Avaliação do desempenho de um motor de combustão interna operando com etanol e adição de hidrogênio

Abstract

This work evaluates, experimentally and computationally, the effects of hydrogen addition on the performance of a turbocharged ethanol fueled internal combustion engine. In particular, the aim is to determine the best operating parameters for this system and fuel mixture for use as a range extender. Thus, two operating regimes in a turbocharged engine were investigated: (i) Increasing in H2 content for a constant equivalence ratio; and (ii) Operating in leaner mixtures with a fixed H2 content. Therefore, experimental tests were carried out to evaluate the performance and emissions for the first regime. The results indicated that the second operating regime is more favorable, which was then investigated computationally. To this end, a method for auto-calibration of combustion and heat transfer parameters was proposed and validated. This approach proved to be successful in predicting the pressure curve inside the cylinder and was then used in the lean operating regime. It was observed that operating in leaner mixtures resulted in efficiency gains and emission reductions. However, stable lean operation was only possible thanks to hydrogen enrichment. Furthermore, turbocharging compensated for the power losses associated with diluted mixtures. Finally, exergetic and exergoeconomic analysis were used to assess this system. These analyzes confirmed that the addition of hydrogen to lean ethanol turbocharged engines has high potential for hybrid mobility applications.