4. Working of CRDI System
Common rail is a fuel injection system found in modern diesel engines.
CRDI consists of Common Rail, Fuel Tank, Fuel Filter,High Pressure
Pump,Electronic controller Module,Sensors,Injectors.
Fuel tank where there is fuel stored in tank and low pressure fuel pump
in fuel tank.It pumps 3-5 bar pressure fuel to fuel filter. Fuel filter filters
the fuel and sends to the High Pressure Pump.
Fuel Filter has two sensors
a)Water Fuel Sensors:It detects the fuel in water.
b)Temperature Sensors:It detects the temperature of the fuel.
5. Low pressure fuel is transfered to High Pressure Fuel in High Pressure
Fuel Pump and then transfered to Common Rail
When fuel is transfered to the Common rail there will be a Fuel Pressure
Regulator Valve which regulates the pressure of the fuel.It releases extra
fuel back to the fuel tank.
Common Rail has bar pressure
Common Rail has Two Sensors
Then the fuel go backs to the fuel tank.
BOSCH 1000-1500 BAR
DELPHI 1050-1600 BAR
a)Fuel Pressure Sensor:
It detects the pressure in Common Rail
b)Pressure Limit Valve:
It controls the pressure in Common Rail
6. Four Injectors with same pressure are activated by Electronic Controller
Module(ECM)
ECM recieves the input signals and activates the activators in the engine.
Input signals are:
Crank Sensor:It detects the crank position
CAM Sensor:It detects the cam position
Accelerator Pedal Sensor:It detects the accelerator Position
Boost Temperature:It detects the turbo pressure
Air Temperature:It detects the temperature of the air in the inlet
Coolent Temperature: It detects the cool temperature in the engine
Oil Temperature:It detects the temperature in the Engine oil
Speed Sensor:It detects the speed of the vehicle
7. By taking the input signals ECM sends the input signals to
injectors that how much fuel has to be injected at which time and
how much quantity has to be injected is calculated by the ECM
The diesel pressure is injected into the internal combustion
chamber and then the Engine starts.
8. Advantages of CRDI
It has the ability to increase the power and torque of engine by 25%.
It increases the power and efficiency and reduces the emission
It increase the fuel efficiency and decrease the fuel consumption i.e.
mileage of the engine would be increased.
Reduction of exhaust and noise emissions, better fuel efficiency and
improved overall engine performance.
The main advantage of CRDI is fuel economy
9. Disadvantages of CRDI
Its cost of vehicles with this technology is high.
This technology cannot be implemented in all type of engines.
The cost of maintenance is also high because its spare parts are expensive.
This system is complex than MPFI system and needs good engineering work.
Applications of CRDI
The CRDI technology is feasible with both petrol engine and diesel engine.As
this technology is very useful, so most of the car manufacturer are using this
technology now. And this technology has given a prominent benefits to the
automobile industry.This technology can also be used in engine locomotives
and marines.
