An indirect refrigeration system based on a three-way proportional control valve

Abstract

The present invention discloses an indirect refrigeration system based on a three-way proportional regulating valve, which relates to the technical field of refrigeration cycle, including a refrigeration circuit and a defrosting circuit. The refrigeration circuit includes a summer refrigeration circuit, including a compression condensing unit. The inlet and outlet of the compression condensing unit are connected to a water tank 1. The outlet of the water tank 1 is connected to two branches, which are respectively connected to a stop valve 8 and a stop valve 9. The stop valve 9 is connected to a three-way proportional regulating valve 1, and the stop valve 8 is connected to a three-way proportional regulating valve 2. The three-way proportional regulating valve 1 is connected to the three-way proportional regulating valve 2. Beneficial effect: The refrigerant return liquid is regulated by the three-way proportional regulating valve, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continues to enter the cycle, thereby reducing the compressor power, improving the circulation efficiency of the system, and being able to stably adjust the liquid supply temperature, maintain the stability of the warehouse temperature, ensure a small heat exchange temperature difference, and save energy and reduce emissions.

Description

Technical Field

[0001] The invention relates to the technical field of refrigeration cycles, and in particular to an indirect refrigeration system based on a three-way proportional regulating valve. Background Art

[0002] As an important part of the modern logistics system, cold storage has attracted much attention. Cold storage is an important part of the food cold chain. Only when cold storage is included in a relatively complete cold chain can the sales of quick-frozen food increase significantly. Therefore, the status of cold storage in food storage is more realistic.

[0003] At present, many liquid pump recirculation systems supply too much liquid but cannot guarantee the minimum flow rate of each path, and the lift is too high but it is still difficult to ensure the uniform liquid supply of multi-layer cold storage. The flow rate basically cannot change according to the change of refrigeration load, and it is difficult to achieve energy-saving operation.

[0004] Retrieval of Chinese invention patent CN102470728A discloses a refrigeration cycle suitable for a vehicle air conditioning device, which can accurately estimate the refrigerant flow rate used in the compressor torque estimation by accurately detecting the pressure difference before and after the throttle hole with a high correlation with the refrigerant flow rate, and then accurately estimate the compressor torque, and can save space and reduce costs by the estimation. The refrigeration cycle is characterized in that it includes a subcooling condenser, which integrally includes: a condensing part of the refrigerant; a liquid storage tank; and a subcooling part, and is provided with a throttle hole for throttling the refrigerant flow through the condensing part of the subcooling condenser, a pressure difference detection unit that can detect the pressure difference before and after the throttle hole, and a refrigerant flow estimation unit that estimates the refrigerant flow rate with reference to the detected pressure difference, and a compressor torque estimation unit that estimates the torque of the compressor with reference to the estimated refrigerant flow rate. However, it has a complex structure, high cost, and poor adaptability, and cannot meet the use requirements of different environments.

[0005] Searching for Chinese invention patent CN111479896 A discloses a refrigeration cycle, which is a refrigeration cycle using a mixed refrigerant containing at least 1,2-difluoroethylene (HFO-1132(E)) as a flammable refrigerant, and is equipped with a compressor, a heat exchanger on the heat source side, an expansion mechanism, a heat exchanger on the utilization side, and a decompression mechanism. The decompression mechanism decompresses the mixed refrigerant flowing in the heat exchanger on the heat source side that functions as an evaporator between the inlet and the outlet of the heat exchanger on the heat source side. However, it has a complex structure, cannot meet the use requirements of different environments, and does not meet the requirements of energy conservation and emission reduction.

[0006] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0007] In response to the problems in the related technology, the purpose of the present invention is to propose an indirect refrigeration system based on a three-way proportional regulating valve, which adjusts the refrigerant return liquid through the three-way proportional regulating valve, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continues to enter the circulation, thereby reducing the compressor power and improving the circulation efficiency of the system. It can stably adjust the liquid supply temperature, maintain the stability of the warehouse temperature, and ensure a smaller heat exchange temperature difference, so as to overcome the above-mentioned technical problems existing in the existing related technology.

[0008] The technical solution of the present invention is achieved in this way:

[0009] An indirect refrigeration system based on a three-way proportional regulating valve comprises a refrigeration flow path and a defrosting flow path, wherein;

[0010] The refrigeration circuit includes a summer refrigeration circuit, including a compression condensing unit, the inlet and outlet of the compression condensing unit are connected to the water tank 1, the outlet of the water tank 1 is connected to two branches respectively connected to the stop valve 8 and the stop valve 9, the stop valve 9 is connected to the three-way proportional regulating valve 1, the stop valve 8 is connected to the three-way proportional regulating valve 2, and the three-way proportional regulating valve 1 is connected to the three-way proportional regulating valve 2;

[0011] The three-way proportional regulating valve 1 is connected to the water pump 1, the temperature sensor 1, the stop valve 1, the electric butterfly valve 1, the three-way solenoid valve 1, the evaporator 1, the manual butterfly valve 1 and the three-way solenoid valve 3 respectively in sequence;

[0012] The three-way proportional regulating valve 2 is connected to the water pump 2, the temperature sensor 2, the stop valve 3, the electric butterfly valve 2, the three-way solenoid valve 2, the evaporator 2, the manual butterfly valve 2 and the three-way solenoid valve 4 respectively in sequence;

[0013] The three-way solenoid valve three and the three-way solenoid valve four are respectively connected to the water tank one;

[0014] The defrosting flow path includes a water tank 2, the outlet of the water tank 2 is connected to a stop valve 10, a water pump 4 and a stop valve 6 in sequence through a pipeline, and the outlet of the stop valve 6 is connected to two paths respectively, one of which is connected to the three-way solenoid valve 2, the evaporator 2, the manual butterfly valve 2 and the three-way solenoid valve 4 in sequence;

[0015] The other outlet of the stop valve 6 is connected to the three-way solenoid valve 1, the evaporator 1, the manual butterfly valve 1 and the three-way solenoid valve 3 in sequence;

[0016] The three-way solenoid valve three and the three-way solenoid valve four are respectively connected to the water tank two.

[0017] Furthermore, the refrigeration circuit also includes a winter refrigeration circuit, including a stop valve 13 and a stop valve 12 respectively connected to the water pump 1 and the water pump 2, and the three-way proportional regulating valve 2 is connected between the stop valve 12 and the water pump 2, and the three-way proportional regulating valve 1 is connected between the stop valve 13 and the water pump 1.

[0018] Furthermore, the water tank 1 and the water tank 2 are connected via a stop valve 14 to balance the liquid level.

[0019] Furthermore, the water tank 1 is a 15°C water tank.

[0020] Furthermore, the water tank 2 is a -12°C water tank.

[0021] Furthermore, the water tank 1 is also connected in sequence to the stop valve 7, the three-way proportional regulating valve 3, the water pump 3, the temperature sensor 3 and the stop valve 5, wherein;

[0022] The three-way proportional regulating valve is connected to the stop valve eleven, and the stop valve five is connected to the stop valve six and the stop valve three respectively.

[0023] Furthermore, the stop valve 2 is connected between the stop valve 1 and the stop valve 3.

[0024] Furthermore, a stop valve four is connected between the stop valve three and the stop valve five.

[0025] Furthermore, the three-way proportional regulating valve 1, the three-way proportional regulating valve 2 and the three-way proportional regulating valve 3 are interconnected.

[0026] Furthermore, the stop valve 10, the stop valve 11, the stop valve 12 and the stop valve 13 are interconnected.

[0027] Beneficial effects of the present invention:

[0028] The indirect refrigeration system of the present invention is based on a three-way proportional regulating valve. The three-way proportional regulating valve is used to adjust the return liquid of the refrigerant, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continue to enter the circulation, thereby reducing the power of the compressor and improving the circulation efficiency of the system. The liquid supply temperature can be stably adjusted to maintain the stability of the warehouse temperature, ensure a smaller heat exchange temperature difference, and save energy and reduce emissions.

[0029] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a flow chart of an indirect refrigeration system based on a three-way proportional control valve according to an embodiment of the present invention.

[0033] In the figure:

[0034] 1. Evaporator 1; 2. Evaporator 2; 3. Water tank 2; 4. Compression condensing unit; 5. Water tank 1; 6. Water pump 1; 7. Water pump 2; 8. Water pump 3; 9. Water pump 4; 10. Temperature sensor 3; 11. Temperature sensor 2; 12. Temperature sensor 1; 13. Stop valve 1; 14. Stop valve 2; 15. Stop valve 3; 16. Stop valve 4; 17. Stop valve 5; 18. Stop valve 6; 19. Electric butterfly valve 2; 20. Electric butterfly valve 1; 21. Three-way solenoid valve one; 22, three-way solenoid valve two; 23, manual butterfly valve two; 24, manual butterfly valve one; 25, three-way solenoid valve three; 26, three-way solenoid valve four; 27, stop valve seven; 28, stop valve eight; 29, stop valve nine; 30, three-way proportional control valve one; 31, three-way proportional control valve two; 32, three-way proportional control valve three; 33, stop valve ten; 34, stop valve eleven; 35, stop valve twelve; 36, stop valve thirteen; 37, stop valve fourteen. DETAILED DESCRIPTION

[0035] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0036] According to an embodiment of the present invention, an indirect refrigeration system based on a three-way proportional control valve is provided.

[0037] like Figure 1 As shown, an indirect refrigeration system based on a three-way proportional control valve includes a refrigeration flow path and a defrosting flow path, wherein;

[0038] The refrigeration circuit includes a summer refrigeration circuit, including a compression condensing unit 4, the inlet and outlet of the compression condensing unit 4 are connected to a water tank 5, the outlet of the water tank 5 is connected to two branches respectively connected to a stop valve 8 28 and a stop valve 9 29, the stop valve 9 29 is connected to a three-way proportional regulating valve 1 30, the stop valve 8 28 is connected to a three-way proportional regulating valve 2 31, and the three-way proportional regulating valve 1 30 is connected to the three-way proportional regulating valve 2 31;

[0039] The three-way proportional regulating valve 30 is connected to the water pump 6, the temperature sensor 12, the stop valve 13, the electric butterfly valve 20, the three-way solenoid valve 21, the evaporator 1, the manual butterfly valve 24 and the three-way solenoid valve 25 in sequence;

[0040] The three-way proportional regulating valve 2 31 is connected to the water pump 2 7, the temperature sensor 2 11, the stop valve 3 15, the electric butterfly valve 2 19, the three-way solenoid valve 2 22, the evaporator 2 2, the manual butterfly valve 2 23 and the three-way solenoid valve 4 26 in sequence;

[0041] The three-way solenoid valve three 25 and the three-way solenoid valve four 26 are respectively connected to the water tank one 5;

[0042] The defrosting flow path includes a water tank 23, the outlet of the water tank 23 is connected to the stop valve 10 33, the water pump 4 9 and the stop valve 6 18 in sequence through a pipeline, and the outlet of the stop valve 6 18 is connected to two paths respectively, one of which is connected to the three-way solenoid valve 22, the evaporator 22, the manual butterfly valve 23 and the three-way solenoid valve 4 26 in sequence;

[0043] The outlet of the other stop valve 6 18 is connected to the three-way solenoid valve 1 21, the evaporator 1, the manual butterfly valve 1 24 and the three-way solenoid valve 3 25 in sequence;

[0044] The three-way solenoid valve 3 25 and the three-way solenoid valve 4 26 are respectively connected to the water tank 2 3 .

[0045] Among them, the refrigeration circuit also includes a winter refrigeration circuit, including a stop valve thirteen 36 and a stop valve twelve 35 respectively connected to the water pump one 6 and the water pump two 7, and the three-way proportional regulating valve two 31 is connected between the stop valve twelve 35 and the water pump two 7, and the three-way proportional regulating valve one 30 is connected between the stop valve thirteen 36 and the water pump one 6.

[0046] Among them, water tank 1 5 and water tank 2 3 are connected to balance the liquid level through stop valve 14 37.

[0047] Among them, water tank 5 is a 15℃ water tank.

[0048] Among them, water tank 2 3 is a -12℃ water tank.

[0049] Among them, the water tank 1 5 is also connected in sequence to the stop valve 7 27, the three-way proportional regulating valve 3 32, the water pump 3 8, the temperature sensor 3 10 and the stop valve 5 17, among which;

[0050] The three-way proportional regulating valve three 32 is connected to the stop valve eleven 34, and the stop valve five 17 is connected to the stop valve six 18 and the stop valve three 15 respectively.

[0051] Among them, the stop valve 1 13 and the stop valve 3 15 are connected with the stop valve 2 14 .

[0052] Among them, the stop valve four 16 is connected between the stop valve three 15 and the stop valve five 17.

[0053] Among them, the three-way proportional regulating valve 1 30, the three-way proportional regulating valve 2 31 and the three-way proportional regulating valve 3 32 are interconnected, and the three-way proportional regulating valve is used to adjust the return liquid of the refrigerant, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continue to enter the circulation.

[0054] Among them, the stop valve ten 33, the stop valve eleven 34, the stop valve twelve 35 and the stop valve thirteen 36 are connected to each other.

[0055] With the help of the above technical solution, the refrigerant return liquid is regulated by a three-way proportional regulating valve, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continue to enter the circulation, thereby reducing the compressor power and improving the system's circulation efficiency. The liquid supply temperature can be stably adjusted to maintain the stability of the warehouse temperature, ensure a smaller heat exchange temperature difference, and save energy and reduce emissions.

[0056] In addition, three-way proportional regulating valve 1 30, three-way proportional regulating valve 2 31 and three-way proportional regulating valve 3 32 are interconnected, and the three-way proportional regulating valve is used to regulate the return liquid of the refrigerant, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continue to enter the circulation.

[0057] In addition, if Figure 1 As shown, its winter refrigeration flow path specifically includes: the outlet of the 15°C water tank is divided into two branches, both of which are connected to the stop valve 13 36 and the stop valve 12 35 in sequence through pipelines, and the stop valve 13 36 and the stop valve 12 35 are connected to the water pump 1 6 and the water pump 2 7 respectively; the water pump 1 6 is connected to the temperature sensor 1 12, the stop valve 1 13, the electric butterfly valve 1 20, the three-way solenoid valve 1 21, the evaporator 1, the manual butterfly valve 1 24 and the three-way solenoid valve 3 25 in sequence; the water pump 2 7 is connected to the temperature sensor 2 11, the stop valve 3 15, the electric butterfly valve 2 19, the three-way solenoid valve 2 22, the evaporator 2 2, the manual butterfly valve 2 23 and the three-way solenoid valve 4 26 in sequence; finally, it flows into the 15°C water tank refrigerant inlet and the three-way proportional regulating valve 1 30 and the three-way proportional regulating valve 2 31;

[0058] Specifically, when applied, the following steps are included:

[0059] Summer working flow path: The refrigerant acts on the -12℃ water tank through the refrigeration compressor unit 4 to cool the refrigerant. After the refrigerant flows out of the -12℃ water tank, it is divided into two branches. One branch passes through the stop valve 929 and then flows through the three-way proportional regulating valve 130 to mix with the refrigerant return liquid. It passes through the water pump 16 and the temperature sensor 12, and the temperature reaches -3℃ and continues to enter the circulation. After flowing through the stop valve 13, the electric butterfly valve 120, the three-way solenoid valve 121, and the evaporator 1, the refrigerant temperature rises, and then enters the return liquid pipe and flows through the manual butterfly valve 124 and the three-way electronic regulating valve 325. The other branch is mixed with the refrigerant return liquid through the stop valve eight 28 and the three-way proportional regulating valve two 31, and passes through the water pump two 7 and the temperature sensor two 11. The temperature reaches -3°C and continues to enter the circulation. After flowing through the stop valve three 15, the electric butterfly valve two 19, the three-way solenoid valve two 22, and the evaporator 2, the refrigerant temperature rises, and then enters the return liquid pipe, flows through the manual butterfly valve two 23 and the three-way electronic regulating valve four 26 to merge with the branch one. Part of the proportional return liquid flows through the three-way proportional regulating valve one 30, the three-way proportional regulating valve two 31 and is mixed with the refrigerant flowing out of the -12°C water tank 5 to -3°C and continues to enter the circulation, and the other part of the return liquid directly returns to the -12°C water tank.

[0060] In addition, the working flow path in winter: when the outside temperature is below 0℃, the 15℃ water tank is electrically heated to heat the refrigerant. After the refrigerant flows out of the 15℃ water tank, it is divided into two branches. One of them passes through the stop valve thirteen 36 and then flows through the water pump 16 and the temperature sensor 12, and mixes with the refrigerant return liquid flowing through the three-way proportional control valve 130. After the temperature reaches 1℃, it enters the circulation, and after passing through the stop valve 13, the electric butterfly valve 120, the three-way solenoid valve 21, and the evaporator 1, the refrigerant temperature is reduced, and then it enters the return liquid pipe and flows through the manual butterfly valve 124 and the three-way electronic control valve 325. The other branch passes through the stop valve twelve 35, flows through the water pump two 7 and the temperature sensor two 11, and mixes with the refrigerant return liquid flowing through the three-way proportional regulating valve two 31. The temperature reaches 1°C and continues to enter the circulation. After flowing through the stop valve three 15, the electric butterfly valve two 19, the three-way solenoid valve two 22, and the evaporator 2, the refrigerant temperature decreases, and then enters the return liquid pipe, flows through the manual butterfly valve two 23 and the three-way electronic regulating valve four 26 to merge with the branch one. Part of the proportional return liquid enters the three-way proportional regulating valve one 30, the three-way proportional regulating valve two 31, mixes with the refrigerant to 1°C and continues to enter the circulation, and the other part of the return liquid directly returns to the 15°C water tank.

[0061] In addition, the defrost flow path: the electrically heated 15℃ water tank heats up the refrigerant. After the refrigerant flows out of the 15℃ water tank, it passes through the stop valve 10 33, the water pump 4 9, and the stop valve 6 18 in sequence and is divided into two paths. One path flows through the three-way solenoid valve 1 21 to enter the evaporator 1 to defrost, and then the returned liquid enters the defrost return pipe and flows through the manual butterfly valve 1 24 and the three-way electronic regulating valve 3 25. The other branch flows through the three-way solenoid valve 2 22 to enter the evaporator 2 2 to defrost, and then the returned liquid enters the defrost return pipe and flows through the manual butterfly valve 2 23 and the three-way electronic regulating valve 4 26 to merge with the first branch and directly flow into the 15℃ water tank.

[0062] In addition, water pump 3 8 is used as a backup. When the branch where water pump 1 6 is located fails, the stop valve 1 13 and the stop valve 3 15 are closed, the stop valve 2 14 and the stop valve 4 16 are opened, and water pump 3 8 is operated; when the branch where water pump 2 7 is located fails, the stop valve 3 15 is closed, the stop valve 4 16 is opened, and water pump 3 8 is operated; when the branch where water pump 4 9 is located fails, that is, the defrost flow path fails, the stop valve 10 33 is closed, the stop valve 11 34 and the stop valve 5 17 are opened, and water pump 3 8 is operated.

[0063] In summary, with the aid of the above-mentioned technical scheme of the present invention, the following effects can be achieved: the refrigerant return liquid is regulated by the three-way proportional regulating valve, so that part of the return liquid does not need to return to the water tank and is directly mixed in the process to reach the required temperature and then continues to enter the circulation, thereby reducing the compressor power and improving the circulation efficiency of the system. The liquid supply temperature can be stably adjusted to maintain the stability of the warehouse temperature, ensure a smaller heat exchange temperature difference, and save energy and reduce emissions.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An indirect refrigeration system based on a three-way proportional control valve, It is characterized in that It includes a refrigeration flow path and a defrosting flow path, wherein; The refrigeration circuit comprises a summer refrigeration circuit, comprising a compression condensing unit (4), the inlet and outlet of the compression condensing unit (4) are connected to a water tank one (5), the outlet of the water tank one (5) is connected to two branches respectively connected to a stop valve eight (28) and a stop valve nine (29), the stop valve nine (29) is connected to a three-way proportional regulating valve one (30), the stop valve eight (28) is connected to a three-way proportional regulating valve two (31), and the three-way proportional regulating valve one (30) is connected to the three-way proportional regulating valve two (31); The three-way proportional regulating valve 1 (30) is respectively connected to the water pump 1 (6), the temperature sensor 1 (12), the stop valve 1 (13), the electric butterfly valve 1 (20), the three-way solenoid valve 1 (21), the evaporator 1 (1), the manual butterfly valve 1 (24) and the three-way solenoid valve 3 (25); The three-way proportional regulating valve 2 (31) is connected to the water pump 2 (7), the temperature sensor 2 (11), the stop valve 3 (15), the electric butterfly valve 2 (19), the three-way solenoid valve 2 (22), the evaporator 2 (2), the manual butterfly valve 2 (23) and the three-way solenoid valve 4 (26) in sequence; The three-way solenoid valve three (25) and the three-way solenoid valve four (26) are respectively connected to the water tank one (5); The defrosting flow path comprises a water tank 2 (3), the outlet of the water tank 2 (3) is connected to a stop valve 10 (33), a water pump 4 (9) and a stop valve 6 (18) in sequence through a pipeline, and the outlet of the stop valve 6 (18) is connected to two paths respectively, one of which is connected to the outlet of the stop valve 6 (18) in sequence to the three-way solenoid valve 2 (22), the evaporator 2 (2), the manual butterfly valve 2 (23) and the three-way solenoid valve 4 (26); The other outlet of the stop valve six (18) is connected in sequence to the three-way solenoid valve one (21), the evaporator one (1), the manual butterfly valve one (24) and the three-way solenoid valve three (25); The three-way solenoid valve three (25) and the three-way solenoid valve four (26) are respectively connected to the water tank two (3).

2. An indirect refrigeration system based on a three-way proportional control valve according to claim 1, It is characterized in that The refrigeration circuit also includes a winter refrigeration circuit, including a stop valve thirteen (36) and a stop valve twelve (35) respectively connected to the water pump one (6) and the water pump two (7), and the three-way proportional regulating valve two (31) is connected between the stop valve twelve (35) and the water pump two (7), and the three-way proportional regulating valve one (30) is connected between the stop valve thirteen (36) and the water pump one (6).

3. An indirect refrigeration system based on a three-way proportional control valve according to claim 2, It is characterized in that The water tank 1 (5) and the water tank 2 (3) are connected to balance the liquid level via a stop valve 14 (37).

4. An indirect refrigeration system based on a three-way proportional control valve according to claim 3, It is characterized in that The water tank 1 (5) is a 15°C water tank.

5. An indirect refrigeration system based on a three-way proportional control valve according to claim 4, It is characterized in that The water tank 2 (3) is a -12°C water tank.

6. An indirect refrigeration system based on a three-way proportional control valve according to claim 5, It is characterized in that The water tank one (5) is also connected in sequence to the stop valve seven (27), the three-way proportional regulating valve three (32), the water pump three (8), the temperature sensor three (10) and the stop valve five (17), wherein; The three-way proportional regulating valve three (32) is connected to the stop valve eleven (34), and the stop valve five (17) is respectively connected to the stop valve six (18) and the stop valve three (15).

7. An indirect refrigeration system based on a three-way proportional control valve according to claim 6, It is characterized in that A stop valve 2 (14) is connected between the stop valve 1 (13) and the stop valve 3 (15).

8. An indirect refrigeration system based on a three-way proportional control valve according to claim 7, It is characterized in that A stop valve four (16) is connected between the stop valve three (15) and the stop valve five (17).

9. An indirect refrigeration system based on a three-way proportional control valve according to claim 8, It is characterized in that The three-way proportional regulating valve 1 (30), the three-way proportional regulating valve 2 (31) and the three-way proportional regulating valve 3 (32) are interconnected.

10. An indirect refrigeration system based on a three-way proportional control valve according to any one of claims 6 to 9, It is characterized in that The stop valve ten (33), the stop valve eleven (34), the stop valve twelve (35) and the stop valve thirteen (36) are interconnected.

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