Analysis of EAHE through a coupled mathematical model solved by Laplace transform and Gaver-Stehfest algorithm

Authors

DOI:

https://doi.org/10.5902/2179460X74745

Keywords:

Earth-air heat exchanger, Laplace transform, Semi-analytical solution

Abstract

The earth-air heat exchangers (EAHEs) are devices that are shown to be a great alternative to assist in the thermal comfort of buildings, mainly due to their low energy cost. The proposed model considers the heat exchange between the soil, the duct and the air, generating coupled equations. This work seeks to employ and verify EAHE applications in two scenarios, first in a literature experiment and then in a EAHE application in Pelotas. In both scenarios, it is considered that the soil and air temperature functions are time dependent. The solution is obtained by applying the Laplace transform and for the inversion of the integral transform the numerical method known as the Gaver-Stehfest Algorithm was used. The obtained results show that the proposed model follows the behavior of the experimental data. In addition to the experimental data, the proposed model was compared with the analytical model by Nóbrega, where the results had a small variation (of 0.20 ºC between them) by considering the heat transfer process in the duct material, modeling a more close to the real situation.

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Author Biographies

Felipe Augusto Silva Martins, Federal University of Pelotas

Student of the Electronic Engineering course at the Federal University of Pelotas. He is a scientific initiation fellow working on heat exchanger problems.

Guilherme Jahnecke Weymar, Federal University of Pelotas

Graduated in Mathematics, master's and PhD in Mechanical Engineering. He is currently a Professor at the Engineering Center and participates in the PPGMMat at the Federal University of Pelotas. The research and projects developed are in the area of transport phenomena.

Igor da Cunha Furtado, Instituto Federal Sul-rio-grandense

Graduated in Mathematics, master's and PhD in Mechanical Engineering. Professor at the Instituto Federal Sul-Rio-Grandense since 2018. Develops research in the area of transport phenomena.

 

Fernanda Tumelero, Federal University of Pelotas

Graduated in Mathematics, master's and post-doctorate in Mathematical Modeling, and doctorate and post-doctorate in Mechanical Engineering. She participates as a collaborator in the PPGMMat. She develops work and projects in the area of Nuclear Engineering.

 

Ruth da Silva Brum, Federal University of Pelotas

Graduated in Mathematics, Master's in Computational Modeling, PhD in Mechanical Engineering, and post-doctorate at the Institut National des Sciences Appliquées de Toulouse. Professor at the Department of Mathematics and Statistics and participates in the PPGMMat, the work developed is in the area of applied mathematics and engineering.

 

Régis Sperotto de Quadros, Federal University of Pelotas

Graduated in Mathematics, master's and PhD in Applied Mathematics, and post-doctorate in Nuclear Energy. He is a professor in the Department of Mathematics and Statistics and participates in the PPGMMat. The work developed is in Mathematics with an emphasis on Numerical Analysis and Optimization.

 

Daniela Buske, Federal University of Pelotas

Graduated in Mathematics, master's and PhD in Mechanical Engineering, and a post-doctorate in Nuclear Engineering. Professor at the Department of Mathematics and Statistics at UFPel and participates in the PPGMMat and PPGCAmb, the research and projects developed are in the area of Geosciences and Applied Mathematics.

 

References

Bejan, A., Kraus, A. (2003). Heat transfer handbook, 1º edn. John Wiley & Sons.

Brum, R. S., Rocha, L. A. O., Vaz, J., dos Santos, E. D., Isoldi, L. A. (2012). Development of simplified numerical model for evaluation of the influence of soil-air heat exchanger installation depth over its thermal potential. International Journal of Advanced Renewable Energy Research, 1, 505–514.

Brum, R. S., Vaz, J., Rocha, L. A. O., Santos, E. D., Isoldi, L. A. (2013). A new computational modeling to predict the behavior of earth-air heat exchangers. Energy and Buildings, 64, 395–402.

Minaei, A., Safikhani, H. (2021). A new transient analytical model for heat transfer of earth-to-air heat exchangers. Journal of Building Engineering, 33, 1–11.

Nóbrega, E. S. B. (2021). Abordagem analítica para análise térmica dos trocadores de calor solo-ar na cidade de Pelotas/RS. Master’s Thesis, Programa de Pós-Graduação em Modelagem Matemática da Universidade Federal de Pelotas, Pelotas.

Qi, D., Zhao, C., Li, S., Chen, R., Li, A. (2021). Numerical assessment of earth to air heat exchanger with variable humidity conditions in greenhouses. Energies, 14, 1368–1385.

Stehfest, H. (1970). Numerical inversion of laplace transforms algorithm. Communications of the ACM, 13, 47–49.

Vaz, J., Sattler, M. A., dos Santos, E. D., Isoldi, L. A. (2011). Experimental and numerical analysis of an earth–air heat exchanger. Energy and Buildings, 43(9), 2476–2482.

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Published

2023-12-01

How to Cite

Martins, F. A. S., Weymar, G. J., Furtado, I. da C., Tumelero, F., Brum, R. da S., Quadros, R. S. de, & Buske, D. (2023). Analysis of EAHE through a coupled mathematical model solved by Laplace transform and Gaver-Stehfest algorithm. Ciência E Natura, 45(esp. 3), e74745. https://doi.org/10.5902/2179460X74745