Combustion Characteristics and Performance Evaluation of Modified Mesoscale Annular Combustor

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.

KEYWORDS:

• Mesoscale annular combustor
• heat loss rate
• exergy loss rate
• heat output
• power density

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).