Three-return-stroke powder steam boiler

Abstract

The invention discloses a three-return-stroke powder steam boiler. The three-return-stroke powder steam boiler comprises a boiler barrel, a hearth, a burnout chamber, a convection tube bundle, tail heat exchange equipment, a combustor, a slag falling device, a lower header and an upper header, wherein the lower header is arranged at the bottom of a boiler body; the upper header is arranged at the top of the boiler body; the combustor is arranged at the front part, the top, the bottom or the side part of the hearth of the boiler; the boiler body has a full-film type water-cooled wall structure, and four main downcomers are arranged at four corners; the convection tube bundle is arranged in a convection tube bundle flue, the convection tube bundle flue is longitudinally arranged, and the height of the convection tube bundle flue is equal to that of the hearth; the upper and lower ends of the convection tube bundle, the main downcomers and a film type water-cooled wall are communicated with the upper header and the lower header respectively; the burnout chamber and the hearth are longitudinally arranged abreast in a back-to-back way, and the height of the burnout chamber is equal to that of the hearth; the hearth, the burnout chamber, the convection tube bundle flue and the tail heat exchange equipment are sequentially conducted in series; two-stage combustion-supporting and denitration secondary air is distributed in the hearth. The three-return-stroke powder steam boiler has the characteristics of long flue gas flow, complete fuel combustion and high heat exchange efficiency.

Description

technical field [0001] The invention belongs to the field of coal-fired industrial boilers, and in particular relates to a three-pass powder boiler which uses coal powder, oil, gas, biomass powder and other combustible solid powder as fuel for generating steam. Background technique [0002] my country's energy structure is dominated by coal. For a long time in the future, industrial boilers that mainly burn coal and supplement oil, gas, biomass and other solid fuels will still be the leading products of industrial boilers. [0003] The traditional industrial coal-fired boilers are mainly layer-fired boilers. The disadvantages are low combustion efficiency and serious pollution, which makes it difficult to meet the requirements of energy saving, emission reduction and pollutant discharge. [0004] Coal powder combustion, oil gas combustion, powder biomass combustion, and powder combustion of other solid fuels are one of the efficient and clean combustion methods of fuel, and ...

AI Technical Summary

Problems solved by technology

[0005] 1) The height of the SHS double-drum bulk water tube boiler is too high, making it inconvenient to manufacture and install, and difficult to maintain

[0006] 2) The furnace of D-type double drum assembly or bulk boiler is too low, and the fuel combustion is not sufficient if the furnace is too low

[0007] 3) The combustion is not uniform enough, and the temperature difference between front and back is relatively large, which is not conducive to reducing NO X Content

[0008] 4) The load adjustment range is small, only a single fuel can be used

[0009] 5) Boiler ash and slag cleaning is inconvenient

[0010] 6) Large consumption of boiler steel and furnace wall materials

[0011] 7) The boiler room occupies a large area and the cost of civil construction is high

For boilers with this structure, on the one hand, the heat of the side wall of the furnace 2’ cannot be effectively utilized; on the other hand, the height of the burnout chamber is limited, and the flow of high-temperature flue gas is relatively short, so the thermal efficiency of the boiler is low

In addition, since there is no maintenance space, it is not conducive to maintenance

[0014] figure 2 Shown is another vertical pulverized coal corner tube boiler, whose burnout chamber is set on the rear side of the furnace 13', which also has the problems of short flue gas flow, low heat exchange efficiency, and difficult maintenance.

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