Structural Design And Combustion Characteristics Study Of Burners For Hydrogen-rich Biomass Gasification Gas

By biomass gasification, biomass enormously stored can be converted into gas,which will be an important means for the future energy supply. In the future energy，hydrogen will be a main representative of clean energy, and hydrogen-rich gas can beobtained by biomass gasification. So studying and exploiting a special burner suit forthe hydrogen-rich gas is endowed with significance for improving energy structure,reducing environmental pollution and controlling greenhouse effect.In this paper, a dual-swirl diffusion burner for the characteristics of hydrogen-richgas is designed, and its flow characteristics match different air distribution ratio andstructural parameters are studied. It shows that when the inner ring air accounts for70%of the total air, the flow field in the combustor chamber is best; increasing the size of theisolation ring plate can strengthen the reflow capacity of the central recirculation zone.In the following experiments, the flow characteristics of the combustor are researched.The results indicate that the pressure loss in the inner ring pipe is biggest and outer ringpipe is smallest among the fuel pipe, inner ring pipe and outer ring pipe; when theexcess air coefficient is more than1.1, the pressure loss in the fuel pipe descends withthe excess air coefficient increasing; with the changing of the excess air coefficient, theaxial velocity distribution along the axial direction is greatly affected, while along theradial direction is little, and the size and reflow capacity of central recirculation zonereach the maximum value when the excess air coefficient is1.1.Then the numerical simulation for the temperature distribution, combustiblecomponent concentration distribution and NO_Xemission are conducted. The resultsshow that: when the inner ring air accounts for70%of the total air, and the diameter ofthe isolation ring plate and the bluff body are48mm and34mm respectively, thetemperature distribution in the chamber is most uniform. Increasing the content of theH₂and CO can speed up and reduce the burning rate of the gas, decrease and increasethe range of the high-temperature region respectively, while increasing the content ofthe CH₄affects little; changing the size of isolation ring plate, excess air coefficient andcombustible component content will have significant impact on the NO_Xemission whilechanging the size of blunt body and heat load will impact little, the NO_Xemission areleast when the diameter of the isolation ring plate is48mm and the excess air coefficientis1.1. By numerical simulation and experiment study, the flow and combustioncharacteristics of the burner are investigated, and it lays the theoretical and technicalfoundation for the application of the hydrogen-rich biomass gasification gas.