RU2278276C1 - Steam turbine cylinder - Google Patents

Abstract

FIELD: power engineering; steam turbines.

SUBSTANCE: invention can be used to create cylinders of steam turbines in which passages of high and medium pressures are combined. Propose cylinder of steam turbine includes outer and inner housing, high and medium pressure passages with opposite direction of flows, two steam intake chambers and high and medium pressure exhaust branch pipes, Passages and steam intake chambers of high and medium pressures are arranged in separate inner housings, and high pressure exhaust branch pipes are arranged at end of medium pressure inner housing separated from following extraction chamber by ring partition. Proposed invention improves heat stressed state of stator and rotor of steam turbine cylinder in which passages of high and medium pressure are combined, increases maneuverability of cylinder and steam turbine as a whole at starting, i.e. provides quick heating of cylinder and rotor without warping of walls of outer and inner housings without excess stresses in housings, flanges and fasteners of horizontal split and in rotor.

EFFECT: improved reliability of turbine.

1 dwg

Description

The invention relates to the field of energy and can be used to create cylinders of steam turbines, in which flow parts of high and medium pressure are combined.

The constructive solution of combining the flow parts of high and medium pressure in one cylinder makes it possible to reduce the number of cylinders and, accordingly, the dimensions of the turbine, reduce the number of bearings and, consequently, the friction losses in them, and reduce the number of end seals, which increases the efficiency of the turbine.

Known combined cylinder, comprising an outer casing, a stator for the high-pressure flow part located in the inner casing and in the cage of the last two stages, a high-pressure steam inlet located on the front bearing side, while the high-pressure part is exhausted near the middle of the outer casing, and the stator is flow-through part of the medium pressure is located in the cages installed in the outer casing, the medium pressure exhaust is directed towards the rear bearing, the steam inlet chamber of the flow part of the middle yes The phenomena are organized in the middle part of the outer casing so that it is separated from the exhaust chamber of the high-pressure flow part by a dividing wall in the form of a cage installed in the outer casing, and on the side of the medium pressure steam inlet a thin-walled heat-insulating screen is installed on it (Trukhniy A.D., Losev S.M. Stationary Steam Turbines.- M .: Energoizdat, 1981. P.236-237. Fig. 7.31).

A disadvantage of the known cylinder is the location of the high-pressure steam inlet from the front bearing, which causes an increase in the axial dimensions of the front seal, the internal high-pressure housing is surrounded by hot steam with a temperature corresponding to the exit from the first stage guide apparatus, the separation wall between the exhaust pipe and the medium-pressure steam inlet experiences a large temperature difference (about 170 ° -190 ° C), and the thin-walled screen is not reliable enough - it warps on the program modes eva turbine and not tight enough.

A known cylinder of a steam turbine, in which the flowing parts of high and medium pressure are combined, including the outer casing, the inner casing, in which the stator of the flowing part of the high pressure and the stator stages of the flowing part of the medium pressure are located, the rest of the stator of the flowing part of the medium pressure is located in the clips, installed in the outer casing, the exhaust of the high-pressure duct is directed towards the front bearing, and the exhaust of the medium-pressure duct is directed towards the rear bearings, high- and medium-pressure steam inlet chambers are located in the middle of the cylinder in a common inner casing and are separated by a partition made integral with the inner casing. (RU 2189449, IPC F 01 D 1/16, published September 20, 2002, FIG. 1).

By the totality of the features, this known technical solution is the closest to the claimed one and is taken as a prototype.

A disadvantage of the known cylinder adopted as a prototype is that the walls of the outer and inner bodies in the area between the partition with the exhaust chamber from the high-pressure flow part and the partition with the chamber behind the inner case after the first group of medium pressure stages are not cooled, since the cooling steam duct, in addition, the rotor blades and the rotor in the intermediate seal area between high and medium pressure steam inlets are exposed to high temperatures, which reduces maneuverability, that is, the operational qualities of the turbine at starting conditions.

The claimed technical solution allows to improve the thermally stressed state of the stator and rotor of the steam turbine cylinder, in which the flow parts of high and medium pressure are combined, to increase the maneuverability of the cylinder and steam turbine as a whole in starting conditions, that is, the possibility of rapid heating of the cylinder and rotor without warping the walls of the external and internal cases and without excessive stress in them, in the flanges and fasteners of the horizontal connector, as well as in the rotor, which leads to increased reliability of the turbine.

A cylinder of a steam turbine is proposed, including the outer and inner casings, flowing parts of high and medium pressure with opposite flow directions, two steam inlet chambers and exhaust pipes of high and medium pressure, while the flowing parts and steam inlet chambers of high and medium pressure are located in separate inner casings, and high-pressure exhaust pipes are located at the end of the medium-pressure inner casing, separated from the subsequent selection chamber by an annular partition.

The invention is illustrated in the drawing, which shows a longitudinal section of a cylinder.

The cylinder of the steam turbine includes an outer casing 1, an inner casing 2, in which the stator of the high-pressure flow part 3 is located, the flow of which is directed towards the front bearing 4, an inner casing 5, in which the first group of stator stages of the medium-pressure flow part 6 is located, the second and the third group of steps is installed in cages 7 and 8, the flow of the medium-pressure part 6, 7, 8 is directed towards the rear bearing 9. The high-pressure steam inlet chamber 10 is located at the beginning of the inner housing 2, steam Such a medium-pressure chamber 11 is located at the beginning of the inner casing 5. Thus, the flow parts 3 of high pressure, 6 - medium pressure and the steam inlet chambers of high 10 and medium 11 pressure are located in separate inner casings 2 and 5. The exhaust pipe of the flow-through part of the medium pressure 12 located at the end of the outer casing 1 from the side of the rear bearing 9, and between the inner housings 2, 5 and the outer casing 1 there is formed an interbody space 13, with which the exhaust pipes 14 of the high-pressure flow part are connected radial openings 17 located at the end of the inner medium-pressure housing 5, separated from the subsequent selection chamber 15, by an annular partition 16. In the inner medium-pressure housing 5, radial openings 17 are made between the medium pressure steam inlet chamber 11 and the annular partition 16 in the wall behind the intermediate (second) stage 17 connected to the annular collector 18, in communication with the pipe 19, passing through the outer housing 1 into the external pipe 20 using a piston compensator 21. Between the camera behind the guide device high pressure stage and the rotor 22 is set intermediate seal 23, and between the chamber for directing device medium pressure rotor 22 and a seal 24.

During the operation of the turbine, fresh high-pressure steam is supplied to the steam inlet chamber 10 of the internal high-pressure housing 2, passes through the high-pressure flow part 3, enters the inter-chamber space 13, passes through it to the exhaust pipes 14, goes to intermediate overheating, and from it enters the cylinder again into the medium-pressure steam inlet chamber 11, a group of stages of the medium-pressure flow part 6 passes, the stator of which is located in the inner housing 5, in the clips 7, 8 and exits into the exhaust pipe of the medium-sized flow part phenomena 12. In this case, passing through the interbody 13, the relatively cold (about 370 ° С) exhaust vapor from the high-pressure flow part 3 cools the internal high-pressure housing 2, the hot (540 ° -565 ° С) high-pressure steam inlet chamber 10, hot (540 ° -565 ° C) medium pressure steam inlet chamber 11, internal medium pressure housing 5. The flanges of the horizontal connectors of the inner housings 2, 5 and their fasteners are also cooled. A small part of the steam leaves the chamber behind the directing device of the first high-pressure stage through the intermediate seal 23 and is mixed with the exhaust pair from the high-pressure flow part into the housing 13. Also, a small part of the relatively cold steam from the housing 13 is sucked through the seal 24 into the chamber behind the guide by the apparatus of the first stage of the flow part of the medium pressure 6, along the way, cooling the middle part of the rotor 22 and its end at the working blades of the first stage of the flow part of the medium pressure of 6. During operation of the steam turbine for the intermediate stage pressure medium passes through the radial holes 17 in the inner housing 5, an annular manifold 18, the inner tube 19, outer tube 20 in the selection of the regenerative heating condensate. Mutual thermal expansions between these nozzles are compensated by means of a piston compensator 21.

Claims (1)

The cylinder of the steam turbine, including the outer and inner bodies, flowing parts of high and medium pressure with opposite flow directions, two steam inlet chambers and exhaust pipes of high and medium pressure, characterized in that the flowing parts and steam inlet chambers of high and medium pressure are located in separate inner cases while the exhaust pipes of high pressure are located at the end of the inner medium-pressure housing, separated from the subsequent selection chamber by an annular partition.