Abstract The shortages in conventional fuels along with the continuous rise in their prices have led to an increased emphasis on using solar energy as an alternative source of energy. However, establishing reliable and affordable solar collectors for different applications is a great challenge. Therefore, this study aimed to design and fabricate an efficient and cheap solar air collector from recyclable aluminum cans. Two dryers of different configurations (closed and open modes) were then constructed and examined for drying tomatoes under different operating conditions. The results revealed that the thermal efficiency of the designed solar collectors increased considerably from 25 to 63% when the air-flow rate increased from 15 to 45 m3h-1. In comparison to the conventional method of open sun drying, the designed solar dryers enhanced both the drying rate and the overall quality of the final product. In the designed solar dryer, over three days of consecutive drying (30 h of drying), the moisture content of tomato wedges was reduced from 19 to less than 1 kg [H2O] kg−1 [dry matter]. The closed-mode dryer configuration, which recirculates the drying air, showed a considerable increase in the drying rate and weigh loss over the traditional sun dryers and open-mode dryer systems. Among all mathematical models, a non-linear quadratic model (Wang and Singh model) has shown a better fit to the experimental drying data compared to the other models.

中文翻译：

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可回收铝罐在制造用于干燥农产品的高效太阳能集热器中的有效性

摘要 传统燃料的短缺以及其价格的不断上涨导致人们越来越重视使用太阳能作为替代能源。然而，为不同应用建立可靠且价格合理的太阳能集热器是一项巨大的挑战。因此，本研究旨在利用可回收铝罐设计和制造一种高效且廉价的太阳能空气收集器。然后构建并检查了两个不同配置（封闭和开放模式）的干燥机，用于在不同操作条件下干燥西红柿。结果表明，当空气流量从 15 m3h-1 增加到 45 m3h-1 时，设计的太阳能集热器的热效率从 25% 显着增加到 63%。与传统的露天晒干方法相比，设计的太阳能干燥机提高了最终产品的干燥速度和整体质量。在设计的太阳能干燥机中，连续干燥三天（干燥 30 小时），番茄楔子的水分含量从 19 减少到小于 1 kg [H2O] kg−1 [干物质]。与传统的阳光干燥机和开放式干燥机系统相比，封闭式干燥机配置使干燥空气再循环，干燥速度和重量损失显着增加。在所有数学模型中，非线性二次模型（Wang 和 Singh 模型）与其他模型相比更适合实验干燥数据。番茄楔子的水分含量从 19 降至不到 1 kg [H2O] kg−1 [干物质]。与传统的阳光干燥机和开放式干燥机系统相比，封闭式干燥机配置使干燥空气再循环，干燥速度和重量损失显着增加。在所有数学模型中，非线性二次模型（Wang 和 Singh 模型）与其他模型相比更适合实验干燥数据。番茄楔子的水分含量从 19 降至不到 1 kg [H2O] kg−1 [干物质]。与传统的阳光干燥机和开放式干燥机系统相比，封闭式干燥机配置使干燥空气再循环，干燥速度和重量损失显着增加。在所有数学模型中，非线性二次模型（Wang 和 Singh 模型）与其他模型相比更适合实验干燥数据。