Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
ACCESSING THE THERMAL PERFORMANCE OF EARTH-AIR HEAT EXCHANGERS BY ADDING GALVANIZED BRIDGES TO THE SOIL
Submission Author:
Jairo Ramalho , RS
Co-Authors:
Nibia Navarro, Marcos Burlon, Ana Maria Domingues, Honório Joaquim Fernando, Jairo Ramalho, Ruth Brum
Presenter: Ana Maria Domingues
doi://10.26678/ABCM.COBEM2021.COB2021-1446
Abstract
Due to the thermal inertia of the ground, it can be warmer or colder than the environment. Taking advantage of that, Earth-air heat exchangers (EAHE) connect a building ventilation system to one or more buried ducts. The research of EAHE is valuable because they employ a renewable thermal source, and they can work with little electrical energy. Regarding the heating and cooling capacities of EAHE, they depend on many factors like local climate, duct design, and soil properties. This paper aims to evaluate the thermal performance of EAHE after coupling the ducts with galvanized bridges. The idea is to increase the overall heat exchange, as the bridges have a thermal conductivity much higher than the soil around them. This work considers the scenario of the south Brazilian city of Viamão, which has a subtropical climate. The simulations use the 1D GAEA model for EAHE after validating it with experimental data. As the model depends on estimating the soil temperatures without the ducts, this work computes them by solving the heat transfer equations in 2D with finite element methods. The methodology allows considering the soil, the galvanized bridges, and dynamic boundary conditions, varying along the year. The results show that the thermal potential of EAHE improves by equipping the ducts with the bridges. This paper adopts some types of vertical bridges, and it studies how changing their position can enhance the thermal potential and efficiency of EAHE.
Keywords
Earth-Air Heat Exchangers (EAHE), Thermal performance, numerical simulations, Sustainability.
