Double-grade compound swirl nozzle for gaseous fuel low-pollution combustion chamber

Abstract

The invention provides a double-grade compound swirl nozzle for a gaseous fuel low-pollution combustion chamber comprising an on-duty-grade swirler 1, a main-combustion-grade swirler 2, a simplified flame tube 3, a diffuser 4, a stabilized flame 5, a main swirl 6 and a wall-attached jet flow 7. The on-duty-grade swirler 1 and the main-combustion-grade swirler 2 mutually act to form the stabilizedflame 5, so that a detached flame is then formed; the mixing and ignition effect of an on-duty-grade high-equivalence-ratio combustion product and a main-combustion-grade fresh fuel gas is improved, the temperature of a main combustion area and the length of the flame are lowered, the standing time of the flame is shortened, and therefore the low emission purpose is achieved; the work range is widened and stabilized, the selectable types of fuel are increased, and the backfire problem, the carbon deposition problem and the like are avoided. The low-temperature wall-attached jet flow 7 providesa natural thermal barrier layer, so that the wall face of the simplified flame tube 3 is kept at a low temperature, design of a floating wall and other complicated cooling structures are basically avoided, the weight of the simplified flame tube 3 is reduced, the complexity of design is lowered, the strength of the simplified flame tube 3 is improved, and the protective effect is better.

Description

technical field [0001] The invention belongs to the application field of gas turbine staged low-pollution combustion chambers, and in particular relates to a two-stage composite swirl nozzle used in gaseous fuel low-pollution combustion chambers. Background technique [0002] To achieve low emission requirements, it is necessary to reduce the temperature of the main combustion zone, shorten the residence time of the gas in the high temperature zone, and improve the uniformity. Although lean-burn premixed combustion can achieve the goal of low emissions, from the perspective of low-pollution combustion mechanism, completely uniform lean-fuel premixed combustion has disadvantages such as combustion instability. Therefore, when applying lean-burn premixed combustion technology, it is often used Staged or stratified combustion methods. Foreign researchers have studied the working mode of the duty class and found that when the duty class adopts the premixed flame for stable comb...

AI Technical Summary

Problems solved by technology

Even so, due to the relatively high equivalent of the duty class, problems such as tempering and carbon deposition are still prone to occur. At the same time, there are still local high temperatures, and the gas stays in the high temperature area for a long time, which is not conducive to emission control.

When hydrogen-doped fuel is used, the flashback problem is particularly serious; when syngas and pyrolysis gas fuel are used, due to the large range of gas composition changes, the flame propagation speed fluctuates in a large range and the flame pulsation is relatively severe

These are all unfavorable factors in the application of low emission technology

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