Patent Application
20240125519
The present technology pertains to systems and methods for cascaded heat pump systems most suitable for cold climates and situations where there are high pressure differentials in a heating system. In particular, but not by way of limitation, the present technology provides systems and methods for cascade cold climate heat pump systems (also referred to herein as “cascaded CCHP,” or “CCCHP”).
This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the presently described embodiments to help facilitate a better understanding of various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Heat pump systems and electrification are the most recent fast-growing trends within the heating, ventilation, and air conditioning (“HVAC”) industry. A combination of factors including an increased emphasis on reducing combustion-based heating and reliance on fossil fuels, and the expansion of using heat pump (“HP”) systems in cold climates necessitates heat-pump systems with improved thermal performance at low temperatures.
A heat pump is a refrigerant system that is typically operable in both cooling and heating modes. While air conditioners are familiar examples of heat pumps, the term “heat pump” is more general and applies to many heating, ventilating, and air conditioning (“HVAC”) devices used for space heating or space cooling. A cold climate heat pump (“CCHP”) system is a heat pump system specially designed for use in cold outdoor temperatures and can provide mechanical air heating utilizing a refrigerant vapor compression cycle or a combination of mechanical air heating and electrical resistance or combustion heating. The US Department of Energy specifies that 5 F CCHPs are capable of heat pump operation down to at least 5 F (−15 C) ambient temperature, and −15 F CCHPs are capable of heat pump operation down to at least −15 F (−26 C).
In a cooling mode, a heat pump system operates like a typical air conditioner system, i.e., a refrigerant flows through an HVAC circuit where the refrigerant is compressed in a compressor and delivered to a condenser (or an outdoor heat exchanger). In the condenser, heat is exchanged between a medium such as outside air, water, or the like and the refrigerant. From the condenser, the refrigerant passes to an expansion device, at which the refrigerant is expanded to a lower pressure and temperature, and then to an evaporator (or an indoor heat exchanger). In the evaporator, heat is exchanged between the refrigerant and the indoor air, to condition the indoor air. When the refrigerant system is operating, the evaporator cools the air that is being supplied to the indoor environment. In addition, as the temperature of the indoor air is lowered, moisture usually is also taken out of the air. In this manner, the humidity level of the indoor air can also be controlled. When a heat pump is used for heating, it employs the same basic refrigeration-type cycle used by an air conditioner or a refrigerator, but refrigerant flows through the HVAC circuit in the opposite direction, releasing heat into the conditioned space rather than the surrounding environment. In this use, heat pumps generally draw heat from cooler external air, water, or from the ground.
Reversible heat pump systems (generally referred to herein simply as “heat pumps”) work in either direction to provide heating or cooling to the internal space as mentioned above. Reversible heat pumps employ a reversing, or four-way, valve to reverse the flow of refrigerant from the compressor through the condenser and evaporation coils. In heating mode, the outdoor coil is an evaporator and the indoor coil is a condenser. The refrigerant flowing from the evaporator (outdoor coil) carries the thermal energy from outside air (or source such as water, soil, etc.) indoors. Vapor temperature is augmented within the pump by compressing it. The indoor coil then transfers thermal energy (including energy from the compression) to the indoor air, which is then moved around the inside of the building by an air handler. The refrigerant is then allowed to expand, cool, and absorb heat from the outdoor environment in the outside evaporator, and the cycle repeats.
For a constant amount of compressor work input, a pressure difference between the input and the output of the compressor is constant. The compressor operation thus increases the enthalpy of the refrigerant by a constant magnitude, between the upper and lower pressures of the compressor. Thus, the pressure and temperature difference of the refrigerant (e.g., an operational range) between the indoor and outdoor heat exchangers is set by the upper and lower pressures of the compressor in a standard heating and cooling refrigeration cycle. With a set operational range, the lower limit temperature for the outdoor heat exchanger is thus also limited and the use of the heat pump system is limited to outdoor temperatures greater than or equal to the outdoor heat exchanger temperature. However, the use of heat pump systems is increasingly desirable in colder and colder environments, and thus a need exists for systems and methods that allow for an expansion of the operational range between the indoor and outdoor heat exchangers. Additionally, a need exists for systems and methods to improve compressor energy efficiency. Recognizing these needs, the US Department of Energy launched a CCHP Technology Challenge in 2021 to accelerate innovation, development, and commercialization of 5° F. CCHP and −15° F. CCHP technologies.
Conventional heat pumps including those with variable speed compressors are either not designed to operate, or fail to operate in low temperatures due to constraints in variable speed compressor technology. In many instances these conventional HP systems or variable speed HP systems need to be supplemented by combustion heating or electric heating in cold ambient temperatures, these supplemental heating methods are less efficient and more expensive than the HP system. These conventional HP systems reach threshold efficiency levels, and the threshold of their ability to function due to these in-built inefficiencies or constraints on the compressor or its speed which do not allow the compressor to exceed the required level to operate at low ambient temperatures. When the coefficient of performance (“COP”) in the heating mode of operation becomes 1 or lower, then using electric heating becomes more economical since the electric heating has a COP of 1.
Certain aspects of some embodiments of heat pump systems disclosed herein are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
In various embodiments, disclosed is a cascaded cold climate heat pump system that includes a high-pressure circuit with a first compressor, a first outer heat exchange unit, a first metering device, and a first reversing valve for flowing a first refrigerant through the high-pressure circuit, a low-pressure circuit fluidly isolated from the high-pressure circuit and including a second compressor, a second outer heat exchange unit, a second metering device, and a second reversing valve for flowing a second refrigerant through the low-pressure circuit. The cascaded cold climate heat pump system also includes an intermediary heat exchange unit thermally connecting the fluidly isolated high pressure circuit and the low pressure circuit to facilitate heat exchange between the first refrigerant and the second refrigerant in the intermediary heat exchange unit to reduce a temperature lift needed by each of the high pressure circuit and the low pressure circuit, the high pressure circuit operating within a first pressure differential, and the low pressure circuit operating within a second pressure differential.
In various embodiments, a method for operating a cascaded cold climate heat pump system is disclosed, including pressurizing a first refrigerant by a first compressor to a first pressure in a first heat pump circuit. The method also includes pressurizing a second refrigerant by a second compressor to a second pressure in a second heat pump circuit fluidly isolated from the first heat pump circuit. The method also includes circulating the first refrigerant through the first heat pump circuit, where the first heat pump circuit further includes a first outdoor heat exchange unit, a first metering device, a first accumulator, and a first reversing valve. The method also includes circulating the second refrigerant through the second heat pump circuit, where the second heat pump circuit includes a second outer heat exchange unit, a second metering device, a second accumulator, and a second reversing valve. The method also includes flowing the first refrigerant in the first heat pump circuit through an intermediary heat exchange unit of the first heat pump circuit. The method also includes flowing the second refrigerant flowing in the second heat pump through the intermediary heat exchange unit, the second heat pump circuit also including the intermediary heat exchange unit. The method also includes exchanging heat between the first refrigerant and second refrigerant via the intermediary heat exchange unit so as to reduce a temperature lift needed by each of the first heat pump circuit and the second heat pump circuit allowing the first heat pump circuit to operate within a first pressure differential, and the second heat pump circuit to operate within a second pressure differential, improving efficiency of the first compressor and second compressor.
Various refinements of the features noted above may exist in relation to various aspects of the present embodiments. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of some embodiments without limitation to the claimed subject matter.
These and other features, aspects, and advantages of certain embodiments 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.
The accompanying drawings, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate aspects of concepts that include the claimed disclosure and explain various principles and advantages of those aspects.
The methods and systems disclosed herein have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the aspects of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation may be described. 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.
When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” 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.
The present disclosure relates to cascaded cold climate HP (CCCHP) systems that allow improved efficiency heating operation at low ambient temperatures, such a cold climates. Efficiency in heat pump systems may refer to the amount of energy required by a compressor to compress a refrigerant or gas from one pressure (P1) to a second pressure (P2) compared to theoretical ideal operating conditions. The closer the amount of energy used by the compressor to the ideal operating conditions (and the less energy the compressor needs), the more efficient the overall heat pump system may be. In situations where the temperature and/or pressure lift is very high, there is usually a large drop in compressor efficiency, because the compressor is attempting to reach a high pressure from a low pressure point or in an inherently low-pressure environment. These effects are most pronounced in situations where the temperature difference between heat rejection/ejection and the heat source is high, for example, when delivering heating in cold climates, such as environments below 14° F.
Solutions presented herein increase and improve the efficiency of cold climate heat pump systems. For example, when a heat pump system provides heat in a climate with low ambient temperatures, pressure lift of the heat pump may be very high. Pressure lift is the difference between current or ambient pressure and necessary pressure to be reached in a heat pump circuit, or the system as a whole, to provide a desired level of heating or cooling. Similarly, temperature lift may also be high in a cold climate environment. Temperature lift is the difference between current or ambient temperature and the necessary temperature that must be reached in a heat pump circuit, or the system as a whole, to produce a desired level of cooling or heating. In some embodiments, a cascaded CCHP is presented that is composed of at least two cascaded heat pump circuits that are fluidly isolated and thermally connected together through an internal or intermediary heat exchanger therebetween. CCHP systems are thus extended to a CCCHP system which not only extends the range of applications the system may be used and designed for, but also increases the capacity and operating range of the heat pump system at lower temperatures. One or more circuits may be added in a modular system. Each additional pressure circuit may further fine-tune the system by operating at the same or different pressure differential, and may have a similar or different configuration of heat exchange units, circuit refrigerants, and other components to further improve the efficiency of the system in various operating environments. Depending on the operating environment, the number of pressure circuits added may be balanced with the cost effectiveness and efficiency gains realized from each additional circuit.
In various aspects, the mode of operation of the circuits can be switched from cooling to heating and vice versa. However, both circuits in the system must be synchronized and thus operated in the same mode. In several aspects, a four-way valve may be used to control a direction of flow of the refrigerant and control the mode of operation. The cascaded CCHP design allows the use of two separate independent but connected circuits, each at a more restricted pressure differential or ratio. The various pressure differentials allow each circuit to pressurize its refrigerant separately from the other circuit and reduce the pressure lift on each individual circuit, since each circuit may be configured to operate at a smaller range of pressures and temperatures. Improving the efficiency of each compressor by restricting its operations within a smaller pressure differential or range may result in a larger mass flow through the circuit. Thus, less efficient supplemental heating (e.g., by combustion or electric heating) may be eliminated.
Each circuit can operate independently at part-load or full-load conditions (based on the conditioned space demand and environmental conditions, as well as optimized control logic). If the circuits include a variable speed compressor, a speed of the compressor can be adjusted independently for each circuit. The disclosed cascaded systems allow a compressor for each independent circuit to operate over a lower pressure differential, and therefore increase the refrigerant mass flow rate circulation for each circuit (or reduce the compressor size). Each circuit may have a different refrigerant (that may be suitable for specific operating conditions), different compressor size, different compressor type, different heat exchange unit size, and the like. Each compressor may be a fixed speed or variable speed compressor, to improve system thermal capacity at low operating temperatures and to extend system operating envelope. Each circuit may also include a reversible 4-way reversing valve which may be reversed simultaneously/synchronously. In several embodiments, the cascaded heat pump systems may include more than two circuits (e.g., three or more) connected to each other directly via a common heat exchange unit. Further, multiple circuits may be connected to each other serially, where a circuit is connected to one or more other circuits via a heat exchange unit, and where the other circuit(s) is in turn connected to other circuit(s) through another heat exchange unit, and so forth. Thus, various types of cascaded configurations with different numbers of circuits are possible and are not to be limited to configurations described herein. Different configurations may produce different efficiency outcomes and thus allow for additional possible fine tuning options.
Turning now to the figures,
Each circuit 110, 115 includes a compressor. For example, circuit 110 may include a high pressure compressor 101 that compresses the refrigerant of circuit 110 flowing through flow channel 102, within a high pressure range. Meanwhile, circuit 115 may include a low pressure compressor 108 that compresses the refrigerant running in circuit 115 through channels 109 at a low pressure range. In this disclosure, flow channel(s) may also be referred to as “line(s)”, “flow line(s)”, “channel(s)”, “flow channel(s)”, “flow line channel(s)”, “pipe(s)”, or “pipe channel(s)”, all of which may include any of pipes, tubes, channels, or other refrigerant, liquid, gas, or vapor delivery and circulation mechanisms that could be of various shapes and sizes and manufactured from various materials.
High pressure circuit 110 includes at least one reversing valve 103. Reversing valve 103 may be a 4-way valve and determines the direction of the refrigerant flow 150, 151 in high pressure circuit 110. Reversing valve 103 may have several connection points on the circuit 110, including connection point 103A and connection point 103B. Various refrigerants or refrigerant combinations may be used in each circuit, based on the desired operating condition of each circuit, including, for example, CO2 and R32.
Low pressure circuit 115 has at least one reversing valve 111. Reversing valve 111 may be a 4-way valve and determine the direction of the refrigerant flow 152, 153 in low pressure circuit 115. Reversing valve 111 may have several connection points on the circuit 115, including connection point 111A and connection point 111B. Various refrigerants or refrigerant combinations may be used in each circuit, based on the desired operating condition of each circuit, including, for example, CO2 and R32.
Reversing valves 103, 111 are synchronized to operate circuits 110, 115 in the same mode at a given time. Reversing valves 103, 111 may be synchronized and controlled by a controller unit or computing unit 2000,
Each circuit 110, 115 may also include one or more metering devices. For example, high pressure circuit 110 may include metering devices 105, 117, 118 and low pressure circuit 115 may include metering devices 112, 121, 122. Metering devices may depressurize the refrigerant in the respective circuit. Metering devices 105, 117, 118, 112, 121, 122 may be an expansion valve, an electronic expansion valve, a capillary tube, a thermostatic expansion valve, or a piston device. Depending on the configuration of circuits 110, 115, any of these metering devices may be optional and may be located at different points or connections in their respective circuits 110, 115. Each of high pressure circuit 110 and low pressure circuit 115 may include an optional accumulator 107, 114, respectively, which may ensure that liquid refrigerant in refrigerant flow 150, 152, is not sucked into compressors 101, 108, respectively, by a suction line or suction input of compressors 101, 108.
Between the two circuits 110, 115 an intermediary heat exchange unit 106 may allow the transfer of heat or facilitate heat exchange between flow channel 102 carrying a refrigerant of high pressure circuit 110 and flow channel 109 carrying a refrigerant of low pressure circuit 115. The refrigerants remain fluidly isolated in their respective circuits 110, 115 but exchange heat via intermediary heat exchange unit 106 that connects circuits 110, 115 together in the cascade configuration. Apart from intermediary heat exchange unit 106 that connects two circuits 110, 115, each circuit 110, 115 also include an outer heat exchange unit. For example, circuit 110 includes an outer heat exchange unit 104 and circuit 115 includes an outer heat exchange unit 113. Depending on the mode of operation of system 100, each outer heat exchange unit 104, 113 may switch between operating as a condenser that rejects heat and an evaporator that absorbs heat. In the heating configuration illustrated in
CCCHP 100 includes two or more heat pump circuits 110, 115 connected to each other, to allow a compressor 101, 108 for each independent circuit 110, 115 to operate over a lower pressure differential, and therefore increase the refrigerant mass flow rate circulation for each circuit 110, 115 and/or allow for a reduction in a size of a respective compressor 101, 108. Each circuit 110, 115 may have a different refrigerant (that may be preferably suitable for specific operating conditions), different compressor size, different compressor type, different heat exchange unit sizes, different configurations, and the like.
In several aspects, CCCHP 100 operates per method 500 discussed with respect to
In various aspects, one of circuits 110, 115, or in some aspects both circuits 110, 115, may include a vapor injection compressor configuration (components that are only included in embodiments with a vapor injection compressor configuration or “VCHP” are represented by dashed lines). When circuit 110, 115 includes a vapor injection compressor configuration, an auxiliary heat exchange unit 116, 120 may be added to circuit 110, 115. One or both of circuits 110, 115 may include an auxiliary heat exchange unit 116, 120, respectively. In a vapor injection compressor configuration each circuit 110, 115 may include an additional or auxiliary channel, for example flow channel 119 in circuit 110, and channel 123 in circuit 115. The optional auxiliary metering devices 117 for circuit 110 and optional auxiliary metering devices 121 for circuit 115 may be located at, preceding, or proceeding auxiliary flow channel 119, 123, respectively to provide additional points of depressurizing the refrigerant. In a VCHP configuration any and all of the metering devices 105, 118, 112, 122 may be deployed to increase depressurization points in the circuits 110, 115 to depressurize the refrigerant at different points. In the optional vapor injection compressor configuration, a portion of refrigerant flow 150, 152 in flow channels 102, 109 is diverted to auxiliary flow channel 119, 123, respectively, to go through installed or activated optional auxiliary metering device 117 for circuit 110 and installed or activated optional auxiliary metering device 121 for circuit 115. This refrigerant flow 151, 153 is diverted into auxiliary flow channels 119, 123 (e.g., an auxiliary flow) of the refrigerant in the respective circuit, and main flow 150, 152 continues through flow channels 102, 109, depending on the circuit.
The refrigerant in auxiliary flow 151, 153 may be at a subcooled state, depressurized further than main flow 150, 152 of the refrigerant, and therefore is able to further cool main refrigerant flow 150, 152 in auxiliary heat exchange unit 106, 120 as auxiliary flow 151, 153 travels through auxiliary flow channel 119, 123 into auxiliary heat exchange unit 116, and main flow 150, 152 travels through main flow channels 102, 109 towards auxiliary heat exchange unit 116 where heat exchange between two channels 102, 109 and auxiliary flow channels 119, 123, respectively may take place. The vapor in auxiliary channels 119, 123 are then fed into an intermediate stage of compressor 101, 108, respectively. The intermediate stage coming after the suction line/suction stage and before the discharge stage or discharge line. This injection of vapor in the intermediate stage increases the compression ratio and, in the process, further improving the efficiency of compressor 101, 108 and the capacity for heat pump system 100. The vapor injection flow separation points in the cooling and heating mode of operation can be switched respectively from downstream to upstream of heat exchangers 116, 120.
The disclosed CCCHP 100, with at least one vapor injection compressor configuration (which may be referred to herein as a “vapor injection CCCHP” or “VCHP”), may operate according to one embodiment of a method 600 discussed with respect to
In the VCHP configuration, if first circuit 110 deploys vapor injection, then a portion of the first refrigerant is diverted (operation 605) from main refrigerant flow 150 in first flow channel 102 to a first auxiliary flow 151 in first auxiliary flow channel 119. If second circuit 115 deploys vapor injection, then a portion of the second refrigerant is diverted (operation 606) from a main refrigerant flow 152 in second flow channel 109 to a second auxiliary flow 153 in auxiliary pipe channel 123. Diverted auxiliary flow 151, in first circuit 110 may be depressurized (operation 607) by one or more metering devices 117, 118 that may include one or more of which may be located at, preceding to, or proceeding from first auxiliary flow channel 119. Diverted auxiliary flow 153 in the second circuit 115 may be depressurized (operation 608) by one or more metering devices 121, 122 that may include one or more of which may be located at, preceding to, or proceeding from second auxiliary flow channel 123. First auxiliary flow 151 is run (operation 609) through a first auxiliary heat exchange unit 116, via first auxiliary flow channel 119 to exchange heat with main refrigerant flow 150 that flows through first auxiliary heat exchange unit 116, via first flow channel 102. Second auxiliary flow 153 is run (operation 610) through a second auxiliary heat exchange unit 120, via second auxiliary flow channel 123 to exchange heat with main refrigerant flow 152 that flows through second auxiliary heat exchange unit 120 via second pipes 109. This exchange of heat (operations 609, 610) allows further efficiency gains in system 100 further reducing the load on each compressor 101, 108 in system 100.
First refrigerant flow 150 flowing through first flow channel 102 are run (operation 611) through an intermediary heat exchange unit 106. Second refrigerant flow 152, flowing through second flow channel 109 is run (operation 612) through intermediary heat exchange unit 106. As first refrigerant flow 150 from first circuit 110 and second refrigerant flow 152 from second circuit 115 proceed through intermediary heat exchange unit 106, heat is exchanged (operation 613) between the refrigerants in circuits 110, 115. This exchange of heat allows each circuit 110, 115 to operate at a restricted pressure differential or envelope since each circuit 110, 115 covers one portion of an otherwise larger pressure differential of a conventional heat pump system.
High pressure circuit 210 includes a compressor, high pressure compressor 201 that compresses the refrigerant of circuit 210 running through flow channel 202 within a high-pressure range. High pressure circuit 210 has at least one reversing valve 203. Reversing valve 203 may be a 4-way valve and determines the direction of the refrigerant flow in system 200. Reversing valve 203 may have several connection points on circuit 210, including connection point 203A and connection point 203B. Various refrigerants or refrigerant combinations may be used in circuit 210, based on the desired operating condition of circuit 210, including for example CO2 and R32.
Low pressure circuit 215 includes a low pressure compressor 208 that compresses the refrigerant in circuit 215 running through flow channel 209 within a low-pressure range. Low pressure circuit 215 has at least one reversing valve 211. Reversing valve 211 may be a 4-way valve and determines the direction of the refrigerant flow in system 200. Reversing valve 211 may have several connection points on circuit 215, including connection points 211A, 211B. Various refrigerants or refrigerant combinations may be used in circuit 215, based on the desired operating condition of circuit 215, including for example CO2 and R32.
Reversing valves 203, 211 are synchronized, since circuits 210, 215 operate together in the same mode of operation, and may be synchronized and controlled by a controller unit or computing unit 2000,
Between two circuits 210, 215, an intermediary heat exchange unit 206 may allow the transfer of heat or facilitate heat exchange between flow channel 202 of high pressure circuit 210 and flow channel 209 of low pressure circuit 215. Refrigerants of respective circuits 210, 215 remain fluidly isolated but exchange heat via intermediary heat exchange 206 that connects two circuits 210, 215 together in a cascade configuration. Apart from intermediary heat exchange unit 206 that connects two circuits 210, 215, circuit 210 includes an outer heat exchange unit 204 and circuit 215 includes an outer heat exchange unit 213. Depending on the mode of operation of system 200, each of outer heat exchange units 204, 213 may switch between operating as a condenser that rejects heat and an evaporator that absorbs heat. In the cooling configuration of
CCCHP 200, includes two or more heat pump circuits 210, 215 connected to each other, to allow a compressor 201, 208 for each independent circuit to operate over a lower pressure differential and therefore increase the refrigerant mass flow rate circulation for each circuit, and/or allow for a reduction in the compressor size of compressor 201, 208. Each circuit 210, 215 may have a different refrigerant (that may be preferably suitable for specific operating conditions), different compressor 201, 208 size or type, different heat exchange unit 204, 213 sizes, different configurations and the like.
In several aspects, CCCHP 200, for example per method 500 discussed with respect to
In various aspects, at least one of circuits 210, 215, or in some aspects both circuits 210, 215, includes a vapor injector compressor configuration (represented by dashed lines). When a circuit 210, 215 includes a vapor injector compressor configuration, an auxiliary heat exchange unit 216, 220 is added to the circuit. One or both of circuits 210, 215 may include an extra/auxiliary heat exchange unit 216, 220, respectively. In a vapor injector compressor configuration each circuit 210, 215 may include an additional or auxiliary pipe channel, for example, flow channel 219 and flow channel 223, respectively. The optional auxiliary metering devices 217, 221 for circuits 210, 215, respectively, may be located on, preceding, or following auxiliary flow channels 219, 223, respectively, to provide additional depressurizing of the respective refrigerant. In a VCHP configuration any and all of metering devices 205, 218, 212, 222 may be deployed to increase depressurization points in the circuits to depressurize the refrigerant at different points as it flows through the circuit 210, 215. In the optional vapor injection compressor configuration, a portion of the refrigerant flowing 250, 252, in flow channels 202, 209 are diverted to auxiliary flow channels 219, 223, respectively to go through any of the installed or activated optional auxiliary metering devices 205, 217 for circuit 210 and any of the installed or activated optional auxiliary metering devices 212, 221 for circuit 215. This refrigerant flow 251, 253 that has been diverted into the auxiliary flow channels 219, 223 is an auxiliary flow 251, 253, of the refrigerant in the respective circuit 210, 215, meanwhile the main flow 250, 251, continues through the flow channel 202, 209 depending on the circuit.
The refrigerant in auxiliary flow 251, 253 may be in a subcooled state, depressurized further than the main flow 250, 251 of the refrigerant, and therefore is able to further cool the main refrigerant flow 250, 251 in auxiliary heat exchange unit 206, 220 as auxiliary flows 251, 253 travels through auxiliary flow channel 219, 223 into auxiliary heat exchange unit 216, and the main flow 250, 252 travels through main flow channel 202, 209 towards auxiliary heat exchange unit 216 where heat exchange between the two flow channels, main flow channel 202, 209 and auxiliary flow channel 219, 223 may take place. The vapor in auxiliary flow channel 219, 223 is then fed into an intermediate stage of compressor 201, 208, respectively. The intermediate stage coming after the suction line/suction stage and before the discharge stage or discharge line. The vapor injection flow separation points in the cooling and heating mode of operation can be switched respectively from downstream to upstream of auxiliary heat exchanger unit 216, 220.
The disclosed CCCHP 200 with at least one vapor injection compressor configuration (this configuration may be referred to herein as a “vapor injection CCCHP” or “VCHP”) may operate according to one embodiment of a method 600 discussed with respect to
In the VCHP configuration if first circuit 210 deploys vapor injection, then a portion of first refrigerant is diverted (operation 605) from main refrigerant flow 250 in first flow channel 202 to a first auxiliary flow 251 in first auxiliary flow channel 219. If second circuit 215 deploys vapor injection, then a portion of second refrigerant is diverted (operation 606) from a main refrigerant flow 252 in second flow channel 209 to a second auxiliary flow 253 in auxiliary pipe channel 223. The diverted auxiliary flow 251, in first circuit 210 may then be depressurized (operation 607) by one or more metering devices that may include one or more of 217, 218 which may be located on, preceding to, or proceeding from first auxiliary flow channel 219. The diverted auxiliary flow 253 in second circuit 215 may then be depressurized (operation 608) by one or more metering devices that may include one or more of 221 or 222 which may be placed on, preceding to, or proceeding from second auxiliary flow channel 223. First auxiliary flow 251 is run (operation 609) through first auxiliary heat exchange unit 216, via first auxiliary flow channel 219 to exchange heat with main refrigerant flow 250 that flows through first auxiliary heat exchange unit 216, via first flow channel 202. Second auxiliary flow 253 is run (operation 610) through second auxiliary heat exchange unit 220, via second auxiliary flow channel 223 to exchange heat with main refrigerant flow 252 that flows through second auxiliary heat exchange unit 220 via second flow channel 209. This exchange of heat (operations 609, 610) allows further efficiency gains in the systems 200 further reducing the load on each compressor 201, 208 in system 200.
First refrigerant flow 250 through first flow channel 202 is run (operation 611) through intermediary heat exchange unit 206. Second refrigerant flow 252, flowing through second flow channel 209 is run (operation 612) through intermediary heat exchange unit 206. As first refrigerant flow 250 from first circuit 210 and second refrigerant flow 252 from second circuit 215 proceed through intermediary heat exchange unit 206, heat is exchanged (operation 613) between the refrigerants in two circuits 210, 215. This exchange of heat allows each circuit 210, 215 to operate at a restricted pressure differential or envelope since each circuit covers one portion of an otherwise larger pressure differential of a conventional heat pump system.
High pressure circuit 310 may include a high pressure compressor 301 that compresses the refrigerant of circuit 310 running through flow channel 302 within a high pressure range. High pressure circuit 310 has at least one reversing valve 303. Reversing valve 303 may be a 4-way valve and determines the direction of the refrigerant flow in system 300. Reversing valve 303 may have several connection points on circuit 310, including connection point 303A and connection point 303B. Various refrigerants or refrigerant combinations may be used in each circuit, based on the desired operating condition of each circuit, including for example CO2 and R32.
Low pressure circuit 325 includes low pressure compressor 311 that compresses the refrigerant running in circuit 325 through flow channel 312 within a low-pressure range. Low pressure circuit 325 has at least one reversing valve 313. Reversing valve 313 may be a 4-way valve and determines the direction of the refrigerant flow in system 300. Reversing valve 313 may have several connection points on circuit 325, including connection points 313A and 313B. Various refrigerants or refrigerant combinations may be used in each circuit, based on the desired operating condition of each circuit, including for example CO2 and R32.
Reversing valves 303, 313 are synchronized, since circuits 310, 325 operate together in the same mode of operation and may be synchronized and controlled by a controller unit or computing unit 2000, see
Between circuits 310, 325, an intermediary heat exchange unit 308 may allow the transfer of heat or facilitates heat exchange between flow channel 302 of high pressure circuit 310 and flow channel 312 of low pressure circuit 325. Refrigerants 350, 352 of their respective circuits 310, 325 remain fluidly isolated but exchange heat via intermediary heat exchange unit 308 that connects circuits 310, 325 together in a cascade configuration. High-pressure circuit 310 also includes an outer heat exchange unit 304, while low-pressure circuit 325 includes an outer heat exchange unit 319. Depending on the mode of operation of system 300, each of outer heat exchange units 304, 319 may switch between operating as a condenser that rejects heat and an evaporator that absorbs heat. In the heating configuration illustrated, outer heat exchange unit 304 operates as a condenser that rejects heat, for example into an indoor room, by running air over flow channel 302 with a compressed and high temperature refrigerant which heats the rejected air. In this configuration, outer heat exchange unit 319 in circuit 325 acts as an evaporator that absorbs heat from air running over it into refrigerant of circuit 325 that is flowing through flow channel 312.
CCCHP 300, includes two or more heat pump circuits 310, 325 connected to each other, to allow a compressor 301, 311 for each independent circuit 310, 325 to operate over a lower pressure differential and therefore increase the refrigerant mass flow rate circulation for each circuit, and/or allow for a reduction in the compressor size of compressor 301, 311. Each circuit may have a different refrigerant (that may be preferably suitable for specific operating conditions), different compressor sizes or types, different heat exchange unit sizes, different configurations and the like.
In several aspects, system 300, for example per method 500 discussed with respect to
Apart from intermediary heat exchange unit 308 that connects circuits 310, 325, these circuits in various aspects may also share one or more other heating exchange units also referred to herein as “economizer heat exchange unit” 305. System 300 includes a vapor injection compressor configuration circuit 330 that includes an auxiliary flow channel 317 that is connected to flow channel 312. Vapor injection compressor configuration circuit 330 forms a sub-part or sub-circuit of low-pressure circuit 325. In several aspects, a portion of refrigerant in refrigerant flow 352 in flow channel 312 is diverted into an auxiliary flow 353 through flow channel 317 and is depressurized at one or more metering devices 314 thus reducing its temperature before flowing though economizer heat exchange unit 305. Economizer heat exchange unit 305 also receives flow channel 302 from high pressure circuit 310 containing a flow of refrigerant 350, allowing the exchange of heat between flow channel 317 and flow channel 302. This feeding of refrigerant flow 353 from low pressure circuit 325 into heat exchange unit 305 provides even more efficient cooling than conventional vapor injection compressor configuration designs, because low-pressure refrigerant flow 352 of low pressure circuit 325 is in most aspects already cooler than the refrigerant in refrigerant flow 350 in high pressure circuit 310. Therefore an even lower temperature diverted refrigerant in refrigerant flow 353 provides a stronger cooling effect to cool refrigerant flow 350 in high pressure circuit 310. In several aspects, vapor auxiliary refrigerant flow 353 leaves economizer heat exchange unit 305 and is then fed back into intermediate stage of compressor 311 as vapor, for example via vapor injection compressor configuration portion 321 of circuit 325.
CCCHP 300 with a one-circuit vapor injection compressor configuration (“VCHP”) in a low pressure circuit 325 may be designed to cool high pressure circuit 310 or any other connected circuit. CCCHP 300 may be operated according to method 700 discussed with respect to
First refrigerant flow 350 now cooled with economizer heat exchange unit 305 flows through first flow channel 302 and is run (operation 709) through an intermediary heat exchange unit 308. The main flow of second refrigerant flow 352 (the flow not diverted) continues through second flow channel 312, and is then run (operation 710) through intermediary heat exchange unit 308. As first refrigerant flow 350 from first circuit 310 and second refrigerant flow 352 from second circuit 325 continue through intermediary heat exchange unit 308, heat is exchanged (operation 711) between the refrigerants in refrigerant flows 350, 352 in circuits 310, 325. This exchange of heat (operation 711) allows each circuit 310, 325 to operate within a restricted pressure differential, range, or envelope, where each circuit may cover or be run within one portion of a larger pressure differential of a conventional heat pump system.
High pressure circuit 410 and low-pressure circuit 425 each have at least one reversing valve 403, 413, respectively. Reversing valves 403, 413 may be 4-way valves and may determine the direction of refrigerant flow 450 in system 400. Reversing valve 403 may have several connection points on the circuit 410, including connection point 403A and connection point 403B, while reversing valve 413 may have several connection points on circuit 425, including connection points 413A and 413B. Various refrigerants or refrigerant combinations may be used in each circuit 410, 425, based on the desired operating condition of each circuit, including for example CO2 and R32.
Reversing valves 403, 413 are synchronized since circuits 410, 425 operate in the same mode of operation. Reversing valves 403, 413 may be synchronized and controlled by a controller unit or computing unit 2000 see
Any of metering devices 406, 407, 414, 415, 418 may be optional, and depending on the configuration of the circuits, any of these metering devices 406, 407, 414, 415, 418 may be located at different points or connections in their respective circuits 410, 425. A metering device 406, 407, 414, 415, 418 depressurizes the refrigerant and can be any of an expansion valve, an electronic expansion valve, a capillary tube, a thermostatic expansion valve, or a piston device. Finally, each of high-pressure circuit 410 and low-pressure circuit 425 may include an optional accumulator 409, 420, respectively, which ensures that liquid refrigerant is not sucked into compressor 401, 411 by a suction line or suction input of compressors 401, 411.
Between circuits 410, 425, an intermediary heat exchange unit 408 allows the transfer of heat, or facilitates heat exchange between flow channel 402 carrying a refrigerant in a refrigerant flow 450 of high pressure circuit 410 and flow channel 412 carrying a refrigerant in a refrigerant flow 452 of low pressure circuit 425. Refrigerant flows 450, 452 remain in their respective circuits 410, 425 but exchange heat via intermediary heat exchange unit 408 that connects circuits 410, 425 together in a cascade configuration. High-pressure circuit 410 includes an outer heat exchange unit 404 and low-pressure circuit 425 includes an outer heat exchange unit 419. Depending on the mode of operation of system 400, each of outer heat exchange units 404, 419 may switch between operating as a condenser that rejects heat and an evaporator that absorbs heat. In the heating configuration illustrated, outer heat exchange unit 404 operates as an evaporator that absorbs heat from air running over it into refrigerant of circuit 410, and supplies cool air, into an indoor room for example. In this configuration, outer heat exchange unit 419 in circuit 425 acts as a condenser that rejects heat, for example into an outdoor environment, by running air over flow channel 412 with a compressed and high temperature refrigerant 452 heating the outdoor air.
CCCHP 400 may include two or more heat pump circuits 410, 425 connected to each other, to allow a compressor 401, 411 for each independent circuit 410, 425 to operate over a lower pressure differential and therefore increase the refrigerant mass flow rate circulation for each circuit 410, 425, and/or allow for a reduction in compressor 401, 411 size. Each circuit 410, 425 may have a different refrigerant (that may be preferably suitable for specific operating conditions), different compressor size, different compressor type, different heat exchange unit sizes, different configurations and the like. In several aspects, system 400, for example per method 500 as discussed in regards to
Apart from intermediary heat exchange unit 408 that connects the two circuits 410, 425, the circuits in various aspects may also share one or more other heat exchange units also referred to herein as “economizer heat exchange unit” 405. System 400 includes a vapor injection compressor configuration circuit 430 that includes an auxiliary flow channel 417 that is connected to flow channel 412. The vapor injection compressor configuration circuit 430 forms a sub-part or sub-circuit of low-pressure circuit 425. In several aspects, a portion of the refrigerant in refrigerant flow 452 in flow channel 412 is diverted into an auxiliary flow 453 through flow channel 417 and is depressurized at one or more metering devices 414 and thus its temperature is reduced before flowing though economizer heat exchange unit 405. The economizer heat exchange unit 405 also receives flow channel 402 from high pressure circuit 410 which contains flow 450 of the refrigerant, allowing the exchange of heat between flow channel 417 and flow channel 402. This feeding of refrigerant in refrigerant flow 453 from low pressure circuit 425 into heat exchange unit 405 provides even more efficient cooling than conventional vapor injection compressor configuration cooling models, because low pressure refrigerant in refrigerant flow 452 of low pressure circuit 425 is in most aspects already cooler than the refrigerant in refrigerant flow 450 in high pressure circuit 410, and therefore the diverted cooler refrigerant in refrigerant flow 453 provides a more effective way to cool the refrigerant in refrigerant flow 450 in high pressure circuit 410. In several aspects, the vapor leaving economizer heat exchange unit 405 is then fed back into the intermediate stage of compressor 411 as vapor. Alternate piping arrangements can be made, so that the refrigerant in circuit 410 passes through economizer heat exchanger 405 before it passes through internal heat exchanger 408. Even though additional refrigerant piping is required in this case, this counterflow configuration may provide a more efficient heat transfer arrangement.
CCCHP 400 may include a one-circuit vapor injection compressor configuration (“VCHP”) in a low-pressure circuit, e.g., low-pressure circuit 425, utilized to cool high-pressure circuit 410 or any other circuit. This one-circuit VCHP may be operated according to method 700 as discussed regarding
First refrigerant flow 450 now cooled with the economizer heat exchange unit 405 flows through first flow channel 402 and runs (operation 709) through an intermediary heat exchange unit 408. The main flow 452 of second refrigerant, flow 452 (that was not diverted) running through second flow channel 412 continues to run (operation 710) through intermediary heat exchange unit 408. As first refrigerant flow 450 from first circuit 410 and second refrigerant flow 452 from second circuit 425 flow through intermediary heat exchange unit 408, heat is exchanged (operation 711) between the refrigerants in circuits 410, 425. This exchange of heat allows each circuit 410, 425 to operate at a restricted pressure differential or envelope since each circuit 410, 425 covers one portion of an otherwise larger pressure differential of a conventional heat pump system.
In any of the embodiments described in
Additional components may be necessary to be added to any of the systems described herein in addition to the inclusion of a 4-way valve system, to allow these systems to operate in both a heating and cooling mode and switch from one mode to the other. In one embodiment, a reservoir or charge compensators may be added to each circuit in a system. A reservoir or charge compensator would allow each circuit to go from a high pressure to a low pressure by either releasing additional refrigerant into the flow channels of a circuit to increase pressure of the circuit, or by absorbing refrigerant from the circuit to fill the reservoir and take the refrigerant out of the system. This reservoir or charge compensation system may be automated and adjustable and controlled by systems such as a computing device as described in
Examples of the devices, systems, and methods disclosed herein, according to various aspects of the present disclosure, are provided below in the following numbered clauses. An aspect of the devices, systems, and methods may include any one or more than one, and any combination of, the numbered clauses described below.
Clause 1. A cascaded cold climate heat pump system comprising a high pressure circuit comprising a first compressor, a first outer heat exchange unit, a first metering device, and a first reversing valve for flowing a first refrigerant through the high pressure circuit; a low pressure circuit fluidly isolated from the high pressure circuit and comprising a second compressor, a second outer heat exchange unit, a second metering device, and a second reversing valve for flowing a second refrigerant through the low pressure circuit; and an intermediary heat exchange unit thermally connecting the fluidly isolated high pressure circuit and the low pressure circuit to facilitate heat exchange between the first refrigerant and the second refrigerant in the intermediary heat exchange unit such that the heat exchange reduces a temperature lift needed by each of the high pressure circuit and the low pressure circuit, the high pressure circuit operating within a first pressure differential, and the low pressure circuit operating within a second pressure differential.
Clause 2. The system of Clause 1 wherein at least one of the high-pressure circuit and the low-pressure circuit further comprises an accumulator.
Clause 3. The system of any one of Clauses 1-2, wherein at least one of the first reversing valve and the second reversing valve is a 4-way reversing valve.
Clause 4. The system of any one of Clauses 1-3, wherein at least one of the first compressor and the second compressor is a variable speed compressor.
Clause 5. The system of any one of Clauses 1-4, wherein the system may operate in a cooling mode or a heating mode.
Clause 6. The system of any one of Clauses 1-5, wherein the first outer heat exchange unit and the second outer heat exchange unit may function as a condenser or evaporator.
Clause 7. The system of any one of Clauses 1-6 further comprising an additional pressure circuit for flowing a refrigerant comprising: a refrigerant flowing through a channel in the additional pressure circuit; a compressor to modulate a flow pressure of the refrigerant; a reversing valve to determine a flow direction of the refrigerant, wherein the flow direction determines a mode of operation; an outer heat exchange unit capable of operating as a condenser or evaporator and capable of connecting to other additional pressure circuits; a metering device; and wherein the additional pressure circuit is thermally coupled either with the high pressure circuit via the first outer heat exchange unit, or the low pressure circuit via the second outer heat exchange unit to allow customization of the system with the additional pressure circuit configured to perform within a specific pressure differential to improve system efficiency.
Clause 8. The system of any one of Clauses 1-7, wherein the metering device comprises an expansion valve, an electronic expansion valve, a capillary tube, a thermostatic expansion valve, or a piston device.
Clause 9. The system of any one of Clauses 1-8, wherein at least one of the high pressure circuit and the low pressure circuit further comprises a vapor injection configuration, the vapor injection configuration comprising an auxiliary circuit, to receive at least a portion of a redirected main refrigerant flow from a main flow channel to an auxiliary flow through an auxiliary flow channel, wherein the auxiliary flow channel is a connected sub-part of the main flow channel; an auxiliary metering device to depressurize the auxiliary flow in the auxiliary circuit; and an auxiliary heat exchange unit, wherein the auxiliary pipe channel and a portion of the main pipe channel pass through the auxiliary heat exchange unit to facilitate the exchange of heat between the auxiliary flow and the main refrigerant flow.
Clause 10. The system of any one of Clauses 1-9 wherein the low pressure circuit further comprises an economizer vapor injection configuration, the economizer vapor injection configuration comprising an auxiliary circuit in fluid communication with the low pressure circuit and fluidly isolated from the high pressure circuit and comprising: an auxiliary metering device, wherein at least a portion of the second refrigerant is flowable through the auxiliary circuit and depressurized by the auxiliary metering device; and an economizer heat exchange unit that receives the depressurized second refrigerant; wherein the high pressure circuit also comprises the economizer heat exchange unit so as to facilitate heat exchange between the depressurized second refrigerant and the first refrigerant in the high pressure circuit; and wherein the auxiliary circuit is configured to flow the second refrigerant from the economizer heat exchange unit to the second compressor.
Clause 11. A cascaded heat pump system comprising a plurality of fluidly isolated heat pump circuits, each of the heat pump circuits being thermally connected to another of the heat pump circuits via an intermediary heat exchange unit and each heat pump circuit comprising: a refrigerant flowing through the heat pump circuit; a compressor; a reversing valve operable to direct a flow of the refrigerant in a first direction or a second direction opposite the first direction depending on a mode of operation; a metering device; and one of the intermediary heat exchange units usable as a condenser or an evaporator depending on the mode of operation; and wherein the plurality of fluidly isolated heat pump circuits allows each heat pump circuit to operate within a specific pressure differential to improve efficiency of the compressor.
Clause 12. The system of Clause 11 wherein the plurality of fluidly isolated heat pump circuits are synchronized in a mode of operation, wherein the mode of operation is either a cooling mode or a heating mode.
Clause 13. The system of any one of Clauses 11-12 wherein each heat pump circuit further comprises an accumulator.
Clause 14. The system of any one of Clauses 11-13 wherein the compressor comprises a variable speed compressor.
Clause 15. The system of any one of Clauses 11-14, wherein the metering device comprises an expansion valve, an electronic expansion valve, a capillary tube, a thermostatic expansion valve, or a piston device.
Clause 16. The system of any one of Clauses 11-15, wherein a heat pump circuit of the plurality of fluidly isolated heat pump circuits comprises a vapor injection configuration, the vapor injection configuration comprising an auxiliary circuit, to receive at least a portion of a redirected main refrigerant flow from a main flow channel to an auxiliary flow through an auxiliary flow channel, wherein the auxiliary flow channel is a connected sub-part of the main flow channel; an auxiliary metering device to depressurize the auxiliary flow in the auxiliary circuit; and an auxiliary heat exchange unit, wherein the auxiliary flow channel and a portion of the pipe channel pass through the auxiliary heat exchange unit to facilitate the exchange of heat between the auxiliary flow and the main refrigerant flow.
Clause 17. The system of any one of Clauses 11-16, wherein a heat pump circuit further comprises an economizer vapor injection configuration, the economizer vapor injection configuration comprising an auxiliary circuit in fluid communication with the heat pump circuit and fluidly isolated from another heat pump circuit of the plurality of fluidly isolated heat pump circuits, and comprising: an auxiliary metering device, wherein at least a portion of the main refrigerant is flowable through the auxiliary circuit and depressurized by the auxiliary metering device; and an economizer heat exchange unit that receives the depressurized main refrigerant; wherein the another heat pump circuit also comprises the economizer heat exchange unit so as to facilitate heat exchange between the depressurized main refrigerant and another refrigerant that is flowable through the another heat pump circuit; and wherein the auxiliary circuit is configures to flow the main refrigerant from the economizer heat exchange unit to the compressor.
Clause 18. A method of operating a cascaded cold climate heat pump system comprising pressurizing a first refrigerant by a first compressor to a first pressure in a first heat pump circuit; pressurizing a second refrigerant by a second compressor to a second pressure in a second heat pump circuit fluidly isolated from the first heat pump circuit; circulating the first refrigerant through the first heat pump circuit, wherein the first heat pump circuit further comprises a first outdoor heat exchange unit, a first metering device, a first accumulator, and a first reversing valve; circulating the second refrigerant through the second heat pump circuit, wherein the second heat pump circuit comprises a second outer heat exchange unit, a second metering device, a second accumulator, and a second reversing valve; flowing the first refrigerant in the first heat pump circuit through an intermediary heat exchange unit of the first heat pump circuit; flowing the second refrigerant flowing in the second heat pump through the intermediary heat exchange unit, the second heat pump circuit also comprising the intermediary heat exchange unit; and exchanging heat between the first refrigerant and second refrigerant via the intermediary heat exchange unit so as to reduce a temperature lift needed by each of the first heat pump circuit and the second heat pump circuit allowing the first heat pump circuit to operate within a first pressure differential, and the second heat pump circuit to operate within a second pressure differential, improving efficiency of the first compressor and second compressor.
Clause 19. The method of Clause 18 further comprising diverting at least a portion of the first refrigerant from the first heat pump circuit to a first auxiliary circuit; diverting at least a portion of the second refrigerant from the second heat pump circuit to a second auxiliary circuit; depressurizing the diverted first refrigerant in the first auxiliary circuit with a first auxiliary metering device in the first auxiliary circuit; depressurizing the diverted second refrigerant in the second auxiliary circuit with a second auxiliary metering device in the second auxiliary circuit; flowing the first refrigerant in the first heat pump circuit and the diverted first refrigerant in the first auxiliary heat pump circuit through a first auxiliary heat exchange unit to exchange heat between the first refrigerant and the diverted first refrigerant; flowing the second refrigerant in the second heat pump circuit and the diverted second refrigerant in the second auxiliary heat pump circuit through a second auxiliary heat exchange unit to exchange heat with between the second refrigerant and the diverted second refrigerant; and wherein multiple heat exchange points improves control of heat exchange between the first heat pump circuit and the second heat pump circuit.
Clause 20. The method of any one of Clauses 18-19, further comprising diverting at least a portion of the second refrigerant from the second heat pump circuit to a second auxiliary circuit; depressurizing the diverted second refrigerant in the second auxiliary circuit with a second auxiliary metering device in the second auxiliary circuit; flowing the diverted second refrigerant in the second auxiliary circuit through an auxiliary heat exchange unit; flowing the first refrigerant in the first heat pump circuit through the auxiliary heat exchange unit; and exchanging heat between the diverted second refrigerant in the second auxiliary circuit and the first refrigerant in the first refrigerant circuit via the auxiliary heat exchange unit so as to provide additional cooling to the first refrigerant by the diverted second refrigerant. cascaded cold climate heat pump system comprising a high pressure circuit comprising a first compressor, a first outer heat exchange unit, a first metering device, a first reversing valve, and a first refrigerant flowing through the high pressure circuit in a first pipe channel; a low pressure circuit comprising a second compressor, a second outer heat exchange unit, a second metering device, a second reversing valve, and a second refrigerant flowing through the low pressure circuit in a second pipe channel; and an intermediary heat exchange unit connecting the high pressure circuit and the low pressure circuit, wherein at least a portion of each of the first pipe channel and the second pipe channel connect to the intermediary heat exchange unit, to facilitate heat exchange between the first refrigerant in the first pipe channel and the second refrigerant in the second pipe channel.
The foregoing detailed description has set forth various forms of the systems and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution.
While the aspects of the present disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. But it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. For example, certain embodiments disclosed here envisage usage with a powered fan rather than an inducer fan, or no fan at all. Moreover, the rotating equipment (e.g., motors) and valves disclosed herein are envisaged as being operable at specified speeds or variable speeds through inverter circuitry, for example. Moreover, the internal and external communication of the furnace may be accomplished through wired and or wireless communications, including known communication protocols, Wi-Fi, 802.11(x), Bluetooth, to name just a few.
As used in any aspect herein, the term “logic” may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices.
As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution.
As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states.
Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the present disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
One or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise.
Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.
In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.”
With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.
It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects.
In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.
