Effect of injection and ignition timing on a hydrogen-lean stratified charge combustion engine

Abstract

Hydrogen can be used as a fuel for internal combustion engines to realize a carbon-neutral transport society. By extending the lean limit of spark ignition engines, their efficiency, and emission characteristics can be improved. In this study, stratified charge combustion (SCC) using monofueled hydrogen direct injection was used to extend the lean limit of a spark ignition engine. The injection and ignition timing were varied to examine their effect on the SCC characteristics. An engine experiment was performed in a spray-guided single-cylinder research engine, and the nitrogen oxide and particulate emissions were measured. Depending on the injection timing, two different types of combustion were characterized: mild and hard combustion. The advancement and retardation of the ignition timing resulted in a high and low combustion stability, respectively. The lubricant-based particulate emission was attributed to the in-cylinder temperature and area of the flame surface. Therefore, the results of the study suggest that the optimization of the hydrogen SCC based on the injection and ignition timing could contribute to a clean and efficient transport sector.

Numerical characterization of hydrogen under-expanded jets with a focus on Internal Combustion Engines applications

“…An optimized directinjection strategy results in a higher engine efficiency and lower NOx production. Delaying the Start of Injection (SOI) produces a stratified mixture, 5 with a 1 Department of Mechanics, Mathematics and Management -Politecnico di Bari, Bari, Italy 2 rich mixture near the spark and a lean one close to the walls. 6 In this way, wall heat losses and the mean cycle temperature are reduced, resulting in near-to-zero NOx emissions.…”

Studying the effects of manifold pressure boosting and EGR on combustion and NOx emission of hydrogen-fueled SI engine

“…A common observation from the previous research is that the engine efficiency improves by boosting, while NO x emission increases. Lee et al 25 had observed retarded ignition to reduce NO x slightly; similarly, Zareei and Ghadamkheir 26 had also reported a slight drop in NO x emission with retarded ignition. However, the NO x reduction was not satisfactory under minimum performance drop range.…”

Introduction to the current and future use of H2 and H2-based e-fuels in combustion engines and fuel cells Special Issue

“…Papers in the no-carbon emission group touch on topics such as: the efficiency of hydrogen fuel cell vehicles under real-world operating conditions, 1 the use of hydrogen in internal combustion engines in both spark-ignited and compression ignition operation, [2][3][4] the concept of a split-cycle hydrogen engine with argon as the working fluid 5 and the use of ammonia in a spark-ignited engine. 6 A number of papers focused on intermediate-term solutions that would be accompanied by some engine-out carbon emissions.…”

“…the use of hydrogen in internal combustion engines in both spark-ignited and compression ignition operation, 2–4…”