切圆燃烧反切风风量与位置对炉内流场的影响

Fired Boiler Furnace with Changing the Flow Rat and Location of Opposing Tangential Circle of Air

本文采用数值分析技术对大容量切圆燃烧锅炉改变燃烧器二次风反切风量以及反切风位置时的炉内流场特性进行了全三维模拟和研究,研究结果表明在燃烧器上部二次风采用反切布置的情况下,无量纲数XJ在1左右时炉膛出口残余旋转较小,炉内气流湍动混合较好,炉内气流运动稳定;研究亦表明反切风位置对炉内流场影响较大。同时,对7个电厂13台大型锅炉进行了改造效果统计,验证了数值分析的结论。

In this thesis, 3D numerical simulation is carried out to investigate the flow characteristics in the large tangentially fired boiler furnace with changing the flow rate and location of opposing tangential circle of air. The simulation results show that the residual swirl can be effectively weakened, the turbulent intensity in furnace is great and the flow is stable when XJ is about 1.0 with using opposing tangential circle of second air on upper burners. The simulation results also show that the location of opposing tangential circle of air influences the flow field in the furnace greatly. The practical verification is performed directing thirteen large tangentially fired boilers of seven power plants, the result is in accord with the conclusion of the numerical simulation.