Hydrogenation machine refrigerating unit with double operation modes

Abstract

The utility model relates to the technical field of hydrogenation machine refrigerating units, in particular to a hydrogenation machine refrigerating unit with double operation modes. The utility model relates to a high-temperature-stage refrigeration system, which comprises a high-temperature-stage refrigeration system, a low-temperature-stage refrigeration system and a water cooling system, and a refrigerant outlet of the high-temperature stage oil-gas separator is connected with a gas inlet of the finned tube type condenser through a pipeline. According to the utility model, various valves such as the high-temperature evaporator, the electromagnetic valve and the expansion valve are added on the basis of the cascade machine, so that the unit has two modes of single-stage compression refrigeration and cascade compression refrigeration, and can be suitable for cooling two hydrogenation machines, namely a 70MPa hydrogenation machine and a 35MPa hydrogenation machine; on the basis of the cascade unit, the unit has the functions of a single-stage refrigerating unit and a cascade refrigerating unit by adding a small number of parts such as the valves and the high-temperature evaporator, the investment cost is low, and the economical efficiency is high.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogenator refrigeration units, in particular to a hydrogenator refrigeration unit with dual operation modes. Background Art

[0002] At present, the hydrogenation machine refrigeration units used in the market are all designed according to the chilled water temperature required by the hydrogenation machine. The temperature range of the refrigerant is small and the versatility is poor. During the initial startup, due to the high temperature of the refrigerant, the unit may have exceeded the operating range of the compressor during operation, affecting the service life and reliability of the unit. At the same time, the unit's single operating mode makes it impossible for the unit to achieve energy conservation and environmental protection. Different hydrogenation machines need to be equipped with different refrigeration units. There are many product varieties, which is not conducive to management and the investment cost is relatively high. Utility Model Content

[0003] In view of the shortcomings of the above-mentioned existing production technology, the present application provides a hydrogenation machine refrigeration unit with dual operation modes. On the basis of the cascade machine, various valve components such as a high-temperature evaporator, a solenoid valve, and an expansion valve are added to enable the unit to have two modes: single-stage compression refrigeration and cascade compression refrigeration. The temperature range of the unit for producing cold water is wide, and it can be adapted to refrigeration equipment that requires cold water at different temperatures.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A hydrogenation machine refrigeration unit with dual operation modes, comprising a high-temperature refrigeration system, a low-temperature refrigeration system and a water cooling system, wherein the high-temperature refrigeration system comprises a high-temperature compressor, the exhaust port of the high-temperature compressor is connected to the air inlet of a high-temperature oil-gas separator through a pipeline, the refrigerant outlet of the high-temperature oil-gas separator is connected to the air inlet of a fin-tube condenser through a pipeline, the liquid outlet of the fin-tube condenser is connected to the liquid inlet of a high-temperature filter drier through a pipeline, the liquid outlet of the high-temperature filter drier is connected to the first liquid inlet of an economizer through a pipeline, the liquid outlet of the high-temperature filter drier is connected to the liquid inlet of a second solenoid valve through a pipeline, the liquid outlet of the second solenoid valve is connected to the liquid inlet of a second expansion valve through a pipeline, the liquid outlet of the second expansion valve is connected to the second liquid inlet of an economizer through a pipeline, the air outlet of the economizer is connected to the air inlet of a check valve through a pipeline, the air outlet of the check valve is connected to the air inlet of a vibration-proof pipe through a pipeline, the air outlet of the vibration-proof pipe is connected to the energy-saving port of a low-temperature compressor through a pipeline, The liquid outlet of the economizer is connected to the liquid inlet of the third solenoid valve through a pipeline, the liquid outlet of the third solenoid valve is connected to the liquid inlet of the third expansion valve through a pipeline, the liquid outlet of the third expansion valve is connected to the liquid inlet of the high-temperature evaporator through a pipeline, the air outlet of the high-temperature evaporator is connected to the air inlet of the high-temperature gas-liquid separator through a pipeline, the liquid outlet of the economizer is connected to the liquid inlet of the fourth solenoid valve through a pipeline, the liquid outlet of the fourth solenoid valve is connected to the liquid inlet of the fourth expansion valve through a pipeline, the liquid outlet of the fourth expansion valve is connected to the liquid inlet of the intermediate heat exchanger through a pipeline, the air outlet of the intermediate heat exchanger is connected to the air inlet of the high-temperature gas-liquid separator through a pipeline, and the air outlet of the high-temperature gas-liquid separator is connected to the air intake of the high-temperature compressor through a pipeline;

[0006] The low-temperature refrigeration system comprises a low-temperature compressor, the air outlet of the low-temperature compressor is connected to the air inlet of the low-temperature oil-gas separator through a pipeline, the air outlet of the low-temperature oil-gas separator is connected to the air inlet of the fin-tube precooler through a pipeline, the air outlet of the fin-tube precooler is connected to the air inlet of the low-temperature secondary oil-gas separator through a pipeline, the air outlet of the low-temperature secondary oil-gas separator is connected to the air inlet of the intermediate heat exchanger through a pipeline, the liquid outlet of the intermediate heat exchanger is connected to the liquid inlet of the liquid storage through a pipeline, the liquid outlet of the liquid storage is connected to the liquid inlet of the low-temperature filter drier through a pipeline, and the outlet of the low-temperature filter drier is connected to the liquid outlet of the low-temperature filter drier. The liquid port is connected to the liquid inlet of the regenerator through a pipeline, the liquid outlet of the regenerator is connected to the liquid inlet of the sixth expansion valve through a pipeline, the liquid outlet of the sixth expansion valve is connected to the liquid inlet of the low-temperature evaporator through a pipeline, the gas outlet of the low-temperature evaporator is connected to the gas inlet of the regenerator through a pipeline, the gas outlet of the regenerator is connected to the air intake of the low-temperature compressor through a pipeline, the liquid outlet of the low-temperature filter drier is connected to the liquid inlet of the sixth solenoid valve through a pipeline, the liquid outlet of the sixth solenoid valve is connected to the liquid inlet of the low-temperature liquid injection expansion valve through a pipeline, and the liquid outlet of the low-temperature liquid injection expansion valve is connected to the air intake of the low-temperature compressor through a pipeline;

[0007] The water cooling system includes a chilled water tank, a water outlet of the chilled water tank is connected to the water inlet of a ninth solenoid valve through a pipeline, the water outlet of the ninth solenoid valve is connected to the water inlet of a low-temperature evaporator through a pipeline, the water outlet of the low-temperature evaporator is connected to a first water return port of the chilled water tank through a pipeline, the water outlet of the chilled water tank is connected to the water inlet of an eighth solenoid valve through a pipeline, the water outlet of the eighth solenoid valve is connected to the water inlet of a high-temperature evaporator through a pipeline, and the water outlet of the high-temperature evaporator is connected to a second water return port of the high-temperature evaporator through a pipeline.

[0008] Furthermore, the liquid outlet of the high-temperature stage filter drier is connected to the liquid inlet of the first expansion valve through a pipeline, the liquid outlet of the first expansion valve is connected to the medium-pressure liquid injection port of the high-temperature stage compressor through a pipeline, the liquid outlet of the high-temperature stage filter drier is connected to the liquid inlet of the fifth solenoid valve through a pipeline, the liquid outlet end of the fifth solenoid valve is connected to the liquid inlet end of the fifth expansion valve through a pipeline, and the liquid outlet end of the fifth expansion valve is connected to the air intake port of the high-temperature stage compressor through a pipeline.

[0009] Furthermore, a pressure maintaining valve is arranged on the pipeline between the exhaust port of the high-temperature compressor and the air inlet of the high-temperature oil-gas separator, and the low-pressure side pressure point of the pressure maintaining valve is connected to the air intake port of the high-temperature compressor through a pipeline.

[0010] Furthermore, a first pressure transmitter is connected to the pipeline connected to the air outlet of the high-temperature dry filter, a second pressure transmitter is connected to the pipeline connected to the air intake of the high-temperature compressor, a fourth pressure transmitter is connected to the liquid inlet of the low-temperature dry filter, and a third pressure transmitter is arranged on the pipeline connected to the air outlet of the low-temperature evaporator.

[0011] Furthermore, the air outlet of the fin-tube precooler is connected to the air inlet of the normally open solenoid valve through a pipeline, the air outlet of the normally open solenoid valve is connected to the air inlet of the expansion tank through a pipeline, the air outlet of the expansion tank is connected to the air inlet of the capillary tube through a pipeline, and the air outlet of the capillary tube is connected to the air intake of the low-temperature compressor through a pipeline.

[0012] Furthermore, a first exhaust fan is arranged on the fin-tube condenser, and the first exhaust fan can discharge the air flowing through the fin-tube condenser into the atmosphere, and a second exhaust fan is arranged on the fin-tube precooler, and the second exhaust fan can discharge the air flowing through the fin-tube precooler into the atmosphere.

[0013] Furthermore, the oil return port of the high temperature oil-gas separator is connected to the air intake port of the high temperature compressor through a pipeline, and a first solenoid valve is arranged on the pipeline connected to the oil return port of the high temperature oil-gas separator.

[0014] Furthermore, the oil return port of the low-temperature oil-gas separator is connected to the air intake port of the low-temperature compressor through a pipeline, and the oil return port of the low-temperature secondary oil-gas separator is connected to the air intake port of the low-temperature compressor through a pipeline.

[0015] Furthermore, the water outlet of the chilled water tank is connected to a chilled water pump, which can provide power to allow the chilled water to flow in the pipeline.

[0016] The beneficial effects of the utility model are as follows:

[0017] The utility model adds various valve parts such as a high-temperature evaporator, a solenoid valve, and an expansion valve on the basis of a cascade machine, so that the unit has two modes of single-stage compression refrigeration and cascade compression refrigeration, and can be suitable for cooling two hydrogenation machines, 70MPa hydrogenation machine and 35MPa hydrogenation machine; the utility model is based on a cascade unit, and by adding a small amount of valve parts and high-temperature evaporator components, the unit has the functions of two refrigeration units, single-stage refrigeration and cascade refrigeration, with low investment cost and high economy; the unit of the utility model can automatically operate the single-machine refrigeration or cascade refrigeration mode according to the required refrigerant temperature and the actual refrigerant temperature during operation, which is energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a working principle diagram of the utility model.

[0019] Among them: 1. high temperature compressor; 2. pressure maintaining valve; 3. first expansion valve; 4. high temperature oil-gas separator; 5. first solenoid valve; 6. vibration-proof pipe; 7. one-way valve; 8. second expansion valve; 9. economizer; 10. second solenoid valve; 11. first pressure transmitter; 12. high temperature filter drier; 13. finned tube condenser; 14. first exhaust fan; 15. high temperature evaporator; 16. third expansion valve; 17. third solenoid valve; 18. liquid storage tank; 19. intermediate heat exchanger; 20. fourth solenoid valve; 21. fourth expansion valve; 22. high temperature gas-liquid separator; 23. fifth solenoid valve; 24. 5. Expansion valve; 25. Second pressure transmitter; 26. Low temperature compressor; 27. Low temperature primary oil-gas separator; 28. Fin-tube precooler; 29. ​​Second exhaust fan; 30. Low temperature liquid injection expansion valve; 31. Normally open solenoid valve; 32. Sixth solenoid valve; 33. Low temperature secondary oil-gas separator; 34. Capillary tube; 35. Regenerator; 36. Third pressure transmitter; 37. Chilled water tank; 38. Low temperature evaporator; 39. Sixth expansion valve; 40. Low temperature filter drier; 41. Fourth pressure transmitter; 42. Eighth solenoid valve; 43. Chilled water pump; 44. Ninth solenoid valve; 45. Expansion tank. DETAILED DESCRIPTION

[0020] The specific implementation of the utility model is described below in conjunction with the accompanying drawings.

[0021] like Figure 1 As shown, a hydrogenation machine refrigeration unit with dual operation modes includes a high-temperature refrigeration system, a low-temperature refrigeration system and a water cooling system.

[0022] like Figure 1 As shown, the high-temperature refrigeration system includes a high-temperature compressor 1, the exhaust port of the high-temperature compressor 1 is connected to the air inlet of the high-temperature oil-gas separator 4 through a pipeline, the refrigerant outlet of the high-temperature oil-gas separator 4 is connected to the air inlet of the fin-tube condenser 13 through a pipeline, and the oil return port of the high-temperature oil-gas separator 4 is connected to the air intake port of the high-temperature compressor 1 through a pipeline. A first solenoid valve 5 is arranged on the pipeline connected to the oil return port of the high-temperature oil-gas separator 4, and the first solenoid valve 5 can control the on-off of the pipeline. A first exhaust fan 14 is arranged on the fin-tube condenser 13, and the first exhaust fan 14 can discharge the air flowing through the fin-type condenser into the atmosphere.

[0023] like Figure 1 As shown, the liquid outlet of the fin-tube condenser 13 is connected to the liquid inlet of the high-temperature filter drier 12 through a pipeline, the liquid outlet of the high-temperature filter drier 12 is connected to the liquid inlet of the first expansion valve 3 through a pipeline, and the liquid outlet of the first expansion valve 3 is connected to the medium-pressure liquid injection port of the high-temperature compressor 1 through a pipeline. The liquid outlet of the high-temperature filter drier 12 is connected to the air inlet of the fifth solenoid valve 23 through a pipeline, the liquid outlet end of the fifth solenoid valve 23 is connected to the liquid inlet end of the fifth expansion valve 24 through a pipeline, and the liquid outlet end of the fifth expansion valve 24 is connected to the air intake port of the high-temperature compressor 1 through a pipeline. The liquid outlet of the high-temperature filter drier 12 is connected to the first liquid inlet of the economizer 9 through a pipeline, the liquid outlet of the high-temperature filter drier 12 is connected to the liquid inlet of the second solenoid valve 10 through a pipeline, the liquid outlet of the second solenoid valve 10 is connected to the liquid inlet of the second expansion valve 8 through a pipeline, and the liquid outlet of the second expansion valve 8 is connected to the second liquid inlet of the economizer 9 through a pipeline. The air outlet of the economizer 9 is connected to the air inlet of the one-way valve 7 through a pipeline, the air outlet of the one-way valve 7 is connected to the air inlet of the vibration-proof pipe 6 through a pipeline, and the air outlet of the vibration-proof pipe 6 is connected to the energy-saving port of the high-temperature compressor 1 through a pipeline.

[0024] like Figure 1 As shown, the liquid outlet of the economizer 9 is connected to the liquid inlet of the third solenoid valve 17 through a pipeline, the liquid outlet of the third solenoid valve 17 is connected to the liquid inlet of the third expansion valve 16 through a pipeline, and the liquid outlet of the third expansion valve 16 is connected to the liquid inlet of the high-temperature evaporator 15 through a pipeline. The liquid outlet of the economizer 9 is connected to the liquid inlet of the fourth solenoid valve 20 through a pipeline, the liquid outlet of the fourth solenoid valve 20 is connected to the liquid inlet of the fourth expansion valve 21 through a pipeline, and the liquid outlet of the fourth expansion valve 21 is connected to the liquid inlet of the intermediate heat exchanger 19 through a pipeline.

[0025] The air outlet of the intermediate heat exchanger 19 is connected to the air inlet of the high-temperature gas-liquid separator 22 through a pipeline, the air outlet of the high-temperature evaporator 15 is connected to the air inlet of the high-temperature gas-liquid separator 22 through a pipeline, and the air outlet of the high-temperature gas-liquid separator 22 is connected to the air intake of the high-temperature compressor 1 through a pipeline.

[0026] like Figure 1 As shown, a pressure maintaining valve 2 is arranged on the pipeline between the exhaust port of the high-temperature compressor 1 and the air inlet of the high-temperature oil-gas separator 4. The low-pressure point of the pressure maintaining valve 2 is connected to the air intake port of the high-temperature compressor (1) through a pipeline. The pressure maintaining valve 2 can maintain the pressure difference between the intake and exhaust gases within the design index range.

[0027] like Figure 1 As shown, the first pressure transmitter 11 is connected to the pipeline connected to the liquid outlet of the high-temperature filter drier 12. The first pressure transmitter 11 can detect the pressure in the pipeline in real time and transmit the pressure data to the control system. The control system adjusts the pressure according to the detected pressure signal. The second pressure transmitter 25 is connected to the pipeline connected to the air intake of the high-temperature compressor 1. The second pressure transmitter 25 can detect the pressure in the pipeline and transmit the pressure data to the control system. The control system adjusts the pressure according to the detected pressure signal. When the pressure parameter is abnormal and reaches the warning value, an accident will occur, and the unit will be shut down due to fault or protective operation will be performed, and an alarm signal will be issued.

[0028] like Figure 1 As shown, the low-temperature refrigeration system includes a low-temperature compressor 26, the air outlet of the low-temperature compressor 26 is connected to the air inlet of the low-temperature oil-gas separator 27 through a pipeline, the oil return port of the low-temperature oil-gas separator 27 is connected to the air intake of the low-temperature compressor 26 through a pipeline, and the air outlet of the low-temperature oil-gas separator 27 is connected to the air inlet of the fin-tube precooler 28 through a pipeline. The air outlet of the fin-tube precooler 28 is connected to the air inlet end of the normally open solenoid valve 31 through a pipeline, the air outlet end of the normally open solenoid valve 31 is connected to the air inlet of the expansion tank 45 through a pipeline, the air outlet of the expansion tank 45 is connected to the air inlet of the capillary 34 through a pipeline, and the air outlet of the capillary 34 is connected to the air intake of the low-temperature compressor 26 through a pipeline.

[0029] The air outlet of the fin-tube precooler 28 is connected to the air inlet of the low-temperature stage secondary oil-gas separator 33 through a pipeline, the oil return port of the low-temperature stage secondary oil-gas separator 33 is connected to the air intake of the low-temperature compressor 26 through a pipeline, the air outlet of the low-temperature stage secondary oil-gas separator 33 is connected to the air inlet of the intermediate heat exchanger 19 through a pipeline, the liquid outlet of the intermediate heat exchanger 19 is connected to the liquid inlet of the liquid reservoir 18 through a pipeline, the liquid outlet of the liquid reservoir 18 is connected to the liquid inlet of the low-temperature stage drying filter 40 through a pipeline, the liquid outlet of the low-temperature stage drying filter 40 is connected to the liquid inlet of the sixth solenoid valve 32 through a pipeline, the liquid outlet of the sixth solenoid valve 32 is connected to the liquid inlet of the low-temperature stage liquid injection expansion valve 30 through a pipeline, and the liquid outlet of the low-temperature stage liquid injection expansion valve 30 is connected to the air intake of the low-temperature compressor 26 through a pipeline.

[0030] The liquid outlet of the low-temperature stage filter drier 40 is connected to the liquid inlet of the regenerator 35 through a pipeline, the liquid outlet of the regenerator 35 is connected to the liquid inlet of the sixth expansion valve 39 through a pipeline, the liquid outlet of the sixth expansion valve 39 is connected to the liquid inlet of the low-temperature stage evaporator 38 through a pipeline, the air outlet of the low-temperature stage evaporator 38 is connected to the air inlet of the regenerator 35 through a pipeline, and the air outlet of the regenerator 35 is connected to the air intake of the low-temperature stage compressor 26 through a pipeline.

[0031] The fin-tube precooler 28 is provided with a second exhaust fan 29, which can exhaust the air flowing through the fin-tube precooler 28 into the atmosphere. The liquid inlet of the low-temperature stage drying filter 40 is connected to a fourth pressure transmitter 41, which can detect the pressure in the pipeline and transmit the pressure data to the control system, and the control system adjusts the pressure according to the detected pressure signal. The pipeline connected to the outlet of the low-temperature stage evaporator 38 is provided with a third pressure transmitter 36, which can detect the pressure in the pipeline and transmit the pressure data to the control system, and the control system adjusts the pressure according to the detected pressure signal.

[0032] like Figure 1 As shown, the water cooling system includes a chilled water tank 37, the water outlet of the chilled water tank 37 is connected to the water inlet of the ninth solenoid valve 44 through a pipeline, the water outlet of the ninth solenoid valve 44 is connected to the water inlet of the low-temperature stage evaporator 38 through a pipeline, and the water outlet of the low-temperature stage evaporator 38 is connected to the first water return port of the chilled water tank 37 through a pipeline. The water outlet of the chilled water tank 37 is connected to the water inlet of the eighth solenoid valve 42 through a pipeline, the water outlet of the eighth solenoid valve 42 is connected to the water inlet of the high-temperature stage evaporator 15 through a pipeline, and the water outlet of the high-temperature stage evaporator 15 is connected to the second water return port of the chilled water tank 37 through a pipeline. The water outlet of the chilled water tank 37 is connected to the chilled water pump 43, and the chilled water pump 43 can provide power to allow the chilled water to flow in the pipeline.

[0033] The utility model has two modes, namely, single-stage compression refrigeration and cascade compression refrigeration, which broadens the temperature range of the unit for producing cold water and can be applied to cold equipment requiring cold water at different temperatures; when the required cold water temperature is not very low, the unit operates in single-stage refrigeration mode, which is energy-saving and environmentally friendly; the utility model adds a small number of components on the basis of the cascade unit, so that the unit has two modes, namely, single-stage compression refrigeration and cascade compression refrigeration, which is equivalent to a combination of two chillers, sharing most of the parts, with low overall investment cost, high degree of integration, optimized space and small space occupation.

[0034] The unit of the utility model is designed with an expansion tank, a normally open solenoid valve, a capillary tube, etc., which release the pressure when the low-temperature stage pressure of the unit is too high. The capillary tube prevents the low-temperature compressor from inhaling too much air at the initial start-up of the cascade machine, causing the low-temperature stage compressor to overload, thereby improving the reliability of the unit.

[0035] The unit of the utility model is designed with a pressure transmitter, which detects the unit pressure at all times and transmits it to the control system. The control system automatically adjusts according to the detected pressure signal; when the pressure parameter is abnormal and reaches the warning value and an accident occurs, the unit is shut down due to fault or protective operation is performed, and an alarm signal is issued.

[0036] The high temperature stage of the unit of the utility model is designed with low pressure liquid spray and medium pressure liquid spray, and various valves are used to ensure that the exhaust temperature of the high temperature stage compressor will not be too high or too low, thereby improving the reliability of the unit.

[0037] The working principle of the utility model is:

[0038] When the utility model cools the 35MPa hydrogenation machine, the unit operates in single refrigeration mode. The high-temperature and high-pressure oil-gas mixture discharged from the high-temperature compressor 1 enters the high-temperature oil-gas separator 4 through the condensing pressure maintaining valve 2. After the oil and gas are separated in the high-temperature oil-gas separator 4, the separated lubricating oil returns to the high-temperature compressor 1. The separated high-temperature and high-pressure refrigerant gas enters the fin-tube condenser 13. The high-temperature and high-pressure refrigerant gas condenses and releases heat in the condenser 13 to become a high-temperature and high-pressure refrigerant liquid. The heat released by the condensation of the refrigerant is taken away by the air flowing through the fin-type condenser 13 and discharged into the atmosphere by the exhaust fan 14. The high-temperature and high-pressure refrigerant liquid is filtered by the high-temperature drying filter 12 and then divided into four paths. , two of which are connected to the low-pressure liquid injection port and the medium-pressure liquid injection port of the high-temperature compressor 1 respectively, and the first solenoid valve 5 and the fifth solenoid valve 23 are automatically controlled according to the exhaust temperature of the high-temperature compressor 1. The high-temperature compressor 1 is cooled down after throttling by the first expansion valve 3 and the fifth expansion valve 24, and the exhaust temperature of the high-temperature compressor 1 is controlled. The third route enters the main liquid pipe side of the economizer 9 for supercooling, and the fourth route enters the gas pipe side of the economizer 9 after throttling by the second expansion valve 8 to vaporize and absorb heat to supercool the refrigerant in the main liquid pipe. The refrigerant that absorbs heat and vaporizes in the economizer 9 flows out of the economizer 9 and enters the energy-saving port of the high-temperature compressor 1. The supercooled refrigerant liquid flows to the third expansion valve 16 through the third solenoid valve 17, and the fourth solenoid valve 20 is closed at this time. After being throttled by the third expansion valve 16, it becomes a low-temperature and low-pressure gas-liquid two-phase mixture. The low-temperature and low-pressure gas-liquid two-phase mixture enters the high-temperature evaporator 15. The refrigerant liquid vaporizes and absorbs heat in the high-temperature evaporator 15, absorbs heat from the cold water flowing through the high-temperature evaporator 15, and cools the cold water. After the refrigerant vaporizes in the high-temperature evaporator 15, it flows to the high-temperature gas-liquid separator 22, and is sucked into the high-temperature compressor 1 after gas-liquid separation in the high-temperature gas-liquid separator 22, and is discharged after pressurization, and enters the next cycle. At this time, the eighth solenoid valve 42 is opened, the ninth solenoid valve 44 is closed, and the power is provided by the chilled water pump 43, so that the chilled water circulates between the high-temperature evaporator 15, the cold equipment and the chilled water tank 37, and cools the chilled water in the cold equipment and the chilled water tank 37. The unit is designed with a first pressure transmitter 11 and a second pressure transmitter 25. The first pressure transmitter 11 and the second pressure transmitter 25 detect the unit pressure and transmit it to the control system. The control system automatically adjusts according to the detected pressure signal; when the pressure parameter is abnormal and reaches the warning value and an accident occurs, the unit is shut down due to fault or protective operation is performed, and an alarm signal is issued.

[0039] When the utility model cools a 70MPa hydrogenation machine, when the temperature of the chilled water is higher than minus 20°C, the unit operates in a single refrigeration mode. When the temperature of the chilled water is lower than minus 20°C, the unit automatically switches to a cascade refrigeration mode. The high-temperature and high-pressure oil-gas mixture discharged from the high-temperature compressor 1 enters the high-temperature oil-gas separator 4 through the condensing pressure maintaining valve 2. After oil and gas separation in the high-temperature oil-gas separator 4, the separated lubricating oil returns to the high-temperature compressor 1. The separated high-temperature and high-pressure refrigerant gas enters the fin-tube condenser 13. The high-temperature and high-pressure refrigerant gas condenses and releases heat in the fin-tube condenser 13 to become a high-temperature and high-pressure refrigerant liquid. The heat released by the condensation of the refrigerant is taken away by the air flowing through the fin-type condenser 13 and discharged into the atmosphere by the first exhaust fan 14. The high-temperature and high-pressure refrigerant liquid is filtered by the high-temperature drying filter 12 and then separated. It is divided into four routes, two of which are respectively connected to the low-pressure liquid injection port of the high-temperature compressor 1 and the medium-pressure liquid injection port of the high-temperature compressor 1. The first solenoid valve 5 and the fifth solenoid valve 23 are automatically controlled according to the exhaust temperature of the high-temperature compressor 1. The high-temperature compressor 1 is cooled down after throttling by the first expansion valve 3 and the fifth expansion valve 24 to control the exhaust temperature of the high-temperature compressor 1. The third route enters the main liquid pipe side of the economizer 9 for supercooling. The fourth route enters the gas pipe side of the economizer 9 after throttling by the second expansion valve 8 to vaporize and absorb heat to supercool the refrigerant in the main liquid pipe. The refrigerant that absorbs heat and vaporizes in the economizer 9 flows out of the economizer 9 and enters the energy-saving port of the high-temperature compressor 1. The supercooled refrigerant liquid flows to the fourth expansion valve 21 through the fourth solenoid valve 20, and the third solenoid valve 17 is closed at this time. The refrigerant liquid is throttled by the fourth expansion valve 21 and becomes a low-temperature and low-pressure gas-liquid two-phase mixture. The low-temperature and low-pressure gas-liquid two-phase mixture enters the intermediate heat exchanger 19, and the refrigerant liquid vaporizes and absorbs heat on the evaporation side of the intermediate heat exchanger 19, and absorbs heat from the low-temperature refrigerant flowing through the intermediate heat exchanger 19, so that the low-temperature refrigerant is condensed. After the high-temperature refrigerant is vaporized in the intermediate heat exchanger, it flows to the high-temperature gas-liquid separator 22, and is sucked into the high-temperature compressor 1 after gas-liquid separation in the high-temperature gas-liquid separator 22, and is discharged after being pressurized to enter the next cycle.

[0040] At the same time, the high-temperature and high-pressure oil-gas mixture discharged from the low-temperature compressor 26 enters the low-temperature first-stage oil-gas separator 27. After oil and gas separation in the low-temperature first-stage oil-gas separator 27, the separated lubricating oil returns to the low-temperature compressor 26, and the separated high-temperature and high-pressure refrigerant gas enters the fin-tube precooler 28. After the high-temperature and high-pressure refrigerant gas is precooled in the fin-tube precooler 28, it enters the low-temperature second-stage oil separator 33. The separated lubricating oil returns to the low-temperature compressor 26, and the separated medium-temperature and high-pressure refrigerant gas enters the intermediate heat exchanger 19, condenses and releases heat in the intermediate heat exchanger 19 to become a low-temperature and high-pressure refrigerant liquid. The heat released by the condensation of the refrigerant is passed through the intermediate heat exchanger 19. The refrigerant on the evaporation side of the intermediate heat exchanger 19 goes, and the low-temperature and high-pressure refrigerant liquid enters the regenerator 35 after passing through the liquid receiver 18 and the low-temperature stage drying filter 40. After being supercooled in the regenerator 35, it flows to the sixth expansion valve 39, and after being throttled by the sixth expansion valve 39, it becomes a low-temperature and low-pressure gas-liquid two-phase mixture. The low-temperature and low-pressure gas-liquid two-phase mixture enters the low-temperature stage evaporator 38. The refrigerant liquid vaporizes and absorbs heat in the low-temperature stage evaporator 38, absorbs heat from the cold water flowing through the low-temperature stage evaporator 38, and cools the cold water. After being vaporized in the low-temperature stage evaporator 38, the refrigerant flows to the regenerator 35, and after heat exchange in the regenerator 35, it is sucked into the low-temperature stage compressor 26, and is discharged after being pressurized to enter the next cycle. At this time, the eighth solenoid valve 42 is closed, and the ninth solenoid valve 44 is opened. The chilled water pump 43 provides power to circulate the chilled water between the low-temperature evaporator 38, the cold equipment and the chilled water tank 37, so as to cool the chilled water in the cold equipment and the chilled water tank 37. The unit is designed with an expansion tank 45, a normally open solenoid valve 31, a capillary tube 34, etc., which release the pressure when the low-temperature pressure of the unit is too high. The capillary tube 34 prevents the low-temperature compressor 26 from overloading due to excessive air intake at the initial start of the cascade machine, thereby improving the reliability of the unit. The low-temperature stage of the unit is designed with a third pressure transmitter 36 and a fourth pressure transmitter 41. The third pressure transmitter 36 and the fourth pressure transmitter 41 detect the pressure of the unit at all times and transmit it to the control system. The control system automatically adjusts according to the detected pressure signal; when the pressure parameter is abnormal and reaches the warning value, an accident will occur, and the unit will be shut down or perform protective operations, and send an alarm signal.

[0041] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. Any form of modification can be made within the protection scope of the utility model.

Claims

1. A hydrogenation machine refrigeration unit with dual operation modes, comprising a high-temperature refrigeration system, a low-temperature refrigeration system and a water cooling system, characterized in that: The high-temperature refrigeration system comprises a high-temperature compressor (1), the exhaust port of the high-temperature compressor (1) being connected to the air inlet of a high-temperature oil-gas separator (4) via a pipeline. The refrigerant outlet of the high-temperature oil-gas separator (4) is connected to the air inlet of the fin-tube condenser (13) through a pipeline, the liquid outlet of the fin-tube condenser (13) is connected to the liquid inlet of the high-temperature filter drier (12) through a pipeline, the liquid outlet of the high-temperature filter drier (12) is connected to the first liquid inlet of the economizer (9) through a pipeline, the liquid outlet of the high-temperature filter drier (12) is connected to the liquid inlet of the second solenoid valve (10) through a pipeline, the liquid outlet of the second solenoid valve (10) is connected to the liquid inlet of the second expansion valve (8) through a pipeline, the liquid outlet of the second expansion valve (8) is connected to the second liquid inlet of the economizer (9) through a pipeline, the air outlet of the economizer (9) is connected to the air inlet of the check valve (7) through a pipeline, the air outlet of the check valve (7) is connected to the air inlet of the vibration-proof pipe (6) through a pipeline, the air outlet of the vibration-proof pipe (6) is connected to the energy-saving port of the low-temperature compressor (1) through a pipeline, and the air outlet of the low-temperature compressor (1) is connected to the energy-saving port of the economizer (1). 9) The liquid outlet is connected to the liquid inlet of the third solenoid valve (17) through a pipeline, the liquid outlet of the third solenoid valve (17) is connected to the liquid inlet of the third expansion valve (16) through a pipeline, the liquid outlet of the third expansion valve (16) is connected to the liquid inlet of the high-temperature evaporator (15) through a pipeline, the gas outlet of the high-temperature evaporator (15) is connected to the gas inlet of the high-temperature gas-liquid separator (22) through a pipeline, the liquid outlet of the economizer (9) is connected to the liquid inlet of the fourth solenoid valve (20) through a pipeline, the liquid outlet of the fourth solenoid valve (20) is connected to the liquid inlet of the fourth expansion valve (21) through a pipeline, the liquid outlet of the fourth expansion valve (21) is connected to the liquid inlet of the intermediate heat exchanger (19) through a pipeline, the gas outlet of the intermediate heat exchanger (19) is connected to the gas inlet of the high-temperature gas-liquid separator (22) through a pipeline, and the gas outlet of the high-temperature gas-liquid separator (22) is connected to the air intake of the high-temperature compressor (1) through a pipeline; The low-temperature refrigeration system comprises a low-temperature compressor (26), the air outlet of the low-temperature compressor (26) is connected to the air inlet of a low-temperature oil-gas separator (27) via a pipeline, the air outlet of the low-temperature oil-gas separator (27) is connected to the air inlet of a fin-tube precooler (28) via a pipeline, the air outlet of the fin-tube precooler (28) is connected to the air inlet of a low-temperature secondary oil-gas separator (33) via a pipeline, the air outlet of the low-temperature secondary oil-gas separator (33) is connected to the air inlet of an intermediate heat exchanger (19) via a pipeline, the liquid outlet of the intermediate heat exchanger (19) is connected to the liquid inlet of a liquid storage device (18) via a pipeline, the liquid outlet of the liquid storage device (18) is connected to the liquid inlet of a low-temperature filter drier (40) via a pipeline, and the liquid outlet of the low-temperature filter drier (40) is connected to the liquid outlet of the low-temperature filter drier (40). The liquid inlet of the regenerator (35) is connected via a pipeline, the liquid outlet of the regenerator (35) is connected via a pipeline to the liquid inlet of the sixth expansion valve (39), the liquid outlet of the sixth expansion valve (39) is connected via a pipeline to the liquid inlet of the low-temperature evaporator (38), the gas outlet of the low-temperature evaporator (38) is connected via a pipeline to the gas inlet of the regenerator (35), the gas outlet of the regenerator (35) is connected via a pipeline to the air intake of the low-temperature compressor (26), the liquid outlet of the low-temperature filter drier (40) is connected via a pipeline to the liquid inlet of the sixth solenoid valve (32), the liquid outlet of the sixth solenoid valve (32) is connected via a pipeline to the liquid inlet of the low-temperature liquid injection expansion valve (30), and the liquid outlet of the low-temperature liquid injection expansion valve (30) is connected via a pipeline to the air intake of the low-temperature compressor (26); The water cooling system comprises a chilled water tank (37), a water outlet of the chilled water tank (37) being connected to a water inlet of a ninth solenoid valve (44) via a pipeline, a water outlet of the ninth solenoid valve (44) being connected to a water inlet of a low-temperature evaporator (38) via a pipeline, a water outlet of the low-temperature evaporator (38) being connected to a first water return port of the chilled water tank (37) via a pipeline, a water outlet of the chilled water tank (37) being connected to a water inlet of an eighth solenoid valve (42) via a pipeline, a water outlet of the eighth solenoid valve (42) being connected to a water inlet of a high-temperature evaporator (15) via a pipeline, and a water outlet of the high-temperature evaporator (15) being connected to a second water return port of the chilled water tank (37) via a pipeline.

2. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 1, characterized in that: The liquid outlet of the high-temperature filter drier (12) is connected to the liquid inlet of the first expansion valve (3) via a pipeline, the liquid outlet of the first expansion valve (3) is connected to the medium-pressure liquid injection port of the high-temperature compressor (1) via a pipeline, the liquid outlet of the high-temperature filter drier (12) is connected to the liquid inlet of the fifth solenoid valve (23) via a pipeline, the liquid outlet end of the fifth solenoid valve (23) is connected to the liquid inlet end of the fifth expansion valve (24) via a pipeline, and the liquid outlet end of the fifth expansion valve (24) is connected to the air intake port of the high-temperature compressor (1) via a pipeline.

3. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 2, characterized in that: The exhaust port of the high-temperature compressor (1) is provided with a pressure maintaining valve (2), and the low-pressure point of the pressure maintaining valve (2) is connected to the suction port of the high-temperature compressor (1) through a pipeline.

4. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 3, characterized in that: The first pressure transmitter (11) is connected to the pipeline connected to the liquid outlet of the high-temperature filter drier (12), the second pressure transmitter (25) is connected to the pipeline connected to the air intake of the high-temperature compressor (1), the fourth pressure transmitter (41) is connected to the liquid inlet of the low-temperature filter drier (40), and the third pressure transmitter (36) is arranged on the pipeline connected to the liquid outlet of the low-temperature evaporator (38).

5. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 4, characterized in that: The air outlet of the fin-tube precooler (28) is connected to the air inlet of a normally open solenoid valve (31) via a pipeline, the air outlet of the normally open solenoid valve (31) is connected to the air inlet of an expansion tank (45) via a pipeline, the air outlet of the expansion tank (45) is connected to the air inlet of a capillary tube (34) via a pipeline, and the air outlet of the capillary tube (34) is connected to the air intake of a low-temperature compressor (26) via a pipeline.

6. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 5, characterized in that: A first exhaust fan (14) is provided on the fin-tube condenser (13), and the first exhaust fan (14) is capable of exhausting air flowing through the fin-tube condenser (13) into the atmosphere. A second exhaust fan (29) is provided on the fin-tube precooler (28), and the second exhaust fan (29) is capable of exhausting air flowing through the fin-tube precooler (28) into the atmosphere.

7. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 6, characterized in that: The oil return port of the high-temperature oil-gas separator (4) is connected to the air intake port of the high-temperature compressor (1) via a pipeline, and a first solenoid valve (5) is provided on the pipeline connected to the oil return port of the high-temperature oil-gas separator (4).

8. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 7, characterized in that: The oil return port of the low-temperature oil-gas separator (27) is connected to the air intake port of the low-temperature compressor (26) via a pipeline, and the oil return port of the low-temperature secondary oil-gas separator (33) is connected to the air intake port of the low-temperature compressor (26) via a pipeline.

9. A hydrogenation machine refrigeration unit with dual operation modes as claimed in claim 8, characterized in that: The water outlet of the freezing water tank (37) is connected to a freezing water pump (43), and the freezing water pump (43) can provide power to allow the freezing water to flow in the pipeline.

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