Circulating fluidized bed boiler device using low calorific value coal gangue for post ignition

Abstract

The invention discloses a circulating fluidized bed boiler device using low calorific value coal gangue for post ignition, and belongs to a combustion system of a coal fired boiler. The device mainly comprises a hearth, a cyclone separator, a riser, a circulating ash heat exchanger, a header, a fluidized bed slag cooler and the like. The device is characterized in that: heat exchange and combustion are separated; the combustion is performed in a heat insulation region; a heating surface is arranged in a fluidized bed with finer particles; the device comprises a fine particle fluidized bed, a circulating ash heat exchanger and a fluidized bed slag cooler; the bottom part of the hearth is divided into two fluidizing regions; the flow direction of the bed material between the two fluidizing regions is changed by changing the fluidizing air parameter and slag discharge of the two fluidizing regions so as to fulfill the aim of adjusting the bed temperature; and both the hearth and the circulating ash heat exchanger are communicated with the fluidized bed slag cooler, so that the ash and the slag of the fluidized bed slag cooler can be independently discharged to greatly improve the adaptability of the boiler to fuels. The device has the main advantages of burning the fuels such as coal gangue with a low calorific value and the like and solving the problem of heavy wearing of the heating surface well.

Description

technical field [0001] The invention belongs to the combustion system of a coal-fired boiler, and in particular relates to a circulating fluidized bed boiler device for purely burning coal gangue with low calorific value. Background technique [0002] At present, in the process of coal mining and washing in my country, 500-700 million tons of gangue are produced every year, of which less than 15% of gangue is used as fuel, and the remaining gangue is mostly dumped in cones or valleys. Naturally stacked loosely around the mine. The reason why the utilization rate of coal gangue is low is that coal gangue is an inferior fuel with low calorific value and high ash content. When it is burned in a common circulating fluidized bed boiler, it has large wear, low combustion intensity, large smoke loss and difficult evaporation. Warranty etc. According to the existing domestic patented technology, coal gangue with low calorific value is used as fuel, usually in the way of co-firing w...

AI Technical Summary

Problems solved by technology

[0003] The present invention aims to provide a circulating fluidized bed boiler device for purely burning low calorific value coal gangue, which can efficiently burn various coal gangues with low calorific value or calorific value ranging from 4 to 12MJ / kg, and solve the problem of general low calorific value coal gangue combustion. Value, high ash coal circulating fluidized bed boilers have problems such as large wear, low combustion intensity, large exhaust smoke loss and difficulty in ensuring evaporation.

Images