Description of the Technical Evolution and Trends in the Future for Petrol and Diesel Fuel Injections Systems - Essay Example

The paper also discusses the various mechanisms that result in low or high cylinder pressure, provides a brief on the global warming phenomena as the increased use of automotives contributes to the green house gas emissions and finally a note on the issues related to automotive fuel systems. Introduction Fuel injection system, which has become a major form of fuel delivery used in automotive petrol engines, involves injection of fuel into an internal combustion engine. From the late 1980s this fuel injection system has replaced the carburetors, which was till then the most widely used in engines.

Most of the fuel injection systems are designed and calibrated to handle gasoline or diesel applications specifically. The advent of the electronic fuel injection (EFI) systems has enabled the use of similar hardware for both diesel and gasoline ("Fuel injection", 2010). The EFI system uses a solenoid-operated injector to spray the atomized fuel into a 3-inch manifold near the intake valve. This technique is not being commonly employed in several vehicles or in some cases the air and fuel is directly injected.

This system mainly depends on the injectors which come in various designs, cylinder pressure, fuel line pressure and other similar factors. . \\ Carburetors A basic model carburetor consists of the following components: Fuel tank that stores the fuel fuel lines or pipes that carry the fuel within the system a pump which passes the fuel from the tank to the engine fuel cleaning filter system that supplies clean air a carburetor that mixes the incoming fuel and the air and it also control the amount of mixture entering into the engine the intake-manifold to supply the mixture to the engine.

Inside the carburetor the liquid fuel is converted into a fine spray which mixes with the air. A correct amount of this mixture is supplied to the engine via a throttle valve connected to the accelerator or gas pedal. Of the various models, the down-draft carburetor is very common while the side-draft model is not widely used nowadays. In the down-draft model the carburetor is placed on top of the intake manifold and it consists of a floating bowl for the fuel. A tube immersed into the fuel passes the fuel into the discharge nozzle placed at the other end in the venturi.

The venturi is narrow and is shaped in a way that will enable the air to pass at a fast speed. This set up can be compared to the wings of an aircraft the shape of which causes the air to flow at a higher speed that creates an area of low-pressure than the atmospheric pressure. This difference in pressure provides an upward trust that lifts the aircraft. This phenomena is referred to as the 'Bernoulli effect' and in the case of the venturi the end of the nozzle protruding into the airflow is an area of low-pressure compared to the fuel injected into the float bowl.

This pressure difference causes the fuel to flow from the nozzle which atomizes as it mixes with air. The air-fuel ratio required by a light vehicle is about 15:1 which is terms of weight is