Numerical Study on Shell- and-Tube Moving Packed Bed Heat Exchanger: Effect of Tube Arrangement on the Particle Side

Moving packed bed heat exchanger has been key equipment in the waste energy recovery and concentrated solar power. However, the effect of tube arrangement still deserve investigation to optimize heat transfer. In the present paper, the flow and heat transfer of gravity-driven particles flowing around the tube bank are numerically studied by the discrete element method. It was found that the stagnation zone of the staggered tubes is less than 45° and the cavity zone is in the range of 160° - 180°. The stagnation zone of the aligned tubes is in the range of 0° - 65° and 125° - 180°, and there is no cavity zone below the aligned tubes. The heat transfer performance of the staggered tubes is better than that of the aligned tubes. The best heat transfer region of the staggered tubes is at the top of the tube, and that of the aligned tubes is at the side of the tube. The bottom of the tube has the worst heat transfer in both the staggered and aligned tubes. It is necessary to improve the performance of the staggered tubes by optimizing the particle flow in the range 0° - 45° and 160° - 180°. Reducing the vertical tube spacing may be an effective option for the aligned tubes.