The principle of EGR is briefly described, and the influence of EGR on the engine is analyzed.

EGR is an exhaust gas recirculation system, that is, a device that guides part of the exhaust gas discharged from the exhaust manifold to the intake to participate in the next combustion. The specific principle can be found easily by referring to relevant materials, so I won't say much here.

The main purpose of EGR is to control the emission of NOX produced by combustion, because the components of exhaust gas generally have large inertia and high specific heat, that is to say, there are more molecules, so increasing the same temperature will absorb more energy than normal gas. When the exhaust gas from EGR is mixed in the intake air, the combustion temperature can be effectively reduced, the combustion intensity can be reduced, the occurrence of severe impact can be reduced, and the generation of NOX can be suppressed. If EGR distributes too little exhaust gas, the expected effect will be relatively small. Too large EGR exhaust volume will also have disadvantages, which will increase CO2 emissions and increase the PPM value of C particles, and even affect the engine power.