Numerical study on the integrated effects of supplied air velocity and exhaust velocity on particles removal for industrial buildings

Due to production particularity in industrial buildings, high concentrations of particulate matter are always important environmental issues. Long-term exposure to such hazardous environment may lead to respiratory and cardiovascular diseases. Mechanical ventilation plays a vital role in reducing indoor particulate matter concentrations. However, the current industrial ventilation generally has the disadvantage of low ventilation efficiency and high energy consumption. In this study, we proposed a ventilation design by integrating supply and exhaust ventilation (i.e., SEV), and further investigated the effects of combined velocities on both indoor particles removal and energy efficiency. Computational Fluid Dynamics (CFD) coupled with Discrete Phase Model (DPM) was employed. The RNG k-ε model was adopted to simulate airflow field. Lagrangian method was used to trace particles’ dispersion processes. A series of cases were conducted under ventilated conditions with combinations of different supplied velocities of 0.75, 1.12, 1.50 and 1.87 m/s, and exhausted velocities of 0, 0.28 and 0.56 m/s. Temperature effects were not considered in this work. The quantification of combined effects of supply velocity and exhaust velocity were investigated in terms of particle removal efficiency as well as energy saving. Results showed that combined effects of supply velocity and exhaust velocity can improve the ventilation efficiency by 20%-40% compared to the conventional supply ventilation without exhaust velocity. Moreover, the reasonable design of integrated velocities will save up to 70% energy while keeping the same ventilation efficiency of SEV. These findings will be of great importance for energy-efficient design for industrial ventilation systems. © 2020 Southwest Jiatong University