摘要:
In a steam turbine, a combined brush and labyrinth seal is provided between a diaphragm web and a sealing surface on a rotatable component radially outwardly of the rotor surface. The contact between the brush seal and sealing surface lies along an axially upstream projecting flange of an annular platform such that heat generated by frictional contact between the bristles and the sealing surface has minimal effect on the rotor surface and hence rotor dynamics. A backup labyrinth seal is provided between the web and platform. Additionally, axially upstream projecting flanges are provided on the downstream buckets and which flanges are spaced radially outwardly of the rotor surface and lie in registration with the diaphragm web. Labyrinth teeth seal between the diaphragm web and the bucket flanges serving as a backup seal.
摘要:
Disclosed is an actuator that includes a cylinder having an input port, a piston disposed at least partially inside of the cylinder, and one or more piston rings disposed in a circumferential piston ring groove or grooves. The actuator also includes at least one spring, inserted into the circumferential piston ring groove adjacent to the one or more piston rings and a high pressure side of said piston ring. The spring preloads the one or more piston rings to seal between a low pressure face of the one or more piston rings and a low pressure face of the circumferential piston ring groove. The invention also includes a method for moving an adjustable seal in a radial direction using the piston-ring sealed actuator. The method includes moving the adjustable seal in an axial direction, breaking a primary axial contact between the adjustable seal and a primary sealing face.
摘要:
A steam turbine comprises a steam turbine casing, a rotor, and at least one compliant plate seal assembly situated between the casing and the rotor. The compliant plate seal assembly comprises a supporting member being stationary with respect to the casing, a plurality of plate members movably mounted to the supporting member and extending towards the rotor, each plate member being inclined with respect to a rotation direction of the rotor, and an actuator for selectively exerting a pressure to retract the plate members in a direction away from the rotor.
摘要:
Disclosed is an actuator that includes a cylinder having an input port, a piston disposed at least partially inside of the cylinder, and one or more piston rings disposed in a circumferential piston ring groove or grooves. The actuator also includes at least one spring, inserted into the circumferential piston ring groove adjacent to the one or more piston rings and a high pressure side of said piston ring. The spring preloads the one or more piston rings to seal between a low pressure face of the one or more piston rings and a low pressure face of the circumferential piston ring groove. The invention also includes a method for moving an adjustable seal in a radial direction using the piston-ring sealed actuator. The method includes moving the adjustable seal in an axial direction, breaking a primary axial contact between the adjustable seal and a primary sealing face.
摘要:
A steam turbine comprises a steam turbine casing, a rotor, and at least one compliant plate seal assembly situated between the casing and the rotor. The compliant plate seal assembly comprises a supporting member being stationary with respect to the casing, a plurality of plate members movably mounted to the supporting member and extending towards the rotor, each plate member being inclined with respect to a rotation direction of the rotor, and an actuator for selectively exerting a pressure to retract the plate members in a direction away from the rotor.
摘要:
A plurality of packing ring segments are provided in a stationary component and about a rotating shaft. Each packing ring segment includes a brush seal insert and a plurality of labyrinth seal teeth along a concave sealing face thereof. Each segment is formed of a pair of components which, in assembly, have a split line through a slot receiving the brush seal insert. The brush seal insert includes a pair of narrow strips or rods welded to outer ends of the bristle pack and is bendable to a range of diameters. By forming forward and backing surfaces defining the slot integral with the components, the width of the bristle slot and the gap between the bristle pack and the forward surface can be readily manufactured and obtained.
摘要:
An actuation pressure control system effects actuation of adjustable seal segments between stationary and rotating turbomachinery members. At least one actuator is coupled with each of the adjustable seal segments and controls a position of the seal segments, respectively. A pressure system is disposed within the turbomachinery that measures or estimates ambient pressure representing an actuator back pressure acting against the actuator. A pressure regulator via a controller pressurizes the actuator to a level sufficient for a desired seal operation and controls actuator pressure based on the actuator back pressure.
摘要:
In a steam turbine high pressure end seal region, brush seals are provided between first and second pressure regions having a pressure drop in excess of the sealing capacity of an individual brush seal. To use brush seals between the first and second regions, one or more intermediate pressure regions are maintained at a substantially fixed predetermined pressure between the first and second pressure regions. Brush seals are interposed between adjacent pressure regions whereby the pressure drop between adjacent pressure regions is within the sealing capacity of the individual brush seal disposed between the adjacent pressure regions.
摘要:
In a steam turbine, a combined brush and labyrinth seal is provided between a diaphragm web and a radially outwardly projecting platform between axially adjacent wheels on the rotor. The brush seal is located upstream of the labyrinth seal teeth. The platform has at least one and preferably a pair of flanges or fins projecting in opposite axial directions adjacent radial outer ends of the platform. Non-uniform heat distribution resulting from the frictional contact between the bristles of the brush seal and a sealing surface on the platform along the rotor surface affecting rotor dynamics is thereby eliminated or minimized.
摘要:
A steam turbine has a rotor mounting axially spaced rotor wheels having male dovetails for mounting a plurality of axially spaced buckets having female dovetails. A plurality of arcuate bridging members extend axially between the axially adjacent bucket dovetails at locations spaced radially outwardly of the surface of the rotor shaft. A diaphragm in radial opposition to the bridging member mounts a brush seal having bristles engaging the bridging member. The bridging member carries backup labyrinth seal teeth for sealing with the diaphragm. The friction generated by contact between the brush seal bristles and bridging members lies radially outwardly of the rotor whereby non-uniform distribution of heat about the rotor surface due to frictional contact with the brush seal is avoided, with consequent avoidance of rotor bowing.