Exhaust pipeline control system for natural gas screw compressor

Abstract

The utility model discloses an exhaust pipeline control system for a natural gas screw compressor, and belongs to the technical field of natural gas compression. According to the exhaust pipeline control system for the natural gas screw compressor, an oil-gas mixed exhaust port of the screw compressor is connected to an oil-gas separator through a pipeline, a cooler and a gas-liquid separator are sequentially arranged on an exhaust pipeline of the oil-gas separator, on one hand, the exhaust pipeline of the gas-liquid separator is connected to a rear-end pipe network, and on the other hand, the exhaust pipeline of the gas-liquid separator is connected to a rear-end pipe network. And on the other hand, the air inlet pipeline is connected to the screw compressor through the self-operated pressure regulating valve and the first circulating pipeline. The exhaust pipeline control system of the screw compressor is optimally designed, so that the exhaust pressure stability of an exhaust pipe network can be effectively improved, and the operation stability and safety of the whole compressor system are guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of natural gas compression, and more specifically, relates to an exhaust pipeline control system for a natural gas screw compressor. Background Technique

[0002] Natural gas is mainly applied in fields such as natural gas power generation, natural gas chemical industry, and urban gas utilities. During 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 into gaseous natural gas with a pressure greater than or equal to 10 MPa and not greater than 25 MPa, so as to be able to store the compressed natural gas in a container.

[0003] At present, the collection, production increase, boosting, and transportation methods of natural gas wells are all to reduce the wellhead back pressure of natural gas through a boosting compressor, and then boost the natural gas and transport it to the pipeline network to achieve the purpose of production increase. With the increasingly wide application of screw compressor systems in industrial production, screw compressors have been widely used in the collection, production increase, boosting, and transportation of natural gas wells. Among them, ensuring the stability of the compressor exhaust pressure is of great significance. In addition, after natural gas is compressed into high-pressure gas by a screw compressor, its exhaust temperature will rise to a high temperature, which is easy to cause scalding and affect the subsequent use. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an exhaust pipeline control system for a natural gas screw compressor. By optimizing the design of the exhaust pipeline control system of the screw compressor, the exhaust pressure stability of the exhaust pipeline network can be effectively improved, and further, the operation stability and safety of the entire compressor system can be ensured.

[0005] To achieve the above purpose, the technical solution provided by the utility model is as follows:

[0006] The utility model provides an exhaust pipeline control system for a natural gas screw compressor. The oil-gas mixed discharge port of the screw compressor is connected to an oil-gas separator through a pipeline. A cooler and a gas-liquid separator are successively arranged on the exhaust pipeline of the oil-gas separator. One aspect of the exhaust pipeline of the gas-liquid separator is connected to the subsequent pipeline network, and the other aspect is connected to the intake pipeline of the screw compressor through a self-operated pressure regulating valve and a first circulation pipeline.

[0007] Furthermore, a pressure sensor is arranged on the exhaust pipeline of the gas-liquid separator, and the self-operated pressure regulating valve is in interlock control with the pressure sensor.

[0008] Furthermore, a manual ball valve is connected in parallel with the self-operated pressure regulating valve.

[0009] Furthermore, the exhaust pipeline of the gas-liquid separator is also connected to the intake end of the screw compressor through a second circulation pipeline, and a solenoid valve and a pneumatic two-piece / three-piece unit are provided on the second circulation pipeline.

[0010] Furthermore, the exhaust pipeline of the cooler is also connected to the evacuation pipeline through a relief pipeline, and a solenoid valve is provided on the relief pipeline.

[0011] Furthermore, safety valves are provided on both the oil-gas separator and the gas-liquid separator, and the outlets of the safety valves are connected to the evacuation pipeline through pipelines.

[0012] Furthermore, pressure sensors, liquid level sensors, and differential pressure transmitters are provided on both the oil-gas separator and the gas-liquid separator.

[0013] Furthermore, a filter element and a mist eliminator are provided inside the oil-gas separator, and a mist eliminator is provided inside the gas-liquid separator.

[0014] Furthermore, a minimum pressure valve is provided on the exhaust pipeline of the gas-liquid separator.

[0015] Adopting the technical solution provided by the present utility model, compared with the prior art, the following beneficial effects can be achieved:

[0016] (1) In the present utility model, the oil-gas mixed discharge port of the screw compressor is connected to the oil-gas separator through a pipeline. The exhaust pipeline of the oil-gas separator is successively provided with a cooler and a gas-liquid separator. Through the settings of the cooler and the gas-liquid separator, the compressed gas after oil-gas separation can be cooled and temperature-reduced and gas-liquid separation operations can be carried out in sequence, thereby preventing scalding or corrosion of the backend pipe network, and further facilitating ensuring the normal use of the terminal working conditions and the service life of the entire set of equipment. At the same time, the exhaust pipeline of the gas-liquid separator is also connected to the intake pipeline of the screw compressor through a self-operated pressure regulating valve and a first circulation pipeline, so that the automatic opening of the self-operated pressure regulating valve can be controlled according to the gas pressure in the exhaust pipe network, which is beneficial to ensuring the stability of the exhaust pressure.

[0017] (2) In the present utility model, a manual ball valve is also connected in parallel with the self-operated pressure regulating valve, so the adjustment of the exhaust pressure can also be directly controlled manually; furthermore, the exhaust pipeline of the gas-liquid separator is also connected to the intake end of the screw compressor through a second circulation pipeline, and part of the exhaust is circulated to the screw compressor, thereby realizing the overflow of the compressed gas and reducing the power of the main motor.

[0018] (3) The present utility model further provides a discharge pipeline on the exhaust pipeline of the cooler, so that automatic discharge can be controlled according to the magnitude of the exhaust pressure, which is beneficial to further ensure the stability of the exhaust pressure. That is to say, through the cooperation of the following three components, the present utility model can achieve triple protection of the pipeline network pressure for the high-pressure gas compressed by the screw compressor: safety valve, discharge pipeline and self-acting pressure regulating valve. Brief Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the screw compressor exhaust system according to an embodiment of the present utility model;

[0020] In the figure: 1, screw compressor; 2, oil-gas separator; 201, filter element; 202, mist eliminator; 3, oil heater; 4, safety valve; 5, cooler; 6, gas-liquid separator; 7, minimum pressure valve; 8, solenoid valve; 9, self-acting pressure regulating valve; 10, manual ball valve; 11, discharge pipeline; 12, evacuation pipeline; 13, first circulation pipeline; 14, second circulation pipeline. Detailed Embodiment

[0021] To further understand the content of the present utility model, the present utility model will be described in detail below with reference to the drawings and embodiments.

[0022] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limited conditions for the implementation of the present invention. Therefore, they do not have technical substance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the efficacy that the present invention can produce and the purpose that can be achieved, should still fall within the scope that the technical content disclosed by the present utility model can cover. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not used to limit the scope of implementation. The change or adjustment of their relative relationship, without substantial change of the technical content, should also be regarded as the scope that the present invention can implement.

[0023] In addition, the terms "installation", "setting", "provided with", "connection" referred to in this application should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] Such as Figure 1As shown in the figure, the embodiment of the present utility model provides an exhaust pipeline control system for a natural gas screw compressor. The oil-gas mixed discharge port of the screw compressor 1 is connected to an oil-gas separator 2 through a pipeline, and the separation of compressed natural gas and lubricating oil is achieved through the oil-gas separator 2. The natural gas is compressed by the screw compressor into a high-pressure gas, and its exhaust temperature will rise to a high temperature, which is likely to cause scalding and affect the subsequent use. Therefore, in the embodiment of the present utility model, a cooler 5 is provided on the exhaust pipeline of the oil-gas separator 2, so as to cool down the high-temperature compressed gas. After being cooled down by the cooler 5, the natural gas is easily mixed with liquid condensate. If not separated, it will cause corrosion of the subsequent pipeline network, greatly reducing the service life of the entire set of equipment. At the same time, the high water content in the compressed gas will also affect the use of the terminal working conditions. Therefore, in the embodiment of the present utility model, a gas-liquid separator 6 is further provided at the rear end of the cooler 5, so as to effectively separate the liquid condensate generated by the cooled gas.

[0025] As one implementation method, a filter element 201 and a mist eliminator 202 are provided inside the oil-gas separator 2, and a mist eliminator is provided inside the gas-liquid separator 6. After the compressed oil-gas mixture enters the oil-gas separator 2, the lubricating oil in it is effectively removed by the mist eliminator 202 first, and then discharged after further filtration by the filter element 201. It should be noted that other existing structures can also be adopted for the oil-gas separator 2 and the gas-liquid separator 6, as long as the purpose of the present utility model can be achieved. In order to heat the lubricating oil after oil-gas separation to ensure the stability of the output lubricating oil temperature of the oil-gas separator 2, in some embodiments, an oil heater 3 is provided on the oil-gas separator 2, so as to ensure that the oil temperature in the oil-gas separator meets the operating requirements of the screw compressor in the cold climate in winter.

[0026] Furthermore, pressure sensors, liquid level sensors and differential pressure transmitters are provided on both the oil-gas separator 2 and the gas-liquid separator 6, and solenoid valves are provided on the corresponding drain pipes. The solenoid valves are in interlock control with the corresponding liquid level sensors, so that the liquid level can be monitored in real time through the liquid level sensors and fed back to the control system (such as PLC). When the liquid level reaches the discharge position, the solenoid valves are automatically opened, so as to achieve the rapid discharge of water / oil, ensure the dryness of the compressed gas, effectively ensure the service life and safety of the entire set of equipment, but manual operation of the discharge can also be carried out.

[0027] To effectively ensure the stability of the gas pressure in the exhaust network, the exhaust pipeline of the gas-liquid separator 6 is connected to the back-end pipeline network for use by terminal equipment on the one hand, and is connected to the intake pipe 101 of the screw compressor 1 on the other hand via a self-operated pressure regulating valve 9 and a first circulation pipeline 13. A pressure sensor is provided on the exhaust pipeline of the gas-liquid separator 6. The self-operated pressure regulating valve 9 is interlocked with the pressure sensor. When the pressure sensor detects that the exhaust pressure is high, the self-operated pressure regulating valve 9 is automatically opened to adjust the exhaust pressure. Furthermore, the self-operated pressure regulating valve 9 is connected in parallel with a manual ball valve 10, so that the exhaust pressure can also be adjusted manually.

[0028] In some embodiments, the exhaust pipe of the gas-liquid separator 6 is also connected to the air inlet end of the screw compressor 1 through the second circulation pipe 14, and the second circulation pipe 14 is provided with a solenoid valve 8 and a gas source double / triplet, so as to effectively compress the gas overflow and reduce the power of the main motor.

[0029] As a preferred embodiment of any control system of the present invention, the exhaust line of the cooler 5 is further connected to the drain line 12 via a discharge line 11. A solenoid valve is installed on the discharge line 11, which is interlocked with a pressure sensor on the exhaust network. The pressure sensor transmits real-time pressure, allowing the PLC to automatically control the discharge line 11 based on the pressure to ensure stable exhaust pressure.

[0030] Preferably, to ensure the safety of the exhaust pipeline, a safety valve 4 is provided on both the oil-gas separator 2 and the gas-liquid separator 6, the outlet of which is connected via a pipe to the exhaust pipeline 12. As a further preferred embodiment, a minimum pressure valve 7 is provided on the exhaust pipeline of the gas-liquid separator 6 (i.e., the exhaust pipeline of the entire system), thereby ensuring that the exhaust system establishes a minimum tank pressure and reducing the operating load of the main engine.

[0031] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the inventive purpose of the present invention, designs a structure and embodiment similar to the technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. An exhaust pipeline control system for a natural gas screw compressor, characterized in that, The oil-gas mixture discharge port of the screw compressor (1) is connected to the oil-gas separator (2) through a pipeline. A cooler (5) and a gas-liquid separator (6) are successively arranged on the exhaust pipeline of the oil-gas separator (2). The exhaust pipeline of the gas-liquid separator (6) is connected to the backend pipeline network on the one hand, and on the other hand, it is connected to the intake pipeline (101) of the screw compressor (1) through a self-operated pressure regulating valve (9) and a first circulation pipeline (13).

2. The exhaust pipe control system for a natural gas screw compressor according to claim 1, wherein A pressure sensor is arranged on the exhaust pipeline of the gas-liquid separator (6), and the self-operated pressure regulating valve (9) is in interlocking control with the pressure sensor.

3. The exhaust gas pipeline control system for a natural gas screw compressor according to claim 2, characterized in that, A manual ball valve (10) is connected in parallel with the self-operated pressure regulating valve (9).

4. The exhaust pipe control system for a natural gas screw compressor according to any one of claims 1-3, characterized in that The exhaust pipeline of the gas-liquid separator (6) is also connected to the intake end of the screw compressor (1) through a second circulation pipeline (14), and a solenoid valve (8) and an air source duplex / triplex unit are arranged on the second circulation pipeline (14).

5. The exhaust gas pipeline control system for a natural gas screw compressor according to any one of claims 1-3, characterized in that, The exhaust pipeline of the cooler (5) is also connected to the evacuation pipeline (12) through a relief pipeline (11), and a solenoid valve is arranged on the relief pipeline (11).

6. The exhaust gas pipeline control system for a natural gas screw compressor according to any one of claims 1-3, characterized in that Safety valves (4) are arranged on both the oil-gas separator (2) and the gas-liquid separator (6), and the outlets of the safety valves (4) are connected to the evacuation pipeline (12) through pipelines.

7. The exhaust gas pipeline control system for a natural gas screw compressor according to any one of claims 1-3, characterized in that, Pressure sensors, liquid level sensors and differential pressure transmitters are arranged on both the oil-gas separator (2) and the gas-liquid separator (6).

8. The exhaust pipeline control system for a natural gas screw compressor according to any one of claims 1-3, characterized in that, A filter element (201) and a mist eliminator net (202) are arranged inside the oil-gas separator (2), and a mist eliminator net is arranged inside the gas-liquid separator (6).

9. The exhaust gas pipeline control system for a natural gas screw compressor according to any one of claims 1-3, characterized in that, A minimum pressure valve (7) is arranged on the exhaust pipeline of the gas-liquid separator (6).

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