Appliance airflow detection using differential pressure sensing

Patent metadata

Field	Value
Publication number	US-9267700-B2
Application number	US-201113198037-A
Country	US
Kind code	B2
Filing date	Aug 4, 2011
Priority date	Aug 4, 2011
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A device for detecting and/or measuring air flow in a cooling air flow passageway of an appliance using solid-state flow detectors. Heat generating components of the appliance are controlled in response to detected air flow. More specifically, the disclosure provides a device for detecting the presence of airflow and/or the approximate rate of airflow in a cooling channel of an appliance chassis. Based on this information, the appliance can perform safety-related tasks, such as de-energizing associated heating elements if there is too-low (or no) airflow detected. The solid-state flow detectors are easily fabricated, installed, and calibrated and avoids the calibration, fabrication and/or installation difficulties associated with sail switches and other such approaches such as thermal limit switches.

First claim

What is claimed is:

1. An appliance comprising:
a chassis and an internal housing including an electronics bay, said electronics bay containing electrical components;
a blower;
an air passageway for circulating air drawn from outside the appliance through the blower from the blower within and/or around at least one surface of the chassis and through the electronics bay;
an air flow measuring device including a differential pressure unit, the air flow measuring device for measuring a rate of flow of air flowing through the air passageway, the air flow measuring device supported within the air passageway such that air flowing in the passageway flows against and around, but not through, the air flow measuring device;
and
a controller that monitors the air flow measuring device to calculate the air flow rate within the air passageway and which performs certain actions based on the measured air flow rate,
wherein the differential pressure unit includes a double-cup flow detector having a first opening positioned within the air passageway essentially facing a direction of air flow through the passageway, a second opening opposite the first opening within the air passageway essentially facing away from the direction of air flow, and at least one pressure sensor for measuring the differential pressure between a stagnant pressure at a location within the first opening and a static pressure at a location within the second opening, and
wherein a first cavity is defined at least in part by the first opening, a second cavity is defined at least in part by the second opening, and a solid partition physically separates the first cavity from the second cavity.

2. An appliance as set forth in claim 1 , wherein the air flow measuring device is installed as a unit within the appliance.

3. An appliance as set forth in claim 1 , further comprising: a heat source wherein the controller interprets the differential pressure measured by the air flow measuring device so as to determine air flow rate within the air flow passageway and at least one of permits or restricts operation of the heat source based on whether the air flow rate is above or below a prescribed threshold.

4. An appliance as set forth in claim 1 , wherein the controller determines an airflow rate with an analog circuit or with a digital circuit.

5. An appliance as set forth in claim 1 , wherein the differential pressure unit includes a single-cup flow detector having an opening positionable within the air passageway essentially facing a direction of air flow through the passageway, and at least one pressure sensor for measuring the differential pressure between the stagnant pressure at a location within the single-cup flow detector and the static pressure outside of the single-cup flow detector.

6. An air flow measuring device for detecting air flow in a passageway of an associated appliance comprising: a differential pressure unit for measuring pressure in two locations; and circuitry for calculating air flow rate based on the sensed pressure differential; wherein the air flow measuring device is installable as a unit within the passageway of the associated appliance such that air flows against and around the air flow measuring device,
wherein the differential pressure sensor unit includes a double-cup flow detector having a first opening positioned within the passageway orthogonal to facing a direction of flow, and a pressure sensor for measuring the differential pressure between a stagnant pressure at a location within the first opening and a static pressure at a location within a second opening, and
wherein a first cavity is defined at least in part by the first opening, a second cavity is defined at least in part by the second opening, and a solid partition physically separates the first cavity from the second cavity.

7. An air flow measuring device as set forth in claim 6 , wherein the circuitry includes an analog circuit.

8. An air flow measuring device as set forth in claim 6 , wherein the circuitry includes a digital circuit.

9. An air flow measuring device as set forth in claim 8 , wherein the digital circuit further comprises any combination of discrete logic and/or microprocessor executing software.

10. An air flow measuring device as set forth in claim 6 , wherein the differential pressure unit includes a single-cup flow detector having an opening positionable within the air passageway essentially facing a direction of air flow through the passageway, and at least one pressure sensor for measuring the differential pressure between the stagnant pressure at a location within the single-cup flow detector and the static pressure outside of the single-cup flow detector.

11. An air flow measuring device for detecting air flow in an air passageway of an associated appliance comprising: a differential pressure unit for measuring pressure in two locations; and circuitry for calculating air flow rate based on the sensed pressure differential; wherein the air flow measuring device is installable as a unit within the air passageway of the associated appliance such that air flows against and around the air flow measuring device,
wherein the differential pressure sensor unit includes a single-cup flow detector having an opening positionable within the air passageway essentially facing a direction of air flow through the passageway, and at least one pressure sensor for measuring the differential pressure between a stagnant pressure at a location within the single-cup flow detector and a static pressure outside of the single-cup flow detector.

12. The air flow measuring device of claim 11 , wherein the a downstream pressure sensor is positioned directly downstream of the single-cup flow detector opposite the opening of the single-cup flow detector.

13. The air flow measuring device of claim 12 , wherein the single-cup flow detector defines a cavity, and a solid partition physically separates the cavity from the downstream pressure sensor.

14. The air flow measuring device of claim 11 , wherein the circuitry includes an analog circuit.

15. The air flow measuring device of claim 11 , wherein the circuitry includes a digital circuit.

16. The air flow measuring device of claim 15 , wherein the digital circuit further comprises any combination of discrete logic and/or microprocessor executing software.

17. The air flow measuring device of claim 11 , wherein the appliance further comprises a heat source and a controller that interprets the differential pressure measured by the air flow measuring device so as to determine air flow rate within the air flow passageway and at least one of permits or restricts operation of the heat source based on whether the air flow rate is above or below a prescribed threshold.

Assignees

• Bach James Carter
• Newsom Paul E
• Gen Electric

Inventors

• Bach James Carter
• Newsom Paul E

Classifications

• F24F11/00 Primary

  Control or safety arrangements · CPC title

• F24C15/006

  Arrangements for circulation of cooling air · CPC title

• G01F1/34

  by measuring pressure or differential pressure · CPC title

• G01F11/44

  for liquid or semiliquid · CPC title