Engine Operation 14 UENR0623-02 Illustration 10 g02720984 Typical example The NOx Reduction System (NRS) operates with the transfer of the hot exhaust gas from the exhaust manifold to the assembly of the exhaust gas valve. Exhaust gases from the exhaust manifold enter the inlet of the turbocharger in order to turn the turbocharger turbine wheel. The turbine wheel is connected to a shaft that rotates. The exhaust gases pass from the turbocharger through the following components: exhaust outlet, Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) and exhaust pipe. The assembly of the exhaust gas valve consists of an exhaust gas valve and an electronically controlled actuator.
As the electronically controlled actuator (7) starts to open the flow of exhaust gas from the exhaust gas valve mixes with the air flow from the charge air aftercooler. The mixing of the exhaust gas and the air flow from the charge air aftercooler reduces the oxygen content of the gas mixture. This results in a lower combustion temperature, so decreases the production of NOx. As the demand for more exhaust gas increases the electronically controlled actuator opens further. The further opening of the actuator increases the flow of exhaust gas from the exhaust gas valve. As the demand for exhaust gas decreases, the electronically controlled actuator closes.
This decreases the flow of exhaust gas from the exhaust gas valve. The hot exhaust gas is then cooled in the exhaust cooler (6). The cooled gas then travels from the exhaust cooler (6) to the inlet manifold.