Dev Ashutosh, Amatya Sunam, Dumre Yogesh, Shah Malesh, Baral Bivek
Department of Mechanical Engineering, Kathmandu University, Dhulikhel, Nepal.
Project 22-05 Laboratory, Kathmandu University, Dhulikhel, Nepal.
Heliyon. 2024 Oct 26;10(21):e39855. doi: 10.1016/j.heliyon.2024.e39855. eCollection 2024 Nov 15.
The intermittent nature of solar energy presents a significant challenge to its reliability, particularly in applications that require a consistent energy supply, such as cooking. This issue is especially critical in emerging economies with abundant solar resources, where sustainable energy solutions are needed to reduce reliance on traditional fuels. To address this challenge, this study introduces a novel solar thermal storage (STS), utilizing a metal-based material to accumulate and retain heat for off-sunshine hour cooking. The research focuses on optimizing aluminium as the STS material, evaluating its temperature suitability, efficiency, and heat retention capabilities for household solar cooking applications. Numerical simulations using the OpenFOAM framework were conducted to analyze heat transfer within the cooker, determining the optimal size of the aluminium block based on existing literature and predefined parameters. Practical experiments, including solar-induced heating-cooling cycles and controlled cooking tests, were carried out to validate the findings. Experimental results demonstrate STS's ability to efficiently absorb and retain heat, reaching a maximum of 235 °C during a 5.5-h heating session. The water boiling experiment further confirmed STS's practical utility, effectively transferring stored heat to cooking tasks and sustaining temperatures up to 160 °C even after the test. Additionally, experiments with black lentils and chicken stew highlighted aluminium's suitability for practical cooking applications, showcasing its ability to sustain high temperatures and efficiently transfer stored heat despite longer cooking times. The study's novelty lies in integrating numerical modeling with experimental analysis to optimize STS systems, providing practical guidelines for efficient thermal storage in cooking applications. This research advances beyond previous efforts by providing a validated methodology for the design and optimization of thermal storage systems. It improves the reliability and adaptability of solar energy for cooking applications.
太阳能的间歇性对其可靠性构成了重大挑战，尤其是在需要持续能源供应的应用中，如烹饪。在太阳能资源丰富的新兴经济体中，这个问题尤为关键，因为这些地区需要可持续能源解决方案来减少对传统燃料的依赖。为应对这一挑战，本研究引入了一种新型太阳能蓄热（STS）技术，利用金属基材料来积累和保留热量，以供非日照时间烹饪使用。该研究着重于优化将铝作为STS材料，评估其在家庭太阳能烹饪应用中的温度适用性、效率和蓄热能力。利用OpenFOAM框架进行了数值模拟，以分析炊具内的热传递情况，根据现有文献和预定义参数确定铝块的最佳尺寸。开展了包括太阳诱导加热 - 冷却循环和受控烹饪测试在内的实际实验，以验证研究结果。实验结果表明，STS能够有效吸收和保留热量，在5.5小时的加热过程中最高可达235°C。水煮实验进一步证实了STS的实际效用，它能将储存的热量有效地传递到烹饪任务中，即使在测试后仍能将温度维持在160°C。此外，用黑扁豆和鸡肉炖菜进行的实验突出了铝在实际烹饪应用中的适用性，展示了其尽管烹饪时间较长仍能维持高温并有效传递储存热量的能力。该研究的新颖之处在于将数值建模与实验分析相结合以优化STS系统，为烹饪应用中的高效蓄热提供了实用指南。这项研究超越了以往的努力，提供了一种经过验证的蓄热系统设计和优化方法。它提高了太阳能在烹饪应用中的可靠性和适应性。
