Orthogonal analysis of multi-factors of hydrogen-fueled combustion in a micro recuperative planar with porous media

Abstract

To improve the energy conversion and efficiency of hydrogen-fueled combustion, a micro recuperative planar with porous media is proposed. Numerical simulation model of premixed H2/air combustion is verified by experimental test, then orthogonal analysis of multi-factors, i.e., porous media setting and flow rate, on the combustion characteristics and heat transmission are compared and analyzed. The results indicate that combustion characteristics and heat release are strongly impacted by porous media, that is, preheating of unburnt reactants and heat transmission of gases and gas-solid are improved via the heat recirculation in/around porous media. For instance, the difference of mean wall temperatures of the combustor with/without porous media reaches 4.5% at mf = 6.67 × 10−7 kg/s. So, the inserted porous media boosts the burner radiation temperature, and porous media dimensions and porosity affect the thermal performance of the burner, reducing exhaust gas temperature and improving energy efficiency. Besides, orthogonal analysis is also employed to understand the coupling effects of multi-factors on burning and heat transmission, the effect degree on Tm is ranked by mf, L, H and φ. Hence, an optimal burning setting is obtained, i.e., combustor C4.8–6.8, where Tm is increased by 4.6% compared to the combustor C3-3 at mf = 9.17 × 10−7 kg/s. It achieves the maximum radiation efficiency 35.26% at mf = 6.34 × 10−7 kg/s.