RU2764494C1 - Support of the cylinder body of a steam turbine - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to the field of power engineering, in particular to the coupling of cylinder housings and housing elements (bearing housings, as well as other housing parts) of a steam turbine with the provision of specified thermal expansions and minimum resistance forces in the coupling. The support of the cylinder body of a steam turbine contains a key body fixed to the housing element with a longitudinal groove and a vertical hole made in it and a key consisting of upper and lower parts. The upper part of the key is placed in the support groove of the cylinder body, and the lower part of the key is placed in the longitudinal groove and connected to the key body by a sleeve mounted in a vertical hole. The upper and lower parts of the key are made in one piece. The upper part of the key has side surfaces equipped with diamond-shaped removable inserts, and end surfaces with cutouts in which stops are installed. In the upper part of the body of the key, projections are made, on the end surfaces of which, symmetrically relative to the longitudinal and transverse planes of the key, grooves are made in which inserts with axial gaps are installed to ensure the function of turning the key. A hole is made in the lower part of the key coaxially with the vertical hole, while the bushing is installed in both holes.

EFFECT: increase in the workability of the support structure during installation, repair and commissioning, as well as the prevention of jamming of the body parts of the steam turbine and, consequently, an increase in the reliability of the steam turbine.

1 cl, 6 dwg

Description

The proposed technical solution relates to the field of power engineering, in particular, to the pairing of cylinder bodies and housing elements (bearing housings, as well as other body parts) of a steam turbine with the provision of specified thermal expansions and minimum resistance forces in mating.

In modern turbomachines, one of the main technical problems is to ensure the reliability of their operation in terms of vibrational and thermal conditions. The thermal expansion of the turbine ensures, within acceptable limits, the mutual position of the rotor and stator parts of the turbine, which change their geometric dimensions as they warm up or cool down. Thermal expansions simultaneously provide the given thermal displacements of the cylinder bodies and bearing housings relative to the foundation and each other in the given directions; proper fit of bearing housings to foundation frames; alignment of the flow path, shafting and bores of the bearing housing within the specified limits in all operating modes; axial clearances between rotor and stator parts within specified limits (RD 34.30.506-90 Guidelines for the normalization of thermal expansion of steam turbine cylinders of thermal power plants, Ministry of Energy and Electrification of the USSR, Moscow, 1991, p. 2).

The forces of resistance (friction) arising in the interface can lead to an abrupt expansion or jamming of body parts, their damage, increased vibration and distortions, which can later cause a turbine malfunction and an accident.

Also, for the supports of body parts, a significant technical problem is to ensure the required manufacturability during a complex of installation, repair and commissioning works, including assembly and disassembly of the structure, fitability, etc.

Supports in the form of prismatic transverse keys, diamond-shaped transverse keys, split keys (USSR Author's certificate No. 1617159, F01D 25/28, publ. 12/30/1990), and rotary transverse keys (RF patent No. 2134797; IPC F01D 25/28, publ. 08.20.1999; RF patent No. 2165532; IPC F01D 25/28, publ. 04.20.2001), allowing significant, compared with prismatic transverse keys, angular movements of the paws of the cylinder housings relative to the bearing housings.

The above designs of transverse keys have a number of disadvantages in terms of reliability and manufacturability. So, for example, the angle of rotation of diamond-shaped keys is not enough to prevent complete jamming, and in the case of a split key, it is impossible to control the angle of rotation when the cylinder is deflected.

By solving these technical problems is the development of a reliable and manufacturable design of the turbine housing support.

The invention "Support for the body of a turbomachine" is known (RF patent No. 2134797; IPC F01D 25/28, publ. 20.08.1999). According to the invention, the support comprises a lower support element fixed on the base, an upper support element in the form of a prism, on which the body paw rests, and a cylindrical insert. On cylindrical surfaces, the insert is conjugated with the lower support element. The upper support element and the cylindrical insert are made in one piece. A vertical hole is made in the lower support element, into which a cylindrical insert is installed vertically and coaxially. The transfer of force along the axis of the turbine occurs due to the interaction of the paw of the body, made as an integral whole of the upper support element and the insert, the lower support element, the base.

The known technical solution provides free rotation of the paw of the body of the turbomachine, based on the upper support element in the horizontal plane, relative to the lower support element, fixedly fixed on the base, and eliminates the angular movement of the paw of the body relative to the base.

The disadvantage of this solution is the low manufacturability of the design of the support at the installation, since in the case of installation and repair work, it is necessary to raise the paw of the body, which increases the complexity of the work, and if it is necessary to fit in place, to ensure the required thermal gaps, it is necessary to dismantle the entire support, which requires additional mounting hardware.

The closest technical solution to the proposed technical solution in terms of the set of essential features and selected as a prototype is the invention "Support for the body of a turbomachine" (USSR Author's certificate No. 1617159, F01D 25/28, publ. 12/30/1990). The turbomachine body support comprises a lower support element (key body) fixed on the base (body element). The lower support element has a longitudinal groove and a vertical hole. The upper support element (the upper part of the key) and the insert (the lower part of the key) are connected to each other along the cylindrical surfaces and are made separately. The upper support element is placed in the support groove of the paw (cylinder body). The insert is placed in a longitudinal groove and is connected to the lower support element by a cylindrical ledge (sleeve) installed in a vertical hole.

With temperature movements of the body and deformations of the paws and the body, the upper support element together with the paw rotate relative to the lower support element along cylindrical surfaces, compensating for changes in the position of the paw in three mutually perpendicular directions. The mutual position of the paw, body and base remains unchanged.

The disadvantage of this device is the low manufacturability of the support design, since for a complex of installation, repair and commissioning works it is necessary to lift the paw, which increases the complexity of such work. And also the unlimited possibility of angular movement of the paw relative to the base in the vertical plane can lead to an excess of the allowable value of the radial clearances in the flow path, which leads to a violation of the alignment of the turbine, and, consequently, reduces the reliability of the turbomachine.

The technical result, to which the claimed invention is directed, is to increase the manufacturability of the support structure during installation, repair and commissioning, as well as to prevent jamming of the steam turbine body parts, and, consequently, to increase the reliability of the steam turbine.

To achieve the above technical result, the support of the cylinder body of the steam turbine contains a key body fixed on the base, with a longitudinal groove and a vertical hole made in it, and a key consisting of an upper and lower parts. The upper part of the key is placed in the bearing groove of the cylinder body. The lower part of the key is located in the longitudinal groove and is connected to the key body by a bushing installed in the vertical hole.

In this case, according to the claimed invention, the upper and lower parts of the key are made in one piece.

The upper part of the key has side surfaces equipped with diamond-shaped removable inserts, and end surfaces with cutouts, in which stops are installed.

In the upper part of the body of the key, projections are made, on the end surfaces of which, symmetrically with respect to the longitudinal and transverse planes of the key, grooves are made, in which inserts with axial gaps are installed to ensure the function of turning the key.

A hole is made in the lower part of the key coaxially with the vertical hole, while the sleeve is installed in both holes.

The execution of the upper and lower parts of the key as a whole excludes unlimited angular displacements in the vertical plane of the cylinder body relative to the body element, thereby eliminating the misalignment of the steam turbine.

Equipping the key with rhomboid removable inserts increases the manufacturability of the design (fitability), since during installation, repairs and commissioning it allows for the rapid completion of removable inserts without lifting the legs of the cylinder body, simplifies the exposure of the steam turbine cylinders in the axial direction, reduces the time of these works. Installing stops in the cutouts of the end surfaces of the upper part of the key fixes the diamond-shaped removable inserts, and, if necessary, makes it easy to dismantle them. The proposed design of the support is completely collapsible, which ensures the versatility of its application.

The projections in the upper part of the key body restrict the vertical movement of the key. Installation of inserts in the grooves of the protrusions of the upper part of the key body with the necessary axial clearances provides the function of turning the key to the required angle around the vertical axis of the support in the horizontal plane of the cylinder body and body element. At the same time, the transmitted axial forces from the cylinder body to the casing element are preserved, and thus, thermal expansions are provided within acceptable limits, which prevents jamming of casing parts and, consequently, increases the reliability of the steam turbine.

Making a hole in the lower part of the key coaxially with the vertical hole, and installing a sleeve in both holes, is necessary to ensure guaranteed transfer of axial force through the support from the cylinder body to the body element.

The proposed design of the steam turbine cylinder housing support in the set of essential features disclosed above makes it possible to improve the manufacturability of the support design during installation, repair and commissioning, as well as to prevent jamming of the steam turbine body parts, and, consequently, to increase the reliability of the steam turbine.

Presented graphic materials contain an example of a specific implementation of the support of the cylinder casing of a steam turbine.

1 is a front view of a turbine cylinder housing support; figure 2 is a top view (rotated) supports of the turbine cylinder housing; figure 3 - section A-A along the longitudinal plane of the key; figure 4 is a front view of the key housing with a longitudinal groove; figure 5 - key in a perspective view; figure 6 is a top view (rotated) supports of the turbine cylinder housing with the angle of rotation a.

The support of the casing of the cylinder 1 of the steam turbine comprises a casing 3 of the key 4, fixed on the casing element 2, by means of fasteners, for example, pins 5, and a key 4. In a particular case, the casing element 2 is a bearing housing. Also, the housing element 2 may be other housing parts of the steam turbine. In the body 3 of the key 4, a longitudinal groove 6 and a vertical hole 7 are made. The key 4 consists of an upper part 8 and a lower part 9. The upper part 8 of the key 4 is placed in the support groove 10 of the cylinder body 1. The lower part 9 of the key 4 is placed in the longitudinal groove 6 and is connected to the body 3 of the key 4 by a sleeve 11. The cross-sectional shape of the lower part 9 of the key 4 coincides with the corresponding shape of the longitudinal groove 6. In a specific example, the shape is trapezoidal, but it can also be rectangular, etc. Sleeve 11 is installed in vertical hole 7.

The upper part 8 and the lower part 9 of the key 4 are made in one piece.

The upper part 8 has side surfaces 12 and end surfaces with cutouts 13. The width and height of the cutouts 13 are structurally determined.

The side surfaces 12 are equipped with diamond-shaped removable inserts 14, which form the working surfaces of the support. The upper part 8 with diamond-shaped removable inserts 14 is installed with the necessary thermal gap ε in the support groove 10 to prevent jamming of the support. The height of the diamond-shaped removable inserts 14 is equal to the height h of the cutout 13, and their length is equal to the length L of the key 4 minus the width 1 of the cutouts 13 on both sides. The diamond-shaped removable inserts 14 are provided with threaded holes 15 for their dismantling. Stops 16 are installed in the cutouts 13 of the end surfaces for fixing inserts 13. Stops 16 are fixed to the key 4 with fasteners, for example, bolts 17 and washers 18.

In the upper part of the body 3 there are protrusions 19, on the end surfaces of which, symmetrically with respect to the longitudinal 20 and transverse 21 planes of the key 4, grooves 22 are made, in which inserts 23 are installed. In a specific example, the grooves 22 are L-shaped. The inserts 23 are installed in the grooves 22 with the necessary axial clearance δ to ensure the function of turning the key 4 through the angle α. The axial clearance δ is adjustable by adjusting the inserts 23 on the mounting of the support by removing or welding the metal of the side surfaces of the inserts 23. The lower part 9 of the key 4 is installed in the longitudinal groove 6 with an axial clearance α. The axial clearance α is greater than the axial clearance δ and ensures that there is no contact in the pair of key 4 - longitudinal groove 6. The range of the angle of rotation α is equal to the angle of rotation of the cylinder body 1 in the event of thermal displacements. Inserts 23 are attached to the body with 2 fasteners, for example, screws 24.

In the lower part 9 of the key 4, a hole 25 is made coaxially with the vertical hole 7. The sleeve 11 is installed in both holes 7 and 25 and mates with the surfaces of both of these holes. The sleeve 11 is fastened to the key 4 with a fastener, for example, a screw 26.

The device works as follows. With temperature deformations of the cylinder body 1 of the steam turbine, the cylinder body 1 together with the key 4, diamond-shaped removable inserts 14 and stops 16 can rotate in the horizontal plane 27 relative to the body element 2 at an angle α. The possibility of turning the key through an angle α around the axis of the sleeve 28, fitting in place the required thermal clearance ε of the pair "cylinder body 1 - diamond-shaped removable inserts 14" and the axial clearance δ of the pair "insert 23 - key 4" enable the required rotation of the support of the cylinder body 1 and eliminate jamming of body parts. At the same time, the transmitted axial forces P _os from the cylinder body 1 to the body element 2 are preserved.

Claims (1)

Support of the cylinder body of a steam turbine, containing a key body fixed on the body element, with a longitudinal groove and a vertical hole made in it, and a key consisting of an upper and lower parts, while the upper part of the key is placed in the support groove of the cylinder body, and the lower part of the key is placed in a longitudinal groove and is connected to the key body by a bushing installed in a vertical hole, characterized in that the upper and lower parts of the key are made in one piece, the upper part of the key has side surfaces equipped with diamond-shaped removable inserts, and end surfaces with cutouts in which stops, in the upper part of the body of the key there are protrusions, on the end surfaces of which symmetrically with respect to the longitudinal and transverse planes of the key, grooves are made, in which inserts with axial clearances are installed to ensure the function of turning the key, in the lower part of the key, a hole is made coaxially with the vertical hole, while the sleeve setting Lena in both holes.

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