一、概述对于各种类型的换热器,都要求保持换热器体积与换热量、功率消耗与换热量这两个比值尽可能小。在气—气热交换器中,管外常用扩展表面强化传热,管内的传热能力可能成为传热的制约条件。使用各种插入件强化管内传热十分经济有效,常用的插入件有:扭带(俗称麻花铁)、错开扭带、静态混合器、螺旋片以及螺旋线圈等。在强化管内传热中,扭带具有结构简单、易于安装、效果显著等优点,各国学者进行了很多的研究。研究表明扭带强化传热的作用有三个方面: I. Overview For all types of heat exchangers, are required to maintain the heat exchanger volume and heat transfer, power consumption and heat exchange these two ratios as small as possible. In gas-to-air heat exchangers, the commonly used extended surfaces outside the tube enhance heat transfer and the heat transfer capability within the tube can become a constraint for heat transfer. Use a variety of inserts to strengthen the tube heat transfer is very cost-effective, commonly used inserts are: twist band (commonly known as twist iron), staggered twist band, static mixer, spiral and spiral coil. In strengthening the tube heat transfer, the twisted band has the advantages of simple structure, easy installation, significant effect and so on, and scholars in many countries have carried out a lot of researches. Studies have shown that the role of twisted band enhanced heat transfer has three aspects: