燃煤锅炉中过/再热器工质温差与积灰程度关联研究

Correlation Analysis between Fouling Degree and Steam Temperature Difference in Superheater/Reheater of Coal-fired Boiler

为实现对燃煤锅炉无烟温测点的对流受热面积灰程度的监测,对锅炉对流受热面的传热特性及工质吸热特性进行热平衡机理分析,在热力学基础上,用相关性分析、回归分析和灰色关联分析方法对实际生产数据进行挖掘、分析,计算了对流受热面的出入口工质温差与清洁因子的灰色关联特性,建立了利用受热面进出口温差表征积灰程度的函数模型。结果表明:负荷稳定时,锅炉燃烧释放的热量也是一定的,对流受热面单位工质吸热量能反映该对流受热面的积灰程度;受热面温差与清洁因子具有极强的关联性,受热面进出口工质温差模型能很好地反映对流受热面的积灰程度。

This paper aims to monitor heating surface fouling degree of boiler without recording fume temperature data. Based on thermodynamics mechanism,this paper analyzes heat balance mechanism on the heat-transfer characteristic and heating-trap characteristic of convection heating surface of boiler,and obtains the relationship between heat transfer coefficient and temperature difference by means of correlation analysis,regression analysis and grey relation analysis methods on actual production data. And then a model is built to reflect the fouling degree of the heated surface. It is concluded that the released heat in a boiler is constant when load is stable,and the absorbed heat through a unit area of convection heating surface indicates fouling degree of the same convection surface. There is strong relevance between temperature difference of heating surface and cleaning factor. The temperature difference between inlet and outlet of heating surface model can greatly indicate the fouling degree of the convection surface.