Effects of Pulsed Airflow on Ventilation Efficiency and Contaminant Dispersion in Electronic Cleanrooms

This study explores the effects of pulsed airflow with varying amplitudes and cycles on pollutant ventilation efficiency and flow distribution in electronic cleanrooms, aiming to achieve ISO Class 5 or higher cleanliness standards while reducing energy consumption and optimising ventilation schemes. Computational Fluid Dynamics (CFD) was utilised as the numerical simulation method to examine pulsed air supply’s influence on cleanroom airflow patterns. Three-dimensional geometric and mathematical models of the cleanroom were established and rigorously validated. Subsequent analyses under different operating conditions examined changes in particulate concentration and airflow characteristics, enabling a comparison of airflow organisation optimisation across multiple scenarios. The findings demonstrate that pulsed air supply significantly improves airflow organisation in cleanrooms. It markedly reduces vortex intensity and effectively suppresses upward airflow recirculation around process equipment and in corner areas, leading to more stable and uniform flow fields. Analysis of indoor air residence time indicates that, for a fixed air supply rate and period T, a low-amplitude pulsed air supply reduces residence time more effectively than a steady-state supply. With a constant amplitude A, the period exerts only a minor impact on residence time, though shorter periods generally yield lower values. Furthermore, the pulsed air supply enhances the cleanroom’s overall pollutant removal efficiency, contributing to better contamination control and potential energy savings.