Computational tool to evaluate the efficency of hydrogen in internal combustion engines

Abstract

Behavioral studies on the efficiency of a hydrogen engine are important, as they are part of a global initiative to decarbonize the automotive sector, and this technological route for the use of hydrogen is promising within recent energy transition studies. In this sense, the exploration of new technological development routes around production, commercialization and use of hydrogen for the state of Minas Gerais and for Brazil has been proposed through various government initiatives in recent years. For this reason, this work has developed a computational tool based on a zero-dimensional mathematical model capable of predicting the efficiency of a spark ignition engine when using hydrogen as fuel. The simplicity of the model offers a quick view of the operation and thermodynamics of the engine, which reduces computational effort and produces results that represent the real behavior of hydrogen combustion. This focus helps in the study of combustion and in making decisions about the economic viability of using hydrogen in internal combustion engines. To do this, the compression, combustion and expansion processes in the Otto cycle were mathematically modeled to represent the combustion behavior of the air-hydrogen blend inside the engine cylinder, using code written in MATLAB. The mathematical model was validated with experimental data taken from the research engine bench and those reported in the literature in relation to the pressure curve for the different engines and operating conditions evaluated, and the efficiency produced by the engine under these conditions was estimated. A graphical interface was generated in AppDesigner for the computational tool, making it easier for the user to develop the behavioral and operational study of a hydrogen engine. The results obtained with the computational tool show that the estimated pressure and efficiency values are in good agreement with those found in the literature in all the cases evaluated. The maximum error when comparing the pressure curve was 1.32% for an engine with a speed of 3300 RPM. In addition, the minimum fit of the mathematical model to the experimental data was 86%, which represents a good alternative for estimating the thermal efficiency value.