Heat pump system and defrosting control method and controller thereof

Abstract

The invention relates to a heat pump system and a defrosting control method and controller thereof. An air outlet mesh enclosure of the heat pump system is provided with a pipeline which can be used for water to pass through and is spirally coiled, a water inlet end of the air outlet mesh enclosure is connected with a water outlet pipe of a heat exchanger through a pipe, the water outlet pipe of the air outlet mesh enclosure is connected with a water inlet pipe of the heat exchanger, a defrosting water path is constructed, and a defrosting control valve is arranged on the defrosting water path. And the defrosting control valve is controlled to communicate with the defrosting water way, the circulating water pump is started, hot water flowing out of the heat exchanger flows to the pipeline of the air outlet mesh enclosure under the action of the circulating water pump and flows in the pipeline, frost on the surface of the air outlet mesh enclosure is melted, and defrosting control over the air outlet mesh enclosure is achieved. In the defrosting process, the water inlet temperature and the water outlet temperature of the air outlet net cover are monitored, under the condition that the water temperature difference is smaller than the preset water temperature difference, the defrosting control valve is controlled to close the defrosting water path, and the heat pump system continues to work in the mode before defrosting.

Description

Technical Field

[0001] The present application relates to the technical field of defrost control of air-energy heat pump systems, and in particular to a heat pump system and a defrost control method and controller thereof. Background Art

[0002] Air-source heat pumps are increasingly being used in various scenarios due to their energy-saving and high safety features. However, in cold or snowy weather, the air outlet grille of the air-source heat pump is prone to frost or snow accumulation, resulting in reduced air volume, affecting the heat exchange efficiency of the outdoor unit heat exchanger, and thus reducing the energy efficiency of the air-source heat pump. Summary of the Invention

[0003] The technical problem solved by the present application is to provide a heat pump system and its defrost control method and controller, which can effectively defrost the air outlet grille, ensure the energy efficiency of the heat pump system, and improve performance reliability and stability.

[0004] The above technical problems are solved by the following technical solutions:

[0005] In one embodiment, a defrost control method is provided, which is applied to a heat pump system. The heat pump system includes a circulating water pump, a heat exchanger, an air outlet mesh cover, and a defrost control valve. The circulating water pump is provided on a water inlet pipe of the heat exchanger. The air outlet mesh cover is formed by spirally winding a pipe. The water inlet pipe of the air outlet mesh cover is connected to the water outlet pipe of the heat exchanger. The water outlet pipe of the air outlet mesh cover is connected to the water inlet pipe of the heat exchanger. The water inlet pipe of the air outlet mesh cover, the pipe of the air outlet mesh cover, and the water outlet pipe of the air outlet mesh cover constitute a defrost water circuit. The defrost control valve is provided on the defrost water circuit for connecting or closing the defrost water circuit.

[0006] The defrost control method comprises:

[0007] When the defrost start condition is met, the defrost control valve and the circulating water pump are opened, and the defrost water path is connected with the defrost control valve in the open state;

[0008] Obtaining the water inlet temperature and the water outlet temperature of the air outlet grille;

[0009] When the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille is less than the preset water temperature difference, the defrost control valve is closed, and the defrost water path is closed when the defrost control valve is in the closed state.

[0010] The defrost control method described in this application has the following beneficial effects compared with the background technology:

[0011] The air outlet mesh cover has a pipe that can pass water, and the pipe is spirally coiled. The water inlet end of the air outlet mesh cover is connected to the water outlet pipe of the heat exchanger, and the water outlet pipe of the air outlet mesh cover is connected to the water inlet pipe of the heat exchanger to construct a defrost water circuit, and a defrost control valve is arranged on the defrost water circuit. When the defrost start condition is met, the defrost control valve is controlled to connect to the defrost water circuit, and the circulating water pump is turned on. The hot water flowing out of the heat exchanger is brought to the pipe of the air outlet mesh cover by the action of the circulating water pump and flows in the spirally coiled pipe. During the flow of hot water in the pipe of the air outlet mesh cover, the frost on the surface of various positions of the air outlet mesh cover can be melted. With the heat exchange, the water temperature in the pipe of the air outlet mesh cover drops. The water flowing out through the water outlet pipe of the air outlet mesh cover is returned to the heat exchanger through the water inlet pipe of the heat exchanger, and the reflux water is heated again based on the circulation system of the heat pump system. Based on the large circulation of the heat pump system, the defrost control of the air outlet mesh cover of the heat pump system can be realized. During the defrosting process, the inlet and outlet water temperatures of the air outlet grille are continuously monitored. When the water temperature difference between the two is less than the preset water temperature difference, it is considered that the frost on the surface of the air outlet grille has been cleared. Therefore, there is no need for a large amount of heat exchange for defrosting. At this time, the defrost control valve is controlled to close the defrost water circuit, and the heat pump system continues to work in the mode before defrosting.

[0012] In one embodiment, the defrost control method further includes:

[0013] Acquire the ambient temperature of the heat pump system, the operating time of the heat pump system, and the ambient humidity of the heat pump system;

[0014] The defrost start condition includes: the ambient temperature is lower than the preset temperature threshold, the ambient humidity is higher than the humidity threshold, and the running time is longer than a preset time period.

[0015] When the ambient temperature is lower than the preset temperature threshold and the ambient humidity is higher than the humidity threshold, it means that the ambient temperature of the air outlet grille is low and the humidity is high. When the air outlet grille is operated in this environment for a long time, it is easy to frost. Therefore, it is judged in conjunction with the operating time of the heat pump system. If the operating time in this environment reaches the preset time, it is considered that the air outlet grille is at risk of frost at this time and the defrost start condition is met. By controlling the defrost control valve to connect the defrost water circuit and start the circulating water pump, the hot water flowing out of the heat exchanger flows into the pipe of the air outlet grille, and defrosting is performed through heat exchange. The water flowing out of the air outlet grille flows back to the heat exchanger, and the hot water flowing out of the heat exchanger flows into the pipe of the air outlet grille again after heat exchange, and this cycle continues until the water temperature difference between the outlet water temperature and the inlet water temperature of the air outlet grille is less than the preset water temperature difference. The defrost control valve is controlled to close the defrost water circuit and return to the mode before defrosting.

[0016] In one embodiment, the heat pump system further includes an electric heating module, which is provided on the water inlet pipe of the air outlet grille and is used to heat the water in the pipe; after the step of controlling the defrost control valve to connect to the defrost water circuit and start the circulating water pump, and before the step of controlling the defrost control valve to close the defrost water circuit, the method further includes:

[0017] Obtaining the return water temperature of the water inlet pipe of the heat exchanger;

[0018] When the return water temperature is less than or equal to the preset return water temperature, the electric heating module is turned on.

[0019] When the defrost water path is connected, the return water temperature of the heat exchanger inlet pipe is also obtained. Based on the heat exchange principle, the lower the temperature of the air outlet mesh cover, the greater the heat energy exchange of the water flow in the air outlet mesh cover, and the lower the return water temperature. Therefore, when the return water temperature is less than or equal to the preset return water temperature, it means that the temperature of the air outlet mesh cover is very low and a large amount of frost may have formed on the surface. At this time, turn on the electric heating module on the water inlet pipe of the air outlet mesh cover, and heat based on the electric heating module to quickly increase the temperature of the water flow flowing into the air outlet mesh cover, thereby improving the defrosting efficiency.

[0020] If the return water temperature is greater than or equal to the preset return water temperature, the electric heating module is not activated. When the return water temperature is greater than or equal to the preset return water temperature, it is assumed that the frost on the air outlet grille surface is not serious. Therefore, only the defrost control valve and circulating water pump are activated, using the hot water flowing out of the heat exchanger for defrosting. This can achieve defrosting while controlling energy consumption.

[0021] In one embodiment, the heat pump system further includes a drain pipe connected to the pipeline of the air outlet grille, and a drain valve provided on the drain pipe, the drain valve being used to connect or close the drain pipe; the method further includes:

[0022] When the defrost start condition is met, controlling the drain valve to close;

[0023] When the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille is less than the preset water temperature difference, the drain valve is controlled to open. When the drain valve is opened, the water in the pipeline of the air outlet grille flows out through the drain pipe.

[0024] When the defrost start conditions are met, the drain valve is controlled to close, and the defrost control valve and the circulating water pump are controlled to start. The hot water flowing out of the heat exchanger flows into the air outlet mesh cover through the water inlet pipe of the air outlet mesh cover. After heat exchange in the pipeline of the air outlet mesh cover, it returns to the water inlet pipe of the heat exchanger through the water outlet pipe of the air outlet mesh cover. After being heated by the heat exchanger, it circulates to the air outlet mesh cover again to defrost the air outlet mesh cover. During the defrost process, the drain valve is closed, and the hot water flowing out of the heat exchanger can efficiently act on the heat exchange of the air outlet mesh cover, thereby improving the defrost efficiency.

[0025] If the temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than a preset temperature difference, defrosting is considered complete and the defrost control valve is controlled to close the defrost water circuit. Hot water from the heat exchanger is then pumped to the user's water supply, for example, the farthest water supply, and then flows back to the heat exchanger through the user's water supply pipe. Furthermore, if the temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than a preset temperature difference, the drain valve is controlled to open, allowing any remaining water in the outlet grille pipe to drain through the drain pipe. This prevents the water in the pipe from freezing and damaging the grille, thereby improving the structural reliability and service life of the air outlet grille.

[0026] In one embodiment, a controller is provided. The controller is used in a heat pump system and is configured to execute the steps of the above-mentioned defrost control method.

[0027] The controller described in this application has the following beneficial effects compared with the background technology:

[0028] When the defrost start conditions are met, the controller controls the defrost control valve to connect the defrost water circuit and turns on the circulating water pump. The hot water flowing out of the heat exchanger is carried to the pipe of the air outlet grille by the circulating water pump. As the hot water flows in the pipe of the air outlet grille, it can melt the frost on the surface of the air outlet grille. As the heat is exchanged, the water temperature in the pipe of the air outlet grille drops. The water flowing out of the water outlet pipe of the air outlet grille then flows back to the heat exchanger through the water inlet pipe of the heat exchanger. Based on the heat exchange of the heat exchanger, the returned water is heated again and then circulated to the air outlet grille, realizing the defrost control of the air outlet grille of the heat pump system. During the defrost process, the controller continuously monitors the inlet and outlet water temperatures of the air outlet grille. When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than the preset water temperature difference, the defrost control valve is controlled to close the defrost water circuit. The heat pump system continues to operate in the mode before defrosting, realizing the automatic opening and closing of the defrost function.

[0029] In one embodiment, a heat pump system is provided, comprising: a circulating water pump, a heat exchanger, an air outlet screen, a defrost control valve, and the above-mentioned controller;

[0030] The circulating water pump is arranged on the water inlet pipe of the heat exchanger;

[0031] The air outlet screen is formed by spirally winding the pipe;

[0032] The water inlet pipe of the air outlet grille is connected to the water outlet pipe of the heat exchanger;

[0033] The water outlet pipe of the air outlet grille is connected to the water inlet pipe of the heat exchanger;

[0034] The water inlet pipe of the air outlet mesh cover, the pipeline of the air outlet mesh cover, and the water outlet pipe of the air outlet mesh cover constitute a defrosting water circuit;

[0035] The defrost control valve is provided on the defrost water path and is used to connect or close the defrost water path;

[0036] The controller is connected to the defrost control valve and the circulating water pump respectively.

[0037] The heat pump system described in this application has the following beneficial effects compared with the background technology:

[0038] The air outlet mesh cover has a pipe that can pass water. The water inlet end of the air outlet mesh cover is connected to the water outlet pipe of the heat exchanger, and the water outlet pipe of the air outlet mesh cover is connected to the water inlet pipe of the heat exchanger to construct a defrost water circuit. When the defrost start conditions are met, the controller controls the defrost control valve to connect the defrost water circuit and turns on the circulating water pump. The hot water flowing out of the heat exchanger is brought to the pipe of the air outlet mesh cover by the circulating water pump. The hot water can melt the frost on the surface of the air outlet mesh cover during the flow in the pipe of the air outlet mesh cover. With the heat exchange, the water temperature in the pipe of the air outlet mesh cover drops, and the water flowing out through the water outlet pipe of the air outlet mesh cover flows back to the heat exchanger through the water inlet pipe of the heat exchanger. Based on the heat exchange of the heat exchanger, the reflux water is heated again and then circulated to the air outlet mesh cover, thereby realizing the defrost control of the air outlet mesh cover of the heat pump system. During the defrosting process, the controller continuously monitors the inlet water temperature and outlet water temperature of the air outlet grille. When the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille is less than the preset water temperature difference, the defrost control valve is controlled to close the defrost water circuit, and the heat pump system continues to work in the mode before defrosting, realizing automatic opening and closing of the defrosting function.

[0039] In one embodiment, the heat pump system further comprises:

[0040] an ambient temperature sensor, used to obtain the ambient temperature of the heat pump system;

[0041] A return water temperature sensor is provided on the water inlet pipe of the heat exchanger;

[0042] An ambient humidity sensor, used to obtain the ambient humidity of the heat pump system;

[0043] The controller is connected to the ambient temperature sensor, the return water temperature sensor and the ambient humidity sensor respectively.

[0044] The controller obtains the ambient temperature collected by the ambient temperature sensor, the return water temperature collected by the return water temperature sensor, and the ambient humidity collected by the ambient humidity sensor. When the ambient temperature is less than the preset temperature threshold and the ambient humidity is greater than the humidity threshold, it means that the ambient temperature of the air outlet grille is low and the humidity is high. When the air outlet grille operates in this environment for a long time, it is easy to frost. Therefore, based on the operating time of the heat pump system, if the operating time in this environment reaches the preset time, it is judged that the defrost start condition has been met, and the defrost control valve and circulating water pump are controlled to achieve defrosting. When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than the preset water temperature difference, the defrost control valve is closed to achieve the start and stop control of the automatic defrost function of the air outlet grille.

[0045] In one embodiment, the heat pump system further comprises:

[0046] an inlet water temperature sensor, provided on the water inlet pipe of the air outlet grille, for obtaining the inlet water temperature of the air outlet grille;

[0047] An outlet water temperature sensor is provided on the outlet pipe of the air outlet grille, and is used to obtain the outlet water temperature of the air outlet grille;

[0048] A controller is connected to the water inlet temperature sensor and the water outlet temperature sensor respectively.

[0049] The controller determines whether defrosting is completed by monitoring the inlet and outlet water temperatures of the air outlet grille in real time. When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than the preset water temperature difference, the defrost control valve is controlled to close, and the water use mode of the heat pump system is restored to provide hot water to the user's water use end, realizing automatic switching control of the defrost function.

[0050] In one embodiment, the heat pump system further comprises:

[0051] An electric heating module is provided on the water inlet pipe of the air outlet mesh cover, and is used to heat water in the water inlet pipe of the air outlet mesh cover. The electric heating module is connected to the controller.

[0052] By adding an electric heating module to the water inlet pipe of the air outlet mesh cover, when the return water temperature is less than or equal to the preset return water temperature, the controller turns on the electric heating module on the water inlet pipe of the air outlet mesh cover. Based on the heating of the electric heating module, the temperature of the water flowing into the air outlet mesh cover is quickly increased, thereby improving the defrosting efficiency.

[0053] In one embodiment, the heat pump system further comprises:

[0054] A drain pipe, wherein the water inlet end of the drain pipe is connected to the pipeline of the air outlet mesh cover, and the water inlet end of the drain pipe is lower than the water outlet of the pipeline of the air outlet mesh cover;

[0055] A drain valve is provided on the drain pipe, the drain valve is used to connect or close the drain pipe, and the drain valve is connected to the controller.

[0056] When the defrost start conditions are met, the controller controls the drain valve to close, and controls the defrost control valve and the circulating water pump to open. The hot water flowing out of the heat exchanger flows into the air outlet mesh cover through the water inlet pipe of the air outlet mesh cover. After heat exchange in the pipeline of the air outlet mesh cover, it returns to the water inlet pipe of the heat exchanger through the water outlet pipe of the air outlet mesh cover. After being heated by the heat exchanger, it circulates to the air outlet mesh cover again to defrost the air outlet mesh cover. During the defrost process, the drain valve is closed, and the hot water flowing out of the heat exchanger can efficiently act on the heat exchange of the air outlet mesh cover, thereby improving the defrost efficiency.

[0057] When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than the preset water temperature difference, the defrost is considered complete, and the controller controls the defrost control valve to close the defrost water circuit. At this time, the hot water flowing out of the heat exchanger flows to the user water end, for example, the farthest water end, under the action of the circulating water pump, and flows back to the heat exchanger through the user water end pipeline. And when the water temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than the preset water temperature difference, the drain valve is controlled to open. Since the water inlet end of the drain pipe is lower than the water outlet of the pipeline, the water remaining in the pipeline of the air outlet grille is discharged through the drain pipe under the action of gravity, so as to prevent the water in the pipeline from freezing and damaging the grille, thereby improving the structural reliability and service life of the air outlet grille. In addition, this drainage is achieved without the need to introduce devices such as water pumps, saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0059] Figure 1 is a schematic structural diagram of a heat pump system according to one or more embodiments;

[0060] Figure 2 One of the flowcharts of the defrost control method of one or more embodiments;

[0061] Figure 3 This is a second flow chart of the defrost control method according to one or more embodiments;

[0062] Figure 4 A schematic structural diagram of an air outlet grille according to one or more embodiments;

[0063] Figure 5A schematic structural diagram of a drain pipe according to one or more embodiments;

[0064] Figure 6 Schematic diagram of the structure of a controller according to one or more embodiments.

[0065] Description of reference numerals:

[0066] 1. Heat pump system; 10. Circulating water pump; 20. Heat exchanger; 30. Air outlet grille; 31. Pipeline; 32. Grille flow path fixing strip; 33. Grille fixing plate; 40. Defrost control valve; 41. Electric two-way valve 1; 42. Electric two-way valve 2; 60. Ambient temperature sensor; 70. Return water temperature sensor; 80. Ambient humidity sensor; 90. Inlet water temperature sensor; 100. Outlet water temperature sensor; 110. Electric heating module; 120. Drain pipe 130. Drain valve; 131. Electric drain valve 1; 132. Electric drain valve 2; 91. Expansion tank; 911. Expansion tank heating belt; 92. Liquid reservoir; 93. Expansion valve; 94. Evaporator; 95. Chassis heating belt; 96. Fan; 97. Coil temperature sensor; 98. Four-way valve; 99. Return air temperature sensor; 992. Compressor; 993. Exhaust temperature sensor; 994. Water flow switch; 995. Exhaust valve; 996. Automatic water replenishment valve. DETAILED DESCRIPTION

[0067] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0069] It will be understood that the terms "first," "second," etc. used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element.

[0070] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other. It is understood that "plurality" means two or more.

[0071] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0072] In one embodiment, the present application provides a defrost control method, which is applied to a heat pump system, such as Figure 1 As shown, the heat pump system 1 includes a circulating water pump 10, a heat exchanger 20, an air outlet mesh cover 30 and a defrost control valve 40. The circulating water pump 10 is arranged on the water inlet pipe of the heat exchanger 20, and the air outlet mesh cover 30 is formed by a spirally coiled pipe 31. The water inlet pipe of the air outlet mesh cover 30 is connected to the water outlet pipe of the heat exchanger 20, and the water outlet pipe of the air outlet mesh cover 30 is connected to the water inlet pipe of the heat exchanger 20. The water inlet pipe of the air outlet mesh cover 30, the pipeline of the air outlet mesh cover 30, and the water outlet pipe of the air outlet mesh cover 30 constitute a defrost water circuit; the defrost control valve 40 is arranged on the defrost water circuit, and is used to connect or close the defrost water circuit.

[0073] like Figure 2 As shown, the defrost control method includes:

[0074] S201, when the defrost start condition is met, opening the defrost control valve and the circulating water pump, and connecting the defrost water path with the defrost control valve in the open state;

[0075] S202, obtaining the water inlet temperature and the water outlet temperature of the air outlet grille;

[0076] S203, when the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille is less than a preset water temperature difference, closing the defrost control valve, and closing the defrost water path when the defrost control valve is in the closed state.

[0077] Specifically, the air outlet mesh cover has a water-permeable pipe, the water inlet end of the air outlet mesh cover is connected to the water outlet pipe of the heat exchanger, and the water outlet pipe of the air outlet mesh cover is connected to the water inlet pipe of the heat exchanger to construct a defrost water circuit, and a defrost control valve is arranged on the defrost water circuit. When the defrost start condition is met, the defrost control valve is controlled to connect to the defrost water circuit, and the circulating water pump is turned on. The hot water flowing out of the heat exchanger is brought to the pipe of the air outlet mesh cover by the circulating water pump and flows in the spirally coiled pipe. In the process of flowing in the pipe of the air outlet mesh cover, the hot water can melt the frost on the surface of various positions of the air outlet mesh cover based on the structural characteristics of the spirally coiled pipe. With the heat exchange, the water temperature in the pipe of the air outlet mesh cover drops, and the water flowing out through the water outlet pipe of the air outlet mesh cover is returned to the heat exchanger through the water inlet pipe of the heat exchanger, and the reflux water is heated again based on the circulation system of the heat pump system. Based on the large circulation of the heat pump system, the defrost control of the air outlet mesh cover of the heat pump system can be realized. During the defrosting process, the inlet and outlet water temperatures of the air outlet grille are continuously monitored. When the water temperature difference between the two is less than the preset water temperature difference, it is considered that the frost on the surface of the air outlet grille has been cleared. Therefore, there is no need for a large amount of heat exchange for defrosting. At this time, the defrost control valve is controlled to close the defrost water circuit, and the heat pump system continues to work in the mode before defrosting.

[0078] In one embodiment, Figure 3 As shown, the air outlet mesh cover 30 may include: a water inlet pipe, a water outlet pipe, a pipeline 31 , a mesh cover flow path fixing strip 32 , and a mesh cover fixing piece 33 .

[0079] The water inlet of pipe 31 communicates with the water outlet of heat exchanger 20 via the water inlet pipe of air outlet mesh cover 30, while the water outlet of pipe 31 communicates with the water inlet of heat exchanger 20 via the water outlet pipe of air outlet mesh cover 30. Multiple mesh flow path fixing strips 32 are radially distributed around mesh fixing sheet 33, with one end of each strip 32 fixedly connected to mesh fixing sheet 33. Pipe 31 is arranged around mesh fixing sheet 33 and mesh flow path fixing strips 32, and the outer surface of pipe 31 is fixedly connected to mesh fixing sheet 33 and mesh flow path fixing strips 32, for example, by welding.

[0080] The defrost control valve 40 is arranged on the water inlet pipe and / or water outlet pipe of the air outlet mesh cover 30. When the defrost start condition is met, the defrost control valve is controlled to open, and the hot water flowing out of the heat exchanger 20 flows into the water inlet D of the pipeline 31 through the water inlet pipe of the air outlet mesh cover 30, flows in the pipeline 31, melts the frost on the pipeline 31, and the water flowing out of the pipeline 31 flows back to the water inlet of the heat exchanger 20 through the water outlet pipe of the air outlet mesh cover 30.

[0081] The pipe 31 can be formed by surrounding an ABS pipe. For example, an 8-10 mm ABS pipe can be formed by surrounding an ABS pipe. The mesh flow path fixing strips 32 can be determined according to the area of the air outlet mesh 30. For example, 7 mesh flow path fixing strips 312 can be used. The drain pipe 120 (such as Figure 4 As shown) passes through the drainage hole provided on the pipeline 31 and is connected to the pipeline 31. When the drainage valve 130 is opened, the water in the pipeline 31 is discharged through the drainage pipe 120.

[0082] In one embodiment, Figure 2 As shown, the drain hole is set at a lower position of the pipeline 31, for example, at the position of the pipeline 31 closest to the ground and / or the water outlet E of the pipeline 31, so that at the end of defrosting, the drain valve 130 is opened and the water is automatically drained based on the gravity of the water to prevent the water in the air outlet mesh cover 30 from freezing at low temperature and damaging the mesh cover.

[0083] In one embodiment, Figure 5 As shown, the defrost control method further includes:

[0084] Acquire the ambient temperature of the heat pump system, the operating time of the heat pump system, and the ambient humidity of the heat pump system;

[0085] The defrost start condition includes: the ambient temperature is lower than the preset temperature threshold, the ambient humidity is higher than the humidity threshold, and the running time is longer than a preset time period.

[0086] When the ambient temperature is lower than the preset temperature threshold and the ambient humidity is higher than the humidity threshold, it means that the ambient temperature of the air outlet grille is low and the humidity is high. When the air outlet grille is operated in this environment for a long time, it is easy to frost. Therefore, it is judged in conjunction with the operating time of the heat pump system. If the operating time in this environment reaches the preset time, it is considered that the air outlet grille is at risk of frost at this time and the defrost start condition is met. By controlling the defrost control valve to connect the defrost water circuit and start the circulating water pump, the hot water flowing out of the heat exchanger flows into the pipe of the air outlet grille, and defrosting is performed through heat exchange. The water flowing out of the air outlet grille flows back to the heat exchanger, and the hot water flowing out of the heat exchanger flows into the pipe of the air outlet grille again after heat exchange, and this cycle continues until the water temperature difference between the outlet water temperature and the inlet water temperature of the air outlet grille is less than the preset water temperature difference. The defrost control valve is controlled to close the defrost water circuit and return to the mode before defrosting.

[0087] In one embodiment, the heat pump system 1 further includes an electric heating module 110, which is provided on the water inlet pipe of the air outlet mesh cover 30 and is used to heat water flowing through the water inlet pipe of the air outlet mesh cover 30; after the step of controlling the defrost control valve to connect to the defrost water circuit and start the circulating water pump, and before the step of controlling the defrost control valve to close the defrost water circuit, the method further includes:

[0088] Obtaining the return water temperature of the water inlet pipe of the heat exchanger;

[0089] When the return water temperature is less than or equal to the preset return water temperature, the electric heating module is turned on.

[0090] When the defrost water path is connected, the return water temperature of the heat exchanger inlet pipe is also obtained. Based on the heat exchange principle, the lower the temperature of the air outlet mesh cover, the greater the heat energy exchange of the water flow in the air outlet mesh cover, and the lower the return water temperature. Therefore, when the return water temperature is less than or equal to the preset return water temperature, it means that the temperature of the air outlet mesh cover is very low and a large amount of frost may have formed on the surface. At this time, turn on the electric heating module on the water inlet pipe of the air outlet mesh cover, and heat based on the electric heating module to quickly increase the temperature of the water flow flowing into the air outlet mesh cover, thereby improving the defrosting efficiency.

[0091] If the return water temperature is greater than or equal to the preset return water temperature, the electric heating module is not activated. When the return water temperature is greater than or equal to the preset return water temperature, it is assumed that the frost on the air outlet grille surface is not serious. Therefore, only the defrost control valve and circulating water pump are activated, using the hot water flowing out of the heat exchanger for defrosting. This can achieve defrosting while controlling energy consumption.

[0092] In one embodiment, the heat pump system 1 further includes a drain pipe 120 connected to the pipeline of the air outlet grille 30, and a drain valve 130 provided on the drain pipe 120, the drain valve 130 being used to connect or close the drain pipe 120; the method further includes:

[0093] When the defrost start condition is met, controlling the drain valve to close;

[0094] When the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille is less than the preset water temperature difference, the drain valve is controlled to open. When the drain valve is opened, the water in the pipeline of the air outlet grille flows out through the drain pipe.

[0095] There may be multiple drain pipes 120, and there may be multiple drain valves 130 on the drain pipe 120. The drain valve 130 may be a normally open electric drain valve.

[0096] Specifically, when the defrost start conditions are met, the drain valve 130 is controlled to be closed, and the defrost control valve 40 and the circulating water pump 10 are controlled to be opened. The hot water flowing out of the heat exchanger 20 flows into the air outlet mesh cover 30 through the water inlet pipe of the air outlet mesh cover 30. After heat exchange in the pipeline of the air outlet mesh cover 30, it flows back to the water inlet pipe of the heat exchanger 20 through the water outlet pipe of the air outlet mesh cover 30. After being heated by the heat exchanger 20, it circulates to the air outlet mesh cover 30 again to defrost the air outlet mesh cover 30. During the defrost process, the drain valve 130 is closed, and the hot water flowing out of the heat exchanger 20 can efficiently act on the heat exchange of the air outlet mesh cover 30, thereby improving the defrost efficiency.

[0097] When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille 30 is less than the preset water temperature difference, defrosting is considered complete, and the defrost control valve 40 is controlled to close the defrost water circuit. At this time, the hot water flowing out of the heat exchanger 20 flows to the user water end, for example, the farthest water end, under the action of the circulating water pump 10, and then flows back to the heat exchanger 20 through the user water end pipeline. In addition, when the water temperature difference between the inlet and outlet water temperatures of the air outlet grille 30 is less than the preset water temperature difference, the drain valve 130 is controlled to open, and the residual water in the pipeline of the air outlet grille 30 can be discharged through the drain pipe 120, thereby preventing the water in the pipeline of the air outlet grille 30 from freezing and damaging the grille, thereby improving the structural reliability and service life of the air outlet grille 30.

[0098] For better explanation, the implementation of the defrost control method provided in the embodiment of the present application is illustrated here by way of example:

[0099] The preset temperature threshold is -5°C, the humidity threshold is 70%, the preset duration is 6 hours, the preset return water temperature is 15°C, and the preset water temperature difference is 2°C. The drain valve 130 includes an electric drain valve 1 ( Figure 1 131) and electric drain valve 2 ( Figure 1 132). The defrost control valve 40 is a normally closed electric two-way valve. The electric two-way valve is installed on the water inlet pipe and the water outlet pipe of the air outlet mesh cover 30:

[0100] like Figure 5 As shown, the ambient temperature of the heat pump system 1, the operating time of the heat pump system 1 and the ambient humidity of the heat pump system 1 are obtained; when the ambient temperature TA<-5°C, the relative humidity RH>70%, the cumulative operating time Tr of the heat pump system 1 unit>6h, and the return water temperature Twr>15°C, the air outlet grille 30 enters the defrosting state, and the electric drain valve 1 ( Figure 1 131) and electric drain valve 2 ( Figure 1 132) is powered on and closed, electric two-way valve 1 ( Figure 1 41) and electric two-way valve 2 ( Figure 1 42) The power is turned on, the circulating water pump 10 starts to run, and the hot water flowing out of the heat exchanger 20 flows into the air outlet mesh cover 30, and defrosting is achieved based on heat exchange.

[0101] When it is detected that the inlet water temperature Tj-outlet water temperature Tc < 2°C, the circulating water pump 10 returns to the state before defrosting, and the electric two-way valve 1 ( Figure 1 41) and electric two-way valve 2 ( Figure 1 42) Power off and close, electric drain valve 1 ( Figure 1 131) and electric drain valve 2 ( Figure 1The water in the air outlet grille 30 flows out through the drain pipe 120 due to gravity, preventing the water in the air outlet grille 30 from freezing and damaging the grille.

[0102] When the ambient temperature TA<-5°C, the relative humidity RH>70%, the cumulative running time Tr of the heat pump system 1 unit>6h, and the return water temperature Twr≤15°C, the air outlet grille 30 enters the defrosting state, and the electric drain valve 1 ( Figure 1 131) and electric drain valve 2 ( Figure 1 132) is powered on and closed, electric two-way valve 1 ( Figure 1 41) and electric two-way valve 2 ( Figure 1 42) The power is turned on, the circulating water pump 10 starts running, the electric heating module 110 is powered on and works, the hot water flowing out of the heat exchanger 20 is heated by the electric heating module 110 and then flows into the air outlet mesh cover 30, and based on the heat exchange, rapid defrosting is achieved.

[0103] When it is detected that the inlet water temperature Tj-outlet water temperature Tc<2°C, the electric heating module 110 is powered off and stops working, the circulating water pump 10 returns to the state before defrosting, and the electric two-way valve 1 ( Figure 1 41) and electric two-way valve 2 ( Figure 1 42) Power off and close the electric drain valve 1 ( Figure 1 131) and electric drain valve 2 ( Figure 1 The water in the air outlet grille 30 flows out through the drain pipe 120 due to gravity, preventing the water in the air outlet grille 30 from freezing and damaging the grille.

[0104] Of course, it should be noted that the examples of threshold values and preset values here do not limit the actual protection scope of this application. These threshold values and preset values can support configuration and can be set based on the start and stop control that can achieve automatic defrosting.

[0105] The defrost control method provided in the embodiment of the present application realizes the defrost control of the air outlet mesh cover, avoids the reduction of air volume due to frost and snow accumulation on the mesh cover, thereby ensuring the heat exchange efficiency of the outdoor heat exchanger and ensuring the capacity and energy efficiency of the heat pump system.

[0106] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless clearly stated herein, the execution of these steps is not strictly limited in order, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of the steps or stages in other steps or other steps. It is understandable that the various steps in different embodiments can be freely combined as needed, and the various non-contradictory schemes formed by the combination all fall within the scope of protection of this application.

[0107] In an exemplary embodiment, a controller is provided. The controller may be a control mainboard, and its internal structure may be as shown in FIG. Figure 6 As shown. The controller includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the controller is used to provide computing and control capabilities. The controller is used to store data such as a preset water temperature difference, a preset temperature threshold, a humidity threshold and a preset duration. The input / output interface of the controller is used to exchange information between the processor and an external device. The communication interface of the controller is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a defrost control method is implemented.

[0108] In one embodiment, a controller is provided. The controller is used in a heat pump system and is configured to execute the steps of the above-mentioned defrost control method.

[0109] When the defrost start conditions are met, the controller controls the defrost control valve to connect the defrost water circuit and turns on the circulating water pump. The hot water flowing out of the heat exchanger is carried to the pipe of the air outlet grille by the circulating water pump. As the hot water flows in the pipe of the air outlet grille, it can melt the frost on the surface of the air outlet grille. As the heat is exchanged, the water temperature in the pipe of the air outlet grille drops. The water flowing out of the water outlet pipe of the air outlet grille then flows back to the heat exchanger through the water inlet pipe of the heat exchanger. Based on the heat exchange of the heat exchanger, the returned water is heated again and then circulated to the air outlet grille, realizing the defrost control of the air outlet grille of the heat pump system. During the defrost process, the controller continuously monitors the inlet and outlet water temperatures of the air outlet grille. When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille is less than the preset water temperature difference, the defrost control valve is controlled to close the defrost water circuit. The heat pump system continues to operate in the mode before defrosting, realizing the automatic opening and closing of the defrost function.

[0110] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned defrost control method are implemented.

[0111] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0112] In one embodiment, Figure 1 As shown, a heat pump system 1 is provided, which includes: a circulating water pump 10, a heat exchanger 20, an air outlet screen 30, a defrost control valve 40 and the above-mentioned controller (not shown).

[0113] The circulating water pump 10 is arranged on the water inlet pipe of the heat exchanger 20, and the air outlet mesh cover 30 is formed by a spirally coiled pipe 31. The water inlet pipe of the air outlet mesh cover 30 is connected to the water outlet pipe of the heat exchanger 20; the water outlet pipe of the air outlet mesh cover 30 is connected to the water inlet pipe of the heat exchanger 20; the water inlet pipe of the air outlet mesh cover 30, the pipe 31 of the air outlet mesh cover 30, and the water outlet pipe of the air outlet mesh cover 30 constitute a defrost water circuit; the defrost control valve 40 is arranged on the defrost water circuit, for connecting or closing the defrost water circuit; the controller is respectively connected to the defrost control valve 40 and the circulating water pump 10.

[0114] Specifically, the air outlet grille 30 has a water-permeable pipe 31, and the water inlet end of the air outlet grille 30 is connected to the water outlet pipe of the heat exchanger 20, and the water outlet pipe of the air outlet grille 30 is connected to the water inlet pipe of the heat exchanger 20 to construct a defrost water circuit. When the defrost start condition is met, the controller controls the defrost control valve 40 to connect to the defrost water circuit and turns on the circulating water pump 10. The hot water flowing out of the heat exchanger 20 is brought to the pipe 31 of the air outlet grille 30 under the action of the circulating water pump. 1. As hot water flows through the pipe 31 of the air outlet grille 30, it can melt the frost on the surface of the air outlet grille 30. As heat exchange occurs, the water temperature in the pipe 31 of the air outlet grille 30 drops. The water flowing out of the water outlet pipe of the air outlet grille 30 then flows back to the heat exchanger through the water inlet pipe of the heat exchanger 20. Based on the heat exchange in the heat exchanger 20, the returned water is reheated and then circulated back to the air outlet grille 30, thereby achieving defrost control of the air outlet grille 30 of the heat pump system 1. During the defrost process, the controller continuously monitors the inlet and outlet water temperatures of the air outlet grille 30. When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille 30 is less than a preset water temperature difference, the defrost control valve 40 is controlled to close the defrost water circuit. The heat pump system 1 continues to operate in the pre-defrost mode, achieving automatic opening and closing of the defrost function.

[0115] In one embodiment, Figure 1 As shown, the heat pump system 1 further includes: an ambient temperature sensor 60 , a return water temperature sensor 70 , and an ambient humidity sensor 80 .

[0116] The ambient temperature sensor 60 is used to obtain the ambient temperature of the heat pump system, the return water temperature sensor 70 is arranged on the water inlet pipe of the heat exchanger 20, and the ambient humidity sensor 80 is used to obtain the ambient humidity of the heat pump system. The controller is connected to the ambient temperature sensor 60, the return water temperature sensor 70 and the ambient humidity sensor 80 respectively.

[0117] Specifically, the controller obtains the ambient temperature collected by the ambient temperature sensor 60, the return water temperature collected by the return water temperature sensor 70, and the ambient humidity collected by the ambient humidity sensor 80. When the ambient temperature is less than the preset temperature threshold and the ambient humidity is greater than the humidity threshold, it indicates that the ambient temperature of the air outlet grille 30 is low and the humidity is high. When the air outlet grille 30 operates in this environment for a long time, it is easy to frost. Therefore, according to the operating time of the heat pump system 1, if the operating time in this environment reaches the preset time, it is determined that the defrost start condition has been met, and the defrost control valve 40 and the circulating water pump 10 are controlled to achieve defrosting. When the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille 30 is less than the preset water temperature difference, the defrost control valve 40 is closed to achieve the start and stop control of the automatic defrost function of the air outlet grille 30.

[0118] In one embodiment, the heat pump system 1 further includes: an inlet water temperature sensor 90 and an outlet water temperature sensor 100 .

[0119] The inlet water temperature sensor 90 is provided on the water inlet pipe of the air outlet mesh cover 30, and is used to obtain the inlet water temperature of the air outlet mesh cover 30. The outlet water temperature sensor 100 is provided on the outlet pipe of the air outlet mesh cover 30, and is used to obtain the outlet water temperature of the air outlet mesh cover 30. The controller is connected to the inlet water temperature sensor 90 and the outlet water temperature sensor 100, respectively.

[0120] Specifically, the controller determines whether defrosting is completed by monitoring the water inlet temperature and the water outlet temperature of the air outlet mesh cover 30 in real time. When the water temperature difference between the water inlet temperature and the water outlet temperature of the air outlet mesh cover 30 is less than the preset water temperature difference, the defrost control valve 40 is controlled to close, and the water use mode of the heat pump system 1 is restored to provide hot water to the user's water use end, thereby realizing automatic switching control of the defrost function.

[0121] In one embodiment, the heat pump system 1 further includes: an electric heating module 110, which is arranged on the water inlet pipe of the air outlet mesh cover 30, and is used to heat the water in the water inlet pipe of the air outlet mesh cover 30, and the electric heating module 110 is connected to the controller.

[0122] By adding an electric heating module 110 to the water inlet pipe of the air outlet mesh cover 30, when the return water temperature is less than or equal to the preset return water temperature, the controller turns on the electric heating module 110 on the water inlet pipe of the air outlet mesh cover 30. Based on the heating of the electric heating module 110, the temperature of the water flowing into the air outlet mesh cover 30 is quickly increased, thereby improving the defrosting efficiency.

[0123] In one embodiment, the heat pump system 1 further includes a drain pipe 120 and a drain valve 130 .

[0124] The water inlet end of the drain pipe 120 is connected to the pipe 31 of the air outlet mesh cover 30, and the water inlet end of the drain pipe 120 is lower than the position of the water outlet E of the pipe 31 of the air outlet mesh cover 30. The drain valve 130 is provided on the drain pipe 120. The drain valve 130 is used to connect or close the drain pipe 120, and the drain valve 130 is connected to the controller.

[0125] Specifically, when the defrost start conditions are met, the controller controls the drain valve 130 to close, and controls the defrost control valve 40 and the circulating water pump 10 to open. The hot water flowing out of the heat exchanger 20 flows into the air outlet mesh cover 30 through the water inlet pipe of the air outlet mesh cover 30, and after heat exchange in the pipe 31 of the air outlet mesh cover 30, it flows back to the water inlet pipe of the heat exchanger 20 through the water outlet pipe of the air outlet mesh cover 30. After being heated by the heat exchanger 20, it circulates to the air outlet mesh cover 30 again to defrost the air outlet mesh cover 30. During the defrost process, the drain valve 130 is closed, and the hot water flowing out of the heat exchanger 20 can efficiently act on the heat exchange of the air outlet mesh cover 30, thereby improving the defrost efficiency.

[0126] When the water temperature difference between the inlet and outlet water temperatures of the air outlet grille 30 is less than the preset water temperature difference, defrosting is considered complete, and the controller controls the defrost control valve 40 to close the defrost water circuit. At this time, the hot water flowing out of the heat exchanger 20 flows to the user water use end, for example, the user end water inlet A, under the action of the circulating water pump 10, and flows back to the heat exchanger 20 from the user end water outlet B through the internal circulation pipeline of the user end water point. And when the water temperature difference between the inlet and outlet water temperatures of the air outlet grille 30 is less than the preset water temperature difference, the drain valve 130 is controlled to open. At this time, since the water inlet end of the drain pipe 120 is lower than the water outlet E of the pipe 31 of the air outlet grille, the residual water in the pipe 31 of the air outlet grille 30 is discharged through the drain pipe under the action of gravity, preventing the water in the pipe 31 from freezing and damaging the grille, thereby improving the structural reliability and service life of the air outlet grille 30. During the drainage process, there is no need to rely on power equipment such as water pumps, saving costs.

[0127] It should be noted that the heat pump system provided in the embodiment of the present application may also include an expansion tank 91, an expansion tank heating belt 911, a liquid reservoir 92, an expansion valve 93, an evaporator 94, a chassis heating belt 95, a fan 96, a coil temperature sensor 97, a four-way valve 98, a return air temperature sensor 99, a compressor 992, an exhaust temperature sensor 993, a water flow switch 994, an exhaust valve 995 and an automatic water replenishment valve 996.

[0128] Tap water flows from the tap water inlet C through the pipeline where the automatic water replenishment valve 996 is located, enters the heat exchanger's water inlet pipe, flows through the circulating water pump 10, and flows into the heat exchanger 20. The outlet pipe of the heat exchanger 20 is equipped with a water flow switch 994 and an exhaust valve 995. When the water flow switch 994 is turned on, the heat exchanger 20 can supply water to the user's terminal water inlet A. Conversely, when the water flow switch 994 is turned off, the passage to the user's terminal water inlet A is cut off. The exhaust valve 995 prevents expansion of the heat exchanger 20's outlet pipe caused by excessive air pressure.

[0129] Compressor 992, evaporator 94, and four-way valve 98 work together to form an airflow loop with heat exchanger 20, as shown in the figure. An expansion valve 93 can be installed between liquid storage tank 92 and evaporator 94. A chassis heating belt 95 can be installed at the bottom of evaporator 94, and a coil temperature sensor 97 can be installed on the side to monitor coil temperature. A fan 96 is located near evaporator 94. A return air temperature sensor 99 is installed on the intake pipe of compressor 992, and an exhaust air temperature sensor 993 is installed on the outlet pipe of compressor 992.

[0130] In the description of this specification, reference to the terms "some embodiments" or "other embodiments" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0131] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0132] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A defrost control method, characterized in that: Applicable to a heat pump system, the heat pump system includes a circulating water pump, a heat exchanger, an air outlet mesh cover and a defrost control valve, the circulating water pump is provided on the water inlet pipe of the heat exchanger, the air outlet mesh cover is formed by spirally winding a pipe, the water inlet pipe of the air outlet mesh cover is connected to the water outlet pipe of the heat exchanger, the water outlet pipe of the air outlet mesh cover is connected to the water inlet pipe of the heat exchanger, and the water inlet pipe of the air outlet mesh cover, the pipe of the air outlet mesh cover, and the water outlet pipe of the air outlet mesh cover constitute a defrost water circuit; The defrost control valve is provided on the defrost water path and is used to connect or close the defrost water path; The method comprises: When the defrost start condition is met, the defrost control valve and the circulating water pump are opened, and the defrost water path is connected with the defrost control valve in the open state; Obtaining the water inlet temperature and the water outlet temperature of the air outlet grille; When the water temperature difference between the water inlet temperature and the water outlet temperature of the air outlet grille is less than the preset water temperature difference, the defrost control valve is closed, and the defrost water path is closed when the defrost control valve is closed.

2. The method according to claim 1, characterized in that The method further comprises: Acquire the ambient temperature of the heat pump system, the operating time of the heat pump system, and the ambient humidity of the heat pump system; The defrost start condition includes: the ambient temperature is lower than the preset temperature threshold, the ambient humidity is higher than the humidity threshold, and the running time is longer than a preset time period.

3. The method according to claim 1, characterized in that The heat pump system further includes an electric heating module, which is provided on the water inlet pipe of the air outlet grille and is used to heat water in the pipe. After the step of controlling the defrost control valve to connect to the defrost water circuit and start the circulating water pump, and before the step of controlling the defrost control valve to close the defrost water circuit, the method further includes: Obtaining the return water temperature of the water inlet pipe of the heat exchanger; When the return water temperature is less than or equal to the preset return water temperature, the electric heating module is turned on.

4. The method according to any one of claims 1 to 3, characterized in that The heat pump system further includes a drain pipe connected to the pipeline of the air outlet grille, and a drain valve provided on the drain pipe, the drain valve being used to connect or close the drain pipe; the method further includes: When the defrost start condition is met, controlling the drain valve to close; When the water temperature difference between the inlet water temperature and the outlet water temperature of the air outlet grille is less than the preset water temperature difference, the drain valve is controlled to open. When the drain valve is opened, the water in the pipeline of the air outlet grille flows out through the drain pipe.

5. A controller, characterized in that: The controller is used in a heat pump system, and is used to execute the steps of the defrost control method according to any one of claims 1 to 4.

6. A heat pump system, characterized in that: The heat pump system comprises: a circulating water pump (10), a heat exchanger (20), an air outlet screen (30), a defrost control valve (40), and the controller according to claim 5; The circulating water pump (10) is arranged on the water inlet pipe of the heat exchanger (20); The air outlet screen (30) is formed by spirally winding the pipe (31); The water inlet pipe of the air outlet mesh cover (30) is in communication with the water outlet pipe of the heat exchanger (20); The water outlet pipe of the air outlet mesh cover (30) is in communication with the water inlet pipe of the heat exchanger (20); The water inlet pipe of the air outlet mesh cover (30), the pipeline (31) of the air outlet mesh cover (30), and the water outlet pipe of the air outlet mesh cover (30) constitute a defrosting water path; The defrost control valve (40) is provided on the defrost water path and is used to connect or close the defrost water path; The controller is connected to the defrost control valve (40) and the circulating water pump (10) respectively.

7. The heat pump system according to claim 6, characterized in that The heat pump system further comprises: An ambient temperature sensor (60) for obtaining the ambient temperature of the heat pump system; a return water temperature sensor (70), provided on the water inlet pipe of the heat exchanger (20); An ambient humidity sensor (80), used for obtaining the ambient humidity of the heat pump system; The controller is respectively connected to the ambient temperature sensor (60), the return water temperature sensor (70), and the ambient humidity sensor (80).

8. The heat pump system according to claim 6, characterized in that The heat pump system further comprises: an inlet water temperature sensor (90), provided on the water inlet pipe of the air outlet mesh cover (30), for obtaining the inlet water temperature of the air outlet mesh cover (30); An outlet water temperature sensor (100) is provided on the outlet pipe of the air outlet mesh cover (30) and is used to obtain the outlet water temperature of the air outlet mesh cover (30); The controller is connected to the water inlet temperature sensor (90) and the water outlet temperature sensor (100) respectively.

9. The heat pump system according to claim 6, characterized in that The heat pump system further comprises: An electric heating module (110) is provided on the water inlet pipe of the air outlet mesh cover (30), the electric heating module (110) is used to heat water in the water inlet pipe of the air outlet mesh cover (30), and the electric heating module (110) is connected to the controller.

10. The heat pump system according to any one of claims 6 to 9, characterized in that: The heat pump system further comprises: a drain pipe (120), wherein a water inlet end of the drain pipe (120) is in communication with the pipe (31) of the air outlet mesh cover (30), and the water inlet end of the drain pipe (120) is lower than the position of the water outlet of the pipe (31) of the air outlet mesh cover (30); A drain valve (130) is provided on the drain pipe (120), the drain valve (130) is used to connect or close the drain pipe (120), and the drain valve (130) is connected to the controller.

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