Vapor compression system, method of retrofitting vapor compression system, and controller for vapor compression system
By introducing auxiliary heating circuits and heat storage units into the steam compression system, the system's energy consumption is solved, and the system can be achieved with lower cost and more reliable indoor heating.
Patent Information
- Application Number
- CN202411652615.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-21
- Filing Date
- 2024-11-19
- Publication Date
- 2025-05-23
AI Technical Summary
In cold climates, steam compression systems need to consume more energy when meeting indoor heating needs, resulting in increased energy costs and risk of supply interruption.
An auxiliary heating circuit is introduced to optimize system operation through a heat storage unit and controller, which utilizes the heat storage unit to store additional heat energy and releases to assist in heating the indoor space when needed.
Through the use of auxiliary heating circuits, it is possible to store heat energy at low electricity prices and use it at high electricity prices or peak energy consumption, reducing energy costs and reducing the risk of supply cuts.
Smart Images
Figure CN120027535A_ABST
Abstract
Description
Technical Field
[0001] The field relates generally to heating, ventilation, and air conditioning (HVAC) systems and, more particularly, to vapor compression systems that can function as heat pumps. Background Art
[0002] The vapor compression cycle is used to regulate the temperature and humidity of an interior space. In some applications, the vapor compression system is constructed to be reversible so that the same system can be operated to heat or cool the interior space as needed. Heat pumps or reversible vapor compression systems that can be constructed as heat pumps are often used to heat indoor spaces in very cold environments. However, subjecting the outdoor condensing unit to very cold temperatures requires the system to consume more energy to meet the heating needs of the indoor space. In addition, in cold climates, when many users are operating the heat pump, the overall energy demand may peak, thereby increasing energy costs and the possibility of power outages. Therefore, there is a need for a vapor compression system that can meet the heating needs of indoor spaces in a more cost-effective and energy-efficient manner.
[0003] This section is intended to introduce the reader to various technical aspects that may be relevant to various aspects of the present disclosure described and / or claimed below. This discussion is considered helpful in providing the reader with background information to facilitate a better understanding of various aspects of the present disclosure. Therefore, it should be understood that these statements are to be read from this perspective, and not as an admission of prior art. Summary of the invention
[0004] One aspect relates to a vapor compression system, which includes a main circuit, an auxiliary circuit, a first valve and a second valve. The main circuit includes an indoor heat exchanger, an outdoor heat exchanger and a compressor that can be operated to compress a refrigerant. The first valve can be selectively positioned in a first position and a second position, so that the first valve connects the indoor heat exchanger fluid to the compressor in the first position. The second valve can be selectively positioned in a third position and a fourth position, so that the second valve connects the indoor heat exchanger fluid to the outdoor heat exchanger in the third position. The auxiliary circuit includes a thermal storage unit, a supply pipe and a return pipe. The thermal storage unit has an inlet, an outlet and a heating pipe extending between the inlet and the outlet. When the first valve is in the second position, the supply pipe connects the outlet fluid of the thermal storage unit to the indoor heat exchanger. When the second valve is in the fourth position, the return pipe connects the inlet fluid of the thermal storage unit to the indoor heat exchanger.
[0005] Another aspect relates to a method of converting a vapor compression system to have an auxiliary heating loop having a thermal storage unit. The vapor compression system includes an indoor heat exchanger, an outdoor heat exchanger, and a compressor fluidly connected between the indoor heat exchanger and the outdoor heat exchanger. The method includes: fluidly connecting a first path of a first valve between the indoor heat exchanger and the compressor; fluidly connecting a third path of a second valve between the indoor heat exchanger and the outdoor heat exchanger; fluidly connecting a supply conduit between the thermal storage unit and a second path of the first valve; and fluidly connecting a return conduit between a fourth path of the second valve and the thermal storage unit.
[0006] Another aspect relates to a controller for a vapor compression system, the vapor compression system comprising a main loop and an auxiliary loop. The main loop comprises an indoor heat exchanger, an outdoor heat exchanger, and a compressor. The auxiliary loop comprises a supply conduit, a return conduit, and a thermal storage unit having a heating conduit fluidly connecting the supply conduit and the return conduit. The main loop and the auxiliary loop are connected by a first valve and a second valve. The controller comprises a processor and a memory storing instructions for programming the processor to: operate the vapor compression system to provide a refrigerant flow through the main loop; determine whether a condition has been met; and adjust the position of the first valve and / or the second valve when the condition is met.
[0007] Another aspect of the present disclosure relates to a vapor compression system, which includes an indoor heat exchanger, an outdoor heat exchanger, a compressor fluidly connected between the indoor heat exchanger and the outdoor heat exchanger, a first valve selectively positionable in a first position and a second position, a second valve selectively positionable in a third position and a fourth position, and a thermal storage unit fluidly connected between the first valve and the second valve. When the first valve is in the first position and the second valve is in the third position, the indoor heat exchanger, the outdoor heat exchanger, and the compressor are fluidly connected to allow refrigerant to flow in a main circuit therebetween. When the first valve is in the second position and the second valve is in the fourth position, the thermal storage unit and the indoor heat exchanger are fluidly connected to allow refrigerant to flow in an auxiliary circuit therebetween.
[0008] There are various improvements on the features indicated in the above-mentioned aspects of the present disclosure. Additional features may also be included in the above-mentioned aspects of the present disclosure. These improvements and additional features may exist alone or in any combination. For example, the various features discussed below with respect to any of the illustrated embodiments of the present disclosure may be incorporated into any of the above-mentioned aspects of the present disclosure alone or in any combination. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 is a schematic diagram of a first example vapor compression system configured in a cooling mode.
[0010] Figure 2 yes Figure 1 Schematic diagram of a first example vapor compression system configured in a heat pump heating mode is shown in FIG.
[0011] Figure 3 is a schematic diagram of a second example vapor compression system comprising Figure 2 A first example vapor compression system and a thermal storage unit configured in a cooling mode are shown.
[0012] Figure 4 yes Figure 3 Schematic diagram of a second example vapor compression system configured in a heating mode is shown in FIG.
[0013] Figure 5A yes Figure 3 Schematic diagram of a second vapor compression system configured in auxiliary heating mode is shown in FIG.
[0014] Figure 5B yes Figure 5A Schematic diagram of a second vapor compression system configured in auxiliary heating mode and additionally comprising a pump is shown in FIG.
[0015] Figure 6 is a schematic diagram of a third example vapor compression system comprising Figure 3 A second example vapor compression system configured in a heating mode and a defrost duct are shown.
[0016] Figure 7 yes Figure 6 Schematic diagram of a third example vapor compression system configured in an auxiliary heating mode is shown in FIG.
[0017] Figure 8 yes Figure 6 A schematic diagram of a third example vapor compression system configured in a defrost mode is shown in FIG.
[0018] Fig. 9 is a flow chart of an example method for retrofitting a vapor compression system with an auxiliary heating loop.
[0019] Fig.10 is a block diagram of a control system for the vapor compression system shown in the previous figures.
[0020] Fig.11 is a block diagram of an example control algorithm for the vapor compression system shown in the previous figures.
[0021] Corresponding reference numerals indicate corresponding parts throughout the drawings. DETAILED DESCRIPTION
[0022] Examples will be described with respect to a reversible vapor compression system operable to heat or cool an interior space. However, other example systems and methods may be used to regulate the temperature of an enclosed space.
[0023] Figure 1 and Figure 2 Schematic diagram of a first example vapor compression system 100 for cooling or heating an interior space 60 surrounded by an exterior space 80. The first system 100 includes a single reversible closed refrigerant circuit including a compressor 160, a first expansion device 130, a second expansion device 135, a reversing valve 180, an indoor heat exchanger 140, and an outdoor heat exchanger 120. In other embodiments of the present disclosure (not shown), the first system 100 may be an irreversible system, such as a heat pump. In still other embodiments, the first system 100 may include multiple refrigerant circuits to accommodate multiple compressors, or may operate in parallel with another system, such as a humidity control system. The configuration of the reversing valve 180 determines the direction of flow through the system, and therefore determines whether the system is configured to cool or heat the interior space 60.
[0024] Figure 1 The first system 100 is illustrated operating in a cooling mode. Refrigerant enters the compressor 160 at the compressor inlet 110 as a low pressure, low temperature gas (i.e., suction flow). The compressor 160 increases the pressure of the refrigerant, which leaves the compressor 160 at the compressor outlet 115 as a high pressure, high temperature gas (i.e., discharge flow). The compressor 160 may be driven by a first variable frequency drive (VFD) 162 or any other suitable motor.
[0025] The discharge flow passes through the first discharge path 181 of the reversing valve 180, which guides the refrigerant to the outdoor heat exchanger 120. The outdoor heat exchanger 120 acts as a condenser to transfer the heat Q 出 Remove heat from the refrigerant and 出 The first fan 190 generates a first airflow 194 from the outdoor heat exchanger 120 toward the external space 80, thereby discharging warm air toward the external space 80. The first fan 190 can be driven by a second VFD 192 or any other suitable motor.
[0026] Downstream of the outdoor heat exchanger 120, the refrigerant bypasses the second expansion device 135 and flows through the first expansion device 130, which reduces the pressure of the refrigerant. In some embodiments, the pressure can be reduced until the temperature of the liquid refrigerant becomes the boiling temperature at the pressure, and the refrigerant becomes a two-phase mixture as some of the liquid refrigerant boils and turns into a gas. The first expansion device 130 can be a fixed orifice, a thermal expansion valve, an electronic expansion valve, or another type of expansion device that allows the first system 100 to function as described.
[0027] The first expansion device 130 is fluidly connected to the indoor heat exchanger 140, which receives a low-pressure and low-temperature liquid refrigerant or a two-phase mixture of liquid refrigerant and gaseous refrigerant at its inlet. The indoor heat exchanger 140 acts as an evaporator, wherein the refrigerant absorbs heat Q from the interior space 60. 入 , so that the phase of the refrigerant changes from liquid to gas. The second fan 150 generates a second airflow 154 toward the interior space 60 through the indoor heat exchanger 140, thereby cooling the interior space 60. The second fan 150 can be driven by a third variable frequency drive (VFD) 152 or by any other suitable motor. The gaseous refrigerant flow then passes through the first suction path 182 of the reversing valve 180 and returns to the compressor inlet 110 as a suction flow.
[0028] Figure 2 The first system 100 is illustrated as being operated in a heating mode. Similar to the cooling mode, the refrigerant enters the compressor 160 at the compressor inlet 110 as a low pressure, low temperature gas (i.e., the suction flow). The compressor 160 increases the pressure of the refrigerant, and the refrigerant leaves the compressor 160 at the compressor outlet 115 as a high pressure, high temperature gas (i.e., the discharge flow). The discharge flow passes through the second discharge path 183 of the reversing valve 180, which directs the refrigerant to the indoor heat exchanger 140. The indoor heat exchanger 140 acts as a condenser, transferring the heat Q 出 The second fan 150 generates a second airflow 154 through the indoor heat exchanger 140 toward the interior space 60, thereby removing the heat Q 出 Released into the interior space 60 .
[0029] Downstream of the indoor heat exchanger 140, the refrigerant bypasses the first expansion device 130 and flows through the second expansion device 135, which reduces the pressure of the refrigerant. The pressure can be reduced until the current temperature of the liquid refrigerant becomes the boiling temperature at the pressure, and the refrigerant becomes a two-phase mixture as some of the liquid refrigerant boils and turns into a gas. The second expansion device 135 can be a fixed orifice, a thermal expansion valve, an electronic expansion valve, or any type of expansion device that allows the first system 100 to function as described.
[0030] The second expansion device 135 is fluidly connected to the outdoor heat exchanger 120, which receives a low-pressure and low-temperature liquid refrigerant or a two-phase mixture of liquid refrigerant and gaseous refrigerant at its inlet. The outdoor heat exchanger 120 acts as an evaporator, wherein the refrigerant absorbs heat Q from the external space 80. 入 The first fan 190 generates a first airflow 194 from the outdoor heat exchanger 120 toward the external space 80. The gaseous refrigerant flow then passes through the second suction path 184 of the reversing valve 180 and returns to the compressor inlet 110 as a suction flow.
[0031] If the first system 100 is installed in an external environment that is subject to very low temperatures (eg, less than 17 degrees Fahrenheit), the outdoor heat exchanger 120 will have a limited ability to absorb heat from the exterior space 80 . Figure 3 5 is a schematic diagram of a second example vapor compression system 200 for heating or cooling the interior space 60 using an additional thermal storage unit 300. The second vapor compression system 200 is substantially similar to Figure 1 to Figure 2 A first example vapor compression system 100 is shown in FIG. 2 , and unless otherwise noted, the description of the first system 100 applies to the second system 200 .
[0032] In the second example system 200, the compressor 160, the reversing valve 180, the outdoor heat exchanger 120, the first expansion device 130 and the second expansion device 135, and the indoor heat exchanger 140 form a main loop (in Figure 3 and Figure 4 The main circuit also includes a first valve 210 that can be selectively positioned in a first position and a second position and a second valve 230 that can be selectively positioned in a third position and a fourth position. The second system 200 also includes an auxiliary circuit (in the Figure 5A and Figure 5B ), which will be discussed in more detail further in this article.
[0033] Figure 3 and Figure 4A second system 200 is illustrated in which the first valve 210 is positioned in a first position and the second valve 230 is positioned in a third position to allow refrigerant to flow through the primary circuit and prevent refrigerant from flowing through the secondary circuit. In such a configuration, the refrigerant flows through a first path of the first valve 210 to fluidly connect the compressor 160 to the indoor heat exchanger 140, and flows through a third path of the second valve 230 to fluidly connect the indoor heat exchanger 140 to the outdoor heat exchanger 120.
[0034] When the first valve 210 is positioned in the first position and the second valve 230 is positioned in the third position, the second system 200 can operate in a cooling mode or a heating mode. Figure 3 ), in the first system 100 Figure 1 When configured as shown in , the operation of the second system 200 is the same as or substantially similar to the operation of the first system 100. The first valve 210 is fluidly connected between the indoor heat exchanger 140 and the compressor 160 via the first suction path 182 of the reversing valve 180, and the second valve 230 is fluidly connected between the outdoor heat exchanger 120 and the indoor heat exchanger 140. In the heating mode ( Figure 4 ), when the first system 100 is Figure 2 When configured as shown in , the operation of the second system 200 is the same as or substantially similar to the operation of the first system 100. The first valve 210 is fluidly connected between the compressor 160 and the indoor heat exchanger 140 via the second discharge path 183 of the reversing valve 180, and the second valve 230 is fluidly connected between the outdoor heat exchanger 120 and the indoor heat exchanger 140.
[0035] Reference Figure 5A , the auxiliary circuit is fluidly connected to the main circuit via the first valve 210 and the second valve 230. In addition to the first valve 210 and the second valve 230, the auxiliary circuit also includes a thermal storage unit 300, and the thermal storage unit 300 includes an inlet 302, an outlet 304, and a heating pipe 310 extending between the inlet 302 and the outlet 304. The supply pipe 330 fluidly connects the outlet 304 of the thermal storage unit 300 to the indoor heat exchanger 140 via the second path of the first valve 210, and the return pipe 350 fluidly connects the inlet 302 of the thermal storage unit 300 to the indoor heat exchanger 140 via the fourth path of the second valve 230.
[0036] The thermal storage unit 300 includes a receiving portion 315 defining a cavity 317. The receiving portion 315 may be composed entirely or partially of any insulating material, such as, but not limited to, NUTEC MaxBoard HS2400, NUTEC MaxBulk3000Fiber Fill, or Fiberfrax Durablanket. The cavity 317 is filled with a plurality of particles 319 having low thermal conductivity. The particles 319 may be any suitable particles that can be heated to a high temperature (e.g., up to 1200 degrees Fahrenheit) without significant changes in their properties. For example, the particles 319 may be sand particles, pea gravel, very dry soil, a combination of two or more types of particles, or any other suitable type of particles. In other embodiments, the cavity 317 may be filled with a non-granular material having low thermal conductivity (e.g., between 0.15 W / mK and 0.35 W / mK). The cavity 317 may be sized to accommodate any volume of particles 319, such as, but not limited to, particles 319 between 0.5 cubic meters and 1000 cubic meters.
[0037] The thermal storage unit 300 also includes one or more heating elements 370 that are operable to increase the temperature of the plurality of particles 319. In some embodiments, the one or more heating elements 370 are resistive heating elements powered by a power source (not shown). In other embodiments, the heating element 370 can be any other suitable type of heating element. The heating element 370 is operable to heat the plurality of particles 319 to a high temperature, for example, between 800°F and 1200°F. In other embodiments, the heating element 370 can be configured to heat the plurality of particles 319 to any other suitable temperature, for example, but not limited to, between 200°F and 400°F, between 400°F and 600°F, between 600°F and 800°F, or any other suitable temperature.
[0038] The power source may supply renewable electricity, locally generated electricity, off-peak electricity, a combination of different power sources, or any other suitable source to the heating element 370. The renewable power source may include wind, photovoltaic, solar thermal, geothermal, nuclear, or any other suitable renewable source. The locally generated electricity may include electricity generated on the same property as the second system 200. Off-peak electricity may include electricity generated when demand decreases below a threshold or current supply, for example, as determined by usage or pricing trends.
[0039] The heating element 370 can be powered all the time, or the heating element 370 can also be powered intermittently. For example, the heating element 370 can be heated until a temperature sensor (not shown) determines that the plurality of particles 319 have reached a desired temperature, after which the heating element 370 is de-energized until the temperature sensor determines that the plurality of particles 319 have dropped below the desired temperature. Additionally or alternatively, the heating element 370 can be powered when power demand is low so that the plurality of particles 319 are heated when power is cheapest. Additionally or alternatively, the heating element 370 can be powered when excess power generated on site is available. The thermal energy transferred from the heating element 370 to the plurality of particles 319 can be stored for later use.
[0040] When the first valve 210 is positioned in the second position and the second valve 230 is positioned in the fourth position, the refrigerant is diverted through the auxiliary loop and circulates between the thermal storage unit 300 and the indoor heat exchanger 140 to transfer the heat stored in the plurality of particles 319 to the interior space 60. Figure 5A In the second example system 200 embodiment shown in , the refrigerant flow is driven by gravity as long as the indoor heat exchanger 140 is positioned above the thermal storage unit 300. Figure 5B In the embodiment of the second example system 200 shown in , the refrigerant flow between the second valve 230 and the thermal storage unit 300 is driven by a pump 353 positioned in the return conduit 350 .
[0041] The refrigerant leaves the indoor heat exchanger 140, bypasses the first expansion device 130 and flows through the fourth path of the second valve 230. The refrigerant then passes through the return pipe 350, passes through the inlet 302 of the thermal storage unit 300 and enters the heating pipe 310. The heating pipe 310 is positioned within the cavity 317 so that the plurality of particles 319 surround the heating pipe 310 to allow heat transfer between the plurality of particles 319 and the heating pipe 310. Specifically, the heating element 370 increases the temperature of the plurality of particles 319, which in turn increases the temperature of the refrigerant flowing through the heating pipe. In the illustrated embodiment, the heating pipe 310 follows a tortuous path to maximize the surface area of the heating pipe 310 in contact with the particles 319, and thus maximize the heat transfer between the heating pipe 310 and the particles 319. In an alternative embodiment, the heating pipe 310 may extend directly between the inlet 302 and the outlet 304 of the thermal storage unit 300.
[0042] After passing through the heating pipe 310 and being in thermal communication with the plurality of particles, the heated refrigerant flows through the outlet of the thermal storage unit 300, flows through the supply pipe 330, and flows through the second path of the first valve 210. The refrigerant is then provided to the indoor heat exchanger 140, which acts as a condenser and removes heat Q from the refrigerant. 出 The second fan 150 generates a second airflow 154 passing through the indoor heat exchanger 140 toward the interior space 60, thereby transferring the heat Q 出 Released into the interior space 60 .
[0043] In other embodiments (not shown), the refrigerant is moved along the Figure 5A That is, the refrigerant flows from the indoor heat exchanger 140 through the second path of the first valve 210, flows through the supply pipe 330 and the outlet 304 of the thermal storage unit, flows through the heating pipe 310, flows through the inlet 302 of the thermal storage unit 300 and the return pipe 350, flows through the fourth path of the second valve 230, and flows back to the indoor heat exchanger 140.
[0044] Figures 6 to 8 is a schematic diagram of a third example vapor compression system 400 for heating or cooling the interior space 60. The third vapor compression system 400 and Figure 3 5 is substantially similar, and unless otherwise noted, the description of the second system 200 applies to the third system 400. In addition to the main circuit and the auxiliary circuit, the third example system 400 also includes a defrost circuit (such as Figure 8 ), the defrost circuit includes a first defrost valve 410, a second defrost valve 420 and a defrost pipe 430.
[0045] The first defrost valve 410 is positioned in the supply conduit 330 of the auxiliary circuit and can be selectively positioned in a fifth position ( Figure 7 ) and the sixth position ( Figure 8 ). The defrost conduit 430 is fluidly connected between the thermal storage unit 300 and the outdoor heat exchanger 120, and the first defrost valve 410 is operable to selectively allow the refrigerant to flow through the defrost conduit 430. In the illustrated embodiment, the first defrost valve 410 and the second defrost valve 420 are both three-way valves. In other embodiments, the first defrost valve 410 and the second defrost valve 420 may be any other suitable type of valve, such as, but not limited to, a valve assembly including two solenoid valves or two ball valves, or a reversing valve having a closed port. In further embodiments, the first defrost valve 410 and the second defrost valve may each be a different type of valve.
[0046] When the first valve 210 is Figure 6 When the first position is shown in FIG. 4 , no refrigerant flows through the first defrost valve 410 or the defrost pipe 430. Instead, the refrigerant flows through the main circuit, and the third system 400 is configured as follows according to the configuration of the reversing valve 180. Figure 3 and Figure 4 The refrigerant passes through the second defrost valve 420 configured in the seventh position between the outdoor heat exchanger 120 and the reversing valve 180 .
[0047] When the first valve 210 is positioned in the second position and the first defrost valve 410 is positioned in the fifth position, as shown in FIG. Figure 7 As shown in FIG. 4 , refrigerant is delivered from the first defrost valve 410 to the first valve 210 and flows through the auxiliary circuit. No refrigerant flows through the defrost pipe 430 or the second defrost valve 420, as shown in FIG. Figure 7 The operation of the third system 400 shown in FIG. Figure 5A The operation of the second system 200 shown in FIG. 2 is the same or substantially similar.
[0048] When the first valve 210 is positioned in the second position and the first defrost valve 410 is positioned in the sixth position, as shown in FIG. Figure 8 As shown in FIG. 1 , the refrigerant flows through the defrost circuit. The refrigerant circulates between the thermal storage unit 300 and the outdoor heat exchanger 120 to remove (i.e., melt) ice from the outer surface of the coil 129 of the outdoor heat exchanger 120. The refrigerant flows through the return pipe 350, flows through the inlet 302 of the thermal storage unit 300, and flows into the heating pipe 310.
[0049] The plurality of particles 319 transfer heat to the heating pipe 310, which in turn increases the temperature of the refrigerant flowing through the heating pipe 310. The heated refrigerant flows through the outlet 304 of the thermal storage unit 300, the supply pipe 330, the first defrost valve 410 in the sixth position, the defrost pipe 430, and the second defrost valve 420 positioned in the eighth position before being provided to the outdoor heat exchanger 120. The heated refrigerant increases the surface temperature of the coil 129 of the outdoor heat exchanger 120, thereby allowing ice on the coil 129 to melt without absorbing heat from the interior space 60. The refrigerant bypasses the second expansion device 135, flows through the second valve positioned in the ninth position, flows through the return pipe 350, and flows back into the thermal storage unit 300.
[0050] Fig. 9A flow chart of an example method 900 for retrofitting the first system 100 with an auxiliary heating loop is illustrated. The method 900 includes: fluidly connecting 902 a first path of the first valve 210 between the indoor heat exchanger 140 and the compressor 160, fluidly connecting 904 a third path of the second valve 230 between the indoor heat exchanger 140 and the outdoor heat exchanger 120, fluidly connecting 906 a supply conduit 330 between the thermal storage unit 300 and the second path of the first valve 210; and fluidly connecting 908 a return conduit 350 between the fourth path of the second valve 230 and the thermal storage unit 300.
[0051] Fluid connection 908 return conduit 350 may additionally or alternatively include connecting return conduit 350 between second valve 230 and thermal storage unit 300 such that indoor heat exchanger 140 is positioned above thermal storage unit 300, such that refrigerant flow through return conduit 350 is gravity driven. That is, the system operates as a thermosyphon and return conduit 350 need not include a pump.
[0052] Reference Fig.10 The disclosed vapor compression systems 100, 200, 400 each include a controller 510 that is programmed to control the operation of the vapor compression systems 100, 200, 400 to cool or heat the interior space 60 to a desired temperature. The controller 510 includes a processor 520 and a memory 530. The memory 530 stores instructions that program the processor 520 to operate the vapor compression systems 100 to 200 to control the temperature of the interior space 60 to a temperature set point.
[0053] The controller 510 is operable to control at least one operating parameter of the vapor compression system 100, 200, 400, such as, but not limited to, the speed of the first fan 150 or the second fan 190, the position of the expansion device 130, 135, the position of the three-way valve 210, 230, 410, 420, the position of the four-way valve 180, or the speed of the compressor 160. The controller 510 may control these parameters in response to at least one measured or calculated property of the air in the interior space 60, the air in the exterior space 80, or a signal from another controller. The measured property may include, for example, but not limited to, dry bulb temperature, wet bulb temperature, dew point temperature, partial pressure of water vapor, or relative humidity.
[0054] For example, in each of the example vapor compression systems 100, 200, 400, the controller 510 is configured to control the position of the reversing valve 180 to direct the discharge flow to the indoor heat exchanger 140 or the outdoor heat exchanger 120 so that the system 100, 200, 400 operates in a heating mode or a cooling mode. When the controller 510 programs the operation of the vapor compression system 100, 200, 400 to direct the discharge flow to the outdoor heat exchanger 120, the controller 510 is also configured to bypass the second expansion device 135. When the controller 510 programs the operation of the vapor compression system 100, 200, 400 to direct the discharge flow to the indoor heat exchanger 140, the controller 510 is also configured to bypass the first expansion device 130.
[0055] The memory 530 stores instructions for programming the processor 520 to operate the vapor compression system 200, 400 to provide refrigerant flow through the primary loop; determine whether a condition has been met, and adjust the position of the first valve 210 and / or the second valve 230 when the condition is met.
[0056] Fig.11 is a block diagram of an example control algorithm for the vapor compression system 200, 400. In some embodiments, determining whether a condition has been met includes determining whether a high utility demand event has occurred. For example, a high utility demand event may occur when usage or pricing exceeds a threshold and may be indicated via a signal sent to a field smart meter.
[0057] Determining whether the condition has been met may additionally or alternatively include determining whether advanced heating is required. For example, when the interior air temperature set by the thermostat cannot be reached within a 30-minute period via heat pump heating (i.e., heating the interior space 60 using the vapor compression system 200, 400 configured in the main loop), or if the interior air temperature continues to drop during heat pump heating, advanced heating may be required.
[0058] If a high utility demand event has occurred, or if advanced heating is desired, adjusting the position of the first valve 210 and / or the second valve 230 includes adjusting the first valve 210 to fluidly connect the indoor heat exchanger 140 to the supply conduit 330, and adjusting the second valve 230 to fluidly connect the indoor heat exchanger 140 to the return conduit 350, as shown. Figure 5A As shown in FIG, the refrigerant will flow through the auxiliary circuit to provide auxiliary heating to the indoor space.
[0059] Determining whether the condition has been met may additionally or alternatively include determining whether low-stage heating is required. For example, when the air temperature in the interior space 60 drops below the temperature set point value minus the deadband value, low-stage heating may be required. Additionally or alternatively, when the air temperature in the interior space 60 rises above the temperature set point value minus the deadband value, low-stage heating may be required. In such an embodiment, the first valve 210 and the second valve 230 are configured in respective first and third positions to allow refrigerant to flow through the main circuit, thereby providing heat to the interior space 60 as a heat pump.
[0060] Determining whether the condition has been met may additionally or alternatively include determining whether the coil 129 of the outdoor heat exchanger 120 needs to be defrosted. For example, determining that the coil 129 needs to be defrosted may include determining that the temperature difference between the air in the exterior space 80 and the saturation temperature of the outdoor heat exchanger 120 has exceeded a threshold, such as, but not limited to, a temperature difference greater than 18°R. In this embodiment, adjusting the position of the first valve 210 and / or the second valve 230 includes adjusting the first defrost valve 410 to fluidly connect the supply conduit 330 to the outdoor heat exchanger 120, and adjusting the second valve 230 to fluidly connect the outdoor heat exchanger 120 to the return conduit 350. Thus, the heated refrigerant will circulate between the thermal storage unit 300 and the outdoor heat exchanger 120 to melt any ice on the coil 129.
[0061] The vapor compression system 100, 200, 400 can be switched between any of the high-stage heating, low-stage heating, auxiliary heating, defrost, or off modes. For example, when the air temperature of the interior space 60 drops below the temperature set point-deadband value, the system 100, 200, 400 can be switched from the off mode to the low-stage heating or from the low-stage heating to the auxiliary heating. Additionally or alternatively, when the air temperature of the interior space 60 increases above the temperature set point-deadband value, the system 100, 200, 400 can be switched from the auxiliary heating to the low-stage heating or from the low-stage heating to the off mode. Additionally or alternatively, when the air temperature of the exterior space 80 crosses a temperature limit (e.g., 17 degrees Fahrenheit), the system 100, 200, 400 can alternate between auxiliary heating and low-stage heating.
[0062] The vapor compression system 100, 200, 400 also includes a user interface 540 configured to output (e.g., display) and / or receive (e.g., from a user) information associated with the vapor compression system 100 to 200. In some embodiments, the user interface 540 is configured to receive activation and / or deactivation inputs from a user to activate and deactivate (i.e., turn on and off) the vapor compression system 100 to 200 or otherwise enable the operation of the vapor compression system 100 to 200. For example, the user interface 540 may receive a temperature set point specified by a user. The user interface 540 in this example is operable to output information associated with one or more operating features of the vapor compression system 100 to 200, including, for example, but not limited to, warning indicators such as severity alarms, occurrence alarms, fault alarms, motor speed alarms, and any other suitable information.
[0063] The user interface 540 may include any suitable input devices and output devices that enable the user interface 540 to function as described. For example, the user interface 540 may include input devices including, but not limited to, a keyboard, a mouse, a touch screen, a joystick, a throttle, a button, a switch, and / or other input devices. In addition, the user interface 540 may include output devices including, for example, but not limited to, a display (e.g., a liquid crystal display (LCD) or an organic light emitting diode (OLED) display), a speaker, an indicator light, an instrument, and / or other output devices. In addition, the user interface 540 may be part of a different component, such as a system controller (not shown). Other embodiments do not include the user interface 540.
[0064] The controller 510 generally controls the operation of the vapor compression system 100, 200, 400. The controller 510 controls the operation by programming and instructions from another device or controller, or the controller 510 is integrated with the vapor compression system 100, 200, 400 through a system controller. For example, the controller 510 receives user input from the user interface 540 and controls one or more components of the vapor compression system 100, 200, 400 in response to such user input. The controller 510 can also control the first fan 150 based on the user input received from the user interface 540. The vapor compression system 100, 200, 400 is appropriately controlled, such as through a remote control interface. For example, the vapor compression system 100, 200, 400 may include a communication interface 550 configured to be connected to a wireless control interface (not shown), which enables remote control and activation of the vapor compression system 100, 200, 400. The wireless control interface can be implemented on a portable computing device, such as a tablet or a smart phone.
[0065] The controller 510 includes any suitable computer and / or other processing unit, including any suitable combination of computers, processing units, and / or the like that can be communicatively connected to each other and can operate independently or in association with each other (e.g., the controller 510 can form all or part of a controller network). The controller 510 can include one or more modules or devices, one or more of which are enclosed within the vapor compression system 100, 200, 400 or can be located remotely from the vapor compression system 100, 200, 400. The controller 510 can be part of the vapor compression system 100, 200, 400, or the controller 510 can be part of a system controller in an HVAC system. The controller 510 and / or components of the controller 510 can be integrated or incorporated into other components of the vapor compression system 100, 200, 400. The controller 510 can include one or more processors 520 and associated memory devices 530 that are operable to perform various computer-implemented functions (e.g., perform the disclosed calculations, determinations, and functions).
[0066] The term "processor" refers not only to integrated circuits, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. In addition, the storage device 530 of the controller 510 can generally be a storage element or include a storage element, which includes but is not limited to a computer-readable medium (e.g., random access memory (RAM)), a computer-readable non-volatile medium (e.g., flash memory), a floppy disk, a read-only compact disk memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD), and / or other suitable storage elements. Such a memory device 530 can generally be configured to store appropriate computer-readable instructions, which, when implemented by the processor 1220, configure or cause the controller 510 to perform various functions, including but not limited to controlling the vapor compression system 100 to 200, receiving input from the user interface 540, providing output to an operator via the user interface 540, and / or various other suitable computer-implemented functions.
[0067] Technical advantages of the disclosed systems and apparatus include: (1) An example vapor compression system is able to add thermal energy to a thermal storage unit when electricity costs are low and use the stored thermal energy to heat the interior space when electricity costs are high, when grid demand is low, or when a heat pump system cannot meet the heating requirements of the space. (2) An existing vapor compression system can be simply modified to include an auxiliary loop and a defrost loop by adding two three-way valves to its existing piping. (3) The outdoor heat exchanger can use the thermal energy stored in the thermal storage unit for defrosting, rather than absorbing heat from the interior space for defrosting. (4) If the inlet of the thermal storage unit is maintained below the indoor heat exchanger, no pump is required in the return piping, thereby reducing system complexity and power requirements.
[0068] When used in conjunction with ranges of size, concentration, temperature, or other physical or chemical property or characteristic, the terms "about," "substantially," and "approximately" are intended to encompass variations that may exist in the upper and / or lower limits of the range of the property or characteristic, including variations due to, for example, rounding, measurement method or other statistical variations.
[0069] When introducing elements of the present disclosure or embodiments of the present disclosure, the articles "a," "an," "the," and "said" are intended to indicate that there are one or more elements. The terms "comprising," "including," "containing," and "having" are intended to be inclusive and mean that additional elements may be present in addition to the listed elements. The use of terms indicating a particular orientation (e.g., "top," "bottom," "side," etc.) is for convenience of description and does not require any particular orientation of the described items.
[0070] As various changes could be made in the above constructions and methods without departing from the scope of the present disclosure, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Claims
1. A steam compression system comprising: A main circuit, the main circuit comprising: Indoor heat exchanger; outdoor heat exchanger; and a compressor operable to compress a refrigerant; a first valve selectively positionable between a first position and a second position, wherein the first valve fluidly connects the indoor heat exchanger to the compressor in the first position; a second valve selectively positionable in a third position and a fourth position, wherein the second valve fluidly connects the indoor heat exchanger to the outdoor heat exchanger in the third position; and An auxiliary circuit, the auxiliary circuit comprising: a thermal storage unit having an inlet, an outlet, and a heating conduit extending between the inlet and the outlet; a supply conduit fluidly connecting the outlet of the thermal storage unit to the indoor heat exchanger when the first valve is in the second position; and A return conduit fluidly connects the inlet of the thermal storage unit to the indoor heat exchanger when the second valve is in the fourth position.
2. The vapor compression system according to claim 1 further includes a reversing valve, which is operable to selectively configure the main circuit to operate in a cooling mode or a heating mode. In the cooling mode, the compressor provides the refrigerant to the outdoor heat exchanger, and in the heating mode, the compressor provides the refrigerant to the indoor heat exchanger.
3. The vapor compression system of claim 1, wherein: The thermal storage unit includes a cavity filled with a plurality of particles.
4. The vapor compression system of claim 3, wherein: The thermal storage unit also includes a heating element operable to increase the temperature of the plurality of particles.
5. The vapor compression system of claim 4, wherein: The heating element heats the plurality of particles to a temperature between 800F and 1200F.
6. The vapor compression system of claim 4, wherein: The heating element is powered by renewable electricity or off-peak electricity.
7. The vapor compression system of claim 3, wherein: The plurality of particles are sand particles.
8. The vapor compression system of claim 3, wherein: The plurality of particles surround the heating tube to allow heat transfer between the plurality of particles and the heating tube.
9. The vapor compression system of claim 1 , further comprising: a defrost conduit fluidly connected between the thermal storage unit and the outdoor heat exchanger; as well as a defrost valve operable to selectively allow refrigerant to flow through the defrost conduit, The defrost valve is positionable in a sixth position to fluidly connect the outdoor heat exchanger to the thermal storage unit, thereby allowing refrigerant to flow in a defrost circuit between the thermal storage unit and the outdoor heat exchanger.
10. The vapor compression system of claim 1, wherein: Each of the first valve and the second valve is a valve assembly including at least two solenoid valves.
11. A method for retrofitting a vapor compression system, the method retrofitting the vapor compression system to have an auxiliary heating loop, the auxiliary heating loop having a thermal storage unit, the vapor compression system comprising an indoor heat exchanger, an outdoor heat exchanger, and a compressor fluidly connected between the indoor heat exchanger and the outdoor heat exchanger, the method comprising: connecting a first path fluid of a first valve between the indoor heat exchanger and the compressor; connecting a third path fluid of a second valve between the indoor heat exchanger and the outdoor heat exchanger; fluidly connecting a supply conduit between the thermal storage unit and a second path of the first valve; and A return conduit is fluidly connected between the fourth path of the second valve and the thermal storage unit.
12. The method according to claim 11, wherein: Fluidly connecting the return conduit includes connecting the return conduit between the second valve and the thermal storage unit such that the indoor heat exchanger is positioned above the thermal storage unit such that refrigerant flow through the return conduit is driven by gravity.
13. The method according to claim 11, wherein: Fluidly connecting the return conduit includes fluidly connecting a pump in the return conduit between the second valve and the thermal storage unit.
14. A controller for a vapor compression system, the vapor compression system comprising a main loop and an auxiliary loop, the main loop comprising an indoor heat exchanger, an outdoor heat exchanger and a compressor, the auxiliary loop comprising a supply pipe, a return pipe and a thermal storage unit, the thermal storage unit having a heating pipe fluidically connecting the supply pipe and the return pipe, the main loop and the auxiliary loop being connected by a first valve and a second valve, the controller comprising: processor; as well as a memory storing instructions for programming the processor to: operating the vapor compression system to provide a flow of refrigerant through the primary circuit; determine whether the conditions have been met; and The position of the first valve and / or the second valve is adjusted when the condition is met.
15. The controller according to claim 14, wherein: Adjusting the positions of the first valve and the second valve includes adjusting the first valve to fluidly connect the indoor heat exchanger to the supply conduit and adjusting the second valve to fluidly connect the indoor heat exchanger to the return conduit.
16. The controller according to claim 15, wherein: Determining whether the condition has been met includes determining whether a utility high demand event has occurred.
17. The controller according to claim 15, wherein: Determining whether the conditions have been met includes determining whether advanced heating is required.
18. The controller according to claim 14, wherein: Determining whether a condition has been met includes determining whether a temperature of the outdoor heat exchanger has dropped below a threshold, and wherein adjusting the position of the first valve and / or the second valve includes adjusting a first defrost valve to connect the supply conduit fluid to the outdoor heat exchanger and adjusting the second valve to connect the outdoor heat exchanger fluid to the return conduit.