【作者】 赵鹏；

【导师】 汪荣顺；

【作者基本信息】 上海交通大学 ， 制冷与低温工程， 2010， 硕士

【摘要】 竖直星形翅片管换热器由于其结构简单、制造方便、成本低等优点,被广泛运用于低温液体气化领域中。低温液体的温度通常较低,因此翅片管表面结霜将不可避免。结霜一方面减少了空气与翅片表面的流通面积,另一方面由于霜的导热系数很低,将影响翅片管的传热效果。由于霜的生长对翅片管传热性能有很大影响,因此,对竖直星形翅片管结霜过程进行实验和理论研究是非常必要的。本文设计并搭建了竖直星形翅片管的传热以及结霜特性测试实验台。通过改变相关条件(空气温度、空气湿度、翅片管液氮流量、翅片管内压力),测量翅片管进出口温度,进出口压差,以及翅片上相应位置的翅表面温度、霜层厚度。一方面考察翅片管霜层的生长规律,另一方面考察翅片管结霜对翅片管传热性能的影响。全面了解各环境参数对霜层生长以及翅片管气化能力的影响程度。建立结霜条件下翅片管传热模型,用于霜层生长达到稳定的情况。编制翅片管式计算程序,计算沿着液氮流程方向,翅片管各位置表面霜层厚度、翅片管内温度变化情况。并与实验所得数据进行对比,进行验证、修正,为星形竖直翅片管优化设计提供实验依据和设计参考。通过对竖直星形翅片管结霜性能的研究,对优化环境参数、提高气化器传热性能具有重要意义。更多还原

【Abstract】 Star-shaped finned-tube has been widely used in the field of cryogenic liquid gasification for its simple structure, manufacturing convenience and low cost. Generally the temperature of cryogenic liquids are low which inevitably case the formation of frost on the finned-tube surface. On the one hand, Frost reduced the flow area of air and fin surface, On the other hand, Frost affect the heat transfer performance of finned tube for its low coefficient of heat conductivity. Because the growth of frost on the finned tube affect the heat transfer performance, Star-shaped finned-tube frosting process of theoretical and experimental research is very necessary.In this paper, An experimental rig is designed and installed to test the performance of the star-shaped fin-tube in the frosting process. By changing the relevant conditions(air temperature, air humidity, fin-tube liquid nitrogen flow, the pressure inside the finned tube),We measured the import and export temperature, the differential pressure between import and export of fin-tube, the Frost layer thickness and temperature on finned-tube surface. On the one hand, We studied the growth pattern of frost layer, On the other hand, We studied the affect of frost formation to the heat transfer performance of finned-tube and comprehensively learned the affect level of circumstance parameters to the frost grow and gasification capacity of fin-tube.In this paper, A heat transfer model and calculation program of fin-tube in frost conditions has been built to predict the frost layer thickness and the export temperature of nitrogen. By comparing with the experimental date, we can verify and correct the model. And provide experimental basis and design reference to the optimization of Star-shaped finned-tube.Through the study on the frosting process on the star-shaped fin tube, it shows great significance to the optimization of circumstance parameters and improvement of the heat transfer performance.更多还原