Biofuels such as ethanol have been used in internal combustion engines to reduce polluting emissions. However, some studies show that they affect engine performance due to their differences in thermophysical properties. Besides, pure ethanol has not been properly evaluated in compression ignition engines. Therefore, this work shows the results of an exergy analysis in a single cylinder compression ignition engine converted to spark ignition engine of varying compression ratio, operated with diesel, ethanol, and gasoline/ethanol blends, in different operating parameters. Tests were carried out on the engine without modifications operating diesel at a compression ratio of 17:1 and converted to spark ignition with 50%, 10% gasoline/ethanol blends and pure ethanol at compression ratios of 9:1, 12:1 at rotation speeds of 1500, 2100, 2600 and 3200 rpm. Under the experimental operating conditions, the results of the modified engine showed that the blend 50% and ethanol performs better by operating with 12:1 compression ratio, in relation to exergetic efficiency and environmental effect factor. Besides, the engine showed a better performance by becoming to spark ignition operating with ethanol and gasoline/ethanol blends.

诸如乙醇之类的生物燃料已用于内燃机中以减少污染排放。但是，一些研究表明，由于热物理性质的差异，它们会影响发动机性能。此外，在压缩点火发动机中还没有对纯乙醇进行适当的评估。因此，这项工作显示了将单缸压缩点火发动机转换为可变压缩比的火花点火发动机后，以柴油，乙醇和汽油/乙醇混合物在不同的运行参数下运行的能值分析结果。在未修改的发动机上进行了测试，以17：1的压缩比运行柴油，并在旋转时以50：10、10％的汽油/乙醇混合物和纯乙醇以9：1、12：1的压缩比转换为火花点火转速为1500、2100、2600和3200 rpm。在实验操作条件下，改进后的发动机的结果表明，与50％乙醇和50％的乙醇混合，压缩比为12：1时，性能，能量效率和环境因子都更好。此外，通过使用乙醇和汽油/乙醇混合物进行火花点火，发动机表现出更好的性能。