作　　者： (张静）; (张艳秋）; (吴剑华）;

机构地区： 天津大学化工学院,天津300072 沈阳化工大学高校化工混合技术省级重点实验室,辽宁沈阳110142

出　　处： 《过程工程学报》 2017年第4期697-703,共7页

摘　　要： 以导热油YD-300为介质,采用数值模拟方法研究了恒壁温条件下流体的传热和阻力特性,分析了强化传热机理.结果表明,螺距参数τ接近1.96时强化传热效果最好,阻力最高.τ>1.96的非搭接结构,螺距变化对半管夹套侧传热系数和阻力系数的影响很小;τ<1.96的搭接结构,随螺距缩短半管夹套侧传热系数增加下降明显.小范围搭接形式(1.96>τ≥1.86)改善了搭接壁面与换热壁面附近的速度场结构,有利于强化换热;大范围搭接(τ≤1.47)降低了搭接壁面和换热壁面附近的速度、温度梯度与静压力梯度间的协同程度,降低了换热系数,同时提高了阻力. On the constant wall temperature boundary condition, the heat transfer and pressure drop characteristics were investigated numerically by heat conducting oil YD-300 used as working fluid. The comprehensive heat transfer and heat enhancement mechanism were analyzed. The results showed that Nusselt number and flow resistance coefficient were the highest at the condition of pitch τ≈1.96. The effects on enhanced heat transfer and resistance coefficient were very small for half-coil jackets at varying pitch for the non-overlapping structure τ〉1.96. Nusselt number decreased with pitch shortened for the overlapping structure τ〈1.96. 1.96〉τ≥ 1.86 was beneficial for heat transfer because the speed field was improved near the overlapping and heat exchange walls. But fields coordination was reduced between speed, temperature gradient and static pressure gradient when τ≤1.47, also heat transfer was declined and resistance was improved.

关 键 词： 螺旋半管夹套 螺距 搭接 强化传热 场协同