Energy efficiency of automotive gasoline engine: current approaches

Introduction. To meet the promising requirements fuel consumption and CO₂ emissions of passenger cars and commercial vehicles of 2025-2030 further improvement of the design and workflowof a gasoline internal combustion engine (ICE) is required in the full range of the working map, especially at high loads.

The purpose of the study was to review and analyze ways to improve the indicator efficiency of a gasoline ICE and approaches aimed at increasing efficiency by reducing heat losses.

Methodology and research methods. The review of barriers to increasing the indicator efficiency of a gasoline ICE was based on the analysis of the ideal and real Otto cycle and the results of experimental and calculated foreign and domestic studies of recent years aimed at increasing fuel efficiency by reducing heat losses.

Scientific novelty and results. It was shown that effective new approaches to reduce the heat losses of the ICE of the future were: organization of combustion of a stoichiometric mixture diluted with a large amount of cooled recirculated exhaust gases (up to 25-35%) at high loads; increasing the ratio of the piston stroke to the cylinder diameter S/D to a value of the order of 1.5; the use of thin thermal barrier coatings that provide a “temperature swing” of the combustion chamber surface. Combined with proven modern technologies (direct fuel injection, variable valve drive, etc.), they can significantly increase the optimal geometric compression ratio, significantly reduce heat loss to the walls of the combustion chamber and the tendency of the ICE to detonate, and provide an increase in the indicator efficiency up to 49-53%.

The practical significance lies in the possibility of using the results of the work when choosing a scheme and design solutions for a promising gasoline ICE with reduced fuel consumption and CO₂ emissions.

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