Low emission high efficiency grate-firing combustion device and method

Abstract

The invention relates to a low emission high efficiency grate-firing combustion device and a method. The method is characterized in that coal dust and a sulfur-fixing agent are fully mixed so as to enter into a grate-fired furnace through a hopper, a gas recirculation and spray water combined technology is utilized to rapidly pyrolyze coal dust so as to generate reducing gas, recirculation fume is utilized to carry the reducing gas and part of fine granule semicoke to enter into a recrudescence region in the furnace, and the combustion flow of the furnace is strengthened; and the purpose of reduction NOx is achieved, the no-burnout grains are continually combusted above a combustor, staged combustion of a fuel in the furnace is realized in a hearth, and meanwhile, and the combustion efficiency of the grate-fired furnace is also improved. According to the invention, the grate-fired furnace is introduced through a fuel staged combustion technology, on the one hand, the NOx and SOx discharge of the grate-fired furnace is reduced through combustion adjustment, namely, the NOx deprivation rate is 35%-55%, the SOx deprivation rate is more than 80%, thereby protecting an atmospheric environment; on the other hand, the combustion efficiency of the grate-fired furnace is improved by 1%-2%.

Description

technical field [0001] The invention belongs to the technical field of clean energy, and specifically relates to a combustion adjustment method (combination of flue gas recirculation technology and water steam injection technology) to reduce NOx and SOx emissions of a floor-burning furnace, and can also improve the combustion efficiency of the floor-burning furnace. Background technique [0002] The application of industrial boilers in my country is characterized by a large quantity and a wide range. At present, there are about 550,000 industrial boilers in operation. Although with the development of the national economy and the improvement of people's living standards, the number of oil-fired and gas-fired boilers is gradually increasing, but due to Coal is the main fuel in my country, so most industrial boilers are coal-fired boilers, and they are mainly layer-fired boilers. Due to design and operation reasons, the thermal efficiency of industrial boilers in my country is ge...

AI Technical Summary

Problems solved by technology

However, in this patent, the combustible gas and small particle semi-coke produced by the oxidation pyrolysis chamber of the layer combustion furnace can reduce the production of NOx, and since the pyrolysis chamber pyrolyzes in an oxidizing environment (air) and a relatively low temperature, it produces Reducing gas (NH i , HCN, CH i 、H 2 and CO, etc.), and the pyrolysis rate is low, especially for low-quality bituminous coal, which produces less reducing gas, and the effect of reducing NOx is not obvious; this patent affects the output of the boiler due to the installation of an oxidation pyrolysis chamber in the layer combustion furnace ; In addition, this patent has a large modification to the boiler body in engineering application, and the construction is relatively difficult

With the increasing environmental protection requirements, NOx emissions will be more stringent, so the industrial applicability of this patent is poor, and it cannot meet the increasingly stringent environmental protection requirements

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