ADHESIVE FLOW METER

• US 20180306618A1
• Filed: 04/21/2017
• Published: 10/25/2018
• Est. Priority Date: 04/21/2017
• Status: Active Grant

• Current Assignee: Trane International Inc. (Trane Technologies plc)
• Original Assignee: Trane International Inc. (Trane Technologies plc)
• Inventors: Han, Dong Hyouck
• Granted Patent: US 10,845,226 B2
• Time in Patent Office: Days
• CPC Class Codes: G01F 1/684 Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
• CPC Class Codes: G01F 1/6847 where sensing or heating elements are not disturbing the fluid flow, e.g. elements mounted outside the flow duct
• CPC Class Codes: G01F 1/688 using a particular type of heating, cooling or sensing element G01F1/6847 takes precedence
• CPC Class Codes: G01F 1/6986 with pulsed heating, e.g. dynamic methods

Abstract

Methods and apparatus for non-intrusively measuring fluid flow in a conduit, such as a pipe or tubing. The apparatus includes an insulator having self-adhesive inner surface attachable to the conduit, a temperature sensor on the inner surface of the insulator that senses the conduit surface temperature, a heat source on the inner surface of the insulator that imparts heat into the conduit, and a microcontroller connected to the heat source activator and the sensor assembly. In one embodiment, a baseline conduit temperature is measured, and the heat source raises the temperature of the conduit by a predetermined amount. When the conduit reaches target temperature, the heat source is deactivated and the cooling time for the conduit to return to its baseline temperature is measured. Fluid flow rate is determined from the cooling time, the temperature rise within a predetermined time, a temperature drop within a predetermined time, and/or a temperature gradient over time.

Claims

1. A method for non-intrusively determining fluid flow in a conduit, comprising:

sensing a first temperature of an exterior surface of the conduit;

changing the temperature of the exterior surface of the conduit to a second temperature;

measuring the time required for the exterior surface of the conduit to return to the first temperature from the second temperature; and

determining fluid flow based at least in part upon the time.

2. The method in accordance with claim 1, wherein changing the temperature of the exterior surface of the conduit includes increasing the temperature of the exterior surface of the conduit.

3. The method in accordance with claim 1, wherein determining fluid flow includes multiplying the time by a predetermined coefficient.

4. The method in accordance with claim 1, wherein sensing a first temperature of an exterior surface of the conduit includes determining that the temperature of an exterior surface of the conduit has fallen within a predetermined temperature range for at least a predetermined period of time.

5. The method in accordance with claim 1, wherein sensing a first temperature of an exterior surface of the conduit includes determining that the temperature of an exterior surface of the conduit has not changed by more than a predetermined amount for at least a predetermined period of time.

6. The method in accordance with claim 1, further comprising thermally insulating the exterior surface of the conduit from an ambient environment.

7. The method in accordance with claim 1, wherein the determining is performed in accordance with the formula

8. A method for non-intrusively determining fluid flow in a conduit, comprising:

sensing a baseline temperature of an exterior surface of the conduit;

heating the exterior surface of the conduit for a predetermined period of time;

sensing a post-heating temperature of an exterior surface of the conduit; and

determining fluid flow based at least in part upon the difference between the baseline temperature and the post-heating temperature.

9. The method in accordance with claim 8, wherein determining fluid flow includes multiplying the difference between the baseline temperature and the post-heating temperature by a predetermined coefficient.

10. The method in accordance with claim 8, wherein sensing a baseline temperature of an exterior surface of the conduit includes determining that the temperature of an exterior surface of the conduit has fallen within a predetermined temperature range for at least a predetermined period of time.

11. The method in accordance with claim 8, wherein sensing a baseline temperature of an exterior surface of the conduit includes determining that the temperature of an exterior surface of the conduit has not changed by more than a predetermined amount for at least a predetermined period of time.

12. The method in accordance with claim 8, further comprising thermally insulating the exterior surface of the conduit from an ambient environment.

13. The method in accordance with claim 8, wherein the determining is performed in accordance with the formula

14. Apparatus for non-intrusively determining a fluid flow rate within a conduit, comprising:

an insulator having an inner surface configured for attachment to the conduit;

a temperature sensor disposed on the inner surface of the insulator and configured for sensing a temperature of the conduit;

a heat source disposed on the inner surface of the insulator and configured for imparting heat into the conduit; and

a microcontroller in operative communication with the heat source activator and the sensor assembly.

15. The apparatus in accordance with claim 14, wherein the microcontroller is configured to:

measure a baseline temperature of the conduit;

activate the heat source to raise the temperature of the conduit by a predetermined amount;

deactivate the heat source;

measure the cooling time for the conduit to cool to its original temperature; and

determine the fluid flow rate within the conduit from the cooling time.

16. The apparatus in accordance with claim 14, wherein the microcontroller is configured to:

measure a baseline temperature of the conduit;

activate the heat source to raise the temperature of the conduit for a predetermined amount of time;

deactivate the heat source;

measure the raised temperature of the conduit; and

determine the fluid flow rate within the conduit from the difference between the baseline temperature and the raised temperature.

17. The apparatus in accordance with claim 14, wherein the heat source is formed from resistance wire.

18. The apparatus in accordance with claim 14, further comprising an electronic switch in communication with the microcontroller and configured to selectively activate the heat source.

19. The apparatus in accordance with claim 14, further comprising an adhesive coating on the inner surface of the insulator.

20. The apparatus in accordance with claim 14, wherein the insulator is formed from material selected from the group consisting of polyethylene foam and glass wool.