Low-NOx mixed burning system and method with coupling of pyrolyzing furnace and pulverized coal boiler

Abstract

The invention discloses a low-NOx mixed burning system and method with coupling of a pyrolyzing furnace and a pulverized coal boiler. The low-NOx mixed burning system comprises a coal pyrolyzing system formed by a raw coal cabin, a drying device, a coal pyrolyzing furnace, a semicoke collection device, a pyrolysis dust removal device and the like and a mixed burning system of pyrolyzing semicoke and bituminous coal; and the mixed burning system of pyrolyzing the semicoke and the bituminous coal is formed by a semicoke small material cabin, a coal mill, a desulfurization device and the like. For the low-NOx mixed burning system and method with coupling of the pyrolyzing furnace and the pulverized coal boiler, by putting the pyrolyzing furnace in front of the pulverized coal boiler, a semicoke large material and a semicoke small material obtained by pyrolyzing are separately stored and utilized, the semicoke large material is used as a chemical product, the semicoke small material is used as burning and bituminous coal for layering mixed burning, and a part of pyrolysis gas is used as a reburning fuel for a boiler to be sprayed into a furnace hearth for reburning. The low-NOx mixed burning system and method with coupling of the pyrolyzing furnace and the pulverized coal boiler lower production of NOx while solving resource waste of the semicoke small material and the pyrolysis gas and the various problems in the burning process, realizes full utilization of energy, is economic and environmentally friendly without improving the existing pulverized coal furnace, is wide in adaptability range and has a wide application prospect.

Description

technical field [0001] The invention belongs to the field of coal cascade conversion and high-efficiency clean combustion, and particularly relates to a low NO x Co-firing system and method. Background technique [0002] Rich in coal, poor in oil, and low in gas are the structural characteristics of my country's energy sources. Coal accounts for about 70% of my country's primary energy consumption. Although my country's total coal resources are abundant, the proportion of high-quality coal is not high, and low-rank coal accounts for 58.13% of the total coal reserves. Due to the poor grade and low utilization rate, it is usually used after pyrolysis. While improving coal quality and reducing pollution, pyrolysis expands the scope of application of low-rank coal. The main products of coal pyrolysis are tar, semi-coke and pyrolysis gas. Among them, semi-coke, especially semi-coke with small particle size, has low chemical utilization value, so it is generally burned as a hig...

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Problems solved by technology

On the other hand, the pyrolysis gas produced by coal pyrolysis has a low calorific value and is difficult to use directly. Although it has been used in the fields of power generation, heat supply, and chemical industry, nearly half of the remaining pyrolysis gas is vented and incinerated, causing serious damage. Resource waste and environmental pollution

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