| 摘要 |
PURPOSE:To improve operability by memorizing combustion region detected from fuel feed amount at the time of flame failure, by correcting a proportional relation so that the amount of the air for combustion may be decreased on the basis of the memorized combustion region at the time of reiginition, and by controlling toward a decrease of the amount of the air for combustion in order that the proportional relation can be retained during the recombustion period. CONSTITUTION:When a flame sensor 6 detects flame failure, fuel feed amount at the time of flame failure, namely, ON time of fuel valve drive signal S1 corresponding to the fuel feed amount is memorized in memory. Next, when the operator reignites, combustion region at the flame failure is judged for fuel valve drive signal S1 memorized in memory on the basis of the length of ON time. For example, when ON time of the fuel valve drive signal S1 is less than 10ms, it is judged as flame failure in low temperature combustion region, while when ON time of the signal S1 is more than 30ms, it is judged as flame failure in the high temperature combustion region, and when ON time of the signal S1 is between 10ms and 30ms, it is judged as flame failure in moderate temperature combustion region. Thus, when judged as flame failure in the low temperature combustion region, amount of the air for combustion is particularly decreased in the low temperature combustion region. |
