| 摘要 |
[PROBLEMS]A structure for recovering heat from engine exhaust gas has increased waste heat recovery efficiency. To achieve this, no member is placed between exhaust gas and a separation wall of an engine coolant passage. This makes the exhaust gas directly collide with the separation wall of the engine coolant passage to increase the speed of gas flow in a heat exchange section.[MEANS FOR SOLVING PROBLEMS]An engine exhaust heat recovery device (1) for recovering heat from engine exhaust gas by performing heat exchange between the engine exhaust gas and engine coolant. An outer tube (22) of an exhaust gas inflow tube (2) is provided with nozzle holes (20) directed toward an inner tube (31) of a coolant passage (3), and the exhaust gas is made to directly collide with the inner tube (31) of the coolant passage (3). The minimum distance from each nozzle hole (20) to the inner tube (31) of the coolant passage (3) is within the range of 1.5 to 7 times the diameter of the nozzle hole. The sum of the opening areas of the nozzle holes (20) and the flow rate of exhaust gas satisfy the following relation: (the sum of the areas of the nozzle holes/exhaust gas mass flow rate) is in the range from 2.0 to 4.5 cm/(kg/min). |
