Title of Invention

STEAM TURBINE WITH A PLURALITY OF STAGE SECTIONS AND A DEVICE FOR OUTPUT CONTROL OF THE STEAM TURBINE

Abstract

The invention relates to a multistage steam turbine (1) having a second MD control wheel (27), which is situated behind the first stage part (7) of the turbine and which can be subjected to the action of additional steam (31) during overload operation. The inventive steam turbine (1) can be operated both in the partial load range as well as at the nominal point and which a high overload with a uniformly high efficiency.

Full Text

PCT/KP2005/053972 - 1 - 2 0 04P14 6 87 Descr ipti on S loam tu rb i ne The invention relates to a steam turbine as claimed in the p roamo! o o I" c l.a i m 1 . Steam turbines should be ab.le to bo opera Loci re i iably and with constantly high efficiency over a largest possible output range. Those rcqui remonts cannot be completely fulfil led by steam turbines of conventional type of construction. 'i'ho invention is based on the object of" making ava i lable a s Learn Lurbinc wh.i ch both in normal operation and in the partial load range is operable with good efficiencies at outputs which I io aop roc i.ab.l y below the nominal output. Furthermore, the steam turbine according to the invention is also t.o nave a good efficiency in overload operation. This object i.s achieved according to the invent ion by the o;-;a rac '..e r i s t. i c features of claim 1. Due to the fact that: in overload operation additional steam can bo introduced into the steam turbine and that the second IP control 'wheel Is subjected to admission of this additional steam, the output of the steam turbine according to the invention can bo significantly increased without appreciable 1 ossos i n ei f" i c i ency . The optimization of the process is influenced by means of a problem-free mixing o\' the reintegrated st.eam downstream of the ' P control wheel . It, is proved that, with high. I i ve steam conditions (IIP steam), the four-fold mass flow can be processed in overload operation without; appreciable losses in off iciency ir; normal load and partial Load operations. PCT/KP2 0 05/053 972 - 2 - 2 0 04 PI '1687 This w i. 1 i especially be achieved when a suitable? al location of trie two steam flows is undertaken and the control wheels and stage q roups are designed so that in the chamber of the IP control wheel the two steam Hows have approximately the same steam data. l)i tferent steam temperatures of the two steam ;' ' ows j ro acceptable. The construction of the turbine with the optimized additional ; i; control wheel, with food through nozzles, is advisable at, :: i qh steam parameters so that the HP cont.ro 1 wheel can be f u I ly u s eci, b u t w i f h o u t: co s fly i nn o r ca s .i n q c o n s f r u c f i or.s . The a r ranqoment, according t;o the invention, of a second control wheel, w.i th the associated control 'able nozzles in a chamber between the fi.rst stage section of the steam turbine and the second stage section of the steam turbine can be effectively used both in drum-fypo turbines and in chamber-type tu rb i nos . The invent, ion can be effectively used in ("qua I measure in turbines 'with impulse b lading and in turbines with react, ion b I ad ing in the piura! i L y of stages of the steam turbine}. 'i'r o HP control wheel and also the iP con L re wheel can bo designed both in single row configuration as we I ! as in double row configuration (Curtis wheel.) . Trie construction of the turbine with HP control wheel and subsequent sfaqe sect i.on is often optimum. However, this construction is not necessary for the invention. The HP control wheel can also be substituted as a stage section with a possible inner casing and a throttle control in bypass operafion/i nterna 1. bypjass operation, or as a combination of both IIP cont.ro. 1 wheel and bypass operation in the inner casing. PC'!',/HP2 0 0b/053 972 - 3 - -'¦0 04 P"! 4 687 The basic p.r i nc.i p.l o, Lho.ro fore, docs not. chanqe s i ncc Lho IP :":pL: : sc whoo.l wi Lh no/./,lo can be add i L i ona ! ; y put. i nt.o operaL ion, w.i Lh ouLpuL increasinq effect. whon roqu, red, on account, of Lho pressure drop between HP in.! of. cond i t. i on and opt. i m i zed, selected IP cond iL.ion. The principle of Lho IP impulse; wheel w i Lh nozzles can a.l so be i mp i omen Loci as a rot. rofit. or conversion in an ox Is Li nq Lurbino. ! f Lho s Learn Lurbino is Lo be run in overload opt; rat. ion, t. ho roqui rod or des i rod overload out. put. is introduced according i.o Lho invonLion by moans of Lho necessary HP st.c;am through Lhc impulse; st.aqc which is add i t. i ona 1 iy i nt.eq r a Led downs t. roar:.. The; f c;ed of Lh i s add i L i ona I HP sLoam is carried out. via cor; von;. i ona ! nozzle; cont.ro is so Lhat. Lho impulse; wheel, 1 ike; a ; roc control wheel., introduces addil.ional output. through Lhc nozzles i.n variable-pressure operation. The add i t. i ona i out.put. results from Lho enthalpy difference bcLweon IIP steam cond i L i on and Lho local steam condi L i on downstream of the; IP eont.rol v.'hoo 1 , and t.he steam volume; which is Lo be; opt. i mi zed. f'j.'tricr advantages and advantageous developments of t.he i n v o r I L i o ri are; q a L hi c; r a b I e; f r om L he; s u b s c; q u e r 11 a r a w i n q , i t. s description, and t.he; patent claims. A: 1 features which arc disclosed in the drawing, its description and the patent, claims can bo essential for the invention both individual iy and in combination with each other. ]*, I n the d raw i no, : I'iqure 1 shows a 1 onqi tudi na.l section through an exemplary embodiment of a steam turbine; accord: nq to the i riven t. i on and Figure '?. shows an exemplary embodiment, of a conLrol wheel w i Lh a q roup o f: cont; ro 1 1 ab 1 o no/ z I e;s . PCT/l<:p2005> 2 0 04.PI 4 6 87 ijosor'i pt. i on of Lho exemplary embodiments ;¦' i qu r ¦¦'¦' ! shows a steam Lurbinc with a cas inq 3 and a rotor b in 1 onq i i.ud i na i section. The steam turbine 1 has a first staqe section 7 and a second stage section 9. Kach of the stages 7 and 9 comprises a group of rot,or blades 11 which are fastened on the rotor b, and a group of" sl.at.or blades 13 which arc customari ly fastened on the casing 3 of the steam turbine 1 Py means of stator blade carriers. in Figure 1, for .reasons of clarity not a! 1 rotor blades and not a! i stator blades have been provided with designations. A first control whec i 1b .is fastened on the rotor b, upstream of the f i rst s'.cjge section 7' in the f 1 ow direction. The rotor blades of the ¦control wheel 1b, which are not shown individual ly in Figure 1, .-:. re des i qned as i mpu 1 se b 1 ados . A no/,zic ring 17 is provided in di reel, proximi fy of the f i rst control wheel i5, which nozzle ring has a plural ity of nozzles 19 which arc distributed over the circumference. The nozzle ring 1.7 is subjected to admission of steam through a I i ve steam I ino 21 with the 1 ino sections 21a and 21b. A f i rst control valve 2 3 is provided in the i ino sections 21a and 21b in each case. The live steam, which i.s fed to 'uric nozzle: r: nq 1 / through the controllable nozzles 19, is di reefed onto trie f i rst control, wheel l.b and then roaches a first wheel chamber 2b wriieh is bounded by the rotor b and by the casing 3. Ait: or this, the 1 i ve steam (not shown in figure 1 ) reaches the : i rst stage section 7 of the steam turbine 1 and is expanded A second IP control wheel 27 is provided on the rotor b downstream of the first staqe section "I. 'l.'he IP control wheel PCT/EP2005/053972 - 4a - 2 0 04 PI 4687 ?',', in Lho exemplary cmbod i.merit, which is shown hero, is also formed as an impulse wheel . 'The second IP conl.ro: wheel ?. i is PC'!'/ I-lP2005/053972 - 5 - 2 0 04 PI 46 87 subject.od Lo t.ho admission of additional steam by one or more nozzles 29, of which only one] is shown in Figure 1, and, as a result., acts i i k c; a contro.l wheel stage in va r i an i e-p ressu re opcrat. i.on. This additional steam, which is indicated by moans of an arrow 31 in Figure 1, is mixed before entry into the second stage section 9 w.i th the partially expanded S i vc: steam which is issued from the first stage section 7. This partially expanded 1 i vc steam has been provided with the designation 33 in Figure '1 . The space which exists between f i rst. st.age ;¦•:: eti or: ; and second stage section 9, in which trio second IP control whoe.l 2 7 is located, is referred Lo hereafter as the seco n d whe e. L ch amb or 3b. Trie no//, io 29 is also controllable, and can be optimized, for example by means of a second control valve 37 or a valve group, which is not shown. By moans of this second control valve 37, the food of additional steam info the steam t'.-rDiru '! through, the nozzle 2 9 can be control led. After the who.lc steam volume has f [own through the second stage section and has expanded therein, the exhaust ' steam is discharged from the steam turbine 1 through an exhaust 39. in normal operation, that., means when the sfcan: turoine is operated at its nomina.I output or in the partial load range, the second control, valve 37, or the va i ve group, is closed and the steam turbine 1 operates hike a conventional steam turbine. Trio out.put control of the steam turbine 1 is carried out. exclusively by means of the f i rst. control wheel 1b or' by moans of ¦control of the nozzies 19, as the case may bo, w:; to steam admission. The output control o.f the steam turbine 1 i.n nominal or normal operation, and in partial load operation, is sufficiently we'll-known from the prior art, and so is not explained in detail in connection with the: invention. PCT/I';P200b/053972 - 5a -¦ :;.0 0'l Pl'l 6 8 7 The constantly good off i c.ioncy of" Lho steam turbine \ , at nominal load as we I 1. as in PCT/KP2 0 0b/053 972 6 - 2004.P14 687 partial load ope rat. ion, is advantageous in th i s oui.pul. com. ro i wi LriouL s i qn.i f i cant. add i t i ona ! const rucL i on cost, such as inner casing, Lurbincs wiLh centra.1 admiss.ion, or' simi ar. If the steam turb.ino 1 is now to be operated at overload, according to the invent.ion the second control valve 37 or the valve group, which is not shown, .is opened so that add i t i ona.l steam can flow through the nozzle 29 onto the second control wheel /7. in this case, the nozzle 2 9 is designed and optimized so that trie steam condition of trio additional steam 31 corresponds as far as possible t.o the: steam condition of the part, iai !y expanded live steam 33, so that in the second whee 1 oriarnbc r 3b a good and problem-tree m.i x i nq of those two partial si. earn flows can take pi ace. The partial ly expanced 1 i vc steam 33, due to a larger distance whien is to be provided between second 1 P control wheel 27 and the casing 3 of the steam turbine 1, can ( low around the second IP control wheel 27 more or less unh i ride rod . '"ho valve flow fosses in the flow circu'latinq operation are reduced by means of a conventional vcnt.i la'.ion protection device. if the vorfi 1 at. ion protect i or: device i s not s u: i ioi.onf, an admixing through the second control valve 3'.' is recommended. The two part.iai steam f .1 ows 3.1 and 33 now flow t.h rough the second st..age section 9 and del ivcr work or power there t.o the rotor b, as the case may be. Wi t.h a suitable desior: of both, the 1 irst stage section 7 and the second stage sect, ion 9, and also the first control, wheel 1b with its nozzles 19 and the second control wheel 27 with its nozzles 29, in overload operation the four-fol.d steam flow can bo transformed compared with the design point of the steam turbine 1. This loads to a correspondingly significantly improved output increase of the steam turbine without appreciable efficiency losses of the steam tu rb i no . PCT/KP200b/0S3972 - 6a -- 20 0-1 PI'1687 Therefore, i. L is possible by the steam turbine i according t.o the invention to operate the steam turbine 1 from the partial i oad ope ra t i on, th rough PCT/KP2 00b/053 972 - 7 - 2 0 04 PI 46 87 operation at, nominal load, up Lo overload opera Li on with qooa, -:pp " ox i rr;a ;.c i y consLant. ofi iciency. In Figure 2, Lho second conLroJ wheel 2/ and also Lhe nozzles 2 9 arc schema!, i.ca.l .1 y shown i.n a view f rom Lho front,. The second oonLroJ wheel 27 has roLor blades 39 which are only schema L i ca 1 iy shown in Figure 2. in Lho exemplary embodiment. ;-.;p. i oh i.s shown .in Figure 2, three no/./les '9, which are re; or red Lo in Lhe literature as nozzle segments, arc arranaed so t.naL by means of the out. tots of Lho nozzle 2 9 Lho ro Lor blades 39 of Lhe second IP cont.ro. 1 wheel 27 can be subjected to additional steam admission. For th.i s purpose, a valve 43 is provided in each case between a steam inlet, chest 41 and the nozzles 29. According to how many of the valves 4 3 ate opened, a greater or lesser volume of additional steam f : ows through the nozzles 29 onto the second IP cont.ro! whoo i 27 and is then mixed '/¦/1 t.i'i the partiaj.iy expanded i i ve steam (sec designation 3 3 in Fi gure 1) . 3 PCri'/i-:P2 00b/053 972 8 2 0 0-1 PI 4 687 Patent claims 1 . A steam turbine with a plurality of stage sections (7, 9) and with a device for output; control of the st.eam turbine, which i.s located upstream of the f i r s t stage section ( /) , characterized in that a second IP contro.l wheel (27), with nozzles (29), i.s provided downstream of the first stage section (7) . /. . The st.eam turbine as claimed in claim i, characterized in that the aevicc for out,put contro.l of the steam turbine, which is .located upstream of the first stage sect, ion (7), is designed as a contro.l wheel (15) with a nozzle ring (.17) and with a plurality of controllable nozzles (19). 3. The steam turbine as claimed In claim 1 or 2, characterized in that the first, control wheel (1b), and/o: the second 1 P control whee i (27), is designed as an impulse rot. or whee i , cspecia.i ly in Curt, i.s design, or is designed as an impulse whoo 1 . ¦'i . The steam turbine as claimed in one of the preceding c i ai ms, characterized in that the second control wheel (77) is subjected to admission of additional st.eam from a I i ve steam line (21) through a group of controllable nozzles (29) :; . 'I'ho st.eam turbine as claimed in one of the preceding cla ims, cha rac te r i zcd in f ha t; the steam turbine (1) is designed as a chamber-typo t u r b i n e . PCT/ !vP2 0 05/ 0 53 9 72 - 8a - 2 0 0-1P14 68 7 6. '"he steam turbine as claimed in one of the procodinq c i a i m s , characterised i.n that the stage sections (7, 9) o.f the steam turbine (1) have an impulse b 1 ad i ng or a react.ion b.ladinq. The invention relates to a multistage steam turbine (1) having a second MD control wheel (27), which is situated behind the first stage part (7) of the turbine and which can be subjected to the action of additional steam (31) during overload operation. The inventive steam turbine (1) can be operated both in the partial load range as well as at the nominal point and with a high overload with a uniformly high efficiency.

Documents:

00696-kolnp-2007 correspondence-1.1.pdf

00696-kolnp-2007 international search authority report-1.1.pdf

00696-kolnp-2007-correspondence-1.2.pdf

00696-kolnp-2007-correspondence-1.3.pdf

00696-kolnp-2007-form-18.pdf

00696-kolnp-2007-pct request.pdf

00696-kolnp-2007-priority document.pdf

0696-kolnp-2007 abstract.pdf

0696-kolnp-2007 assignment.pdf

0696-kolnp-2007 claims.pdf

0696-kolnp-2007 correspondence others.pdf

0696-kolnp-2007 description(complete).pdf

0696-kolnp-2007 drawings.pdf

0696-kolnp-2007 form-1.pdf

0696-kolnp-2007 form-2.pdf

0696-kolnp-2007 form-3.pdf

0696-kolnp-2007 form-5.pdf

0696-kolnp-2007 international publication.pdf

0696-kolnp-2007 international search authority report.pdf

0696-kolnp-2007 others.pdf

696-KOLNP-2007-(27-07-2012)-CORRESPONDENCE.pdf

696-KOLNP-2007-(29-01-2013)-CORRESPONDENCE.pdf

696-KOLNP-2007-(29-01-2013)-OTHERS.pdf

696-KOLNP-2007-ABSTRACT 1.1.pdf

696-KOLNP-2007-AMANDED CLAIMS.pdf

696-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

696-KOLNP-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

696-KOLNP-2007-FORM 1-1.1.pdf

696-KOLNP-2007-FORM 2-1.1.pdf

696-KOLNP-2007-FORM 3-1.1.pdf

696-KOLNP-2007-FORM 5-1.1.pdf

696-KOLNP-2007-OTHERS 1.1.pdf

696-KOLNP-2007-PETITION UNDER RULE 137.pdf

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