Diesel Engine Working System: from Intake to Exhaust

Illustration of a diesel engine (Unsplash)

YOGYAKARTA - Diesel engines include engines with internal combustion types. This machine uses the compression result to create a flame. This means that diesel does not require a spark when starting. The working system of diesel engines is indeed different from gasoline engines that use spark plugs. Watch this article to understand how diesel works.

Diesel Engine Working System

In a scientific article written by David Firdaus Bijaksana Sianturi, et al. (Dinamis Journal: 2020) it is explained that diesel is an internal combustion engine. The engine uses the result of compression to create a flame that then burns the fuel that has previously been injected into the combustion chamber.

Currently, diesel engines continue to develop. As a result, there are 4-stroke diesel engines based on piston movement. Here's how 4-stroke diesel works.

Hisap (Intake) Step

Simply put, this stage aims to introduce air into the combustion chamber so that a flame can occur. At this stage, the piston will move down from the top position to the bottom position. The suction valve is open, while the exhaust valve remains closed.

As the volume of the combustion chamber increases, the pressure inside the combustion chamber becomes lower than the outside air pressure. Due to this pressure difference, air from the outside flows in through the air filter. At the end of the suction step, the combustion chamber is filled with clean air.

Compression Step (Compression)

This stage will compress the air so that the pressure and temperature rise and prepare for combustion. The piston moves up from the bottom position to the top position. Both valves are tightly closed so that the air that has just entered cannot come out.

The air is then compressed in a narrow space until high pressure is created. When that happens, the air temperature will rise. Towards the piston reaches the top position, the injector sprays diesel fuel thinly. The goal is for the fuel to easily mix with hot air.

Work Steps (Power/Expansion)

The fuel spray will meet the high-temperature air. This condition makes the combustion in the diesel engine occur without using a spark plug. The combustion gas pressure then increases. The pressure then pushes the piston down strongly.

The piston stroke will be the main source of power, then passed to the crankshaft shaft until it changes the up-and-down motion of the piston into a rotating motion. This rotation is what drives the vehicle or engine.

Exhaust step (Exhaust)

After the piston is pushed down, the piston will move back up again to the upper position. The exhaust valve is open, while the suction valve is closed. The piston then pushes out the remaining combustion gas from the inside of the cylinder. This gas then flows into the exhaust manifold and then to the car's exhaust. After the residual gas comes out, the combustion chamber is clean again. The engine is ready to enter the suction step again from the beginning.

That's the information related to the diesel engine working system. Visit VOI.id to get other interesting information.