亚临界及近临界压力区低质量流速光管的传热特性研究  

Experimental investigation on heat transfer characteristics of smooth tubes at low mass flux under subcritical and nearcritical pressure

作　　者：潘杰[1] 杨冬[1] 董自春[1] 朱探[1] 毕勤成[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《高技术通讯》2012年第2期217-223,共7页Chinese High Technology Letters

基　　金：国家科技支撑计划（2006BAA03B02-03）资助项目.

摘　　要：在低质量流速条件下，对垂直上升光管内汽水两相流动沸腾传热特性进行了系统的实验研究。实验段采用了φ22mm×2．5mm的1Cr18Ni9Ti不锈钢管。实验条件为压力P=10～21MPa，管内质量流速G=448～1233kg／（m^2·s），内壁热流密度q=130～541kW／m^2。实验得到了不同工况下垂直上升光管的壁温分布特性。分析了压力、热负荷和质量流速变化对光管传热特性的影响，探讨了传热恶化的发生机理，并给出了能用于工程实际的传热实验关联式。结果表明：在亚临界及近临界压力区，垂直上升光管通常会发生两类传热恶化：膜态沸腾和干涸。压力与热负荷的增大以及质量流速的减小，均会导致传热恶化提前发生和传热恶化后的壁温飞升值增大。与亚临界区相比，光管在近临界区的传热特性变差，发生传热恶化的临界干度下降，甚至在过冷区就发生壁温飞升。The flow boiling heat transfer characteristics of water in vertical upward smooth tubes were investigated experimentally at low mass flux. The test section was the φ22 × 2.5 mm stainless steel tube. The operating conditions were the pressure of 10-21 MPa, mass flux of 448-1233 kg/（ m^2 · s） , and inner wall heat flux of 130-541 kW/m^2. The tube wall temperature distribution was obtained in the experiment. The effects of pressure, wall heat flux and mass flux on heat transfer were analyzed, the heat transfer deterioration mechanism was discussed, and the corresponding empirical correlations were also presented. The experimental results showed that heat transfer deteriorations, including film boiling and dryout, occurred in the smooth tube. With the increase of pressure and wall heat flux, and with the decrease of mass flux, the heat transfer deterioration occurred ahead and the peak value of wall temperature rose obviously. The heat transfer performance at nearcritieal pressure got worse, the critical quality became low, and the abrupt wall temperature rise even occurred in the subcooled water region.

关 键 词：亚临界及近临界压力 低质量流速 光管 壁温 膜态沸腾 干涸 

分 类 号：TK124[动力工程及工程热物理—工程热物理]