EGRjärjestelmän

EGRjärjestelmän, short for Exhaust Gas Recirculation system, is a component found in internal combustion engines. Its primary function is to reduce the emission of nitrogen oxides (NOx). NOx is a byproduct of high combustion temperatures and pressures within the engine cylinders. The EGR system works by recirculating a portion of the exhaust gas back into the intake manifold. This exhaust gas is relatively inert and has a lower oxygen content than fresh air. When mixed with the incoming air-fuel mixture, it lowers the peak combustion temperature. This reduction in temperature directly leads to a decrease in the formation of NOx emissions.

There are typically two main types of EGR systems: positive-backpressure EGR and negative-backpressure EGR. Positive-backpressure systems use a valve that restricts exhaust flow, forcing some exhaust gas into the intake. Negative-backpressure systems, often found in older designs, rely on a pressure differential to draw exhaust into the intake. Modern EGR systems are often electronically controlled, allowing for precise management of the amount of exhaust gas recirculated based on engine operating conditions such as load, speed, and temperature. This precise control optimizes both emissions reduction and engine performance. Over time, EGR systems can become clogged with carbon deposits, which can lead to reduced efficiency and increased emissions, necessitating cleaning or replacement of components.