循环流化床锅炉风水联合冷渣器的数值模拟

Numerical Simulation in Slag Cooler of CFB Boiler

数值模拟计算在很多行业为设备的设计、计算提供了可靠的数据。为了验证数值计算对风水联合冷渣器这类设备的预测能力及为以后的设计改型提供依据,本文采用FLUENT软件,在特定情况下对风水联合冷渣器内气固两相运动情况作了数值模拟。主要研究不同粒径固体颗粒在冷渣器完全流化的前提下的运动轨迹,并将典型的计算结果与实际进行比较。计算中选用欧拉拉格朗日模型,计算几何尺寸参照冷渣器的实际尺寸,网格为非结构化网格,进口边界条件按照实验测定值给定。结果表明:冷渣器采用不均等配风,出渣效率较高;流场湍能变化明显,总体流场比较均匀,出口处速度最大;隔墙附近有涡流存在有利于颗粒翻越隔墙,同时隔墙还起到对渣的粒径进行分选的作用;灰渣颗粒进入冷渣器的速度不能太大,否则冷渣器不能起到冷却作用。

Numerical simulation can supply applied credible data to optimize design of equipments in all kinds of industries. Gas-solid flow numerical simulation in a slag cooler of a CFB boiler under a specific and simple condition was done in this paper, The main research was to track a large number of particles of different diameters in a even flow, which validate the forecasted capacity of numerical simulation to the slag cooler. Hopefully it can afford foundation for design and model change. The Euler-Lagrange model was adopted in the calculation. Geometry dimensions of calculation refer to the real dimensions of the slag cooler. An unstructured mesh was adopted and boundary conditions of the entrance were given by referring to experiment values. It is shown that the result of numerical calculation accords with the practical result and the numerical calculation can provide a scientific approach to this equipment＇s design and improvement.