100MW超高温亚临界低热值煤气锅炉再循环烟气数值模拟

Numerical Simulation of Recycled Flue Gas in 100MW Ultra-high Temperature Subcritical Low Calorific Value Gas Fired Boiler

低热值燃气为钢铁生产中的副产品,利用该种燃气作为钢铁企业自备电厂的燃料,可促进钢铁企业节能降耗。以国内首台100 MW超高温亚临界低热值煤气发电机组箱式锅炉为研究对象,该锅炉采用了烟气再循环的方式调节蒸汽温度。利用数值模拟方法,分析了三种再循环烟气进入锅炉的方式对锅炉的速度场、温度场的影响,并结合锅炉水冷壁安全性和蒸汽温度调节特性方面的考虑,得出再循环烟气由锅炉下方进入的方式对锅炉速度场和温度场影响最小,并且炉膛出口烟气平均温度最高,蒸汽温度调节特性最优,所以再循环烟气由锅炉下方进入锅炉的方式最适合该种锅炉。

Low calorific value gas is a by-product of iron and steel production. Using this kind of gas as fuel of self provided power plant of iron and steel enterprises can promote energy saving and consumption reduction of iron and steel enterprises. The first 100 MW ultra-high temperature subcritical low calorific value gas generator box boiler in China is taken as the research object, the boiler adopts flue gas recirculation to regulate the steam temperature. By using numerical simulation method, the influence of three kinds of recirculation flue gas entering the boiler on the velocity field and temperature field of the boiler is analyzed, the safety of water wall and the characteristics of steam temperature regulation are considered. It is concluded that the way of recirculation flue gas entering from the bottom of the boiler has the least influence on the velocity and temperature field of the boiler, the average temperature of flue gas at the furnace outlet is the highest and the steam temperature regulation characteristic is the best. So the way of recirculation flue gas entering from the bottom of the boiler is the most suitable for this kind of boiler.