Investigation of flame characteristic in porous media burner with pores step distribution in radial direction

Abstract

In recent years, attention has been focused on the use of porous materials to enhance the efficiency of combustion systems and reduce the pollutants emission. However, the porous media burners have the problem of inclined flame when used for surface heat treatments. In order to solve this problem, a new structure of porous media burner with pores step distribution in radial direction is proposed in this paper, four representative pores distributions in radial direction are chosen in order to reveal the influences of the new structure on flame characteristic of the porous media burner. Results show that the radial distribution of pores in combustion zone of burner affects the flame characteristic greatly. In the pore concentrated region, the increase of resistance loss reduces the gas flow rate, and causes the temperatures of gas and solid lower than that in the other regions. Combustion in porous media burner with radial pores concentrated gradually from the centre to the wall is the optimal structure in the four cases. Compared with the other cases, the optimal structure can reduce the temperature difference between the wall and environmental, and then reduce the wall heat loss, increase the thermal efficiency of the burner, improve the flame distribution characteristics, reduce the pore blocking and the possibility of structural failure, and increase the service life of the burner.

Keywords:

• porous media
• step distribution
• combustion
• flame distribution
• numerical simulation

Disclosure statement

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

Additional information

Funding

The authors wish to acknowledge the research grant from the National Natural Science Foundation of China [grant number 51606031, No. 51704072], and the Fundamental Research Funds for the Central Universities [N182504017].