Estudo experimental da emissão de poluentes em um motor de combustão interna diesel-gás

Abstract

Growing concerns about climate change due to human activity, mainly because of fuel combustion, have motivated the development of new combustion technologies. In this context, the diesel-natural gas engine is presented as an alternative to diesel engines. The present study aims to evaluate, based on experimental data, the influence that the main engine calibration parameters have on the pollutant emissions in a diesel-gas engine, as well as to analyze the potential that this technology has to reduce emissions of greenhouse gases. A literature review was conducted on the following topics: diesel combustion, natural gas combustion in internal combustion engines, dual fuel combustion, pollutant formation and the fundamentals of engine calibration. Particular attention was given to the Design of Experiments, a technique that minimizes the number of experimental tests and, at the same time, maximizes the information that can be obtained in an experimental study. For the analyzed condition, it was found that specific fuel consumption and emission levels of nitrogen oxides, carbon dioxide and soot are strongly affected by fuel to air ratio (lambda), substitution rate and start of injection angle. Furthermore, the conducted experimental study allowed to suggest a particular engine calibration for the combined use of natural gas and diesel fuel, which resulted in a reduction of 14% in greenhouse gases emission; 95% in soot emissions and 3% in specific fuel consumption.