Automotive
Diesel engine system
While there are many applications for diesel engines, the system is broadly the same, since the majority are four-stroke engines. That means power is harnessed in four steps (stroke cycles), which we go through below.Before anything happens in the engine, fuel is pumped from the tank to the engine. The fuel passes through the fuel filter which removes any particles that could damage the engine or block the fuel injector nozzles – such as diesel bug, dirt, or in cold conditions, waxed FAME biodiesel which causes many problems in cold winter, to the point where the 7% biodiesel content in red diesel used in agriculture is sometimes reduced by refineries to assist farmers
Stroke 1 – Intake stroke
The appropriate amount of fuel is brought in through the fuel injection system and mixed with air in the pistons, where they become compressed.
Stroke 2 – Compression stroke
The intake valve closes and compression begins resulting in compressed air and fuel
Stroke 3 – Combustion stroke
Fuel, air under intense pressure combusts, releasing fumes of ignited diesel.
Stroke 4 – Exhaust stroke
Spent combustion gases are forced out of the exhaust valves, through the exhaust manifold, and into the turbine (exhaust) side of the turbocharger.
Turbocharger
After the exhaust stroke, any remaining fuel fumes are sent through to the turbocharger. The turbocharger pressurises air into the cylinder which increases the oxygen content, resulting in a better burn. In fact, the turbocharging process can increase the power of a diesel vehicle by 50% while reducing the engine’s fuel consumption by around 25%.
