Pressure sensing device in gas furnace and method for controlling operation thereof

• US 6,401,708 B1
• Filed: 02/25/2000
• Issued: 06/11/2002
• Est. Priority Date: 02/26/1999
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Yeong Soo, Kim, Yang Ho, Kim, Kyeong Soo, Kim, In Kyu
• Primary Examiner(s): CLARKE, SARA SACHIE
• Application Number:
  US09/512,374
• Time in Patent Office: 837 Days
• Field of Search: 431/20, 431/18, 431/19, 126/116.A, 126/85.B, 126/116.R, 417/44.2, 417/53, 340/608, 340/611
• US Class Current: 126/116.00A
• CPC Class Codes: F23N 2005/181 using detectors sensitive to rate of flow of air
• CPC Class Codes: F23N 2225/06 for determining flow
• CPC Class Codes: F23N 2231/20 Warning devices
• CPC Class Codes: F23N 2231/26 for clogging air inlet
• CPC Class Codes: F23N 2233/06 at the air intake
• CPC Class Codes: F23N 2235/14 electromagnetically operated
• CPC Class Codes: F23N 5/242 using electronic means

Abstract

Pressure sensing device in a gas furnace including a first tube in communication with a position of an air supply pipe on an inlet side of an air supply fan having a pressure identical to an inlet of the air supply fan, a second tube in communication with a position of an air supply pipe on an outlet side of the air supply fan having a pressure identical to an outlet of the air supply fan, and a pressure difference sensing means respectively connected to the first and second tubes for providing an electric signal according to a pressure difference caused by pressure on the first and the second tubes, thereby detecting clogging states both of the air supply pipe and the exhaust gas pipe, and method for controlling operation of a gas furnace, including the steps of (1) a pressure difference sensing device providing an electric signal according to a pressure difference between inlet/outlet of an air supply fan during operation or a pre-purge step for starting operation, (2) comparing the electric signal to a preset signal at the controller, and (3) either stopping the operation or continuing a normal operation according to a pressure state detected in the comparing step.

Claims

1. A pressure sensing device in a gas furnace, comprising:

a first tube in communication with an air supply pipe on an inlet side of an air supply fan having a pressure identical to an inlet of the air supply fan;

a second tube in communication with an air supply pipe on an outlet side of the air supply fan having a pressure identical to an outlet of the air supply fan;

a pressure difference sensing means respectively connected to the first and second tubes for providing an electrical signal according to a pressure difference caused by pressure on the first and the second tubes; and

a controller that receives the electric signal generated at the pressure difference sensing means, compares the electric signal to a preset value, and detects and/or determines clogging of the air supply pipe or an exhaust gas pipe in communication with the air supply pipe based on the results of the comparison.

2. The pressure sensing device as claimed in claim 1, further comprising a timer for measuring a time period since a clogged state is detected by the controller for re-determining the clogged state detected by the controller within a present time period.

3. The pressure sensing device as claimed in claim 1, further comprising an informing means for informing the clogged state of the air supply pipe or the exhaust gas pipe detected or determined at the controller.

4. The pressure sensing device as claimed in claim 3, wherein the informing means includes at least one selected from a character display for providing an error message, a light for a visual effect, and a buzzer for a hearing effect.

5. A pressure sensing device as claimed in claim 1, wherein the controller shuts off a gas valve for the gas furnace and stops operation of the gas furnace once the controller determines that the air supply pipe or the exhaust gas pipe is clogged.

6. A method for controlling operation of a gas furnace, comprising:

providing an electric signal by a pressure difference sensing device according to a pressure difference between an inlet and an outlet of an air supply fan disposed in an air inlet supply pipe during operation or a pre-purge step for staring operation of the gas furnace;

comparing the electric signal to a preset signal at a controller to detect and/or determine clogging of the inlet or outlet of the air supply fan based on the results of the comparison; and

either stopping operation or continuing the operation according to a pressure state detected in the comparing step.

7. A method as claimed in claim 6, wherein the determining step includes measuring a time period since the clogged state is detected in the step (2),

comparing a measured time period in the measuring step to a preset time period, re-providing the electric signal coming from the pressure difference between the inlet and outlet of the air supply fan when the measured time period is shorter than the preset time period in the comparing step, and

re-comparing the electric signal in the re-providing step to the preset signal at the controller,

wherein the re-providing step and the re-comparing step are repeated if the measured time period is shorter than the preset time period, and the present operation state is determined to be the clogged state if the measured time period is longer than the preset time period.

8. A method as claimed in claim 7, wherein the present operation state is determined to be a normal state if the re-provided electric signal in the signal re-comparing step is different from the preset signal.

9. The method as claimed in claim 6, further including informing the clogged state to the user by sounding a buzzer or displaying a message before stopping the operation if the present operation state is detected or determined to be the clogged state.

10. A pressure sensing device in a gas furnace, comprising:

a first tube in fluid communication with an air supply pipe on an inlet side of an air supply fan having a pressure identical to an inlet of the air supply fan;

a second tube in fluid communication with an air supply pipe on an outlet side of the air supply fan having a pressure identical to an outlet of the air supply fan; and

a pressure difference sensor respectively connected to the first and second tubes that provide an electrical signal according to a pressure difference caused by pressure on the first and the second tubes; and

a controller that receives the electric signal generated at the pressure difference sensor, compares the electric signal to a preset value, and detects and/or determines clogging of the air supply pipe or the exhaust gas pipe based on the results of the comparison.

11. The pressure sensing device as claimed in claim 10, further comprising a timer that measures a time period since a clogged state is detected by the controller to re-determine the clogged state detected by the controller within a present time period.

12. The pressure sensing device as claimed in claim 10, further comprising an informing device that informs a user of the clogged state of the air supply pipe or the exhaust gas pipe detected or determined at the controller.

13. The pressure sensing device as claimed in claim 12, wherein the informing device includes at least one selected from a character display that provides an error message, a light that provides a visual indicator, and a buzzer that provides an auditory signal.

14. The pressure sensing device as claimed in claim 10, wherein the controller shuts off a gas valve for the gas furnace and stops operation of the gas furnace once the controller determines that the air supply pipe or the exhaust gas pipe is clogged.

15. A device for detecting and/or determining clogging of an air supply pipe or an exhaust gas pipe in a gas furnace, comprising:

a first tube in communication with an air supply pipe on an inlet side of an air supply fan;

a second tube in communication with an air supply pipe on an outlet side of the air supply fan;

a detector respectively connected to the first and second tubes; and

a controller that receives an electric signal generated by the detector, compares the electric signal to a preset value, and detects and/or determines clogging of the air supply pipe or an exhaust gas pipe in communication with the air supply pipe based on the results of the comparison.