Air-cooled heating and power integrated system and control method

Abstract

The technical scheme of the present application discloses a kind of air-cooled heating integrated system, including power component separate sealed box and outdoor finned air heat exchanger assembly, the power component separate sealed box includes refrigerant condensing device, water system component and control system, the outdoor finned air heat exchanger assembly includes fin, air pipe, liquid pipe and bypass defrosting pipe;The control method of air-cooled heating integrated system includes the following steps: determining defrosting condition, defrosting operation control and determining defrosting exit condition, through the structure of outdoor finned air heat exchanger assembly and the connecting structure of power component separate sealed box, in combination with corresponding control method, defrosting of each fin is realized, the fin that does not defrosting operation continues to carry out heating operation, so that the whole unit can continuously carry out heating operation, the water temperature fluctuation of overall unit is small, and user experience is good.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, specifically to an integrated air-cooled heating system and its control method. Background Technology

[0002] Existing large-scale distributed heating projects in northern China generally use air-source heat pump units or air-cooled screw chillers. Individual air-source heat pump units have small performance, and large-scale projects require multiple units combined, resulting in a large footprint. Furthermore, both air-source and air-cooled screw chillers suffer from reversing defrosting issues. When the outdoor finned heat exchanger is frosted, defrosting requires stopping the compressor and then reversing the four-way reversing valve to allow the compressor to directly discharge hot air into the outdoor finned heat exchanger to melt the frost. However, after the four-way reversing valve is reversed, the condenser becomes the evaporator side (cooling), causing a drop in water temperature, large temperature fluctuations, and significant heat loss, affecting heating efficiency and user experience. In addition, the compressors and water pumps of both air-source and air-cooled screw chillers are exposed, resulting in high noise levels.

[0003] Patent CN 112629085 A discloses a novel defrosting method for air-source heat pump units. This method intelligently adjusts the refrigerant flow from the compressor bypass to the evaporator based on the frosting condition of the outdoor finned heat exchanger on the evaporator. This adjustment is achieved by utilizing a bypass proportional control device, an outdoor ambient temperature sensor, an outdoor finned heat exchanger coil temperature sensor, and high-pressure and low-pressure sensors fixedly installed on the compressor's exhaust and suction pipes. This defrosting effect can be achieved even during normal heating operation of the air-source heat pump unit. However, the finned heat exchanger is divided into two parts: one for heating and the other for defrosting. The defrosted refrigerant then flows back to the heating finned heat exchanger, resulting in low overall defrosting efficiency. Furthermore, in practical applications, the defrosted refrigerant cannot be reused for heating. Therefore, a northern winter air-cooled heating system and control method with minimal water temperature fluctuations during defrosting are needed. Summary of the Invention

[0004] To address existing technical problems, this invention provides an integrated air-cooled heating system and control method. Through the structure of the outdoor finned air heat exchanger assembly and its connection structure with the power component in a separate sealed box, combined with the corresponding control method, defrosting of each fin is achieved. Fins that do not undergo defrosting continue to operate in heating mode, thereby enabling the entire unit to operate in heating mode without interruption. The overall water temperature fluctuation of the unit is small, resulting in a good user experience.

[0005] The technical solution of this invention is: an integrated air-cooled heating system, comprising a separately sealed housing for power components and an outdoor finned air heat exchanger assembly. The separately sealed housing for power components includes a refrigerant condensation device, a water system assembly, and a control system. The refrigerant condensation device includes a compressor, an oil separator, a condenser, an economizer, and a gas-liquid separator. The compressor inlet is connected to the gas-liquid separator outlet, the compressor outlet is connected to the oil separator inlet, the oil separator outlet is connected to the condenser inlet, the condenser outlet is connected to the dryer filter inlet, and the dryer filter outlet is connected to the economizer inlet. The water system assembly is used to exchange heat between the water in the water system assembly and the condenser, and the water system assembly is connected to the indoor heat exchanger. The control system is used to control the operation of the compressor and the water system assembly, as well as the opening and closing of the pipeline valves.

[0006] The outdoor finned air heat exchanger assembly includes fins, air pipes, liquid pipes, and bypass defrosting pipes. The air pipes are connected to the fins, and the liquid pipes, bypass defrosting pipes, and fins are connected via T-joints. Each pair of fins forms a group of fins. The air pipes of each group of fins are connected to form an air pipe branch pipe, the liquid pipes of each group of fins are connected to form a liquid pipe branch pipe, and the bypass defrosting pipes of each group of fins are connected to form a bypass defrosting branch pipe. The liquid pipe branch pipes of different groups of fins are connected to form a fin-liquid pipe junction pipe, and the bypass defrosting branch pipes of different groups of fins are connected to form a bypass defrosting junction inlet pipe. The air pipe branch pipes are divided into two paths, the first path being an air... A first solenoid valve is installed on the branch pipe. The first air branch pipes of different groups of fins are connected to form a fin air branch pipe. A first check valve is installed on the second air branch pipe. The second air branch pipes of different groups of fins are connected to form a bypass defrost outlet pipe. A second solenoid valve, an expansion valve, and a second check valve are installed on the liquid branch pipe. A third solenoid valve and a third check valve are installed on the bypass defrost branch pipe. The fin air branch pipe and the bypass defrost outlet pipe are connected to the inlet of the gas-liquid separator. The fin liquid branch pipe is connected to the outlet of the economizer. The bypass defrost inlet pipe is connected to the outlet of the oil separator.

[0007] Furthermore, the bottom of the oil separator is connected to the compressor inlet via a bypass pipeline.

[0008] Furthermore, the bottom of the gas-liquid separator is connected to one end of the ejector, the other end of the ejector is connected to the outlet of the oil separator, the outlet of the ejector is connected to the inlet of the compressor, a solenoid valve is installed between the gas-liquid separator and the ejector, and an oil filter and a solenoid valve are installed sequentially between the outlet of the oil separator and the ejector.

[0009] Furthermore, the fins are provided with an air pipe, a liquid pipe and a bypass defrosting pipe. The air pipe is located on the outer side of each group of fins, the liquid pipe is located on the inner side of each group of fins, and the bypass defrosting pipe is located between the air pipe and the liquid pipe.

[0010] Furthermore, the outdoor finned air heat exchanger assembly is installed on top of a separately sealed housing for the power components, which helps save space.

[0011] A control method for an integrated air-cooled heating system includes the following steps:

[0012] S1. Determine the defrosting conditions. First, determine the time condition, as follows: the compressor's continuous running time upon initial power-on is greater than T1, and the compressor's cumulative heating running time is greater than or equal to T2, and the compressor's continuous running time is greater than or equal to T1, while the ambient temperature Ta is less than or equal to 10℃. Then, determine the temperature condition, as follows: when Ta is greater than or equal to 6℃, and the coil temperature Te of the fins is less than or equal to -2 - correction parameter℃, and Ta and Te last for 5 minutes; when 5℃ is less than or equal to Ta but less than 6℃, and Te is less than or equal to (11×Ta-107) / 16 - correction parameter℃, and Ta and Te last for 5 minutes; when -10℃ is less than or equal to Ta but less than or equal to 5℃, and Te is less than or equal to (18×Ta-70) / 16 - correction parameter℃, and Ta and Te last for 5 minutes; when Ta is less than or equal to -10℃, and Te is less than or equal to (17×Ta-112) / 21 - correction parameter℃, and Ta and Te last for 5 minutes. Only when the fins simultaneously meet both the time and temperature conditions are the defrosting conditions met, and defrosting operation begins.

[0013] S2. Defrosting operation control: When the fins meet the defrosting conditions, the defrosting operation begins. The second solenoid valve corresponding to the fin closes, the fan corresponding to the fin closes after time T3, and the first solenoid valve corresponding to the fin closes after time T4. The third solenoid valve opens. After the defrosting operation time is ≥ T5, it is determined whether the defrosting exit condition has been met.

[0014] S3. Determine the defrosting exit conditions. The defrosting exit conditions are as follows: Te≥10℃ and lasts for 5s, or the defrosting operation time≥T6. After the defrosting exit conditions are met, the third solenoid valve corresponding to the fin closes after time T7, the fan corresponding to the fin turns on after time T8, and the first and second solenoid valves corresponding to the fin open after time T9, thus ending the defrosting process.

[0015] Furthermore, in S1, Te is the minimum temperature of the coil temperature of each fin itself, and in S3, Te is the maximum temperature of the coil temperature of each fin itself.

[0016] Furthermore, in S2, when the fins meet the defrosting conditions, the fins that meet the defrosting conditions first enter the defrosting operation, and only one fin is allowed to perform defrosting operation at the same time.

[0017] By adopting the above technical solution, the beneficial effects achieved by the present invention are as follows:

[0018] (1) The present invention can achieve defrosting of each fin through the structure of fins, gas pipes, liquid pipes and bypass defrosting pipes and the connection structure with the refrigerant condensation device, etc., and can achieve good defrosting effect without the need for four-way valve reversal. Through the control method of the air-cooled heating integrated system, the fins that need to be defrosted are defrosted, and only one fin is allowed to be defrosted. The fins that are not defrosted continue to operate for heating, so that the entire unit can operate for heating without interruption. The overall unit has small water temperature fluctuation, high heating efficiency and good user experience.

[0019] (2) The design of the power components with separate sealed boxes and outdoor finned air heat exchanger components provides protection for the compressor, water pump, etc., resulting in low noise, space saving, and easy installation.

[0020] (3) The control method of the air-cooled heating integrated system in this invention is reasonable, which not only ensures high defrosting efficiency and good defrosting effect, but also reduces energy consumption. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the outdoor finned air heat exchanger assembly of the present invention;

[0023] Figure 3 This is a schematic diagram of the refrigerant condensation device of the present invention.

[0024] In the diagram, the components are: 1. Power component separately sealed box; 2. Outdoor finned air heat exchanger assembly; 11. Compressor; 12. Oil separator; 13. Condenser; 14. Economizer; 15. Dryer filter; 16. Gas-liquid separator; 17. Ejector; 18. Oil filter; 19. Water system assembly; 21. Fins; 22. Gas pipe; 23. Liquid pipe; 24. Bypass defrost pipe; 25. Finned liquid pipe manifold; 26. Bypass defrost manifold inlet pipe; 27. Finned gas pipe manifold; 28. Bypass defrost manifold outlet pipe; 221. First solenoid valve; 222. First check valve; 231. Second solenoid valve; 232. Expansion valve; 233. Second check valve; 241. Third solenoid valve; 242. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments.

[0026] Example 1

[0027] Reference Figure 1-3As shown, an integrated air-cooled heating system includes a separately sealed power component housing 1 and an outdoor finned air heat exchanger assembly 2. The separately sealed power component housing 1 includes a refrigerant condensation device, a water system assembly 19, and a control system. The refrigerant condensation device includes a compressor 11, an oil separator 12, a condenser 13, an economizer 14, a dryer filter 15, and a gas-liquid separator 16. The inlet of the compressor 11 is connected to the outlet of the gas-liquid separator 16, the outlet of the compressor 11 is connected to the inlet of the oil separator 12, the outlet of the oil separator 12 is connected to the inlet of the condenser 13, the outlet of the condenser 13 is connected to the inlet of the dryer filter 15, and the outlet of the dryer filter 15 is connected to the inlet of the economizer 14. The water system assembly 19 is used to exchange heat between the water in the water system assembly 19 and the condenser 13, and the water system assembly 19 is connected to the indoor heat exchanger. The control system is used to control the operation of the compressor 11 and the water system assembly 19, as well as the opening and closing of the pipeline valves.

[0028] The outdoor finned air heat exchanger assembly 2 includes fins 21, air pipes 22, liquid pipes 23, and bypass defrosting pipes 24. Air pipes 22 are connected to fins 21, and liquid pipes 23, bypass defrosting pipes 24, and fins 21 are connected via T-junction pipes. Each pair of fins 21 forms a group of fins 21. The air pipes 22 of each group of fins 21 are connected to form an air pipe branch pipe, the liquid pipes 23 of each group of fins 21 are connected to form a liquid pipe branch pipe, and the bypass defrosting pipes 24 of each group of fins 21 are connected to form a bypass defrosting branch pipe. The liquid pipe branch pipes of different groups of fins 21 are connected to form a fin liquid pipe junction pipe 25, and the bypass defrosting branch pipes of different groups of fins 21 are connected to form a bypass defrosting junction inlet pipe 26. The air pipe branch pipes are divided into two paths, the first path being an air... A first solenoid valve 221 is installed on the branch pipe. The first air branch pipes of different groups of fins 21 are connected to form a finned air branch pipe 27. A first check valve 222 is installed on the second air branch pipe. The second air branch pipes of different groups of fins 21 are connected to form a bypass defrost outlet pipe 28. A second solenoid valve 231, an expansion valve 232, and a second check valve 233 are installed on the liquid branch pipe. A third solenoid valve 241 and a third check valve 242 are installed on the bypass defrost branch pipe. The finned air branch pipe 27 and the bypass defrost outlet pipe 28 are connected to the inlet of the gas-liquid separator 16. The finned liquid branch pipe 25 is connected to the outlet of the economizer 14. The bypass defrost inlet pipe 26 is connected to the outlet of the oil separator 12.

[0029] Furthermore, the bottom of the oil separator 12 is connected to the inlet of the compressor 11 via a bypass pipe.

[0030] Furthermore, the bottom of the gas-liquid separator 16 is connected to one end of the ejector 17, the other end of the ejector 17 is connected to the outlet of the oil separator 12, the outlet of the ejector 17 is connected to the inlet of the compressor 11, a solenoid valve is installed between the gas-liquid separator 16 and the ejector 17, and an oil filter 18 and a solenoid valve are installed sequentially between the outlet of the oil separator 12 and the ejector 17.

[0031] Furthermore, the fin 21 is provided with an air pipe 22, a liquid pipe 23 and a bypass defrosting pipe 24. The air pipe 22 is located on the outer side of each group of fins 21, the liquid pipe 23 is located on the inner side of each group of fins 21, and the bypass defrosting pipe 24 is located between the air pipe 22 and the liquid pipe 23.

[0032] Furthermore, the compressor 11 is a screw compressor.

[0033] When the air-cooled heating integrated system of the present invention is in operation, when the outdoor finned air heat exchanger assembly 2 is running in heating mode, the unit is turned on. The low-temperature superheated refrigerant flows to the compressor 11 through the inlet of the compressor 11. The compressor 11 compresses the refrigerant into a high-temperature, high-pressure gas. Then, the high-temperature, high-pressure refrigerant enters the oil separator 12 through the outlet of the compressor 11. After the oil separator 12 separates the compressor oil from the refrigerant, the refrigerant enters the condenser 13. In the condenser 13, the refrigerant exchanges heat with water, releasing heat. The refrigerant changes from a high-temperature, high-pressure gaseous state to a high-pressure, medium-temperature liquid state, and then enters the dryer filter 15 for drying. After water filtration by filter 15, the refrigerant enters economizer 14, is subcooled by economizer 14, enters finned liquid pipe manifold 25, and then flows into liquid pipe branch pipe. After refrigerant throttling by expansion valve 232, the refrigerant changes from a high-pressure, medium-temperature liquid state to a low-pressure, low-temperature gas-liquid two-phase state. It then flows into fin 21 through liquid pipe 23. Fin 21 exchanges heat with air and absorbs heat, changing the refrigerant from a low-pressure, low-temperature gas-liquid two-phase state to a low-pressure, low-temperature gas state. It then flows into gas pipe branch pipe, finned gas pipe manifold 27, and gas-liquid separator 16 through gas pipe 22, and finally flows into compressor 11 inlet.

[0034] When the outdoor finned air heat exchanger assembly 2 is defrosting, the control system determines that the fins 21 have reached the defrosting conditions. The second solenoid valve 231 corresponding to the fins 21 that have reached the defrosting conditions is closed, the first solenoid valve 221 is closed, the fan corresponding to the fins 21 (the fan is installed outside the fins 21) is closed, and the third solenoid valve 241 corresponding to the fins 21 is opened. The high-temperature and high-pressure refrigerant flows from the outlet of the oil separator 12 into the bypass defrosting confluence pipe 26, and then enters the fins 21 through the bypass defrosting branch pipe and the bypass defrosting pipe 24. It exchanges heat with the refrigerant in the fins 21 and the frost on the fins 21 to defrost the fins 21. Then the refrigerant enters the gas pipe 22, enters the first one-way valve 222 through the gas pipe branch pipe, and finally flows to the inlet of the gas-liquid separator 16.

[0035] In the operation of the air-cooled heating integrated system of the present invention, oil return is required. The oil return process is as follows: When the refrigerant flows out from the outlet of the compressor 11 and passes through the oil separator 12, the lubricating oil mixed in the refrigerant collects at the bottom of the oil separator 12. The lubricating oil at the bottom of the oil separator 12 flows back to the inlet of the compressor 11 through a bypass pipeline, returning to the compressor 11. The refrigerant at the bottom of the gas-liquid separator 16 is in a liquid state and is mixed with lubricating oil. The liquid at the outlet of the oil separator 12 and the bottom of the gas-liquid separator 16 is ejected by the ejector 17 to the inlet of the compressor 11, realizing oil return. The oil return frequency is controlled by a solenoid valve.

[0036] Furthermore, the outdoor finned air heat exchanger assembly 2 is installed on the upper part of the power component's separate sealed box 1, which helps to save space.

[0037] Example 2

[0038] Reference Figure 1-3 As shown, a control method for an integrated air-cooled heating system includes the following steps:

[0039] S1. Determine the defrosting conditions. First, determine the time condition, which is as follows: the compressor 11's continuous running time upon initial power-on is >10 min, and the compressor 11's cumulative heating operation time is ≥50 min, with the compressor 11's continuous running time ≥10 min, and the ambient temperature Ta ≤10℃. Then, determine the temperature condition, which is as follows: when Ta ≥6℃, and the coil temperature Te of fin 21 ≤ -2 - correction parameter℃, with the correction parameter being 4, and Ta and Te last for 5 min; when 5... When -10℃ < Ta < 5℃, and Te ≤ (18×Ta-70) / 16 - correction parameter℃, and Ta and Te last for 5 minutes; when -10℃ < Ta ≤ 5℃, and Te ≤ (18×Ta-70) / 16 - correction parameter℃, and Ta and Te last for 5 minutes; when Ta ≤ -10℃, and Te ≤ (17×Ta-112) / 21 - correction parameter℃, and Ta and Te last for 5 minutes; when fin 21 simultaneously meets both the time and temperature conditions, the defrosting condition is met, and defrosting operation is initiated.

[0040] S2. Defrosting operation control: When the fin 21 meets the defrosting conditions, it enters the defrosting operation. The second solenoid valve 231 corresponding to the fin 21 is closed. After 10 seconds, the fan corresponding to the fin 21 is turned off. After another 10 seconds, the first solenoid valve 221 corresponding to the fin 21 is closed and the third solenoid valve 241 is opened. After the defrosting operation time is ≥40 seconds, it starts to determine whether the defrosting exit conditions have been met.

[0041] S3. Determine the defrosting exit conditions. The defrosting exit conditions are as follows: Te≥10℃ for 5s, or defrosting operation time≥8min. After the defrosting exit conditions are met, the third solenoid valve 241 corresponding to fin 21 closes after 10s, the fan corresponding to fin 21 turns on after another 5s, and the first solenoid valve 221 and the second solenoid valve 231 corresponding to fin 21 open after another 5s, and the defrosting ends.

[0042] Furthermore, in S1, Te is the minimum temperature of the coil temperature of each fin 21, and in S3, Te is the maximum temperature of the coil temperature of each fin 21.

[0043] Furthermore, in S2, when the fin 21 meets the defrosting conditions, the fin 21 that meets the defrosting conditions first enters the defrosting operation first, and only one fin 21 is allowed to perform defrosting operation at the same time.

Claims

1. A wind-cooled integrated heating system, characterized in that: The system includes a separately sealed housing (1) for power components and an outdoor finned air heat exchanger assembly (2). The separately sealed housing (1) for power components includes a refrigerant condenser, a water system assembly (19), and a control system. The refrigerant condenser includes a compressor (11), an oil separator (12), a condenser (13), an economizer (14), a dryer filter (15), and a gas-liquid separator (16). The inlet of the compressor (11) is connected to the outlet of the gas-liquid separator (16), and the outlet of the compressor (11) is connected to the outlet of the oil separator (12). The inlet connection is provided, the outlet of the oil separator (12) is connected to the inlet of the condenser (13), the outlet of the condenser (13) is connected to the inlet of the dryer filter (15), and the outlet of the dryer filter (15) is connected to the inlet of the economizer (14); the water system component (19) is used to exchange heat between the water in the water system component (19) and the condenser (13), and the water system component (19) is connected to the indoor heat exchanger; the control system is used to control the operation of the compressor (11) and the water system component (19), as well as the opening and closing of the pipeline valves; The outdoor finned air heat exchanger assembly (2) includes fins (21), air pipes (22), liquid pipes (23), and bypass defrosting pipes (24). The air pipes (22) are connected to the fins (21), and the liquid pipes (23), bypass defrosting pipes (24), and fins (21) are connected by a T-junction. Each pair of fins (21) forms a group of fins (21). The air pipes (22) of each group of fins (21) are connected to form an air pipe branch pipe, the liquid pipes (23) of each group of fins (21) are connected to form a liquid pipe branch pipe, and the bypass defrosting pipes (24) of each group of fins (21) are connected to form a bypass defrosting branch pipe. The liquid pipe branch pipes of different groups of fins (21) are connected to form a fin liquid pipe junction pipe (25), and the bypass defrosting branch pipes of different groups of fins (21) are connected to form a bypass defrosting junction inlet pipe (26). The air pipe branch pipe is divided into two paths. The first solenoid valve (221) is installed on the first air branch pipe. The first air branch pipes of different groups of fins (21) are connected to form the fin air branch pipe (27). The first check valve (222) is installed on the second air branch pipe. The second air branch pipes of different groups of fins (21) are connected to form the bypass defrost outlet pipe (28). The second solenoid valve (231), expansion valve (232) and second check valve (233) are installed on the liquid branch pipe. The third solenoid valve (241) and third check valve (242) are installed on the bypass defrost branch pipe. The fin air branch pipe (27) and the bypass defrost outlet pipe (28) are connected to the inlet of the gas-liquid separator (16). The fin liquid branch pipe (25) is connected to the outlet of the economizer (14). The bypass defrost outlet pipe (26) is connected to the outlet of the oil separator (12). The bottom of the gas-liquid separator (16) is connected to one end of the ejector (17), the other end of the ejector (17) is connected to the outlet of the oil separator (12), the outlet of the ejector (17) is connected to the inlet of the compressor (11), a solenoid valve is installed between the gas-liquid separator (16) and the ejector (17), and an oil filter (18) and a solenoid valve are installed sequentially between the outlet of the oil separator (12) and the ejector (17); The fin (21) is provided with an air pipe (22), a liquid pipe (23) and a bypass defrosting pipe (24). The air pipe (22) is located on the outside of each group of fins (21), the liquid pipe (23) is located on the inside of each group of fins (21), and the bypass defrosting pipe (24) is located between the air pipe (22) and the liquid pipe (23).

2. The air-cooled heating integrated system according to claim 1, characterized in that: The bottom of the oil separator (12) is connected to the inlet of the compressor (11) via a bypass pipeline.

3. The air-cooled heating integrated system according to claim 1, characterized in that: The outdoor finned air heat exchanger assembly (2) is installed on the upper part of the separate sealed box (1) for the power components.

4. The control method for an integrated air-cooled heating system as described in claim 1, characterized in that: Includes the following steps: S1. Determine the defrosting conditions. First, determine the time conditions, which are as follows: the continuous running time of the compressor (11) upon initial power-on is greater than T1, and the cumulative running time of the compressor (11) in heating mode is greater than or equal to T2, and the continuous running time of the compressor (11) is greater than or equal to T1, and the ambient temperature Ta is less than or equal to 10℃. Then, determine the temperature conditions, which are as follows: when Ta is greater than or equal to 6℃, and the coil temperature Te of the fins (21) is less than or equal to -2 - correction parameter ℃, and Ta and Te last for 5 minutes; when 5℃ < Ta < 6℃, and Te≤(11×Ta-107) / 16-correction parameter℃, and Ta and Te last for 5min; when -10℃<Ta≤5℃, and Te≤(18×Ta-70) / 16-correction parameter℃, and Ta and Te last for 5min; when Ta≤-10℃, and Te≤(17×Ta-112) / 21-correction parameter℃, and Ta and Te last for 5min; when the fin (21) simultaneously meets the time judgment condition and the temperature judgment condition, the defrosting condition is met and defrosting operation is performed; S2, defrosting operation control: when the fin (21) meets the defrosting conditions, it enters the defrosting operation. The second solenoid valve (231) corresponding to the fin (21) is closed. After time T3, the fan corresponding to the fin (21) is turned off. After time T4, the first solenoid valve (221) corresponding to the fin (21) is closed and the third solenoid valve (241) is opened. After the defrosting operation time is ≥ T5, it is determined whether the defrosting exit condition is met. S3. Determine the defrosting exit conditions. The defrosting exit conditions are as follows: Te≥10℃ and lasts for 5s, or the defrosting operation time≥T6. After the defrosting exit conditions are met, the third solenoid valve (241) corresponding to the fin (21) closes after time T7, the fan corresponding to the fin (21) turns on after time T8, and the first solenoid valve (221) and the second solenoid valve (231) corresponding to the fin (21) open after time T9, and the defrosting ends.

5. The control method for an integrated air-cooled heating system according to claim 4, characterized in that: In S1, Te is the minimum temperature of the coil temperature of each fin (21), and in S3, Te is the maximum temperature of the coil temperature of each fin (21).

6. The control method for an integrated air-cooled heating system according to claim 4, characterized in that: Furthermore, in S2, when the fin (21) meets the defrosting conditions, the fin (21) that meets the defrosting conditions first enters the defrosting operation first, and only one fin (21) is allowed to perform defrosting operation at the same time.

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