Effect of the double vacancy on heat transfer performance of solid particle bed in particle waste heat recovery

Abstract

In industrial processes, a huge number of high temperature solid particles are produced, and thus, the waste heat resource is abundant. In order to improve the efficiency of waste heat recovery heat exchanger, based on the primary recovery method, a heat transfer model of two-dimensional steady-state particle bed with double vacancy was established. The effects of double vacancy and the variation of vacancy gap on heat transfer of particle bed were studied. The results showed that the double vacancy hinders heat transfer, causing heat currents to flow around the vacancy. In the area close to the vacancy, the particle temperature fluctuates violently and the isotherm changes greatly. At the vacancy area, the heat conduction in X direction increases, in Y direction decreases, and the radiative heat transfer increases. As the number of the gap between double vacancies increases from 0 to 4, the interaction between double vacancies on the temperature field gradually decreases. Compared with the condition without vacancy particle bed, the total heat transfer decreases, and the minimum heat transfer is 33.24 W, the apparent thermal resistance is increased,and the maximum gap is 11.63 °C/W.