Cycle analysis of gas turbine-fuel cell cycle hybrid micro generation system

Hybrid systems, which are based on a micro gas turbine (muGT) and a solid oxide fuel cell (SOFC), are expected to achieve much higher efficiency than traditional muGT's. In this paper the effects of cycle design parameters on the performance and feasibility of a,muGT-SOFC hybrid system of 30 kW power output are investigated. It is confirmed that the hybrid system is much superior to a recuperated gas turbine in terms of its power generation efficiency and aptitude for small distributed generation. General design strategy is found that less direct fuel input to a combustor as well as higher recuperator effectiveness leads to higher generation efficiency, while higher steam-carbon ratio moderates requirements for the material strength. The best possible conceptual design of a 30-kW muGT-SOFC hybrid system is shown to give power generation efficiency over 65% (lower heating value).