Combustion of Lean Hydrogen-Based Mixtures in a Spark Ignition Engine

Abstract

In this paper, the results of an experimental and modeling study of the combustion of lean mixtures based on hydrogen in a spark ignition engine are presented. A hydrogen and a hydrogen (90 vol %)-methane (10 vol %) mixture with air excess coefficients of 1.4–3.0 were used as fuel. “Back flashes” in the intake manifold were experimentally observed when the hydrogen-air mixture was burned at the air excess coefficient of 1.4. At large air excess coefficients, the key indicators of the engine performance are determined by using the experimental indicator diagrams. The efficiency indicator for hydrogen-air mixtures was 30–32%. The highest efficiency of 37% was obtained by using an earlier ignition in mixtures with methane addition. A weak dependence of the efficiency on the air excess coefficient was found. The major qualitative relationships obtained experimentally were supported by the performed 2D numerical simulation of the dynamics and combustion of mixtures under experimental conditions. Incomplete hydrogen combustion of up to 60% is observed at an air excess factor of 3.0.