Waste heat recovery is one of the main strategies to reduce the use of primary resources. This work develops a cascade phase change regenerator to recover energy from exhaust air to fresh air of a natural gas-fired batch dryer in an existing industrial laundry, taken as a case study, where an experimental campaign is conducted. The regenerator comprises two vertical stoves made of horizontal rod bundles in an aligned configuration to mitigate the fouling. The rods are hollow smooth cylinders that are grouped into sectors, each of which is filled with a phase change material properly selected among paraffins. The number of cylinders per row and the cylinder diameter are investigated by a parametric analysis; the number of sectors and the materials filling each sector are optimized by two alternative algorithms, one based on the process physics and the other on a statistical method. At last, an economic analysis is applied to the optimal configuration. This optimal configuration turns to be an 8-sector regenerator that attains an energy recovered of 61.5% and a net annual saving of 3340 €/year and that requires a total cost of about 9500 €, yielding a payback time lower than 3 years.

余热回收是减少主要资源使用的主要策略之一。这项工作开发了一种级联相变蓄热器，以在现有工业洗衣房中的天然气分批干燥机中将废气中的能量回收到新鲜空气中，以此作为案例研究，并进行了实验。蓄热器包括两个水平排列的成束的垂直炉，排列成水平排列，以减轻结垢。所述杆是中空的圆柱体光滑被分组成扇区，其中的每一个填充有石蜡中适当选择的相变材料。每排气缸数和气缸直径通过参数分析进行研究；扇区数和填充每个扇区的材料通过两种替代算法进行了优化，一种基于过程物理学，另一种基于统计方法。最后，对最优配置进行了经济分析。这种最佳配置变成了一个8扇区再生器，其能量回收率达到61.5％，每年净节省3340欧元/年，总成本约为9500欧元，投资回收期少于3年。