Combustion Characteristics and Performance Evaluation of Modified Mesoscale Annular Combustor

Abstract

ABSTRACT The combustion characteristics and performance of a cylindrical stagnation flow-type mesoscale annular combustor were evaluated. The combustor comprised inner and outer porous tubes made of stainless steel and nickel – chromium–iron alloy, respectively. A rich C3H8–air mixture and air were supplied to the inner and outer tubes, respectively. The cylindrical flame was formed around the inner tube; consequently, a petal-type flame was formed downstream of the cylindrical flame. Experiments were conducted by maintaining a constant flow rate q i of the rich C3H8–air mixture in the inner tube while varying the equivalence ratio φ i of the mixture and the airflow rate q o of the outer tube. To investigate the combustion characteristics, the temperature was measured inside and at the outlet of the combustion chamber. The burned gas compositions, O2, CO, and NO, were analyzed. The heat loss rate η hl and the exergy loss rate η ex,loss were evaluated from the obtained temperature data. The minimum values of η hl and η ex,loss were 0.06 at φ i = 1.5, φ all = 0.3, and 0.44 at φ i = 5.0, φ all = 0.8, respectively. The values of η hl and η ex,loss verified that the combustor offers high performance.