Does diesel need a spark to ignite?
Why do diesel internal combustion engines require no spark plug to ignite the fuel unlike petrol engines? Spark plugs are used in the petrol engines to ignite the air fuel mixture whereas in diesel engines the presence of spark plugs is not necessary.
Why does diesel engine does not have spark plug?
A spark plug has no use with diesel fuel because there is no need to ‘light’ the diesel fuel. Instead, the glow plug only heats the combustion chamber.” In combination with the piston design, and the heated chamber from the glow plugs, the diesel fuel becomes atomized into a mist.
How is the fuel ignited inside the diesel engine?
Injected fuel is ignited by its reaction to compressed hot air in the cylinder, a more efficient process than that of the spark-ignition internal-combustion engine. The diesel engine gains its energy by burning fuel injected or sprayed into the compressed, hot air charge within the cylinder.
How is diesel fuel ignited in a cold diesel engine?
When a diesel engine is cold, the compression process may not raise the air temperature high enough to ignite the fuel. The glow plug is an electrically heated wire that facilitates fuel ignition when the engine is cold. Glow plugs are typically found on small diesel engines.
Why does a diesel engine not need a spark plug?
Diesel engines don’t require a spark plug, because they rely on high compression. I like to use the example of holding a bicycle tyre pump over the flat of your hand, and pumping it hard. The burning sensation on your skin is the answer. High compression of air = heat. Add atomised diesel fuel and you have ignition.
How does fuel ignite in a diesel engine?
In a diesel engine, however, the air is compressed first, and then the fuel is injected. Because air heats up when it’s compressed, the fuel ignites. One thing we know. We can’t use fuel in liquid form during compression, because liquids are incompressible. Now we have option to use diesel in vapour form.
How is a diesel engine different from a gas engine?
Gas powered engines and diesel powered engines ignite differently. Gas powered engines start when the fuel is ignited by a spark from a spark plug. In contrast, diesel engines are ignited by the heat caused by compression. In a diesel truck, the fuel and air must get hot enough to create combustion, which then creates the spark to start the engine.
Can a spark plug be used for ignition?
But still we can’t use spark plug for ignition, since mixture present in the cylinder is heterogeneous (somewhere mixture within ignition limits and somewhere not). Ignition by spark plug required homogenous air fuel mixture.