Combustion power generating process of lignite processing and upgrading long-distance transportation power plant boiler

Abstract

The invention relates to a combustion power generating process of a lignite processing and upgrading long-distance transportation power plant boiler, which mainly comprises the following steps of: raw material lignite preprocessing, crushing and screening, drying and dehydrating, lignite particle fine crushing, high pressure rolled molding, molded lignite cold processing and hardening, long-distance transportation, storage, recrushing and combustion power generation by sending to a circulating fluid bed boiler, wherein a tubular drier for drying adopts low pressure superheated steam for indirectly drying, and avoids explosion generated by the reaction of volatile components and oxygen at overhigh temperature in the drying process; in the molding step, a little water still remaining in a lignite capillary after drying is used as an adhesive, and gaps among lignite particles are rolled and filled under certain temperature, moisture, granularity and pressure, so that the contact among the lignite particles is enhanced for molding, the secondary moisture adsorption of the lignite particles is reduced, the transportation cost is lowered, and the lignite is convenient for long-distance transportation; the molded lignite transported to the power plant is recrushed to be smaller than or equal to 10 millimeters through a coal grinding machine, and the recrushed molded lignite is sent to the boiler for combustion power generation. The invention effectively improves the economic value of the lignite and has little influence on environment pollution, and the entire process is safe andreliable.

Description

technical field [0001] The invention relates to the technical field of comprehensive and high-efficiency utilization of lignite processing and quality improvement, in particular to a process for long-distance transport of lignite for power plant boiler combustion and power generation and key equipment thereof. The lignite undergoes raw material crushing, drying and dehydration, large-scale high-pressure roll forming, long-distance transportation of briquettes, storage and re-crushing of briquettes to meet the requirements of circulating fluidized bed boilers in power plants for combustion and power generation. Background technique [0002] The drying and upgrading of lignite rich in water is converted into upgraded coal with properties similar to bituminous coal after dehydration at a certain temperature. The upgraded lignite will be more conducive to comprehensive utilization, transportation and storage. Since moisture is one of the characteristics of lignite, it can be di...

AI Technical Summary

Problems solved by technology

[0003] The water content of lignite rich in water is usually 15wt% ~ 55wt%. If it is directly involved in combustion, on the one hand, it needs to consume a lot of energy during the fire process; on the other hand, lignite has high volatile content and is prone to explosion

In addition, because the process of water evaporation will take away a lot of heat energy, the heat loss of combustion exhaust is large, the thermal efficiency is low, and the large amount of greenhouse gas emissions makes the use of water-rich lignite face special challenges

A large amount of lignite with high moisture content is directly used for combustion, which not only causes unstable combustion of the boiler, but also has low efficiency

At the same time, long-distance transportation of these high-moisture and low-calorific-value lignites in the raw coal state will cost too much and is not safe

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