United Technologies Corporation

James G Griffin

Frederick M Schwarz

Gary F Chaplin

Raymond A Dreisbach, Jr

John P Nikkanen

Irwin D Singer

Edward F Cole

Francis L DeTolla

Vytautis P Gudaitus

John P Beck

Robert J McHale

Roger L Summers

Heat transfer systems for maintaining a thermal balance between a gas turbine engine and heat generating accessory components of the engine are disclosed. In the embodiment illustrated, heat is removed from the cooling system 48 of an electrical generator 46 and is transferred to the fuel supply system 32 of the engine. In one detailed embodiment, the cooling system 48 is in direct heat transfer communication with the downstream portion 62 of the fuel supply system through a heat exchanger 76 and in indirect heat transfer communication with the upstream portion 60 of the fuel supply system through the fuel recirculation system 42.

Balancing the heat flow between components associated with a gas turbine

Apparatus for supplying pressurized cooling air to the turbine blades (20) of a gas turbine engine is disclosed. Multiple nozzles (38 and 40) of a tangential on-board injection system for pressurizing the cooling air are staged to provide variable rates of cooling airflow to the blades.

Turbine cooling air supply system

Methods and apparatus for improving the thrust specific fuel consumption (TSFC) of a gas turbine engine employing an exterior active clearance control system are disclosed. The pressure within the nacelle compartment to which active clearance control air is discharged is operated under altitude cruise conditions at a level on the order of one to two and one-half pounds per square inch (1-21/2 psi) above the ambient atmosphere. Flow discharging from the nacelle is directed through an aft facing vent nozzle for purposes of thrust recovery.

Pressurized nacelle compartment for active clearance controlled gas

A structure and method for providing cooling fluids from a compression section 10 to a turbine section 14 of an axially flow rotary machine is disclosed. Various construction details and steps of the method enable the machine to minimize the effect that unscheduled variations in the temperature of the cooling fluids have on operating clearances in the turbine section. These unscheduled variations may result from changes in ambient temperature and component deterioration. An internal cooling fluid from the discharge region 52 of the rearmost compressor 18 is used to modulate the flow of a second fluid impinged on the exterior of the outer case 24 for controlling the clearance between an array of rotor blades 26 and a coolable stator shroud 64 spaced radially outwardly of the rotor blades. In one embodiment, a valve 32 for modulating the flow of the second fluid has at least one thermostatic bimetallic spring 86 for transducing a change in temperature into a displacement. The displacement changes the flow area A.sub.f between a valve head 82 and a conical seat 80 in the conduit 30 for the second fluid through the valve 32.

Modulated clearance control for an axial flow rotary machine

A cooling system 44 for an electrical generator 42 is disclosed. The cooling system rejects excess heat to the engine fuel through a primary heat exchanger 46 and at low fuel flow rates, supplementarily rejects heat to fan air at a secondary heat exchanger 48 located remotely from the fan duct 30. In one embodiment, the secondary heat exchanger is disposed in a nacelle fan compartment 14. In another embodiment, the secondary heat exchanger is disposed in a nacelle core compartment 16.

Cooling system for the electrical generator of a turbofan gas turbine

To accommodate fuel having higher freezing points the continuous bypass flow of fuel from the fuel control is selectively diverted to pick up the rejected heat from the engine's lubrication system to heat the fuel in the aircraft fuel tank.

Fuel heating system for gas turbine engine

To improve on thrust specific fuel consumption for a gas turbine engine, compressor bleed for turbine cooling is divided into an air distribution system where at least one duct is valved and the other is continuously flowing restrictively with the excess air passing through the turbine mixing with gas path air in the vicinity of the rotating turbine labyrinth type seal to assure seal cooling with sufficient heating of the rotating parts to achieve minimum gap clearance of the seal.

Compressor bleed system for cooling and clearance control

A seal means for confining cooling air to a cooling air flowpath extending between a case structure and a flowpath for hot working medium gases in a gas turbine engine is disclosed. Various construction details which enable the seal means to block the leakage of cooling air into the working medium flowpath are discussed. The seal means has a center section which expands axially in response to the temperature of the working medium gases to develop a sealing force.

Seal means for a gas turbine engine

An active clearance control (ACC) for a turbofan engine is disclosed herein where the cross section of the external spray bars are fabricated in square or substantially square configurations.

External gas turbine engine cooling for clearance control

A support structure for an outer air seal of a gas turbine engine is disclosed. Various construction details which improve the sealing effectiveness of the outer air seal are developed. The outer air seal is held in close proximity to the rotor blades by the circumferentially adjacent support segments.

Outer air seal support structure for gas turbine engine

This invention serves to cool the lubricant used by a mechanical constant speed drive (CSD) driving an aircraft alternator which aircraft is powered by a turbofan engine. The system cooling capacity is supplemented by an existing engine fuel/oil heat exchanger thereby effectuating a reduction in size of the CSD fan air/oil heat exchanger and minimizing an aircraft engine performance penalty.

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West Hartford, CT, United States of America

James G Griffin