What are the reasons for the rapid drop in low-pressure nitrogen pressure, and how to address it?
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What are the reasons for a rapid drop in low-pressure nitrogen pressure during system operation, and how should it be addressed? Thank you
In the event of a leak in the low-pressure nitrogen system or an increase in consumption by certain users, it is necessary to reduce the pressure from the ultra-high-pressure nitrogen system to low pressure; meanwhile, the dispatch team should be informed to help maintain nitrogen balance
The valve is leaking internally, resulting in insufficient N2 supply from the air separation unit; notify the dispatch team and switch from high pressure to low pressure.
If there is a leak in the low-pressure nitrogen system or it is being used individually, then the fire-fighting nitrogen valve S1103 must have opened
Regarding the sharp drop in low-pressure nitrogen pressure, there may be several reasons: one is a sudden increase in the demand for low-pressure nitrogen by downstream users； Secondly, there is a problem with the self-acting pressure reducing valve or control valve in the upstream section, which handles the transition from high-pressure nitrogen to low-pressure nitrogen; of course, it’s also possible that there is an issue with the pressure of the high-pressure nitrogen itself ； Third, consider whether there are any leakage points in the low-pressure nitrogen pipeline – all of these factors need to be taken into account!
The first thing to do is to contact the air separation unit to check whether it is an issue with that unit; inform the dispatch team to switch from high pressure to low pressure and ask the air separation unit to pay attention to the high-pressure levels in order to maintain operation, while simultaneously investigating the cause of the problem
Compare the nitrogen pressure with the pressure of nitrogen supplied by the air separation unit to determine whether the problem lies with the air separation unit or the user, and then conduct a more thorough investigation to find the leak.
The low-pressure nitrogen pipeline network is generally supplied by the air separation unit for use throughout the plant; if the pressure of low-pressure nitrogen drops too rapidly during operation, it should be reported to the dispatch team promptly. This falls under the category of public systems, which must be understood and balanced by dispatchers.
The low-pressure nitrogen definitely comes from the pipeline network, as there are users throughout the entire plant. If the output pressure from the air separation unit does not decrease, it indicates that there are significant leaks in various components of the subsequent system; it is necessary to conduct a thorough inspection for leaks.
Possible reasons include: a sudden increase in the demand for low-pressure nitrogen in gasification or other processes, resulting in a drop in pressure； Problem with the low-pressure nitrogen outlet valve in the air separation unit.
It is also possible that there is a leak in the low-pressure nitrogen pipeline; if everything else is normal, instrument problems cannot be ruled out either. Of course, once the pressure drops, it is necessary to contact the dispatch team for prompt handling.