A gas turbine engine includes a compressor, combustor, and turbine, and a cooling air closed-circuit having an extraction line from the compressor to a hot turbine component such as vanes, blades, or shrouds, and a return line to the compressor The extraction line may be joined to any suitable compressor stage for extracting air at a suitable pressure for flow to the turbine, with the return line being joined to any suitable injection stage of the compressor having a lower pressure than the extraction stage for driving the cooling air through the closed-circuit The compressor itself therefore drives the closed-circuit and is self regulated

Closed-circuit air cooled turbine

Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor (22, 26) and delivered to passages internal to one or more of a combustor and turbine hot parts (100). The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts.

Closed loop air cooling system for combustion turbines

The clearance between the outer air seal of a gas turbine engine and the tip of the turbine rotor is controlled by selectively turning on and off or modulating the cool air supply which is directed in proximity to the air seal supporting structure so as to control its thermal growth. The cooling causes shrinkage thereby holding the clearance low and effectively reducing fuel consumption.

Clearance control for gas turbine engine

A gas turbine engine including in-line intercooling wherein compressor intercooling is achieved without removing the compressor main flow airstream from the compressor flowpath is described. In an exemplary embodiment, a gas turbine engine suitable for use in connection with in-line intercooling includes a low pressure compressor, a high pressure compressor, and a combustor. The engine also includes a high pressure turbine, a low pressure turbine, and a power turbine. For intercooling, fins are located in an exterior surface of the compressor struts in the compressor flowpath between the outlet of the low pressure compressor and the inlet of the high pressure compressor. Coolant flowpaths are provided in the compressor struts, and such flowpaths are in flow communication with a heat exchanger. In operation, air flows through the low pressure compressor, and compressed air is supplied from the low pressure compressor to the high pressure compressor. The fins increase the heat transfer area between the gas turbine main compressor airflow and the coolant flow in the struts. Specifically, the flowpaths in the struts serve as heat sinks for cooling the high temperature compressor mainstream flow. The cooled airflow is supplied to the inlet of the high pressure compressor, and the highly compressed air is delivered to the combustor. Airflow from the combustor drives the high pressure turbine, the low pressure turbine, and the power turbine. Waste heat is captured by the boilers, and the heat from the boilers in the form of steam is delivered to upstream components. The steam could, alternatively, be delivered to a steam turbine or to other equipment.

Gas turbine in-line intercooler

Method and apparatus are disclosed for providing a closed-loop air cooling system for a turbine engine. The method and apparatus provide for bleeding pressurized air from a gas turbine engine compressor for use in cooling the turbine components. The compressed air is cascaded through the various stages of the turbine. At each stage a portion of the compressed air is returned to the compressor where useful work is recovered.

Closed-loop air cooling system for a turbine engine

This invention relates to gas turbine engines, and, more particularly, to multishaft turbojet aero engines having a plurality of compressors and turbines, in which air is bled from one or several compressors in the engine for cooling engine components and for providing a seal between the rotary and stationary assemblies of the several rotor systems, and in which means are additionally provided for compressor control.

G Kohler

Papers

Turbojet aero engines having means for engine component cooling and compressor control