套管管束式换热器换热特性试验研究

An experimental study on the heat transfer characteristics of a double-tube bundle heat exchanger

清华大学核能与新能源技术研究院对具有特殊结构的套管管束换热器(其传热单元由带螺旋肋片的外套管和带微波浪弯的内套管组成,通过自身结构实现传热管的支撑和定位)的换热特性进行了试验研究。试验结果表明,与一般流道的换热性能相比,不规则环形窄缝流道的换热系数不仅降低,而且随雷诺数的变化趋势也较平缓;外套管管间流道的换热系数降低,但变化趋势与普通流道相同。根据试验数据,采用分离系数法,拟合出了不规则环形窄缝流道和外套管管间流道的换热公式。

The experimental study on a double-tube bundle heat exchanger with a special type of structure （Its heat transfer as- sembly consists of an external tube with lengthways spiral fins and an internal tube with microwave bends and implements supporting and positioning through the structure） was conducted in the Institute of Nuclear and New Energy Technology, Tsinghua University. The results show that compared with an ordinary flow path, an anomalous narrow annulus reduces the heat transfer and its heat transfer coefficient has little relation with the Reynolds number. The heat transfer perfor- mance of the flow path between external tubes is depressed, however its disciplinarian is the same as an ordinary one. Based on the experimental data, a heat transfer formula of the flow path of anomalous narrow annulus and the flow path between external tubes is given by using the coefficient partition method, respectively.