System performance analyses of sulfur-based thermal energy storage

Elemental sulfur is a promising storage material for low to high temperature thermal energy storage (TES) applications due to its high chemical stability, high heat transfer rate, and low cost. In this study, we investigate the performance of sulfur-based TES systems (SulfurTES) in a single-tank thermal battery configuration. In general, the results show that a moderate shell aspect ratio and standard tube diameters can be used to provide a range of high performance. An experimentally validated 2D numerical model is used here. The model predicts system-level performance based on the energetic and exergetic efficiencies for a range of geometric parameters and operating mass flow rates. This analysis shows the competing effects of the design and operating conditions on the performance parameters, and reveals governing parameter spaces unique to the specified performance targets. We have proposed a strategy to identify this parameter space, for which, the SulfurTES system will achieve required thermal performance, and a design procedure to incorporate such parameter space in system design. This work provides a systematic approach in TES performance investigation, and establishes an important framework to design industrial-scale SulfurTES systems that will offer high thermal performance using low-cost materials.