Journals Proceedings

Abstract

A permeable matrix is placed in the flow of the combustible gas mixture in infrared (IR) burners for the organization and stabilization of the surface combustion regime. A stable regime of surface combustion occurs on the surface of the permeable matrix. Until the combustion rate of the gas mixture near the surface exceeds the velocity of the gas mixture, the surface combustion process is stable. If the combustion rate becomes less than the velocity of the gas mixture, the combustion zone is separated from the surface and combustion passes into the flare mode. In our previous works it is shown that the introduction of recuperative elements into the design of the IR burner allows to increase the heat flow from the combustion products to the surface of the permeable matrix and to increase the maximum value of the specific combustion power for the surface combustion mode to values of more than 100 W/cm2. However, at such high values of the specific power of surface combustion, the surface temperature of the permeable matrix increases to the values at which the surface of the permeable matrix is destroyed. Application to the surface of the permeable matrix of metal foam or wire ceramic material has increased the specific combustion power to values of more than 120 W/cm2. A further increase in the specific combustion power led to the destruction of the surface of the permeable metal matrix with a ceramic coating. Studies conducted, the results of which are presented in this paper, showed that it is possible to implement the surface combustion mode in the IR burner with specific power values of more than 200 W/cm2, if you use the design of the IR burner without a permeable matrix. To do this, it is necessary to organize the regime of stimulated surface combustion (StSC) on the surface of the recuperative elements. Mode (StSC) in the IR burner may sustained combustion of gas mixtures not capable of self-combustion, or when the velocities of the gas mixtures exceed the rate of combustion. In our experiments on laboratory models of the IR burner, the stimulated surface combustion mode with a specific combustion power of more than 290 W/cm2 was implemented. Plates 1 mm thick were used as recuperative elements. The material of the plates is made of high-temperature resistant iron-based alloy (chromium 25%, aluminium 6%,) strengthened by yttrium oxide. Environmental characteristics of IR burners operating in the mode of stimulated surface combustion with a specific power of 170-290 W/cm2 do not differ from the values typical for conventional IR burners operating at a specific power of 20-30 W/cm2. The proposed design of the IR burner allows you to get away from the problems associated with the destruction of permeable matrices.