Study of hydrogen fumigation in compression ignition engine (MS)

Abstract

Transportation sector consumes 63 % of the oil extracted worldwide and produces 22 % of the total global greenhouse gas (GHG) emissions. The rapacious growth of transport sector in last few decades has made it a front line source of air pollution. Dual fuel and advanced combustion technologies are being extensively researched for meeting the emission norms. Additionally, such technologies coupled with an alternative fuel not only reduce the emissions but also deflate the energy dependency on fossil fuels. Among such alternative fuels, hydrogen is particularly attractive due to its extremely clean combustion properties, yet remains relatively unexplored. The thesis focuses on Experimental study of combustion, performance, regulated and unregulated emissions from hydrogen diesel dual fuel internal combustion engine. Numerical study of effects of compression ratio and injection timing variation on combustion performance and emissions of a hydrogen-diesel dual fuel compression ignition engine. Assessment of combustion performance of neat hydrogen operated CI engine under HCCI mode using stochastic zero-dimensional numerical model. Experiments have been conducted at Renewable Fuels and Internal Combustion Engine Laboratory, IIT Mandi on an in-house designed and constructed dual fuel CI engine test setup. The experiments were performed at 25, 50 and 75 % engine load with a timed manifold injection of hydrogen. Hydrogen energy substitution is varied as 5, 10 and 20 %. LabView codes have been developed to acquire and analyse the data of combustion and engine performance. Cycle to cycle variability of dual fuel engine is studied. Other than regulated emissions, unregulated hazardous air pollutants (HAPs) such as formaldehyde, acetaldehyde, ethylene, propylene and aromatic hydrocarbons along with NOx components are the focus of study. Using convergeCFD software integrated with the LLNL combustion chemistry solver, full load combustion performance and emissions of hydrogen diesel dual fuel engine under full load are evaluated. Engine performance at compression ratio of 14.5, 16.5 and 19.5 along with pilot diesel fuel injection timings variation are assessed. The study accesses the possibility of stable engine combustion at high levels of hydrogen substitution. For exploration of possibility towards operating a CI engine on neat hydrogen, the 0-D model is developed using Cantera (Open-Source combustion chemistry Solver) to predict combustion behaviour in an H2HCCI engine.