The EGR cooler is the core component of the EGR cooling system, which can effectively reduce NOx emissions. At higher car speeds, a small amount of exhaust gas is redirected into the intake valves. Exhaust gas temperature affects NOx emissions. The lower the temperature of the exhaust gas, the better the NOx suppression effect of the engine. Normally, exhaust temperature of the engine is as high as 600-700 degrees Celsius. The EGR cooler can reduce the temperature of the exhaust gas entering the cylinder and reduce the heat load of the engine.