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 into a hearth, an air lock is used for preventing coal powder against air channeling so as to keep the coal powder smooth in circulation, an air exhaust preheater further heats warm air to obtain hot air, one part of the hot air and 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 air and powder mixtures, the other part of the hot airis used as secondary air to be directly fed into a coal powder burner, the air exhaust preheater is connected with an exhaust water recycling device, cold exhaust with water recycled is heated to form hot exhaust, and the other part of the exhaust, part of smoke extracted out of a smoke extraction opening and the hot exhaust 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 pulverizing steam heating type boiler unit of a coal-fired power station and its power generation system, in particular to boiler air supply, cold air preheating, pulverizing, pulverized coal combustion and flue gas water recovery technologies. Background technique [0002] Lignite has the characteristics of high moisture, high volatile content, low calorific value, low ash melting point, low abrasiveness and easy spontaneous combustion. Lignite accounts for about 40% of the world's total coal reserves worldwide. my country's lignite accounts for about 16% of the total domestic coal reserves, mainly distributed in the eastern part of Inner Mongolia and the junction of the three northeastern provinces and Yunnan. The lignite in Inner Mongolia and Northeast China belongs to aged lignite, with a total moisture of 25-40%; the lignite in Yunnan belongs to young lignite, with a total moisture of 40-60%, and contains wood fib...

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 the conventional intermediate storage bunker type pulverizing system, in order to have a certain coal feeding buffer capacity and make the pulverizing process and the combustion process relatively independent, a pulverized coal bin is often provided. However, for high volatile coal such as lignite and Zhundong coal In other words, setting 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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