Modeling the mining of energy storage salt caverns using a structural dynamic mesh

Modeling is significant for the design and control of the mining of energy storage salt caverns for capacity and stability considerations. Traditional elastic mesh methods lose accuracy and cannot properly describe the upward development of a cavern. In this paper a salt cavern mining model is proposed using a structural dynamic mesh method. The salt dissolution rate is introduced as being related to the brine concentration and the salt-brine interface angle. A set of points with two degrees of freedom is used to describe the moving salt-brine boundary. The order and number of the points are modifiable to keep their distance reasonable and to avoid boundary self-crossing. The interior elements are dynamically determined. Mass and momentum conservation are used to solve the concentration and flow field. A C++ program is developed to implement the proposed model. A laboratory salt dissolution experiment and a field simulation are conducted for verification. Compared with a traditional model, the upward dissolution of salt can be simulated with higher accuracy. The model shows good reliability in simulating an irregularly shaped cavern, JT86, in Jintan, China. The study indicates that the uneven development of the cavern occurs due to the development of self-locking and cavern fingers. (C) 2019 Elsevier Ltd. All rights reserved.