The problem of sawtooth fluctuations in turbine vacuum
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The turbine vacuum level shows a sawtooth pattern of variation, rising slowly from 13 to 21 within ten minutes, reaching its peak before suddenly dropping back to around 13, and this cycle repeats itself. The surface cooler has just been cleaned as part of the parking maintenance. I earnestly request the guidance of all teachers!
1. Verify on-site whether there is such a trend in vacuum level changes. 2. If no such situation is found during on-site inspection, it is recommended to contact the instrumentation team to calibrate the measurement points.
Check the extractor or vacuum pump: whether there are regular fluctuations in the pressure at the outlet of the steam ejector or jet pump, and whether the water pressure of the vacuum pump fluctuates
We have encountered this situation before as well; in the end, by contacting the control department and installing the transmitter near the sampling valve, things improved significantly.
The steam pressure might have an impact; I’ll check and confirm later
Is the height of the liquid seal layer of the atmospheric safety valve stable?
Well, I’ll check that later as well; I haven’t touched the valve that connects the water pump to the atmospheric safety valve in a long time
1. Check whether the gauge is accurate； 2. Check whether the steam nozzles of the surface cooler are unobstructed ； 3. Check whether the cooling water system is operating properly.
Check if there are any \"U\"-tubes in the pressure measurement pipeline It’s possible that steam condensation has created a liquid seal; when the pressure difference reaches a certain level, the condensed water is drawn back, resulting in regular sawtooth-like fluctuations. Try changing the pressure measurement pipeline and eliminating the \"U\" shape