【摘要】 蒸发式冷凝器是一种高效冷却散热设备,其传热性能目前还需要深入研究。在总结蒸发式冷凝器传热特点的基础上,提出了采用新的钢质弹形管、扭曲管和弹形-扭曲间断管强化传热的新结构,并测试了它们应用于蒸发式冷凝器的流动与传热性能,与传统的圆管和椭圆管进行了对比。研究结果表明,在冷却水喷淋密度为0.06kg·m-1s-1、管截面风速为3.4m·s-1时,椭圆管、弹形管、扭曲管和间断管比圆管总传热系数K分别高19.2%、24.4%、26.8%和31.2%。管内冷凝、管外水和空气的传热过程对总传热性能均有重要影响,弹形管可有效强化管外水膜与空气间的传热,同时降低空气流动压降;扭曲管可改善水膜分布,强化水膜传热,同时会增大空气流动压降;弹形-扭曲间断管可同时强化水膜、水膜与空气间的传热,略为减小空气流动压降。更多还原

【Abstract】 Evaporative condenser(EC)is a type of effective cooling equipment and a comprehensive study on its heat transfer performance is needed at present.Base on the understanding of the heat transfer characteristics of EC,three types of special-shaped steel heat exchange tubes(bullet-tube,twisted tube and bullet-twisted tube) were contrived respectively to enhance the heat transfer process in the EC.The fluid flow and heat transfer performances of the EC consisted of the above special-shaped steel heat exchange tubes separately were investigated and compared with those of the EC consisted of the conventional rounded tube and elliptical tube. The results indicate that,when the spraying density of water is 0.06 kg m-1·s-1 and airflow velocity is 3.4 m·s-1,the total heat transfer coefficients of the EC consisted of ellipse-tube,bullet-tube,twisted-tube and bullet-twisted tube are respectively 19.2%,24.4%,26.8%and 31.2%higher than that of the EC consisted of round-tube.The use of bullet-tube can enhance the heat transfer between water and air and decrease the pressure drop of the airflow.The use of twisted-tube can enhance the heat transfer of water film but will increase the pressure drop of the airflow.The use of bullet-twisted-tube can improve both the heat transfer processes of water film and airflow.更多还原