JPH09107687A - Thermoelectronic generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoelectronic generator in which a heat loss is reduced by a method wherein a shielding member is arranged and installed near an emitter electrode in a space which is formed of the emitter electrode, of a collector electrode, of an emitter-side heat choke, of a collector-side heat choke and of a ceramic seal. SOLUTION: A shielding member 10 is bent to the inside in such a way that its cross section is a right-angled shape, the member is formed to be a ring shape, and the whole surface is mirrorworked. Then, a thermal radiation to a collector electrode 3 from an emitter electrode 2 which is heated to a high-temperature, or to an emitter-side heat choke 5 in a high-temperature part from the emitter electrode 2, or to the collector electrode 3 from the emitter-side heat choke 5 in the high-temperature part or to a collector-side heat choke 6 from the emitter-side heat choke 5 in the high-temperature part is stopped by the shielding member 10 which functions as a thermal resistance. In addition, when the surface is mirror-worked, the thermal radiation from the emitter electrode 2 which is heated to the high temperature or from the emitter-side heat choke 5 in the high-temperature part can be reflected. As a result, a heat loss due to the thermal radiation can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectron generator that generates electric power by utilizing thermoelectron emission, and more particularly to an internal structure of the thermoelectron generator.

[0002]

2. Description of the Related Art A cross-sectional structure of a conventional parallel plate type thermionic power generator is shown in FIG. In the figure, a parallel plate type thermionic power generator 20 includes an emitter electrode 21 for emitting thermoelectrons,
A collector electrode 22 arranged to face the emitter electrode 21 via spacers 23, 23 for collecting thermoelectrons emitted by the emitter electrode 21, and one end of the emitter electrode 21 fixedly attached to the collector electrode 22. The emitter-side heat choke 24 is formed in a cylindrical shape in the central axis direction, and the collector-side heat choke 25 is formed in a cylindrical shape in the central axis direction of both electrodes, one end of which is fixed to the end of the collector electrode 22.
And a ceramic seal 26.

As the power generation operating temperature, the emitter electrode 21 is
The temperature is 1200 to 1700 ° C., and the collector electrode 22 is kept at a high temperature of 400 to 700 ° C. In order to reduce heat loss due to heat conduction from the high-temperature emitter electrode 21, a thin-walled cylinder called a heat choke is used as the emitter electrode 21,
It is provided on the collector electrode 22, and the ceramic seal 2 is provided on the low temperature side.
6, the emitter-side heat choke 24 and the collector-side heat choke 25 are vacuum-tightly joined, and both electrodes are electrically insulated.

The thermionic power generator 20 configured as described above
For example, as shown in FIG. 3, the thermoelectron power generation device 30 is configured by radially disposing and fixing a plurality of heat sources around the heat source 31 that heats the emitter electrode.

[0005]

The temperatures of the main constituent elements when the thermionic generator is in operation are, in order from the highest temperature, the emitter electrode, the emitter-side heat choke, the collector-side heat choke, and the collector electrode in that order. The thermoelectric generator has a high applied temperature as described above, and has a large heat loss due to heat radiation from the high temperature side to the low temperature side between the main constituent elements.

In the above-mentioned conventional thermoelectric generator,
Although it was considered to reduce the heat loss due to heat conduction between the above components by using heat chokes for both the emitter and collector electrodes, special consideration is given to the reduction of heat loss due to heat radiation inside the thermionic generator. Was not done.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermionic power generator in which the heat loss due to heat radiation inside the thermionic power generator is reduced.

[0008]

To achieve the above object, a thermoelectron generator of the present invention comprises an emitter electrode which is heated by a heat source and emits thermoelectrons, and an emitter electrode which is arranged so as to face the emitter electrode. A collector electrode that collects the emitted thermoelectrons, an emitter-side heat choke whose one end is fixed to the end of the emitter electrode and is formed in a tubular shape in the direction of the central axis of both electrodes, and the end of the collector electrode. The collector side heat choke, which has one end fixed to the portion and is formed in a tubular shape in the central axis direction of both electrodes, and the emitter side heat choke and the collector side heat choke are joined to electrically connect the emitter electrode and the collector electrode. In a thermionic generator having a ceramic seal that insulates into the above, the emitter electrode, collector electrode, emitter side heat choke, collector side heat choke Characterized by being provided near the emitter electrode of at least the space shielding member for preventing heat radiation to the cold side from the hot side of the space formed by the click and ceramic seal.

With this structure, the shielding member functions as a thermal resistance, and the high temperature portion side to the low temperature portion side between the main constituent elements inside the thermoelectron generator, specifically, from the emitter electrode to the collector electrode. , Or the heat loss due to heat radiation from the emitter electrode to the high temperature emitter side heat choke, or from the emitter side heat choke to the collector electrode, or from the emitter side heat choke to the collector side heat choke.

Further, in the thermionic power generator of the present invention, at least one surface of the shielding member is mirror-finished.

With this configuration, heat radiation from the emitter-side heat choke of the emitter electrode or the high-temperature portion heated to a high temperature to the emitter-side heat choke or the collector electrode or the collector-side heat choke of the emitter electrode or the high-temperature portion is performed. The heat loss can be reflected toward the emitter side heat choke, and the heat loss due to heat radiation from the high temperature side to the low temperature side between the main components of the thermionic generator can be more effectively reduced.

As described above, according to the present invention, the heat loss due to the heat radiation from the high temperature side to the low temperature side between the main constituent elements in the thermoelectron generator is significantly reduced, and the power generation efficiency is improved accordingly. Can be achieved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the essential parts of a thermionic power generator according to the present invention. In FIG. 1, a thermoelectron generator 1 includes an emitter electrode 2 which is heated by a heat source and emits thermoelectrons, and a thermoelectron which is disposed facing the emitter electrode 2 via a spacer 4 and is emitted by the emitter electrode 2. And a collector electrode 3 that operates.

The emitter electrode 2 is provided with an emitter-side heat choke 5 having one end fixed to the end thereof and formed in a tubular shape in the direction of the central axis of both electrodes and the other end formed in a substantially L-shaped cross section. ing.

Further, the collector electrode 3 is provided with a collector-side heat choke 6 having one end fixed to the end thereof and formed in a cylindrical shape in the direction of the central axis of the both electrodes. The other end of the collector-side heat choke 6 is joined to the upper end of the cesium introducing part 8 having the cesium introducing port 8a.

The heat choke 5 on the emitter side and the heat choke 6 on the collector side are vacuum-tightly joined via a supporting member 7 and a ceramic seal 9 joined to the outer peripheral surface of the cesium introducing portion 8, and the collector electrode 3 is joined to the collector electrode 3 by the ceramic seal 9. The emitter electrode 2 is electrically insulated.

Further, in the space 13 formed by the emitter electrode 2, the collector electrode 3, the emitter-side heat choke 5, the collector-side heat choke 6 and the ceramic seal 9, the collector electrode 3 is fixedly mounted near the emitter electrode 2. The shielding member 10 is disposed on the member 11 via the support member 12. The mounting member 11 has a collar portion 11a to which the support member 12 is fixed, is formed in a ring shape, is fitted to the collector electrode 3, and is fixed.

The shielding member 10 is bent inward at a right angle in cross section and formed in a ring shape, and the entire surface thereof is mirror-finished. The shielding member 10 can be manufactured using a metal material such as Ta, Mo, or Ni. It should be noted that even if the mirror surface processing is performed only on the inner surface of the shielding member 10, a sufficient heat radiation shielding effect can be obtained.

Further, the shielding member 10 is provided on the flange portion 11a of the mounting member 11 at several positions in the circumferential direction at predetermined intervals and at the support member 12.
Supported by This is to reduce heat conduction from the shielding member 10 to the mounting member 11 by reducing the contact area between the shielding member 10, the mounting member 11 and the support member 12.

In the above structure, the emitter electrode 2 to the collector electrode 3 or the emitter electrode 2 heated to a high temperature are heated.
From the emitter side heat choke 5 in the high temperature part, or from the emitter side heat choke 5 in the high temperature part to the collector electrode 3,
Alternatively, heat radiation from the heat choke 5 on the emitter side to the heat choke 6 on the collector side in the high temperature portion is blocked by the shielding member 10 functioning as a heat resistance.

Further, from the emitter electrode 2 or the emitter side heat choke 5 heated to a high temperature by mirror-finishing the surface of the shielding member 10 to the emitter side heat choke 5 or the collector electrode 3 or the collector side heat choke 6. Can be reflected toward the emitter electrode 2 or the heat choke 5 on the emitter side of the high temperature part, and the heat loss due to the heat radiation from the high temperature part to the low temperature part inside the thermoelectron generator can be more effectively performed. It can be reduced.

The amount of heat transferred by thermal radiation depends on the surface temperature and thermal emissivity of the objects as well as the positional relationship between the objects. Therefore, the more the shielding member 10 that blocks heat radiation is applied to a high temperature portion, the higher the effect of reducing heat loss due to heat radiation.

Therefore, in the embodiment shown in FIG. 1, the shielding member 10 is arranged in the vicinity of the emitter electrode 2 which is heated to a high temperature. However, from the high temperature side to the low temperature side inside the thermoelectric generator. It is not limited to this embodiment as long as it blocks heat radiation.

In the embodiment of FIG. 1, the emitter electrode temperature 1800
～2000K, of each part as an emitter electrode heating heat flux 50 W / cm ² temperature and thermal emissivity set appropriately perform simple calculations, heat by thermal radiation inside thermionic generator with respect to the emitter heating amount 100 The loss is expected to be about 10 to 15%, but the heat loss can be halved by installing the shielding member 10. Therefore, the power generation efficiency can be improved by the reduction amount of the heat loss.

Further, by reducing the heat loss due to heat radiation from a portion which is not preferable as the thermoelectron generator, the electrode temperatures of the thermoelectron emission portion, that is, the emitter electrode and the collector electrode can be made uniform. Can also improve power generation efficiency.

[0026]

As described above, according to the present invention, the space formed by the emitter electrode, the collector electrode, the emitter side heat choke, the collector side heat choke, and the ceramic seal changes from the high temperature side to the low temperature side. Since the shielding member for blocking the heat radiation of is arranged at least near the emitter electrode in the space, from the high temperature portion side to the low temperature portion side between the main constituent elements inside the thermoelectron generator, specifically, from the emitter electrode. It is possible to significantly reduce heat loss due to heat radiation from the collector electrode or the emitter electrode to the high temperature emitter side heat choke, or from the emitter side heat choke to the collector electrode, or from the emitter side heat choke to the collector side heat choke.

Further, according to the present invention, since at least one surface of the shielding member is mirror-finished, the emitter side heat choke from the emitter electrode or the high temperature side emitter side heat choke to the emitter side heat choke or The heat radiation to the collector electrode or collector side heat choke can be reflected to the emitter electrode or the emitter side heat choke in the high temperature part, and from the high temperature side to the low temperature side between the main components of the thermionic generator. The heat loss due to heat radiation can be reduced more effectively.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a main part of a thermionic power generator according to the present invention.

FIG. 2 is a sectional view showing a structure of a conventional parallel plate type thermionic power generator.

FIG. 3 is a diagram showing an external configuration of a thermionic power generator configured by mounting a plurality of conventional parallel plate thermionic power generators shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermionic generator 2 Emitter electrode 3 Collector electrode 4 Spacer 5 Emitter side heat choke 6 Collector side heat choke 7 Support member 8 Cesium introduction part 8a Cesium introduction port 9 Ceramic seal 10 Shielding member 11 Attachment member 11a Collar part 12 Support member 13 space

Claims (2)

[Claims] 1. An emitter electrode which is heated by a heat source to emit thermoelectrons, a collector electrode which is arranged to face the emitter electrode and collects thermoelectrons emitted by the emitter electrode, and an end portion of the emitter electrode. An emitter-side heat choke having one end fixedly formed in the central axis direction of both electrodes, and one end fixed to the end portion of the collector electrode having a cylindrical shape in the central axis direction of both electrodes. A collector side heat choke, and a ceramic seal that joins the emitter side heat choke and the collector side heat choke to electrically insulate the emitter electrode and the collector electrode. From the high temperature side in the space formed by the emitter side heat choke, collector side heat choke and ceramic seal Thermionic generator, characterized in that disposed in the vicinity emitter electrode of at least the space shielding member for preventing heat radiation to the sensing portion side. 2. The thermoelectric generator according to claim 1, wherein at least one surface of the shielding member is mirror-finished.