Water-tube boiler achieving internal circulation of flue gas and low-nitrogen combustion control method

Abstract

The invention relates to the technical field of boilers, in particular to a water-tube boiler achieving internal circulation of flue gas and a low-nitrogen combustion control method. The water-tube boiler achieving internal circulation of the flue gas comprises a boiler wall and a boiler chamber which is communicated with an outlet of a combustor, an outer side water-cooling wall is installed on the side wall of the boiler chamber, an inner side water-cooling wall is installed in the boiler chamber, and a water-cooling interlayer is formed between the outer side water-cooling wall and the inner side water-cooling wall; a flue gas backflow inlet is formed in the end, far away from the outlet of the combustor, of the water-cooling interlayer, and a lower-temperature flue gas backflow outlet is formed in the end, close to the outlet of the combustor, of the water-cooling interlayer; a low-temperature flue gas backflow zone is formed by the water-cooling interlayer, and a high-temperature flue gas radiation zone is formed by the portion, located on the inner side of the inner side water-cooling wall, of the boiler chamber. According to the water-tube boiler achieving internal circulation of the flue gas and the low-nitrogen combustion control method, by means of the circulation mode of flue gas in the boiler chamber, decreasing of combustion temperature is facilitated, generation of nitrogen oxides is reduced, the load of an induced draft fan cannot be increased, the system is easy to control, and combustion stability is good.

Description

technical field [0001] The invention relates to the technical field of boilers, in particular to a flue gas internal circulation water tube boiler and a low-nitrogen combustion control method. Background technique [0002] During the combustion of fuel, nitrogen oxides are one of the products of combustion. Generally, the nitrogen oxides produced by combustion come from two aspects: one is the oxidation of nitrogen in the air required for combustion; the other is the nitrogen oxides contained in fuel during the combustion process. decomposed and oxidized continuously. Nitrogen oxides are extremely harmful to the environment and human health. It is a major issue facing the development of boiler technology to take technical measures to reduce the formation of nitrogen oxides and reduce the emission of nitrogen oxides. [0003] In the prior art, such technical measures are divided into two categories: one is denitrification in the furnace, and the other is denitrification at t...

AI Technical Summary

Problems solved by technology

This flue gas recirculation method increases the flue gas volume of the system due to the introduction of a large amount of low-temperature flue gas, which leads to an increase in the flue gas flow rate and increases the load on the induced draft fan. At the same time, it is necessary to add a circulating fan, which makes the control complicated. , increased investment and energy consumption

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