Real over speed test
Real over speed test
(OP)
in steam turbines 364MW Units equipped with electronic main and back up over speed protection system ,how often should we perform real over speed test.
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RE: Real over speed test
I suggest checking with your insurance company as a good start. Otherwise once per year or after a major overhaul is quite common. Also if you replace any speed measuring components (within reason)
RE: Real over speed test
RE: Real over speed test
if the generator breaker was opened while the turbine remained reset, the emergancy governor speed should NOT be reached. The primary governor should control and limit peak speed less than EG trip speed. Now that was true with mechanical and anolog control systems. I don't know if it is true with digitals.
Now for the original question, I would refer to insurance carrier. I really no longer see the need to perform and actual and I recall suppliers use that as a sales pitch. I never saw the need nor pursued an actual speed test of the electronic backup on units with mechancal EG and if customer tested, I knew calibration data was much more acurrate than data taken during actual speed trip
RE: Real over speed test
I'd refer to turbine manufacturer's recommendations, or your insurance carrier, as previously suggested.
RE: Real over speed test
RE: Real over speed test
here is a copy of a newspaper report which provides some of the reports finding in laymans terms
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RE: Real over speed test
RE: Real over speed test
Steam turbines with centrifugal overspeed device need to be tested at real overspeed (10% of nominal speed), I've worked with 33, 66 and 135 MW steam turbines. As a back-up, is necessary to test a push button trip, after that one operator is checking the speed ready to trip the turbine with that button if mechanical device doesn't respond. sometimes is necessary adjust it. All emergency trip devices are tested once per year.
Manufacter manual for gas turbines 180 MW pemits simulate that test decreasing the set point, speed sensors are electronic too.
Bye there!
RE: Real over speed test
I'll try to remember to ask specificly tomorrow during Ovation's chance.