mpfi system ppt
- 1. KUMAR GAURAV,B.TECH THIRD YEAR, DEPATMENT OF MECHANICAL ENGINEERING I.T.S. ENGINEERING COLLEGE ,GR. NOIDA
- 2. KUMAR GAURAV,B.TECH THIRD YEAR, DEPATMENT OF MECHANICAL ENGINEERING I.T.S. ENGINEERING COLLEGE ,GR. NOIDA
- 3. In a multi-cylinder engine with a carburetor , it is difficult to obtain a uniform mixture in each cylinder. The various cylinders receive the air-gasoline mixture in varying quantities and richness. This problem is called the mal-distribution and can be solved by the port injection system by having the same amount of gasoline injected at each intake manifold. By adopting gasoline injection each cylinder can get the same richness of air-gasoline mixture and the mal-distribution can be avoided to a great extent. Before discussing the MPFI system , lets take a glance over the gasoline injection.
- 5. #To have uniform distribution of fuel in a multi-cylinder engine. #To reduce or eliminate detonation. #To improve the breathing capacity and hence the volumetric efficiency. #To prevent fuel loss during scavenging in case of two- stroke engines.
- 6. To supply a proper ratio of gasoline and air to the cylinders. These system function under two basic arrangements viz., (i) Port injection (ii) Throttle body injection 1.Gasoline direct injection 2.port-injection 3.Manifold injection
- 7. IIIIIIIIIIIIIIIIIIIIIIIIIII #In this system , the injector is placed on the intake manifold near the intake port . The injector sprays gasoline into the air, inside the intake manifold. #The gasoline mixes with the air in areasonably uniform manner.This mixture of gasoline and air then passes through the intake valve and enters into the cylinder. Figure 2:port injection
- 8. Every cylinder is provided with an injector in its intake manifold . If there are six cylinders , there will be six injectors . Figure shows simplified view of a port or MPFI system. IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIFigure 3: port injection
- 9. # Figure illustrate the simplified sketch of throttle body injection system(single point injection).This throttle body is similar to the carburetor throttle body , with the throttle valve controlling the amount of air entering the intake manifold. Figure 3: throttle body injection
- 10. 1.Exhaust gas or oxygen sensor 2.Engine temperature sensor 3.Air flow sensor 4.Air inlet temperature sensor 5.Throttle position sensor 6.Manifold pressure sensor 7.Camshaft position sensor 8.Knock sensor
- 11. (i) D-MPFI System (ii)L-MPFI System (i) D-MPFI System-It is the manifold fuel injection system . In this type , the vacuum in the intake manifold is first sensed. Further it senses the volume of air by its density. Figure 5: D-MPFI System
- 12. #As air enters into the intake manifold , the manifold pressure sensor detects the intake manifold vacuum and sends the information to the ECU . The speed sensor also sends information about the rpm of the engine to the ECU. #The ECU in turn sends commands to the injector to regulate the amount of gasoline supply for injection . When the injector sprays fuel in the intake manifold the gasoline mixes with the air and the mixture enters the cylinder.
- 13. The L-MPFI system is a port fuel-injection system . Here , the fuel metering is regulated by the engine speed and the amount of air that actually enters the engine . This is called air-mass metering or air-flow metering. Figure 6: L-MPFI System
- 14. #As air enters into the intake manifold ,the air flow sensor measures the amount of air and sends information to ECU . Similarly, the speed sensor sends information about the speed of the engine to the ECU. #The ECU processes the information received and sends appropriate commands to the injector to regulate the amount of gasoline supply for injection . When injection takes place, the gasoline mixes with air and mixture enters the cylinder.
- 15. #The MPFI system can be functionally divided into following three main components; (i) Electronic control system (ii) Fuel System (iii)Air Induction System
- 16. #The MPFI-electronic control system is shown in above block diagram . The sensors that monitor intake air temperature , the oxygen ,the water temperature , the starter signal and the throttle piston send signals to ECU. Figure 7: MPFI Electronic control system
- 17. #The air-flow sensor sends signals to the ECU regarding the intake air volume . #The ignition sensor sends information about the engine speed . #The ECU processes all these signals and sends appropriate commands to the injectors to control the volume of the fuel for injection . #When necessary the cold-start injector which is a part of fuel system.
- 18. #Here, the fuel is supplied by the fuel pump . At the time of starting , the cold start injector time switch. The cold start injector injects fuel into the air intake chamber , thus enriching the air-fuel mixtures . The pressure regulator regulates the pressure of the fuel . The injector receive signals from the ECU and inject the fuel into the intake manifold. Figure 8: MPFI Fuel system
- 19. #Here , the air cleaner ,the air –flow meter , the throttle body and the air valve supply a proper amount of air to the air intake chamber and intake manifold . The quantity of air supplied is just what is required for complete combustion. Figure 9: MPFI Air induction system
- 20. 1.Ganesan V , Internal Combustion Engine , Tata McGraw Hill. 2.Mathur M L,and Sharma RP,A Course in Internal Combustion Engines , Dhanpat Rai & Sons , New Delhi 3.http://www.eng.fsu.edu/ME_senior_desi gn/2002/folder14/ccd/Combustion