Tosiba 300mw steam turbine rotor long, short etc.
Tosiba 300mw steam turbine rotor long, short etc.
(OP)
Hope I am in the right place for this.
I have a toshiba 300mw steam turbine that whent down on HP diff. expansion we lost stages 5 to 12 what I need to know is what should be done when you have the following problems.
1. Rotor Long and just going into alarm
2. Rotor Long and in red zone
3. Rotor short and just going into alarm
4. Rotor short and in red zone
5. High Bearing temp
And what are some other Abnormal operations to look for and what to do for them.
Thanks for the information
I have a toshiba 300mw steam turbine that whent down on HP diff. expansion we lost stages 5 to 12 what I need to know is what should be done when you have the following problems.
1. Rotor Long and just going into alarm
2. Rotor Long and in red zone
3. Rotor short and just going into alarm
4. Rotor short and in red zone
5. High Bearing temp
And what are some other Abnormal operations to look for and what to do for them.
Thanks for the information





RE: Tosiba 300mw steam turbine rotor long, short etc.
When in a long condition, the correction is to lower the steam tempurture being admitted to the turbine. besides boiler firing controls, transferring from full to partial arc will help.
Once long alarm is reached, and there are no ways to reduce steam to metal mismatch, the unit will need to be returned to turning gear. I have seen it take 8 to 12 hours to get back to normal due to not prewarming.
When the unit is tripped, it will go slightly longer as the speed decays. The centerpedal makes the rotor short.
Going Short---the steam got to cold. so opposite actions to get steam temp back up or trip out
bearing hot--- shut down, verify sight glass drain flow, watch for very rapid increase in temp on coast down.
Was your rotor long damage the result of trying to load too quick from a cold start?
RE: Tosiba 300mw steam turbine rotor long, short etc.
RE: Tosiba 300mw steam turbine rotor long, short etc.
For a rotor to go long that much I would expect the steam at the turbine had to be 200F hotter than the turbine casing.
Did you have wet insulation?
RE: Tosiba 300mw steam turbine rotor long, short etc.
on T/G for 2 weeks
Rolled S/T @ 0317 start
HP upper metal inner casing metal temp 144f
HP lower metal inner casing metal temp 141f
IP upper metal inner casing metal temp 127f
IP lower metal inner casing metal temp 131f
IP crossover 143f
LP induction 289f
0335 S/T at 800 rpm a 136 min soak this is a auto
HP upper metal inner casing metal temp 200f
HP lower metal inner casing metal temp 196f
IP upper metal inner casing metal temp 130f
IP lower metal inner casing metal temp 136f
IP crossover 167f
LP induction 289f
0632 S/T at 3600 rpm a 20 min soak
HP upper metal inner casing metal temp 257f
HP lower metal inner casing metal temp 252f
IP upper metal inner casing metal temp 193f
IP lower metal inner casing metal temp 216f
IP crossover 333f
LP induction 401f
0652 S/T on grid Auto Load to 15 MW 20 min soak
HP upper metal inner casing metal temp 270f
HP lower metal inner casing metal temp 262f
IP upper metal inner casing metal temp 233f
IP lower metal inner casing metal temp 262f
IP crossover 391f
LP induction 412f
0710 started raising load on S/T
HP upper metal inner casing metal temp 291f
HP lower metal inner casing metal temp 274f
IP upper metal inner casing metal temp 293f
IP lower metal inner casing metal temp 327f
IP crossover 453f
LP induction 421f
1st stage inner surface metal 584f
1st stage outer shell surface 497f
at this point everything was going as normal
the HP dif went from .49 at start to .293 but this has been normal and as we load up it would come back but this time it didnt.
RE: Tosiba 300mw steam turbine rotor long, short etc.
Is this a dual admission configuration? I don't know the term LP induction. but if this is an LP admission, i would think there needs to be some cooling steam going thru the HP. So if this is the case, check the valving for HP reverse flow
From My experance, that HP shell was way to cold to roll the unit. and by being cold the shell will be short. addidng any heat to the rotor either by steam (or windage) would make it grow long rapidly.
So with out getting deeply envolved with some configuration drawings, more operation data and OEM instructions, I want be able to add any more.
Maybe some else can