refrigerant 106 exiting the compressor 102 at or adjacent to the outlet 108, a second sensor 120 (e.g., a suction pressure sensor) is configured to detect a suction pressure of a portion of the refrigerant 106 entering the compressor 102 at or adjacent to the inlet 104, a third sensor 122 (e.g., a discharge temperature sensor) is configured to detect a discharge temperature of a portion of the refrigerant 106 exiting the compressor 102 at or adjacent to the outlet 108, and a fourth sensor 124 (e.g., a suction temperature sensor) is configured to detect a suction temperature of a portion of the refrigerant 106 entering the compressor 102 at or adjacent to the inlet 104. As will be appreciated in view of later description and various equations included therein, in some embodiments, fewer than the sensors 118, 120, 122, 124 are included. For example, certain embodiments may include only two of the sensors 118, 120, 122, 124, and certain other embodiments may include only three of the sensors 118, 120, 122, 124. Further, in certain embodiments, one or more additional sensor(s) 126 are employed to detect a rotational frequency of the compressor 102, an input power of the compressor 102, or both, although the rotational frequency and the input power may be known (e.g., via a variable frequency drive of the compressor 102) in other embodiments. That is, while reference numeral 126 may indicate one or more additional sensors in certain embodiments, reference numeral 126 may indicate a variable frequency drive (VFD) in certain embodiments. Accordingly, while description below may refer to reference numeral 126 as one or more additional sensors, it should be understood that reference numeral 126 may denote a VFD in certain embodiments.

[0048] In general, sensor feedback from at least some of the sensors 118, 120, 122, 124, 126 is employed to determine (e.g., infer or estimate) various operating characteristics of the vapor compression cycle 100 and / or the compressor 102 thereof, such as a suction mass flow rate of the refrigerant 106 entering the compressor 102, an input power of or to the compressor 102, a cooling capacity of the vapor compression cycle 100 (referred to as a system diagnostics characteristic), and / or a cooling coefficient of performance (COP) of the vapor compression cycle 100 (also referred to as a system diagnostics characteristic). Additionally or alternatively, in certain embodiments, a particular temperature of the refrigerant 106 may be determined based on sensor feedback from at least some of the sensors 118, 120, 122, 124, 126. As an example, in an embodiment excluding the third sensor 122 configured to detect the discharge temperature, the discharge temperature may be determined based at least in part on sensor feedback from the first sensor 118 configured to detect the discharge pressure, the second sensor 120 configured to detect the suction pressure, and the fourth sensor 124 configured to detect the suction temperature. As another example, in an embodiment excluding the fourth sensor 124 configured to detect the suction temperature, the suction temperature may be determined based at least in part on sensor feedback from the first sensor 118 configured to detect the discharge pressure, the second sensor 120 configured to detect the suction pressure, and the third sensor 122 configured to detect the discharge temperature.

[0049] In certain embodiments, the vapor compression cycle 100 may be a heat pump in which a flow direction of the refrigerant 106 is reversible. For example, the vapor compression cycle 100 illustrated in FIG. 5 includes a reversing valve 128 controllable to change a flow direction of the refrigerant 106. That is, while the refrigerant 106 is illustrated in FIG. 5 as flowing from the compressor 102 toward the outdoor heat exchanger 112 by way of the reversing valve 128, the reversing valve 128 may be controllable to cause the refrigerant 106 to flow from the compressor 102 toward the indoor heat exchanger 116 by way of the reversing valve 128 (e.g., in certain operating conditions). In this way, the roles of the outdoor heat exchanger 112 and the indoor heat exchanger 116 are reversible such that both cooling and heating may be provided via the vapor compression cycle 100 to a conditioned space. Although not shown in FIG. 5, a processing system 200 illustrated in (and described in greater detail with respect to) FIG. 7 may be employed to control the reversing valve 128 in certain embodiments, although other control mechanisms are also possible.

[0050] FIG. 6 is a schematic illustration of an embodiment of the compressor 102 of FIG. 5, including various conditions (e.g., temperature and pressure conditions) associated with the compressor 102. Conditions illustrated in FIG. 6 that are bounded by a box or block indicate conditions that may be, in certain embodiments, detected or detectable by a sensor (e.g., one of the sensors 118, 120, 122, 124, 126 illustrated in FIG. 5) and / or otherwise known (e.g., by a variable frequency drive of the compressor 102). For example, the refrigerant 106 exiting the compressor 102 via the outlet 108 includes a discharge pressure 150 (e.g., pd), which may be detected by the first sensor 118 in FIG. 5 in certain embodiments, and the refrigerant 106 entering the compressor 102 via the inlet 104 includes a suction pressure 152 (e.g., ps), which may be detected by the second sensor 120 in FIG. 5 in certain embodiments. Further, the refrigerant 106 exiting the compressor 102 via the outlet 108 includes a discharge temperature 154 (e.g., Td), which may be detected by the third sensor 122 in FIG. 5 in certain embodiments, and the refrigerant 106 entering the compressor 102 via the inlet 104 includes a suction temperature 156 (e.g., Ts), which may be detected by the fourth sensor 124 in FIG. 5 in certain embodiments. Further still, the compressor 102 may be operated at a particular rotational frequency 158 (e.g., N) and may receive an input power 160 (We), each of which may be detected by the one or more additional sensor(s) 126 in FIG. 5 in certain embodiments and / or otherwise known (e.g., by a variable frequency drive of the compressor 102). As previously described, in some embodiments, not all of the conditions 150, 152, 154, 156, 158 need be detected by sensors. For example, in certain embodiments, the suction temperature 156 is not detected by a sensor, and is instead determined based at least in part on certain of the other detected conditions, such as the discharge temperature 154, the discharge pressure 150, and the suction pressure 152. Likewise, in certain embodiments, the discharge temperature 154 is not detected by a sensor, and is instead determined based at least in part on certain of the other detected conditions, such as the suction temperature 156, the discharge pressure 150, and the suction pressure 152.

[0051] As shown in FIG. 6 and described in greater detail below with reference to FIGS. 7 and 8, a suction mass flow rate 159 (e.g., {dot over (m)}s) of the refrigerant 106 entering the compressor 102 and, in some embodiments, the input power 160 (e.g., {dot over (W)}e) of or to the compressor 102 may be determined based at least in part on certain of the conditions 150, 152, 154, 156, 158 referenced above, along with other possible information, such as a specific volume characteristic (e.g., a refrigerant specific volume characteristic), a density characteristic (e.g., a refrigerant density characteristic), and / or one or more fitting coefficients derived from experimental testing with respect to a particular compressor type. In some embodiments, a processing system (e.g., a control system) is employed to determine the suction mass flow rate 159 and the input power 160, among other possible operating characteristics of the vapor compression cycle and / or the compressor 102 thereof.

[0052] For example, FIG. 7 is a schematic illustration of an embodiment of a processing system 200 (e.g., a control system) corresponding to the vapor compression cycle 100 of FIG. 5 and / or the compressor 102 thereof illustrated in FIG. 6. In the illustrated embodiment, the processing system 200 includes a computing device 202 having processing circuitry 204, memory circuitry 206, communications circuitry 208, and a display 210. The processing circuitry 204 may be a general purpose or specific purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable processing components. In general, the processing circuitry 204 is configured to execute computer code or instructions stored in the memory circuitry 206 or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.). The memory circuitry 206 may include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and / or computer code for completing and / or facilitating the various processes described in the present disclosure. Further, the memory circuitry 206 may include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and / or computer instructions. Further still, the memory circuitry 206 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure.

[0053] The computing device 202 may be communicatively coupled with the sensors 118, 120, 122, 124, 126 such that the processing circuitry 204 is configured to receive sensor feedback from the sensors 118, 120, 122, 124, 126, noting that, in some embodiments and as previously described above, reference numeral 126 may additionally or alternatively denote a variable frequency drive communicatively coupled with the computing device 202. While all five of the sensors 118, 120, 122, 124, 126 are illustrated in FIG. 7, as previously described, certain of the sensors 118, 120, 122, 124, 126 may be excluded in certain embodiments. In general, the processing circuitry 204 is configured to execute the instructions stored, for example, on the memory circuitry 206 to determine various operating characteristics of the vapor compression cycle 100 illustrated in FIG. 5 and / or the compressor 102 thereof, which is illustrated in detail in FIG. 6, based at least in part on sensor feedback from at least some of the sensors 118, 120, 122, 124, 126. In some embodiments, the processing circuitry 204 is configured to perform a control action in response to an analysis of one or more of the operating characteristics, such as outputting a notification to the display 210, transmitting (e.g., via the communication circuitry 208) the notification or an additional notification to a separate device 212, controlling an aspect of the compressor 102 in FIGS. 5 and 6 (e.g., a rotational frequency or speed), controlling an aspect of a component (e.g., a valve, such as opening or closing the valve, changing a setting of the valve, etc.) besides the compressor 102 in the vapor compression cycle 100 of FIG. 5, or any combination thereof.

[0054] In determining the operating characteristics of the vapor compression cycle 100 and / or the compressor 102 thereof illustrated in FIGS. 5 and 6, the processing circuitry 204 may employ various equations that receive various information, such as some or all of the sensor feedback described above and other information. For example, Equations 1-8, described in detail below and also referred to as Models 1-8, are employed by the processing circuitry 204 to determine various operating characteristics. In Equations 1-8 below, pd is employed to denote the discharge pressure 150 illustrated in FIG. 6, ps is employed to denote the suction pressure 152 illustrated in FIG. 6, Td is employed to denote the discharge temperature 154 illustrated in FIG. 6, Ts is employed to denote the suction temperature 156 illustrated in FIG. 6, N is employed to denote the rotational frequency 158 illustrated in FIG. 6, {dot over (m)}s is employed to denote the suction mass flow rate 159 illustrated in FIG. 6, and {dot over (W)}e is employed to denote the input power 160 illustrated in FIG. 6. Further, in Equations 1-8 below, ρs is employed to denote a density characteristic (e.g., a refrigerant density characteristic), vs is employed to denote a specific volume characteristic (e.g., a refrigerant specific volume), and a0, a1, b0, b1, b2, b3, c0, c1, c2, and c3 are employed to denote various fitting coefficients (e.g., derived from experimental testing of a particular compressor type).

[0055] The processing circuitry 204 may determine the suction mass flow rate via Equation 1 and based on the density characteristic, the rotational frequency (e.g., detected rotational frequency), the discharge pressure (e.g., detected discharge pressure), suction pressure (e.g., detected suction pressure), and various fitting coefficients as follows:m˙s=ρs·N·[a0+a1·(pdps)]Equation⁢ 1

[0056] The processing circuitry 204 may determine the input power via Equation 2 and based on the suction mass flow rate (e.g., determined by way of Equation 1), the suction pressure (e.g., detected suction pressure), the discharge pressure (e.g., detected discharge pressure), the specific volume characteristic, and various fitting coefficients as follows:W˙e=b0+m˙s·ps·vs·[b1+b2·(pdps)b3]Equation⁢ 2

[0057] The processing circuitry 204 may determine the discharge temperature via Equation 3 and based on the suction temperature (e.g., detected suction temperature), the suction pressure (e.g., detected suction pressure), the discharge pressure (e.g., detected discharge pressure), and various fitting coefficients as follows:Td=c0+Ts·[c1+c2·(pdps)c3]Equation⁢ 3

[0058] The processing circuitry 204 may determine the suction temperature via Equation 4, which is a reconfiguration of Equation 3, based on the discharge temperature (e.g., detected discharge temperature), the suction pressure (e.g., detected suction pressure), the discharge pressure (e.g., detected discharge pressure), and various fitting coefficients as follows:Ts=Td-c0[c1+c2·(pdps)c3]Equation⁢ 4

[0059] In some embodiments, the processing circuitry 204 may employ Equation 5 below to determine a ratio of the discharge pressure to the suction pressure (also referred to as the pressure ratio), which can then be used in Equation 1 to determine the suction mass flow rate and / or Equation 2 to determine the input power. For example, the processing circuitry 204 may determine the pressure ratio via Equation 5 based on the suction temperature (e.g., detected suction temperature), the discharge temperature (e.g., detected discharge temperature), and various fitting coefficients as follows:pdps=Td-c0Ts-c1c2c3Equation⁢ 5

[0060] In some embodiments, the processing circuitry 204 may employ Equation 6 below to determine a ratio of the discharge pressure to the suction pressure (also referred to as the pressure ratio), which can then be used in Equation 1 to determine the suction mass flow rate and / or Equation 3 to determine the discharge pressure. For example, the processing circuitry 204 may determine the pressure ratio via Equation 6 based on the input power to the compressor (e.g., detected or otherwise known input power), the rotational frequency of the compressor (e.g., detected or otherwise known rotational frequency), the suction pressure (e.g., detected suction pressure), and various fitting coefficients as follows:W˙e-b0ps·N-a0·b1=pdps·[a1·b1+a0·b2·(pdps)b3-1+a1·b2·(pdps)b3]Equation⁢ 6

[0061] It should be noted that, in some implementations of Equation 6 above, an iterative procedure may be needed to ultimately isolate and / or yield the pressure ratio for use in, for example, Equation 1 and / or Equation 3 that output the suction mass flow rate and / or the discharge pressure, respectively. In embodiments employing Equation 6, a discharge pressure sensor may not be needed for determining some or all of the operating characteristics (including but not limited to the system diagnostic characteristics) at issue in the present disclosure, while a variable frequency drive (VFD) of the compressor already may be equipped to output the input power and / or the rotational frequency, thereby reducing costs relative to at least some traditional configurations.

[0062] As previously described, the processing circuitry 204 may also determine various system diagnostics characteristics, such as a cooling capacity (i.e., Qc) of the vapor compression cycle 100 of FIG. 5 and / or the cooling coefficient of performance (i.e., COPc) of the vapor compression cycle 100 of FIG. 5. For example, the processing circuitry may employ Equation 7 below to determine the cooling capacity based on the suction mass flow rate and an enthalpy difference (i.e., hs−h1) as follows:Q˙c=m˙s·(hs-hl)Equation⁢ 7

[0063] Further, the processing circuitry 204 may employ Equation 8 below to determine the cooling coefficient of performance based on the cooling capacity and the input power as follows:COPc=Q.cW˙eEquation⁢ 8

[0064] FIG. 8 is a process flow diagram illustrating an embodiment of a method 300 of determining, via the processing system 200 of FIG. 7, various characteristics (e.g., operating characteristics) of the vapor compression cycle 100 of FIG. 5 and / or the compressor 102 thereof illustrated in FIG. 6. In the illustrated embodiment, the method 300 includes receiving (block 302), via processing circuitry, data indicative of at least a first known compressor operating condition and a second known compressor operating condition. The first known compressor operating condition and the second known compressor operating condition may include, for example, detected operating conditions, such as a first detected discharge or suction condition (e.g., of refrigerant leaving or entering the compressor, respectively) and a second detected discharge or suction condition (e.g., of refrigerant leaving or entering the compressor, respectively). Other known compressor operating conditions may include rotational frequency of the compressor and / or input power of or to the compressor. Further, in some embodiments, more than two known compressor operating conditions may be employed. That is, in some embodiments, the processing circuitry may receive, for example, data indicative of a third known compressor operating condition.

[0065] The method 300 also includes determining (block 304), via the processing circuitry, based on the first known compressor operating condition, based on the second known compressor operating condition, and based on other information, at least one operating characteristic of the vapor compression cycle and / or the compressor thereof. The operating characteristic(s) may include, for example, a suction mass flow rate, an input power, a cooling capacity, a cooling coefficient of performance (COP), or any combination thereof, among other possible operating characteristics. Equations 1-8 above outline various operating characteristics that may be determined (e.g., inferred or estimated) by the processing circuitry based on various detected or otherwise known conditions.

[0066] The method 300 also includes performing (block 306), via the processing circuitry, at least one control action based on an analysis of the operating characteristic(s). For example, the processing circuitry may perform the control action in response to an operating characteristic deviating from an expected or reference operating characteristic, an operating characteristic meeting a pre-defined relationship with a threshold operating characteristic, or the like. The action(s) may include, for example, outputting a notification to a display, transmitting the notification or an additional notification to a separate device, controlling an aspect of the compressor (e.g., a rotational frequency of the compressor), controlling an aspect of a component (e.g., a valve) of the vapor compression cycle separate from the compressor, or any combination thereof.

[0067] Technical benefits associated with presently disclosed embodiments include determining various operating characteristics of a vapor compression cycle and / or a compressor thereof, including system diagnostics characteristics, via less expensive sensor technologies than traditional configurations, more accurately and / or reliably determining such operating characteristics relative to traditional configurations, or any combination thereof.

[0068] While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed disclosure). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0069] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112 (f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112 (f).

Claims

1. A heating, ventilation, and / or air conditioning (HVAC) system, comprising:a vapor compression cycle comprising a compressor;a first sensor configured to detect a discharge pressure of a refrigerant leaving the compressor;a second sensor configured to detect a suction pressure of the refrigerant entering the compressor; andprocessing circuitry configured to:receive, from the first sensor and the second sensor, sensor feedback indicative of the discharge pressure and the suction pressure, respectively; anddetermine, based at least in part on the discharge pressure and the suction pressure, a suction mass flow rate of the refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, or any combination thereof.

2. The HVAC system of claim 1, wherein the processing circuitry is configured to:determine the suction mass flow rate based at least in part on the discharge pressure and the suction pressure; anddetermine a cooling capacity of the vapor compression cycle based at least in part on the suction mass flow rate.

3. The HVAC system of claim 2, wherein the processing circuitry is configured to:determine the input power based at least in part on the discharge pressure, the suction pressure, and the suction mass flow rate; anddetermine a cooling coefficient of performance of the vapor compression cycle based at least in part on the cooling capacity and the input power.

4. The HVAC system of claim 3, comprising a third sensor configured to detect a rotational frequency corresponding to the compressor, wherein the processing circuitry is configured to:receive, from the third sensor, additional sensor feedback indicative of the rotational frequency; anddetermine the input power based at least in part on the rotational frequency, the suction mass flow rate, the discharge pressure, and the suction pressure.

5. The HVAC system of claim 1, comprising a third sensor configured to detect the suction temperature, wherein the processing circuitry is configured to:receive, from the third sensor, additional sensor feedback indicative of the suction temperature; anddetermine the discharge temperature based at least in part on the suction temperature, the discharge pressure, and the suction pressure.

6. The HVAC system of claim 1, comprising a third sensor configured to detect the discharge temperature, wherein the processing circuitry is configured to:receive, from the third sensor, additional sensor feedback indicative of the discharge temperature; anddetermine the suction temperature based at least in part on the discharge temperature, the discharge pressure, and the suction pressure.

7. The HVAC system of claim 1, wherein the processing circuitry is configured to determine, based at least in part on one or more fitting coefficients, the discharge pressure, and the suction pressure, the suction mass flow rate, the input power, the discharge temperature, the suction temperature, or any combination thereof.

8. The HVAC system of claim 1, wherein the processing circuitry is configured to determine the suction mass flow rate based at least in part on a refrigerant density of the refrigerant, the discharge pressure, and the suction pressure.

9. The HVAC system of claim 1, wherein the processing circuitry is configured to perform an action based at least in part on an analysis of the suction mass flow rate, the input power, the discharge temperature, the suction temperature, a cooling capacity derived at least in part from the suction mass flow rate, or a cooling coefficient of performance derived at least in part from the cooling capacity and the input power, wherein the action comprises:transmitting a notification or outputting the notification to a display;controlling an operating characteristic of the compressor; orcontrolling an operating characteristic of a component of the HVAC system separate from the compressor.

10. One or more tangible, non-transitory, computer readable media storing instructions thereon that, when executed by processing circuitry, are configured to cause the processing circuitry to:receive first data indicative of a first known operating condition of a compressor;receive second data indicative of a second known operating condition of the compressor; anddetermine, based at least in part on the first known operating condition and the second known operating condition, a suction mass flow rate of a refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, a pressure ratio of the refrigerant entering and leaving the compressor, or any combination thereof.

11. The one or more tangible, non-transitory, computer readable media of claim 10, wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to determine the suction mass flow rate based at least in part on a discharge pressure corresponding to the first known operating condition of the compressor and a suction pressure corresponding to the first known operating condition of the compressor.

12. The one or more tangible, non-transitory, computer-readable media of claim 11, wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to determine the input power based at least in part on the suction mass flow rate.

13. The one or more tangible, non-transitory, computer readable media of claim 10, wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to:determine the suction mass flow rate based at least in part on the first known operating condition and the second known operating condition; anddetermine a cooling capacity of a vapor compression cycle comprising the compressor based at least in part on the suction mass flow rate.

14. The one or more tangible, non-transitory, computer readable media of claim 13, wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to determine a cooling coefficient of performance (COP) of the vapor compression cycle based at least in part on the cooling capacity and the input power.

15. The one or more tangible, non-transitory, computer readable media of claim 10, wherein the first known operating condition of the compressor comprises the input power, the second known operating condition of the compressor comprises a rotational frequency of the compressor, and wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to:receive third data indicative of a third known operating condition of the compressor, the third known operating condition of the compressor comprising a suction pressure; anddetermine the pressure ratio based at least in part on the first known operating condition, the second known operating condition, and the third known operating condition.

16. The one or more tangible, non-transitory, computer readable media of claim 10, wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to:receive the first data from a first sensor configured to detect the first known operating condition; andreceive the second data from a second sensor configured to detect the second known operating condition.

17. The one or more tangible, non-transitory, computer readable media of claim 10, wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to perform an action based at least in part on an analysis of the suction mass flow rate, the input power, the discharge temperature, the suction temperature, a cooling capacity derived at least in part from the suction mass flow rate, or a cooling coefficient of performance derived at least in part from the cooling capacity and the input power, wherein the action comprises:transmitting a notification or outputting the notification to a display;controlling an operating characteristic of the compressor; orcontrolling an operating characteristic of a component of the HVAC system separate from the compressor.

18. A heating, ventilation, and / or air conditioning (HVAC) system, comprising:a vapor compression cycle comprising a compressor;a first sensor configured to detect a first discharge or suction condition of a refrigerant;a second sensor configured to detect a second discharge or suction condition of the refrigerant; andprocessing circuitry configured to:receive, from the first sensor and the second sensor, sensor feedback indicative of the first discharge or suction condition and the second discharge or suction condition, respectively; anddetermine, based at least in part on the first discharge or suction condition and the second discharge or suction condition, a suction mass flow rate of the refrigerant entering the compressor, an input power of the compressor, a discharge temperature of the refrigerant leaving the compressor, a suction temperature of the refrigerant entering the compressor, or any combination thereof.

19. The HVAC system of claim 18, wherein the processing circuitry is configured to determine a cooling capacity of the vapor compression cycle based at least in part on the suction mass flow rate.

20. The HVAC system of claim 19, wherein the processing circuitry is configured to determine a cooling coefficient of performance of the vapor compression cycle based at least in part on the cooling capacity and the input power.

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