管材种类和污垢对凝汽器传热性能的影响

The Impact of Tube Types and Fouling on the Heat Transfer Performance of Condensers

用凝汽器热力计算中的分布计算公式，对电厂常用的黄铜管HSn70—1、钛管TA2、奥氏体不锈钢管304、317L，铁素体不锈钢管444、SEA—CURE（海优）进行了传热性能的计算，定量分析研究了管材的导热系数和污垢对凝汽器传热性能的影响。结果表明，尽管不同管材的导热系数相差数倍，常用管材凝汽器的总传热系数K差别一般不到6％，有污垢时差别进一步缩小；污垢热阻是控制热阻，0．015ram碳酸钙垢就占总热阻的50％以上，使K降低一半左右；管壁热阻占比最小，清洁时约为3％-11％，0．015mm碳酸钙垢时，约占总热阻的1．5％-6％。

The step formula of thermodynamic calculations of condensers was applied on tube HSn70- 1, TA2, TP304, TP317L, TP444 and SEA - CURE. Quantitative analysis has been researched on the impact of the tube thermal conductivity and fouling on heat transfer performance of condensers. The result showed that despite the large difference of thermal conductivity of tubes,the difference in overall heat transfer coefficient K is generally less than 6%, and the difference is further reduced when the tube is with fouling. Fouling thermal resistance is the controlled thermal resistance; a thickness of 0. 015mm calcium carbonate scale occupies more than 50% of the total thermal resistance,and reduces the half of K. The thermal resistance of tube walls counts the smallest proportion,about 3% - 11% when they are clean and 1.5% to 6% when there exist a calcium carbonate scale of 0.015mm thick.