Performances of the Chemical Gas Turbine System and Comparison with Other Gas Turbine Based Cycles

This paper describes a novel combined cycle based on a “Chemical Gas Turbine” system. The system consists of fuel-rich and fuel-lean combustors with their gas turbines, recuperators, and a steam bottoming cycle. Important features of this system are the gas turbine with C/C composites blades and the fuel-rich combustion techniques. These techniques result in no cooling of turbine blades and much higher turbine inlet temperature, therefore, much higher thermal efficiency. This paper analyzes the energy, exergy, and heat exchanger sizes of the proposed system. Furthermore, optimizations from pressure ratio aspects are discussed. All results are compared with a simple gas turbine system and a conventional combined cycle. The following results were obtained: the chemical gas turbine system achieves a thermal efficiency of 64%, and low exergy loss in the combustion processes. In addition, characteristics of the system are similar to the simple gas turbine system. This paper was presented at the ECOS'00 Conference in Enschede, July 5-7, 2000