Frequent trip due to burner pressure difference
Thread Content
GE gasifiers, and the high-pressure slurry pumps in Shenyang, frequently shut down due to low burner pressure differences. This issue also occurs with new burners. The phenomenon is as follows: the burner pressure difference gradually decreases, while the slurry flow rate remains normal and stable; there are no obvious abnormalities with the high-pressure slurry pump. When the burner pressure difference reaches its lowest level (either 100 KPa or 30 KPa), it may stay at that level for a period of time (from a few minutes to several hours), after which it suddenly returns to normal – in most cases, this leads to the shutdown of the system. The only modification made to the high-pressure coal slurry pump was the removal of the buffer tank at the inlet end, with a blind cover being installed in its place. I seek guidance from all the experts out there
This post was last edited by pyp222 on 2018-11-9 at 10:59. I think you should first check and confirm whether it is indeed a decrease in slurry pressure that is causing the continuous decline in burner pressure difference. We know that the burner pressure difference is the difference between the pressure in the gasification furnace and the pressure at the coal slurry burner tip. If, with stable pressure in the gasifier, the burner pressure difference continues to decrease, it means that the pressure in the slurry pipeline is also continuously dropping. You can then check the trend of the pressure readings at other monitoring points along the slurry pipeline, as well as those at the outlet of the high-pressure slurry pump; additionally, you can observe the changes in the local pressure gauges during inspections by on-site staff to see whether these pressures also drop significantly as the pressure difference at the burner decreases. When the burner pressure difference is normal, it ranges between 0.6 and 1.2 MPa. In the case in question, the burner pressure difference has dropped to 0.1 MPa or even lower. Therefore, if the pressure in the slurry pipeline is indeed low, then the pressure values at other pressure monitoring points along that pipeline should decrease by at least 0.5 MPa. If the pressures at these pressure monitoring points are all normal with no obvious downward trend, it is likely that there is a problem with the sensing elements of the burner pressure difference instruments. The instrumentation technicians should check the pressure sensing diaphragms and transmitters at the two pressure sampling points (those located on the slurry burner pipeline and the gasifier furnace pressure sampling pipeline) and replace them if necessary. If these pressure monitoring points also show a corresponding downward trend as the burner pressure difference decreases, it is very likely that there is a problem with the slurry pump; therefore, the slurry pump should be checked carefully. For anything not mentioned, please have other colleagues add to it
I heard that ZTHC dropped out for this reason; you can ask
Recommendation 1: Check whether the pressure in the accumulator at the outlet of the high-pressure coal slurry pump is stable. 2. What is the quality of the coal slurry, and is it stratified? 3. Changes in coal quality: such coal may tend to coking at the burner, thereby affecting the atomization effect
Thank you for your analysis; all the other pressure gauges at the outlet of the slurry pipeline are showing a downward trend
First, determine if there is a problem with the instruments; then check whether the slurry flow rate has indeed decreased, by looking at factors such as furnace temperature, the oxygen-to-coal ratio, and furnace pressure. Also, verify whether there is any uneven spraying from the burners
This post was last edited by pyp222 on 2018-11-12 08:46. Since there are corresponding trend changes at other pressure monitoring points along the slurry pipeline, it is very likely that the problem lies with the pipeline itself, the slurry pump, the slurry tank, or the quality of the slurry. Since the original poster mentioned that both the slurry flow rate and the slurry pump are operating normally with no significant abnormalities, I believe the problem is most likely to lie before the inlet of the slurry pump – including the inlet pipelines, the slurry tank, and the quality of the slurry. The original poster should focus their investigations in this area. On that day, such a situation can also occur due to severe wear of the burner. If it’s a newly installed burner that shows this behavior as well, then the factors mentioned above should be considered first. If the burner has been in use for some time, then in addition to those factors, issues related to the burner itself need to be taken into account.
You guys are amazing – you actually dared to remove the buffer tanks! Removing this component is the reason why you end up jumping out of the vehicle – the pump’s performance is unstable
Removing the inlet buffer tank of the slurry pump carries certain risks, but it is not considered to be the main cause