Mehrdruck-Dampfturbine zur Krafterzeugung

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The invention concerns a mixed pressure steam turbine for force production.

The technical task of the invention consists of it, preferably in the capacity range of small steam turbines, thus from some zig KW to few MW offering economical and practicable solutions. For such steam turbines in particular in the range of the Abwärmen use from fluid flow and quantities of exhaust gas to the generation of current, in industry, in the force production and behind internal combustion engines, an increasing need would exist, since this kind of the generation of current takes place emissionsund C02-frei.

In the standard work by Fritz Dietzel: „Steam turbines ", 1950 one looks for the keyword mixed pressure steam turbines in vain. By arising combined Gasund of steam turbine process (combination power stations; However the mixed pressure steam turbine moved GuD power stations) in the power plant technology in the field of vision. With this type of power station the exhaust gas heat of the gas turbine is used again for generation of current, as in a waste heat boiler several steam quantities with different pressures are usually produced and these for the mixed pressure steam turbine for the generation of current are supplied. In accordance with the state of the art practiced the high pressure steam quantity is led across a high pressure part of the turbine, which low pressure steam expands added and the sum quantity from Hochdruckund low pressure steam in a low pressure part of the turbine of far up to the pressure of the condenser, whereby high pressure and the low pressure part on a common Turbinenrotor are arranged and the flows, related to the rotor axis, gel-calibrationintimately takes place. This design has however some disadvantages: in the mixing place it comes to thermal loads, if expanded high pressure steam and added low pressure steam do not have exactly the same temperature, further becomes with a change of the flowing through quantities the 2

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entire pressure ratios in · the ^Twfcine `b · eeύήflusst and

finally add themselves the oh thrusts because of the flow in the same direction of the turbine parts, which by the balance piston, which can be partly compensated causes however unused leakage steam quantities. In summary this appearing at first sight simple kind of turbine construction exhibits substantial disadvantages with the rejection of the design parameters concerning the efficiency losses and the flexibility.

Like that it is not amazing that into newer patent specifications alternatives will suggest, in order to avoid some disadvantages of the state of the art practiced. The patent specification US5411365 suggests flowmoderately separated Hochund of medium pressure parts, which sit on a common rotor, but regarding the rotor axis to be moving in opposite directions flowed through and between the neighbouring inlets Hochdruckund of low pressure steam a separating equipment plan (a poetry) to plan, which is to prevent rushing over high steam to the low pressure part. Thus one decouples the systems Hochdruckund of the low pressure part and one the oh thrusts because of by the against-intimate flow of the turbine parts. The patent specification EP0394894B1 describes, based on a similar arrangement, a temperature management for the reduction of thermal loads, while the patent specification EP0926316B1 aims at also the reduction of the internal pressure load of the turbine. These improvements are bought by a complication by the separating equipment, for a poetry, which removes about in the center of the rotor, thus from the two turbine camps, their service to make are and by the higher number of the turbine stages, since Hochund the low pressure steam quantity is separately expanded.

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The descriptive technologies mbgerΐ · in ·•Krwftw'erksbereich, for some zig to hundred MW steam turbine achievement and for controlled and in sections constant process parameters, suitable appear. For the initially mentioned problem definition to offer also within the range of small steam turbines and for strongly varying process parameters a carry outable and accepted concept for a mixed pressure steam turbine sharpens past state of the art problem consciousness, it offers however no specific solution.

The invention avoids the aforementioned disadvantages and is characterized by the fact that for each of the steam streams at least its own nozzle box and/or its own nozzle is intended, blows out and works what altogether on only turbine wheel. Further characteristics are aforementioned in the secondary claims.

The invention is more near described on the basis a remark example in accordance with the designs. The figures 1 to 4 clarify the Erfindungsgedanken and the execution forms:

Fig. 1 shows the execution form according to invention of the mixed pressure steam turbine.

Fig. 2 shows the sketch of the execution form of the cut in accordance with AA the Fig. 1.

Fig. 3 shows the blade cascades and the velocity triangles with the execution form in accordance with the Fig. 1.

Fig. a variant points 4 to the Fig. 1.

The Fig. 1 shows the mixed pressure steam turbine according to invention, implemented as mixed pressure steam turbine, for example with one

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senkrechten turbine shaft. On der* ΐksrbi · nemJel · IE' · i*, which the turbine case 2 with wave-depressed with storage and poetry 3 is those enters the turbine wheel 4 with a rotor blade row 5 arranged. The turbine shaft 1 delivers the mechanical energy, for example at a generator rotor 6 of an electrical generator 7 with the back support 8 outside of the turbine case for the purpose of the production of electricity.

High pressure (HP) steam enters over the hp steam inlet 9 ', if necessary over a hp heat case 10 ' the turbine case 2 and flows the hp nozzle box 11 ' too, which consists of a hp steam distributor 12 ' and hp-guidancelook-finely the 13 '; the center that guidancelook-finely exhibits the radius distance r 27 to the turbine shaft axle 17. With small steam throughput the nozzle box can be implemented also as individual nozzle.

Similarly that steps lp steam enters over the lp steam inlet 9 ““, if necessary over a lp heat case 10 '' the turbine case 2 and flows the lp nozzle box 11”” too, which consists of a lp steam distributor 12 '' and the lp guide vanes 13 ''.

In innovative way thus its own nozzle box is intended and the steam quantities diverting from the nozzle boxes affects the rotor blade row 5 of the turbine wheel 4th further is implemented in innovative way the rotor blade row 5 than equal printing blading for each pressure level, i.e. before and after the rotor blade row (about) equivalent steam pressures prevail (in run-look-protect takes place only more a small or no acceleration and that

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• · · · · · · 4 •• · Shovel acceptance angle βi is into ** et$fe φlefδh *dem **

To shovel angle of outlet β2, see Fig. 3). That evaporate flows after the rotor blade row over an evaporation withdrawal 14 for example an evaporation condenser 15.

The Fig. 2 shows the cut AA of the mixed pressure steam turbine according to invention of the Fig. 1., implemented as mixed pressure steam turbine.

High pressure (HP) steam enters over the hp steam inlet 9 ', if necessary over a hp heat case 10 ' the turbine case 2 and flows the hp nozzle box 11 ' too, whereby this is torus-shaped and with a radius distance r' 27 between the rotor blade center and the turbine shaft axle 17 arranged and is sektorenförmig limited; because of the enormous recoil forces of the nozzle box a turning stop 16 is thermalflexibly intended with the turbine case connected prop ' in form of one. With small steam throughput the nozzle box can be implemented also as individual nozzle.

Similarly with lp steam will proceed.

Since are called, steam-prominent nozzle boxes 11 only by heat traps 10 and turning old person 16 with the turbine case 2 are connected, take this for instance the saturation temperature of the Abdampfes, thus e.g. 50 °C with an evaporation printing of 0,1 bar exp.

A mixture of the HDund of the lp evaporation stream takes place only evaporate-laterally after the rotor blade row; then however those have

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the same (saturation) temperature, so that a mixture without a thermal load and without Exergieverlust takes place.

The Fig. „the blade cascades " that show 3 guidancelook-finely of the nozzle boxes and the turbine rotor blades. The blade cascades are a cut by the cylinder with the radius distance r 27 between guide vane center and the turbine shaft axle 17 and the radius (see Fig. 2). Hp steam flows over the hp steam inlet 9 ' into the hp nozzle box 11 ', distributes themselves in the hp steam distributor 12 ' and flows over the hp guide vanes 13 ' and leaves these under the hp nozzle angle oci 18 “. With small steam throughput the hp nozzle box 11 can reduce” to only one nozzle, which is implemented with a convergent cross section, a closest cross section and a diverging cross section usually because of the supercritical pressure ratio before and after the nozzle > 1.7 5… 1.90 as Laval nozzle, thus. Dependent on the adiabatic downward gradient of steam to the pressure at the withdrawal from the absolute hp nozzle speed of Ci 19 guidancelook-finely results ', too lossless counted

Ci = (2*Gefälle)^0,5.

The speed vectors in the blade cascade („velocity triangles ") are represented in the right, lower field. The hp nozzle speed of Ci 19 ' decreases vectorially by the peripheral speed u 20 of the rotor blade row 5 to the relative hp enter velocity wi 21 ' and enters under the hp shovel acceptance angle ßi 22 ' (there in-smooth and low-loss entrance is presupposed) the rotor blade row 5. The guide vane row 5 diverts the steam stream in accordance with the hp shovel angle of outlet ß2 23 ', so that the steam stream leaves the rotor blade row 5 with the relative hp exhaust velocity w2 24 '; this relative hp exhaust velocity w2 24 ' decreases vectorially by the peripheral speed u 20 to the “t absolute err) * *HD “* exhaust velocity C2 25”, which exhibits the hp angle of outlet α2 26 '.

Like the Fig. similarly to hp steam lp steam shows, flows 3 in the left field over the lp steam inlet 9 '' into the lp nozzle box 11 '', distributes themselves in the lp steam distributor 12 '' and flows over the lp guide vanes 13 '' and leaves these under the lp nozzle angle αx 18 ''. „The velocity triangles " are represented in the left, lower field. The lp nozzle speed of Ci 19 '' decreases vectorially by the peripheral speed u 20 of the rotor blade row 5 to the relative lp enter velocity Wi 21 '' and enters under the lp shovel acceptance angle ßi 22 ''the rotor blade row 5. The guide vane row 5 steers steam-flows in accordance with the lp shovel angle of outlet b2 23 '' off, so that the steam stream leaves the rotor blade row 5 with the relative lp exhaust velocity w2 24 ''; this relative lp exhaust velocity w2 24 '' decreases vectorially by the peripheral speed u 20 to the lp exhaust velocity c2 25 '', which exhibit the lp angle of outlet α2 26 ''.

As from the Fig. 3 evidently the lp nozzle angle can be selected αx 18 '' in inventive way smaller than the hp nozzle angle αi 18 ', as the lp shovel acceptance angle is eieint ßi 22 '' and the Hp-Schauf ride angles ßx 22 ' equally large, with which the NDund the hp steam streams with the common rotor blade row and the common turbine wheel without entrance impact can be converted into mechanical energy. Diverting conditions after the turbine wheel remain in the long run however different. The losses resulting from it are usually so small that it becomes by the decreased friction loss at the doubly used turbine run raf*m℮fl*sfc · *ul9℮r*k©mpensiert.

Fig. a further, additional variant shows 4. Opposite the Fig. 1 as well as the Fig. 2 is concentrically arranged to the turbine shaft axle 17 the nozzle boxes 11 ' and 11 '' not in sectors, but, whereby the lp nozzle box 11 is arranged '' with the radius distance r '' 27 '' more near to the turbine shaft axle 17 than the hp nozzle box 11 ' with the radius distance r' 27 '. One selects in particular

(_r' “/r”) = (ci' “/ci”) = (Hp-Ge fälle/ND Ge fell)^0,5

like that the velocity triangles for the HDund the lp part are similar, i.e. the angles for these are ident: succeeds establishing also with diverting conditions after the turbine wheel continuous optimal conditions.

The longer rotor blades 5 at the turbine wheel 4 continue to improve the turbine efficiency.

From the views it follows that with the different steam streams, which are to be expanded in the turbine the respective adiabatic downward gradient determines the angle and the radius the nozzle box, whereby the respective steam pressure has mostly the dominating influence. It can enter the strange case that two steam streams have the same pressure, but different overheating degrees and/or concentrations and thus different adiabatic curve downward gradient to exhibit. The more according to invention „downward gradients " - turbine can bear such steam streams behaviourless, while mixed pressure steam turbines are not after the state of the art practiced in addition able.

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After the views it is obvious, * nrircht? nzrr two to expand but three or still more steam streams in the steam turbine according to invention there the additional expenditure - differently than with the turbines after the state of the art is relatively small. However that becomes thermodynamically advantage with more than three steam streams with different downward gradients increasingly smaller, so that borders are set also here.

In the Fig. 1 is arranged the turbine wheel flying, which with the steam turbine according to invention is favourable. With the direct coupling shown of the turbine with the high-speed electrical generator one finds the sufficiency with a double storage of the turbine shaft. The horizontal arrangement that of turbine wheel decreases the danger of its thermal twisting in the stop by temperature stratification.

Turbine shaft

Turbine case

Wave-depressed with storage and poetry turbine wheel

Rotor blade row

Generator rotor

Electrical generator

Back support

Dampfeinlass (hp… ', lp… '')

Heat case (hp… ', lp… “)

Nozzle box (hp… lp… '')

Dampfverteiler (hp… ', lp… '')

Guide vanes (hp… ', lp… '')

Evaporation withdrawal

Evaporation condenser

Turning stop (hp… ', lp… '')

Turbine shaft axle

Nozzle angle cg (hp… “, lp… '') nozzle speed of Ci (hp…”, lp… '“) peripheral speed u (hp…”, lp… '')

Relative enter velocity wi (hp… “, lp… '') shovel acceptance angles ßi (hp…”, lp… '') shovel angle of outlet ß2 (hp… “, lp… '') relative exhaust velocity w2 (hp…”, lp… ““) exhaust velocity c2 (hp… lp… '') angle of outlet α2 (hp… lp…””) radius distance r between guide vane center and turbine shaft axle (hp… ', lp… '')