CN1218533A

CN1218533A - Steam turbine with blades and use thereof

Info

Publication number: CN1218533A
Application number: CN97194591A
Authority: CN
Inventors: 海因里希·奥因豪森
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1996-03-14
Filing date: 1997-03-06
Publication date: 1999-06-02
Anticipated expiration: 2017-03-06
Also published as: WO1997034075A1; EP0886722B1; JP3863185B2; EP0886722A1; CN1084823C; DE59710616D1; JP2000506246A

Abstract

The invention concerns a steam turbine (14) with a turbine blade (1) aligned along a principal axis (2) and provided with a curved flow surface (3) for steam. A fluid feed duct (5) is provided in the interior (4) of the turbine blade (1) and connected fluidically to a plurality of fluid outlets (6), each fluid outlet (6) opens out at the flow surface (3). The invention also relates to a use of the steam turbine (14) in a facility (17) for drying brown coal, in which the steam(21) released in the drying process is fed into the steam turbine (14).

Description

The steam turbine and the application thereof of band turbine blade

The present invention relates to a kind of steam turbine, especially a kind of its turbine blade is along the main axis orientation and have the lp steam turbine of the steam fluoran stream surface of a bending, the invention still further relates to the application to steam turbine.

In DE43355981A1, related in the compression or be prepended to this problem of deposition dirt on the expansion gas turbine of gas-turbine plant.Owing to be cooled and be transported to the expansion gas turbine, therefore can occur freezing or danger that dirt gathers from the air of air compressor.This point can prevent by center hole on the expansion gas turbine blades and the radial hole that is diverted to thus on the blade surface.Blade pass is crossed the air that heats and is heated in compressor, cause the ice on the blade to be melted.Form a water conservation film thus on expansion gas turbine blades surface, film is got rid of dirt particles thus in case of necessity.With same medium, promptly the air by compressor compresses drives at this expansion gas turbine, and blade also has been compressed air and has flow through.

The Di Zeer that publishes according to Munich-Vienna Han Zeer publishing house shows " steam turbine " third edition in 1980, and various steam turbine is well known.Its 333rd section " blade edge erosion " specialized in the erosion of avoiding flowing out on the edge on large-scale condensing steam turbine.In order to reduce the erosion of appearance, to the steam turbine dehydration, on the other hand turbine bucket is carried out machine treatment on the one hand.This machine treatment be to burn-on anti abrasive material or turbine blade induction hardening.

The object of the present invention is to provide a kind of being suitable for corroding steam-powered steam turbine.Another object of the present invention is to provide the purposes of this steam turbine.

Wherein, the purpose of relevant steam turbine is by a steam turbine, especially a kind of lp steam turbine realizes, this steam turbine has the blade along spindle-directing, this blade has at casing (guide vane) or turbine shaft (working blade) goes up the root of blade of grappling, reach the fluidic channel of portion within it with the crooked fluoran stream surface for steam, fluidic channel is connected with fluid technique with many jet exits.Pass at this each jet exit and to meet stream surface, it has one to be used for the passage of pure delivery of steam to fluidic channel in root of blade and exterior in the groove that root of blade is installed.

By importing pure steam or free from admixture jet, make it pass root of blade and turbine blade arrival fluoran stream surface, at fluoran stream surface, also produce protection jet film, especially a steam blanket sometimes at other position of turbine blade surface.This steam blanket forms a boundary layer around turbine blade, and turbine blade surface is isolated with the steam that steam turbine is flowed into as much as possible.Can realize that thus such erosion steam for example has by dry brown coal or other combustible material, as family or the resulting contaminated steam of industrial refuse to corrode the steam driven steam turbine.As impurity can be sodium, potassium, calcium, magnesium, iron, chlorine, nitrate and sulphide.A kind ofly be known as " residual air " by the steam that dry brown coal produced.By having avoided the deposition of impurity around the steam blanket of fluoran stream surface and having reduced the dangerous and erosion of corroding significantly.

Having the turbine blade that is connected to the fluidic channel of fluoran stream surface with fluid technique can realize corroding on the steam-powered steam turbine, flows into and penetrate jet at exit face (Abstroemflaeche) by fluidic channel to make and corrode steam as far as possible away from the turbine bucket surface.Come the size of this fluidic channel of respective design according to the required jet flow that passes through fluidic channel.This fluidic channel can be designed to a hole or a plurality of hole, thereby at the inner hollow hole that forms of a turbine blade.The for example erosion steam that is produced by the dry wet brown coal may comprise a lot of impurity, and these impurity may cause corroding on common turbine blade, corrosion or deposition.Certainly,, for example have the material of low-stress state or apply the special coating of one deck, can avoid turbine blade to be etched and corrode at turbine blade surface by adopting special material.

Turbine blade preferably has a root of blade that is used to be anchored on casing (guide vane) or the turbine shaft (working blade), wherein, and fluidic channel in root of blade and external communications.Thereby fluid, especially pure steam or air can pass casing by root of blade simply and turbine shaft enters fluidic channel.Thereby this fluidic channel makes that the fluid resistance and the loss in efficiency that produce are very little in steam turbine.

Fluidic channel is arranged essentially parallel to main shaft and constitutes.This fluidic channel has one or more axial bores.

Jet exit preferably is substantially perpendicular to the main shaft setting.They can form by boring or casting especially simply.The through-hole structure of jet input channel and output channel also allows to make on turbine blade afterwards.Jet exit also can change according to the steam condition in the steam turbine in the distribution of fluoran stream surface and other surface area of turbine blade afterwards thus.By importing pure steam, make it to pass jet exit, at fluoran stream surface and may be on the turbine blade surface in downstream more and form a steam blanket.This steam blanket reduces or prevents that fully the erosion steam that has impurity from contacting with turbine blade surface.Steam blanket prevents to corrode impurity entrained in the steam and deposits from the teeth outwards, and can obviously reduce the erosion and the corrosion of turbine blade fluoran stream surface.

The fluid passage is designed to a groove in described groove, this groove and a plurality of turbine blade refer to that at this root of blade interconnects on fluid technique.Be circular groove and be positioned on steam turbine casing or the turbine shaft in this this groove first-selection.

Steam turbine is particularly suitable for being applied in a dry power station fuel, particularly on the equipment of wet brown coal.For example can improve the efficient of the power station plant that acts as a fuel with brown coal by the dry wet brown coal.Can use low value steam at these brown coal, carry out drying as drawing gas by the turbo machine low pressure stage.Be collected in the steam by the moisture content of vaporizing in the brown coal, and become a kind of saturated-vapor state.Limit kind saturated vapour can reduce pressure below the 0.1bar at the turbo machine low pressure stage.Have a part of heat energy thus at least, the heat energy that promptly is used for the dry wet brown coal is recovered again.The steam that is produced by wet brown coal contains a large amount of impurity equally, especially sodium, potassium, calcium, magnesium, iron, chlorine, nitrate and sulphide.When lp steam turbine was moved, these impurity may cause the corrosion or the erosion of more serious turbine blade, and this situation structural design by turbine blade in according to steam turbine of the present invention is avoided as far as possible.

By the accompanying drawing illustrated embodiment steam turbine and the application thereof that has turbine blade is described in further detail below, in the accompanying drawing:

Fig. 1 is the longitudinal sectional drawing that has the steam turbine of turbine blade,

Fig. 2 is the drawing in side sectional elevation by Fig. 1 turbine blade group,

Fig. 3 is the schematic layout diagram of steam turbine in fuel or garbage drying equipment.

Shown in Figure 1 one by steam turbine 14, the especially longitudinal sectional drawing of a lp steam turbine.One turbine shaft 9 is arranged on the casing 8 of steam turbine 14.This turbine shaft 9 has an annular recess 12 and is used for supporting working blade 1a.Similarly on casing 8, also there is an annular recess 12 to be used for supporting guide vane 1b.More clear for diagrammatic sketch, working blade 1a and guide vane 1b only illustrate half respectively.Each turbine blade 1, promptly each working blade 1a and each guide vane 1b have a corresponding root of blade 7.The shape of each groove 12 all is complementary with the shape of root of blade.Each turbine blade 1 is provided with along main shaft 2.On each blade 1, all have one by root of blade 7 beginning and be parallel to main shaft 2, almost completely penetrate turbine blade 1 by fluidic channel 5 that the hole constituted.Branch out many perpendicular crossing equally with jet exit 6 that the hole was constituted by fluidic channel 5.Described jet exit 6 extends to semicircle shape fluoran stream surface 3 (see figure 2)s that the vapor stream 21 that drives steam turbine 14 is faced from fluidic channel 5 always.Described jet exit 6 is distributed on the fluoran stream surface 3 that constitutes turbine blade 1 surface portion, so that fluoran stream surface 3 is covered by steam blanket 11.Steam blanket 11 produces by vapor stream 10, and vapor stream is by 13 inputs of the fluid passage in groove 12.Fluoran stream surface 3 and may be in the flow surface on the turbine blade 1 in downstream more thereby be protected at vapor stream 21.Together import along with vapor stream 21, for example the impurity of being brought into by the dry wet brown coal can not be deposited on the fluoran stream surface 3, also can not cause serious erosion and corrosion to turbine blade 1.Fluid passage 13 is one to be positioned at the annular groove 13a of 12 li of grooves, by this groove all guide vane groups and working blade group is connected with each other with fluid technique.Groove 13a for example can provide pure steam 16 by unshowned axial bore that is positioned on turbine shaft 9 and the casing 8 in the drawings, can be connected with the groove 13a of a plurality of axial spaces on this hole.

Fig. 2 illustrates the drawing in side sectional elevation by the amplification of the working blade group that has two working blade 1a.Each working blade 1a has the fluoran stream surface 3 along main shaft 2 direction orientations of a semicircle sigmoid.Greatly be provided with one and have the fluidic channel 5 in circular hole cross section about the center of the fluoran stream surface 3 of semicircle shape bending.Shown in the stream of upper edge, cross section and vapor stream 21 have one to lead to the jet exit 6 of fluoran stream surface 3 in the opposite direction by fluidic channel 5.Shown in the figure along shown in main shaft 2 directions another jet exit 6 with respect to 45 ° of described jet exit 6 deflections is arranged respectively on an other cross section of the top in described cross section or bottom.Arrange jet exit 6 by alternation on main shaft 2 directions, can form a uniform especially steam blanket structure.

Fig. 3 simply illustrates and has the power station plant 19 of a high pressure turbine 22, as the low-pressure turbine of steam source 20 and a coupled generator 15.This low-pressure turbine is the steam source 20 of pure steam 16, and has the head that draws gas of an output low pressure steam.Pure steam 16 flows to the equipment 17 that is used for dry fuel 18 or rubbish.Because dry the generation corroded steam, wherein contains impurity, as sodium, potassium, calcium, magnesium, iron, chlorine, nitrate and sulphide.This steam is transported to the lp steam turbine 14 that links to each other with generator 15 equally.Lp steam turbine 14 has and Fig. 1 and the similar turbine blade 1 of Fig. 2, and this blade pass is crossed the pure steam 16 that is positioned at its inner fluidic channel input steam source 20.Pure steam 16 flows out to going on the stream interface 3 of turbine blade 1, prevents to corrode steam thus.

Outstanding part of the present invention is that steam turbine has a kind of like this turbine blade, and portion has a pure steam jet passage within it, and this fluidic channel is connected with fluoran stream surface by many jet exits.By the input of pure steam, especially the root by turbine blade enters fluidic channel and enters into fluoran stream surface, forms a steam blanket that covers on fluoran stream surface.This steam blanket is for providing protective layer with the blade that corrodes in the steam turbine that steam was driven.The most suitable during erosion steam that the steam turbine that has a this turbine blade is produced in adopting dry wet brown coal process, a large amount of impurity is arranged in this steam.Can prevent reliably that by this pure steam input structure erodibility impurity from depositing on turbine blade surface, and reduce erosion and corrosion significantly turbine blade.

Claims

1. one kind with unclean steam-powered steam turbine (14), especially a kind of low-pressure turbine, it has along the directed turbine blade (1) of main shaft (2), this turbine blade has root of blade (7) and the crooked steam fluoran stream surface (3) that is used to be anchored on casing (8) or the turbine shaft (9), has a fluidic channel (5) in blade interior (4), this fluidic channel (5)

A) be connected with fluid technique with many jet exits (6), wherein each jet exit (6) passes on the fluoran stream surface (3),

B) this fluidic channel wherein, has a connecting morphism circulation road (5) to be used to carry the fluid passage (13) of pure steam (16) in groove (12) lining that root of blade (7) is installed in root of blade (7) and exterior.

2. according to the described steam turbine of claim 1 (14); the jet exit (6) of wherein said turbine blade (1) is distributed on the fluoran stream surface (3), and the feasible vapor stream (10) that is provided by fluidic channel (5) forms the steam blanket (11) of a covering protection fluoran stream surface (3).

3. according to claim 1 or 2 described steam turbines (14), the fluidic channel (5) of wherein said turbine blade (1) is arranged essentially parallel to main shaft (2).

4. according to the described steam turbine of above-mentioned each claim (14), each jet exit (6) of wherein said turbine blade (1) is substantially perpendicular to main shaft (2) setting.

5. according to the described steam turbine of above-mentioned each claim (14), wherein said fluid passage (13) are an annular groove (13a) that couples together with fluid technique with a plurality of turbine blades in groove (12) lining.

6. be applied in one according to claim 4 or 5 described steam turbines (14) and be used for dry fuel (18); particularly in the equipment (17) of wet brown coal; to be used for a power generating equipment (19); wherein; the steam (21) that is produced by dry fuel (18) is fed to a steam turbine (14), in order to protect turbine blade (1), by steam source (20); for example, pure delivery of steam is arrived in the fluid passage (13) by a steam turbine of power station (19).