Experimental study on one-side confined jets from a parallel-flow outlet in a push–pull ventilation system

Abstract

This study conducted a series of experiments on the airflow characteristics of one-side confined jets from a parallel-flow outlet with a two-tier perforated plate and a honeycomb in a push–pull ventilation system. Maximum velocity, maximum temperature and airflow trajectory were analysed and compared with previous studies about different outlets. The results showed that the dimensionless turbulence coefficient of the parallel-flow outlet was smaller than either the cased axial fan with open grille’s or the swirl diffuser’s turbulence coefficients from isothermal condition. Different development laws for the parallel-flow outlet discharging a hot air jet (Ar0 = 0.024) on the floor were put forward. Furthermore, it was found that the velocity decay rate of the hot air jets with a parallel-flow outlet on the floor was slower than with the circular aperture over a flat surface. When Ar0 ranged from 0.024 to 0.044, a semi-empirical equation was established to describe the trajectory of the hot jets from a parallel-flow outlet in a push–pull ventilation system. In addition, the baffle height of the suction outlet could be determined and corrected appropriately.

Experimental comparison of local low velocity unit combined with radiant panel and diffuse ceiling ventilation systems

“…41,42 In industrial premises, there has long time realized that only the near zone around workers would need to be protected from pollution and thermal stress. 43,44 Based on this, local exhaust ventilation 45,46 and push-pull ventilation strategies 47 have been widely used to directly remove the contaminant and heat. In operating theatres, only the local indoor environment for patients and medical personnel would need to be secured.…”

Cooling load for the design of air terminals in a general non-uniform indoor environment oriented to local requirements

“…In industrial buildings, only the zone around the products or workers needs to be protected from pollution and thermal stress [23][24] . Based on this, local exhaust ventilation [25][26] and push-pull ventilation [27] have been widely used to directly remove the contaminant and heat. In operating rooms and hospital wards, only the local indoor environment for patients and medical personnel needs to be secured [28] .…”

Numerical Simulation of the Capture Efficiency of a Domestic Range Hood for Different Burner Scenarios

“…Huang et al [9] found that increasing the jet-isolated flow rate can reduce moderately the spillage levels. In industrial production, the push-pull ventilation is widely used [10], [11], but it is rarely used for pollution control in the kitchen. Zhou et al [12] proposed a push-pull ventilation system for a residential kitchen, and they observed a capture efficiency improvement with a good air distribution in the kitchen area.…”