Low-load steady combustion type ultralow-NOX combustion system and combustor thereof

Abstract

The invention discloses a low-load steady combustion type ultralow-NOX combustion system and a combustor of the low-load steady combustion type ultralow-NOX combustion system. The combustor comprisesa pre-combustion chamber, a center air channel, a primary air channel, a direct-stream air channel, an inner secondary air channel and an outer secondary air channel, wherein the center air channel, the primary air channel, the direct-stream air channel and the inner secondary air channel are sequentially and coaxially arranged on one side of an inlet of the pre-combustion chamber in a sleeved manner from inside to outside, and the outer secondary air channel is arranged on an outer shell of the pre-combustion chamber. The combustion system comprises the combustor, a fuel bin connected with the front end of the combustor, a boiler and an air preheater, wherein the boiler and the preheater are sequentially connected with the back end of the combustor. The fuel bin communicates with the primary air channel through a variable-diameter pipeline. The preheating output end of the air preheater is divided into three parts, preheated three hot air streams are guided by an induced draft fan into the combustor and connected with the direct-stream air channel, the inner secondary air channel and the outer secondary air channel. The combustor can effectively lower the emission of thermal NOX and fuel NOX, when the combustion system operates with the load being changed, a pulverized coal bin can reasonably utilize the variable-diameter pipeline to control the amount of conveyed fuel, and smoke recirculation and low-load steady combustion are achieved.

Description

technical field [0001] The invention belongs to the field of thermal energy and power engineering, and relates to a low-load stable combustion ultra-low NO X Combustion systems and their burners. Background technique [0002] Although the research and development of new energy sources are gradually accelerating, the current energy structure in my country is still dominated by coal, and the pollutants such as nitrogen oxides, sulfur oxides, and dust produced by its combustion have caused serious damage to people's health and living environment. Influence, the resulting pollution problem has been paid attention to by people. [0003] Nitrogen oxides are one of the main air pollutants, mainly referring to NO and NO 2 , and most of the nitrogen oxides produced by the combustion of pulverized coal at high temperature are NO. Nitrogen oxides in the atmosphere are the main factor for the formation of photochemical smog, and also the main source of PM2.5 particles, one of the main...

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Problems solved by technology

However, when the existing burner with pre-combustion chamber is under low load, the air volume and powder volume do not match linearly, which leads to excessive reduction of coal powder concentration when the primary air volume is reduced. The dust phenomenon seriously affects the pulverized coal; the inner wall and outlet of the pre-combustion chamber are prone to slagging, and the central air passage of the burner with the pre-combustion chamber is prone to powder accumulation, and the ignition gun is easy to be blocked; during the low-load operation of the boiler, the The circulating flue gas temperature is too low, which is not conducive to reducing NO X Generate and affect the combustion of pulverized coal in the pre-combustion chamber; for the combustion system with a pre-combustion chamber, except for the primary air, all the secondary air comes from the hot air after the air preheater, and the air is supplied by the same blower, resulting in serious cross-winding of each secondary air and mutual greater impact

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