亚临界及近临界压力区倾斜上升管传热特性研究

Investigation on the Heat Transfer Characteristics of the Steam-Water Two-Phase Flow in the Inclined Upward Smooth Tube in Sub-Critical and Near Critical Pressure Regions

在亚临界及近临界压力下,对倾角α=20 的Φ323mm不锈钢倾斜上升光管内汽水两相流体的传热特性进行了试验研究。试验参数范围:p=13～21.5MPa;质量流速G=600～1200kg/(m2·s);内壁热负荷q=200～600kW/m2。试验结果表明:倾斜管壁温及内壁热负荷沿管壁周向不均匀分布;提高质量流速可以减弱甚至消除这种不均匀性;在不同工况下,压力对传热的影响规律是不同的。还提出了倾斜管最小传热系数的计算关联式。

Under sub-critical and near critical pressures, the heat transfer characteristics of the steam-water two-phase flow in the inclined upward smooth tube with the diameter of φ32×3 mm and the inclined angle of α=20 were investigated experimentally. The tests were performed at p=13-21.5 MPa, G=600-1200 kg/(m2&middots) and q=200-600 kW/m2. The results show that the wall temperatures and the internal wall heat fluxes non-uniformly distribute along the circumference of the inclined upward tube, and that the non-uniform distribution can be decreased and even eliminated by increasing the mass velocity. At different working conditions, the influence laws of the pressures on the heat transfer are different. The correlation of the minimum heat transfer coefficient of the inclined tube has been provided and can be used as a reference in the design of engineering practices.