Concrete is tested as a sensible heat thermal energy storage (TES) material in the temperature range of 400–500 °C (752–932 °F). A molten nitrate salt is used as the heat transfer fluid (HTF); the HTF is circulated though stainless steel heat exchangers, imbedded in concrete test prisms, to charge the TES system. During charging, significant cracking occurs in both the radial and longitudinal directions in the concrete prisms. The cracking is due to hoop stress induced by the dissimilar thermal strain rates of concrete and stainless steel. A 2D finite element model (FEM) is developed and used to study the stress at the prism/exchanger interface. Polytetrafluoroethylene (PTFE) and a heat-curing, fibered paste (HCFP) are tested as interface materials to mitigate the stress in the concrete. Significant reduction in the size and number of cracks is observed after incorporating interface materials. A heat exchanger with a helical fin configuration is incorporated to improve the heat transfer rate in the concrete. Testing confirms that the fins increase the rate of heat transfer in the concrete; however, large cracks form at each of the fin locations. Only the HCFP is tested as an interface material for the finned heat exchanger. The HCFP decreases the number and size of the cracks, however, not to the desired hairline levels.
Testing of High-Performance Concrete as a Thermal Energy Storage Medium at High Temperatures
Contributed by the Solar Energy Division of ASME for publication in the Journal of Solar Energy Engineering. Manuscript received July 9, 2012; final manuscript received February 28, 2013; published online August 21, 2013. Assoc. Editor: Rainer Tamme.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Skinner, J. E., Strasser, M. N., Brown, B. M., and Panneer Selvam, R. (August 21, 2013). "Testing of High-Performance Concrete as a Thermal Energy Storage Medium at High Temperatures." ASME. J. Sol. Energy Eng. May 2014; 136(2): 021004. https://doi.org/10.1115/1.4024925
Download citation file:
- Ris (Zotero)
- Reference Manager