热力蒸汽管道保温性能恶化的影响机制研究

Study of the deterioration mechanisms of thermal insulation performance of steam pipe

通过对典型长期在役热力蒸汽管道保温材料导热系数和保温结构进行实地测量,并在此基础上进行数值建模,探究两种不同因素对热力蒸汽管道保温性能的影响机制。其中,保温材料导热系数通过现场采样并利用Hot Disk热常数分析仪进行实验测量,保温结构参数以结构偏心率和底部镂空夹层厚度为关键特征参数。研究结果表明,数值计算与实验测量的管道散热损失能够很好吻合,其保温性能恶化系数分别为1.65和1.64。进一步分析表明,对于所选取热力管道,保温材料导热系数、偏心和镂空结构对保温性能恶化所占比重分别为67.7%,13.8%和18.5%。

The effects of thermal conductivity of insulation materials and the structure of thermal insulation layer was analyzed to investigate the deterioration mechanisms of thermal insulation performance of steam pipe numerically.The geometric data of insulation layer was determined by the on-site measurement of a typical steam pipe for 14 years in service.The structure of insulation layer was characterized by structural eccentricity and bottom hollow interlayer thickness.Thermal conductivity of the insulation materials was measured by the Transient Plane Source Method,TPS,using Hot Disk thermal constants analyzer.The results show that heat loss determined by the field test and numerical simulation were matched very well for the same condition.The deterioration coefficient determined by the numerical and experimental methods were 1.65 and 1.64,respectively.Moreover,for the typical steam pipe in this work,the contribution of thermal conductivity,structural eccentricity and bottom hollow interlayer thickness on the deterioration of thermal performance were 67.7%,13.8%and 18.5%,respectively.