A low-emission recirculation combustor using a radial swirl intake fuel staging scheme

Abstract

The invention discloses a low-emission reverse flow combustor adopting the radial swirl injection and fuel oil grading schemes. The low-emission reverse flow combustor adopting the radial swirl injection and fuel oil grading schemes is that air flows from a head part of a radial grading three-grade swirler into a flame tube, and while fuel oil flows through an on-duty-grade oil channel and a main-combustion-grade oil channel to reach the combustor, so as to form an on-duty area and a main combustion area in the head part of the combustor; diffusive combustion occurs in the on-duty area, and while pre-mixing combustion is caused in the main combustion area; and a high-temperature product produced by the combustion flows to the downstream, turns in 180 degrees at an exhaust elbow and then is discharged from the combustor. The low-emission reverse flow combustor has the advantages that a central on-duty-grade part works when the combustor is under ignition, starting, slow running and other low load states, thus the combustion efficiency is improved, and the emission of un-combusted materials CO and UHC is decreased; in case of relatively large load above slow running load, the main-combustion-grade oil channel and the on-duty-grade oil channel work together, the on-duty-stage oil channel provides a stable ignition source to the main-combustion-grade oil channel so as to expand the boundary of the combustor; the main combustion area is designed to perform lean-oil combustion under equivalence ratio of 0.6 to 0.65, and the reaction temperature is far below the adiabatic flame temperature, and thus the produced and emitted nitric oxide (NOX) are decreased; and the multi-grade swirl injection and fuel oil grading schemes are applied to the combustor of an aircraft engine or a ground gas turbine.

Description

technical field [0001] The invention relates to a low-emission combustion chamber adopting a fuel classification scheme, in particular a low-emission recirculation combustion chamber matched with a radial swirl intake scheme, and has a simple and compact structure. The stable working boundary of the combustor adopting this scheme is greatly widened, and the emission can be significantly reduced. Background technique [0002] With the rapid development of the global economy and the increasing awareness of environmental protection, aero-engines and ground gas turbines are the most efficient power equipment, and their pollutant emission levels are increasingly restricted. International Civil Aviation Organization (International Civil Aviation Organization, ICAO) emissions from aircraft engines, especially nitrogen oxides NO X Emission requirements are becoming increasingly stringent. According to the recommendations of the International Civil Aviation Organization's Committee...

AI Technical Summary

Problems solved by technology

The disadvantage of this type of combustion chamber is that the fuel is injected to the downstream of the main swirler to form a pre-mixed and pre-evaporated fuel-air mixture, but the fuel cannot be fully atomized and evaporated in this injection method, in order to make the fuel-gas mixture evenly mixed , the mixing distance required by this injection method is longer, and the evaporation time is also longer, which is very unfavorable for reducing the length and weight of the combustion chamber

[0005] The low-pollution combustor technologies proposed by domestic scientific research institutes all have the following disadvantages to varying degrees: the main combustion grade fuel is injected at the end of the swirler blade, and the mixing length is short; the atomization effect of the fuel in the duty area is not good, It cannot be fully mixed with the swirling air, which is not conducive to the flame stabilization effect of the duty class; adding an intermediate stage between the central duty class and the outer main combustion stage will block the coupling of the duty class and the main combustion stage flame to a certain extent, causing Possibility of main combustion stage flame extinguishing; main combustion stage fuel oil adopts tangential or axial fuel supply method, which increases the complexity of the fuel and air mixing device at the head of the combustion chamber, and is not conducive to weight loss of the combustion chamber; its main combustion stage The fuel injection source is not located in the swirler vane channel, and the fuel cannot be violently mixed with the swirling air, so that the premixing effect of fuel and air is not good

If mild and low-temperature combustion can be achieved, NO X On the other hand, if the combustion temperature is too low, it will cause incomplete combustion, increase CO and UHC emissions, and reduce combustion efficiency

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