Dry gas seal protection system of low-pressure centrifugal compressor unit

Abstract

The utility model discloses a dry gas seal protection system for a low-pressure centrifugal compressor unit. A low-pressure nitrogen pipe network gas source is connected with a low-pressure nitrogen storage tank; the medium-pressure nitrogen pipe network gas source is connected with a medium-pressure nitrogen storage tank; the low-pressure nitrogen storage tank is connected with a low-pressure nitrogen source pipeline, and the medium-pressure nitrogen storage tank is connected with a medium-pressure nitrogen source pipeline; a connecting pipeline is arranged between the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline; and a self-operated pressure reducing valve is mounted on the connecting pipeline. The system is carried out according to the following steps that the purpose of protecting the dry gas seal is achieved by additionally arranging a medium-pressure nitrogen storage tank, a low-pressure nitrogen storage tank, a gas source pipeline and a booster pump, the running stability of the dry gas seal is improved, and the service life of the dry gas seal is prolonged. Due to the arrangement of the self-operated pressure reducing valve and the pipeline, the pressure of the secondary seal and the pressure of the isolated seal gas source are effectively improved, the purpose of preventing oil mist from polluting the end face of the dry gas seal is achieved, the service life of the dry gas seal is prolonged, and the emergency shutdown risk of the system caused by dry gas seal faults is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to chemical centrifugal compressor unit technical field, concretely relates to a low pressure centrifugal compressor unit dry gas seal protection system. BACKGROUND

[0002] In synthetic ammonia process, ammonia compressor mainly is applied to ammonia refrigeration system, with gas ammonia as compressed refrigeration medium to reach the purpose of ammonia refrigeration, and provides cold quantity to purification device and synthetic ammonia device for use.

[0003] The ammonia compressor unit is a centrifugal compressor unit, and the cylinder body of the unit is sealed in a dry gas sealing mode. During the operation of the ammonia compressor, the low pressure of the low pressure nitrogen gas source affects the pressure of the secondary seal and the isolation gas seal, so that the lubricating oil cannot be effectively isolated, the oil mist enters the dry gas seal to contaminate the end face, and the primary seal is contaminated by the liquid drops condensed by the residual gas on the end face after the air separation device is stopped, so that the primary seal is invalid. SUMMARY

[0004] In view of the above technical problems, the utility model provides a low pressure centrifugal compressor unit dry gas seal protection system, which achieves the purpose of protecting the dry gas seal by increasing the medium pressure and low pressure nitrogen gas storage tanks, one-way gas source pipelines and booster pumps, and improves the operation stability and service life of the dry gas seal.

[0005] To solve the above technical problems, the utility model provides a low pressure centrifugal compressor unit dry gas seal protection system, and low pressure nitrogen gas pipe network gas source is connected with low pressure nitrogen gas storage tank;

[0006] The medium pressure nitrogen gas pipe network gas source is connected with the medium pressure nitrogen gas storage tank.

[0007] The low pressure nitrogen gas storage tank is connected with the low pressure nitrogen gas source pipeline, and the medium pressure nitrogen gas storage tank is connected with the medium pressure nitrogen gas source pipeline.

[0008] A connecting pipeline is arranged between the medium pressure nitrogen gas source pipeline and the low pressure nitrogen gas source pipeline; and a self-operated pressure reducing valve is installed on the connecting pipeline.

[0009] The low pressure nitrogen gas source pipeline is also connected with the isolation seal assembly.

[0010] The medium pressure nitrogen gas source pipeline is also connected with the dry gas seal primary seal assembly.

[0011] A low pressure nitrogen gas first valve is arranged on the low pressure nitrogen gas source pipeline, and the low pressure nitrogen gas first valve is connected with the check valve.

[0012] A low pressure nitrogen gas second valve is arranged on the connecting pipeline of the low pressure nitrogen gas source pipeline and the isolation seal assembly, and the low pressure nitrogen gas second valve is connected with the low pressure nitrogen gas ball valve.

[0013] The medium-pressure nitrogen first valve is arranged on the medium-pressure nitrogen gas source pipeline;

[0014] The medium-pressure nitrogen second valve is arranged on the connecting pipeline between the medium-pressure nitrogen gas source pipeline and the isolation sealing assembly.

[0015] The self-operated pressure reducing valve on the connecting pipeline is provided with a self-operated pressure reducing valve front first valve and a self-operated pressure reducing valve front second valve at one end and a self-operated pressure reducing valve rear first valve and a self-operated pressure reducing valve rear second valve at the other end.

[0016] The self-operated pressure reducing valve on the connecting pipeline is connected with the booster pump through a pipeline and forms a closed loop pipeline, and the booster pump is provided with a booster pump rear hand valve and a booster pump front hand valve at two ends.

[0017] The low-pressure nitrogen storage tank top is connected with a low-pressure nitrogen storage tank safety valve;

[0018] The medium-pressure nitrogen storage tank top is connected with a medium-pressure nitrogen storage tank safety valve;

[0019] The connecting pipeline between the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline is provided with a field pressure gauge.

[0020] The low-pressure centrifugal compressor set dry gas seal protection system provided by the utility model, low-pressure nitrogen pipe network gas source enters low-pressure nitrogen storage tank, pressure control is at 0.3-0.45MPa, the storage tank is provided with a field pressure gauge for monitoring, the storage tank top is provided with a safety valve, and the safety valve jumps when reaching the designed setting pressure, preventing the storage tank from overpressure. The low-pressure nitrogen storage tank outlet is combined with the nitrogen gas source from the self-operated pressure reducing valve through a low-pressure nitrogen first valve and a check valve, and then enters the dry gas seal secondary seal and isolation sealing assembly through a low-pressure nitrogen second valve and a low-pressure nitrogen ball valve. Medium-pressure nitrogen pipe network gas source enters medium-pressure nitrogen storage tank, pressure control is at 5.0-6.8MPa, the storage tank is provided with a remote pressure gauge for monitoring, the storage tank top is provided with a safety valve, and the safety valve jumps when reaching the designed setting pressure, preventing the storage tank from overpressure. The medium-pressure nitrogen storage tank outlet is divided into two streams after a medium-pressure nitrogen first valve, the first stream is reduced to 0.3-0.4MPa through a self-operated pressure reducing valve front first valve and a self-operated pressure reducing valve front second valve, and then enters the dry gas seal secondary seal and isolation sealing assembly together with the low-pressure nitrogen pipe network gas source through a self-operated pressure reducing valve rear first valve and a self-operated pressure reducing valve rear second valve; the second stream enters the dry gas seal primary seal assembly through a medium-pressure nitrogen second valve.

[0021] Preferably, the self-operated pressure reducing valve is provided with a low-pressure nitrogen first valve and a low-pressure nitrogen second valve before and after the connecting point between the pipeline and the low-pressure nitrogen gas source pipeline, so as to facilitate the disconnection and maintenance of the front and rear systems.

[0022] Preferably, the pipeline where the self-operated pressure reducing valve is located is connected with a manual control valve before and after the connection point of the medium-pressure nitrogen gas source pipeline, and a first medium-pressure nitrogen gas valve and a second medium-pressure nitrogen gas valve are arranged before and after the system to facilitate disconnection and maintenance.

[0023] Preferably, a check valve is arranged on the pipeline after the first low-pressure nitrogen gas valve to prevent medium-pressure nitrogen gas from entering the low-pressure nitrogen gas source after pressure reduction.

[0024] Preferably, a field pressure gauge is arranged on the pipeline connecting the second valve before the self-operated pressure reducing valve and the self-operated pressure reducing valve to facilitate monitoring of the pressure of the medium-pressure nitrogen gas source when the pressure reducing valve is adjusted and the field is patrolled.

[0025] Further preferably, the medium-pressure nitrogen gas source is connected with the low-pressure nitrogen gas source after pressure reduction, a self-operated pressure reducing valve is arranged on the connecting pipeline, and both the front and rear hand valves are double valves.

[0026] Further preferably, a nitrogen gas storage tank is arranged on each of the pipelines of the medium-pressure nitrogen gas source and the low-pressure nitrogen gas source entering the dry gas system, which can effectively alleviate pressure fluctuation of the pipeline network and can more effectively ensure low-flow nitrogen gas supply within 2 hours after the pipeline network is disconnected.

[0027] Further preferably, a safety valve and a pressure gauge are arranged on each of the medium-pressure nitrogen gas storage tank and the low-pressure nitrogen gas storage tank to ensure safe discharge when the storage tank is overpressured.

[0028] Further preferably, a pneumatic booster pump is arranged on the bypass of the pressure reducing valve, which can be used to deliver low-pressure nitrogen gas from the low-pressure nitrogen gas backup system pipeline network to the primary seal through the booster pump when the medium-pressure nitrogen gas pipeline network is disconnected, to blow off residual medium on the primary seal end face and protect the seal end face.

[0029] The utility model discloses the beneficial effect lies in:

[0030] 1. The low-pressure nitrogen gas source pipeline is provided with a check valve, which effectively prevents the safety risk of high-pressure nitrogen gas entering the low-pressure nitrogen gas system and process gas entering the low-pressure nitrogen gas system.

[0031] 2. The arrangement of the self-operated pressure reducing valve and the pipeline effectively improves the pressure of the secondary seal and the isolation seal gas source, prevents oil mist from polluting the dry gas seal end face, prolongs the service life of the dry gas seal, and reduces the risk of emergency shutdown of the system caused by dry gas seal failure.

[0032] 3. The arrangement of the booster pump effectively prevents the safety risk of ammonia gas leakage after the medium-pressure nitrogen gas is disconnected. DETAILED DESCRIPTION

[0033] The application will be further described below in conjunction with the drawings and embodiments:

[0034] Figure 1 The utility model discloses the whole system flow chart.

[0035] In the figure: 1 is a low-pressure nitrogen gas pipeline network gas source, 2 is a low-pressure nitrogen gas storage tank, 3 is a low-pressure nitrogen gas storage tank safety valve, 4 is a low-pressure nitrogen gas first valve, 5 is a check valve, 6 is a low-pressure nitrogen gas second valve, 7 is a low-pressure nitrogen gas ball valve, 8 is a dry gas seal secondary seal and isolation seal assembly, 9 is a medium-pressure nitrogen gas pipeline network gas source, 10 is a medium-pressure nitrogen gas storage tank, 11 is a medium-pressure nitrogen gas storage tank safety valve, 12 is a medium-pressure nitrogen gas first valve, 13 is a medium-pressure nitrogen gas second valve, 14 is a dry gas seal primary seal assembly, 15 is a first valve before a self-operated pressure reducing valve, 16 is a second valve before a self-operated pressure reducing valve, 17 is a pressure gauge before a self-operated pressure reducing valve, 18 is a self-operated pressure reducing valve, 19 is a first valve after a self-operated pressure reducing valve, 20 is a second valve after a self-operated pressure reducing valve, 21 is a hand valve before a booster pump, 22 is a booster pump, and 23 is a hand valve after a booster pump. DETAILED DESCRIPTION

[0036] The technical scheme of the utility model will be further explained and described below in combination with the drawings and specific embodiments. It should be noted that the following embodiments are only preferred embodiments of the utility model and should not be understood as limiting the utility model. The protection scope of the utility model should be subject to the content recorded in the claims. The modifications and replacements of the technical scheme of the utility model made by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0037] Embodiment 1

[0038] A low-pressure centrifugal compressor set dry gas seal protection system, a low-pressure nitrogen gas pipeline network gas source 1 is connected with a low-pressure nitrogen gas storage tank 2;

[0039] A medium-pressure nitrogen gas pipeline network gas source 9 is connected with a medium-pressure nitrogen gas storage tank 10;

[0040] The low-pressure nitrogen gas storage tank 2 is connected with a low-pressure nitrogen gas source pipeline, and the medium-pressure nitrogen gas storage tank 10 is connected with a medium-pressure nitrogen gas source pipeline;

[0041] A connecting pipeline is arranged between the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline; a self-operated pressure reducing valve 18 is installed on the connecting pipeline.

[0042] The low-pressure nitrogen gas source pipeline is also connected with the isolation seal assembly 8;

[0043] The medium-pressure nitrogen gas source pipeline is also connected with the dry gas seal primary seal assembly 14.

[0044] A low-pressure nitrogen gas first valve 4 is arranged on the low-pressure nitrogen gas source pipeline, and the low-pressure nitrogen gas first valve 4 is connected with a check valve 5;

[0045] The low-pressure nitrogen gas source pipeline is connected with the connecting pipeline of the isolation sealing assembly 8, and a low-pressure nitrogen gas second valve 6 is arranged on the connecting pipeline.

[0046] A medium-pressure nitrogen gas first valve 12 is arranged on the medium-pressure nitrogen gas source pipeline.

[0047] A medium-pressure nitrogen gas second valve 13 is arranged on the connecting pipeline of the medium-pressure nitrogen gas source pipeline and the isolation sealing assembly 8.

[0048] The self-operated pressure reducing valve 18 on the connecting pipeline is provided with a self-operated pressure reducing valve front first valve 15 and a self-operated pressure reducing valve front second valve 16 at one end, and is provided with a self-operated pressure reducing valve rear first valve 19 and a self-operated pressure reducing valve rear second valve 20 at the other end.

[0049] The self-operated pressure reducing valve 18 on the connecting pipeline is connected with a booster pump 22 through a pipeline to form a closed loop pipeline, and the booster pump 22 is provided with a booster pump rear hand valve 21 and a booster pump front hand valve 23 at two ends.

[0050] The low-pressure nitrogen gas storage tank 2 is connected with a low-pressure nitrogen gas storage tank safety valve 3 at the top.

[0051] The medium-pressure nitrogen gas storage tank 10 is connected with a medium-pressure nitrogen gas storage tank safety valve 11 at the top.

[0052] A field pressure gauge 17 is arranged on the connecting pipeline between the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline.

[0053] Preferably, the self-operated pressure reducing valve is provided with a low-pressure nitrogen gas first valve and a low-pressure nitrogen gas second valve before and after the connecting point of the pipeline and the low-pressure nitrogen gas source pipeline, so as to facilitate disconnection and maintenance of the front and rear systems.

[0054] Preferably, the self-operated pressure reducing valve is provided with a medium-pressure nitrogen gas first valve and a medium-pressure nitrogen gas second valve before and after the connecting point of the pipeline and the medium-pressure nitrogen gas source pipeline, so as to facilitate disconnection and maintenance of the front and rear systems.

[0055] Preferably, a check valve is arranged on the pipeline after the low-pressure nitrogen gas first valve, so as to prevent medium-pressure nitrogen gas source from entering the low-pressure nitrogen gas source after pressure reduction.

[0056] Preferably, a field pressure gauge is arranged on the connecting pipeline of the self-operated pressure reducing valve front second valve and the self-operated pressure reducing valve, so as to facilitate monitoring of the medium-pressure nitrogen gas source pressure when adjusting the pressure reducing valve and conducting on-site inspection.

[0057] Further preferably, the medium-pressure nitrogen gas source is reduced in pressure and then enters the low-pressure nitrogen gas source, a self-operated pressure reducing valve is arranged on the connecting pipeline, and the front and rear hand valves are both double valves.

[0058] Further preferably, the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline are each provided with a nitrogen gas storage tank at the dry gas system, which can effectively alleviate the pressure fluctuation of the pipeline network and ensure the supply of low-flow nitrogen gas within 2 hours after the pipeline network is interrupted.

[0059] Further preferably, the medium-pressure nitrogen gas storage tank and the low-pressure nitrogen gas storage tank are each provided with a safety valve and a pressure gauge to ensure safe discharge when the storage tank is overpressured.

[0060] Further preferably, a pneumatic booster pump and an electromagnetic valve control are arranged on the bypass of the pressure reducing valve, which can deliver the low-pressure nitrogen gas from the backup system pipeline network to the primary seal through the booster pump to blow off the residual medium on the end face of the primary seal and protect the seal end face when the medium-pressure nitrogen gas pipeline network is interrupted. The booster pump is interlocked and started when the remote pressure of the medium-pressure nitrogen gas storage tank is lower than 0.3 MPa.

[0061] Example 2

[0062] The low-pressure nitrogen gas pipeline network gas source enters the low-pressure nitrogen gas storage tank, and the pressure is controlled at 0.3-0.45 MPa. A field pressure gauge is arranged on the storage tank for monitoring. A safety valve is arranged on the top of the storage tank, which is triggered when the design setting pressure is reached to prevent overpressure of the storage tank. The outlet of the low-pressure nitrogen gas storage tank is combined with the nitrogen gas source from the self-operated pressure reducing valve after passing through the first valve and the check valve of the low-pressure nitrogen gas, and then enters the secondary seal and the isolation seal assembly of the dry gas seal through the second valve and the ball valve of the low-pressure nitrogen gas.

[0063] The medium-pressure nitrogen gas pipeline network gas source enters the medium-pressure nitrogen gas storage tank, and the pressure is controlled at 5.0-6.8 MPa. A remote pressure gauge is arranged on the storage tank for monitoring. A safety valve is arranged on the top of the storage tank, which is triggered when the design setting pressure is reached to prevent overpressure of the storage tank. The outlet of the medium-pressure nitrogen gas storage tank is divided into two streams after passing through the first valve. The first stream passes through the first valve and the second valve before the self-operated pressure reducing valve, is reduced to 0.3-0.4 MPa by the self-operated pressure reducing valve, and then enters the secondary seal and the isolation seal assembly of the dry gas seal together with the low-pressure nitrogen gas pipeline network gas source after passing through the first valve and the second valve after the self-operated pressure reducing valve. The second stream enters the primary seal assembly of the dry gas seal after passing through the second valve of the medium-pressure nitrogen gas.

[0064] When the medium-pressure nitrogen gas source is interrupted and the medium-pressure nitrogen gas storage tank has no pressure, the first valve of the medium-pressure nitrogen gas is closed. The low-pressure nitrogen gas pipeline network gas source passes through the check valve, the self-operated pressure reducing valve, the first valve and the second valve, and then passes through the hand valve before the booster pump, the hand valve after the booster pump, and then the second valve of the medium-pressure nitrogen gas to enter the primary seal assembly of the dry gas seal, thereby achieving the purpose of protecting the primary seal. The pneumatic pump is interlocked and started when the remote pressure of the medium-pressure nitrogen gas storage tank is lower than 0.3 MPa.

[0065] Self-reliance decompression in the set pressure can not be other operations, decompression pressure to two sealing and isolation sealing pressure control requirements as the standard to carry out adjustment, daily inspection should pay attention to check the pressure of medium pressure nitrogen gas source.

Claims

1. A low-pressure centrifugal compressor set dry gas seal protection system characterized in that: a low-pressure nitrogen pipe network gas source (1) is connected with a low-pressure nitrogen storage tank (2); a medium-pressure nitrogen pipe network gas source (9) is connected with a medium-pressure nitrogen storage tank (10); the low-pressure nitrogen storage tank (2) is connected with a low-pressure nitrogen gas source pipeline, and the medium-pressure nitrogen storage tank (10) is connected with a medium-pressure nitrogen gas source pipeline; a connecting pipeline is arranged between the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline; and a self-operated pressure reducing valve (18) is installed on the connecting pipeline.

2. The low-pressure centrifugal compressor set dry gas seal protection system according to claim 1, characterized in that: the low-pressure nitrogen gas source pipeline is further connected with an isolation sealing assembly (8); the medium-pressure nitrogen gas source pipeline is further connected with a dry gas seal primary sealing assembly (14).

3. The low-pressure centrifugal compressor train dry gas seal protection system of claim 2, wherein: a low-pressure nitrogen first valve (4) is arranged on the low-pressure nitrogen gas source pipeline, and the low-pressure nitrogen first valve (4) is connected with a check valve (5); a low-pressure nitrogen second valve (6) is arranged on the connecting pipeline of the low-pressure nitrogen gas source pipeline and the isolation sealing assembly (8), and the low-pressure nitrogen second valve (6) is connected with a low-pressure nitrogen ball valve (7).

4. The low-pressure centrifugal compressor set dry gas seal protection system according to claim 2, characterized in that: a medium-pressure nitrogen first valve (12) is arranged on the medium-pressure nitrogen gas source pipeline; a medium-pressure nitrogen second valve (13) is arranged on the connecting pipeline of the medium-pressure nitrogen gas source pipeline and the isolation sealing assembly (8).

5. The low-pressure centrifugal compressor train dry gas seal protection system according to claim 1, characterized by: One end of the self-operated pressure reducing valve (18) on the connecting pipeline is provided with a self-operated pressure reducing valve front first valve (15) and a self-operated pressure reducing valve front second valve (16), and the other end is provided with a self-operated pressure reducing valve rear first valve (19) and a self-operated pressure reducing valve rear second valve (20).

6. The low-pressure centrifugal compressor package dry gas seal protection system of claim 1, wherein: The self-operated pressure reducing valve (18) on the connecting pipeline is connected with a booster pump (22) through a pipeline and forms a closed loop pipeline, and the booster pump (22) is respectively provided with a booster pump rear hand valve (21) and a booster pump front hand valve (23) at two ends.

7. The low-pressure centrifugal compressor set dry gas seal protection system according to claim 1, characterized in that: the low-pressure nitrogen storage tank (2) is connected with a low-pressure nitrogen storage tank safety valve (3) at the top; the medium-pressure nitrogen storage tank (10) is connected with a medium-pressure nitrogen storage tank safety valve (11) at the top; a field pressure gauge (17) is arranged on the connecting pipeline between the medium-pressure nitrogen gas source pipeline and the low-pressure nitrogen gas source pipeline.

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