Pre-Heated Ethanol Direct Injection Under Low Pressures to Otto Type Engines

The present work intends to approach the use of pre-heated ethanol direct injection through Otto type engine cylinders during the compression of air and under low pressures (600 kPa). A system of direct injection was developed and incorporated to the engine, which was submitted to tests. Results revealed that the partial fuel vaporization during the isoentalpic expansion process which happened in the nozzle during the fuel injection was responsible for a significant decrease in specific consumption and an increase of the engine's thermal efficiency in comparison to the same engine using carburetor or cold ethanol direct injection (at room temperature). It was still verified that cold start problems were completely eliminated.