Can anyone help me to find the vapour pressure of diesel fuel? I need it for NPSHA calculations. Does anyone know a good site/resource for this kind of data?
Sorry, I didn't explain the situation well enough. The turbine/generator is running continuously at 3000rpm. The vibration events come and go. The vibration increases to a peak and then decreases with the same gradient and returns to normal vibration levels. This process takes 10-20 minutes.
I expected that bearing oil temperature would increase due to the increased friction associated with vibration in a journal bearing. Let me know if this is wrong, we have considered oil flow problems but as yet have not run any tests for it.
The problem has not occured for some time as the...
This is a single stage back pressure turbine with an impeller oil pressure governor. The governor inpeller and main oil impeller are on a small 'stub' shaft outside of bearing 1 so it is only supported at one end.
The prox probes look onto this stub shaft very close to the bearing... it may be...
byrdj,
The increase in steam flow is more steam at inlet/nozzle plate. This is due to opening of governor valve. We do see an increase in MW with increase in steam flow...as expected.
The turbine only has one stage. I have entertained the idea of a loose component in steam path as you...
Thanks for the useful replies everyone. We have investigated control system feedback... the reason I beleieve that the machine is not being externally excited(or excited by control system)is that the peak in amplitude occurs at running speed of 50Hz. The machine's critical speeds/natural freq...
yes, the vibration is seen by proximity probes... there are also accelerometers on the bearing casing which do not show much action.
On the steam side, there is normally a rise in steam flow when the vibration event occurs. This happens after vibration begins... seemingly a result not a cause...
Sorry... should have given more info.
It occurs out of the blue during normal steady running speed.
There are a governor & auxilliary oil pump impeller on stub shaft. This vibration is shown by x-y proximity probes. It is defineitely 1x... no 1/2x vibration.
Phase undergoes changes as well...
It is a steady operating speed ocurrence. There is no indication of 1/2x running speed vibration usually associated with a rub. I agree it must be some kind of excitation but can't find the cause.
I have a steam turbine that suddenly undergoes high radial vibration at the front bearing, this then subsides after about 10 minutes and returns to normal running conditions. There is not much vibration on the bearing casing... only the shaft. Any ideas what is causing it?
I have a steam turbine/generator that undergoes huge escalations in 1x radial vibration at the front turbine bearing. The odd part is that the vibration increases greatly and then reduces to normal running conditions over about a 10-20 minute period. Has anyone seen this before?