Patent ID: 9702292
Date: 2017-07-11
CPC Classifications: F01N,F28D,F28F,Y02T

Claim:
1. An exhaust heat recovery device performing a heat exchange between exhaust gas discharged from an internal combustion engine and a heat exchange medium, comprising: an inner member forming a part of a main passage that connects a receiving inlet receiving the exhaust gas flowing from an upstream side to a main sending outlet sending the received exhaust gas into a downstream side, and forming an upstream side main passage, which is a part of the receiving inlet side of the main passage; an outer member disposed to surround the inner member and forming a heat exchange passage with the inner member; a heat exchanger disposed on the heat exchange passage to surround the inner member and performing the heat exchange between the exhaust gas and the heat exchange medium; and a switching unit switching between a first mode in which the exhaust gas received with the main passage is passed through only the main passage to flow into the main sending outlet, and a second mode in which the exhaust gas received with the main passage flows from the upstream side main passage through the heat exchange passage into a subsending outlet different from the main sending outlet, wherein: the heat exchange passage includes a first heat exchange passage formed between the heat exchanger and the inner member, and a second heat exchange passage formed between the heat exchanger and the outer member, the inner member and the heat exchanger are disposed such that a heat exchange outflow port through which the exhaust gas flows out from the upstream side main passage into the first heat exchange passage is formed on an end of the first heat exchange passage on the main sending outlet side, and the subsending outlet is formed on an end of the second heat exchange passage on the main sending outlet side, in the second mode, the exhaust gas flows out from the heat exchange outflow port into the heat exchange passage, the exhaust gas having flowed out into the heat exchange passage flows in a radial direction from an inner side to an outer side of the heat exchanger while flowing through the first heat exchange passage toward the upstream side to reach the second heat exchange passage from the first heat exchange passage and flows through the second heat exchange passage toward the downstream side, and the heat exchange is performed in the heat exchanger while the exhaust gas flows, the heat exchanger is formed to have a shape along the inner member and the outer member respectively and includes a plurality of heat exchanger simple components disposed while being laminated with a predetermined interval therebetween, the heat exchanger performs the heat exchange by the flowing of the heat exchange medium inside each of the heat exchanger simple components and the flowing of the exhaust gas on a heat exchange area between the plurality of heat exchanger simple components, and the heat exchanger is disposed with a diffuser configured to diffuse the exhaust gas flowing into the heat exchange area in a circumferential direction of the heat exchange area.