Comparative thermal efficiency analysis between a 4-stroke engine versus a 6-stroke steam injection engine

Currently there are several studies in order to obtain more efficient engines through the use of different techniques, including heat recovery. A six stroke engine is considered as one of these technologies, as it uses heat from the exhaust gases and proposes the addition of an extra cycle power carried by steam injection. This work consists in undertaking an energy analysis of a six stroke steam injection engine for comparisons to be made with conventional four strokes engine. Increases were observed in the exergetic efficiency of up to 14 % for different amounts of water injected at different injection temperatures for the six stroke engine. It was also noted a decrease of about 21% in lost exergy by the engine, a fact that proves the best use of exergy released by the fuel. The six stroke engine thermodynamic analysis shows that this technology has significant potential to achieve a better use of fuel and therefore achieve better efficiencies.