Combustion organization method in the middle and downstream of pulverized coal jet in tangential pulverized coal combustion boiler

Abstract

The invention discloses a pulverized coal jet flow midstream and downstream combustion organization method in a tangent circle pulverized coal combustion boiler. Corresponding wall air nozzles are distributed in a hearth main combustion area of the pulverized coal combustion boiler in a manner of corresponding to primary air pulverized coal combustors, and are formed in the positions, close to the pulverized coal jet flow midstream and downstream positions of outlets, of a hearth water cooling wall, part of hot air is introduced into the wall air nozzles, and is directly sprayed into the corresponding primary air pulverized coal jet flow midstream and downstream interval in a jet flow manner, pulverized coal jet flow midstream and downstream combustion organization is carried out, the oxygen concentration and the pulverized coal combustion rate of the pulverized coal jet flow midstream and downstream interval are improved, and wall attaching happening of the pulverized coal jet flow midstream and downstream interval is directly obstructed. According to the method, pulverized coal jet flow midstream and downstream interval combustion organization and control can be achieved, happening of water cooling wall coking and high-temperature corrosion is prevented, the pulverized coal combustion efficiency is further improved, NOx generation and emissions are reduced, the proper combustion capacity of the pulverized coal combustion boiler for combustion low-volatile lower-ash-melting-point coal is expanded, and the fuel procurement cost is reduced.

Description

technical field [0001] The middle and downstream combustion organization method of pulverized coal jet flow in a tangential pulverized coal combustion boiler of the present invention relates to the technical field of boiler pulverized coal combustion; in particular, it relates to the requirement of low NOx generation and emission, or the requirement of high efficiency combustion and energy saving, or the prevention of coking and prevention of boiler The boiler pulverized coal combustion power generation field that requires high temperature corrosion of the water wall; specifically relates to the boiler pulverized coal combustion technology field that uses pulverized coal jets and hot air jets to form a tangential circular combustion flow field organization in the furnace. Background technique [0002] In the field of tangential pulverized coal boiler combustion technology and the engineering application of boiler pulverized coal combustion power generation based on this, the ...

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Problems solved by technology

[0011] 1. In the main combustion area and reduction area of ​​the furnace, the water-cooled wall of the furnace where the burner jet flows to the fire side has high-temperature corrosion of the water-cooled wall in different degrees of severity;

[0012] 2. In the main combustion area and reduction area of ​​the furnace, the water wall of the furnace where the burner jet flows to the fire side has different degrees of slagging or coking, especially when lean coal with low volatile content is used, or coal with a low ash melting point When the furnace is often severely coked, which affects the safe and stable operation of the boiler;

[0013] 3. The carbon content of the fly ash at the outlet of the furnace and the carbon content of the large slag at the outlet of the furnace bottom increase to varying degrees when burning coal with low volatile content, resulting in a decrease in the combustion efficiency of boiler pulverized coal to varying degrees;

[0014] 4. The adaptability of boilers to use coal with low ash melting point or low volatile content decreases, which affects the increase in coal procurement costs for boilers

[0018] In view of the above-mentioned problems, the inventor, on the basis of serious and sufficient investigation, understanding, analysis, and summary of the existing known technologies and the current situation, found that all the combustion organization technologies and various low-nitrogen combustion technologies of tangential pulverized coal combustion boilers have been The focus of the research is on the ignition and jet combustion organization in the early stage of combustion near the jet outlet of the pulverized coal burner, as well as the post-combustion organization of pulverized coal combustion in the direction of the furnace height, and a large number of technical research and equipment development have been carried out. So far, no technical research and equipment development have been conducted on the combustion structure of the middle and lower reaches of the pulverized coal jet on the horizontal section of the furnace. This is the root cause of the widespread occurrence of the above-mentioned problems in the pulverized coal combustion of boilers.

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