| 摘要 |
<p>An evaporator (23) disposed between an exhaust manifold (22) and an exhaust pipe (24), comprising, in order, a first exhaust gas passage (56) having a third stage heat exchanger (H3) extending from an upstream side to a downstream side, a second exhaust gas passage (55) having a second stage heat exchanger (H2), and a third exhaust gas passage (50) having a first stage heat exchanger (H1), wherein a spiral passage partitioned by spiral heat transfer plates (68) is formed in the annular second exhaust gas passage (55) for the second stage heat exchanger (H2), and a plurality of waveform heat transfer pipes (67) overlapped with each other at shifted phases are spirally disposed in the spiral passage so as to be positioned along the heat transfer plate (68), whereby a heat exchange efficiency can be increased by increasing the length of the exhaust gas passage by the heat transfer plate (68) and bringing the flow of exhaust gas into a turbulent flow by the heat transfer pipes (67) to increase the chance of contact of the exhaust gas with the heat transfer plate (68) and the heat transfer pipes (67).</p> |
