JPH062538A - Exhaust gas power generating set - Google Patents

Abstract

PURPOSE:To successively efficiently generate power in each heat electric generating element by a temperature difference between exhaust gas and the atomospheric air by arranging a plurality of heat electric generating elements, having a different operating temperature region, in a different part of an exhaust pipe in accordance with a plurality of temperature regions in the exhaust pipe. CONSTITUTION:In this exhaust gas generating set 29, an exhaust pipe 22 of an engine 21 has a plurality of different temperature regions by gradually decreasing a temperature toward the downstream from the upstream. In the inside of the exhaust pipe 22, a catalyst 20, submuffler 30 and a main muffler 3 are successively arranged. Here are respectively arranged a plurality of heat electric generating elements 23 to 25 having a different operating temperature region in a catalytic upstream part 26, catalytic downstream part 27 and main muffler upstream part 28 of the exhaust pipe 22. Each heat electric generating element 23 to 25 successively generates power by a temperature difference between exhaust gas and the atmospheric air, in each temperature region of the exhaust pipe 22. In this way, each heat electric generating element 23 to 25 efficiently generates power in an optimum condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas power generation device.

[0002]

2. Description of the Related Art As a prior art relating to the present invention, there is an "automobile generator" disclosed in, for example, Japanese Utility Model Laid-Open No. 62-200111. This conventional technique will be described with reference to the drawings. A plurality of thermoelectric generators 74 are arranged on an exhaust pipe 72 and a radiator 73 of an automobile engine 71. Here, due to the temperature difference between the high temperature exhaust gas flowing through the exhaust pipe 72 and the atmosphere and the temperature difference between the high temperature cooling water flowing through the radiator 73 and the atmosphere, the thermoelectric generator element 74 generates power and the battery 75
To charge.

However, the thermoelectric generator 74 has an optimum operating temperature range depending on the material, and the exhaust pipe 72 and the radiator 7 are provided.
The same thermoelectric generator element 7 under different temperature regions like 3
If 4, the power generation failure of the thermoelectric generator 74 may occur.

[0004]

Therefore, according to the present invention,
When using a thermoelectric generator under different temperature regions, the technical problem is to prevent the generation of power generation failure.

[0005]

[Constitution of the invention]

[0006]

The technical means of the present invention taken to solve the above-mentioned technical problem of the present invention is to provide a plurality of thermoelectric generators having different operating temperature ranges with a temperature range of an exhaust pipe. It is arranged at different places on the exhaust pipe according to the above.

[0007]

According to the above-mentioned technical means of the present invention, a plurality of thermoelectric generators having different operating temperature regions are provided with high heat of exhaust gas at different places on the exhaust pipe depending on the temperature region of the exhaust pipe. Power is generated according to the temperature difference from the atmosphere.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the technical means of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a thermoelectric generator 11 is constructed by connecting a P-type semiconductor 12 and an N-type semiconductor 13 in series using electrodes 15 formed on two substrates 14 (generally a plurality of sets). ing. Here, the substrate 14 on the upper side in the figure acts as the heat dissipation surface 16, and the substrate 14 on the lower side in the figure acts as the heat collecting surface 17. Then, by giving an arbitrary temperature difference between the heat radiating surface 16 and the heat collecting surface 17, a potential difference is generated between the output lines 18 and 19 connected to both ends of the electrode 15. Further, the P-type semiconductor 12 and the N-type semiconductor 13 are formed of a semiconductor of an appropriate material, the substrate 14 is formed of ceramics mixed with alumina or the like, and the electrode 15 is excellent in thermal conductivity and electrical conductivity of copper or the like. Formed from the material. However,
The materials of the P-type semiconductor 12 and the N-type semiconductor 13 are appropriately selected according to the temperature range used.

In the exhaust gas power generation system 20 shown in FIG. 2, the exhaust pipe 22 of the engine 21 has a temperature range as shown in FIG. 3 (in FIG. 3, the "vehicle speed" on the horizontal axis is when the engine 21 is used in an automobile. The temperature of the exhaust pipe 22 is higher in the upstream side of the exhaust pipe 22 as a matter of course.
The temperature of the exhaust pipe 22 becomes lower as it goes downstream. In the exhaust pipe 22, a catalyst 29 and a sub muffler 30 are provided.
And a main muffler 31 is provided. Therefore, the thermoelectric generators 23, 24, 25 are arranged so as to cover the exhaust pipe 22 at the catalyst 29 upstream portion 26, the catalyst 29 downstream portion 27, and the main muffler 31 upstream portion 28 of the exhaust pipe 22, respectively.

Here, the material of the semiconductor of the thermoelectric generator 23 is FeSi type or SiGe type, and its operating temperature range is 600 ° C. to 900 ° C. In addition, the material of the semiconductor of the thermoelectric generator 24 is PbTe system, and its operating temperature range is 300 ° C to 700 ° C.

Finally, the material of the semiconductor of the thermoelectric generator 25 is BiTe system, and its operating temperature range is 100 ° C to 40 ° C.
It is 0 ° C.

In the exhaust gas power generator 20 having the above-described structure, the hot exhaust gas flows through the exhaust pipe 22 as the engine 21 is operated. In the upstream part 26 of the catalyst 29,
The very high temperature exhaust gas acts on the heat collecting surface 17 of the thermoelectric generator 23, and a very large temperature difference is generated between the atmosphere and the heat radiating surface 16 facing the thermoelectric generator 23.
A potential difference occurs between the nine.

After that, when the exhaust gas flows through the catalyst 29, it radiates heat to the catalyst 29 and the temperature thereof drops. Therefore, catalyst 2
The temperature region of the downstream portion 27 of the catalyst 9 is lower than the temperature region of the upstream portion 26 of the catalyst 29. Then, the high-temperature exhaust gas is used as the thermoelectric generator element 2.
4 acts on the heat collecting surface 17 and a large temperature difference occurs between the atmosphere and the heat radiating surface 16 facing the atmosphere, and a potential difference occurs between the output lines 18 and 19 of the thermoelectric generator 24.

After that, the exhaust gas radiates heat to the sub-muffler 30 when flowing through the sub-muffler 30, and the temperature thereof further decreases. Therefore, the temperature region of the upstream portion 28 of the main muffler 31 is lower than the temperature region of the downstream portion 27 of the catalyst 29. Then, the high-temperature exhaust gas acts on the heat collecting surface 17 of the thermoelectric generator 25,
A temperature difference occurs between the atmosphere and the heat radiating surface 16 facing the atmosphere, and a potential difference occurs between the output lines 18 and 19 of the thermoelectric generator 25.

In this embodiment, the thermoelectric generators 23, 2
4, 25 are respectively the catalyst 29 upstream portion 2 of the exhaust pipe 22.
6, the catalyst 29 is arranged in the downstream part 27 and the main muffler 31 in the upstream part 28, but each thermoelectric generator 23, 24, 25
It goes without saying that the exhaust pipe 22 may be arranged at any part as long as it fits in the above-mentioned operating temperature range.

[0017]

As described above, in the exhaust gas power generator of the present invention, a plurality of thermoelectric generators having different operating temperature regions are arranged at different locations on the exhaust pipe according to the temperature region of the exhaust pipe. Therefore, each thermoelectric generator can efficiently generate electric power under the optimum conditions.

[Brief description of drawings]

FIG. 1 shows a configuration diagram of a thermoelectric generator.

FIG. 2 shows a configuration diagram of an exhaust gas power generation device according to an embodiment of the present invention.

FIG. 3 is a characteristic diagram of the temperature range of the exhaust pipe in FIG.

FIG. 4 shows a block diagram of a conventional vehicle generator.

[Explanation of symbols]

 20 exhaust gas power generator, 22 exhaust pipe, 23, 24, 25 thermoelectric generator,

Claims (1)

[Claims] 1. An exhaust gas power generation apparatus, wherein a plurality of thermoelectric generators having different operating temperature regions are arranged at different locations on the exhaust pipe according to the temperature region of the exhaust pipe.