螺旋管内高压汽水两相流动沸腾干涸点的研究

Experimental Investigation on the Dryout Point for Two-Phase Flow Boiling of Steam-Water at High Pressures in Helical Coils

在较宽的实验参数范围内(系统压力P=8～15 MPa,质量流速G=800～1800 kg·m^(-2)·s^(-1),壁面热流密度q_w=200～950 kW·m^(-2))对一立式螺旋管内(管内径为10 mm,螺旋直径为300 mm,节距为50 mm)汽水两相流动沸腾干涸特性进行了实验研究。通过研究,获得了干涸发生时螺旋管圈壁温的分布特征以及压力、质量流速和壁面热流密度这三个参数对临界干度的影响规律。同时在实验数据的基础上,提出了一个适用于计算螺旋管内高压高含汽率工况下汽水两相流临界干度的经验关系式。

The dryout characteristics of flow boiling of steam-water mixtures were experimentally studied in a vertically-oriented helically-coiled tube,which was constructed of a 10 mm ID stainless steel tube with the coil diameter of 300 mm and the pitch of 50 mm.Experiments were performed in wide ranges of system pressure 8～15 MPa,mass velocity 800～1800 kg·m^（-2）·s^（-1）and wall heat flux 200～950 kW·m^（-2）.The wall temperature distribution of the helical coils in the zone where dryout occurred was obtained,and the effects of pressure,mass velocity and wall heat flux on the critical quality were systematically investigated.Based on the experimental data,a new correlation for the prediction of the critical quality of steam-water two-phase flow boiling in helical coils at high pressures was proposed.