Steam Turbine Megawattage spikes
Steam Turbine Megawattage spikes
(OP)
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?
Is there anyway to fix this without doing a total plant outage?
RE: Steam Turbine Megawattage spikes
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.