Direct fired pulverizing system of smoke drying lignite coal fan mill

Abstract

The invention discloses a direct fired pulverizing system of a smoke drying lignite coal fan mill, which comprises a high temperature furnace smoke pipe and a hot wind mixer, wherein the high temperature furnace smoke pipe is formed by arranging a cluster of circular pipes in parallel to form a flue; the circular pipes are located in a vapor-water circulating system of a power plant; an outlet of the high temperature furnace smoke pipe is communicated with a down drying tube; an inlet is communicated with a hot smoke pumping port of a boiler furnace; the hot wind mixer is connected between a classifier and a pulverized coal distributer; the other route of the hot wind device is connected to the hot wind mixer; and a coal inlet of the fan coal mill is further connected with a cool smoke pumping port of the boiler flue. The direct fired pulverizing system of the smoke drying lignite coal fan mill has the advantages of safety in operation, simple structure, low investment and being capable of effectively utilizing heat energy of high-quality smoke.

Description

technical field [0001] The invention belongs to the technical field of coal-fired power generation, and relates to lignite power generation technology, in particular to a pulverizing system and a combustion system of a lignite-fired power station boiler. Background technique [0002] Lignite is the mineral coal with the lowest degree of coalification. It is the initial product of peat deposition that is dehydrated and compacted into organic biorock. It is named for its brown or dark brown appearance. Lignite accounts for about 18% of my country's thermal coal reserves, mainly distributed in Inner Mongolia, Northeast China and Yunnan. Lignite has high volatile content (Vdaf > 37%), high moisture (total moisture is about 30%, external moisture mostly exceeds 19%), low calorific value (about 12.56MJ / kg), and low ash melting point (about 1150°C) , low abrasiveness (HGI is 50-70) and easy spontaneous combustion. The characteristics of "two highs and three lows" of lignite de...

AI Technical Summary

Problems solved by technology

[0007] In summary, it can be seen that the two-medium and three-medium lignite pulverization systems widely used in power plant boilers focus on the drying and pulverization of high-moisture lignite, and fail to effectively solve the safety problems of lignite pulverization systems

Moreover, the high-temperature furnace flue pipes with internal or external thermal insulation structures in the fan milling system have the outstanding problems of large investment and poor operational reliability.

Images