What is the automobile EGR system?

EGR (exhaust gas recirculation) is an exhaust gas recirculation system.

Exhaust gas recirculation refers to the technology (technology or method) that the internal combustion engine separates a part of the burned exhaust gas and introduces it to the intake side for re-combustion.

The task of EGR system is to make the exhaust gas recirculation reach the best state at each working point, make the combustion process always in the best state, and finally ensure the lowest pollution components in the emissions.

Extended data

Now we use the low-pressure exhaust gas recirculation system most, and the main component of this system is the numerical control EGR valve. The numerical control EGR valve is installed on the right exhaust manifold, and its function is to control the amount of exhaust gas recirculated to the engine independently and accurately, regardless of the vacuum degree of the manifold.

The EGR valve controls the amount of exhaust gas flowing back from the exhaust manifold to the intake manifold through three metering holes with gradually increasing diameters, thus generating seven different air flow combinations. Each metering hole consists of 1 solenoid valve and needle valve. When the solenoid valve is energized, the armature is attracted upward by the magnet to open the metering hole. The characteristics of rotary needle valve ensure a good seal when EGR valve is closed.

The exhaust gas recirculation valve usually opens under the following conditions:

1, engine warm-up operation. ?

2. The speed exceeds the idle speed.

Baidu encyclopedia -EGR