高温含凝尘烟气净化中换热管式除尘器初始沉积特性研究

Study on the initial deposition characteristics of heat exchange tube precipitator in purification of high temperature flue gas containing condensation dust

文章提出了一种针对高温烟气中凝尘净化的换热管式除尘技术。在余热回收时一方面将烟气中的凝尘捕集下来并在重力作用下实现凝尘自动清理,另一方面利用换热管外形成的结渣层保护换热管免受高温腐蚀。根据换热管外固态及液态渣层厚度合理设定管间距,是实施该项技术必须要解决的关键问题,为此需要对凝尘在换热管外的沉积分布进行分析。采用FLUENT中的DPM模型结合UDF进行数值模拟。结果表明:凝尘主要沉积在换热管迎风面,粒径大于5μm的凝尘粒子最大角沉积率出现在10°的位置,粒径为1μm时最大角沉积率出现在0°位置。单排沉积率在第二或第三排出现最大值。

The paper presents a heat exchange tube dedusting technology for the purification of condensation dust in high temperature flue gas.In the process of waste heat recovery,on the one hand,the condensed dust in the flue gas is collected and cleaned automatically under the action of gravity,on the other hand,the slag layer formed outside the heat exchange tube is used to protect the heat exchange tube from high temperature corrosion.The key problem to be solved in the implementation of this technology is to reasonably set the pipe spacing according to the thickness of solid and liquid slag layer outside the heat exchange tube.Therefore,it is necessary to analyze the deposition distribution of condensation dust outside the heat exchange tube.The DPM model in FLUENT and UDF are used to simulate.The results show that the dust is mainly deposited on the windward side of the heat exchange tube.The maximum angular deposition rate of particles larger than 5μm occurs at 10 degree and the maximum angular deposition rate appears at 0 degree when the particle size is 1μm.The single row deposition rate has the maximum value in the second or third row.