Lagrangian simulation and exergy analysis for waste heat recovery from high-temperature particles using countercurrent moving beds

The gas-solid countercurrent moving bed provides an effective method of waste heat recovery from high-temperature particles. The Lagrangian descriptions of particle and gas energy equation in a countercurrent moving bed are established. Two typical scenarios for waste heat recovery from high-temperature particles are studied. The first scenario is the calculation of the necessary particle cooling time and bed height for different cases, where the value of outlet particle temperature is first set as a required design condition. The second is the investigation of the effects of particle size and gas velocity on the heat recovery process and recovery gas exergy in a moving bed with a fixed bed height. Detailed results regarding the particle cooling behavior, necessary cooling time, particle, and gas temperature distribution in the bed, and the pressure drop of each case are obtained. The corresponding thermal exergy, pressure exergy loss, and net exergy of the recovered gas are analyzed. Suggestions on the design and operation for waste heat recovery from high-temperature particles using countercurrent moving beds are proposed.