Control method of heat pump system

Abstract

The present invention discloses a pressure buffer assembly and a heat pump system. The pressure buffer assembly includes: a buffer tank, on which a liquid inlet and a liquid outlet are provided; a flexible airbag filled with gas, and the flexible airbag is arranged in the buffer tank. By configuring a flexible airbag in the buffer tank, during actual use, when the heat exchange medium expands and contracts due to temperature changes, the flexible airbag can deform under the action of the water pressure in the buffer tank to buffer the volume change of the heat exchange medium caused by temperature changes, avoiding the impact on the indoor pipeline and preventing the occurrence of pipeline rupture, so as to improve the operation reliability of the heat pump system.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and in particular to a pressure buffering component and a heat pump system. Background Art

[0002] Currently, a heat pump system is usually configured with a refrigeration circuit and a user heat exchange terminal. Among them, the refrigeration circuit generally includes a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger connected together. And the indoor heat exchanger is usually configured with a refrigerant flow channel and a medium flow channel that exchange heat with each other. During actual use, the refrigerant flow channel participates in the flow of the refrigerant in the refrigeration circuit, and the heat exchange medium flowing in the medium flow channel exchanges heat with the refrigerant flowing through the refrigerant flow channel and then flows into the user heat exchange terminal to change the indoor temperature through the user heat exchange terminal. However, during actual use, there are at least the following problems: The heat exchange medium circulating between the medium flow channel and the user heat exchange terminal is affected by thermal expansion and contraction, which will cause changes in the indoor pipeline water pressure. Especially after the temperature of the heat exchange medium rises, it is easy to cause pipeline rupture and affect the use reliability. How to design a heat pump system with high operating reliability is the technical problem to be solved by the present invention. Summary of the Invention

[0003] The present invention provides a pressure buffering component and a heat pump system, which buffer the influence of thermal expansion and contraction of the heat exchange medium on the pipeline through the pressure buffering component, so as to improve the operating reliability of the heat pump system.

[0004] To achieve the above technical purpose, the present invention is implemented by the following technical solutions:

[0005] A pressure buffering component, comprising:

[0006] A buffer tank, which is provided with a liquid inlet and a liquid outlet;

[0007] A flexible airbag filled with gas, and the flexible airbag is arranged in the buffer tank.

[0008] Further, a plurality of the flexible airbags are arranged at the upper end part inside the buffer tank.

[0009] Further, the buffer tank includes: a tank body, which is provided with the liquid inlet and the liquid outlet; a tank cover, and the tank cover is detachably installed on the tank body.

[0010] Further, the flexible airbag is fixed on the inner surface of the tank cover.

[0011] Further, a switchable first inflation nozzle is further arranged on the tank cover, and the first inflation nozzle communicates with the flexible airbag.

[0012] Further, the flexible airbag is fixed on the inner wall of the tank body.

[0013] Further, a second air nozzle which can be opened and closed is arranged outside the tank body, and the second air nozzle communicates with the flexible airbag.

[0014] Further, a first outward flange is arranged on the upper edge of the tank body, a second outward flange is arranged on the edge of the tank cover, a plurality of first mounting holes are formed in the first outward flange, a plurality of second mounting holes are formed in the second outward flange, and bolts penetrate through the first mounting holes and the second mounting holes and are threadedly connected with nuts; alternatively, an external thread is arranged on the tank body, an internal thread is arranged on the tank cover, and the tank cover is threadedly connected to the tank body.

[0015] Further, a phase change energy storage component is further arranged in the buffer tank.

[0016] The present invention further provides a heat pump system, including a refrigeration circuit and a user heat exchange terminal. The refrigeration circuit includes a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger. A refrigerant flow channel and a medium flow channel for heat exchange with each other are arranged in the indoor heat exchanger. The compressor, the outdoor heat exchanger, the throttling device, and the refrigerant flow channel are connected in sequence. The user heat exchange terminal is connected to the medium flow channel. The pressure buffer assembly as described above is further included, and the buffer tank in the pressure buffer assembly is connected in series between the user heat exchange terminal and the medium flow channel.

[0017] Compared with the prior art, the advantages and positive effects of the present invention are as follows: By arranging a flexible airbag in the buffer tank, during actual use, when the heat exchange medium expands and contracts due to temperature changes, the flexible airbag can deform under the action of the water pressure in the buffer tank to buffer the volume change of the heat exchange medium caused by temperature changes, avoid affecting the indoor pipeline and prevent the occurrence of pipeline rupture, so as to improve the operation reliability of the heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is the structural schematic diagram of the embodiment of the heat pump system of the present invention;

[0020] Figure 2 It is one of the structural schematic diagrams of the pressure buffer assembly in the embodiment of the heat pump system of the present invention;

[0021] Figure 3 This is the second structural schematic diagram of the pressure buffer component in the embodiment of the heat pump system of the present invention. Specific implementation manners

[0022] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] As Figures 1-3 shown, the heat pump system of this embodiment includes a refrigeration circuit 100 and a user heat exchange terminal 200. The refrigeration circuit 100 includes a compressor 101, an outdoor heat exchanger 102, a throttling device 103, and an indoor heat exchanger 104. The indoor heat exchanger 104 is configured with a refrigerant flow channel (not marked) and a medium flow channel (not marked) that exchange heat with each other. The compressor 101 is sequentially connected to the outdoor heat exchanger 102 and the refrigerant flow channel through a four-way valve 105. A throttling device 103 is connected between the outdoor heat exchanger 102 and the refrigerant flow channel. The user heat exchange terminal 200 is connected to the medium flow channel. Among them, the manifestation entity of the user heat exchange terminal 200 can adopt a radiator, a fan coil unit, etc. In order to accelerate the circulation of the heat exchange medium between the user heat exchange terminal 200 and the medium flow channel, a circulation pump 201 is usually configured. In addition, the indoor heat exchanger 104 usually adopts a plate heat exchanger or a shell-and-tube heat exchanger. The above structural configuration is the configuration method of a conventional heat pump system, which will not be elaborated and limited here.

[0024] In order to meet the requirement of reducing the impact on the indoor pipeline caused by the thermal expansion and contraction of the heat exchange medium, the heat pump system of this embodiment is further configured with a pressure buffer component 300; the pressure buffer component 300 includes a buffer tank 1 and a flexible airbag 2. The buffer tank 1 is provided with a liquid inlet 11 and a liquid outlet 12; the flexible airbag 2 is arranged in the buffer tank 1, and the liquid inlet 11 and the liquid outlet 12 are respectively communicated with the inside of the buffer tank 1. The buffer tank 1 is connected in series between the user heat exchange terminal 200 and the medium flow channel through the liquid inlet 11 and the liquid outlet 12.

[0025] Specifically, during the actual operation of the heat pump system, the refrigerant in the refrigeration circuit 100 circulates, and there is a circulation of the heat exchange medium between the user heat exchange terminal 200 and the indoor heat exchanger 104. The heat exchange medium and the refrigerant then conduct heat exchange in the indoor heat exchanger 104. In the winter heating mode, the temperature of the heat exchange medium is relatively high, causing the heat exchange medium to expand in volume. After the heat exchange medium expands due to the temperature increase, it will increase the liquid pressure in the buffer tank 1, and the flexible airbag 2 will deform under the action of the liquid pressure to buffer the impact of the volume expansion of the heat exchange medium on the pipeline.

[0026] Among them, in order to achieve a better buffering effect, a plurality of flexible airbags 2 can be provided at the upper end of the buffer tank 1. Specifically, the plurality of flexible airbags 2 cooperate with each other to obtain a better buffering effect. By arranging the flexible airbag 2 at the upper end of the buffer tank 1, the buffer medium mainly flows below the flexible airbag 2, and during the flow of the heat exchange medium, the flexible airbag 2 has less influence on the flowing heat exchange medium.

[0027] Furthermore, to facilitate the assembly of the flexible airbag 2 into the buffer tank 1. The buffer tank 1 includes: a tank body 13 and a tank cover 14, and a liquid inlet 11 and a liquid outlet 12 are provided on the tank body 13; the tank cover 14 is detachably installed on the tank body 13. Specifically, during the actual assembly process, the flexible airbag 2 can be first installed on the tank body 13 or the tank cover 14; then, the tank cover 14 is installed on the tank body 13 to complete the assembly process.

[0028] In the case where the flexible airbag 2 is installed on the tank cover 14, the flexible airbag 2 is installed on the inner surface of the tank cover 14. For example: the flexible airbag 2 can be bonded to the tank cover 14 by means of glue. Preferably, in order to facilitate inflation of the flexible airbag 2 during assembly, a switchable inflation nozzle 21 is further provided on the tank cover 14, and the inflation nozzle 21 communicates with the flexible airbag 2. Specifically, after the tank body 13, the tank cover 14 and the flexible airbag 2 are assembled, the flexible airbag 2 can be inflated through the inflation nozzle 21 outside the buffer tank 1. Similarly, during the later use process, when the flexible airbag 2 deflates, the flexible airbag 2 can also be replenished with gas through the inflation nozzle 21.

[0029] In the case where the flexible airbag 2 is installed on the tank body 13, the flexible airbag 2 is installed on the inner wall of the tank body 13. The specific installation method can refer to the method of installing the flexible airbag 2 on the tank cover 14, which will not be elaborated here.

[0030] In addition, to facilitate the assembly of the tank body 13 and the tank cover 14, a first outward flange (not marked) is provided at the upper edge of the tank body 13, and a second outward flange (not marked) is provided at the edge of the tank cover 14. A plurality of first mounting holes are formed in the first outward flange, and a plurality of second mounting holes are formed in the second outward flange. Bolts pass through the first mounting holes and the second mounting holes and are threadedly connected with nuts. Specifically, through the cooperation of the nuts and bolts, the first outward flange and the second outward flange can be made to cooperate, so that the tank body 13 and the tank cover 14 are tightly connected together. Alternatively, an external thread is provided on the tank body 3, and an internal thread is provided on the tank cover 14, and the tank cover 14 is threadedly connected to the tank body 13.

[0031] Furthermore, a phase change energy storage component 3 is also provided in the tank body 13. Specifically, a phase change material is configured in the phase change energy storage component 3, and the phase change material can play a role in energy storage. In the winter heating mode, heat can be stored through the phase change material; while in the summer cooling mode, cold can be stored through the phase change material.

[0032] More importantly, for the buffer tank 1 configured with the phase change energy storage component 3, its functions are different in different modes, which are specifically described as follows.

[0033] In the summer cooling mode:

[0034] After the user heat exchange terminal 200 receives the refrigeration operation instruction, the circulation pump 201 starts, and the user heat exchange terminal 200 begins to release cold to the room. The cold water at the outlet of the circulation pump 201 enters the user heat exchange terminal 200, cools the indoor air (for example: the user heat exchange terminal 200 uses a fan coil unit to blow cold air into the room to produce an air-conditioning refrigeration effect), and then the temperature of the heat exchange medium rises. Then it enters the indoor heat exchanger 104. If the return water temperature T of the indoor heat exchanger 104 is detected to be ≥ 13°C (the first temperature value) at this time, the refrigeration circuit 100 starts refrigeration operation. The cold water flowing out of the indoor heat exchanger 104 enters the buffer tank 1, cools and stores energy in the phase change energy storage material inside the phase change energy storage component 3 to a certain extent, then flows out of the buffer tank 1, enters the circulation pump 201, and then enters the user heat exchange terminal 200, repeating this cycle to complete the refrigeration cycle of the indoor water system. During the operation of the refrigeration circuit 100, when T ≤ 10°C (the second temperature value), the refrigeration circuit 100 stops refrigeration operation, and the circulation pump 201 continues to operate. During this process, the air-conditioning cold of the user heat exchange terminal 200 comes from the release of the stored cold in the phase change energy storage component 3 of the buffer tank 1. Since the buffer tank 1 has a certain amount of stored cold, it can provide cold for the user heat exchange terminal 200 for a long time, reducing the start-stop times of the refrigeration circuit 100 and avoiding the waste of electric energy caused by the frequent start-stop of the refrigeration circuit 100, with better energy-saving effects. When T ≥ 13°C, the stored cold in the buffer tank 1 has been released, and at this time the refrigeration circuit 100 starts refrigeration operation, and at the same time provides cold for the cold storage of the buffer tank 1 and the air cooling of the user heat exchange terminal 200 until T ≤ 10°C, and then starts the above cycle again, repeating this cycle.

[0035] In the case of winter heating:

[0036] After the user heat exchange terminal 200 receives the heating operation instruction, the circulation pump 201 starts, and the user heat exchange terminal 200 begins to operate; the hot water at the outlet of the circulation pump 201 enters the user heat exchange terminal 200, heats the indoor air, and then the water temperature decreases and enters the indoor heat exchanger 104. If the return water temperature T in the return water pipe 15 at the inlet of the indoor heat exchanger 104 is detected to be ≤ 39°C (the third temperature value) at this time, the refrigeration circuit 100 starts the heating operation. The heating hot water coming out of the indoor heat exchanger 104 enters the buffer tank 1, heats and stores the phase change energy storage material inside the phase change energy storage component 3 in the buffer tank 1 to a certain extent, and then the hot water output from the buffer tank 1 enters the circulation pump 201 and then enters the user heat exchange terminal 200 to heat the indoor air, and so on in a cycle, thus completing the heating cycle of the indoor water system. When T ≥ 42°C (the fourth temperature value), the refrigeration circuit 100 stops the heating operation, and the circulation pump 201 continues to operate. During this process, the heating heat of the user heat exchange terminal 200 comes from the release of the stored heat in the phase change energy storage component 3 of the buffer tank 1. Since the buffer tank 1 has a certain amount of stored heat, it can provide heat for the user heat exchange terminal 200 for a long time, thus reducing the start-stop times of the refrigeration circuit 100 and avoiding the waste of electric energy caused by the frequent start-stop of the refrigeration circuit 100, and having a good energy-saving effect. When T ≤ 39°C, the stored heat in the buffer tank 1 has been released completely. At this time, the refrigeration circuit 100 starts the heating operation and provides heat for both the heat storage of the buffer tank 1 and the air heating of the user heat exchange terminal 200 until T ≥ 42°C, and then the above cycle starts again, and so on.

[0037] During the heating process, when the refrigeration circuit 100 receives a defrosting instruction, the four-way valve 105 of the refrigeration circuit 100 changes its direction. The indoor heat exchanger 104 changes from a condenser under the heating condition to an evaporator under the defrosting condition, while the outdoor heat exchanger 102 changes from an evaporator under the heating condition to a condenser under the defrosting condition. At this time, the indoor circulation pump 201 continues to operate, and the phase change energy storage material in the phase change energy storage component 3 of the buffer tank 1 changes from a liquid state to a solid state to release heat. This heat first heats the indoor air through the user heat exchange terminal 200, and then enters the indoor heat exchanger 104 through the water pipeline, causing the liquid refrigerant therein to evaporate into a gas. After that, it enters the compressor 101 through the refrigerant pipeline, is compressed by the compressor 101 into a high-temperature and high-pressure refrigerant exhaust, and enters the outdoor heat exchanger 102 to defrost the outdoor heat exchanger 102. Therefore, the heat released from the buffer tank 1 provides sufficient heat for the defrosting of the refrigeration circuit 100 and also provides heat for maintaining the continuous heating of the user heat exchange terminal 200 during the defrosting process. This process can significantly reduce the defrosting time and maintain a relatively high air outlet temperature of the user heat exchange terminal 200. During the defrosting process, the indoor temperature can be kept stable without periodic fluctuations in the indoor temperature decrease, significantly improving the user experience, especially the comfort experience. After the defrosting is completed, the four-way valve 105 of the refrigeration circuit 100 changes its direction again to restore the heating state, and at the same time provides heat for the heat storage of the buffer tank 1 and the air heating of the user heat exchange terminal 200.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a heat pump system, comprising a refrigeration circuit and a user heat exchange terminal. The refrigeration circuit includes a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger. A refrigerant flow channel and a medium flow channel for heat exchange with each other are arranged in the indoor heat exchanger. The compressor, the outdoor heat exchanger, the throttling device, and the refrigerant flow channel are connected in sequence. The user heat exchange terminal is connected to the medium flow channel, characterized in that, It further includes a pressure buffer assembly; The pressure buffer assembly includes: A buffer tank, on which a liquid inlet and a liquid outlet are provided. The buffer tank is connected in series between the user heat exchange terminal and the medium flow path, and a phase change energy storage component is also provided in the buffer tank; A flexible airbag filled with gas, and the flexible airbag is arranged in the buffer tank; In the summer cooling mode: The circulation pump starts, and the user heat exchange terminal begins to release cold to the room. The cold water at the outlet of the circulation pump enters the user heat exchange terminal. After cooling the indoor air, the temperature of the heat exchange medium rises, and then it enters the indoor heat exchanger. If it is detected that the return water temperature T of the indoor heat exchanger is ≥ the first temperature value at this time, the refrigeration circuit starts refrigeration operation; The cold water flowing out of the indoor heat exchanger enters the buffer tank, cools and stores energy in the phase change energy storage material inside the phase change energy storage component to a certain extent, then flows out of the buffer tank and enters the circulation pump, and then enters the user heat exchange terminal, and so on in a cycle, thus completing the refrigeration cycle of the indoor water system; During the operation of the refrigeration circuit, when T ≤ the second temperature value, the refrigeration circuit stops refrigeration operation, and the circulation pump continues to operate. During this process, the air-conditioning cold of the user heat exchange terminal comes from the release of the stored cold in the phase change energy storage component of the buffer tank; The second temperature value is less than the first temperature value; In the winter heating mode: The circulation pump starts, and the user heat exchange terminal begins to operate; The hot water at the outlet of the circulation pump enters the user heat exchange terminal. After heating the indoor air, the water temperature decreases, and then it enters the indoor heat exchanger; If it is detected that the return water temperature T in the return water pipe at the inlet of the indoor heat exchanger is ≤ the third temperature value at this time, the refrigeration circuit starts heating operation; The heating hot water flowing out of the indoor heat exchanger enters the buffer tank, heats and stores energy in the phase change energy storage material inside the phase change energy storage component of the buffer tank to a certain extent, and the hot water output from the buffer tank enters the circulation pump, and then enters the user heat exchange terminal to heat the indoor air, and so on in a cycle, thus completing the heating cycle of the indoor water system; When T ≥ the fourth temperature value, the refrigeration circuit stops heating operation, and the circulation pump continues to operate. During this process, the heating heat of the user heat exchange terminal comes from the release of the stored heat in the phase change energy storage component of the buffer tank; The third temperature value is less than the fourth temperature value; During the heating process, when the refrigeration circuit receives a defrosting instruction, the four-way valve of the refrigeration circuit changes direction. The indoor heat exchanger changes from a condenser in the heating condition to an evaporator in the defrosting condition, and the outdoor heat exchanger changes from an evaporator in the heating condition to a condenser in the defrosting condition; The indoor circulation pump continues to operate. The phase change energy storage material in the phase change energy storage component of the buffer tank changes from a liquid state to a solid state to release heat. This heat first heats the indoor air through the user heat exchange terminal, and then enters the indoor heat exchanger through the water pipeline, causing the liquid refrigerant in the indoor heat exchanger to evaporate into a gas. Then it enters the compressor through the refrigerant pipeline, and is compressed by the compressor into high-temperature and high-pressure refrigerant exhaust gas to defrost the outdoor heat exchanger.

2. The control method of the heat pump system according to claim 1, characterized in that, A plurality of the flexible airbags are arranged at the upper end inside the buffer tank.

3. The control method of the heat pump system according to claim 1, characterized in that The buffer tank includes: A tank body, on which the liquid inlet and the liquid outlet are provided; A tank cover detachably installed on the tank body.

4. The control method of the heat pump system according to claim 3, characterized in that, The flexible airbag is fixed on the inner surface of the can lid.

5. The control method of the heat pump system according to claim 4, characterized in that, A switchable first air nozzle is further provided on the can lid, and the first air nozzle communicates with the flexible airbag.

6. The control method of the heat pump system according to claim 3, wherein The flexible airbag is fixed on the inner wall of the can body.

7. The control method of the heat pump system according to claim 6, characterized in that, A switchable second air nozzle is provided outside the can body, and the second air nozzle communicates with the flexible airbag.

8. The control method of the heat pump system according to claim 3, wherein A first outward flange is provided at the upper edge of the can body, a second outward flange is provided at the edge of the can lid, a plurality of first mounting holes are formed in the first outward flange, a plurality of second mounting holes are formed in the second outward flange, and bolts pass through the first mounting holes and the second mounting holes and are threadedly connected with nuts; alternatively, an external thread is provided on the can body, an internal thread is provided on the can lid, and the can lid is threadedly connected to the can body.

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