JP2006138296A - Exhaust heat recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust heat recovery device having high reliability while preventing the degradation of thermoelectric conversion efficiency by preventing disorderly deformation of a sealed container storing a thermoelectric conversion element. <P>SOLUTION: The exhaust heat recovery device 1 has an exhaust flow path 11. In the exhaust flow path 11, a fin member 12 is provided for recovering the heat of exhaust gas. On the side of the fin member 12, a thermoelectric conversion module 13 is arranged for converting the heat energy of heat recovered by the fin member 12 into electric energy. The plurality of thermoelectric conversion modules 13 are stored in a case 14. In the case 14, a groove 14C is formed as a thermal expansion absorbing part for preventing disorderly deformation of the case 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust heat recovery device that is used in a vehicle such as a hybrid vehicle and recovers heat energy contained in gas in order to convert heat energy contained in gas into electric energy.

  Exhaust gas discharged from an automobile engine contains thermal energy, so if the exhaust gas is discarded as it is, energy is wasted. Therefore, there is a power generation device for recovering thermal energy contained in exhaust gas by an exhaust heat recovery device, converting it into electrical energy, and charging a battery, for example.

As such a power generation device, there is a conventional exhaust heat power generation device disclosed in JP-A-61-240882. The exhaust thermoelectric generator includes a thermoelectric conversion element, and the thermoelectric conversion element is accommodated in a holding portion and held on the outer periphery of the exhaust gas flow path.
JP 61-254082 A

  However, the thermoelectric conversion element in the exhaust thermoelectric generator disclosed in Patent Document 1 is accommodated in a state of being in close contact with the holding portion. For this reason, in the thermoelectric conversion element, heat is generated when thermoelectric conversion is performed. However, in the exhaust thermoelectric generator disclosed in Patent Document 1, heat generated from the thermoelectric conversion element is transmitted to the holding unit (encapsulated container). There is a risk that this holding part will be deformed. When such deformation occurs in a disorderly manner, there is a problem in that it may lead to a decrease in reliability such as a decrease in thermoelectric conversion efficiency.

  Accordingly, an object of the present invention is to prevent exhaustion of the encapsulated container in which the thermoelectric conversion element is housed in the encapsulated container, thereby preventing a decrease in thermoelectric conversion efficiency and the like, and thereby obtaining high reliability. It is to provide a recovery device.

  The exhaust heat recovery apparatus according to the present invention that has solved the above problems includes a plurality of thermoelectric conversion elements that generate power by thermoelectric conversion using the heat of gas that is released from a heat source and flows through a flow path, and the plurality of thermoelectric conversion elements includes In the exhaust heat recovery apparatus disposed apart from each other outside the gas flow path, the heat recovery device includes a sealed container that houses a plurality of thermoelectric conversion elements, and the sealed container absorbs deformation due to thermal expansion. Is formed.

  In the exhaust heat recovery apparatus according to the present invention, a plurality of thermoelectric conversion elements are accommodated in a sealed container, and the sealed container is formed with a thermal expansion absorbing portion that absorbs deformation due to thermal expansion. By forming this thermal expansion absorption part, it is possible to prevent the enclosing container from being deformed in a disorderly manner. It is possible to prevent a decrease in thermoelectric conversion efficiency and to obtain high reliability.

  Here, the said thermal expansion absorption part can be made into the aspect which is the groove | channel formed in the said enclosure. Thus, a thermal expansion absorption part can be easily formed by forming a groove | channel in an enclosure and making this groove into a thermal expansion absorption part.

  According to the exhaust heat recovery apparatus according to the present invention, by preventing disordered deformation of the encapsulated container in which the thermoelectric conversion element is accommodated in the encapsulated container, it is possible to prevent a decrease in thermoelectric conversion efficiency and thereby obtain high reliability. Can do.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each embodiment, portions having the same function are denoted by the same reference numerals, and redundant description may be omitted. FIG. 1 is a plan sectional view of an exhaust heat recovery apparatus according to an embodiment of the present invention, and FIG. 2 is a side section thereof.

  As shown in FIGS. 1 and 2, the exhaust heat recovery apparatus 1 has four exhaust passages 11 formed therein. The four exhaust passages 11 are connected to an engine (not shown) that is a heat source of the present invention, and exhaust gas discharged from the engine flows and is discharged in the direction of a catalyst (not shown). The exhaust gas flows in the direction indicated by the arrow F in the exhaust passage 11. The engine is arranged on the upstream side in the direction indicated by the arrow F, and the catalyst is arranged on the downstream side.

  Each exhaust passage 11 is provided with a fin member 12 for recovering thermal energy contained in the exhaust gas. The fin member 12 includes a heat transfer section 12A and a fin main body 12B, and a plurality of fin main bodies 12B are attached to the heat transfer section 12A. These heat transfer portions 12A and the plurality of fin main bodies 12B are integrally formed by extrusion molding or the like.

  Moreover, the thermoelectric conversion module 13 which is the thermoelectric conversion element of this invention is arrange | positioned by the side of the heat-transfer part 12A in the fin member 12. FIG. The thermoelectric conversion module 13 is an element that converts thermal energy into electrical energy using a so-called Seebeck effect. The thermoelectric conversion module 13 is accommodated in a case 14 that is an enclosure of the present invention, and the case 14 is in contact with the heat transfer portion 12 </ b> A of the fin member 12. For this reason, heat from the fin member 12 is transmitted to the thermoelectric conversion module 13 via the case 14.

As shown in FIG. 3, the thermoelectric conversion module 13 includes P-type elements 13 </ b> A and N-type elements 13 </ b> B arranged alternately along the exhaust flow path 11. N ₂ gas 13C is filled with the gas 13B. Further, adjacent P-type elements 13A and N-type elements 13B are electrically connected by electrodes 13D alternately on the low temperature side (lower side) or the high temperature side (upper side). Specifically, the P-type element 13A on the most upstream side and the N-type element 13B adjacent on the downstream side thereof are connected by the electrode 13D on the low temperature side, and the N-type element 13B and further on the downstream side thereof. Is connected to the P-type element 13A arranged on the high temperature side by an electrode 13D.

  An insulating sheet 14A is disposed outside the electrode 13D, and a case main body 14B in the case 14 is disposed outside the insulating sheet 14A. Therefore, the thermoelectric conversion module 13 is insulated from the case body 14B.

  As shown in FIG. 1, a plurality of thermoelectric conversion modules 13 in the present embodiment are accommodated in the case main body 14 </ b> B of the case 14. The plurality of thermoelectric conversion modules 13 are arranged apart from each other along the exhaust passage 11 outside the exhaust passage 11. Further, between the portions of the case main body 14B in which the thermoelectric conversion module 13 is accommodated, grooves 14C that are thermal expansion absorbing portions of the present invention are formed on the upper and lower surfaces of the case main body 14B, respectively. As shown in FIG. 3, the groove 14 </ b> C has a bellows shape that is linearly formed along the lateral direction (direction perpendicular to the exhaust flow path 11) in the case main body 14 </ b> B. When the case 14 is expanded by heat, the portion of the groove 14C in the case main body 14B is deformed to absorb the thermal expansion and prevent the case 14 from being randomly deformed.

  Further, a module cooling member 15 is attached to a surface of the case 14 opposite to the surface that contacts the fin member 12, and a cooling water passage 15 </ b> A is formed in the module cooling member 15. In addition, a coolant pipe (not shown) is connected to the coolant channel 15A in the module cooling member 15, and a radiator is connected to the coolant pipe. From this radiator, the coolant is circulated and supplied to the module cooling member 15 via the coolant piping, and the module cooling member 15 provides a temperature difference in the thermoelectric conversion module 13.

  Further, a spring 16 is attached to the surface of the module cooling member 15 opposite to the surface in contact with the fin member 12. The spring 16 is a disc spring and presses the module cooling member 15 against the fin member 12 by urging the module cooling member 15 toward the fin member 12.

  In the exhaust heat recovery apparatus according to the present embodiment having the above-described configuration, the exhaust gas exhausted from the engine flows through the exhaust passage 11. When the exhaust gas flows through the exhaust passage 11, the exhaust gas contacts the fin main body 12B of the fin member 12, and the heat contained in the exhaust gas is transferred from the fin main body 12B to the thermoelectric conversion module 13 via the heat transfer section 12A. Is done. In the thermoelectric conversion module 13, thermoelectric conversion utilizing the Seebeck effect is performed by cooling the opposite side of the surface with which the fin member 12 is in contact with the module cooling member 15. Thus, the heat contained in the exhaust gas is recovered.

  When recovering the heat contained in the exhaust gas, the heat is transferred to the thermoelectric conversion module 13, so that the temperature of the thermoelectric conversion module 13 rises. As the temperature rises, the temperature of the thermoelectric conversion module 13 rises and the temperature of the case 14 also rises. Further, the heat of the exhaust gas is directly transmitted to the case 14 so that the temperature of the case 14 rises. When the temperature of the case 14 rises, the case 14 is deformed. When this deformation occurs randomly, the heat transfer between the fin member 12, the thermoelectric conversion module 13, and the module cooling member 15 is deteriorated, and the thermoelectric conversion efficiency is increased. There is a concern about the decline.

  In this regard, in the exhaust heat recovery apparatus according to the present embodiment, a groove 14 </ b> C is formed in the case 14. By forming the groove 14C, when the case 14 is deformed by the heat transmitted to the case 14, the groove 14C is first deformed. For this reason, the deformation | transformation in the contact part with the fin member 12, the thermoelectric conversion module 13, and the module cooling member 15 in case 14 is prevented. Therefore, since heat can be smoothly transmitted from the fin member 12 to the thermoelectric conversion module 13, the thermoelectric conversion efficiency can be prevented from being lowered.

  In the above-described embodiment, the case 14 is formed by forming the case main body 14B with the groove 14C as the thermal expansion absorbing portion. However, a plurality of thermoelectric conversions are formed in a rectangular case in which the groove 14C is not formed. It can also be set as the exhaust heat recovery apparatus which accommodated the module. In this exhaust heat recovery apparatus, the number of case walls (wall cross section through which heat is transmitted) may be reduced as compared with the case where the thermoelectric conversion modules housed in the case are attached to the plurality of fin members, respectively. it can. Therefore, since heat transmitted to other than the thermoelectric conversion module can be reduced, it is possible to contribute to improvement of thermoelectric conversion efficiency. Moreover, the assembly | attachment property at the time of assembling | attaching a thermoelectric conversion module as an exhaust heat recovery apparatus improves, and can make the assembly | attachment easy.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the groove is provided in the case between the thermoelectric conversion modules. However, the groove may be formed only in a part of the groove. Moreover, in the said embodiment, although the four thermoelectric conversion modules are accommodated in the case, it can also be set as the aspect which accommodates another number of thermoelectric conversion modules.

It is a plane sectional view of the exhaust heat recovery device concerning the present invention. It is a sectional side view of the waste heat recovery apparatus which concerns on this invention. It is an expanded side sectional view of a thermoelectric conversion module. It is a perspective view of the case which accommodates a thermoelectric conversion module.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Waste heat recovery apparatus, 11 ... Exhaust flow path, 12 ... Fin member, 12A ... Heat-transfer part, 12B ... Fin main body, 13 ... Thermoelectric conversion module, 13A ... P-type element, 13B ... N-type element, 14 ... Case , 14A ... insulating sheet, 14B ... case body, 14C ... groove, 15 ... module cooling member, 16 ... spring.

Claims (2)

A plurality of thermoelectric conversion elements that generate electricity by thermoelectric conversion using heat of gas that flows from the heat source and flows through the flow path, and the plurality of thermoelectric conversion elements are arranged apart from each other outside the gas flow path In the exhausted heat recovery device,
An enclosure for housing the plurality of thermoelectric conversion elements;
The exhaust heat recovery apparatus according to claim 1, wherein a thermal expansion absorbing portion that absorbs deformation due to thermal expansion is formed in the sealed container.   The exhaust heat recovery apparatus according to claim 1, wherein the thermal expansion absorption part is a groove formed in the sealed container.

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