Principal of Two-Shaft Gas Turbine Control System

Principal of Two-Shaft Gas Turbine Control System Points : Principal of Two-Shaft Gas Turbine Control System The fig shows the main features of a gas turbine control system. The fundamental requirement is to maintain the safety of the engine, regardless of how the operator moves the throttle lever or how the inlet conditions e.g attitude arc changing. The control system must en sure that the critical operating limits of rotational speed and turbine inlet temp are never exceed, and the compressor surge is avoided. The sensing of rotational speed prevents no problems and a variety of frequency measuring devices are available. Turbine temp on an the other hand is very difficult to measure It is not normally practicable to locate temperature probes at inlet to the turbine. Where the temp is very high and the temp is measured at some down stream location, typically at inlet to the power turbine on shaft power units. The temp used to protect the turbines are indirect measures of the critical temp. In the case of turbines with highly closed blades it is the actual blade temp. Which is important and this may sense by radiation pyrometer in advance engines. Analysis a transient performance over the entire range can be predict the maximum duel flow which can be used for acceleration with en counting surcharge or exceeding temp Limits, the variation of all the key controlled parameters arc wholly determined by the matching of the compressor, turbine and nozzle characteristic. It is important to realize that if the engine has fixed geometry, the study-state performance cannot be altered in any way by the controlled system, thermodynamic measurements, combined the vibration analysis of the lube oil can all be used for Gas turbine health monetching. The successful development of EHM system will result in gain in maintenance cost and over haul life and in the subject of intensive research.