Control method of heat pump water heater, controller, heat pump water heater and medium

Abstract

The embodiment of the invention provides a control method of a heat pump water heater, a controller, the heat pump water heater and a medium, the heat pump water heater comprises a water tank and a heat pump system, the heat pump system comprises a compressor, an evaporator, a main path condensing coil, an auxiliary path condensing coil and a valve assembly, and the compressor, the main path condensing coil and the evaporator communicate with one another; the compressor is communicated with the evaporator through a valve assembly and an auxiliary condensing coil; the main condensing coil is arranged on the side wall of the water tank, and the auxiliary condensing coil is arranged at the bottom of the water tank. The valve assembly is used for adjusting the flow of refrigerants flowing through the main path condensing coil and the auxiliary path condensing coil respectively. The heat pump water heater can adjust system refrigerants through the valve assembly, the refrigerant amount can be concentrated in a low-water-temperature area system to rapidly heat part of cold water, and therefore the system energy efficiency is improved, and part of water on the water tank can be rapidly heated; and after the water temperature rises in the later period, the effect of improving the energy efficiency is achieved by reducing refrigerant accumulation, and the power of the compressor is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of heat pump water heaters, and in particular to a control method, a controller, a heat pump water heater and a medium for a heat pump water heater. Background Art

[0002] In the related art, the conventional heat pump water heater system has a phenomenon of greatly reduced energy efficiency at high water temperature. The reason is that when heating the water at high temperature, the amount of refrigerant required in the refrigeration system is not large, resulting in a large amount of system refrigerant staying in the bottom area of ​​the condenser, occupying the area of ​​the condenser, but failing to achieve the effect of heat exchange. At the same time, it causes a large pressure drop and resistance in the system, resulting in an increase in power. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a control method, a controller, a heat pump water heater and a medium for improving the heat exchange effect and reducing the compressor power.

[0004] In a first aspect, an embodiment of the present application provides a heat pump water heater, comprising:

[0005] Water tank;

[0006] A heat pump system, comprising a compressor, an evaporator, a main condensing coil, a secondary condensing coil and a valve assembly, wherein the compressor, the main condensing coil and the evaporator are interconnected, and the compressor and the evaporator are also connected through the valve assembly and the secondary condensing coil;

[0007] Among them, the main condensing coil is arranged on the side wall of the water tank, and the secondary condensing coil is arranged at the bottom of the water tank; the valve assembly is used to adjust the refrigerant flow rate flowing through the main condensing coil and the secondary condensing coil respectively.

[0008] According to some embodiments of the present application, the valve assembly includes a switching valve and a one-way valve, the switching valve is provided with at least a first port, a second port and a third port, the first port is connected to the evaporator through the secondary condensing coil and the one-way valve, the second port is connected to the return air port of the compressor, and the third port is connected to the exhaust port of the compressor.

[0009] According to some embodiments of the present application, the diameter of the secondary condensing coil is smaller than the diameter of the primary condensing coil.

[0010] According to some embodiments of the present application, the heat pump system further includes a four-way valve, which is respectively connected to the main condensing coil, the exhaust port of the compressor, the evaporator, and the return air port of the compressor.

[0011] In a second aspect, an embodiment of the present application provides a control method for a heat pump water heater, which is applied to the heat pump water heater of the first aspect, and the method includes:

[0012] Acquiring a temperature parameter of the heat pump water heater, wherein the temperature parameter includes a water temperature parameter of the water tank or a supercooling parameter of the heat pump water heater;

[0013] The refrigerant flow direction inside the switching valve is controlled according to the temperature parameter, so as to adjust the refrigerant flow rates respectively flowing through the main condensing coil and the secondary condensing coil by changing the refrigerant flow direction of the secondary condensing coil.

[0014] According to some embodiments of the present application, controlling the flow direction of the refrigerant inside the switching valve according to the temperature parameter includes:

[0015] When the temperature parameter satisfies the first entry condition, the heat pump water heater is controlled to enter the first hot water making mode, wherein, in the first hot water making mode, the first port and the second port of the switching valve are connected, and the refrigerant of the secondary condensing coil flows into the return air port of the compressor through the first port and the second port in sequence;

[0016] The first entry condition includes one of the following:

[0017] When the water temperature parameter is a set water temperature, the set water temperature is lower than a first preset temperature;

[0018] In the case where the water temperature parameter includes a set water temperature and a water temperature at the bottom of the water tank, the set water temperature is greater than the first preset temperature and the water temperature at the bottom of the water tank is less than the first preset temperature;

[0019] The supercooling parameter is less than or equal to the second preset temperature.

[0020] According to some embodiments of the present application, the method further includes:

[0021] When a first exit condition is met, controlling the heat pump water heater to exit the first hot water making mode to cut off the first port and the second port of the switching valve;

[0022] The first exit condition includes one of the following:

[0023] The water temperature at the lower part of the water tank is greater than the first preset temperature;

[0024] A shutdown signal is received;

[0025] The subcooling parameter is greater than the second preset temperature.

[0026] According to some embodiments of the present application, controlling the flow direction of the refrigerant inside the switching valve according to the temperature parameter includes:

[0027] When the temperature parameter meets the second entry condition, the heat pump water heater is controlled to enter the second water-heating mode, wherein, in the second water-heating mode, the first port and the third port of the switching valve are connected, and the refrigerant discharged from the exhaust port of the compressor flows to the evaporator through the third port, the first port and the secondary condensing coil in sequence;

[0028] The second entry condition includes one of the following:

[0029] The set water temperature is greater than a first preset temperature and the water temperature at the lower part of the water tank is greater than or equal to the first preset temperature;

[0030] The supercooling parameter is greater than a second preset temperature.

[0031] According to some embodiments of the present application, the method further includes:

[0032] When a second exit condition is met, controlling the heat pump water heater to exit the second hot water making mode to cut off the first port and the third port of the switching valve;

[0033] The second exit condition includes one of the following:

[0034] Receive the temperature reaching shutdown signal;

[0035] A shutdown signal is received;

[0036] The subcooling parameter is less than the second preset temperature;

[0037] The exhaust temperature of the compressor is greater than a third preset temperature.

[0038] According to some embodiments of the present application, before obtaining the temperature parameter of the heat pump water heater, the method further includes:

[0039] A hot water production start instruction is received, and the heat pump water heater is controlled to enter a second hot water production mode according to the hot water production start instruction, and operates in the second hot water production mode for at least a first preset time period.

[0040] According to some embodiments of the present application, the heat pump system further includes a four-way valve, a first throttling device and a second throttling device, the four-way valve is respectively connected to the main condensing coil, the exhaust port of the compressor, the evaporator and the return port of the compressor, the first throttling device is connected to the main condensing coil, and the second throttling device is connected to the secondary condensing coil; the method further includes:

[0041] When the heat pump water heater is operating in the first hot water making mode, when the third entry condition is met, the heat pump water heater is controlled to enter the first defrosting mode, wherein, in the first defrosting mode, the first port and the second port are cut off, the first port and the third port of the switching valve are connected, the opening of the first throttling device is reduced and / or the opening of the second throttling device is increased;

[0042] Among them, the third entry condition includes: the outdoor ambient temperature is greater than or equal to the fourth preset temperature and less than or equal to the fifth preset temperature, the cumulative time that the evaporator coil temperature is less than the sixth preset temperature is greater than or equal to the second preset time, and the operating time of the heat pump system is greater than or equal to the third preset time.

[0043] According to some embodiments of the present application, the method further includes:

[0044] When the heat pump water heater is operating in the second hot water making mode, when the third entry condition is met, the heat pump water heater is controlled to enter the second defrost mode, wherein in the second defrost mode, the opening of the first throttling device is reduced and / or the opening of the second throttling device is increased.

[0045] According to some embodiments of the present application, the method further includes:

[0046] When the fourth entry condition is met, the heat pump water heater is controlled to enter the third defrost mode, wherein in the third defrost mode, the four-way valve is controlled to be powered on and the fan is powered off, and the opening of the first throttling device is set to a target opening;

[0047] Among them, the fourth entry condition includes: the outdoor ambient temperature is lower than the fourth preset temperature, the cumulative time of the evaporator coil temperature being lower than the sixth preset temperature is greater than or equal to the second preset time, and the operation time of the heat pump system is greater than or equal to the third preset time.

[0048] According to some embodiments of the present application, the method further includes:

[0049] When the third exit condition is met, the heat pump water heater is controlled to stop defrosting; wherein the third exit condition includes one of the following:

[0050] The defrost time is greater than or equal to the fourth preset time;

[0051] The evaporator coil temperature is greater than or equal to the seventh preset temperature;

[0052] Receive the temperature reaching shutdown signal;

[0053] The sensor for collecting the evaporator coil temperature has failed.

[0054] In a third aspect, an embodiment of the present application provides a controller comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the control method of the heat pump water heater of the second aspect mentioned above when running the computer program.

[0055] In a fourth aspect, an embodiment of the present application provides a heat pump water heater, comprising the controller of the third aspect described above.

[0056] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the control method of the heat pump water heater as described in the second aspect above.

[0057] In a sixth aspect, an embodiment of the present application provides a computer program product, comprising a computer program or computer instructions, characterized in that the computer program or the computer instructions are stored in a computer-readable storage medium, a processor of a computer device reads the computer program or the computer instructions from the computer-readable storage medium, and the processor executes the computer program or the computer instructions, so that the computer device executes the control method of the heat pump water heater as described in the second aspect above.

[0058] According to the technical solution of the embodiment of the present application, at least the following beneficial effects are achieved: the embodiment of the present application adds a secondary condensing coil at the bottom of the water tank, and also adds a valve assembly to adjust the refrigerant flow through the main condensing coil and the secondary condensing coil. The heat pump water heater can adjust the system refrigerant through the valve assembly, and in the low water temperature zone system, the refrigerant can be concentrated to quickly heat part of the cold water, thereby improving the system energy efficiency, and can quickly heat the water temperature of the upper part of the water tank; after the water temperature rises in the later stage, by reducing the refrigerant accumulation, the effect of improving energy efficiency is achieved and the compressor power is reduced.

[0059] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0061] Figure 1 is a system schematic diagram of a heat pump water heater provided by an embodiment of the present application;

[0062] Figure 2is a schematic diagram of the flow direction of the refrigerant of a heat pump water heater in a first hot water making mode provided by an embodiment of the present application;

[0063] Figure 3 is a schematic diagram of the flow direction of the refrigerant of a heat pump water heater in a second hot water making mode provided by an embodiment of the present application;

[0064] Figure 4 is a flow chart of a control method of a heat pump water heater provided by an embodiment of the present application;

[0065] Figure 5 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0066] Figure 6 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0067] Figure 7 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0068] Figure 8 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0069] Fig. 9 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0070] Fig.10 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0071] Fig.11 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0072] Fig.12 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0073] Fig.13 is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application;

[0074] Fig.14 It is an overall flow chart of a control method of a heat pump water heater provided by an embodiment of the present application;

[0075] Fig.15 It is a schematic diagram of a controller for executing a control method for a heat pump water heater provided in one embodiment of the present application. DETAILED DESCRIPTION

[0076] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0077] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0078] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0079] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0080] In some cases, the energy efficiency of conventional heat pump water heater systems drops significantly when the water temperature is high. The reason is that when heating the water at high temperature, the amount of refrigerant required in the refrigeration system is not large, resulting in a large amount of system refrigerant staying in the bottom area of ​​the condenser, occupying the area of ​​the condenser but failing to achieve the heat exchange effect. At the same time, it causes a large pressure drop and resistance in the system, resulting in an increase in power.

[0081] Based on the above situation, the embodiments of the present application propose a control method, a controller, a heat pump water heater and a medium for a heat pump water heater, aiming to improve the heat exchange effect and reduce the power of the compressor.

[0082] The various embodiments of the heat pump water heater of the present application are further described below in conjunction with the accompanying drawings.

[0083] like Figure 1 As shown, Figure 1 This is a system schematic diagram of a heat pump water heater provided in one embodiment of the present application.

[0084] In one embodiment, the heat pump water heater includes a water tank 150 and a heat pump system, wherein the heat pump system includes a compressor 110, an evaporator 120, a main condensing coil 130, a secondary condensing coil 140 and a valve assembly, the compressor 110, the main condensing coil 130 and the evaporator 120 are interconnected, and the compressor 110 and the evaporator 120 are also connected to the secondary condensing coil 140 through the valve assembly; in addition, the main condensing coil 130 is arranged on the side wall of the water tank 150, and the secondary condensing coil 140 is arranged at the bottom of the water tank 150; the valve assembly is used to adjust the refrigerant flow rate flowing through the main condensing coil 130 and the secondary condensing coil 140 respectively.

[0085] Specifically, the refrigerant discharged by the compressor 110 can enter the main condensing coil 130 for condensation, thereby heating the water at the top of the water tank 150, and then the refrigerant will flow back to the compressor 110 through the evaporator 120; in addition, the embodiment of the present application can adjust the valve component so that part of the refrigerant discharged by the compressor 110 will flow to the secondary condensing coil 140 for condensation, thereby heating the water at the bottom of the water tank 150, and then the refrigerant will flow back to the compressor 110 through the evaporator 120; or, the embodiment of the present application can adjust the valve component so that the compressor 110 extracts the refrigerant in the secondary condensing coil 140, and discharges the extracted refrigerant to the main condensing coil 130 through the compressor 110 for condensation. By increasing the refrigerant flow rate of the main condensing coil 130, the water at the top of the water tank 150 can be quickly heated. At the same time, the heat pump water heater does not heat the bottom of the water tank 150 or reduces the heating effect of the bottom of the water tank 150.

[0086] It is worth noting that the embodiment of the present application adds a secondary condensing coil 140 at the bottom of the water tank 150, and also adds a valve assembly to adjust the refrigerant flow through the main condensing coil 130 and the secondary condensing coil 140. The heat pump water heater can adjust the system refrigerant through the valve assembly, and in the low water temperature area system, the refrigerant can be concentrated to quickly heat part of the cold water, thereby improving the system energy efficiency, and can quickly heat the water temperature of the upper part of the water tank 150; after the water temperature rises in the later stage, by reducing the refrigerant accumulation, the effect of improving energy efficiency is achieved, and the power of the compressor 110 is reduced.

[0087] In one embodiment, the valve assembly includes a switching valve 160 and a one-way valve 170, and the switching valve 160 is provided with at least a first port, a second port and a third port. The first port is connected to the evaporator 120 through the secondary condensing coil 140 and the one-way valve 170, the second port is connected to the return air port of the compressor 110, and the third port is connected to the exhaust port of the compressor 110.

[0088] Specifically, the positive direction of the one-way valve 170 refers to the direction of flow from the secondary condensing coil 140 to the evaporator 120. At the same time, the embodiment of the present application can adjust the switching valve 160 to connect the first port and the second port, so that the compressor 110 can extract the refrigerant in the secondary condensing coil 140; or, the embodiment of the present application can adjust the switching valve 160 to connect the first port and the third port, so that part of the refrigerant discharged from the compressor 110 can flow to the secondary condensing coil 140 for condensation.

[0089] In one embodiment, the diameter of the secondary condensing coil 140 is smaller than the diameter of the primary condensing coil 130 . In addition, a capillary tube 190 may be provided between the one-way valve 170 and the secondary condensing coil 140 .

[0090] In one embodiment, the heat pump system further includes a four-way valve 180 , which is respectively connected to the main condensing coil 130 , the exhaust port of the compressor 110 , the evaporator 120 and the return air port of the compressor 110 .

[0091] In one embodiment, the heat pump system further includes a first throttling device and a second throttling device, wherein the first throttling device is connected to the main condensing coil 130, and the second throttling device is connected to the secondary condensing coil 140. The first throttling device and the second throttling device may be an electronic expansion valve or a capillary tube, which is not specifically limited in the embodiment of the present application.

[0092] For the heat pump water heater of the embodiment of the present application, the following two water-making modes can be implemented:

[0093] The first hot water mode: Figure 2 As shown, the first port and the second port of the switching valve 160 are connected. Due to the presence of the one-way valve 170, the compressor 110 will extract the refrigerant inside the secondary condensing coil 140, and the refrigerant inside the secondary condensing coil 140 will flow into the return air port of the compressor 110 through the first port and the second port in sequence; at the same time, the refrigerant of the main condensing coil 130 will flow back to the return air port of the compressor 110 through the evaporator 120. Finally, the compressor 110 will compress the refrigerant from the secondary condensing coil 140 and the main condensing coil 130, and discharge the refrigerant to the main condensing coil 130 for condensation, thereby heating the water at the top of the water tank 150. For the first water-heating mode, the refrigerant flow rate of the main condensing coil 130 is increased, and the water at the top of the water tank 150 can be quickly heated. At the same time, the heat pump water heater does not heat the bottom of the water tank 150 or reduces the heating effect of the bottom of the water tank 150.

[0094] The second hot water production mode: Figure 3As shown, the first port and the third port of the switching valve 160 are connected, and most of the refrigerant discharged from the exhaust port of the compressor 110 will flow to the main condensing coil 130 for condensation, thereby heating the water at the top of the water tank 150, and then return to the return air port of the compressor 110 through the evaporator 120; at the same time, the other refrigerant discharged from the exhaust port of the compressor 110 flows to the secondary condensing coil 140 through the third port and the first port in sequence for condensation, thereby heating the water at the bottom of the water tank 150, and then return to the return air port of the compressor 110 through the evaporator 120. For the second hot water making mode, the excess refrigerant is circulated through the secondary condensing coil 140 at the bottom to heat the water temperature at the bottom of the water tank 150, while ensuring the appropriate amount of refrigerant in the main condensing coil 130.

[0095] Based on the system structures of the heat pump water heaters of the above-mentioned embodiments, various overall embodiments of the control method of the heat pump water heater of the present application are respectively proposed below.

[0096] like Figure 4 As shown, Figure 4 It is a flow chart of a control method of a heat pump water heater provided by an embodiment of the present application; the control method includes but is not limited to step S410 and step S420.

[0097] Step S410, obtaining temperature parameters of the heat pump water heater, wherein the temperature parameters include water temperature parameters of the water tank or supercooling parameters of the heat pump water heater;

[0098] Step S420, controlling the refrigerant flow direction inside the switching valve according to the temperature parameter, so as to adjust the refrigerant flow rates respectively flowing through the main condensing coil and the secondary condensing coil by changing the refrigerant flow direction of the secondary condensing coil.

[0099] In one embodiment, the embodiment of the present application can understand the water temperature of the water tank through the temperature parameters of the heat pump water heater, and control the flow direction of the refrigerant inside the switching valve according to the water temperature, thereby controlling the heat pump water heater to enter the first hot water making mode or the second hot water making mode.

[0100] It is worth noting that the embodiment of the present application can adjust the refrigerant flow through the main condensing coil and the secondary condensing coil respectively through the switching valve. The heat pump water heater can adjust the system refrigerant through the switching valve. In the low water temperature area system, the refrigerant can be concentrated to quickly heat part of the cold water, thereby improving the system energy efficiency, and can quickly heat the water temperature of part of the water tank; after the water temperature rises in the later stage, by reducing the refrigerant accumulation, the effect of improving energy efficiency is achieved and the compressor power is reduced.

[0101] In one embodiment, the above-mentioned water temperature parameters may include a set water temperature, the water temperature at the top of the water tank, the water temperature at the bottom of the water tank, or the average water temperature of the upper and lower parts of the water tank. This embodiment of the present application does not specifically limit this.

[0102] In one embodiment, the above-mentioned subcooling parameter may refer to the difference between the exhaust temperature of the compressor and the outlet refrigerant temperature of the main condensing coil.

[0103] It should be noted that the above step S420 may include but is not limited to: Figure 5 or Figure 6 The two implementations shown are as follows:

[0104] like Figure 5 As shown, Figure 5 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; regarding the above-mentioned step S420, it may include but is not limited to step S510 and step S520.

[0105] Step S510, determining whether the temperature parameter satisfies the first entry condition;

[0106] Step S520, control the heat pump water heater to enter the first hot water making mode, wherein in the first hot water making mode, the first port and the second port of the switching valve are connected, and the refrigerant of the secondary condensing coil flows into the return air port of the compressor through the first port and the second port in sequence.

[0107] In one embodiment, if the set water temperature is lower than the first preset temperature, the first entry condition is met. At this time, the first port and the second port of the switching valve are connected, so that the compressor extracts the refrigerant from the secondary condensing coil and supplies it to the main condensing coil, thereby entering the first hot water making mode and quickly heating the water tank.

[0108] In one embodiment, if the set water temperature is greater than the first preset temperature and the water temperature at the bottom of the water tank is less than the first preset temperature, it indicates that the water temperature required by the user is higher and the water temperature at this time has not yet met the user's requirements. At this time, the first port and the second port of the switching valve will be connected, so that the compressor can extract the refrigerant from the secondary condensing coil and supply it to the main condensing coil, thereby entering the first hot water making mode and quickly heating the water tank.

[0109] In one embodiment, if the supercooling parameter is less than or equal to the second preset temperature, it indicates that the hot water making capacity at this time needs to be improved. In response, the first port and the second port of the switching valve will be connected, so that the compressor can extract the refrigerant from the secondary condensing coil and supply it to the main condensing coil, thereby entering the first hot water making mode, increasing the refrigerant flow, and quickly heating the water tank.

[0110] It can be understood that the first preset temperature and the second preset temperature mentioned above can be pre-set, and the embodiment of the present application does not specifically limit the specific numerical values ​​of the first preset temperature and the second preset temperature.

[0111] like Figure 6 As shown, Figure 6 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; regarding the above-mentioned step S420, it may include but is not limited to step S610 and step S620.

[0112] Step S610, determining whether the temperature parameter satisfies the second entry condition;

[0113] Step S620, control the heat pump water heater to enter the second hot water making mode, wherein in the second hot water making mode, the first port and the third port of the switching valve are connected, and the refrigerant discharged from the exhaust port of the compressor flows to the evaporator through the third port, the first port and the secondary condensing coil in sequence.

[0114] In one embodiment, if the set water temperature is greater than the first preset temperature and the water temperature at the bottom of the water tank is greater than or equal to the first preset temperature, it indicates that the water temperature required by the user is higher and the water temperature at this time has met the user's needs. At this time, the heating efficiency of the water tank can be appropriately reduced. In this regard, the first port and the third port of the switching valve will be connected at this time, so that part of the refrigerant discharged from the compressor is diverted to the secondary condensing coil, thereby entering the second hot water making mode.

[0115] In one embodiment, if the supercooling parameter is greater than the second preset temperature, it indicates that the heat pump water heater has a better hot water making effect at this time, and the heating efficiency of the water tank can be appropriately reduced. In this regard, the first port and the third port of the switching valve will be connected at this time, so that part of the refrigerant discharged from the compressor is diverted to the secondary condensing coil, thereby entering the second hot water making mode.

[0116] like Figure 7 As shown, Figure 7 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; when executing the above-mentioned first hot water making mode, the control method may also include but is not limited to step S710 and step S720.

[0117] Step S710: determine whether the first exit condition is met;

[0118] Step S720: Control the heat pump water heater to exit the first hot water making mode to cut off the first port and the second port of the switching valve.

[0119] In one embodiment, when executing the above-mentioned first hot water making mode, if the water temperature in the lower part of the water tank is greater than the first preset temperature, it indicates that the water temperature at this time has met the user's needs and there is no need for rapid heating. In this regard, the heat pump water heater will cut off the first port and the second port of the switching valve and choose to exit the first hot water making mode.

[0120] In one embodiment, when executing the above-mentioned first hot water making mode, if the heat pump water heater receives a shutdown signal, it means that the user has no demand for hot water at this time and there is no need for rapid heating. In this regard, the heat pump water heater will cut off the first port and the second port of the switching valve and choose to exit the first hot water making mode.

[0121] In one embodiment, when executing the above-mentioned first hot water making mode, if the supercooling parameter is greater than the second preset temperature, it indicates that the hot water making capacity of the heat pump water heater at this time is strong enough and there is no need for rapid heating. In this regard, the heat pump water heater will cut off the first port and the second port of the switching valve and choose to exit the first hot water making mode.

[0122] like Figure 8 As shown, Figure 8 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; when executing the above-mentioned second hot water making mode, the control method may also include but is not limited to step S810 and step S820.

[0123] Step S810: Determine whether the second exit condition is met;

[0124] Step S820: Control the heat pump water heater to exit the second hot water making mode to cut off the first port and the third port of the switching valve.

[0125] In one embodiment, when executing the above-mentioned second hot water making mode, if a temperature reaching shutdown signal is received, it indicates that the hot water temperature has reached the user's temperature requirement. In this regard, the heat pump water heater will cut off the first port and the third port of the switching valve and choose to exit the second hot water making mode.

[0126] In one embodiment, when executing the above-mentioned second hot water making mode, if a shutdown signal is received, it indicates that the user has no demand for hot water at this time. In this regard, the heat pump water heater will cut off the first port and the third port of the switching valve and choose to exit the second hot water making mode.

[0127] In one embodiment, when executing the above-mentioned second hot water making mode, if the supercooling parameter is less than the second preset temperature, it indicates that the hot water making capacity at this time needs to be improved. In this regard, the heat pump water heater will cut off the first port and the third port of the switching valve, choose to exit the second hot water making mode, and enter the first hot water making mode.

[0128] In one embodiment, when executing the above-mentioned second hot water making mode, if the exhaust temperature of the compressor is greater than the third preset temperature, in order to ensure the stable operation of the system, the heat pump water heater will cut off the first port and the third port of the switching valve and choose to exit the second hot water making mode.

[0129] It can be understood that the third preset temperature mentioned above can be pre-set, and the embodiment of the present application does not specifically limit the specific value of the third preset temperature.

[0130] like Fig. 9 As shown, Fig. 9 This is a flow chart of a control method for a heat pump water heater provided in another embodiment of the present application; when started, the control method may also include but is not limited to step S910 and step S920.

[0131] Step S910: receiving a hot water start instruction;

[0132] Step S920: Control the heat pump water heater to enter a second water heating mode according to the water heating start instruction, and operate in the second water heating mode for at least a first preset time.

[0133] In one embodiment, when the heat pump water heater is started, it will first run in the second hot water making mode for a first preset time. After the system is stable, it will then determine whether to execute the first hot water making mode or the second hot water making mode.

[0134] It can be understood that the above-mentioned first preset time length can be pre-set and can be 5 minutes or 10 minutes. The embodiment of the present application does not specifically limit the specific value of the first preset time length.

[0135] It should be noted that, regarding the above-mentioned heat pump water heater, other configurations may be provided, but not limited to: Figures 10 to 12 The three defrost control modes shown are as follows:

[0136] like Fig.10 As shown, Fig.10 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; the control logic of the first defrost mode may include but is not limited to step S1010 and step S1020.

[0137] Step S1010: when the heat pump water heater operates in the first hot water making mode, determining whether the third entry condition is satisfied;

[0138] Step S1020, control the heat pump water heater to enter the first defrost mode, wherein, in the first defrost mode, the first port and the second port are cut off, the first port and the third port of the switching valve are connected, the opening of the first throttling device is reduced and / or the opening of the second throttling device is increased.

[0139] In one embodiment, when the heat pump water heater is operating in the first hot water making mode, if the outdoor ambient temperature is greater than or equal to the fourth preset temperature and less than or equal to the fifth preset temperature, the cumulative time that the evaporator coil temperature is less than the sixth preset temperature is greater than or equal to the second preset time, and the operation time of the heat pump system is greater than or equal to the third preset time, then the third entry condition is met, indicating that the outdoor ambient temperature is at a relatively low temperature, the evaporator coil temperature has been at a low temperature for a long time, and the heat pump has been running for a long time, indicating that the evaporator may have frosted but the frosting is not serious. In this regard, the heat pump water heater needs to adjust the refrigerant flow direction of the switching valve, switch the switching valve from connecting the first port and the second port to the third port and the first port, and at the same time reduce the opening of the first throttling device of the flow path where the main condensing coil is located, or increase the opening of the second throttling device of the flow path where the secondary condensing coil is located, so as to reduce the hot water making effect and reduce the evaporation effect of the evaporator, thereby playing a defrosting role.

[0140] In one embodiment, in the first defrost mode, the heat pump water heater can directly close the opening of the first throttling device of the flow path where the main condensing coil is located to the minimum number of steps, and at the same time, can directly increase the opening of the second throttling device of the flow path where the secondary condensing coil is located to the maximum number of steps.

[0141] It can be understood that the fourth preset temperature, the fifth preset temperature and the sixth preset temperature mentioned above can be pre-set, and the embodiment of the present application does not specifically limit the specific numerical values ​​of the fourth preset temperature, the fifth preset temperature and the sixth preset temperature.

[0142] It can be understood that the above-mentioned second preset time length and third preset time length can be pre-set, and the embodiment of the present application does not specifically limit the specific values ​​of the second preset time length and the third preset time length.

[0143] like Fig.11 As shown, Fig.11 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; the control logic of the second defrost mode may include but is not limited to step S1110 and step S1120.

[0144] Step S1110: when the heat pump water heater operates in the second water-heating mode, determining that the third entry condition is satisfied;

[0145] Step S1120: Control the heat pump water heater to enter a second defrost mode, wherein in the second defrost mode, the opening of the first throttling device is reduced and / or the opening of the second throttling device is increased.

[0146] In one embodiment, when the heat pump water heater is operating in the second hot water making mode, if the outdoor ambient temperature is greater than or equal to the fourth preset temperature and less than or equal to the fifth preset temperature, the cumulative time that the evaporator coil temperature is less than the sixth preset temperature is greater than or equal to the second preset time, and the operation time of the heat pump system is greater than or equal to the third preset time, then the third entry condition is met, indicating that the outdoor ambient temperature is at a relatively low temperature, the evaporator coil temperature has been at a low temperature for a long time, and the heat pump has been running for a long time, indicating that the evaporator may have frosting but the frosting is not serious. In this regard, the heat pump water heater can directly reduce the opening of the first throttling device of the flow path where the main condensing coil is located, or increase the opening of the second throttling device of the flow path where the secondary condensing coil is located, so as to reduce the hot water making effect and reduce the evaporation effect of the evaporator, thereby playing a defrosting role.

[0147] In one embodiment, in the second defrost mode, the heat pump water heater can directly close the opening of the first throttling device of the flow path where the main condensing coil is located to the minimum number of steps, and at the same time, can directly increase the opening of the second throttling device of the flow path where the secondary condensing coil is located to the maximum number of steps.

[0148] like Fig.12 As shown, Fig.12 It is a flow chart of a control method of a heat pump water heater provided by another embodiment of the present application; the control logic of the third defrost mode may include but is not limited to step S1210 and step S1220.

[0149] Step S1210, determining whether the fourth entry condition is met;

[0150] Step S1220, controlling the heat pump water heater to enter the third defrost mode, wherein, in the third defrost mode, the four-way valve is controlled to be powered on and the fan is powered off, and the opening of the first throttling device is set to a target opening.

[0151] In one embodiment, if the outdoor ambient temperature is lower than a fourth preset temperature, the cumulative time that the evaporator coil temperature is lower than a sixth preset temperature is greater than or equal to a second preset time, and the operation time of the heat pump system is greater than or equal to a third preset time, then the fourth entry condition is satisfied, indicating that the outdoor ambient temperature is extremely low, the evaporator coil temperature has been in a low temperature state for a long time, and the heat pump has been running for a long time, indicating that the evaporator may have frosted and the frosting is very serious. In this regard, the heat pump water heater will control the four-way valve to energize, so that the high-temperature and high-pressure refrigerant of the compressor flows directly to the evaporator through the four-way valve, thereby defrosting the evaporator. At the same time, the first throttling device of the fan that has been opened to a certain degree will be closed.

[0152] In addition, if Fig.13 As shown, Fig.13It is a flow chart of a control method of a heat pump water heater provided in another embodiment of the present application; regarding the exit logic of the defrost mode, it may include but is not limited to step S1310 and step S1320.

[0153] Step S1310: Determine whether the third exit condition is met;

[0154] Step S1320, control the heat pump water heater to stop defrosting; wherein, the third exit condition includes one of the following: the defrost time is greater than or equal to the fourth preset time, the evaporator coil temperature is greater than or equal to the seventh preset temperature, a temperature reaching shutdown signal is received, or a sensor for collecting the evaporator coil temperature fails.

[0155] In one embodiment, during the defrosting period, if the defrosting time is greater than or equal to a fourth preset time, it indicates that the defrosting has been long enough and a certain defrosting effect has been achieved. At this time, the heat pump water heater can choose to exit the defrosting mode.

[0156] In one embodiment, during the defrosting period, if the evaporator coil temperature is greater than or equal to the seventh preset temperature, it indicates that the evaporator coil temperature is increased and is not prone to frost at this temperature. At this time, the heat pump water heater can choose to exit the defrosting mode.

[0157] In one embodiment, during the defrosting period, if a temperature reaching shutdown signal is received, the user has no need for hot water production, and the heat pump water heater can choose to directly exit the defrosting mode.

[0158] In one embodiment, during the defrost period, if the sensor for collecting the evaporator coil temperature fails, since the evaporator coil temperature cannot be determined, it is necessary to exit the defrost mode for accurate operation of the system.

[0159] It can be understood that the seventh preset temperature mentioned above can be pre-set, and the embodiment of the present application does not specifically limit the specific value of the seventh preset temperature.

[0160] It can be understood that the fourth preset time length mentioned above can be pre-set, and the embodiment of the present application does not specifically limit the specific value of the fourth preset time length.

[0161] Based on the control methods of the heat pump water heaters of the above-mentioned embodiments, various overall embodiments of the control methods of the heat pump water heaters of the present application are respectively proposed below.

[0162] like Fig.14 As shown, Fig.14 This is an overall flow chart of a control method for a heat pump water heater provided by an embodiment of the present application, and its control logic is as follows:

[0163] When the heat pump has energy demand, it will run in the second hot water mode for 5 minutes before starting the judgment;

[0164] 1. Operate in the first hot water mode, entry conditions: (meet any condition)

[0165] 1. Set the water temperature Ts<45℃;

[0166] 2. Set the water temperature to Ts>45℃ and T5L<45℃;

[0167] 3. Subcooling degree Tp-TLc ≤ 15℃.

[0168] Execute action:

[0169] Operate in the first hot water mode.

[0170] Exit condition; (meet any condition)

[0171] 1. The water temperature reaches 45℃;

[0172] 2. Turn off the computer;

[0173] 3. Subcooling Tp-TLc>15℃.

[0174] 2. Operate in the second hot water mode and enter the conditions; (meet any condition)

[0175] 1. Set the water temperature Ts>45℃ and T5L≥45℃;

[0176] 2. Subcooling Tp-TLc>15℃.

[0177] Perform actions;

[0178] Operate in the second hot water mode.

[0179] Exit condition; (meet any condition)

[0180] 1. Shut down when reaching the temperature;

[0181] 2. Turn off the computer;

[0182] 3. Subcooling Tp-TLc<15℃;

[0183] 4.Tp exhaust temperature>85℃.

[0184] The switching operation time between the first hot water making mode and the second hot water making mode is not less than a preset time, for example, 3 minutes.

[0185] Defrost control: When the ambient temperature is between 2-10℃, the evaporator of the conventional system is defrosted by switching the four-way valve, or the fan is defrosted after the compressor is powered off. Both methods will lead to a decrease in system energy efficiency. The above system can use the small heat exchange area of ​​the bottom coil to guide the high-temperature exhaust gas of the system through the coil and then into the evaporator for defrosting. The specific control is as follows:

[0186] Entry Condition A:

[0187] 1. Judgment 2≤T4≤10;

[0188] 2. Coil T3<0℃ cumulative time ≥T3ErrHpRunTime1;

[0189] 3. Heat pump operation time ≥ HpMinRunTime.

[0190] Entry Condition B:

[0191] 1. Determine that T4 is less than 2;

[0192] 2. Coil T3<0℃ cumulative time ≥T3ErrHpRunTime1;

[0193] 3. Heat pump operation time ≥ HpMinRunTime.

[0194] Enter the execution action from condition A;

[0195] When the first hot water making mode is in operation, the switching valve is switched from C→S to D→C, and at the same time the electronic expansion valve of the main circuit is closed to the minimum number of steps, and the throttling device in the chassis pipe circuit is opened to the maximum if it is an electronic expansion valve.

[0196] When the second hot water making mode is in operation, the electronic expansion valve of the direct main circuit is closed to the minimum step number, and the throttling device in the chassis pipe circuit is opened to the maximum if it is an electronic expansion valve.

[0197] Enter the execution action from condition B;

[0198] 1. The four-way valve is energized;

[0199] 2. The fan is powered off;

[0200] 3. The main circuit electronic expansion valve is opened to 480 steps.

[0201] Enter the defrost exit condition from A or B (either one is satisfied);

[0202] 1.Defrost time ≥ DefrostTimeA;

[0203] 2. T3 has no fault and T3 ≥ T3_ExitFrostA;

[0204] 3. Shut down when reaching the temperature;

[0205] 4.T3 failure.

[0206] The technical solution of the embodiment of the present application circulates excess refrigerant through the chassis pipe by adjusting the water temperature and the set temperature. When heating at low water temperature, when the system requires a large amount of refrigerant, the effect of rapid heating can be achieved. When heating at low water temperature, when the amount of refrigerant required is small, the evaporation amount can be guaranteed while reducing the accumulation of refrigerant in the main circuit, thereby improving the heat exchange effect and reducing the compressor power.

[0207] Based on the control methods of the heat pump water heaters in the above-mentioned embodiments, various embodiments of the controller, the heat pump water heater, the computer-readable storage medium and the computer program product of the present application are respectively proposed below.

[0208] like Fig.15 As shown, Fig.15 2 is a schematic diagram of a controller for executing a control method provided by an embodiment of the present application. The controller 200 implemented in the present application includes: a processor 210, a memory 220, and a computer program stored in the memory 220 and executable on the processor 210, wherein: Fig.15 In the figure, a processor 210 and a memory 220 are taken as an example.

[0209] The processor 210 and the memory 220 may be connected via a bus or other means. Fig.15 The example of connecting through bus is taken in the following.

[0210] The memory 220, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer executable programs. In addition, the memory 220 may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 220 may optionally include a memory 220 remotely arranged relative to the processor 210, and these remote memories 220 may be connected to the controller 200 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0211] Those skilled in the art will understand that Fig.15 The device structure shown in the figure does not constitute a limitation on the controller 200, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0212] exist Fig.15 In the controller 200 shown, the processor 210 can be used to call the control program stored in the memory 220 to implement the above control method. Specifically, the non-transient software program and instructions required to implement the control method of the above embodiment are stored in the memory 220, and when executed by the processor 210, the control method of the above embodiment is executed.

[0213] It is worth noting that since the controller 200 of the embodiment of the present application can execute the control method of any of the above embodiments, the specific implementation methods and technical effects of the controller 200 of the embodiment of the present application can refer to the specific implementation methods and technical effects of the control method of any of the above embodiments.

[0214] In addition, an embodiment of the present application further provides a heat pump water heater, which includes the controller of the above embodiment.

[0215] It is worth noting that since the heat pump water heater of the embodiment of the present application includes the controller of the above embodiment, and the controller of the above embodiment can execute the control method of any of the above embodiments, the specific implementation methods and technical effects of the heat pump water heater of the embodiment of the present application can refer to the specific implementation methods and technical effects of the control method of any of the above embodiments.

[0216] In addition, an embodiment of the present application further provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to execute the above-described control method. Figures 4 to 14 The method steps in .

[0217] It is worth noting that since the computer-readable storage medium of the embodiments of the present application can execute the control method of any of the above embodiments, the specific implementation methods and technical effects of the computer-readable storage medium of the embodiments of the present application can refer to the specific implementation methods and technical effects of the control method of any of the above embodiments.

[0218] In addition, an embodiment of the present application further provides a computer program product, including a computer program or computer instructions, the computer program or computer instructions are stored in a computer-readable storage medium, the processor of the computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, so that the computer device executes the above-described control method. Figures 1 to 14 The method steps in .

[0219] It is worth noting that since the computer program product of the embodiments of the present application can execute the control method of any of the above embodiments, the specific implementation methods and technical effects of the computer program product of the embodiments of the present application can refer to the specific implementation methods and technical effects of the control method of any of the above embodiments.

[0220] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media generally include computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0221] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the above implementation mode. Technical personnel familiar with the field can also make various equivalent modifications or substitutions under the shared conditions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A heat pump water heater, characterized in that: include: Water tank; A heat pump system, comprising a compressor, an evaporator, a main condensing coil, a secondary condensing coil and a valve assembly, wherein the compressor, the main condensing coil and the evaporator are interconnected, and the compressor and the evaporator are also connected through the valve assembly and the secondary condensing coil; Among them, the main condensing coil is arranged on the side wall of the water tank, and the secondary condensing coil is arranged at the bottom of the water tank; the valve assembly is used to adjust the refrigerant flow rate flowing through the main condensing coil and the secondary condensing coil respectively.

2. The heat pump water heater according to claim 1, characterized in that: The valve assembly includes a switching valve and a one-way valve, and the switching valve is provided with at least a first port, a second port and a third port. The first port is connected to the evaporator through the secondary condensing coil and the one-way valve, the second port is connected to the return air port of the compressor, and the third port is connected to the exhaust port of the compressor.

3. The heat pump water heater according to claim 1, characterized in that: The diameter of the secondary condensing coil is smaller than the diameter of the primary condensing coil.

4. The heat pump water heater according to claim 1, characterized in that: The heat pump system further comprises a four-way valve, which is respectively connected to the main condensing coil, the exhaust port of the compressor, the evaporator and the return air port of the compressor.

5. A control method for a heat pump water heater, characterized in that: Applicable to the heat pump water heater according to any one of claims 1 to 4, the valve assembly comprises a switching valve and a one-way valve, the switching valve is provided with at least a first port, a second port and a third port, the first port is connected to the evaporator through the secondary condensing coil and the one-way valve, the second port is connected to the return air port of the compressor, and the third port is connected to the exhaust port of the compressor; the method comprises: Acquiring a temperature parameter of the heat pump water heater, wherein the temperature parameter includes a water temperature parameter of the water tank or a supercooling parameter of the heat pump water heater; The refrigerant flow direction inside the switching valve is controlled according to the temperature parameter, so as to adjust the refrigerant flow rates respectively flowing through the main condensing coil and the secondary condensing coil by changing the refrigerant flow direction of the secondary condensing coil.

6. The method according to claim 5, characterized in that The controlling the refrigerant flow direction inside the switching valve according to the temperature parameter includes: When the temperature parameter satisfies the first entry condition, the heat pump water heater is controlled to enter the first hot water making mode, wherein, in the first hot water making mode, the first port and the second port of the switching valve are connected, and the refrigerant of the secondary condensing coil flows into the return air port of the compressor through the first port and the second port in sequence; The first entry condition includes one of the following: When the water temperature parameter is a set water temperature, the set water temperature is lower than a first preset temperature; In the case where the water temperature parameter includes a set water temperature and a water temperature at the bottom of the water tank, the set water temperature is greater than the first preset temperature and the water temperature at the bottom of the water tank is less than the first preset temperature; The supercooling parameter is less than or equal to the second preset temperature.

7. The method according to claim 6, characterized in that The method further comprises: When a first exit condition is met, controlling the heat pump water heater to exit the first hot water making mode to cut off the first port and the second port of the switching valve; The first exit condition includes one of the following: The water temperature at the lower part of the water tank is greater than the first preset temperature; A shutdown signal is received; The subcooling parameter is greater than the second preset temperature.

8. The method according to claim 6, characterized in that The controlling the refrigerant flow direction inside the switching valve according to the temperature parameter includes: When the temperature parameter meets the second entry condition, the heat pump water heater is controlled to enter the second water-heating mode, wherein, in the second water-heating mode, the first port and the third port of the switching valve are connected, and the refrigerant discharged from the exhaust port of the compressor flows to the evaporator through the third port, the first port and the secondary condensing coil in sequence; The second entry condition includes one of the following: The set water temperature is greater than a first preset temperature and the water temperature at the lower part of the water tank is greater than or equal to the first preset temperature; The supercooling parameter is greater than a second preset temperature.

9. The method according to claim 8, characterized in that The method further comprises: When a second exit condition is met, controlling the heat pump water heater to exit the second hot water making mode to cut off the first port and the third port of the switching valve; The second exit condition includes one of the following: Receive the temperature reaching shutdown signal; A shutdown signal is received; The subcooling parameter is less than the second preset temperature; The exhaust temperature of the compressor is greater than a third preset temperature.

10. The method according to claim 8, characterized in that Before obtaining the temperature parameter of the heat pump water heater, the method further includes: A hot water production start instruction is received, and the heat pump water heater is controlled to enter a second hot water production mode according to the hot water production start instruction, and operates in the second hot water production mode for at least a first preset time period.

11. The method according to claim 8, characterized in that The heat pump system further includes a four-way valve, a first throttling device and a second throttling device, wherein the four-way valve is respectively connected to the main condensing coil, the exhaust port of the compressor, the evaporator and the return port of the compressor, the first throttling device is connected to the main condensing coil, and the second throttling device is connected to the secondary condensing coil; the method further includes: When the heat pump water heater is operating in the first hot water making mode, when the third entry condition is met, the heat pump water heater is controlled to enter the first defrosting mode, wherein, in the first defrosting mode, the first port and the second port are cut off, the first port and the third port of the switching valve are connected, the opening of the first throttling device is reduced and / or the opening of the second throttling device is increased; Among them, the third entry condition includes: the outdoor ambient temperature is greater than or equal to the fourth preset temperature and less than or equal to the fifth preset temperature, the cumulative time that the evaporator coil temperature is less than the sixth preset temperature is greater than or equal to the second preset time, and the operating time of the heat pump system is greater than or equal to the third preset time.

12. The method according to claim 11, characterized in that The method further comprises: When the heat pump water heater is operating in the second hot water making mode, when the third entry condition is met, the heat pump water heater is controlled to enter the second defrost mode, wherein in the second defrost mode, the opening of the first throttling device is reduced and / or the opening of the second throttling device is increased.

13. The method according to claim 11, characterized in that The method further comprises: When the fourth entry condition is met, the heat pump water heater is controlled to enter the third defrost mode, wherein in the third defrost mode, the four-way valve is controlled to be powered on and the fan is powered off, and the opening of the first throttling device is set to a target opening; Among them, the fourth entry condition includes: the outdoor ambient temperature is lower than the fourth preset temperature, the cumulative time of the evaporator coil temperature being lower than the sixth preset temperature is greater than or equal to the second preset time, and the operation time of the heat pump system is greater than or equal to the third preset time.

14. The method according to any one of claims 11 to 13, characterized in that The method further comprises: When the third exit condition is met, the heat pump water heater is controlled to stop defrosting; wherein the third exit condition includes one of the following: The defrost time is greater than or equal to the fourth preset time; The evaporator coil temperature is greater than or equal to the seventh preset temperature; Receive the temperature reaching shutdown signal; The sensor for collecting the evaporator coil temperature has failed.

15. A controller, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the control method for a heat pump water heater according to any one of claims 1 to 14 when executing the computer program.

16. A heat pump water heater, characterized in that: Comprising a controller as claimed in claim 15.

17. A computer-readable storage medium, characterized in that: Computer executable instructions are stored, and the computer executable instructions are used to execute the control method of the heat pump water heater according to any one of claims 1 to 14.

18. A computer program product comprising a computer program or computer instructions, characterized in that The computer program or the computer instructions are stored in a computer-readable storage medium, and a processor of a computer device reads the computer program or the computer instructions from the computer-readable storage medium. The processor executes the computer program or the computer instructions, so that the computer device executes the control method of the heat pump water heater as described in any one of claims 1 to 14.

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