Annular combustor in gas turbine engine and method of operation

Abstract

This invention relates to mechanical and power engineering, transportation and other fields, and in particular to the design of low-emission annular combustors in jet turbine engines and stationary gas turbine plants based on the low Drain the burner and use an efficient method of operation. A summary of the invention is as follows: - An annular combustor gas turbine engine comprising two coaxial annuli of a dual circuit low emission combustor with a porous member. The burner is mounted on the front wall of the flame tube. The ends of the burner lie in one plane. The inner channel of the burner is supplied with pilot fuel only. Diffusion combustion of the fuel takes place in an alternate flame. The outer channel is supplied with main fuel and compressed air from behind the compressor. With the first-stage injection supply of the main fuel in air cross-flow and the second-stage subsequent delivery of the lean fuel and air mixture through the microchannels of the porous body of the porous structure, a high quality lean fuel and air mixture is obtained. Prepared in advance. Power combustion of a lean fuel and air mixture is maintained using an alternate flame; the inner burner passages of the inner ring are grouped in the inner ring pilot fuel manifold and the burner ring fuel receivers are grouped in the inner ring main fuel rail Middle;‑When the direction of swirl flow in the burner is switched from one burner to the other adjacent burner in each ring, the direction of swirl flow in the burner is replaced by the reverse, using an axial vane swirler, to form periodic paired swirls covering two burners, one of which is associated with the outer ring of the combustion chamber and the other with the inner ring of the combustion chamber;‑in start-up mode and transition mode , when the load increases to near idle power, the supply of main and pilot fuel to the inner annular combustor is achieved by closing off the main and pilot fuel supply lines upstream of the inner main and pilot fuel manifolds The valve is disconnected, which allows a two-fold reduction in the excess air factor in the burner of the outer ring;- By maintaining a specific total consumption of main fuel and pilot fuel and a specific total excess air factor, when using The relative pilot fuel consumption in all burners is reduced while maintaining a lean fuel and air mixture, with fuel regulators in the main and pilot fuel lines providing for minimal NOx emissions. combustion stability. The above-mentioned and some other proposed technical solutions allow to reduce the total pressure loss, increase the reliability of the operation of gas turbine engines with annular combustors, widen the range of stable combustion of lean fuel and air mixtures and provide and better homogeneity of the temperature field in the circumferential direction, while reducing the emissions of nitrogen oxides and carbon oxides, which provide the benefits of the proposed annular combustion chamber compared to the operating method of the combustion chamber and its prototype. The claims consist of two independent claims and five dependent claims. The description includes five drawings.

Description

technical field [0001] The present invention relates to a combustor mainly used in jet gas turbine engines and stationary gas turbine installations, and to methods of operation thereof. Background technique [0002] In order to ensure a stable combustion of the fuel and air mixture, blunt body or vane swirlers are used (sometimes simultaneously) in this type of burner. In annular combustors, unidirectional swirls in separate burners result in coaxial annular swirls. Typically there is a pressure loss due to wall friction in the flame tube while maintaining these swirls. This is why this toroidal swirl is considered derivative. In addition to the pressure loss, the flame strength of the burner and the combustion stability of the fuel and air mixture are reduced since a part of the derived swirl does not participate in the combustion. [0003] It should be noted that if all burners have the same swirl direction, the transfer of the flame from a burner actively ignited by a ...

AI Technical Summary

Problems solved by technology

[0027] - lower combustion chamber combustion intensity and fuel combustion efficiency, and part of the fuel is lost due to the expansion of the front wall and the volume of the annular combustion chamber caused by the alternating displacement of every two burners outwards or towards the center of each ring and Air mixture combustion stability

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