High-moisture lignite medium-speed coal mill pulverizing system heating primary air through coal gas burning

Abstract

The invention discloses a high-moisture lignite medium-speed coal mill pulverizing system heating primary air through coal gas burning. The system comprises a medium-speed coal mill, a coal gas generator, a fan, a high-temperature flue gas generator, a primary air fan, a coal feeder and an air preheater, can complete drying of high-moisture lignite and is composed of the medium-speed coal mill, the coal gas generator, the fan and the high-temperature flue gas generator. The system leads part of boiler heat primary air and coal gas generated by the coal gas generator into the high-temperature flue gas generator for burning, and hot flue gas generated by burning and rest heat primary air are mixed to serve as a drying agent to enter the coal mill, so that temperature of the drying agent is increased, and drying capability of the lignite boiler pulverizing system is improved. By the system, the problem that an existing high-moisture lignite medium-speed coal mill pulverizing system heating primary air through pulverized coal burning is insufficient in drying capability is solved well.

Description

technical field [0001] The invention belongs to the field of pulverization of lignite boilers, and in particular relates to a high-moisture lignite medium-speed coal pulverization system for coal gas combustion and heating of primary air. Background technique [0002] Lignite is one of the main types of thermal coal in my country, accounting for about 18% of thermal coal reserves, mainly distributed in the northeast, Inner Mongolia and southwest regions. The main feature of lignite is high total moisture, which is a key factor in the selection of lignite boiler pulverization system. Traditional lignite boilers are generally equipped with a fan mill direct-blowing pulverizing system. High-temperature furnace smoke, hot air and cold furnace smoke are used as drying media. The drying capacity is strong, but the impeller impact plate is easy to wear, the maintenance workload is large, and the maintenance cost is high. problem. [0003] In the 1990s, my country introduced the m...

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Problems solved by technology

In order to increase the primary air volume, judging from the actual operation of boilers burning high-moisture lignite, the power plant increases the primary air volume in order to increase the drying output of the pulverizing system. Wind speed will have an adverse effect on the ignition and embers of pulverized coal. At the same time, an excessive increase in the primary air volume also means a significant reduction in the secondary air volume, which will bring difficulties to the flow field and combustion organization in the furnace.

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