Methane MILD Combustion Flame Characteristic And The Entropy Generation Analysis

Confronted with increasingly tough environment resources and environmental pressures around the world, Mild combustion which has high efficiency and low emission has attracted many countries' s attention.Mild combustion technology has been hailed as one of the new era of most potential combustion by international combustion community. In-depth study and understanding of Mild combustion characteristics and Entropy production,it is necessary to conduct the theoretical study of the mild combustion.The key current is to research the realization of methane Mild combustion mold and the characteristic of combustion under the environment of carbon dioxide and water vapor.Preheating the oxidant jets in the apparatus could increase the reaction temperature and reduce the mean temperature gradient, better able to obtain a uniform temperature field; Preheating the oxidant jets in the apparatus could increase imported initial momentum, it could not only increase the temperature of the mixture, but also enable O2 content to distribute more evenly in Mild combustion state. More research and analysis of methane Mild combustion characteristics in normal temperature or high temperature air have conducted by the former,meanwhile,there was little research and analysis about Mild combustion characteristics in other gas component; and little Entropy generation analysis and comparison about Mild combustion.Realizable k-? turbulence mode and EDC combustion model which has a detail chemical mechanism of methane has been adopted.Based on GRI3.0 detailed chemical mechanism and JL1 simplified mechanism, putting CFD numerical simulations into the jet stream with the methane fuel thermal combustion process in hot jets burner. By changing the the oxidant jets of preheating temperature and oxygen concentration in diffident CFD numerical simulations,to explore the realization of methane Mild combustion mold and the characteristic of combustion under the environment of carbon dioxide and water vapor and how to influence Mild combustion flame characteristics, temperature distribution, OH concentration, OH distribution, generation of carbon monoxide and entropy generation.The CFD numerical simulation research results on Mild combustion showed that the detailed chemical reaction mechanisms could well forecast temperature field and species field of Mild combustion. Mild combustion could also be achieve in the environment of carbon dioxide and water vapor,the temperature after the reaction could increase as the rise of the oxygen concentration and the preheating temperature of the oxidant jets.The average temperature of carbon dioxide environment is higher under the same conditions,on one hand,OH maximum concentration and the maximum concentration of carbon monoxide after the reaction added with the rise of the preheating temperature of the oxidant jets,moreover,they reveal approximately linear growth, on the other hand,the corresponding OH distribution area also enlarges with the rise of the preheating temperature of the oxidant jets.In two different environments, as the rise of the oxygen concentration and the preheating temperature of the oxidant jets,the Entropy production will continue to decline.