Why is there such a large difference in temperature behind the machine after the expander trips and is restarted?
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This post was last edited by you*n*nyou on 2012-2-29 at 19:53. Our expander shut down once a few days ago due to high temperature before the liquid oxygen pump tripped, and then it shut down again due to excessively high vibration levels after being restarted. Although it didn’t shut down again after that, the vibration level was found to be slightly higher by 1 um compared to before. Please share your thoughts – what factors can cause vibration in an expander? Let me reveal a little more: it has been found that the efficiency of this expander has decreased. With no changes in speed, nozzle opening, degree of expansion, temperature before the machine, or pressure, the temperature after the machine has become much higher than before. It used to be around -173°C, but now it is -153°C. What could be the reason for this? Could it be related to the high vibration levels of the expander?
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It can’t be that much off, right? If what you say is true, then it’s possible that the temperature gauge is broken
Since it is a chain-type vehicle jump, it is necessary to check whether the automatic control mechanical transmission mechanisms associated with each chain have become loose due to weak mechanical connections. It is recommended to inspect all valves related to interlocks as well as the instrument control solenoids, especially to check whether there is any looseness in the emergency shut-off valves and nozzle control connections, and whether their opening degrees match the actual values. (For reference)
Check whether there are any changes in the pressure ratio of the booster and the pressure behind the nozzle; rule out instrument issues first, and then look for problems with the machine itself.
Is it certain that there’s no problem with the gauge? I think there must be an issue with it. If there’s no serious problem with heat exchange in this area, then why is the inlet temperature changing so much? You can contact the manufacturer to ask if there is any issue with the seal ?
Based on your description, it is possible that 1. \"the bushing material has loosened, the bushing material is damaged, the fit of the bearing housing is loose, and the bearing clearance is too large, etc.\" 2. There may be an internal leak.
I suggest you take a close look at the parameters before and after the vehicle left the vehicle before conducting an analysis. A change of 1 um in the vibration value is not significant for an expander; with such a large difference in outlet temperature, has the outlet backpressure increased? Or it is suspected that the nozzle or impeller may have been slightly damaged during the jump-out process