Sealing device for a cold-end part of a thermocouple wire arrangement with a mineral-insulated cable and thermocouple

Patent metadata

Field	Value
Publication number	US-11519791-B2
Application number	US-201816771540-A
Country	US
Kind code	B2
Filing date	Dec 4, 2018
Priority date	Dec 12, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

Various embodiments of the teachings herein include a sealing device for sealing a cold-end part of a thermocouple wire arrangement based on a mineral-insulated cable, the sealing device comprising: a sealing element including an electrically insulating material, the sealing element defining a through-hole for passing through a respective thermocouple wire of the mineral-insulated cable; a sealing ring arranged at an outer rim of the sealing element for fixing the sealing device to a sheath or a support tube of the mineral-insulated cable; and an electric temperature sensing element for sensing an absolute temperature of the cold-end part. The temperature sensing element has at least one temperature-dependent electrical property.

First claim

What is claimed is:

1. A sealing device for sealing a cold-end part of a a mineral-insulated cable, the sealing device comprising:
a sealing element including an electrically insulating material, the sealing element defining a through-hole for allowing a first thermocouple wire to pass therethrough;
a sealing ring arranged at an outer rim of the sealing element for fixing the sealing device to a sheath or a support tube of the mineral-insulated cable; and
an electric temperature sensing element for sensing an absolute temperature of the cold-end part;
wherein the temperature sensing element has at least one temperature-dependent electrical property.

2. A sealing device according to claim 1 , wherein the temperature sensing element comprises a resistance sensor.

3. A sealing device according to claim 1 , wherein the temperature sensing element comprises an inductive temperature sensor and/or a capacitive temperature sensor.

4. A sealing device according to claim 1 , wherein the temperature sensing element is integrated into the sealing element.

5. A sealing device according to claim 1 , wherein the temperature sensing element is attached to the sealing element.

6. A sealing device according to claim 1 , wherein the temperature sensing element comprises two electrical contacts; and
wherein one of the two contacts is electrically connectable to the first thermocouple wire; and
the other contact of the two contacts is electrically connected to a separate electrical connecting element different from any thermocouple wires of the mineral-insulated cable.

7. A sealing device according to claim 1 , further comprising a connecting element for connecting the first thermocouple wire to an electronic measuring circuit connected to a second thermocouple wire over the sensor element.

8. A sealing device according to claim 1 , wherein the temperature sensing element comprises two electrical contacts; and
wherein the temperature sensing element is connected to a four-wire connection with two wires per electrical contact of the temperature sensing element.

9. A sealing device according to claim 1 , wherein the electrically insulating material comprises a glass or a ceramic.

10. A sealing device according to claim 1 , wherein:
the sealing element defines multiple sealing areas at multiple respective through-holes and at the sealing ring for hermetically sealing the mineral-insulated cable by soldering or welding the sealing device to each of multiple thermocouple wires and the sheath or the support tube of the mineral-insulated cable; and
the sealing areas each include a surface comprising a metal.

11. A thermocouple temperature sensing device comprising:
a mineral-insulated cable including multiple thermocouple wires;
a sealing device sealing the mineral-insulated cable at a cold-end part;
the sealing device comprising:
a sealing element including an electrically insulating material, the sealing element defining a through-hole allowing a first thermocouple wire to pass therethrough;
a sealing ring arranged at an outer rim of the sealing element for fixing the sealing device to a sheath or a support tube of the mineral-insulated cable; and
an electric temperature sensing element for sensing an absolute temperature of the cold-end part;
wherein the temperature sensing element has at least one temperature-dependent electrical property; and
an electronic temperature measuring circuit connected to the multiple thermocouple wires over a respective electric conducting element;
wherein the measuring circuit determines an absolute temperature of the cold-end part by measuring an electric property and/or electric quantity of an electric temperature sensing element.

12. A thermocouple temperature sensing device according to claim 11 , wherein the measuring circuit comprises a switching element for alternatingly determining the temperature of the cold-end part and a temperature of a hot-end part of the mineral-insulated cable.

13. A thermocouple temperature sensing device according to claim 11 , wherein the measuring circuit provides a supply voltage for the thermocouple wires and modulates the supply voltage using a measuring voltage for the temperature sensing element.

14. A thermocouple temperature sensing device according to claim 11 , wherein the measuring circuit:
provides a supply current for the temperature sensing element;
measures a resulting voltage over the temperature sensing element; and
determines the temperature of the cold-end part as a function of the measured resulting voltage.

Assignees

• Vitesco Tech Gmbh

Inventors

• Gajdarus Tomá{Hacek Over (S)}

Classifications

• G01K1/08

  Protective devices, e.g. casings · CPC title

• H02G15/04

  Cable-end sealings · CPC title

• G01K7/00

  Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat (giving results other than momentary value of temperature G01K3/00) {; Power supply therefor, e.g. using thermoelectric elements} · CPC title

• H02G15/046 Primary

  with bores or protruding portions allowing passage of cable conductors · CPC title

• G01K7/12 Primary

  Arrangements with respect to the cold junction, e.g. preventing influence of temperature of surrounding air · CPC title