Experimental Study on Energy Storage Characteristics of Sintered Ore Particle Packed Beds

The particle packed bed energy storage system has advantages such as low costs and wide temperature ranges,which can be combined with solar thermal power generation systems to solve the inherent volatility and discontinuity of renewable energy.Developing new materials with low costs and excellent storage performances is one of the eternal research hotspots in the field of energy storage.This paper innovatively uses sintered ore particles as energy storage material and studies the effect of particle size on the airflow resistance characteristics,energy storage characteristics,and thermocline evolution characteristics of the packed bed through thermal energy storage experiments.The results indicate that for the particles in the macro scale,the smaller the particle,the lower the absolute permeability of the bed and the greater the airflow resistance.The packed bed with smaller particles has a larger specific surface area,larger bulk mass,and smaller bed voidage.Therefore,the packed beds with smaller particles have better thermocline characteristics,less irreversible loss,and can achieve higher thermal efficiency and higher exergy efficiency in the heat storage cycle.The cycle thermal efficiency in packed beds with 25-40 mm,16-25 mm,and 10-16 mm particles is 53.58%,56.27%,and 57.60%,respectively,and the cycle exergy efficiency is 61.81%,69.25%,and 74.13%,respectively.Moreover,this paper also studies the effect of discharging airflow rates on thermal storage performance.The experimental results indicate that suitable discharging strategies should be selected based on different heat demands.