US 12,492,816 B2Granted

High turndown combustion system and method

AssigneeCamus Hydronics Limited

InventorsPayam Tavakoli, Bishavdeep Singh Brar

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Abstract

Combustion systems configured to achieve, and methods of operating combustion systems to attain, enhanced high turndown operation, are disclosed herein. In one example embodiment, a combustion system includes an air flow tube, an air inlet damper, a gas train, a mixing chamber, a burner, and a blower. A flow of air via the tube into the mixing chamber is governed at least in part by a status of the air inlet damper. Further, the air inlet damper includes a damper plate having an outer perimeter with a first edge portion that is complementary to an inner surface of the tube and one or more additional edge portions that define a first inwardly-extending cutout. In another example embodiment, the combustion system includes a control device configured to cause a control signal for receipt by the damper motor to vary nonlinearly in response to variation of a modulation signal.

Claims20

Dependent claims

A combustion system configured to achieve enhanced turndown operation, the combustion system comprising:

an air flow tube;
an air inlet damper positioned along the air flow tube and including a damper motor and a first damper plate,
a gas train having a first gas valve positioned along the gas train;
a mixing chamber coupled to the air flow tube and to the gas train;
a burner;
a blower coupled between the mixing chamber and the burner;
and
at least one control device coupled at least indirectly to the damper motor of the air inlet damper;
wherein a first flow of air via the air flow tube into the mixing chamber is governed at least in part by a first status of the air inlet damper and also at least in part by a speed of the blower,
wherein a second flow of a gas via the gas train into the mixing chamber is governed at least in part by a second status of the first gas valve and also at least in part by the speed of the blower, wherein at least a first amount of the air and at least a second amount of the gas are mixed within the mixing chamber to form an air/gas mixture,
wherein a third flow of the air/gas mixture from the mixing chamber to the burner is governed at least in part by the speed of the blower,
wherein a position of the first damper plate is controlled at least in part by the damper motor, wherein the at least one control device is configured to provide at least one control signal for receipt by the damper motor that governs an actuation of the damper motor, wherein the at least one control signal includes or is based at least partly upon a modulation signal, and
wherein a flow path past the air inlet damper varies nonlinearly in response to a variation of the modulation signal because either:
(a) the at least one control device is configured to cause the at least one control signal to vary nonlinearly in response to the variation of the modulation signal;
or
(b) the first damper plate has an outer perimeter with a first edge portion that is complementary to an inner surface of the air flow tube and also a first inwardly-extending cutout.

13 more elements

A method of operating a combustion system to attain enhanced turndown operation, wherein the combustion system includes a blower, a mixing chamber, a burner, an air flow tube, a gas train, an air inlet damper, and at least one control device, wherein the blower is coupled between the mixing chamber and the burner, wherein the mixing chamber is coupled between the blower and each of the air flow tube and the gas train, wherein a first damper plate of the air inlet damper is positioned along the air flow tube, and wherein the at least one control device is coupled at least indirectly to a damper motor of the air inlet damper, the method comprising:

receiving a modulation signal at the at least one control device;
monitoring the modulation signal;
making a first determination, at a first time by the at least one control device, that the modulation signal has a first status in comparison with a first threshold;
upon the first determination being made, causing a first control signal to be output from the at least one control device for receipt by the damper motor of the air inlet damper, wherein the air inlet damper takes on a first position in response to the first control signal;
making a second determination, at a second time by the at least one control device, that the modulation signal has experienced a variation from having the first status to having a second status in comparison with the first threshold;
upon the second determination being made, causing a second control signal to be output from the at least one control device for receipt by the damper motor of the air inlet damper, wherein the air inlet damper changes from having the first position to having a second position in response to the second control signal,
wherein, when the air inlet damper changes from having the first position to having the second position, an air flow path past the air inlet damper varies in a nonlinear manner relative to the variation in the modulation signal from the first status to the second status.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/203,420Filed 30 May 2023
Published: US 2024/0401803 A15 Dec 2024
Granted: 9 Dec 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

F23N 1/025
Conjointly with air supply: using electrical or electromechanical means
F23C 7/008
Combustion apparatus characterised by arrangements for air supply: flow control devices
F23D 14/02
Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid: premix gas burners, i.e. in which gaseous fuel is mixed with…
F23L 3/00
Arrangements of valves or dampers before the fire