Lubricating oil circulating system for natural gas screw compressor

Abstract

The utility model discloses a lubricating oil circulation system for a natural gas screw compressor, and belongs to the technical field of compressor lubricating oil circulation. The lubricating oil circulating system comprises a screw compressor and an oil-gas separator, an oil heater is arranged in the oil-gas separator, a three-way temperature control valve is arranged on a lubricating oil discharge pipeline of the oil-gas separator, one output port of the three-way temperature control valve is directly connected to a lubricating oil inlet of the screw compressor, and the other output port of the three-way temperature control valve is directly connected to a lubricating oil outlet of the screw compressor. And the other output port of the three-way temperature control valve is connected with a lubricating oil inlet on the screw compressor through an oil cooler. And through the arrangement of the oil heater, the lubricating oil after oil-gas separation can be heated, so that the oil temperature in the oil-gas separator meets the operation requirement of the screw compressor in a cold climate environment in winter. And the temperature stability of the lubricating oil in the compressor can be further guaranteed through matched use of the three-way temperature control valve and the oil cooler.

Description

Technical Field

[0001] The utility model belongs to the technical field of compressor lubricating oil circulation, and more specifically relates to a lubricating oil circulation system for a natural gas screw compressor. Background Art

[0002] Natural gas is mainly used in natural gas power generation, natural gas chemical industry, urban gas industry and other fields. In the process of natural gas boosting and transportation, the natural gas compressor system is an indispensable and important component, which is used to compress natural gas to a gaseous natural gas with a pressure greater than or equal to 10MPa and not greater than 25MPa, so that the compressed natural gas can be stored in a container.

[0003] Among them, screw compressors have been widely used in natural gas well collection, production increase, pressurization and transportation. During the operation of the screw compressor, the rotating parts need to be filled with lubricating oil. On the one hand, it plays a lubricating role, and on the other hand, it can reduce the temperature to a certain extent, thereby protecting the main operating parts of the compressor and extending its service life.

[0004] However, screw compressors have higher requirements for the temperature of the lubricating oil, especially in cold winter climates. Ensuring the stability of the lubricating oil temperature is important for the normal operation of the screw compressor. Utility Model Content

[0005] The utility model aims to provide a lubricating oil circulation system for a natural gas screw compressor, thereby solving the problem in the prior art that the external environment temperature fluctuation easily affects the normal operation of the screw compressor.

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by the utility model is:

[0007] The utility model provides a lubricating oil circulation system for a natural gas screw compressor, comprising: a screw compressor and an oil-gas separator, wherein the screw compressor is provided with a natural gas inlet, a lubricating oil inlet and an oil-gas mixed outlet, the oil-gas separator is used to separate the lubricating oil from the natural gas, the oil-gas inlet pipeline of the lubricating oil separator is connected to the oil-gas mixed outlet on the screw compressor, and the lubricating oil discharge pipeline of the lubricating oil separator is connected to the lubricating oil inlet on the screw compressor; the oil-gas mixture discharged from the screw compressor is separated into oil and gas by the oil-gas separator, so that the lubricating oil can be recycled.

[0008] The oil-gas separator is provided with an oil heater for heating the lubricating oil after oil-gas separation, thereby effectively ensuring that the oil temperature in the oil-gas separator meets the operating requirements of the screw compressor in a cold winter climate.

[0009] Furthermore, a three-way temperature control valve is provided on the lubricating oil discharge pipeline of the oil-gas separator, one of the output ports of the three-way temperature control valve is directly connected to the lubricating oil inlet port on the screw compressor, and the other output port of the three-way temperature control valve is connected to the lubricating oil inlet port on the screw compressor via an oil cooler. The lubricating oil discharged after being heated by the oil-gas separator is circulated to the compressor, but as the screw main engine runs, the lubricating oil temperature will gradually increase. Therefore, the three-way temperature control valve and the oil cooler are used in conjunction to effectively ensure the stability of the lubricating oil temperature in the compressor, which is conducive to enhancing the lubrication effect of the screw main engine, reducing friction, and extending the operation cycle of the screw main engine.

[0010] Furthermore, the lubricating oil discharge port of the oil-gas separator is also provided with an oil pump, and the oil pump outlet is connected to the three-way temperature control valve. The setting of the oil pump can ensure that there is sufficient oil injection pressure and flow at the screw machine inlet, preventing the fluctuation of the natural gas intake pressure range from affecting the operation of the compressor.

[0011] Furthermore, an oil filter is provided on the lubricating oil discharge pipeline of the oil-gas separator at one side of the output end of the oil cooler, so as to filter the lubricating oil circulating into the compressor.

[0012] Furthermore, the oil filter comprises a first oil filter and a second oil filter which are arranged in parallel, and one oil filter is used and the other is reserved, which is beneficial to ensure the continuous operation of the natural gas screw compressor and improve the working efficiency.

[0013] Furthermore, a ball valve and a differential pressure sensor protection system are provided on one side of the input end of the oil filter.

[0014] Furthermore, a multi-stage oil separation core is provided in the oil-gas separator, thereby improving the oil-gas separation effect.

[0015] Furthermore, the oil-gas separator is provided with a two-stage oil separator core, namely, a second-stage oil separator core and a first-stage oil separator core which are arranged in a package.

[0016] Furthermore, a differential pressure sensor protection system is provided in the oil-gas separator.

[0017] Furthermore, the oil-gas separator is also connected to the screw compressor through an oil return pipeline.

[0018] In summary, the technical solution provided by the utility model can achieve the following beneficial effects compared with the prior art:

[0019] (1) The oil-gas separator of the utility model is equipped with an oil heater, so that the lubricating oil after oil-gas separation can be heated to improve the stability of the lubricating oil temperature and ensure that the oil temperature separated by the oil-gas separator meets the operating requirements of the compressor in the cold winter climate environment.

[0020] (2) The utility model further provides a temperature control valve and an oil cooler on the lubricating oil output pipeline of the oil-gas separator, so that the lubricating oil entering the compressor can be cooled as needed to prevent the lubricating oil temperature from rising due to long-term operation of the compressor, which is beneficial to ensuring the stability of the lubricating oil temperature.

[0021] (3) The utility model sets an oil pump at the lubricating oil outlet of the oil-gas separator, so as to pressurize the lubricating oil entering the screw compressor, eliminate the influence of the fluctuation of the intake pressure range of the screw compressor on the pressure in the inner cavity of the compressor host, ensure that the screw host always has sufficient oil injection pressure and flow, which is beneficial to ensure the life and performance of the host.

[0022] (4) The utility model arranges a double filter on the lubricating oil output pipeline of the oil-gas separator, with one filter used and one spare, which is beneficial to ensure the continuous and normal operation of the compressor; at the same time, a two-stage oil separation core is also arranged in the oil-gas separator, which is beneficial to further improve the oil-gas separation effect, making it safer and more reliable, and ensuring that the final gas oil content is <1PPM. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic structural diagram of a lubricating oil circulation system for a natural gas screw compressor according to an embodiment of the present invention.

[0024] In the attached drawings: 1. screw compressor; 2. oil-gas separator; 301. first throttle; 302. second throttle; 401. first oil return sight glass; 402. second oil return sight glass; 501. first oil return filter; 502. second oil return filter; 601. second oil separator core; 602. first oil separator core; 7. oil heater; 8. oil pump; 9. three-way temperature control valve; 10. oil cooler; 1101. first oil filter; 1102. second oil filter. DETAILED DESCRIPTION

[0025] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the drawings and embodiments.

[0026] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in this utility model without affecting the effects and purposes that can be achieved by the present invention.

[0027] Combination Figure 1The embodiment of the utility model provides a lubricating oil circulation system for a natural gas screw compressor, comprising: a screw compressor 1 and an oil-gas separator 2, wherein the screw compressor is provided with a natural gas inlet, a lubricating oil inlet and an oil-gas mixed outlet, the oil-gas separator 2 is used to separate the lubricating oil from the natural gas, and its oil-gas inlet pipeline is connected to the oil-gas mixed outlet on the screw compressor 1, and its lubricating oil discharge pipeline is connected to the lubricating oil inlet on the screw compressor 1; the oil-gas mixture discharged through the oil-gas mixed outlet of the screw compressor enters the oil-gas separator, and after the oil-gas separation, the lubricating oil re-enters the screw compressor.

[0028] Specifically, in this embodiment, an oil heater 7 is configured in the oil-gas separator 2. The oil heater 7 can heat the lubricating oil after oil and gas separation to ensure the stability of the temperature of the lubricating oil output by the oil-gas separator 2, thereby ensuring that the oil temperature in the oil-gas separator meets the operating requirements of the screw compressor in the cold climate environment in winter.

[0029] As a further improvement of this embodiment, a three-way temperature control valve 9 is provided on the lubricating oil discharge pipeline of the oil-gas separator 2. When the oil temperature is lower than the valve core setting value, one of the output ports of the three-way temperature control valve 9 is directly connected to the lubricating oil inlet on the screw compressor 1. When the oil temperature is higher than the valve core setting value, the other output port of the three-way temperature control valve 9 is connected to the lubricating oil inlet on the screw compressor 1 through the oil cooler 10. With the continuous operation of the screw compressor main engine, the lubricating oil temperature will gradually increase. Therefore, through the combined use of the oil cooler 10 and the temperature control valve, the lubricating oil can be cooled as needed, so that the lubricating oil temperature remains constant, which is conducive to enhancing the lubrication effect of the screw main engine, reducing friction, and extending the operation cycle of the screw main engine. Specifically, a temperature sensor can be set in the screw compressor 1 to monitor the temperature of the lubricating oil in real time. When the temperature is too high, the three-way temperature control valve 9 is controlled to start through the control system, so that the lubricating oil passes through the oil cooler 10 for cooling.

[0030] The natural gas inlet pressure range of the screw compressor often fluctuates greatly, 0-1 MPa. Different inlet pressures will lead to different compressor pressure ratios, and the pressure difference in the inner cavity of the screw main engine is too large, which will lead to the phenomenon of lack of oil lubrication. Therefore, this embodiment is further preferred that the lubricating oil discharge port of the oil-gas separator 2 is also provided with an oil pump 8, and the outlet of the oil pump 8 is connected to the three-way temperature control valve 9. The setting of the oil pump 8 can pressurize the lubricating oil entering the screw compressor, ensure that there is sufficient injection pressure and flow at the screw machine inlet, and ensure the life and performance of the main engine.

[0031] In the embodiment of the utility model, an oil filter is provided on the lubricating oil discharge pipe of the oil-gas separator 2 on one side of the output end of the oil cooler 10, so as to filter the lubricating oil entering the compressor. Further preferably, the oil filter includes a first oil filter 1101 and a second oil filter 1102 arranged in parallel. Through the setting of the double oil filter, one can be used and the other can be reserved, which is conducive to ensuring the continuous operation of the compressor and improving its working efficiency. A ball valve and a differential pressure sensor protection system are provided on one side of the input end of the above-mentioned oil filter. The value transmitted by the differential pressure sensor represents the blockage condition of the oil filter element. When the value is close to the differential pressure alarm value of the filter element, the valves at both ends are closed to replace the first oil filter online, and the ball valve in front of the second oil filter is opened to switch the second oil filter to work.

[0032] More preferably, the oil-gas separator 2 is provided with a multi-stage oil separation core, so that multi-stage oil-gas separation can be performed to ensure its separation effect. Specifically, in this embodiment, the oil-gas separator 2 is provided with a two-stage oil separation core, namely, a second-stage oil separation core 601 and a first-stage oil separation core 602 which are set together.

[0033] The existing oil separation technology is usually a single-stage oil separation core, and the oil content of the gas is <5PPM. Due to the particularity of natural gas, this embodiment designs a double oil separation core for two-stage separation, which is safer and more reliable, and can ensure that the final gas oil content is <1PPM.

[0034] Furthermore, a differential pressure sensor protection system is also provided in the oil-gas separator 2 to ensure its normal operation, wherein the differential pressure value of the oil separator core represents the blockage condition of the oil separator core. The oil-gas separator 2 is also connected to the screw compressor 1 through an oil return pipe. Specifically, the oil return pipe includes a first and a second oil return pipe. The first oil return pipe returns oil from the bottom of the first-stage oil separator core, and the second oil return pipe returns oil from the bottom of the second-stage oil separator core. After being collected, the oil returns to the main inlet of the screw compressor. The first oil return pipe is provided with a first oil return filter 501, a first oil return sight glass 401 and a first throttle 301 in sequence, and the second oil return pipe is provided with a second oil return filter 502, a second oil return sight glass 402 and a first throttle 302 in sequence.

[0035] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A lubricating oil circulation system for a natural gas screw compressor, comprising: A screw compressor (1) and an oil-gas separator (2), wherein the oil-gas separator (2) is used to separate lubricating oil from natural gas, wherein its oil-gas inlet pipeline is connected to the oil-gas mixed outlet on the screw compressor (1), and its lubricating oil discharge pipeline is connected to the lubricating oil inlet on the screw compressor (1); the characteristics are: an oil heater (7) is arranged in the oil-gas separator (2) for heating the lubricating oil after oil-gas separation, and a three-way temperature control valve (9) is arranged on the lubricating oil discharge pipeline of the oil-gas separator (2), one of the output ports of the three-way temperature control valve (9) is directly connected to the lubricating oil inlet on the screw compressor (1), and the other output port of the three-way temperature control valve (9) is connected to the lubricating oil inlet on the screw compressor (1) via an oil cooler (10).

2. The lubricating oil circulation system for a natural gas screw compressor according to claim 1, characterized in that: The lubricating oil discharge port of the oil-gas separator (2) is also provided with an oil pump (8), and the outlet of the oil pump (8) is connected to a three-way temperature control valve (9).

3. The lubricating oil circulation system for a natural gas screw compressor according to claim 2, characterized in that: An oil filter is provided on the lubricating oil discharge pipeline of the oil-gas separator (2) at one side of the output end of the oil cooler (10).

4. The lubricating oil circulation system for a natural gas screw compressor according to claim 3, characterized in that: The oil filter comprises a first oil filter (1101) and a second oil filter (1102) which are arranged in parallel.

5. The lubricating oil circulation system for a natural gas screw compressor according to claim 4, characterized in that: A ball valve and a differential pressure sensor protection system are provided on one side of the input end of the oil filter.

6. The lubricating oil circulation system for a natural gas screw compressor according to any one of claims 1 to 5, characterized in that: The oil-gas separator (2) is provided with a multi-stage oil separation core.

7. The lubricating oil circulation system for a natural gas screw compressor according to claim 6, characterized in that: The oil-gas separator (2) is provided with a two-stage oil separator core, namely, a second-stage oil separator core (601) and a first-stage oil separator core (602) which are arranged in a package.

8. The lubricating oil circulation system for a natural gas screw compressor according to any one of claims 1 to 5, characterized in that: A differential pressure sensor protection system is provided in the oil-gas separator (2).

9. The lubricating oil circulation system for a natural gas screw compressor according to any one of claims 1 to 5, characterized in that: The oil-gas separator (2) is also connected to the screw compressor (1) via an oil return pipeline.

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