18 February 2016

Working Principle of CRDI engine

Working Principle :

CRDi is meant for direct injection of the fuel into the cylinders of a diesel engine via a single, common line, called the common rail and is connected to all the fuel injectors.

As can be seen from above figure fuel from the fuel tank passes through the fuel filter to a low-pressure pump where the pressure is raised to a high. The fuel temperature also monitored by a temperature sensor. then fuel goes to the high-pressure pump. A pressure regulator valve controls the pressure. 

In the modern CRDi system, outlet pressure can be as high as 1800 bar.

High-pressure pump stores a reservoir of fuel at very high pressure and the supply this high pressure to the multiple injectors. 

The fuel injectors are controlled by ECU full meaning is the Electronic Control Unit.

When the fuel injectors are electrically activated, a hydraulic valve is opened and fuel is sprayed into the cylinders at the desired pressure.