Low-nitrogen combustion process and device combining direct flow with rotational flow and supplying air at multiple stages in hearth

Abstract

The invention belongs to the field of gas combustion, and particularly relates to a low-nitrogen combustion process and device combining direct flow with rotational flow and supplying air at multiplestages in a hearth. 30%-80% of fuel gas is fed from a basic load gas pipe into a rotational flow mixing area as the basic heat load, 20%-70% of combustion air enters a combustion air channel tangentially from a volute type air box as primary combustion air; and a rotational flow air regulator is arranged at an outlet of the combustion air channel, the combustion air rotationally flows out of the channel according to the angle of the air regulator and is rotationally injected into directly entering gas flow, and the combustion air and the directly entering gas flow are mixed in a rotational flow mixing area and ignited and combusted by an igniter. Other fuel gas and secondary combustion air enter a combustion area as corner tangential direct flow through 2-7 stages of pipelines penetratingthrough the side wall of the hearth, and are mixed and combusted. A flue gas recirculation pipeline penetrates through the side wall of the hearth in a staged mode and enters the combustion area, andthe combustion effect is improved. The integrated design of a burner and the hearth can be realized, a high-power combustion device is compact in structure, and the investment cost and the operation cost can be reduced.

Description

technical field [0001] The invention belongs to the field of gas combustion, and relates to a combustion device, in particular to a low-nitrogen combustion process and device with a combination of direct current and swirling flow, multi-stage air supply in a furnace, and a combustion device. Background technique [0002] The information disclosed in this background section is only intended to increase the understanding of the general background of the present invention, and is not necessarily taken as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. [0003] Blast furnace gas and biomass pyrolysis gas are widely used as low calorific value fuel gas. Due to its low calorific value, when the thermal power demand is large, multiple sets of combustion devices are often required, and the system is complicated; the gas volume is large, the mixture with the air is uneven, the combustion is incomple...

AI Technical Summary

Problems solved by technology

Due to its low calorific value, when the thermal power demand is large, multiple sets of combustion devices are often required, and the system is complicated; the gas volume is large, the mixture with the air is uneven, the combustion is incomplete and uneven, and the combustion efficiency is low; the gas nozzle is large, and the flame Large, long torch, requires a large cross-section and depth of the furnace, but the furnace cannot be used to adjust the combustion atmosphere, and it is difficult to control nitrogen oxides

[0004] When the system needs to burn low-calorific-value gas to generate high-power heat, the combustion device especially needs to solve the above problems: a single set of burners is bulky, insufficient mixing leads to insufficient combustion, and nitrogen oxide emissions cannot meet the emission requirements

[0005] The existing swirling flow and direct current combined type gas burners are used to reduce the difficulty of mixing high calorific value gas fuels, but they are only limited to the mixing on the gas channel of the burner, and it is difficult for the gas to be supplied multiple times in a small space. Can make full use of furnace tissue combustion

[0006] And the three-stage classification is highly efficient, energy-saving and low NO X The gas burner realizes the staged combustion of three-stage fuel gas, but it is limited to stages on the gas supply channel of the burner, limited by the structure, and the number of stages is small; the gas is only mixed in a small space with limited gas supply channels, and the mixed gas is burned at the nozzle , failed to make full use of the furnace to organize combustion

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