The exhaust gas recirculation (EGR) system is used to reduce the amount of nitrogen oxide (NOX) emitted from the exhaust gas. Nitrogen and oxygen only in the high temperature and pressure conditions will occur Sensor under the chemical reaction, the engine combustion chamber temperature and pressure to meet the above conditions, during the forced acceleration even more so.

    When the engine is running under load, the EGR valve opens, allowing a small amount of exhaust gas to enter the intake manifold, entering the combustion chamber with the combustible mixture. At idle, the EGR valve is closed and almost no exhaust gas is recycled to the engine. Automotive exhaust gas is a non-combustible gas (excluding fuel and oxidants), in the combustion chamber does not participate Suction Control Valve in combustion. It reduces the combustion temperature and pressure by absorbing part of the heat generated by combustion to reduce the amount of nitrogen oxide produced. The amount of exhaust gas entering the combustion chamber increases as the engine speed and load increase.

    Automotive exhaust gas recirculation system works: EGR system is the main component of CNC EGR valve. The NC EGR valve is mounted on the right exhaust manifold and is used to independently control the amount of exhaust gas recirculated to the engine regardless of the size of the manifold vacuum. The EGR valve controls the amount of exhaust gas flowing back from the exhaust manifold to the intake manifold through three metering wells with increasing aperture to produce a combination of seven different flows. Each metering hole is composed of a solenoid valve and a needle valve. When the solenoid valve is energized, the armature is sucked upward by the magnet to open Fuel Rail Pressure Sensor the metering hole. The characteristics of the rotary needle valve ensure good sealing when the EGR valve is closed.

    The EGR valve is normally opened under the following conditions: 1. The engine is warm and running. 2. Speed ​​exceeds idle speed. The ECM controls the EGR system according to the engine cooling water temperature sensor, the throttle position sensor and the air flow sensor.