Heat pump system and control method and control device of heat pump system

Abstract

The invention provides a heat pump system and a control method and device of the heat pump system. The heat pump system comprises a compressor, a four-way valve, an outdoor heat exchanger and a water-fluorine heat exchanger which are connected with one another through refrigerant pipelines. The heat regeneration device comprises a heat regenerator and a heat regeneration pipeline, the heat regenerator is installed on a refrigerant pipeline between the four-way valve and an air suction port of the compressor, and the heat regeneration pipeline flows through the heat regenerator and is provided with a plurality of electronic expansion valves; the two ends of the heat return pipeline are connected to the portion, between the outdoor heat exchanger and the water fluorine heat exchanger, of the refrigerant pipeline in parallel. According to the heat pump system and the control method and device of the heat pump system, on one hand, the air suction superheat degree of the air suction side of the compressor can be increased, so that the exhaust temperature and the exhaust superheat degree are increased, and on the other hand, the supercooling degree of a refrigerant used for heat exchange of the heat exchanger in the system can be increased; and the heat exchange efficiency of the outdoor heat exchanger or the water-fluorine heat exchanger is improved.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment technology, and in particular to a heat pump system, a control method and a control device for the heat pump system. Background Art

[0002] In the related technologies, with the advancement of the current European low-carbon emission policy, as a representative of low global warming potential, R290 refrigerant with zero carbon emissions has gradually come into people's view. As a high-quality refrigerant with low carbon emissions, R290 has its disadvantages of low pressure, low exhaust temperature and superheat. Since low exhaust has a decisive influence on system stability, improving the suction and exhaust superheat of R290, a low-temperature and low-pressure refrigerant, and then increasing its exhaust temperature, is a difficult problem that needs to be solved urgently in the heat pump field.

[0003] The existing low-temperature and low-pressure refrigerant system generally increases the suction superheat by closing the electronic expansion valve, and then further increases the exhaust temperature and exhaust superheat. As we all know, the reduction of the opening of the electronic expansion valve cannot be sustained. Therefore, finding a way or method that can use the system heat exchange principle to increase the suction and exhaust temperatures can effectively solve the problems of the current low-pressure and low-temperature refrigerant such as R290. Summary of the invention

[0004] The present invention provides a heat pump system, a control method and a control device for the heat pump system, which are used to solve the defects in the prior art and achieve the following technical effects: on the one hand, the suction superheat of the compressor suction side can be increased, thereby increasing the exhaust temperature and the exhaust superheat; on the other hand, the subcooling of the refrigerant used for heat exchange in the heat exchanger in the system can be increased, thereby improving the heat exchange efficiency of the outdoor heat exchanger or the water-fluorine heat exchanger.

[0005] A heat pump system according to a first embodiment of the present invention comprises:

[0006] A compressor, a four-way valve, an outdoor heat exchanger and a water-fluorine heat exchanger interconnected by refrigerant pipes;

[0007] The heat recovery device includes a heat regenerator and a heat recovery pipe. The heat regenerator is installed on the refrigerant pipe between the four-way valve and the air intake of the compressor. The heat recovery pipe flows through the heat regenerator and is provided with a plurality of electronic expansion valves. Both ends of the heat recovery pipe are connected in parallel to the refrigerant pipe between the outdoor heat exchanger and the water-fluorine heat exchanger.

[0008] According to one embodiment of the present invention, the heat recovery pipe comprises an inlet pipe, a first outlet pipe and a second outlet pipe, and the first outlet pipe is connected in parallel with the second outlet pipe;

[0009] In the direction from the outdoor heat exchanger to the water-fluorine heat exchanger, a first node, a second node and a third node are sequentially arranged on the refrigerant pipeline, the first outlet pipeline is connected to the first node, the inlet pipeline is connected to the second node, and the second outlet pipeline is connected to the third node;

[0010] A first valve is provided on the first outlet pipe and a second valve is provided on the second outlet pipe. In the heating state, the first valve is in a connected state and the second valve is in a disconnected state; in the cooling state, the first valve is in a disconnected state and the second valve is in a connected state, so that the refrigerant for heat exchange in the regenerator always flows in reverse.

[0011] According to one embodiment of the present invention, the first valve and the second valve are respectively a first solenoid valve and a second solenoid valve whose switches are adjustable;

[0012] In the heating state, the first solenoid valve is opened and the second solenoid valve is closed; in the cooling state, the first solenoid valve is closed and the second solenoid valve is opened.

[0013] According to one embodiment of the present invention, the first valve and the second valve are respectively a first one-way valve and a second one-way valve, and the flow direction of the first one-way valve is oriented along the direction from the return device to the first node, and the flow direction of the second one-way valve is oriented along the direction from the return device to the third node;

[0014] A third valve is connected in series between the third node and the second node, and a fourth valve is connected in series between the second node and the first node. In the heating state, the third valve is in a connected state and the fourth valve is in a disconnected state; in the cooling state, the third valve is in a disconnected state and the fourth valve is in a connected state, so that the refrigerant for heat exchange in the regenerator always flows in reverse.

[0015] According to one embodiment of the present invention, the third valve and the fourth valve are respectively a third solenoid valve and a fourth solenoid valve with adjustable switches;

[0016] In the heating state, the third solenoid valve is opened and the fourth solenoid valve is closed; in the cooling state, the third solenoid valve is closed and the fourth solenoid valve is opened.

[0017] According to one embodiment of the present invention, the third valve and the fourth valve are respectively a third one-way valve and a fourth one-way valve, and the flow direction of the third one-way valve is oriented along the direction from the third node to the second node, and the flow direction of the fourth one-way valve is oriented along the direction from the first node to the second node.

[0018] According to one embodiment of the present invention, the electronic expansion valve includes a first expansion valve provided on the first outlet pipe and a second expansion valve provided on the second outlet pipe.

[0019] According to an embodiment of the present invention, the electronic expansion valve comprises a master expansion valve, and the master expansion valve is arranged on a main outlet pipe located upstream of the first outlet pipe and the second outlet pipe.

[0020] According to a second aspect of the present invention, a control method for a heat pump system based on the first aspect of the present invention comprises:

[0021] Obtain the current working mode of the air conditioner and the suction superheat of the compressor;

[0022] A control logic is generated according to the current working mode and the suction air superheat, and the opening degree of the electronic expansion valve on the heat recovery pipe is adjusted according to the control logic.

[0023] According to an embodiment of the present invention, when the electronic expansion valve includes a first expansion valve and a second expansion valve, the step of generating a control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat recovery pipe according to the control logic specifically includes:

[0024] Determining that the current working mode is a heating mode, adjusting the opening of the first expansion valve according to a comparison result between the suction superheat and the target superheat;

[0025] Alternatively, if it is determined that the current working mode is the cooling mode, the opening degree of the second expansion valve is adjusted according to a comparison result between the suction superheat and the target superheat.

[0026] According to an embodiment of the present invention, when the electronic expansion valve includes a master expansion valve, the step of generating a control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat recovery pipe according to the control logic specifically includes:

[0027] If it is determined that the current working mode is the heating mode or the cooling mode, the opening of the main expansion valve is adjusted according to a comparison result between the suction superheat and the target superheat.

[0028] According to a third aspect of the present invention, a control device for a heat pump system based on the first aspect of the present invention comprises:

[0029] An acquisition module is used to acquire the current working mode of the air conditioner and the suction superheat of the compressor;

[0030] The control module is used to generate control logic according to the current working mode and the suction air superheat, and adjust the opening of the electronic expansion valve on the heat recovery pipe according to the control logic.

[0031] The present invention provides a heat pump system and a control method and a control device thereof. The system arranges a heat regenerator in front of the suction port of the compressor, and uses a heat recovery pipe to flow the high-temperature refrigerant in the system through the heat regenerator, thereby superheating the refrigerant flowing into the suction port of the compressor and supercooling the refrigerant flowing into the outdoor heat exchanger / water-fluorine heat exchanger. In this way, on the one hand, the suction superheat of the compressor suction side can be increased, thereby increasing the exhaust temperature and exhaust superheat. On the other hand, the supercooling of the refrigerant used for heat exchange in the heat exchanger in the system can also be increased, thereby improving the heat exchange efficiency of the outdoor heat exchanger or the water-fluorine heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 is a schematic structural diagram of a heat pump system provided in Embodiment 1 of the present invention;

[0034] Figure 2 is a schematic structural diagram of a heat pump system provided in Embodiment 2 of the present invention;

[0035] Figure 3 It is a flow chart of a control method of a heat pump system provided by the present invention;

[0036] Figure 4 is a schematic structural diagram of a control device for a heat pump system provided by the present invention;

[0037] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention.

[0038] Reference numerals:

[0039] 1. Compressor; 2. Four-way valve; 3. Outdoor heat exchanger; 4. Water-fluorine heat exchanger;

[0040] 51. Regenerator; 52. Regenerator pipe; 53. Inlet pipe; 54. First outlet pipe; 55. Second outlet pipe; 61. First node; 62. Second node; 63. Third node;

[0041] 71. First one-way valve; 72. Second one-way valve; 73. Third one-way valve; 74. Fourth one-way valve; 8. Main expansion valve; 81. First expansion valve; 82. Second expansion valve; 9. Water pump. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The following describes a heat pump system, a control method and a control device of the heat pump system proposed in the present invention with reference to the accompanying drawings. It should be pointed out that the control method of the heat pump system described in the second aspect of the present invention and the control device described in the third aspect are both based on the heat pump system described in the first aspect of the present invention.

[0044] like Figure 1 and 2 As shown, the heat pump system according to the first embodiment of the present invention includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a water-fluorine heat exchanger 4 and a heat recovery device.

[0045] The compressor 1, the four-way valve 2, the outdoor heat exchanger 3 and the water-fluorine heat exchanger 4 are connected to each other through a refrigerant pipeline.

[0046] The heat recovery device includes a heat regenerator 51 and a heat recovery pipe 52. The heat regenerator 51 is installed on the refrigerant pipe between the four-way valve 2 and the suction port of the compressor 1. The heat recovery pipe 52 flows through the heat regenerator 51 and is provided with a plurality of electronic expansion valves. Both ends of the heat recovery pipe 52 are connected in parallel to the refrigerant pipe between the outdoor heat exchanger 3 and the water-fluorine heat exchanger 4.

[0047] According to the heat pump system of the embodiment of the present invention, its specific working principle and working process are as follows: the reheater 51 can realize heat exchange between the heat recovery pipe 52 and the refrigerant pipe located upstream of the suction port of the compressor 1, so as to use the refrigerant in the heat recovery pipe 52 to heat the low-temperature refrigerant in front of the suction port of the compressor 1. In this way, on the one hand, the low-temperature refrigerant in front of the suction port of the compressor 1 enters the suction port of the compressor 1 after being heated, which can increase the suction superheat of the suction side of the compressor 1, and then increase the exhaust temperature and exhaust superheat. On the other hand, the refrigerant in the heat recovery pipe 52 flows back to the refrigerant pipe between the outdoor heat exchanger 3 and the water-fluorine heat exchanger 4 after being supercooled, thereby improving the supercooling of the refrigerant in the refrigerant pipe between the outdoor heat exchanger 3 and the water-fluorine heat exchanger 4, and then improving the heat exchange efficiency of the outdoor heat exchanger 3 or the water-fluorine heat exchanger 4.

[0048] Specifically, in the heating mode, the refrigerant flows from the compressor 1 through the four-way valve 2 and flows to the water-fluorine heat exchanger 4, then enters the outdoor condenser through the throttling device, and then flows to the compressor 1 through the four-way valve 2, thereby completing a complete heating cycle. In the above heating cycle, the refrigerant flows into the return pipe after flowing out of the water-fluorine heat exchanger 4, and flows through the regenerator 51 and heats the low-temperature refrigerant flowing to the suction port of the compressor 1 in the regenerator 51. On the one hand, the overheated refrigerant flows out of the regenerator and flows to the suction port of the compressor 1 to increase the suction superheat on the suction side, thereby increasing the exhaust temperature and exhaust superheat; on the other hand, the supercooled refrigerant flows out of the return pipe and flows to the outdoor heat exchanger 3 to increase the refrigerant supercooling, thereby increasing the heat exchange efficiency of the outdoor heat exchanger 3.

[0049] In the cooling mode, the refrigerant flows from the compressor 1 through the four-way valve 2 to the outdoor condenser, then enters the water-fluorine heat exchanger 4 through the throttling device, and then flows to the compressor 1 through the four-way valve 2, thereby completing a complete refrigeration cycle. In the above refrigeration cycle, the refrigerant flows into the return pipe after flowing out of the outdoor heat exchanger 3, and flows through the regenerator 51 and heats the low-temperature refrigerant flowing to the suction port of the compressor 1 in the regenerator 51. On the one hand, the superheated refrigerant flows out of the regenerator and flows to the suction port of the compressor 1 to increase the suction superheat on the suction side, thereby increasing the exhaust temperature and exhaust superheat; on the other hand, the supercooled refrigerant flows out of the return pipe and flows to the water-fluorine heat exchanger 4 to increase the supercooling of the refrigerant flowing into the water-fluorine heat exchanger 4, thereby improving the refrigeration effect and efficiency of the water-fluorine heat exchanger 4.

[0050] In the related technologies, with the advancement of the current European low-carbon emission policy, as a representative of low global warming potential, R290 refrigerant with zero carbon emissions has gradually come into people's view. As a high-quality refrigerant with low carbon emissions, R290 has its disadvantages of low pressure, low exhaust temperature and superheat. Since low exhaust has a decisive influence on system stability, improving the suction and exhaust superheat of R290, a low-temperature and low-pressure refrigerant, and then increasing its exhaust temperature, is a difficult problem that needs to be solved urgently in the heat pump field.

[0051] The existing low-temperature and low-pressure refrigerant system generally increases the suction superheat by closing the electronic expansion valve, and then further increases the exhaust temperature and exhaust superheat. As we all know, the reduction of the opening of the electronic expansion valve cannot be sustained. Therefore, finding a way or method that can use the system heat exchange principle to increase the suction and exhaust temperatures can effectively solve the problems of the current low-pressure and low-temperature refrigerant such as R290.

[0052] In summary, in order to solve the technical problems existing in the related art, the present invention provides a heat pump system, which sets a reheater 51 in front of the suction port of the compressor 1, and uses the heat recovery pipe 52 to flow the high-temperature refrigerant in the system through the reheater 51, so as to superheat the refrigerant flowing into the suction port of the compressor 1, and supercool the refrigerant flowing into the outdoor heat exchanger 3 / water-fluorine heat exchanger 4. In this way, on the one hand, the suction superheat of the suction side of the compressor 1 can be increased, thereby increasing the exhaust temperature and the exhaust superheat. On the other hand, the supercooling of the refrigerant used for heat exchange in the heat exchanger in the system can also be increased, thereby improving the heat exchange efficiency of the outdoor heat exchanger 3 or the water-fluorine heat exchanger 4.

[0053] like Figure 1 and 2 As shown, according to some embodiments of the present invention, the heat recovery pipe 52 includes an inlet pipe 53, a first outlet pipe 54 and a second outlet pipe 55, and the first outlet pipe 54 and the second outlet pipe 55 are connected in parallel.

[0054] In the direction from the outdoor heat exchanger 3 toward the water-fluorine heat exchanger 4, a first node 61, a second node 62 and a third node 63 are sequentially provided on the refrigerant pipeline, the first outlet pipeline 54 is connected to the first node 61, the inlet pipeline 53 is connected to the second node 62, and the second outlet pipeline 55 is connected to the third node 63.

[0055] A first valve is provided on the first outlet pipe 54 and a second valve is provided on the second outlet pipe 55. In the heating state, the first valve is in a connected state and the second valve is in a disconnected state; in the cooling state, the first valve is in a disconnected state and the second valve is in a connected state, so that the refrigerant for heat exchange in the regenerator 51 always flows in reverse.

[0056] It can be understood that there are two refrigerant paths for heat exchange with each other in the recirculator. When the two refrigerant paths are always in a countercurrent state, that is, the directions of the two refrigerant paths are always opposite, the heat exchange efficiency in the recirculator can be guaranteed to be at the highest state.

[0057] In the present embodiment, one of the refrigerant paths in the recirculator is the first refrigerant path flowing from the four-way valve 2 to the suction port of the compressor 1, and the other refrigerant path in the recirculator is the second refrigerant path with the heat recovery pipe 52 as the main body. It can be understood that the refrigerant flow direction of the first refrigerant path is directional and will not change with the change of the system working mode. Therefore, in order to achieve the effect of always countercurrent in the recirculator, the refrigerant flow direction in the second refrigerant path (that is, the return pipe) must also be directional and will not change with the change of the system working mode.

[0058] Furthermore, in order to achieve the purpose of directional flow of the refrigerant in the above-mentioned return pipe and not changing with the change of the working mode, the return pipe in this embodiment is designed to have an inlet pipe 53 and two outlet pipes, and a valve is arranged on each outlet pipe. In this way, whether in cooling mode or heating mode, although the flow direction of the four-way valve 2 has changed, through the control of the valve, the refrigerant in the system can enter the recirculator from the same inlet pipe 53 and flow out from different outlet pipes, thereby ensuring that the flow direction of the second refrigerant path in the recirculator always remains directional, and countercurrent heat exchange in the recirculator can be achieved in both cooling and heating modes.

[0059] For example, in the heating mode, the first valve is in the connected state and the second valve is in the disconnected state. At this time, the high-temperature refrigerant flows out of the water-fluorine heat exchanger 4 and enters the inlet pipe 53, and flows through the regenerator 51 to heat the low-temperature refrigerant before the suction port of the compressor 1. The overcooled refrigerant flows out along the first outlet pipe 54 and flows to the outdoor heat exchanger 3, and finally flows to the compressor 1 to complete the heating cycle. Figure 1 and 2 As shown, during the heating cycle, the refrigerant flow direction of the refrigerant in the return pipe in the reheater 51 (that is, the second refrigerant flow direction) is from bottom to top, and the refrigerant flow direction of the refrigerant in front of the suction port of the compressor 1 in the reheater 51 (that is, the first refrigerant flow direction) is from top to bottom. Therefore, the reheater 51 realizes countercurrent heat exchange.

[0060] In the cooling mode, the first valve is in the disconnected state and the second valve is in the connected state. At this time, the four-way valve 2 is switched, and the high-temperature refrigerant flows out of the outdoor heat exchanger 3 and enters the inlet pipe 53, and flows through the regenerator 51 to heat the low-temperature refrigerant in front of the suction port of the compressor 1. The overcooled refrigerant flows out along the second outlet pipe 55 and flows to the water-fluorine heat exchanger 4, and finally flows to the compressor 1 to complete the refrigeration cycle. Figure 1 and 2 As shown, during the refrigeration cycle, the refrigerant flow direction of the refrigerant in the return pipe in the reheater 51 (that is, the second refrigerant flow direction) is also from bottom to top, and the refrigerant flow direction of the refrigerant in front of the suction port of the compressor 1 in the reheater 51 (that is, the first refrigerant flow direction) is still from top to bottom. Therefore, the reheater 51 realizes countercurrent heat exchange.

[0061] According to some embodiments of the present invention, the first valve may be a one-way valve or a solenoid valve. Similarly, the second valve may be a one-way valve or a solenoid valve. In this way, by controlling the valve direction of the one-way valve and controlling the switch of the solenoid valve, the above-mentioned purpose of "in the heating state, the first valve is in a connected state and the second valve is in a disconnected state; in the cooling state, the first valve is in a disconnected state and the second valve is in a connected state" can be achieved.

[0062] In one embodiment of the present invention, the first valve and the second valve are respectively a first solenoid valve and a second solenoid valve whose switches are adjustable.

[0063] In the heating state, the first solenoid valve is opened and the second solenoid valve is closed; in the cooling state, the first solenoid valve is closed and the second solenoid valve is opened.

[0064] like Figure 1 and 2 As shown, in another embodiment of the present invention, the first valve and the second valve are respectively a first one-way valve 71 and a second one-way valve 72, and the flow direction of the first one-way valve 71 is oriented along the direction from the returner to the first node 61, and the flow direction of the second one-way valve 72 is oriented along the direction from the returner to the third node 63.

[0065] Furthermore, a third valve is connected in series between the third node 63 and the second node 62, and a fourth valve is connected in series between the second node 62 and the first node 61. In the heating state, the third valve is in a connected state and the fourth valve is in a disconnected state; in the cooling state, the third valve is in a disconnected state and the fourth valve is in a connected state, so that the refrigerant for heat exchange in the regenerator 51 always flows in reverse.

[0066] In this way, through the setting of the third valve and the fourth valve, all refrigerants flowing out of the heat exchanger (water-fluorine heat exchanger 4 or plate heat exchanger) can be forced to pass through the reflux device without diversion, thereby further enhancing the superheat and subcooling of the corresponding part of the refrigerant in the system and improving the working efficiency of the system.

[0067] It should be pointed out that the third valve can be a one-way valve or a solenoid valve. Similarly, the fourth valve can also be a one-way valve or a solenoid valve. In this way, by controlling the valve direction of the one-way valve and controlling the switch of the solenoid valve, the above-mentioned purpose of "all refrigerant flowing out of the heat exchanger (water-fluorine heat exchanger 4 or plate heat exchanger) can be forced to pass through the reflux device without diversion" can be achieved.

[0068] For example, the third valve and the fourth valve are respectively a third solenoid valve and a fourth solenoid valve whose switches are adjustable.

[0069] And in the heating state, the third solenoid valve is opened and the fourth solenoid valve is closed; in the cooling state, the third solenoid valve is closed and the fourth solenoid valve is opened.

[0070] For example, Figure 1 and 2 As shown, the third valve and the fourth valve are the third one-way valve 73 and the fourth one-way valve 74 respectively, and the flow direction of the third one-way valve 73 is oriented along the direction from the third node 63 to the second node 62, and the flow direction of the fourth one-way valve 74 is oriented along the direction from the first node 61 to the second node 62.

[0071] like Figure 1 As shown, according to some embodiments of the present invention, the electronic expansion valve includes a first expansion valve 81 provided on the first outlet pipe 54 and a second expansion valve 82 provided on the second outlet pipe 55. In this way, by controlling the opening of the first expansion valve 81, the degree of increase of the suction superheat of the compressor 1 in the heating mode can be adjusted; by controlling the opening of the second expansion valve 82, the degree of increase of the suction superheat of the compressor 1 in the cooling mode can be adjusted.

[0072] like Figure 2 As shown, according to some other embodiments of the present invention, the electronic expansion valve includes a total expansion valve 8, and the total expansion valve 8 is arranged on the main outlet pipe located upstream of the first outlet pipe 54 and the second outlet pipe 55. In this way, whether in cooling mode or heating mode, by adjusting the opening of the total expansion valve 8, the degree of increase of the suction superheat of the compressor 1 can be adjusted.

[0073] Some specific embodiments of the heat pump system of the present invention are described below with reference to the accompanying drawings.

[0074] like Figure 1 and 2 As shown, the heat pump system includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a water-fluorine heat exchanger 4 and a heat recovery device.

[0075] The compressor 1, the four-way valve 2, the outdoor heat exchanger 3 and the water-fluorine heat exchanger 4 are interconnected through a refrigerant pipe. A water pump 9 is provided on the water supply pipe flowing through the water-fluorine heat exchanger 4. The heat recovery device includes a heat regenerator 51 and a heat recovery pipe 52. The heat regenerator 51 is installed on the refrigerant pipe between the four-way valve 2 and the air intake of the compressor 1. The heat recovery pipe 52 flows through the heat regenerator 51, and both ends of the heat recovery pipe 52 are connected in parallel to the refrigerant pipe between the outdoor heat exchanger 3 and the water-fluorine heat exchanger 4.

[0076] The heat recovery pipe 52 includes an inlet pipe 53, a first outlet pipe 54 and a second outlet pipe 55, and the first outlet pipe 54 is connected in parallel with the second outlet pipe 55. In the direction from the outdoor heat exchanger 3 to the water-fluorine heat exchanger 4, a first node 61, a second node 62 and a third node 63 are sequentially arranged on the refrigerant pipe, the first outlet pipe 54 is connected to the first node 61, the inlet pipe 53 is connected to the second node 62, and the second outlet pipe 55 is connected to the third node 63.

[0077] A first one-way valve 71 is provided on the first outlet pipe 54 and a second one-way valve 72 is provided on the second outlet pipe 55. A third one-way valve 73 is also connected in series between the third node 63 and the second node 62. A fourth one-way valve 74 is also connected in series between the second node 62 and the first node 61. The flow direction of the first one-way valve 71 is oriented along the direction from the reflux device to the first node 61, the flow direction of the second one-way valve 72 is oriented along the direction from the reflux device to the third node 63, the flow direction of the third one-way valve 73 is oriented along the direction from the third node 63 to the second node 62, and the flow direction of the fourth one-way valve 74 is oriented along the direction from the first node 61 to the second node 62.

[0078] The difference between the first embodiment and the second embodiment of the present invention is only the difference in the position and number of the electronic expansion valves on the return pipe. Figure 1 As shown, in the first embodiment, a total expansion valve 8 is provided on the main outlet pipe of the return pipe located upstream of the first outlet pipe 54 and the second outlet pipe 55. At this time, whether in the cooling mode or the heating mode, the degree of increase of the suction superheat of the compressor 1 can be adjusted by adjusting the opening of the total expansion valve 8; Figure 2 As shown, in the second embodiment, the return pipe is provided with a first expansion valve 81 and a second expansion valve 82 on the first outlet pipe 54 and the second outlet pipe 55, respectively. At this time, by controlling the opening of the first expansion valve 81, the degree of increase of the suction superheat of the compressor 1 in the heating mode can be adjusted; by controlling the opening of the second expansion valve 82, the degree of increase of the suction superheat of the compressor 1 in the cooling mode can be adjusted.

[0079] The working process of the heat pump system is as follows: when it is turned on, the system judges the mode. If the system unit requires heating, the refrigerant flows from the compressor 1 through the four-way valve 2 to the water-fluorine heat exchanger 4, flows to the regenerator 51 through the inlet pipe 53, and then passes through the first expansion valve 81 (or the main expansion valve 8) and flows through the first check valve 71 to the outdoor heat exchanger 3, and finally flows through the four-way valve 2 to the regenerator 51, and finally returns to the compressor 1 to complete a complete heating cycle.

[0080] It can be seen from the above heating cycle that after the refrigerant flows out of the water-fluorine heat exchanger 4, the condensed refrigerant is a high-temperature and high-pressure refrigerant. When it flows to the regenerator 51, since the suction side of the compressor 1 is a low-temperature and low-pressure refrigerant, the heat exchange through the regenerator 51 can increase the suction superheat of the suction side of the compressor 1, thereby increasing the exhaust temperature and the exhaust superheat.

[0081] The working process of the refrigeration cycle is the same as that of the heating cycle, except that the refrigerant in the refrigeration cycle passes through the second expansion valve 82 (or the total expansion valve 8 ) and the second one-way valve 72 and flows out from the second outlet pipe 55 .

[0082] like Figure 3 As shown, according to the second embodiment of the present invention, a control method for a heat pump system based on the first embodiment of the present invention includes:

[0083] Step S1, obtaining the current working mode of the air conditioner and the suction superheat of the compressor 1;

[0084] Step S2, generating control logic according to the current working mode and suction air superheat, and adjusting the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic.

[0085] According to the control method of the heat pump system of an embodiment of the present invention, the superheat of the refrigerant flowing into the suction port of the compressor 1 is adjusted by controlling the opening of the electronic expansion valve on the heat return pipe 52, and the subcooling of the refrigerant flowing into the outdoor heat exchanger 3 / water-fluorine heat exchanger 4 is adjusted. In this way, on the one hand, the suction superheat of the suction side of the compressor 1 can be increased, thereby increasing the exhaust temperature and the exhaust superheat. On the other hand, the subcooling of the refrigerant used for heat exchange in the heat exchanger in the system can also be increased, thereby improving the heat exchange efficiency of the outdoor heat exchanger 3 or the water-fluorine heat exchanger 4.

[0086] According to some embodiments of the present invention, when the electronic expansion valve includes a first expansion valve 81 and a second expansion valve 82, the step of generating a control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic specifically includes:

[0087] If the current working mode is determined to be the heating mode, the opening of the first expansion valve 81 is adjusted according to the comparison result between the suction superheat and the target superheat;

[0088] Alternatively, if it is determined that the current working mode is the cooling mode, the opening degree of the second expansion valve 82 is adjusted according to the comparison result between the suction superheat and the target superheat.

[0089] According to some other embodiments of the present invention, when the electronic expansion valve includes a master expansion valve 8, the steps of generating control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic specifically include:

[0090] If it is determined that the current working mode is the heating mode or the cooling mode, the opening degree of the main expansion valve 8 is adjusted according to the comparison result between the suction superheat and the target superheat.

[0091] The control device of the heat pump system provided by the present invention is described below. The control device of the heat pump system described below and the control method of the heat pump system described above can be referred to each other.

[0092] like Figure 4As shown, according to the third aspect of the present invention, a control device for a heat pump system based on the first aspect of the present invention comprises:

[0093] The acquisition module 110 is used to acquire the current working mode of the air conditioner and the suction superheat of the compressor 1;

[0094] The control module 120 is used to generate control logic according to the current working mode and suction air superheat, and adjust the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic.

[0095] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the control method of the heat pump system, including: obtaining the current working mode of the air conditioner and the suction superheat of the compressor 1; generating control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic.

[0096] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0097] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a control method for a heat pump system, including: obtaining the current operating mode of the air conditioner and the suction superheat of the compressor 1; generating control logic according to the current operating mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic.

[0098] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute a control method for a heat pump system, including: obtaining the current operating mode of the air conditioner and the suction superheat of the compressor 1; generating control logic according to the current operating mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat return pipe 52 according to the control logic.

[0099] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0100] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat pump system, characterized in that: include: A compressor, a four-way valve, an outdoor heat exchanger and a water-fluorine heat exchanger interconnected by refrigerant pipes; The heat recovery device includes a heat regenerator and a heat recovery pipe. The heat regenerator is installed on the refrigerant pipe between the four-way valve and the air intake of the compressor. The heat recovery pipe flows through the heat regenerator and is provided with a plurality of electronic expansion valves. Both ends of the heat recovery pipe are connected in parallel to the refrigerant pipe between the outdoor heat exchanger and the water-fluorine heat exchanger.

2. The heat pump system according to claim 1, characterized in that: The heat recovery pipeline includes an inlet pipeline, a first outlet pipeline and a second outlet pipeline, and the first outlet pipeline is connected in parallel with the second outlet pipeline; In the direction from the outdoor heat exchanger to the water-fluorine heat exchanger, a first node, a second node and a third node are sequentially arranged on the refrigerant pipeline, the first outlet pipeline is connected to the first node, the inlet pipeline is connected to the second node, and the second outlet pipeline is connected to the third node; A first valve is provided on the first outlet pipe and a second valve is provided on the second outlet pipe. In the heating state, the first valve is in a connected state and the second valve is in a disconnected state; in the cooling state, the first valve is in a disconnected state and the second valve is in a connected state, so that the refrigerant for heat exchange in the regenerator always flows in reverse.

3. The heat pump system according to claim 2, characterized in that: The first valve and the second valve are respectively a first solenoid valve and a second solenoid valve with adjustable switches; In the heating state, the first solenoid valve is opened and the second solenoid valve is closed; in the cooling state, the first solenoid valve is closed and the second solenoid valve is opened.

4. The heat pump system according to claim 2, characterized in that: The first valve and the second valve are respectively a first one-way valve and a second one-way valve, and the flow direction of the first one-way valve is oriented along the direction from the return device to the first node, and the flow direction of the second one-way valve is oriented along the direction from the return device to the third node; A third valve is connected in series between the third node and the second node, and a fourth valve is connected in series between the second node and the first node. In the heating state, the third valve is in a connected state and the fourth valve is in a disconnected state; in the cooling state, the third valve is in a disconnected state and the fourth valve is in a connected state, so that the refrigerant for heat exchange in the regenerator always flows in reverse.

5. The heat pump system according to claim 4, characterized in that: The third valve and the fourth valve are respectively a third solenoid valve and a fourth solenoid valve with adjustable switches; In the heating state, the third solenoid valve is opened and the fourth solenoid valve is closed; in the cooling state, the third solenoid valve is closed and the fourth solenoid valve is opened.

6. The heat pump system according to claim 4, characterized in that: The third valve and the fourth valve are respectively a third one-way valve and a fourth one-way valve, and the flow direction of the third one-way valve is oriented along the direction from the third node to the second node, and the flow direction of the fourth one-way valve is oriented along the direction from the first node to the second node.

7. The heat pump system according to any one of claims 1 to 6, characterized in that: The electronic expansion valve includes a first expansion valve disposed on the first outlet pipe and a second expansion valve disposed on the second outlet pipe.

8. The heat pump system according to any one of claims 1 to 6, characterized in that: The electronic expansion valve comprises a main expansion valve, which is arranged on a main outlet pipe located upstream of the first outlet pipe and the second outlet pipe.

9. A control method for a heat pump system according to any one of claims 1 to 8, characterized in that: include: Obtain the current working mode of the air conditioner and the suction superheat of the compressor; A control logic is generated according to the current working mode and the suction air superheat, and the opening degree of the electronic expansion valve on the heat recovery pipe is adjusted according to the control logic.

10. The control method of the heat pump system according to claim 9, characterized in that: In the case where the electronic expansion valve includes a first expansion valve and a second expansion valve, the step of generating a control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat recovery pipe according to the control logic specifically includes: Determining that the current working mode is a heating mode, adjusting the opening of the first expansion valve according to a comparison result between the suction superheat and the target superheat; Alternatively, if it is determined that the current working mode is the cooling mode, the opening degree of the second expansion valve is adjusted according to a comparison result between the suction superheat and the target superheat.

11. The control method of the heat pump system according to claim 9, characterized in that: In the case where the electronic expansion valve includes a master expansion valve, the step of generating a control logic according to the current working mode and the suction superheat, and adjusting the opening of the electronic expansion valve on the heat recovery pipe according to the control logic specifically includes: If it is determined that the current working mode is the heating mode or the cooling mode, the opening of the main expansion valve is adjusted according to a comparison result between the suction superheat and the target superheat.

12. A control device for a heat pump system according to any one of claims 1 to 8, characterized in that: include: An acquisition module is used to acquire the current working mode of the air conditioner and the suction superheat of the compressor; The control module is used to generate control logic according to the current working mode and the suction air superheat, and adjust the opening of the electronic expansion valve on the heat recovery pipe according to the control logic.

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