| 摘要 |
PURPOSE:To keep the combustion state stable as well as prevent the generation of unburnt matter by compensating the leak from a nonoperating burner and the increased portion of the leak air from an extinguished burner and supplying air for combustion burners of a burner group. CONSTITUTION:Leak air volume from unoperating burners can be created by a function generator 18 on the basis of the differential pressure signal detected by a furnace/wind box differential pressure detector 17. Then, a total signal of leak air volume of a burner group is produced by multiplying the leak air volume by the signal 16 of the number of nonoperating burners by means of a multiplier 19. The total signal of leak air volume is sent to an adder 13 to be added to the signal of necessary combustion-air flow rate in accordance with the fuel flow rate. The difference between this signal and the output of a detector 15 of air flow rate supplied to the burner group is created by a subtracter 14, and this deviation signal is converted to the operating signal of damper opening by a proportional integrator 20 in order to adjust an adjusting damper 22 through an automatic/manual operation switcher. In this way, the shortage of air for combustion of burners during combustion is prevented, and the optimum state of combustion is always maintained. |
