Improving the fuel efficiency of a spark ignition engine under full load conditions by adding nitrogen oxide to the air charge

Abstract

The article presents the results of the oretical studies on the impact of methods for improving the energy characteristics on the fuel economy of a spark ignition engine with feedback and a three-way catalytic converter under full load conditions. Various methods for improving the energy characteristics of spark ignition engines to achieve high energy efficiency are known. The most commonly used method is enriching the fuel-air mixture under full load conditions. However, this method has several drawbacks, including reduced fuel economy and inefficient operation of the catalytic converter. Another known method for improving the energy characteristics of spark ignition engines is by adding oxygen-containing gases, particularly nitrogen oxide, to the air charge, where oxygen by volume constitutes 33%, significantly higher than in air (21%). This method is widely used for boosting the performance of sports car engines. However, there is a lack of research on the impact of this method on fuel economy compared to the enrichment method in the literature. Improving the fuel economy of the engine without deteriorating the energy characteristics is possible by transitioning from operating on enriched fuel-air mixtures to operating on a stoichiometric mixture by adding nitrogen oxide to the engine's air charge. This task was addressed in the article through calculations using experimental data. Fuel economy was evaluated by comparing the specific effective gasoline consumption determined by the engine's work when using an enriched fuel-air mixture and adding nitrogen oxide to the air charge to regulate it to a stoichiometric mixture. It was shown that using nitrogen oxide additives to the engine's air charge can improve fuel economy and increase engine energy characteristics compared to the method of enriching the fuel-air mixture.