Exhaust diffuser for a gas turbine

Abstract

The invention relates to an exhaust diffuser (1) for a gas turbine (2) including: a tubular transition sheath (5) having a central axis (10); a circular cross-sectional sheath input end (6) to be connected downstream from the turbine (2); and a sheath output end (8) to be connected upstream from an exhaust pipe (4), the sheath output end (8) having a generally polygonal cross-section; the diffuser (1) also including at least one baffle (13) attached to the transition sheath (5) and placed relative to the sheath input end (6) so as to be able to divert part of an incoming gas flow. The baffle (13) includes a tubular wall coaxial to the central axis (10) and opening out in the direction of the sheath output end (8); the tubular wall having, on one end on the side of the sheath input end (6), a circular baffle input section (13a) and, on the opposite end, a generally polygonal baffle output section (13b), said baffle output section (13b) having a number of corner areas and an orientation around the central axis (10) of said corner areas corresponding to the corners of the polygonal section of the sheath output end (8).

Description

technical field [0001] The present invention relates to the field of gas turbines, and in particular to the field of diffusers for gas turbines, said diffuser being installed between the turbine and a muffler in the exhaust duct downstream of said gas turbine. Background technique [0002] The gas from the gas turbine exits the final expansion stage at a very high velocity. For proper treatment of turbine exhaust noise, the velocity of the gas must be significantly reduced before it is expelled into the atmosphere. [0003] In a turbine, the rotor blades convert the kinetic energy of the gas into thermomechanical energy. The manifold of the turbine stator funnels the gas that has flowed between the vanes. Such manifolds generally have a circular cross-section. The transition jacket connects the manifold of the turbine stator to the muffler. [0004] A muffler capable of reducing gas exhaust noise is usually inserted on the exhaust pipe, and the cross section of the exhau...

AI Technical Summary

Problems solved by technology

That is, such a diffuser has the disadvantage that it is not suitable for concentrating the airflow in the center of the air duct

[0009] Some turbines cannot be combined with a diffuser surrounding the turbine rotor due to e.g. space availability etc.

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