Development of a 20MW-Class High-Efficiency Gas Turbine L20A

The L20A gas turbine is a newly developed 20 MW class single-shaft machine. With its high simple-cycle efficiency and high exhaust gas temperature, it is particularly suited for use in distributed power generation, cogeneration and combined cycle applications. A design philosophy has been adopted for the turbine which includes a high efficiency transonic axial-flow compressor with eight can-type combustors and a high inlet temperature of 1250°C. This results in a thermal efficiency of 35% and an overall thermal efficiency of 80% for cogeneration system. In addition, the NOx emissions from the combustor is low and the L20A has a long service life. These features permit long-term continuous operation under various environmental limitations. Due to the engine’s high efficiency and its low component totals, the lowest life cycle cost is achieved. Development testing has verified that the performance, the mechanical characteristics and the emission have satisfied the initial design goals. The engine has been in operation from November 2001 as the first operating unit in a co-generation system at Kawasaki Akashi Works.