摘要
换热器作为关键设备,广泛运用于能源高效利用及能量交换等领域.其中,螺旋套管换热器是高效紧凑的流体换热设备,换热能力受流体物性、管材以及结构等因素的影响.内管偏心对螺旋套管环形侧的流动和换热特性具有重要影响.文中通过数值方法模拟了不同偏心程度的螺旋套管,探究对比了五个偏心率对应环形流道的流动阻力及换热特性.研究结果表明:偏心螺旋套管环形侧的努塞尔数(Nu_(a))和摩擦因数(f_(a))随着内管偏心率的增加分别增大和减小.当偏心率从0增加至0.8,偏心螺旋套管环形侧的努塞尔数(Nu_(a))和摩擦因数(f_(a))分别增加9.8%和减小5.1%.此外,以同心直套管环形侧为强化传热技术评价的参照,偏心率为0.8的螺旋套管换热器的环形流道的综合传热性能PEC_(a)为1.39.与同心螺旋结构相比,偏心螺旋套管环形侧的PEC_(a)增加了11.9%.
As a key equipment,heat exchangers are widely used in fields such as energy efficient utilization and energy exchange.The spiral tube heat exchanger is a highly efficient and compact fluid heat exchange device,and the heat exchange capacity is affected by factors such as fluid physical properties,pipe materials,and structure.The eccentricity of the inner tube has an important influence on the flow and heat transfer characteristics of the annular side of the spiral sleeve.This paper simulates spiral sleeves with different degrees of eccentricity through numerical methods,and explores and compares the flow resistance and heat transfer characteristics of annular channels corresponding to five eccentricities.The research results show that the Nusselt number(Nu_(a))and friction f_(a)ctor(f_(a))on the annular side of the eccentric spiral casing increase and decrease with the increase of the inner tube eccentricity.small.When the eccentricity increases from 0 to 0.8,the Nusselt number(Nu_(a))and friction f_(a)ctor(f_(a))on the annular side of the eccentric spiral casing increase and decrease by 9.8%,respectively 5.1%.In addition,taking the annular side of the concentric straight sleeve as a reference for the evalu_(a)tion of enhanced heat transfer technology,the overall heat transfer performance PEC_(a) of the annular flow channel of the spiral sleeve heat exchanger with an eccentricity of 0.8 is 1.39.Compared with the concentric spiral structure,the PEC_(a) on the annular side of the eccentric spiral casing increased by 11.9%.
作者
罗文
韩怀志
于瑞天
蔡磊
高瑞琛
Luo Wen;Han Huaizhi;Yu Ruitian;Cai Lei;Gao Ruishen(School of Chemical Engineering,Sichuan University,Chengdu Sichuan 610065)
出处
《东北电力大学学报》
2021年第6期53-60,共8页
Journal of Northeast Electric Power University
基金
四川大学科研人才引进基金(20822041C4013)。
关键词
偏心螺旋套管换热器
偏心率
环形流道
换热强化因子
Eccentric helically coiled tube in tube heat exchanger
Eccentricity
Annular flow channel
Heat transfer enhancement factor
