Effect of particle characteristic parameters on the heat transfer process of double vacancy particle bed

In order to improve the heat recovery efficiency of high-temperature solid particles, a two-dimensional heat transfer model of double vacancy particle bed was established. This paper investigated the effects of particle size and thermal conductivity on the heat transfer process of double vacancy particle bed. With the increase of the thermal conductivity from 0.4678 W/m·K to 46.78 W/m·K, in the area near the vacancy, the particle isotherm is significantly affected, the influence area of double vacancy in X direction increases from 1.5 to 4.5 times of particle size, the influence area of double vacancy in Y direction increases from 2.2 to 7.2 times of particle size, and the wall heat flux increases from 0.53 kW/m2 to 36.28 kW/m2. The particle size has little effect on the overall temperature distribution of the particle bed, the maximum influence area in the X direction is approximately the same, all are 4.5 times particle size, and the maximum influence area in the Y direction is increased from 7.1 to 7.4 times particle size, but as the particle size increases, the wall heat flux increases obviously. The results will further improve the thermal resistance network theory.