Modelling the feasibility of using disused mines for heat extraction and storage
- 1Department of Earth Sciences, Durham University, UK
- 2James Watt School of Engineering, University of Glasgow, UK
- 3Advanced Research Computing, Durham University, UK
- 4The Coal Authority, Mansfield, UK
The subsurface offers significant opportunities for geothermal heat extraction and storage. Disused, flooded coal mines, in particular, are capable of providing a major low-enthalpy, renewable and long-term heat resource if carefully managed. To establish a mine water geothermal system requires significant capital investment and a large amount of time. Therefore, a solid investigation of the feasibility of a mine as heat source or storage medium is essential.
We have developed a modelling tool, GEMSToolbox, to investigate the feasibility of abandoned mines for long-term heat extraction and/or storage. This tool allows for a computationally fast and a low-cost study into the viability of mine water heating for given mine workings. We combine numerical and analytical methods with digitised legacy mine plan data to estimate the variations in the abstraction water temperature over the lifetime of a project. We couple the heat transfer approximation method originally proposed by Rodriguez and Diaz (2009) to that of flow in a pipe network as described by Todini and Pilati (1987), and refine the original heat transfer approximation by accounting for a flow regime specific heat transfer coefficient between the rock mass and the water, as prescribed by Loredo et al. (2017). A novel weighting function is also developed to account for the interference between adjacent mine galleries. This tool has been successfully applied to a range of mine system in the North East of England, and the results of this study are used to draw widely applicable conclusions on the feasibility of mine workings for heat extraction or storage more generally.
References:
- Loredo C, Banks D, Roqueñí N. Evaluation of analytical models for heat transfer in mine tunnels. Geothermics 2017; 69; 153-164.
- Rodriguez R and Díaz M. Analysis of the utilization of mine galleries as geothermal heat exchangers by means a semi-empirical prediction method. Renewable Energy 2009; 34(7), 1716-1725.
- Todini E and Pilati S. A gradient method for the analysis of pipe networks. Computer app. In water supply 1987; 1-20, v1.
How to cite: van Hunen, J., Mouli-Castillo, J., Sweeney, A., Tu, J., Wang, Y., and Adams, C.: Modelling the feasibility of using disused mines for heat extraction and storage, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9394, https://doi.org/10.5194/egusphere-egu24-9394, 2024.
