DE1539280C

DE1539280C - Thermionic converter

Info

Publication number: DE1539280C
Authority: DE
Original assignee: Commissariat a lEnergie Atomique CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Publication date: 1971-11-11

Description

1 21 2

Die Erfindung bezieht sich auf einen thermioni- den NachbarkoHektoren verbunden. Zwar ist es bei sehen Wandler, bestehend aus mehreren zylindri- diesem Wandler möglich, seine Länge ohne weiteres sehen, längs einer Achse hintereinander angeordneten zu variieren, indessen sind die Keramringe von Hause und in Reihe geschalteten Dioden, die jeweils aus aus zerbrechlich und werden unter der Einwirkung einem von einer elektrisch leitenden, als Emitter- 5 der nuklearen Strahlung noch zerbrechlicher,
elektrode dienenden Hülle umgebendeji Kernbrenn- Der Erfindung liegt die Aufgabe zugrunde, den stab und einem diesen im Abstand kqfaxial umgeben- zuletzt erwähnten Wandler derart zu ändern, daß er den, als Kollektorelektrode dienenden Bauteil be- mehr Festigkeit und Haltbarkeit erhält,
stehen, bei dem die Kernbrennstäbe im Abstand von- Diese Aufgabe wird erfindungsgemäß dadurch geeinander angeordnet sind, bei dem jeweils die io löst, daß jedes Kollektorbauteil aus zwei koaxial inEmitterelektrode einer Diode mit der Kollektorelek- einanderliegenden Hülsen mit zwischen diesen betrode der benachbarten Diode elektrisch leitend vef- findlicher Schicht aufgebaut ist, daß jede äußere bunden ist und bei dem die als Kollektorelektrode Hülse aus Metall mit hohem elektrischem Widerstand, dienenden Bauteile der einzelnen Dioden miteinander verglichen mit dem Widerstand der inneren Hülse, verbunden und ihre Außenflächen von einem Kühl- 15 besteht und unmittelbar mit den äußeren Hülsen bemedium umspült sind. . nachbarter Dioden verbunden ist, daß jede innereThe invention relates to a thermionic neighboring cohector connected. Although it is possible with see converters, consisting of several cylindrical converters, to vary its length without further ado, arranged one behind the other along an axis, the ceramic rings are made from house and series-connected diodes, each made of fragile and are under the action of one of an electrically conductive 5, even more fragile as an emitter of nuclear radiation,
The invention is based on the object of changing the rod and a transducer that surrounds it at a distance kqfaxially - the last mentioned transducer in such a way that the component serving as the collector electrode is given more strength and durability,
stand, in which the nuclear fuel rods are arranged at a distance from each other, in which the io is achieved in that each collector component consists of two coaxially in-emitter electrode of a diode with the collector electrode mutually lying sleeves with between these electrodes of the adjacent diode electrically conductive A sensitive layer is constructed so that each outer is bonded and in which the components of the individual diodes, which serve as the collector electrode sleeve made of metal with high electrical resistance, are connected to one another compared to the resistance of the inner sleeve, and their outer surfaces consist of a cooling element and immediately washed around with the outer sleeves. . neighboring diodes is connected to that each inner

Durch die deutsche Auslegeschriff 1130 873 ist ein Hülse aus Metall mit niedrigem elektrischem Widerthermionischer Wandler bekanntgeworden, der einen stand, verglichen mit dem Widerstand der äußeren aus einem Stück bestehenden, durch den gesamten Hülse, besteht, Abstände zu den inneren Hülsen der Wandler hindurchgehenden Kernbrennstab aufweisV ao beiden benachbarten Dioden aufweist und mit der auf dem die Emitterelektroden der einzelnen elek- Hülle des Kernbrennstabs einer der beiden benachtrisch in Reihe verbundenen Dioden angeordnet sind. barten Dioden verbunden ist, und daß die Schicht Die Kollektorelektroden der einzelnen Dioden um- zwischen den Hülsen pulverförmig ausgebildet ist geben die Emitterelektroden koaxial und unter Zwi- und aus einem Material hoher thermischer Leitfähig- **. schensdhaltung einer elektrisch isolierenden Schicht 35 keit und hohen elektrischen Widerstandes besteht,
mit einem den äußeren Mantel des Wandlers bilden- Neben der großen Stabilität hat der erfindungsgeden Metallrohr, das von einem Kühlmittel umflossen mäße Wandler gegenüber dem Wandler gemäß Fig. 1 ist, zu einem Bauteil verbunden. Dieser Wandler der Schrift zum französischen Patent 1382968 kann nicht ohne weiteres verlängert oder verkürzt noch den weiteren Vorteil, daß die schwierig herzuwerden. - . 30 stellenden Metall-Keramik-Verbindungen entfallen.The German Auslegeschriff 1130 873 has made known a sleeve made of metal with a low electrical counter-thermionic transducer, which, compared with the resistance of the outer one-piece, consists of the entire sleeve, spaced apart from the inner sleeves of the transducers, has a nuclear fuel rod ao has two adjacent diodes and with which the emitter electrodes of the individual elec- Sheath of the nuclear fuel rod of one of the two adjacent diodes connected in series are arranged. barten diodes is connected, and that the layer of the collector electrodes of the individual diodes is formed in powder form between the sleeves give the emitter electrodes coaxially and with intermediate and made of a material of high thermal conductivity **. Keeping an electrically insulating layer 35 speed and high electrical resistance is made,
with a forming the outer jacket of the transducer. In addition to the great stability, the metal tube according to the invention, which is surrounded by a coolant, is connected to the transducer according to FIG. 1 to form a component. This converter of the document for French patent 1382968 cannot easily be extended or shortened yet has the further advantage that it is difficult to obtain. -. There are no 30 metal-ceramic connections.

Bei einem weiteren thermionischen Wandler Die Metalle oder Metall-Legierungen für die bei-(s. die F ig. 5 der Schrift zum britischen Patent 920198), den Hülsen, nämlich der inneren und der äußeren bei dem einzelne Kernbrennstäbe längs einer Achse Hülse, müssen einerseits die Betriebstemperatur des hintereinander angeordnet sind, die jeweils von einer Wandlers aushalten, die größenordnungsmäßig die Emitterelektrode der einzelnen Dioden bildenden 35 600° C beträgt. Andererseits muß das Metall oder Hülle umgeben sind, sind die Kollektorbauteile in die Metall-Legierung, welche die äußere Hülse bildet, gleicher Weise wie bei dem vorstehend genannten so ausgewählt werden, daß der spezifische WiderWandler ausgebildet. Auch hierbei ist der aus einzel- stand ausreicht, um eine gute Isolation zwischen den nen Bauelementen bestehende Wandler von einem Kollektoren der einzelnen Dioden und damit zwi-Rohr umgeben, das die Längenänderung des Wand- 40 sehen Eingang und Ausgang des Wandlers zu sichern, lers erschwert. In der Praxis ist die Isolierung ausreichend, wenn dieIn another thermionic converter, the metals or metal alloys for the two (s. the fig. 5 of British Patent 920198), the sleeves, namely the inner and outer In the case of the individual nuclear fuel rods along an axis, the operating temperature of the sleeve must be on the one hand are arranged one behind the other, each of which can withstand a converter, the order of magnitude the emitter electrode of the individual diodes forming 35 600 ° C. On the other hand, the metal must or Are surrounded by the shell, the collector components are made of the metal alloy that forms the outer shell, in the same way as the above can be selected so that the specific resistance transducer is formed. Here, too, the individual stand is sufficient to ensure good insulation between the NEN components existing transducers from a collector of the individual diodes and thus zwi-Rohr surround that see the change in length of the wall 40 to secure the input and output of the transducer, difficult. In practice, the insulation is sufficient if the

Ferner ist ein thermionischer Wandler vorge- Stromverluste infolge des Stromdurchgangs in derFurthermore, a thermionic converter is present against current losses due to the passage of current in the

schlagen worden (deutsches Patent 1281 002), der äußeren Hülse in bezug auf den in dem Wandler er-beat (German Patent 1281 002), the outer sleeve with respect to the one in the transducer

ebenfalls mehrere längs einer Acfyse angeordnete zeugten Gesamtstrom nicht größer als 10 bis 15%also several arranged along an Acfyse generated total current no greater than 10 to 15%

Dioden aufweist. Hierbei sind alle Emitter- und 45 sind.Has diodes. Here are all emitter and 45 are.

Kollektorelektroden der einzelnen Dioden zu starren Erfindungsgemäß besteht die äußere Hülse ausCollector electrodes of the individual diodes too rigid. According to the invention, the outer sleeve consists of

Bauteilen verbunden, die jeweils aus einem metalli- einer Legierung auf der Basis von Titan. Dieser Le-Components connected, each made of a metallic alloy based on titanium. This Le-

schem TragrohrI bestehen, auf dessen Innen- bzw. gierung kann ein Hauptzuschlag zugefügt sein, derSchem support tubeI exist, on the inside or yaw of which a main surcharge can be added, the

Außenfläche unter Zwischenschaltung einer isolieren- aus folgenden Metallen besteht: Aluminium, YttriumOuter surface with the interposition of an isolating- consists of the following metals: aluminum, yttrium

den Zwischenschicht die einzelnen Kollektor- bzw. 50 oder Beryllium. Zweckmäßigerweise liegt der Haupt-the intermediate layer is the individual collector or 50 or beryllium. Appropriately, the main

Emitterelektrodefa aufgebracht sind. Diese Bauteile Zuschlag in einer Menge von 2 bis 8% vor. FernerEmitter electrodes are applied. These components surcharge in an amount of 2 to 8% before. Further

werden durch einen Schmiedevorgang hergestellt. wird vorgeschlagen, daß die Legierung noch einenare made through a forging process. it is suggested that the alloy add another

Dieser Wandler; läßt ebenfalls seine Verlängerung zusätzlichen Zuschlag aufweist, der aus folgendenThis converter; also lets its extension have an additional surcharge, the one from the following

oder Verkürzung in einfacher Weise nicht zu. Metallen besteht: Molybdän, Vanadium, Zirkon, wo-or shortening in a simple way not too. Metals: molybdenum, vanadium, zirconium, where-

Durch die Fig. 3 der Schrift zum französischen 55 bei die Konzentration dieses Zuschlags 0 bis 5%By the Fig. 3 of the font to the French 55 with the concentration of this surcharge 0 to 5%

Patent 1 382 96ß ist ein thermionischer Wandler be- betragen kann.Patent 1,382,969 is a thermionic transducer.

kanntgeworden, bei dem ein sich über den gesamten Bei einer bevorzugten Ausführungsform desbecome known, in which one is over the entire In a preferred embodiment of the

Wandler erstreckendes, aus einem Stück bestehendes Kollektorbauteils für einen thermionischen WandlerTransducer extending, one-piece collector component for a thermionic transducer

Rohr vorgesehen ist, das aus dickeren Wandteilen, nach der Erfindung besteht die äußere Hülse ausTube is provided, which consists of thicker wall parts, according to the invention, the outer sleeve

welche die Kollektoren bilden, und aus dünneren 60 einer Legierung von Titan und Aluminium mit 6%which form the collectors, and made of thinner 60 an alloy of titanium and aluminum with 6%

Wandteilen besteht, welche den unerwünschten elek- Aluminium, deren spezifischer Widerstand 162"Mi-Wall parts consists of the undesired elec- Aluminum, the specific resistance of which is 162 "Mi-

trischen Strom von Kollektor zu Kollektor reduzieren. kro-Ohm · Zentimeter bei 20° C und 210 Mikro-Reduce the electrical current from collector to collector. cro-ohm centimeters at 20 ° C and 210 micro-

Auch diesem Wandler haftet der Nachteil an, daß er Ohm · Zentimeter bei der Betriebstemperatur vonThis transducer also suffers from the disadvantage that it is ohm · centimeter at the operating temperature of

nicht bequem verlängert oder verkürzt werden kann. 600° C beträgt. Eine andere Ausführungsform weistcannot be easily extended or shortened. 600 ° C. Another embodiment has

Der thermionische Wandler der eingangs erwähn- 65 eine Legierung aus Titan, 6% Aluminium und 2%The thermionic converter mentioned at the beginning is an alloy of titanium, 6% aluminum and 2%

ten Art ist durch die F i g. 1 der Schrift zum franzö- Vanadium auf, deren spezifischer Widerstand beith type is through the F i g. 1 of the writing on the French vanadium, whose specific resistance is

sischen Patent 1 382 968 bekanntgeworden. Bei die- Raumtemperatur 164 Mikro-Ohm · Zentimeter be-sian patent 1,382,968 became known. At room temperature, 164 micro-ohm centimeters

sem ist jeder Kollektor über Keramringe mit den bei- trägt.Each collector is with the contribution via ceramic rings.

Claims

3 43 4

The inner sleeve is preferably made of niobium. The transducer consists of a certain number

Molybdenum or zirconium. of diodes Dl to Dn connected in series.

Such a composite collector component Each of these diodes, for example the diode D 1. must be manufactured so that the insulating intermediate consists of an emitter 1, which is formed in anrieh known selenium layer both at ambient temperature as 5 way of a uranium oxide rod ία , which also at the intended operating temperature one from an envelope IB . Tungsten or Motyt) residual pressure from the side of the outer sleeve / exposed then is enclosed. In the event that this remains around, in such a way that the component consists of good electrical insulation made of molybdenum, it may have lation properties and good thermal properties with a coating made of tungsten or rhenium. Contact guaranteed. io The emitter 1 itself is the collector elec-

The invention also relates to a method for the herrode-forming sleeve 2 of a cylindrical collector position of the component described above. The new torbauteils 2, 7, 6 surround which conducts the electricity Process is characterized in that it is one and either of molybdenum, of niobium or of Zir forging process or the like, which exists at a Tem- kon. The annulus 3 between the emitter temperature. takes place that is equal to or preferably higher than 15 and the sleeve 2 is from a cesium plasma than that which fills up during the operation of the transducer, which one enters by heating a cesium, such that when the component is cooled, the amount 4 is in a container 5, which is with the outer sleeve maintains a bias. Annular space communicates.

Such processing can be carried out using the coaxially outer

various means and arranged according to the most diverse 20 sleeve 6, and both cylindrical sleeves 2

Carry out method, for example, through one and 6 are through an insulating layer 7 from each other

magnetic forging process, an isostatic insulated. Each of the sleeves 2 is on parts 8, 9 with the

Pressing method or a rolling method; preferably emitter electrode la of the neighboring diode connected

if the procedure consists in a meeting. These connecting pieces 8 * 9 must be possible

forge, which with the help of a reducing or 35 lends great electrical conductivity and a possible

Hammering machine can be carried out. lent to have low thermal conductivity. she

The interconnection of the powdery insulation are on the collector and emitter electrodes

layer made of aluminum or aluminum with attached by brazing.

Yttrium oxide can exist, according to one of the parts 8 on the individual diodes have holes

The following procedure is carried out: 3 ° 8 a, through which the cesium plasma enters the annulus

a) Insertion of beforehand (partially or completely) ge can penetrate within the various diodes, sintered rings in a blank, which the pre- The various cylindrical sleeves 6 of the molded outer sleeve and the preformed diodes are .verinnere at points 10 with one another Sleeve includes. In this case, welds are obtained and form the outer jacket 11 of the the powdery texture due to the 35 converter. It can do this, for example, by breaking electricity carried out in the course of the transversely directed tron bombardment.

Contraction; The transducer has disks 12 at its ends

b) Insertion and compression in longitudinal and 13 on, through which outer clamps 14 and 15 naler direction of a selected refractory airtight pass, one of which is attached to the insulating powder in a holder, the wäh- * ° emitter electrode at one end of the Transducer end of the manufacturing process firmly connects the inner and negative diode and the other on the collector electrode, the outer sleeve; be trode of are those on the other side of the transducer compression can in cold or ^de "D ^lode is connected. The two terminals in the hot state by means of two ring-shaped J ⁴ _u ^un _u ^{d lf>} ^are ™ mechanical contact with ger piston made ; ⁴⁵ discs 12 and 13 through the outer jacket 11

ν. . _. ■,. ,. . _TT ... a current flows, the strength of which appears to be sustainable

c) spraying the previous inner sleeve _(RESIZE ß _e it is UTHORISATION moderate 10 to 15 · /. with a coating of the selected Isohermate- f ^^ _{of Ges} ^B _{amt stream} _de ^S _{n of the converter} supplies), rials. This procedure can be carried out with the help of a _{Def wall} , _{he w {rd} . _{ώ &} _{liquid of the Reaktoi} ! _s plasma torch, a Schoop's spray gun _{5oei, which} provides for the cooling. He is carried out or carried out in another way. The covering ⁶ _enenfalls _b ^ t of an insulating layer covering the beiwird then processed, for example, J _ielsweise bedurch _{from aufgespr} itztem alumina grinding to precisely defined dimensions _61n J ^{6 F}

gen to get the element _ß \ obtained in this way. _{Arrangement of this kind the} heat flows

is covered with a cylindrical Rohimg _w ^ . ^ J _Rich . _{& e} coolant

and subjected to a smearing process. _{kek ab Wegefl des} _{Omck $} ^^ _{insulating material} , f _n

In the majority of cases one must be exposed to a different expansion of the outer and inner sleeves of metal under the annular space between the two tubular sleeves, so that the passage is strictly avoided. For this purpose one can at- cross section for the heat flow high,
for example the outer ends of the two sleeves 60

fixed by a suitable mechanical device
keep.

The drawing shows an exemplary embodiment. 1. Thermionic converter, consisting of

placed. It shows several cylindrical,

1 shows a longitudinal section through a thermionic 65 arranged one above the other and connected in series

see converter according to the invention and diodes, each consisting of one of an electrical

F i g. 2 shows a longitudinal section through a single conductive sheath serving as an emitter electrode

Collector component. surrounded nuclear fuel rod and one of these in

There are components that surround the distance coaxially and serve as the collector electrode, in which the nuclear fuel rods are arranged at a distance from one another, in which the emitter electrode of a diode is electrically conductively connected to the collector electrode of the adjacent diode and in which the components of the individual diodes serving as collector electrodes are connected to one another and their outer surfaces are surrounded by a cooling medium, characterized in that each collector component is made up of two coaxially nested sleeves (2, 6) with a layer (7) between them, that each outer sleeve (6) is made of metal with a high electrical resistance, compared to the resistance of the inner sleeve (2), and is directly connected to the outer sleeves of adjacent diodes (D ₁ , D ₂ ... D _n ) that each inner sleeve (2) is made of metal with low electrical resistance, compared to the resistance of the outer sleeve (6), there are clearances to the inner sleeves of the two adjacent diodes (D ₁ , D ₂ ... D _n ) and with the sleeve (1 b) of the nuclear fuel rod (la) one of the two adjacent diodes (D ₁ , D, ... D _n ) is connected and that the layer (7) between the sleeves (2, 6) is powdery and consists of a material of high thermal conductivity and high electrical resistance.

2. Converter according to claim 1, characterized in that the outer sleeve (6) consists of an alloy based on titanium.
. '

3. Converter according to claim 2, characterized in that the alloy has a main allowance is added, which consists of the following metals: aluminum, yttrium or beryllium.

4. Converter according to claim 3, characterized in that the alloy has an additional one Has surcharge, which consists of the following metals: molybdenum, vanadium, zirconium.

5. Converter according to claim 2, characterized in that the alloy 6 ⁰ Zo aluminum are added.

6. Converter according to claim 5, characterized in that 2% vanadium is added to the alloy are.

7. Converter according to claim 1, characterized in that the inner sleeve (2) made of tungsten or molybdenum.

. 8. A method for producing a collector component according to any one of claims 1 to 7, characterized in that characterized in that it comprises a forging process or the like that takes place at a temperature occurs which is equal to or preferably higher than that which occurs when the converter is operated, such that when the component cools, the outer sleeve maintains a preload.

9. The method according to claim 8, characterized in that a magnetic forging process, an isostatic pressing method or a rolling method is used.

10. The method according to claim 8, characterized in that it is done with the aid of a reducing machine is carried out.

11. The method according to claim 8, characterized in that that the interposition of the powdery insulating layer takes place in that sintered rings can be used in a blank **. that comprising the preformed outer sleeve and the preformed inner sleeve.

12. The method according to claim 8, characterized in that that a sleeve or mounting device is used to introduce the insulating powder, which the position of the outer and inner Sleeve fixed during insertion, and that the powder in cold or warm state with The help of two annular pistons is compressed in the longitudinal direction.

13. The method according to claim 8, characterized in that the interposition of the powdery insulating layer is carried out by first applying a layer to the inner sleeve made of insulating material, which is then mechanically processed and what is obtained in this way Element inserted in a cylindrical blank and subjected to a forging process will.

1 sheet of drawings