Performance optimizing and entropy generation analysis of a platinum–stainless-steel segmented microreactor

In this study, stainless-steel-platinum segmented microreactors were designed, their combustion performance was evaluated, and optimized designs were produced. Flames have been stabilized in such microreactors by including holes that provide a low-velocity zone that facilitates flow mixing between the inner and outer tubes of the reactors. However, the optimal number and size of these hole arrays had not been thoroughly explored. Three combustor designs with four or six pores of various sizes and a fixed platinum catalyst area were thus investigated. The combustion performance for various methane-air mixture and hydrogen-air mixture inlet velocities and equivalence ratios was evaluated through experiment and simulation in terms of both the second-law irreversibilities of the reaction and the unburned fuel content in the exhaust gases. The reactor designs were optimized using a Kriging model to reduce the cost of experimentation, and a sensitivity analysis was performed. The hydrogen–air equivalence ratio dominated the combustion efficiency. The six-hole design had the best performance and achieved complete combustion.