Combustion apparatus

Patent metadata

Field	Value
Publication number	US-12055291-B2
Application number	US-202117396099-A
Country	US
Kind code	B2
Filing date	Aug 6, 2021
Priority date	Sep 10, 2020
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

A controller memorizes an accumulated combustion time by accumulating combustion time of a burner, and is set in a first lower-limit and a second lower-limit higher than the first lower-limit as a lower-limit lower than an initial value of an excess air ratio when reducing an excess air limit of a mixture gas of combustion air and a fuel gas, and the former is the lower-limit in case the accumulated combustion time is under a predetermined set time and the latter is the one in case the accumulated combustion time is the predetermined set time and over.

First claim

The invention claimed is:

1. A combustion apparatus comprising: a burner disposed in a combustion chamber and for combusting a mixture gas of combustion air and a fuel gas; a fan for supplying the burner with combustion air; a gas supply passage for supplying the burner with the fuel gas; a proportional valve installed in the gas supply passage; an igniter for igniting the burner; an ignition detector for detecting ignition at the burner; and a controller for controlling the fan, the proportional valve, and the igniter, respectively;
the controller having set in advance an initial value of such an excess air ratio of the mixture gas as is suitable for the ignition at the burner;
the controller adjusting an air volume of the combustion air and a gas volume of the fuel gas for making the excess air ratio of the mixture gas an initial value upon receipt of instruction of combustion at the burner, stepwise reducing the excess air ratio of the mixture gas from the initial value in case the burner fails to ignite despite an ignition operation of the igniter, and causing the igniter to repeatedly perform a re-ignition operation,
wherein the controller memorizes an accumulated combustion time by accumulating combustion time of the burner, and wherein the controller is set as a lower-limit value of the excess air ratio of the mixture gas for reducing from the initial value in the re-ignition operation of the igniter, a first lower-limit value in case the accumulated combustion time is under a predetermined set time, and a second lower-limit value which is higher than the first lower-limit value in case the accumulated combustion time is the predetermined set time and over.

2. The combustion apparatus according to claim 1 , wherein the controller performs the stepwise reduction of the excess air ratio of the mixture gas from the initial value in the re-ignition operation of the igniter by stepwise increasing the gas volume of the fuel gas supplied to the burner.

3. The combustion apparatus according to claim 1 , wherein the controller counts the number of repetitions of the re-ignition operations of the igniter, judges that an ignition error has occurred in case the ignition at the burner fails to take place even after the number of repetitions has reached the predetermined number of repetitions, cancels the instruction of the combustion, and warns an ignition error,
wherein the controller memorizes the excess air ratio of the mixture gas in the such re-ignition operation of the igniter as was performed immediately before the judgment of the ignition error, and
wherein the controller adjusts the excess air ratio of the mixture gas in the ignition operation of the igniter to not more than the memorized excess air ratio after the judgment of the ignition error, cancellation of the instruction of the combustion and warning of the ignition error, when the warning of the ignition error has been cancelled and the combustion is once again re-instructed, in case elapsed time from the judgment of ignition error or from the cancellation of the warning of the ignition error to the re-instruction of combustion is within a predetermined elapsed time.

4. The combustion apparatus according to claim 1 , wherein the controller further comprises an accumulated combustion time eraser for erasing the accumulated combustion time that the controller has memorized.

Assignees

• Rinnai Kk

Inventors

• Takeuchi Masaru

Classifications

• F23N5/203

  using electronic means · CPC title

• F23N2231/12

  for ignition failures · CPC title

• F23N2227/02

  Starting or ignition cycles · CPC title

• F23N2227/34

  Continuously applied ignition cycles · CPC title

• F23D14/16

  using permeable blocks · CPC title