Modeling and Parameter Optimization of Multi-Step Horizontal Salt Cavern Considering Heat Transfer for Energy Storage

Abstract

Horizontal salt caverns represent a prime choice for energy storage within bedded salt formations. Constructing multi-step horizontal salt caverns involves intricate fluid and chemical dynamics, including salt boundary dissolution, cavern development, brine flow, heat transfer, and species transportation. In this paper, the influence of heat transfer and turbulent flow is considered in developing a 3D multi-physics coupled flow model for the construction of multi-step horizontal salt caverns. The feasibility and accuracy of the model are verified by comparisons with the field data of the Volgograd horizontal salt cavern. The effects of turbulent flow and heat transfer on the dissolution process are thoroughly analyzed. By analyzing the characteristics of the flow field, the brine concentration distribution, and cavern expansion, the results indicate a steady rise in cavity brine concentrations throughout the leaching phases, with the previously formed cavities continuing to enlarge during subsequent leaching stages, albeit at a diminishing rate of expansion. Furthermore, the results reveal that a larger injection flow rate results in a larger cavern volume, whereas higher injection concentrations result in smaller cavern volumes. While the step distance has a minimal impact on cavern volume, identifying the optimal step distance remains crucial. This analysis of construction parameters aims to provide valuable insights into the design and engineering practices involved in developing multi-step horizontal salt caverns for energy storage purposes.