带烟气回流W型辐射管热过程数值模拟

基于商业软件FLUENT同时,采用RNG k-ε模型和非预混燃烧模型,建立了带烟气回流W型辐射管燃烧器的燃烧及传热的三维数学模型,对辐射管内湍流和燃烧状况进行了模拟,并得到了出口NOx排放的计算结果;通过与相应实验数据的对比,验证了模型的可靠性.分析了辐射管内流体流动,传热和燃烧的特征,研究了燃气流量及空气预热温度对辐射管使用性能的影响;结果表明:燃气流量的提高,会增大辐射管壁面温度的不均匀性,而提高预热温度则相反;两者与辐射管加热能力呈正相关,但都会使得出口烟气内的NOx含量增大.

Numerical simulation of thermal process of W - type radiant tube

Based on commercial software FLUENT, applied the RNG k - ε model and the non - premixed combustion model, a three-dimensional mathematical model of combustion and heat transfer in a W-type radianttube burner with flue back flow was established. The turbulence and combustion status in the radiant tube were simulated, NOx emissions at exit was calculated. Through comparison with the corresponding experimental data, the reliability of the model is verified. Details of the fluid flow, heat transfer and combustion status in the radiant tube were analyzed. In addition, effects of gas flow rate and air preheating temperature on the performance of the radiant tubewere studied. The results showed that the gas flow rate increasing will increase unevenness of the radiation tube wall temperature. The case will be opposite when the preheating temperature increases. Both of them have a positive effect on the radiant tube heating ability,however both of them increase NOx content in the outlet fuel gas.