,- Silesian university of technology, Faculty of mining, industrial automation and safety engineering, Geoengineering and raw materials extract, Gliwice, Poland (wk310338@student.polsl.pl)
The transition from fossil fuels to renewable energy sources has created an urgent demand for large-scale energy storage. Repurposing unused mining infrastructure for Adiabatic Compressed Air Energy Storage (A-CAES) presents a promising solution. However, a critical research gap remains in optimizing the Thermal Energy Storage (TES) component: specifically, the lack of experimental data comparing the thermal efficiency of low-cost, circular economy materials against traditional natural rocks used specifically to store heat.
The primary aim of this study was to design a physical TES model to experimentally evaluate and compare the heat transfer dynamics of two distinct storage media: irregular rocks of pure basalt and regular spherical beds made of a cement-waste mixture.
The research methodology involved the construction of a small scale physical model featuring dual vertical chambers powered by active fan heating systems. One chamber contained the randomly packed basalt, while the other contained arranged in an ordered manner, cement-waste spheres. This setup allowed for a precise, comparative analysis of heat distribution, airflow resistance, and thermal saturation speeds. Data was acquired in real-time using a custom Arduino-based sensor array.
To rigorously analyze the thermal charging cycles, a novel analytical methodology was developed using Matlab. Unlike standard linear approximations, this study implemented an algorithm based on the sigmoid function to model the temperature increment. This approach provided a superior fit to the non-linear thermal saturation data, allowing for more accurate characterization of the bed's performance.
The results provide critical insights into the viability of using mining waste for thermal energy storage by demonstrating the aerodynamic and thermal advantages of ordered bed geometries.
Keywords: A-CAES, Thermal Energy Storage, mining waste, heat transfer sigmoid function
How to cite: Korpak, W., Snarski, O., Lutyński, M., and Kołodziej, K.: Experimental comparative analysis of thermal energy storage beds using sigmoid function approximation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18372, https://doi.org/10.5194/egusphere-egu26-18372, 2026.
