GB2398106A

GB2398106A - Guide vane cooling system

Info

Publication number: GB2398106A
Application number: GB0400102A
Authority: GB
Inventors: Richard James Flatman
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 2003-01-13
Filing date: 2004-01-06
Publication date: 2004-08-11
Anticipated expiration: 2024-01-06
Also published as: GB0400102D0; GB2398106B

Abstract

A stage of guide vanes 20 in a gas turbine engine are cooled by compressor air delivered via piping 36, 38 and by leakage air in the space volume bounded by the combustion apparatus and the turbine shafting. The leakage air is drawn through tubing 40 by the compressor air which is directed via space 43 over the exit ends of the tubing 40 to create the necessary pressure drop in the tubing 40.

Description

2398 1 06

GAS TURBINE COOLING SYSTEM

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The present invention relates to the cooling system of a gas r.urbine engine.

Some gas turbine en<:3ines operate at temperatures which are such as to requi He that at least sorre parts of i Us turbine aE:paraA us be provided with appropriate suppli es of cool ing air f-rc:>m the engine compressor. However, air taken from the compressor for turbir.re cooling reduces the amount available for burning in the combustion system, thus generating an entire performance per.ialty. That situation :i..s further exacerbated in that the air lost to the c ombustion system through cooling needs, adds to air lost through unavoidable leakage thereof through seals A-ret wr-.?er, the static acre rotating members that make up the compressor assemb] y, the leaked air passi.r-y into the space volume bounded by the cornbt.stion apparatus and turbi ne shafts.

The present invention seeks to provide a gas tomb rue engine with an i.. mproved cool ing mode.

The present inventior cornet i.ses a gas t urbine engine includir g a stage Or <:rrir? guide var es, each o. w.:i Oh K',1'; a passage therethrough, the Labia ly inner end of said passage, with respect to the engine axis, having a respective tubu.1.ar mer..oer in nested spaced relationship trlereln, all said tubular nemJ::>ers being in airf].ow co. mmutlication witAir a space volume bounded by combustion apparatus and turbine shafts of said engine, and suction means connected to draw air f rem said space volume vita se, i..d tubu ar members, and force said drawn ai r through said guide vanes.

T ne i. r^ver-lt i À.:n w i. l. I. now he described by way of example and with reference Lo the accompanying drawings in which: Figure 1 is a diagrammatic sketch of a gas turbine engine of the ki ad whi ch may incorporate cooling air delivery apparatus i s accordance wi th the present nvention.

Figure 2 is al. enla:r:ged part view of the turbine appara. us of Figure including, cooling air delivery apparatus in accordance wi -th the preser?t.irivent i or. . E'icJure 3 is an alternative form of coolinc3 air entry structure into the tabular members, ar d Figure 4 its a further alternative form of cooling entry str.ucture into the tub la:r st ruct ares.

lO Referring to Fic3ure 1, a <gas t:.urbine engine incica?,ed cleneral ly by arrow lO, has a c.o.-npressor 12, combustion appara-tr.:s 14, a tu<??inc section 26 and an exhaust nozzle 18.

Curbine section 16 includes a stage of guide vanes 20, irarnediately followed is a downstream direction by restack of turbine blades 22. The stage of turbine blades 22 is carried on a di sk 24 in known mail?ler. 7i. sk 24 co-rotates with a connected shaft 26. The combustion apparatus 14, with shaft 26, bound a space volume 28 that is full of air d.rir-. operation o engine 10, which air continuously leaks through seals (not shown) betweer; the static and rotating parts (riot: shown) a.- compressor 12.

Referrlr g now i c Figaro 2, in the present example the i.nteri or of each Guide vane 20 is divided into three compartments numbered 30' 32 and 34 respectively.

Compartment 30 is conrlec-t ed via piping 36 and.28, to compressor lo [Figure] ) for direct delivery of coolir,g air therein. The two opposing flows meet at the exit of pipe 36 and expand lateral].y around t he exit: end portior- of a tubular member 40:into chamber 42 and into compartment 32 vita a COrlverCJinC3 space 43 ciefined between tubular. merntoer 40 and th? wall S defir ink co,npartment 32.

Each tubular member '10 is located in the rim 44 or an otherwise hollow annular member 46, the radially inner portion of which is open to the space volume 28, and thereby to air that has leaked in-to space voluTne 28 clurinr.7 operation of' erig.ine 10. By this means, -Lhe corr;pressor air flowing over the converc3i..ng space A,3 around the exit end of tubular members 40 creates a pressure drop w.i.thi.n the exit ends which resi.tlt in the initiation of a flow of leakage air from space volume 28, through tubular members 40 into respective gui..cle vanes 2(). 'the resulting mixture of compressor air and leakage air then flows into compartment 34, and from there via slots 48 ire t he trailinr3 edges of the c,uide vanes 26) into the gas annulus of turbine section i. 6.

Rr,ferrinr7 now to Figure 3r should it prove necessary to modi...fy the relative pressures of the compressor air and 1.5 leakage air i.r, order to Ed feet the desired flow of leakage air through tubular members 40, a metering plate 50 may be utilised at the radially inrush er d 46 of ann.:l.ar member 44.

Met.erinc3 plate 50 has a nt.mUc,r of holes drilled in it so as to provicie an appropriate f low restriction area having 2) regard to the=. air flow requ.i.rements for a >ar:t.i.cu].ar enr3i.r-e 10.

Referri.n. now to Fi.gtre 4, this example of the present invention ant y all.. fers from the example of Figure 2 in -t'nat the r,.ldially inner end of annular member 46 is curved towards the pstrearn face.-,f the adjacent turbine rli.sk 24, and each wal..i or member 46 kc.ates in radially xpar.ed rel.at.ions'rip.it bin respectivr lards 51 a:-;d 56 i'orne>-i;-r I.r.rbine disk 24. The radi.a I spaces are f'i...].l.ed by annular seals 58 and 6(') supported on trte curved end portions of annular rnernber 4 6. An ann.;ar chamber 62 is thus formed.

.ri..ng operation of engine 10 compressor leakage air in space vo,.urne 28 erter.C; chamber 6 via seal 60. However, Compressor ai r f l.owi.nc3 throng} convergi.nr3 space 43 slicks the air from chamber 62 and passes it through the guide vanes exactly as ciescribed with reference to Figure 2.

The present inversion provides two advantages over and above prior art. One advart.age which is attained by all three variants described and i.'. lustrated in this specifi.ca.ion is that uti.lisation of co.npressor leakage air for the cool.iny of the stage of guide vanes 40! enables a reduction of up to.'?0',, of the amount of cool.i.nc; air hith.ertc ext.r. cted di.rect,ly from the COrnpreSSQr for that 1.) purpose. The farther advant..-ge.rel.ates only to Figure 3 described anct i.1.1ustrated herein. I.eakage air is contani.natecl with particulate matter from the ambient atmosphere, and prior to -the provision o,' c-.hariber- 62, it leaked past ex.isr.irig sea.1 58 into the cooling air passages ways (not shown in the turbine blades 22 which resulted in their h].ockage. The leakage air also leaked past existi..n- seal 6; and thence through the spaced over].ap 66 between the vane arid blade stages, thus disturbing the a<is flow.

Removal.. of the leakage air from chamber 62 by the suctior means of the present i.nventi.on as described hereinbefore obviated both blockage and flow disturbance.

Claims

CI AIM8 1. . A gas Curb i.ne engine inc lading a s Cage of turbine guide

vanes each of which has a passage therethroug}l, the radial.! y inner end of: said passable wit h.r.espect. to the engine axis, having a respective tubular member in nested' spaced re:l.aticnship therein, all said tubular member being in airflow communication with a space vcl.ume bounded by combustion apparatus and turbine shafts of' said ergirie a-!isci suction means c onnected to draw air rom said space volume vita said tubular members and force said drawn air thorough said guide vanes.
2. A gas turbine erScirle including a stage of turbine guide vanes as cl. airned in claim 1 wherein said suctior means comprises air reed pi.p.i.rg connecting a compressor of said engine to said space sep;.arati.ng eactri said faceted tubular member from the wa l..l of its assoc:i ated passage whereby in operation to provide a flow of' pressurized air over each saici tubular member into said associ.ated passage so as to cause a sufficient pressure differential between the opposing ends of each tub,. l.-r member, as to promote a f low of lea kage a i. .r t}ierethrough f rom said spa ce vol. use into their respective passages.
3. A clas turbine engine including a stage of turbine gSa..de vanes as cl. ai mad in claim 1 or claim 2 wherein each said tubular member is in direct blow connection with said space volume.
4. A -as turoi ne engine i.rscl uding a stage of turbine guide vanes as claimed in claim 1. S:r c.l.ai.m 2 w}erei.n each said tabular member i..s in i ndirect f low conreciior. wi th sai d space volume.
i;. A gas Carbine engine including a stage of turbine gi.de vanes as claimed in claim 4 whereir each said tubular member is in flow connection with said space volume via a chamber into which leakage air in said space volume l eaks via sealmembers.
6. A gas turbi.ne engine incluc:ting a stage o:E tu.r:bi..re guide vanes as -:laimed in arúy of c]ai.ms 1 to 5 4herein said tubular members are supported.i.n the rim of a hollow ann<:lar member and pi o ject radially outwardly therefrom.
7. \ gas turbine engine includirc3 a stage of turbine guide vanes as claimed in ck.im witen dependar!t on.:.laims 4. arid. 5 wherein said hollow annular member comprises a rim, the opposing faces of which extend.r.,-dially inwards i. the form of Ll.anges, the radially inward portions of which are curved so as to, parallel the axis of said annular member and with the face of a turbine disk of said eng i.ne, enibl.e the.':o rrning of said charr.ber.
8. A gas turbine engine i.nclcdirig a sLac eof turbine g.i.de vanes substantially as describedin this specificat.i..on and with reference to Fi.gu.r:e 2 of the accompanying ctrawinc3s.
9- A gas turbi.ne engine including a stageof turbi.ne guide vanes substant.ial.l.y as describedin this speci.f ication and with reference to Figure3 of the accompar;yi ng cir-aw i ncs.
10. A colas turbi.ne ends ne i.nciudinc a stageof turbine guide vanes sul^'stantially as describedin this specification, arid.,i.tI reference to Fi.c3re4 of the accompar-yinc drawings.