Effects of particle contact characteristics on heat transfer performance of calcined petroleum coke heat exchanger

The present paper investigated the effect of particle contact characteristics (contact area coefficient) on heat transfer performance of heat exchanger. An unsteady heat transfer model of single-layer calcined petroleum coke was established. The average temperature, heat storage, heat transfer contribution rate and wall heat transfer coefficient were studied with different times. The research shows that with increase of contact area coefficient, the heat conduction capacity is enhanced and the average temperature of particles layer reduction rate and the heat storage reduction rate are obviously accelerated. The average contribution rate of solid phase heat transfer, wall comprehensive heat transfer coefficient and heat release rate increase, and the effective heat transfer time decreases. When the contact area coefficient increased from 0.03 to 0.07, the average contribution rate of solid phase heat transfer increased from 83.4% to 90.5%. The wall heat transfer coefficient increased from 12.7 W/(m(2).K) to 27.1 W/(m(2).K), the heat release rate increased from 83.79% to 98.2%, and the effective heat transfer time decreased from 8.02 h to 5.07 h.