Smoke multistage drying brown coal power generation system

Abstract

The invention relates to a smoke multistage drying brown coal power generation system. Brown coal passes through a smoke multistage drying system to be fed into a boiler, and the smoke multistage drying system comprises a first-stage drying machine and a second-stage drying machine which are connected in series in sequence; a desulfurizing tower smoke outlet is connected with a smoke inlet of thesmoke cooler through a smoke pipe, the first-stage drying machine is connected with the smoke cooler to form a closed type heat circulation loop, and low-temperature smoke waste heat is used for conducting first-stage drying on the brown coal; a second-stage drying machine smoke inlet is connected with a boiler smoke extraction opening, part of boiler high temperature smoke is extracted for conducting deep drying on the brown coal; and the brown coal is subject to the pre-drying in the coal-fired power generation process, and the brown coal power generation efficiency is greatly improved.

Description

technical field [0001] The invention belongs to the field of coal-fired thermal power generation systems, and relates to a lignite or bituminous coal drying and dehydration system in front of a boiler in a thermal power plant. Background technique [0002] Lignite is a low-metamorphic coal, a low-quality coal with the characteristics of high moisture and low calorific value. At present, in most lignite power plants, lignite with a moisture content of 30% to 50% is not pre-dried, but is directly in contact with the high-temperature flue gas extracted from the furnace in the coal mill to achieve the purpose of drying, and the flue gas used for drying And the water vapor produced by drying is sent into the furnace together with the pulverized coal, resulting in a decrease in furnace temperature, poor combustion stability, increased flue gas volume, a corresponding increase in furnace cross-sectional area and volume, and increased boiler manufacturing and installation costs. At...

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Problems solved by technology

However, the pre-drying process of high-moisture lignite consumes a lot of heat energy, and a separate lignite pre-drying system often needs to burn part of the lignite to provide energy for the drying process. Considering the consumption of this part of lignite, the overall efficiency of lignite power generation is still low

Currently there are problems: 1) The volume of boiler flue gas is large, the volume of the boiler is huge, and the cost is expensive; 2) The output of the auxiliary equipment of the boiler is large, and the power consumption rate of the plant is high; 3) The moisture content of the boiler exhaust gas is high, the exhaust gas temperature is high, and the efficiency of the boiler is low (generally less than 91%)

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