Influence of convection on the thermal storage performance of energy tunnels

IF 3.3 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment Pub Date : 2024-09-10 DOI:10.1016/j.gete.2024.100595

Annik Schaufelberger , Lyesse Laloui , Alessandro F. Rotta Loria

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引用次数: 0

Abstract

The decarbonization of the built environment requires rapid growth in energy storage solutions due to the intermittent nature of most renewable energy sources. This paper focuses on the efficacy of so-called energy tunnels (i.e., tunnels equipped with pipe heat exchangers) used for underground thermal energy storage. By harnessing a 3-D thermo-hydraulic finite element model validated against full-scale experimental data, this work specifically explores seasonal, medium-temperature, thermal energy storage operations of energy tunnels. Numerical simulations are performed to unravel the influence of convection resulting from groundwater flows and airflows on the thermal energy storage performance of energy tunnels. The analyses address the impact of different groundwater flow velocities, air temperatures, and airflow velocities on the thermal losses and storage efficiency of energy tunnels used as thermal batteries. The study discourages underground thermal energy storage in the presence of convection due to significant heat losses. It shows that thermal energy storage operations via energy tunnels are feasible in site conditions characterized by no groundwater flow, limited temperature differentials between the heat carrier fluid circulating in the pipe heat exchangers and the surroundings, and thermal insulation on the tunnel intrados.

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对流对能量隧道蓄热性能的影响

由于大多数可再生能源的间歇性，建筑环境的去碳化要求能源储存解决方案的快速增长。本文重点研究了用于地下热能存储的所谓能源隧道（即配备管道热交换器的隧道）的功效。通过利用根据全尺寸实验数据验证的三维热液有限元模型，这项工作专门探讨了能源隧道的季节性中温热能存储操作。通过数值模拟来揭示地下水流和气流产生的对流对能源隧道热能储存性能的影响。分析涉及不同地下水流速、空气温度和气流速度对用作热电池的能源隧道的热损失和存储效率的影响。由于存在大量热损失，该研究不鼓励在存在对流的情况下进行地下热能存储。研究表明，在无地下水流、管道热交换器中循环的载热流体与周围环境的温差有限以及隧道内侧有隔热层的情况下，通过能量隧道进行热能储存是可行的。

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

Geomechanics for Energy and the Environment Earth and Planetary Sciences-Geotechnical Engineering and Engineering Geology

CiteScore

5.90

自引率

11.80%

发文量

期刊介绍： The aim of the Journal is to publish research results of the highest quality and of lasting importance on the subject of geomechanics, with the focus on applications to geological energy production and storage, and the interaction of soils and rocks with the natural and engineered environment. Special attention is given to concepts and developments of new energy geotechnologies that comprise intrinsic mechanisms protecting the environment against a potential engineering induced damage, hence warranting sustainable usage of energy resources. The scope of the journal is broad, including fundamental concepts in geomechanics and mechanics of porous media, the experiments and analysis of novel phenomena and applications. Of special interest are issues resulting from coupling of particular physics, chemistry and biology of external forcings, as well as of pore fluid/gas and minerals to the solid mechanics of the medium skeleton and pore fluid mechanics. The multi-scale and inter-scale interactions between the phenomena and the behavior representations are also of particular interest. Contributions to general theoretical approach to these issues, but of potential reference to geomechanics in its context of energy and the environment are also most welcome.