中文摘要：

通过梯形微通道内水的单相流动摩擦压降和水蒸气凝结压降实验，分析水蒸气冷凝过程及压力和温度等参数对其水蒸气凝结压降的影响，根据实验数据修正Lockhart—Martinelli的两相流压降模型，提出了新的实验关联式，并将实验结果与现有微通道和常规通道的压降关联式进行比较．结果表明：单相层流摩擦因数随Re的增加而缓慢增大；凝结压降在质量流量保持不变的条件下，随干度的增加而增大，在相同干度条件下，随质量流量增加而增大，同时随微通道水力直径的增加而减小；根据实验结果回归得到适用于梯形微通道内凝结摩擦压降Martinelli—Chisholm常数C的关联式．

英文摘要：

According to the experiments of friction pressure drop of laminar flow of deionized water and the two-phase pressure drop of steam during condensing process in silicon microchannels with trapezoidal cross section, the steam condensation process and the effects of pressure drop and temperature parameters on steam condensation pressure drop were analyzed. Based on the modified two-phase pressure drop model of Lockhart-Martinelli, a new experimental correlation was developed. The experimental results were compared with the current correlations of pressure drop both in microchannels and conventional channels. The visualization of steam condensation, as well as the experimental results, shows that the friction constant increases slightly with Reynolds number, while the condensation pressure drop increases with mass flux and quality, decreases with the increase in hydraulic diameter of microchannel. Based on the experimental data, a new correlation for the Martinelli-Chisholm constant C is developed.