A passive feedback-controlled regulator and method for regulating gas turbine bleed air is provided, which automatically regulates the flow of coolant air directed to the turbine vanes, blades, and other hot section components based on the inherent differential pressure between the diffused compressor discharge pressure and the compressor impeller exit air. The differential pressure used to operate the regulator is a measure of the turbine mass flow rate, and, therefore is a measure of the instantaneous engine coolant flow requirement.

Passive turbine coolant regulator responsive to engine load

A passive clearance control system is provided in the turbine section of a gas turbine engine in which turbine casing nozzle vanes and rotor blades are provided. The rotor blades are arranged on a rotor and preferably fitted with a shroud. The tips of the blades or shroud are surrounded by shroud segments suspended in the turbine casing, and a clearance between the tips and the shroud segments is formed and has a width which is controlled by a heating-cooling channel system. The channel system is supplied with a stream of air from the compressor section of the gas turbine and bypasses the combustion chamber to reach, via a plurality of metering holes, an annulus bounded by a stator ring. In a preferred aspect of the present invention, a ring-shaped orifice plate interacting with the metering holes is provided within the annulus which closes these metering holes to a varying degree depending on the temperature of the air stream reaching the heating-cooling channel system. A fraction of the hot gas flowing across the nozzle vanes and rotor blades is allowed to reach the annulus via a clearance between the stator ring and the stator shroud segments at least at a low turbine load.

Passive clearance control system for a gas turbine

A gas turbine engine includes a compressor rotor assembly which directs air at a sufficient pressure and temperature to a downstream turbine for cooling. The compressor assembly includes a compressor including an impeller and a cooling circuit. The impeller includes an exit, an inlet, and a body extending therebetween. The impeller body includes a first opening positioned a distance from the impeller exit. The cooling circuit extends between the compressor and the turbine and is in flow communication with the impeller opening.

Methods and apparatus for delivering cooling air within gas turbines

In a gas turbine engine having a rim cavity formed between a rotor disk and a stator, and a brush seal or other seal member providing an airflow seal between the stator and a side plate of the rotor disk, a thermally responsive valve device is located in the bypass passage of the stator to form a parallel air flow path with the brush seal. As the brush seal wears and the leakage airflow around the worn brush seal increases, the air flow temperature in the rim cavity would decrease. The thermally responsive valve device would detect the decreasing airflow temperature, and reduce the airflow passing through the bypass passage in order to prevent the temperature of the rim cavity from decreasing. The temperature responsive valve device makes use of a bimetallic valve member that regulates airflow based upon temperature.

Passive thermostatic bypass flow control for a brush seal application

The invention concerns a gas turbine stator comprising: at least first injection means (1) providing a passage for main cooling air stream into a pressurized chamber (16), means for evacuating discharge air coming from an internal labyrinth gland (13) of a first cavity (9) towards a lower-pressure second cavity (10), second injection means for evacuating the air contained in said second cavity (9) towards a main duct. The inventive stator is characterized in that it further comprises third injection means designed to generate an overpressure close to the internal labyrinth gland (13a, 13b) in said pressurized chamber (16).

Gas turbine stator

An apparatus for modulating a flow of cooling air from a compressor to a turbine in a gas turbine engine is disclosed. The apparatus includes a support member which forms a channel for receiving the cooling flow and has a throat at a downstream end with a radial orientation. A radial flow inducer is connected to the support member adjacent to the channel downstream end for accelerating the cooling flow through the throat of the support member. Apparatus for modulating the quantity of the cooling air flowing through the throat and into the turbine is provided in the form of an axially translating endwall, wherein variation of the throat area is accomplished through modulation of the endwall with respect to the support member. The support member may also house either a stationary, unmodulated axial flow inducer or a second modulated radial flow inducer in addition to the modulated radial flow inducer.

John P. McKay

Papers

Turbine cooling flow modulation apparatus