330 MW前墙燃烧煤粉锅炉炉内温度场的数值模拟及优化

某电厂330 MW机组锅炉采用双调风旋流燃烧器，前墙布置。该厂实际运行中一次风速与设计值相比相差较大，较大的一次风速造成了燃烧器一次风管磨损严重，同时后墙水冷壁高温腐蚀的可能性增大。该文提出保持原燃烧器一次风管尺寸不变，减小中心风管直径、增大一次风流通面积以减小一次风速的改造方案。为研究改变中心风管直径后的4层燃烧器对炉膛燃烧的影响，采用数值模拟的方法对该型锅炉炉内的温度场进行数值计算，得到5种不同方案下该型锅炉炉内的温度场分布，并分析了中心风管直径的改变对炉内温度场的影响规律，即后墙近壁区温度随着中心风管直径的减小呈现先降低后升高的趋势。通过对5种方案数值模拟结果的比较分析，得到了对炉膛后墙安全性影响最小的方案，为电厂的实际改造提供参考。

Numerical Simulation and Optimization on Temperature Field of 330 MW Front Wall Fired Furnace

The utility boiler is wall-fired with dual channel swirl burners fit on the front wall. The actual speed of the primary air was much higher than that of the design value, which caused serious abrasion of the burner and the possibility of high-temperature corrosion to the backing water wall increased. To solve this problem, keeping the original size of burner’s primary wind pipe unchangeable was put forward. The diameter of the center air pipe was reduced and the flow area is increased to reduce the primary air speed. In order to analyze the influence of the center air pipe diameter change on the combustion effect, numerical modeling was applied to numerical calculation on the temperature field of such type of boiler，through which temperature field in five different schemes were obtained. In addition, the influence law of change of the diameter of the center air pipe on the temperature field was analyzed. The temperature of the nearly-back wall region takes on a firstly decreasing and then increasing change with the diametrical decrease of the central wind pipe． Through the comparative analysis of simulation results for five schemes, the scheme of the minimum influence to the furnace backing wall’ s safety was obtained, which provided a basis for the actual transformation of power plant.