Multiple stage modulating gas fired heat exchanger
AssigneeLennox Industries Inc.
InventorsSteven Schneider, Eric Perez, Bryan Smith, John Tran
Life of this patent
Estimating the term…
Abstract
A modulating heating system includes a tube heat exchanger having a plurality of burners, a combustion air blower (CAB) having an exhaust vent connected with the plurality of burners, the CAB operable at a first speed and a second speed, a first valve connecting a fuel source to a first subset of the plurality of burners, and a second valve connecting a fuel source to a second subset of the plurality of burners, wherein the first and second valves each have a low fire rate and a high fire rate. The heat exchanger is operable through multiple heat stages at a constant fuel-air mixture.
Claims29
A heating system, comprising:
- a heat exchanger comprising burners configured to burn a combustible fuel-air mixture;
- a combustion air blower (CAB) operable at a low speed and a high speed to supply air to the burners;
- a first subset of the burners connected to a fuel source through a first valve;
- a second subset of the burners connected to the fuel source through a second valve,
- wherein the first valve and the second valve each have an off position, a low fire rate, and a high fire rate;
- and
- wherein the burners are configured to operate in a low fire mode at the low speed and the low fire rate and operated in a high fire mode at the high speed and the high fire rate and the heat exchanger is operable through multiple heat stages.
A heating system, comprising:
- a tube heat exchanger comprising a plurality of burners;
- a combustion air blower (CAB) having an exhaust vent connected with the plurality of burners, the CAB operable at a first speed and a second speed;
- a first valve connecting a fuel source to a first subset of the plurality of burners;
- a second valve connecting a fuel source to a second subset of the plurality of burners,
- wherein the first and second valves each have a low fire rate and a high fire rate;
- and
- an electronic controller in connection with the CAB, the first valve and the second valve, the electronic controller configured to operate the heat exchanger through multiple heat stages at constant fuel-air mixture.
A method, comprising:
- modulating a gas-fired heat exchanger of a heating system through multiple heat stages while maintaining a constant gas-air ratio, wherein the heating system comprises:
- the heat exchanger having burners;
- a combustion air blower (CAB) having an exhaust vent connected with the burners, the CAB operable at a first speed and a second speed;
- a first valve connecting a fuel source to a first subset of the burners;
- and
- a second valve connecting a fuel source to a second subset of the burners, wherein the first and second valves each have a low fire rate and a high fire rate.
Dependencies are inferred from the claim text.