| 摘要 |
PURPOSE:To prevent heat transfer pipes from wearing out and from decreasing of thickness of pipes due to corrosion in a splash zone, by adopting a structure in which heat transfer pipes are not disposed in the position corresponding to the splash zone, and by controlling the height of a fluidized bed layer so that the heat transfer pipes will not enter the splash zone during operation. CONSTITUTION:A group 16 of heat transfer pipes is disposed in a bubble zone 13, and a group 17 of heat transfer pipes is disposed in a freeboard zone 8, kept away from a splash zone 12. In order to increase the efficiency of heat transfer pipes, it is necessary to position the groups of heat transfer pipes as close as possible to the zone where the temperature of combustion gas is high, that is, directly below or directly above the splash zone 12. The position of a splash zone 12 is changeable by the change in loading of fuel while a furnace is operated. Oxygen sensors 21a and 21b are respectively provided at the position directly below the heat transfer pipes on the lowest stage among the group 17 of heat transfer pipes in the freeboard zone 8, and at the position directly above the heat transfer pipes on the top stage of the group 16 of heat transfer pipes in the bubble zone 13, and in such a manner that the height of fluidized bed layer can be controlled. |
