Abstract: A gas turbine has a cooling air system supplying air for cooling a high temperature part of the gas turbine and a spray air system supplying air for spraying fuel into a combustor and is formed so that a part of high-pressure air compressed by a gas turbine compressor is used as air of the cooling air system and spray air system, wherein a heat exchanger and a boost compressor are arranged downstream of the outlet of compressed air of the gas turbine compressor, and the boost compressor is composed of a parallel connection of a compressor driven by the turbine shaft and ae compressor driven by a driven source other than the turbine shaft, and pressurized air from the boost compressor is used as air for the cooling air system and the spray air system.

Abstract: In order to avoid the “buckling” of multi-shell turbomachine casings during a cooling phase following the shutdown, it is proposed to provide means in order to suitably discharge warm medium which collects at a point of the casing cavity situated at the highest geodetic level. In an embodiment, it is proposed to allow the corresponding lines to open out in the stack of a power plant; the stack draft effect assists the flow even further. Regulating members are advantageously provided in the lines in order to shut off these lines during operation of the turbomachine on the one hand and in order not to arrange the flow through the casing cavities too intensively on the other hand.

Abstract: A device and method for recuperating a gas turbine engine comprises a compressor being configured to receive a coolant fluid stream, to compress the coolant fluid stream and to discharge the compressed coolant fluid stream to a turbine in fluid communication with the compressor. The compressed coolant fluid stream undergoing thermal exchange within the turbine, exit the turbine thereafter. A source of a working fluid stream is in fluid communication with the turbine. The working fluid stream is fluidly isolated from a portion of the coolant fluid stream and undergoing thermodynamic expansion through the turbine to extract energy therefrom. Where desired, the entire coolant fluid stream is fluidly isolated from the working fluid stream. At least a portion of the coolant fluid stream is channeled downstream of the turbine to supply a preheated process fluid stream to an adjacent system.

Abstract: A turbine engine compressor design utilizing multiple component integration, thereby reducing the number of required engine components. In conventional compressor designs, a multiple component system makes it difficult to predict the structural behaviors due to thermal and mechanical loading during transient conditions. The compressor design of the present invention has three main parts: a forward bearing housing, a bell-mouth (heat shield) and a coupled impeller shroud/diffuser. Such a design achieves the design objectives of the present invention, including reducing weight, reducing cost, minimizing tolerance build up and improving aerodynamic performance by utilizing multiple component integration for multiple modes of engine operation.

Abstract: Aspects of the invention relate to a turbine engine configuration and method for overcoming a turbine blade tip clearance problem that can arise when the turbine inlet temperature is maintained at a high level during part load operation of the turbine. Aspects of the invention relate to reducing rotor cooling air to a temperature below the design temperature level by using, for example, additional heat extraction devices or by reconfiguring or resizing existing heat exchanger devices. Upon exposure to the cooled air, the discs and blades of the turbine will shrink so as to provide a clearance between the blade tips and surrounding stationary support structure. The design rotor cooling air temperature can be from about 350 degrees Fahrenheit to about 480 degrees Fahrenheit. Aspects of the present invention can be used to decrease the rotor cooling air to about 150 degrees Fahrenheit at about 70 percent load.

Abstract: A casing air temperature Ta and a steam temperature Ts are measured, and if an absolute value ?T of a difference between these two temperatures is within a predetermined temperature, the gas turbine is connected to the generator. After the connection is done, the load is gradually increased, and the coolant changeover signal is sent from a processor to a controller. The coolant is then changed to the steam, thereby completing the connection of the gas turbine with the generator and the changeover of the coolant.

Abstract: Methods of increasing lifetimes of components in a gas turbine engine. Ordinarily, components are replaced after they experience a certain number of thermal cycles, or a certain operating temperature limit is exceeded. Under one form of the invention, the components are not replaced at that time, but are subjected to increased cooling, which decreases the highest temperature reached in subsequent thermal cycles. Also, many components are replaced when acceleration of an engine falls below a target. In one form of the invention, the components are not replaced, but (1) scheduled fuel flow is increased and (2) compressor stall margin also increased, in order to attain the target acceleration.

Abstract: Cooling air to the blades and disks of a gas turbine may be modulated to provide a variable turbine cooling flow. A bellows may be extended by providing a high pressure compressor discharge flow to an interior of the bellows. The bellows may be compressed when the interior of the bellows communicates with ambient pressure air. The extension/compression of the bellows moves an arm over orifices in a cooling air flow path. The pressure inside of the bellows is metered to move the arm over at least one orifice, thereby restricting cooling air flow when the engine is running at low power. The pressure inside of the bellows is metered to move the arm to uncover all of the slots to provide maximum cooling flow when the engine is running at high power. The resulting variable cooling flow system results in less need for cooling air at low powers, thus reducing engine fuel consumption.

Abstract: A pilot air system for providing pilot air to a combustor of a gas turbine wherein the system includes: an inlet to receive a portion of compressed air discharged by a compressor of the gas turbine, wherein the portion of the compressed air is pilot air; a main passageway coupled to the inlet and providing a passage for the pilot air; an inline throttling valve coupled to the main passageway and metering a pressure of the compressed air in the main passageway; a pilot air compressor in series with the main passageway; a by-pass passageway for the pilot air and arranged in parallel to the main passageway and compressor, wherein the by-pass passageway receives pilot air from the main passageway downstream of the compressor and passes a portion of the compressed pilot air to the main passageway upstream of the compressor; a by-pass throttling valve inline with the by-pass passageway to meter pilot air flowing through said by-pass passageway, and the main passageway is connectable to the combustor.

Abstract: A turbine overspeed control system for a gas turbine electrical powerplant. The powerplant may employ an aeroderivative gas turbine engine for producing electrical power. The overspeed control system preferably comprises a compression relief system and an air directing system. When an overspeed condition of the gas turbine engine is detected, the compression relief system acts to remove air from a combustion section of the engine. Preferably, the air is removed to the atmosphere. The air directing system operates to ensure that air entering a compressor section of the gas turbine engine does not impinge on the blades of a compressor turbine located therein at the optimum angle. The result of operating the compression relief and air directing systems is a reduced combustor efficiency. Consequently, a reduced amount of hot gases are available to drive the turbines of the gas turbine engine, and the rotational speed thereof decreases.

Abstract: A method of monitoring radial clearances in a steam turbine during operation of the turbine is provided. The method, in an exemplary embodiment, includes measuring a temperature of the rotor shaft at a time1 and at a time2, measuring a temperature of the rotor blade at time1 and at time2, measuring a temperature of the shell at time1 and at time2, calculating a shaft radial growth between time1 and time2, calculating a blade growth between time1 and time2, calculating a shell radial growth between time1 and time2, and determining a change in a radial gap between the shell and a distal end of the rotor blade from time1 to time2 using the following equation: change in radial gap=shell radial growth?shaft radial growth?blade growth.

Abstract: A fluid flow actuated valve for controlling the fluid flow in a conduit comprises a support structure adapted to be mounted within the conduit and at least one flap member pivotally mounted to the support structure. The at least one flap member is pivotable between an first position for a minimum fluid flow and a second position for a maximum fluid flow. A torsion spring is attached to the at least one flap member to urge the same to pivot against a fluid pressure differential, from the first position to the second position when the fluid pressure differential is smaller than a predetermined level.

Abstract: A gas turbine engine combustor inlet diffuser assembly has at least one diverging annular wall including a flowpath surface bounding a diffuser flowpath. An annular blowing slot is axially located along the annular wall and an annular blowing air flowpath leads to and is in fluid communication with the blowing slot. An annular array of scoops disposed in the diffuser flowpath downstream of the blowing slot have upstream facing openings and are in fluid communication with the blowing air flowpath. The annular scoops are supported on hollow struts. Each of the hollow struts has at least one radially extending flow passage for directing blowing air from the scoop to the blowing air flowpath. The blowing slot opens in a downstream direction with respect to the diffuser flowpath. A row of blowing air compressor blades disposed across the blowing air flowpath may be used to pump up the pressure of the blowing air.

Abstract: The invention relates to a gas turbine (3) with reheat in the turbine section (11), whereby a fuel injection device (37) is provided for the injection of fuel (33) in to a combustion air flow (61) in the direction of flow before a cooling air flow (65) branching. By means of the early mixing of fuel (63) in the combustion air flow (61) and concomitant additional use of the cooling air flow (65) as combustion air, the specific output and the efficiency of the gas turbine (3) are improved.

Abstract: In a reheat gas turbine engine for power generation, fuel is burnt with compressed air from a compressor in a first or primary combustor, the combustion products are passed through a high pressure turbine, the exhaust of the high pressure turbine is then burnt together with further fuel in a reheat combustor to consume the excess air, and the exhaust of the second combustor is passed through a lower pressure turbine. Excess air is supplied to the first combustor, thereby enabling so-called “lean burn” combustion for production of low levels of pollutants in the exhaust of the engine. Some turbine components of the turbines, e.g., blades or vanes, are cooled by cooling air supplies tapped off from the compressor.

Abstract: A process is provided for the control of the amount of cooling air of a gas turbine set. Suitable means are provided in the cooling system to enable the amount of cooling air to be varied. The control of this means takes place in dependence on an operating parameter (X). This operating parameter is made dependent on the fuel type used.

Abstract: A gas turbine combustion system and method used for generating electrical power includes a compressor that receives and compresses air. A first stage turbine nozzle is flowise connected to the compressor and receives a portion of the compressed air from the compressor within a first air flow. A torus configured combustion chamber is positioned around the first stage turbine nozzle and receives a portion of the compressed air from the compressor within a second air flow that is passed through the combustion chamber where air and fuel are mixed and combusted. The air is discharged at the first stage turbine nozzle to mix with the first air while achieving a dry low NOx combustion.

Abstract: It is the object of the present invention to feed cooling air suitable for cooling the high-temperature part of the gas turbine. The present invention comprises a compressor, a combustor, and a turbine. Further, a turbine-cooling system to feed the gas from the compressor to the turbine is provided, and the turbine-cooling system comprises a heat exchanger to cool the gas compressed by the compressor, and a means for separating liquid from the gas cooled by the heat exchanger. Thus, according to the present invention, it becomes possible to feed cooling air suitable for cooling the high-temperature part of the gas turbine and to achieve higher reliability of the gas turbine unit.

Abstract: A system and method for an engine bleed flow-sharing control system is disclosed. For a multi-engine bleed system, one (10) of the engines is selected as the master channel (15) such that the bleed air supply pressure of the control system receiving the bleed air is controlled (11, 12, 13) to achieve a desirable supply pressure range. To slave the other engine airflow control channels (25, 35, 45), the airflow rate (14) is also measured in the master channel (15) and the measured airflow rate is used as the airflow setpoint for other channels (25, 35, 45). The difference between the airflow setpoint and the airflow rate in the other channel is applied to control (21, 31, 41) the pressure or the valve/actuator opening area at the inlet of that channel (25, 35, 45).

Abstract: A bleed case assembly is provided comprising an annular outer case and an inner case. The inner case comprises an annular shroud portion having a radially outer surface opposite a radially inner surface, and a generally planar flange extending radially outwardly from the radially outer surface. The flange includes a circumferential array of bleed openings formed therethrough. The flange is attached to the outer case so as to reduce the thermal response of the inner case.

Abstract: A method of operating a combustor in a gas turbine that receives combustion air from a compressor includes a) controlling combustion temperature as a function of compressor discharge air bled from the compressor by determining a minimum amount of compressor discharge air required for maintaining a predetermined minimum combustion temperature; and b) bleeding compressor discharge air in excess of the minimum amount from the compressor via a control valve.

Abstract: Bleeding is operated by annularly providing plural stationary blades at an interior side of a vehicle; annularly providing plural moving blades around rotor disk adjacent to stationary blades; providing plural stage units comprising the stationary and moving blades; introducing bleed air into each stage unit from a compressor; supplying bleed air extracted from a final stage of the compressor into a first stage unit; and supplying bleed air extracted from compressed air which has not yet arrived at a final stage unit of the compressor.

Abstract: A gas turbine has a cooling air system supplying air for cooling a high temperature part of the gas turbine and a spray air system supplying air for spraying fuel into a combustor and is formed so that a part of high-pressure air compressed by a gas turbine compressor is used as air of the cooling air system and spray air system, wherein a heat exchanger and a boost compressor are arranged downstream of the outlet of compressed air of the gas turbine compressor, and the boost compressor is composed of a parallel connection of a compressor driven by the turbine shaft and ae compressor driven by a driven source other than the turbine shaft, and pressurized air from the boost compressor is used as air for the cooling air system and the spray air system.

Abstract: A system and method for an engine bleed flow-sharing control system is disclosed. For a multi-engine bleed system, one (10) of the engines is selected as the master channel (15) such that the bleed air supply pressure of the control system receiving the bleed air is controlled (11, 12, 13) to achieve a desirable supply pressure range. To slave the other engine airflow control channels (25, 35, 45), the airflow rate (14) is also measured in the master channel (15) and the measured airflow rate is used as the airflow setpoint for other channels (25, 35, 45). The difference between the airflow setpoint and the airflow rate in the other channel is applied to control (21, 31, 41) the pressure or the valve/actuator opening area at the inlet of that channel (25, 35, 45).

Abstract: A device and method for recuperating a gas turbine engine comprises a compressor being configured to receive a coolant fluid stream, to compress the coolant fluid stream and to discharge the compressed coolant fluid stream to a turbine in fluid communication with the compressor. The compressed coolant fluid stream undergoing thermal exchange within the turbine, exit the turbine thereafter. A source of a working fluid stream is in fluid communication with the turbine. The working fluid stream is fluidly isolated from a portion of the coolant fluid stream and undergoing thermodynamic expansion through the turbine to extract energy therefrom. Where desired, the entire coolant fluid stream is fluidly isolated from the working fluid stream. At least a portion of the coolant fluid stream is channeled downstream of the turbine to supply a preheated process fluid stream to an adjacent system.

Abstract: A method of operating a combustor in a gas turbine that receives combustion air from a compressor includes a) controlling combustion temperature as a function of compressor discharge air bled from the compressor by determining a minimum amount of compressor discharge air required for maintaining a predetermined minimum combustion temperature; and b) bleeding compressor discharge air in excess of the minimum amount from the compressor via a control valve

Abstract: A plurality of moving blades are provided around rotor disks and rotate together with said rotor disks. Compressor rear case rings surround the periphery of these moving blades and form a compression flow path therein. A bleeding chamber is provided around the compressor rear case rings and introduces a portion of a main flow moving through the compression flow path as bleed air. Cooling flow path is formed between the compressor rear case rings and the bleeding chamber in which bleed air cf on its way to the bleeding chamber flows along the outer surface of the compressor rear case rings.

Abstract: A butterfly valve for a gas turbine engine includes a valve shaft and a valve disk. The valve disk has a centerline axis that extends through the valve disk. The valve disk also includes a shaft opening, an outer periphery, an outer surface, a first side, and a second side. The first side is opposite the second side. The shaft opening extends through the valve disk adjacent the centerline axis, and is sized to receive the valve shaft therein. The disk outer surface extends over the first and second sides, and is tapered between the outer periphery and the centerline axis over at least one of the disk first and second sides.

Abstract: A system and method of using a variable geometry ejector for a bleed air system using integral bleed pressure feedback which utilizes a minimal amount of high-pressure air, thus improving the overall engine cycle performance and is easily adaptable to a multitude of different engine types. This is accomplished through the use of a variable ejector using downstream pressure feedback to control the flow and pressure.

Abstract: A bleed valve 60 for regulating a fluid flow through a bleed hole 88 defined by a casing 49 of a gas turbine engine 10 compressor 22, the bleed valve 60 comprises a central axis 92, a piston 62 and a static structure 70, the static structure 70 generally surrounds the piston 62, and is arranged to define in axial sequence from the bleed hole 88 first, second and third chambers 82, 84, 86 respectively, the piston 62 comprises a spindle 66, a first end plate 90 slidably sealed against the static structure 70 and a valve face end plate 64 from which walls 68 axially extend, the walls 68 being slidably sealed to the static structure 70, the static structure 70 comprises a radially inwardly extending flange 74, the flange 74 defining an aperture 76 through which the spindle 66 axially extends and is slidably sealed against, the first chamber 82 is in fluid communication with the compressor 22 via pressure balancing apertures 108 defined in the valve face end plate 64, the third chamber 86 is also in fluid communic

Abstract: A gas turbine engine cooling system for providing cooling air to engine components includes a core engine and, in downstream serial flow relationship, a high pressure compressor, a combustor, and high pressure turbine. A first flowing system is used for flowing a portion of the pressurized air to a heat exchanger to cool the pressurized air and provide the cooling air and a second flowing system is used for flowing a first portion of the cooling air to a compressor impeller operably connected to a compressor disk of the high pressure compressor for boosting pressure of the first portion of the cooling air. A second portion of the cooling air is supplied to turbine cooling. The heat exchanger may be a fuel to air heat exchanger for cooling the portion of the pressurized air from the first flowing means with fuel.

Abstract: In a turbine engine, low temperature air is diverted from a low pressure section of the compressor section of the engine to cool the high pressure turbine of the engine. Low pressure air is diverted from the compressor section, and its pressure is thereafter increased. Preferably, the pressure is increased in an intermediate cavity in the engine, where rotational energy of the diverted air is converted to static pressure by way of an obstruction that converts dynamic head of the air in the cavity into static pressure.

Abstract: A system and method of using a variable geometry ejector for a bleed air system using integral bleed pressure feedback which utilizes a minimal amount of high-pressure air, thus improving the overall engine cycle performance and is easily adaptable to a multitude of different engine types. This is accomplished through the use of a variable ejector using downstream pressure feedback to control the flow and pressure.

Abstract: This invention relates to a method and an apparatus for the cooling of the casing (1) of the turbines (2, 3) of jet engines, in which cooling air is diverted from a bypass flow and supplied to the outer side of the casing via an inlet duct (8) provided with a shut-off element (5). According to the present invention, the cooling air is supplied to a first chamber (6) in which it is divided by volume. One portion of the cooling air is issued to the casing (1) via orifice holes (10), while another portion is ducted via several tubes (9) to a second chamber (7) which annularly encloses the casing (1) in the area of a low-pressure turbine (3).

Abstract: An axially loaded floating brush seal useful in a stationary gas turbine engine having a first rotary compressor component having a rotor having a radial surface, a second non-rotary component having an end ending near the radial surface with the floating brush seal being positioned between the first and the second components to substantially reduce the flow of air between the first and second components. A method for controlling the flow of cooling air into a chamber in the second component using the rotary brush seal is also disclosed.

Abstract: A cooling air cooling system is selectively operable to reduce fuel gum deposits within the cooling system during gas turbine engine operations. The cooling system includes a recirculating loop that includes at least three heat exchangers in fluid communication with the recirculating loop. A first heat exchanger cools cooling air supplied to the gas turbine engine. A second heat exchanger cools fluid exiting the first of the heat exchangers with fan discharge air prior to the fluid entering the third heat exchanger. A third heat exchanger uses combustor main fuel flow to cool the fluid circulating in the recirculating loop.

Abstract: A land based gas turbine apparatus includes an integral compressor; a turbine component having a combustor to which air from the integral compressor and fuel are supplied; and a generator operatively connected to the turbine for generating electricity; wherein hot gas path component parts in the turbine component are cooled entirely or at least partially by cooling air or other cooling media supplied by an external compressor. A method is also provided which includes the steps of supplying compressed air to the combustor from the integral compressor; and supplying at least a portion of the cooling air or other cooling media to the hot gas path parts in the turbine component from an external compressor.

Abstract: A cooling air cooling system operable to reduce fuel gum deposits within the cooling system when a gas turbine engine operates above a predefined percentage of rated engine power. The cooling system includes a recirculating loop including a plurality of heat exchanges in fluid communication with the recirculating loop. A first head exchange uses heat transfer fluid to cool cooling air used by the gas turbine engine. A second head exchange is a fluid-fuel head exchanger that uses combustor main fuel flow to cool the head transfer fluid circulating in the recirculating loop.

Abstract: Air captured from the tips of a compressor of a gas turbine engine is diverted from the engine core and can be collected for auxiliary uses. Gas path separation can be achieved using part-span shrouded compressor blades or using blade tip cut-outs conforming to an airflow dividing annular shroud. In a preferred application for the present invention, the gas turbine engine is the auxiliary power unit of an aircraft. This permits compressed air generation for Auxiliary Power Unit oil cooling and for compartment pressurization without loosing significant mass flow to the engine core, while eliminating the need to provide a separate active cooling system such as an engine driven fan.

Abstract: In a method for operating a gas turbo group, partial streams of compressed air are cooled in cooling air coolers and are used as cooling air for thermally highly stressed components of the gas turbo group. The cooling air coolers are constructed as steam generators. Steam generated in the cooling air coolers is fed in part to the gas turbo group and is expanded there while providing usable power, while another part of the steam is fed into the cooling system, where the steam displaces air, which air then becomes available again to the gas turbine process. In this way, the steam generated with the help of heat removed from the cooling air is re-used.

Abstract: In a turbine engine, low temperature air is diverted from a low pressure section of the compressor section of the engine to cool the high pressure turbine of the engine. Low pressure air is diverted from the compressor section, and its pressure is thereafter be increased. Preferably, the pressure is increased in an intermediate cavity in the engine, where rotational energy of the diverted air is converted to static pressure by way of an obstruction that converts dynamic head of the air in the cavity into static pressure.

Abstract: In turbomachinery, first and second flowpaths coupled to stages of the compressor flow cooling medium at different temperatures and pressures to components of the turbine. An ejector is provided in the first flowpath for suctioning flow from the second flowpath and combining the two flows for delivery to a component of the turbine at a temperature and pressure intermediate the temperature and pressure of the first and second flows. A flow sensor, flow controller and throttling valve are interposed in the motive flowpath, the exit flowpath or the suction flowpath relative to the ejector for controlling the flow through the ejector.

Abstract: A land based gas turbine apparatus includes an integral compressor; a turbine component having a combustor to which air from the integral compressor and fuel are supplied; and a generator operatively connected to the turbine for generating electricity; wherein hot gas path component parts in the turbine component are cooled entirely or at least partially by cooling air or other cooling media supplied by an external compressor. A method is also provided which includes the steps of supplying compressed air to the combustor from the integral compressor; and supplying at least a portion of the cooling air or other cooling media to the hot gas path parts in the turbine component from an external compressor.

Abstract: A gas turbine system comprises a compressor that takes in suction air on the inlet side and compresses it to compressor end air that is available on the outlet side, a combustor in which a fuel is burned by using the compressor end air while resulting in the formation of hot gas, as well as a turbine in which the hot gas is expanded while providing work output. In a method for cooling this gas turbine system, compressed air is removed from the compressor, is fed as cooling air for cooling inside an internal cooling channel through thermally loaded components of the combustor and/or the turbine, is then recooled and subsequently compressed and added to the compressor end air. The influence of the cooling on the efficiency of the system is minimized by the fact that at least part of the compressor end air is used to recool the cooling air.

Abstract: A steam temperature Ts and a casing air temperature Ta are measured by thermometers. The measurement results are taken into measuring devices and converted into electric signals. The electric signal is A/D converted by the measuring device and then, is sent to a control apparatus where a difference between both the temperature is calculated by a subtracter of a processor provided in the control apparatus. When an absolute value &Dgr;T=|Ta−Ts of this difference is contained within 10° C. continuously ten times, a control signal is sent from a computing unit to a controller which is the control section, a pressure adjusting valve and the like are controlled and a cooling medium is switched to steam.

Abstract: In turbomachinery, first and second flowpaths coupled to stages of the compressor flow cooling medium at different temperatures and pressures to components of the turbine. An ejector is provided in the first flowpath for suctioning flow from the second flowpath and combining the two flows for delivery to a component of the turbine at a temperature and pressure intermediate the temperature and pressure of the first and second flows. A flow sensor, flow controller and throttling valve are interposed in the motive flowpath, the exit flowpath or the suction flowpath relative to the ejector for controlling the flow through the ejector.

Abstract: A gas turbine has a cooling air system supplying air for cooling a high temperature part of the gas turbine and a spray air system supplying air for spraying fuel into a combustor and is formed so that a part of high-pressure air compressed by a gas turbine compressor is used as air of the cooling air system and spray air system, wherein a heat exchanger and a boost compressor are arranged downstream of the outlet of compressed air of the gas turbine compressor, and the boost compressor is composed of a parallel connection of a compressor driven by the turbine shaft and ae compressor driven by a driven source other than the turbine shaft, and pressurized air from the boost compressor is used as air for the cooling air system and the spray air system.

Abstract: A gas turbine engine includes a compressor including a casing and a stator assembly. The casing extends around the stator assembly, the stator assembly including a plurality of stator vanes, and a plurality of bleed scoops. Adjacent stator vanes define a static high-pressure region, the bleed scoops formed at least partially within the high pressure region.

Abstract: This invention relates to a gas-turbine engine which is provided in the turbine interior with a bearing chamber for a turbine shaft, the bearing chamber being sealed by sealing elements, and with a scavenge line for the lubricating oil which is supplied to the bearing chamber, in particular is sprayed onto the bearing(s) arranged therein. In accordance with the present invention, the single scavenge line, which is connected to a suitable lubricating-oil collecting compartment, features such an ample cross-section and the sealing elements have such a high sealing effect that the pressure in the bearing chamber is essentially equal to the pressure in the lubricating-oil-collecting compartment and maximally half the pressure in the turbine interior.

Abstract: A bleed valve 60 for regulating a fluid flow through a bleed hole 88 defined by a casing 49 of a gas turbine engine 10 compressor 22, the bleed valve 60 comprises a central axis 92, a piston 62 and a static structure 70, the static structure 70 generally surrounds the piston 62, and is arranged to define in axial sequence from the bleed hole 88 first, second and third chambers 82, 84, 86 respectively, the piston 62 comprises a spindle 66, a first end plate 90 slidably sealed against the static structure 70 and a valve face end plate 64 from which walls 68 axially extend, the walls 68 being slidably sealed to the static structure 70, the static structure 70 comprises a radially inwardly extending flange 74, the flange 74 defining an aperture 76 through which the spindle 66 axially extends and is slidably sealed against, the first chamber 82 is in fluid communication with the compressor 22 via pressure balancing apertures 108 defined in the valve face end plate 64, the third chamber 86 is also in fluid communic