Combustion acoustic noise prevention in a heating furnace

• US 10,344,975 B2
• Filed: 04/19/2018
• Issued: 07/09/2019
• Est. Priority Date: 07/24/2012
• Status: Active Grant

• Current Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Original Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Inventors: Noman, Shiblee S. M.
• Primary Examiner(s): Savani, Avinash A
• Assistant Examiner(s): Becton, Martha M
• Application Number:
  US15/957,310
• Publication Number:
  US 20180238544A1
• Time in Patent Office: 446 Days
• Field of Search: None
• CPC Class Codes: F23N 2227/02 Starting or ignition cycles
• CPC Class Codes: F23N 2233/04 with variable speed
• CPC Class Codes: F23N 2233/10 forcing air through heat exchangers
• CPC Class Codes: F23N 2237/10 High or low fire
• CPC Class Codes: F23N 2237/16 secondary air
• CPC Class Codes: F23N 3/082 using electronic means
• CPC Class Codes: F23N 5/203 using electronic means
• CPC Class Codes: F24H 15/35 Control of the speed of fans
• CPC Class Codes: F24H 15/36 of burners
• CPC Class Codes: F24H 15/414 using electronic processing, e.g. computer-based
• CPC Class Codes: F24H 3/087 using fluid fuel
• CPC Class Codes: F24H 3/105 using fluid fuel
• CPC Class Codes: F24H 9/2085 using fluid fuel

Abstract

A control module for preventing acoustic resonance noise generation from a heat exchanger of a heating furnace, comprising a control signal generated by the control module. The control signal is configured to operate an induction fan of the heating furnace at more than one speed for a given heat demand mode of the heating furnace.

Claims

1. A heating furnace comprising:

a control module, wherein the control module is configured to generate a control signal, wherein the control signal is configured to;

for a given heat demand mode of the heating furnace, operate an induction fan of the heating furnace at more than one fan speed;

in response to a request for a high heat demand mode of the heating furnace, operate the induction fan at a low fan speed during flame ignition within a burner and for a stabilization period after the flame ignition within the burner; and

operate the induction fan at a high fan speed following the stabilization period; and

wherein the low fan speed is less than a higher fan speed designed to support the heating furnace operating at a maximum rated thermal output.

2. The heating furnace of claim 1, wherein the control signal is configured to regulate a fuel supply rate to the burner.

3. The heating furnace of claim 2, wherein, in a low heat demand mode, the fuel supply rate is lower than the fuel supply rate in a high heat demand mode.

4. The heating furnace of claim 1, wherein the low fan speed is a value in a range from about 25 percent less to about 75 less than the higher fan speed.

5. The heating furnace of claim 1, wherein the stabilization period is at least about 3 seconds.

6. The heating furnace of claim 1, wherein the stabilization period is a value in a range from 5 to 60 seconds.

7. The heating furnace of claim 1, wherein the heating furnace is a single-stage heating furnace having a single demand mode corresponding to a maximum rated thermal output of the heating furnace.

8. A control module comprising:

a circuit board configured to generate a control signal, wherein the control signal is configured to;

for a given heat demand mode of a heating furnace, operate an induction fan of the heating furnace at more than one fan speed;

in response to a request for a high heat demand mode of the heating furnace, operate the induction fan at a low fan speed during flame ignition within a burner and for a stabilization period after the flame ignition within the burner;

operate the induction fan at a high fan speed following the stabilization period;

wherein the low fan speed is less than a higher fan speed designed to support the heating furnace operating at a maximum rated thermal output.

9. The control module of claim 8, wherein the low speed is a value in a range from about 25 percent less to about 75 less than the higher speed.

10. The control module of claim 8, wherein the stabilization period is at least about 3 seconds.

11. The control module of claim 8, wherein the stabilization period is a value in a range from 5 to 60 seconds.

12. The control module of claim 8, wherein the control signal is configured to regulate a fuel supply rate to the burner.

13. The control module of claim 12, wherein, in a low heat demand mode, the fuel supply rate is lower than the fuel supply rate in a high heat demand mode.

14. A method of preventing acoustic resonance noise generation from a heat exchanger of a heating furnace, the method comprising:

generating, by a control module, a control signal wherein the control signal is configured to;

for a given heat demand mode of the heating furnace, operate an induction fan of the heating furnace at more than one fan speed;

in response to a request for a high heat demand mode of the heating furnace, operate the induction fan at a low fan speed during flame ignition within a burner and for a stabilization period after the flame ignition within the burner; and

operate the induction fan at a high fan speed following the stabilization period; and

wherein the low fan speed is less than a higher fan speed designed to support the heating furnace operating at a maximum rated thermal output.

15. The method of claim 14, further comprising supplying fuel to a burner of the heating furnace at a fuel input rate that is less than a high heat demand mode fuel input rate until an end of the stabilization period.

16. The method of claim 15, further comprising supplying fuel at the high heat demand mode fuel input rate following the stabilization period.