Diesel fuel injection system

Diesel fuel injection and components are discussed

1. FUEL DELIVERY SYSTEM (DIESEL) ASSIGNMENT- PTMS Submitted by – INTAKHAB KHAN &VISHWAM PANCHAL Under the guidance of – Dr. SANJAY A PATIL

2. Table of contents Introduction About diesel fuel Fuel injection system working Components of fuel injection system Fuel tank Fuel filter Fuel lines Fuel pumps Injectors and nozzles ECU & sensors References 07/09/2021 Diesel fuel injection system 2

3. 1. INTRODUCTION In diesel fuel injection system the fuel(diesel) is to being atomized and injected a precise amount of fuel into the chamber when the air is compressed at proper time. The fuel stored in the tank is supplied to the injector by low pressure and high pressure pumps and the ECU controls the time and amount of fuel to be injected into the cylinder for perfect combustion of fuel. 07/09/2021 Diesel fuel injection system 3 By perfect combustion it means all the fuel is utilized to produce the power, low emission and optimum fuel economy. The ECU controls the amount of fuel by lifting the solenoid valve for certain amount of time and for certain amount of nozzle opening.

4. 2. Some important points about diesel fuel It is a linear saturated hydrocarbon obtained by distillation of crude oil. High energy content hence have better mileage than gasoline other reason for better mileage is that diesel can burn even when the air fuel mixture is too lean since the combustion starts at multiple points. Less volatile due to higher flash point hence do not use spark plug Less auto ignition temperature hence uses compressed air temperature for ignition More viscous hence injected at higher pressure for atomization(Around 2000 bar) and also swirl motion of air is generated for perfect atomization and mixing Dense as compared to petrol hence it needs more powerful fuel pumps for raising the pressure up to 2000 bar. To raise the temperature to auto ignition temperature it’s compression ratio is higher (14:1-25:1) as compared to petrol engine. And due to this it have better thermal efficiency. Also it takes in lot of air due to larger size of cylinder producing better power and torque. The ignition starts at the multiple points inside the cylinder at which the temperature is above auto ignition temperature and perfect amount of fuel and air is present. 07/09/2021 Diesel fuel injection system 4

5. 07/09/2021 Diesel fuel injection system 5 3 . Fuel injection system working

6. A- Rail Pressure sensor, B-High pressure rail , C-pressure control valve, D-ECU, E-Piezo injector, F- Fuel return line G- Pressure holding valve H-High pressure pump, I-Electric Pre supply pump, J-Pre filter, K-Fuel filter 07/09/2021 Diesel fuel injection system 6

7. Types of fuel injection Air injection type Solid injection type Individual pump and injector for each cylinder Unit injector type Distributor type  Common rail System 07/09/2021 Diesel fuel injection system 7

8. 4. Components of fuel injection system and their types a) FUEL TANK 07/09/2021 Diesel fuel injection system 8 BMW x3 PLASTIC FUEL TANK Toyota Hilux sheet metal Fuel tank They store the fuel and consists of low pressure transfer pump inside it. They are made up of either sheet metal or plastic as shown in the figure and consists of fuel level sensor. It also contains fuel vapour vent tube connected to canister to store the vaporized fuel, return line tube connected with the tank. It also consists of drain plug at the bottom. Fuel level sensor helps to indicate the fuel indicator in dashboard.

9. 07/09/2021 Diesel fuel injection system 9 Drain plug Fuel pump Fuel level sensor Vapor vent tube

10. 4. Components of fuel injection system and their types b) Fuel filter 07/09/2021 Diesel fuel injection system 10 The fuel from the fuel tank needs to be filtered to remove foreign particle which may damage fuel pump, injector and engine cylinder, lead to wear or moving parts, blockage in fuel flow hose and corrosion. Hence the diesel fuel is filtered more than once before injecting into cylinder. It consists of two filters primary and secondary filter.

11. 4. Components of fuel injection system and their types c) Fuel lines 07/09/2021 Diesel fuel injection system 11 They are the hoses used to transfer the fuel from fuel tank to the engine cylinder. They are of 3 types in case of Diesel engines heavyweight lines for the high pressures found between the injection pump and the injectors, medium weight lines for the light or medium fuel pressures found between the fuel tank and injection pump, and lightweight lines where there is little or no pressure.

12. 4. Components of fuel injection system and their types d ) Fuel pumps 07/09/2021 Diesel fuel injection system 12 An electric pump has a similar diaphragm-and-valve arrangement, but instead of the camshaft, a solenoid (an electromagnetic switch ) provides the pull on the diaphragm. The solenoid attracts an iron rod that pulls the diaphragm down, drawing petrol into the chamber. At the end of its travel the iron rod forces apart a set of contacts, breaking the current to the electromagnet and relaxing the pull on the diaphragm. When the diaphragm return spring raises the diaphragm, it also pulls the rod away from the contacts; they then close so that the solenoid pulls the rod and diaphragm down again.

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15. 4. Components of fuel injection system and their types e ) Fuel injectors and nozzels 07/09/2021 Diesel fuel injection system 15 The injectors used now a days are electrically actuated solenoid valve after receiving the signal from ECU for certain amount of time as per the amount of fuel decided to be injected. The injectors through which the fuel is sprayed are screwed, nozzle-first, into the cylinder head and are placed in such a way that the fuel is sprayed evenly all over the chamber. The injectors are one of two types, depending on the injection system. The first system uses continuous injection where the fuel is squirted into the inlet port all the time the engine is running. The injector simply acts as a spray nozzle to break up the fuel into a fine spray - it doesn't actually control the fuel flow. The amount of fuel sprayed is increased or decreased by a mechanical or electrical control unit - in other words, it is just like turning a tap on and off. The other popular system is timed injection (pulsed injection) where the fuel is delivered in bursts to coincide with the induction stroke of the cylinder. As with continuous injection, timed injection can also be controlled either mechanically or electronically.

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17. 07/09/2021 Diesel fuel injection system 17 Multiple injection-pilot injection

18. 07/09/2021 Diesel fuel injection system 18 4. Components of fuel injection system and their types e) ECU and Sensors

19. 07/09/2021 Diesel fuel injection system 19 Sensors used : Mass air flow sensor Throttle position sensor Engine temperature sensor Cam shaft position sensor Engine speed sensor Crankshaft position sensor Knock sensor Manifold pressure sensor Air inlet temperature sensor Oxygen sensor

20. 07/09/2021 Diesel fuel injection system 20 Fuel map-for ECU to control amount of fuel to be injected

21. References https:// dieselnet.com/tech/diesel_fi.php https:// www.ezoil.com/resources-diesel-engines-diesel-fuel-system-basics https:// www.gcoeara.ac.in/learning_material/auto/Unit%205-AEE.pdf https:// www.heinzmann.com/en/products/efi-controllers https:// www.youtube.com/watch?v=jWW0BsIQ2mQ https:// www.youtube.com/watch?v=5VLNOFh0a3k 07/09/2021 Diesel fuel injection system 21

22. THANK YOU 07/09/2021 Diesel fuel injection system 22 Submitted by INTAKHAB KHAN & VISWAM PANCHAL