Vacuum insulated appliance with pressure monitoring

Patent metadata

Field	Value
Publication number	US-11959696-B2
Application number	US-202217717421-A
Country	US
Kind code	B2
Filing date	Apr 11, 2022
Priority date	Apr 11, 2022
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

A method of measuring pressure includes the steps of (1) providing a vacuum cabinet with a storage compartment and an insulating space, and three temperature sensors; (2) sensing a first temperature level of an interior wall of the storage compartment; (3) sensing an ambient temperature level within the storage compartment; (4) sensing a second temperature level of an exterior wall of the storage compartment; (5) calculating an overall heat transfer coefficient (Q) using the ambient temperature level, the first temperature level, and a convective heat transfer coefficient for the interior wall of the storage compartment; (6) calculating a temperature differential between the second and first temperature levels; (7) determining a conductivity level (K) using the temperature differential, the overall heat transfer coefficient (Q) and a thickness of the insulating space; and (8) determining a pressure level (P) within the insulating space using the conductivity level (K).

First claim

What is claimed is:

1. A method of measuring insulation performance in a vacuum insulated cabinet structure, the method comprising the steps of:
providing a refrigerator having a vacuum insulated cabinet structure with a storage compartment and an insulating space having a thickness, a first sensor positioned on an interior wall of the storage compartment, a second sensor positioned on an exterior wall of the vacuum insulated cabinet structure, a third sensor positioned within the storage compartment, and a controller operably coupled to the first, second and third sensors;
sensing a first temperature level of the interior wall of the storage compartment using the first sensor;
sensing an ambient temperature level within the storage compartment using the third sensor;
sensing a second temperature level of the exterior wall of the storage compartment using the second sensor;
calculating an overall heat transfer coefficient (Q) using the ambient temperature level, the first temperature level, and a convective heat transfer coefficient for the interior wall of the storage compartment;
calculating a temperature differential between the second temperature level and the first temperature level;
determining a conductivity level (K) using the temperature differential, the overall heat transfer coefficient (Q) and the thickness of the insulating space; and
determining a pressure level (P) within the insulating space using the conductivity level (K).

2. The method of claim 1 , wherein the step of determining a pressure level (P) within the insulating space using the conductivity level (K) further includes, referencing a reference chart, wherein the reference chart plots conductivity vs. vacuum pressure.

3. The method of claim 2 , wherein the reference chart includes conductivity levels through a plurality of resistive mediums.

4. The method of claim 3 , wherein the resistive mediums include one or more mediums selected from the group consisting of fumed silica, precipitated silica, polystyrene foam, polyurethane foam, and glass fibers.

5. The method of claim 4 , wherein the insulating space includes a polyurethane foam insulating material disposed therein.

6. The method of claim 1 , wherein the second sensor is positioned on the exterior wall of the vacuum insulated cabinet structure in a manner that is opposed to a position of the first sensor on the interior wall of the storage compartment.

7. A method of measuring pressure within a vacuum insulated cabinet structure, the method comprising the steps of:
(i) providing a vacuum insulated cabinet structure having a storage compartment and an insulating space positioned between interior and exterior walls of the storage compartment, a first temperature sensor positioned on the interior wall of the storage compartment, a second temperature sensor positioned on the exterior wall of the storage compartment, a third temperature sensor positioned outside of the storage compartment;
(ii) sensing a first temperature level of the interior wall of the storage compartment using the first temperature sensor;
(iii) sensing a second temperature level of the exterior wall of the storage compartment using the second temperature sensor;
(iv) calculating a first temperature differential between the second temperature level and the first temperature level;
(v) sensing an ambient temperature level for an environment in which the storage compartment is disposed using the third temperature sensor;
(vi) calculating an overall heat transfer coefficient (Q) using the ambient temperature level, the second temperature level, and a convective heat transfer coefficient for the exterior wall of the storage compartment;
(vii) determining a first conductivity level (K) using the first temperature differential, the overall heat transfer coefficient (Q) and a thickness of the insulating space; and
(viii) determining a first pressure level (P) within the insulating space using the first conductivity level (K).

8. The method of claim 7 , further comprising:
(ix) repeating steps (ii)-(iv) to provide a plurality of temperature differential levels.

9. The method of claim 8 , further comprising:
(x) calculating an average temperature differential using the plurality of temperature differential levels.

10. The method of claim 9 , further comprising:
(xi) determining an average conductivity level using the average temperature differential, the overall heat transfer coefficient (Q) and the thickness of the insulating space.

11. The method of claim 10 , further comprising:
(xii) determining an average pressure level within the insulating space using the average conductivity level (K).

12. The method of claim 7 , wherein the step of determining a first pressure level (P) using the first conductivity level (K) further includes, referencing a reference chart, wherein the reference chart plots conductivity as a function of vacuum pressure.

13. The method of claim 12 , wherein the reference chart includes conductivity levels through a plurality of resistive mediums.

14. The method of claim 13 , wherein the resistive mediums include one or more mediums selected from the group consisting of fumed silica, precipitated silica, polystyrene foam, polyurethane foam, and glass fibers.

15. The method of claim 7 , wherein the third temperature sensor is positioned on the exterior wall of the storage compartment.

16. The method of claim 7 , wherein the third temperature sensor is spaced-apart from the vacuum insulated cabinet structure.

17. A method of measuring insulation performance on a vacuum insulated cabinet structure, the method comprising the steps of:
(i) providing a vacuum insulated cabinet structure having an insulation space surrounding a storage compartment, a first temperature sensor positioned on a first side of the insulation space, a second temperature sensor positioned on a second side of the insulation space, a third temperature sensor positioned within the storage compartment, and a controller operably coupled to the first, second and third temperature sensors;
(ii) sensing a first temperature level (T 1 ) using the first temperature sensor;
(iii) sensing a second temperature level (T 2 ) using the second temperature sensor;
(iv) calculating a temperature differential (ΔT) by subtracting the first temperature level (T 1 ) from the second temperature level (T 2 );
(v) sensing an ambient temperature level (T i ) within the storage compartment using the third temperature sensor;
(vi) calculating an overall heat transfer coefficient (Q) using the ambient temperature level (T i ), the first temperature level (T 1 ), and a convective heat transfer coefficient for the first side of the storage compartment; and
(vii) determining a first conductivity level (K) using the temperature differential (ΔT), the overall heat transfer coefficient (Q) and a thickness of the insulating space.

18. The method of claim 17 , further comprising:
(viii) determining a first pressure level (P) within the insulating space using the first conductivity level (K).

19. The method of claim 17 , further comprising:
(viii) repeating steps (ii)-(vii) at separate time intervals to provide a plurality of conductivity levels; and (ix) determining a first pressure level (P) within the insulating space using the first conductivity level (K).

20. The method of claim 19 , wherein the step of determining a first pressure level (P) within the insulating space using the first conductivity level (K) further includes, referenci

Assignees

• Whirlpool Co

Inventors

• Allard Paul B
• Ekshinge Sunil S
• Gomes Alberto Regio
• Naik Abhay
• Pathak Sanjesh Kumar

Classifications

• F25D2500/04

  Calculation of parameters · CPC title

• F25D29/006 Primary

  Safety devices · CPC title

• F25D23/065

  Details · CPC title

• F25D2201/126

  of cellular type · CPC title

• F25D2201/14

  using subatmospheric pressure · CPC title