Multi-core high-temperature, irradiation-resistant thermocouple, and related methods

Patent metadata

Field	Value
Publication number	US-2021404884-A1
Application number	US-202016946657-A
Country	US
Kind code	A1
Filing date	Jun 30, 2020
Priority date	Jun 30, 2020
Publication date	Dec 30, 2021
Grant date	—

Abstract

A multi-core thermocouple includes a plurality of wires, an insulation core surrounding the plurality of wires, a sheath surrounding the insulation core, and a plurality of electrical junctions. The plurality of electrical junctions may include a first electrical junction formed between a first wire of the plurality of wires and the sheath at a first axial mid-section of the multi-core thermocouple, the first electrical junction including a first swaged axial mid-section of the sheath and a second electrical junction formed between a second wire of the plurality of wires and the sheath at a second, different axial mid-section of the multi-core thermocouple, the second electrical junction including a second swaged axial mid-section of the sheath.

First claim

What is claimed is:

1 . A multi-core thermocouple, comprising:
a plurality of wires; an insulation core surrounding the plurality of wires; a sheath surrounding the insulation core; and a plurality of electrical junctions comprising:
a first electrical junction formed between a first wire of the plurality of wires and the sheath at a first axial mid-section of the multi-core thermocouple, the first electrical junction comprising a first swaged axial mid-section of the sheath; and
a second electrical junction formed between a second wire of the plurality of wires and the sheath at a second, different axial mid-section of the multi-core thermocouple, the second electrical junction comprising a second swaged axial mid-section of the sheath.

2 . The multi-core thermocouple of claim 1 , wherein the plurality of electrical junctions further comprises a third electrical junction formed between a third wire of the plurality of wires and the sheath and at one longitudinal end of the multi-core thermocouple, the third electrical junction comprising a swaged end with an outer diameter of the sheath reducing in diameter along a longitudinal length of the multi-core thermocouple until the sheath contacts the third wire within the insulation core.

3 . The multi-core thermocouple of claim 1 , wherein at least one wire of plurality of wires comprises one of molybdenum (Mo) or niobium (Nb), and wherein the sheath comprises the other of molybdenum (Mo) or niobium (Nb).

4 . The multi-core thermocouple of claim 1 , wherein at least one wire of plurality of wires comprises a platinum-rhodium alloy, and wherein at least a portion of the sheath comprises platinum.

5 . The multi-core thermocouple of claim 1 , wherein the plurality of wires of the multi-core thermocouple comprises at least twenty-one wires.

6 . The multi-core thermocouple of claim 1 , wherein each wire of the plurality of wires and the sheath are doped with a dopant reducing a brittleness of the wire and the sheath.

7 . A multi-core thermocouple, comprising:
a first wire comprising a first material; a second wire comprising the first material; an insulation core surrounding both the first wire and the second wire; a sheath surrounding the insulation core, the sheath comprising at least a second material; a first electrical junction formed between the first wire and the sheath at a first axial position along a longitudinal axis of the sheath; and a second electrical junction formed between the second wire and the sheath at a second, different axial position along the longitudinal axis of the sheath, wherein the first material comprises one of molybdenum (Mo) or niobium (Nb) and the second material comprises the other of molybdenum (Mo) or niobium (Nb).

8 . The multi-core thermocouple of claim 7 , wherein the first and second wires comprise molybdenum (Mo) and the sheath comprises niobium (Nb).

9 . The multi-core thermocouple of claim 7 , wherein the first electrical junction comprises a swaged longitudinal end of the multi-core thermocouple with an outer diameter of the sheath reducing in diameter along the longitudinal axis of the multi-core thermocouple until the sheath contacts the first wire within the insulation core.

10 . The multi-core thermocouple of claim 7 , wherein the second electrical junction comprises a swaged axial mid-section of the sheath.

11 . The multi-core thermocouple of claim 10 , wherein the second electrical junction further comprises a folded end of the second wire pressed against an inner surface of the sheath.

12 . The multi-core thermocouple of claim 11 , wherein the second electrical junction further comprises a cavity formed in the insulation core and extending radially inward from an outer surface of the insulation core, and wherein the folded end of the second wire is disposed within the cavity.

13 . The multi-core thermocouple of claim 7 , wherein the multi-core thermocouple comprises at least twenty-one wires per 31.7 mm 2 of cross-sectional area of the multi-core thermocouple.

14 . The multi-core thermocouple of claim 7 , wherein the first and second wires comprise molybdenum (Mo) doped with Lanthanum (La) oxide by an amount within a range of about 0% and about 2% by weight.

15 . The multi-core thermocouple of claim 7 , wherein the first and second wires comprise molybdenum (Mo) doped with one or more of potassium (K), silicate (SiO 4 ) 4− , tungsten (W), or silicon (Si) by an amount within a range of about 100 ppm and about 300 ppm per dopant.

16 . The multi-core thermocouple of claim 7 , further comprising:
a third wire comprising a third material different from the first material; and a third electrical junction formed between the third wire and the sheath at a third axial position along the longitudinal axis of the sheath.

17 . The multi-core thermocouple of claim 16 , wherein the third wire comprise a platinum-rhodium alloy.

18 . The multi-core thermocouple of claim 17 , wherein at least a portion of the sheath comprises platinum.

19 . A method of forming a multi-core thermocouple, comprising:
forming a plurality of first elements; forming an insulation core; disposing the plurality of first elements within the insulation core; folding a longitudinal end of at least one first element of the plurality of first elements back upon itself to form a folded end; forming a second common element around the insulation core; and forming an electrical junction between each first element of the plurality of first elements and the second common element.

20 . The method of claim 19 , wherein forming an electrical junction between each first element of the plurality of first elements and the second common element comprises swaging a mid-section of the second common element to contact the folded end of a first element of the plurality of first elements.

Assignees

• Battelle Energy Alliance Llc

Inventors

• Skifton Richard S
• Daw Joshua
• Corbett Douglas A

Classifications

• G01K1/026

  arrangements for monitoring a plurality of temperatures, e.g. by multiplexing · CPC title

• G01K1/08

  Protective devices, e.g. casings · CPC title

• G01K7/021 Primary

  Particular circuit arrangements (G01K7/026, G01K7/12, G01K7/14 take precedence) · CPC title

• G01K7/04

  the object to be measured not forming one of the thermoelectric materials · CPC title

• G01K7/023

  provided with specially adapted connectors (connectors per se H01R) · CPC title