基于大涡模拟的煤粉湍流燃烧研究

Large eddy simulation of pulverized coal turbulent combustion

基于开源计算流体力学(computational fluid dynamics,CFD)计算程序包OpenFOAM模拟煤粉燃烧特性,运用大涡模拟(large eddy simulation,LES)方法模拟炉内燃烧情况,研究煤粉颗粒直径对火焰特性的影响,通过对比分析模拟结果和试验数据,验证LES及所用模型对气-固两相煤粉湍流射流燃烧模拟的有效性。研究表明:细煤粉燃烧的高温区域更广,火焰中心离喷嘴出口更近,局部温度更高,燃烧更加充分;建立的湍流及燃烧模型可靠有效,可为锅炉、内燃机及其他动力装置中燃烧流动的稳定性研究及系统优化设计提供理论依据,对揭示其他复杂的燃烧现象也有一定的参考价值。

An open-source computational fluid dynamics(CFD)code-Open FOAM(open field operation and manipulation)is applied to predict the combustion characteristics of pulverized coal with large eddy simulation(LES)method.The effect of coal particle diameters on the flame characteristics is also investigated.The simulation is validated by the experimental data of reference.It has been observed that the region of high temperature is wider,the flame center is closer to the nozzle exit,and the local temperature is higher for smaller particles.The simulation results show that the turbulence and combustion models are reliable and effective.The researching results can provide theoretical basis for the stability and system optimization design of combustion flow and system optimization design in boilers,internal combustion engines and other power plants,and provide reference for other more complex combustion phenomenon.