弥散流工况下矩形窄缝通道鼓包对流动传热的影响  

Effect of blisters on flow heat transfer in rectangular narrow channels under dispersed flow condition

作　　者：卢嘉鸣 王言 姚嘉晔 洪钢 张尧立 LU Jiaming;WANG Yan;YAO Jiaye;HONG Gang;ZHANG Yaoli(College of Energy,Xiamen University,Xiamen 361102,China)

机构地区：[1]厦门大学能源学院,福建厦门361102

出　　处：《厦门大学学报(自然科学版)》2025年第1期177-185,共9页Journal of Xiamen University:Natural Science

摘　　要：[目的]分析弥散流膜态沸腾工况下鼓包尺寸及间距对通道流动传热的影响.[方法]采用Ansys Fluent软件对带鼓包结构的矩形窄缝通道进行几何建模和网格划分,并针对弥散流传热机理构建弥散流传热数值计算模型,对不同鼓包高度、直径和间距的矩形窄缝通道流动传热特性进行计算分析.[结果]鼓包对流体出口温度及鼓包区域局部温度产生明显影响.鼓包的出现导致流域横截面变小、鼓包顶部和壁面间的流体流速增大,使得局部传热能力增强,但由于多个鼓包排列导致阻力增大,使燃料板后段的整体传热能力下降,壁面温度波动接近15.0 K,容易导致传热恶化的提前发生.鼓包高度、直径和间距的增大,均使流体温度和壁面温度上升的趋势逐渐增强,温度最高值也呈上升趋势.[结论]弥散流工况下,鼓包的出现使得矩形窄缝通道后段的整体传热能力下降,壁面温度波动加剧,容易导致传热恶化的提前发生.在实际应用中需充分考虑该因素,以保证燃料元件在冷却剂丧失事故下的安全性和完整性.[Objective]In the core of a nuclear reactor,a loss of coolant accident(LOCA)can result in the rapid depletion of coolant,resulting in insufficient cooling of fuel elements and the possibility of dispersed flow film boiling conditions.Under these circumstances,blistering on the fuel elements may further deteriorate heat transfer.This study focuses on the influence of blister size and spacing on channel flow heat transfer under the condition of dispersed flow film boiling.[Methods]Ansys Fluent software was used for geometric modeling and meshing of the rectangular narrow channel with blisters structures.A numerical model of dispersed flow heat transfer was constructed for the mechanism of dispersed flow heat transfer.The Eulerian model,wall and vapor-liquid two-phase heat transfer model,and interphase model coupling were used to describe the pressure and mass transfer between the liquid phase and the gas phase and to construct the boiling model of dispersed flow.The flow heat transfer characteristics of rectangular narrow channels with different blisters heights,diameters,and spacings were calculated and analyzed.[Results]The blisters destabilize the flow field,causing a significant obstruction to the local flow velocity and a significant effect on the interface temperature.When multiple blisters are arranged along the flow direction,the first blister receives the strongest fluid shock and has the lowest surface temperature.The highest temperature occurs at the end of the last blister.An increase in the height of the blisters results in a greater influence of the blisters on the fluid temperature and the wall temperature.From the starting point of the first blister to the end position of the last blister,the fluid temperature varies by 1.1 K for the no-blister condition,while the fluid temperature fluctuates up to 3.9 and 5.8 K when the blister height is 1.3 and 1.6 nm(conditions 2 and 3),respectively.In terms of the wall temperature,there is a variation of 1.9 K for the no-blister condition,and the wall temperatur

关 键 词：矩形窄缝通道 鼓包 弥散流膜态沸腾 数值模拟 

分 类 号：TL352.1[核科学技术—核技术及应用]