A Numerical Simulation of Analysis of Backfiring Phenomena in a Hydrogen-Fueled Spark Ignition Engine

Abstract

Hydrogen utilization in spark ignition (SI) engines could reduce urban pollution including particulate matter as well as greenhouse gas emission. However, backfiring, which is an undesirable combustion process of intake charge in hydrogen-fueled SI engine with manifold-based injection, is one of the major technical issues in view of safety of engine operation. Backfiring occurs generally during suction stroke as the hydrogen–air charge interacts with residual gas, resulting in flame growth and propagation toward upstream of engine's intake manifold, resulting in stalling of engine operation and high risk of safety. This work is aimed at analysis of backfiring in a hydrogen-fueled SI engine. The results indicate that backfiring is mainly function of residual gas temperature, start of hydrogen injection timing, and equivalence ratio. Any hot-spot present in the cylinder would act as ignition source resulting in more chances of backfiring. In addition to this, computational fluid dynamics (CFD) analysis was carried out in order to assess flow characteristics of hydrogen and air during suction stroke in intake manifold. Furthermore, numerical analysis of intake charge velocity, flame speed (deflagration), and flame propagation (backfiring) toward upstream of intake manifold was also carried out. Some notable points of backfiring control strategy including exhaust gas recirculation (EGR) and retarded (late) hydrogen injection timing are emerged from this study for minimizing chance of backfiring. This study results are useful for development of dedicated SI engine for hydrogen fuel in the aspects of elimination of backfiring.

Comprehensive analysis of the combustion of low carbon fuels (hydrogen, methane and coke oven gas) in a spark ignition engine through CFD modeling

“…Hydrogen has been widely studied as combustion fuel using CFD models in direct injection (DI) [34][35][36] and port-fuel injection (PFI) locations [10,[37][38][39]. Besides the analysis of the performance and emissions, the start of injection (SOI) has been studied to reduce the residual H 2 in the intake manifold and to avoid backfire in PFI engines [40][41][42][43]. Generally, temperature, OH mass and NOx emissions distribution in the cylinder are the main variables plotted in 3D graphs.…”

Effects of Injection Strategies on Mixture Formation and Combustion in a Spark-Ignition Engine Fueled with Syngas-Biogas-Hydrogen

“…Many studies on fuel supply systems for spark-ignition (SI) engines using gaseous fuels have been reported about the addition of a hydrogen injector on the intake manifold to improve the performance of the gasoline SI engine (Banapurmath et al, 2011;Fiore et al, 2020;Ji and Wang, 2011;Konde and Yarasu, 2014;Le et al, 2020). Adjusting injection time to reduce the amount of hydrogen residual on the intake manifold can limit the backfire (Duan et al, 2014;Liu et al, 2008;Subramanian and Salvi, 2016). For SI engines, directly injecting hydrogen into the combustion chamber improves engine efficiency and reduces pollutant emissions (Fiore et al, 2020;Hagos et al, 2016).…”