Performance of laboratory scale packed-bed thermal energy storage using new demolition waste based sensible heat materials for industrial solar applications

Thermal energy storage (TES) is essential for cost-effective use of solar energy in industries. The most energy intensive processes in industry operate below 200 degrees C. This study tested a new sustainable and low-cost sensible thermal energy storage material (STESM) based on demolition wastes in a lab-scale packed bed TES system, specifically built to analyze its performance in industrial solar applications below 200 degrees C. This system was investigated both experimentally and numerically under different operating conditions. One-dimensional continuous phase model used verified that experimental results were in good agreement with numerical ones during charging and discharging steps. Performance of demolition waste STESM was compared with Therminol 66 synthetic oil as a liquid heat storage media. The maximum system energy efficiency of the packed-bed filled with demolition waste STESM was 67% at charging temperature of 150 degrees C and superficial fluid velocity of 0.95 mm s(-1), while it was 63% for Therminol 66. Packed bed TES system with demolition waste STESM showed good performance up to 180 degrees C in fully laminar flow regime (Rep < 10) and Bi number < 0.1. The material cost of demolition waste STESM is at least tenfold cheaper than the alternative natural rock based packing materials. Packed bed TES systems using demolition wastes can be recommended for low cost and sustainable solar applications in industry.