管内插偏重式螺旋轮自转及对流传热特性  

Self-rotating and convective heat transfer performance of imbalance spiral-gear insert in tubes

作　　者：彭德其[1] 田清[1] 俞天兰[1,2] 王伟强[1] 王志奇[1] 罗谷[1] 

机构地区：[1]湘潭大学机械工程学院,湖南湘潭411105 [2]湖南工业大学机械清洗研究所,湖南株洲412008

出　　处：《化工学报》2013年第8期2833-2838,共6页CIESC Journal

基　　金：湖南省自然科学基金项目(11JJ9003);博士启动基金项目(10QDZ32)~~

摘　　要：针对换热管内污垢在线清洗的难题,提出了管内插偏重式螺旋轮自动防除垢技术。理论分析了螺旋轮获得的自转动力矩,并通过实验研究其自转特性;进一步对管内插偏重式螺旋轮的对流传热特性进行实验研究,对比分析偏重因素对传热强化性能的影响。结果表明:在一正一反交替连接时螺旋轮获得的自转速度最大,更有利于螺旋轮的旋转;传热温差为7℃时,管内插螺旋轮的总传热系数比内插螺旋线、内插扭带时分别提高22.2%和12%;传热温差为15℃时,内插不同偏重式螺旋轮的总传热系数与光管相比分别提高89%和112%,与内插普通螺旋轮的传热系数相比分别提高12%和25%,但相应的沿程阻力损失随之增加。考虑传热和阻力两方面因素,对上述管内插物的综合性能进行比较,结果显示内插偏重式螺旋轮的综合性能最好。Aiming at the online fouling removal problem in heat transfer tubes,the imbalance spiral-gear inserts are proposed.The self-rotation force moment of such inserts is analyzed theoretically,and the self-rotation performance is examined experimentally.The convective heat transfer characteristics are investigated through experiments in order to evaluate the effect of imbalance on heat transfer enhancement.The result shows that the spiral-gears connected clockwise and counterclockwise alternately have the greatest force moment and can spin more easily.For the heat transfer temperature difference of 7℃,the overall heat transfer coefficient of balanced spiral-gear inserts is 22.2% and 12% higher than that of spiral-wire insert and twisted-tape insert,respectively.For the heat transfer temperature difference of 15℃,the overall heat transfer coefficients of the two kinds of imbalance spiral-gear tubes are 89% and 112% greater than that of straight tubes without any inserts,and are 12% and 25% higher than that with balanced spiral-gear inserts.The flow resistance is increased correspondingly but still in an appropriate range for engineering applications.From the comprehensive performance on heat transfer rate and resistance,the imbalance spiral-gears give the best result.

关 键 词：螺旋轮 自转特性 对流传热 防除垢 

分 类 号：TK124[动力工程及工程热物理—工程热物理]