EP3390833A1

EP3390833A1 - Compressor rotor blade, compressor, and method for profiling the compressor rotor blade

Info

Publication number: EP3390833A1
Application number: EP17700921.4A
Authority: EP
Inventors: Christian Cornelius; Christoph Starke
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2016-02-10
Filing date: 2017-01-11
Publication date: 2018-10-24
Anticipated expiration: 2037-01-11
Also published as: US10837450B2; KR102206204B1; KR20180110054A; JP6715941B2; CN108603509B; EP3390833B1; US20190048880A1; JP2019504962A; WO2017137201A1; EP3205885A1; CN108603509A

Abstract

The invention relates to compressor rotor blade for an axial-type compressor having a blade profile having a transsonic section and has a profile section (21) of the blade profile which extends in the transonic section and which has a concave suction-side region (10) and a convex suction-side region (11) on the suction side (5) of said profile section, the convex suction-side region being arranged downstream of the concave suction-side region (10), and which has a convex pressure-side region (14) and a concave pressure-side region (13) on the pressure side (4) of said profile section, the concave pressure-side region being arranged downstream of the convex pressure-side region (14), wherein a curvature progression (27) on the pressure side (4) of the profile section (21) and a curvature progression (28) on the suction side (5) of the profile section (21) are both applied in a continuous manner over a profile chord (22) of the profile section (21), the positions of the minimum values of the curvature progressions (27, 28) deviate from each other by not more than 10% of the length of the profile chord (22), and the positions of the maximum values of the curvature progressions (27, 28) deviate from each other by not more than 10% of the length of the profile chord (22).

Description

description

Compressor rotor, compressor and method for

Profiling the compressor rotor

The invention relates to a Verdichterlaufschaufei and a method for profiling the Verdichterlaufschaufei.

An axial-flow compressor has at least one blade ring with a plurality of compressor blades for compressing a working fluid. The

Compressor blade has a radially inner subsonic section, in which the compression takes place by means of a deflection of the flow of the working medium. WEI terhin, the compressor blade to a transonic section in which the compression for the most part by means of a shock wave, wherein the Ar ^¬ beitsmedium is delayed from supersonic velocity to Unterschallge ^¬ speed.

Losses in the flow of the working medium in the transonic section occur, for example, in the compression ^¬ shock and by detachment of the boundary layer at the

Compressor bucket in the area of the compression shock. The losses cause a reduction in the efficiency of the compressor.

The object of the invention is therefore a

Compressor bucket, a compressor with the

Compressor blade and to provide a method for profiling the compressor blade, with which an increase in the efficiency of the compressor ^{blade ¬ have} the compressor can be reached. The compressor blade according to the invention for a ^¬ Ver tight in axial construction, has a blade profile having a transonic section and an extending portion in the transonic profile section of the Blade profile, which has on its suction side a concave suction side region and a convex suction side region which is disposed downstream of the concave suction side region, and which has on its pressure side a convex pressure side region and a concave pressure side region, which is arranged downstream of the convex pressure side region where ^¬ in the case of a curvature course on the pressure side of the profile section and a curvature profile on the suction side of the profile section applied in each case are continuous over a chord of the profile section, the positions of the minimum values of the curvature courses do not deviate from one another by more than 10% of the length of the chord and the positions of the maximum values of the profile chords curvatures vary by no more than 10% of the length of the chord vonei ^¬ Nander, the minimum values multiplied by the length of the chord from -1.2 to -0.5, and the maximum values, multiplied by the length of the chord of 1.5 to 4 are.

The inventive method for profiling a

A compressor rotor blade for a compressor for compressing a working medium in axial construction, which has a blade ^¬ row with the compressor blades, wherein the compressor blades have a blade profile with a transonic section, has the steps: providing a geometric model of the blade profile, where ^¬ in the Blade profile has a profile section extending in the transonic section, and the Laufschau ^¬ felreihe is set that sets a nominal operating condition of the compressor, a compression shock in which the working fluid is delayed from supersonic to Un ^¬ terschallgeschwindigkeit; Specifying edge ^¬ conditions for the blade flow flowing around which occurs at the nominal operating condition; Changing the profile section such that the suction side has a concave suction side portion and a convex suction side portion disposed downstream of the concave suction side portion and having on its pressure side a convex pressure side portion and a concave pressure side portion downstream The curve of the convex pressure side region is arranged, wherein a curvature course on the pressure side of the profile section and a curvature on the suction side of the profile section each applied over a chord of the profile section are continuous, the positions of the minimum values of the curvature curves by not more than 10% of the length of the chord each other ^¬ soft as well as the positions of the maximum values of the Krümmungsverläu ^¬ fe by no more than 10% of the length of the chord of the voneinan ^¬ differ, the minimum values multiplied by the length of the chord from -1.2 to -0.5, and the maximum values multi ^¬ plied with the chord length being from 1.5 to 4, the convex suction side region being at least partially upstream of a compression stroke exhibited by a flow adjusting in the compressor at the boundary conditions, whereby the compression shock related to the length of the chord downstream of a compression shock is arranged which would have a flow that would occur in the geometric model prior to changing the profile section and at the nominal operating condition.

It has been found that the compressor with the erfindungsge ^¬ MAESSEN Verdichterlaufschaufei and / or with the profiled with the OF INVENTION ^¬ to the invention process has a higher efficiency Verdichterlaufschaufei at least the same operating range as a compressor with the conventional

Compressor rotor. In addition, the Mach numbers on the suction side of the Verdichterlaufschaufei inventive front of the shock are lower than on the suction side of her ^¬ conventional Verdichterlaufschaufei. Thus, separations of the flow on the suction side of the invention

Compressor rotor less likely than the conventional compressor rotor blade. In addition, the Verdichterlaufschaufei invention can be performed with a shorter length of its chord than is the case with conven- tional Verdichterlaufschaufei without thereby to accept Einbu ^¬ SEN of efficiency or a reduction of the Arbeitsbe ^¬ kingdom. It is preferable that in the convex Saugseitenbereich the curvature multiplied by the length of the chord has a maximum value of 2 to 4 and in the konka ^¬ ven pressure side region of the curvature multiplied by the length of the chord has a maximum value of 1, 5 to 2.5.

It is preferred that the point of the concave Saugseitenbe ^¬ empire with the minimum curvature when projecting perpendicular to the chord of the profile section on this one Pro ^¬ jectionpunkt sets that of the leading edge of the profile ^{¬ section} of 40% to 80%, in particular of 60 % to 75%, the length of the chord is removed. It is preferred that the point of the convex suction side region with the maximum curvature when projecting perpendicularly onto the profile chord of the profile section predetermines ^{thereon a} projection point which is from 70% to 95%, in particular 80% to 90%, of the leading edge of the profile section. , the length of the chord is removed. Each of these measures can further increase the efficiency of the compressor.

It is preferred that the thickness of the profile section at all points of the profile section perpendicular to the chord is shorter than 2.5% of the length of the chord.

The compressor according to the invention for compressing a working ^¬ medium, has a blade row on which the

Compressor blades has, wherein the blade row is set up that at a nominal operating condition of the compressor precompression of the working fluid current ^¬ on a compression shock, in which the working medium of supersonic speed to subsonic speed is ver ^¬ hesitated, and upstream of one of two adjacent

Compressor blades limited flow channel takes place.

It is preferred that the profile section on a cylinder surface ^¬ whose axis coincides with the axis of the compressor ^¬ , on a conical surface, whose axis with the axis of the Compressor coincides, is located on a S i flow area of the compressor or in a tangential plane of the compressor. The S i flow surface extends in the circumferential direction and in the axial direction of the axial flow machine and describes a surface that follows an idealized flow.

When changing the profile section whose skew ^¬ lettlinie is preferably moved, in particular only the skeleton line is moved. As a result, it is advantageously achieved that the width of the channel remains unchanged between two compressor blades arranged adjacent in a blade ring. It is preferred that the geometric model before the change of the profile section on the pressure side from ^¬ finally concave and / or formed exclusively convex on the suction side.

It is preferable that the profile section is changed such that in the convex suction side area, the curve of the curve has a maximum value larger than the maximum value of the curve of the curve in the corresponding area of the conventional compressor blade. The profile section is preferably modified such that in the convex suction ^¬ lateral region of the curve of the curvature multiplied by the length of the chord has a maximum value which is from 2 to 4 and in the concave pressure side region of the curve of the curvature multiplied by the length of the chord Maximum value, which is from 1.5 to 2.5. It is preferred that the blade row is designed in such a way that at the nominal operating conditions, a maximum pre isentropic shock Mach number of 1.4, in particular of a maximum of 1.3, has ^¬. It is preferred that the profile section is changed ^¬ changed such that the point of the concave Saugseitenbereichs with the minimum curvature in vertical projection on the chord of the profile section specifies a projection point on this, the from the front edge of the profiled-section of 40% to 80 % of the length of the chord is removed. Each of these measures can further increase the efficiency of the compressor. The invention will be explained in more detail below with reference to the accompanying schematic drawings and mathematically determined data. Show it

1 shows the compressor rotor blade according to the invention with a mathematically determined flow field,

Figure 2 Machzahlverläufe on the conventional

Verdichterlaufschaufei and at the invention

Compressor rotor,

Figure 3 is a profile section of the invention

Compressor rotor,

FIG. 4 shows curves of the invention

Compressor run and

5 shows the Machzahlverläufe of Figure 2 with normalized lengths of the chords.

As is apparent from Figures 1 and 3, has a

Verdichterlaufschaufei 1 for a compressor in Axialbauwei ^¬ se a blade ^profile . The blade profile has a radially inner subsonic section and a radially outer transonic section, wherein in FIGS. 1 and 3 only the transonic section is shown. The blade profile has a profile section 21 which extends in the transonic section. For example, the profile section 21 is located on a cylindrical surface whose

Axis coincides with the axis of the compressor, on a Ke ^¬ gel surface whose axis coincides with the axis of the compressor coincides ^¬ on an S i flow area of the compressor or in a tangential plane of the compressor.

The profile section 21 has a front edge 2, a rear edge ^¬ 3, a pressure side 4 and a suction side 5. In addition, a profile chord 22 is shown in FIG straight line from the leading edge 2 to the trailing edge 3 extends. Furthermore, FIG. 3 shows a skeleton line 23 which extends from the front edge 2 to the rear edge 3 and is always located centrally between the pressure side 4 and the suction side 5 in a direction perpendicular to the chord 22.

FIG. 1 shows a two-dimensional flow distribution of a working medium flowing in the compressor in a region of the compressor. In Figure 1, a blade row 15 with the compressor blades 1, one of the blade row 15 downstream guide blade row 16 and one of the rotor blade row ^¬ felreihe 15 upstream guide blade row 17 is shown. The profile section 21 has on its suction side 5 a concave suction side region 10, which is arranged at least partially upstream of a compression joint 18, which has a flow which is established in the compressor under a nominal operating condition of the compressor. The compression stroke 18 is arranged in the regions of the flow in FIG. 1 in which the Mach number decreases from higher than 1 to lower than 1. In addition, Figure 1 shows that in the rated operation condition of the compressor ^¬ a precompression of the Arbeitsme ^¬ diums upstream of the shock wave 18 and upstream of one of two adjacent compressor blades 1 limited flow channel is made.

Due to the concave suction side region, the compaction shock 18 is arranged downstream of a compaction shock, relative to the length of the chord 22, which would have a flow that is similar to that of a conventional one

Compressor running, which differs from the

Compressor blade 1 may differ in that it is formed exclusively convex on its suction side 5, and would set in the nominal operating condition.

Figure 2 shows a comparison of the Mach number curves of the Verdichterlaufschaufei 1 and the Mach number curves of the conventional forth ^¬ Verdichterlaufschaufei. Above the horizontal axis 19 is a point on the chord 22 of the profile section 21 and over the vertical axis 20, the Mach number is plotted. Reference numeral 6 denotes the Machzahlverlauf on the pressure side of the conventional Verdichterlaufschaufei, with the reference numeral 7 is the Machzahlverlauf on the suction ^¬ side of the conventional Verdichterlaufschaufei, with the reference numeral 8 is the Machzahlverlauf on the pressure side 4 of the compressor rotor 1 and the Bezugszei ^¬ chen 9 is the Mach number distribution on the suction side 5 of the

Compressor rotor 1 denotes.

5 shows the Machzahlverläufe of Figure 2 based on the length of the chord 22. For this purpose, the Machzahlverlauf the compressor rotor 1 was scaled so that the front edge 2 and the trailing edge 3 of the compressor rotor 1 coincide with the leading edge and the trailing edge of the conventional Verdichterlaufschaufei.

From Figure 2 it can be seen that the Machzahlverlauf 9 on the suction side 5 of the Verdichterlaufschaufei 1 immediately upstream of the compression shock 18 lower supersonic Mach numbers than the Machzahlverlauf 7 on the suction side of the conventional Verdichterlaufschaufei immediately upstream of the compression shock. These lower supersonic Machzah- len will keep ^¬ ge over a longer extension along the chord 22 than in the conventional Verdichterlaufschaufei. Due to the lower supersonic Mach numbers before the compression shock 18 losses are reduced. Due to the fact that the supersonic Mach numbers are held over the longer extent, the total profile load, which correlates with the Mach number difference on the pressure side 4 and the suction side 5, is comparably high in the subsonic region downstream of the compression joint 18 ^¬ conventional compressor blade. In addition, ER is clear from Figure 1 that the shock wave 18 is arranged obliquely, which means that the shock wave 18 moves with increasing distance from the suction side 5 ^¬ upstream. This also leads to a reduction of losses. Of Furthermore, it can be seen from FIG. 2 that the profile load in the compressor rotor 1 after the compression stroke 18 is markedly higher than in the conventional compressor rotor. Due to the reduced losses and higher profile load in the subsonic region, a higher efficiency can be achieved with the compressor rotor 1 than with the conventional compressor rotor. As a result of the higher efficiency, the compressor rotor blade 1, as shown in FIG. 2, can be made shorter than the conventional compressor rotor ^blade , as a result of which losses due to friction of the working fluid on the ^{piston are increased}

Verdichterlaufschaufei 1 can be reduced.

FIG. 4 shows a curvature profile 27 along the pressure side 4 and a curvature profile 28 along the suction side 5.

Both curvature curves 27, 28 are continuous. About the Horizon ^¬ talachse 25 is the length of the chord 22 and the vertical axis 26, the curvature k multiplied by the length of the chord 22 is applied. The curvature k is defined as

Aa there

k = lim =,

As is the length of a circular arc and Δ the difference angle between the tangents at the endpoints of the circular arc.

Concave suction side areas and convex pressure side areas are characterized by a negative sign of the curvature. Convex and concave pressure side Saugseitenbereiche preparation ^¬ che characterized by a positive sign of the curvature.

In the concave suction side region 10, the curve of the curvature multiplied by the length of the chord 22 has a minimum value that is from -1.2 to -0.5. The profile section 21 has on its suction side 5 a first convex suction side region 11, which is arranged downstream of the concave suction side region 10. The profile section 21 has, on its suction side 5 to a ^¬ Saugseitenbereich second convex 12, which is located upstream of the concave Saugseitenbereichs 10th In the convex suction side region 11, the course of the

Curvature has a maximum value which is greater than the maximum ^¬ value of the curve of the curvature in the corresponding region of the conventional Verdichterlaufschaufei, in particular, in the convex suction side region 11 of the curve of the curvature multiplied by the length of the chord 22 has a maximum value, from 2 to 4 is.

The point of the concave Saugseitenbereichs 10 with the minima ^¬ len curvature in vertical projection on the chord 22 of the profile section 21 sets a projection ^¬ point 24 on this, of the leading edge of the profile section 21 of 40% to 80% of the length of the chord 22 is removed. The point of the convex suction side region 11 with the maxima ^¬ len curvature in the vertical projection on the chord 22 of the profile section 21 are on this one projection ^¬ point 24, which removes from the leading edge of 21 of 80% to 100% of the length of the chord 22 is. The ^{profiled section} 21 has on its pressure side 4 a convex pressure-side region 14, which is arranged in a region which is arranged opposite the concave suction-side region 10.

By way of example, the compressor blade 1 is profiled as follows: providing a geometrical model of the blade profile, wherein the blade profile has a profile section 21 which extends in the transonic section and on a surface of revolution, the axis of which coincides with the axis of the compressor, on a conical surface, the axis of which coincides with the axis of the compressor, lies on an S i flow surface of the compressor or in a tan ^¬ gentialen plane of the compressor, and the blade ^¬ row 15 is set that sets a compression stroke 18 at a nominal operating condition of the compressor . in which the working medium is delayed from supersonic speed to subsonic speed; - Setting boundary conditions for a flow around the blade 14, 15, which occurs at the nominal operating condition;

- Changing the profile section 21 such that only the skeleton line is displaced and the suction side 5 a konka ^¬ ven suction side region 10 and a convex suction side region 11 which is disposed downstream of the concave suction side region 10, and at its pressure side 4 a convex pressure side region 14 and a concave pressure side region 13, which is arranged downstream of the convex pressure side region 14, wherein a curvature 27 on the pressure ^¬ side 4 of the profile section 21 and a curvature 28 on the suction side 5 of the profile section 21 respectively applied via a chord 22 of the profile section 21 are continuous in that the positions of the minimum values of the curvature courses 27, 28 do not deviate from one another by more than 10% of the length of the chord 22 and the positions of the maximum values of the curvature courses 27, 28 do not differ by more than 10% of the length of the chord 22, multiply the minimum values with the length of the Pr Ofilsehne (22) from -1.2 to -0.5 and the Ma ^¬ ximalwerte multiplied by the length of the chord 22 from 1.5 to 4, wherein the convex suction side region 11 at least partially upstream of a compression shock 18 is arranged, a flow adjusting in the compressor at the boundary conditions, whereby the compaction shock 18 is arranged downstream of a compaction shock with respect to the length of the chord 22, which would have a flow, which in the geometric model before changing the profile section and in the Nennbetriebsbe ^¬ dingung would set.

Whether the shock wave moves downstream by changing the Pro ^¬ filschnitts 18, can mathematically insbesonde- re be a finite volume method, or experimentally be ^¬ true.

Although the invention is described in detail by the preferred embodiment has been illustrated in detail and described, for example approximately, so ^¬ not limited by the disclosed examples is the invention, and other variations can be derived therefrom by the skilled artisan without departing from the scope of the invention.

Claims

claims

1. Verdichterlaufschaufei for a compressor in Axialbau ^¬ example, with a blade profile having a transonic section, and extending in the transonic section profile section (21) of the blade profile, on its suction side (5) a concave suction side region (10 ) and a convex suction side portion (11) disposed downstream of the concave suction side portion (10) and having on its pressure side (4) a convex pressure side portion (14) and a concave pressure side portion (13) downstream of the convex pressure side portion (11). 14), wherein a curvature (27) on the pressure ^¬ side (4) of the profile section (21) and a curvature (28) on the suction side (5) of the profile section (21) each applied on a chord (at ^¬ sorted 22 ) of the profile section

(21) are continuous, the locations of the minimum values of the curve ^¬ gradients (27, 28) by no more than 10% of the length of the Pro ^¬ filsehne (22) differ from each other as well as the positions of the maximum values of the curvature profiles (27, 28) by not more than 10% of the length of the chord (22), the minimum values multiplied by the length of the chord

(22) are from -1.2 to -0.5 and the maximum values multiplied by the length of the chord (22) are from 1.5 to 4.

2. Verdichterlaufschaufei according to claim 1,

wherein in the convex Saugseitenbereich (11) of the curvature (28) multiplied by the length of the chord (22) has a maximum value which is from 2 to 4 and in the konka- ven pressure side portion (13) of the curvature (27) multi ^¬ plied with the length of chord (22) has a maximum value that is from 1.5 to 2.5.

3. Verdichterlaufschaufei according to claim 1 or 2, wherein the point of the concave suction side portion (10) with the minimum curvature when projecting perpendicular to the chord (22) of the profile section (21) on this one projecting point (24) dictates that of Leading edge (2) of the Pro ^¬ filschnitts (21) from 40% to 80% of the length of the chord (22) is removed.

4. Verdichterlaufschaufei according to one of claims 1 to 3, wherein the thickness of the profile section perpendicular to the chord

(22) is shorter than 2.5% of the length of the chord (22).

5. A compressor for compressing a working medium, comprising a blade row (15) comprising the compressor blades (1) according to one of claims 1 to 4,

wherein the blade row (15) is arranged such that, under a nominal operating condition of the compressor, precompression of the working fluid upstream of a compression surge (18) delays the working fluid from supersonic to subsonic and upstream of a flow channel bounded by two adjacent compressor blades (1) he follows.

6. A method for profiling a Verdichterlaufschaufei (1) for a compressor for compressing a working medium in axial construction, the one blade row (15) with the

Compressor blades (1),

wherein the compressor blades (1) have a blade profile with a transonic section and the method comprises the steps of:

Is configured providing a geometric model of the Schaufelpro- fils, wherein the blade profile comprises a profile section (21) on ^¬ extending in the transonic section and the blade row (15), that at a rated operating condition of the compressor, a compression shock (18 - ) sets, in which the working fluid from supersonic velocity to subsonic velocity is deferrers ^¬ Gert;

- Setting boundary conditions for a flow around the blade (14, 15), which occurs at the nominal operating condition;

- Changing the profile section (21) such that the Saugsei ^¬ te (5) has a concave suction side region (10) and a convex suction side region (11) which is disposed downstream of the concave suction side region (10), and at its pressure side (4 ) having a convex pressure side portion (14) and a concave pressure side portion (13) which is arranged downstream of the convex pressure side portion (14), a curvature (27) on the pressure side (4) of the profile ^¬ section (21) and a Curvature profile (28) on the suction side (5) of the profile section (21) applied in each case continuously over a chord (22) of the profile section (21), the La ^¬ conditions of the minimum values of the curvature curves (27, 28) by not more than 10% The lengths of the chord (22) from each other soft ^¬ deviate and the positions of the maximum values of ^{Krümmungsverläu ¬} Fe (27, 28) by not more than 10% of the length of the chord (22) differ from each other, the minimum values multiplied by the Län of the chord (22) is from -1.2 to -0.5 and the maximum values multiplied by the length of the chord (22) are from 1.5 to 4, the convex suction side region (11) being at least partially upstream of a compression joint (18) is arranged, which has a in the compressor at the Rand ^¬ conditions adjusting flow, whereby the compression shock (18) relative to the length of the chord (22) is arranged downstream of a compression shock, the one

Flow which would occur in the geometric model before changing the profile section and in the nominal operating condition.

7. The method according to claim 6,

wherein the profile section (21) on a cylindrical surface, whose axis coincides with the axis of the compressor, on a conical surface whose axis coincides with the axis of the compressor ^¬ falls on an S i flow area of the compressor or in a tangential plane of the compressor ,

8. The method according to claim 6 or 7,

wherein when changing the profile section (21) whose skeleton ^¬ line (23) is moved, in particular only the skeleton line (23) is moved.

9. The method according to any one of claims 6 to 8,

wherein the geometric model before changing the profile section ^¬ (21) on the pressure side (4) is exclusively concave and / or on the suction side (5) exclusively ^¬ convex.

10. The method according to any one of claims 6 to 9,

wherein the profile section (21) is changed such that in the convex suction side region (11) the curve of the curvature has a maximum value which is greater than the maximum value of the curve of the curvature in the corresponding region of the conventional compressor rotor.

11. The method according to any one of claims 6 to 10, wherein the profile section is changed such that in the convex suction side region (11) the course of the curvature mul- tipliziert with the length of the chord (22) has a maximum ^¬ value, the value of 2 is up to 4 and in the concave ^¬ tenbereich Drucksei (13) of the course of the curvature multiplied by the length of the chord (22) has a maximum value of 1.5 to 2.5.

12. The method according to any one of claims 6 to 11,

wherein the profile section (21) is changed such that the point of the concave Saugseitenbereichs (10) with the minimum curvature in vertical projection on the chord of the profile section is on said one projection point (24) in front ^¬ that from the front edge of the profiled-section of 40 % to 80% of the length of the chord (22) is removed.

13. The method according to any one of claims 6 to 12,

wherein the blade row (15) is designed such that at the nominal operating conditions has a maximum isentropic Mach number of 1.4, in particular of at most 1.3.

14. The method according to any one of claims 6 to 13,

wherein the profile section is designed such that the thickness of the profile section perpendicular to the chord (22) is shorter than 2.5% of the length of the chord (22).