Ramírez-Restrepo R, Sagastume-Gutiérrez A, Cabello-Eras J, Hernández B, Duarte-Forero J
KAI Research Unit, Department of Mechanical Engineering, Universidad del Atlántico, Carrera 30 Número 8-49, Puerto Colombia, Barranquilla, Colombia.
Department of Energy, Universidad de la Costa CUC, Calle 58 Número 55 - 66, Barranquilla, Colombia.
Heliyon. 2021 Oct 28;7(11):e08273. doi: 10.1016/j.heliyon.2021.e08273. eCollection 2021 Nov.
Improving the thermal efficiency of internal combustion engines is essential to reduce the operating costs and complaints with the increasing environmental requirements. Thermoelectric generators came up as an opportunity to reuse part of the heat loss with the exhausts. This paper evaluates the performance of a thermoelectric generator to improve the efficiency of a stationary diesel engine under different rotational speeds and torques. The data was obtained through CFD simulations and validated with experiments. The proposed solution uses a cooling system to control the temperature of the thermoelectric modules. The results show that the torque and the rotational speed of the engine are the most significant performance parameters of the thermoelectric generator, while the influence of the cooling water temperature has a minor but still significant influence. Additionally, the results show a change from 1.3% to 6.2% in the thermoelectric generator efficiency, while the exergy efficiency varies between 1.8% and 7.9%. The exergy balance indicates that most of the exergy is loss because of the irreversibilities in the thermoelectric generator and of the exergy loss with the exhausts. The exergy loss can be reduced by optimizing the design of the heat exchanger. Since the thermoelectric generator improved the engine efficiency by a marginal 0.2%-0.8%. Therefore, it is important to further research how to improve the design of heat exchangers for thermoelectric generators to increase their energy conversion efficiency and their impact on the energy efficiency of internal combustion engines.
随着环境要求的提高，提高内燃机的热效率对于降低运营成本和减少投诉至关重要。热电发电机作为一种重新利用部分废气热损失的机会应运而生。本文评估了热电发电机在不同转速和扭矩下提高固定式柴油发动机效率的性能。数据通过计算流体动力学（CFD）模拟获得，并通过实验进行了验证。所提出的解决方案使用冷却系统来控制热电模块的温度。结果表明，发动机的扭矩和转速是热电发电机最重要的性能参数，而冷却水温度的影响较小但仍然显著。此外，结果表明热电发电机效率从1.3%变化到6.2%，而㶲效率在1.8%和7.9%之间变化。㶲平衡表明，大部分㶲损失是由于热电发电机中的不可逆性以及废气中的㶲损失。通过优化热交换器的设计可以减少㶲损失。由于热电发电机仅将发动机效率提高了0.2%-0.8%。因此，进一步研究如何改进热电发电机的热交换器设计以提高其能量转换效率及其对内燃机能量效率的影响非常重要。
