Abstract This paper presents the results of experimental study and mathematical modeling of thermal energy recovery from the flue gases in a packed bed using phase change materials (PCMs). Air and water were used as the heat transfer fluids (HTFs) in the heating and cooling periods, respectively. Paraffin wax was used as the PCM which was encapsulated within polyethylene spheres of 40 mm diameter. The effect of temperature and velocity of the entering air to the bed on the system performance was investigated. In addition, mathematical modeling was conducted, and its numerical results were compared with experimental data. Moreover, two dimensionless parameters (i.e. efficiency and yield) were defined to evaluate the system performance under various operating conditions. The results of this study showed that the efficiency of energy recovery in the considered system could be increased by increasing the inlet gas temperature and decreasing the inlet gas velocity. A 40% increase in inlet gas temperature at constant gas velocity increases the system efficiency by up to 44%. Besides, the mathematical modeling results showed a good agreement with the experimental data.

中文翻译：

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烟气热回收两级固定床蓄热系统数学建模与实验研究

摘要 本文介绍了使用相变材料 (PCM) 从填充床中的烟道气中回收热能的实验研究和数学建模的结果。空气和水分别用作加热和冷却期间的传热流体 (HTF)。石蜡用作 PCM，它被封装在直径为 40 毫米的聚乙烯球中。研究了温度和进入床层的空气速度对系统性能的影响。此外，还进行了数学建模，并将其数值结果与实验数据进行了比较。此外，定义了两个无量纲参数（即效率和产量）以评估各种操作条件下的系统性能。这项研究的结果表明，通过提高入口气体温度和降低入口气体速度，可以提高所考虑系统的能量回收效率。在恒定气体速度下，入口气体温度增加 40%，系统效率最多可提高 44%。此外，数学建模结果与实验数据吻合良好。