Open powder making steam warm air type boiler unit and power generation system thereof

Abstract

The invention provides an open powder making steam warm air type boiler unit connected with a turbine unit with a turbine. The open powder making steam warm air type boiler unit is characterized in that a weighing coal feeder meters, adjusts and controls the raw coal weight corresponding to the boiler coal supply quantity fed in a hearth, a coal powder collector separates air and powder mixtures to obtain coal powder and exhaust, an air lock is used for preventing the coal powder against air channeling so as to keep the coal powder smooth in circulation, a cold air pre-heating device preheats environment cold air to obtain warm air through low-pressure steam drawn out of a steam extraction opening of the turbine, an air preheater further heats the warm air to obtain hot air, one part of the hot air and part of the environment cold air are mixed to be used as primary air, an air and powder mixer mixes the primary air and the coal powder to obtain the air and powder mixtures, the other part of the hot air is used as secondary air to be directly fed into a coal powder burner, and the first part of the exhaust and part of smoke extracted out of a smoke extraction opening are mixed to be fed into a raw coal pre-drying device through a drying agent mixing chamber.

Description

technical field [0001] The invention relates to an open-type pulverizing steam-heating-air boiler unit of a coal-fired power station and a power generation system thereof, in particular to the technologies of boiler air supply, cold air preheating, pulverizing, pulverized coal combustion and flue gas water recovery. Background technique [0002] Lignite has the characteristics of high moisture content, high volatile content, low calorific value, low ash melting point, low abrasiveness and easy spontaneous combustion. Worldwide, lignite accounts for about 40% of the world's total coal reserves. my country's lignite accounts for about 16% of the total domestic coal reserves, mainly distributed in the junction of eastern Inner Mongolia and the three northeastern provinces and Yunnan. The lignite in Inner Mongolia and Northeast China is aged lignite, with a total moisture content of 25-40%; Yunnan lignite is a young lignite with a total moisture content of 40-60% and contains w...

AI Technical Summary

Problems solved by technology

However, compared with conventional bituminous coal boilers, the thermal efficiency of these lignite boilers is lower (about 2 percentage points lower) and the price is higher. This is mainly due to the large amount of flue gas in the lignite boiler, so the heat loss of the boiler exhaust is higher. , the boiler volume is also larger

In addition, the high-moisture coal-fired direct blowing pulverizing system needs to extract high-temperature furnace smoke as the main component of the desiccant of the pulverizing system, which makes the primary air contain a large amount of inert gases such as furnace smoke and water vapor, which makes the stable combustion of the boiler more difficult. difficulty

[0006] In conventional intermediate storage bunker-type pulverizing system boilers, in order to have a certain coal feeding buffer capacity and make the pulverizing process and the combustion process relatively independent, a pulverized coal bunker is often provided. However, for lignite and Zhundong coal with high volatility In terms of coal types, setting up a pulverized coal bunker in the pulverizing system to store flammable, explosive and highly volatile pulverized coal requires high requirements for the explosion-proof design of the pulverized coal bunker, which increases the difficulty of ensuring the safe operation of the pulverizing system

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