Influence combustion method of natural gas in ceramic tube at indirect heating

Abstract

The aim of the authors’ work was using mathematical simulations to simulate various modes of combustion of natural gas at a constant input power recuperative burner. In case of indirect heating of materials, realized through the wall - the radiant tube wall is required uniform distribution of temperatures. When burned with a conventional burner, the ceramic radiant tube is overheated locally and then the system is destroyed and rendered inoperable. A regenerative burner model has been designed, operating in two modes as conventional flame and flameless. The boundary conditions in the mathematical model were defined of the selected industrial plant for indirect heating to verify the results achieved. By mathematical modeling, the hypothesis of local temperature peaks at conventional burner type and uneven temperature distribution on the ceramic tube surface was confirmed. This local disproportion in the temperature distribution was particularly evident in the area behind the burner outlet orifice. In the case, flameless combustion mode was the temperatures more evenly in the working area of the tube, as well as on the surface, over its entire length. The use of flameless combustion ensures a more even distribution of temperatures, thus more uniform heating of the material under indirect heating. Using this method, it is possible to use a material of radiant tubes with lower heat resistance or burner power to increase the indirect heating power. Using the ANSYS mathematical model, it is possible to model the temperature field in and on the surface of the radiant tube for various operating conditions and burner inputs.