Amey Barde

Solar Thermochemical Energy Storage Through Carbonation Cycles of SrCO3/SrO Supported on SrZrO3

Solar thermochemical energy storage has enormous potential for enabling cost-effective concentrated solar power (CSP). A thermochemical storage system based on a SrO/SrCO3 carbonation cycle offers the ability to store and release high temperature (≈1200 °C) heat. The energy density of SrCO3/SrO systems supported by zirconia-based sintering inhibitors was investigated for 15 cycles of exothermic carbonation at 1150 °C followed by decomposition at 1235 °C. A sample with 40 wt % of SrO supported by yttria-stabilized zirconia (YSZ) shows good energy storage stability at 1450 MJ m(-3) over fifteen cycles at the same cycling temperatures. After further testing over 45 cycles, a decrease in energy storage capacity to 1260 MJ m(-3) is observed during the final cycle. The decrease is due to slowing carbonation kinetics, and the original value of energy density may be obtained by lengthening the carbonation steps.

Thermal Analysis of Elemental Sulfur in a Shell-and-Tube Configuration for Thermal Energy Storage Applications

Currently, concentrated solar power (CSP) plants utilize thermal energy storage (TES) in order to store excess energy so that it can later be dispatched during periods of intermittency or during times of high energy demand. Elemental sulfur is a promising candidate storage fluid for high temperature TES systems due to its high thermal mass, moderate vapor pressure, high thermal stability, and low cost. The objective of this paper is to investigate the behavior of encapsulated sulfur in a shell and tube configuration. An experimentally validated, transient, two-dimensional numerical model of the shell and tube TES system is presented. Initial results from both experimental and numerical analysis show high heat transfer performance of sulfur. The numerical model is then used to analyze the dynamic response of the elemental sulfur based TES system for multiple charging and discharging cycles. A sensitivity analysis is performed to analyze the effect of geometry (system length), cutoff temperature, and heat transfer fluid on the overall utilization of energy stored within this system. Overall, this paper demonstrates a systematic parametric study of a novel low cost, high performance TES system based on elemental sulfur as the storage fluid that can be utilized for different high temperature applications.Copyright