Dry gas sealing system of compressor

Abstract

The utility model discloses a dry gas sealing system of a compressor. The gas outlet end of a low-pressure nitrogen pipeline is respectively communicated with a primary sealing gas inlet and a secondary sealing gas inlet of the compressor through pipelines; an air outlet of the compressor is communicated with an air inlet of the filter through a pipeline, an air outlet of the filter is communicated with an air inlet of the dryer through a pipeline, and an air outlet of the dryer is communicated with a primary sealing air inlet of the compressor through a pipeline. The system has the advantages that after the system operates stably, the mixed gas is used as the primary sealing gas of the compressor, so that the purity of the mixed gas entering the synthesis tower can meet the process requirement; sealing gas can be filtered and dried through the filter and the dryer, so that the service life of a sealing piece is prolonged, and stable operation of a dry gas sealing system is guaranteed; by adjusting the opening degree of the adjusting valve, it can be ensured that the pressure difference between first-stage sealing gas and medium gas in the cylinder body is controlled to be 0.2 Mpa, and the sealing effect is ensured.

Description

Technical field:

[0001] The utility model relates to the field of compressors, in particular to a compressor dry gas sealing system. Background technology:

[0002] In the process of synthetic ammonia, the nitrogen sent from the previous process is mixed with the hydrogen sent from the previous process in proportion, and then the hydrogen-nitrogen mixture needs to be pressurized by the synthesis gas compressor and sent to the synthesis tower. In order to prevent the process gas in the synthesis gas compressor from leaking, it will be sealed by a sealing structure. Commonly used sealing structures include labyrinth seals, floating ring oil film seals, mechanical contact seals and dry seals. Compared with mechanical contact seals and floating ring oil film seals, dry gas seals have the advantages of less leakage, less wear, longer service life, lower energy consumption, simple and reliable operation, etc. Therefore, at present, dry gas seals are often used to seal synthesis gas compressors.

[0003] However, dry gas sealing has high requirements for sealing gas. Impurities or moisture carried in the sealing gas will cause blockage or corrosion of the seal, affecting the service life of the seal and the operating stability of the entire system. In addition, the current sealing gas mostly uses inert gas, but this will cause the purity of the process gas to decrease, which will in turn affect subsequent processes. Utility model content:

[0004] In order to solve the above problems, the purpose of the utility model is to provide a compressor dry gas sealing system.

[0005] The utility model is implemented by the following technical solutions:

[0006] A compressor dry gas sealing system comprises a nitrogen source, a hydrogen source, a gas mixer, a compressor and a low-pressure nitrogen pipeline;

[0007] The gas outlets of the nitrogen source and the hydrogen source are both connected to the gas inlet of the gas mixer through pipelines, and the gas outlet of the gas mixer is connected to the gas inlet of the compressor;

[0008] The outlet end of the low-pressure nitrogen pipeline is connected to the primary sealing gas and secondary sealing gas inlets of the compressor through pipelines respectively; the air outlet of the compressor is connected to the air inlet of the filter through a pipeline, the air outlet of the filter is connected to the air inlet of the dryer through a pipeline, and the air outlet of the dryer is connected to the primary sealing gas inlet of the compressor through a pipeline;

[0009] A switching valve is provided on the pipeline connecting the compressor outlet and the filter; a first pressure sensor is provided at the compressor outlet, a signal output end of the first pressure sensor is signal-connected to a signal input end of a controller, and a signal output end of the controller is signal-connected to a signal input end of the switching valve.

[0010] Furthermore, a second pressure sensor is provided at the first-level sealing gas inlet of the compressor, a third pressure sensor is provided in the compressor cylinder body, and a flow regulating valve is provided at the first-level sealing gas inlet of the compressor; the signal output ends of the second pressure sensor and the third pressure sensor are both signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the flow regulating valve.

[0011] Furthermore, the primary sealing gas outlet of the compressor is connected to the isolation gas inlet of the compressor through a pipeline.

[0012] Advantages of the utility model:

[0013] After the system is running stably, the mixed gas is used as the primary sealing gas of the compressor, so as to ensure that the purity of the mixed gas entering the synthesis tower meets the process requirements, thereby ensuring the stable operation of the synthesis section; the sealing gas can be filtered and dried through the filter and dryer, thereby extending the life of the seal and ensuring the stable operation of the dry gas sealing system; the pressure difference between the primary sealing gas and the medium gas in the cylinder can be controlled at 0.2Mpa by adjusting the opening size of the regulating valve; the primary sealing gas discharged from the primary sealing gas outlet of the compressor is used as isolation gas, so that the primary sealing gas can be reused, thereby reducing the use of inert gas. Description of the drawings:

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 Schematic diagram of system connection of this embodiment;

[0016] Figure 2 Schematic diagram of signal control principle of this embodiment.

[0017] In the figure: nitrogen source 1, hydrogen source 2, gas mixer 3, compressor 4, filter 5, dryer 6, low-pressure nitrogen pipeline 7, first pressure sensor 8, second pressure sensor 9, third pressure sensor 10, controller 11, switching valve 12, flow regulating valve 13. Specific implementation method:

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0019] Embodiment 1:

[0020] like Figure 1 , 2 A compressor dry gas sealing system shown includes a nitrogen source 1, a hydrogen source 2, a gas mixer 3, a compressor 4 and a low-pressure nitrogen pipeline 7;

[0021] The gas outlets of the nitrogen source 1 and the hydrogen source 2 are both connected to the gas inlet of the gas mixer 3 through pipelines, and the gas outlet of the gas mixer 3 is connected to the gas inlet of the compressor 4;

[0022] The outlet end of the low-pressure nitrogen pipeline 7 is connected to the primary sealing gas and secondary sealing gas inlets of the compressor 4 through pipelines respectively; the outlet of the compressor 4 is connected to the air inlet of the filter 5 through a pipeline, the outlet of the filter 5 is connected to the air inlet of the dryer 6 through a pipeline, and the outlet of the dryer 6 is connected to the primary sealing gas inlet of the compressor 4 through a pipeline; the primary sealing gas outlet of the compressor 4 is connected to the isolation gas inlet of the compressor 4 through a pipeline.

[0023] A switching valve 12 is provided on the pipeline connecting the air outlet of the compressor 4 and the filter 5; a first pressure sensor 8 is provided at the air outlet of the compressor 4, and the signal output end of the first pressure sensor 8 is signal-connected to the signal input end of the controller 11, and the signal output end of the controller 11 is signal-connected to the signal input end of the switching valve 12.

[0024] A second pressure sensor 9 is provided at the primary sealing gas inlet of the compressor 4, a third pressure sensor 10 is provided in the cylinder body of the compressor 4, and a flow regulating valve 13 is provided at the primary sealing gas inlet of the compressor 4; the signal output ends of the second pressure sensor 9 and the third pressure sensor 10 are both signal-connected to the signal input ends of the controller 11, and the signal output end of the controller 11 is signal-connected to the signal input end of the flow regulating valve 13.

[0025] Job Description:

[0026] At the initial stage of system start-up, the nitrogen provided by the low-pressure nitrogen pipeline 7 can be used as the sealing gas for the primary and secondary seals of the compressor 4; when the first pressure sensor 8 detects that the mixed gas pressure at the outlet of the compressor 4 reaches 3.6MPa, the switching valve 12 is opened to use the mixed gas as the primary sealing gas of the compressor 4, so as to ensure that the purity of the mixed gas entering the synthesis tower meets the process requirements, thereby ensuring the stable operation of the synthesis section.

[0027] At the same time, the filter 5 and the dryer 6 can prevent impurities and moisture from clogging and corroding the seal, thereby extending the life of the seal and ensuring the stable operation of the dry gas sealing system.

[0028] The pressure difference between the primary sealing gas and the medium gas in the cylinder can be monitored by the second pressure sensor 9 and the third pressure sensor 10, and the pressure difference between the two can be controlled within 0.2 MPa by adjusting the opening of the regulating valve.

[0029] By using the primary sealing gas discharged from the primary sealing gas outlet of the compressor 4 as isolation gas, the primary sealing gas can be reused, thereby reducing the use of inert gas.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A compressor dry gas sealing system, characterized in that: It includes a nitrogen source, a hydrogen source, a gas mixer, a compressor and a low-pressure nitrogen pipeline; The gas outlets of the nitrogen source and the hydrogen source are both connected to the gas inlet of the gas mixer through pipelines, and the gas outlet of the gas mixer is connected to the gas inlet of the compressor; The outlet end of the low-pressure nitrogen pipeline is connected to the primary sealing gas and secondary sealing gas inlets of the compressor through pipelines respectively; the air outlet of the compressor is connected to the air inlet of the filter through a pipeline, the air outlet of the filter is connected to the air inlet of the dryer through a pipeline, and the air outlet of the dryer is connected to the primary sealing gas inlet of the compressor through a pipeline; A switching valve is provided on the pipeline connecting the compressor outlet and the filter; a first pressure sensor is provided at the compressor outlet, a signal output end of the first pressure sensor is signal-connected to a signal input end of a controller, and a signal output end of the controller is signal-connected to a signal input end of the switching valve.

2. A compressor dry gas seal system according to claim 1, characterized in that: A second pressure sensor is provided at the first-level sealing gas inlet of the compressor, a third pressure sensor is provided in the compressor cylinder body, and a flow regulating valve is provided at the first-level sealing gas inlet of the compressor; the signal output ends of the second pressure sensor and the third pressure sensor are both connected to the signal input end of the controller, and the signal output end of the controller is connected to the signal input end of the flow regulating valve.

3. A compressor dry gas seal system according to claim 1, characterized in that: The primary sealing gas outlet of the compressor is connected to the isolation gas inlet of the compressor through a pipeline.

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