Experimental simulation on the integration of solid oxide fuel cell and micro-turbine generation system

Solid oxide fuel cell (SOFC) is characterized in high performance and high temperature exhaust, and it has potential to reach 70% efficiency if combined with gas turbine engine (GT). Because the SOFC is in developing stage, it is too expensive to obtain. This paper proposes a feasibility study by using a burner (Comb A) to simulate the high temperature exhaust gas of SOFC. The second burner (Comb B) is connected downstream of Comb A, and preheated hydrogen is injected to simulate the condition of sequential burner (SeqB). A turbocharger and a water injection system are also integrated in order to simulate the situation of a real SOFC/GT hybrid system. The water injection system is used to simulate the water mist addition at external reformer. Results show that this configuration can simulate the SOFT/GT hybrid system successfully. Water mist addition will increase the GT rotational speed, but an optimal amount exists during the variation of water injection. In residual fuel addition test, hydrogen shows good combustion efficiency and preheating temperature is the dominant parameter for hydrogen burning in SeqB even without flame holding mechanism in it. When preheating temperature is among 450-600 °C, hydrogen will have almost 100% combustion efficiency at 90% engine loading, and GT will get a higher rotational speed for the same energy input. But when the engine operates at 100% loading, the combustion efficiency will decrease while fuel utilization (U_f) setting is increasing. When raising the preheated temperature to 650-700 °C, the combustion efficiency will increase rapidly.