Experimental and numerical investigation on H2-fueled micro-thermophotovoltaic with CH4 and C3H8 blending in a tube fully/partially inserted porous media

Energy conversion and utilization of micro-thermophotovoltaic (TPV) system are limited by the micro-combustor, so the stepped tube inserted with porous media (PM) is proposed for H2-powered systems with blending CH4 or C3H8. Effects of blended CH4 and C3H8 on the H2/air combustion are experimentally investigated and numerically simulated. The results show that the addition of CH4 and C3H8 improves the thermal performance at lower blending ratios to stabilize the combustion and increase the energy efficiency, and the addition of CH4 gives superior thermal performance compared to C3H8. In addition, to increase the power output of micro-TPV system, the effects of micro-burners with different PM setups are investigated under varied operating conditions, which indicate that the insertion of PM alters the flame regime, enhancing combustion stability and energy conversion. For instance, the maximum radiant efficiency is obtained in the burner with PM L3 = 19 mm at vp = 4 m/s, while burner with PM L3 = 25 mm gains the maximum radiant efficiency of 46 % at vp = 6 m/s and is 12.4 % higher than that without PM. Therefore, the power output of the burner with longer PM is higher at high flow rates. When vp = 8 m/s, the maximum radiated power and system output power of the micro-TPV system with InGaAsSb cells reached 81.2 W and 4.2 W, respectively.