FUEL SYSTEMS AND ITS COMPONENTS THERMAL ENGINEERING FUEL SYSTEMS AND ITS COMPONENTS Presented by :- Jestin Thomas S5 -26 ME

The Fuel System All internal combustion engines need three things to run... Air, Fuel and Spark. Fuel is a substance consumed by the engine to produce energy. The common fuels for internal combustion engines are: 1. Petrol 2. Power kerosene 3. High speed diesel oil 4. Light diesel oil. The fuel system is critical in storing and deliverying the gasoline or diesel fuel your engine needs to run.

IMPORTANTS OF FUEL SYSTEMS The fuel injection should be occur at the correct moment. It should supply the fuel in correct quantity as per varying load. The injected fuel must be in fine droplets. It should supply same quantity of fuel in all cylinder In multi engine cylinders. The beginning and ending of injection must be sharp.

COMPONENTS OF FUEL SYSTEMS Main components of any fuel systems are :- Fuel tank: Basically a holding tank for your fuel. When you fill up at a gas station the gas travels down the filler tube and into the tank. In the tank there is a sending unit which tells the gas gauge how much gas is in the tank. Fuel tank and Fuel gauge

COMPONENTS OF FUEL SYSTEMS Fuel Pump: Fuel pump are used to pump the fuel from the fuel tank to the engine cylinder Fuel Filter: Clean fuel is critical to engine life and performance. Fuel injectors and carburetors have tiny openings which clog easily so filtering the fuel is a necessity. Filters can be before or after the fuel pump, sometimes both. They are most often made from a paper element, but can be stainless steel or synthetic material and are designed to be disposible in most cases.

COMPONENTS OF FUEL SYSTEMS Carburettor or Injectors :- The fuel injector is basically a tiny electric valve which opens and closes with an electric signal. A carburetor take the fuel and mixes it with air without computer intervention. While simple in operation, they tend to need frequent tuning and rebuilding

COMPONENTS OF FUEL SYSTEMS Engine control unit:- The engine control unit is central to an EFI system. The ECU interprets data from input sensors to, among other tasks, calculate the appropriate amount of fuel to inject. Fuel lines:- Pipes which carries fuel from one another.

TYPES OF FUEL SYSTEMS Major types of fuel systems are:- CRDI (Common Rail Direct Injection) MPFI(Multipoint Fuel Injection) TDI(Throttle Body Injection)

CRDI (Common Rail Direct Injection) Common Rail Direct Injection meaning, direct injection of the fuel into the cylinders of a diesel engine via a single, common line, called the common rail which is connected to all the fuel injectors.  Instead of providing separate piston pumps for fuel supply, the common rail alone supplies high pressure fuel to each cylinder CRDI engines maintain constant pressure regardless of the injection sequence. This pressure then remains permanently available throughout the fuel line. The electronic control unit (ECU) modifies injection pressure precisely as needed, based on data obtained from sensors on the cam and crankshafts.This technique allows fuel to be injected as needed, saving fuel and lowering emissions.

CRDI (Common Rail Direct Injection)

CRDI (Common Rail Direct Injection) Advantages:- Cars fitted with this new engine technology are believed to deliver 25% more power and torque than the normal direct injection engine. It also offers superior pick up, lower levels of noise and vibration, higher mileage, lower emissions, lower fuel consumption, and improved performance. Disadvantages:- The key disadvantage of the CRDi engine is that it is costly than the conventional engine. It also includes high degree of engine maintenance and costly spare parts. Also this technology can’t be employed to ordinary engines  

MULTIPOINT FUEL INJECTION The MPFI is a system or method of injecting fuel into internal combustion engine through multi ports situated on intake valve of each cylinder. It delivers an exact quantity of fuel in each cylinder at the right time. MPFI includes a fuel pressure regulator, fuel injectors, cylinders, pressure spring and a control diaphragm. It uses multiple individual injectors to insert fuel in each cylinder through intake port situated upstream of cylinder’s intake value. The control diaphragm and pressure spring controls the outlet valve opening and the amount of fuel that can return. The pressure in the intake manifold significantly changes with the engine speed and load.

MULTIPOINT FUEL INJECTION

THROTTLE BODY INJECTION Throttle body injection (TBI), also called single point injection was the first type of fuel injection widely in use in cars.  It worked very similarly to a carburetor in that it metered out fuel into the front of the intake manifold, behind the throttle body. The fuel and air mix in the intake manifold and are drawn into the cylinders by the suction produced during each cylinder's intake stroke. Throttle body injection was a big improvement over carburetion. The vehicles onboard computer, the engine control unit (ECU), could control the amount of fuel metered out and the timing of the fuel. That makes TBI more efficient than carburetion over a wider range of operating conditions.

THROTTLE BODY INJECTION

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