With the aim to analyze the flow pattern and heat transfer characteristics of the working fluid in a flat plate heat pipe (FPHP) which was sealed by a transparent tempered glass plate, ethanol, acetone, and R141b were taken as the working medium, and visual experiments were performed at different heat flux when the inclination angle was 90°. The vapor-liquid distribution and the heat transfer characteristics of the FPHP were investigated at different liquid filling ratios. According to the experimental results and the recording of high-speed cameras, some important conclusions had been drawn as follows: (i) As the power increases, the vapor-liquid interface in the FPHP declines and the effects of dryout is significantly intnsified, leading to a sharp increase in temperature. The FPHP with a filling ratios of 25.7% owns better thermal performance than that with the filling ratios of 11.8% and 66% at different heating power; (ii) the bubble generation inside the FPHP became more intense with increasing heat flux, and various bubble movement patterns were found at different the liquid filling ratios; (iii) As the liquid film flowed downward, the thickness of the liquid film increased at first and then decreases. The condensation of steam was reduced due to the thickening of the liquid film on the wall. The liquid film became thinner when it was entrapped and evaporated in the downward flow.

为了分析工作液在由透明钢化玻璃板密封的平板热管（FPHP）中的流动方式和传热特性，以乙醇，丙酮和R141b为工作介质，并进行了可视化分析。当倾角为90°时，在不同的热通量下进行了实验。在不同的液体填充率下，研究了FPHP的气液分布和传热特性。根据实验结果和高速相机的记录，得出了一些重要的结论：（i）随着功率的增加，FPHP中的气液界面下降，并且变干的影响明显增强，导致温度急剧上升。FPHP的填充率为25。在不同的加热功率下，7％的热性能要好于11.8％和66％的填充率；（ii）随着热通量的增加，FPHP内部的气泡产生变得更加强烈，并且在不同的液体填充率下发现了各种气泡运动模式；（iii）随着液膜向下流动，液膜的厚度首先增加然后减小。由于壁上液膜的增厚，减少了蒸汽的冷凝。当液体膜被截留并在向下的流中蒸发时，其变薄。（iii）随着液膜向下流动，液膜的厚度首先增加然后减小。由于壁上液膜的增厚，减少了蒸汽的冷凝。当液体膜被截留并在向下的流中蒸发时，其变薄。（iii）随着液膜向下流动，液膜的厚度首先增加然后减小。由于壁上液膜的增厚，减少了蒸汽的冷凝。当液体膜被截留并在向下的流中蒸发时，其变薄。