The Ultra Low Calorific Value Gas Porous Medium Burner For Structure Optimization And Pollution Emission Control

This paper devoted to the theory and technology of combustion in porous media which is used to deal with low calorific value gas,based on existing low calorific value of porous media combustion experiment platform,to reasonably optimized the burner inner core,according to the stable combustion characteristics of different calorific value gas,carry out laboratory test and numerical simulation researches,which provide data and theoretical support for gas processing and heat utilization system of design and development of the engineering medium low calorific value.Through experiment and numerical simulation method,we study the stable combustion characteristic of different calorific value low calorific value gas under the eight kinds of modular arrangement structure,the test results of stability combustion limit of the structure of B type burner inner core and the numerical simulation results are compared;Through test and numerical simulation research,it is concluded that type H of burner with inner core porous media of comprehensive performance is more outstanding,it can realize that gas is burnning stablely,whose calorific value is 1.2 ~ 3.0 MJ/Nm3.When the combustion heat value of gas is 1.2 MJ/Nm3,the minimum combustion intensity is 76.43 kW/m2,the load adjustment ratio is 1:2.4.When the combustion heat value of gas is 3.0 MJ/Nm3,the minimum combustion intensity is 198.73 kW/m2,the load adjustment ratio is 1:1.9.Decorate in the combustion chamber of the foam ceramic from upstream to downstream arrangement pore density decrease is favorable to the stability of the flame,which can enlarge the combustion intensity of burner fire off limits,but also occur tempering easily;Decorate radiation shield in the combustion chamber exit can effectively reflux combustion heat release,and the bigger the hole density the more good for the reverse flow of combustion heat release,and good for low calorific value gas combustion;Combustion chamber temperature distribution affected by equivalent ratio and combustion intensity,on the basis of guaranteeing the stability of the flame,appropriately increasing air coefficient is beneficial to reduce the emissions of CO.In numerical simulation for water vapor to the premixed combustion chamber CO emissions,we found that after adding water vapor,the axial temperature of combustion chamber is reduced,stable combustion flame will move to the downstream of the porous medium,when the amount of water vapor reaches a certain degree,premixed gas speed is greater than the flame burning speed,flame would be blown out of porous media area.In addition,adding suitable amount of water vapor can reduce CO emissions in a large extent,when the equivalent ratio of the type H burner with inner core structure is 0.94,CO emissions can be reduced to 116 ppm,adding 8% water vapor quality can reduce CO emissions to 18 ppm.Predict the equivalent ratio is 0.94,adding 5% water vapor quality,can burn gas whose calorific value is 3.0 MJ/Nm3,CO emissions control under 60 ppm.