Heat pump system

Abstract

The utility model discloses a heat pump system which comprises a first refrigerant system and a second refrigerant system, and the first refrigerant system comprises a first compressor, a first condenser, a first throttling device, a first evaporation pipeline and a first auxiliary evaporation pipeline which are sequentially connected to form a loop. The second refrigerant system comprises a second compressor, a second auxiliary condensation pipeline, a second throttling device and a second heat exchange pipeline which are sequentially connected to form a loop; wherein the first auxiliary evaporation pipeline and the second auxiliary evaporation pipeline form an auxiliary heat exchanger. Therefore, the first compressor can work independently to achieve work of the first condenser, the first compressor and the second compressor can work at the same time, and the heating capacity of the first condenser is improved. According to the heat pump system, on one hand, energy consumption is effectively reduced, and on the other hand, comprehensive energy efficiency of the system can be improved.

Description

Technical Field

[0001] This utility model relates to the field of heat pump system technology, and in particular to a cascade heat pump system. Background Technology

[0002] A cascade heat pump system typically consists of two independent systems: a high-temperature stage and a low-temperature stage. The high-temperature stage uses a high-temperature refrigerant, while the low-temperature stage uses a different refrigerant with a lower evaporation temperature. The cooling capacity of the refrigerant evaporating in the high-temperature stage serves as the condensing heat of the refrigerant in the low-temperature stage. This cycle is completed in a condenser-evaporator, which acts as both the evaporator for the high-temperature refrigerant and the condenser for the low-temperature refrigerant.

[0003] Existing cascade heat pump systems have the following problems: 1. When there is a demand for hot water, the high-temperature stage unit starts operating. Since the evaporator of the high-temperature stage unit is the condenser of the low-temperature refrigerant, the low-temperature stage unit must also operate. The compressors of both systems operate simultaneously, resulting in high energy consumption. 2. The condenser of the low-temperature stage unit acts as the evaporator of the high-temperature stage, but the evaporator of the low-temperature stage may not be effectively utilized, leading to low overall energy efficiency of the heat pump system.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0005] This invention proposes a heat pump system that solves the technical problem of high energy consumption caused by the requirement for the low-temperature unit to operate while the high-temperature unit of the existing cascade heat pump system is running.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0007] A heat pump system, comprising:

[0008] First refrigerant system;

[0009] Second refrigerant system;

[0010] The first refrigerant system includes a first compressor, a first condenser, a first throttling device, and a first evaporator pipe connected in sequence to form a circuit;

[0011] The second refrigerant system includes a second compressor, a second auxiliary condenser pipe, a second throttling device, and a second heat exchange pipe connected in sequence to form a circuit;

[0012] The first refrigerant system also includes:

[0013] The first auxiliary evaporation pipe is connected between the suction port of the first compressor and the first evaporation pipe;

[0014] The first auxiliary evaporation pipeline and the second auxiliary condensation pipeline together form an auxiliary heat exchanger.

[0015] The above technical solution has the following advantages or beneficial effects: The heat pump system includes a first refrigerant system and a second refrigerant system. The first refrigerant system includes a first compressor, a first condenser, a first throttling device, a first evaporator pipe, and a first auxiliary evaporator pipe connected in sequence to form a loop. The second refrigerant system includes a second compressor, a second auxiliary condenser pipe, a second throttling device, and a second heat exchanger pipe connected in sequence to form a loop. The first and second auxiliary evaporator pipes together form an auxiliary heat exchanger. Therefore, the first compressor can operate independently to operate the first condenser, and the first and second compressors can operate simultaneously to improve the heating capacity of the first condenser. The heat pump system effectively reduces energy consumption and improves the overall energy efficiency of the system.

[0016] In some embodiments, the auxiliary heat exchanger is a plate heat exchanger or a shell-and-tube heat exchanger;

[0017] And / or, the first condenser is a plate heat exchanger or a shell-and-tube heat exchanger.

[0018] The above technical solution has the following advantages or beneficial effects: the auxiliary heat exchanger is set as a plate heat exchanger or a shell-and-tube heat exchanger, and the second refrigerant system acts on the first refrigerant system through the plate heat exchanger or the shell-and-tube heat exchanger.

[0019] The first condenser is a plate heat exchanger or a shell-and-tube heat exchanger, through which the heat output of the first condenser is realized.

[0020] In some embodiments, the first condenser is connected to a water pipe, and a water pump is installed on the water pipe.

[0021] The above technical solution has the following advantages or beneficial effects: by using water pipes and water pumps to output heat from the first condenser, the function of producing domestic hot water can be realized.

[0022] In some embodiments, the first evaporation pipe and the second heat exchange pipe share heat exchange fins.

[0023] The above technical solution has the following advantages or beneficial effects: the first evaporation pipe and the second heat exchange pipe share heat exchange fins, which can save space and energy, and improve the evaporation capacity of the first evaporation pipe and the condensation capacity of the second heat exchange pipe when the second heat exchange pipe realizes the condensation function.

[0024] In some embodiments, the heat pump system includes an outdoor fan, and the first evaporation pipe and the second heat exchange pipe share the outdoor fan.

[0025] The above technical solution has the following advantages or beneficial effects: the first evaporation pipe and the second heat exchange pipe share an outdoor fan, which can save space and energy. Furthermore, when the first compressor is turned on alone, the outdoor fan can be used to dissipate heat from the first evaporation pipe without turning on the second compressor, thus achieving energy saving.

[0026] In some embodiments, the second refrigerant circulation system includes:

[0027] A four-way valve, wherein the first port of the four-way valve is connected to the exhaust port of the second compressor, the third port of the four-way valve is connected to the suction port of the second compressor, and the fourth port of the four-way valve is connected to the second heat exchange pipeline.

[0028] An indoor heat exchanger is connected to the second throttling device and to the second port of the four-way valve via a switching device.

[0029] The second auxiliary condensing line is connected to the exhaust port of the second compressor via a second switching device; the second auxiliary condensing line is connected to the second throttling device via an electronic expansion valve.

[0030] The above technical solution has the following advantages or beneficial effects: the second refrigerant system of the heat pump system is equipped with an indoor heat exchanger, so that all the heat exchangers of the second refrigerant system can be effectively utilized. The indoor heat exchanger can realize the functions of cooling and heating. When the indoor heat exchanger has no cooling or heating demand, the first refrigerant system can still operate, which reduces energy consumption and improves the overall energy efficiency of the entire system.

[0031] In some embodiments, the second switching device is a second four-way valve, the first port of the second four-way valve is connected to the exhaust port of the second compressor, the second port of the second four-way valve is connected to the second auxiliary condenser pipe, the third port of the second four-way valve is connected to the suction port of the second compressor and the third port of the four-way valve, and the fourth port of the second four-way valve is connected to the suction port of the second compressor through a fourth switching device.

[0032] The above technical solution has the following advantages or beneficial effects: the second four-way valve can selectively conduct the high-temperature and high-pressure refrigerant of the second compressor to exchange heat with the auxiliary heat exchanger according to the demand.

[0033] In some embodiments, the heat pump system includes:

[0034] Indoor unit, including the indoor heat exchanger;

[0035] The first outdoor unit includes the first compressor, the first condenser, and the auxiliary heat exchanger;

[0036] The second outdoor unit includes the second compressor, the first evaporation pipe, the second heat exchange pipe, the first four-way valve, and the second four-way valve.

[0037] The above technical solution has the following advantages or beneficial effects: dividing the heat pump system into two outdoor units and one indoor unit facilitates transportation, installation and disassembly.

[0038] In some embodiments, the indoor unit includes a switching device; the first outdoor unit includes a first throttling device; and the second outdoor unit includes a second throttling device and an electronic expansion valve.

[0039] The above technical solution has the following advantages or beneficial effects: the switching device and the throttling device are installed in the associated outdoor unit or indoor unit to facilitate control.

[0040] In some embodiments, the indoor unit is connected to the second outdoor unit via a shut-off valve, and the second outdoor unit is connected to the first outdoor unit via a shut-off valve.

[0041] The above technical solution has the following advantages or beneficial effects: the indoor unit is connected to the second outdoor unit, and the second outdoor unit is connected to the first outdoor unit through a shut-off valve, which facilitates the installation and disassembly of the heat pump system.

[0042] Other features and advantages of this utility model will become clearer after reading the detailed embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of a heat pump system according to an embodiment.

[0045] Figure 2 This is a schematic diagram of the circulation process for producing low-temperature hot water using a heat pump system according to an embodiment.

[0046] Figure 3 This is a schematic diagram of the circulation process for producing high-temperature hot water using a heat pump system according to an embodiment.

[0047] Figure 4 This is a schematic diagram of a heat pump system according to another embodiment.

[0048] Figure 5 This is a schematic diagram of a low-temperature hot water indoor cooling cycle according to another embodiment.

[0049] Figure 6 This is a schematic diagram of a high-temperature hot water indoor cooling cycle according to another embodiment.

[0050] Figure 7 This is a schematic diagram of a low-temperature hot water indoor heating cycle according to another embodiment.

[0051] Figure 8 This is a schematic diagram of a high-temperature hot water indoor heating cycle according to another embodiment.

[0052] Figure 9 This is a schematic diagram of a low-temperature hot water circulation system according to another embodiment.

[0053] Figure 10 This is a schematic diagram of the circulation of high-temperature hot water according to another embodiment.

[0054] In the picture:

[0055] 11. First compressor; 12. First condenser; 121. Water pipeline; 122. Water pump; 13. First throttling device; 14. First evaporator pipeline; 15. First auxiliary evaporator pipeline; 1522. Auxiliary heat exchanger.

[0056] 21. Second compressor; 22. Second auxiliary condenser piping; 23. Second throttling device; 24. Second heat exchange piping; 25. Four-way valve; 26. Second switching device; 27. Electronic expansion valve; 28. Fourth switching device;

[0057] 3. Indoor heat exchanger; 31. Switching device. Detailed Implementation

[0058] 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.

[0059] 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.

[0060] 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.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal conduction of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0062] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0063] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes or the use of other materials.

[0064] A refrigerant cycle system executes a refrigeration cycle using a compressor, condenser, throttling device, and evaporator. The refrigeration cycle involves a series of processes, including compression, condensation, expansion, and evaporation, to cool or heat an indoor space.

[0065] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0066] The throttling device expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the throttling device and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled.

[0067] To improve the capacity of the heat pump system, a cascade heat pump system is implemented using two refrigerant systems.

[0068] exist Figure 1 In this example, the heat pump system includes a first refrigerant system and a second refrigerant system.

[0069] The first refrigerant system includes a first compressor 11, a first condenser 12, a first throttling device 13, a first evaporator pipe 14, and a first auxiliary evaporator pipe 15, which are connected in sequence to form a circuit.

[0070] The first auxiliary evaporation pipe 15 is connected between the suction port of the first compressor 11 and the first evaporation pipe 14, and the first auxiliary evaporation pipe 15 is connected between the outlet of the first evaporation pipe 14 and the suction port of the first compressor 11.

[0071] That is, the refrigerant flow direction of the first refrigerant system is: first compressor 11, first condenser 12, first throttling device 13, first evaporator pipe 14, first auxiliary evaporator pipe 15, and first compressor 11.

[0072] The second refrigerant system includes a second compressor 21, a second auxiliary condenser pipe 22, a second throttling device 23, and a second heat exchange pipe 24 connected in sequence to form a circuit.

[0073] That is, the refrigerant flow direction of the second refrigerant system is: second compressor 21, second auxiliary condenser pipe 22, second throttling device 23, second heat exchange pipe 24, and second compressor 21.

[0074] The first auxiliary evaporation pipe 15 and the second auxiliary condensation pipe 22 together form an auxiliary heat exchanger 1522.

[0075] The heat pump system includes a first refrigerant system and a second refrigerant system. The first refrigerant system includes a first compressor 11, a first condenser 12, a first throttling device 13, a first evaporator pipe 14, and a first auxiliary evaporator pipe 15, connected in sequence to form a loop. The second refrigerant system includes a second compressor 21, a second auxiliary condenser pipe 22, a second throttling device 23, and a second heat exchanger pipe 24, connected in sequence to form a loop. The first auxiliary evaporator pipe 15 and the second auxiliary condenser pipe 22 form an auxiliary heat exchanger 1522. Therefore, the first compressor 11 can operate independently to heat the first condenser 12, and the first compressor 11 and the second compressor 21 can operate simultaneously to improve the heating capacity of the first condenser 12. The heat pump system effectively reduces energy consumption and improves the overall energy efficiency of the system.

[0076] When the first compressor 11 operates alone, the heating temperature of the first condenser 12 is the first temperature; when the first compressor 11 and the second compressor 21 operate simultaneously, the heating temperature of the first condenser 12 is the second temperature; the first temperature is lower than the second temperature.

[0077] That is, when the first compressor 11 works alone, the first condenser 12 achieves low-temperature heating; when the first compressor 11 and the second compressor 21 work simultaneously, the first condenser 12 achieves high-temperature heating.

[0078] In some embodiments, the first refrigerant system uses a high-temperature refrigerant, and the second refrigerant system uses a low-temperature refrigerant.

[0079] In some embodiments, the auxiliary heat exchanger 1522 is a plate heat exchanger or a shell-and-tube heat exchanger.

[0080] The auxiliary heat exchanger 1522 is set as a plate heat exchanger or a shell-and-tube heat exchanger, and the second refrigerant system enhances the heating effect of the first refrigerant system through the plate heat exchanger or the shell-and-tube heat exchanger.

[0081] In some embodiments, the first condenser 12 is a plate heat exchanger or a shell-and-tube heat exchanger.

[0082] The first condenser 12 is a plate heat exchanger or a shell-and-tube heat exchanger, through which the heat output of the first condenser 12 is realized.

[0083] In some embodiments, the auxiliary heat exchanger 1522 is a plate heat exchanger or a shell-and-tube heat exchanger, and the first condenser 12 is a plate heat exchanger or a shell-and-tube heat exchanger.

[0084] In some embodiments, the first condenser 12 is connected to a water pipe 121, and a water pump 122 is installed on the water pipe 121.

[0085] The heat output of the first condenser 12 is achieved through water pipe 121 and water pump 122, which enables the production of domestic hot water.

[0086] In some embodiments, the first evaporation pipe 14 and the second heat exchange pipe 24 share heat exchange fins.

[0087] The first evaporation pipe 14 and the second heat exchange pipe 24 share heat exchange fins to form a finned heat exchanger.

[0088] In some embodiments, the first evaporation pipe 14 is located below the second heat exchange pipe 24.

[0089] The first evaporation pipe 14 and the second heat exchange pipe 24 share heat exchange fins, which can save space and energy. When the second heat exchange pipe 24 performs the condensation function, it can improve the evaporation capacity of the first evaporation pipe 14, thereby improving the condensation capacity of the second heat exchange pipe 24.

[0090] In some embodiments, the heat exchange area of ​​the second heat exchange pipe 24 is greater than the heat exchange area of ​​the first evaporation pipe 14.

[0091] In some embodiments, the heat pump system includes an outdoor fan (not shown in the figure), and the first evaporation pipe 14 and the second heat exchange pipe 24 share the outdoor fan.

[0092] The first evaporation pipe 14 and the second heat exchange pipe 24 share an outdoor fan, which can save space and energy. Furthermore, when the first compressor 11 is turned on alone, the outdoor fan can dissipate heat from the first evaporation pipe 14 without turning on the second compressor 21, thus achieving energy saving.

[0093] Heat pump systems can produce both low-temperature and high-temperature hot water.

[0094] exist Figure 2 In the example, when the heat pump system produces low-temperature hot water, the first compressor 11 runs, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15, completing one refrigerant cycle.

[0095] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0096] The first evaporator pipe 14 provides cooling, and the first evaporator pipe 14 dissipates heat through an outdoor fan.

[0097] The first auxiliary evaporator pipe 15 provides cooling. At this time, the first auxiliary evaporator pipe 15 dissipates heat naturally, and its cooling capacity is generally limited. The first condenser 12 can produce low-temperature hot water.

[0098] exist Figure 3 In the example, when the heat pump system produces high-temperature hot water, the first compressor 11 runs, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15, completing one refrigerant cycle.

[0099] When the second compressor 21 is running, the refrigerant enters the second auxiliary condenser pipe 22. After passing through the second throttling device 23, the refrigerant enters the second heat exchange pipe 24 and then returns to the suction port of the second compressor 21, completing one refrigerant cycle.

[0100] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0101] The first evaporator pipe 14 provides cooling, and the first evaporator pipe 14 dissipates heat through an outdoor fan.

[0102] The second heat exchange pipe 24 is used for cooling, and the second heat exchange pipe 24 dissipates heat through an outdoor fan.

[0103] The first auxiliary evaporator pipe 15 is used for refrigeration.

[0104] The second auxiliary condenser pipe 22 heats and exchanges heat with the first auxiliary evaporator pipe 15, which improves the evaporation capacity of the first refrigerant system, thereby improving the heating capacity of the first condenser 12, which can produce high-temperature hot water.

[0105] exist Figure 4-10 In one embodiment, the second refrigerant system includes a four-way valve 25 and an indoor heat exchanger 3. The indoor heat exchanger 3 forms the indoor unit of the second refrigerant system.

[0106] The first port of the four-way valve 25 is connected to the exhaust port of the second compressor 21, the third port of the four-way valve 25 is connected to the suction port of the second compressor 21, and the fourth port of the four-way valve 25 is connected to the second heat exchange pipeline 24.

[0107] The indoor heat exchanger 3 is connected to the second throttling device 23 and to the second port of the four-way valve 25 via the switching device 31.

[0108] The second auxiliary condenser pipe 22 is connected to the exhaust port of the second compressor 21 via the second switching device 26; the second auxiliary condenser pipe 22 is connected to the second throttling device 23 via the electronic expansion valve 27.

[0109] The second refrigerant system of the heat pump system is equipped with an indoor heat exchanger 3, which allows all heat exchangers in the second refrigerant system to be effectively utilized. The indoor heat exchanger 3 can realize cooling and heating functions, and when the indoor heat exchanger 3 has no cooling or heating demand, the first refrigerant system can still operate, reducing energy consumption and improving the overall energy efficiency of the entire system.

[0110] In some embodiments, the second switching device 26 is a second four-way valve. The first port of the second four-way valve is connected to the exhaust port of the second compressor 21, the second port of the second four-way valve is connected to the second auxiliary condenser pipe 22, the third port of the second four-way valve is connected to the suction port of the second compressor 21 and the third port of the four-way valve 25, and the fourth port of the second four-way valve is connected to the suction port of the second compressor 21 through the fourth switching device 28.

[0111] The second four-way valve allows for selective flow of the high-temperature, high-pressure refrigerant from the second compressor 21 to the auxiliary heat exchanger 1522, depending on demand.

[0112] The electronic expansion valve 27 can regulate flow rate while maintaining conduction.

[0113] The heat pump system includes an indoor unit, a first outdoor unit, and a second outdoor unit.

[0114] The indoor unit includes an indoor heat exchanger 3.

[0115] The first outdoor unit includes a first compressor 11, a first condenser 12, and an auxiliary heat exchanger 1522.

[0116] The second outdoor unit includes a second compressor 21, a first evaporation pipe 14, a second heat exchange pipe 24, a four-way valve 25, and a second four-way valve.

[0117] The heat pump system is divided into two outdoor units and one indoor unit, which facilitates transportation, installation and dismantling.

[0118] In some embodiments, the indoor unit includes a switch 31; the first outdoor unit includes a first throttling device 13; and the second outdoor unit includes a second throttling device 23 and an electronic expansion valve 27.

[0119] The switching device 31 and the throttling device are installed in the associated outdoor or indoor unit for easy control.

[0120] In some embodiments, the indoor unit is connected to the second outdoor unit via a shut-off valve, and the second outdoor unit is connected to the first outdoor unit via a shut-off valve.

[0121] A shut-off valve is installed on the pipes connecting the indoor unit to the second outdoor unit, on the pipes connecting the second outdoor unit to the indoor unit, on the pipes connecting the second outdoor unit to the first outdoor unit, and on the pipes connecting the first outdoor unit to the second outdoor unit.

[0122] The indoor unit is connected to the second outdoor unit, and the second outdoor unit is connected to the first outdoor unit via a shut-off valve, which facilitates the installation and disassembly of the heat pump system.

[0123] exist Figure 4-10In this example, the heat pump system includes a high-temperature stage unit and a low-temperature stage unit. The low-temperature stage unit includes a low-temperature outdoor unit and a low-temperature indoor unit, which are connected via a shut-off valve-pipeline-shut-off valve configuration. The high-temperature stage uses a high-temperature refrigerant, while the low-temperature stage uses a different refrigerant with a lower evaporation temperature. The high-temperature stage unit is used to produce hot water, and the low-temperature stage unit is divided into indoor units, which can meet both cooling and heating needs. To reduce energy consumption, the second switching device 26 in this system only operates when the high-temperature stage is producing high-temperature hot water.

[0124] The high-temperature stage unit includes: a first compressor 11, a first condenser 12, a first throttling device 13, an auxiliary heat exchanger 1522, a water pump 122, a water pipeline 121, and a shut-off valve.

[0125] The low-temperature outdoor unit includes: a second compressor 21, a four-way valve 25, a second switching device 26, an electronic expansion valve 27, a fourth switching device 28, an outdoor heat exchanger consisting of a first evaporation pipe 14 and a second heat exchange pipe 24, a second throttling device 23, and a shut-off valve.

[0126] The low-temperature indoor unit includes: an indoor heat exchanger 3, a switching device 31, and a shut-off valve.

[0127] The shut-off valves between the high-temperature stage unit and the low-temperature stage outdoor unit are connected by pipelines, and the shut-off valves between the low-temperature stage outdoor unit and the low-temperature stage indoor unit are connected by pipelines.

[0128] The heat pump system can simultaneously meet the space cooling, heating and high-temperature hot water needs of the low-temperature indoor unit (low-temperature unit). When the hot water temperature demand is not high, only the compressor and outdoor fan of the high-temperature unit can be operated, and the compressor of the low-temperature system can be shut down, effectively reducing energy consumption.

[0129] Therefore, the heat pump system can achieve the following 8 operating states: 1. High-temperature stage heating operation - low-temperature stage cooling operation (low outlet water temperature); 2. High-temperature stage heating operation - low-temperature stage cooling operation (high outlet water temperature); 3. High-temperature stage heating operation - low-temperature stage heating operation (low outlet water temperature); 4. High-temperature stage heating operation - low-temperature stage heating operation (high outlet water temperature); 5. High-temperature stage heating operation - low-temperature stage no cooling or heating demand (low outlet water temperature); 6. High-temperature stage heating operation - low-temperature stage no cooling or heating demand (high outlet water temperature); 7. High-temperature stage not operating - low-temperature stage cooling operation; 8. High-temperature stage not operating - low-temperature stage heating operation.

[0130] 1. High-temperature stage heating operation - low-temperature stage cooling operation (low outlet water temperature):

[0131] exist Figure 5In the example, the high-temperature stage unit operates as follows: the first compressor 11 is running, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15, completing one refrigerant cycle.

[0132] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0133] Low-temperature stage unit operation: The second compressor 21 is running, and the four-way valve 25 bypasses the high-pressure refrigerant to the second heat exchange pipeline 24. After the refrigerant exchanges heat in the second heat exchange pipeline 24, it passes through the second throttling device 23. The second throttling device 23 opens to throttle, and the electronic expansion valve 27 is disconnected. The throttled refrigerant then enters the indoor heat exchanger 3 for heat exchange. The switching device 31 is fully open, and the refrigerant enters the four-way valve 25 to bypass the suction port of the second compressor 21.

[0134] The high-pressure refrigerant bypasses the second switching device 26 to the fourth switching device 28, and the fourth switching device 28 closes, cutting off the refrigerant supply.

[0135] 2. High-temperature stage heating operation - low-temperature stage cooling operation (high outlet water temperature):

[0136] exist Figure 6 In the example, the high-temperature stage unit operates as follows: the first compressor 11 is running, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15 (which exchanges heat with the second auxiliary condenser 22 to increase the high pressure), thus completing one refrigerant cycle.

[0137] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0138] Low-temperature stage unit operation status: Second compressor 21 is running, and the high-temperature refrigerant flow is split into two paths:

[0139] In the first path, the four-way valve 25 bypasses the high-pressure refrigerant to the second heat exchange pipeline 24. After the refrigerant exchanges heat in the second heat exchange pipeline 24, it passes through the second throttling device 23. The second throttling device 23 opens to throttle, and the throttled refrigerant enters the indoor heat exchanger 3 for heat exchange. The switching device 31 is fully open, and the refrigerant enters the four-way valve 25 to bypass the suction port of the second compressor 21.

[0140] In the second circuit, the second switching device 26 bypasses the high-pressure refrigerant to the second auxiliary condenser pipe 22. The electronic expansion valve 27 opens to throttle the refrigerant, which then enters the indoor heat exchanger 3 for heat exchange. The switching device 31 is fully open and enters the four-way valve 25 to bypass the suction port of the second compressor 21.

[0141] 3. High-temperature stage heating operation - low-temperature stage heating operation (low outlet water temperature);

[0142] exist Figure 7 In the example, the high-temperature stage unit operates as follows: the first compressor 11 is running, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15, completing one refrigerant cycle.

[0143] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0144] Low-temperature stage unit operation: The second compressor 21 is running, the switching device 31 is fully open, and the four-way valve 25 bypasses the high-pressure refrigerant to the indoor heat exchanger 3. After the refrigerant exchanges heat in the indoor heat exchanger 3, it passes through the second throttling device 23. The second throttling device 23 opens to throttle, the electronic expansion valve 27 is disconnected, and the throttled refrigerant passes through the second heat exchange pipeline 24 for heat exchange, and then enters the four-way valve 25 to bypass to the suction port of the second compressor 21.

[0145] The high-pressure refrigerant bypasses the second switching device 26 to the fourth switching device 28, and the fourth switching device 28 closes, cutting off the refrigerant supply.

[0146] 4. High-temperature stage heating operation - Low-temperature stage heating operation (high outlet water temperature):

[0147] exist Figure 8 In the example, the high-temperature stage unit operates as follows: the first compressor 11 is running, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15 (which exchanges heat with the second auxiliary condenser 22 to increase the high pressure), thus completing one refrigerant cycle.

[0148] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0149] Low-temperature stage unit operation status: Second compressor 21 is running, and the high-temperature refrigerant flow is split into two paths:

[0150] In the first path, the switch device 31 is fully open, and the four-way valve 25 bypasses the high-pressure refrigerant to the indoor heat exchanger 3. After the refrigerant exchanges heat in the indoor heat exchanger 3, it passes through the second throttling device 23. The second throttling device 23 is opened to throttle, and the throttled refrigerant passes through the second heat exchange pipeline 24 for heat exchange, and then enters the four-way valve 25 to bypass the suction port of the second compressor 21.

[0151] In the second circuit, the second switching device 26 bypasses the high-pressure refrigerant to the second auxiliary condenser pipe 22. The electronic expansion valve 27 opens to throttle the refrigerant, which then enters the second heat exchange pipe 24 for heat exchange and enters the four-way valve 25 to bypass the suction port of the second compressor 21.

[0152] 5. High-temperature stage heating operation - low-temperature stage with no cooling or heating requirement (low outlet water temperature):

[0153] exist Figure 9 In the example, the high-temperature stage unit operates as follows: the first compressor 11 is running, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15, completing one refrigerant cycle.

[0154] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0155] Low-temperature stage unit operation status: Outdoor fan is running.

[0156] 6. High-temperature stage heating operation - low-temperature stage has no cooling or heating requirements (high outlet water temperature):

[0157] exist Figure 10 In the example, the high-temperature stage unit operates as follows: the first compressor 11 is running, the refrigerant enters the first condenser 12, the refrigerant enters the first evaporator 14 after passing through the first throttling device 13, and the refrigerant returns to the suction port of the first compressor 11 after passing through the first auxiliary evaporator 15 (which exchanges heat with the second auxiliary condenser 22 to increase the high pressure), thus completing one refrigerant cycle.

[0158] The first condenser 12 is used for heating, and the water pump 122 is started. Water and refrigerant exchange heat in the first condenser 12.

[0159] Low-temperature stage unit operation: Switch device 31 is disconnected, second switch device 26 bypasses the high-pressure refrigerant to the second auxiliary condenser pipe 22, electronic expansion valve 27 is opened, the throttled refrigerant enters the second heat exchange pipe 24 for heat exchange, and bypasses to the suction port of the second compressor 21 through four-way valve 25.

[0160] For the two scenarios of 7. High-temperature stage not running - low-temperature stage cooling operation and 8. High-temperature stage not running - low-temperature stage heating operation, the high-temperature stage group should stop running, and the operation of the outdoor and indoor units of the low-temperature stage can refer to 1-4.

[0161] The fourth switching device 28 is turned on only during differential pressure switching and turned off in all other cases.

[0162] The defrosting process of a heat pump system is similar to that of a refrigeration system; see 1 and 2 for reference.

[0163] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0164] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A heat pump system, comprising: First refrigerant system; The second refrigerant system; characterized in that... The first refrigerant system includes a first compressor, a first condenser, a first throttling device, and a first evaporator pipe connected in sequence to form a circuit; The second refrigerant system includes a second compressor, a second auxiliary condenser pipe, a second throttling device, and a second heat exchange pipe connected in sequence to form a circuit; The first refrigerant system also includes: The first auxiliary evaporation pipe is connected between the suction port of the first compressor and the first evaporation pipe; The first auxiliary evaporation pipeline and the second auxiliary condensation pipeline together form an auxiliary heat exchanger.

2. The heat pump system according to claim 1, characterized in that, The auxiliary heat exchanger is a plate heat exchanger or a shell-and-tube heat exchanger. And / or, the first condenser is a plate heat exchanger or a shell-and-tube heat exchanger.

3. The heat pump system according to claim 2, characterized in that, The first condenser is connected to a water pipe, and a water pump is installed on the water pipe.

4. The heat pump system according to claim 1, characterized in that, The first evaporation pipe and the second heat exchange pipe share the same heat exchange fins.

5. The heat pump system according to claim 1, characterized in that, The heat pump system includes an outdoor fan, and the first evaporation pipe and the second heat exchange pipe share the outdoor fan.

6. The heat pump system according to any one of claims 1-5, characterized in that, The second refrigerant circulation system includes: A four-way valve, wherein the first port of the four-way valve is connected to the exhaust port of the second compressor, the third port of the four-way valve is connected to the suction port of the second compressor, and the fourth port of the four-way valve is connected to the second heat exchange pipeline. An indoor heat exchanger is connected to the second throttling device and to the second port of the four-way valve via a switching device. The second auxiliary condensing line is connected to the exhaust port of the second compressor via a second switching device; the second auxiliary condensing line is connected to the second throttling device via an electronic expansion valve.

7. The heat pump system according to claim 6, characterized in that, The second switching device is a second four-way valve. The first port of the second four-way valve is connected to the exhaust port of the second compressor. The second port of the second four-way valve is connected to the second auxiliary condenser pipe. The third port of the second four-way valve is connected to the suction port of the second compressor and the third port of the four-way valve. The fourth port of the second four-way valve is connected to the suction port of the second compressor through a fourth switching device.

8. The heat pump system according to claim 6, characterized in that, The heat pump system includes: Indoor unit, including the indoor heat exchanger; The first outdoor unit includes the first compressor, the first condenser, and the auxiliary heat exchanger; The second outdoor unit includes the second compressor, the first evaporator pipe, the second heat exchange pipe, the four-way valve, and the second four-way valve.

9. The heat pump system according to claim 8, characterized in that, The indoor unit includes a switch; the first outdoor unit includes a first throttling device; and the second outdoor unit includes a second throttling device and an electronic expansion valve.

10. The heat pump system according to claim 8, characterized in that, The indoor unit is connected to the second outdoor unit via a shut-off valve, and the second outdoor unit is connected to the first outdoor unit via a shut-off valve.

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