| 摘要 |
PURPOSE:To make the evaporation amount in a boiler coincide with a set value with a high accuracy by a method in which the supply preferential order and supply flow rate upper limit value of a fuel used are regulated, and the variations in the heating quantities of each fuel are compensated by the preferential order by adjusting the supply flow rate of the fuel at the lowest level. CONSTITUTION:The flow rates F1-F4 of gases B, C and K and liqueified petroleum gas are measured by flow meters 11-14, and the unit heating quantities H1-H4 by combustion of the gases are actually measured by heating quantity measures 21-24. By arithmetical units 31- 34, coming heat quantities Q1-Q4 are calculted for every gas by using said unit heating quantities and said flow rates. Total sum Q of the coming heat quantities is obtained by an arithmetical unit 101 and sent out to a fuel controller 102. In the controller 102, fuel control amounts are sent out to flow rate regulators 41-44 for adjusting the opening degrees of flow rate regulating valves 51-54 for fuels and a regulating valve for air. Even when the flow rate of the gas B reaches th upper limit value although the flow rate of the gas B at the highest level in terms of preferential order is increased, the flow rates of the gases are increased in order in as much as the evaporation amount of the boiler does not reach a set value. For the fuel at the lowest level in terms of preferential order, since the variations in the unit heating amountis the smallest, the evaporation amount of the boiler can be stabilized with a high accuracy. |
