Performance, Emissions, and Combustion Characteristics of a Hydrogen-Fueled Spark-Ignited Engine at Different Compression Ratios: Experimental and Numerical Investigation

Abstract

This paper investigates the performance of hydrogen-fueled, spark-ignited, single-cylinder Cooperative Fuel Research using experimental and numerical approaches. This study examines the effect of the air–fuel ratio on engine performance, emissions, and knock behaviour across different compression ratios. The results indicate that λ significantly affects both engine performance and emissions, with a λ value of 2 yielding the highest efficiency and lowest emissions for all the tested compression ratios. Combustion analysis reveals normal combustion at λ ≥ 2, while knocking combustion occurs at λ < 2, irrespective of the tested compression ratios. The Livenwood–Wu integral approach was evaluated to assess the likelihood of end-gas autoignition based on fuel reactivity, demonstrating that both normal and knocking combustion possibilities are consistent with experimental investigations. Combustion analysis at the ignition timing for maximum brake torque conditions demonstrates knock-free stable combustion up to λ = 3, with increased end-gas autoignition at lower λ values. To achieve knock-free combustion at those low λs, the spark timings are significantly retarded to after top dead center crank angle position. Engine-out NOx emissions consistently increase in trend with a decrease in the air–fuel ratio of up to λ = 3, after which a distinct variation in NOx is observed with an increase in the compression ratio.

Research and Development of Hydrogen-Fueled Internal Combustion Engines in China

“… 17 The structure of HICEs is basically the same as that of a conventional internal combustion engine, with the difference that a hydrogen internal combustion engine has a separate hydrogen supply system that includes a series of auxiliary components such as hydrogen storage, hydrogen delivery, and hydrogen injection. In Figure 1 , 18 the structure of a typical hydrogen internal combustion engine test stand is shown. Although this is a single-cylinder piston engine, it can be adapted to other types of engines by replacing the accessories on the stand and making minor structural changes, such as different hydrogen injection positions, different engine types, different fuel types, 19 different ignition positions and modes, 20 , 21 etc.…”

“… Structural arrangement of a typical hydrogen internal combustion engine and accessories from the literature. 18 Reprinted with permission from ref ( 18 ). Copyright 2023 MDPI (Basel, Switzerland).…”

Scaling Performance Parameters of Reciprocating Engines for Sustainable Energy System Optimization Modelling

“…The focus of this work is on the scaling laws for spark-ignition (SI) engines. The electrofuels most likely to reach a certain level of cost-competitiveness (e.g., hydrogen, methanol, methane and ammonia) tend more toward spark-ignition operation than to their compression-ignition (CI) counterpart [29][30][31][32][33]. However, as there has been less interest in large-bore SI engines in the past, and the scaling laws for general ICEs and CI engines are also examined.…”