Design point analysis of two-shaft gas turbine engines topped by four-port wave rotors for power generation systems
General Department, National and Kapodistrian University of Athens, Evripus Complex, Psachna, 34400, Greece
Abstract: Wave rotors are rotating equipment designed to exchange energy between high and low enthalpy fluids by means of unsteady pressure waves. In ground power plants, they can be used as topping devices to existing gas turbines aiming to improve their performance characteristics. A four-port wave rotor is an attractive configuration to be integrated into the gas generator of a two-shaft gas turbine, typical for power generation and propulsion systems, by slightly modifying the architecture of existing engines. In particular, in the present article the wave rotor-topped engine utilizes the same compressor, combustion chamber and turbine inlet temperature of the baseline engine. Cycle analysis for two-shaft gas turbine engines topped with four-port wave rotors is studied and their performance at design point is compared to the performance of the baseline engines accordingly. It is concluded that important benefits are obtained with respect to the ones of the baseline engines in terms of specific work and specific fuel consumption. Furthermore calculations by varying the pressure ratio within the wave rotor and the pressure losses in the ducts connecting the wave rotor to the engine’s components indicate the effect on performance, for engines with different compressor pressure ratios and turbine inlet temperatures.
Keywords: Pressure exchanger; Wave rotor; Gas turbine; Turboshaft; Ground power unit