Control method for heat pump system, heat pump system, and storage medium

Abstract

The application discloses a control method of a heat pump system, the heat pump system and a storage medium. The heat pump system comprises a refrigerant main circuit and a refrigerant branch circuit, the refrigerant branch circuit comprises an energy storage device, a first end of the refrigerant branch circuit is communicated with a discharge port of a compressor, and a pipeline between an indoor unit and an outdoor heat exchanger is connected with a second end of the refrigerant branch circuit. The method comprises the following steps: controlling a reversing assembly to operate in a first state, so that the outdoor heat exchanger is communicated with the gas return port of the compressor; when the heat pump system operates to reach a preset condition, the reversing assembly is controlled to operate in a second state, so that the indoor unit is communicated with the discharge port of the compressor; wherein the preset condition indicates that there is a frosting risk of the indoor unit when the heat pump system operates in a defrosting mode. The application aims to reduce the frosting risk of the indoor heat exchanger and improve the defrosting effect of the outdoor heat exchanger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat pump, in particular to a control method of heat pump system, a heat pump system and a storage medium. BACKGROUND

[0002] In addition to setting the indoor unit to provide the required energy for indoor regulation, the heat pump system also sets an energy storage device to store energy to meet other regulation requirements. Among them, the energy storage device can be communicated with the exhaust side of the compressor to store the heat of the high-temperature refrigerant discharged by the compressor in the energy storage device. When the energy storage device is in the energy storage state, the outdoor heat exchanger in the heat pump system generally needs to absorb heat from the environment as an evaporator, and the outdoor heat exchanger is easy to frost when the heat pump system operates in a low-temperature environment, which affects the normal operation of the system.

[0003] When the heat pump system starts the defrosting mode under the energy storage device, the outdoor heat exchanger is generally switched to the condensing state to melt the frost by releasing heat, and the indoor heat exchanger needs to be switched to the evaporating state to absorb environmental heat for defrosting. However, the energy storage device cannot be switched to a low-pressure state, and the heat required for defrosting can only be obtained by evaporative heat absorption of the indoor heat exchanger. Especially when the system frequently operates in the defrosting mode, the indoor heat exchanger coil temperature is easy to be too low to frost, which not only affects the normal operation of the system, but also leads to poor defrosting effect of the outdoor heat exchanger. SUMMARY

[0004] The main purpose of the present application is to provide a control method of heat pump system, a heat pump system and a storage medium, which aims to reduce the frosting risk of indoor heat exchanger and improve the defrosting effect of outdoor heat exchanger.

[0005] To achieve the above-mentioned purpose, the present application provides a control method of heat pump system, the heat pump system comprising a main refrigerant circuit and a branch refrigerant circuit, the main refrigerant circuit comprising an indoor unit, an outdoor heat exchanger, a reversing component and a compressor, the indoor unit, the outdoor heat exchanger, the exhaust port of the compressor and the return port of the compressor are connected with the reversing component, the branch refrigerant circuit comprising an energy storage device, the first end of the branch refrigerant circuit is communicated with the exhaust port of the compressor, or the first end of the branch refrigerant circuit is connected with the exhaust port or return port of the compressor through the reversing component, the pipeline between the indoor unit and the outdoor heat exchanger is connected with the second end of the branch refrigerant circuit, the control method of the heat pump system comprising the following steps:

[0006] Controlling the reversing component to operate in a first state to make the outdoor heat exchanger communicated with the return port of the compressor;

[0007] When the heat pump system operates to reach a preset condition, controlling the reversing component to operate in a second state to make the indoor unit communicated with the exhaust port of the compressor;

[0008] wherein the preset condition represents that the indoor unit has a risk of frosting when the heat pump system operates in the defrosting mode.

[0009] Optionally, before the step of controlling the reversing component to operate in the second state when the heat pump system operates to reach the preset condition, the method further comprises:

[0010] obtaining an indoor environment temperature corresponding to the heat pump system and / or a defrosting duration when the heat pump system operates the defrosting mode last time and / or a characteristic temperature of an indoor heat exchanger in the indoor unit;

[0011] determining a target duration according to the indoor environment temperature and / or the defrosting duration and / or the characteristic temperature;

[0012] The step of controlling the reversing component to operate in the second state when the heat pump system operates to reach the preset condition comprises:

[0013] controlling the reversing component to operate in the second state for the target duration when the heat pump system operates to reach the preset condition.

[0014] Optionally, the step of determining the target duration according to the indoor environment temperature and / or the defrosting duration and / or the characteristic temperature comprises:

[0015] determining a reference duration according to the indoor environment temperature, determining a first correction duration according to the defrosting duration, and determining a second correction duration according to the characteristic temperature;

[0016] correcting the reference duration according to the first correction duration and the second correction duration to obtain the target duration.

[0017] Optionally, the indoor environment temperature is negatively correlated with the reference duration, the defrosting duration is positively correlated with the first correction duration, and the second correction duration is negatively correlated with the characteristic temperature.

[0018] Optionally, the number of the indoor units is more than one, and the step of obtaining the indoor environment temperature corresponding to the heat pump system comprises:

[0019] obtaining a first temperature of an indoor environment adjusted by the indoor unit;

[0020] determining the indoor environment temperature according to more than one first temperature.

[0021] Optionally, the number of the indoor units is more than one, and the step of obtaining the characteristic temperature of the indoor heat exchanger in the indoor unit comprises:

[0022] obtaining an inlet temperature and an outlet temperature of the indoor heat exchanger in the indoor unit;

[0023] determining a second temperature of the indoor heat exchanger corresponding to the inlet temperature and the outlet temperature;

[0024] determining the feature temperature based on the plurality of second temperatures.

[0025] Optionally, the preset condition comprises at least one of the following conditions:

[0026] an outdoor ambient temperature corresponding to the heat pump system is less than a first preset ambient temperature;

[0027] a defrosting duration of the heat pump system in a last time when the heat pump system runs the defrosting mode is greater than a preset duration;

[0028] a feature temperature of an indoor heat exchanger in the indoor unit is less than a preset temperature;

[0029] an outdoor ambient temperature corresponding to the heat pump system is less than or equal to a second preset ambient temperature.

[0030] Optionally, the indoor unit comprises an indoor heat exchanger and a first control valve connected in series with the indoor heat exchanger, and the control method of the heat pump system further comprises:

[0031] controlling the reversing assembly to operate in the first state so that the outdoor heat exchanger and the indoor unit are both communicated with the gas return port of the compressor, and controlling the first control valve to operate at a degree less than a preset degree;

[0032] when the heat pump system operates to reach the preset condition, controlling the reversing assembly to operate in the second state so that the indoor unit is communicated with the gas discharge port of the compressor, and controlling the first control valve to operate at a degree greater than or equal to the preset degree.

[0033] Optionally, the control method of the heat pump system further comprises:

[0034] when the heat pump system operates to reach a starting condition of the defrosting mode, controlling the reversing assembly to operate in a third state so that the outdoor heat exchanger is communicated with the gas discharge port of the compressor, and the indoor unit is communicated with the gas return port of the compressor;

[0035] when the heat pump system operates to reach an exiting condition of the defrosting mode, performing the step of controlling the reversing assembly to operate in the first state so that the outdoor heat exchanger and the indoor unit are both communicated with the gas return port of the compressor.

[0036] Optionally, the reversing assembly comprises a first reversing valve and a second reversing valve, the indoor unit, the gas return port and the gas exhaust port are respectively communicated with different valve ports of the first reversing valve, the outdoor heat exchanger, the gas return port and the gas exhaust port are respectively communicated with different valve ports of the second reversing valve, the step of controlling the reversing assembly to operate in the first state so that the outdoor heat exchanger and the indoor unit are both communicated with the gas return port of the compressor comprises:

[0037] controlling the first reversing valve to operate in the second valve position so that the gas return port is communicated with the indoor unit and the gas exhaust port is blocked from the indoor unit, and controlling the second reversing valve to operate in the fourth valve position so that the gas return port is communicated with the outdoor heat exchanger and the gas exhaust port is blocked from the outdoor heat exchanger;

[0038] the step of controlling the reversing assembly to operate in the second state so that the indoor unit is communicated with the gas exhaust port of the compressor comprises:

[0039] controlling the first reversing valve to switch to the first valve position so that the gas exhaust port is communicated with the indoor unit and the gas return port is blocked from the indoor unit, and controlling the second reversing valve to maintain the fourth valve position.

[0040] In addition, in order to achieve the above-mentioned purpose, the present application further provides a heat pump system, which comprises a control device, a main refrigerant circuit and a branch refrigerant circuit, the main refrigerant circuit comprises an indoor unit, an outdoor heat exchanger, a reversing assembly and a compressor, the indoor unit, the outdoor heat exchanger, a gas exhaust port of the compressor and a gas return port of the compressor are connected with the reversing assembly, the branch refrigerant circuit comprises an energy storage device, a first end of the branch refrigerant circuit is communicated with the gas exhaust port of the compressor, and a pipeline between the indoor unit and the outdoor heat exchanger is connected with a second end of the branch refrigerant circuit.

[0041] The reversing assembly is connected with the control device, the control device comprises a memory, a processor and a control program of the heat pump system stored in the memory and executable on the processor, and the control program of the heat pump system realizes the steps of the control method of the heat pump system according to any one of the above-mentioned heat pump systems when executed by the processor.

[0042] In addition, in order to achieve the above-mentioned purpose, the present application further provides a storage medium, which stores a control program of a heat pump system, and the control program of the heat pump system realizes the steps of the control method of the heat pump system according to any one of the above-mentioned heat pump systems when executed by a processor.

[0043] The application provides a control method of a heat pump system, wherein in addition to a refrigerant main circuit, the heat pump system is provided with a refrigerant branch circuit comprising an energy storage device, one end of the refrigerant branch circuit is connected with a discharge port of a compressor in the refrigerant main circuit, and the other end of the refrigerant branch circuit is in communication with a pipeline between an indoor unit and an outdoor unit in the refrigerant main circuit. Based on this, when a reversing assembly operates in a first state, the outdoor heat exchanger and the indoor unit are both on the low-pressure side, and the energy storage device is on the high-pressure side. The indoor heat exchanger can absorb heat in the environment and store the heat in the energy storage device. In this process, when it is identified that the indoor unit has a frosting risk when the heat pump system operates in a defrosting mode, the reversing assembly is switched to a second state to switch the indoor heat exchanger from the low-pressure side to the high-pressure side. High-temperature refrigerant discharged by the compressor can flow into the indoor heat exchanger to heat the indoor heat exchanger, so that the temperature of the indoor heat exchanger is prevented from being too low to cause frosting when the heat pump system operates in the defrosting mode in the subsequent operation, and heat can also be provided for defrosting of the outdoor heat exchanger, so that the frosting risk of the indoor heat exchanger is reduced and the defrosting effect of the outdoor heat exchanger is improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 FIG. 1 is a structural schematic diagram of an embodiment of the heat pump system of the application;

[0045] Figure 2 FIG. 2 is a structural schematic diagram of hardware involved in operation of an embodiment of the heat pump system of the application;

[0046] Figure 3 FIG. 3 is a flow schematic diagram of an embodiment of the control method of the heat pump system of the application;

[0047] Figure 4 FIG. 4 is a flow schematic diagram of another embodiment of the control method of the heat pump system of the application;

[0048] Figure 5 FIG. 5 is a flow schematic diagram of another optional embodiment of the control method of the heat pump system of the application.

[0049] The implementation, functional features and advantages of the application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are merely intended to explain the application and are not intended to limit the application.

[0051] The embodiment of the application provides a heat pump system.

[0052] In the embodiment of the application, referring to Figures 1 to 3 , the heat pump system comprises a control device 100, a refrigerant main circuit and a refrigerant branch circuit connected with the refrigerant main circuit, the refrigerant main circuit comprises an indoor unit, and the refrigerant branch circuit comprises an energy storage device 6.

[0053] In this embodiment, the refrigerant main circuit includes a compressor 1, an indoor unit, a throttling device 3, an outdoor heat exchanger 4, and a reversing assembly 5. The indoor unit, the throttling device 3, and the outdoor heat exchanger 4 are connected in sequence. The exhaust port of the compressor 1, the return port of the compressor 1, the indoor unit, and the outdoor heat exchanger 4 are all connected to the reversing assembly 5. The compressor 1, the throttling device 3, and the indoor unit are all connected to the control device 100.

[0054] The indoor unit includes an indoor heat exchanger 21 and a first control valve 22 connected in series with the indoor heat exchanger 21. The indoor unit also includes an indoor fan 23 corresponding to the indoor heat exchanger 21, which drives indoor air to exchange heat with the indoor heat exchanger 21. Both the first control valve 22 and the indoor fan 23 are connected to the control device 100.

[0055] In this embodiment, the number of indoor units is more than one, such as two, three, or four. In other embodiments, the number of indoor units may be one.

[0056] The reversing assembly 5 is used to switch the refrigerant flow direction between the indoor unit and the outdoor heat exchanger 4.

[0057] In this embodiment, as Figure 1 As shown, the reversing assembly 5 includes a first reversing valve 51 and a second reversing valve 52. The first reversing valve 51 includes a first three-way valve or a first four-way valve, and the second reversing valve 52 includes a second three-way valve or a second four-way valve. The indoor heat exchanger 21, the exhaust port, and the return port are respectively connected to different valve ports of the first reversing valve 51, and the outdoor heat exchanger 4, the exhaust port, and the return port are respectively connected to different valve ports of the second reversing valve 52.

[0058] The first reversing valve 51 has a first valve position and a second valve position. When the first reversing valve 51 is in the first valve position, the exhaust port of the compressor 1 is connected to the indoor unit, and the return port of the compressor 1 is blocked from the indoor unit. When the first reversing valve 51 is in the second valve position, the exhaust port of the compressor 1 is blocked from the indoor unit, and the return port of the compressor 1 is connected to the indoor unit.

[0059] The second reversing valve 52 has a third valve position and a fourth valve position. When the second reversing valve 52 is in the third valve position, the exhaust port of the compressor 1 is connected to the outdoor heat exchanger 4, and the return port of the compressor 1 is blocked from the outdoor heat exchanger 4. When the second reversing valve 52 is in the fourth valve position, the exhaust port of the compressor 1 is blocked from the outdoor heat exchanger 4, and the return port of the compressor 1 is connected to the outdoor heat exchanger 4. In this embodiment, the energy storage device 6 includes a water tank or a water heater. In other embodiments, the energy storage device 6 may also be a device that stores other energy storage media.

[0060] The first end of the refrigerant branch is connected to the discharge port of the compressor 1, and the pipeline between the indoor unit and the outdoor heat exchanger 4 is connected to the second end of the refrigerant branch. In the embodiment, the pipeline between the throttling device 3 and the first control valve 22 communicates with the second end of the refrigerant branch.

[0061] The refrigerant branch further comprises a second control valve 7 connected in series with the energy storage device 6. The second control valve 7 is connected to the control device 100, and the second control valve 7 can be used to control the flow of the refrigerant branch, and the second control valve 7 is connected to the control device 100. When the second control valve 7 is opened, the energy storage device 6 is in an energy storage state; when the second control valve 7 is closed, the energy storage device 6 is in a stop energy storage state.

[0062] In an implementation manner of the embodiment, the reversing assembly further comprises a switching valve (not shown in the figure), which can be a four-way valve or a three-way valve, and the switching valve has a first state and a second state. When the switching valve is in the first state, the gas inlet of the compressor 1 communicates with the energy storage device 6; when the switching valve is in the second state, the discharge port of the compressor 1 communicates with the energy storage device 6.

[0063] Based on the above structure, the heat pump system can achieve at least the following operating states through the state switching of the reversing assembly 5:

[0064] When the reversing assembly 5 operates in the first state, the first reversing valve 51 operates in the second valve position, the second reversing valve 52 operates in the fourth valve position, the discharge port of the compressor 1 communicates with the energy storage device 6 (if the reversing assembly comprises the above-mentioned switching valve, the switching valve is in the second state), the outdoor heat exchanger 4 and the indoor unit both communicate with the gas inlet of the compressor 1, and when the second control valve 7 is opened or the second control valve 7 is not provided, all the refrigerant discharged by the compressor 1 flows into the refrigerant branch, and when the refrigerant flows through the energy storage device 6, the heat in the refrigerant is stored in the energy storage device 6. The refrigerant flowing out of the refrigerant branch can all or part of the refrigerant flow into the outdoor heat exchanger 4 and then return to the compressor 1 after heat exchange. Among them, when the first control valve 22 is opened, the refrigerant flowing out of the refrigerant branch can part of the refrigerant flow into the indoor heat exchanger 4 and then return to the compressor 1 after heat exchange; when the first control valve 22 is closed, the refrigerant flowing out of the refrigerant branch stops flowing into the indoor heat exchanger 21. In the first state, the outdoor heat exchanger 4 is in an evaporation state, and the indoor heat exchanger 21 is in a stop heat exchange state or an evaporation state. At this time, the heat pump system is in a separate energy storage state.

[0065] When the reversing assembly 5 is in the second state, the first reversing valve 51 is in the first valve position, the second reversing valve 52 is in the fourth valve position, the exhaust port of the compressor 1 is connected to the energy storage device 6 (if the reversing assembly includes the aforementioned switching valve, the switching valve is in the second state), the outdoor heat exchanger 4 is connected to the return port of the compressor 1, and the indoor unit is connected to the exhaust port of the compressor 1. When the second control valve 7 is open, a portion of the refrigerant discharged from the compressor 1 flows into the refrigerant branch. As it flows through the energy storage device 6, the heat in the refrigerant is stored in the energy storage device 6. The refrigerant flowing out of the refrigerant branch can flow into the outdoor heat exchanger 4 for heat exchange and then return to the compressor 1. Another portion of the refrigerant discharged from the compressor 1 flows into the indoor unit, raising its temperature. When the first control valve 22 is open, the refrigerant flowing out of the indoor heat exchanger 4 flows sequentially through the throttling device 3 and the outdoor heat exchanger 4 before returning to the compressor 1. Furthermore, when the second control valve 7 is closed, the refrigerant discharged from the compressor 1 stops flowing into the refrigerant branch and instead flows sequentially through the indoor unit, the throttling device 3, and the outdoor heat exchanger 4 before returning to the compressor. In the second state, the outdoor heat exchanger 4 is in an evaporating state, and the indoor heat exchanger 21 is in a condensing state. When the second control valve 7 is open, the heat pump system is in an energy storage state while simultaneously heating the indoor heat exchanger. When the second control valve 7 is closed, the heat pump system stops energy storage while the indoor heat exchanger provides heating.

[0066] When the reversing assembly 5 operates in the third state, the first reversing valve 51 operates in the second valve position, the second reversing valve 52 operates in the fourth valve position, the exhaust port of the compressor 1 is connected to the energy storage device 6 (if the reversing assembly includes the aforementioned switching valve, the switching valve is in the second state), the outdoor heat exchanger 4 is connected to the exhaust port of the compressor 1, and the indoor unit is connected to the return port of the compressor 1. A portion of the refrigerant discharged from the compressor 1 flows into the refrigerant branch, and the heat in the refrigerant is stored in the energy storage device 6 as it flows through it. The refrigerant flowing out of the refrigerant branch flows back to the compressor 1 after heat exchange in the indoor unit. Another portion of the refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 4 to release heat. The refrigerant flowing out of the outdoor heat exchanger 4 flows back to the compressor 1 after heat exchange in the indoor unit. In the third state, the outdoor heat exchanger 4 is in a condensing state, and the indoor heat exchanger 21 is in an evaporating state. At this time, the heat pump system can use the heat of the refrigerant flowing through the outdoor heat exchanger 4 to melt the frost in the outdoor unit, or the heat pump system can cool the indoor environment.

[0067] Furthermore, in this embodiment, referring to Figures 1 to 3The heat pump system further comprises a temperature detection module 01 connected with the control device 100. The temperature detection module 01 is arranged at the indoor heat exchanger 21 to detect the characteristic temperature of the indoor heat exchanger. In the embodiment, the temperature detection module 01 comprises a first temperature sensor arranged at the inlet of the indoor heat exchanger 21 and / or a second temperature sensor arranged at the outlet of the indoor heat exchanger 21. In other embodiments, the temperature detection module 01 can further comprise a third temperature sensor arranged at the middle part of the indoor heat exchanger coil.

[0068] Further, in the embodiment, the heat pump system further comprises an environment detection module 02 connected with the control device 100. The environment detection module 02 can be arranged at the environment where the heat pump system is located to detect the environment temperature corresponding to the heat pump system. In the embodiment, the environment detection module 02 comprises an indoor temperature sensor arranged at the indoor space regulated by the indoor unit and / or an outdoor temperature sensor arranged at the outdoor environment where the heat pump system is located. Figures 1 to 3

[0069] In the embodiment of the present application, referring to Figure 2 The control device 100 of the heat pump system comprises a processor 1001 such as CPU, a memory 1002, and a timer 1003. These components are connected through a communication bus for communication. The memory 1002 can be a high-speed RAM memory or a stable memory such as a disk memory. The memory 1002 can optionally be a storage device independent of the aforementioned processor 1001.

[0070] Those skilled in the art can understand that, Figure 2 The device structure shown in the embodiment is not a limitation on the device, and can include more or fewer components than shown, or combine certain components, or different component arrangements.

[0071] As shown in Figure 2 The memory 1002 as a computer storage medium can include a control program of the heat pump system.

[0072] In the device shown in Figure 2 The processor 1001 can be used to call the control program of the heat pump system stored in the memory 1002, and perform the related step operations of the control method of the heat pump system in the following embodiments.

[0073] The embodiment of the present application further provides a control method of a heat pump system, applied to the heat pump system.

[0074] Referring to Figure 3 An embodiment of the control method of the heat pump system is provided. In the embodiment, the control method of the heat pump system comprises:​

[0075] Step S10, control the reversing assembly to operate in a first state, so that the outdoor heat exchanger is communicated with the return gas port of the compressor; at this time, the indoor unit can be communicated with the return gas port of the compressor.

[0076] Wherein, the step S10 can be performed when a first instruction of starting the separate energy storage mode is received by the user; the step S10 can also be performed when the indoor unit of the heat pump system stops running in the heating state or the cooling state; the step S10 can also be performed after the defrosting mode is run during the operation of the separate energy storage mode of the heat pump system and the defrosting mode is exited, etc.

[0077] In one implementation manner of the embodiment, the reversing assembly includes the first reversing valve and the second reversing valve described above. The first reversing valve is controlled to operate in the second valve position so that the return gas port is communicated with the indoor unit and the discharge port is blocked from the indoor unit, and the second reversing valve is controlled to operate in the fourth valve position so that the return gas port is communicated with the outdoor heat exchanger and the discharge port is blocked from the outdoor heat exchanger.

[0078] During the process of controlling the reversing assembly to operate in the first state, the first reversing valve can be controlled to operate in the second valve position and the second reversing valve can be controlled to operate in the fourth valve position, at this time, the outdoor heat exchanger and the indoor unit are both communicated with the return gas port of the compressor, when the second control valve is opened or when the second control valve is not provided, all the refrigerant discharged by the compressor flows into the refrigerant branch, when the refrigerant flows through the energy storage device, the heat in the refrigerant is stored in the energy storage device, and the refrigerant flowing out of the refrigerant branch can all or partially flow into the outdoor heat exchanger to exchange heat and then return to the compressor. Wherein, when the first control valve is opened, the refrigerant flowing out of the refrigerant branch can partially flow into the indoor heat exchanger to exchange heat and then return to the compressor; when the first control valve is closed, the refrigerant flowing out of the refrigerant branch stops flowing into the indoor heat exchanger 21. In the first state, the outdoor heat exchanger 4 is in the evaporation state, and the indoor heat exchanger 21 is in the stop heat exchange state or the evaporation state, at this time, the heat pump system is in the separate energy storage state.

[0079] In another implementation manner of the embodiment, the reversing assembly can also be a single refrigerant adjusting piece with a multi-flow switching function, then the reversing assembly can be controlled to operate in a first operating position, so that the return gas port is communicated with the indoor unit and the discharge port is blocked from the indoor unit, and the return gas port is communicated with the outdoor heat exchanger and the discharge port is blocked from the outdoor heat exchanger.

[0080] Step S20, when the heat pump system operates to reach a preset condition, control the reversing assembly to operate in a second state, so that the indoor unit is communicated with the discharge port of the compressor;

[0081] The preset condition indicates that the indoor unit has a frosting risk when the heat pump system operates in the defrosting mode.

[0082] In the embodiment, the indoor heat exchanger is in the evaporating state and the outdoor heat exchanger is in the condensing state in the defrosting mode. At this time, the energy storage device is in the energy storage state or the non-energy storage state.

[0083] The frosting risk here can be the frosting risk caused by the operation of the heat pump system in the defrosting mode before the current time, or can be the frosting risk that can exist after the heat pump system operates in the defrosting mode.

[0084] The preset condition includes the condition required for the operating parameters of the heat pump system itself and / or the environmental parameters of the environment in which the heat pump system is located to reach when the indoor unit has a frosting risk caused by the operation in the defrosting mode.

[0085] In one implementation of the embodiment, the reversing assembly includes the first reversing valve and the second reversing valve described above, the first reversing valve is controlled to switch to the first valve position to operate so that the exhaust port is communicated with the indoor unit and the return port is blocked from the indoor unit, and the second reversing valve is controlled to maintain the fourth valve position.

[0086] The reversing assembly is controlled to operate in the second state, and specifically, the first reversing valve is controlled to operate in the first valve position, and the second reversing valve is controlled to operate in the fourth valve position. At this time, the outdoor heat exchanger is communicated with the return port of the compressor, and the indoor unit is communicated with the exhaust port of the compressor. When the second control valve is opened or is not provided, part of the refrigerant discharged by the compressor flows into the refrigerant branch, and the heat in the refrigerant is stored in the energy storage device when the refrigerant flows through the energy storage device. The refrigerant flowing out of the refrigerant branch can flow into the outdoor heat exchanger to exchange heat and then return to the compressor. Another part of the refrigerant discharged by the compressor flows into the indoor unit to increase the temperature of the indoor unit. The refrigerant flowing out of the indoor unit flows through the throttling device and the outdoor heat exchanger in sequence and then returns to the compressor. In addition, when the second control valve is closed, the refrigerant discharged by the compressor stops flowing into the refrigerant branch, but flows through the indoor unit, the throttling device, and the outdoor heat exchanger in sequence and then returns to the compressor. In the second state, the outdoor heat exchanger is in the evaporating state, and the indoor heat exchanger is in the condensing state. The temperature of the indoor heat exchanger is increased. Based on this, even if the heat pump system enters the defrosting mode subsequently, the indoor heat exchanger can absorb the heat of the coil in the evaporating state, thereby avoiding icing due to too low temperature.

[0087] In another implementation of the embodiment, the reversing assembly can also be a single refrigerant adjusting piece with a multi-flow path switching function. The reversing assembly can be controlled to operate in the second operating position so that the exhaust port is communicated with the indoor unit, the return port is blocked from the indoor unit, the return port is communicated with the outdoor heat exchanger, and the exhaust port is blocked from the outdoor heat exchanger.

[0088] The control method of the heat pump system provided in the embodiment of the present application is based on the fact that, in addition to the main refrigerant circuit, the heat pump system is also provided with a refrigerant branch circuit including an energy storage device, one end of the refrigerant branch circuit is connected with the discharge port of the compressor in the main refrigerant circuit, and the other end of the refrigerant branch circuit is in communication with the pipeline between the indoor unit and the outdoor unit in the main refrigerant circuit. Based on this, when the reversing assembly is operated in the first state, the outdoor heat exchanger and the indoor unit are both on the low-pressure side, and the energy storage device is on the high-pressure side. The indoor heat exchanger can absorb heat from the environment and store the heat in the energy storage device. In this process, when it is identified that the indoor unit has a frosting risk when the heat pump system is defrosted, the reversing assembly is switched to the second state to switch the indoor heat exchanger from the low-pressure side to the high-pressure side. The high-temperature refrigerant discharged by the compressor can flow into the indoor heat exchanger to heat the indoor heat exchanger, so as to ensure that the temperature of the indoor heat exchanger will not be too low to cause frosting when the heat pump system is subsequently operated in the defrosting mode, and the heat pump system can also provide heat for the defrosting of the outdoor heat exchanger, thereby reducing the frosting risk of the indoor heat exchanger and improving the defrosting effect of the outdoor heat exchanger.

[0089] Further, based on the above-mentioned embodiment, another embodiment of the control method of the heat pump system of the present application is provided. In this embodiment, referring to Figure 4 , the step S20 further includes:

[0090] Step S201: acquiring the indoor environment temperature corresponding to the heat pump system and / or the defrosting duration when the heat pump system is operated in the defrosting mode last time and / or the characteristic temperature of the indoor heat exchanger in the indoor unit.

[0091] The indoor environment temperature can be the temperature detected by the temperature sensor in the indoor space regulated by the indoor unit, or can be the temperature determined according to the temperature data detected by the temperature sensor in the indoor space regulated by the indoor unit.

[0092] When the number of indoor units is more than one, the indoor environment temperature can be determined according to the indoor temperatures corresponding to the more than one indoor units, or the indoor temperature corresponding to the indoor unit that meets the set condition can be determined as the indoor environment temperature.

[0093] The defrosting duration is 0 when the heat pump system has not been operated in the defrosting mode before the current time. When the heat pump system has been operated in the defrosting mode before the current time, the operation duration in the last defrosting mode closest to the current time is taken as the defrosting duration.

[0094] The characteristic temperature of the indoor heat exchanger can be directly detected by the temperature sensor on the indoor heat exchanger, or can be determined according to the temperature data detected by the temperature sensor on the indoor heat exchanger.

[0095] When the number of indoor units is more than one, the feature temperature can be determined according to the indoor heat exchanger temperature corresponding to the more than one indoor units, or the indoor heat exchanger temperature corresponding to the indoor unit satisfying the set condition can be determined as the feature temperature.

[0096] After step S10, when the running time length of the reversing assembly in the first state reaches the set time length, step S201 is performed.

[0097] In step S202, the target time length is determined according to the indoor environment temperature and / or the defrosting time length and / or the feature temperature.

[0098] The target time length is specifically a target value of the running time length of the heat pump system in the second state when the heat pump system runs to the preset condition.

[0099] In the embodiment, the target time length is determined according to the indoor environment temperature, the defrosting time length and the feature temperature. In other embodiments, the target time length can also be determined according to one or two of the indoor environment temperature, the defrosting time length and the feature temperature.

[0100] Different indoor environment temperatures and / or different defrosting time lengths and / or different feature temperatures correspond to different target time lengths. The target time length can be determined according to the result of looking up a pre-set mapping table through the indoor environment temperature and / or the defrosting time length and / or the feature temperature. Alternatively, a relationship between the indoor environment temperature and / or the defrosting time length and / or the feature temperature and the target time length can be pre-set, and the target time length can be calculated by substituting the indoor environment temperature and / or the defrosting time length and / or the feature temperature into the relationship.

[0101] Step S20 includes:

[0102] In step S21, when the heat pump system runs to the preset condition, the reversing assembly is controlled to run in the second state for the target time length.

[0103] The process returns to step S10 when the running time length of the reversing assembly in the second state reaches the target time length.

[0104] In the embodiment, the indoor environment temperature and / or the defrosting time length and / or the feature temperature of the indoor heat exchanger can accurately reflect whether the frosting risk of the indoor heat exchanger and the defrosting heat are sufficient when the heat pump system defrosts, and based on this, the target time length of the preheating of the indoor heat exchanger is determined according to the indoor environment temperature and / or the defrosting time length and / or the feature temperature of the indoor heat exchanger, which is beneficial to further reduce the frosting risk of the indoor heat exchanger and improve the defrosting effect when defrosting.

[0105] In other embodiments, the reversing assembly is also controlled to run in the second state for a pre-set fixed time length.

[0106] Further, in the embodiment, step S202 comprises: determining a reference time length according to the indoor environment temperature, determining a first correction time length according to the defrosting time length, and determining a second correction time length according to the feature temperature; correcting the reference time length according to the first correction time length and the second correction time length to obtain the target time length.

[0107] Different indoor environment temperatures correspond to different reference time lengths, different defrosting time lengths correspond to different first correction time lengths, and different feature temperatures correspond to different second correction time lengths. In the embodiment, the indoor environment temperature is negatively correlated with the reference time length, the defrosting time length is positively correlated with the first correction time length, and the second correction time length is negatively correlated with the feature temperature. In other embodiments, the indoor environment temperature can also be positively correlated with the reference time length, or the defrosting time length is negatively correlated with the first correction time length, or the feature temperature is positively correlated with the second correction time length.

[0108] In the embodiment, the reference time length is determined according to the temperature interval in which the indoor environment temperature is located, the first correction time length is determined according to the time length interval in which the defrosting time length is located, and the second correction time length is determined according to the temperature interval in which the feature temperature is located. In other embodiments, the reference time length can also be calculated by substituting the indoor environment temperature into the first formula, or the first correction time length can be calculated by substituting the defrosting time length into the second formula, or the second correction time length can be calculated by substituting the feature temperature into the third formula.

[0109] In order to better understand the scheme of the embodiment, define Ti-env' as the indoor environment temperature, t_fro as the defrosting time length, and Ti_pipe' as the feature temperature of the indoor heat exchanger. The following is a specific example to illustrate the determination process of the target time length mentioned in the embodiment:

[0110] 1) The corresponding relationship between the indoor environment temperature and the reference time length is shown in Table 1 below:

[0111] Ti-env' (°C) Reference duration (s) Ti-env' ≥ 20 0 15 < Ti-env' < 20 10 10 < Ti-env' < 15 20 5 < Ti-env' < 10 30 0 < Ti-env' < 5 40 Ti-env' < 0 60

[0112] Table 1

[0113] 2) The relationship between the defrosting time length and the first correction time length is shown in Table 2 below:

[0114] t fro (min) First correction duration (s) t fro < 4 0 4 < t fro < 6 20 6 < t fro < 8 40 8 < t fro < 10 50 t fro > 10 60

[0115] Table 2

[0116] 3) The relationship between the feature temperature of the indoor heat exchanger and the second correction time length is shown in Table 3 below:

[0117] Ti pipe' (°C) Second correction duration (s) Ti pipe' > 20 0 10 < Ti pipe' < 20 20 0 < Ti pipe' < 10 40 Ti pipe' < 0 60

[0118] Table 3

[0119] wherein the target duration = the reference duration + the first correction duration + the second correction duration.

[0120] Based on the above relationship, for example, the indoor environment temperature is 17℃, the defrosting duration is 9min, and the characteristic temperature of the indoor heat exchanger is 5℃, the target duration = 10s + 50s + 40s = 100s; for another example, the indoor environment temperature is -5℃, the defrosting duration is 20min, and the characteristic temperature of the indoor heat exchanger is -10℃, the target duration = 60s + 60s + 60s = 180s, and so on.

[0121] In the embodiment, the target duration is determined according to the indoor environment temperature, the defrosting duration, and the characteristic temperature of the indoor heat exchanger in the above manner, which is beneficial to ensure that the target duration can be accurately matched with the actual frosting risk of the indoor heat exchanger, and ensure that the frosting risk of the indoor heat exchanger is effectively reduced and the defrosting effect of the outdoor heat exchanger during defrosting operation can be effectively improved after the reversing component is controlled to operate in the second state according to the target duration.

[0122] Further, in the embodiment, the number of indoor units is more than one, and the step of obtaining the indoor environment temperature corresponding to the heat pump system comprises: obtaining a first temperature of an indoor environment adjusted by the indoor unit; and determining the indoor environment temperature according to more than one first temperature.

[0123] The first temperature can be detected by an environment detection module in the corresponding indoor environment.

[0124] In the embodiment, all indoor units in the defrosting mode are in the evaporation state, the first temperature of the indoor environment adjusted by each indoor unit can be obtained, and the indoor environment temperature is determined according to all the obtained first temperatures. In other embodiments, part of the indoor units in the defrosting mode are in the evaporation state, the first temperature corresponding to the indoor unit in the evaporation state in the defrosting mode can be obtained, and the indoor environment temperature is determined according to all the obtained first temperatures.

[0125] In the embodiment, the mean value of more than one first temperature is determined as the indoor environment temperature. In other embodiments, the minimum value of more than one first temperature can also be determined as the indoor environment temperature.

[0126] In the embodiment, when the number of indoor units is more than one, the indoor environment temperature used to determine the target duration is determined according to the indoor temperature corresponding to more than one indoor unit, which is beneficial to ensure that the determined indoor environment temperature can accurately reflect the frosting risk of the whole of more than one indoor unit, and ensure that the frosting risk of each indoor unit can be effectively reduced when the reversing component operates in the second state.

[0127] Further, in the embodiment, the number of indoor units is more than one, and the step of obtaining the characteristic temperature of the indoor heat exchanger in the indoor unit comprises: obtaining the inlet temperature and the outlet temperature of the indoor heat exchanger in the indoor unit; determining a second temperature corresponding to the indoor heat exchanger according to the inlet temperature and the outlet temperature; and determining the characteristic temperature according to the plurality of second temperatures.

[0128] The inlet temperature and the outlet temperature can be detected by a temperature sensor on the corresponding indoor heat exchanger.

[0129] In the embodiment, the average of the inlet temperature and the outlet temperature is determined as the second temperature. In other embodiments, the characteristic temperature can also be calculated according to the inlet temperature and a corresponding first weight value, and the outlet temperature and a corresponding second weight value, where the first weight value and the second weight value can be determined according to the indoor environment temperature and the defrosting time length.

[0130] In the embodiment, all indoor units are in the evaporation state in the defrosting mode, and the second temperature corresponding to each indoor unit can be determined, and the characteristic temperature of the indoor heat exchanger is determined according to the determined second temperatures. In other embodiments, part of the indoor units are in the evaporation state in the defrosting mode, and the second temperature corresponding to the indoor unit in the evaporation state in the defrosting mode can be determined, and the characteristic temperature of the indoor heat exchanger is determined according to the obtained second temperatures.

[0131] In the embodiment, the lowest temperature of the plurality of second temperatures is determined as the characteristic temperature of the indoor heat exchanger. In other embodiments, the average of the plurality of second temperatures can also be determined as the characteristic temperature of the indoor heat exchanger.

[0132] In the embodiment, when the number of indoor units is more than one, the second temperature corresponding to the plurality of indoor units is determined to determine the characteristic temperature of the indoor heat exchanger used to determine the target time length, which is beneficial to ensure that the determined characteristic temperature of the indoor heat exchanger can accurately reflect the frosting risk of the plurality of indoor units as a whole, and ensure that the frosting risk of each indoor unit can be effectively reduced when the reversing component operates in the second state.

[0133] Further, based on any of the above embodiments, another embodiment of the control method of the heat pump system is provided. In the embodiment, the preset condition comprises at least one of the following conditions:

[0134] The indoor environment temperature corresponding to the heat pump system is less than a first preset environment temperature;

[0135] The defrosting time length of the heat pump system when the heat pump system operates the defrosting mode last time is greater than a preset time length;

[0136] The characteristic temperature of the indoor heat exchanger in the indoor unit is less than a preset temperature;

[0137] The outdoor environment temperature corresponding to the heat pump system is less than or equal to a second preset environment temperature.

[0138] For example, the preset time length is 4s, the preset temperature is 20℃, the first preset environment temperature is 20℃, and the preset environment temperature is 3℃.

[0139] In one implementation form of the embodiment, the indoor environment temperature, the defrosting time length, the characteristic temperature of the indoor heat exchanger, and the outdoor environment temperature can be directly obtained, and when at least one parameter meets the above conditions, it can be determined that the heat pump system has reached the preset condition.

[0140] In another implementation form of the embodiment, when the parameters for determining the target time length include the indoor environment temperature and / or the defrosting time length and / or the characteristic temperature of the indoor heat exchanger, the target time length can be determined in the manner mentioned in the above embodiment, and when the target time length is greater than the preset time length (for example, 0), it can be determined that the indoor environment temperature is less than the first preset environment temperature and / or the defrosting time length is greater than the preset time length and / or the characteristic temperature of the indoor heat exchanger is less than the preset temperature, that is, the heat pump system has reached the preset condition.

[0141] In the embodiment, when the indoor environment temperature, the defrosting time length, the characteristic temperature of the indoor heat exchanger, and the outdoor environment temperature all meet the above conditions, it can be considered that the heat pump system has reached the preset condition. In other embodiments, when one or two or three of the indoor environment temperature, the defrosting time length, the characteristic temperature of the indoor heat exchanger, and the outdoor environment temperature meet the above conditions, it can be considered that the heat pump system has reached the preset condition.

[0142] In the embodiment, the indoor environment temperature is too low, the defrosting time length is too long, the temperature of the indoor heat exchanger is too low, and the outdoor environment temperature is too low, all of which can indicate that the frosting risk of the indoor heat exchanger is relatively high when it is running in the defrosting mode or after the defrosting mode is ended. Therefore, the preset condition is set in the above manner, which is conducive to accurately and timely discovering the frosting risk of the defrosting mode and timely controlling the switching component to switch to the second state to run, so as to effectively reduce the frosting risk of the indoor heat exchanger and improve the defrosting effect of the outdoor heat exchanger.

[0143] Further, based on any of the above embodiments, another embodiment of the control method of the heat pump system is provided. In the embodiment, the indoor unit includes an indoor heat exchanger and a first control valve connected in series with the indoor heat exchanger, and the control method of the heat pump system further includes:

[0144] controlling the switching component to run in the first state, so that the outdoor heat exchanger and the indoor unit are both in communication with the gas return port of the compressor, and controlling the first control valve to run at a smaller preset opening degree;

[0145] when the heat pump system runs to the preset condition, the reversing component is controlled to run in the second state to make the indoor unit communicate with the exhaust port of the compressor, and the first control valve is controlled to run at an opening greater than or equal to the preset opening.

[0146] In the embodiment, the preset opening is the minimum opening of the first control valve, the first control valve is closed when the reversing component runs in the first state, and all heat in the heat pump system is used for heat storage of the energy storage device to effectively improve the heat storage efficiency of the energy storage device. The first control valve runs at the minimum opening when the reversing component runs in the second state.

[0147] In other embodiments, the first control valve can also be opened at a very small opening smaller than the preset opening when the reversing component runs in the first state to effectively improve the system operation reliability. The first control valve runs at a larger opening than in the first state when the reversing component runs in the second state to improve the heat of the indoor heat exchanger.

[0148] In the embodiment, the first control valve is arranged in the indoor unit and is adapted to the running state of the reversing component to run at different openings, and the first control valve runs at a larger opening than in the first state when the reversing component is in the second state, thereby effectively improving the temperature of the indoor heat exchanger when the indoor heat exchanger has a frost risk to effectively reduce the frost risk of the indoor heat exchanger.

[0149] Further, based on any of the above embodiments, another optional embodiment of the control method of the heat pump system is provided. In the embodiment, referring to Figure 5 , the control method of the heat pump system further includes:

[0150] Step S01, when the heat pump system runs to the starting condition of the defrosting mode, the reversing component is controlled to run in the third state to make the outdoor heat exchanger communicate with the exhaust port of the compressor and the indoor unit communicate with the return port of the compressor.

[0151] In the embodiment, when the reversing component runs in the first state, it is identified whether the heat pump system runs to the starting condition of the defrosting mode. When the heat pump system runs to the starting condition of the defrosting mode, it indicates that the outdoor heat exchanger is frosted, and then the reversing component can be controlled to run in the third state to make the outdoor heat exchanger communicate with the exhaust port of the compressor and the indoor unit communicate with the return port of the compressor to defrost the outdoor heat exchanger.

[0152] In the process of controlling the reversing assembly to operate in the third state: the first reversing valve is controlled to operate in the second valve position, the second reversing valve is controlled to operate in the fourth valve position, the outdoor heat exchanger is communicated with the exhaust port of the compressor, the indoor unit is communicated with the back gas port of the compressor, part of the refrigerant discharged by the compressor flows into the refrigerant branch, and the heat in the refrigerant is stored in the energy storage device when the refrigerant flows through the energy storage device, and the refrigerant flowing out of the refrigerant branch flows back to the compressor after heat exchange in the indoor unit; the other part of the refrigerant discharged by the compressor flows into the outdoor heat exchanger to release heat, and the refrigerant flowing out of the outdoor heat exchanger flows back to the compressor in turn through the throttling device and the indoor unit. In the third state, the outdoor heat exchanger is in a condensing state, and the indoor heat exchanger is in an evaporating state, at this time, the heat pump system can melt the ice and frost in the outdoor unit by using the heat of the refrigerant flowing through the outdoor heat exchanger.

[0153] In other embodiments, when the reversing assembly operates in the third state, the second control valve on the refrigerant branch can also be closed, and the refrigerant discharged by the compressor can all flow into the outdoor heat exchanger for defrosting.

[0154] Step S02, when the heat pump system operates to reach the exit condition of the defrosting mode, the step of controlling the reversing assembly to operate in the first state so that the outdoor heat exchanger and the indoor unit are both communicated with the back gas port of the compressor is performed.

[0155] After step S10, when the reversing assembly operates in the first state for a preset time length, it is identified whether the heat pump system operates to reach the preset condition.

[0156] In this embodiment, after the heat pump system exits the defrosting mode and enters the separate energy storage mode, when the separate energy storage mode identifies that the indoor heat exchanger has a defrosting risk, the indoor heat exchanger is preheated by switching the reversing assembly to operate in the second state, thereby effectively reducing the frosting risk of the indoor heat exchanger and ensuring that the defrosting efficiency is effectively improved when the heat pump system subsequently reenters the defrosting mode.

[0157] In addition, an embodiment of the present application also provides a storage medium, and the storage medium stores a control program of a heat pump system. When the control program of the heat pump system is executed by a processor, the related steps of any one of the embodiments of the control method of the heat pump system are implemented.

[0158] It should be noted that in this document, the terms “comprising”, “including”, or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or system that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article, or system. Without more limitations, the element defined by the statement “including a …” does not exclude the presence of other identical elements in the process, method, article, or system that includes the element.

[0159] The above-mentioned embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0160] Through the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be realized by means of software and the necessary general hardware platform, of course, they can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as a ROM / RAM, a magnetic disk, an optical disk) as described above, and includes a plurality of instructions for causing an end device (which can be a mobile phone, a computer, a server, a heat pump system, or a network device, etc.) to execute the methods described in the various embodiments of the present application.

[0161] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A control method of a heat pump system, characterized by, The heat pump system comprises a main refrigerant circuit and a branch refrigerant circuit, the main refrigerant circuit comprises an indoor unit, an outdoor heat exchanger, a switching assembly and a compressor, the indoor unit, the outdoor heat exchanger, the exhaust port of the compressor and the gas inlet of the compressor are connected with the switching assembly, the branch refrigerant circuit comprises an energy storage device, the first end of the branch refrigerant circuit is communicated with the exhaust port of the compressor, or the first end of the branch refrigerant circuit is connected with the exhaust port or the gas inlet of the compressor through the switching assembly, the pipeline between the indoor unit and the outdoor heat exchanger is connected with the second end of the branch refrigerant circuit, and the control method of the heat pump system comprises the following steps: controlling the switching assembly to operate in a first state to make the outdoor heat exchanger communicate with the gas inlet of the compressor; when the heat pump system operates to reach a preset condition, the switching assembly is controlled to operate in a second state to make the indoor unit communicate with the exhaust port of the compressor; wherein the preset condition indicates that the indoor unit has a risk of frosting when the heat pump system operates in a defrosting mode; The control method of the heat pump system further comprises: when the heat pump system operates to reach the starting condition of the defrosting mode, the switching assembly is controlled to operate in a third state to make the outdoor heat exchanger communicate with the exhaust port of the compressor and the indoor unit communicate with the gas inlet of the compressor; when the heat pump system operates to reach the exit condition of the defrosting mode, the step of controlling the switching assembly to operate in the first state to make the outdoor heat exchanger and the indoor unit both communicate with the gas inlet of the compressor is executed.

2. The control method of a heat pump system according to claim 1, characterized by, Before the step of controlling the switching assembly to operate in the second state when the heat pump system operates to reach the preset condition, the following steps are further included: obtaining the indoor environment temperature corresponding to the heat pump system and / or the defrosting time length when the heat pump system operates the defrosting mode last time and / or the characteristic temperature of the indoor heat exchanger in the indoor unit; determining a target time length according to the indoor environment temperature and / or the defrosting time length and / or the characteristic temperature; The step of controlling the switching assembly to operate in the second state when the heat pump system operates to reach the preset condition comprises: controlling the switching assembly to operate in the second state for the target time length when the heat pump system operates to reach the preset condition.

3. The control method of a heat pump system according to claim 2, characterized by, The step of determining a target time length according to the indoor environment temperature and / or the defrosting time length and / or the characteristic temperature comprises: determining a reference time length according to the indoor environment temperature, determining a first correction time length according to the defrosting time length, and determining a second correction time length according to the characteristic temperature; correcting the reference time length according to the first correction time length and the second correction time length to obtain the target time length.

4. The control method of a heat pump system according to claim 3, characterized by, The indoor environment temperature is negatively correlated with the reference time length, the defrosting time length is positively correlated with the first correction time length, and the second correction time length is negatively correlated with the characteristic temperature.

5. The control method of a heat pump system according to claim 2, characterized by, The number of indoor units is more than one, and the step of obtaining the indoor environment temperature corresponding to the heat pump system comprises: obtaining a first temperature of the indoor environment adjusted by the indoor unit; The indoor environment temperature is determined according to the plurality of first temperatures.

6. The control method of a heat pump system according to claim 2, characterized by, The number of indoor units is more than one, and the step of obtaining the characteristic temperature of the indoor heat exchanger in the indoor unit comprises: Obtaining the inlet temperature and outlet temperature of the indoor heat exchanger in the indoor unit; Determining the second temperature of the corresponding indoor heat exchanger according to the inlet temperature and the outlet temperature; More than one second temperature is determined to determine the characteristic temperature.

7. The control method of a heat pump system according to claim 1, characterized by, The preset condition includes at least one of the following conditions: The indoor environment temperature corresponding to the heat pump system is less than a first preset environment temperature; The defrosting time length of the heat pump system when the defrosting mode is last operated is greater than a preset time length; The characteristic temperature of the indoor heat exchanger in the indoor unit is less than a preset temperature; The outdoor environment temperature corresponding to the heat pump system is less than or equal to a second preset environment temperature.

8. The control method of a heat pump system according to any one of claims 1 to 7, characterized by, The indoor unit comprises an indoor heat exchanger and a first control valve connected in series with the indoor heat exchanger, and the control method of the heat pump system further comprises: Controlling the reversing assembly to operate in the first state so that the outdoor heat exchanger and the indoor unit are both communicated with the gas return port of the compressor, and controlling the first control valve to operate at a degree less than a preset degree; When the heat pump system operates to reach the preset condition, controlling the reversing assembly to operate in the second state so that the indoor unit is communicated with the gas discharge port of the compressor, and controlling the first control valve to operate at a degree greater than or equal to the preset degree.

9. The control method of a heat pump system according to any one of claims 1 to 7, characterized by, The reversing assembly comprises a first reversing valve and a second reversing valve, the indoor unit, the gas return port and the gas discharge port are respectively communicated with different valve ports of the first reversing valve, the outdoor heat exchanger, the gas return port and the gas discharge port are respectively communicated with different valve ports of the second reversing valve, and the step of controlling the reversing assembly to operate in the first state so that the outdoor heat exchanger and the indoor unit are both communicated with the gas return port of the compressor comprises: Controlling the first reversing valve to operate at a second valve position to make the gas return port communicated with the indoor unit and the gas discharge port blocked from the indoor unit, and controlling the second reversing valve to operate at a fourth valve position to make the gas return port communicated with the outdoor heat exchanger and the gas discharge port blocked from the outdoor heat exchanger; The step of controlling the reversing assembly to operate in the second state so that the indoor unit is communicated with the gas discharge port of the compressor comprises: Controlling the first reversing valve to switch to a first valve position to make the gas discharge port communicated with the indoor unit and the gas return port blocked from the indoor unit, and controlling the second reversing valve to maintain the fourth valve position.

10. A heat pump system, characterized by, The heat pump system comprises a control device, a main refrigerant circuit and a branch refrigerant circuit, the main refrigerant circuit comprises an indoor unit, an outdoor heat exchanger, a reversing assembly and a compressor, the indoor unit, the outdoor heat exchanger, the gas discharge port of the compressor and the gas return port of the compressor are all connected with the reversing assembly, the branch refrigerant circuit comprises an energy storage device, a first end of the branch refrigerant circuit is communicated with the gas discharge port of the compressor, and a pipeline between the indoor unit and the outdoor heat exchanger is connected with a second end of the branch refrigerant circuit. The reversing assembly is connected with the control device, and the control device comprises a memory, a processor, and a control program of the heat pump system stored in the memory and executable on the processor, and the control program of the heat pump system, when executed by the processor, implements the steps of the control method of the heat pump system according to any one of claims 1 to 9.

11. A storage medium, characterized by The storage medium stores the control program of the heat pump system, and the control program of the heat pump system, when executed by the processor, implements the steps of the control method of the heat pump system according to any one of claims 1 to 9.

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