Water-cooling type precise temperature control heat exchange system

Abstract

The utility model relates to the technical field of heat exchange systems, in particular to a water-cooling type precise temperature control heat exchange system. The first electronic expansion valve and the second electronic expansion valve are arranged and used for adjusting the opening degree according to the temperature of the circulating fluid in the circulating fluid system, a temperature difference and a flow difference are formed after a refrigerant passes through the second electronic expansion valve and the condenser, and therefore temperature control over the circulating fluid in the circulating fluid system is achieved; meanwhile, a third electronic expansion valve used for adjusting the opening degree according to the temperature feedback of the exhaust temperature of the compressor is arranged, and the probability that a low-temperature gas refrigerant passing through the third electronic expansion valve and a high-temperature gas refrigerant passing through the evaporator are not evenly mixed in the gas-liquid separator to cause liquid impact damage to the compressor is reduced; the problem that in the prior art, after a refrigerant subjected to liquid spraying throttling pressure reduction is mixed with an overheat-state refrigerant subjected to heat exchange, much refrigerant liquid is possibly not evaporated and gasified, and finally liquid impact damage of a compressor is caused is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange systems, in particular to a water-cooled precision temperature-controlled heat exchange system. Background Art

[0002] For precision temperature-controlled refrigeration systems with compressors as the core, when the demand load decreases, it is still not desirable to shut down the system. Hot gas bypass energy regulation is usually used, which is an energy regulation method that bypasses the gas on the high-pressure side of the refrigeration system to the low-pressure side. Since the temperature of the hot gas bypass is close to the exhaust temperature, the entry of high-temperature hot gas will cause the suction temperature to rise, which will also increase the exhaust temperature and may exceed the maximum allowable exhaust temperature.

[0003] In order to ensure the normal operation of the refrigeration system, the refrigerant liquid is usually throttled and depressurized before being directly sprayed onto the suction end of the compressor to reduce the suction temperature of the compressor and thus the exhaust temperature. Ideally, the refrigerant mixed with the superheated refrigerant after heat exchange is in a saturated state after the liquid injection throttling and depressurization. However, in actual operation, uneven mixing and incomplete heat exchange may occur. The return air temperature may meet the system requirements, but a large amount of refrigerant liquid has not evaporated and gasified in the return air flow, which eventually leads to liquid hammer damage to the compressor. Utility Model Content

[0004] In view of the shortcomings of the prior art, the utility model provides a water-cooled precision temperature control heat exchange system, which solves the problem in the prior art that a large amount of refrigerant liquid may not evaporate and gasify after the refrigerant after liquid injection throttling and pressure reduction is mixed with the superheated refrigerant after heat exchange, which eventually leads to liquid shock damage to the compressor.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A water-cooled precision temperature-controlled heat exchange system, comprising a circulating fluid system for supplying water to customers, a main circulation system for controlling the temperature of the circulating fluid system, and a service water system for cooling the refrigerant in the main circulation system by heat exchange, a compressor for providing refrigerant flow power, and an evaporator for heat exchange between the circulating fluid system and the main circulation system, and a gas-liquid separator on the air inlet side of the compressor;

[0007] A second electronic expansion valve is arranged between the compressor exhaust side and the evaporator refrigerant inlet side, a first electronic expansion valve located on the main circulation system is also arranged on the evaporator refrigerant inlet side, and a third electronic expansion valve is arranged between the first electronic expansion valve and the gas-liquid separator inlet side.

[0008] Preferably, the circulating fluid system includes a flow meter, a heating water tank, a water pump, a third pressure sensor and a second temperature sensor through which the circulating fluid flows in sequence, a bypass valve is arranged between the water outlet side of the second temperature sensor and the water outlet side of the flow meter, and a drain valve for draining water is also arranged on the water outlet side of the flow meter.

[0009] Preferably, the main circulation system also includes a condenser arranged between the compressor exhaust side and the first electronic expansion valve for heat exchange with the plant water system, a drying filter is arranged between the refrigerant outlet side of the condenser and the first electronic expansion valve, and the third electronic expansion valve is arranged on the outlet side of the drying filter.

[0010] Preferably, a heat exchanger for heat exchange with the plant water system is arranged between the second electronic expansion valve and the refrigerant inlet side of the evaporator, and a temperature-type water flow regulating valve is arranged on the water inlet side pipeline of the heat exchanger. The temperature sensing package of the temperature-type water flow regulating valve is installed on the refrigerant outlet side of the heat exchanger.

[0011] Preferably, a first temperature sensor is provided on the exhaust side pipeline of the compressor.

[0012] Preferably, the heat exchanger is a plate heat exchanger or a shell and tube heat exchanger.

[0013] Compared with the prior art, the utility model provides a water-cooled precision temperature control heat exchange system, which has the following beneficial effects:

[0014] 1. By setting the first electronic expansion valve and the second electronic expansion valve, the opening is adjusted according to the temperature of the circulating fluid in the circulating fluid system. After the refrigerant passes through the second electronic expansion valve and the condenser, a temperature difference and a flow difference are formed, thereby realizing the temperature control of the circulating fluid in the circulating fluid system. At the same time, a third electronic expansion valve is set to adjust the opening according to the temperature feedback of the compressor exhaust temperature, thereby reducing the probability of uneven mixing of the low-temperature gas refrigerant passing through the third electronic expansion valve and the high-temperature gas refrigerant passing through the evaporator in the gas-liquid separator, resulting in liquid shock damage to the compressor.

[0015] 2. A heat exchanger is set up to exchange heat with the plant water system, and a temperature-type water flow regulating valve is set up to adjust the opening of the water inlet side of the heat exchanger according to the temperature feedback of the refrigerant outlet side of the heat exchanger, so as to ensure the temperature of the refrigerant outlet side of the heat exchanger and improve the stability of the refrigerant temperature, so as to better realize the precise control of the circulating fluid temperature in the circulating fluid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 It is a schematic diagram of the heat exchange system of the utility model;

[0018] Figure 2 It is a schematic diagram of the main circulation system of the utility model;

[0019] Figure 3 It is a schematic diagram of the circulating fluid system of the utility model.

[0020] In the figure: 1. circulating fluid system; 11. flow meter; 12. heating water tank; 13. water pump; 14. third pressure sensor; 15. second temperature sensor; 16. bypass valve; 17. drain valve; 2. main circulation system; 21. compressor; 22. evaporator; 23. gas-liquid separator; 24. condenser; 25. drying filter; 26. heat exchanger; 27. temperature-type water flow regulating valve; 28. first temperature sensor; 3. factory water system; 4. second electronic expansion valve; 5. first electronic expansion valve; 6. third electronic expansion valve. DETAILED DESCRIPTION

[0021] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0022] In order to solve the problem that a large amount of refrigerant liquid may not evaporate and gasify after the refrigerant after liquid spray throttling and pressure reduction is mixed with the superheated refrigerant after heat exchange, which eventually leads to compressor liquid hammer damage, the utility model provides a water-cooled precision temperature control heat exchange system, which makes the refrigerant state after the refrigerant after liquid spray throttling and pressure reduction and the superheated refrigerant after heat exchange close to the saturated state, thereby reducing the amount of refrigerant liquid that is not fully evaporated and gasified in the return air flow, so as to reduce the probability of compressor liquid hammer damage, please refer to Figure 1-Figure 3 The heat exchange system includes a circulating fluid system 1 for supplying water to customers, a main circulating system 2 for controlling the temperature of the circulating fluid system 1, and a service water system 3 for cooling the refrigerant in the main circulating system 2 by heat exchange. The main circulating system 2 is provided with a compressor 21 for providing refrigerant flow power, and an evaporator 22 for heat exchange between the circulating fluid system 1 and the main circulating system 2. A gas-liquid separator 23 is provided on the air inlet side of the compressor 21. The gas-liquid separator 23 realizes gas-liquid separation of the air inlet of the compressor 21 to prevent liquid from directly entering the compressor 21 and causing liquid hammer;

[0023] A second electronic expansion valve 4 is provided between the exhaust side of the compressor 21 and the refrigerant inlet side of the evaporator 22. A first electronic expansion valve 5 located on the main circulation system 2 is also provided on the refrigerant inlet side of the evaporator 22. A third electronic expansion valve 6 is provided between the first electronic expansion valve 5 and the inlet side of the gas-liquid separator 23. The high-temperature and high-pressure gas discharged from the compressor 21 is cooled to become a refrigerant liquid after heat exchange with the plant water system 3. The refrigerant liquid enters the evaporator 22 after throttling and reducing the pressure by the first electronic expansion valve 5. The refrigerant evaporates by heat exchange with the circulating fluid in the evaporator 22. The evaporated gaseous refrigerant returns to the gas-liquid separator 23 and finally returns to the compressor 21, completing the refrigeration cycle and preparing the circulating fluid at the required temperature. When the circulating fluid temperature is greater than 100 °C, the refrigerant is cooled to a temperature lower than 100 °C. When the temperature of the circulating fluid is lower than the set value, the first electronic expansion valve 5 is opened to a larger extent and the second electronic expansion valve 4 is opened to a smaller extent. When the temperature of the circulating fluid is lower than the set value, the first electronic expansion valve 5 is opened to a smaller extent and the second electronic expansion valve 4 is opened to a larger extent. When the exhaust temperature of the compressor 21 is higher than the target value, the opening of the third electronic expansion valve 6 is increased. When the exhaust temperature of the compressor 21 is lower than the target value, the opening of the third electronic expansion valve 6 is decreased. Thus, by reducing the opening of the third electronic expansion valve 6, the third electronic expansion valve 6 may even not be opened, thereby avoiding the phenomenon that the low-temperature gas refrigerant passing through the third electronic expansion valve 6 and the high-temperature gas refrigerant exchanged after passing through the evaporator 22 are unevenly mixed in the gas-liquid separator 23, resulting in liquid hammer damage to the compressor 21, and reducing the energy loss caused by liquid injection.

[0024] The functions of the first electronic expansion valve 5 and the second electronic expansion valve 4 are dependent on the feedback of the outlet water temperature of the circulating fluid system 1, and at the same time, the water supply demand for customers needs to be guaranteed. Therefore, a structure of a circulating fluid system 1 is introduced for illustration. The circulating fluid system 1 includes a flow meter 11, a heating water tank 12, a water pump 13, a third pressure sensor 14 and a second temperature sensor 15 through which the circulating fluid flows in sequence. A bypass valve 16 is provided between the outlet water side of the second temperature sensor 15 and the outlet water side of the flow meter 11. A drain valve 17 for drainage is also provided on the outlet water side of the flow meter 11. The temperature feedback of the second temperature sensor 15 is the basis for adjusting the opening of the first electronic expansion valve 5 and the second electronic expansion valve 4, so as to achieve precise control of the circulating fluid temperature.

[0025] There are many ways of heat exchange between the refrigerant in the main circulation system 2 and the plant water system 3. The following introduces a structure of the main circulation system 2. The main circulation system 2 also includes a condenser 24 arranged between the exhaust side of the compressor 21 and the first electronic expansion valve 5 for heat exchange with the plant water system 3. A drying filter 25 is arranged between the refrigerant outlet side of the condenser 24 and the first electronic expansion valve 5. The third electronic expansion valve 6 is arranged on the outlet side of the drying filter 25, so that the refrigerant after drying and filtering by the drying filter 25 enters the gas-liquid separator 23 or the evaporator 22, so as to ensure the purity of the refrigerant and the refrigeration effect of the refrigerant.

[0026] The temperature of the refrigerant that directly passes through the second electronic expansion valve 4 follows the exhaust temperature of the compressor 21 due to the lack of necessary cooling method, which may affect the temperature control of the circulating fluid in the circulating fluid system 1. Therefore, a heat exchanger 26 for heat exchange with the plant water system 3 is arranged between the second electronic expansion valve 4 and the refrigerant inlet side of the evaporator 22 to cool the refrigerant. A temperature-type water volume regulating valve 27 is arranged on the water inlet side pipeline of the heat exchanger 26. The temperature sensing package of the temperature-type water volume regulating valve 27 is installed on the refrigerant outlet side of the heat exchanger 26. The opening of the temperature-type water volume regulating valve 27 is automatically adjusted through the temperature feedback of the refrigerant outlet side of the heat exchanger 26, thereby realizing automatic control of the temperature of the refrigerant outlet side of the heat exchanger 26 and improving the temperature control accuracy of the circulating fluid in the circulating fluid system 1.

[0027] The temperature feedback on the exhaust side of the compressor 21 is a key factor in the adjustment of the third electronic expansion valve 6. Therefore, a simple method for detecting the temperature of the refrigerant in the exhaust side pipeline of the compressor 21 is provided here. A first temperature sensor 28 is provided on the exhaust side pipeline of the compressor 21. The temperature feedback of the first temperature sensor 28 is used to automatically adjust the opening of the third electronic expansion valve 6, thereby greatly reducing the probability of uneven mixing of the low-temperature gas refrigerant passing through the third electronic expansion valve 6 and the high-temperature gas refrigerant passing through the evaporator 22 in the gas-liquid separator 23, resulting in liquid shock damage to the compressor 21.

[0028] The heat exchanger 26 is used for heat exchange between the refrigerant in the main circulation system 2 and the plant water system 3. In order to further ensure the effect of heat exchange, the heat exchanger 26 is a plate heat exchanger or a shell and tube heat exchanger. The heat exchange efficiency between the two is very high and can meet the refrigerant cooling requirements.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water-cooled precision temperature-controlled heat exchange system, comprising a circulating fluid system (1) for supplying water to customers, a main circulating system (2) for controlling the temperature of the circulating fluid system (1), and a service water system (3) for cooling the refrigerant in the main circulating system (2) by heat exchange, wherein the main circulating system (2) is provided with a compressor (21) for providing refrigerant flow power, and an evaporator (22) for heat exchange between the circulating fluid system (1) and the main circulating system (2), and a gas-liquid separator (23) is provided on the air inlet side of the compressor (21), characterized in that: A second electronic expansion valve (4) is arranged between the exhaust side of the compressor (21) and the refrigerant inlet side of the evaporator (22), a first electronic expansion valve (5) located on the main circulation system (2) is also arranged on the refrigerant inlet side of the evaporator (22), and a third electronic expansion valve (6) is arranged between the first electronic expansion valve (5) and the inlet side of the gas-liquid separator (23).

2. The heat exchange system according to claim 1, characterized in that: The circulating fluid system (1) comprises a flow meter (11), a heating water tank (12), a water pump (13), a third pressure sensor (14) and a second temperature sensor (15) through which the circulating fluid flows in sequence, a bypass valve (16) is provided between the water outlet side of the second temperature sensor (15) and the water outlet side of the flow meter (11), and a drain valve (17) for draining water is also provided on the water outlet side of the flow meter (11).

3. The heat exchange system according to claim 1, characterized in that: The main circulation system (2) further comprises a condenser (24) arranged between the exhaust side of the compressor (21) and the first electronic expansion valve (5) for heat exchange with the plant water system (3); a drying filter (25) is arranged between the refrigerant outlet side of the condenser (24) and the first electronic expansion valve (5); and the third electronic expansion valve (6) is arranged at the outlet side of the drying filter (25).

4. The heat exchange system according to claim 1, characterized in that: A heat exchanger (26) for heat exchange with the plant water system (3) is arranged between the second electronic expansion valve (4) and the refrigerant inlet side of the evaporator (22), and a temperature-type water flow regulating valve (27) is arranged on the water inlet side pipeline of the heat exchanger (26), and a temperature-sensing package of the temperature-type water flow regulating valve (27) is installed on the refrigerant outlet side of the heat exchanger (26).

5. The heat exchange system according to claim 1, characterized in that: A first temperature sensor (28) is provided on the exhaust side pipeline of the compressor (21).

6. The heat exchange system according to claim 4, characterized in that: The heat exchanger (26) is a plate heat exchanger or a shell and tube heat exchanger.

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