螺旋通道内受限外流传热和阻力特性的数值模拟  

Numerical Simulation of Heat Transfer and Resistance Characteristics of the Restricted Outgoing Flow in a Spiral Channel

作　　者：雷勇刚[1] 楚攀[1] 何雅玲[1] 高亚甫 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《热能动力工程》2007年第6期656-660,共5页Journal of Engineering for Thermal Energy and Power

基　　金：国家重点基础研究发展规划(973)基金资助项目(2007CB206902);教育部科学技术研究重大基金资助项目(306014)

摘　　要：通过三维数值模拟,对不同螺旋角度(15、20、30、40、45、50、60°)的螺旋通道内受限外流传热和流动特性进行了研究,提出了在一定的Re数范围内(0.8×104≤Re≤6×104)的优化形式,从而改善管壳式换热器壳侧流动和传热。研究结果表明,螺旋通道内受限外流形成理想的柱塞流,流道内速度分布均匀,有效地减小和消除了流动死区;与垂直折流板形成的"Z"字形受限外流相比,在相同的压降梯度下具有较高的传热系数,具有明显的节能效果。在研究的Re数范围内,当螺旋角α=45°时具有最佳的传热和阻力综合性能。研究结果可为管壳式换热器壳侧高效低阻结构设计和进一步优化提供理论依据。Through a three-dimensional numerical simulation,a study was conducted of the heat transfer and flow characteristics of restricted outgoing flows inside a spiral channel with different spiral angles(15°,20°,30°,40°,45°,50°,60°).The authors have proposed several optimization modes applicable in a certain range of Reynolds Number(0.8×104≤Re≤6×104),thereby improving the flow conditions and heat transfer at the shell side of a tube-and-shell type heat exchanger.The results of the study show that the restricted outgoing flow in the spiral channel can form an ideal plunger flow with the velocity distribution inside the channel being uniform,thus effectively minimizing and eliminating flow dead areas.Compared with a 'Z'-shaped restricted outgoing flow formed by vertical baffles,the above-mentioned flow inside the spiral channel can boast a relatively high heat transfer coefficient and enjoy an obvious energy-saving effectiveness at a same pressure-drop gradient.In the range of Reynolds number under investigation,the flow in question has a comprehensive performance of optimum heat transfer and resistance when the spiral angle α is around 45°.The research findings can well provide a theoretical basis for the design of a high-efficiency and low-resistance structure at the shell side of a shell-and-tube type heat exchanger and for its further optimization.

关 键 词：管壳式换热器 受限外流 螺旋角 数值模拟 压降 

分 类 号：TK124[动力工程及工程热物理—工程热物理]