Study Of Oxygen-enriched Premixed Combustion Flame Characteristics And Heat Transfer Characteristics In The Shuttle Kiln

Oxygen-enriched combustion technology is one of the latest energy saving technologies recently,which is called'technology of resource creativity'by developed countries for its debasing fire point of fuel,increasing velocity of combustion,promoting the complete combustion,enhancing flame temperature,reducing air displacement after burning,increasing the using of heat,decreasing air overmuch coefficient,and having predominant energy saving capability.Currently , researches on oxygen-enriched combustion technology at home and abroad are mainly focused on combustion mechanism and emission characteristics of NOX and SO2,and there are less researches on oxygen-enriched combustion flame characteristics which mostly study the oxygen-enriched non-premixed combustion diffusion flame characteristics , and researches on oxygen-enriched premixed combustion turbulent flame characteristics almostly don't exist;there are more application researchs on oxygen-enriched combustion technology in the heating furnace and boiler,less in the kiln specially shuttle kiln which mainly studys the emission characteristics of oxygen-enriched combustion in the kiln,and currently no research on the specific temperature field distribution situation in the kiln. However,mastering temperature field distribution situation in the kiln and understanding the heat transfer characteristics in the kiln,can play an important guiding role in the stable operation of kiln oxygen-enriched combustion;also have great meaning and value on the application and promotion of oxygen-enriched combustion technology in the kiln.Therefore , the subject firstly carried on the experimental study of oxygen-enriched premixed combustion turbulent flame characteristics,in order to verify the feasibility of the later numerical simulation study of oxygen-enriched premixed combustion heat transfer characteristics in the shuttle kiln;then innovatively used the Fluent software selecting RNGk-e turbulence model,eddy dissipation combustion model,and PI radiation heat transfer model to numerically simulate and study heat transfer characteristics in the shuttle kiln when using oxygen-enriched air with different oxygen concentration to support combustion with entire oxygen-increasing.By analyzing the test results and numerical simulation results,we can draw the following main conclusions:1. With the increasing of the oxygen concentration,the flame gradually became powerful,the maximum flame temperature was gradually increased,the location of the maximum temperature gradually moved toward the direction of the burner exit,the flame temperature gradient was gradually increased,the flame high temperature zone gradually turned reduced,and the flame intensity was gradually enhanced. 2. Using oxygen-enriched air combustion-supporting technology could reduce flue gases jet erosion on the kiln wall,and extend the useful life of the kiln wall materials;adopting oxygen-enriched air by more than 24% oxygen concentration for combustion-supporting could lower the temperature of the kiln top,thus prolong the useful life of the kiln top materials.3. Using oxygen-enriched air combustion-supporting technology could enhance the the flame bottom temperature and the kiln heat transfer,and the long-term use of oxygen-rich combustion method could make the kiln car (kiln bottom) burnt out,which would result in instability of material stacks and cause body collapse phenomenon,so it was necessary to check the kiln car periodically.4. Using oxygen-enriched air combustion-supporting technology could make the temperature difference in the kiln become larger,and adjusting the location of flue gas outlets and changing the stacking way of material stacks would reduce the temperature difference in the kiln.