Experimental and Numerical Study on the Combustion Characteristics of Premixed Methane/Air in Porous Media Burner

ABSTRACT

The porous media burner is considered as the promising alternative for residential water heaters. In this work, a two-layer porous media burner was designed and the maximum NO_x emission was 48.7 mg/m³ under the firing rate of 666 kW/m². A two-dimensional model was established; the effect of the pore parameters on the flame stability limit and NO_x emission was investigated. The flashback, blow-off and flame instability were observed in the experimental and numerical investigations. Through the numerical optimization, the preferred pore parameters were 0.8 mm & 0.4 (preheating zone) and 1.6 mm & 0.7 (combustion zone); the predicted NO_x emission was 32.9 mg/m³. The preferred porous media were produced and studied experimentally. Under the same condition, NO_x emission was 28.7 mg/m³, which was less than 35 mg/m³ (the standard requirement, GB 18,111-2021) and reduced by 41% compared with that of the initial burner (48.7 mg/m³). The flash back limit was increased and the flame was stable at φ = 0.71.

KEYWORDS:

• Porous media burner
• pore parameter
• NO_x
• flame stability limit
• numerical study

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Key Technologies R & D Program of Foshan (Enlisting and Leading) (2120001009066) and the Natural Science Basic Research Program of Shaanxi-Shaanxi Coal Joint Fund Project (2021JLM-24).