Heat pump air conditioning system and defrosting control method thereof

Abstract

The application provides a heat pump air conditioning system and a defrosting control method thereof. The heat pump air conditioning system comprises a compressor assembly, a first heat exchanger, a second heat exchanger, a pump component, an indoor unit, a heat storage water tank and a branch pipeline. A throttling pipeline is connected between the first heat exchanger and a first medium channel. The heat storage water tank is arranged at a pipeline evaporation section of the throttling pipeline and located at an upstream side of a throttling component. The first medium channel is respectively connected with a first medium inlet pipe and a first medium outlet pipe at two ends. An upstream end of the throttling pipeline is connected with a downstream end of the first medium outlet pipe, and a downstream end of the throttling pipeline is connected with the first heat exchanger. The branch pipeline is respectively connected with the upstream end of the throttling pipeline and the first medium inlet pipe at two ends. In a heating mode, the branch pipeline is cut off, and the first medium inlet pipe and the first medium outlet pipe are both conducted. In a defrosting mode, the branch pipeline is conducted, and the first medium inlet pipe and the first medium outlet pipe are both cut off. The air conditioning system solves the problem of large indoor temperature fluctuation during defrosting in the heating season.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically, to a heat pump air conditioning system and its defrosting control method. Background Technology

[0002] Hot water heater air conditioning systems (also known as heat pump air conditioning systems) are characterized by cooling without excessive dehumidification and high comfort. Compared with existing refrigerant-based air conditioning systems that use refrigerant to achieve indoor cooling and heating effects, heat pump air conditioning systems have a larger outlet air temperature difference and have better application prospects.

[0003] In areas with low temperatures and high humidity, heat pump air conditioning systems require a defrosting process during heating. The traditional defrosting control process involves switching from heating mode to cooling mode, using high-temperature, high-pressure superheated steam discharged from the compressor to melt the frost layer. During this process, the indoor unit is in cooling mode, which means that in the cold winter season, the air outlet of the air conditioner will experience a sudden drop in temperature for a period of time, which greatly affects the user's comfort.

[0004] There is an existing air conditioner defrosting control method and air conditioner. In the defrosting stage, the indoor unit switches to cooling mode, just like the traditional control method. At the same time, the method alleviates the drop in air outlet temperature by turning on the indoor electric heater. This method greatly increases household electricity consumption, which goes against the general trend of energy conservation and environmental protection. Moreover, during the temperature drop, water vapor in the air condenses and is easily blown onto the electric heating element that is being turned on, increasing the safety hazard. Summary of the Invention

[0005] The primary objective of this invention is to provide a heat pump air conditioning system that solves the problem of large indoor temperature fluctuations during defrosting in existing heat pump air conditioning systems during the heating season by using sensible heat storage.

[0006] A second objective of this invention is to provide a defrosting control method for the aforementioned heat pump air conditioning system.

[0007] A third objective of this invention is to provide another defrosting control method for the aforementioned heat pump air conditioning system.

[0008] To achieve the aforementioned first objective, the present invention provides a heat pump air conditioning system, comprising a first refrigerant circulation system and a second refrigerant circulation system; the first refrigerant circulation system includes a compressor assembly, a first heat exchanger, and a first medium channel for the second heat exchanger; the second refrigerant circulation system includes a pump assembly, an indoor unit, and a second medium channel for the second heat exchanger; the first medium channel and the second medium channel are independently arranged; a throttling pipe is connected between the first heat exchanger and the first medium channel, and a throttling component is provided on the throttling pipe; the heat pump air conditioning system further includes a hot water storage tank and branch pipes, the throttling pipe includes an evaporation section, and the hot water storage tank is located on the pipe... The evaporation section is located upstream of the throttling component; the two ends of the first medium channel are respectively connected to the first medium inlet pipe and the first medium outlet pipe, the upstream end of the first medium inlet pipe is connected to the compressor assembly, the upstream end of the throttling pipe is connected to the downstream end of the first medium outlet pipe, and the downstream end of the throttling pipe is connected to the first heat exchanger; the two ends of the branch pipe are respectively connected to the upstream end of the throttling pipe and the first medium inlet pipe; the heat pump air conditioning system has a heating mode and a defrosting mode. In the heating mode, the branch pipe is closed, and both the first medium inlet pipe and the first medium outlet pipe are open; in the defrosting mode, the branch pipe is open, and both the first medium inlet pipe and the first medium outlet pipe are closed.

[0009] As can be seen from the above scheme, by adding a hot water storage tank, branch pipes, and valves to control the opening and closing of the branch pipes, the first medium inlet pipe, and the first medium outlet pipe to the existing heat pump air conditioning system, the branch pipes are closed in the heating mode, the first medium inlet pipe and the first medium outlet pipe are open, the hot water storage tank stores heat, the first refrigerant circulation system and the second refrigerant circulation system work respectively, and the indoor unit delivers hot air into the corresponding indoor space. Furthermore, in defrost mode, the connection between the indoor unit and the outside is disconnected, and the branch pipe is opened. The branch pipe connects the throttling pipe and the compressor assembly to form the first refrigerant circuit. The refrigerant inside the throttling pipe at the hot water storage tank (i.e., the evaporation section of the pipe) exchanges heat with the hot water and other media inside the hot water storage tank. The evaporation section of the pipe acts as the evaporator in this first refrigerant circuit, and the first heat exchanger acts as the condenser in this first refrigerant circuit, thereby realizing the defrosting operation of the first heat exchanger. At the same time, in defrost mode, both the first medium inlet pipe and the first medium outlet pipe are closed, and the second refrigerant circulation system operates normally. Since the second refrigerant circulation system still circulates the hot water produced in heating mode, the indoor unit still delivers hot air into the room, achieving no cold air blowing directly during the defrosting stage, resulting in higher comfort. Therefore, there is no problem of indoor temperature fluctuation in defrost mode. In addition, this heat pump air conditioning system can utilize the original piping of the air conditioning system without the need for a separate water system, fully utilizing the advantages of heat pump air conditioning products.

[0010] A preferred embodiment is that the heat pump air conditioning system further includes a first valve, a second valve, and a third valve; the first valve is located on the first medium outlet pipe, the second valve is located on the first medium inlet pipe, and the third valve is located on a branch pipe; the connection between the branch pipe and the first medium inlet pipe is located upstream of the second valve.

[0011] Therefore, it can be seen that the opening and closing of the first medium outlet pipe, the first medium inlet pipe, and the branch pipe can be controlled by three valves respectively.

[0012] A further option is that the third valve is a one-way valve, which allows unidirectional flow from the end of the branch pipeline connected to the throttling pipeline to the end of the branch pipeline connected to the first medium inlet pipe; or, at least one of the first valve, the second valve, and the third valve is a solenoid valve.

[0013] Therefore, the third valve can be either a solenoid valve or a check valve, while the first and second valves can both be solenoid valves.

[0014] A preferred embodiment is that the heat pump air conditioning system also includes a first valve and a second valve; the first valve is a three-way valve, and the upstream end of the throttling pipe, the downstream end of the first medium outlet pipe, and the branch pipe are connected through the first valve; the second valve is located on the first medium inlet pipe.

[0015] A preferred embodiment is that the heat pump air conditioning system further includes a first valve and a second valve; the first valve is located on the first medium outlet pipe; the second valve has a three-way structure, the first medium inlet pipe includes a compression section and a heat exchange section, the upstream end of the compression section is connected to the compressor assembly, the downstream end of the heat exchange section is connected to the first medium channel, and the downstream end of the compression section, the upstream end of the heat exchange section, and the branch pipe are connected through the second valve.

[0016] Therefore, it can be seen that a three-way valve can be used to connect and switch the corresponding pipeline on and off.

[0017] A preferred option is to locate the evaporation section of the pipeline inside the hot water storage tank.

[0018] Therefore, it can be seen that the evaporation section of the pipeline is located inside the hot water storage tank. The hot water stored in the tank exchanges heat with the first refrigerant in the evaporation mode. The fact that the evaporation section of the pipeline is located inside the hot water storage tank can increase the contact area between the evaporation section of the pipeline and the hot water, thereby greatly improving the heat exchange efficiency.

[0019] A further proposed solution is to connect a second medium inlet pipe and a second medium outlet pipe to the two ends of the second medium channel, with the second medium outlet pipe connected to the hot water storage tank.

[0020] Therefore, it can be seen that the hot water in the second circulation system in the heating mode can be filled into the hot water storage tank so that heat exchange with the first refrigerant can be achieved in the defrosting mode.

[0021] To achieve the second objective mentioned above, the present invention provides a defrosting control method for the aforementioned heat pump air conditioning system. The defrosting control method includes: in heating mode, cutting off the branch pipe and connecting the first medium inlet pipe and the first medium outlet pipe; in defrosting mode, connecting the branch pipe and cutting off the first medium inlet pipe and the first medium outlet pipe.

[0022] As can be seen from the above scheme, in heating mode, the branch pipes of the heat pump air conditioning system are closed, while the first refrigerant inlet and outlet pipes are open. The hot water storage tank stores heat, and the first and second refrigerant circulation systems operate separately. The indoor unit delivers hot air into the corresponding indoor space. In defrosting mode, the branch pipes are open, connecting the throttling pipe to the compressor assembly to form the first refrigerant circuit, enabling defrosting of the first heat exchanger. At the same time, the first refrigerant inlet and outlet pipes are closed, disconnecting the indoor unit from the outside. The second refrigerant circulation system operates normally. Since the second refrigerant circulation system still circulates the hot water generated in heating mode, and the indoor unit still delivers hot air into the room, there is no problem of indoor temperature fluctuation in defrosting mode.

[0023] A preferred embodiment is that the compressor assembly includes a compressor; the defrosting control method further includes: in heating mode, determining whether at least one of the following conditions is met: the compressor running time is greater than a first preset time t1, the difference between the defrosting temperature sensor and the outdoor ambient temperature is less than a preset temperature difference ΔT, and the defrosting temperature sensor is less than a first preset temperature T1; if at least one of the above conditions is met, then the defrosting mode is entered.

[0024] Therefore, by limiting the conditions for starting the defrost mode, when there is a deviation or malfunction in the ambient temperature sensor, the defrost mode can be entered in time based on the temperature detected by the defrost temperature sensor itself. This avoids damage to the heat pump air conditioning system caused by the failure of any temperature sensor to enter the defrost mode correctly.

[0025] A further solution is that the defrosting control method also includes: determining whether at least one of the following conditions is met: the compressor's exhaust pipe side pressure is greater than the preset pressure Pd, the defrosting temperature sensor temperature is greater than the second preset temperature T2, and the defrosting time is greater than the second preset time t2; if at least one of the above conditions is met, the defrosting mode is exited.

[0026] Therefore, exiting defrost mode only when any one condition is met ensures a complete defrost process. However, in real-world environments, requiring two or more conditions to be met simultaneously before exiting defrost mode could significantly extend the defrost exit time, negatively impacting user experience.

[0027] To achieve the third objective mentioned above, the present invention provides a defrosting control method for the aforementioned heat pump air conditioning system. The defrosting control method includes: in heating mode, cutting off the branch pipe and connecting the first medium inlet pipe and the first medium outlet pipe, and supplying hot water to the hot water storage tank through the second medium outlet pipe; in defrosting mode, connecting the branch pipe and cutting off the first medium inlet pipe and the first medium outlet pipe.

[0028] Therefore, it can be seen that the hot water in the second circulation system in the heating mode can be filled into the hot water storage tank so that heat exchange with the first refrigerant can be achieved in the defrosting mode. Attached Figure Description

[0029] Figure 1 This is a system block diagram of the first embodiment of the heat pump air conditioning system of the present invention.

[0030] Figure 2 This is a system flowchart of the first embodiment of the heat pump air conditioning system of the present invention.

[0031] Figure 3 This is a partial block diagram of the second embodiment of the heat pump air conditioning system of the present invention.

[0032] Figure 4 This is a partial block diagram of the third embodiment of the heat pump air conditioning system of the present invention.

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0034] Various exemplary embodiments of the invention will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the invention or its application or use. The invention can be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0035] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after it, without excluding the possibility of encompassing other elements. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0036] In this invention, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0037] All terms used in this invention (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0038] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0039] First embodiment of a heat pump air conditioning system and its defrosting control method:

[0040] See Figure 1 and Figure 2 The heat pump air conditioning system includes a compressor assembly 1, a first heat exchanger 2, a second heat exchanger 3, a throttling device 4, a pump assembly 5, a valve assembly, a temperature sensing bulb assembly, a pressure testing device 6, a hot water storage tank 7, branch pipes 8, and an indoor unit 9.

[0041] To more clearly illustrate the connection relationship between the components, this embodiment uses the flow direction of the refrigerant in heating mode as a reference to represent the "upstream side" and "downstream side".

[0042] The throttling component 4 is an electronic expansion valve 4, and the second heat exchanger 3 is a plate heat exchanger. The second heat exchanger 3 is provided with independent first medium channels and second medium channels. A throttling pipe 10 is connected between the first heat exchanger 2 and the first medium channel, and the electronic expansion valve 4 is installed on the throttling pipe 10.

[0043] The throttling pipeline 10 includes an evaporation section 101. The hot water storage tank 7 is located at the evaporation section 101 of the throttling pipeline 10 and upstream of the electronic expansion valve 4. The evaporation section 101 is located inside the hot water storage tank 7. By placing the evaporation section 101 inside the hot water storage tank 7, the contact area between the evaporation section 101 and the hot water in the hot water storage tank 7 is increased, thereby significantly improving the heat exchange efficiency.

[0044] The compressor assembly 1 includes a compressor 11, a gas-liquid separator 12, and a four-way valve 13. The four-way valve 13 includes a D-pipe 131, an E-pipe 132, an S-pipe 133, and a C-pipe 134. The D-pipe 131 is connected to the discharge pipe 111 of the compressor 11, the E-pipe 132 is connected to the first medium passage of the second heat exchanger 3, the C-pipe 134 is connected to the first heat exchanger 2, and the S-pipe 133 is connected to the suction pipe 112 of the compressor 11 through the gas-liquid separator 12.

[0045] The compressor assembly 1, the first heat exchanger 2, and the first medium passage of the second heat exchanger 3 constitute the first refrigerant circulation system 100. The pump assembly 5, the indoor unit 9, and the second medium passage of the second heat exchanger 3 constitute the second refrigerant circulation system 200. The refrigerant in the first refrigerant circulation system 100 is a refrigerant medium, and the refrigerant in the second refrigerant circulation system 200 is water.

[0046] The temperature sensing element assembly includes an ambient temperature sensing element 21 and a defrost temperature sensing element 22. The ambient temperature sensing element 21 is located on the windward side of the first heat exchanger 2 and is used to detect the outdoor ambient temperature. The defrost temperature sensing element 22 is located in the middle of the heat exchange fins of the first heat exchanger 2 and is used to detect the temperature at the test point in the middle of the first heat exchanger 2. The pressure testing element 6 is located on the exhaust pipe 111 of the compressor 11 and is used to detect the pressure on the exhaust pipe side of the compressor 11.

[0047] The first medium channel is connected to a first medium inlet pipe 31 and a first medium outlet pipe 32 at its two ends respectively. The upstream end of the first medium inlet pipe 31 is connected to the E pipe 132 of the four-way valve 13 in the compressor assembly 1. The upstream end of the throttling pipe 10 is connected to the downstream end of the first medium outlet pipe 32. The downstream end of the throttling pipe 10 is connected to the first heat exchanger 2. The two ends of the branch pipe 8 are connected to the upstream end of the throttling pipe 10 and the first medium inlet pipe 31 respectively.

[0048] The valve assembly includes a first valve 81, a second valve 82, and a third valve 83. The first valve 81 is located on the first medium outlet pipe 32, the second valve 82 is located on the first medium inlet pipe 31, and the third valve 83 is located on the branch pipe 8, with the connection point between the branch pipe 8 and the first medium inlet pipe 31 upstream of the second valve 82. The third valve 83 is a one-way valve, allowing unidirectional flow from the end of the branch pipe 8 connected to the throttling pipe 10 to the end of the branch pipe 8 connected to the first medium inlet pipe 31. Both the first valve 81 and the second valve 82 are solenoid valves.

[0049] The two ends of the second medium channel are respectively connected to the second medium inlet pipe 33 and the second medium outlet pipe 34. The second medium outlet pipe 34 is connected to the hot water storage tank 7 through a connecting pipe (not shown). A solenoid valve (not shown) for connecting or closing the connecting pipe is provided on the connecting pipe.

[0050] Heat pump air conditioning systems have cooling mode, heating mode, and defrost mode. Defrost control methods for heat pump air conditioning systems include:

[0051] After the heat pump air conditioning system is turned on, step S1 is executed first to determine whether it is in heating mode. If so, the branch pipe 8 is cut off and the first valve 81 and the second valve 82 are opened to connect the first medium inlet pipe 31 and the first medium outlet pipe 32. The first refrigerant circulation system 100, which consists of the compressor assembly 1, the first heat exchanger 2 and the first medium channel of the second heat exchanger 3, and the second refrigerant circulation system 200, which consists of the pump assembly 5, the indoor unit 9 and the second medium channel of the second heat exchanger 3, respectively, are put into operation.

[0052] At this time, the second heat exchanger 3 is a condenser and the first heat exchanger 2 is an evaporator. The high-temperature and high-pressure gas from the compressor 11 enters the first medium channel of the second heat exchanger 3 through the first medium inlet pipe 31 after passing through the four-way valve 13. The high-temperature and high-pressure gas exchanges heat with the water in the second medium channel of the second heat exchanger 3 and becomes a high-temperature and high-pressure liquid. The high-temperature and high-pressure liquid enters the throttling pipe 10 from the first medium outlet pipe 32, flows through the evaporation section 101 of the pipe, and then passes through the electronic expansion valve 4. After passing through the electronic expansion valve 4, the high-temperature and high-pressure liquid becomes a low-temperature and high-pressure liquid. The low-temperature and high-pressure liquid passes through the first heat exchanger 2 and then enters the compressor 11 through the four-way valve 13, completing the circulation of the refrigerant in the first refrigerant circulation system 100.

[0053] At the same time, the pump component 5 operates, driving the water in the second refrigerant circulation system 200 to circulate continuously, thereby causing the hot water in the second medium channel to circulate after heat exchange with the refrigerant in the first medium channel. At the same time, the solenoid valve on the connecting pipe opens, and the second medium outlet pipe 34 delivers hot water to the hot water storage tank 7.

[0054] Next, step S2 is executed to determine if one of the following conditions is met: the compressor 11 running time is greater than the first preset time t1; the temperature difference between the defrost temperature sensor 22 and the outdoor ambient temperature is less than the preset temperature difference ΔT; or the temperature of the defrost temperature sensor 22 is less than the first preset temperature T1. If at least one of the above conditions is met, the defrost mode is entered. By limiting the conditions for starting the defrost mode, when the ambient temperature sensor 21 detects a deviation or malfunction, the defrost mode can be entered in a timely manner based on the temperature detected by the defrost temperature sensor 22 itself. This avoids damage to the heat pump air conditioning system caused by any temperature sensor failure preventing the air conditioning system from correctly entering the defrost mode. The compressor 11 running time is the continuous working time of the compressor in the heat pump air conditioning system in heating mode. When the air conditioning system exits the defrost mode, it indicates that one defrost process has been completed, and the compressor running time needs to be reset. The compressor 11 running time is used as a criterion for entering the defrost mode. This can prevent the air conditioning system from failing to defrost for a long time due to a deviation in the defrost temperature sensor detection, thus affecting the reliable operation and user comfort of the system.

[0055] Next, step S3 is executed. In defrost mode, the four-way valve 13 reverses, and simultaneously, the branch pipe 8 is opened, while the first valve 81, the second valve 82, and the solenoid valve on the connecting pipe are closed to cut off the first medium inlet pipe 31, the first medium outlet pipe 32, and the connecting pipe. At this time, the first refrigerant circuit, composed of the compressor assembly 1, the first heat exchanger 2, and the pipeline evaporation section 101, and the second refrigerant circulation system 200, composed of the pump assembly 5, the indoor unit 9, and the second medium passage of the second heat exchanger 3, respectively, are operating.

[0056] At this time, the first heat exchanger 2 is a condenser, and the pipeline evaporation section 101 is an evaporator. The high-temperature and high-pressure gas from the compressor 11 enters the first heat exchanger 2 after passing through the four-way valve 13. After heat exchange in the first heat exchanger 2, it becomes a high-temperature and high-pressure liquid and then enters the throttling pipeline 10. After entering the first heat exchanger 2, the high-temperature and high-pressure gas liquefies and releases heat, which can achieve defrosting of the first heat exchanger 2. The high-temperature and high-pressure liquid becomes a low-temperature and high-pressure liquid after passing through the electronic expansion valve 4 on the throttling pipeline 10. The low-temperature and high-pressure liquid flows into the pipeline evaporation section 101 and exchanges heat with the hot water in the hot water storage tank 7. After heat exchange, it becomes a low-temperature and low-pressure gas and enters the compressor 11 through the four-way valve 13, completing the circulation of the refrigerant in the first refrigerant circuit.

[0057] At the same time, the pump component 5 operates, driving the water in the second refrigerant circulation system 200 to circulate continuously. Since the first medium channel is not connected to the first refrigerant circuit, the water in the second medium channel will not exchange heat with the refrigerant in the first medium channel. The water circulating in the second refrigerant circulation system 200 is still the hot water generated in the heating mode. Therefore, the indoor unit 9 still sends hot air into the room. In the defrosting mode, there will be no problem of indoor temperature fluctuation.

[0058] Next, step S4 is executed to determine whether one of the following conditions is met: the pressure on the exhaust pipe side of compressor 11 is greater than the preset pressure Pd, the temperature of defrost sensing bulb 22 is greater than the second preset temperature T2, or the defrost time is greater than the second preset time t2. If at least one of the above conditions is met, the defrost mode is exited. The defrost time starts counting from the moment the heat pump air conditioning system enters the defrost mode.

[0059] As can be seen from the above, by adding a hot water storage tank, branch pipes, and valves to control the opening and closing of the branch pipes, the first medium inlet pipe, and the first medium outlet pipe to the existing heat pump air conditioning system, the branch pipes are closed in the heating mode, the first medium inlet pipe and the first medium outlet pipe are open, the hot water storage tank stores heat, the first refrigerant circulation system and the second refrigerant circulation system work respectively, and the indoor unit delivers hot air into the corresponding indoor space. Furthermore, in defrost mode, the connection between the indoor unit and the outside is disconnected, and the branch pipe is opened. The branch pipe connects the throttling pipe to the compressor assembly to form the first refrigerant circuit. The portion of the throttling pipe at the hot water storage tank location corresponds to the external thermal environment, serving as the evaporator in this first refrigerant circuit. The first heat exchanger serves as the condenser in this first refrigerant circuit, thus enabling defrosting of the first heat exchanger. Simultaneously, in defrost mode, both the first medium inlet and outlet pipes are closed, and the second refrigerant circulation system operates normally. Since the second refrigerant circulation system still circulates hot water generated in heating mode, the indoor unit still delivers hot air into the room, ensuring no cold air blows directly during defrosting and providing high comfort. Therefore, there is no issue of indoor temperature fluctuations in defrost mode. Additionally, this heat pump air conditioning system can utilize the existing piping of the air conditioning system, eliminating the need for a separate water system, fully leveraging the advantages of heat pump air conditioning products.

[0060] Second embodiment of heat pump air conditioning system and its defrosting control method:

[0061] As a description of the second embodiment of the heat pump air conditioning system and defrosting control method of the present invention, the following description only focuses on the differences from the first embodiment of the heat pump air conditioning system and defrosting control method described above.

[0062] See Figure 3In this embodiment, the valve assembly includes a first valve 28 and a second valve 29. The first valve 28 is a three-way valve. Preferably, the first valve 28 is an electromagnetic three-way valve. The upstream end of the throttling pipeline 210, the downstream end of the first medium outlet pipe 232, and the branch pipeline 280 are connected through the first valve 28. The first valve 28 includes a first connecting port 281, a second connecting port 282, and a third connecting port 283. The first connecting port 281 is connected to the upstream end of the throttling pipeline 210, the second connecting port 282 is connected to the downstream end of the first medium outlet pipe 232, and the third connecting port 283 is connected to the branch pipeline 280. The second valve 29 is located on the first medium inlet pipe 231.

[0063] In heating mode, the first connection port 281 and the second connection port 282 of the electromagnetic three-way valve 28 are connected, and the first connection port 281 and the third connection port 283 are disconnected. The second valve 29 is opened, thereby achieving the cut-off of the branch pipeline 280 and the connection between the first medium inlet pipe 231 and the first medium outlet pipe 232.

[0064] In defrosting mode, the first connection port 281 and the third connection port 283 of the electromagnetic three-way valve 28 are connected, and the first connection port 281 and the second connection port 282 are disconnected. The second valve 29 is closed, thereby realizing the conduction of the branch pipeline 280 and the cut-off of the first medium inlet pipe 231 and the first medium outlet pipe 232.

[0065] Third embodiment of heat pump air conditioning system and its defrosting control method:

[0066] As a description of the third embodiment of the heat pump air conditioning system and defrosting control method of the present invention, the following description only focuses on the differences from the first embodiment of the heat pump air conditioning system and defrosting control method described above.

[0067] See Figure 4 In this embodiment, the valve assembly includes a first valve 38 and a second valve 39. The first valve 38 is located on the first medium outlet pipe 332. The second valve 39 is a three-way valve. Preferably, the second valve 39 is an electromagnetic three-way valve. The first medium inlet pipe 331 includes a compression section 3311 and a heat exchange section 3312. The upstream end of the compression section 3311 is connected to a four-way valve in the compressor assembly, and the downstream end of the heat exchange section 3312 is connected to the first medium channel. The downstream end of the compression section 3311, the upstream end of the heat exchange section 3312, and the branch pipe 380 are connected through the second valve 39. The second valve 39 includes a first connecting port 391, a second connecting port 392, and a third connecting port 393. The first connecting port 391 is connected to the downstream end of the compression section 3311, the second connecting port 392 is connected to the upstream end of the heat exchange section 3312, and the third connecting port 393 is connected to the branch pipe 380.

[0068] In heating mode, the first connection port 391 and the second connection port 392 of the electromagnetic three-way valve 39 are connected, and the first connection port 391 and the third connection port 393 are disconnected. The first valve 38 is opened, thereby achieving the cut-off of the branch pipeline 380 and the connection of the first medium inlet pipe 331 and the first medium outlet pipe 332.

[0069] In defrosting mode, the first connection port 391 and the third connection port 393 of the electromagnetic three-way valve 39 are connected, and the first connection port 391 and the second connection port 392 are disconnected. The first valve 38 is closed, thereby realizing the conduction of the branch pipeline 380 and the cut-off of the first medium inlet pipe 331 and the first medium outlet pipe 332.

[0070] In addition, at least one of the first valve, the second valve, and the third valve may also be a solenoid valve.

[0071] The inner and outer diameters, length, wall thickness, and extension methods of the evaporation section of the pipeline can all be changed as needed. For example, the evaporation section of the pipeline can extend in L-shape, U-shape, or S-shape.

[0072] The type and number of throttling components and valves can be changed as needed.

[0073] Pressure testing components can be pressure sensors, etc., and the specific choice can be made according to the needs.

[0074] An insulation layer can also be installed outside the hot water storage tank to prevent the water stored inside from transferring heat to the outside.

[0075] Alternatively, the evaporation section of the pipeline can be wrapped around the outside of the hot water storage tank. In heating mode, the refrigerant transfers heat to the water in the hot water storage tank as it passes through the evaporation section. In this case, the hot water storage tank needs to be made of a material with good thermal conductivity. Alternatively, after wrapping the evaporation section of the pipeline around the outside of the hot water storage tank, an insulation layer can be installed on both the evaporation section and the outside of the hot water storage tank. In this way, heat can be transferred to the water in the hot water storage tank as the refrigerant passes through it in heating mode, without the need to transport the hot water from the second medium outlet pipe in heating mode to the hot water storage tank.

[0076] The condition for entering defrost mode can also be that at least one of the three conditions is met.

[0077] The condition for exiting defrost mode can also be that at least one of the three conditions is met.

[0078] The first preset time t1, preset temperature difference ΔT, first preset temperature T1, preset pressure Pd, second preset temperature T2, and second preset time t2 can all be selected according to actual needs.

[0079] The above changes can also achieve the purpose of this invention.

[0080] Finally, it should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A heat pump air conditioning system, including a first refrigerant circulation system and a second refrigerant circulation system; The first refrigerant circulation system includes a compressor assembly, a first heat exchanger, and a first medium passage for a second heat exchanger; The second refrigerant circulation system includes a pump component, an indoor unit, and a second medium passage for a second heat exchanger; The first medium channel and the second medium channel are set up independently of each other; A throttling pipe is connected between the first heat exchanger and the first medium channel, and a throttling component is provided on the throttling pipe; Its features are: The heat pump air conditioning system also includes a hot water storage tank and branch pipes. The throttling pipe includes an evaporation section, and the hot water storage tank is located at the evaporation section and upstream of the throttling component. The first medium channel is connected to a first medium inlet pipe and a first medium outlet pipe at its two ends respectively. The upstream end of the first medium inlet pipe is connected to the compressor assembly, the upstream end of the throttling pipe is connected to the downstream end of the first medium outlet pipe, and the downstream end of the throttling pipe is connected to the first heat exchanger. The two ends of the branch pipeline are respectively connected to the upstream end of the throttling pipeline and the first medium inlet pipe; The heat pump air conditioning system has a heating mode and a defrosting mode. In the heating mode, the branch pipe is closed, and both the first medium inlet pipe and the first medium outlet pipe are open. In the defrosting mode, the branch pipe is open, and both the first medium inlet pipe and the first medium outlet pipe are closed.

2. The heat pump air conditioning system according to claim 1, characterized in that: The heat pump air conditioning system also includes a first valve, a second valve, and a third valve; The first valve is located on the first medium outlet pipe, the second valve is located on the first medium inlet pipe, and the third valve is located on the branch pipe; The branch pipeline is located upstream of the first medium inlet pipe.

3. The heat pump air conditioning system according to claim 2, characterized in that: The third valve is a one-way valve, which allows one-way flow from the end of the branch pipe connected to the throttling pipe to the end of the branch pipe connected to the first medium inlet pipe. Alternatively, at least one of the first valve, the second valve, and the third valve may be a solenoid valve.

4. The heat pump air conditioning system according to claim 1, characterized in that: The heat pump air conditioning system also includes a first valve and a second valve; The first valve is a three-way valve, and the upstream end of the throttling pipeline, the downstream end of the first medium outlet pipe, and the branch pipeline are connected through the first valve. The second valve is located on the first medium inlet pipe.

5. The heat pump air conditioning system according to claim 1, characterized in that: The heat pump air conditioning system also includes a first valve and a second valve; The first valve is located on the first medium outlet pipe; The second valve is a three-way valve. The first medium inlet pipe includes a compression section and a heat exchange section. The upstream end of the compression section is connected to the compressor assembly, and the downstream end of the heat exchange section is connected to the first medium channel. The downstream end of the compression section, the upstream end of the heat exchange section, and the branch pipeline are connected through the second valve.

6. The heat pump air conditioning system according to any one of claims 1 to 5, characterized in that: The evaporation section of the pipeline is located inside the hot water storage tank.

7. The heat pump air conditioning system according to claim 6, characterized in that: The two ends of the second medium channel are respectively connected to a second medium inlet pipe and a second medium outlet pipe, and the second medium outlet pipe is connected to the hot water storage tank.

8. A defrosting control method for a heat pump air conditioning system, characterized in that, The heat pump air conditioning system is as described in any one of claims 1 to 7; The defrosting control method includes: In the heating mode, the branch pipe is shut off, and the first medium inlet pipe and the first medium outlet pipe are connected. In the defrosting mode, the branch pipeline is opened, and the first medium inlet pipe and the first medium outlet pipe are closed.

9. The defrosting control method according to claim 8, characterized in that: The compressor assembly includes a compressor; The defrosting control method further includes: In the heating mode, it is determined whether at least one of the following conditions is met: the compressor running time is greater than the first preset time t1, the difference between the temperature of the defrost sensing bulb and the outdoor ambient temperature is less than the preset temperature difference ΔT, and the temperature of the defrost sensing bulb is less than the first preset temperature T1. If at least one of the above conditions is met, the defrosting mode will be entered.

10. The defrosting control method according to claim 9, characterized in that: The defrosting control method further includes: Determine whether at least one of the following conditions is met: the compressor's exhaust pipe side pressure is greater than the preset pressure Pd, the defrost sensing bulb temperature is greater than the second preset temperature T2, and the defrost time is greater than the second preset time t2. If at least one of the above conditions is met, the defrosting mode will be exited.

11. A defrosting control method for a heat pump air conditioning system, characterized in that, The heat pump air conditioning system is as described in claim 7; The defrosting control method includes: In the heating mode, the branch pipe is shut off, and the first medium inlet pipe and the first medium outlet pipe are connected, and the second medium outlet pipe delivers hot water to the hot water storage tank. In the defrosting mode, the branch pipeline is opened, and the first medium inlet pipe and the first medium outlet pipe are closed.

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