A gas decoupling burner and its use method

Abstract

The invention relates to a gas decoupling burner and its use method. The gas decoupling burner adopts a zoned and graded combustion mode in which the center and the periphery are poor in oxygen, and the middle area is lean in combustion; The low diffusion oxygen-lean combustion ensures reliable ignition and low-load stable combustion in the lean-burn zone; the outer-edge lean-oxygen combustion zone controls the temperature distribution of the combustion chamber by precisely controlling the mixing of gas and air in different regions to improve radiation heat transfer Ability to promote the mixed burnout of the outer edge gas and the main combustion zone. In a word, the present invention effectively solves the problem that the combustion temperature is too high in the middle stage of the diffusion combustion method, the heat intensity of the combustion chamber is more uniform, the flame fullness is high, the heat transfer capacity is strong, the flue gas stays for a long time, and the combustion chamber is low in power consumption. Guaranteed combustion efficiency while reducing thermal NO X The generation of gas realizes the decoupled combustion of gas.

Description

technical field [0001] The invention belongs to the technical field of combustion, and relates to a burner, in particular to a gas decoupling burner and a use method thereof. Background technique [0002] High calorific value gas has the characteristics of rapid combustion and high theoretical combustion temperature, but it is easy to generate thermal NO in the combustion process. X , for the traditional diffusion combustion method, due to the poor uniformity of air-fuel mixing and combustion, it is easy to cause a wide distribution of flame high-temperature areas and a high peak temperature of flame combustion. X Very unfavorable. [0003] Premixed combustion can significantly improve the uniformity of combustion, but the combustion stability and safety are reduced. Surface combustion technology is the most widely used fully premixed combustion method at present. Through dense hole network and narrowing the outlet aperture of the mixed gas to the limit tempering However, ...

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Problems solved by technology

Due to the small flow rate and high temperature of the flue gas internal circulation, it is necessary to make full use of the heat dissipation capacity of the combustion chamber and require a high flow rate of the combustion gas, which further increases the energy consumption of the fan. Therefore, specific combustion methods and furnace types are often used. ; When external circulation of flue gas with low flue temperature is adopted, the combustion temperature and thermal NO can be significantly reduced by increasing the circulating air volume X generation, but the combustion stability and combustion efficiency decrease, the flow rate of the fan and the system resistance increase, and the energy consumption increases

[0005] In the prior art, there are also technical solutions that simultaneously adopt staged diffusion combustion or a small amount of premixing. This type of technical solution mainly uses fuel segmented mixed combustion, and the fuel injection ports are arranged in groups and intervals on the outer circumference of the combustion-supporting air, and the circumference is relatively long. The annular air flow can reduce the local air volume, increase the air-fuel mixing time and the length of the diffusion combustion flame, but the main combustion area of ​​the diffusion combustion method is small, and the high-temperature area is concentrated, which reduces the radiation heat dissipation and convective heat transfer of the flue gas; Part of the gas leaves the airflow in the main combustion zone at the front end, which can control the local thermal intensity of the diffusion combustion in the middle and front stages, but it will cause a large amount of unstable low-temperature combustible gas to accumulate, increase combustion fluctuations, and cause a large risk of deflagration. Safety at low load and ignition stages reduce

[0006] In addition, in order to control and prolong the air-fuel mixture and increase the entrainment capacity, the main air flow of the above-mentioned technical solution mostly adopts a straight-line injection with the nozzle shrinking inward, and the fullness of the combustion chamber flame is reduced, which is not good for heat dissipation and stable combustion.

In addition, in order to reduce the central temperature of the flame, the amount of fuel arranged in the central combustion area is very small, which is not conducive to the stable combustion of the flame, but also causes the relative concentration of the peripheral fuel, which strengthens the way of diffusion combustion, which is not conducive to reducing the heat Type NO X generation

[0007] For measures such as fuel segmental mixed combustion and flue gas internal circulation, such technical solutions weaken the combustion at the front of the combustion chamber, reduce the radiation heat dissipation of the flue gas, concentrate the high temperature area of ​​the combustion chamber to the rear, and the average flue gas temperature is still high ; Moreover, the fullness of the flue gas in the combustion chamber is low, the smoke velocity in the main combustion zone increases, and the residence time of combustibles is short, which is not conducive to ensuring the combustion efficiency after staged combustion

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