JP2015140713A - Thermoelectric generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a uniform heat transmission amount transmitted to electrothermal element modules installed at an upstream side and a downstream side in a flow passage where exhaust gas flows, improve an entire generating efficiency, and increase a frequency in which gaseous molecules in the exhaust gas are brought into contact with heat collection pins to improve a heat transmission amount.SOLUTION: There are provided: a housing module 7 where exhaust gas 4 discharged out of an engine 2 flows in an internal flow passage 7a; several heat collective pins 8 and 9 spaced apart and installed at the inner surface of the housing module 7; and an electrothermal element module 10 for generating electricity by heat transmitted from the heat collective pins 8 and 9. The heat collective pins 8 and 9 and the electrothermal element module 10 are installed at the surface of the housing module 7 in pairs. An extremity end part 8a of the heat collective pin 8 placed on the upper surface of the housing module 7 and an extremity end 9a of the heat collective pin 9 placed on the lower surface of the housing module 7 are arranged to overlap each other and they are arranged in such a way that an overlapping amount L of the extremity ends 8a and 9a is increased from the upstream side toward the downstream side of the flow passage 7a where the exhaust gas 4 flows.

Description

  The present invention relates to a thermoelectric power generation apparatus that recovers heat of a high-temperature gas such as exhaust gas and generates power.

Exhaust gas discharged from engines such as automobiles is high temperature, and much of the heat energy is discharged without being used. Therefore, in recent years, a thermoelectric generator that uses a thermoelectric element (thermoelectric conversion element) as an exhaust heat recovery unit and converts the exhaust gas thermal energy into electric power and recovers it has been proposed in order to improve the utilization efficiency of exhaust gas thermal energy. Has been. Thermoelectric elements use the Seebeck effect (generally an effect that an electromotive force is generated by joining two different kinds of metals and semiconductors and providing a temperature difference between one surface and the other). It generates electricity.
Such a thermoelectric generator used for heat recovery of exhaust gas is generally disposed in the middle of an exhaust pipe through which high-temperature exhaust gas exhausted from an engine passes, and in the exhaust pipe, there is a thermoelectric element. A heat collecting pin for efficiently guiding the heat of the exhaust gas to the high temperature end surface of the thermoelectric element is provided on one surface, and the other surface of the thermoelectric element is configured to be cooled by air cooling or water cooling. Yes.

By the way, as a type of the thermoelectric power generation apparatus currently known, a heat receiving fin is arranged in an exhaust passage through which exhaust gas flows inside the thermoelectric unit, and a heat receiving fin is arranged inside the exhaust passage through which exhaust gas flows. A thermoelectric unit that is provided so as to be uniformly overlapped from the upstream side to the downstream side of the exhaust flow path, and whose flow area is set uniformly from the upstream side to the downstream side of the exhaust flow path is exemplified ( For example, see Patent Document 1).
Further, heat collecting fins are provided inside the exhaust passage through which the exhaust gas flows, and the number and length of the heat collecting fins are configured to increase from the upstream side to the downstream side of the exhaust passage. An exhaust heat power generation apparatus is mentioned (for example, refer patent document 2).
Further, by using a plurality of fixed fins and movable fins arranged between the fixed fins and configured to be movable with respect to the fixed fins as heat absorption fins for transmitting the heat of the exhaust gas to the thermoelectric element. The cross-sectional area of the exhaust gas flow path formed between the fixed fin and the movable fin can be adjusted, and the cross-sectional area of the endothermic fin disposed on the upstream side of the flow path is A thermoelectric generator configured to be larger than the cross-sectional area of the flow path of the endothermic fin disposed on the downstream side (see, for example, Patent Document 3).

JP 2010-275976 A JP 2001-12240 A JP 2008-42994 A

In such a thermoelectric generator, the figure of merit representing the performance of the thermoelectric element varies depending on the material used for the thermoelectric element, and the figure of merit is a temperature-dependent function and has a peak value (for example, 900 ° C. or higher). Lanthanum-tellurium-based, silicon-germanium-based, lead-tin and tellurium-selenium-based at 400 ° C to 600 ° C, and bismuth-tellurium-based materials at 150 ° C or lower) to improve power generation efficiency It is important to keep the amount of heat transferred to the thermoelectric element optimal. When generating heat using the thermoelectric element with the heat of the exhaust gas, the exhaust gas flowing through the exhaust flow path has a high temperature on the upstream side and a large amount of heat, while the amount of power generation is large. As the gas temperature decreases, the amount of power generation decreases on the downstream side. For this reason, the overall power generation efficiency of the thermoelectric power generation device is deteriorated.
On the other hand, when gas molecules in the exhaust gas come into contact with the heat collection pin, heat is transferred from the exhaust gas to the heat collection pin. Therefore, when the exhaust gas flows through the thermoelectric generator, it is important to frequently bring gas molecules in the exhaust gas into contact with the heat collecting pins.

However, from the above viewpoint, the prior arts of Patent Documents 1 to 3 described above have the following four problems.
In the thermoelectric unit of Patent Document 1, the area of the flow path through which the exhaust gas flows and the amount of overlap of the heat receiving fins are both uniform from upstream to downstream of the flow path. Therefore, the temperature of the exhaust gas decreases on the downstream side, whereas the heat transfer capability of the heat receiving fin is the same from upstream to downstream of the flow path, so the heat transfer amount on the downstream side of the flow path decreases. It will be. Therefore, there is a problem that the power generation amount of the thermoelectric unit decreases as a result, and the power generation efficiency is poor.

  Moreover, in the exhaust heat power generator for automobiles of Patent Document 2, the number and length of the heat collection fins arranged are increased from the upstream to the downstream of the flow path through which the exhaust gas flows. For this reason, the number of heat collecting fins arranged on the upstream side of the flow path is small, the length of the heat collecting fins is also short, the amount of heat transfer on the upstream side of the flow path is small, and the power generation efficiency is not sufficient. As a result, there is a problem that the amount of power generated by the exhaust heat power generation device is reduced.

Furthermore, in the thermoelectric generator of Patent Document 3, two types of heat collecting fins, a fixed fin and a movable fin, are used. For this reason, the structure of the thermoelectric generator is complicated, and the manufacturing cost of one unit is increased.
Moreover, in the thermoelectric generator of Patent Document 3, the heat absorption amount of the fixed fin or the movable fin is increased by increasing the flow velocity of the heat medium flowing near the fixed fin and the movable fin on the downstream side of the flow path through which the exhaust gas flows. The amount of heat transfer on the downstream side of the flow path is increased. In this case, although the amount of heat transfer per unit time has increased, there is no change in the frequency of contact with the fixed and movable fins per gas molecule of the exhaust gas, and heat transfer from the exhaust gas is not sufficient. Has the problem.

  The present invention has been made in view of such a situation, and an object thereof is to make the amount of heat transferred to the thermoelectric element modules arranged on the upstream side and the downstream side of the flow path through which the exhaust gas flows uniform. Accordingly, an object of the present invention is to provide a thermoelectric generator capable of improving the overall power generation efficiency and increasing the frequency with which gas molecules in the exhaust gas come into contact with the heat collecting pins, thereby improving the amount of heat transfer.

  In order to solve the above-described problems of the prior art, the present invention includes a casing module in which exhaust gas discharged from an engine flows through an internal flow path, and a plurality of the casing modules arranged at intervals on the inner surface of the casing module. In the thermoelectric generator provided with the heat collecting pin and the thermoelectric element module as a pair on the surface of the housing module, the heat collecting pin and the thermoelectric element module that generates electricity by the heat transmitted from the heat collecting pin, The tip portion of the heat collecting pin disposed on one surface of the housing module and the tip portion of the heat collecting pin disposed on the other surface of the housing module are disposed so as to overlap, and It arrange | positions so that the amount of overlaps of the front-end | tip part of the said heat collection pin may become large toward the downstream from the upstream of the said flow path through which exhaust gas flows.

  In the present invention, the cross-sectional area of the housing module is formed so as to decrease from the upstream side to the downstream side of the flow path through which the exhaust gas flows.

Further, in the present invention, the housing module is composed of a plurality of unit housings having different cross-sectional areas, and the unit housing has a cross-sectional area from the upstream side to the downstream side of the flow path through which the exhaust gas flows. Are arranged in a stepwise manner, and the heat collecting pins provided in the unit casing located on the most upstream side of the flow path are arranged without overlapping the tip portions.
And in this invention, each of the said unit housing | casing is connected, the said housing | casing module is comprised, and the level | step difference is provided in each connection part of the said unit housing | casing.
Moreover, in the present invention, the heat collecting pins arranged on one surface of the unit housing and the heat collecting pins arranged on the other surface of the unit housing are offset in the width direction of the unit housing. The direction in which the heat collecting pins are arranged is offset so as to be reversed for each of the casing units arranged side by side from upstream to downstream of the flow path through which the exhaust gas flows.

In the present invention, the surface of the heat collecting pin is subjected to porous alumite processing or shot blast processing.
Alternatively, in the present invention, the surface of the heat collecting pin is coated with a catalyst.

  Further, in the present invention, the heat collecting pins are arranged in the same number per unit area on the upstream side and the downstream side of the flow path through which the exhaust gas flows, and have the same length and thickness. Is formed.

  As described above, the thermoelectric generator according to the present invention includes a housing module in which exhaust gas discharged from an engine flows through an internal flow path, and a large number of heat collectors arranged at intervals on the inner surface of the housing module. A thermoelectric element module that generates electricity by heat transmitted from the heat collecting pin, and the heat collecting pin and the thermoelectric element module are provided as a pair on the surface of the casing module, and one of the casing modules The tip portion of the heat collecting pin arranged on the surface of the housing module and the tip portion of the heat collecting pin arranged on the other surface of the housing module are arranged so as to overlap and the exhaust gas flows. Since it is arranged so that the amount of overlap of the tip portion of the heat collecting pin increases from the upstream side to the downstream side of the flow path, the following effects can be obtained.

That is, in the thermoelectric power generator of the present invention, the amount of overlap of the heat collecting pins increases as the exhaust gas flow path goes downstream, so that the heat collecting pins are densely located downstream of the flow path. The exhaust gas can be guided and the heat transfer amount on the downstream side can be increased. Therefore, according to the thermoelectric power generation device of the present invention, it is possible to make the heat transfer amount uniform between the upstream side of the flow path and the downstream side of the flow path where the temperature of the exhaust gas decreases, and the power generation efficiency of the thermoelectric element module Can be improved.
Further, in the thermoelectric generator of the present invention, the heat collecting pins are densely arranged in the downstream flow path, and these heat collecting pins become an obstacle, and the flow of the exhaust gas is disturbed and becomes a turbulent flow. The frequency of contacting the heat collecting pin per gas molecule in the gas can be increased. Therefore, according to the thermoelectric power generation device of the present invention, it is possible to increase the amount of heat transfer to the thermoelectric element module, so that the power generation amount can be increased as compared with the conventional thermoelectric power generation device.

  In the present invention, the cross-sectional area of the housing module is formed so as to decrease from the upstream side to the downstream side of the flow path through which the exhaust gas flows. Exhaust gas can be guided more efficiently to a place where pins are densely packed, and the amount of heat transfer on the downstream side can be further increased. Therefore, according to the thermoelectric power generation device of the present invention, it is possible to further uniform the heat transfer amount on the upstream side of the flow path and on the downstream side of the flow path where the temperature of the exhaust gas decreases. Efficiency can be further improved. Moreover, in the thermoelectric generator of the present invention, the flow of exhaust gas is further disturbed in the downstream flow path arranged so that the heat collecting pins are densely packed, resulting in turbulent flow. The frequency of contact with the heat collecting pin per pin can be further increased. Therefore, according to the thermoelectric power generation device of the present invention, it is possible to further increase the amount of heat transfer to the thermoelectric element module, and therefore it is possible to further increase the power generation amount as compared with the conventional thermoelectric power generation device.

Further, in the present invention, the housing module is composed of a plurality of unit housings having different cross-sectional areas, and the unit housing has a cross-sectional area from the upstream side to the downstream side of the flow path through which the exhaust gas flows. Since the heat collecting pins provided in the unit housing located on the most upstream side of the flow path are arranged without overlapping the tip portion, the exhaust gas It becomes possible to flow a part to the downstream side while maintaining the amount of heat, and the heat transfer amount on the downstream side can be increased. Therefore, according to the thermoelectric power generator of the present invention, the power generation efficiency can be improved by making the amount of heat transfer on the upstream side and the downstream side uniform.
Moreover, in the thermoelectric generator of the present invention, the heat collecting pins can be overlapped in stages, and if the installation surface of the heat collecting pins is inclined, the downstream unit housing that interferes structurally There is no need to bend the heat collecting pins arranged opposite to each other. Therefore, according to the thermoelectric generator of the present invention, it is possible to avoid structural interference without bending the heat collecting pins, and the cost can be reduced.
In addition to that, the unit casing constituting the casing module is smaller as it goes downstream, so vibration transmitted to the muffler assembled at the downstream position of the thermoelectric generator can be reduced, and fastening by vibration Bolts can be prevented from coming off and the muffler can be prevented from falling off.

  In the present invention, each of the unit casings is connected to form the casing module, and a step is provided at each connection portion of the unit casing. When flowing through the connecting portion, the flow collides with the step of the connecting portion and the flow is disturbed, resulting in turbulent flow. Therefore, according to the thermoelectric power generation device of the present invention, the frequency of contact between the exhaust gas and the heat collecting pins is increased, so that the amount of heat transfer can be increased and the amount of power generation can be increased.

  Further, in the present invention, the heat collecting pins arranged on one surface of the unit housing and the heat collecting pins arranged on the other surface of the unit housing are offset in the width direction of the unit housing. The direction in which the heat collecting pins are arranged is offset so as to be reversed for each of the casing units arranged side by side from upstream to downstream of the flow path through which the exhaust gas flows. That is, in the thermoelectric generator of the present invention, the heat collecting pins are not only offset in the flow direction of the unit housing, but also offset in the width direction (for example, the tip portions of the upper and lower heat collecting pins are arranged alternately. In other words, the unit is shifted by about 1 pin in total, and is further arranged so that the direction in which the heat collecting pins are offset is reversed for each unit housing (for example, the upper side of the unit housing at the upstream position) The heat collection pins arranged on the left are offset to the right and the heat collection pins arranged on the lower side are offset to the left. Therefore, the exhaust gas passing between the plurality of heat collecting pins arranged in the upstream unit housing must always be in the adjacent downstream side. Arranged in the unit housing Because it is in contact with a plurality of heat collecting pins, the flow of exhaust gas is disturbed and tends to become turbulent, and it becomes possible to further increase the frequency with which exhaust gas contacts the heat collecting pins. The amount of heat transfer to can be further increased, and the amount of power generation can be further increased.

On the other hand, in the present invention, the surface of the heat collection pin is processed by porous anodizing or shot blasting, and the surface area of the heat collection pin is increased by applying surface treatment to the surface of the heat collection pin. The frequency with which the gas contacts the heat collecting pins is further increased, the amount of heat transfer to the thermoelectric element module is increased, and the amount of power generation can be increased.
In the present invention, since the surface of the heat collecting pin is coated with a catalyst, it is possible to directly transfer reaction heat due to the heat generation effect of the catalyst to the heat collecting pin, and the amount of heat transfer to the thermoelectric element module. The power generation amount can be further increased.

  Further, in the present invention, the heat collecting pins are arranged in the same number per unit area on the upstream side and the downstream side of the flow path through which the exhaust gas flows, and have the same length and thickness. Since it is formed, both the power generation amount and the power generation efficiency on the upstream side of the flow path can be increased, and only one type of heat collecting pin is used, and the structure can be simplified.

It is a conceptual diagram which shows the state by which the thermoelectric generator which concerns on 1st Embodiment of this invention is arrange | positioned at the exhaust system of an engine. 1 is a perspective view showing a thermoelectric generator according to a first embodiment of the present invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is CC sectional view taken on the line in FIG. It is sectional drawing which shows the flow of the exhaust gas in the connection part vicinity of the unit housing | casing which comprises the housing | casing module of the thermoelectric generator which concerns on 1st Embodiment of this invention. It is a conceptual diagram which shows the electric circuit of the thermoelectric power generating apparatus which concerns on 1st Embodiment of this invention. It is a conceptual diagram which shows the state by which the thermoelectric power generating apparatus which concerns on 2nd Embodiment of this invention is arrange | positioned at the exhaust system of an engine. It is a perspective view which shows the thermoelectric power generating apparatus which concerns on 2nd Embodiment of this invention. It is the DD sectional view taken on the line in FIG.

[First Embodiment]
The thermoelectric power generator according to the first embodiment of the present invention will be described in detail below.
1 to 7 show a thermoelectric generator according to a first embodiment of the present invention. 4 and 5, the arrow W direction indicates the width direction of the unit housing, and the arrow X direction and the arrow Y direction indicate the offset direction of the heat collecting pins.

  As shown in FIG. 1, the thermoelectric generator 1 of the present embodiment generates heat from a hot exhaust gas 4 discharged from an engine 2 such as an automobile or a two-wheeled vehicle through an exhaust pipe 3 extending toward the rear of the vehicle. It is an apparatus that generates electricity by collecting and converting into electric power using the thermal energy of the exhaust gas 4. For this reason, the thermoelectric generator 1 is disposed in an intermediate part in the vehicle longitudinal direction of the exhaust pipe 3 through which the exhaust gas 4 passes in the exhaust system of the engine 2 and via flanges 1a, 1b and the like positioned at the upstream and downstream ends. The exhaust gas 4 flows through the inside. An exhaust pipe 3 located between the thermoelectric generator 1 and the engine 2 and upstream of the thermoelectric generator 1 is provided with a catalyst 5, and exhaust located downstream of the thermoelectric generator 1. The pipe 3 is provided with a muffler 6.

  As shown in FIGS. 1 to 3, the thermoelectric generator 1 of this embodiment includes a housing module 7 in which exhaust gas 4 flows through an internal flow path 7 a and a plurality of openings 7 b on upper and lower walls, and the housing. A large number of upper and lower heat collecting pins 8 and 9 that are arranged facing each other with a certain distance above and below the inner surface of the body module 7 and the outer surface of the peripheral portion of the opening 7b of the housing module 7 A thermoelectric element module 10 that generates electricity by heat transmitted from the heat collecting pins 8 and 9. The upper and lower heat collecting pins 8 and 9 and the thermoelectric element module 10 are provided on the inner and outer surfaces of the housing module 7 as a pair. Yes. The base end side of the upper and lower heat collecting pins 8 and 9 has a plate-like body integrally formed with the upper and lower heat collecting pins 8 and 9. The thermoelectric generator 1 of the present embodiment is disposed on the tip 8a of the upper heat collecting pin 8 disposed on the upper surface, which is one surface of the housing module 7, and on the lower surface, which is the other surface of the housing module 7. The front end portions 8a of the upper and lower heat collection pins 8, 9 are arranged so as to overlap with the front end portions 9a of the lower heat collection pins 9 and from the upstream side to the downstream side of the flow path 7a through which the exhaust gas 4 flows. It is arranged so that the overlap amount L in the vertical direction of 9a becomes large.

The housing module 7 of the present embodiment is arranged along the vehicle longitudinal direction, and the cross-sectional area of the housing module 7 decreases from the upstream side to the downstream side of the flow path 7a through which the exhaust gas 4 flows. It is formed as follows. That is, as shown in FIGS. 1 to 3, the housing module 7 is composed of a plurality of (four in the present embodiment) unit housings 11, 12, 13, and 14 having different cross-sectional areas. The casings 11, 12, 13, and 14 are arranged so that the cross-sectional area gradually decreases from the upstream side to the downstream side of the flow path 7a through which the exhaust gas 4 flows.
In the housing module 7 having such a cross-sectional area, the exhaust gas 4 is efficiently guided to a place where the upper and lower heat collecting pins 8 and 9 are densely arranged on the downstream side of the flow path 7a, and the heat transfer on the downstream side. The amount is getting bigger. Therefore, the amount of heat transfer between the upstream side of the flow path 7a of the casing module 7 and the downstream side of the flow path 7a of the casing module 7 where the temperature of the exhaust gas 4 decreases is made uniform, and the power generation efficiency of the thermoelectric element module 10 Can be improved. Further, in the downstream flow path 7a in which many upper and lower heat collecting pins 8 and 9 are arranged, the flow of the exhaust gas 4 is turbulent and becomes turbulent, and the upper and lower heat collecting pins per gas molecule in the exhaust gas 4 The frequency of contact with 8, 9 is increased, the amount of heat transfer to the thermoelectric element module 10 is further increased, and the amount of power generation is increased.

Moreover, the upper and lower heat collecting pins 8 and 9 provided in the unit housing 11 located on the most upstream side of the flow path 7a of the housing module 7 are disposed without overlapping the front end portions 8b and 9b. A space S is formed between the upper and lower sides of 8b and 9b.
As a result, the upper and lower heat collecting pins 8 and 9 are arranged so as to be overlapped in stages, and the structure of the upper and lower heat collecting pins 8 and 9 arranged so as to face the unit housings 13 and 14 on the downstream side. In order to avoid large interference and secure a large overlap, it is not necessary to bend the upper and lower heat collecting pins 8 and 9, and the structure and manufacture of the upper and lower heat collecting pins 8 and 9 are simplified. Moreover, since the housing module 7 becomes smaller toward the downstream side by the unit housings 11, 12, 13, and 14, vibration transmitted to the muffler 6 located on the downstream side of the thermoelectric generator 1 is reduced, and the muffler 6 is prevented from falling off, and the housing module 7 can be easily attached by weight reduction. Furthermore, since a part of the exhaust gas 4 flows downstream through the space S while maintaining the amount of heat, the amount of heat transfer on the downstream side increases, and the amount of heat transfer on the upstream side and the downstream side is made uniform. The power generation efficiency is improved.

Moreover, in the thermoelectric generator 1 of this embodiment, as shown in FIG.4 and FIG.5, all the upper heat collection pins arrange | positioned at the upper surface which is one surface of the unit housing | casing 11, 12, 13, 14. 8 and all the lower heat collecting pins 9 arranged on the lower surface which is the other surface of the unit housings 11, 12, 13, 14 are offset in the width direction W of the unit housings 11, 12, 13, 14. Has been placed. The direction in which the upper and lower heat collecting pins 8 and 9 are offset is every case unit 11, 12, 13, 14 arranged side by side from upstream to downstream of the flow path 7 a of the case module 7 through which the exhaust gas 4 flows. Are arranged so as to be reversed. That is, in the thermoelectric generator 1 of the present invention, the unit housings 11, 12, 13 total about 1 pin so that the tip portions 8 a, 8 b, 9 a, 9 b of the upper and lower heat collecting pins 8, 9 are alternately arranged. , 14 are shifted in the width direction W of the unit housing by shifting in the width direction W, and the upper and lower heat collecting pins 8, 9 for each of the unit housings 11, 12, 13, 14 are also offset. It is arranged so that the offset direction of is reversed. For example, in the unit housing 11 at the upstream side position shown in FIG. 4, the upper heat collecting pin 8 disposed on the upper side is offset in the right direction X, and the lower heat collecting pin 9 disposed on the lower side is offset in the left direction Y. In the unit casing 12 at the adjacent downstream position shown in FIG. 5, the upper heat collecting pin 8 disposed on the upper side is offset in the left direction Y, and the lower heat collecting pin 9 disposed on the lower side is offset in the right direction X. Yes. In the unit housing 13, the upper and lower heat collecting pins 8 and 9 are offset in the same direction as the unit housing 11, and in the unit housing 14, the upper and lower heat collecting pins 8 and 9 are offset in the same direction as the unit housing 12. Has been.
Therefore, the exhaust gas 4 that has passed between the plurality of upper and lower heat collecting pins 8 and 9 arranged in the upstream unit housing (for example, the unit housing 11) is always adjacent to the downstream unit housing (for example, , The upper and lower heat collecting pins 8 and 9 arranged in the unit housing 12) come into contact with each other. As a result, the flow of the exhaust gas 4 in the flow path 7a is disturbed and tends to be turbulent, the frequency with which the exhaust gas 4 contacts the upper and lower heat collecting pins 8 and 9 is increased, and the heat to the thermoelectric element module 10 is increased. The amount of transmission increases and the amount of power generation can be increased.

In addition, the upper and lower heat collecting pins 8 and 9 of the present embodiment are made of a highly heat conductive ceramic material such as AIN or SiC, in addition to a metal material having a good heat conductivity such as aluminum, copper or stainless steel. . Further, the surface of the upper and lower heat collecting pins 8 and 9 is subjected to surface treatment such as porous anodizing or shot blasting, and the surface treatment increases the surface area of the upper and lower heat collecting pins 8 and 9 so that the exhaust gas 4 is generated. The frequency of contact with the upper and lower heat collecting pins 8 and 9 is increased, the amount of heat transfer to the thermoelectric element module 10 is increased, and the power generation amount is increased. Alternatively, the surfaces of the upper and lower heat collecting pins 8 and 9 may be coated with a catalyst. As this catalyst, a known catalyst can be used, and a preferable catalyst includes a platinum-aluminum oxide catalyst. By such surface treatment, an exothermic effect based on the chemical reaction of the catalyst can be used, and the reaction heat is directly transmitted to the upper and lower heat collecting pins 8 and 9, and to the thermoelectric element module 10 as in the above surface treatment. The amount of heat transfer increases, the temperature of the thermoelectric element module 10 rises, and the amount of power generation is increased.
Further, the upper and lower heat collecting pins 8 and 9 are equivalent per unit area of each unit casing 11, 12, 13, 14 on the upstream side and the downstream side of the flow path 7 a of the casing module 7 through which the exhaust gas 4 flows. The number is arranged, and the length and thickness are all the same. As a result, the power generation amount and power generation efficiency of the thermoelectric element module 10 located on the upstream side of the flow path 7a of the housing module 7 are increased, and only one type of the upper and lower heat collecting pins 8 and 9 is required. Is configured to be simple.

Further, as shown in FIGS. 3 and 6, the housing module 7 of the present embodiment is configured by connecting each of the adjacent unit housings 11, 12, 13, and 14. Steps are provided at the connecting portions 15, 16, and 17 of 12, 13, and 14, respectively. By providing such a step in the connection portions 15, 16, 17, when the exhaust gas 4 flows through the connection portions 15, 16, 17 of the unit housings 11, 12, 13, 14, the exhaust gas 4 is As shown by the arrows in FIG. 6, it collides with the steps of the connecting portions 15, 16, and 17 and bounces, collides with the exhaust gas 4 flowing from the upstream side of the flow path 7a, and the flow is disturbed to become turbulent flow. It is configured. For this reason, the frequency of contact between the exhaust gas 4 and the upper and lower heat collecting pins 8 and 9 is increased, the amount of heat transfer to the thermoelectric element module 10 is increased, and the power generation amount of the thermoelectric element module 10 is increased.
In addition, each connection part 15,16,17 arrange | positions a stainless steel plate to the edge part of the adjacent unit housing | casing 11,12,13,14 in the up-down direction, and is the end of these unit housing | casing 11,12,13,14. It is comprised by joining the overlapping part of a part and the upper-lower-end part of a stainless steel plate by welding, and airtightness and heat resistance are ensured.

  On the other hand, the type of the thermoelectric element module 10 used in the thermoelectric power generation apparatus 1 of the present embodiment is not particularly limited, but one composed of two types of semiconductors, p-type and n-type, can be used. is there. Such a thermoelectric element module 10 is configured to generate electric power by converting thermal energy into electric energy based on a temperature difference between a heating surface and a cooling surface of the thermoelectric element. For this reason, upper and lower heat collecting pins 8 and 9 are arranged on the inner side surface of the housing module 7 in order to transfer the heat of the exhaust gas 4 to the heating surface of the thermoelectric element module 10. In order to improve thermal conductivity, high thermal conductive grease is applied and interposed between the thermoelectric element module 10 and the thermoelectric element module 10.

  In addition, the cooling surface of the thermoelectric element module 10 of the present embodiment may be air cooling by contact with the atmosphere, but if it is arranged in a place where the traveling wind does not hit, the heat dissipation is likely to be delayed, so There is a possibility that the power generation efficiency is lowered due to the cooling performance of the element module 10 being lowered and the temperature difference being unable to be secured. Considering such a case, in the thermoelectric generator 1 of the present embodiment, a water-cooled cooling module 18 is used. The cooling module 18 is manufactured using stainless steel or copper, and a water cooling pipe 18a for circulating cooling water is embedded in the module (or the cooling water passage is drawn out). Can be good). Further, the cooling module 18 is fixed to the outer periphery of each of the unit housings 11, 12, 13, 14 with screws in a state where the thermoelectric element module 10 is sandwiched between the upper and lower heat collecting pins 8, 9. ing. As a means for introducing the circulating cooling medium, a pipe branched from the cooling water path of the water-cooled engine, or a cooling water and a circulation path newly installed for the cooling module 18 are used. May be.

The electric energy generated by the thermoelectric element module 10 of the present embodiment is stored in the battery 20 after the voltage is boosted by the DC-DC converter 19 in the electric circuit shown in FIG. For this reason, the thermoelectric element module 10, the DC-DC converter 19, and the battery 20 are electrically connected via a cable or the like. The electricity stored in the battery 20 can be used normally in automobiles, motorcycles and the like.
Further, by electrically connecting a DC12V-AC100V converter 21 to the battery 20, it can also be used as a driving power source for household electrical appliances. That is, the thermal energy of the exhaust gas 4 can be used effectively as an emergency power generation unit during an emergency disaster such as an earthquake or fire, such as an automobile or a motorcycle.

As described above, in the thermoelectric generator 1 according to the first embodiment of the present invention, the casing module 7 in which the exhaust gas 4 discharged from the engine 2 of the automobile or the like through the exhaust pipe 3 flows through the internal flow path 7a, A large number of upper and lower heat collecting pins 8 and 9 that are arranged to face the inner upper and lower surfaces of the housing module 7 and a heat that is transmitted from the upper and lower heat collecting pins 8 and 9 are disposed so as to contact the outer surface of the housing module 7. A thermoelectric element module 10 for generating electricity, and a lower heat collecting member disposed on the tip 8a of the upper heat collecting pin 8 disposed on one upper surface of the housing module 7 and the other lower surface of the housing module 7. The tip 9 of the pin 9 is disposed so as to overlap with the tip 9 a of the upper and lower heat collecting pins 8, 9 a from the upstream side to the downstream side of the flow path 7 a through which the exhaust gas 4 flows. Overlay in the vertical direction The housing module 7 is composed of four unit housings 11, 12, 13, 14 having different cross-sectional areas, and the unit housings 11, 12, 13, 14 are disconnected. Since the area is arranged so as to decrease stepwise from the upstream side to the downstream side of the flow path 7a, the exhaust gas is disposed at a place where the upper and lower heat collecting pins 8 and 9 are densely arranged on the downstream side of the flow path 7a. 4 can be reliably guided, the flow of the exhaust gas 4 is turbulent and becomes a turbulent flow, and the frequency of contact with the upper and lower heat collecting pins 8 and 9 can be increased, and the amount of heat transfer on the downstream side is increased. be able to.
Therefore, according to the thermoelectric generator 1 of the present invention, on the upstream side of the flow path 7 a and the downstream side of the flow path 7 a where the temperature of the exhaust gas 4 decreases while passing through the inside of the housing module 7, the thermoelectric element module. The amount of heat transfer to 10 can be made uniform, and the power generation efficiency of the thermoelectric element module 10 can be improved.

[Second Embodiment]
The thermoelectric generator according to the second embodiment of the present invention will be described in detail below.
8 to 10 show a thermoelectric generator 31 according to a second embodiment of the present invention. The thermoelectric generator 31 of the second embodiment is basically the thermoelectric generator 1 of the first embodiment. It is configured in the same way. The same components as those in the first embodiment will be described using the same symbols and terms as those in the first embodiment. Here, a configuration different from the first embodiment will be described.

As shown in FIG. 8 to FIG. 10, the housing module 37 of the present embodiment is configured by one cylindrical body having an integrally formed square cross section, and is disposed along the vehicle front-rear direction. The cross-sectional area of the housing module 37 is formed so as to gradually decrease from the upstream side to the downstream side of the flow path 37a through which the exhaust gas 4 flows. In the housing module 37 having such a cross-sectional area, the upper and lower heat collecting pins 8 and 9 and the thermoelectric element module 10 are paired and provided at upstream and downstream positions on the inner and outer surfaces of the housing module 7. It has been. Further, the cooling surface of the thermoelectric element module 10 is disposed so as to be in contact with the atmosphere, and is configured to cool the air. A plurality of openings 37b are provided on the upper and lower walls of the housing module 37 at regular intervals.
In other words, in the thermoelectric generator 31 of the present embodiment, a pair of upper and lower heat collecting pins 8 and 9 and the thermoelectric element module 10 are formed on the inner and outer surfaces of an integrally molded casing module 37 having a tapered cross-sectional area. Therefore, the exhaust gas 4 can be efficiently guided to a place where the upper and lower heat collecting pins 8 and 9 are densely arranged on the downstream side of the flow path 37a, and heat is transferred to the thermoelectric element module 10 on the downstream side. The amount can be increased. Therefore, according to the thermoelectric generator 31 of the present embodiment, the amount of heat transfer between the upstream side of the flow path 37a of the housing module 37 and the downstream side of the flow path 37a of the housing module 37 where the temperature of the exhaust gas 4 decreases. The power generation efficiency of the thermoelectric element module 10 can be improved. Further, in the downstream side flow passage 37 a where a large number of the upper and lower heat collecting pins 8 and 9 are arranged, the flow of the exhaust gas 4 is disturbed to become a turbulent flow, and the upper and lower heat collecting pins per gas molecule in the exhaust gas 4. Since the frequency of contact with 8 and 9 is increased, the amount of heat transfer to the thermoelectric element module 10 can be increased, and the power generation amount of the thermoelectric element module 10 can be increased.

While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.
For example, the case module 7 of the first embodiment described above is composed of four unit cases 11, 12, 13, and 14, but the number of unit cases is arbitrarily selected as long as it is two or more. can do. However, if the housing module 7 becomes too long using a large number of unit housings, the temperature of the exhaust gas 4 may decrease.
Further, the shape of the upper and lower heat collecting pins 8 and 9 may be changed to a prism or a star in addition to the cylinder to increase the surface area and increase the contact area with the exhaust gas 4.

DESCRIPTION OF SYMBOLS 1,31 Thermoelectric power generator 2 Engine 3 Exhaust pipe 4 Exhaust gas 5 Catalyst 6 Muffler 7, 37 Housing module 7a, 37a Flow path 8 Upper heat collecting pin 8a, 8b Tip 9 Lower heat collecting pin 9a, 9b Tip 10 Thermoelectric module 11 to 14 Unit housing 15 to 17 Connection 18 Cooling module L Overlap amount S Space

Claims (8)

A casing module in which exhaust gas discharged from the engine flows through an internal flow path, a plurality of heat collecting pins arranged at intervals on the inner surface of the casing module, and a thermoelectric power generated by heat transmitted from the heat collecting pins In the thermoelectric generator provided with the element module, the heat collecting pin and the thermoelectric element module are provided as a pair on the surface of the housing module,
A tip portion of the heat collecting pin disposed on one surface of the housing module and a tip portion of the heat collecting pin disposed on the other surface of the housing module are disposed so as to overlap; and The thermoelectric power generator is arranged such that the amount of overlap of the tip of the heat collecting pin increases from the upstream side to the downstream side of the flow path through which the exhaust gas flows.   The thermoelectric generator according to claim 1, wherein a cross-sectional area of the casing module is formed so as to decrease from an upstream side to a downstream side of the flow path through which the exhaust gas flows.   The housing module is composed of a plurality of unit housings having different cross-sectional areas, and the unit housing gradually decreases in cross-sectional area from the upstream side to the downstream side of the flow path through which the exhaust gas flows. The heat collection pin provided in the unit housing located at the most upstream side of the flow path is disposed without overlapping the tip portion. The thermoelectric generator as described.   The thermoelectric generator according to claim 3, wherein each of the unit casings is connected to form the casing module, and a step is provided at each connection portion of the unit casing.   The heat collecting pins arranged on one surface of the unit housing and the heat collecting pins arranged on the other surface of the unit housing are arranged offset in the width direction of the unit housing, and the heat collecting pins The direction in which the pin is offset is arranged so as to be reversed for each of the casing units arranged side by side from the upstream to the downstream of the flow path through which the exhaust gas flows. The thermoelectric generator according to 3 or 4.   The thermoelectric generator according to any one of claims 1 to 5, wherein the surface of the heat collecting pin is subjected to porous alumite processing or shot blast processing.   The thermoelectric generator according to claim 1, wherein the surface of the heat collecting pin is coated with a catalyst. The heat collecting pins have the same number and the same length and thickness per unit area on the upstream side and the downstream side of the flow path through which the exhaust gas flows. The thermoelectric power generator according to any one of claims 1 to 7,

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