摘要
提出并分析了一种新型的传热强化元件——旋流片作为管壳式换热器管隙间支撑物的传热强化机理.在实验基础上,采用周期性单元流道模型数值模拟了旋流片产生的衰减性自旋流的流动和传热特性,并采用分段综合因子分析了传热强化的机理.结果显示,旋流片能起到扰流作用,并使流体强烈地冲刷传热管壁面强化传热.有旋流片段的综合因子最小,尾流段的综合因子接近于1,在自旋流段的综合因子最佳,应当充分利用自旋流段低阻高效的特点对换热器进行优化.
As a new type of heat transfer augmentation element, twisted-leaf tube bundle support was conducted. Based on the experimental investigation, a shell-side periodic unit channel model of the longitudinal flow type heat exchanger was developed for numerical simulation to analyze the flow and heat transfer information of swirl flow induced by twisted leaf. The section-by-section performance evaluation factors were used to analyze the mechanism of heat transfer enhancement. The results demonstrate that the twisted leaf can produce a helical flow, resulting in the disruption of the continuity and stability of the fluid. The distur- bing flow can promote turbulent intensity and enhance heat transfer effectively. The twistedleaf section gives worst integrated performance with a big increase in both heat transfer and pressure loss, and the trail-flow section also has no good performance because of the decayed swirl flow. The free-swirl-flow section provides the best performance with high efficiency and low pressure loss. In order to improve the integrated performance along the whole heat exchanger, it is recommended to optimize the shell side structure parameters to fully use the free swirl flow.
出处
《陕西科技大学学报（自然科学版）》
2007年第2期42-46,共5页
Journal of Shaanxi University of Science & Technology
基金
国家重点基础研究发展规划项目(973项目No.G2000026301)
关键词
旋流片
自旋流
换热器
数值模拟
传热综合因子
twisted leaf
free swirl flow
heat exchanger
numerical simulation
thermal performance evaluation factor
