用于无烟室内太阳能烹饪的多功能级联潜热储能系统

Abstract The need for the present study arises from the limited availability of thermal energy storage systems capable of operating with a single heat source while delivering stable heat outputs at multiple temperatures suited to diverse end-use applications. To meet this objective, a novel two-stage cascade latent heat storage unit was developed using a shell-and-multiple-tube arrangement. The system was specifically designed to support an indoor cooking setup composed of three dedicated cooking units: a cooking plate, a frying pan, and a cooking vessel, each requiring distinct operating temperatures. During testing, the storage system consistently delivered heat at 473 K, 452 K, and 373 K to the respective cooking units, allowing baking, frying, and boiling tasks to be completed within 4 min, 4 min, and 13 min, respectively. The total energy retrieved from the CLHS from stage 1 and stage 2 is 57.04 % and 42.96 % of the stored heat, respectively. The system achieved a cyclic thermal efficiency of 55.82 % and an end-use efficiency of 38.24 %, confirming its ability to manage and utilize heat effectively across multiple temperature levels. A thermal delay was observed in the lower parts of the unit due to uneven phase change material distribution, likely caused by buoyancy effects, suggesting the need for further optimization of the heat transfer design. Overall, the results confirm the feasibility of using a cascade latent heat storage approach for community-scale solar cooking, providing a flexible solution for varied thermal needs beyond the scope of traditional solar cookers.