Retta Habtamu Terefe, Hailu Mesele Hayelom, Baheta Aklilu Tesfamichael, Haile Misrak Girma
Mekelle University, Ethiopia.
Addis Ababa Science and Technology University, Ethiopia.
Heliyon. 2024 Aug 24;10(17):e36864. doi: 10.1016/j.heliyon.2024.e36864. eCollection 2024 Sep 15.
Injera baking poses a significant energy demand and strain on the national grid, requiring temperatures of 180-220 °C with traditional clay Mitads. This study aimed to design a solar thermal system to replace electrical baking energy at the Mekelle University student cafeteria. The system, designed for baking 11,000 Injera within a 6-h daily operation, comprises 92 Anodized aluminum plate Mitads heated by hot oil from an oil gallery, stored in a hot oil storage unit, and recharged via a parabolic trough solar collector. A heat exchanger and thermal storage system ensure efficient heat transfer and storage. Computational Fluid Dynamics (CFD) and Soltrace analyses were conducted to assess temperature distribution on the baking pan and oil gallery surfaces, as well as solar thermal heat flux. Results revealed a heating capacity of 2.11 kW per Mitad, meeting the required capacity, and a system energy consumption of 1216.5 MJ per hour, achieving a thermal efficiency of 57.4 %. Baking Injera at higher temperatures, enabled by a uniform temperature distribution, yielded uniformly textured Injera with an optimal number of eye bubbles and prevented sticking to the Mitad. Consequently, this design offers a viable alternative for the energy-intensive application at the Mekelle University student cafeteria, providing valuable insights for future solar thermal Injera baking system designers.
英吉拉烘焙对国家电网提出了巨大的能源需求和压力，使用传统的黏土米塔德烘焙时需要180 - 220摄氏度的温度。本研究旨在设计一种太阳能热系统，以取代梅凯勒大学学生食堂的电烘焙能源。该系统设计为在每天6小时的运营时间内烘焙11000片英吉拉，由92个阳极氧化铝板米塔德组成，由来自油道的热油加热，热油储存在热油储存单元中，并通过抛物槽式太阳能集热器进行补充。热交换器和蓄热系统确保了高效的热传递和储存。进行了计算流体动力学（CFD）和Soltrace分析，以评估烤盘和油道表面的温度分布以及太阳能热通量。结果显示，每个米塔德的加热能力为2.11千瓦，满足所需容量，系统每小时能耗为1216.5兆焦，热效率达到57.4%。通过均匀的温度分布能够在更高温度下烘焙英吉拉，烘焙出的英吉拉质地均匀，有最佳数量的气孔，并且不会粘在米塔德上。因此，该设计为梅凯勒大学学生食堂的高能耗应用提供了一个可行的替代方案，为未来太阳能热英吉拉烘焙系统的设计者提供了有价值的见解。
