Exploratory computational fluid and particle dynamics analyses in multi-layered vertical duct-type ventilation system for heat exchange and air purification

Abstract

This study aims to develop a vertical air duct which is embedded inside the building envelop. It is also designed as a counter-flow heat recovery ventilator (HRV). The vertical air duct model in this study adopted baffle structure considering two methods to suppress the inflow of the particulate matters from outdoor: 1) trapping by wall surface and airflow structure and 2) gravitational sedimentation in the air duct. Design parametric analyses are conducted using computational fluid dynamics to determine optimal design of vertical air duct. Three types of analytical case with various set-up of baffles inside air passages are prepared, and heat exchange efficiency is estimated by heat transfer analysis inside ventilator. In addition, particulate pollutants’ behaviour inside air passages is predicted based on Euler-Lagrange particle transport analysis. Through the series of numerical analysis, differences in heat exchange efficiency and effectiveness of particulate pollutant removal corresponding to different baffle design are quantitatively discussed, and finally optimal design for air passages in HRV is determined. The building-integrated HRV introduced in this study could contribute to sustainable design of building environment.