| 摘要 |
PURPOSE:To provide the combustion control, which has neither error nor damage and is excellent in controllability, of a small furnace by a method wherein the opening of a control valve is regulated based upon a valve opening signal and at the same time fuel system is controlled by a furnace temperature signal issued from a temperature sensor and combustion air is cascade-controlled by the temperature controller of the fuel system based upon an oxygen concentration signal. CONSTITUTION:A temperature controller 52 brings a feed-back signal from a valve opening transmitter 54 annexed to a fuel control valve 50 through a converter 55 and outputs a control signal to the fuel control valve 50. Further, the amount of fuel is PID-controlled by the temperature controller 52 based upon a furnace temperature signal issued from a temperature sensor 7. Furthermore, the amount of combustion air is PID-controlled directly by an oxygen concentration controller 53 based upon an oxygen concentration signal issued from an oxygen concentration sensor 20 and at the same time cascade-controlled by changing the set value of an oxygen concentration controller 53 based upon the output signal of the temperature controller 52 at that time. |
