The experimental study of the frictional pressure drop characteristics of flow boiling heat transfer of CO₂ in a horizontal minichannel with an inner diameter of Φ1.5 mm was carried out. Experimental conditions: heat flux (7.5 ~ 30 kW•m⁻²), mass flow rate (50 ~ 600 kg•m⁻²•s⁻¹), saturation temperature (−40 ~ 0 °C), vapor quality (0 ~ 1). The comparison between the experimental results and theoretical flow pattern diagrams shows that the change of heat flux has little effect on the frictional pressure drop at high vapor quality area, but it has a decisive effect on the dryout and mist flow areas. The mass flow rate is the most important factor affecting the frictional pressure drop which has a decisive effect on the flow pattern experienced during the heat transfer process. The saturation temperature has an important influence on the flow pattern transition characteristics and the friction pressure drop decreases with the increase of saturation temperature. The influence of vapor quality on the frictional pressure drop is mainly caused by the flow pattern change in the minichannel. The flow visualization study shows that the theoretical flow pattern diagram can better reflect the flow pattern of CO₂ in the phase-change heat transfer process and the transition trend of flow pattern under different working conditions.

对内径为Φ1.5mm的水平微通道中CO _2的沸腾传热的摩擦压降特性进行了实验研究。实验条件：热通量（7.5〜30 kW•m ^-2），质量流率（50〜600 kg•m ^-2 •s ^-1），饱和温度（−40〜0°C），蒸气质量（0〜1）。实验结果与理论流图的比较表明，热通量的变化对高蒸气质量区的摩擦压降影响不大，但对干馏区和雾流区具有决定性影响。质量流率是影响摩擦压降的最重要因素，摩擦压降对传热过程中经历的流动模式具有决定性的影响。饱和温度对流型转变特性有重要影响，并且摩擦压力降随着饱和温度的升高而减小。蒸汽质量对摩擦压降的影响主要是由微通道中的流型变化引起的。₂在相变传热过程中和不同工况下流型的过渡趋势。