Improvements of the hydrogen engine setup and continuation of the experimental investigation

Abstract

From early human existence, the need to enhance comfort in life has created an ongoing climate change leading to devastating natural catastrophes. Such comforts include the transportation sector which throughout the years evolved to take place on land, on water, in the air and even in space. In past years, researchers have focused on improving existing technologies such as the internal combustion engine which use traditional fuels such as diesel and gasoline. Hence this vast evolution of technology and knowledge on internal combustion engines might be the key in solving the current environmental crisis through the utilisation of hydrogen fuel. This dissertation mainly focuses on improving the existing hydrogen engine setup by calibrating and installing an in-house viscous flow metre to closely monitor the mass air flow of the engine. This system required the usage of differential pressure sensors which were key to monitoring the real time mass air flow during engine testing. From the collected mass air flow measurements, a reliable, precise air to fuel ratio was calculated and used throughout the various hydrogen experiments. The air to fuel calculations were also dependent on correct hydrogen flow measurements which were properly calculated through numerous injector flow tests. The injector flow tests were also carried out by different gases and the corresponding behaviour was compared to theory. The possibility of changing the port fuelled system with direct injection was also explored. Such investigations were useful in deducing the appropriate pressure and allowed time of hydrogen injection on the J.A.P 6 engine. Additional exhaust oxygen analyser sensors were also mounted onto the setup for further air to fuel confirmation. After necessary preparations were done, multiple engine tests were performed by utilising propane, gasoline and hydrogen fuels. Fuel and spark sweeps of the mentioned fuels were performed at different engine speeds. The data was collected through the improved LabVIEW system. The experiments showed that the engine operated well at mixtures of λ=3 using hydrogen in comparison to λ=1.1 using gasoline. For hydrogen the maximum brake thermal efficiency was of 25% at λ=2 and 21% for gasoline at λ=1. It was also concluded that during lean H2 operation at λ=2, only water was being expelled from the exhaust. Hence, no pollution was being emitted since the only pollutant (NOx) formed through H2 combustion does not form beyond λ values of 2.