Segmented upgrading and hot flue gas gradient utilization system for low-rank coal and utilization method thereof

Abstract

The invention relates to a segmented upgrading and hot flue gas gradient utilization system for low-rank coal and a utilization method thereof, and belongs to the technical field of low-order pulverized coal pyrolysis. The outlet of a discharging cover of a rotary kiln is connected with a coal falling channel; an upgrading pyrolysis section is arranged at the upper part of the coal falling channel; a multi-stage cooler is arranged at the lower part of the coal falling channel; the upgrading pyrolysis section comprises a plurality of heat exchange tubes mounted in the coal falling channel; thehot air outlet of the hot air furnace is connected with the heat exchange medium inlet of the upgrading pyrolysis section; the heat exchange medium outlet of the upgrading pyrolysis section is connected with the inlet of the gas inlet cover of the rotary kiln; the outlet of the gas outlet cover of the rotary kiln is connected with a desulfurization and denitrification system through a fan; a firsttemperature sensor, a flow meter and a butterfly valve are further mounted on a pipeline between the outlet of the air outlet cover of the rotary kiln and the fan; and the first temperature sensor and the fan are in linkage control, the upgraded coal subjected to secondary pyrolysis in the upgrading pyrolysis section enters the cooling section to exchange heat with desalted water, and therefore,the structural design is reasonable, flue gas heat can be fully utilized, and energy consumption is reduced.

Description

technical field

[0001] The invention relates to a low-rank coal staged quality improvement and hot flue gas cascade utilization system and utilization method thereof, belonging to the technical field of low-rank pulverized coal pyrolysis. Background technique

[0002] Coal is the main energy source in my country for a period of time. In 2006, China's coal reserves amounted to 1.0345 billion tons, and the remaining proven recoverable reserves accounted for about 13% of the world's total, ranking third in the world, of which low-rank coal reserves accounted for about 57%. In recent years, my country has developed more than 3 billion tons of coal every year, more than half of which are low-rank coals. At the same time, my country's coal utilization is relatively simple, mostly used for combustion and power generation, and the oil and gas resources in coal are burned in a simple form, which does not conform to the principle of "high quality for high use, low quality for low use...

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