本文对超临界压力二氧化碳在内径为1 mm的竖直细圆管中的对流换热进行了实验研究.分析了流体的热流密度、进口温度、质量流量以及流动方向对超临界压力二氧化碳对流换热的影响.实验研究发现,热流密度、进口温度、质量流量以及浮升力对细圆管内对流换热的影响很大,对流换热系数在准临界温度附近存在峰值.在加热的前半段向上流动的对流换热强于向下流动,在加热的后半段则相反.随着热流密度与质量流量比值的不断增加,向上流动与向下流动对流换热强弱转换的交点不断向流体进口方向推移,并且向上流动的壁面温度出现峰值,发生换热恶化,而向下流动则没有出现换热恶化.
参考文献
| [1] | Man-Hoe Kim;Jostein Pettersen;Clark W. Bullard .Fundamental process and system design issues in CO_2 vapor compression systems[J].Progress in energy and combustion science,2004(2):119-174. |
| [2] | Dostal V;Driscoll M J;Hejzlar P.Supercritical CO2 Cycle for Fast Gas-Cooled Reactors[A].Vienna,Austria:ASME TurboExpo,2004:1-8. |
| [3] | Liao S M;Zhao T S.A Numerical Solution to Laminar Forced Convection Of Supercritical Carbon Dioxide in Small Diameter Tubes[A].北京,2000:592-597. |
| [4] | S.M.Liao;T.S.Zhao .An experimental investigation of convection heat transfer to supercritical carbon dioxide in miniature tubes[J].International Journal of Heat and Mass Transfer,2002(25):5025-5034. |
| [5] | Polyakov A F.Heat Transfer Under Supercritical Pressures[A].San Diego,CA:ACM Press,1991:1-53. |
| [6] | Pei-Xue Jiang;Yi-Jun Xu;Jing Lv;Run-Fu Shi;S. He;J. D. Jackson .Experimental investigation of convection heat transfer of CO_2 at super-critical pressures in vertical mini-tubes and in porous media[J].Applied thermal engineering: Design, processes, equipment, economics,2004(8-9):1255-1270. |
| [7] | Jiang PX;Shi RF;Xu YJ;He S;Jackson JD .Experimental investigation of flow resistance and convection heat transfer of CO2 at supercritical pressures in a vertical porous tube[J].The Journal of Supercritical Fluids,2006(3):339-346. |
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