Cooling And Applied Research For Porous Media Burner

Porous media burner technology has the characteristics of high firing rate.Compared with traditional free space burner,porous media burner technology will result in the damage of porous media with the phenomenon of “Excess Enthalpy”.But the research on this technology has little attention to how to protect the porous media and prolong its service life.In this paper,the association method of experimental investigation and numerical simulation has carried on the preliminary exploration to the study on water-cooled porous media burner.Establishing the Water-cooled porous media burner test system,the test gas is methane and air,burned under the condition of equivalent ratio 0.9,firing rate is 266.7kW/m2,400.0kW/m2,533.3kW/m2,666.7kW/m2 and 800.0kW/m2,cooling water flow is 100L/h,200L/h and 300L/h.Experimental results show that,in the case of a certain firing rate,with cooling water flow rate increased,water side heat absorption increased,the flue gas temperature decreased,pollutant discharge of CO increased,pollutant discharge of NO decreased,in the case of a certain cooling water rate,with firing rate increased,water side heat absorption increased observably,the flue gas temperature increased,pollutant discharge of CO decreased,pollutant discharge of NO increased.We also see from the experiment that the burner starts with a long time under the condition of the firing rate 266.7kW/m2 and 800.0kW/m2,the burner starts with a short time under the condition of the firing rate 400.0kW/m2,533.3kW/m2 and 666.7kW/m2.Under the test conditions,burner heat dissipation ratio increased with firing rate increased.The three-dimensional model of water-cooled porous media burner is established by the software of FLUENT.The results show that the chamber temperature of the burners on both sides is lower than the middle burner under the condition of the firing rate 266.7kW/m2 and 400.0kW/m2,when firing rate increases to 800.0kW/m2,the chamber temperature gradually become the same.Under the condition of normal pressure,the feed-water temperature of the cooling-chamber increases from 20? to 90?,it has little or no effect on burner characteristic.In the condition of the same gas flow,when the pipe diameter is 6mm,the pipe gas velocity is higher,the flame in the chamber is smaller and the hot dipping depth is shorter,when the pipe diameter is 14 mm,the pipe gas velocity is lower,the flame in the chamber becomes flat and the hot dipping depth is longer,when the pipe diameter is 10 mm,the pipe gas velocity,the flame in the chamber and the hot dipping depth are more in line with the design requirements of the burner.