A field measurement study of a parallel-flow push–pull system for industrial ventilation applications

Abstract

The initial characteristics of a jet have a strong effect on velocity distribution during its development, and the resulting contaminant distribution and ventilation system performance will also change correspondingly. To achieve quantitative improvement by adopting a parallel-flow jet than a normal jet accurately, the velocity and contaminant distribution associated with a parallel-flow push--pull ventilation system (the parallel-flow opening: the first non-uniform perforated plate: porosity Φ = 17.48%; the second uniform perforated plate: porosity Φ = 16.63%; the honeycomb: length l = 2 mm, depth d = 42 mm) and a normal push--pull ventilation system (the shutter opening: the effective area coefficient ϵ = 85%) under the same conditions were experimentally studied, respectively. An accurate calculation method for the size of the main polluted region is proposed to reflect the contaminant diffusion region. The results showed that by adopting the parallel-flow jet, the standard deviation of the velocity on the push open face was reduced by 61%. The main polluted zone was reduced by 75%. When the capture effect was satisfied, the capture efficiency was improved by 0.63% and indoor air quality was improved by 5%. The conclusions of this investigation can serve as a reference for quantitatively improving the push--pull ventilation system performance.