纳米颗粒对超临界二氧化碳流体传热特性的影响  

Influence of nanoparticles on heat transfer characteristics of supercritical carbon dioxide fluid

作　　者：代威 刘丽丽 杨智 廖传军 陆浩然 DAI Wei;LIU Lili;YANG Zhi;LIAO Chuanjun;LU Haoran(Beijing Institute of Astronautical System Engineering,Beijing 100076,China;Beijing Branch,Xi’an Aerospace Shenzhou Architectural Design Co.,Ltd.,Beijing 100040,China;School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]北京宇航系统工程研究所,北京100076 [2]西安航天神舟建筑设计院有限公司北京分公司,北京100040 [3]广东工业大学材料与能源学院,广州510006

出　　处：《兵器装备工程学报》2023年第5期142-149,共8页Journal of Ordnance Equipment Engineering

摘　　要：针对超临界二氧化碳纳米流体,采用数值模拟方法研究了纳米颗粒体积分数、壁面热流密度对其在水平管内传热特性的影响。结果表明:当给定入口质量流量,纳米颗粒的掺杂会增大流体密度,入口流速因此而减小,不利于传热;但纳米颗粒的掺杂使得纳米流体热导率显著增大,这有助于提升壁面热流向体相空间的传输速率。因此纳米粒子体积分数越大,其体相流体温度在沿程方向上升温速率也越快。当壁面热流密度q=30 kW·m^(-2)时,纳米流体在沿程方向上均具有传热强化效果;在更高热流密度时,纳米流体仅在流动充分发展初期具有强化传热效果,在换热管末端其传热效果随体积分数增加显著恶化。For supercritical carbon dioxide nanofluids,this paper studies the effects of volume fraction and wall heat flux of nanoparticles on their heat transfer characteristics in horizontal tubes by numerical simulation.The results show that when the inlet flow rate is given,doping of nanoparticles will increase the fluid density and reduce the inlet flow rate,which is not beneficial to heat transfer.However,this doping increases the thermal conductivity of the nanofluids significantly,which is helpful to improve the transfer rate of wall heat flow into the volume phase space.Therefore,the larger the volume fraction of nanoparticles,the faster the temperature of the bulk phase fluid will warm up along the path.When the wall heat flux q=30 kW·m^(-2),heat transfer is enhanced by nanofluids along the flow direction.At a higher heat flux,the heat transfer enhancement only occurs in the early stage of fully developed flow,and the heat transfer deteriorates significantly at the end of the heat exchange tube with an increasing volume fraction.

关 键 词：纳米颗粒 超临界二氧化碳 数值模拟 传热特性 温度分布 

分 类 号：V19[航空宇航科学与技术—人机与环境工程]