Gas turbine unit

Claim 1

In a gas turbine power plant unit, including in sequence, an expansion turbine connected to the input end of a compressor and a main turbine connected to the output end of the compressor by way of a combustion chamber for supplying a flow of hot gas to drive the main turbine, the expansion turbine being provided with adjustable guide vanes for directint the flow of air thereto; the improvement which enables the expansion turbine to operate alternately as compressor and auxilliary turbine without use of clutch means with consequent minimized power losses, said improvement comprising: (a) a rotor for said expansion turbine, comprising a series of fan blades having the profile of a symmetrical air foil; (b) said guide vanes being adjustable relative to said fan blades to direct the flow of air to said air foil blades to vary their angle of attack relative to the air flow to provide the sole means for continuously alternating the operation of said expansion turbine between maximum compressor operation and maximum turbine operation in response to variations in power plant load conditions between full load and idle load respectively; (c) said expansion turbine, said compressor, and said main turbine being mounted on an uninterrupted common shaft.