Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Enhancing Efficiency and Thermal Potential of Earth-Air Heat Exchangers with Galvanized Materials and Elliptical Shapes
Submission Author:
Ana Maria Domingues , RS
Co-Authors:
Ana Maria Domingues, Honório Joaquim Fernando, Jairo Ramalho, Michel Kepes Rodrigues
Presenter: Ana Maria Domingues
doi://10.26678/ABCM.COBEM2023.COB2023-1445
Abstract
This paper presents a study on Earth-Air Heat Exchangers (EAHEs), a sustainable and economical alternative for improving thermal conditions in enclosed spaces. EAHEs consist of buried ducts and a ventilation system that needs little electrical energy. The air flowing inside the ducts exchanges heat with the surrounding soil; therefore, in the winter, for example, the cold air entering the system exits warmed in the environments, while the opposite occurs in the summer. In this study, we simulate new types of EAHE based on the climatic and geotechnical characteristics of Viamão city, located in the Brazilian state of Rio Grande do Sul. An alternative to improve the local soil thermal potential is placing galvanized materials around the duct because they have high thermal conductivity. However, recent literature shows that the galvanized structure shape matters for EAHE performance; hence, we examine an elliptical case. Our research aims to estimate the ellipse dimensions that maximize the efficiency and thermal potential of EAHEs. We made different tests modifying the ellipse area and changing the size of its major and minor axis. We simulated EAHE using the analytical model GAEA, where the soil temperature is estimated numerically in two dimensions by finite element methods. We found that incorporating galvanized material improved the EAHE efficiency by about 20% compared to the literature results without any additional material. We also assessed ways to reduce the elliptical area without compromising thermal performance.
Keywords
Earth-Air Heat Exchangers (EAHE), Thermal Potential, Efficiency, Elliptical shape, Galvanized structure
