Experimental Studies Of A Porous Media Combustor With A Reciprocating System

A novel combustion manner, which is called porous media combustion with a reciprocating flow system, has been presented with its predominant advantages of high thermal efficiency, stable combustion, broad combustion limits and low pollutant emissions. It became one of the most efficient and practical combustion manner in combustion strengthening and emissions control. Experimental and theoretical approaches in porous media combustor with a reciprocating flow system are presented in this paper.The work done by this article mainly includes four parts: first, the research development of combustion in porous media with a reciprocating flow system is summarized. Two important concepts: superadiabatic combustion and porous media combustion was introduced. Then, the detailed introductions on both mechanical and application research on porous media combustion with a reciprocating flow system are presented.Second, cold experimental tests were carried out, and a simple mathematic model was developed based on the experimental results. The effects of the superficial velocity and porous media thickness on the pressure drop and the steady time of the burner were analyzed. The calculation results from the model were compared with the experimental data. The results showed that keeping other parameters constant, the differential pressure AP in the burner is in direct ratio with the square of the superficial velocity and the porous media thickness. However, the steady time is independent of them. The calculation results are in good agreement with the experimental ones.Third, the thermal state experimental research was carried out in the porous media burner with a reciprocating flow system. The effects of various equivalent ratios, circulating cycle time and gas flow velocity on the temperature distribution and pollutant emission are analyzed. The main results are: The measuring points temperature decreases, the flame center shifts up, and the top temperature of the burner decreases as functions of equivalent ratio , during <1; the all measuring points temperature increases as the superficial velocity increase; when the circulating cycle time increases, the export temperature and measuring points temperature of the burner increases, and a large change of the temperature can be found near the flame center; Compared with simple porous media burner, much more homogeneous temperature distribution and lower exit flue temperature can be obtained using the reciprocating porous media burner.Forth, comprehensively describing the burner with a reciprocating flow system in the porous media, we found the character in the course of the burning and constitute the mathematics modle of the burner. We compute and analysis the infection of the equivalent ratio, gas flow velocity and heat loss coefficient on the temperature distribution.and compare the results with the experiment and the others. We found that the temperature distribution is like M shape along the axes of the burner. The monolithic temperature of the burner increased with the increase of the equivalent ratio, gas flow velocity, but decease with the increase of the heat loss coefficient. Calculating results accord with the experimental results.