Bareen Abdullah, Dash Soumya, Kalita Paragmoni, Dash Kshirod Kumar
Department of Food Engineering and Technology, Tezpur University, Tezpur, Assam, 784028, India.
Centre for Management Studies, North Eastern Regional Institute of Science and Technology, Nirjuli, Arunachal Pradesh, 791109, India.
Environ Sci Pollut Res Int. 2024 Mar;31(12):18209-18225. doi: 10.1007/s11356-023-26690-2. Epub 2023 Apr 11.
An indirect-type forced convection solar dryer implementing a phase-changing material (PCM) as the energy-storing medium was designed, fabricated, and investigated in this study. The effects of changing the mass flow rate on the valuable energy and thermal efficiencies were studied. The experimental results showed that the instantaneous and daily efficiencies of the indirect solar dryer (ISD) increased with the initial increase in mass flow rate, beyond which the change is not prominent both with and without using the PCM. The system consisted of a solar energy accumulator (solar air collector with a PCM cavity), a drying compartment, and a blower. The charging and discharging characteristics of the thermal energy storage unit were evaluated experimentally. It was found that after using PCM, drying air temperature was higher than ambient air temperature by 9-12 ℃ after sunset for 4 h. Using PCM accelerated the process by which Cymbopogon citratus was effectively dried between 42 and 59 °C of drying air. Energy and exergy analysis of the drying process was performed. The daily energy efficiency of the solar energy accumulator reached 35.8%, while the daily exergy efficiency reached 13.84%. The exergy efficiency of the drying chamber was in the range of 47-97%. A free energy source, a large reduction in drying time, a higher drying capacity, a decrease in mass losses, and improved product quality all contributed to the proposed solar dryer's high potential.
本研究设计、制造并研究了一种采用相变材料（PCM）作为储能介质的间接式强制对流太阳能干燥器。研究了改变质量流量对有效能量和热效率的影响。实验结果表明，间接太阳能干燥器（ISD）的瞬时效率和日效率随着质量流量的初始增加而提高，超过该点后，无论是否使用PCM，变化都不显著。该系统由一个太阳能蓄热器（带有PCM腔的太阳能空气集热器）、一个干燥室和一个鼓风机组成。对热能存储单元的充放电特性进行了实验评估。结果发现，使用PCM后，日落后4小时内干燥空气温度比环境空气温度高9 - 12℃。使用PCM加速了柠檬草在42至59℃干燥空气温度下有效干燥的过程。对干燥过程进行了能量和火用分析。太阳能蓄热器的日能量效率达到35.8%，日火用效率达到13.84%。干燥室的火用效率在47 - 97%范围内。免费能源、干燥时间大幅缩短、干燥能力提高、质量损失减少以及产品质量改善，所有这些都促成了所提出的太阳能干燥器具有很高的潜力。
