塔式炉膛烟气流动特性及非线性现象的数值和实验分析

为研究不同负荷超(超)临界塔式炉膛内燃烧及烟气流动的非线性特性，以某1 000 MW塔式炉膛为原型设计出几何结构和边界条件完全对称的三维简化锅炉模型，运用FLUENT软件模拟了锅炉在3种不同负荷(100%,75%和50%阀门全开工况(VWO))下炉膛内的速度场、温度场及NO_x的分布情况，并分析了非线性特性，最后建立了一个三维冷态切圆射流实验模型并进行验证，提出顺序启动的喷口启动方式。结果表明：不同负荷下，完全对称的炉膛内烟气流动速度、温度和组分分布均存在非线性现象，模拟结果得到关于模型几何竖直中心线不对称的解；喷嘴通过顺序启动方式可使切圆偏斜程度更小，流动形成的切圆能稳定在一个位置，实现流动的精准控制。

Numerical and experimental analysis of flue gas flow characteristics and nonlinear phenomena in tower furnace

In order to study the combustion characteristics and nonlinear characteristics of flue gas flow in a ultra super critical tower furnace under different loads, a three dimensional simplified boiler model with fully symmetrical geometric structure and boundary conditions was designed with a 1 000 MW tower furnace as prototype. FLUENT software was used to simulate the velocity field, temperature field and NOxdistribution in the furnace under three different loads of 100%, 75% and 50% VWO (valve fully open condition), and analyze their nonlinear characteristics. Finally, a three dimensional cold tangential jet experimental model was established for verification, and a new nozzle startup mode, sequential startup, was proposed. The results show that under different loads, there are nonlinear phenomena in flue gas flow velocity, temperature and component distribution in the fully symmetric furnace, and the simulation results are asymmetric solutions about the vertical centerline of the model geometry; the nozzle can make the tangential circle deflect less through the sequential startup mode, and the tangential circle formed by the flow can be stabilized at a position to achieve precise control of the flow.