| 摘要 |
PURPOSE:To reduce effects afforded by the variation in a quantity of combustion onto the upper outlet of a furnace by conducting the variation in the combustion quantity due to the load variation in a small width by the variation in the combustion quantity of only a lowermost stage burner, and making the combustion quantity of an upper burner constant. CONSTITUTION:When a load variation in a boiler of a small width such as in the case of employing an automatic frequency control (AFC) or the like, only the load of the combustion quantity of only a mill 5c for a lowermost stage burner 4 is varied, respective upper stage burners 2 and 3 are set as they are at the combustion quantity of a constant value, and the variation in the combustion quantity at the time of the load variation of a small width is carried out by only the variation in the combustion quantity of lowermost burner 4. By this procedure, since the combustion quantity due to the load variation in a small width such as in the case of employing AFC depends not on the variation in the combustion quantities of respective upper burners 2 and 3 but only on the variation of the combustion quantity of the lowermost stage burner 4, the effect of flame received by an superheater 7c at the outlet of the upper part of the furnace at the time of the small load variation is reduced and the variation in the performance of the boiler is small and is easily controlled. |
