摘要
本文运用数值模拟的方法,对带有多重V形肋片的平板型太阳能空气集热器的换热与流动特性进行了研究.在雷诺数5 000～20 000范围内,采用RNGk-ε湍流模型,研究了相对肋宽比（W/w）对集热器换热特性的影响规律,并对集热器内部流场进行了分析.研究结果表明,V形肋片增强了空气的对流换热.这是由于流体掠过肋片后,产生旋涡和回流,加强了流体扰动,从而使换热增强.相对其它肋宽比而言,W/w=6时,集热器具有较好的换热效果,努塞尔数为光滑壁面的2.54倍,但肋片的存在导致摩擦损失增加,换热性能因数最大为1.55。
A numerical simulation is conducted for the flow and heat transfer characteristics in solar air collector with multi v-shaped fins.Effects of the relative roughness width ratio （W/w） on the heater transfer performance and flow field were investigated adopting the RNG k-ε turbulence model for the Reynolds number range from 5 000 to 20 000.The results show that usage of the v-shaped fins can enhance the convective heat transfer as a result of the disturbance of the vortex and the backflow that form during the air flow pasts the v-shaped fins.Compared with other values of W/w,air collector has better heat transfer enhancement at W/w =6 and the Nusselt number is 2.54 times of that without fins.However,using the fins leads to the increase of the friction loss.The maximum thermal enhancement factor is 1.55.
出处
《节能技术》
CAS
2014年第5期414-418,共5页
Energy Conservation Technology
基金
辽宁省自然科学基金项目(2013020156)
关键词
太阳能空气集热器
平板型集热器
数值模拟
强化换热
V形肋片
solar air collector
fiat-plate collector
numerical simulation
heat transfer enhancement
v-shaped fin
