A power station start-up auxiliary system with fuel drying function and its working method

Abstract

The invention discloses a power station starting auxiliary system with a fuel drying function and a working method. The system comprises at least one power generation internal combustion engine, discharged smoke of the power generation internal combustion engine enters a waste heat boiler, and steam is generated in the waste heat boiler and enters a steam header. The steam in the steam header enters a coal drying heat exchanging device for coal drying, after the steam is cooled and condensed in the drying heat exchanging device, the steam enters a condensing water tank. Moisture evaporated from coal enters a recycling water tank for reusing, and the steam entering the steam header can be used as steam for starting of a coal-fired power station boiler during coal-fired power station starting. Power generated by the power generation internal combustion engine is connected into a power grid or is used as a starting power supply for coal-fired power station black starting. Energy of smoke discharged by the power generation internal combustion engine is effectively used, the waste heat boiler is used for generating steam, the steam can be used for coal-fired power station starting, the coal-fired power station does not need to be provided with a starting boiler additionally, and investment and resource wasting are lowered.

Description

technical field [0001] The invention relates to the technical field of energy and power, in particular to a power station start-up auxiliary system with a fuel drying function. Background technique [0002] The existing coal-fired power station system has the following technical shortcomings: [0003] 1. Coal-fired power plants generally need to be equipped with a start-up boiler, because before the start-up of the power plant, it is necessary to provide steam to the deaerator for deoxygenation, steam for turbine shaft seals, and steam for boiler heating pipes, etc., so that the thermal equipment and The pipeline is preheated to avoid damage to the equipment and pipeline due to excessive thermal stress of the material of the equipment and pipeline caused by sudden start-up. The start-up boiler generally has low power and low utilization efficiency. When the power station is in normal operation, the start-up boiler is generally idle, resulting in a waste of resources. The p...

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Problems solved by technology

Excessive moisture content in coal will reduce the efficiency of coal combustion heat utilization

At present, there is a technology of drying lignite by extracting boiler fume, but the extraction of furnace fume changes the flow field and the balance of the smoke and air system in the coal-fired power plant boiler, making the design and operation control of the coal-fired power plant boiler more complicated.

Moreover, the smoke from the coal-fired power plant boiler contains a lot of dust, and the recirculation of the extracted smoke will increase the dust concentration of the smoke, which will increase the wear and tear of the coal-fired power plant boiler

[0005] 3. High-moisture coal is directly fed into the furnace for combustion, which not only reduces the efficiency of coal combustion heat utilization, but also wastes the moisture in the coal

[0006] 4. The exhaust gas temperature of the internal combustion engine for power generation is 350 to 400 ℃, which is directly discharged to the atmosphere, causing serious energy waste

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