System and method for detecting flame rollout in a furnace
AssigneeCarrier Corporation
InventorsHall Virgil, Jr., Kevin Thompson
Life of this patent
Estimating the term…
Abstract
A method and system for detecting flame rollout is disclosed. The detection system includes a processor programmed to execute a furnace lockout when the flame proving signal is lost three times after successful burner ignition has been established on each of three heating cycles within a predetermined period of accumulated burner on-time. In one embodiment the period of accumulated burner on-time is 60 minutes. The program executed by the processor resides in firmware. The system and method of present invention mitigates the potentially harmful accumulation of flue gasses when flame sense is lost due to flame rollout.
Claims27
A method for controlling a furnace, the furnace including a gas valve, at least one gas burner, and a flame proving sensor, the flame proving sensor being operative to supply the furnace with a flame proving signal when a flame is detected in the at least one gas burner, the method comprising:
- performing a furnace lockout when the flame proving signal is lost during each of a predetermined number of heating cycles within a predetermined period of accumulated gas burner on-time, whereby a heating cycle is a period of gas burner flame detection time that is greater than or equal to a first predetermined period of time.
A method for controlling a furnace, the furnace including a gas valve, at least one gas burner, and a flame proving sensor being operative to supply the furnace with a flame proving signal when a flame is detected in the at least one gas burner, the method comprising the steps of:
- a.) actuating the gas valve to an on-state to thereby provide gas to the at least one gas burner;
- b.) igniting the gas to thereby produce a flame emanating from the at least one gas burner;
- c.) checking the flame proving signal after the gas valve has been in the on-state for a first predetermined period of time;
- d.) actuating the gas valve to an off-state when the flame proving sensor fails to detect a flame in step c;
- e.) repeating steps a, b, c, and d twice;
- and
- f.) performing a furnace lockout when steps a, b, c, d, and e are performed within a second predetermined period of accumulated burner on-time, whereby the furnace ignores requests for heat during the furnace lockout.
A system for detecting flame rollout in a furnace, the furnace including a gas valve and at least one gas burner, the system comprising:
- a flame proving sensor disposed proximate the at least one gas burner, the flame proving sensor being operative to provide a flame proving signal in response to detecting a flame emanating from the at least one gas burner;
- and
- a processor coupled to the flame proving sensor, the processor being programmed to execute a furnace lockout when the flame proving signal is lost in each of a predetermined number of heating cycles within a predetermined period of accumulated gas burner on-time, whereby a heating cycle is a period of gas burner flame detection time that is greater than or equal to a first predetermined period of time.
Dependencies are inferred from the claim text.