四分仓回转空预器热力模型与漏风模型耦合计算
Coupling calculation between thermal model and air leakage model of quad-sectional rotary air preheater

摘要： 为分析四分仓回转空气预热器换热特性及抗低温腐蚀性能,建立热力及漏风计算模型,提出低温区域比的概念。先忽略漏风,基于回转空预器控制方程,利用有限差分法求解热力模型,得到温度分布,根据热力计算结果,求解漏风能量及质量方程组,得到漏风率,再根据进出口参数对两模型进行迭代。结果表明,计算值与设计值误差在5%以内;与同样面积的三分仓空预器对比,四分仓空气预热器的漏风率显著降低;各通道流体温度分布呈连续性,且与换热元件的温度分布基本一致;进口烟气流量沿转动方向的递减可显著地降低低温区域比,有效减少低温腐蚀。
Abstract: In order to analyze the heat transfer performance and low-temperature corrosion resistance property of quad-sectional rotary air preheater, the thermal and air-leakage calculation model were built and a concept named low-temperature area rate was proposed. With the air leakage ignored, thermal model was solved by numerical finite difference method based on control equations of rotary air preheater and temperature distribution was acquired. The energy and mass equations of air leakage were solved according to the results of thermal calculation and air leakage rate was obtained. Then iterative calculation of these two models was carried out in accordance with inlet and outlet parameters. The results showed that the difference between the calculated value and the designed value was less than 5%. Air leakage of quad-sectional air preheater was much less than that of tri-sectional one with the same heat transfer area. The temperature distributions of fluids in different channels were continuous and consistent with matrix. The low-temperature area rate was reduced with the decline of inlet gas flow along the direction of rotary, which helped to avoid low-temperature corrosion