Investigation on premixed methane/air combustion characteristics in heat recirculation micro combustor with separating cylinder

Nowadays, the low combustion efficiency and combustion instability are the two major challenges in the design and development of meso/micro combustor. Heat recirculation and catalytic combustion are one of the best methods to solve those problems. The low combustion rate far from catalytic surfaces in micro combustor is a serious issue in catalytic combustion. To solve this problem, the novel micro combustor with separating cylinder is proposed. The fuel combustion efficiency in HRMCC is higher than that of HRMC at the same inlet velocity. When the inlet velocity is 0.5 m/s, the combustion efficiency gap between HRCC and HRMCC reaches up to the maximum value of 7.4 %. The methane conversion per unit catalyst in HRMCC is higher than that of HRMC, and it also increases as inlet velocity increases. Besides, the location of separating cylinder in HRMCC does not show obvious influence on combustion efficiency and methane conversion per unit catalyst. However, it has a great influence on the size of high temperature region in HRMCC. The high temperature area size becomes larger as the separating cylinder in HRMCC becomes further from outlet.