Heat extraction performance and techno-economic analysis of a deep U-type borehole heat exchanger under intermittent operation

IF 3.5 2区工程技术 Q3 ENERGY & FUELS

Geothermics Pub Date : 2025-03-16 DOI:10.1016/j.geothermics.2025.103307

Chao Huan , Fei Meng , Zhengna Yang , Wanlong Cai , Zhihua Wang , Fenghao Wang , Chaofan Chen

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引用次数: 0

Abstract

The deep U-type borehole heat exchanger (DUBHE) has been extensively investigated in terms of its long-term heat extraction capacity and economic feasibility. In this work, a 3D numerical model of DUBHE was established based on the open-source numerical software OpenGeoSys (OGS). Three- and sixty-day experimental data from two pilot projects in Xi’an, China, were used for the model validation. Subsequently, the model was extended to the long-term operational period by introducing different operation-shutdown ratios. In the long-term operation, the extension of the daily operational time from 8 to 24 h resulted in a reduction of the soil temperature difference from 14.87 °C to 7.51 °C. Compared to the continuous operational scenario with an operation-shutdown ratio of 24:0, the total heat extraction for operation-shutdown ratios of 8:16, 12:12, and 16:8 was discovered to be 65.15 %, 76.14 %, and 84.85 %, respectively. Considering the system’s initial investment and the operational costs coupled with the heat pump and circulating water pump, a techno-economic analysis was also executed based on benchmark parameters. For the DUBHE heating system with an operation-shutdown ratio of 8:16, the investment payback period is approximately 8.2 years, which is the shortest among all scenarios. The related suggestions proposed in this work aim to provide insightful references for engineers and decision-makers in practice.

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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.