What does EGR mean in cars?
1 Answers
EGR stands for Exhaust-Gas-Recycling in English, which means Exhaust Gas Recirculation system in Chinese. The purpose of the EGR system is to reduce the emission of NOX in vehicle exhaust, ultimately decreasing atmospheric pollution. More detailed information is as follows: 1. There are two conditions for the generation of NOX: high temperature and excess oxygen. Since exhaust gas contains a large amount of CO2, which cannot burn but can absorb a significant amount of heat, introducing exhaust gas into the combustion process can lower the combustion temperature of the air-fuel mixture in the cylinder, improving the high-temperature and oxygen-rich conditions, thereby effectively suppressing NOX emissions. 2. Due to the characteristics of NOX generation, the EGR system does not operate continuously. It only works during high-speed and medium-load conditions when NOX generation is likely, controlling the pollution levels of NOX emissions. Moreover, the amount of exhaust gas recirculated varies based on engine speed, load, temperature, and exhaust gas temperature to minimize NOX in the exhaust. During engine idling, low speed, light load, or when the engine is cold, excessive exhaust gas recirculation can affect the ignition and performance of the air-fuel mixture, thus impacting engine power. Therefore, the EGR system does not operate under these conditions. 3. If the EGR system is damaged, it may lead to issues such as increased fuel consumption, unstable engine idling, insufficient power, and incomplete combustion.
