CA1264062A - Carbon fibre filament heater for nuclear rod simulators - Google Patents
Carbon fibre filament heater for nuclear rod simulatorsInfo
- Publication number
- CA1264062A CA1264062A CA000491664A CA491664A CA1264062A CA 1264062 A CA1264062 A CA 1264062A CA 000491664 A CA000491664 A CA 000491664A CA 491664 A CA491664 A CA 491664A CA 1264062 A CA1264062 A CA 1264062A
- Authority
- CA
- Canada
- Prior art keywords
- filament
- carbon fibre
- subassembly
- heater
- bundle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims description 25
- 229910052799 carbon Inorganic materials 0.000 title claims description 25
- 239000000835 fiber Substances 0.000 title claims description 21
- 239000003758 nuclear fuel Substances 0.000 claims abstract description 16
- 238000004519 manufacturing process Methods 0.000 claims abstract description 6
- 238000010438 heat treatment Methods 0.000 claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 8
- 239000008188 pellet Substances 0.000 claims description 8
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 8
- 229910052715 tantalum Inorganic materials 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 6
- 238000005219 brazing Methods 0.000 claims description 5
- 238000012546 transfer Methods 0.000 claims description 5
- FCTBKIHDJGHPPO-UHFFFAOYSA-N uranium dioxide Inorganic materials O=[U]=O FCTBKIHDJGHPPO-UHFFFAOYSA-N 0.000 claims description 5
- 238000002788 crimping Methods 0.000 claims description 4
- 239000011810 insulating material Substances 0.000 claims description 4
- OOAWCECZEHPMBX-UHFFFAOYSA-N oxygen(2-);uranium(4+) Chemical compound [O-2].[O-2].[U+4] OOAWCECZEHPMBX-UHFFFAOYSA-N 0.000 claims description 4
- 238000005485 electric heating Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 claims description 3
- 229910052582 BN Inorganic materials 0.000 claims description 2
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 2
- 238000007747 plating Methods 0.000 claims description 2
- 238000005245 sintering Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 claims 3
- 239000000945 filler Substances 0.000 claims 2
- -1 for example Inorganic materials 0.000 claims 1
- 238000012360 testing method Methods 0.000 abstract description 6
- 230000004907 flux Effects 0.000 description 8
- 239000000446 fuel Substances 0.000 description 7
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 4
- 229910010271 silicon carbide Inorganic materials 0.000 description 4
- 229910001093 Zr alloy Inorganic materials 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 239000002826 coolant Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 229910000990 Ni alloy Inorganic materials 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910001120 nichrome Inorganic materials 0.000 description 1
- 230000009972 noncorrosive effect Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C17/00—Monitoring; Testing ; Maintaining
- G21C17/06—Devices or arrangements for monitoring or testing fuel or fuel elements outside the reactor core, e.g. for burn-up, for contamination
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/40—Heating elements having the shape of rods or tubes
- H05B3/42—Heating elements having the shape of rods or tubes non-flexible
- H05B3/48—Heating elements having the shape of rods or tubes non-flexible heating conductor embedded in insulating material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Monitoring And Testing Of Nuclear Reactors (AREA)
- Resistance Heating (AREA)
Abstract
ABSTRACT
The present invention generally relates to high temperature electric heaters for use as simulators for nuclear fuel rods in testing the performance of nuclear reactor fuel designs, and more particularly to the fabrication of simulators which closely match the physical characteristics and thermal characteristics of an actual nuclear fuel rod or pin, but may also be useful for general purpose ultra high temperature heaters.
The present invention generally relates to high temperature electric heaters for use as simulators for nuclear fuel rods in testing the performance of nuclear reactor fuel designs, and more particularly to the fabrication of simulators which closely match the physical characteristics and thermal characteristics of an actual nuclear fuel rod or pin, but may also be useful for general purpose ultra high temperature heaters.
Description
f~6~6;2 CARBON FIBRE FILAMENT HEATER FOR NUCLEAR ROD SIMULATORS
The present invention generally relates to high temperature electric heaters for use as simulators for nuclear fuel rods in testing the performance of nuclear reactor fuel designs, and more particularly to the fabrication of simulators which closely match the physical characteristics and thermal characteristics of an actual nuclear fuel rod or pin, but may also be useful for general purpose ultra high temperature heaters.
The present invention is directed to an improved high temperature electric heater which is particularly useful as a nuclear fuel rod simulator for use in thermodynamic studies for the advancement of nuclear reactor technology. Nuclear fuel rod simulators of the type described herein use electrical energy to simulate the heating produced in reactors by neutron irradiation of uranium dioxide fuel pellets. Since, at temperatures in excess of 800C, the zirconium alloy fuel sheaths may undergo gross deformations, and a rigid heater element would tend to inhibit these, rigid heaters are not suitable for tests in excess of 800C.
It is known to employ silicon carbide as an electric heating ~0 element because of its desirable characteristic of providing stable heating over relatively long periods of time. Also, silicon carbide is virtually non-corrosive and is able to be operated under elevated temperature conditions, well above the operating limit of most conventional metallic elements. One common form of silicon carbide heating element comprises an elongated rod having a centrally located, sintered portion of silicon carbide, $~J
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The present invention generally relates to high temperature electric heaters for use as simulators for nuclear fuel rods in testing the performance of nuclear reactor fuel designs, and more particularly to the fabrication of simulators which closely match the physical characteristics and thermal characteristics of an actual nuclear fuel rod or pin, but may also be useful for general purpose ultra high temperature heaters.
The present invention is directed to an improved high temperature electric heater which is particularly useful as a nuclear fuel rod simulator for use in thermodynamic studies for the advancement of nuclear reactor technology. Nuclear fuel rod simulators of the type described herein use electrical energy to simulate the heating produced in reactors by neutron irradiation of uranium dioxide fuel pellets. Since, at temperatures in excess of 800C, the zirconium alloy fuel sheaths may undergo gross deformations, and a rigid heater element would tend to inhibit these, rigid heaters are not suitable for tests in excess of 800C.
It is known to employ silicon carbide as an electric heating ~0 element because of its desirable characteristic of providing stable heating over relatively long periods of time. Also, silicon carbide is virtually non-corrosive and is able to be operated under elevated temperature conditions, well above the operating limit of most conventional metallic elements. One common form of silicon carbide heating element comprises an elongated rod having a centrally located, sintered portion of silicon carbide, $~J
. ~,.
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~,,'.' .
,~, :' ,'' ' ' :
., ' : :
~: .
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-2- CW-1096 constituting the hot zone or heating section of the element and metallized opposite portions providing the cold end termination for the element, these cold ends being suitably connected to electrical terminals. Such heater elements are very rigid, brittle and fragile due to their ceramic nature, and quite un-suitable for simulation of nuclear fuel.
While the ispecification concludes with claims particularly pointing out and distinctly claiming the subject matter which I
regard as my invention, it is believed the invention will be better understood from the following description taken in conn-ection with the accompanying drawings in whicho Figure 1 is a prior art electrical heater using a nickel alloy heating element;
Figure 2 is a prior art electrical heater using a tantalum heatlng element;
Figures 3a and 3b show a carbon fibre filament heater of type 2 construction; and Figures 4a and 4b show a carbon fibre filament heater of alternate cons~truction.
Prior art electrical heaters which have been used for simulating the heating effects of nuclear fuel comprise three basic types. The first and most common is the directly or Joule heated fuel simulator, in which the current is passed through the tubular, metallic representation of the fuel sheath. These 2~ heaters tend to fail, under the coolant pressure, due to the re-duction in yield strength as temperature increases, when there is a significant reduction in heat transfer, such reduction being known as the heat transfer crisis. Since most experimental in-vestigations concern the critical heat flux, i.e., the heat flux " ,:
, ' " ~ .
While the ispecification concludes with claims particularly pointing out and distinctly claiming the subject matter which I
regard as my invention, it is believed the invention will be better understood from the following description taken in conn-ection with the accompanying drawings in whicho Figure 1 is a prior art electrical heater using a nickel alloy heating element;
Figure 2 is a prior art electrical heater using a tantalum heatlng element;
Figures 3a and 3b show a carbon fibre filament heater of type 2 construction; and Figures 4a and 4b show a carbon fibre filament heater of alternate cons~truction.
Prior art electrical heaters which have been used for simulating the heating effects of nuclear fuel comprise three basic types. The first and most common is the directly or Joule heated fuel simulator, in which the current is passed through the tubular, metallic representation of the fuel sheath. These 2~ heaters tend to fail, under the coolant pressure, due to the re-duction in yield strength as temperature increases, when there is a significant reduction in heat transfer, such reduction being known as the heat transfer crisis. Since most experimental in-vestigations concern the critical heat flux, i.e., the heat flux " ,:
, ' " ~ .
-3- CW-1096 which causes the heat transfer crisis to occur under a given set of conditions, and such heaters cannot be allowed to oper-ate beyond incipient critical heat flux (CHF), their use is strictly limited to detecting the onset of CHF. To operate in post HF conditions, the nuclear fuel must be more closely sim-ulated, as is the case with the second type.
The second type of prior art heater is a cartridge type assembly in which a cylindrical metal housing is provided to represent the fuel sheath, with a longitudinally and concentric-ally disposed heating element with the heating element beingseparated from the metal housing by a suitable mineral insulator, for example boron ~itride (BN). The mineral must provide both electrical insulation and sufficient thermal conductivity to permit operation of the simulator at a heat flux of 250 watt/
cm . The electrical heating element disposed within the meta]
housing is a helicall~ wound ribbon of nickel alloys such as Nichrome ~ or KanthalTMA-l through which an electrical curr-ent is passed. The cavity within the electric heating element formed by the helical winding is similarly filled with insulat-ing material. Although the filament in these heaters operatesat a much higher temperature than the sheath, neither the fila-ment nor the sheath can fail due to coolant pressure, and high melting point alloys such as KanthalTM which are unsuitable for sheaths because of their lack of ductility, can be used for the filaments. This, together with the greater mass, and hence greater thermal storage capacity of the type 2 heater, allows limited post CHF testing. This method of construction results in a rigid heater, making it unsuitable for high temperature tests.
For higher temperatures, a third type of prior art heater, using helically wound tantalum ribbon or wire filaménts has been used. A tantalum heater, shown in Figure 2 consists of a flexible filament inserted into short tubular sections of insul-ating ceramic, which are in turn inserted into hollow pellets of real uranium dioxide fuel. This subassembly is then clad in zirconium alloy sheaths. Such heaters have operated at average filament temperatures up to 2000C. Above this temperature .
.~
. ::
.~ :
~6~2
The second type of prior art heater is a cartridge type assembly in which a cylindrical metal housing is provided to represent the fuel sheath, with a longitudinally and concentric-ally disposed heating element with the heating element beingseparated from the metal housing by a suitable mineral insulator, for example boron ~itride (BN). The mineral must provide both electrical insulation and sufficient thermal conductivity to permit operation of the simulator at a heat flux of 250 watt/
cm . The electrical heating element disposed within the meta]
housing is a helicall~ wound ribbon of nickel alloys such as Nichrome ~ or KanthalTMA-l through which an electrical curr-ent is passed. The cavity within the electric heating element formed by the helical winding is similarly filled with insulat-ing material. Although the filament in these heaters operatesat a much higher temperature than the sheath, neither the fila-ment nor the sheath can fail due to coolant pressure, and high melting point alloys such as KanthalTM which are unsuitable for sheaths because of their lack of ductility, can be used for the filaments. This, together with the greater mass, and hence greater thermal storage capacity of the type 2 heater, allows limited post CHF testing. This method of construction results in a rigid heater, making it unsuitable for high temperature tests.
For higher temperatures, a third type of prior art heater, using helically wound tantalum ribbon or wire filaménts has been used. A tantalum heater, shown in Figure 2 consists of a flexible filament inserted into short tubular sections of insul-ating ceramic, which are in turn inserted into hollow pellets of real uranium dioxide fuel. This subassembly is then clad in zirconium alloy sheaths. Such heaters have operated at average filament temperatures up to 2000C. Above this temperature .
.~
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.~ :
~6~2
-4- CW-1096 frequent failures tend to occur, possibly due to hot spots which exceed the melting point of 2850C. Tantalum also possesses a large and non-linear temperature coefficient of resistance, making it impossible to maintain any desired axial heat flux variations as temperature is varied.
The above-cited disadvantages indicate the need for an im-proved electric heater capable of such higher temperatures and of eliminating the problems connected with the above devices and providing a specific non-uniform power distribution in order to obtain a more realistic simulation of actual reactor fuel element behaviour.
It is the objective of my invention to provide an electric heater wherein the heater can be utilized to simulate a reactor fuel element for use in safety related experiments and on which thermodynamic tests of simulated nuclear reactor systems may be carried out.
Another object of my invention is to provide an electrical heater in which the heating element has an extxemely high melting point, and can thus provide heat fluxes and temperatures approaching those of nuclear fuel in post CHF and loss of coolant accident conditions. Yet another object of my invention is to provide an electrical heater with a more linear and smaller temperature coefficient than prior art high temperature (1500C) heaters.
Still another object of my invention is to provide an electrical heater which is highly flexible and can be bent easily during operation at high temperature, by applying very small bending moments.
.
The above-cited disadvantages indicate the need for an im-proved electric heater capable of such higher temperatures and of eliminating the problems connected with the above devices and providing a specific non-uniform power distribution in order to obtain a more realistic simulation of actual reactor fuel element behaviour.
It is the objective of my invention to provide an electric heater wherein the heater can be utilized to simulate a reactor fuel element for use in safety related experiments and on which thermodynamic tests of simulated nuclear reactor systems may be carried out.
Another object of my invention is to provide an electrical heater in which the heating element has an extxemely high melting point, and can thus provide heat fluxes and temperatures approaching those of nuclear fuel in post CHF and loss of coolant accident conditions. Yet another object of my invention is to provide an electrical heater with a more linear and smaller temperature coefficient than prior art high temperature (1500C) heaters.
Still another object of my invention is to provide an electrical heater which is highly flexible and can be bent easily during operation at high temperature, by applying very small bending moments.
.
-5- CW-109 SUMMARY OF THE INVENTION
The present invention fulfills all of the foregoing re-quirements of electrical heaters with a minimum of expense and complexity.
Broadly, the invention allows for the simulation of heat-ing produced by nuclear fuel elements for experiments in which high temperature and high heat flux conditions are produced by utilizing a heat-generating element consisting of a carbon fibre yarn filament formed into an elongated bundle of filaments.
The filament bundle is connected at its ends to electrical term-inals (electrodes) thus forming a subassembly, which may be placed in a suitable housing (type ~) or inserted directly into hollow U02 pellets (type 3). The housing or pellets and sub-assembly are insulated from each other by use of a suitable, tubular insulating material (e.g. A12 03 or BN).
Referring now to the drawings, there is illustrated in Figure 3a a typical installation of carbon fibre filament heater comprising carbon yarn filament 1. The ends 2 of carbon yarn filament 1 are connected to electrical end terminals (electrodes) 3, either by swaging or crimping the ends of the carbon yarn filament within metallic (e.g. tantalum) rings 7 or hollow electrodes, to result in a tightly compressed assembly, or by metallizing the end region of the fibres and joining them to the electrode by a metallic bond, e.g. brazing (see Figure 4a).
This subassembly is placed into a housing or can (sheath) 4 and the annular space between the subassembly is filled with high temperature ceramic insulation 5. Figures 3b and 4b provide ilIustrations of ends of the assembly which are encapsulated by end cap 6; ~or straight through heaters, the diagrams showing the right ends of heaters in Figs.3a and 4a would be complemented by , - .
~6~
The present invention fulfills all of the foregoing re-quirements of electrical heaters with a minimum of expense and complexity.
Broadly, the invention allows for the simulation of heat-ing produced by nuclear fuel elements for experiments in which high temperature and high heat flux conditions are produced by utilizing a heat-generating element consisting of a carbon fibre yarn filament formed into an elongated bundle of filaments.
The filament bundle is connected at its ends to electrical term-inals (electrodes) thus forming a subassembly, which may be placed in a suitable housing (type ~) or inserted directly into hollow U02 pellets (type 3). The housing or pellets and sub-assembly are insulated from each other by use of a suitable, tubular insulating material (e.g. A12 03 or BN).
Referring now to the drawings, there is illustrated in Figure 3a a typical installation of carbon fibre filament heater comprising carbon yarn filament 1. The ends 2 of carbon yarn filament 1 are connected to electrical end terminals (electrodes) 3, either by swaging or crimping the ends of the carbon yarn filament within metallic (e.g. tantalum) rings 7 or hollow electrodes, to result in a tightly compressed assembly, or by metallizing the end region of the fibres and joining them to the electrode by a metallic bond, e.g. brazing (see Figure 4a).
This subassembly is placed into a housing or can (sheath) 4 and the annular space between the subassembly is filled with high temperature ceramic insulation 5. Figures 3b and 4b provide ilIustrations of ends of the assembly which are encapsulated by end cap 6; ~or straight through heaters, the diagrams showing the right ends of heaters in Figs.3a and 4a would be complemented by , - .
~6~
6 CW-1096 mirror images of these figures at the left end.
A heater of the third type would be constructed by taking the subassembly of carbon fibre filament and electrodes and replacing with it the tantalum filament/electrode subassembly normally used in type 3 heaters.
As described in the afore-mentioned invention, a heating element 1 consisting of a carbon fibre yard filament forms an e10ngated bundle of desired length and thickness and is terminated at its ends 2 by plating or metallizing with a suitable meta1 such as tantalum which reduces the electrical resistance which thereby reduces the heat flux, at the termination ends. The metallizing also facilitates the connection to the metal terminals which may be attached to the metallized yarn by sintering, shaping and metallurgical bonding (e.g. brazing). ~lternatively the termination may be made by swaging or crimping the ends of the yarn within metallic rings or hollow electrodes. For type 2 heaters, after completing termination of ends 2 to form solid cylinders which are then connected to electrical end terminals 3 by machining or metallurgically bonding (e.g. by high temperature brazing), the formed subassembly is then placed into housing or can (sheath) 4 and the annular space between said subassembly and can 4 is filled with a suitable insulating material 5 such as boron nitride. For better internal heat transfer, the whole assembly is swaged or compacted. One of ends of said assembly may be encapsulated by end cap 6. For type 3 heaters, said subassembly is freely inserted into uranium dioxide or other suitable pellets having axial, concentric, cylindrical holes, each pellet cavity lined with a suitable, insulating refractory tube. The stack of pellets, containing the carbon fibre filament is then inserted into a zirconium alloy fuel sheath, which may be capped at one end.
, ,, .
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A heater of the third type would be constructed by taking the subassembly of carbon fibre filament and electrodes and replacing with it the tantalum filament/electrode subassembly normally used in type 3 heaters.
As described in the afore-mentioned invention, a heating element 1 consisting of a carbon fibre yard filament forms an e10ngated bundle of desired length and thickness and is terminated at its ends 2 by plating or metallizing with a suitable meta1 such as tantalum which reduces the electrical resistance which thereby reduces the heat flux, at the termination ends. The metallizing also facilitates the connection to the metal terminals which may be attached to the metallized yarn by sintering, shaping and metallurgical bonding (e.g. brazing). ~lternatively the termination may be made by swaging or crimping the ends of the yarn within metallic rings or hollow electrodes. For type 2 heaters, after completing termination of ends 2 to form solid cylinders which are then connected to electrical end terminals 3 by machining or metallurgically bonding (e.g. by high temperature brazing), the formed subassembly is then placed into housing or can (sheath) 4 and the annular space between said subassembly and can 4 is filled with a suitable insulating material 5 such as boron nitride. For better internal heat transfer, the whole assembly is swaged or compacted. One of ends of said assembly may be encapsulated by end cap 6. For type 3 heaters, said subassembly is freely inserted into uranium dioxide or other suitable pellets having axial, concentric, cylindrical holes, each pellet cavity lined with a suitable, insulating refractory tube. The stack of pellets, containing the carbon fibre filament is then inserted into a zirconium alloy fuel sheath, which may be capped at one end.
, ,, .
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7 CW-1096 This invention has been described by way of illustration rather than by limitation and it should be apparent that it is equally applicable in fields other than those described. The basic technique described above is suited for other uses where very high temperatures are required and it can be extended to radiant, and other types of heaters, for example.
' ':.
' ':.
Claims (9)
1. A carbon fibre filament heater comprising a heating element consisting of a carbon fibre yarn filament forming an elongated bundle of predetermined length and thickness, said filament bundle connected at its ends to electrical terminals thus forming a subassembly, said subassembly being used directly as a radiant heat source or enclosed in a suitable housing, said subassembly being insulated from said housing by means of a suitable insulating filler materials.
2. A carbon fibre filament heater according to claim 1 wherein the ends of said filament bundle are plated or metallized with a suitable metal and said ends are subsequently sintered or brazed together to form solid cylinders which are bonded to said electrical end terminals.
3. A carbon fibre filament heater as claimed in claim 1 in which the ends are terminated by crimping or swaging within a suitable metal structure.
4. A carbon fibre filament heater according to claim 2 wherein termination of ends of said filament bundle is provided by suitable metal, for example, tantalum.
5. A carbon fibre filament heater according to claim 2 wherein insulating filling material is boron nitride.
6. A method of fabrication of carbon fibre filament heater comprising a heating element consisting of a carbon fibre yarn filament forming an elongated bundle of predetermined length and thickness where said filament bundle is connected by its ends to electrical terminals, a housing enclosing said subassembly and insulated therefrom by a suitable insulating filler material, said method comprising the steps of termination of ends of said carbon fibre yard filament bundle by plating or metallizing, sintering, brazing, crimping or swaging of said terminal regions of said carbon yarn filament to form or connect to solid cylinders, connecting said ends to solid metal terminals, placing said subassembly into housing, filling annular space between said housing and said subassembly with a suitable insulating material and swaging or compacting whole assembly to improve internal heat transfer.
7. A method of fabrication of a carbon fibre filament heater according to claim 6, wherein said terminal regions which forming solid cylinders are machined and metallurgically bonded, (e.g. by high temperature brazing) to solid metal terminal electrodes.
8. A method of fabrication of a carbon fibre filament heater wherein the subassembly of the filament and its electrode terminations according to claim 6 is inserted into hollow, insulated uranium dioxide pellets to be inserted freely into a nuclear fuel sheath.
9. A method of fabrication of a carbon fibre filament heater wherein the subassembly of the filament and its electrode terminations according to claim 6 is used directly as a radiant heat source for very high temperature electric heating, for example in a vacuum oven.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000491664A CA1264062A (en) | 1985-09-26 | 1985-09-26 | Carbon fibre filament heater for nuclear rod simulators |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000491664A CA1264062A (en) | 1985-09-26 | 1985-09-26 | Carbon fibre filament heater for nuclear rod simulators |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1264062A true CA1264062A (en) | 1989-12-27 |
Family
ID=4131476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000491664A Expired CA1264062A (en) | 1985-09-26 | 1985-09-26 | Carbon fibre filament heater for nuclear rod simulators |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1264062A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012156474A1 (en) * | 2011-05-18 | 2012-11-22 | Commissariat à l'énergie atomique et aux énergies alternatives | Electrical heating device for heating a liquid, method for producing same, and use in the electrical simulation of nuclear fuel rods |
-
1985
- 1985-09-26 CA CA000491664A patent/CA1264062A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012156474A1 (en) * | 2011-05-18 | 2012-11-22 | Commissariat à l'énergie atomique et aux énergies alternatives | Electrical heating device for heating a liquid, method for producing same, and use in the electrical simulation of nuclear fuel rods |
| FR2975527A1 (en) * | 2011-05-18 | 2012-11-23 | Commissariat Energie Atomique | DEVICE FOR ELECTRICALLY HEATING A LIQUID, ITS PRODUCTION METHOD AND APPLICATION TO THE ELECTRICAL SIMULATION OF NUCLEAR FUEL PENCILS |
| CN103650060A (en) * | 2011-05-18 | 2014-03-19 | 原子能与替代能源委员会 | Electrical heating device for heating a liquid, method for producing same, and use in the electrical simulation of nuclear fuel rods |
| JP2014517465A (en) * | 2011-05-18 | 2014-07-17 | コミサリア ア レネルジィ アトミーク エ オ ゼネ ルジイ アルテアナティーフ | Apparatus for electrically heating liquid and method for manufacturing the same |
| US9468041B2 (en) | 2011-05-18 | 2016-10-11 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Electrical heating device for heating a liquid, method for producing same, and use in the electrical simulation of nuclear fuel rods |
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