A low-pressure nitrogen gas connection system and its usage method

Abstract

This invention discloses a low-pressure nitrogen interconnection system and its usage method, comprising a 35,000 kW oxygen generator unit, a water-cooled tower, a 12,000 kW nitrogen compressor, a 6,000 kW nitrogen compressor, a 7,200 kW nitrogen compressor, a 6,000 kW oxygen generator unit A, and a 6,000 kW oxygen generator unit B. The outlet of the 35,000 kW oxygen generator unit is connected via pipelines to the inlets of the 35,000 kW nitrogen compressor A, the 35,000 kW nitrogen compressor B, a flow valve, and a main connecting valve. The outlet of the flow valve is connected via a pipeline to the inlet of the water-cooled tower, and the outlet of the water-cooled tower is discharged to the atmosphere via a pipeline. This invention optimizes the structure of the low-pressure nitrogen interconnection system, fully utilizes the surplus nitrogen produced by the oxygen generator, avoids resource waste, improves economic efficiency, and increases the output of low-pressure nitrogen with the same power consumption, saving electricity consumption, reducing production costs, achieving the goal of energy saving and efficiency improvement, and meeting the gas demand of the nitrogen pipeline network.

Description

Technical Field

[0001] This invention relates to the field of nitrogen supply technology, specifically to a low-pressure nitrogen connection system and its usage method. Background Technology

[0002] An oxygen concentrator is a machine that produces oxygen. Its principle is based on air separation technology. First, air is compressed to a high density, and then the different condensation points of the air components are used to separate the gas and liquid phases at a certain temperature. Finally, distillation is performed to separate the oxygen and nitrogen. Because it is primarily used to produce oxygen, it is commonly called an oxygen concentrator. Due to the wide range of uses for oxygen and nitrogen, oxygen concentrators are widely used in the national economy, especially in industries such as metallurgy, chemical engineering, petroleum, and defense. However, the low-pressure nitrogen connection system of traditional oxygen concentrators has a relatively simple structure, failing to fully utilize the surplus nitrogen produced, resulting in resource waste and low economic efficiency. For the same power consumption, the low-pressure nitrogen output is relatively small, leading to low energy efficiency, high power consumption, and high production costs, making it unable to meet the gas demand of nitrogen pipeline networks. Summary of the Invention

[0003] The purpose of this invention is to provide a low-pressure nitrogen gas interconnection system and its usage method to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a low-pressure nitrogen interconnection system, comprising a 35,000 kW oxygen generator unit, a water-cooled tower, a 12,000 kW nitrogen compressor, a 6,000 kW nitrogen compressor, a 7,200 kW nitrogen compressor, a 6,000 kW oxygen generator unit A, and a 6,000 kW oxygen generator unit B. The outlet of the 35,000 kW oxygen generator unit is connected via pipes to the inlets of the 35,000 kW nitrogen compressor A, the 35,000 kW nitrogen compressor B, a flow valve, and a main connecting valve, respectively. The outlet of the flow valve is connected via pipes to the inlet of the water-cooled tower. The outlet of the water-cooled tower is discharged into the atmosphere via an exhaust pipe. The outlets of the 35,000 kW nitrogen compressor A and the 35,000 kW nitrogen compressor B are both connected via pipes to the inlet of a main nitrogen pipeline network. An output pressure gauge is connected to the inlet of the main nitrogen pipeline network.

[0005] Preferably, the outlet of the main connecting valve is connected to the inlet of the first connecting valve and the inlet of the second connecting valve via a pipe. The outlet of the first connecting valve is connected to the inlet of the 12,000 nitrogen compressor via a pipe. A pressure gauge A is connected to the inlet of the 12,000 nitrogen compressor. The outlet of the 12,000 nitrogen compressor is connected to the inlet of the main nitrogen pipeline via a pipe.

[0006] Preferably, the outlet of the second connecting valve is connected to the inlet of the 6,000 nitrogen compressor via a pipeline. A pressure gauge B is connected to the inlet of the 6,000 nitrogen compressor. The outlet of the 6,000 nitrogen compressor is connected to the inlet of the main nitrogen pipeline via a pipeline. The inlets of the 6,000 nitrogen compressor and the 12,000 nitrogen compressor are respectively connected to the outlets of the gas supply valve B and the gas supply valve A via pipelines.

[0007] Preferably, the outlet of the gas supply valve A is connected to the inlet of the 7200 Nm³ / h nitrogen compressor via a pipeline, a pressure gauge C is connected to the inlet of the 7200 Nm³ / h nitrogen compressor, and the outlet of the 7200 Nm³ / h nitrogen compressor is connected to the inlet of the main nitrogen pipeline via a pipeline.

[0008] Preferably, the air inlet of the 7200 Nm³ / h nitrogen compressor is connected to the air outlet of the air supply valve A via a pipe, and the air inlets of both the 7200 Nm³ / h nitrogen compressor and the 12000 Nm³ / h nitrogen compressor are connected to the air outlet of the air supply valve C via pipes.

[0009] Preferably, the air inlet of the air supply valve C is connected to the air outlet of the 6,000 oxygen generator unit A via a pipe, the air outlet of the 6,000 oxygen generator unit A is connected to the air inlet of the vent valve A via a pipe, and the air outlet of the vent valve A is connected to the air inlet of the silencer A.

[0010] Preferably, the air inlets of the air supply valve B and the air supply valve A are both connected to the air outlet of the 6,000 oxygen generator unit B via pipes, the air outlet of the 6,000 oxygen generator unit B is connected to the air inlet of the vent valve B via pipes, and the air outlet of the vent valve B is connected to the air outlet of the silencer B via pipes.

[0011] A method for using a low-pressure nitrogen interconnection system includes the following steps: Step 1, normal operation; Step 2, simultaneous operation; Step 3, partial shutdown; Step 4, complete shutdown.

[0012] In step one above, the 35,000 kW oxygen generator, 35,000 kW nitrogen compressor A, 35,000 kW nitrogen compressor B, water cooling tower, and 12,000 kW nitrogen compressor are started. The flow valve, main connecting valve, and first connecting valve are opened, allowing the main nitrogen produced by the 35,000 kW oxygen generator to enter the 35,000 kW nitrogen compressor A and 35,000 kW nitrogen compressor B through pipelines. After compression, it is transported to the main nitrogen network through pipelines. At the same time, some of the surplus nitrogen produced enters the 12,000 kW nitrogen compressor through pipelines, the main connecting valve, and the first connecting valve. After compression, it is transported to the main nitrogen network through pipelines. The remaining surplus nitrogen produced enters the water cooling tower through pipelines and flow valves to lower the water temperature. In high-temperature conditions, it is used for cooling and load adjustment, and then discharged into the atmosphere. If the nitrogen output pressure shown on the output pressure gauge continues to decrease, the second connecting valve is opened and the 6,000 kW nitrogen compressor is started to supplement the nitrogen compression and ensure that the nitrogen output pressure meets the standard.

[0013] In step two above, the 6,000 kW oxygen generator A, 6,000 kW oxygen generator B, and 7,000 kW nitrogen compressor are then started. Gas supply valves B, A, and C are opened, while vent valves A and B are gradually closed. The main connecting valve, the first connecting valve, and the second connecting valve are then slowly closed in sequence. The pressure displayed on pressure gauges A and B is carefully observed. If necessary, the nitrogen compressor's backflow is activated to prevent surge. This allows the main nitrogen produced by the 35,000 kW oxygen generator to enter the 35,000 kW nitrogen compressor A and B through pipelines. After compression, the nitrogen is delivered to the main nitrogen network through pipelines. Simultaneously, the nitrogen produced by the 6,000 kW oxygen generator A and B enters the 12,000 kW nitrogen compressor, the 6,000 kW nitrogen compressor, and the 7,000 kW nitrogen compressor through pipelines, gas supply valves B, A, and C. After compression, the nitrogen is delivered to the main nitrogen network through pipelines.

[0014] In step three above, gas supply valves B and C are closed, the 6,000 Nm³ / h and 7,200 Nm³ / h nitrogen compressors are shut down, the main connecting valve and the first connecting valve are opened, the flow valve is reduced, and then gas supply valve A is gradually closed. The pressure displayed on pressure gauge A is carefully observed until gas supply valve A is completely closed. This allows the main nitrogen produced by the 35,000 Nm³ / h oxygen generator to be compressed by nitrogen compressors A and B and then supplied to the main nitrogen pipeline. A portion of the surplus nitrogen produced by the 35,000 Nm³ / h oxygen generator is compressed by the 12,000 Nm³ / h nitrogen compressor and supplied to the main nitrogen pipeline. The remaining surplus nitrogen is used as a refrigerant in a water-cooled tower to lower the water temperature. In high-temperature conditions, after cooling and load adjustment, the nitrogen is discharged to the atmosphere through the discharge pipe. Then, the 6,000 Nm³ / h oxygen generators A and B are shut down according to the procedure, and vent valves A and B are opened. The system is partially air-separated by silencers A and B.

[0015] In step four above, the main connecting valve and the first connecting valve are closed in sequence, the 12,000 Nm2 nitrogen compressor is shut down, and the flow valve is gradually opened. Then, the 35,000 Nm2 oxygen generator, 35,000 Nm2 nitrogen compressor A and 35,000 Nm2 nitrogen compressor B are shut down in sequence according to the shutdown operation procedure, and the system is completely vented through the water cooling tower.

[0016] Compared with the prior art, the beneficial effects of the present invention are: the low-pressure nitrogen interconnection system and its usage method make full use of the surplus nitrogen produced by the oxygen generator through the structure of the low-pressure nitrogen interconnection system, avoid resource waste, improve economic efficiency, output more low-pressure nitrogen under the same power consumption, save power consumption, reduce production costs, achieve the purpose of energy saving and efficiency creation, and meet the gas demand of the nitrogen pipeline network. Attached Figure Description

[0017] Figure 1 This is a system structure diagram of the present invention;

[0018] Figure 2 This is a flowchart of the method of the present invention;

[0019] In the diagram: 1. 35,000 kW oxygen generator unit; 2. 35,000 kW nitrogen compressor A; 3. 35,000 kW nitrogen compressor B; 4. Flow valve; 5. Main connecting valve; 6. Water cooling tower; 7. Discharge pipe; 8. Main nitrogen pipeline network; 9. Output pressure gauge; 10. First connecting valve; 11. Second connecting valve; 12. 12,000 kW nitrogen compressor; 13. Pressure gauge A; 14. 6,000 kW nitrogen compressor; 15. Pressure gauge B; 16. Gas supply valve B; 17. Gas supply valve A; 18. 7,200 kW nitrogen compressor; 19. Pressure gauge C; 20. Gas supply valve C; 21. 6,000 kW oxygen generator unit A; 22. Vent valve A; 23. Silencer A; 24. 6,000 kW oxygen generator unit B; 25. Vent valve B; 26. Silencer B. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1One embodiment of the present invention provides a low-pressure nitrogen interconnection system, comprising a 35,000 kW oxygen generator unit 1, a water-cooled tower 6, a 12,000 kW nitrogen compressor 12, a 6,000 kW nitrogen compressor 14, a 7,200 kW nitrogen compressor 18, a 6,000 kW oxygen generator unit A21, and a 6,000 kW oxygen generator unit B24. The outlet of the 35,000 kW oxygen generator unit 1 is connected via pipes to the inlets of the 35,000 kW nitrogen compressors A2 and B3, a flow valve 4, and a main connecting valve 5. The outlet of the flow valve 4 is connected via a pipe to the inlet of the water-cooled tower 6. The outlet of the water-cooled tower 6 discharges into the atmosphere through an exhaust pipe 7. The outlets of the 35,000 kW nitrogen compressors A2 and B3 are connected via pipes... Each pipeline is connected to the inlet of the main nitrogen pipeline network 8. An output pressure gauge 9 is connected to the inlet of the main nitrogen pipeline network 8. The outlet of the main connecting valve 5 is connected via pipelines to the inlets of the first connecting valve 10 and the second connecting valve 11. The outlet of the first connecting valve 10 is connected via pipelines to the inlet of a 12,000 kW nitrogen compressor 12. A pressure gauge A13 is connected to the inlet of the 12,000 kW nitrogen compressor 12. The outlet of the 12,000 kW nitrogen compressor 12 is connected via pipelines to the inlet of the main nitrogen pipeline network 8. The outlet of the second connecting valve 11 is connected via pipelines to the inlet of a 6,000 kW nitrogen compressor 14. A pressure gauge B1 is connected to the inlet of the 6,000 kW nitrogen compressor 14. 5. The outlet of the 6,000 Nm³ / h nitrogen compressor 14 is connected to the inlet of the main nitrogen pipeline network 8 via a pipe. The inlets of the 6,000 Nm³ / h nitrogen compressor 14 and the 12,000 Nm³ / h nitrogen compressor 12 are respectively connected to the outlets of the air supply valves B16 and A17 via pipes. The outlet of the air supply valve A17 is connected to the inlet of the 7,200 Nm³ / h nitrogen compressor 18 via a pipe. A pressure gauge C19 is connected to the inlet of the 7,200 Nm³ / h nitrogen compressor 18. The outlet of the 7,200 Nm³ / h nitrogen compressor 18 is connected to the inlet of the main nitrogen pipeline network 8 via a pipe. The outlet of the 7,200 Nm³ / h nitrogen compressor 18 is connected to the outlet of the air supply valve A17 via a pipe. The 7,200 Nm³ / h nitrogen compressor 18 and the 12,000 Nm³ / h nitrogen compressor 12... The air inlets are all connected to the outlet of the air supply valve C20 via pipes. The air inlet of the air supply valve C20 is connected to the outlet of the 6,000 kW oxygen generator A21 via pipes. The outlet of the 6,000 kW oxygen generator A21 is connected to the air inlet of the vent valve A22 via pipes. The outlet of the vent valve A22 is connected to the air inlet of the silencer A23. The air inlets of the air supply valves B16 and A17 are all connected to the outlet of the 6,000 kW oxygen generator B24 via pipes. The outlet of the 6,000 kW oxygen generator B24 is connected to the air inlet of the vent valve B25 via pipes. The outlet of the vent valve B25 is connected to the outlet of the silencer B26 via pipes.

[0022] Please see Figure 2 The present invention provides an embodiment of a method for using a low-pressure nitrogen interconnection system, comprising the following steps: Step 1, normal operation; Step 2, simultaneous operation; Step 3, partial shutdown; Step 4, complete shutdown.

[0023] In step one above, the 35,000 kW oxygen generator unit 1, 35,000 kW nitrogen compressor A2, 35,000 kW nitrogen compressor B3, water cooling tower 6, and 12,000 kW nitrogen compressor 12 are started. The flow valve 4, the main connecting valve 5, and the first connecting valve 10 are opened, allowing the main nitrogen produced by the 35,000 kW oxygen generator unit 1 to enter the 35,000 kW nitrogen compressor A2 and 35,000 kW nitrogen compressor B3 through pipelines. After compression, it is transported to the main nitrogen pipeline network 8 through pipelines. Simultaneously, a portion of the surplus nitrogen produced flows through pipelines, the main connecting valve 5, and the first connecting valve. The nitrogen gas enters the 12,000 Nm³ / h nitrogen compressor 12 through the valve 10. After compression, it is delivered to the main nitrogen network 8 through the pipeline. The excess nitrogen produced is delivered to the water cooling tower 6 through the pipeline and flow valve 4. It is used as a refrigerant to lower the water temperature and to cool down and adjust the load under high temperature conditions. Then it is discharged to the atmosphere through the discharge pipe 7. If the nitrogen output pressure shown by the output pressure gauge 9 continues to decrease, the second connecting valve 11 is opened and the 6,000 Nm³ / h nitrogen compressor 14 is turned on to supplement the nitrogen compression and ensure that the nitrogen output pressure meets the standard.

[0024] In step two above, the following steps are taken: First, start the 6kWh oxygen generator A21, 6kWh oxygen generator B24, and 7kWh nitrogen compressor 18. Then, open the gas supply valves B16, A17, and C20. Simultaneously, gradually close the vent valves A22 and B25. Next, slowly close the main connecting valve 5, the first connecting valve 10, and the second connecting valve 11 in sequence. Carefully observe the pressure displayed on pressure gauges A13 and B15. If necessary, activate the nitrogen compressor's backflow prevention mechanism to prevent nitrogen compressor failure. The surge causes the main nitrogen produced by the 35,000-kilowatt oxygen generator unit 1 to enter the 35,000-kilowatt nitrogen compressors A2 and B3 through pipelines. After compression, it is transported to the main nitrogen pipeline network 8 through pipelines. At the same time, the nitrogen produced by the 6,000-kilowatt oxygen generator units A21 and B24 enters the 12,000-kilowatt nitrogen compressors 12, 6,000-kilowatt nitrogen compressor 14 and 7,000-kilowatt nitrogen compressor 18 through pipelines, gas supply valves B16, A17 and C20. After compression, it is transported to the main nitrogen pipeline network 8 through pipelines.

[0025] In step three above, the gas supply valves B16 and C20 are closed, the 6,000 Nm³ / h nitrogen compressor 14 and the 7,200 Nm³ / h nitrogen compressor 18 are shut down, the main connecting valve 5 and the first connecting valve 10 are opened, the flow rate valve 4 is closed, and then the gas supply valve A17 is gradually closed, while carefully observing the pressure displayed on the pressure gauge A13, until the gas supply valve A17 is completely closed. This allows the main nitrogen produced by the 35,000 Nm³ / h oxygen generator unit 1 to be compressed by the 35,000 Nm³ / h nitrogen compressors A2 and B3 and then delivered to the total nitrogen supply. Pipeline 8: Some of the surplus nitrogen produced by the 35,000 kW oxygen generator unit 1 is compressed by the 12,000 kW nitrogen compressor 12 and transported to the main nitrogen pipeline 8. The remaining surplus nitrogen produced is used as a refrigerant in the water cooling tower 6 to lower the water temperature. In high-temperature conditions, after cooling and load adjustment, it is discharged into the atmosphere through the discharge pipeline 7. Then, the 6,000 kW oxygen generator units A21 and B24 are shut down according to the procedure, and the vent valves A22 and B25 are opened. The system is partially air-separated through the silencers A23 and B26.

[0026] In step four above, the main connecting valve 5 and the first connecting valve 10 are closed in sequence, the 12,000 Nm2 compressor 12 is shut down, and the flow valve 4 is gradually opened. Then, the 35,000 Nm2 oxygen generator 1, the 35,000 Nm2 compressor A2 and the 35,000 Nm2 compressor B3 are shut down in sequence according to the shutdown operation procedure, and the system is completely vented through the water cooling tower 6.

[0027] Working Principle: When using this invention, first start the 35,000 rpm oxygen generator unit 1, 35,000 rpm nitrogen compressor A2, 35,000 rpm nitrogen compressor B3, water cooling tower 6, and 12,000 rpm nitrogen compressor 12. Open flow valve 4, main connecting valve 5, and first connecting valve 10. This allows the main nitrogen produced by the 35,000 rpm oxygen generator unit 1 to enter the 35,000 rpm nitrogen compressor A2 and 35,000 rpm nitrogen compressor B3 through pipelines. After compression, it is transported to the main nitrogen network 8 through pipelines. Simultaneously, some surplus nitrogen produced enters the 12,000 rpm nitrogen compressor 12 through pipelines, main connecting valve 5, and first connecting valve 10. After compression, it is transported to the main nitrogen network 8 through pipelines. The remaining surplus nitrogen enters the water cooling tower 6 through pipelines and flow valve 4, serving as a refrigerant to lower the water temperature, thus regulating temperature in high-temperature conditions. The nitrogen is loaded and then discharged into the atmosphere through the discharge pipe 7. If the nitrogen output pressure displayed on the output pressure gauge 9 continues to decrease, the second connecting valve 11 is opened and the 6,000 kW nitrogen compressor 14 is started to supplement the nitrogen compression and ensure that the nitrogen output pressure meets the standard. Then, the 6,000 kW oxygen generator A21, the 6,000 kW oxygen generator B24, and the 7,000 kW nitrogen compressor 18 are started. The gas supply valves B16, A17, and C20 are opened, while the vent valves A22 and B25 are gradually closed. The main connecting valve 5, the first connecting valve 10, and the second connecting valve 11 are closed slowly in sequence. The pressure displayed on the pressure gauges A13 and B15 is carefully observed. If necessary, the nitrogen compressor backflow is turned on to prevent the nitrogen compressor from surging and to ensure that the 35,000 kW oxygen generator 1 produces The main nitrogen output enters the 35,000 Nm³ / h nitrogen compressors A2 and B3 through pipelines. After compression, it is delivered to the main nitrogen network 8 through pipelines. Simultaneously, nitrogen produced by the 6,000 Nm³ / h oxygen generators A21 and B24 enters the 12,000 Nm³ / h nitrogen compressors 12, 6,000 Nm³ / h nitrogen compressor 14, and 7,000 Nm³ / h nitrogen compressor 18 through pipelines, supply valves B16, A17, and C20. After compression, it is delivered to the main nitrogen network 8 through pipelines. Then, supply valves B16 and C20 are closed, shutting down the 6,000 Nm³ / h nitrogen compressors 14 and 7,000 Nm³ / h nitrogen compressor 18. The main connecting valve 5 and the first connecting valve 10 are opened, the flow rate valve 4 is closed slightly, and then the supply valve A17 is gradually closed, while carefully observing the pressure displayed on the pressure gauge A13 until… The gas supply valve A17 is fully closed, allowing the main nitrogen produced by the 35,000 kW oxygen generator unit 1 to be compressed by the 35,000 kW nitrogen compressors A2 and B3 and then supplied to the main nitrogen pipeline network 8. A portion of the surplus nitrogen produced by the 35,000 kW oxygen generator unit 1 is compressed by the 12,000 kW nitrogen compressor 12 and supplied to the main nitrogen pipeline network 8. The remaining surplus nitrogen is used as a refrigerant in the water-cooled tower 6 to lower the water temperature. In high-temperature conditions, after cooling and load adjustment, it is discharged into the atmosphere through the discharge pipe 7. Then, following the procedure, the 6,000 kW oxygen generator units A21 and B24 are shut down. The vent valves A22 and B25 are opened, allowing partial air separation in the system via air-cooled towers A23 and B26. Finally, the main connecting valve 5 and the first connecting valve 10 are closed sequentially, and the 12,000 kW nitrogen compressor 12 is shut down.Simultaneously, gradually increase the flow rate of valve 4, then sequentially shut down the 35,000 kW oxygen generator unit 1, 35,000 kW nitrogen compressor A2, and 35,000 kW nitrogen compressor B3 according to the shutdown procedure, and completely vent the system through water-cooling tower 6. This fully utilizes the surplus nitrogen produced by the oxygen generator, avoiding resource waste, improving economic efficiency, and achieving a higher output of low-pressure nitrogen with the same power consumption, saving electricity, reducing production costs, achieving energy conservation and efficiency, and meeting the nitrogen pipeline network's gas demand.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A low-pressure nitrogen connection system, comprising a 35000 oxygen generating unit (1), a refrigeration unit, a 12000 nitrogen compressor (12), a 6000 nitrogen compressor (14), a 7000 nitrogen compressor (18), a 6000 oxygen generating unit A (21) and a 6000 oxygen generating unit B (24), characterized in that: The gas outlet of the thirty-five thousand oxygen machine group (1) is connected with the gas inlet of the thirty-five thousand nitrogen compressor A (2), the thirty-five thousand nitrogen compressor B (3), the flow valve (4) and the total communication valve (5) through pipelines respectively, the gas outlet of the flow valve (4) is connected with the gas inlet of the water cooling tower (6) through a pipeline, the gas outlet of the water cooling tower (6) is discharged to the atmosphere through a discharge pipeline (7), the gas outlets of the thirty-five thousand nitrogen compressor A (2) and the thirty-five thousand nitrogen compressor B (3) are connected with the gas inlet of the total nitrogen gas pipeline network (8) through pipelines, and the gas inlet of the total nitrogen gas pipeline network (8) is connected with the output gas pressure gauge (9) in parallel; The gas outlet of the total communication valve (5) is connected with the gas inlets of the first communication valve (10) and the second communication valve (11) through pipelines respectively, the gas outlet of the first communication valve (10) is connected with the gas inlet of the twelve thousand nitrogen compressor (12) through a pipeline, the gas inlet of the twelve thousand nitrogen compressor (12) is connected with the gas pressure gauge A (13) in parallel, and the gas outlet of the twelve thousand nitrogen compressor (12) is connected with the gas inlet of the total nitrogen gas pipeline network (8) through a pipeline; The gas outlet of the second communication valve (11) is connected with the gas inlet of the six thousand nitrogen compressor (14) through a pipeline, the gas inlet of the six thousand nitrogen compressor (14) is connected with the gas pressure gauge B (15) in parallel, the gas outlet of the six thousand nitrogen compressor (14) is connected with the gas inlet of the total nitrogen gas pipeline network (8) through a pipeline, and the gas inlets of the six thousand nitrogen compressor (14) and the twelve thousand nitrogen compressor (12) are connected with the gas outlets of the gas sending valve B (16) and the gas sending valve A (17) through pipelines respectively; The gas outlet of the gas sending valve A (17) is connected with the gas inlet of the seven thousand two nitrogen compressor (18) through a pipeline, the gas inlet of the seven thousand two nitrogen compressor (18) is connected with the gas pressure gauge C (19) in parallel, and the gas outlet of the seven thousand two nitrogen compressor (18) is connected with the gas inlet of the total nitrogen gas pipeline network (8) through a pipeline; The gas inlet of the seven thousand two nitrogen compressor (18) is connected with the gas outlet of the gas sending valve A (17) through a pipeline, and the gas inlets of the seven thousand two nitrogen compressor (18) and the twelve thousand nitrogen compressor (12) are connected with the gas outlet of the gas sending valve C (20) through pipelines; The gas inlet of the gas sending valve C (20) is connected with the gas outlet of the six thousand oxygen machine group A (21) through a pipeline, the gas outlet of the six thousand oxygen machine group A (21) is connected with the gas inlet of the vent valve A (22) through a pipeline, and the gas outlet of the vent valve A (22) is connected with the gas inlet of the silencer A (23); The gas inlets of the gas sending valve B (16) and the gas sending valve A (17) are connected with the gas outlets of the six thousand oxygen machine group B (24) through pipelines respectively, the gas outlet of the six thousand oxygen machine group B (24) is connected with the gas inlet of the vent valve B (25) through a pipeline, and the gas outlet of the vent valve B (25) is connected with the gas inlet of the silencer B (26) through a pipeline.

2. The low pressure nitrogen gas communication system of claim 1, wherein: A use method of a low-pressure nitrogen gas communication system, comprising the following steps: step one, normal operation; step two, simultaneous operation; step three, partial shutdown; and step four, complete shutdown; characterized in that: Wherein the above step one, open three five oxygen unit (1), three five nitrogen compressor A (2), three five nitrogen compressor B (3), water cooling tower (6) and one two nitrogen compressor (12), open the flow valve (4), total communication valve (5) and first communication valve (10), make three five oxygen unit (1) output main nitrogen gas through pipeline into three five nitrogen compressor A (2) and three five nitrogen compressor B (3), after compression, through pipeline to total nitrogen gas network (8), at the same time, part of the nitrogen gas output through pipeline, total communication valve (5) and first communication valve (10) into one two nitrogen compressor (12), after compression, through pipeline to total nitrogen gas network (8), in addition, the remaining nitrogen gas output through pipeline and flow valve (4) into water cooling tower (6), high temperature cooling load, as refrigerant to reduce water temperature, and then through the exhaust pipe (7) to the atmosphere, if the output pressure gauge (9) shows that the nitrogen output pressure continues to decrease, then open the second communication valve (11) and open six thousand nitrogen compressor (14), supplement the nitrogen compression amount, ensure that the nitrogen output pressure meets the standard; Wherein the above step two, then open six thousand oxygen unit A (21), six thousand oxygen unit B (24) and seven thousand two nitrogen compressor (18), open the gas valve B (16), gas valve A (17) and gas valve C (20), while gradually closing the vent valve A (22) and vent valve B (25), in turn, slowly close the total communication valve (5), first communication valve (10) and second communication valve (11), and pay attention to the pressure displayed on the pressure gauge A (13) and pressure gauge B (15), if necessary, open the nitrogen compressor backflow, prevent nitrogen compressor surge, make three five oxygen unit (1) output main nitrogen gas through pipeline into three five nitrogen compressor A (2) and three five nitrogen compressor B (3), after compression, through pipeline to total nitrogen gas network (8), at the same time, six thousand oxygen unit A (21) and six thousand oxygen unit B (24) output nitrogen gas through pipeline, gas valve B (16), gas valve A (17) and gas valve C (20) into one two nitrogen compressor (12), six thousand nitrogen compressor (14) and seven thousand two nitrogen compressor (18), after compression, through pipeline to total nitrogen gas network (8); Wherein the above step three, close the air valve B (16) and air valve C (20), shut down six thousand nitrogen compressor (14) and seven thousand two nitrogen compressor (18), open the total communication valve (5) and the first communication valve (10), close the small flow valve (4), then gradually close the air valve A (17), and pay attention to the pressure shown on the pressure gauge A (13), until the air valve A (17) is completely closed, so that the main nitrogen produced by the thirty-five thousand oxygen unit (1) is compressed by the thirty-five thousand nitrogen compressor A (2) and the thirty-five thousand nitrogen compressor B (3) and delivered to the total nitrogen pipe network (8), part of the nitrogen produced by the thirty-five thousand oxygen unit (1) is compressed by the twelve thousand nitrogen compressor (12) and delivered to the total nitrogen pipe network (8), and the remaining nitrogen is cooled by the water cooling tower (6) as a coolant to reduce the water temperature, and then discharged to the atmosphere through the exhaust pipe (7) after the load is adjusted by cooling under high temperature, then according to the procedure, shut down six thousand oxygen unit A (21) and six thousand oxygen unit B (24), open the vent valve A (22) and the vent valve B (25), and make the system partially vent through the silencer A (23) and the silencer B (26); Wherein the above step four, close the total communication valve (5) and the first communication valve (10) in turn, shut down the twelve thousand nitrogen compressor (12), and at the same time, gradually open the large flow valve (4), then according to the shutdown operation procedure, shut down the thirty-five thousand oxygen unit (1), the thirty-five thousand nitrogen compressor A (2) and the thirty-five thousand nitrogen compressor B (3) in turn, and make the system completely air separated through the water cooling tower (6) and the exhaust pipe (7).

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