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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-483-0

ISBN Online: 978-1-56700-482-3

4th Thermal and Fluids Engineering Conference
April, 14–17, 2019 , Las Vegas, NV, USA

EFFECT OF HEAT EXTRACTION ON FLAME POSITION IN COUNTERFLOW POROUS BURNER

Get access (open in a dialog) pages 113-122
DOI: 10.1615/TFEC2019.cbf.027654

摘要

Counterflow porous burner is studied numerically to analyze the effects of internal heat regeneration and heat extraction on flame positioning. Volume averaged numerical model is used to solve steady state governing equations for predicting the flame positions and corresponding temperature profiles. Two different materials for the wall separating firing and exhaust channels of the counterflow burner are considered: silicon carbide and alumina. Numerical simulation of methane-air combustion in porous medium is performed using 30-species combustion mechanism. The flame position is analyzed for various equivalence ratios. The energy content of the flame and the internal heat regeneration define the flame location in the counterflow burner. High energy content flames tend to displace closer to the inlet of the burner whereas those with lower energy content tend to stabilize deeper inside the firing channel. The effect of positioning of heat exchangers operating at high temperatures (1000 K), on the flame location is also investigated. An optimal placement of a heat exchanger allows ideal flame positioning and efficient high temperature heat extraction. The effect of separation wall thickness on the heat extraction efficiency is studied. For silicon carbide separation wall, decreasing the thickness from 0.5 cm to 0.1 cm enhances the heat extraction efficiency from 43 % to 65 %.