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Tuesday, May 02, 2006

Fear and loathing in Bakersfield

Last night was a good night to forget. We've begun cycling the plant due to poor economics for electricity at night. Last night was our first shutdown to be followed a few hours later by a startup.

The oil leak that I thought I'd fixed in the Humpin' post, I didn't correct. Turns out this leak will require competent millwrights to correct, not a worn out operator. Oil is being flung out along the shaft of the generator past a seal. This assembly was taken apart to inspect the hydrogen seals during the outage, and apparently it's not together quite right.

The upshot is that this leak will continue until further notice, and it's nasty. The shaft is flinging the oil everywhere, and the fan is distributing it as well. It's about 1 inch deep in the compartment each time we shut down. No fun to keep cleaning up the same mess over and over. These GE lube oil systems remind me of older Harleys. No matter what you do, they're going to leak oil, from every flange, valve stem, and tubing fitting.

So last night, shortly after we got the plant shut down, started adding oil to several pieces of equipment. We got a pallet of drums out of the oil storage area, located the necessary hoses and pumps, and started refilling. Meanwhile the steam turbine rolled to a stop.

Unfortunately steam turbines have to be continuously rolled until they cool, and the turning motor failed to start... so we fought for an hour and a half to start the turning motor, while rolling the steam turbine manually, with great effort. The rotating assembly weighs several tons, being composed of a generator rotor, High, pressure low pressure and reheat turbines. Lots of iron and copper to roll over by hand. Couldn't get any electricians to come in and fix it either.

Finally for one reason or another, the turning motor started... but by then the hot steam turbine rotor had bowed. We had eccentricity alarms when the steam turbine first rolled, but shortly before start-up the bowing worked its way out.

Anyway, shortly after getting the steam turbine to roll, it was time to fill the boilers and start the gas turbines! Geez I barely had time to get the feedwater pumps lined up and started before running back to the control room to keep an eye on the startup with the somewhat less experienced dudes I'm working overtime with.

So we started both gas turbines, began developing steam pressure and by the time we met all the conditions necessary to admit steam into the steam turbine, its eccentricity was back to normal. Whew! What a night! Happily we made startup on schedule.

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