基于普朗特类比的螺纹管内污垢分析模型  

Fouling Model of Internal Helical-rib Tubes Based on Prandtle Analogy

作　　者：张巍[1] 李冠球[1] 张政江[1] 徐志明[2] 李蔚[1] 

机构地区：[1]浙江大学机械与能源工程学院,浙江省杭州市310027 [2]东北电力大学能源与机械工程学院,吉林省吉林市132012

出　　处：《中国电机工程学报》2008年第35期66-70,共5页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2007CB-206904)~~

摘　　要：对冷却塔中的7根铜质内螺纹管进行了传热性能污垢试验,试验中流体流速为1.07m/s,雷诺数为16000。螺纹管几何参数范围为:螺纹数18～45,螺纹角25°～45°,螺纹高0.33～0.55mm。污垢为颗粒污垢和析晶污垢的混合物,水的硬度为800mg/L。引入普朗特类比法,以(Km/Kmp)/(f/fp)和(j/jp)/(f/fp)1/3作为传热性能评价指标进行分析。与以往的研究相比,文中更加全面地考虑了内螺纹管参数的影响。同时建立了一系列关于螺纹管的污垢热阻与传热效能的半经验函数关系式,可用于评价和预测实际状态下冷却水的结垢情况。The fouling experiments on heat transfer performance of seven copper helically ribbed tubes in cooling tower were taken under the condition of 1.07 m/s water velocity and Reynolds number is 16 000. The ranges of geometric parameters were number of rib starts （18-45）, helix angle 25^o,-45^o, and height （0.33-0.55 mm）. The fouling mechanism is a combination of precipitation fouling and particulate fouling and water hardness is 800mg/L. Based on the Prandtle analogy, （Km/Kmp）/（f/fp） and （j/jp）/（f/fp）^1/3 were used as evaluation indexes of heat transfer. Comparing to previous studies, this study is a comprehensive analysis involving the structure parameters of helical-rib tubes. A series of semi-theoretical fouling correlations as a function ＇of the evaluation indexes were developed. The correlations can be directly used to assess the fouling potential of enhanced tubes in actual cooling water situations.

关 键 词：污垢热阻 普朗特类比 冷却塔 强化传热 

分 类 号：TK172[动力工程及工程热物理—热能工程]