Tangential Combustor

Abstract

A combustion section for a gas turbine includes a casing defining a chamber, a plurality of combustor cans disposed in the casing and oriented in an annular pattern, and a plurality of transition pieces each coupled with one of the combustor cans. The transition pieces direct products of combustion from the combustor cans into contact with rotating buckets of the gas turbine. Each of the transition pieces is angled in two planes to effect turning of the products of combustion and to shorten the gas turbine.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to a gas turbine and, more particularly, to a combustion section for a gas turbine including structure for turning air flow into the turbine.[0002]In operating a gas turbine, gas flow is exhausted from the combustor and routed by the transition duct to first stage vanes and blades (rotating buckets). As the gas flow is discharged from the outlet of the transition duct, the flow passes the first stage vanes. The function of the first stage vanes is to accelerate and turn the flow in a circumferential direction so that the predominant flow direction of the gas flow leaving the trailing edges of the vanes is angled in the circumferential or tangential direction relative to the longitudinal direction. This turned flow thus has a longitudinal component and a circumferential component. The flow angle can be substantial, in the range of 40 degrees to 85 degrees measured from the longitudinal axis. By accelerating and angling the gas fl...

AI Technical Summary

Benefits of technology

[0006]In an exemplary embodiment, a combustion section is provided for a gas turbine including rotating buckets that are driven by products of combustion from the combustion section. The combustion section includes a casing defining a chamber, a plurality of combustor cans disposed in the casing and oriented in an annular pattern, and a plurality of transition pieces one each coupled with each of the combustor cans. The transition pieces direct the products of combustion from the combustor cans into contact with the rotating buckets. Each of the transition pieces is angled in two planes to effect turning of the products of combustion and to shorten the gas turbine.

Problems solved by technology

The use of first stage vanes to accelerate and turn the longitudinal gas flow in the circumferential direction presents several challenges.

The forces and heat involved can crack and otherwise damage the vanes and associated support structure.

To address these various requirements and operating conditions, the first stage vanes and the associated support structure and cooling systems have developed into a complex system that can be expensive to manufacture, install, and, in the event of damage, repair and replace.

The minimum compressor mass flow in current state of the art air-cooled gas turbines represents a major reduction in overall turbine performance.

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