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 qi of the rich C3H8–air mixture in the inner tube while varying the equivalence ratio φi of the mixture and the airflow rate qo 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 ηhl and the exergy loss rate ηex,loss were evaluated from the obtained temperature data. The minimum values of ηhl and ηex,loss were 0.06 at φi = 1.5, φall = 0.3, and 0.44 at φi = 5.0, φall = 0.8, respectively. The values of ηhl and ηex,loss verified that the combustor offers high performance.
Acknowledgments
We would like to thank Mr. Yoichi Takeda for technical assistance.
Disclosure statement
No potential conflict of interest was reported by the author(s).