Patent ID: 11946643
Assignee: NORITZ CORPORATION
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A combustion apparatus comprising:
a combustion mechanism that burns a fuel;
an air blowing fan that supplies air for combustion to the combustion mechanism;
an exhaust vent through which combustion gas in the combustion mechanism is discharged;
a check valve arranged in a supply and exhaust passage from the air blowing fan to the exhaust vent,
the check valve being opened and closed in accordance with a relationship between a gas pressure in the supply and exhaust passage and a biasing force in a closing direction;
a controller that performs a failure diagnosis for detecting an open failure of the check valve when a phenomenon in which the gas pressure is lower than a predetermined normal pressure range is detected in a diagnosis rotation speed region, the diagnosis rotation speed region being set within a rotation speed range of the air blowing fan in which a degree of opening of the check valve changes with an increase in a rotation speed of the air blowing fan when the check valve is normally opened and closed;
a rotation speed sensor that detects the rotation speed of the air blowing fan; and
a current sensor that detects a driving current of the air blowing fan, wherein
the controller prestores a characteristic relationship of a reference current value in association with the rotation speed in the diagnosis rotation speed region, and detects the open failure by detecting the phenomenon in which the gas pressure is lower than the normal pressure range, when a detection value of the driving current at the time of the failure diagnosis is higher than a normal current range including the reference current value, the normal current range being obtained by referring to the characteristic relationship based on a detection value of the rotation speed at the time of the failure diagnosis.