EGR (Exhaust Gas Recirculation)
Exhaust Gas Recirculation (EGR) systems effectively reduce NOx emissions by recirculating a portion of the exhaust gas and mixing it with the intake air to lower the burning temperature. A computer automatically controls the EGR amount in accordance with the engine load or speed.
Continuous Control EGR System (for Light Duty Tucks)
Isuzu light duty trucks employ a continuous control system for the EGR valve and a 9-step control for the intake throttle valve. This system contributes to NOx reduction by electronically controlling the EGR volume and the intake air amount through linkage with the EGR valve and intake throttle valve.
One-Way Cooled EGR (for Heavy Duty Trucks)
|In the EGR gas pipe of heavy duty trucks with intercooler turbo-charger, cooling devices are equipped to lower the EGR gas temperature before feeding it back into the engine intake. This "Cooled EGR system" results in an even cooler combustion temperature than when using an ordinary EGR system.
Using a cooled EGR system raises the density of the intake air so the amount of air entering the combustion chamber increases. This helps to make combustion more complete, thereby reducing the generation of PM. Isuzu has also introduced the world's first check valve-equipped EGR system. The check valve prevents new air from entering the EGR gas pipe as well as a back-flow of gas. Also, the check valve increases the EGR recirculation amount by ensuring the gas flows in one direction.
Continuous control EGR used in engine of the ELF N-Series Light Duty Truck