Engine exhaust gas contains some hazardous pollutants, mainly nitrogen oxide (NOX), carbonic oxide (CO) and particles.
The engine emission after-treatment system consists of an exhaust gas recirculation system (EGR) (EGR valve + EGR cooler), diesel particulate filter (DPF) (DOC+POC) and selective catalytic reduction system (SCR).
The EGR system is one of the primary systems used in gasoline and diesel engines for cleaning exhaust gas before it is released into the air in order to meet EU emission standards (Euro 4, Euro 5 and Euro 6). It is most often comprised of the EGR cooler and EGR valve. The EGR cooler, located in the pipeline which is set between the intake and exhaust manifolds, cools the exhaust gas coming from the combustion chamber. The EGR valve mounted in this pipeline is used to control the amount of exhaust gas introduced back into the combustion chamber. Due to the inertness of the re-circulating exhaust gas, it will slow the combustion process, lower the combustion peak temperature and reduce the engine heat and pressure, leading to a decrease of more than 60% of NOX emission to comply with the emission standards.
EGR coolers are an essential element of the EGR systems, reducing the exhaust gas temperature coming from the combustion chamber of the engine from 800 ℃ to 200 ℃ and thus protecting the EGR valves and engine components from high temperature.
EGR coolers are available in 3 different structures: shell-and-tube, tube-and-fin, and stacked tube.
EGR coolers are directly connected to the exhaust manifold and mounted on the engine, which requires the EGR coolers to have good resistance against high-temperatures, corrosion and clogging, as well as to feature compact structures, excellent thermal performances and low pressure losses. EGR coolers are usually made with anti-corrosion 304/316 stainless steel and are subject to the strict nickel-based high-temperature vacuum brazing.
As the exhaust gas flows through the EGR coolers, carbon can build up inside the EGR coolers over time and this may resist the gas flow. This will cause the EGR coolers to overheat, affect the performance of EGR systems and finally lead to failures to meet emission standards. Because of this, it is necessary to regularly maintain and replace the EGR coolers.
Since its foundation in 1999, CAIEC SHANGHAI, as a cooler unit manufacturer, has been serving the automotive market, providing engine cooling products including EGR coolers, radiators, intercoolers and some other parts that cool down your engines. What ultimately matters is to satisfy customer needs of engine cooling and this focus allows the company to constantly improve its components of automotive cooling system. CAIEC SHANGHAI is committed to deliver excellent customer service to you.