200 MW四角切向燃烧煤粉炉炉内过程的数值模拟

借助FLUENT CFD软件平台，应用Eulerian/Lagrangian方法，在3种不同工况下，对200MW四角切向燃烧煤粉锅炉炉内的流动、传热及燃烧进行了数值模拟。为减小数值伪扩散的影响，采用了改进网格系统的措施。模拟结果表明：炉内最高温度出现天燃烧器区域，随着炉膛高度的增加，温度逐渐降低；整个炉膛空间存在旋转流场，从下至上旋转强度从弱到强，然后再逐渐减弱，直到炉膛出口仍存在残余旋流；炉内CO、O2和CO2的质量浓度分布与温度分布有很大关系，高温区对应着高的CO质量浓度和低的O2、CO2质量浓度。数值模拟结果为锅炉的运行和改造提供了参考依据。

Numerical Simulation of Flow and Combustion Process in the Tangentially Fired Furnace of a 200 MW Pulverized Coal Boiler

Using a CFD software FLUENT, an Eulerian/Lagrangian approach was employed to investigate numerically the flow field, heat transfer and combustion process in a tangentially fired furnace of 200 MW pulverized coal boiler. Three different cases were simulated. To reduce the influence of the numerical pseudo-diffusion on the computational results, a measure was taken to improve the grid system so that fluids enter the control unit in the direction of perpendicular to the unit's border, not 45 degrees to the border. The simulation results show that temperature drops with the increase of furnace height, and the highest temperature appears in the area of the burners; from bottom to top, the intensity of swirl firstly strengthens and then weakens in the furnace, but residual swirl still exists at the exit of furnace; the distributions of CO, O 2 and CO 2 concentration are strongly related to the temperature field, that is, the high temperature area cor-responds to the high CO and low O 2 and CO 2 concentration area. The distributions of the veloci-ty, temperature and the particles' trajectories in the furnace were also obtained and analyzed.