HEAT PUMP WITH MULTIPLE EXPANSION VALVES

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and the benefit of U.S. provisional application No. 63/516,897, filed Aug. 1, 2023, which is hereby incorporated by reference herein in its entirety.

FIELD

The present disclosure relates to a heat pump and more specifically to a heat pump water heater that includes a plurality of expansion valves of different sizes disposed in a parallel arrangement.

BACKGROUND

Heat pumps are used to heat water in water heating systems. Conventional heat pumps are manufactured for a specific range of ambient temperatures in which the heat pumps may effectively operate. For example, a heat pump may be manufactured to effectively heat water when the ambient temperature is more than 5 degrees Fahrenheit, while another heat pump may be manufactured to effectively heat water even when the ambient temperature is below 5 degrees Fahrenheit.

If the heat pump manufactured to operate in ambient temperatures of above 5 degrees Fahrenheit is made to operate in a geographical area where the ambient temperature may drop below 5 degrees Fahrenheit, the heat pump may not effectively heat water and may provide sub-optimal performance. Thus, there exists a need for a heat pump that may operate effectively in a wide range of ambient temperatures.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanying drawings. The use of the same reference numerals may indicate similar or identical items. Various embodiments may utilize elements and/or components other than those illustrated in the drawings, and some elements and/or components may not be present in various embodiments. Elements and/or components in the figures are not necessarily drawn to scale. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably.

FIG. 1 depicts a typical refrigerant circuit of a vapor compression cycle.

FIG. 2 depicts an example refrigerant circuit in accordance with one or more embodiments of the present disclosure.

FIG. 3 depicts another example refrigerant circuit in accordance with one or more embodiments of the present disclosure.

FIG. 4 depicts a controller to control refrigerant circuit operation in accordance with one or more embodiments of the present disclosure.

FIG. 5 depicts a flow diagram of an example method to control refrigerant circuit operation in accordance with one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

The present disclosure is directed towards a heat pump assembly or a refrigerant circuit of a vapor compression cycle that may operate effectively over a wide range of ambient temperatures. In some instances, the refrigerant circuit may be a vapor compression cycle system that may be part of a water heating system configured to heat water. In other instances, the refrigerant circuit may be part of a heating, ventilation, and air conditioning unit or the like. In certain embodiments, the refrigerant circuit may include a first heat exchanger and a second heat exchanger. The second heat exchanger may be configured to output a high-pressure refrigerant in a liquid state. In some aspects, the second heat exchanger may be a condenser. The refrigerant circuit may further include a plurality of expansion valves (e.g., a first expansion valve, a second expansion valve, and so on) that may receive the refrigerant from the second heat exchanger. The plurality of expansion valves may reduce the pressure and temperature of the received refrigerant and output a low-pressure, low-temperature refrigerant. The first heat exchanger may receive the refrigerant from the plurality of expansion valves and may output the refrigerant in a vapor state. In some aspects, the first heat exchanger may an evaporator. The refrigerant circuit may further include a compressor that may receive the refrigerant from the first heat exchanger and output the refrigerant in high pressure, high temperature vapor state. The second heat exchanger may receive the refrigerant from the compressor, thus completing the vapor compression cycle.

As will be appreciated, the refrigerant circuit may include a reversing valve in which the flow of refrigerant may be reversed. In this manner, the first heat exchanger may be a condenser and/or an evaporator and the second heat exchanger may be a condenser and/or an evaporator depending on the flow direction of the refrigerant. As a result, the refrigerant circuit may function as a heat pump. For simplicity, however, only a single flow direction is shown.

In some aspects, the plurality of expansion valves may be arranged in a parallel arrangement between the first and second heat exchangers. Further, each expansion valve may have a different size than sizes of other expansion valves in the refrigerant circuit. For example, an orifice diameter of an inlet of the first expansion valve may be different from an orifice diameter of an inlet of the second expansion valve. Any number of parameters of the first and second expansion valves may be different. Based on one or more parameters, either or both of the first and second expansion valves may be enabled to output the refrigerant towards the first heat exchanger. In an exemplary aspect, the one or more parameters may include, but are not limited to, an ambient temperature, a heat pump interior portion temperature and/or pressure, and/or the like. As an example, an expansion valve with a large orifice diameter may be enabled to output the refrigerant to the first heat exchanger when the ambient temperature may be below a predefined threshold (e.g., below 5 or 10 degrees Fahrenheit).

The refrigerant circuit may further include one or more control valves that may control refrigerant flow into the first and the second expansion valves from the second heat exchanger. A heat pump operator or a heat pump controller may activate the control valves to enable refrigerant flow into the first and/or the second expansion valves, thus controlling refrigerant output from respective expansion valves. For example, the heat pump controller may activate a control valve associated with an expansion value with a large orifice diameter (e.g., the first expansion valve) when the ambient temperature may be below the predefined threshold, thus enabling the first expansion valve to receive the refrigerant from the second heat exchanger. In this case, the heat pump controller may not activate the control valve associated with the expansion value with a small orifice diameter (e.g., the second expansion valve), thus disabling refrigerant flow into the second expansion valve. Since the second expansion valve may not receive the refrigerant from the second heat exchanger and the first expansion valve may receive the refrigerant, the first expansion valve may output the refrigerant to the first heat exchanger. In this manner, the controller may enable the first and/or the second expansion valves to output the refrigerant to the first heat exchanger by selectively activating control valves associated with respective expansion valves.

The present disclosure describes a heat pump assembly that includes a plurality of expansion valves of different sizes in the same heat pump assembly. Since the expansion valves of different sizes operate efficiently in different ambient temperature ranges, the heat pump assembly according to the present disclosure enables the heat pump to operate over a wide range of ambient temperatures. For example, a heat pump with a single expansion valve may not be optimal for a large operating temperature (e.g., operating temperature range from—13F to 150F ambient). The expansion valve needs to be sized to colder conditions or sized to hotter conditions in order to maintain the desired super heat. Multiple expansion vales in parallel may provide optimal operation in a large operating temperature (e.g., operating temperature range from −13F to 150F ambient), a smaller expansion valve for colder climates and wider for hotter climates. For example, the systems and methods disclosed herein allow for operation in extreme ambient conditions, meaning very cold conditions (low pressure) and very hot conditions (high pressure) using the same system and while maintaining the super heat required, widening the range of operation of the unit. The problem with single wider expansion valves is that they lose control resolution when closed below 30% (e.g., they become very nonlinear). Further, the heat pump assembly includes a controller that automatically and dynamically enables one or more expansion valves to output the refrigerant based on ambient temperature, thus minimizing or eliminating manual effort required to selectively enable (e.g., activate or deactivate) respective expansion valves. In some instances, one or more of the plurality of expansion valves may be adjustable.

Although certain examples of the disclosed technology are explained in detail herein, it is to be understood that other examples, embodiments, and implementations of the disclosed technology are contemplated. Accordingly, it is not intended that the disclosed technology is limited in its scope to the details of construction and arrangement of components expressly set forth in the following description or illustrated in the drawings. The disclosed technology can be implemented in a variety of examples and can be practiced or carried out in various ways. In particular, the presently disclosed subject matter is described in the context of being a system and method for heating water with a heat pump. The present disclosure, however, is not so limited, and can be applicable in other contexts. The present disclosure, for example and not limitation, can be applied to heating, ventilation, and air conditioning (HVAC) systems as well. Furthermore, the present disclosure can include other fluid heating systems configured to heat a fluid other than water such as process fluid heaters used in industrial applications. Such implementations and applications are contemplated within the scope of the present disclosure. Accordingly, when the present disclosure is described in the context of being a system and method for heating water with a heat pump, it will be understood that other implementations can take the place of those referred to.

Although the term “water” is used throughout this specification, it is to be understood that other fluids may take the place of the term “water” as used herein. Therefore, although described as a system and method to heat water, it is to be understood that the system and methods described herein can apply to fluids other than water. Further, it is also to be understood that the term “water” can replace the term “fluid” as used herein unless the context clearly dictates otherwise.

Turning now to the drawings, FIG. 1 depicts a conventional refrigerant circuit 100. The refrigerant circuit 100 may be a heat pump assembly that may be part of a water heating system. The refrigerant circuit 100/heat pump assembly may collectively form a vapor compression cycle system. Throughout the present disclosure, the terms “refrigerant circuit” and “heat pump” may be interchangeably used.

The refrigerant circuit 100 may include a first heat exchanger 105, a compressor 110, a second heat exchanger 115 and an expansion valve 120 connected in series by refrigerant tubing 125 through which, during heat pump operation, a refrigerant may flow in the indicated clockwise direction. Specifically, the refrigerant may sequentially flow from an outlet of the compressor 110, through the second heat exchanger 115, through the expansion valve 120, through the first heat exchanger 105, and back to an inlet of the compressor 110. The refrigerant may be, for example, R22 or R410A. Any suitable refrigerant may be used herein. In an exemplary aspect, the first heat exchanger 105 may be an evaporator and the second heat exchanger 115 may be a condenser.

The compressor 110 may be configured to output the refrigerant in vapor state towards the second heat exchanger 115, via the refrigerant tubing 125. The refrigerant output from the compressor 110 may be at high temperature and high pressure state. The second heat exchanger 115 may receive the refrigerant from the compressor 110 via the refrigerant tubing 125 and may convert the refrigerant into liquid state. In some aspects, the heat dissipated by the second heat exchanger 115 while changing the refrigerant phase from vapor to liquid may be used to heat water (e.g., when the heat pump/refrigerant circuit 100 may be part of a water heating system).

The second heat exchanger 115 may output the refrigerant in liquid state towards the expansion valve 120, via the refrigerant tubing 125. The refrigerant output from the second heat exchanger 115 may be at high pressure and medium-to-high temperature state. The expansion valve 120 may receive the refrigerant from the second heat exchanger 115 and may output the refrigerant in low pressure, low temperature state towards the first heat exchanger 105 via the refrigerant tubing 125. The refrigerant output from the expansion valve 120 may be in liquid and vapor state.

The first heat exchanger 105 may receive the refrigerant from the expansion valve 120 and may convert the refrigerant into low pressure, vapor state refrigerant. The first heat exchanger 105 may include a fan (not shown) that may draw heat from ambient environment, and may blow hot air towards the refrigerant received from the expansion valve 120, thereby heating and vaporizing the refrigerant. The first heat exchanger 105 may output the refrigerant in high temperature, vapor state towards the compressor 110 via the refrigerant tubing 125. The compressor 110 may receive the refrigerant from the first heat exchanger 105 and may “compress” the refrigerant to output the refrigerant in high pressure, high temperature state, as described above. In some aspects, the compressor 110 may be a pump that provides additional pressure to the refrigerant to enable the refrigerant to flow through the defined path, as indicated in FIG. 1. In this manner, the refrigerant flows in the refrigerant circuit 100, facilitating heating of water through the second heat exchanger 115.

The compressor 110 may be of any type. For example, the compressor 110 may be a positive displacement compressor, a reciprocating compressor, a rotary screw compressor, a rotary vane compressor, a rolling piston compressor, a scroll compressor, an inverter compressor, a diaphragm compressor, a dynamic compressor, an axial compressor, or any other form of compressor that can be integrated into the heat pump assembly for the particular application.

In some aspects, the expansion valve 120 may be configured to control flow of refrigerant to the first heat exchanger 105 based on one or more parameters. For example, the expansion valve 120 may increase or decrease refrigerant flow into the first heat exchanger 105 based on temperature of the refrigerant output by the first heat exchanger 105. The expansion valve 120 may assist in maintaining a steady temperature of refrigerant output by the first heat exchanger 105. As another example, the expansion valve 120 may increase or decrease refrigerant flow into the first heat exchanger 105 based on desired temperature of hot water (e.g., when the heat pump may be part of a water heating system).

The amount of refrigerant that the expansion valve 120 may output towards the first heat exchanger 105 may depend on an orifice size of an inlet of the expansion valve 120. Typically, a larger amount of refrigerant may be required to be output from the expansion valve 120 towards the first heat exchanger 105 when the heat pump may be required to heat water (or output heat from the second heat exchanger 115) in a geographical area with low ambient temperature. Consequently, a heat pump required to operate in a geographical area with low ambient temperature may require an expansion valve with a large-sized orifice at the expansion valve inlet.

In some aspects, orifice diameters of expansion valves may range from about 3 to 6 mm. To effectively operate a heat pump (installed in a water heating system) in cold weather conditions (e.g., with ambient temperatures of less than about 5 degrees Fahrenheit), a user may use a heat pump with an expansion valve having a large-sized orifice, e.g., having a diameter of about 5 or 6 mm. On the other hand, the user may use a heat pump with an expansion valve having a small-sized orifice, e.g., having a diameter of about 3 or 4 mm, when the heat pump may be expected to operate in ambient temperatures of about more than 5 degrees Fahrenheit.

FIG. 2 depicts an example refrigerant circuit 200 in accordance with one or more embodiments of the present disclosure. The refrigerant circuit 200 may be a heat pump assembly that may be part of a water heating system. The refrigerant circuit 200/heat pump assembly may collectively form a vapor compression cycle system. The various refrigerant circuit components, as described below, may be sized, shaped, and located as would be suitable for the particular application. As will be appreciated, the various refrigerant circuit components may be sized for residential, commercial, or industrial applications and for heating water within various temperature ranges and within various time ranges.

The refrigerant circuit 200 may include a first heat exchanger 205, a compressor 210, a second heat exchanger 215 and refrigerant tubing 220, as described above in conjunction with FIG. 1. The first heat exchanger 205 may be same as the first heat exchanger 105, the compressor 210 may be same as the compressor 110, the second heat exchanger 215 may be same as the second heat exchanger 115, and the refrigerant tubing 220 may be same as the refrigerant tubing 125.

The refrigerant circuit 200 may further include a first expansion valve 225 and a second expansion valve 230 that may be arranged in a parallel arrangement between the first heat exchanger 205 and the second heat exchanger 215, as shown in FIG. 2. The first expansion valve 225 and the second expansion valve 230 may be the same or similar to the expansion valve 120 and may perform the same function in the refrigerant circuit 200 as the function performed by the expansion valve 120 in the refrigerant circuit 100.

In some aspects, a first expansion valve size may be different from a second expansion valve size. Specifically, an orifice diameter of an inlet of the first expansion valve 225 may be different from an orifice diameter of an inlet of the second expansion valve 230. For example, a first expansion valve orifice diameter may be in a range of about 2 to 5 mm (e.g., about 3 mm or 4 mm), and a second expansion valve orifice diameter may be in a range of about 5 to 8 mm (e.g., about 5 mm or 6 mm). Other parameters of the expansions valves may also be varied, including the outlet orifices and any other components thereof.

Each of the first expansion valve 225 and the second expansion valve 230 may be configured to receive the refrigerant from the second heat exchanger 215, in the same manner as described above in conjunction with FIG. 1. In some aspects, the first expansion valve 225 may receive the refrigerant from the second heat exchanger 215 via a first passage 220a of the refrigerant tubing 220 and the second expansion valve 230 may receive the refrigerant from the second heat exchanger 215 via a second passage 220b of the refrigerant tubing 220, as shown in FIG. 2. The first passage 220a and the second passage 220b may be parallel to each other.

The refrigerant circuit 200 may further include a first control valve 235 disposed on the first passage 220a and a second control valve 240 disposed on the second passage 220b. In an exemplary aspect, the first control valve 235 and the second control valve 240 may be solenoid valves. The first control valve 235 may be disposed in the first passage 220a such that the first control valve 235 may be between the second heat exchanger 215 and the first expansion valve 225. Similarly, the second control valve 240 may be disposed on the second passage 220b such that the second control valve 240 may be between the second heat exchanger 215 and the second expansion valve 230.

The first control valve 235 may be configured to control refrigerant flow into the first expansion valve 225 and the second control valve 240 may be configured to control refrigerant flow into the second expansion valve 230. Specifically, the first control valve 235 may enable the refrigerant to flow into the first expansion valve 225 when the first control valve 235 may be activated and may disable or stop the refrigerant to flow into the first expansion valve 225 when the first control valve 235 may be deactivated. Similarly, the second control valve 240 may enable the refrigerant to flow into the second expansion valve 230 when the second control valve 240 may be activated and may disable or stop the refrigerant to flow into the second expansion valve 230 when the second control valve 240 may be deactivated.

In some aspects, a heat pump operator may manually activate or deactivate the first control valve 235 and/or the second control valve 240 based on ambient temperature in which the refrigerant circuit 200/heat pump may be located. For example, the operator may activate the second control valve 240 to enable refrigerant flow into the second expansion valve 230 (which may have large-sized orifice) when the ambient temperature may be low, e.g., less than 5 degrees Fahrenheit. Further, the operator may activate the first control valve 235 to enable refrigerant flow into the first expansion valve 225 (which may have smaller-sized orifice) when the ambient temperature may be more than 5 degrees Fahrenheit. In this manner, same heat pump/refrigerant circuit may operate equally efficiently in different ambient temperatures. The operator may also activate both the first control valve 235 and the second control valve 240 simultaneously, based on heat pump usage requirements and/or ambient temperature.

In other aspects, the refrigerant circuit 200 may further include a heat pump controller (shown as controller 400 in FIG. 4) that may automatically activate or deactivate the first control valve 235 and/or the second control valve 240 based on one or more parameters. For example, the controller may activate or deactivate the first control valve 235 and/or the second control valve 240 based on at least one of an ambient temperature, a heat pump interior portion temperature, a heat pump interior portion pressure, a flow/amount of water to be heated (e.g., water flow intake into the water heating system), first heat exchanger temperature and/or airflow, and/or the like. In some aspects, the heat pump controller may be communicatively connected with the first control valve 235 and the second control valve 240.

The first heat exchanger 205 may receive the refrigerant, via the refrigerant tubing 220, from at least one of the first expansion valve 225 and the second expansion valve 230 based on activation status of respective control valves. For example, the first heat exchanger 205 may receive the refrigerant from the first expansion valve 225 when the first control valve 235 may be activated and may receive the refrigerant from the second expansion valve 230 when the second control valve 240 may be activated.

Functions of different components associated with the refrigerant circuit 200 and the process of refrigerant flow in the refrigerant circuit 200 are same as the functions of components associated with the refrigerant circuit 100 and the process of refrigerant flow described above in conjunction with FIG. 1. Therefore, the component functions and refrigerant flow process are not described again here for the sake of simplicity and conciseness.

Although FIG. 2 depicts two expansion valves 225, 230, the refrigerant circuit 200 may include a plurality of expansion valves (e.g., 3, 4, 5 or more) of different sizes arranged in parallel arrangement, without departing from the present disclosure scope. In this case, each expansion valve may have an associated control valve (or solenoid valve) that may be activated or deactivated based on heat pump usage requirements, as described above. Exemplary refrigerant circuit depiction shown in FIG. 2 and the description described above should not be construed as limiting the present disclosure scope to only two expansion valves.

FIG. 3 depicts an example refrigerant circuit 300 in accordance with one or more embodiments of the present disclosure. The refrigerant circuit 300 may be similar to the refrigerant circuit 200 and may include one or more components including, but not limited to, a first heat exchanger 305, a compressor 310, a second heat exchanger 315, refrigerant tubing 320, a first expansion valve 325, a second expansion valve 330, a first passage 320a and a second passage 320b.

The first and second heat exchangers 305, 315 may be same as the first and second heat exchangers 205, 215, the compressor 310 may be same as the compressor 210, and the refrigerant tubing 320 may be same as the refrigerant tubing 220. Further, the first and second expansion valves 325, 330 may be same as the first and second expansion valves 225, 230, and the first and second passages 320a, 320b may be same as the first and second passages 220a, 220b.

The refrigerant circuit 300 may further include a single control valve 335 that may be disposed between the second heat exchanger 315 and the first and second expansion valves 325, 330, as shown in FIG. 3. The control valve 335 may be a two-way solenoid valve that may control refrigerant flow from the second heat exchanger 315 to the first expansion valve 325 and/or the second expansion valve 330.

In some aspects, the control valve 335 may operate in a first control valve operation mode when the control valve 335 enables the refrigerant to flow from the second heat exchanger 315 to the first expansion valve 325. Similarly, the control valve 335 may operate in a second control valve operation mode when the control valve 335 enables the refrigerant to flow from the second heat exchanger 315 to the second expansion valve 330. The control valve 335 may operate in a third control valve operation mode when the control valve 335 enables the refrigerant to flow from the second heat exchanger 315 to first expansion valve 325 and the second expansion valve 330 simultaneously.

As described above in conjunction with FIG. 2, the operator or a heat pump controller may activate the control valve 335 in either the first control valve operation mode, the second control valve operation mode or the third control valve operation mode based on ambient temperature and one or more parameters described above.

Remaining functions and arrangements of components associated with the refrigerant circuit 300 are same as functions and arrangements of components associated with the refrigerant circuit 200 and hence are not described here again for the sake of simplicity and conciseness.

Similar to the refrigerant circuit 200, the refrigerant circuit 300 too may include more than two expansion valves 325, 330 depicted in FIG. 3. In this case, the control valve 335 may control refrigerant flow in each expansion valve simultaneously, in a similar manner as described above.

FIG. 4 depicts a controller 400 to control refrigerant circuit operation in accordance with one or more embodiments of the present disclosure. The controller 400 may be part of the heat pump assembly or the refrigerant circuit 200, 300 described above.

The controller 400 may include a plurality of components including, but not limited to, a processor 405, a memory 410, and a communication interface 415. The controller 400 may be a computing device configured to receive data, determine actions based on the received data, and output a control signal instructing one or more refrigerant circuit components to perform one or more actions. In some aspects, the controller 400 may be configured to receive ambient temperature data from ambient temperature sensors that may be part of the heat pump assembly or may be external to the heat pump assembly. In additional aspects, the controller 400 may be configured to receive heat pump temperature and pressure data from one or more temperature and pressure sensors that may be disposed in a heat pump assembly interior portion.

In some aspects, the controller 400 may be configured to send and receive wireless or wired signals, and the signals may be analog or digital signals. The wireless signals may include Bluetooth™, BLE, WiFi™, ZigBee™, infrared, microwave radio, or any other type of wireless communication signals as may be suitable for a particular heat pump application. The hard-wired signals can include communication signals between any directly wired connections between the controller 400 and other heat pump components. For example, the controller 400 can have a hard-wired 24 Volts Direct Current (VDC) connection to the sensors described above.

Alternatively, the controller 400 may communicate with the sensors via a digital connection. The digital connection can include a connection such as an Ethernet or a serial connection and can utilize any suitable communication protocol for the heat pump application, such as Modbus, fieldbus, PROFIBUS, SafetyBus, Ethernet/IP, and/or the like. Furthermore, the controller 400 can utilize a combination of wireless, hard-wired, and analog or digital communication signals to communicate with and control the various heat pump components. A person ordinarily skilled in the art may appreciate that the above configurations are given merely as non-limiting examples and the actual configuration can vary depending on the particular heat pump application.

The memory 410 may be configured to store a program and/or instructions associated with the functions and methods described herein. The processor 405 may be configured to execute the program and/or instructions stored in the memory 410. The memory 410 can include one or more suitable types of memory (e.g., volatile or non-volatile memory, random access memory (RAM), read only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, flash memory, a redundant array of independent disks (RAID), and the like) for storing files including the operating system, application programs (including, for example, a web browser application, a widget or gadget engine, and or other applications, as necessary), executable instructions and data. One, some, or all of the processing techniques or methods described herein can be implemented as a combination of executable instructions and data within the memory 410.

The communication interface 415 may be configured to send or receive communication signals between the various heat pump components. Communication interface 415 can include hardware, firmware, and/or software that allows the processor 405 to communicate with the other components via wired or wireless networks, whether local or wide area, private or public, as known in the art. Communication interface 415 can also provide access to a cellular network, the Internet, a local area network, or another wide-area network as suitable for the particular heat pump application.

Additionally, the controller 400 may have or be in communication with a user interface (not shown) for receiving inputs from the user. The user interface may be installed locally on the water heating system (of which the heat pump assembly may be a part). In an exemplary aspect, the user provide inputs to the controller 400, via the user interface, indicating ambient temperature ranges in which each expansion valve (e.g., the first expansion valve 225, 325 or the second expansion valve 230, 330) may be enabled to output the refrigerant to the first heat exchanger 205, 305. For example, the user may provide an input indicating that the second expansion valve 230, 330 may be enabled to provide the refrigerant to the first heat exchanger 205, 305 (by activating the second control valve 240 or activating the control valve 335 in the second control valve operating mode) when the ambient temperature may be less than 5 degrees Fahrenheit. Similarly, the user may provide an input indicating that the first expansion valve 225, 325 may be enabled to provide the refrigerant to the first heat exchanger 205, 305 (by activating the first control valve 235 or activating the control valve 335 in the first control valve operating mode) when the ambient temperature may be more than 5 degrees Fahrenheit. In some aspects, the controller 400 may store the inputs received by the user via the user interface in the memory 410.

In operation, the processor 405 may obtain ambient temperature from the ambient temperature sensors and heat pump interior portion temperature and pressure from respective heat pump sensors. Responsive to obtaining the information described above, the processor 405 may correlate the obtained information with the user inputs stored in the memory 410. The processor 405 may then send an activation signal to the control valve 335 (or the first and/or second control valves 235, 240) to activate the control valve 335 in either the first, second or third control valve operation mode described above, based on the correlation. For example, the processor 405 may activate the control valve 335 in the first control valve operation mode (or activate the first control valve 235) when the ambient temperature may be more than 5 degrees Fahrenheit.

FIG. 5 depicts a flow diagram of an example method 500 to control refrigerant circuit operation in accordance with one or more embodiments of the present disclosure. FIG. 5 may be described with continued reference to prior figures, including FIGS. 1-4. The following process is exemplary and not confined to the steps described hereafter. Moreover, alternative embodiments may include more or less steps that are shown or described herein and may include these steps in a different order than the order described in the following example embodiments.

The method 500 may start at step 502. At step 504, the method 500 may include obtaining, by the controller 400, ambient temperature from the ambient temperature sensors. As described above, the controller 400 may further obtain heat pump interior portion temperature and pressure from respective heat pump sensors.

At step 506, the method 500 may include activating, by the controller 400, the control valve 335 in either the first, second or third control valve operating mode (or activate the first and/or second control valves 235, 240) based on at least one of the ambient temperature, heat pump interior portion temperature and pressure, as described above. The method 500 may stop at step 508.

In the above disclosure, reference has been made to the accompanying drawings, which form a part hereof, which illustrate specific implementations in which the present disclosure may be practiced. It is understood that other implementations may be utilized, and structural changes may be made without departing from the scope of the present disclosure. References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a feature, structure, or characteristic is described in connection with an embodiment, one skilled in the art will recognize such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It should also be understood that the word “example” as used herein is intended to be non-exclusionary and non-limiting in nature. More particularly, the word “example” as used herein indicates one among several examples, and it should be understood that no undue emphasis or preference is being directed to the particular example being described.

With regard to the processes, systems, methods, heuristics, etc. described herein, it should be understood that, although the steps of such processes, etc. have been described as occurring according to a certain ordered sequence, such processes could be practiced with the described steps performed in an order other than the order described herein. It further should be understood that certain steps could be performed simultaneously, that other steps could be added, or that certain steps described herein could be omitted. In other words, the descriptions of processes herein are provided for the purpose of illustrating various embodiments and should in no way be construed so as to limit the claims.

Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent upon reading the above description. The scope should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the technologies discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the application is capable of modification and variation.

All terms used in the claims are intended to be given their ordinary meanings as understood by those knowledgeable in the technologies described herein unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc., should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments could include, while other embodiments may not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.