超临界W型锅炉蒸发系统的分布参数建模研究

Distributed Parameter Modeling of Evaporation System in a Supercritical W-Shaped Boiler

基于图像处理的温度检测信息,对超临界W型直流锅炉蒸发系统进行分布参数建模。建立的模型同时考虑了炉内热负荷分布和锅内工质物性分布的不均匀性,以预测对应工况下的壁面热流分布和壁温分布。仿真结果表明各热力参数在水冷壁上呈现明显的分布参数特性,并且其分布特性随着工况的变化而变化。发现W型火焰锅炉前墙存在3个高热流区,左墙最高壁温为459.85℃,且最大壁面温差为94℃。同时,数值计算结果与现场实测值进行了对比,理论推算与电厂实际运行结果相一致。模型既可用于在线预测,也可用于离线分析计算,对超临界W型锅炉的研究有一定的指导意义。

A distributed parameter model of evaporation system in a supercritical W-shaped once-through boiler was developed based on a 3-D temperature distribution. The mathematical model was formulated for predicting the distributions of the heat flux and the metal-surface temperature considering non-uniform distribution of the surface heat transfer and the frictional resistance coefficient simultaneously. Analyzed results indicate that the characteristics of these parameters are remarkably distributed and will change as the operation condition changes. The results show that the heat flux distribution on front water wall exist three high heat flux zones in the W-shaped boiler, the maximum metal tempertaure on left water wall is 459.85 ℃ and the maximum deviation of metal temperature is nearly 94 ℃ at different load. This distributed parameter model is fit for the in-situ operating status of the boiler. The model can be applied for online prediction or off-line calculation, which provides a reference on heat transfer of supercritical system.