Circulating fluid bed boiler and fluidizing method using same

Abstract

The invention discloses a circulating fluid bed boiler, which comprises a hearth (1), a first air distribution plate (2), a deslagging pipe (3) and a deslagging bed area (4), wherein the first air distribution plate and the deslagging pipe are arranged at the bottom of the hearth; the deslagging bed area (4) enables slag to be in a fluidized state and is arranged at the outer side of the lower part of the hearth (1) and communicated with the hearth (1); the deslagging pipe (3) is arranged at the bottom of the deslagging bed area (4). The invention discloses a fluidizing method using the circulating fluid bed boiler. The circulating fluid bed boiler can reduce the loss of fine bed materials when slag is discharged, the material fluidity near the deslagging pipe is good, flow dead zones do not exist, the temperature field is uniform, and the heat utilization rate is high.

Description

technical field [0001] The invention relates to the field of thermal power generation, in particular to a circulating fluidized bed boiler and a fluidization method using the circulating fluidized bed boiler. Background technique [0002] As a clean coal combustion technology with wide fuel adaptability and high combustion efficiency, circulating fluidized bed boiler has been widely used in the field of thermal power generation in recent years. Circulating fluidized bed boilers mainly discharge slag in the form of bottom slag. In order to control the amount of material stored in the bed and the height of the bed, prevent the deposition of large slag, maintain good fluidization conditions, and avoid coking, the slag discharge procedure, timing and Flow is controlled. However, the high-temperature ash discharged from the circulating fluidized bed boiler will take away a lot of heat, and a large amount of S and N, as well as a lot of incompletely reacted fuel and desulfurizer ...

AI Technical Summary

Problems solved by technology

[0003] At present, most circulating fluidized bed boilers adopt the method of bottom slag discharge, and the bottom slag directly enters the slag cooler for cooling. However, during slag discharge, a large amount of large slag will be deposited at the bottom of the furnace. The fine particles in the dense phase area are also discharged, resulting in a large loss of fine bed material, and this part of the fine bed material is very important for maintaining the material balance in the circulating fluidized bed boiler and ensuring the concentration of solid particles in the furnace, especially It is especially important for some coal types that need a long time to produce a certain amount of fine bed material deposition in the furnace after combustion

At the same time, since the slag discharge at the bottom mainly depends on gravity, a dead zone for material flow will be formed near the slag discharge port, resulting in uneven temperature field, affecting the heat transfer efficiency of buried pipes, and resulting in low thermal efficiency

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