Optimization study of chimney parameters for coal mine gangue hills gravity heat pipe

ABSTRACT

Coal mine gangue hills have a significant impact on the ecological environment. To address this challenge, gravity heat pipes have been recognized as an effective means of controlling deep-seated temperature in coal mine gangue hills. Among various factors affecting heat transfer efficiency, the magnitude of external airflow velocity in the heat dissipation section of the heat pipe is critical. In this study, we develop a novel chimney effect model for gravity heat pipes in coal mine gangue hills. We employ the non-isothermal flow multi-physics transient solution method to analyze the single-factor effects of entrance radius, height of outlet section, and radius of outlet section on the average velocity at the chimney outlet. Furthermore, we utilize a comprehensive factorial response surface research method to fit the functional relationship between the average velocity at the chimney outlet and various chimney parameters. Notably, our study introduces the height and radius of the outlet section as constraint conditions based on field conditions. As a result, we determine the optimal chimney parameters for achieving the chimney effect in gravity heat pipes within coal gangue hills. Specifically, we set the chimney inlet radius at 1.05 m, the chimney outlet height at 0.03 m, and the chimney outlet radius at 0.145 m. Comparative analysis reveals that introducing the chimney improves the heat dissipation efficiency of the gravity heat pipe by 2.6%. Overall, our study offers innovative approaches to addressing the challenges associated with coal gangue hills and provides valuable insights into the optimization of gravity heat pipes for efficient heat dissipation.

KEYWORDS:

• Spoil heaps
• gravity heat pipes
• chimney effect
• parameter optimization
• heat dissipation efficiency

Acknowledgements

The authors would like to give their sincere gratitude for the financial support from the Basic Research Program of Shanxi Province Youth Research Science Institute [grant numbers 202203021212219].

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Basic Research Program of Shanxi Province Youth Research Science Institute [202203021212219].

Notes on contributors

Bailin Zhang

Bailin Zhang is an assistant researcher at the School of Safety and Emergency Management Engineering, Taiyuan University of Technology. He has been engaged in research on deep-seated temperature control technology in coal mine waste rock piles for 13 years. His main research interests include safety technology and engineering, thermal energy utilization, and environmental governance

Aihao Xie

Aihao Xie is a master’s student at the School of Safety and Emergency Management Engineering, Taiyuan University of Technology. His research focuses on ecological restoration of coal mine waste rock piles and deep-seated temperature control using gravity heat pipe technology

Xinghua Zhang

Xinghua Zhang is a professor at the School of Safety and Emergency Management Engineering, Taiyuan University of Technology. He has rich academic and engineering experience and has long been dedicated to the research of mine safety production technology and mine ecological restoration technology

Runxu Zhang

Runxu Zhang is an assistant researcher at the School of Safety and Emergency Management Engineering, Taiyuan University of Technology. He has been committed to the research of internal flow field migration laws in rock masses and mine safety production technology and science.

Chao Li

Chao Li is a lecturer at the State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact, Army Engineering University of PLA. He has been engaged in research on rock mass structural mechanics and mining geological dynamic disasters.

Pengxian Fan

Pengxian Fan is a renowned scholar at the State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact, Army Engineering University of PLA. He has long been engaged in research on structural planes of gate rock masses, as well as rock mechanics and mining geological disasters.

Gan Li

Gan Li is a renowned scholar at the State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact, Army Engineering University of PLA. He has been involved in fundamental research on mining geological disasters and has a wealth of theoretical knowledge.

Jie Li

Jie Li is a renowned scholar at the State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact, Army Engineering University of PLA. He has long been engaged in research on mining geological disaster management and environmental protection.