Pulverized coal fluidized self-preheating device and method

Abstract

The invention provides a coal powder fluidized self-preheating device and method. The coal powder fluidized self-preheating device comprises a fluidized preheating chamber, a coal injection pipe and afluidized air pipe, wherein a large amount of bed materials capable of being fluidized are arranged in the fluidized preheating chamber; the coal injection pipe is arranged at the bottom of the fluidized preheating chamber and conveys pulverized coal to the fluidized preheating chamber; one end of the fluidized air pipe extends to the bottom of the fluidized preheating chamber to provide fluidized air for fluidizing the bed materials and the pulverized coal; and the separation of the bed materials and the preheated pulverized coal is completed in the fluidized preheating chamber by utilizingthe difference in particle terminal velocities caused by the difference in particle sizes between the bed materials and the pulverized coal in combination with different airflow velocity distributions. The invention further provides a method for preheating the pulverized coal by using the device. The large amount of hot bed materials are utilized to rapidly preheat the pulverized coal to a temperature above an ignition point, and partial heat of oxygen-poor combustion is utilized to maintain the temperature of the bed materials, so that the operation is stable, and a technology is simple.

Description

technical field [0001] The present disclosure relates to the field of combustion technology, in particular to a coal powder fluidized self-preheating device and method. Background technique [0002] The by-products of coal pyrolysis and gasification, semi-coke and residual carbon, are burned as high-grade clean fuels to generate electricity, which is an important part of realizing clean and efficient cascade utilization of coal. With the rapid development of my country's coal chemical industry, there are a large number of such fuels that need to be burned and utilized urgently. However, the volatile content of semi-coke and residual carbon is very low, and it is very difficult to achieve clean and efficient combustion. Usually, there are difficulties in ignition and stable combustion, low burnout rate, NO X issues such as high emissions. How to cleanly and efficiently burn and utilize such ultra-low volatile carbon-based fuels has become a key technical bottleneck restrict...

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Problems solved by technology

Among them, the circulating fluidized bed is equipped with an air distribution plate and an air cap, and there is an inert bed material in the circulating fluidized bed. wind, these characteristics cannot meet the requirements of pulverized coal preparation in power plant boilers, and the device involves conveying, separating and returning materials, the process is too large and complex, the operation stability is poor, and it cannot be well realized with the existing pulverized coal boilers docking, resulting in the inability to achieve effective application and promotion of the technology

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