600MW偏转二次风系统锅炉炉内结渣特性的数值模拟

Simulation of Slagging Prevention Property of the Furnace with Deviated Secondary Air System

偏转二次风系统已广泛应用于大型四角切圆燃烧锅炉 ,用以抑制炉内结渣 ,防止水冷壁高温腐蚀等。为降低炉膛出口扭转残余 ,通常采用下部二次风大角度正切、上部二次风和 OFA风反切的布置方式。本文对某台采用偏转二次风系统的 6 0 0 MW燃煤四角切圆燃烧锅炉的炉内结渣过程进行模拟 ,对炉内气固相流动、温度场、气固相燃烧、固相向水冷壁的输运过程和灰粒在水冷壁上的粘附生长过程进行了数值模拟 ,结果表明 ,偏转二次风系统具有较强的防结渣性能 。

The deflected secondary air system has been widely used in the large capacity utility boilers.In such a system,the lower secondary air is deflected to the waterwall and the upper secondary air and the overfire air are deviated to the opposite direction of the flow rotation direction in the furnace,in order to obtain the effect of slagging perevention and decreasing the twisting residual at the exit of the furnace.In this paper,through the numerical methods,the slagging prevention property of a 600 MW utility boiler with a deflected second system is calculated on the basis of the simulation of flow field,temperature field,solid and gas combustion and the deposit growth under slagging conditions.The results illustrate that the numerical methods used in this paper is feasible and it can give reference to the design and operation of a high capacity utility boiler with deflected secondary air system.