Abstract: To address the challenges of low steam penetration efficiency and uneven distribution in microscale lumen structures, this study investigates the regulatory mechanism of vacuum pulsation parameters on steam mass transfer, aiming to improve penetration performance and energy utilization. A steam diffusion dynamics model coupling pulsation frequency (0.5~2.0 Hz) and pressure amplitude (5~15 kPa) was developed, and computational fluid dynamics (CFD) simulations were employed to reveal how pulsating pressure fields influence steam phase change and boundary layer disturbances. A dedicated vacuum pulsation experimental platform was constructed, integrating high-speed micro-imaging and X-ray micro-CT to quantitatively analyze steam penetration depth and 3D distribution under various parameter conditions. Response surface methodology was used to optimize the parameter combinations. The results show that under pulsation conditions, the penetration uniformity index improved by approximately 21%, and the terminal steam saturation reached 0.78±0.05, representing an approximately 50% increase compared to static conditions. At the optimal parameter combination of 1.2 Hz/10 kPa, the unit energy efficiency index (η=5.06 s/J) achieved its highest value, representing an approximate 40% improvement over the baseline, with the corresponding key performance indicator (KPI) reaching 2.37 g/(kW·s), a 58% improvement over the standard. The study confirms that vacuum pulsation parameters can synergistically enhance steam transfer efficiency and energy performance, significantly improving permeation in microscale structures, and providing theoretical guidance and optimization strategies for applications such as microchannel drying, instrument sterilization, and mass transfer in porous media.

Key words: vacuum pulsation, microscale lumen structure, steam penetration efficiency, cycle parameter regulation, CFD simulation