Expanded impinging jet air supply method - Air terminal device analysis and optimization

Abstract

Consulta en la Biblioteca ETSI Industriales (9043)

[EN] At first sight, air suppliers are supposed to have a significant influence on thermal comfort and indoor air quality, but they also deal with the energy consumption of buildings. Therefore, energy consumption can be reduced using low pressure drop systems. The aim of this thesis is to analyze a new air terminal device designed for impinging jet ventilation in order to identify possible operating problems and to propose a new geometry satisfying requirements, and, consequently, reduce energy consumption for ventilation purposes in residential buildings. This method is called ¿expanded impinging jet air supply method¿ because draught is reduced using low velocities than other types of impinging ventilation devices. Most relevant benefits of impinging jet ventilation are: · It supplies air at higher momentum than displacement ventilation systems, and lower momentum than mixing ventilation systems in some cases. · It is possible to achieve higher air exchange efficiency than in using mixing ventilation and more or less same as using displacement ventilation. · It offers possibility of jet entrainment as in mixing ventilation. · Air can be heated before entering into the room, in contrast to displacement ventilation. For that reason, this type of system has potential applications for heating and cooling rooms. Moreover, energy consumption needed for expanded impinging jet ventilation can be highly reduced in comparison with other ventilation systems. Pressure drops are lower in this type of air terminal devices than in traditional ones. In consequence, different CFD simulations have been carried out and this report tries to reflect the process followed to find the best possible solution. The first design has been analyzed and after that different parametric studies have been performed. Using results extracted from those studies, a new geometry has been proposed satisfying all requirements. The results show that the expanded impinging jet air supply method can reduce energy consumption of ventilation systems more than 60%. Using the air terminal device design proposed, outlet velocity profiles are suitable for impinging jet ventilation and recirculation is minimized in order to reduce losses.