Long-term Performance Analysis of Deep Geothermal Energy Heating Systems Using TRNSYS

DOI

10.2991/978-94-6463-415-0_35How to use a DOI?

Keywords

Deep borehole heat exchanger heating system; Numerical simulation; Heat extraction performance; Subsurface temperature attenuation

Abstract

In recent years, deep geothermal energy has gained significant prominence and has witnessed widespread application and development in the realm of building heating. Nevertheless, much of the research has predominantly concentrated on the structural and operational performance of deep borehole heat exchangers, often neglecting the exploration of the operational dynamics associated with above-ground components in the context of deep geothermal energy heating systems.

This study places its primary focus on the field of deep geothermal energy heating systems. It utilizes the TRNSYS software to enable real-time dynamic interactions among system components and explores the long-term thermal response characteristics of the system as it adjusts to dynamic variations across various operational scenarios. This research holds substantial importance in achieving the efficient utilization of deep geothermal energy for building heating systems and makes a substantial contribution to the broader adoption of geothermal energy resource development and utilization technology.

The findings of this investigation unveil that extended periods of system operation show a noteworthy impact: a mere 0.1 m/s increase in the borehole exchanger’s inlet flow rate results in a corresponding 2.03 ℃ increase in the average inlet temperature of the borehole exchanger and a 0.76 ℃ rise in the average outlet temperature. After 20 years of uninterrupted system operation, the inlet water temperature of the borehole exchanger stabilizes at approximately 16–18 ℃, while the outlet temperature stabilizes at 25 ℃. This confirmation underscores the alignment of both the inlet and outlet temperature of the borehole exchanger with the system’s operational requirements.

Moreover, with each consecutive 5-year operational period, several noteworthy temperature changes are observed: the temperature at the bottom of the borehole exchanger decreases by approximately 0.8 ℃, the average temperature along the outer pipe diminishes by about 0.7 ℃, the average temperature along the inner pipe experiences a decrease of roughly 0.8 ℃, and the average temperature of the outer pipe wall within the geotechnical layer declines by approximately 0.7 ℃, and the heat loss along the inner pipe decreases by approximately 0.5 kW.

Copyright

© 2024 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Guang Jin
AU  - Ming Wang
AU  - Hong Guo
AU  - Jianqiang Liu
AU  - Wenbin Li
AU  - Yawen Cao
AU  - Wanlong Cai
PY  - 2024
DA  - 2024/05/14
TI  - Long-term Performance Analysis of Deep Geothermal Energy Heating Systems Using TRNSYS
BT  - Proceedings of the 2023 9th International Conference on Advances in Energy Resources and Environment Engineering (ICAESEE 2023)
PB  - Atlantis Press
SP  - 331
EP  - 341
SN  - 2589-4943
UR  - https://doi.org/10.2991/978-94-6463-415-0_35
DO  - 10.2991/978-94-6463-415-0_35
ID  - Jin2024
ER  -