Analytical investigation on the optimal tube length of Earth-to-Air Heat Exchanger (EAHE)

IF 3.5 2区工程技术 Q3 ENERGY & FUELS

Geothermics Pub Date : 2025-01-10 DOI:10.1016/j.geothermics.2025.103250

Ali Alikhani, Mehdi Maerefat, Seyed Mohammad Jafar Sobhani

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Abstract

The Earth-to-Air Heat Exchanger (EAHE) is a promising passive technology that utilizes the earth's thermal energy for cooling/heating applications in buildings. The tube length is one of the crucial parameters affecting the EAHE system's thermal performance. Using this type of heat exchanger with an optimal tube length can help save materials, reduce operational costs, installation expenses, and required space. Selecting the optimal tube length is a major challenge for designers. In the present paper, a novel analytical study has been conducted to determine the optimal tube length of EAHE based on the Coefficient Of Performance (COP). The results of the optimal tube length in transient conditions reveal that it is affected by operation time. It is found that after 6 days of operation, thermal saturation in the soil around the tube takes place, and the ultimate optimal length is achieved which is about 37.9 % longer than the initial optimal length. Ignoring the ultimate soil thermal saturation may cause a false reduction in the estimated optimal tube length by about 57.9 % and an overestimation of the thermal performance of EAHE.

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地空气换热器（EAHE）最佳管长分析研究

地空热交换器（EAHE）是一种很有前途的被动技术，它利用地球的热能在建筑物中进行冷却/加热。管长是影响热电联产系统热性能的重要参数之一。使用具有最佳管长的这种类型的热交换器可以帮助节省材料，降低运行成本，安装费用和所需的空间。选择最优的管长是设计师面临的主要挑战。本文提出了一种新的基于性能系数（COP）的分析方法来确定EAHE的最佳管长。瞬态条件下的最优管长受运行时间的影响。结果表明，运行6 d后，管道周围土体发生热饱和，达到了最终最优长度，比初始最优长度增加了37.9%。忽略最终的土壤热饱和可能会导致估计的最佳管长错误减少约57.9%，并且高估了EAHE的热性能。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Geothermics 工程技术-地球科学综合

CiteScore

7.70

自引率

15.40%

发文量

237

审稿时长

4.5 months

期刊介绍： Geothermics is an international journal devoted to the research and development of geothermal energy. The International Board of Editors of Geothermics, which comprises specialists in the various aspects of geothermal resources, exploration and development, guarantees the balanced, comprehensive view of scientific and technological developments in this promising energy field. It promulgates the state of the art and science of geothermal energy, its exploration and exploitation through a regular exchange of information from all parts of the world. The journal publishes articles dealing with the theory, exploration techniques and all aspects of the utilization of geothermal resources. Geothermics serves as the scientific house, or exchange medium, through which the growing community of geothermal specialists can provide and receive information.