Method for drying biomass by using secondary air of coal-fired power plant

Abstract

The invention discloses a method for drying biomass by using secondary air of a coal-fired power plant. The problem that at present, during coal-fired biomass coupling power generation, biomass fuel cannot be dried through flue gas is solved. According to the adopted technical scheme, the flue gas in a boiler enters an air preheater, cold secondary air enters the air preheater to be subjected to heat exchanging with the flue gas to be heated into hot secondary air; a hot secondary air bypass is arranged at a hot secondary air duct of an outlet of the air preheater to pump part of the hot secondary air, and meanwhile, a cold secondary air bypass is arranged at a cold secondary air duct before entering the air preheater to pump part of the cold secondary air; the secondary air mixed by the hot secondary air and the cold secondary air serves as mixed drying hot air for drying the biomass; and the mixed drying hot air is conveyed into a biomass drying device through a mixed drying air duct. The method has the characteristics that the process is simple, adaptability of raw materials is wide, the drying effect is good, the working amount of transformation for existing pipelines is small,the calorific value and energy density of the biomass can be significantly increased, and the biomass gasification efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of biomass drying, and relates to the drying treatment of biomass fuel in a coal-fired biomass gasification coupled power generation system, in particular to a method for drying biomass by using secondary air of a coal-fired power plant. Background technique [0002] As the impact of PM2.5 and the greenhouse effect has attracted increasing attention in recent years, biomass energy has attracted more and more attention from all over the world. Biomass energy is an energy form in which solar energy forms chemical energy stored in biomass through photochemical action. It is directly or indirectly derived from the photosynthesis of green plants. It is an important renewable energy source and has the advantage of neutral carbon dioxide emissions. At present, biomass power generation mainly has two directions: direct combustion power generation and coal-fired biomass coupled power generation. Direct combustion po...

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Problems solved by technology

[0007] The purpose of the present invention is to solve the problem that flue gas cannot be used to dry biomass fuel in coal-fired biomass coupled power generation at present, and to provide a method for drying biomass by using the secondary air of coal-fired power plants, which is used for coal-fired biomass coupled power generation The drying of biomass fuel can significantly increase the calorific value and energy density of biomass to improve the efficiency of biomass gasification

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