| 摘要 |
PURPOSE:To make it possible to maintain stable combustion conditions by a method wherein at least either the amount of air supplied or the amount of fuel supplied is adjusted and controlled by the minimum value retrieval output signal of flame current which is detected with a flame rod. CONSTITUTION:A combustion rate control part 11 calculates the combustion rate in accordance with the difference between the temperature measured by a room temperature sensor 13 and the set temperature 14 in order to control a fuel pump 3. When the result of calculation at the combustion rate control part 11 is larger than the predetermined amount, an air flow rate control part 12 calculates the air flow rate in proportion to the combustion rate in order to control a fan 4. Or, when the result of calculation is smaller than the predetermined value, a flame rod 10 detects flame current If in order to control the fan 4 in such a manner that the flame current If turns to be minimum and the resultant fan output is stored in a storage part 19. When the combustion rate is larger than the predetermined rate, the air flow rate control part 12 calculates the rotational speed of the fan 4 in accordance with the oscillation frequency of the fuel pump 3 by means of the contents of memory of the storage part 19 in order to obtain the driving output of the fan 4. |
