Experimental study on superadiabatic combustion in porous media with reciprocating flow

Superadiabatic combustion of premixed combustible gases in porous media with reciprocating flow (RSCP) possesses a number of advantages over conventional combustion technologies. In this paper, a comprehensive experimental study was carried out on the combustion characteristics of RSCP. An experiment facility was set up, which consisted of a ceramic foam ( Al-2 O-3) combustor, a gas flow system controlled by two pairs of solenoid valves for switching alternately the flow directions, and a measurement system. The temperature distribution inside the porous medium combustor and the levels of NO and CO emissions were measured at various working parameters (fuel-air equivalence ratio, gas flow velocity and half cycle period). The experiment results show that the RSCP system have, in comparison with conventional combustion system, outstanding behavior, such as enhancing flame stability I extending flammability limits, and lowering emissions. The lean flammability limit for the mixture of propane and butane was extended to 0.065. Based on the experimental results, the working mechanism of superadiabatic combustion is discussed and the influences of the major parameters on the combustion characteristics of RSCP are clarified.