水平微细管内CO2蒸发相变传热干涸特性
Dryout Characteristics of the CO2 Heat Transferof Evaporation Process in Horizontal Micro-tubes

本文在热流密度为7.5~30 kw/m2、质量流率为300~600 kg/(m2?s)、饱和温度为-40~0 ℃、干度为0~1、内径为1.5 mm的实验工况条件下，对水平微细圆管内CO2在高干度区域干涸特性进行了实验研究，结果表明：质量流率的增加、热流密度的增加、饱和温度升高均会导致干涸起始干度的减小。基于实验数据和干涸机理分析，获得新的临界热流密度理论预测计算模型和干涸干度理论预测模型，并对新的理论预测模型有效性进行验证，结果显示在实验工况范围内，新的理论预测模型预测效果较好。
The drying characteristics of CO2 in horizontal micro-tubes in a high qualityregion were studied under the conditions of heat flux (7.5–30 kw/m2), mass flow rate (300–600 kg/(m2?s)), saturation temperature (-40-0℃), inlet vapor quality (0–1), and inner diameter (1.5 mm). The results show that the inlet vapor quality decreases with an increase in the mass flow rate, heat flux, and saturation temperature when dryout occurs. Based on the experimental data and analysis of the dryout mechanism, a new theoretical prediction model of critical heat flux and dryness are obtained, and the validity of the new theoretical prediction model is verified. The calculation model is predicted using density theory and the validity of the new prediction model is verified. The results show that the new - model has a better prediction effect within the experimental range of this study