| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat exchanger that does not boil up and evaporate cooling water of an engine, even when exhaust heat of the engine is recovered in the cooling water.SOLUTION: A heat exchanger (21) includes an exhaust gas passage (3) for passing exhaust gas of the engine, and a first medium passage (11) for passing a first medium always used in a liquid phase, and performs heat exchange between the exhaust gas and the first medium. In the heat exchanger, a second medium passage (25) for passing a second medium is sandwiched between the exhaust gas passage (3) and the first medium passage (11) which are adjacent to each other, when heat exchange of the exhaust gas and the first medium is activated, the interior of the second medium passage (25) sandwiched between the exhaust gas passage (3) and the first medium passage (11) is filled with the second medium of the liquid phase, and when the heat exchange of the exhaust gas and the first medium is suppressed, the interior of the second medium passage (25) pinched between the exhaust gas passage (3) and the first medium passage (11) is filled with gas. |
