正戊醇添加剂强化喷雾冷却传热实验研究  

Experimental investigation on spray cooling heat transfer enhancement by n-pentanol additive

作　　者：陈晗 蔡畅 刘红[1] 尹洪超[1] CHEN Han;CAI Chang;LIU Hong;YIN Hongchao(Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education,School of Energy and Power Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China;Aircraft and Propulsion Laboratory,Ningbo Institute of Technology,Beihang University,Ningbo 315800,Zhejiang,China)

机构地区：[1]海洋能源利用与节能教育部重点实验室,大连理工大学能源与动力学院,辽宁大连116024 [2]先进飞行器与空天动力创新研究中心,北京航空航天大学宁波创新研究院,浙江宁波315800

出　　处：《化工学报》2025年第1期131-140,F0004,共11页CIESC Journal

基　　金：国家自然科学基金青年基金项目(52206074);中国博士后科学基金面上项目(2023M730464)。

摘　　要：以纯水和低浓度正戊醇-水溶液为工质开展喷雾冷却传热性能实验研究,并探究正戊醇添加剂对喷雾场内冷却工质的液滴Sauter平均直径、液滴数量以及体积通量空间分布特性的影响规律。结果表明少量正戊醇添加剂可显著提高纯水喷雾冷却传热性能,但强化传热效果随着正戊醇浓度的提高呈现先增强后减弱的趋势。相比纯水工质,混合溶液的喷雾液滴数量增加,Sauter平均直径降低,体积通量提高,三者共同作用导致喷雾冷却换热性能的提升。然而,正戊醇较低的比定压热容、热导率和汽化潜热会对换热产生不利影响。在上述强化传热与削弱传热两种机制的共同作用下,实验结果表明体积分数为1.0%的正戊醇-水喷雾冷却传热效果最佳。Spray cooling is a promising heat dissipation technique for the thermal management of high-power devices.In the present research,pure water and bi-component mixtures with low concentrations of n-pentanol are adopted as the working fluid to ascertain the additive effect.Spray cooling heat transfer characteristics are experimentally investigated,and the radial distributions of Sauter mean diameter(SMD)and droplet number are measured by the particle/droplet imaging analysis(PDIA)system,while the fluid volumetric flux distribution is measured by the self-designed precision mobile experiment bench.The results show that a small amount of npentanol additive can significantly improve the heat transfer performance of pure water spray cooling,but the enhanced heat transfer effect first increases and then weakens as the concentration of n-pentanol increases.Measurement shows that the SMD decreases and the droplet number increases monotonously with the n-pentanol volume fraction.The effect of n-pentanol concentration on the fluid volumetric flux is similar to that on the heat transfer coefficient,i.e.,the elevation is the most obvious with the 1%(vol)n-pentanol-water mixture.It is speculated that a smaller SMD,a larger droplet number and a higher volumetric flux caused by the n-pentanol additive significantly enhance both convection and phase change heat transfer.However,since the latent heat of evaporation of n-pentanol is much lower than water,as well as the lower volumetric flux with 2.0%(vol)n-pentanol,the heat transfer enhancement effect weakens at a higher n-pentanol concentration,achieving a peak at the npentanol concentration of 1.0%(vol).

关 键 词：喷雾冷却 传热 正戊醇添加剂 Sauter平均直径 体积通量 两相流 对流 

分 类 号：TK124[动力工程及工程热物理—工程热物理]