Is it necessary to circulate oil for more than 30 minutes when starting the centrifugal compressor driven by a steam turbine?
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Our operating procedures for steam-driven centrifugal compressors require that the turbine lubrication oil pressure be normal; the disk drive can be activated only after the oil has been circulating for more than 30 minutes. Is it not okay if it’s less than 30 minutes? Why
There are some dogmas, right? Generally, once the pressure in the lubricating oil supply system reaches a stable level and oil return can be observed at the oil return sight glass, the machine can be turned over. It mainly prevents damage to the bearing caused by non-oil film friction between the shaft and the bearing shell. (For reference)
Agree with what was said above; one needs to think more
It allows the lubricating oil to flow to the areas that need lubrication, forming an oil film that prevents abnormal wear of the bearings.
Reply to 1#: With Buddha’s blessing. The elements listed in the specifications cannot be moved, but people can move them. As long as the lubrication pressure and temperature are appropriate, it’s possible to start rotating the disk; there’s no need to wait 30 minutes.
Allowing the oil to flow for a longer period ensures that there are no dead corners at the contact points between the shaft journals and bearing shells where lubricant does not reach
Strictly speaking, it must be done in accordance with the operational requirements; 30 minutes should be the minimum time required for the oil to reach all areas, that is, the sufficient time to ensure that the oil covers every part.
In addition to ensuring that oil covers every part of the lubrication system, is it also necessary to take into account the fact that within the oil system itself, the temperature varies in different areas due to the supply of lubricating oil, resulting in many temperature differences? After about 30 minutes, the oil temperature in each area should be able to stabilize, allowing for the final adjustment of the oil temperature
Lubricating the front bearing shells before turning the shaft is primarily for wetting; as for an oil film, it can be formed only after the rotor starts moving, as the oil enters the oil wedge due to adhesion. It must reach a certain rotational speed in order to form a stable oil film.
There’s no such requirement! Turning the turbine is done to ensure even heating of the unit, that is, during the pipe warming process. If you’re not planning to drive, there’s no need to turn the engine over urgently. As for the formation of an oil film, I think it is formed after driving. Because the rotor speed is relatively low. Of course, even in the absence of an oil film, it will not cause the Babbitt metal on the bearing shells to soften, as the shaft is rotated at a very low speed. ;P