How does a RB211 Gas turbine cool, lubricate and control RPM?
Not sure about that model, (I’ve only worked on Ruston TB and TDs) but lubrication is provided by 3 oil pumps – one AC, one DC, one mechanical. The AC electric pump is in operation when the turbine starts, and until it reaches 65% of minimum speed, then switches off. This is when the mechanical oil pump (run off the gearbox) is running fast enough to provide lubrication to all the bearings. When the machine is shutting down, at 65% min speed the AC pump will kcik in to provide lubrication. If AC power fails, the DC battery powered oil pump will come on while the machine shuts down (sometimes called ’emergency lub oil pump’) Cooling is provided by 2 x water cooled external tube-bundle heat exchangers (this will change depending on location, availability of cooling water etc) Speed control depends on what the turbine is driving. For gas compressors, speed control usually revolves around the machine trying to achieve a setpoint at the discharge. If the machine is not achieving discharge p
