Exhaust gas heat exchanger used in exhaust gas recirculation system, has tube made of two U-shaped plates which are fitted facing each other with level difference is formed on portions of second plate

摘要

The exhaust gas heat exchanger (100) has a tube (101) made of two U-shaped plates which are fitted together facing each other. A level difference is formed on each of the portions of the second plate on which the first plate is fitted, in which the level difference is equal in height to the thickness of the first plate and protrudes inwardly of the tube. The second plate is disposed inside the first plate. An inner fin is disposed within the tube to promote heat exchange between the exhaust gas and coolant.