Simulation Design Of Biomass Gas Burner And Simulation Study Of Combustion Characteristics

Biomass is regarded as the fourth largest energy source in the world.For the utilization of biomass,people tend to gasify biomass to obtain biomass gas.Burner is the most important part of the flame furnace,which plays an important role in the combustion organization,heating quality and efficiency of the workpiece.With the increasing awareness of biomass energy utilization in the world,the development and application of matter gas burner has become one of the hot spots.This paper firstly based on the composition of a certain biomass gas,with reference to the design ideas of the relevant gas burners and previous experience,the parameter calculation and preliminary design of the biomass gas burner with a heat load of 125KW.The burner was constructed and the corresponding mathematical physics model was established.The flow characteristics of the designed biomass gas burner were studied based on Fluent software.Under certain conditions of air circulation area,the number of spiral blades and the spiral rising angle will affect the angular velocity distribution of the air outlet;when the spiral rising angle β is constant,the angular velocity of the air outlet gradually decreases as the number of spiral blades increases.When the number of turns of the spiral blade N is constant,as the spiral rising angle β increases,the angular velocity of the air outlet gradually increases.When the number of spiral blade turns does not change,as the air flow area decreases,the angular velocity of the air outlet gradually increases,and the curve gradually moves upward,but the increasing trend gradually becomes slower;as the length of the shrinkage tube decreases,The angular velocity of the air outlet gradually increases,and the shorter the shrinkage tube,the higher the degree of air rotation under the same conditions.The combustion chamber model was constructed and the combustion performance of the burner under different structural parameters was studied based on Fluent software.As the spiral rise angle β increases,the maximum temperature on the central axis of the combustion chamber gradually increases,and the curve gradually moves upward.The high temperature region gradually approaches the center line of the combustion chamber,and the diameter of the flame gradually becomes smaller,and along with the air.The increase in flow rate is more pronounced under the same conditions.When the spiral rising angle is constant,as the flow area decreases,the axial temperature change curve gradually moves upward,the temperature on the axis increases as a whole,the flame becomes long,and the high temperature area is concentrated near the central axis of the combustion chamber.After optimization of the burner outlet pipe,the temperature field in the combustion chamber changes with the length of the nozzle and the radius of curvature.When the length of the nozzle remains the same,as the radius of curvature of the nozzle increases,the diameter of the flame increases.And the flame length becomes shorter.Conversely,when the length of the nozzle remains the same,as the radius of curvature of the nozzle decreases,the diameter of the flame decreases and the length of the flame increases.When the number of spiral blades is N=3,the length of the shrinkage tube is H=80mm,the spiral rising angle is β=45°,the air flow surface is A=0.0339m2,the length of the outlet nozzle is L=200mm,and the radius of curvature of the outlet nozzle is R=250mm,the burner can obtain better combustion effect.