超临界水在倾斜光管中的传热不均匀特性研究  

EXPERIMENTAL INVESTIGATION ON THE CIRCUMFERENTIAL UNUNIFORMITY IN HEAT TRANSFER OF WATER IN INCLINED SMOOTH UPWARD TUBES AT SUPERCRITICAL PRESSURES

作　　者：李会雄[1] 孙树翁[1] 郭斌[1] 陈听宽[1] 

机构地区：[1]f西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《工程热物理学报》2008年第2期241-245,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金专项基金(No．50323001)

摘　　要：对超(超)临界压力下水在倾斜光管内的传热特性进行了比较系统的实验研究。实验段管径为φ32×3mm,倾角α=20°;试验压力P=23～34 MPa,内壁热负荷q=300～500 kW/m^2,管内质量流速G=300～2000 kg/m^2s。得到了不同工况下倾斜光管内壁温和管内换热系数的周向分布及其变化规律,考察了压力、质量流速及热负荷对倾斜光管内壁温度的周向分布的影响,重点分析了管内上下母线处内壁温度差随工质焓值变化的特性及机理,讨论了大比热区水的物性变化对倾斜光管内传热不均匀性的影响,并与亚临界压力下的对应实验结果进行了比较.An experimental investigation on the circumferential un-uniformity in heat transfer of water in inclined upward smooth tubes at supercritical and ultral-supercritical pressures has been fulfilled in the present study. The test section was made up of smooth stainless steel tubes with a diameter of φ32×3 mm, and the inclined angle was α=20°. The experimental conditions were as follows： the pressure P=23～34 MPa, the heat flux q=300～500 kW/m^2 and the fluid mass velocity G=300～2000 kg/m^2s. Both the circumferential and the longitudinal distributions of the wall temperatures and also the heat transfer characteristics of water at supercritical and ultra-supercritical pressures were obtained under different conditions. Effects of the pressure, the heat flux and the mass velocity on the wall temperature distributions were verified, and the variation in the difference between the top generatrix wall temperatures and the bottom generatrix wall temperature was analyzed. The effect of the violent variation in water properties in the so-call ＂large specific heat region＂ on the heat transfer characteristics of water was discussed, and was then considered as the main reason for the circumferential un-uniformity in heat transfer of water in inclined smooth upward tubes at supercritical and ultra-supercritical pressures.

关 键 词：超(超)临界压力 倾斜光管 传热挣陛 大比热区 壁温分布 

分 类 号：TK123[动力工程及工程热物理—工程热物理]