Faults occurring during CNG refueling at a CNG filling station
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There is a CNG filling station, with a CNG compressor in front of it. Once the fourth-stage drainage valve of the CNG compressor is opened, the CNG filling station stops filling gas; then the inlet valve of the CNG filling station is closed. After waiting for a while, the inlet valve is opened again, and the CNG filling station resumes normal operation. I’m not sure what’s causing this issue.
I’m not too familiar with the CNG process; I’m just making some guesses. What does it mean when CNG indicates that filling has stopped? Does it mean the filling station is no longer functional, or was the filling process interrupted suddenly? Could it be that the decrease in outlet pressure after the drain valve is opened is causing this problem? Try reducing the opening of the drain valve
It is best to draw a simple single-line diagram; it is possible that the opening of the drain valve could cause the liquid in the pipeline from the compressor to the gas filler to vaporize.
It’s caused by the low pressure after waste discharge
Is it necessary to discharge waste while filling with gas? Just avoid the time when gas is being added, that’s all. If it’s necessary to discharge waste gas during inflation, reduce the flow rate of the waste gas; once the condensate (I assume that’s what it is) has been discharged, close the valve promptly. To get rid of all the pressure, it certainly can’t be through discharge; the CNG material has been released, meaning it’s been vented
That’s not the case. The natural gas that comes from oil fields is processed and compressed before being filled into tankers. Due to the requirements of the compression system, it’s necessary to discharge waste gases. Now, as soon as the waste gas discharge mechanism is activated, the filling process stops.
The last edit to this post was made by Youyanbujie on 2017-6-20 at 16:59. I don’t think it’s correct; as for the wastewater after level 4 compression, I believe it should be like this. Does this tank come with a drain valve and a level gauge as well? And is it possible that there are also tanks with a similar function between other compression stages?
What is being discharged when you open the drain valve? Where is it in the queue?
The waste fluid is water, with a small amount of engine oil as well. Into the buffer tank before it is compressed by the compressor
That’s it; this is the inter-stage buffer sedimentation tank. There’s no need to keep it running with waste water flowing through it. If exhaust is being discharged when it’s turned on, it can be turned off. If there is a level gauge, check it; discharge is initiated only when there is a liquid level, otherwise not.
There should be a gas storage tank assembly behind the compressor, right?