Low-nitrogen combustion transformation method and system for medium-grade kiln

Abstract

The invention discloses a low-nitrogen combustion transformation method and system of a medium-grade kiln, and belongs to the technical field of low-nitrogen combustion. The transformation method comprises the following steps: dismounting a coal burning device, arranging two fuel gas inlets, introducing natural gas, air and circulating flue gas into the head fuel gas inlet, and introducing air into the middle fuel gas inlet. The system comprises a medium-grade kiln, a natural gas pipeline, an air header pipe, a head air pipeline, a middle air pipeline, a flue gas circulating pipeline, a steam pipeline, a mixer I, an air blower, a filter, a mixer II, an induced draft fan and the like. Circulating flue gas is introduced into the head fuel gas inlet to inhibit combustion, so that insufficient combustion is performed at the front end of the middle-grade kiln, and then air is introduced into the middle fuel gas inlet to promote sufficient combustion at the middle-rear end in the middle-grade kiln so as to promote carbon monoxide to generate carbon dioxide, so that the emission amount of nitrogen oxide is reduced. Compared with a common coal-to-gas technology, the emission of nitrogen oxides can be reduced by more than 35%.

Description

technical field [0001] The invention belongs to the technical field of low-nitrogen combustion, and in particular relates to a low-nitrogen combustion transformation method and system for mid-range furnaces. Background technique [0002] The energy consumption of kilns in my country accounts for about one-third of industrial energy consumption, and the average thermal efficiency of kilns is about 20% lower than that of foreign countries. my country is a country with a large coal consumption, which has caused serious environmental pollution. It will save the equivalent of 100 million tons of standard coal. Therefore, in order to solve the problems of energy and environmental pollution, the industry is gradually promoting the "coal-to-gas" technology. [0003] During the combustion of fuel, the formation of nitrogen oxides (NOx) is a part of the combustion reaction, and the emission of nitrogen oxides (NOx) is also an important factor that pollutes the environment. Therefore, ...

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Problems solved by technology

[0005] Aiming at the problems that the low-nitrogen combustion system of the existing mid-range kiln is difficult to control the combustion temperature of the mixed gas, the heating performance of the mid-range kiln is reduced, even the flameout phenomenon occurs, and the emission of nitrogen oxides is not well controlled, the present invention provides a mid-range kiln The low-nitrogen combustion transformation method and system of the kiln are specially aimed at the "coal-to-gas" transformation of mid-range kilns, and realize stable and reliable low-nitrogen combustion, reduce NOx emissions and ensure the stable heating effect of mid-range kilns

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