摘要
蒸发式冷凝器是一种高效散热设备。能源危机和水环保促进了它的应用。提出了扭曲管强化管外水和空气流动及传热传质,测试了圆管、椭圆管、扭曲管等三种水平管蒸发式冷凝器的流动与传热传质性能.结果表明,扭曲管间为有序的可控制水流,分布均匀,脱落速度快,更易形成柱状流,管表面水膜厚度比现有圆管和椭圆管小;传热传质系数随冷却水喷淋密度及风速的增大而增大,但冷却水喷淋密度增大至一定值后,对传热传质系数基本没有影响;扭曲管的传热传质系数高于椭圆管、特别是圆管,总结了扭曲管传热传质系数经验式.
The energy crisis and water conservation activities have prompted a review of evaporative condenser as an effective means of cooling technology. A twist-tube to enhance the flow and heat-mass transfer was proposed, and air-water flowing characters and heat-mass transfer performance were investigated in comparison with the existing rounded tube and elliptical tube. The results indicate that the twist-tube get better water film distribution between the tubes, the sprayed water could fully cover the coil area and the water film would become thinner. The sprayed water flowing rate and airflow velocity have an important influence to the heat-mass transfer coefficients. The heat-mass transfer coefficients are increased with the airflow velocity and sprayed water flowing rate after it reaches the minimum sprayed flowing rate. In contrast to rounded tube and elliptical tube, it has higher heat and mass transfer coefficients in a twist-tube exchanger. Finally, via regression analysis of the experimental data, the correlation equations for calculating the heat transfer and coefficient of evaporative condenser axe obtained.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2008年第10期1698-1702,共5页
Journal of Engineering Thermophysics
基金
教育部博士点基金(No．20050561017)
粤港关键领域重点突破招标项目(No．TC05B372-8)
广州市科技成果转化项目(No．2007C13G0041)
华南理工大学科研基金(No．B10E5060360)
关键词
蒸发式冷凝器
传热传质
气液两相流
强化传热
扭曲管
evaporative condenser
heat and mass transfer
gas-liquid two-phase flow
enhancedheat transfer
twisted tube
