Setting up of a hydrogen spark ignition engine with in-cylinder pressure measurement for combustion characterization

Abstract

Hydrogen is a fuel that does not contain any hydrocarbons and hence when burnt, it does not emit any greenhouse gases. Instead, only water vapour is produced which is harmless to the environment. Hence hydrogen has been investigated as an alternative means of fuelling internal combustion engines due to the ever increasing regulations related to vehicle emissions imposed by governments around the world. Hydrogen as a fuel in internal combustion engines has been explored because it has wide flammability limits, and fast flame speeds. Hydrogen also has a high energy density per unit mass that is higher than that of conventional fuels of diesel and petrol. The aim of this dissertation was to operate a single cylinder four stroke engine on hydrogen by port fuelled injection and make the appropriate hardware changes. The engine was configured so that the engine starts on petrol and isthen switched to operate on hydrogen fuel injection. The engine was petrol carburettor fuelled and it was converted to operate on both petrol and hydrogen fuel injection seperately. LabVIEW software was used to acquire data during testing to investigate combustion properties of both petrol and hydrogen fuels. Power tests were done at specific tests points using both petrol and hydrogen fuels to compare the performance of the same engine using the different fuels. In-cylinder data measurement was done to acquire the in-cylinder pressure measurement during tests. Data was acquired with respect to time and then converted to crank angles using LabVIEW post processing. Then the indicator diagrams as well as the mass fraction burn diagrams of both hydrogen and petrol fuels at different test points were plotted. The combustion properties of the fuels were investigated and the coefficient of variation of the properties was calculated. The performance of hydrogen and petrol fuel injection was then noted from these parameters. Prior to operating the engine on hydrogen, an engine monitoring system was devised so that if there is a hydrogen leak, then it would be immediately noticed. This system consisted of various hydrogen sensors that detected any hydrogen leakages and an emergency shut off valve so that if a hydrogen leak is detected it would immediately close the supply of hydrogen to the engine. The crankcase was vented by nitrogen to reduce the amount of oxygen in the crankcase. This was done so that if any hydrogen leaked to the crankcase then it would not ignite in the crankcase.