基于Fluent的多种生物质颗粒燃烧数值模拟

Numerical Simulation of Combustion of Biomass Pellets Based on Fluent

基于ANSYS FLUENT(有限元商用计算流体力学)软件模拟烟煤、花生壳、落叶松、玉米秸、稻秆和棉秆6种颗粒在圆筒形燃烧室中的燃烧。对比分析了这6种燃料颗粒燃烧时燃烧室内各截面温度、不均匀系数、氧气质量分数和NO_x质量分数分布。模型燃烧室直径为1 m,长度为10 m。在燃烧室中心径向0.125 m范围内燃料颗粒通过流速为50m/s的高速气流以0.1 kg/s的质量流量喷入燃烧室,在径向0.125~0.5 m范围内通入流速为15 m/s的空气。燃料颗粒粒径为40μm,密度为1 200 kg/m^3。研究表明:高热值的燃料在各个截面上的最高温度均高于低热值燃料,烟煤、花生壳、落叶松、玉米秸、稻秆和棉秆燃烧时燃烧室最高温度分别为2 643.26、2 260.37、2 190.83、2 163.35、2 130.37和2 060.83 K;生物质燃料的温度分布均匀程度优于烟煤;生物质燃料产生的NO_x明显较少,其中棉秆最少;在余气系数均为1时,各燃料燃烧时燃烧室内最高温度均有所提高,但是整体仍然满足高热值燃料温度高于低热值燃料的规律。

Simulation of Combustion of Bituminous Coal,Peanut Shell,Larch,Corn Stalk,Rice Stalk and Cotton Stalk in Cylindrical Combustion Chamber Based on ANSYS FLUENT. The temperature,nonuniformity coefficient,oxygen mass fraction and NO_x mass fraction distribution of the combustion chamber were analyzed and compared. The model of combustor has a diameter of 1 m and a length of 10 m. In the range of 0. 125 m in the radial direction of the combustion chamber,the fuel particles are injected into the combustor at a mass flow rate of 0. 1 kg/s through a high velocity air stream having a flow rate of 50 m/s. In the radial 0. 125 m ~ 0. 5 m range into the flow rate of 15 m/s air. The particle size of the fuel particles is 40 μm and the density is 1 200 kg/m^3. The results show that the maximum temperature of the high calorific value fuel in each section is higher than that of the low calorific value fuel. The maximum temperatures of the combustion chamber were 2 643. 26 K,2 260. 37 K,2 190. 83 K,2 163. 35 K,2 130. 37 K,2 060. 83 K,respectively,when the burning of the bituminous coal,peanut shell,larch,corn stalks,rice straw and cotton stalk; The temperature distribution of biomass fuel is better than that of bituminous coal; Biomass fuels produce less NO_x ,with the least amount of cotton stalks; When the excess air coefficient is 1,the maximum temperature of the combustor is increased when the fuel is burned,but the whole is still satisfied that the high calorific value fuel temperature is higher than the low calorific value fuel.