Steam Turbine Megawattage spikes

[sonckerr]

Our isolation valves cannot fully stop the steam from getting to the steam turbine (combined cycle plant). At around 40psi, the MWs drop or jump by 10-20 MW within a second. I think it is a crack on the stem of the control valve. Could it be something else?

Is there anyway to fix this without doing a total plant outage?

 

[racookpe1978]

What's your total power, and what is your steam cut-out valve and governor valve configuration?

The governor valves downstream of the TV's are not intended to completely stop steam flow - although they can bleed by as well with steam cuts, so I suspect one or the other of your cut-out valves controlling flow into the governor valve is leaking by: On past plants with real bad TV's, the turbine actually ran up to 30+ percent full speed as soon as steam was admitted past the main steam stop valves.

Have you opened the valves and done a blue check of the seats?

To fix the TV's you've got to shut down: Your workers will be inside the steam pipes.