Experimental and Analytical Investigation of a Counter-flow Reactor at Lean Conditions

Abstract

ABSTRACT Heat recirculating reactors have many potential applications as thermal oxidizers, combustors, and fuel reformers due to their extensive operating range. Low emissions and fuel flexibility make such devices highly desirable as heat sources as well as chemical reactors. The dependence on the solid/gas heat transfer implies that wall characteristics and operating conditions significantly influence the stable range. In this paper, the importance of various combustor parameters is examined through an analytical model, and an experimental reactor is fabricated from a new ceramic-metal composite using additive manufacturing. A full range of possible operation modes, from flashback to blow-off, was observed together with characteristic temperature distributions at various firing rates. The new combustor showed improved operational flexibility as compared to a traditionally assembled counterpart. Low CO and NOx emission levels were observed together with an audible sound in the range between 825 Hz and 1000 Hz. The combustor operated for over 70 hours without visible damage to the material. The overall thermal performance, low emissions, and high power density make the heat recirculating reactor a viable solution for combustion applications.