转底炉平焰烧嘴燃烧过程的数值模拟

Numerical Simulation of Combustion in a Flat Burner of Rotary Hearth Furnace

分别采用涡耗散模型和非预混燃烧模型模拟烧嘴内的燃烧条件.结果表明,增加煤气喷入速度和降低空气喷入速度,C_xH_y,CO和H_2的消耗速率及CO_2和H_2O的生成速率减小,火焰长度增加.相同计算条件下,采用涡耗散模型计算的高温区域比非预混燃烧模型计算的高温区域集中;煤气喷入速度增加,涡耗散模型计算的回流区域减小,空气喷入速度增加,回流区域略有增加,煤气喷入速度和空气喷入速度变化对非预混燃烧模型计算的回流区域无影响.涡耗散模型预测流场分布更准确,非预混燃烧模型预测温度分布更准确.

The combustion condition of the burner was calculated by the eddy dissipation model and the non-premixed combustion model respectively. The results showed that when the velocity of coal gas injection increases or the velocity of air injection decreased, each consumption rate of CxHy, CO and H2 reduced, and each production rate of CO2 and H;O also reduced, and the length of the flame adds. The area of the highest temperature calculated by the eddy dissipation model was more concentrated than that by non-premixed combustion model. With the velocity of coal gas injection increasing, the area of backflow region calculated by eddy dissipation model reduced, the velocity of air injection increasing, the area of backflow region increasing slightly. Both the velocities change of coal gas injection and air injection had no influence on the area of backflow region calculated by non-premixed model. Comparing the calculation results of two models, the flow field calculated by eddy dissipation model was more accurate, the temperature field calculated by non-premixed model was more accurate instead.