464 results about "Tip clearance" patented technology

An airfoil for use as rotor blades in compressors for turbomachines, such as gas turbine engines. The airfoil includes increased forward sweep and forward dihedral effective to reduce losses generated by interaction of tip clearance flow, secondary flows and passage shocks.

A turbine shroud assembly includes forward and aft hangers, an axisymmetric plenum assembly, ceramic shroud segments, ceramic spacers, and forward and aft rope seals. The plenum assembly supplies impingement cooling to the shroud and the hangers. The impingement cooling to the forward and aft hangers is controlled independently to improve blade tip clearance. The rope seals are radially inward from the hangers and reduce cooling flow leakage. The turbine shroud assembly can operate in a higher temperature environment using less cooling flow than the prior art.

A turbomachine is provided having at least one row of blades oriented at a predetermined stagger. Casing grooves are provided proximate to at least a portion of the tip of the blades. The grooves are oriented substantially normal to the stagger of the blades. The normal of the blade is determined from a chord of the blade. The chord may be taken across a pair of corresponding points one the upstream and downstream end of the blade, hence across the extent of the cross-sectional shape of the blade. Alternatively, a blade chord may be determined over only a portion of the blade, for instance, from a point along the centerline of the upstream end of the blade to a second point on the centerline midway down the blade from the upstream end. Optimally, the grooves are positioned adjacent to the upstream half of the blades, but may continue across the axial extent of the blades. The spacing between grooves can be optimized for blade stagger in order to find an optimal number of grooves that concurrently cross the blade. Additionally, obtaining an optimal groove depth for a particular turbomachine requires knowing only the tip clearance gap as groove depth is directly related to the tip clearance. Furthermore, since the groove may be substantially smaller than prior art casing treatments, fluid recirculation is reduced. The blade-normal groove may take a variety of cross-sectional shapes. Optimally, the aft surface of the groove will have less than a 45° incline to the radial at that point.

A multi tip clearance measurement system is provided. The clearance measurement system includes a sensor disposed on a first object, wherein the sensor comprises a plurality of probe tips configured to generate signals representative of a sensed parameter corresponding to a second object and a processing unit configured to evaluate the signals from subsets of the sensed parameters from the probe tips to detect an outlier probe tip and to adjust a gain, or an offset of the respective outlier probe tip for estimating the clearance between the first and second objects based upon the signals.

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.

A gas turbine engine blade tip clearance control system and method is described. An annular housing is formed about an engine casing to which an annular shroud segment assembly is secured and closely spaced about blade tips of a stage of blades. The annular housing forms an air passage means communicating with the casing for directing a cooling air stream to the casing. A thermally operable passive ring valve is formed by two overlapped metal ring segments having a dissimilar coefficient of thermal expansion selected whereby to produce a radial gap between the ring segments when the valve temperature reaches a predetermined value. The radial gap admits a cooling air flow into the housing for cooling the casing and its associated shroud segment assembly to control radial growth and thereby prevent blade tip pinching.

A new abrasive blade tip treatment is disclosed with the potential to provide improved blade tip clearance control in the turbine section of modern industrial gas turbines (IGT's). This blade tip treatment is composed of a unique combination of abrasive compounds that result in improved resistance to thermal degradation while retaining desirable initial cutting capacity.

A sealing system for reducing a gap between a tip of a shrouded turbine blade and a stationary shroud of a turbine engine. The sealing system includes one or more seal lands extending from a shrouded turbine blade toward a stationary shroud of a turbine engine. During operation of the turbine engine, the seal lands straighten and extend towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the shrouded turbine blades and increasing the efficiency of the turbine engine. The sealing system may also include one or more protrusions extending from the stationary shroud towards the tips of the shrouded turbine blades.

A gas turbine engine has a plurality of radial struts in a bypass duct. At least one strut has a scoop incorporated with the fairing of the strut and in communication with an air passage of an engine secondary air system. The scoop faces a bypass air flow to scoop a portion of the bypass air flow using available dynamic pressure in the bypass duct. Scooped air may be provided, for example, to an active tip clearance control apparatus in a long duct turbofan engine.

A method for controlling blade tip clearance within a gas turbine engine includes the steps of providing a compressor having at least one first rotor assembly, each first rotor assembly having a plurality of blades with each blade having a blade tip, at least one first stator assembly disposed adjacent at least one first rotor assembly, and a shroud having at least one blade seal surface disposed radially outside of at least one first rotor assembly, wherein the blade tips in each of at least one first rotor assembly has a mating geometry with at least one of at least one blade seal surfaces, and a clearance distance extending between the blade tips and the blade seal surfaces; providing a turbine having at least one second rotor assembly, each second rotor assembly having a plurality of blades with each blade having a blade tip, at least one second stator assembly disposed adjacent at least one second rotor assembly, and the shroud having at least one blade seal surface disposed radially outside of at least one second rotor assembly, wherein the blade tips in each of at least one second rotor assembly has a mating geometry with at least one of at least one blade seal surfaces, and a clearance distance extending between the blade tips and the blade seal surfaces; providing an actuator selectively operable to move at least one rotor assembly relative to the shroud; providing an electronic engine controller having a control logic for operating the actuator; and moving at least one first rotor assemblies and at least one second rotor assembly relative to the shroud using the actuator at a response rate according to the control logic to alter the clearance distance.

The invention discloses a tip clearance measurement method based on all-fiber tip timing. The method comprises the following steps: converting measurement on length measurement in a triangle method into measurement on a tip timing signal; adopting two fiber bundle type timing sensors, and enabling emission fibers in the timing sensors to emit two beams of auto-collimation emergent light with different wavelengths; enabling receiving fibers in the timing sensors to receive moment signals when leaves approach and leave a measurement region; monitoring the rotating speed of a rotor in real time by a rotating speed synchronization sensor; performing high-speed signal acquisition and circuit module processing on all the sensor signals, and reversely calculating a distance between the end face of each sensor and each leaf tip by an upper computer through a math model. According to the tip clearance measurement method, a clearance value is ingeniously converted into a tip timing signal relevant to the clearance value, so that a measurement system is irrelative to most environmental factors such as the leaf and electromagnetic interference, and the interference resistance and the clearance measurement precision of the system are improved.

Provided is a gas turbine plant that enables active clearance control for ensuring tip clearance of first-stage turbine rotor blades required during start-up and for achieving the minimum tip clearance during load operation. In a gas turbine plant including a cooler in an air system used for cooling second-stage turbine stator blades, a first-stage segmented ring and a second-stage segmented ring that oppose tips of first-stage turbine rotor blades and second-stage turbine rotor blades are supported by the same blade ring member, and a cooling-air for the second-stage turbine stator blades forms a cooling air flow cooling the blade ring, to control thermal expansion of the blade ring and to control the clearance with respect to the tips.

A gas turbine engine with a rotor shaft that is moveable in an axial direction so change a blade tip clearance, where the rotor is displaced by a spring to increase the blade tip clearance and is displaced by a pressure created by the compressor and turbine during engine operation that will close the blade tip clearance. This is especially useful during engine shutdown to prevent blade tip rubbing against the stationary shrouds.

A measuring assembly for use in a gas turbine engine includes an indicia portion that extends radially inwardly from an inner surface of a ring seal structure to a location radially inwardly from tips of blades mounted on a rotor. The indicia portion of the measuring assembly comprises a section that is abraded by the blades during rotational movement of the rotor to provide a visual indication of a distance between the tips of the blades and the inner surface.