Decoupling gas burner

Abstract

The invention discloses a decoupling gas burner, and belongs to the technical field of combustion equipment. The decoupling gas burner comprises an outer cylinder body, a separation cylinder body, a gas outer cylinder body and a gas inner cylinder body which are sequentially arranged from outside to inside and coaxial, a first-stage air duct is formed in the gas inner cylinder body, a gas channelis formed between the gas inner cylinder body and the gas outer cylinder body, a second-stage air duct is formed between the gas outer cylinder body and the separation cylinder body, a third-stage airduct is formed between the separation cylinder body and the outer cylinder body, the decoupling burner further comprises a frustum-shaped cylinder body, the small-diameter end of the frustum-shaped cylinder body is connected to the end, which extends into a hearth, of the separation cylinder body, the outer diameter of the large-diameter end of the frustum-shaped cylinder body is smaller than theinner diameter of the outer cylinder body, and in the axial direction of the frustum-shaped cylinder body, the distance between the end, which extents into the hearth, of the outer cylinder body andthe large-diameter end of the frustum-shaped cylinder body is adjustable. According to the provided decoupling gas burner, the frustum-shaped cylinder body is arranged so that the decoupling gas burner can be suitable for different gas and hearth structures.

Description

technical field [0001] The invention relates to the technical field of gas combustion equipment, in particular to a decoupled gas burner. Background technique [0002] Natural gas has good performance, high calorific value, and does not contain fuel nitrogen. The key point is to control the combustion temperature to avoid the formation of thermal NOx. For small-capacity equipment, the theoretical combustion temperature can be reduced by fully premixed surface combustion with a high excess air ratio, and flashback and defiring can be avoided; rich-lean combustion (deviated combustion) and air / fuel staged combustion need to take into account combustion stability and The theoretical combustion temperature of each stage. The process of oxygen-lean combustion first (poor oxygen in the central ignition zone) has high stability, but the combustion temperature is relatively high; the process of fuel-lean combustion first (lean fuel in the central ignition zone) has a large room for...

AI Technical Summary

Problems solved by technology

Many of these gases have low or unstable calorific value, large fluctuations in composition and pressure, and relatively weak combustion stability or low-nitrogen combustion capabilities; some gases contain H 2 Large amount, high-load flame intensity and low-load tempering control problems are prominent; some gases contain fuel nitrogen, and NOx emission control is more complicated

[0004] Diffusion combustion is beneficial to suppress the formation of fuel-type NOx. However, traditional diffusion combustion focuses on the diffusion of gas with a small cross-section to the air with a large air space. Although the two-way diffusion is promoted by air swirl, it is easy to generate local high temperature and high oxygen in the middle of combustion. , it is difficult to control thermal NOx; some premixed flames are easier to control NOx, but there are problems of tempering and defiring, and the stable combustion range is narrow; large industrial burners are not suitable for surface combustion, and high excess air coefficient is used for stable combustion The capacity becomes worse, and the loss of smoke exhaust increases; the gas containing fuel nitrogen is not suitable for traditional thick-lean combustion, and there is no solution to the formation of NOx in the oxygen-enriched area; the use of flue gas recirculation is beneficial to control the formation of NOx, but it will reduce the ability to stabilize combustion , and increased operating power consumption

[0005] Due to the limitation of air and gas diffusion and mixing methods, the staged combustion effect of traditional burners in limited spaces is limited

The use of a large number of burn-off air schemes far away from the main combustion area can realize staged combustion (macro-stage) in a large area, which is beneficial to suppress the formation of fuel-type NOx, but it is difficult to fully mix the combustible gas and combustion-supporting air in a large space, and burn out Shortening the time will increase CO emissions; in addition, due to the instability of fuel, it is difficult to adjust the graded air volume to control NOx emissions

For low calorific value gas, the regional combustion temperature is low at low load, and it is easy to extinguish the fire. At high load, the gas flow rate at the nozzle is high and easy to go off fire; some low calorific value gases need to use oxygen-enriched or blended high calorific value gas to improve the stability of combustion. Measures such as permanent lighting, some adopt guard combustion belt, preheat air and gas to 400-600°C to increase the combustion temperature as a whole, which increases the difficulty of NOx control

Due to the improvement of environmental protection requirements, some industrial gas furnaces need to add more complex flue gas denitrification devices such as SCR, which increases equipment investment and operation and maintenance costs.

[0006] At present, most of the burners used in the industry are only designed for one kind of fuel. The adaptability is insufficient when the fuel composition changes greatly and is unstable, and the control ability of fuel-type NOx is weak. To reduce NOx, CO emissions will increase significantly. Or increase the energy consumption of operation. If the combustion stability and thermal efficiency are improved, more NOx will be produced, that is, there is a more obvious coupling relationship between combustion stability, low nitrogen combustion and thermal efficiency.

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