微通道扩散焊式换热器封头结构对流动特性影响模拟分析  

Numerical Investigation of the Influence of Microchannel Diffusion Welded Heat Exchanger Head Structure on Flow Characteristics

作　　者：费俊杰 刘旻昀 席大鹏 唐佳 刘睿龙 昝元锋 黄彦平[1] Fei Junjie;Liu Minyun;Xi Dapeng;Tang Jia;Liu Ruilong;Zan Yuanfeng;Huang Yanping(China National Nuclear Corporation Key Laboratory on Nuclear Reator Thermal Hydraulics Technology,Nuclear Power Institute of China,Chengdu,610213,China;Department of Engineering Physics,Tsinghua University,Beijing,100084,China)

机构地区：[1]中国核动力研究设计院中核核反应堆热工水力技术重点实验室,成都610213 [2]清华大学工程物理系,北京100084

出　　处：《核动力工程》2023年第S02期176-183,共8页Nuclear Power Engineering

摘　　要：为认识和掌握封头几何结构对以超临界二氧化碳(SCO_(2))为工质的微通道扩散焊式换热器(简称MCD)流量分配能力的影响机理,并优化MCD封头结构设计,改善换热器流量分配均匀性,从而提高换热效能与安全性,本研究采用数值模拟方法,对不同结构MCD封头的流动和流量分配性能进行研究。为解决硬件条件对复杂换热器模型网格数量的限制,开发了一款可广泛用于MCD流体力学性能模拟的UDF程序,大量减少了重复性网格工作,降低了模拟计算的硬件门槛。运用Fluent软件,分析封头局部几何参数(不同封头壁面曲线参数、不同多孔挡板参数等)对压降、流量分配性能、流场的影响。研究结果表明,进口封头腔体内产生的涡旋以及出口封头的突缩结构会造成压力损耗,低高度的二次曲线壁面封头可以有效抑制涡旋产生,减少突缩结构造成的压力损耗,从而降低封头压降,提高流量分配性能。In order to comprehend and grasp the influence mechanism of head geometry on the flow distribution capacity of microchannel diffusion welded heat exchanger(MCD)with supercritical carbon dioxide(SCO_(2))as working fluid,optimize the head structure design of MCD,improve the flow distribution uniformity of heat exchanger,and thus improve the heat exchange efficiency and safety,this study employed numerical simulation methods to investigate the flow and flow distribution performance of MCD heads with different structures.To address the limitations posed by hardware conditions on the grid resolution of complex heat exchanger models,a userdefined function(UDF)code which can be widely used for simulating fluid dynamics performance in MCDs was developed,which can greatly reduce the repetitive grid-related tasks and lower the hardware threshold of simulation calculation.The software Fluent was used to analyze the influence of local geometric parameters of the head(different head wall curve parameters,different porous baffle parameters,etc.)on pressure drop,flow distribution performance and flow field.The results show that the vortex generated in the cavity of the inlet head and the abrupt contraction-expansion structure of the outlet head can cause pressure loss.The head featuring lower-height secondary curved wall can effectively suppress vortex generation and reduce pressure loss attributed to the abrupt contraction-expansion structure,subsequently lowering header pressure drop and enhancing flow distribution performance.tributed to abrupt contraction-expansion structures,thus reducing the head pressure drop and improving the flow distribution performance.

关 键 词：微通道扩散焊式换热器(MCD) 封头结构 流动特性 

分 类 号：TL334[核科学技术—核技术及应用]