三次风反切解决高温对流受热面温度偏差的试验研究

An Experimental Study on Furnace with Anti-tangential Overfire Air

某电厂200MW机组的冷、热态试验结果表明:高温对流受热面的烟气温度偏差是由速度偏差引起的,而水平烟道中的烟速不均是由于炉膛出口的残余扭转引起的,消除和削弱炉膛出口的残余扭转就应使炉内气流的旋转强度减弱。因此,在冷态模化试验台上进行了三次风反切的试验研究,结果发现:通过三次风反切,能够削弱炉膛出口的扭转残余,在水平烟道中形成一个较为均匀的速度分布,且对炉内空气动力结构无明显影响,这对机组的安全经济运行起促进作用。

In large-scale p. f. fired boilers, large deviations of flue gas temperature and velocity often exist at furnace exit and at horizontal flue pass along furnace width, making overheat, ash accumulation and slag boding of convection heating surface. Tests on a 2000MW utility boiler affirm:flue gas temperature deviation on convection heating surface arive from velocity deviation, which arise from residual rotation at furnace exit. Residual rotation at furnace exit can be eliminated by decreasing revolving intensity of airflow in furnace. Through injecting overheated air anti-tangentially into furnace, results show: residual ratation at furnace exit becomes small, an uniform velocity distribution along furnace width can be expected on horizontal flue pass, and aerodynamics in furnace is less affected.