A medium pressure oil return device for large transcritical CO2 refrigeration system

Abstract

The present invention provides a medium-pressure oil return device for a large transcritical CO2 refrigeration system, comprising a transcritical CO2 compressor exhaust hot gas pipeline, a transcritical CO2 barrel pump oil return pipeline disposed to the right of the transcritical CO2 compressor exhaust hot gas pipeline, and the device is characterized in that an oil return solenoid valve is threadedly connected to the inner side of the transcritical CO2 barrel pump oil return pipeline, and a heater is installed at the outlet of the transcritical CO2 barrel pump oil return pipeline; the outlet end of the transcritical CO2 compressor exhaust hot gas pipeline is respectively connected to an ejector hot gas solenoid valve, a heater hot gas solenoid valve, and a transcritical CO2 oil collector hot gas pressurization solenoid valve; and the inlet end of the heater is connected to an ejector valve group. The beneficial effects of the present invention are: the arrangement of the ejector valve group, high-pressure CO2 gas interface, oil circuit access port, and mixing outlet facilitates the application of CO2 in large-scale equipment and improves the safety of the oil use process.

Description

Technical Field

[0001] The present invention belongs to the technical field of medium pressure oil return devices in large transcritical CO2 refrigeration systems, and in particular relates to a medium pressure oil return device in a large transcritical CO2 refrigeration system. Background Art

[0002] The higher exhaust temperature and larger temperature glide of the CO2 transcritical cycle gas cooler can match the temperature rise process of the cooling medium. In large-scale CO2 transcritical refrigeration systems, such as ice rinks, a large amount of CO2 refrigerant is required, and the refrigerant contains a large amount of oil. A special oil return device is needed to ensure the safe operation of the refrigeration system. The existing medium-pressure oil return device in large-scale transcritical CO2 refrigeration systems includes oil inlet pipes, oil outlet pipes and compressor units. The medium-pressure oil return process of the current refrigeration system is unstable and cannot meet the oil safety requirements of CO2 in large-scale applications. Summary of the Invention

[0003] In response to the above technical problems, the present invention provides a medium-pressure oil return device for a large transcritical CO2 refrigeration system. Through the oil return port of the CO2 barrel pump, the oil is returned to the oil-gas separator through the oil heating plate with the help of CO2 exhaust and ejector. The separated oil is depressurized and enters the oil reservoir through liquid level control, thereby ensuring the oil supply of the transcritical CO2 compressor unit.

[0004] The technical solution is as follows: a medium-pressure oil return device for a large transcritical CO2 refrigeration system, comprising a transcritical CO2 compressor unit exhaust hot gas pipeline, a transcritical CO2 barrel pump return oil pipeline being provided on the right side of the transcritical CO2 compressor unit exhaust hot gas pipeline, and characterized in that the inner side of the transcritical CO2 barrel pump return oil pipeline is threadedly connected with an oil return solenoid valve, and a heater is installed at the outlet of the transcritical CO2 barrel pump return oil pipeline; the outlet end of the transcritical CO2 compressor unit exhaust hot gas pipeline is respectively connected with an ejector hot gas solenoid valve, a heater hot gas solenoid valve and a transcritical CO2 oil collector hot gas pressurizing solenoid valve; the inlet end pipeline of the heater is connected with an ejector valve group, and the outlet of the heater is respectively connected with an ejector valve group. It is connected to a hot gas flow regulating valve and an oil-gas separator, and an oil-gas separator safety valve is installed on the upper right part of the oil-gas separator; the upper outlet end pipeline of the oil-gas separator is connected to the oil-gas separator pressure relief solenoid valve, the left side of the oil-gas separator is installed with an oil-gas separator oil level gauge, and the outlet end pipeline of the oil-gas separator is connected to the oil-gas separator oil drain valve; the outlet end pipeline of the oil-gas separator oil drain valve is connected to a transcritical CO2 oil collector, and a transcritical CO2 oil collector level gauge is installed on the right side of the transcritical CO2 oil collector; the upper outlet pipeline of the transcritical CO2 oil collector is connected to the transcritical CO2 oil collector pressure relief solenoid valve, and the left outlet pipeline of the transcritical CO2 oil collector is connected to the transcritical CO2 oil collector oil drain solenoid valve.

[0005] Preferably, a high-pressure CO2 gas interface is provided on the right side of the ejector valve group, and an oil circuit access port is provided at the bottom of the ejector valve group; a mixing outlet is provided on the left side inside the ejector valve group.

[0006] Compared with the prior art, the present invention has the following beneficial effects:

[0007] 1. In the present invention, the arrangement of the ejector valve group, high-pressure CO2 gas interface, oil circuit inlet and mixing outlet is conducive to meeting the application of CO2 in large-scale equipment and improving the safety during the oil use process.

[0008] 2. In the present invention, the arrangement of the oil-gas separator, pressure relief pipeline, ejector outlet pipe and oil discharge pipeline is conducive to separating the oil-gas mixture inside the pipeline, improving the stability of the operation of the device and further improving the safety of oil use. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of the present invention.

[0010] Figure 2 It is a structural schematic diagram of the ejector of the present invention.

[0011] Figure 3 It is a structural schematic diagram of the oil-gas separator of the present invention.

[0012] Figure 4 It is a structural diagram of the transcritical CO2 barrel pump system.

[0013] In the picture:

[0014] 1. Exhaust hot gas pipeline of transcritical CO2 compressor unit; 2. Oil return pipeline of transcritical CO2 barrel pump; 3. Oil return solenoid valve; 4. Ejector hot gas solenoid valve; 5. Heater hot gas solenoid valve; 6. Ejector valve group; 7. Heater; 8. Hot gas flow regulating valve; 9. Oil-gas separator safety valve; 10. Oil-gas separator; 11. Oil-gas separator pressure relief solenoid valve; 12. Oil level gauge for oil-gas separator; 13. Oil drain valve for oil-gas separator; 14. Transcritical CO2 oil collector level gauge; 15. Transcritical CO2 oil collector; 16. Transcritical CO2 oil collector pressure relief solenoid valve; 17. Transcritical CO2 oil collector oil drain solenoid valve; 18. Transcritical CO2 oil collector hot gas pressurization solenoid valve; 19. High-pressure CO2 gas interface; 20. Oil line access port 20; 21. Mixing outlet; 22. Pressure relief pipeline; 23. Ejector outlet pipe; 24. Oil drain pipeline. DETAILED DESCRIPTION

[0015] The present invention will be further described below with reference to the accompanying drawings:

[0016] Example:

[0017] As attached Figure 1 As shown, a medium-pressure oil return device for a large transcritical CO2 refrigeration system includes a transcritical CO2 compressor exhaust hot gas pipeline 1, and a transcritical CO2 barrel pump return oil pipeline 2 is provided on the right side of the transcritical CO2 compressor exhaust hot gas pipeline 1. It is characterized in that the inner side of the transcritical CO2 barrel pump return oil pipeline 2 is threadedly connected with an oil return solenoid valve 3, and a heater 7 is installed at the outlet of the transcritical CO2 barrel pump return oil pipeline 2; the outlet end of the transcritical CO2 compressor exhaust hot gas pipeline 1 is respectively connected with an ejector hot gas solenoid valve 4, a heater hot gas solenoid valve 5 and a transcritical CO2 oil collector hot gas pressurizing solenoid valve 18; the inlet end of the heater 7 is connected with an ejector valve group 6, and the outlet of the heater 7 is respectively connected with a hot gas flow regulating valve 8 and an oil-gas separator 10, and the oil-gas separator 10 An oil-gas separator safety valve 9 is installed on the upper right part; the upper outlet end pipeline of the oil-gas separator 10 is connected to the oil-gas separator pressure relief solenoid valve 11, the left side of the oil-gas separator 10 is installed with an oil-gas separator oil level gauge 12, and the outlet end pipeline of the oil-gas separator 10 is connected to the oil-gas separator oil drain valve 13; the outlet end pipeline of the oil-gas separator oil drain valve 13 is connected to the transcritical CO2 oil collector 15, and the right side of the transcritical CO2 oil collector 15 is installed with a transcritical CO2 oil collector level gauge 14; the upper outlet pipeline of the transcritical CO2 oil collector 15 is connected to the transcritical CO2 oil collector pressure relief solenoid valve 16, and the left side outlet pipeline of the transcritical CO2 oil collector 15 is connected to the transcritical CO2 oil collector oil drain solenoid valve 17.

[0018] As attached Figure 3 As shown, in the above embodiment, specifically, the lower part of the oil-gas separator 10 is integrated with a pressure relief pipeline 22, the front end of the oil-gas separator 10 is integrated with an ejector outlet pipe 23, and the lower part of the oil-gas separator 10 is welded with an oil drain pipe 24.

[0019] In the above embodiment, specifically, the inlet end of the heater hot gas solenoid valve 5 is connected to the heater 7 pipeline, and the outlet end of the ejector hot gas solenoid valve 4 is connected to the inlet end of the ejector valve group 6 pipeline.

[0020] In the above embodiment, specifically, the outlet end of the oil return solenoid valve 3 is connected to the ejector valve group 6 via a pipeline, and the port end of the ejector valve group 6 is connected to the heater 7 via a pipeline.

[0021] In the above embodiment, specifically, the upper portion of the transcritical CO2 oil collector pressure relief solenoid valve 16 is connected to the upper pipe of the oil-gas separator pressure relief solenoid valve 11 .

[0022] In the above embodiment, specifically, the outlet end of the transcritical CO2 oil collector hot gas pressurization solenoid valve 18 is connected to the inlet end pipeline of the upper right part of the transcritical CO2 oil collector 15.

[0023] In the above embodiment, specifically, the inlet end of the high-pressure CO 2 gas interface 19 is connected to the outlet end of the oil return solenoid valve 3 via a pipeline.

[0024] In the above embodiment, specifically, the inlet end of the oil circuit access port 20 is connected to the outlet end of the ejector hot gas solenoid valve 4 through a pipeline.

[0025] In the above embodiment, specifically, the outlet end of the mixing outlet 21 is connected to the pipeline of the heater 7 , and the inner side of the mixing outlet 21 is communicated with the inner side of the ejector outlet pipe 23 .

[0026] In the above embodiment, specifically, the inner side of the outlet end of the heater hot gas solenoid valve 5 is communicated with the inner side of the inlet end of the hot gas flow regulating valve 8 .

[0027] The working principle of the present invention is as follows: the system is connected to the transcritical CO2 barrel pump system, which is connected to the transcritical CO2 barrel and the transcritical CO2 compressor unit through pipelines. When the transcritical CO2 barrel pump oil return pipeline 2 returns oil from the CO2 circulation barrel, the oil return solenoid valve 3 is opened, and the hot gas inside the exhaust hot gas pipeline 1 of the transcritical CO2 compressor unit is discharged. The ejector hot gas solenoid valve 4 is opened, and the hot gas and oil pass through the ejector valve group 6 to increase the oil pressure and enter the heater 7. The hot gas and the hot gas from the heater hot gas solenoid valve 5 are heat exchanged in the heater 7 to heat the oil. The heated oil enters the oil-gas separator 10 after being heated and pressurized, and the separated oil is stored in the oil-gas separator 10. The CO2 gas contained in it flows to the suction pipe of the transcritical CO2 compressor unit through the oil-gas separator pressure relief solenoid valve 11. When the oil level in the oil-gas separator 10 reaches the set upper oil level of the oil-gas separator oil level gauge 12, the oil-gas separator pressure relief solenoid valve 11 is closed, the pressure of the oil-gas separator 10 is increased, the oil-gas separator oil drain valve 13 is opened, and the oil enters the transcritical CO2 oil collector storage 15. When the transcritical CO2 oil collector level gauge 14 detects that the oil level reaches the set oil level upper limit, the transcritical CO2 oil collector pressure relief solenoid valve 16 is closed, the transcritical CO2 oil collector hot gas pressurization solenoid valve 18 is opened, and the transcritical CO2 oil collector oil drain solenoid valve 17 is opened, and the oil enters the transcritical CO2 compressor unit, ensuring oil lubrication of the transcritical CO2 compressor unit.

[0028] Utilizing the technical solution described in the present invention, or those skilled in the art designing similar technical solutions inspired by the technical solution of the present invention to achieve the above technical effects, all fall within the scope of protection of the present invention.

Claims

1. A medium pressure oil return device for a large transcritical CO2 refrigeration system, comprising a transcritical CO2 compressor exhaust hot gas pipeline (1), a transcritical CO2 barrel pump oil return pipeline (2) being provided on the right side of the transcritical CO2 compressor exhaust hot gas pipeline (1), and characterized in that: The inner side of the transcritical CO2 barrel pump oil return pipe (2) is threadedly connected to an oil return solenoid valve (3), and a heater (7) is installed at the outlet of the transcritical CO2 barrel pump oil return pipe (2); the outlet end of the transcritical CO2 compressor unit exhaust hot gas pipe (1) is respectively connected to an ejector hot gas solenoid valve (4), a heater hot gas solenoid valve (5) and a transcritical CO2 oil collector hot gas pressurizing solenoid valve (18); the inlet end of the heater (7) is connected to an ejector valve group (6), and the outlet of the heater (7) is respectively connected to a hot gas solenoid valve (4), a heater hot gas solenoid valve (5) and a transcritical CO2 oil collector hot gas pressurizing solenoid valve (18). A flow regulating valve (8) and an oil-gas separator (10), and an oil-gas separator safety valve (9) is installed on the upper right part of the oil-gas separator (10); the upper outlet pipe of the oil-gas separator (10) is connected to an oil-gas separator pressure relief solenoid valve (11), the left side of the oil-gas separator (10) is installed with an oil-gas separator oil level gauge (12), the outlet pipe of the oil-gas separator (10) is connected to an oil-gas separator oil drain valve (13); the outlet pipe of the oil-gas separator oil drain valve (13) is connected to a transcritical CO2 oil collector (15), and the transcritical CO2 oil collector (15) is connected to the oil-gas separator (10). A transcritical CO2 oil collector level gauge (14) is installed on the right side of the O2 oil collector (15); a transcritical CO2 oil collector pressure relief solenoid valve (16) is connected to the pipe at the upper outlet of the transcritical CO2 oil collector (15); a transcritical CO2 oil collector oil discharge solenoid valve (17) is connected to the pipe at the left outlet of the transcritical CO2 oil collector (15); a high-pressure CO2 gas interface (19) is provided on the right side of the ejector valve group (6), and an oil circuit access port (20) is provided at the lower part of the ejector valve group (6); the interior of the ejector valve group (6) A mixing outlet (21) is provided on the left side; the inlet end of the heater hot gas solenoid valve (5) is connected to the heater (7) pipeline, and the outlet end of the ejector hot gas solenoid valve (4) is connected to the inlet end pipeline of the ejector valve group (6); the outlet end of the return oil solenoid valve (3) is connected to the ejector valve group (6) pipeline, and the port end of the ejector valve group (6) is connected to the heater (7) pipeline; the outlet end of the transcritical CO2 oil collector hot gas pressurization solenoid valve (18) is connected to the inlet end pipeline of the upper right part of the transcritical CO2 oil collector (15).

2. The medium pressure oil return device for a large transcritical CO2 refrigeration system according to claim 1, characterized in that: Specifically, the lower portion of the oil-gas separator (10) is integrally provided with a pressure relief pipeline (22), the front end of the oil-gas separator (10) is integrally installed with an ejector outlet pipe (23), and the lower portion of the oil-gas separator (10) is welded with an oil drain pipeline (24).

3. The medium pressure oil return device for a large transcritical CO2 refrigeration system according to claim 1, characterized in that: The upper portion of the transcritical CO2 oil collector pressure relief solenoid valve (16) is connected to the upper pipe of the oil-gas separator pressure relief solenoid valve (11).

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