Modulating gas valve furnace control method

• US 5,860,411 A
• Filed: 03/03/1997
• Issued: 01/19/1999
• Est. Priority Date: 03/03/1997
• Status: Expired due to Fees

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Thompson, Kevin D., Roy, William J.
• Primary Examiner(s): Dority, Carroll B.
• Application Number:
  US08/810,231
• Time in Patent Office: 687 Days
• Field of Search: 126/116 R, 126/116 A, 431/20, 137/492.5
• US Class Current: 126/116.00A
• CPC Class Codes: F23N 1/027 using mechanical means
• 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 2233/08 with variable speed
• CPC Class Codes: F23N 2233/10 forcing air through heat exchangers
• CPC Class Codes: F23N 2235/20 Membrane valves
• CPC Class Codes: Y10T 137/777 Spring biased

Abstract

A furnace control apparatus is described wherein a flow of gas into a burner assembly is directly dependent on an indicia of burner combustion air airflow, such as heat exchanger pressure drop. According to one embodiment of the invention, a first communication fluid line is interposed between a gas valve regulator and a heat exchanger at a first point, and a second communication fluid line is interposed between a gas valve regulator a heat exchanger at a second point. The main valve of the gas valve is responsive to the pressure differential between the first and second points so that a flow of gas into a furnace burner assembly is commensurate with a present flow level of combustion air.

Claims

1. A gas valve and control assembly for controlling a flow of gas to a burner assembly of a furnace, comprising:

a main valve for controlling a flow of gas to said burner assembly;

a heat exchanger in fluid communication with said burner assembly;

sensing means for sensing a pressure drop across said heat exchanger; and

moving means responsive to said sensing means for moving said main valve to a position dependent on said pressure drop as sensed by said sensing means.

2. The gas valve of claim 1, wherein said gas valve is a servo-regulator type gas valve having a regulator, and wherein said sensing means is provided by said regulator.

3. The gas valve of claim 1, wherein said gas valve is a servo-regulator type gas valve having a regulator, and wherein said regulator is in fluid communication with said heat exchanger in at least two distinct points so that said sensing means senses a pressure drop across the heat exchanger.

5. The furnace assembly of claim 1, wherein said gas valve is a servo-regulator type gas valve having a regulator, and wherein said sensing means is provided by said regulator.

6. The furnace assembly of claim 5, wherein said gas valve is a servo-regulator type gas valve having a regulator, and wherein said regulator is in fluid communication with said heat exchanger in at least two distinct points so that said sensing means senses a pressure drop across said heat exchanger.

4. A furnace assembly comprising:

a burner assembly;

a heat exchanger in fluid communication with said burner assembly; and

a gas valve for controlling a flow of gas to said burner assembly, said gas valve comprising;

a main valve for controlling a flow of gas to said burner assembly;

sensing means for sensing a pressure drop across said heat exchanger; and

moving means responsive to said sensing means for moving said main valve to a position dependent on said pressure drop as sensed by said sensing means.