Double-machine parallel connection type low-temperature water chilling unit

Abstract

The utility model discloses a double-unit parallel low-temperature water chilling unit, and relates to a screw type low-temperature water chilling unit, in particular to the double-unit parallel low-temperature water chilling unit. Main components of the device comprise an evaporator (1), a first compressor (4), a first gas-liquid separator (5), a first oil return stop valve (8), an oil separator (10), an oil cooler (11), a condenser (12), a liquid viewing mirror (14), a filter (15), a first electromagnetic valve (16), a second stop valve (17), a third stop valve (18), a first economizer (21) and the like. The low-temperature water chilling unit is a double-machine-head screw type low-temperature water chilling unit which saves cost, is safe, is not limited by transportation, and solves the problems of cost and transportation.

Description

Technical Field

[0001] The utility model relates to a dual-machine parallel low-temperature water chiller, in particular to a dual-machine parallel low-temperature water chiller. Background Art

[0002] Screw-type low-temperature water chillers are generally used in process sites that require low-temperature cold sources. As the demand for low-temperature cold sources increases, the cooling capacity of a single screw-type low-temperature water chiller cannot meet the requirements of process cooling, and a double-head screw-type low-temperature water chiller is needed to complete it. The traditional double-head screw-type low-temperature water chiller is relatively large in size and difficult to transport, and cannot be transported in containers. At present, most manufacturers use two independent single screw-type low-temperature water chillers to complete this situation, which increases the user's unit cost investment.

[0003] Although great progress has been made in the research of screw-type low-temperature chillers in recent years, and relevant technologies have emerged for practical applications in this area, patent CN208832629U proposes a low-temperature chiller. The low-temperature chiller described in the patent is a single low-temperature chiller with a small cooling capacity and cannot meet excessive cooling requirements.

[0004] Compared with the existing patent achievements, the advantage of the utility model is that the unit is a cost-saving, safe, and transportation-free twin-head screw-type low-temperature chiller, which solves the cost and transportation problems. Summary of the invention

[0005] The utility model aims to provide a dual-unit parallel low-temperature water chiller.

[0006] A dual-machine parallel low-temperature chiller consists of an evaporator 1, a first expansion valve 2, a second expansion valve 3, a first compressor 4, a first gas-liquid separator 5, a second compressor 6, a second gas-liquid separator 7, a first oil return stop valve 8, a second oil return stop valve 9, an oil separator 10, an oil cooler 11, a condenser 12, a first stop valve 13, a sight glass 14, a filter 15, a first solenoid valve 16, a second stop valve 17, a third stop valve 18, a second solenoid valve 19, a third expansion valve 20, a first economizer 21, a third solenoid valve 22, a fourth stop valve 23, a fourth solenoid valve 24, a fourth expansion valve 25, a second economizer 26, and a fifth solenoid valve 27;

[0007] Among them, the first end of the evaporator 1 is connected to the first end of the first gas-liquid separator 5 and the first end of the second gas-liquid separator 7 respectively, the second end of the first gas-liquid separator 5 is connected to the first end of the first compressor 4, the second end of the second gas-liquid separator 7 is connected to the first end of the second compressor 6, the second end of the first compressor 4 and the second end of the second compressor 6 are connected to the first end of the oil separator 10, the second end of the oil separator 10 is connected to the first end of the condenser 12, the second end of the condenser 12 is connected to the first end of the first stop valve 13, the second end of the first stop valve 13 is connected to the first end of the sight glass 14, the second end of the sight glass 14 is connected to the first end of the filter 15, the second end of the filter 15 is connected to the first end of the first solenoid valve 16, the second end of the first solenoid valve 16 is connected to the first end of the second stop valve 17, and the second end of the second stop valve 17 is connected to the first end of the third stop valve 18, the first end of the third solenoid valve 22, and the first end of the fourth stop valve 23 respectively. a first end of the first solenoid valve 24 and a first end of the second solenoid valve 24; a second end of the fourth solenoid valve 24 and a first end of the fourth expansion valve 25; a second end of the fourth expansion valve 25 and a first end of the second economizer 26; a second end of the fifth solenoid valve 27 and a second end of the second economizer 26; a third end of the first economizer 21 and a third end of the second economizer 26 are connected to the first end of the first expansion valve 2 and the first end of the second expansion valve 3 respectively; a second end of the first expansion valve 2 is connected to the second end of the evaporator 1; and a second end of the second expansion valve 3 is connected to the third end of the evaporator 1;

[0008] The fourth end of the first economizer 21 is connected to the third end of the second compressor 6, the fourth end of the second economizer 26 is connected to the third end of the first compressor 4, the fourth end of the second compressor 6 is connected to the first end of the second oil return stop valve 9, the fourth end of the first compressor 4 is connected to the first end of the first oil return stop valve 8, the second end of the first oil return stop valve 8 and the second end of the second oil return stop valve 9 are connected to the first end of the oil cooler 11, and the second end of the oil cooler 11 is connected to the third end of the oil separator 10.

[0009] The first compressor 4 and the second compressor 6 are semi-enclosed screw compressors, which have the remarkable advantages of smooth operation, high efficiency, low vibration and low noise. The compressor has stepless energy adjustment, four-stage energy adjustment or three-stage energy adjustment, and can automatically load or unload according to the change of load, saving energy for users.

[0010] The evaporator 1 is a dry evaporator, the condenser 12 is a shell and tube water-cooled condenser, and the heat transfer tube is a high-efficiency heat exchange tube with internal and external threads, wherein the shell side carries the refrigerant, and the tube side carries the cooling water.

[0011] The first economizer 21 and the second economizer 26 are plate heat exchangers with high heat exchange efficiency, which enhance the heat exchange effect. The configuration of the economizer improves the refrigeration effect and reduces the operating cost.

[0012] The oil cooler 11 is a shell and tube type oil cooler, and the heat pipe is a high-efficiency heat exchange pipe. The shell side carries lubricating oil, and the tube side carries cooling water. The cooling water flow is controlled by a proportional valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 It is the principle diagram of the utility model.

[0014] Attached Figure 1 The reference numbers in the figure are: 1. evaporator, 2. first expansion valve, 3. second expansion valve, 4. first compressor, 5. first gas-liquid separator, 6. second compressor, 7. second gas-liquid separator, 8. first return oil stop valve, 9. second return oil stop valve, 10. oil separator, 11. oil cooler, 12. condenser, 13. first stop valve, 14. sight glass, 15. filter, 16. first solenoid valve, 17. second stop valve, 18. third stop valve, 19. second solenoid valve, 20. third expansion valve, 21. first economizer, 22. third solenoid valve, 23. fourth stop valve, 24. fourth solenoid valve, 25. fourth expansion valve, 26. second economizer, 27. fifth solenoid valve. DETAILED DESCRIPTION

[0015] When the unit starts working, the low-temperature and low-pressure steam coming out of the evaporator 1 enters the first compressor 4 and the second compressor 6, is compressed into high-temperature and high-pressure gas by the first compressor 4 and the second compressor 6, and is discharged into the oil separator 10. The oil separator 10 separates 80% to 90% of the lubricating oil in the exhaust gas of the first compressor 4 and the second compressor 6 and returns it to the first compressor 4 and the second compressor 6. On the one hand, it reduces the system circulation amount of the refrigeration oil and improves the reliability of the first compressor 4 and the second compressor 6; on the other hand, it effectively reduces the heat transfer thermal resistance and improves the refrigeration efficiency. The high-temperature, high-pressure gas enters the condenser 12, and the heat is taken away by the cooling water flowing through the condenser 12. The high-temperature, high-pressure gas is condensed into supercooled liquid, and enters the first economizer 21 and the second economizer 26 through the sight glass 14, the filter 15, the first solenoid valve 16, the second stop valve 17, the third stop valve 18, the second solenoid valve 19, the third expansion valve 20, the third solenoid valve 22, the fourth stop valve 23, the fourth solenoid valve 24, the fourth expansion valve 25, and the fifth solenoid valve 27 for further supercooling, and then enters the first expansion valve 2 and the second expansion valve 3 for throttling and pressure reduction, and then becomes a low-temperature, low-pressure gas-liquid mixture and enters the evaporator 1. The refrigerant in the evaporator 1 evaporates continuously, thereby reducing the temperature of the chilled water flowing through the evaporator 1, and the low-temperature, low-pressure liquid in the evaporator 1 becomes low-temperature, low-pressure steam. In this cycle, the temperature of the chilled water is continuously reduced to the required temperature.

[0016] This device is a cost-saving, safe, and transportation-free twin-head screw-type low-temperature water chiller, solving the cost and transportation problems.

Claims

1. A dual-unit parallel low-temperature chiller, characterized in that: The invention comprises an evaporator (1), a first expansion valve (2), a second expansion valve (3), a first compressor (4), a first gas-liquid separator (5), a second compressor (6), a second gas-liquid separator (7), a first oil return stop valve (8), a second oil return stop valve (9), an oil separator (10), an oil cooler (11), a condenser (12), a first stop valve (13), a sight glass (14), a filter (15), a first solenoid valve (16), a second stop valve (17), a third stop valve (18), a second solenoid valve (19), a third expansion valve (20), a first economizer (21), a third solenoid valve (22), a fourth stop valve (23), a fourth solenoid valve (24), a fourth expansion valve (25), a second economizer (26), and a fifth solenoid valve (27); The first end of the evaporator (1) is connected to the first end of the first gas-liquid separator (5) and the first end of the second gas-liquid separator (7), respectively; the second end of the first gas-liquid separator (5) is connected to the first end of the first compressor (4), the second end of the second gas-liquid separator (7) is connected to the first end of the second compressor (6), the second end of the first compressor (4) and the second end of the second compressor (6) are connected to the first end of the oil separator (10), the second end of the oil separator (10) is connected to the first end of the condenser (12), and the second end of the condenser (12) is connected to the first end of the condenser (12). The two ends are connected to the first end of the first stop valve (13), the second end of the first stop valve (13) is connected to the first end of the sight glass (14), the second end of the sight glass (14) is connected to the first end of the filter (15), the second end of the filter (15) is connected to the first end of the first solenoid valve (16), the second end of the first solenoid valve (16) is connected to the first end of the second stop valve (17), and the second end of the second stop valve (17) is respectively connected to the first end of the third stop valve (18), the first end of the third solenoid valve (22), and the first end of the fourth stop valve (23). The first end of the third stop valve (23) is connected to the first end of the fourth solenoid valve (24), the second end of the fourth solenoid valve (24 ... first economizer (21), the second end of the third solenoid valve (22) is connected to the second end of the first economizer (21), the second end of the fourth stop valve (23) is connected to the first end of the fourth solenoid valve (24), the second end of the fourth solenoid valve (24) is connected to the first end of the third expansion valve (20), the second end of the third expansion valve (20) is connected to the first end of the first economizer (21), the second end of the third solenoid valve (22) is connected to the second end of the first economizer (21), the second end of the fourth stop valve (23) is connected to the first end of the fourth solenoid valve (24), the second end of the fourth solenoid valve (24) is connected to the first end of the fourth expansion valve (20), and the second end of the third expansion valve (20) is connected to the first end of the first economizer (21). The first end of the fourth expansion valve (25) is connected to the first end of the second economizer (26), the second end of the fifth solenoid valve (27) is connected to the second end of the second economizer (26), the third end of the first economizer (21) and the third end of the second economizer (26) are respectively connected to the first end of the first expansion valve (2) and the first end of the second expansion valve (3), the second end of the first expansion valve (2) is connected to the second end of the evaporator (1), and the second end of the second expansion valve (3) is connected to the third end of the evaporator (1); The fourth end of the first economizer (21) is connected to the third end of the second compressor (6), the fourth end of the second economizer (26) is connected to the third end of the first compressor (4), the fourth end of the second compressor (6) is connected to the first end of the second oil return stop valve (9), the fourth end of the first compressor (4) is connected to the first end of the first oil return stop valve (8), the second end of the first oil return stop valve (8) and the second end of the second oil return stop valve (9) are connected to the first end of the oil cooler (11), and the second end of the oil cooler (11) is connected to the third end of the oil separator (10).

2. A dual-unit parallel low-temperature chiller according to claim 1, characterized in that: The first compressor (4) and the second compressor (6) are semi-hermetic screw compressors.

3. The dual-unit parallel low-temperature chiller according to claim 1, characterized in that: The condenser (12) is a shell and tube type water-cooled condenser.

4. The dual-unit parallel low-temperature chiller according to claim 1, characterized in that: The first economizer (21) and the second economizer (26) are plate heat exchangers with high heat exchange efficiency.

5. The dual-unit parallel low-temperature chiller according to claim 1, characterized in that: The evaporator (1) is a dry evaporator.

6. The dual-unit parallel low-temperature chiller according to claim 1, characterized in that: The oil cooler (11) is a shell and tube type oil cooler.

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