Biomass low-nitrogen direct combustion boiler

Abstract

The invention relates to a biomass low-nitrogen direct combustion boiler, comprising a hearth, wherein a boiler body is arranged on the upper part of the hearth, a hopper is arranged at a feeding port in the front of the hearth, a chain grate is arranged on the lower part of the hearth, a front smoke box and a rear smoke box are arranged at the front and the rear ends of the boiler body respectively, an isolating arch, a rear arch, a wing-shaped flue and a flue-gas-isolating wall are arranged inside a hearth cavity, a flue gas guide plate is arranged at the front end of the rear arch, the flue-gas-isolating wall is arranged on the upper part of the rear arch, a secondary air device is arranged on the front arch, and a tertiary air device is arranged on the flue-gas-isolating wall; and the hearth cavity is internally divided into a pyrolysis region, a layer combustion region, a re-combustion reduction region and a gasification combustion region. According to the invention, in accordance with the components and the combustion features of biomass fuel, efficient combustion of the fuel is realized by adopting the technologies of layer combustion and gasification coupling combustion, and ultralow emission of nitrogen oxides is realized by adopting the technologies of hierarchical air distribution, semi-coke reduction and re-combustion of pyrolysis products, therefore, the biomass boiler becomes a real energy-saving and environment-friendly product.

Description

technical field [0001] The invention relates to a biomass boiler, in particular to a biomass low-nitrogen direct-fired boiler. Background technique [0002] At present, under the dual conditions that the country attaches great importance to the development of biomass energy and restricts coal burning, biomass boilers are gradually favored due to policy support and superior environmental protection and economic performance, and have become an important product to replace coal-fired and oil-fired gas-fired boilers. However, most of the biomass boilers currently on the market are simply transformed from coal-fired boilers, or directly use coal-fired boilers (such as: Chinese patent applications 200710049037.3, 200810137245.3, 201010151608.6), which are difficult to take advantage of biomass fuels and are not suitable for Biomass fuel has combustion characteristics such as high volatile content, low ignition point, and non-combustible gas, low combustion efficiency, high exhaust...

AI Technical Summary

Problems solved by technology

However, most of the biomass boilers currently on the market are simply transformed from coal-fired boilers, or directly use coal-fired boilers (such as: Chinese patent applications 200710049037.3, 200810137245.3, 201010151608.6), which are difficult to take advantage of biomass fuels and are not suitable for Biomass fuel has high volatile content, low ignition point, combustible gas is not easy to burn out and other combustion characteristics, low combustion efficiency, high exhaust temperature, and low thermal efficiency

In addition, the nitrogen oxide emissions of biomass boilers are relatively high, and under certain conditions, nitric acid rain can be formed, which has great damage to the ecological environment.

The inventions of Chinese patent applications 200910187815.4 and 201020528853.X adopt secondary air distribution or use fluidization technology to assist combustion, but they ignore the impact of NOx produced by fuel combustion on the environment and the comprehensive utilization efficiency of energy. room for development

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