The differences between the Hydrogen and Gasoline engines
The differences between the Hydrogen and Gasoline engines are brought about by the combustion process, the air/ fuel ratio, flame velocity, ignition energy, auto-ignition temperature, and the fuel diffusivity. These differences result into the modification of the latter with features such as the: Hardened valves seats and valves, Stout connecting rods, Non- tipped platinum spark plugs, advanced voltage ignition coil, Gas fuel injectors rather than liquid fuels, Larger crankshaft damper, Resilient head gasket material, Improved intake manifold (for supercharger), Progressive pressure supercharger, Advanced temperature engine oil, density, and the quenching distance.
The above modifications in hydrogen engines result in their cost being 150% higher than the gasoline engine. However, both the hydrogen and gasoline-driven engines similarly burn the fuel. From a theoretical point of view, the maximum power output generated from a hydrogen engine is determined by the air/fuel ration, and the method of fuel injection used.
Flame velocity in hydrogen engines is much higher in the combustion cylinder, and this creates a more upper air to fuel ratio, which means burning the fuel much quicker and efficiently. The automatic ignition temperatures in hydrogen engines are much higher going to over 500 degrees Celsius when compared to 230 degrees Celsius in gasoline engines. It, therefore, means higher octane in a hydrogen engine to operate at higher compression ratios. Fuel diffusivity in hydrogen engines is much quicker, which allows for an efficient fuel combustion process.
Remember, both the port and carburetor injection methods involve mixing the fuel before feeding it into the combustion chamber, the hydrogen system actual power dissipation is lower than the maximum theoretical power attainable to about 85% obtainable from a gasoline engine at the same conditions.
In direct injections engines, in which the mixture of fuel and air is achieved after the closure of the intake valve, meaning that the combustion chamber will have 100% air, the maximum engine output is about 15% higher when compared to gasoline engines.
It is therefore clearly evident that the maximum power output from a hydrogen engine can either be lower or higher by 15% when compared to the gasoline-fueled engine under the stoichiometric air to fuel ratio. The only limitation of burning hydrogen fuel at a stoichiometric air to fuel ratio is the production of nitrogen oxides (NOx) in large volumes. Since the main reason for using hydrogen fuel-driven engines is to lower the exhaust emissions significantly, hydrogen engines are typically designed not to operate under the stoichiometric air to fuel ratio.
Typically the hydrogen engines are designed to use a double amount of air that, in theory, would be necessary for complete combustion. However, at this air/fuel ratio, the power generated is almost half that of a gasoline engine, although the formation of nitrogen oxides is reduced to nearly zero. For this reason, the hydrogen engines are designed to be larger than the gasoline engine. Moreover, to compensate for this power loss, the hydrogen engine is typically installed with the superchargers and turbochargers. One of the main advantages of hydrogen engines is that there is no emission of C02, which is one of the principal threats every automaker is currently working on means of eliminating it on the earth’s surface.