Multi-pipe heat pump device and multi-pipe heat pump control method

Abstract

The invention relates to a multi-pipe heat pump device and a multi-pipe heat pump control method, and the multi-pipe heat pump device comprises an air side heat exchanger, a multi-way valve, a compressor, a hot water side shell pipe and a defrosting unit. The defrosting unit comprises a heat regenerator and a heat accumulator which are communicated through a first pipeline and a second pipeline which are arranged in parallel; the first pipeline communicates with the second outlet end of the compressor and the inlet end of the hot water side shell pipe. The second pipeline communicates with the input end of the air side heat exchanger and the outlet end of the hot water side shell pipe. A first electromagnetic valve and a third electromagnetic valve are arranged on the first pipeline; a first inlet of the heat accumulator can be communicated with a second outlet end of the compressor through the first electromagnetic valve; a first outlet of the heat accumulator can be communicated with a first inlet of the heat regenerator through a third electromagnetic valve; the defrosting unit can increase the temperature of the refrigerant entering the air side heat exchanger with the frosted surface. And by controlling the multiple electromagnetic valves, heat exchange at the air side heat exchanger is achieved, and the defrosting efficiency can be improved.

Description

Technical Field

[0001] This application relates to the field of heating technology, and in particular to a multi-pipe heat pump device and a multi-pipe heat pump control method. Background Technology

[0002] Multi-pipe heat pumps are a type of efficient and flexible air conditioning system. Taking a four-pipe heat pump as an example, its characteristic is that it achieves the recovery and comprehensive utilization of heat and cold through two supply pipes and two return pipes (i.e., four pipes). When a four-pipe heat pump is operating in heating mode, frost will appear on the evaporator surface when the ambient temperature is too low. This will cause a decrease in the unit's heating capacity and COP (Coefficient of Performance, the ratio of energy to heat conversion), and may even lead to shutdown.

[0003] Currently, hot gas bypass defrosting and reverse defrosting are commonly used. Hot gas bypass defrosting directly introduces high-temperature, high-pressure steam from the compressor into the evaporator, while reverse defrosting defrosts by changing the direction of refrigerant flow. Additionally, antifreeze tanks can be installed on the evaporator fins to prevent excessively low fin surface temperatures during defrosting. However, these defrosting methods suffer from slow defrosting speeds and / or interference with heating supply, resulting in poor defrosting efficiency.

[0004] There is currently no effective solution to the problem that the defrosting efficiency of four-pipe heat pumps needs to be improved in related technologies. Summary of the Invention

[0005] This embodiment provides a multi-pipe heat pump device and a multi-pipe heat pump control method to solve the problem that the defrosting efficiency of four-pipe heat pumps in related technologies needs to be improved.

[0006] Firstly, this embodiment provides a multi-pipe heat pump device, the multi-pipe heat pump device comprising:

[0007] The system includes an air-side heat exchanger, a multi-way valve, a compressor, and a hot water-side shell and tube. The multi-way valve includes a high-pressure inlet end, a first interface end, a second interface end, and a third interface end. The high-pressure inlet end is connected to the first outlet end of the compressor. The first interface end is connected to the first end of the air-side heat exchanger, the second interface end is connected to the inlet end of the hot water-side shell and tube, and the third interface end is connected to the inlet end of the compressor.

[0008] The defrosting unit includes a regenerator and a heat accumulator, which are connected by a first pipeline and a second pipeline, which are arranged in parallel. The first pipeline connects the second outlet end of the compressor and the inlet end of the hot water side shell tube, and the second pipeline connects the input end of the air side heat exchanger and the outlet end of the hot water side shell tube.

[0009] The first pipeline is also equipped with a first solenoid valve and a third solenoid valve. The first inlet of the heat accumulator can be connected to the second outlet of the compressor through the first solenoid valve; the first outlet of the heat accumulator can be connected to the first inlet of the regenerator through the third solenoid valve; the defrosting unit can increase the refrigerant temperature entering the air-side heat exchanger where the surface is frosted.

[0010] In some embodiments, the defrosting unit further includes a second solenoid valve and a fourth solenoid valve;

[0011] The second solenoid valve is arranged in parallel with the first solenoid valve. One end of the second solenoid valve is connected to one end of the first solenoid valve, and the other end of the second solenoid valve is connected to one end of the third solenoid valve. The fourth solenoid valve is arranged in parallel with the third solenoid valve. One end of the fourth solenoid valve is connected to one end of the third solenoid valve, and the other end of the fourth solenoid valve is connected to the first outlet of the regenerator.

[0012] In some embodiments, the defrosting unit further includes a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, and an eighth solenoid valve;

[0013] A heating electronic expansion valve is installed on the second pipeline, located between the hot water side shell tube and the defrosting unit. A sixth solenoid valve and an eighth solenoid valve are installed on the second pipeline. The second inlet of the regenerator is connected to the heating electronic expansion valve via the sixth solenoid valve, and the second outlet of the regenerator is connected to the second inlet of the heat storage unit via the eighth solenoid valve. The sixth solenoid valve and the fifth solenoid valve are connected in parallel, with one end of the sixth solenoid valve connected to one end of the fifth solenoid valve and the other end of the fifth solenoid valve connected to one end of the eighth solenoid valve. The eighth solenoid valve and the seventh solenoid valve are arranged in parallel, with one end of the eighth solenoid valve connected to one end of the seventh solenoid valve and the other end of the seventh solenoid valve connected to the second outlet of the heat storage unit. In some embodiments, the first end of the heating electronic expansion valve is connected to the outlet end of the hot water side shell tube, and the second end of the heating electronic expansion valve is connected to the second inlet of the regenerator.

[0014] The multi-pipe heat pump device also includes a gas-liquid separator, the inlet end of which is connected to the third interface end of the multi-way valve; the outlet end of which is connected to the inlet end of the compressor.

[0015] In some embodiments, the device further includes: a refrigeration electronic expansion valve and a chilled water side shell tube;

[0016] The first end of the refrigeration electronic expansion valve is connected to the outlet end of the cold water side shell tube, and the second end of the refrigeration electronic expansion valve is connected to the first end of the air side heat exchanger; the inlet end of the cold water side shell tube is connected to the outlet end of the gas-liquid separator.

[0017] In some embodiments, the multi-pipe heat pump device includes seven operating modes:

[0018] Heating mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the heating electronic expansion valve, the fifth solenoid valve, and the seventh solenoid valve are energized;

[0019] Heat storage mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the heating electronic expansion valve, the fifth solenoid valve and the seventh solenoid valve are energized; the first solenoid valve and the fourth solenoid valve are energized, and the second outlet end of the compressor is connected to the first inlet of the heat storage device through the first solenoid valve;

[0020] Regenerative mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the heating electronic expansion valve, the sixth solenoid valve and the seventh solenoid valve are energized; the second solenoid valve and the third solenoid valve are energized, and the second outlet end of the compressor is connected to the first inlet of the regenerator through the second solenoid valve and the third solenoid valve;

[0021] Heat storage and regeneration mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the heating electronic expansion valve, the sixth solenoid valve and the seventh solenoid valve are energized; the first solenoid valve and the third solenoid valve are energized, and the second outlet end of the compressor is connected to the first inlet of the heat accumulator through the first solenoid valve;

[0022] Defrosting mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the heating electronic expansion valve, the sixth solenoid valve and the eighth solenoid valve are energized; the first solenoid valve and the third solenoid valve are energized, and the second outlet end of the compressor is connected to the first inlet end of the heat accumulator through the first solenoid valve;

[0023] Cooling mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the refrigeration electronic expansion valve is energized; the first outlet end of the multi-way valve is connected to the first end of the air-side heat exchanger; the second end of the air-side heat exchanger is connected to the inlet end of the chilled water side shell tube through the refrigeration electronic expansion valve; the outlet end of the chilled water side shell tube is connected to the inlet end of the compressor.

[0024] Heat recovery mode: The first outlet end of the compressor is connected to the high-pressure inlet end of the multi-way valve; the refrigeration electronic expansion valve and the heating electronic expansion valve are energized; the second outlet end of the multi-way valve is connected to the inlet end of the hot water side shell tube; the outlet end of the hot water side shell tube is connected to the inlet end of the cold water side shell tube through the refrigeration electronic expansion valve; the outlet end of the cold water side shell tube is connected to the inlet end of the compressor; the outlet end of the hot water side shell tube is also connected to the third end of the air-side heat exchanger through the heating electronic expansion valve.

[0025] Secondly, this embodiment provides a multi-pipe heat pump control method, which is applied to the multi-pipe heat pump device described in the first aspect, wherein the air-side heat exchanger is provided with fins; the method includes:

[0026] The temperature and humidity of the environment in which the multi-pipe heat pump device is located are obtained, and the dew point temperature is determined based on the temperature and humidity.

[0027] Obtain the fin temperature of the air-side heat exchanger, and determine whether the multi-pipe heat pump unit is frosted based on the fin temperature and the dew point temperature;

[0028] Once it is determined that the multi-pipe heat pump device has frosted, a target temperature is obtained; the target temperature is the critical frosting line temperature of the location of the multi-pipe heat pump device.

[0029] When the fin temperature of the air-side heat exchanger is lower than the dew point temperature and the target temperature is within the first threshold temperature range, the first, third, sixth, and eighth solenoid valves are energized according to the target temperature. This causes the second outlet end of the compressor to be connected to the inlet end of the hot water side shell tube through the first and third solenoid valves on the first pipeline, and the second end of the heating electronic expansion valve to be connected to the third end of the air-side heat exchanger through the sixth and eighth solenoid valves on the second pipeline, so as to defrost the air-side heat exchanger whose surface is frosted.

[0030] In some embodiments, prior to obtaining the temperature and humidity of the environment in which the multi-pipe heat pump unit is located, the process includes:

[0031] The system controls the opening of the first, fourth, fifth, and seventh solenoid valves to enter the heat storage mode and determines whether the temperature difference between the inlet and outlet of the heat storage unit is stable.

[0032] If so, then control the closure of the first solenoid valve and the fourth solenoid valve to exit the heat storage mode.

[0033] In some embodiments, determining whether the multi-pipe heat pump unit is frosted based on the temperature of the fins and the dew point temperature includes:

[0034] When the fin temperature of the air-side heat exchanger is lower than the dew point temperature and the target temperature is within the second threshold temperature range, the second, third, sixth, and seventh solenoid valves are opened, so that the second outlet of the compressor is connected to the first inlet of the regenerator through the second and third solenoid valves, the first outlet of the regenerator is connected to the first end of the heating electronic expansion valve, and the second end of the heating electronic expansion valve is connected to the third end of the air-side heat exchanger through the sixth solenoid valve on the second pipeline, so as to enter the regeneration mode.

[0035] After a preset time threshold has elapsed, the temperature and humidity of the environment in which the multi-pipe heat pump device is located are detected, and the dew point temperature is determined based on the temperature and humidity to determine again whether the multi-pipe heat pump device is frosted.

[0036] In some embodiments, determining whether the multi-pipe heat pump unit is frosted based on the temperature of the fins and the dew point temperature further includes:

[0037] When the fin temperature of the air-side heat exchanger is not less than the dew point temperature, and / or the target temperature is not within the first threshold temperature range and the second threshold temperature range, the fifth solenoid valve and the seventh solenoid valve are opened to enter the heating mode.

[0038] After a preset time threshold has elapsed, the temperature and humidity of the environment in which the multi-pipe heat pump device is located are re-detected, and the dew point temperature is determined based on the temperature and humidity to determine again whether the multi-pipe heat pump device is frosted.

[0039] Compared with related technologies, the multi-pipe heat pump device and multi-pipe heat pump control method provided in this embodiment connect a defrosting unit including multiple solenoid valves to one output end of the compressor, and control the multiple solenoid valves to realize multiple working modes of the heat pump device; controlling the opening and closing of multiple solenoid valves according to different environmental conditions to switch different working modes is beneficial to improving the efficiency of heat exchange control, and thus improving defrosting efficiency.

[0040] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0042] Figure 1This is a schematic diagram of the structure of the multi-pipe heat pump device provided in the embodiments of this application;

[0043] Figure 2 This is a schematic diagram of the heating mode provided in this specific embodiment;

[0044] Figure 3 This is a schematic diagram of the heat storage mode provided in this specific embodiment;

[0045] Figure 4 This is a schematic diagram of the regenerative mode provided in this specific embodiment;

[0046] Figure 5 This is a schematic diagram of the heat storage and regeneration mode provided in this specific embodiment;

[0047] Figure 6 This is a schematic diagram of the defrosting mode provided in this specific embodiment;

[0048] Figure 7 This is a schematic diagram of the cooling mode provided in this specific embodiment;

[0049] Figure 8 This is a schematic diagram of the heat recovery mode provided in this specific embodiment;

[0050] Figure 9 This is a flowchart of a multi-pipe heat pump control method according to this embodiment;

[0051] Figure 10 This is a schematic diagram of the enthalpy-humidity curve fitting provided in this specific embodiment.

[0052] Figure descriptions: 1. Air-side heat exchanger; 2. Multi-way valve; 3. Compressor; 4. Gas-liquid separator; 5. Refrigeration electronic expansion valve; 6. Cold water side shell and tube; 7. Hot water side shell and tube; 8. Heating electronic expansion valve; 9. Regenerator; 10. Heat accumulator; F1. First solenoid valve; F2. Second solenoid valve; F3. Third solenoid valve; F4. Fourth solenoid valve; F5. Fifth solenoid valve; F6. Sixth solenoid valve; F7. Seventh solenoid valve; F8. Eighth solenoid valve; 11. Defrosting unit. Detailed Implementation

[0053] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0054] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning as understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these,” used in this application, do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to such processes, methods, products, or devices. The terms “connected,” “linked,” and “coupled,” used in this application, are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. The term “multiple” used in this application refers to two or more. The "and / or" operator describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: A alone, A and B simultaneously, and B alone. Typically, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," and "third," etc., used in this application are merely for distinguishing similar objects and do not represent a specific ordering of the objects.

[0055] When a multi-pipe heat pump operates at certain low temperatures, water vapor in the air encounters the surface of the heat pump heat exchanger (usually the evaporator) at a temperature lower than its dew point. The vapor changes directly from a gaseous state to a solid state, forming a layer of ice crystals that covers the heat exchanger surface. This typically occurs in winter or when the heat pump is operating in a low-temperature, high-humidity environment. When the multi-pipe heat pump unit is in heating mode, frost will form on the evaporator surface due to the low ambient temperature. This will cause a decrease in the unit's heating capacity and COP (Coefficient of Performance), and may even lead to the shutdown of the multi-pipe heat pump unit. Currently, hot gas bypass defrosting and reverse defrosting methods are commonly used to address frost formation on the evaporator surface. Hot gas bypass defrosting involves directly introducing high-temperature, high-pressure steam from the compressor into the evaporator, but this method is usually slow and cannot achieve complete defrosting. Reverse defrosting mainly involves changing the refrigerant flow direction, which is faster, but it does not provide heat to the room during defrosting. Alternatively, an antifreeze tank can be installed on the evaporator fins to prevent the fin surface temperature from getting too low. This method can effectively prevent frost formation, but it requires an additional heating box to heat the antifreeze, resulting in higher energy consumption.

[0056] Therefore, in order to solve the problems of slow defrosting effect of hot gas bypass and the impact of reverse defrosting on heating in the existing technology, this embodiment provides a multi-pipe heat pump device to improve the defrosting efficiency of the multi-pipe heat pump device. Figure 1 This is a schematic diagram of the structure of the multi-pipe heat pump device provided in the embodiments of this application. (Reference) Figure 1 The multi-pipe heat pump device in this embodiment includes: an air-side heat exchanger 1, a compressor 3, a multi-way valve 2, a hot water-side shell and tube 7, and a defrosting unit 11; the multi-way valve 2 includes a high-pressure inlet end, a first interface end, a second interface end, and a third interface end, the high-pressure inlet end being connected to the first outlet end of the compressor 3; the first interface end being connected to the first end of the air-side heat exchanger 1, the second interface end being connected to the inlet end of the hot water-side shell and tube 7, and the third interface end being connected to the inlet end of the compressor 3.

[0057] The defrosting unit 11 includes a regenerator 9 and a heat accumulator 10, which are connected by a first pipeline and a second pipeline, which are arranged in parallel. The first pipeline connects the second outlet end of the compressor 3 and the inlet end of the hot water side shell tube 7, and the second pipeline connects the input end of the air side heat exchanger 1 and the outlet end of the hot water side shell tube 7.

[0058] The first pipeline is also equipped with a first solenoid valve F1 and a third solenoid valve F3. The first inlet of the heat accumulator 10 can be connected to the second outlet of the compressor 3 through the first solenoid valve F1; the first outlet of the heat accumulator 10 can be connected to the first inlet of the regenerator 9 through the third solenoid valve F3; the defrosting unit 11 can increase the refrigerant temperature of the air-side heat exchanger 1 that has frost on its surface.

[0059] The air-side heat exchanger 1 is used to exchange external and internal heat in the multi-pipe heat pump unit; specifically, it can be configured as an evaporator. The compressor 3 includes a first outlet and a second outlet, and the multi-way valve 2 includes a high-pressure inlet, a first interface, a second interface, and a third interface; specifically, the multi-way valve is configured as a four-way valve. Alternatively, the multi-way valve can be configured with three or more ports depending on the actual application requirements; no specific limitation is made here. The first outlet of the compressor 3 is connected to the high-pressure inlet of the multi-way valve 2; the second outlet of the compressor 3 is connected to the first pipeline in the defrost unit 11. The compressor 3 transmits most of the high-temperature, high-pressure refrigerant to the hot water side shell and tube 7 through the multi-way valve 2, while simultaneously transmitting a small portion of the high-temperature, high-pressure refrigerant to the first pipeline for heat exchange through the regenerator 9 and the accumulator 10 in the defrost unit.

[0060] The defrosting unit 11 also includes multiple solenoid valves; by controlling these multiple solenoid valves, heat exchange is achieved at the air-side heat exchanger 1. It should be noted that the multi-pipe heat pump device here can be a four-pipe heat pump device, or a six-pipe heat pump device, etc., without specific limitations.

[0061] In the multi-pipe heat pump device provided in this application embodiment, the compressor 3 is responsible for compressing the low-temperature, low-pressure refrigerant gas into a high-temperature, high-pressure gas. The compression of the refrigerant gas by the compressor 3 is a crucial step in energy conversion. Specifically, a first solenoid valve F1 and a third solenoid valve F3 are installed on the first pipeline of the defrost unit 11. The first inlet of the heat accumulator 10 is connected to the compressor 3 through the first solenoid valve F1, and the first outlet of the heat accumulator 10 is connected to the regenerator 9 through the third solenoid valve F3. This allows some of the high-temperature, high-pressure gas generated by the compressor to exchange heat with the refrigerant in the pipeline through the heat accumulator and regenerator in the first pipeline. The first outlet of the compressor 3 is connected to the high-pressure inlet of the multi-way valve 2, allowing the high-temperature, high-pressure gas at the outlet of the compressor 3 to enter the high-pressure inlet of the multi-way valve 2. Subsequently, it passes through the hot water side shell pipe 7 and the second pipeline in the defrost unit 11, reaching the evaporator. Figure 1 The air-side heat exchanger 1 is shown; at the same time, part of the high temperature and high pressure output by the compressor 3 is connected to the first inlet of the heat accumulator 10 in the first pipeline of the defrosting unit 11 through the second outlet end of the compressor 3, so that part of the high temperature and high pressure output flows to the air-side heat exchanger 1 through the first pipeline of the defrosting unit 11.

[0062] By dividing the high-temperature, high-pressure output of compressor 3 into two parts and directing them to the air-side heat exchanger 1 via different branches, it is beneficial to ensure that the refrigerant temperature in the air-side heat exchanger 1 does not drop too low in low-temperature environments while maintaining the multi-pipe heat pump's ability to supply heat to the room. This also prevents excessively low temperatures on the outer surface of the air-side heat exchanger 1, thus avoiding frost formation on its fins. By setting different circuits at the first and second outlets of compressor 3, the high-temperature, high-pressure steam from compressor 3 can be directly introduced into the air-side heat exchanger 1, and a portion of the high-temperature, high-pressure steam from compressor 3 can enter the air-side heat exchanger 1 through the regenerator 9 and heat accumulator 10 in the defrosting unit 11. This helps solve the problems of slow defrosting efficiency and incomplete defrosting in existing hot gas bypass defrosting methods. The multi-pipe heat pump device provided in this embodiment reduces the possibility of frost formation when the ambient temperature is high and ensures no additional energy input when the ambient temperature is low, while achieving effective defrosting without affecting the system's heating capacity.

[0063] Furthermore, in this embodiment, the multi-pipe heat pump device is specifically a four-pipe heat pump, but it can also be configured according to actual needs, including an evaporator, compressor 3, multi-way valve 2, and other heating devices with multi-pipe systems, without specific limitations. In this embodiment, the multi-way valve 2 is specifically a four-way valve, but it can also be configured with multiple connection ports according to actual heating needs.

[0064] In this multi-pipe heat pump unit, a hot water side shell pipe 7 is installed. The inlet end of the hot water side shell pipe 7 is connected to the second interface end of the multi-way valve 2. Refrigerant flows to the hot water side shell pipe 7 through the aforementioned connected pipe. A circulating water flow is provided outside the hot water side shell pipe 7. This water flow exchanges heat with the refrigerant and absorbs the heat released by the refrigerant. At the same time, some high-temperature and high-pressure steam from the second outlet end of the compressor 3 circulates in the first pipe of the defrost unit 11, raising the temperature of the air-side heat exchanger 1 through internal heat exchange. However, if the first pipe of the defrost unit 11 is always open, the following problems will occur: First, continuous heating will cause the temperature of the refrigeration unit entering the air-side heat exchanger 1 to be too high, affecting the evaporation of the refrigerant and thus affecting the heating of the multi-pipe heat pump unit, resulting in a decrease in indoor temperature; Second, when the surface temperature of the evaporator is high enough and frost is not easily formed, the heat carried out by the refrigerant from the compressor 3 will be wasted. Therefore, multiple solenoid valves and branches are installed on the circuit from the defrosting unit 11 to the air-side heat exchanger 1 to control the refrigerant flow direction, and a heat accumulator 10 that can store a large amount of energy is used to solve the above problems.

[0065] Furthermore, such as Figure 1 As shown, the heat accumulator 10 and the regenerator 9 are connected through a first pipeline and a second pipeline. The outlet end of the hot water side shell tube 7 is connected to the second inlet of the regenerator 9 in the defrosting unit 11 on the second pipeline. The refrigerant flows through the outlet end of the hot water side shell tube 7 to the second pipeline, and then through the second pipeline to the air-side heat exchanger 1. Multiple solenoid valves are installed on both the first and second pipelines respectively. By opening or closing these valves, the refrigerant flow direction in the two pipelines is controlled. In this embodiment, the refrigerant can flow from the compressor 3 to the first pipeline and then through the first pipeline to the inlet end of the hot water side shell tube 7; alternatively, the refrigerant can flow from the compressor 3 to the hot water side shell tube 7 through the multi-way valve 2, then through the outlet end of the hot water side shell tube 7 to the second pipeline, and finally through the second pipeline to the air-side heat exchanger 1.

[0066] The heat accumulator 10 is a device for storing thermal energy. It can collect and store excess thermal energy when production is excessive, and then release this thermal energy when needed. This significantly improves the stability and economy of multi-pipe heat pump systems and reduces energy waste. The regenerator 9 improves system efficiency and operational reliability by promoting the transfer of heat energy from the refrigerant in different states. Specifically, in this embodiment, a phase change heat accumulator 10 is used. The phase change heat accumulator 10 can store a large amount of energy and, when frost appears on the fins of the air-side heat exchanger 1, provides sufficient heat to the refrigerant entering the finned heat exchanger, thereby quickly and thoroughly defrosting. The phase change heat accumulator 10 typically uses materials with high latent heat values, such as waxy substances or water. These materials can change from a solid to a liquid state, or from a liquid to a gaseous state, at specific temperatures.

[0067] In some of these embodiments, reference is made to Figure 1 The defrosting unit 11 also includes a second solenoid valve F2 and a fourth solenoid valve F4; the second solenoid valve F2 is arranged in parallel with the first solenoid valve F1, one end of the second solenoid valve F2 is connected to one end of the first solenoid valve F1, the other end of the second solenoid valve F2 is connected to one end of the third solenoid valve F3, the fourth solenoid valve F4 is arranged in parallel with the third solenoid valve F3, one end of the fourth solenoid valve F4 is connected to one end of the third solenoid valve F3, and the other end of the fourth solenoid valve F4 is connected to the first outlet of the regenerator 9.

[0068] refer to Figure 1 The defrosting unit 11 also includes a fifth solenoid valve F5, a sixth solenoid valve F6, a seventh solenoid valve F7, and an eighth solenoid valve F8; a heating electronic expansion valve 8 is installed on the second pipeline, which is located between the hot water side shell pipe 7 and the defrosting unit 11; the sixth solenoid valve F6 and the eighth solenoid valve F8 are installed on the second pipeline; the second inlet of the regenerator can be connected to the heating electronic expansion valve 8 through the sixth solenoid valve F6, and the second outlet of the regenerator 9 can be connected to the second inlet of the heat storage unit 10 through the eighth solenoid valve F8; the sixth solenoid valve F6 and the fifth solenoid valve F5 are connected in parallel, with one end of the sixth solenoid valve F6 connected to one end of the fifth solenoid valve F5, and the other end of the fifth solenoid valve F5 connected to one end of the eighth solenoid valve F8; the eighth solenoid valve F8 and the seventh solenoid valve F7 are arranged in parallel, with one end of the eighth solenoid valve F8 connected to one end of the seventh solenoid valve F7, and the other end of the seventh solenoid valve F7 connected to the second outlet of the heat storage unit 10.

[0069] By installing multiple solenoid valves on the first and second pipelines and controlling their opening and closing, the flow direction of the refrigerant can be controlled, which improves the efficiency of heat exchange and thus enhances defrosting efficiency. Specifically, the multiple solenoid valves can be configured for unidirectional or bidirectional control, and can be direct-acting, pilot-operated, or two-position three-way solenoid valves, etc. The opening and closing of the multiple solenoid valves can be controlled by the control module in the multi-pipe heat pump device, or manually, depending on the actual scenario requirements; no specific limitations are made here. By installing multiple solenoid valves on the first and second pipelines and controlling their opening and closing, the flow direction of the refrigerant can be controlled. Simultaneously, the two pipelines allow for heating of the room while controlling the refrigerant flow, solving the problem in existing technologies where reverse defrosting methods fail to provide heating while changing the refrigerant flow.

[0070] In some embodiments, the first end of the heating electronic expansion valve 8 is connected to the outlet end of the hot water side shell tube 7, and the second end of the heating electronic expansion valve 8 is connected to the second inlet of the regenerator 9; the multi-pipe heat pump device also includes a gas-liquid separator 4, the inlet end of the gas-liquid separator 4 is connected to the third interface end of the multi-way valve 2; the outlet end of the gas-liquid separator 4 is connected to the inlet end of the compressor 3.

[0071] A heating electronic expansion valve 8 is connected between the outlet end of the hot water side shell pipe 7 and the defrosting unit 11. Refrigerant flows from the outlet end of the hot water side shell pipe 7 to the heating electronic expansion valve 8. The heating electronic expansion valve 8 receives electrical signals from the controller and precisely controls the refrigerant flow, thereby improving heating efficiency and stability. Simultaneously, a gas-liquid separator 4 is connected between the third port of the multi-way valve 2 and the inlet end of the compressor 3. The gas-liquid separator 4 receives the refrigerant mixture, specifically a gas-liquid mixture of vapor, through the third port of the multi-way valve 2. Then, through mechanisms such as gravity settling, centrifugal force, or filtration, it separates the liquid refrigerant from the mixture, allowing only dry gaseous refrigerant to pass through and be output to the inlet end of the compressor 3. This prevents liquid refrigerant from entering the compressor 3 and causing "liquid slugging," thus protecting the compressor 3 from damage.

[0072] Furthermore, the multi-pipe heat pump device also includes: a refrigeration electronic expansion valve 5 and a chilled water side shell tube 6; the first end of the refrigeration electronic expansion valve 5 is connected to the outlet end of the chilled water side shell tube 6, and the second end of the refrigeration electronic expansion valve 5 is connected to the first end of the air side heat exchanger 1; the inlet end of the chilled water side shell tube 6 is connected to the outlet end of the gas-liquid separator 4. The refrigeration effect is achieved by setting the chilled water side shell tube 6 and the refrigeration electronic expansion valve 5. The specific implementation method is not described in detail here.

[0073] Based on the above-mentioned multi-pipe heat pump device, the embodiments of this application also provide the following seven operating modes: heating mode, heat storage mode, heat recovery mode, heat storage and heat recovery mode, defrosting mode, cooling mode, and heat recovery mode.

[0074] Figure 2 This is a schematic diagram of the heating mode provided in a specific embodiment of this application. (Reference) Figure 2 The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; the heating electronic expansion valve 8, the fifth solenoid valve F5, and the seventh solenoid valve F7 are energized; the outlet of hot water side shell pipe 7 is connected to the inlet of air side heat exchanger 1 through heating electronic expansion valve 8, the fifth solenoid valve F5, and the seventh solenoid valve F7, respectively, and the remaining solenoid valves are de-energized. At this time, the refrigerant flow direction can be referenced... Figure 2The arrows indicate the refrigerant flow direction as follows: compressor 3, multi-way valve 2, hot water side shell and tube 7, heating electronic expansion valve 8, air-side heat exchanger 1, multi-way valve 2, gas-liquid separator 4, and compressor 3. At this point, only by opening the fifth solenoid valve F5 and the seventh solenoid valve F7 in the second pipeline can the high-temperature, high-pressure output from compressor 3 reach the air-side heat exchanger 1, achieving energy exchange in the air-side heat exchanger 1.

[0075] Figure 3 This is a schematic diagram of the heat storage mode provided in this specific embodiment. (Reference) Figure 3 The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; the heating electronic expansion valve 8, the fifth solenoid valve F5, and the seventh solenoid valve F7 are energized; the outlet of hot water side shell pipe 7 is connected to the inlet of air side heat exchanger 1 through heating electronic expansion valve 8, the fifth solenoid valve F5, and the seventh solenoid valve F7; the first solenoid valve F1 and the fourth solenoid valve F4 are energized, and the second outlet of compressor 3 is connected to the first inlet of heat accumulator 10 through the first solenoid valve F1; the first outlet of heat accumulator 10 is connected to the outlet of hot water side shell pipe 7 through the fourth solenoid valve F4 and the heating electronic expansion valve 8, and the remaining solenoid valves are de-energized. At this time, the refrigerant flow direction can be referenced... Figure 3 Specifically, the refrigerant flow direction, as indicated by the arrows, is as follows: compressor 3, multi-way valve 2, hot water side shell and tube 7, heating electronic expansion valve 8, air-side heat exchanger 1, multi-way valve 2, gas-liquid separator 4, and compressor 3; the refrigerant branch flow direction is as follows: compressor 3, heat accumulator 10, and hot water side shell and tube 7. At this time, the high temperature and high pressure output by compressor 3 achieves energy exchange in air-side heat exchanger 1, and the heat accumulator 10 stores part of the high temperature and high pressure output by compressor 3.

[0076] Figure 4 This is a schematic diagram of the regenerative mode provided in this specific embodiment. (Reference) Figure 4 The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; the heating electronic expansion valve 8, the sixth solenoid valve F6, and the seventh solenoid valve F7 are energized; the outlet of hot water side shell tube 7 is connected to the second inlet of regenerator 9 through heating electronic expansion valve 8 and the sixth solenoid valve F6; the second outlet of regenerator 9 is connected to the inlet of air side heat exchanger 1 through the seventh solenoid valve F7; the second solenoid valve F2 and the third solenoid valve F3 are energized, and the second outlet of compressor 3 is connected to the first inlet of regenerator 9 through the second solenoid valve F2 and the third solenoid valve F3; the first outlet of regenerator 9 is connected to the inlet of hot water side shell tube 7, and the remaining solenoid valves are de-energized. At this time, the refrigerant flow direction can be referenced... Figure 4Specifically, the refrigerant flow direction, indicated by the arrows, is as follows: compressor 3, multi-way valve 2, hot water side shell and tube 7, heating electronic expansion valve 8, regenerator 9, air-side heat exchanger 1, multi-way valve 2, gas-liquid separator 4, and compressor 3; the refrigerant branch flow direction is as follows: compressor 3, regenerator 9, and hot water side shell and tube 7. At this time, the high temperature and high pressure output by compressor 3 achieves energy exchange in air-side heat exchanger 1, and the regenerator 9 cools part of the high temperature and high pressure output by compressor 3.

[0077] Figure 5 This is a schematic diagram of the heat storage and regeneration mode provided in this specific embodiment. (Reference) Figure 5 The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; the heating electronic expansion valve 8, the sixth solenoid valve F6, and the seventh solenoid valve F7 are energized; the outlet of hot water side shell tube 7 is connected to the second inlet of regenerator 9 through heating electronic expansion valve 8 and the sixth solenoid valve F6; the second outlet of regenerator 9 is connected to the inlet of air side heat exchanger 1 through the seventh solenoid valve F7; the first solenoid valve F1 and the third solenoid valve F3 are energized, and the second outlet of compressor 3 is connected to the first inlet of heat accumulator 10 through the first solenoid valve F1; the first outlet of heat accumulator 10 is connected to the first inlet of regenerator 9 through the third solenoid valve F3; the first outlet of regenerator 9 is connected to the inlet of hot water side shell tube 7, and the remaining solenoid valves are de-energized. At this time, the refrigerant flow direction can be referenced... Figure 5 Specifically, the refrigerant flow direction, as indicated by the arrows, is as follows: compressor 3, multi-way valve 2, hot water side shell and tube 7, heating electronic expansion valve 8, regenerator 9, air-side heat exchanger 1, multi-way valve 2, gas-liquid separator 4, and compressor 3; the refrigerant branch flow direction is as follows: compressor 3, heat accumulator 10, regenerator 9, and hot water side shell and tube 7. At this time, the high temperature and high pressure output by compressor 3 achieves energy exchange in air-side heat exchanger 1, and the heat accumulator 10 stores part of the high temperature and high pressure output by compressor 3. The regenerator 9 then cools part of the high temperature and high pressure output by compressor 3.

[0078] Figure 6 This is a schematic diagram of the defrosting mode provided in this specific embodiment. (Reference) Figure 6The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; the heating electronic expansion valve 8, the sixth solenoid valve F6, and the eighth solenoid valve F8 are energized; the outlet of hot water side shell tube 7 is connected to the second inlet of regenerator 9 through heating electronic expansion valve 8 and the sixth solenoid valve F6; the second outlet of regenerator 9 is connected to the second inlet of heat accumulator 10 through the eighth solenoid valve F8; the second outlet of heat accumulator 10 is connected to the inlet of air side heat exchanger 1; the first solenoid valve F1 and the third solenoid valve F3 are energized, the second outlet of compressor 3 is connected to the first inlet of heat accumulator 10 through the first solenoid valve F1; the first outlet of heat accumulator 10 is connected to the first inlet of regenerator 9 through the third solenoid valve F3; the first outlet of regenerator 9 is connected to the inlet of hot water side shell tube 7, and the remaining solenoid valves are de-energized. At this time, the refrigerant flow direction can be referenced... Figure 6 Specifically, the refrigerant flow direction, as indicated by the arrows, is as follows: compressor 3, multi-way valve 2, hot water side shell and tube 7, heating electronic expansion valve 8, regenerator 9, heat accumulator 10, air-side heat exchanger 1, multi-way valve 2, gas-liquid separator 4, and compressor 3; the refrigerant branch flow direction is as follows: compressor 3, heat accumulator 10, regenerator 9, heat accumulator 10, and hot water side shell and tube 7. At this time, the high temperature and high pressure output by compressor 3 achieves energy exchange in air-side heat exchanger 1, and the heat accumulator 10 stores part of the high temperature and high pressure output by compressor 3. The regenerator 9 then cools part of the high temperature and high pressure output by compressor 3.

[0079] Figure 7 This is a schematic diagram of the cooling mode provided in this specific embodiment. (Reference) Figure 7 The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; the refrigeration electronic expansion valve 5 is energized; the first outlet of multi-way valve 2 is connected to the first end of air-side heat exchanger 1; the second end of air-side heat exchanger 1 is connected to the inlet of cold water-side shell and tube 6 via refrigeration electronic expansion valve 5; the outlet of cold water-side shell and tube 6 is connected to the inlet of compressor 3. In this specific embodiment, the first outlet of compressor 3 is connected to the multi-way valve, thereby allowing the high-temperature, high-pressure gas from compressor 3 to flow to air-side heat exchanger 1, so that the refrigerant in air-side heat exchanger 1 absorbs the heat of the environment in which the device is located, thereby reducing the ambient temperature and achieving a cooling effect. The refrigerant in air-side heat exchanger 1 absorbs the heat of the air in which the device is located, thereby evaporating the refrigerant into a low-pressure gas. Subsequently, through refrigeration electronic expansion valve 5, the refrigerant flows to cold water-side shell and tube 6 for heat exchange, releasing a large amount of heat and causing the refrigerant to liquefy; the refrigerant is then compressed by compressor 3 into a high-pressure gas, providing power for the refrigerant cycle. The refrigerant flows in the following order: compressor 3, multi-way valve 2, air-side heat exchanger 1, refrigeration electronic expansion valve 5, chilled water-side shell and tube 6, and compressor 3.

[0080] Figure 8 This is a schematic diagram of the heat recovery mode provided in this specific embodiment, for reference. Figure 8 The first outlet of compressor 3 is connected to the high-pressure inlet of multi-way valve 2; refrigeration electronic expansion valve 5 and heating electronic expansion valve 8 are energized; the second outlet of multi-way valve 2 is connected to the inlet of hot water side shell tube 7; the outlet of hot water side shell tube 7 is connected to the inlet of cold water side shell tube 6 through refrigeration electronic expansion valve 5; the outlet of cold water side shell tube 6 is connected to the inlet of compressor 3; the outlet of hot water side shell tube 7 is also connected to the third end of air-side heat exchanger 1 through heating electronic expansion valve 8. In this specific embodiment, the high-temperature and high-pressure refrigerant released by compressor 3 flows to the inlet of hot water side shell tube 7 through multi-way valve 2, undergoes heat exchange in the hot water side shell tube, and then enters the cold water side shell tube 6 through the outlet of hot water side shell tube 7, where it undergoes heat exchange again; subsequently, the refrigerant is delivered to compressor 3 through the outlet of cold water side shell tube 6. Additionally, the refrigerant flows to the gas-liquid separator 4 via the multi-way valve 2, where the gaseous and liquid states of the refrigerant are separated to ensure that only gaseous refrigerant enters the compressor. By controlling the opening and closing of multiple solenoid valves, the aforementioned various operating conditions can be achieved without the need for additional heating boxes or other devices, thereby reducing the overall size and energy consumption of the multi-pipe heat pump unit.

[0081] This embodiment also provides a multi-pipe heat pump control method. Figure 9 This is a flowchart of a multi-pipe heat pump control method according to a specific embodiment, applied to the aforementioned multi-pipe heat pump device, such as... Figure 9 As shown, the process includes the following steps:

[0082] To ensure efficient unit operation, solenoid valves are installed at various points in the unit's circuit. Temperature sensors are installed on the surface of the air-side heat exchanger 1, with two sensors respectively attached to one fin and one coil of two adjacent fins on the windward side of the air-side heat exchanger 1. Temperature and humidity sensors are installed on the air inlet side of the air-side heat exchanger 1, placed in the air. Temperature sensors are installed at the inlet and outlet of the heat accumulator 10. The control system of the multi-pipe heat pump unit uses the real-time feedback data from the above sensors to determine and control the opening and closing of the compressor 3 outlet branch, thereby controlling the surface temperature of the air-side heat exchanger 1. The outer surface temperature of the air-side heat exchanger 1 is taken as the average of the surface temperatures of the fins and coils. The unit only frosts during heating operation; therefore, the control method and operation described in this embodiment, i.e., detecting air temperature and humidity and performing subsequent anti-frost control, are only implemented when a heating mode operation command is received.

[0083] In some specific embodiments, before obtaining the temperature and humidity of the environment where the multi-pipe heat pump device is located, the process includes: controlling the opening of the first solenoid valve F1, the fourth solenoid valve F4, the fifth solenoid valve F5 and the seventh solenoid valve F7 to enter the heat storage mode, and determining whether the temperature difference between the inlet end and the outlet end of the heat storage device 10 is stable; if so, controlling the closing of the first solenoid valve F1 and the fourth solenoid valve F4 to exit the heat storage mode.

[0084] Specifically, when the unit is in heating mode, i.e., the fifth solenoid valve F5, the seventh solenoid valve F7, and the heating electronic expansion valve 8 are opened to start heating, and the unit's exhaust temperature stabilizes, the control system in the multi-pipe heat pump device controls the opening of the first solenoid valve F1 and the fourth solenoid valve F4 to enter the heat storage mode. It then determines whether the temperature difference between the inlet and outlet of the heat storage unit 10 is stable. If it is, the first solenoid valve F1 and the fourth solenoid valve F4 are closed to exit the heat storage mode; if it is unstable, the first solenoid valve F1 and the fourth solenoid valve F4 are opened again to enter the heat storage mode. The unit here refers to the multi-pipe heat pump device described in the aforementioned embodiment.

[0085] Subsequently, the temperature and humidity of the environment where the multi-pipe heat pump unit is located are detected by temperature sensors. Based on the enthalpy-humidity chart pre-stored in the unit, the dew point temperature is determined according to the temperature and humidity. The surface temperature of the air-side heat exchanger 1, i.e. the surface temperature of the low-temperature stage evaporator, is obtained to determine whether the air conditioner is frosted. When it is determined that the multi-pipe heat pump unit is frosted, the target temperature is obtained. The target temperature is the critical frosting line temperature of the location of the multi-pipe heat pump unit. When the fin temperature of the air-side heat exchanger 1 is lower than the dew point temperature and the target temperature is within the first threshold temperature range, the first solenoid valve F1, the third solenoid valve F3, the sixth solenoid valve F6, and the eighth solenoid valve F8 are energized according to the target temperature. This causes the second outlet end of the compressor 3 to be connected to the inlet end of the hot water side shell tube 7 through the first solenoid valve F1 and the third solenoid valve F3 on the first pipeline, and the second end of the heating electronic expansion valve 8 to be connected to the third end of the air-side heat exchanger 1 through the sixth solenoid valve F6 and the eighth solenoid valve F8 on the second pipeline, so as to defrost the air-side heat exchanger 1 whose surface is frosted.

[0086] Once the ambient temperature meets the above conditions, the system enters defrost mode. When the time for entering defrost mode reaches a preset time threshold, the system re-determines whether the air conditioner is prone to frosting based on the dew point temperature and the evaporator surface temperature. For example, the preset time threshold is set to five minutes; the first threshold temperature range is set to (0,1), and the target temperature is calculated experimentally.

[0087] Specifically, Figure 10 This is a schematic diagram of enthalpy-humidity chart fitting provided in this specific embodiment. The dew point temperature is determined from the enthalpy-humidity chart based on temperature and humidity. (Reference) Figure 10 The horizontal axis represents the air temperature T.a The unit is °C, and the vertical axis represents the percentage of relative humidity (RH). Based on different air temperatures and humidity levels, critical dew point and critical frost point lines are determined. These lines then divide the area into non-frost, frost, and dew point zones. Compared to directly obtaining dew point temperature via network connection and geographic location, finding and calculating the dew point temperature based on actually measured environmental temperature and humidity parameters yields a more accurate result (because dew point temperature is also affected by factors such as relative humidity), which is beneficial for subsequent precise control.

[0088] The critical frost line is a critical line plotted on a frost diagram. It is used to determine whether frost will form on the surface of the air-side heat exchanger 1 of the unit. Frost will only form on the coils of the air-side heat exchanger 1 when the relative humidity of the air is above the critical condensation line and the air temperature is to the left of the critical frost line. When the air temperature equals the critical frost line temperature, the heat exchanger surface temperature is 0℃. Because there is a temperature difference between the fins and coils on the heat exchanger surface, the critical frost temperature is used to represent the condition that the heat exchanger surface is 0℃. The critical frost line varies with the environment in different regions and for different units. Therefore, it is necessary to operate the unit in winter, and the air temperature at which obvious frost is observed on the heat exchanger surface is the critical frost line temperature.

[0089] In some specific embodiments, determining whether the multi-pipe heat pump device is frosted based on the fin temperature and dew point temperature includes: when the fin temperature of the air-side heat exchanger 1 is lower than the dew point temperature and the target temperature is within the second threshold temperature range, controlling the opening of the second solenoid valve F2, the third solenoid valve F3, the sixth solenoid valve F6, and the seventh solenoid valve F7, so that the second outlet end of the compressor 3 is connected to the first inlet of the regenerator 9 through the second solenoid valve F2 and the third solenoid valve F3, the first outlet end of the regenerator 9 is connected to the first end of the heating electronic expansion valve 8, and the second end of the heating electronic expansion valve 8 is connected to the third end of the air-side heat exchanger 1 through the sixth solenoid valve F6 on the second pipeline, so as to enter the regeneration mode; after a preset time threshold has elapsed, the temperature and humidity of the environment where the multi-pipe heat pump device is located are detected, and the dew point temperature is determined based on the temperature and humidity, so as to determine again whether the multi-pipe heat pump device is frosted.

[0090] Among them, reference Figure 9The system monitors the ambient temperature and humidity in real time and determines the dew point temperature based on a pre-stored enthalpy-humidity chart within the unit. Then, based on the dew point temperature and the surface temperature of the low-temperature evaporator, it determines whether the unit is frosting. The low-temperature evaporator here is the air-side heat exchanger 1 in the aforementioned embodiment; specifically, the unit can be an air conditioner. When it is determined that the outer surface temperature of the heat exchanger is lower than the dew point temperature, and the air temperature (i.e., the target temperature) is within the second threshold temperature range, the second solenoid valve F2, the third solenoid valve F3, the sixth solenoid valve F6, and the seventh solenoid valve F7 are opened, entering the regenerative mode. For example, the second threshold temperature range is set to (-1, 0).

[0091] Furthermore, when the fin temperature of the air-side heat exchanger 1 is not less than the dew point temperature, and / or the target temperature is not within the first threshold temperature range and the second threshold temperature range, the fifth solenoid valve F5 and the seventh solenoid valve F7 are opened to enter the heating mode; after a preset time threshold has elapsed, the temperature and humidity of the environment where the multi-pipe heat pump unit is located are re-detected, and the dew point temperature is determined based on the temperature and humidity to determine again whether the multi-pipe heat pump unit is frosted.

[0092] This application connects a defrosting unit 11, which includes a heat accumulator, a regenerator, and multiple solenoid valves, to one output end of the compressor. By controlling the multiple solenoid valves, multiple operating modes of the heat pump device can be realized. By controlling the opening and closing of the multiple solenoid valves according to different environmental conditions to switch between different operating modes, it is beneficial to improve the efficiency of heat exchange control, thereby improving defrosting efficiency.

[0093] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0094] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0095] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0096] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A multi-pipe heat pump device, characterized in that, The multi-pipe heat pump device includes: The air-side heat exchanger (1), multi-way valve (2), compressor (3), and hot water-side shell and tube (7) are provided. The multi-way valve (2) includes a high-pressure inlet end, a first interface end, a second interface end, and a third interface end. The high-pressure inlet end is connected to the first outlet end of the compressor (3). The first interface end is connected to the first end of the air-side heat exchanger (1). The second interface end is connected to the inlet end of the hot water-side shell and tube (7). The third interface end is connected to the inlet end of the compressor (3). The defrosting unit (11) includes a regenerator (9) and a heat accumulator (10). The regenerator (9) and the heat accumulator (10) are connected by a first pipeline and a second pipeline, which are arranged in parallel. The first pipeline connects the second outlet end of the compressor (3) and the inlet end of the hot water side shell tube (7). The second pipeline connects the input end of the air side heat exchanger (1) and the outlet end of the hot water side shell tube (7). The first pipeline is also equipped with a first solenoid valve (F1) and a third solenoid valve (F3). The first inlet of the heat accumulator (10) can be connected to the second outlet of the compressor (3) through the first solenoid valve (F1); the first outlet of the heat accumulator (10) can be connected to the first inlet of the regenerator (9) through the third solenoid valve (F3); the defrosting unit (11) can increase the refrigerant temperature entering the air-side heat exchanger (1) where the surface is frosted.

2. The multi-pipe heat pump device according to claim 1, characterized in that, The defrosting unit (11) also includes a second solenoid valve (F2) and a fourth solenoid valve (F4); The second solenoid valve (F2) is arranged in parallel with the first solenoid valve (F1). One end of the second solenoid valve (F2) is connected to one end of the first solenoid valve (F1), and the other end of the second solenoid valve (F2) is connected to one end of the third solenoid valve (F3). The fourth solenoid valve (F4) is arranged in parallel with the third solenoid valve (F3). One end of the fourth solenoid valve (F4) is connected to one end of the third solenoid valve (F3), and the other end of the fourth solenoid valve (F4) is connected to the first outlet of the regenerator (9).

3. The multi-pipe heat pump device according to claim 2, characterized in that, The defrosting unit (11) further includes a fifth solenoid valve (F5), a sixth solenoid valve (F6), a seventh solenoid valve (F7), and an eighth solenoid valve (F8); a heating electronic expansion valve (8) is provided on the second pipeline, and the heating electronic expansion valve (8) is located between the hot water side shell pipe (7) and the defrosting unit (11); the sixth solenoid valve (F6) and the eighth solenoid valve (F8) are provided on the second pipeline; the second inlet of the regenerator can be connected to the heating electronic expansion valve (8) through the sixth solenoid valve (F6), and the second outlet of the regenerator (9) can be connected to the fifth solenoid valve (F7) through the sixth solenoid valve (F8). The eighth solenoid valve (F8) is connected to the second inlet of the heat accumulator (10); the sixth solenoid valve (F6) is arranged in parallel with the fifth solenoid valve (F5), one end of the sixth solenoid valve (F6) is connected to one end of the fifth solenoid valve (F5), and the other end of the fifth solenoid valve (F5) is connected to one end of the eighth solenoid valve (F8); the eighth solenoid valve (F8) is arranged in parallel with the seventh solenoid valve (F7), one end of the eighth solenoid valve (F8) is connected to one end of the seventh solenoid valve (F7), and the other end of the seventh solenoid valve (F7) is connected to the second outlet of the heat accumulator (10).

4. The multi-pipe heat pump device according to claim 3, characterized in that, The first end of the heating electronic expansion valve (8) is connected to the outlet end of the hot water side shell tube (7), and the second end of the heating electronic expansion valve (8) is connected to the second inlet of the regenerator (9); The multi-pipe heat pump device also includes a gas-liquid separator (4), the inlet end of which is connected to the third interface end of the multi-port valve (2); the outlet end of which is connected to the inlet end of the compressor (3).

5. The multi-pipe heat pump device according to claim 4, characterized in that, The device also includes: a refrigeration electronic expansion valve (5) and a cold water side shell tube (6); The first end of the refrigeration electronic expansion valve (5) is connected to the outlet end of the cold water side shell tube (6), and the second end of the refrigeration electronic expansion valve (5) is connected to the first end of the air side heat exchanger (1); the inlet end of the cold water side shell tube (6) is connected to the outlet end of the gas-liquid separator (4).

6. The multi-pipe heat pump device according to claim 5, characterized in that, The multi-pipe heat pump device includes seven operating modes: Heating mode: The first outlet end of the compressor (3) is connected to the high pressure inlet end of the multi-way valve (2); the heating electronic expansion valve (8), the fifth solenoid valve (F5) and the seventh solenoid valve (F7) are energized; Heat storage mode: The first outlet end of the compressor (3) is connected to the high pressure inlet end of the multi-way valve (2); the heating electronic expansion valve (8), the fifth solenoid valve (F5) and the seventh solenoid valve (F7) are energized; the first solenoid valve (F1) and the fourth solenoid valve (F4) are energized, and the second outlet end of the compressor (3) is connected to the first inlet of the heat storage device (10) through the first solenoid valve (F1); Regenerative mode: The first outlet end of the compressor (3) is connected to the high-pressure inlet end of the multi-way valve (2); the heating electronic expansion valve (8), the sixth solenoid valve (F6) and the seventh solenoid valve (F7) are energized; the second solenoid valve (F2) and the third solenoid valve (F3) are energized, and the second outlet end of the compressor (3) is connected to the first inlet of the regenerator (9) through the second solenoid valve (F2) and the third solenoid valve (F3); Heat storage and regeneration mode: The first outlet end of the compressor (3) is connected to the high pressure inlet end of the multi-way valve (2); the heating electronic expansion valve (8), the sixth solenoid valve (F6) and the seventh solenoid valve (F7) are energized; the first solenoid valve (F1) and the third solenoid valve (F3) are energized, and the second outlet end of the compressor (3) is connected to the first inlet of the heat storage device (10) through the first solenoid valve (F1); Defrosting mode: The first outlet end of the compressor (3) is connected to the high-pressure inlet end of the multi-way valve (2); the heating electronic expansion valve (8), the sixth solenoid valve (F6) and the eighth solenoid valve (F8) are energized; the first solenoid valve (F1) and the third solenoid valve (F3) are energized, and the second outlet end of the compressor (3) is connected to the first inlet end of the heat accumulator (10) through the first solenoid valve (F1); Cooling mode: The first outlet end of the compressor (3) is connected to the high-pressure inlet end of the multi-way valve (2); the refrigeration electronic expansion valve (5) is energized; the first outlet end of the multi-way valve (2) is connected to the first end of the air-side heat exchanger (1); the second end of the air-side heat exchanger (1) is connected to the inlet end of the cold water-side shell tube (6) through the refrigeration electronic expansion valve (5); the outlet end of the cold water-side shell tube (6) is connected to the inlet end of the compressor (3); Heat recovery mode: The first outlet end of the compressor (3) is connected to the high-pressure inlet end of the multi-way valve (2); the refrigeration electronic expansion valve (5) and the heating electronic expansion valve (8) are energized; the second outlet end of the multi-way valve (2) is connected to the inlet end of the hot water side shell tube (7); the outlet end of the hot water side shell tube (7) is connected to the inlet end of the cold water side shell tube (6) through the refrigeration electronic expansion valve (5); the outlet end of the cold water side shell tube (6) is connected to the inlet end of the compressor (3); the outlet end of the hot water side shell tube (7) is also connected to the third end of the air-side heat exchanger (1) through the heating electronic expansion valve (8).

7. A method for controlling a multi-pipe heat pump, characterized in that, The method is applied to a multi-pipe heat pump device as described in any one of claims 1 to 6, wherein the air-side heat exchanger (1) is provided with fins; the method includes: The temperature and humidity of the environment in which the multi-pipe heat pump device is located are obtained, and the dew point temperature is determined based on the temperature and humidity. Obtain the fin temperature of the air-side heat exchanger (1), and determine whether the multi-pipe heat pump device is frosted based on the fin temperature and the dew point temperature; Once it is determined that the multi-pipe heat pump device has frosted, a target temperature is obtained; the target temperature is the critical frosting line temperature of the location of the multi-pipe heat pump device. When the fin temperature of the air-side heat exchanger (1) is lower than the dew point temperature and the target temperature is within the first threshold temperature range, the first solenoid valve (F1), the third solenoid valve (F3), the sixth solenoid valve (F6), and the eighth solenoid valve (F8) are energized according to the target temperature, so that the second outlet end of the compressor (3) is connected to the inlet end of the hot water side shell tube (7) through the first solenoid valve (F1) and the third solenoid valve (F3) on the first pipeline, and the second end of the heating electronic expansion valve (8) is connected to the third end of the air-side heat exchanger (1) through the sixth solenoid valve (F6) and the eighth solenoid valve (F8) on the second pipeline, so as to defrost the air-side heat exchanger (1) whose surface is frosted.

8. The multi-pipe heat pump control method according to claim 7, characterized in that, Before obtaining the temperature and humidity of the environment in which the multi-pipe heat pump device is located, the following steps are included: The first solenoid valve (F1), the fourth solenoid valve (F4), the fifth solenoid valve (F5) and the seventh solenoid valve (F7) are opened to enter the heat storage mode, and it is determined whether the temperature difference between the inlet and outlet of the heat storage device (10) is stable. If so, the first solenoid valve (F1) and the fourth solenoid valve (F4) are closed to exit the heat storage mode.

9. The multi-pipe heat pump control method according to claim 7, characterized in that, Determining whether the multi-pipe heat pump unit is frosted based on the temperature of the fins and the dew point temperature includes: When the fin temperature of the air-side heat exchanger (1) is less than the dew point temperature and the target temperature is within the second threshold temperature range, the second solenoid valve (F2), the third solenoid valve (F3), the sixth solenoid valve (F6), and the seventh solenoid valve (F7) are opened, so that the second outlet end of the compressor (3) is connected to the first inlet of the regenerator (9) through the second solenoid valve (F2) and the third solenoid valve (F3), the first outlet end of the regenerator (9) is connected to the first end of the heating electronic expansion valve (8), and the second end of the heating electronic expansion valve (8) is connected to the third end of the air-side heat exchanger (1) through the sixth solenoid valve (F6) on the second pipeline, so as to enter the regeneration mode; After a preset time threshold has elapsed, the temperature and humidity of the environment in which the multi-pipe heat pump device is located are detected, and the dew point temperature is determined based on the temperature and humidity to determine again whether the multi-pipe heat pump device is frosted.

10. The multi-pipe heat pump control method according to claim 9, characterized in that, The step of determining whether the multi-pipe heat pump unit is frosted based on the temperature of the fins and the dew point temperature further includes: When the fin temperature of the air-side heat exchanger (1) is not less than the dew point temperature, and / or the target temperature is not within the first threshold temperature range and the second threshold temperature range, the fifth solenoid valve (F5) and the seventh solenoid valve (F7) are controlled to open to enter the heating mode. After a preset time threshold has elapsed, the temperature and humidity of the environment in which the multi-pipe heat pump device is located are re-detected, and the dew point temperature is determined based on the temperature and humidity to determine again whether the multi-pipe heat pump device is frosted.

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