Improvement of energy conversion of H2/CH4 fueled micro-thermophotovoltaic in a micro-planar inserted with bluff-body and porous media

Micro-combustion systems face the challenges of unstable combustion and low energy conversion efficiency owing to a small size at present. So, a micro-planar with bluff-body and porous media (PM) is proposed for blended H2/CH4 fueled micro-thermophotovoltaic. Experimental investigation and numerical studies of blended H2/CH4 combustion are conducted to analyze the energy conversion. The results show that the addition of 25 % CH4 mixing ratio helps the regulation of flame anchoring and remarkably improves combustion energy efficiency in H2/air premixed combustion. The insertion of bluff-body improves the preheating of gases, which enhances flame stability and anchoring. Meanwhile, the coupling effects of blended H2/CH4 and bluff-body achieve a more uniform Tw distribution and higher radiation efficiency. Besides, the combination of PM and bluff-body further improves radiation performance by selecting the appropriate porosity. In particular, the highest radiation effi-ciency of 52 % is achieved at mf = 3.16 x 10-5 kg/s for the combustor with a bluff-body Lc = 5.5 mm and PM of porosity epsilon = 0.83. Simultaneously, the system of micro-thermophotovoltaic, equipped with InGaAsSb cells and combustor with Lc = 5.5 mm, achieves the maximum power generation 2.62 W at mf = 4.15 x 10-5 kg/s.