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 used for burning raw coal and being connected with a turbine unit with a turbine. The open powder making steam warm air type boiler unit is characterized in that a drying agent mixing chamber is connected with a smoke extraction opening and a gas outlet of a coal powder collector, a first part exhaust extracted from exhaust and part of smoke extracted out of the smoke extraction opening are mixed and used as drying agents to be fed to a raw coal pre-drying device, a cold air pre-heating device preheats environment cold air to obtain warm air through low-pressure steam extracted 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 the environment cold air are mixed to be used as primary air, an air and powder mixer mixes the primary air and coal powder to obtain air and powder mixtures, and the other part of the hot air is used as secondary air to be directly fed in a coal powder burner. The invention further provides a power generation system including the open powder making steam warm air type boiler unit and the turbine unit with the turbine.

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

Images