| 摘要 |
WARM-AIR HEATER A target value setting unit (81) sets a target combustion temperature of a gas burner 5 (41) for maintaining a steady combustion in a normal state to be lower than the maximum combustion temperature corresponding to a heating power. A combustion control unit (82) controls a fuel gas supply amount to a gas mixing chamber (44) so that the target combustion temperature is achieved. A fan control unit (83) sets a rotation speed higher than a rotation speed corresponding to the maximum combustion temperature in the 1o steady combustion mode in the normal state as the target rotation speed, and controls the rotation speed of a combustion fan (6) to maintain the target combustion temperature based on the combustion temperature detected by a thermocouple (48). When a change amount obtained by subtracting the current rotation speed of the combustion fan from the target rotation speed thereof becomes equal to or greater than an oxygen-deficient change 15 amount obtained by subtracting a rotation speed corresponding to the target combustion temperature in the oxygen-deficient combustion mode from the target rotation speed, a control unit (8) determines that it is in the oxygen-deficient state, and stops combustion at the gas burner (41). |
