What is the purpose of a control oil system in a turbine?
To act as the shutdown and speed control mechanism. The turbine will not start unless the control oil pressure has been substantiated, and as most interlocks or shutdowns use it to dump the oil pressure and thence shut the throttle valve, it’s a very important part of the system.
Once the turbine is running, the control oil to the throttle valve spindle is controlled by the governor, which allows more or less oil to the throttle spindle and thereby regulates the speed.
There are many control oil circuits on the web which you can look at to choose which relates to your system.
The control oil system usually runs off a branch of the lubricating oil system, using the same engine driven pump. An auxiliary emergency oil pump is also supplied in the event of low LO pressure, and also - not always - a header tank to allow enough oil for the bearings in the event of a power failure.
