turbine speed
turbine speed
(OP)
Hello,I work at a large fossil fuel plant an had a question on turbine speed.we have 4 steam turbines.2 cross compound and 2 tandem compound.they all operate at 3600 rpms.my question was how do you know when there at 3600 rpms?Looking for something more in depth than a basic answer.any input would be greatly appreciated. I'm new to this field and looking for some solid advice.thank you all.






RE: turbine speed
Are large circuit breakers tripping out?
Are there loud, bad sounding noises coming from the turbine hall?
Are the pressure safety valves blowing off a lot of steam?
Are people running around in an excited state saying things like; "Holly Gadzooks!", "Jumpin' Jupiter!", "Pole Slip!" and "Never did that before!"
If none of these things are happening than all of the turbines are probably running at the proper speed.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: turbine speed
When I worked in a fossil/steam generating plant I could generally tell by the relative pitch of the sound of the turbines against the power frequency hum of the transformers in the plant roughly how fast the turbines were spinning; try it sometime.
If the generators are directly coupled to the turbines and are 60 Hz synchronous machines synchronized to the grid, the speed of the turbine will be locked to that of the grid at very close to 3600 RPM.
Won't anyone on site answer your questions?
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: turbine speed
RE: turbine speed
RE: turbine speed
Joking aside though, turbine controllers are generally programmed to regulate shaft speed rather than frequency, so from the generating site's perspective speed is probably of greater interest. After a while you get quite adept at mentally converting speed into frequency. That's when you know you have been doing it too long.
RE: turbine speed
About 20 years ago, we did... sort of, for a few seconds. Operator error caused a 280 megawatt steam turbine driven generator on turning gear to be motorized by direct connection to the 60 Hz grid. Needless to say, there was sudden acceleration that was soon halted by a self-destructing combination of overheating, lubricating oil fire, cooling hydrogen explosion, and mechanical vibration breaking the machine's anchor bolts out of the turbine / generator pedestal. Never made it to 3600 rpm... but the machine tried its best. Repairs / rebuild, that I was involved with, took 18 months.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: turbine speed
RE: turbine speed
RE: turbine speed
That sounds like a very messy incident.
RE: turbine speed
The stator had to be shipped, by special rail car, back to GE for a complete rebuild. The steam turbine was rebuilt on site. I handled the on site lifting / transport of the stator and the pedestal rebuild - anchor bolts 4" diameter x 6 feet long had broken out of the concrete. The entire effort was a corporate high priority project, we were able to get good techical and contractor support.
If there was an upside to the incident, the then 20 year old steam turbine was upgraded with more efficient modern turbine blades to get several more megawatts out of the unit.
wayne440 - The operator was not publicly "blamed", but I don't know what happened behind closed doors - glad I was not there.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: turbine speed
Little damage to the unit itself, but the entire turning gear casting was ripped clean off of its mounting studs and tossed out into the adjacent shipping channel 1000 or so feet away, exiting the plant through a hole that it tore in the roof in its haste to depart and arcing cleanly through the air well above the intervening 115 kV switchyard. Thankfully no vessel was present at the time...
Turning gear was fished out of the shipping channel, rehabilitated and re-installed. Never heard the discipline story on that one, either...
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: turbine speed
Looking back there were a few days where we had a guardian angel watching over us - the manual synchronisation about 60° out of phase, the inadvertent admission of steam to a stationary machine with everything wide open... it's easy to forget just how much power is unleashed.
RE: turbine speed
I also concur with the other posters about the sound / feel of the units when they are running at full speed. You may not be able to explain what it sounds like, but you know when it sounds different.
RE: turbine speed
I suppose there is automated equipment to do this now.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: turbine speed
When the incoming unit was connected correctly the needle would jump to the 1 o-clock position.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: turbine speed
RE: turbine speed
1) A shaft mounted permanent magnet generator that drives flyballs which control speed/load via hydraulics
2) Toothed gear on shaft using a proximity probe to count the teeth as they pass by used by a digital governor
3) looking at the frequency of the generator voltage signal - used for synchronization and digital governor
RE: turbine speed
What's up with the post-and-ghost?
Numerous individuals have supplied what apppear to be legitimate, well-considered, and relevant responses to your query, yet we have never heard from you again...
Have any of the responses been of value to you? If so, please let the readership know; it's the considerate thing to do.
I'm not trying to scare you off, in fact far from it; I for one continue to learn from participating in these fora, and I'd encourage you to keep up the contact. And remember, as others have stated: providing more information leads to better answers.
I hope we hear from you!
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: turbine speed