Effect of thermal load distribution types and ratios on the long-term thermal response of energy diaphragm walls

• Published in: Computers and geotechnics 2025-03, Vol.179, p.107045, Article 107045
• Main Authors: Zhao, Hua, Zhu, Pengxi, Wang, Chenglong, Kong, Gangqiang, Hu, Xiaochuan
• Format: Article
• Language: English
• Subjects: Energy diaphragm walls; Long-term operation; Numerical simulation; Parameter optimization; Thermal load distribution types; Thermal load ratios
• ISSN: 0266-352X
• DOI: 10.1016/j.compgeo.2024.107045

Numerical simulations were conducted to investigate the long-term heat transfer characteristics of energy diaphragm walls (EDWs) about thermal load distribution and thermal load ratio. The heat transfer design was optimized using a 9-parameter, 3-level orthogonal simulation. The results showed that an unbalanced thermal load led to a longer stabilization time compared to a balanced thermal load. Additionally, long-term heat transfer under intermittent or homogeneous input thermal loads resulted in significant deviation of the maximum/minimum fluid temperature and COP compared to temporal thermal loads (daily variations). The thermal load ratio had a notable impact on the development of fluid temperature and COP over time. Wall height was found to be the most significant factor affecting long-term heat transfer, followed by soil thermal conductivity, overlying depth, and flow rate. Soil heat capacity and heat transfer pipe spacing had the least effect. Overall, the simulation results demonstrate the importance of considering various factors in the heat transfer design of EDWs for optimal performance.