1： Preparation before startup

1: All manual valves should be temporarily closed.

2: Check if the pressure of compressed air (0.65mpa -0.75mpa) meets the requirements of the nitrogen generator.

3: Whether the inlet and outlet pressures of the cooling water for the refrigerated dryer (inlet pressure: 0.30mpa -0.40mpa, outlet pressure: 0.20mpa -0.25mpa) meet the requirements.

2： Power on

1: Send the power drawer cabinet R108-5, and at this time, the opening indicator light of the PL201 cabinet is on, which is used to store energy for the universal circuit breaker of the PL201 cabinet. After the energy storage indicator light is on, press the closing button (the green button on the universal circuit breaker). At this moment, the opening indicator light of the PL201 cabinet is off and the closing indicator light is on. Send the drawer cabinet air pre cooling unit power supply PL202-1, AC UPS power supply PL202-3, enter the control room and sequentially close the high segmented circuit breakers, and start the UPS. At this moment, the PLC cabinet is powered on, and the two industrial control computers in the control room are started to enter the control interface.

2: After entering the control interface, click on the purification system interface to convert the automatic (green indicator button) to manual, the operation to pause, step the program to the MS1201 cold blowing stage (MS1202 cold blowing is similar to MS1201 operation), and change all automatic adjustment valves to manual adjustment. 3: Open the manual valve for cold air on the instrument panel (external air) and adjust the air pressure of the pneumatic valve at this moment (the pressure is the same as the compressed air pressure). Adjust the intake pressure of all pneumatic valves (0.3mpa -0.4mpa)

4: Manually close valves V1201-V1210 and start them all in the closed state.

5: Open the compressed air intake valve (manual), slowly adjust the pneumatic control valve PCV101, and slowly open it until the pressure reaches the compressed air intake pressure.

6: Open pneumatic valve V1201 to pressurize MS1201, and open pneumatic valve V1203 to pressurize the pipeline. Open pneumatic valves V1206 and V1208. Open the manual valve to purify the air into the cold box V101 valve, and pressurize the distillation tower. Open the LCV-1 valve to automatic mode and open the product nitrogen vent valve PCV102 (with moderate opening, control the flow rate of FIC102 between 150Nm3/h-200Nm3/h)

7: Turn on the internal compressor of the refrigerated dryer (one or two depending on the actual situation).

8: Turn on the pneumatic control valve PCV103 of the heating furnace to automatic mode (when there is insufficient gas at the beginning of the start-up, PCV103 is usually completely closed), moderately open the manual valve V1212 for purified air to enter the electric furnace, and supplement the air for the heating furnace (based on the moderate opening of PCV103), then turn on heating furnaces PL202-5 and PL202-6.

9: Observe the reading of the upper tower pressure PIC5, which reaches 0.25mpa (or above). Moderately open the pneumatic control valve PCV-5 and prepare to start the expander.

10: Open the manual valve and adjust the bearing gas pressure (above 0.50mpa) and sealing gas pressure (around 0.15mpa) of expansion machines 1 # and 2 #. Open the manual valves V402 and V404 at the outlet of the expansion machine.

11: Turn on the expander. Open manual valve V405 (to supplement gas for the expander), open expander solenoid valve 1 # or 2 # (at this moment, the expander solenoid valve indicator changes from red to green), moderately open the pneumatic control valve HC-401 (HC-403), slowly increase the speed of 1 # (2 #), and when the speed SIAS-401 reaches 20000rpm, maintain it for a period of time, then continue to increase the speed to around 28000rpm.

12: After the outlet temperature TI-402 (TI-404) of the expansion machine gradually decreases, in order to accelerate the refrigeration efficiency, the 2 # expansion machine can be turned on, and both expansion machines can work simultaneously. Open Method System 1 #.

13: As the cooling effect of the expansion mechanism increases, liquid level begins to appear in the lower tower. At this moment, the manual adjustment valve V405 can be moderately or completely closed according to the speed of the expansion machine.

14: As the liquid level in the lower tower increases, the temperature in the upper tower will gradually decrease. Moderately adjust the opening of PCV5 valve to gradually increase the pressure of PIC-5 to 0.30-0.32MPa, and the liquid level will slowly appear in the upper tower. When the liquid level LIA-2 appears in the upper tower (about 150mm is sufficient), close the 2 # expander and moderately until the manual valve V1212 is completely closed. Simultaneously open the manual valve inside the instrument air and close the manual valve outside the instrument air.

15: Change the program from manual to automatic, pause the program to run, and change the pneumatic control valve PCV101 to automatic.

16: When the liquid level LIA-2 in the upper tower rises to 800mm, open the manual valve for measuring nitrogen purity and humidity. At this moment, the computer interface will display the measured oxygen content, and at the same time, observe the differential pressure PdI-1 between the upper and lower towers. Observe the intake volume of FI-101, which is approximately (2000Nm3/h-2400Nm3/h)

17: As time goes by, the liquid level in the lower tower gradually increases, and the oxygen content in the produced nitrogen will gradually decrease. At this time, the program enters an automatic running state, so the step-by-step program will continue to move downwards. When the pressure relief step is reached, moderately open the manual pressure relief valve V1213 to release the pressure of MS1201 within 1200 seconds (less than 0.03mpa). If the pressure is not completely released within 1200 seconds (not less than 0.03mpa), the program will automatically enter the delay stage. The opening of the manual pressure relief valve V1213 should be appropriately increased, and the program delay time should be recorded. After reaching the next step (heating), reduce the delayed time (restore the original time data after the heating is completed and reaches the cold blowing step).

18: From then on, after about 30 hours of operation, the lower tower temperature TI-1 will be around -164 ℃, and the differential pressure PdI-1 between the upper and lower towers will be between 2.8kpa and 3.2kpa. The purity of nitrogen will gradually increase. After reaching 10ppm, moderately open the nitrogen vent valve PCV102 and increase the gas output. After maintaining for a period of time, the purity of nitrogen will continue to improve. When it reaches 3ppm, the product nitrogen can be sent out