A heat pump system and control method

Abstract

The application discloses a heat pump system and a control method, relates to the technical field of heat pumps, and can simultaneously meet the cooling and heating requirements of an indoor heat exchanger. The heat pump system comprises a compressor, a condenser, an indoor heat exchanger, a first electronic expansion valve, a first branch, an outdoor heat exchanger and a second electronic expansion valve. In the case that the heat pump system operates in a cooling mode, the compressor, the condenser, the first electronic expansion valve and the indoor heat exchanger are sequentially connected to form a cooling circulation loop. In the case that the heat pump system operates in a heating mode, the compressor, the indoor heat exchanger, the first electronic expansion valve, the second electronic expansion valve and the outdoor heat exchanger are sequentially connected to form a heating circulation loop. The heat pump system in the application is used for adjusting indoor temperature.

Description

Technical Field

[0001] This application relates to the field of heat pump technology, and in particular to a heat pump system and control method. Background Technology

[0002] A heat pump is a device that uses a compressor to convert low-grade heat energy extracted from the air, water, or soil into high-grade heat energy to cool or heat an indoor environment. Because a heat pump is essentially a heat-lifting device, the electrical energy consumed by the compressor is significantly less than the heat extracted from the environment (water, air, soil, etc.), and this heat is used to improve the indoor temperature. Therefore, heat pumps have higher operating efficiency compared to traditional air conditioning systems.

[0003] In related technologies, a heat pump system includes a compressor, a condenser, a throttling device, and an indoor heat exchanger, which are sequentially connected to form a refrigerant circulation loop. The condenser is connected to the compressor's exhaust port, and the indoor heat exchanger is connected to the compressor's suction port. However, this heat pump system can only cool indoor air through the indoor heat exchanger and cannot heat it, thus failing to simultaneously meet the cooling and heating needs of the indoor heat exchanger. Summary of the Invention

[0004] This application provides a heat pump system and control method that can simultaneously meet the cooling and heating needs of an indoor heat exchanger.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] On the one hand, a heat pump system is provided, which includes a compressor, a condenser, an indoor heat exchanger, a first electronic expansion valve, a first branch, an outdoor heat exchanger, and a second electronic expansion valve.

[0007] The compressor has an intake port and an exhaust port, and the condenser has an inlet port and an outlet port. The inlet port of the condenser is connected to the exhaust port of the compressor. The indoor heat exchanger has a first port and a second port, with the first port connected to the outlet port of the condenser and the second port connected to the intake port of the compressor. A first electronic expansion valve is installed on the pipeline between the indoor heat exchanger and the condenser. One end of a first branch is connected to the exhaust port of the compressor, and the other end is connected to the second port of the indoor heat exchanger. The outdoor heat exchanger has a refrigerant inlet and a refrigerant outlet, with the refrigerant inlet connected to the first port of the indoor heat exchanger and the refrigerant outlet connected to the intake port of the compressor. A second electronic expansion valve is installed on the pipeline between the outdoor heat exchanger and the indoor heat exchanger. When the heat pump system operates in cooling mode, the compressor, condenser, first electronic expansion valve, and indoor heat exchanger are sequentially connected to form a cooling cycle. When the heat pump system operates in heating mode, the compressor, indoor heat exchanger, first electronic expansion valve, second electronic expansion valve, and outdoor heat exchanger are sequentially connected to form a heating cycle.

[0008] The heat pump system provided in this application includes a compressor, a condenser, an indoor heat exchanger, a first electronic expansion valve, a first branch circuit, an outdoor heat exchanger, and a second electronic expansion valve. The compressor, condenser, first electronic expansion valve, and indoor heat exchanger are sequentially connected to form a refrigeration cycle, thereby cooling the indoor air through the indoor heat exchanger. The compressor, indoor heat exchanger, first electronic expansion valve, second electronic expansion valve, and outdoor heat exchanger are sequentially connected to form a heating cycle, thereby heating the indoor air through the indoor heat exchanger. Thus, both cooling and heating needs for indoor air can be met simultaneously. Furthermore, by simply adding a first branch circuit, an outdoor heat exchanger, and a second electronic expansion valve to the heat pump system in the related technology, the system can be upgraded to simultaneously possess the ability to cool and heat indoor air, which helps reduce costs.

[0009] In some embodiments, the heat pump system further includes a liquid receiver tank disposed on a pipeline between the condenser and the first electronic expansion valve, and also disposed on a pipeline between the indoor heat exchanger and the second electronic expansion valve. When the heat pump system operates in cooling mode, the compressor, condenser, liquid receiver tank, first electronic expansion valve, and indoor heat exchanger are sequentially connected to form a cooling cycle loop. When the heat pump system operates in heating mode, the compressor, indoor heat exchanger, first electronic expansion valve, liquid receiver tank, second electronic expansion valve, and outdoor heat exchanger are sequentially connected to form a heating cycle loop.

[0010] In some embodiments, the heat pump system further includes a gas-liquid separator disposed on the pipeline between the indoor heat exchanger and the compressor, and also disposed on the pipeline between the outdoor heat exchanger and the compressor. When the heat pump system operates in cooling mode, the compressor, condenser, liquid receiver, first electronic expansion valve, indoor heat exchanger, and gas-liquid separator are sequentially connected to form a cooling cycle loop. When the heat pump system operates in heating mode, the compressor, indoor heat exchanger, first electronic expansion valve, liquid receiver, second electronic expansion valve, outdoor heat exchanger, and gas-liquid separator are sequentially connected to form a heating cycle loop.

[0011] On the other hand, a control method for a heat pump system is provided, the method comprising: acquiring the cooling and heating demand of an indoor heat exchanger; if the indoor heat exchanger requires heating, controlling the heat pump system to operate in a heating mode; adjusting the opening of a first electronic expansion valve to a first preset opening, adjusting the opening of a second electronic expansion valve to a second preset opening, and maintaining the adjustment for a preset time; acquiring the actual liquid level value of the storage tank, and adjusting the opening of the second electronic expansion valve according to the actual liquid level value.

[0012] The heat pump system control method provided in this application allows the heat pump system to switch to heating mode when the indoor heat exchanger needs heating, enabling the system to operate in heating mode and thus heat the indoor air through the indoor heat exchanger. It is understood that the refrigerant demand differs between cooling and heating modes. After switching the heat pump system to heating mode, adjusting the first electronic expansion valve to a first preset opening and the second electronic expansion valve to a second preset opening, and maintaining this position for a preset time, helps match the refrigerant flow rate in the system with the heating conditions. At this time, adjusting the opening of the second electronic expansion valve based on the actual liquid level in the storage tank can quickly change the refrigerant flow rate in the system to match the operating conditions of the heat pump system, thereby improving the energy efficiency of the heat pump system.

[0013] In some embodiments, adjusting the opening of the second electronic expansion valve according to the actual liquid level value specifically includes: if the actual liquid level value is greater than the preset liquid level value, adjusting to increase the opening of the second electronic expansion valve; if the actual liquid level value is less than the preset liquid level value, adjusting to decrease the opening of the second electronic expansion valve.

[0014] In some embodiments, after adjusting the opening of the second electronic expansion valve according to the actual liquid level, the method further includes: obtaining the temperature and pressure at the compressor suction port, obtaining the compressor suction superheat based on the temperature and pressure at the compressor suction port, and adjusting the opening of the second electronic expansion valve based on the compressor suction superheat.

[0015] In some embodiments, adjusting the opening of the second electronic expansion valve according to the suction superheat of the compressor specifically includes: if the suction superheat of the compressor is greater than the target superheat, then adjusting to increase the opening of the second electronic expansion valve; if the suction superheat of the compressor is less than the target superheat, then adjusting to decrease the opening of the second electronic expansion valve.

[0016] In some embodiments, after obtaining the cooling and heating demand of the indoor heat exchanger, the method further includes: if the indoor heat exchanger needs to cool, controlling the heat pump system to operate in cooling mode; adjusting the opening of the first electronic expansion valve to a third preset opening; obtaining the temperature and pressure at the first port of the indoor heat exchanger, obtaining the superheat of the indoor heat exchanger based on the temperature and pressure at the first port of the indoor heat exchanger; and adjusting the opening of the first electronic expansion valve based on the superheat of the indoor heat exchanger.

[0017] In some embodiments, adjusting the opening of the first electronic expansion valve according to the superheat of the indoor heat exchanger specifically includes: if the superheat of the indoor heat exchanger is greater than a preset superheat, then adjusting to increase the opening of the first electronic expansion valve; if the superheat of the indoor heat exchanger is less than the preset superheat, then adjusting to decrease the opening of the first electronic expansion valve.

[0018] In some embodiments, the control method further includes: acquiring the pressure inside the gas-liquid separator and calculating the actual pressure difference based on the pressure inside the gas-liquid separator; wherein the actual pressure difference is the difference between the pressure inside the gas-liquid separator and the preset pressure; if the actual pressure difference is greater than the target pressure difference, adjusting to increase the operating frequency of the compressor; if the actual pressure difference is less than the target pressure difference, adjusting to decrease the operating frequency of the compressor. Attached Figure Description

[0019] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0020] Figure 1 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application;

[0021] Figure 2 A schematic diagram of the refrigerant flow direction in the cooling mode of a heat pump system provided in some embodiments of this application;

[0022] Figure 3 Structural diagrams of condensers provided in some embodiments of this application;

[0023] Figure 4 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application;

[0024] Figure 5 Schematic diagram of refrigerant flow in the heating mode of a heat pump system provided in some embodiments of this application;

[0025] Figure 6 Structural diagrams of outdoor heat exchangers provided in some embodiments of this application;

[0026] Figure 7 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application;

[0027] Figure 8 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application;

[0028] Figure 9 A schematic flowchart illustrating the control method of a heat pump system provided in some embodiments of this application;

[0029] Figure 10 A schematic flowchart illustrating the control method of a heat pump system provided in some embodiments of this application;

[0030] Figure 11 This is a flowchart illustrating a control method for a heat pump system provided in some embodiments of this application.

[0031] Figure label:

[0032] 100-Heat pump system; 1-Indoor unit; 11-Indoor unit; 111-Indoor heat exchanger; 1111-First port; 1112-Second port; 112-First electronic expansion valve; 2-Compressor; 21-Suction port; 22-Exhaust port; 23-Make-up port; 3-Condenser; 31-Inlet port; 32-Outlet port; 33-Outer casing; 34-Water tank; 35-Cooling water pump; 36-Nozzle; 37-Condensing coil; 38-Axial fan; 4-Stop check valve; 5-First branch; 6-Outdoor heat exchanger; 61-Refrigerant inlet 62-Refrigerant outlet; 63-Cold water inlet; 64-Cold water outlet; 7-Second electronic expansion valve; 8-Liquid storage tank; 9-Gas-liquid separator; 101-First interface; 102-Second interface; 103-Third interface; 104-Fourth interface; 105-Fifth interface; 106-Sixth interface; 20-Second branch; 30-First control valve; 40-Second control valve; 50-Dryer filter; 60-Economizer; 601-Third heat exchange flow path; 602-Fourth heat exchange flow path; 70-Maintenance gas branch; 80-Throttling device. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0036] It should be noted that in practical applications, due to limitations in equipment precision or installation errors, achieving absolute parallelism or perpendicularity is difficult. The descriptions of "perpendicular," "parallel," or "in the same direction" in this application are not absolute limitations, but rather indicate that a vertical or parallel structural arrangement can be achieved within a preset error range, achieving the corresponding preset effect. This maximizes the technical effect of the defined features and makes the corresponding technical solution easy to implement, possessing high feasibility. For example, "perpendicular" includes absolute perpendicularity and near-perpendicularity, where the acceptable deviation range for near-perpendicularity can be, for example, within 5°. "Parallel" includes absolute parallelism and near-parallelism, where the acceptable deviation range for near-parallelism can also be, for example, within 5°. "In the same direction" includes absolute same direction and near-same direction, where the acceptable deviation range for near-same direction can also be, for example, within 5°.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0039] In the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0040] As energy conservation and emission reduction become increasingly important in human production and life, the development of new energy technologies is accelerating. Heat pump technology, as a new energy technology that has received much attention worldwide in recent years, is becoming more and more common in people's daily lives.

[0041] In related technologies, heat pumps typically consist of four parts: a compressor, a condenser, a throttling device, and an evaporator. The working process is as follows: high-temperature, high-pressure gaseous refrigerant flows out of the compressor's exhaust port and into the condenser, where it cools and condenses into low-temperature, high-pressure liquid refrigerant. This low-temperature, high-pressure liquid refrigerant then flows out of the condenser, is reduced in pressure by the throttling device, and is converted into a low-temperature, low-pressure liquid refrigerant, which then flows into the evaporator through pipes. In the evaporator, the low-temperature, low-pressure liquid refrigerant absorbs heat and transforms into a high-temperature, low-pressure gaseous refrigerant. This high-temperature, low-pressure gaseous refrigerant then flows into the compressor through the compressor's suction port, where it is compressed and transformed into a high-temperature, high-pressure gaseous refrigerant. During this process, the heat pump system can cool indoor air through the indoor heat exchanger, but it cannot meet the heating needs of the indoor heat exchanger, resulting in a poor user experience.

[0042] Based on this, such as Figure 1 As shown, Figure 1 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application. Embodiments of this application provide a heat pump system 100 capable of simultaneously meeting the cooling and heating needs of an indoor heat exchanger 111. The heat pump system 100 includes an indoor unit 1, which includes an indoor unit 11. The heat pump system 100 can exchange heat with indoor air through the indoor unit 11 to achieve both cooling and heating of the indoor air.

[0043] The number of indoor units 11 can be multiple, and these multiple indoor units 11 can be connected in parallel. This allows multiple indoor units 11 to be installed in different indoor spaces, enabling the heat pump system 100 to cool and heat multiple different indoor spaces. Alternatively, multiple indoor units 11 can be installed in the same indoor space, exchanging heat with that space simultaneously to improve heat exchange efficiency. The specific choice can be made based on actual conditions, and this disclosure does not impose specific limitations.

[0044] For example, such as Figure 1 As shown, the indoor unit 11 includes an indoor heat exchanger 111 and a first electronic expansion valve 112 arranged in series. The indoor heat exchanger 111 has a first port 1111 and a second port 1112, and the first electronic expansion valve 112 is connected to the first port 1111 of the indoor heat exchanger 111.

[0045] Based on this, the heat pump system 100 also includes a compressor 2 and a condenser 3. The compressor 2 has an intake port 21 and an exhaust port 22, and the condenser 3 has an inlet port 31 and an outlet port 32. The intake port 21 of the compressor 2 is connected to the second port 1112 of the indoor heat exchanger 111, the exhaust port 22 of the compressor 2 is connected to the inlet port 31 of the condenser 3, and the outlet port 32 of the condenser 3 is connected to the first port 1111 of the indoor heat exchanger 111. A first electronic expansion valve 112 is installed on the pipeline between the indoor heat exchanger 111 and the condenser 3. In this configuration, when the heat pump system 100 is operating in cooling mode, the compressor 2, condenser 3, first electronic expansion valve 112, and indoor heat exchanger 111 can be sequentially connected to form a refrigeration cycle loop.

[0046] See Figure 2 , Figure 2 This diagram illustrates the refrigerant flow in the cooling mode of a heat pump system according to some embodiments of this application. In this case, the high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 22 of the compressor 2 flows into the condenser 3 through the inlet 31, where it condenses and releases heat, thus becoming liquid refrigerant. The liquid refrigerant flows out from the outlet 32 ​​of the condenser 3, and after being throttled and depressurized by the first electronic expansion valve 112, it flows into the indoor heat exchanger 111 through the first port 1111. After evaporating and absorbing heat in the indoor heat exchanger 111, the refrigerant flows out from the second port 1112 of the indoor heat exchanger 111, and flows into the compressor 2 through the suction port 21. Finally, the compressor 2 compresses and converts the refrigerant into a high-temperature, high-pressure gaseous refrigerant, which is then discharged through the exhaust port 22 of the compressor 2. In this way, the refrigerant circulation of the heat pump system 100 in cooling mode is completed, achieving the cooling of the indoor air.

[0047] The heat pump system 100 may include multiple compressors 2 connected in parallel, which helps to improve the heat exchange efficiency and heat exchange capacity of the heat pump system 100.

[0048] For example, compressor 2 is an oil-free compressor, which does not require the addition of lubricating oil to its cylinders. For instance, compressor 2 can be either a magnetic levitation compressor or an air-suspended centrifuge, and the specific choice can be made according to the actual situation. This disclosure does not impose any specific limitations on this.

[0049] Understandably, in traditional heat pump systems, the lubricating oil in the compressor cylinders enters the circulation loop along with the refrigerant. This allows the lubricating oil to easily adhere to the surfaces of the heat exchanger and condenser, forming an oil film. This lowers the evaporation temperature and raises the condensation temperature of the heat pump system, leading to reduced energy efficiency. Furthermore, because the indoor and outdoor heat exchangers in a heat pump system are typically installed at different heights, some lubricating oil may remain in the system piping and fail to return to the compressor, causing compressor oil return difficulties and potentially leading to compressor malfunctions.

[0050] Based on this, compared with traditional heat pump systems, the oil-free compressor used in this embodiment can improve the energy efficiency of the heat pump system 100 and reduce the risk of compressor 2 malfunction.

[0051] Among them, such as Figure 1 As shown, a shut-off check valve 4 can also be installed between the exhaust port 22 of the compressor 2 and the inlet port 31 of the condenser 3 to prevent refrigerant from flowing back into the compressor 2. Furthermore, in the case where the heat pump system 100 includes multiple compressors 2, there are multiple shut-off check valves 4, each shut-off check valve 4 is connected in series with one compressor 2 and in parallel with other compressors 2.

[0052] It should be noted that, as Figure 3 As shown, Figure 3 This is a structural diagram of a condenser provided in some embodiments of this application. The condenser 3 provided in the embodiments of this application can be an evaporative condenser. The evaporative condenser includes a housing 33, a water tank 34 is provided at the bottom of the housing 33, the water tank 34 is connected to a nozzle 36 at the top through a cooling water pump 35, a condensing coil 37 is provided below the nozzle 36, and an axial flow fan 38 is installed at the top of the housing 33.

[0053] In this configuration, the high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 22 of compressor 2 flows into the condenser coil 37 of condenser 3 through the air inlet 31. Meanwhile, water from water tank 34 is transported to the top nozzle 36 by cooling water pump 35, spraying water onto the condenser coil 37 to cool the refrigerant. During this process, the synchronously operating axial fan 38 disperses the sprayed water, ensuring even coverage of the condenser coil 37 surface and improving the heat exchange efficiency of condenser 3. Furthermore, some of the sprayed water vaporizes, absorbing a significant amount of heat, which is then discharged by the axial fan 38, further enhancing the heat exchange efficiency of condenser 3.

[0054] In some embodiments, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application. The heat pump system 100 also includes a first branch 5. One end of the first branch 5 is connected to the exhaust port 22 of the compressor 2, and the other end is connected to the second port 1112 of the indoor heat exchanger 111. In this way, the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 22 of the compressor 2 can flow to the indoor heat exchanger 111 through the first branch 5, and then flow into the indoor heat exchanger 111 through the second port 1112.

[0055] Based on this, the heat pump system 100 also includes an outdoor heat exchanger 6 and a second electronic expansion valve 7. The outdoor heat exchanger 6 has a refrigerant inlet 61 and a refrigerant outlet 62, with the refrigerant inlet 61 connected to the first port 1111 of the indoor heat exchanger 111, and the refrigerant outlet 62 connected to the suction port 21 of the compressor 2. The second electronic expansion valve 7 is disposed on the pipeline between the outdoor heat exchanger 6 and the indoor heat exchanger 111. In this manner, when the heat pump system 100 is operating in heating mode, the compressor 2, the indoor heat exchanger 111, the first electronic expansion valve 112, the second electronic expansion valve 7, and the outdoor heat exchanger 6 can be sequentially connected to form a heating circulation loop.

[0056] See Figure 5 , Figure 5This is a schematic diagram of the refrigerant flow in the heating mode of a heat pump system provided in some embodiments of this application. At this time, the high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 22 of the compressor 2 can flow into the indoor heat exchanger 111 through the second port 1112, where it condenses and releases heat, thus becoming liquid refrigerant. The liquid refrigerant flows out from the first port 1111 of the indoor heat exchanger 111, flows through the first electronic expansion valve 112, and after being throttled and depressurized by the second electronic expansion valve 7, it flows into the outdoor heat exchanger 6 through the refrigerant inlet 61. After evaporating and absorbing heat in the outdoor heat exchanger 6, the refrigerant flows out from the refrigerant outlet 62 of the outdoor heat exchanger 6, and flows into the compressor 2 through the suction port 21, where it is finally compressed by the compressor 2 into a high-temperature, high-pressure gaseous refrigerant, which is then discharged through the exhaust port 22 of the compressor 2. In this way, the refrigerant circulation of the heat pump system 100 in heating mode can be completed, thereby heating the indoor air.

[0057] For example, such as Figure 6 As shown, Figure 6 This is a structural diagram of an outdoor heat exchanger provided in some embodiments of this application. The outdoor heat exchanger 6 includes a first heat exchange flow path and a second heat exchange flow path that exchange heat with each other. The two ends of the first heat exchange flow path are the refrigerant inlet 61 and the refrigerant outlet 62 of the outdoor heat exchanger 6, respectively, and the two ends of the second heat exchange flow path are the cold water inlet 63 and the cold water outlet 64, respectively.

[0058] It is understandable that the refrigerant in the first heat exchange path can absorb the heat from the cold water in the second heat exchange path and then evaporate into gaseous refrigerant.

[0059] The outdoor heat exchanger 6 can be either a plate heat exchanger or a shell-and-tube heat exchanger. The choice can be made based on the actual situation, and this disclosure does not impose any specific restrictions.

[0060] For example, the outdoor heat exchanger 6 is a shell-and-tube heat exchanger. It is understood that shell-and-tube heat exchangers have high heat exchange efficiency.

[0061] The heat pump system 100 provided in this embodiment includes a compressor 2, a condenser 3, an indoor heat exchanger 111, a first electronic expansion valve 112, a first branch 5, an outdoor heat exchanger 6, and a second electronic expansion valve 7. The compressor 2, condenser 3, first electronic expansion valve 112, and indoor heat exchanger 111 are sequentially connected to form a refrigeration cycle, thereby cooling the indoor air through the indoor heat exchanger 111. The compressor 2, indoor heat exchanger 111, first electronic expansion valve 112, second electronic expansion valve 7, and outdoor heat exchanger 6 are sequentially connected to form a heating cycle, thereby heating the indoor air through the indoor heat exchanger 111. Thus, the cooling and heating needs of indoor air can be met simultaneously. Furthermore, by simply adding the first branch 5, outdoor heat exchanger 6, and second electronic expansion valve 7 to the heat pump system 100 in the related art, the system can be upgraded to simultaneously possess the ability to cool and heat indoor air, which helps to reduce costs.

[0062] In some embodiments, such as Figure 5 As shown, the heat pump system 100 also includes a liquid receiver 8, which is disposed on the pipeline between the condenser 3 and the first electronic expansion valve 112. At this time, when the heat pump system 100 is operating in cooling mode, the compressor 2, condenser 3, liquid receiver 8, first electronic expansion valve 112 and indoor heat exchanger 111 are sequentially connected to form a cooling cycle loop.

[0063] It is understandable that by setting up the liquid storage tank 8, when the pressure in the refrigeration cycle loop changes, the liquid storage tank 8 can release or store a portion of the refrigerant, so that the amount of refrigerant in the refrigeration cycle loop matches the operating conditions of the heat pump system 100, thereby improving the stability of the heat pump system 100.

[0064] Based on this, the liquid storage tank 8 is also installed on the pipeline between the indoor heat exchanger 111 and the second electronic expansion valve 7. At this time, when the heat pump system 100 is operating in heating mode, the compressor 2, the indoor heat exchanger 111, the first electronic expansion valve 112, the liquid storage tank 8, the second electronic expansion valve 7, and the outdoor heat exchanger 6 are connected in sequence to form a heating circulation loop.

[0065] Similarly, by setting up a liquid storage tank 8, when the pressure in the heating cycle loop changes, the liquid storage tank 8 can release or store a portion of the refrigerant, so that the amount of refrigerant in the heating cycle loop matches the operating conditions of the heat pump system 100, thereby improving the stability of the heat pump system 100.

[0066] It should be noted that, as Figure 5As shown, the heat pump system 100 may further include a gas-liquid separator 9, which is disposed on the pipeline between the indoor heat exchanger 111 and the compressor 2. In this case, when the heat pump system 100 is operating in cooling mode, the compressor 2, condenser 3, liquid receiver 8, first electronic expansion valve 112, indoor heat exchanger 111 and gas-liquid separator 9 are sequentially connected to form a refrigeration cycle loop.

[0067] Based on this, the gas-liquid separator 9 is also installed on the pipeline between the outdoor heat exchanger 6 and the compressor 2. At this time, when the heat pump system 100 is operating in heating mode, the compressor 2, indoor heat exchanger 111, first electronic expansion valve 112, liquid storage tank 8, second electronic expansion valve 7, outdoor heat exchanger 6 and gas-liquid separator 9 are connected in sequence to form a heating circulation loop.

[0068] Understandably, the gas-liquid separator 9 separates and stores the liquid refrigerant, allowing the gaseous refrigerant to flow to the compressor 2. This reduces the risk of liquid slugging in the compressor 2, thereby reducing the risk of damage to the compressor 2.

[0069] In some embodiments, such as Figure 7 As shown, Figure 7 This is a schematic diagram of the composition of a heat pump system provided in some embodiments of this application. A first interface 101 is provided on the pipeline between the compressor 2 and the condenser 3. A second interface 102, a third interface 103, and a fourth interface 104 are provided on the pipeline between the condenser 3 and the first electronic expansion valve 112, wherein the third interface 103 is located between the second interface 102 and the fourth interface 104, and the second interface 102 is located between the third interface 103 and the air outlet 32 ​​of the condenser 3. A fifth interface 105 and a sixth interface 106 are provided on the pipeline between the indoor heat exchanger 111 and the compressor 2, and the sixth interface 106 is located between the fifth interface 105 and the air intake 21 of the compressor 2.

[0070] Based on this, one end of the first branch 5 is connected to the first interface 101, and the other end is connected to the fifth interface 105. The refrigerant inlet 61 of the outdoor heat exchanger 6 is connected to the third interface 103, and the refrigerant outlet 62 is connected to the sixth interface 106. The second electronic expansion valve 7 is installed on the pipeline between the refrigerant inlet 61 and the third interface 103 of the outdoor heat exchanger 6. The heat pump system 100 also includes a second branch 20, one end of which is connected to the second interface 102, and the other end is connected to the fourth interface 104.

[0071] In this case, the heat pump system 100 may also include a plurality of first control valves 30 and a plurality of second control valves 40.

[0072] For example, a first control valve 30 is provided on the pipeline between the first interface 101 and the air inlet 31 of the condenser 3, the pipeline between the second interface 102 and the air outlet 32 ​​of the condenser 3, the pipeline between the third interface 103 and the fourth interface 104, and the pipeline between the fifth interface 105 and the sixth interface 106. A second control valve 40 is provided on the first branch 5, the second branch 20, and the pipeline between the third interface 103 and the refrigerant inlet 61 of the outdoor heat exchanger 6.

[0073] With this configuration, by simply controlling the opening of multiple first control valves 30 and the closing of multiple second control valves 40, the compressor 2, condenser 3, first electronic expansion valve 112, and indoor heat exchanger 111 can be sequentially connected to form a refrigeration cycle loop, thereby enabling the heat pump system 100 to operate in cooling mode. Conversely, by simply controlling the closing of multiple first control valves 30 and the opening of multiple second control valves 40, the compressor 2, indoor heat exchanger 111, first electronic expansion valve 112, second electronic expansion valve 7, and outdoor heat exchanger 6 can be sequentially connected to form a heating cycle loop, thereby enabling the heat pump system 100 to operate in heating mode.

[0074] In this case, the liquid storage tank 8 can be installed on the pipeline between the second interface 102 and the third interface 103, and the gas-liquid separator 9 can be installed on the pipeline between the sixth interface 106 and the suction port 21 of the compressor 2.

[0075] The heat pump system 100 may also include a dryer filter 50, which is installed on the pipeline between the liquid storage tank 8 and the third interface 103. By installing the dryer filter 50, moisture in the system can be absorbed and impurities in the system can be blocked, thereby preventing ice blockage and dirt blockage in the system pipeline and improving the stability of the heat pump system 100.

[0076] It should be noted that, see Figure 8 , Figure 8 This is a schematic diagram illustrating the composition of a heat pump system provided in some embodiments of this application. The heat pump system 100 may further include an economizer 60 and a gas supply branch 70, and the compressor 2 also has a gas supply port 23. One end of the gas supply branch 70 is connected to the gas supply port 23 of the compressor 2, and the other end is connected to the pipeline between the dryer filter 50 and the third interface 103. The economizer 60 has a third heat exchange flow path 601 and a fourth heat exchange flow path 602 that exchange heat with each other. The third heat exchange flow path 601 is connected in series in the pipeline between the dryer filter 50 and the third interface 103, and the fourth heat exchange flow path 602 is connected in series in the gas supply branch 70.

[0077] Based on this, a throttling device 80 is also provided on the gas supply branch 70, and the throttling device 80 is located at the end of the fourth heat exchange flow path 602 away from the gas supply port 23 of the compressor 2.

[0078] In this configuration, the refrigerant flowing from the storage tank 8, after being dried and filtered by the dryer filter 50, partially enters the third heat exchange path 601 of the economizer 60, while the other part, after being throttled and depressurized by the throttling device 80, enters the first heat exchange path of the economizer 60. The heat from the refrigerant in the third heat exchange path 601 is absorbed by the refrigerant in the fourth heat exchange path 602, resulting in subcooling of the refrigerant in the third heat exchange path 601. This increases the cooling capacity of the heat pump system 100, thereby improving its energy efficiency. Simultaneously, the refrigerant in the fourth heat exchange path 602, after absorbing heat from the refrigerant in the third heat exchange path 601, transforms into a gaseous state and enters the compressor 2 through the air inlet 23, thus replenishing the compressor 2 with gas.

[0079] This application also provides a control method for a heat pump system, used to control the aforementioned heat pump system. For example... Figure 9 As shown, Figure 9 This is a flowchart illustrating a control method for a heat pump system provided in some embodiments of this application. The control method may include the following steps:

[0080] S101. Obtain the cooling and heating requirements of the indoor heat exchanger.

[0081] It should be noted that the cooling and heating demand of the indoor heat exchanger refers to the need for cooling or heating in the space where the indoor heat exchanger is located.

[0082] S102. If the indoor heat exchanger needs to provide heat, control the heat pump system to operate in heating mode.

[0083] S103. Adjust the opening of the first electronic expansion valve to the first preset opening, adjust the opening of the second electronic expansion valve to the second preset opening, and maintain it for a preset time.

[0084] The first preset opening degree can be the maximum opening degree of the first electronic expansion valve, and the second preset opening degree can be one-fifth, one-quarter, one-third, two-fifths, one-half, three-fifths, two-thirds, three-quarters, four-fifths, etc. of the second electronic expansion valve. The specific selection can be made according to the actual situation, and this disclosure does not impose specific limitations on it.

[0085] Understandably, maintaining the first electronic expansion valve to the first preset opening and the second electronic expansion valve to the second preset opening for a preset time allows sufficient reaction time for the heat pump system, facilitating its stabilization and enabling precise control of the refrigerant flow rate in the system.

[0086] S104. Obtain the actual liquid level value of the storage tank.

[0087] For example, the heat pump system also includes a liquid level detection device for detecting the liquid level in the storage tank. This allows the actual liquid level in the storage tank to be easily obtained through the liquid level detection device.

[0088] S105. Adjust the opening of the second electronic expansion valve according to the actual liquid level.

[0089] For example, if the actual liquid level is greater than the preset liquid level, the opening of the second electronic expansion valve is increased; if the actual liquid level is less than the preset liquid level, the opening of the second electronic expansion valve is decreased.

[0090] It should be noted that the preset liquid level value can be selected according to the actual situation, and this disclosure does not impose specific limitations on it.

[0091] Understandably, adjusting the opening of the second electronic expansion valve based on the actual liquid level in the storage tank can initially regulate the refrigerant flow rate in the heat pump system, allowing it to quickly match the current operating conditions of the heat pump system. This helps reduce the energy consumption and improve the energy efficiency of the heat pump system.

[0092] The heat pump system control method provided in this application allows the heat pump system to switch to heating mode when the indoor heat exchanger needs heating, enabling the system to operate in heating mode and thus heat the indoor air through the indoor heat exchanger. It is understood that the refrigerant demand differs between cooling and heating modes. After switching the heat pump system to heating mode, adjusting the first electronic expansion valve to a first preset opening and the second electronic expansion valve to a second preset opening, and maintaining this position for a preset time, helps match the refrigerant flow rate in the system with the heating conditions. At this time, adjusting the opening of the second electronic expansion valve based on the actual liquid level in the storage tank can quickly change the refrigerant flow rate in the system to match the operating conditions of the heat pump system, thereby improving the energy efficiency of the heat pump system.

[0093] In some embodiments, see continue to see Figure 9 Following S105, the following steps are also included:

[0094] S106. Obtain the temperature and pressure at the compressor intake port.

[0095] For example, a temperature sensor and a pressure sensor are provided at the compressor's suction port to detect the temperature and pressure at the compressor's suction port. In this way, the temperature and pressure at the compressor's suction port can be easily obtained.

[0096] S107. Obtain the compressor's suction superheat based on the temperature and pressure at the compressor's suction port.

[0097] S108. Adjust the opening degree of the second electronic expansion valve according to the superheat of the compressor's suction.

[0098] For example, if the compressor's suction superheat is greater than the target superheat, the opening of the second electronic expansion valve is increased; if the compressor's suction superheat is less than the target superheat, the opening of the second electronic expansion valve is decreased.

[0099] It should be noted that the target overheat level can be selected according to the actual situation, and this disclosure does not impose specific restrictions on it.

[0100] Understandably, adjusting the opening of the second electronic expansion valve based on the compressor's suction superheat allows for precise regulation of the refrigerant flow rate in the heat pump system, ensuring a better match between the refrigerant flow rate and the current operating conditions of the heat pump system. This, in turn, helps to further reduce the energy consumption of the heat pump system, thereby further improving its energy efficiency.

[0101] In some embodiments, such as Figure 10 As shown, Figure 10 This is a flowchart illustrating a control method for a heat pump system provided in some embodiments of this application. Following step S101, the method further includes the following steps:

[0102] S201. If the indoor heat exchanger needs cooling, control the heat pump system to operate in cooling mode.

[0103] S202. Adjust the opening of the first electronic expansion valve to the third preset opening.

[0104] The third preset opening degree can be one-fifth, one-quarter, one-third, two-fifths, one-half, three-fifths, two-thirds, three-quarters, four-fifths, etc. of the first electronic expansion valve. The specific opening degree can be selected according to the actual situation, and this disclosure does not make specific limitations on it.

[0105] S203. Obtain the temperature and pressure at the first port of the indoor heat exchanger.

[0106] For example, a temperature sensor and a pressure sensor are provided at the first port of the indoor heat exchanger to detect the temperature and pressure at the first port of the indoor heat exchanger. In this way, the temperature and pressure at the first port of the indoor heat exchanger can be easily obtained.

[0107] S204. Obtain the superheat of the indoor heat exchanger based on the temperature and pressure at the first port of the indoor heat exchanger.

[0108] S205. Adjust the opening degree of the first electronic expansion valve according to the superheat of the indoor heat exchanger.

[0109] For example, if the superheat of the indoor heat exchanger is greater than the preset superheat, the opening of the first electronic expansion valve is increased; if the superheat of the indoor heat exchanger is less than the preset superheat, the opening of the first electronic expansion valve is decreased.

[0110] Understandably, adjusting the opening of the first electronic expansion valve based on the superheat of the indoor heat exchanger allows for precise regulation of the refrigerant flow rate in the heat pump system, ensuring that the refrigerant flow rate matches the current operating conditions of the heat pump system. This helps reduce the energy consumption of the heat pump system, thereby improving its energy efficiency.

[0111] In some embodiments, such as Figure 11 As shown, Figure 11 This is a flowchart illustrating a control method for a heat pump system provided in some embodiments of this application. The control method further includes the following steps:

[0112] S301, Obtain the pressure inside the gas-liquid separator.

[0113] For example, a pressure sensor is provided on the gas-liquid separator to detect the pressure inside the gas-liquid separator. In this way, the pressure inside the gas-liquid separator can be easily obtained.

[0114] S302. Calculate the actual pressure difference based on the pressure inside the gas-liquid separator.

[0115] The actual pressure difference is the difference between the pressure inside the gas-liquid separator and the preset pressure.

[0116] S303. If the actual pressure difference is greater than the target pressure difference, adjust and increase the operating frequency of the compressor; if the actual pressure difference is less than the target pressure difference, adjust and decrease the operating frequency of the compressor.

[0117] In other words, if the actual pressure difference is greater than the target pressure difference, the compressor load is increased; if the actual pressure difference is less than the target pressure difference, the compressor load is decreased. This allows the compressor's operating state to match the current operating conditions of the heat pump system, thereby reducing system energy consumption and improving system energy efficiency.

[0118] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0119] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection described in the claims.

Claims

1. A heat pump system, characterized in that, include: The compressor has an intake port and an exhaust port; A condenser having an air inlet and an air outlet, wherein the air inlet is connected to the air outlet; An indoor heat exchanger having a first port and a second port; The first port is connected to the air outlet, and the second port is connected to the air inlet; A first electronic expansion valve is installed on the pipeline between the indoor heat exchanger and the condenser; The first branch has one end connected to the exhaust port and the other end connected to the second port; An outdoor heat exchanger has a refrigerant inlet and a refrigerant outlet; the refrigerant inlet is connected to the first port, and the refrigerant outlet is connected to the air intake. The second electronic expansion valve is installed on the pipeline between the outdoor heat exchanger and the indoor heat exchanger; When the heat pump system is operating in cooling mode, the compressor, the condenser, the first electronic expansion valve, and the indoor heat exchanger are connected in sequence to form a cooling cycle loop; When the heat pump system is operating in heating mode, the compressor, the indoor heat exchanger, the first electronic expansion valve, the second electronic expansion valve, and the outdoor heat exchanger are sequentially connected to form a heating circulation loop.

2. The heat pump system according to claim 1, characterized in that, Also includes: A liquid storage tank is provided on the pipeline between the condenser and the first electronic expansion valve, and also on the pipeline between the indoor heat exchanger and the second electronic expansion valve; When the heat pump system is operating in cooling mode, the compressor, the condenser, the liquid storage tank, the first electronic expansion valve, and the indoor heat exchanger are sequentially connected to form the cooling cycle loop; When the heat pump system is operating in heating mode, the compressor, the indoor heat exchanger, the first electronic expansion valve, the liquid storage tank, the second electronic expansion valve, and the outdoor heat exchanger are sequentially connected to form the heating cycle loop.

3. The heat pump system according to claim 2, characterized in that, Also includes: A gas-liquid separator is installed on the pipeline between the indoor heat exchanger and the compressor, and also on the pipeline between the outdoor heat exchanger and the compressor; When the heat pump system is operating in cooling mode, the compressor, the condenser, the liquid storage tank, the first electronic expansion valve, the indoor heat exchanger, and the gas-liquid separator are sequentially connected to form the refrigeration cycle loop; When the heat pump system is operating in heating mode, the compressor, the indoor heat exchanger, the first electronic expansion valve, the liquid storage tank, the second electronic expansion valve, the outdoor heat exchanger, and the gas-liquid separator are sequentially connected to form the heating cycle loop.

4. A control method for a heat pump system, used to control the heat pump system according to claim 2 or 3, characterized in that, include: Obtain the cooling and heating requirements of the indoor heat exchanger; If the indoor heat exchanger requires heating, then control the heat pump system to operate in heating mode; Adjust the opening of the first electronic expansion valve to a first preset opening, adjust the opening of the second electronic expansion valve to a second preset opening, and maintain the position for a preset time; Obtain the actual liquid level value of the storage tank; Adjust the opening of the second electronic expansion valve according to the actual liquid level value.

5. The control method for a heat pump system according to claim 4, characterized in that, The adjustment of the opening degree of the second electronic expansion valve according to the actual liquid level value specifically includes: If the actual liquid level is greater than the preset liquid level, the opening of the second electronic expansion valve is increased. If the actual liquid level is less than the preset liquid level, the opening of the second electronic expansion valve is adjusted to decrease.

6. The control method for a heat pump system according to claim 4 or 5, characterized in that, After adjusting the opening of the second electronic expansion valve according to the actual liquid level value, the method further includes: The temperature and pressure at the compressor's intake port are obtained; The suction superheat of the compressor is obtained based on the temperature and pressure at the compressor intake port. The opening degree of the second electronic expansion valve is adjusted according to the suction superheat of the compressor.

7. The control method for a heat pump system according to claim 6, characterized in that, The adjustment of the opening degree of the second electronic expansion valve according to the suction superheat of the compressor specifically includes: If the suction superheat of the compressor is greater than the target superheat, then the opening of the second electronic expansion valve is increased. If the suction superheat of the compressor is less than the target superheat, the opening of the second electronic expansion valve is adjusted to decrease.

8. The control method for a heat pump system according to claim 4, characterized in that, After obtaining the cooling and heating requirements of the indoor heat exchanger, the method further includes: If the indoor heat exchanger requires cooling, then control the heat pump system to operate in cooling mode; Adjust the opening of the first electronic expansion valve to the third preset opening; Obtain the temperature and pressure at the first port of the indoor heat exchanger; The superheat of the indoor heat exchanger is obtained based on the temperature and pressure at the first port of the indoor heat exchanger. Adjust the opening degree of the first electronic expansion valve according to the superheat of the indoor heat exchanger.

9. The control method for a heat pump system according to claim 8, characterized in that, The specific steps of adjusting the opening of the first electronic expansion valve according to the superheat of the indoor heat exchanger include: If the superheat of the indoor heat exchanger is greater than the preset superheat, then the opening of the first electronic expansion valve is increased. If the superheat of the indoor heat exchanger is less than the preset superheat, the opening of the first electronic expansion valve is adjusted to decrease.

10. The control method for a heat pump system according to claim 4, characterized in that, The heat pump system also includes a gas-liquid separator, which is installed on the pipeline between the indoor heat exchanger and the compressor, and on the pipeline between the outdoor heat exchanger and the compressor; The control method further includes: Obtain the pressure inside the gas-liquid separator; The actual pressure difference is calculated based on the pressure inside the gas-liquid separator; wherein, the actual pressure difference is the difference between the pressure inside the gas-liquid separator and the preset pressure; If the actual pressure difference is greater than the target pressure difference, then the operating frequency of the compressor is increased. If the actual pressure difference is less than the target pressure difference, the operating frequency of the compressor is adjusted to decrease.

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