Common Rail Direct Injection / Engine (CRDi)

common rail direct injection(CRDi) technology developed for diesel engine fuel injection system. Today all modern diesel engines introduced common rail direct injection(CRDi) technologies so far.

This technology is similar to which petrol engine Bharat stage VI (BS-6) engine called Gasoline Direct Engine.

Both technologies work on similar designs to deliver the pressurized fuel in the engine combustion chamber with the help of their fuel components. All car manufacturers have adopted the same design technologies but given their different names of CRDi engine systems.

Supportive Components

CRDi fuel system support components are fuel tank, fuel filter, fuel pump (low pressure),  pressure regulating valve, high-pressure pump, common rail, pressure relief valve, solenoid-operated fuel injectors, sensors and control unit.

Why the need for CRDi technology?

Diesel is the lower quality member of the petrol family. Diesel particles are larger and heavier than petrol, thus more difficult to pulverise, so imperfect pulverisation of unburned particles emits pollution and low fuel efficiency. To improve pulverisation, fuel should be injected at very high pressure, which cannot be done by the conventional diesel fuel injection pump (FIP) system.

Therefore, CRDi technology was developed.

How does CRDi function?

The function of Common Rail Direct Injection (CRDi) technology it uses to deliver the right amount of fuel to the diesel engine cylinder under high pressure. High pressure of 1500 bar can be produced at a very low engine speed of 1500 rpm.CRDi is controlled by the vehicle  Electronic Control Unit (ECU)  directly.ECU or engine management system that uses various sensors and switches (inputs devices)to send or input information (in the form of electrical signals ) to the Electronic Control Unit (ECU). It then computes an outputs signal that sends to various output device actuators which control the CRDi fuel system for their proper functioning.

This technology coordinate with various sensor uses like, Throttle position sensor, Manifold absolute pressure sensor, Oxygen sensor, Crank position sensor, Fuel temperature sensor, Fuel pressure sensor, Accelerator pedal position sensor. An engine control unit or ECU receives information from those sensors and is programmed to operate fuel systems, signals, circuits, and actuators based on that information.

CRDi technology Benefits

CRDi technology aids in shorting the duration of injection with precise timing and Eliminating the vibration and low noise. Lower emission exhaust control.

Higher power output even lower engine speed revolution per minute (rpm).

Lower fuel consumption and higher mileage, only fewer disadvantages of CRDi engine are that maintenance costs more than conventional fuel injection system. 

Fuel Injection pump Vs CRDi fuel system

The conventional type diesel fuel injection pump system and Common rail direct injection (CRDi) technology work on the same principle only difference is the way diesel fuel is delivered to the engine cylinder by mechanically operated on the fuel injection pump whereas the CRDi fuel system is controlled by the engine management system or ECU, which ensure that fuel can be optimized and high pressure with precise timing.it produced More power and torque than a mechanically operated fuel injection pump (FIP) system.