Power plant mothball procedures 1

[steambreath]

Must lay up a fossil fuel power plant- boilers turbines generator and balance-of-plant for and extended period of time._Any suggestions for an extended, cold weather mothballing?

 

[pmover]

steambreath,

suggest contacting the equipment mfg and obtaining information from them.

moisture is a serious concern. remove all moisture, seal the equipment (vents, bleeds, etc.), think about nitrogen purge, placing dessicant bags inside equipment, rotating machinery needs to have shafts rotated periodically, air intakes and exhaust openings need to be tightly sealed (insects and rodents like to make homes inside).

not sure what to do about electrical openings (if any), enclosures, control panels, display devices, instruments, etc.

general housekeeping to keep the facility fire-hazard free. dust, spider webs, moths, lint, etc. are good sources of fuel.

good luck!
-pmover

 

[MJCronin]

Steambreath...

As always, pmover's comments ate spot-on......

Usually there is some change of operators or management between long periods of layup.

Consider having a set of marked-up PIDs with the final positions of valves/devices etc. Consider a low pressure (5-10 psig)nitrogen blanket for some components. Install gauges for monitoring.

In order to protect your investment, do not forget that some large motors require periodic (semi-monthly ?)rotation of the rotors to prevent sagging and failure. In order to accomplish this, you may have to decouple the motor from the device driven.

Some large motors may also require internal heaters in order to keep them dry. Contact the motor vendor for requirements.

I would drain all lubrication sumps and squirt in preservatives for that purpose.

Develop a checklist for the caretaker to walk around an check things....

My opinion only

 

[unclesyd]

Atop of the advice given above there is one area that is often missed and can cause further damage. As stated above moisture is a killer and any large equipment piece will sweat. If at all possible drain the oil for the equipment and install the proper safeguards to keep it offline. On most turbine there is provision for allowing rotation while down.`
The reason for this precaution is from several experiences I've had over the years with mothball equipment. The last was two large centrifugal compressors that were properly cocooned and stored outside in Northern Alabama for a winter and summer. The oil had been left in the machines as a precaution. As the machines had just experienced a complete work over prior to cocooning they were set without any inspection. Duly hooked up the startup oil pumps were turn on and they could couldn't get any pressure to the bearings. As the other machine hadn't been set temporary power was supplied to the oil pump and again no pressure at the bearing. The cover from the gearbox was removed which revealed that the oil reservoir was reed gelatinous mass, MIC, Every thing below the oil level had been attacked and as the oil level has risen about 5 inches due to he mass of the MIC it essentially took out every thing. The only thing left discernible was the Aluminum housing for the thrust bearing. The result that one of the compressors was scrapped while the other was refurbished at great expense.

Again as posted above use your equipment manufacturer's expertise and consult with inhibitor suppliers. Don't be afraid to ask.