Application of the porous medium combustion technology in the chamber reheating furnaces at Baosteel

The design of the porous medium combustion （PMC） system which has been applied to chamber reheating furnaces is presented in this study and its main application effects are described in detail. Porous medium materials are mainly ceramic ball sucked granular bed porous media and foam ceramic porous media. This study investigates the foam ceramic porous medium and a schematic diagram of the combustion inside this porous medium. The PMC takes a solid medium as its main heat exchange way, thus greatly improving the heat transfer efficiency. Judging from the application effects,the following conclusions have been made： the PMC technology can save more than 25% of energy with remarkable effects; the furnace temperature uniformity can be significantly enhanced; the porous media combustion technology can make the heating furnace design in a more compact way, reduce the time for heating up the furnace, improve the heating rate and reduce energy consumption.

Development of a high performance flexible porous burner(FPMB)with an adjustable cooling effect

A high performance flexible porous medium burner that can burn gaseous and liquid fuel with different type of flames （premixed and non-premixed） is proposed. The merit of the combustion within porous medium is that heat is recirculated from the combustion gas to porous medium at upstream wherein vaporization is taken place （in case of liquid fuel） or preheated ~in case of gaseous fuel） before mixing with the combustion air followed by combustion within another porous medium at downstream. In a former version of the high performance flexible porous medium burner, the upstream porous medium is incorporated with a cooling system using the combustion air as a coolants to prevent thermal decomposition of fuels and thus the burner clogging caused by carbon deposit within the porous medium can be avoided. However, the cooling effect cannot be properly controlled such that the boiling point of the liquid fuel is maintained at suitable value irrespective of the volume flow rate of the combustion air, which is linearly varied with the firing rate of the burner. In particular at the lean burn condition, where high air flow rate is required with high cooling effect with porous medium. This can result in the porous medium temperature lower than the corresponding boiling point of the liquid fuel and thus evaporation of the fuel is failed and the combustion is ceased. Therefore, method of controlling the cooling air flow rate in the porous medium is proposed and studied in order to appropriately control the porous medium temperature and maintain it at above the boiling point irrespective of the combustion conditions. In this research, experimental and computation analysis are used to design the flexible porous burner （FPMB）, with adjustable cooling effect. The result shows that, the new design of FPMB which has temperature in the upstream porous medium is higher than boiling point and lower than thermal decomposition temperature of fuel （kerosene） at all conditions and can be operated at a wide range of equivalence ratio without fuel decomposition and fuel non-vaporization problem.