Abstract
Blow-off limit and unburned gas concentrations were measured for a mult-hole combustor designed for start-up of 4kW class SOFC-Stirling engine combined system. The blow-off limit strongly depended on the preheat temperature and the equivalence ratio and the released heat at the blow-off limit was insufficient for the 4kW system if the operation at higher combustion temperature is avoided to supresss the NOx emission level. The concentrations of CO2 and CH4 at the combustion temperature of 1700K showed the tendency to increase toward the radial direction and with the increase of the flow velocity. Also, the higher preheat temperature showed the lower concentrations of unburned gas. The unburned gas concentrations were still high at 1700K and the higher combustion temperature is needed to improve the combustion efficiency.
