EP0825332B1 - Coolable blade - Google Patents

Coolable blade Download PDF

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Publication number
EP0825332B1
EP0825332B1 EP97810493A EP97810493A EP0825332B1 EP 0825332 B1 EP0825332 B1 EP 0825332B1 EP 97810493 A EP97810493 A EP 97810493A EP 97810493 A EP97810493 A EP 97810493A EP 0825332 B1 EP0825332 B1 EP 0825332B1
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EP
European Patent Office
Prior art keywords
rib
height
local
ribs
blade
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP97810493A
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German (de)
French (fr)
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EP0825332A1 (en
Inventor
Kenneth Hall
Bruce Dr. Johnson
Bernhard Dr. Weigand
Shey Dr. Wu
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General Electric Switzerland GmbH
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Alstom Schweiz AG
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Publication of EP0825332A1 publication Critical patent/EP0825332A1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01DNON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12Blades
    • F01D5/14Form or construction
    • F01D5/18Hollow blades, i.e. blades with cooling or heating channels or cavities; Heating, heat-insulating or cooling means on blades
    • F01D5/187Convection cooling
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05DINDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00Function
    • F05D2260/20Heat transfer, e.g. cooling
    • F05D2260/221Improvement of heat transfer
    • F05D2260/2212Improvement of heat transfer by creating turbulence

Definitions

  • the invention relates to a coolable blade according to the preamble of the first Claim.
  • Such coolable blades are known for example from DE 32 48 162.
  • a coolable shovel that has a leading edge area Has cooling fluid passage. Extend across the width of the cooling fluid passage ribs for triggering and promoting turbulence, which are at an acute angle, about 30 °, to the inside of the leading edge wall obliquely against the Cooling fluid flow direction are arranged in the cooling fluid passage. Ribs are aligned so that the cooling air is directed to the front edge of the blade becomes.
  • the rib height is between 10 to 33% of the height of the Cooling fluid passage.
  • the rib height is constant across the width of the cooling fluid passage and the cooling arrangement is only for the nasal channel Area of the front edge applicable.
  • the invention has for its object in a coolable blade type mentioned to improve the cooling of the blade and the Increase bucket life.
  • the essence of the invention is therefore that at least one rib which Rib is designed so that it has a tip and two legs which thighs of the rib at an acute angle compared to a straight line running parallel to the main flow direction are angled, the ratio of the local rib height to the local one Cavity height is essentially the same at all points on the rib.
  • the advantages of the invention include the fact that the blade through the design of the ribs with a tip and two legs evenly is cooled and the cooling fluid consumption can be reduced. This takes place in essentially by avoiding dead water areas in the area of Front and rear edge of the cooling channel of the blade.
  • By cooling the Shovel smoothes the surface temperature and the thermal Tensions in the blade are reduced, which increases the lifespan of the Bucket is raised. Due to the reduced cooling fluid consumption, the Turbine efficiency can be increased.
  • the blade can adjust the rib geometry in the cooling fluid passage and thus achieve a uniform surface temperature of the blade. shovel with ribs arranged in the cavity are also simple in terms of casting technology manufacture.
  • an embodiment of the invention is based on a schematic representation of a blade of a turbomachine.
  • the Airfoil 1 shows an airfoil 1 of a turbomachine with a cavity 2 shown in cross section, the cavity serving as a cooling fluid passage.
  • the Airfoil 1 has a leading edge area 3, a trailing edge area 4, a suction side wall 5 and a pressure side wall 6, the suction side and the pressure-side wall in the area of the front edge 3 and the rear edge 4 are interconnected. This essentially creates a double triangular shaped cooling duct with acute angled triangle tips in the area of the Front 3 and rear edge 4 of the blade.
  • On the pressure side wall 6 is a V-shaped rib 7 with a tip 9 and legs 14, 15 is arranged.
  • the V-shaped rib 7 can be designed isosceles, depending on the arrangement the rib tip 9 in the cavity, however, are also rib configurations unequal legs possible.
  • a ratio of a height h1 of the rib 7 to A local height H1 of the cavity 2 is the same size as a ratio a height h2 of the rib 7 to a local height H2 of the cavity 2.
  • Das Ratio of rib height h to cavity height H is thus at every point Rib essentially the same.
  • the rib 9 tapers to the passage the cooling fluid in these areas not to inhibit.
  • Fig. 2 shows the inside of the suction side wall 5 with cut Front edge area 3 and rear edge area 4.
  • One blade 10 one Turbomachine consists of the airfoil 1 and the Blade base 11 with which the blade 10 can be mounted. Between Blade 1 and blade root 11 is usually a platform 12 arranged, which the blade root of those flowing around the airfoil Shields fluids.
  • On the suction side wall there are also V-shaped ribs 7a arranged, here a tip 9a of the ribs on a plane 13 of the Cavity 2 is arranged and the tip 9a is downstream.
  • Level 13 runs radially to the blade and perpendicular to the inside of walls 5 and 6 the blade and is arranged at the widest point of the cavity 2. The Tip 9a is therefore at the point where the local rib height h is maximum.
  • a cooling fluid 20 is passed through the cavity 2, starting from the blade root.
  • the ribs are angled at an angle 8 to the main flow direction of the cooling fluid 20, the main flow direction running essentially parallel to the plane 13.
  • the angle 8 is 30 to 60 °, preferably 40 to 50 ° and in particular 45 °. Downstream of the V-shaped fins, vortices and recirculation zones arise, which increase the heat transfer coefficient.
  • Mean Nusselt number depending on the rib height of the V-shaped rib Ratio of rib height / cavity height [%] 0 18 31 44 Nu / Nu smooth 1 2-4 5 - 7 9-12
  • the Nusselt number Nu is defined as the ratio of the convectively dissipated to the conducted amount of heat.
  • Table 1 the average Nusselt number Nu for different rib heights is compared to the Nusselt number Nu smooth of a channel without ribs, the tips of the V-shaped ribs being arranged downstream. Table 1 clearly shows that the average Nusselt number increases sharply with increased rib height.
  • the ratio of local rib height to local cavity height should therefore be between 5 to 50%, preferably between 20 to 40%.
  • Fig. 3 shows the inside of the pressure side wall 6 with cut Front edge area 3 and rear edge area 4.
  • the on the inside of the pressure-side wall 6 arranged ribs 7b are also V-shaped, their Tip 9b is arranged on the level 13 of the cavity 2.
  • the tip 9b lies thus at the point where the local rib height h is maximum.
  • the ribs on the suction and pressure side to each other in Flow direction arranged offset.
  • the mutual arrangement of the ribs 7a and 7b can be seen from FIG.
  • the ribs are offset from one another in the direction of flow, so that the Flow successively onto a rib 7a of the suction side 5 and a rib 7b of the Print page 6 hits.
  • the ribs are advantageously in the middle arranged between the ribs of the opposite wall.
  • Fig. 5 shows the inside of the pressure side wall 6 with cut Front edge area 3 and rear edge area 4 of the blade 10, which from the Blade 1 and the blade root 11 there.
  • the ribs are also in the Angle 8 angled to the main flow direction of the cooling fluid 20.
  • FIG. 6 shows the suction-side wall with ribs 7a and indicated ribs 7c wherein the ribs 7a are arranged according to FIG. 2 on the suction side.
  • the relationship is of course local Rib height to local cavity height always less than 50%.
  • V-shaped ribs can also be in Buckets with several cooling air passages can be arranged if in the Edge zones of the cooling air diffusers have a high flow resistance.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)

Description

Technisches GebietTechnical field

Die Erfindung betrifft eine kühlbare Schaufel nach dem Oberbegriff des ersten Anspruches.The invention relates to a coolable blade according to the preamble of the first Claim.

Stand der TechnikState of the art

Derartige kühlbare Schaufeln sind beispielsweise bekannt aus DE 32 48 162. Dort wird eine kühlbare Schaufel beschrieben, die in ihrem Vorderkantenbereich einen Kühlfluiddurchlass aufweist. Ueber die Breite des Kühlfluiddurchlasses erstrecken sich Rippen zur Turbulenzauslösung und -förderung, die in einem spitzen Winkel, ungefähr 30°, zu der Innenseite der Vorderkantenwand schräg entgegen der Kühlfluidströmungsrichtung im Kühlfluiddurchlass angeordnet sind. Die Rippen sind somit so ausgerichtet, dass die Kühlluft zur Vorderkante der Schaufel geleitet wird. Die Rippenhöhe beträgt dabei zwischen 10 bis 33% der Höhe des Kühlfluiddurchlasses. Die Rippenhöhe ist dabei jeweils konstant über die Breite des Kühlfluiddurchlasses und die Kühlanordnung ist nur für den Nasenkanal im Bereich der Vorderkante anwendbar. Such coolable blades are known for example from DE 32 48 162. There describes a coolable shovel that has a leading edge area Has cooling fluid passage. Extend across the width of the cooling fluid passage ribs for triggering and promoting turbulence, which are at an acute angle, about 30 °, to the inside of the leading edge wall obliquely against the Cooling fluid flow direction are arranged in the cooling fluid passage. Ribs are aligned so that the cooling air is directed to the front edge of the blade becomes. The rib height is between 10 to 33% of the height of the Cooling fluid passage. The rib height is constant across the width of the cooling fluid passage and the cooling arrangement is only for the nasal channel Area of the front edge applicable.

Bei den hinteren Stufen einer modernen Gasturbine erfordert die hohe Aussentemperatur ebenfalls eine Kühlung der Schaufel, wobei hier die Schaufel aus aerodynamischen Gründen jedoch sehr schlank geformt wird. Dadurch entsteht ein im wesentlichen doppelt dreieckig geformter Kühlkanal (engl.: double triangular-shaped coolant passage) mit spitzwinkligen Dreieckspitzen im Bereich der Vorder- und der Hinterkante der Schaufel. Im Bereich der spitzwinkligen Dreieckspitzen ist der Strömungswiderstand sehr hoch und somit findet in diesen Bereichen praktisch keine Kühlung mehr statt.The rear steps of a modern gas turbine require high Outside temperature also cooling the blade, here the blade for aerodynamic reasons, however, is very slim. Thereby an essentially double triangular cooling channel is created triangular-shaped coolant passage) with acute-angled triangular tips in the area the front and rear edge of the bucket. In the area of the acute-angled Triangular tips have very high flow resistance and therefore take place in them Areas practically no longer take place.

Weitere Ausführungen von gekühlten Turbinenschaufeln sind aus US-A-3 171 631 zu entnehmen.Further versions of cooled turbine blades can be found in US-A-3 171 631.

Darstellung der ErfindungPresentation of the invention

Der Erfindung liegt die Aufgabe zugrunde, bei einer kühlbaren Schaufel der eingangs genannten Art die Kühlung der Schaufel zu verbessern und die Lebensdauer der Schaufel zu erhöhen.The invention has for its object in a coolable blade type mentioned to improve the cooling of the blade and the Increase bucket life.

Erfindungsgemäss wird dies durch die Merkmale des ersten Anspruches erreicht.According to the invention, this is achieved by the features of the first claim.

Kern der Erfindung ist es also, dass bei mindestens einer Rippe, welche Rippe so ausgestaltet ist, dass sie eine Spitze und zwei Schenkel aufweist , welche Schenkel der Rippe in einem spitzen Winkel gegenüber einer parallel zur Hauptströmungsrichtung verlaufenden Gerade angewinkelt sind, das Verhältnis der lokalen Rippenhöhe zur lokalen Hohlraumhöhe im Wesentlichen an allen Punkten der Rippe gleich ist.The essence of the invention is therefore that at least one rib which Rib is designed so that it has a tip and two legs which thighs of the rib at an acute angle compared to a straight line running parallel to the main flow direction are angled, the ratio of the local rib height to the local one Cavity height is essentially the same at all points on the rib.

Die Vorteile der Erfindung sind unter anderem darin zu sehen, dass die Schaufel durch die Ausgestaltung der Rippen mit Spitze und zwei Schenkeln gleichmässig gekühlt wird und der Kühlfluidverbrauch gesenkt werden kann. Dies erfolgt im wesentlichen durch eine Vermeidung von Totwassergebieten im Bereich der Vorder- und der Hinterkante des Kühlkanales der Schaufel. Durch die Kühlung der Schaufel wird die Oberflächentemperatur vergleichmässigt und die thermischen Spannungen in der Schaufel werden vermindert, womit die Lebensdauer der Schaufel erhöht wird. Durch den gesenkten Kühlfluidverbrauch kann der Wirkungsgrad der Turbine erhöht werden. Je nach der äusseren Wärmebelastung der Schaufel lässt sich die Rippengeometrie im Kühlfluiddurchlass anpassen und somit eine gleichmässige Oberflächentemperatur der Schaufel erzielen. Schaufeln mit im Hohlraum angeordneten Rippen sind zudem gusstechnisch einfach herzustellen.The advantages of the invention include the fact that the blade through the design of the ribs with a tip and two legs evenly is cooled and the cooling fluid consumption can be reduced. This takes place in essentially by avoiding dead water areas in the area of Front and rear edge of the cooling channel of the blade. By cooling the Shovel smoothes the surface temperature and the thermal Tensions in the blade are reduced, which increases the lifespan of the Bucket is raised. Due to the reduced cooling fluid consumption, the Turbine efficiency can be increased. Depending on the external heat load the blade can adjust the rib geometry in the cooling fluid passage and thus achieve a uniform surface temperature of the blade. shovel with ribs arranged in the cavity are also simple in terms of casting technology manufacture.

Es ist besonders vorteilhaft, die Rippen mit Spitze und zwei Schenkeln in einem doppelt dreieckig mit spitzwinkligen Dreieckspitzen im Bereich der Vorder- und der Hinterkante ausgeformten Hohlraum anzuordnen. Dadurch wird es möglich auch sehr schlank geformte Schaufelprofile, welche einen hohen aerodynamischen Wirkungsgrad aufweisen, mit einem doppelt dreieckig geformtem Kühlkanal effektiv zu kühlen.It is particularly advantageous to have the ribs with the tip and two legs in one double triangular with acute angled triangle tips in the area of the front and the To arrange trailing edge formed cavity. This also makes it possible very slim shaped blade profiles, which have a high aerodynamic Have efficiency, with a double triangular cooling channel to cool effectively.

Es ist vorteilhaft, das Verhältnis von lokaler Rippenhöhe zu lokaler Hohlraumhöhe konstant zu halten. Dadurch wird die lokale Rippenhöhe im Bereich der Vorderund Hinterkante im Vergleich zur lokalen Rippenhöhe im Bereich der Hohlraummitte verkleinert, wodurch die Sekundärströmung intensiviert wird.It is advantageous to have the ratio of local rib height to local cavity height to keep constant. This makes the local rib height in the area of the anterior and Trailing edge compared to the local rib height in the area of the The center of the cavity is reduced, which intensifies the secondary flow.

Weitere vorteilhafte Ausgestaltungen der Erfindung ergeben sich aus den weiteren Unteransprüchen.Further advantageous embodiments of the invention result from the further subclaims.

Kurze Beschreibung der ZeichnungBrief description of the drawing

In der Zeichnung ist ein Ausführungsbeispiel der Erfindung anhand einer schematischen Darstellung einer Schaufel einer Strömungsmaschine dargestellt. In the drawing, an embodiment of the invention is based on a schematic representation of a blade of a turbomachine.

Es zeigen:

Fig. 1
einen Teilquerschnitt durch ein Schaufelblatt der Schaufel;
Fig. 2
einen Teillängsschnitt durch die Schaufel entlang der Linie II-II in Fig. 1;
Fig. 3
einen Teillängsschnitt durch die Schaufel entlang der Linie III-III in Fig. 1;
Fig. 4
einen Teillängsschnitt durch die Schaufel parallel versetzt zur Linie II-II in Fig. 1;
Fig. 5
einen Teillängsschnitt durch die Schaufel entlang der Linie V-V in Fig. 1;
Fig. 6
einen Teillängsschnitt durch die Schaufel parallel versetzt zur Linie V-V in Fig. 1;
Show it:
Fig. 1
a partial cross section through an airfoil of the blade;
Fig. 2
a partial longitudinal section through the blade along the line II-II in Fig. 1;
Fig. 3
a partial longitudinal section through the blade along the line III-III in Fig. 1;
Fig. 4
a partial longitudinal section through the blade parallel to the line II-II in Fig. 1;
Fig. 5
a partial longitudinal section through the blade along the line VV in Fig. 1;
Fig. 6
a partial longitudinal section through the blade parallel to the line VV in Fig. 1;

Es sind nur die für das Verständnis der Erfindung wesentlichen Elemente gezeigt.Only the elements essential for understanding the invention are shown.

Weg zur Ausführung der ErfindungWay of carrying out the invention

In Fig. 1 ist ein Schaufelblatt 1 einer Strömungsmaschine mit einem Hohlraum 2 im Querschnitt dargestellt, wobei der Hohlraum als Kühlfluiddurchlass dient. Das Schaufelblatt 1 weist einen Vorderkantenbereich 3, einen Hinterkantenbereich 4, eine saugseitige Wand 5 und eine druckseitige Wand 6 auf, wobei die saugseitige und die druckseitige Wand im Bereich der Vorderkante 3 und der Hinterkante 4 miteinander verbunden sind. Dadurch entsteht ein im wesentlichen doppelt dreieckig geformter Kühlkanal mit spitzwinkligen Dreieckspitzen im Bereich der Vorder- 3 und der Hinterkante 4 der Schaufel. An der druckseitigen Wand 6 ist eine V-förmige Rippe 7 mit einer Spitze 9 und Schenkeln 14, 15 angeordnet. Die V-förmige Rippe 7 kann dabei gleichschenklig ausgelegt sein, je nach Anordnung der Rippenspitze 9 im Hohlraum sind jedoch auch Rippenkonfigurationen mit ungleich langen Schenkeln möglich. Ein Verhältnis einer Höhe h1 der Rippe 7 zu einer lokalen Höhe H1 des Hohlraumes 2 ist dabei gleich gross wie ein Verhältnis einer Höhe h2 der Rippe 7 zu einer lokalen Höhe H2 des Hohlraumes 2. Das Verhältnis von Rippenhöhe h zu Hohlraumhöhe H ist somit an jeder Stelle der Rippe im wesentlichen gleich. In den Bereichen wo der Hohlraum 2 in den Vorderund Hinterkantenbereich übergeht, verjüngt sich die Rippe 9, um den Durchtritt des Kühlfluides in diesen Bereichen nicht zu hemmen.1 shows an airfoil 1 of a turbomachine with a cavity 2 shown in cross section, the cavity serving as a cooling fluid passage. The Airfoil 1 has a leading edge area 3, a trailing edge area 4, a suction side wall 5 and a pressure side wall 6, the suction side and the pressure-side wall in the area of the front edge 3 and the rear edge 4 are interconnected. This essentially creates a double triangular shaped cooling duct with acute angled triangle tips in the area of the Front 3 and rear edge 4 of the blade. On the pressure side wall 6 is a V-shaped rib 7 with a tip 9 and legs 14, 15 is arranged. The V-shaped rib 7 can be designed isosceles, depending on the arrangement the rib tip 9 in the cavity, however, are also rib configurations unequal legs possible. A ratio of a height h1 of the rib 7 to A local height H1 of the cavity 2 is the same size as a ratio a height h2 of the rib 7 to a local height H2 of the cavity 2. Das Ratio of rib height h to cavity height H is thus at every point Rib essentially the same. In the areas where the cavity 2 in the front and The trailing edge area merges, the rib 9 tapers to the passage the cooling fluid in these areas not to inhibit.

Fig. 2 zeigt die Innenseite der saugseitigen Wand 5 mit geschnittenem Vorderkantenbereich 3 und Hinterkantenbereich 4. Eine Schaufel 10 einer Strömungsmaschine besteht dabei aus dem Schaufelblatt 1 und dem Schaufelfuss 11, mit dem die Schaufel 10 montiert werden kann. Zwischen Schaufelblatt 1 und Schaufelfuss 11 ist üblicherweise eine Plattform 12 angeordnet, welche den Schaufelfuss von den das Schaufelblatt umströmenden Fluiden abschirmt. An der saugseitigen Wand sind ebenfalls V-förmige Rippen 7a angeordnet, wobei hier eine Spitze 9a der Rippen auf einer Ebene 13 des Hohlraumes 2 angeordnet ist und die Spitze 9a stromabwärts liegt. Die Ebene 13 verläuft radial zur Schaufel und senkrecht zu den Innenseiten der Wände 5 und 6 der Schaufel und ist an der breitesten Stelle des Hohlraumes 2 angeordnet. Die Spitze 9a liegt somit an der Stelle wo die lokale Rippenhöhe h maximal ist.Fig. 2 shows the inside of the suction side wall 5 with cut Front edge area 3 and rear edge area 4. One blade 10 one Turbomachine consists of the airfoil 1 and the Blade base 11 with which the blade 10 can be mounted. Between Blade 1 and blade root 11 is usually a platform 12 arranged, which the blade root of those flowing around the airfoil Shields fluids. On the suction side wall there are also V-shaped ribs 7a arranged, here a tip 9a of the ribs on a plane 13 of the Cavity 2 is arranged and the tip 9a is downstream. Level 13 runs radially to the blade and perpendicular to the inside of walls 5 and 6 the blade and is arranged at the widest point of the cavity 2. The Tip 9a is therefore at the point where the local rib height h is maximum.

Durch den Hohlraum 2 wird ausgehend vom Schaufelfuss ein Kühlfluid 20 geleitet. Die Rippen sind dabei in einem Winkel 8 zur Hauptströmungsrichtung des Kühlfluides 20 angewinkelt, wobei die Hauptströmungsrichtung im wesentlichen parallel zur Ebene 13 verläuft. Der Winkel 8 beträgt dabei 30 bis 60°, vorzugsweise 40 bis 50° und insbesondere 45°. Stromabwärts der V-förmigen Rippen entstehen Wirbel und Rezirkulationszonen, welche den Wärmeübergangskoeffizienten erhöhen. Mittlere Nusselt-Zahl abhängig von der Rippenhöhe der V-förmigen Rippe (aus experimentellen Daten) Verhältnis Rippenhöhe / Hohlraumhöhe [%] 0 18 31 44 Nu/ Nuglatt 1 2 - 4 5 - 7 9 - 12 A cooling fluid 20 is passed through the cavity 2, starting from the blade root. The ribs are angled at an angle 8 to the main flow direction of the cooling fluid 20, the main flow direction running essentially parallel to the plane 13. The angle 8 is 30 to 60 °, preferably 40 to 50 ° and in particular 45 °. Downstream of the V-shaped fins, vortices and recirculation zones arise, which increase the heat transfer coefficient. Mean Nusselt number depending on the rib height of the V-shaped rib (from experimental data) Ratio of rib height / cavity height [%] 0 18 31 44 Nu / Nu smooth 1 2-4 5 - 7 9-12

Die Nusselt-Zahl Nu ist definiert als das Verhältnis der konvektiv abgeführten zur geleiteten Wärmemenge. In Tabelle 1 wird die mittlere Nusselt-Zahl Nu für verschiedene Rippenhöhen verglichen mit der Nusselt-Zahl Nuglatt eines Kanales ohne Rippen, wobei die Spitzen der V-förmigen Rippen stromabwärts angeordnet sind. Aus der Tabelle 1 ist deutlich ersichtlich, dass die mittlere Nusselt-Zahl mit erhöhter Rippenhöhe stark zunimmt. Das Verhältnis von lokaler Rippenhöhe zu lokaler Hohlraumhöhe sollte somit zwischen 5 bis 50%, vorzugsweise zwischen 20 bis 40% liegen.The Nusselt number Nu is defined as the ratio of the convectively dissipated to the conducted amount of heat. In Table 1, the average Nusselt number Nu for different rib heights is compared to the Nusselt number Nu smooth of a channel without ribs, the tips of the V-shaped ribs being arranged downstream. Table 1 clearly shows that the average Nusselt number increases sharply with increased rib height. The ratio of local rib height to local cavity height should therefore be between 5 to 50%, preferably between 20 to 40%.

Da die Kühlfluidtemperatur in Strömungsrichtung durch Aufnahme von Wärmeenergie zunimmt und damit der Unterschied zwischen Wandtemperatur und Kühlfluid abnimmt, kann das Verhältnis zwischen lokaler Rippenhöhe h und lokaler Hohlraumhöhe H in Strömungsrichtung kontinuierlich erhöht werden, womit gemäss der vorstehenden Tabelle 1 die Nusselt-Zahl erhöht und damit der Wärmeübergang verbessert wird. Dadurch wird die vom Kühlfluid aufgenommene Wärmeenergie an die äussere Wärmelast der Schaufel angepasst. Dies führt zu einer zusätzlichen Vergleichmässigung der Temperaturverteilung in radialer Richtung der Schaufel und damit zu deutlich niedrigeren Spannungen. Because the cooling fluid temperature in the flow direction by taking Thermal energy increases and with it the difference between wall temperature and cooling fluid decreases, the relationship between local fin height h and local cavity height H can be continuously increased in the direction of flow, with which according to Table 1 above, the Nusselt number increased and thus the Heat transfer is improved. As a result, the one absorbed by the cooling fluid Thermal energy adapted to the external heat load of the bucket. this leads to an additional homogenization of the temperature distribution in the radial Direction of the blade and thus to significantly lower tensions.

Fig. 3 zeigt die Innenseite der druckseitigen Wand 6 mit geschnittenem Vorderkantenbereich 3 und Hinterkantenbereich 4. Die auf der Innenseite der druckseitigen Wand 6 angeordneten Rippen 7b sind ebenfalls V-förmig, wobei ihre Spitze 9b auf der Ebene 13 des Hohlraumes 2 angeordnet ist. Die Spitze 9b liegt somit an der Stelle wo die lokale Rippenhöhe h maximal ist. Wie man aus Fig. 3 ersehen kann sind die Rippen auf Saug- und Druckseite zueinander in Strömungsrichtung versetzt angeordnet.Fig. 3 shows the inside of the pressure side wall 6 with cut Front edge area 3 and rear edge area 4. The on the inside of the pressure-side wall 6 arranged ribs 7b are also V-shaped, their Tip 9b is arranged on the level 13 of the cavity 2. The tip 9b lies thus at the point where the local rib height h is maximum. As can be seen in Fig. 3 can be seen the ribs on the suction and pressure side to each other in Flow direction arranged offset.

Aus der Fig. 4 wird die gegenseitige Anordnung der Rippen 7a und 7b ersichtlich. Die Rippen sind gegeneinander in Strömungsrichtung versetzt, so dass die Strömung nacheinander auf eine Rippe 7a der Saugseite 5 und eine Rippe 7b der Druckseite 6 trifft. Vorteilhafterweise werden die Rippen jeweils in der Mitte zwischen den Rippen der gegenüberliegenden Wand angeordnet.The mutual arrangement of the ribs 7a and 7b can be seen from FIG. The ribs are offset from one another in the direction of flow, so that the Flow successively onto a rib 7a of the suction side 5 and a rib 7b of the Print page 6 hits. The ribs are advantageously in the middle arranged between the ribs of the opposite wall.

Durch die Anordnung nach Fig. 4 wird die Strömung in die spitzwinkligen Bereiche der Vorder- und Hinterkante geleitet wodurch eine deutlich höhere lokale Nusselt-Zahl erreicht wird, als die in der Tabelle 1 angegebenen mittleren Nusselt-Zahlen. Es werden somit sehr hohe Wärmeübergangszahlen im Bereich der Vorder- und der Hinterkante der Schaufel erzielt, während im Bereich der Kanalmitte niedrigere Wärmeübergangszahlen auftreten.4, the flow into the acute-angled areas the leading and trailing edge leads to a significantly higher local Nusselt number is achieved as the mean Nusselt numbers given in Table 1. There are therefore very high heat transfer coefficients in the area of the front and the trailing edge of the blade while in the area of the center of the channel lower heat transfer coefficients occur.

Fig. 5 zeigt die Innenseite der druckseitigen Wand 6 mit geschnittenem Vorderkantenbereich 3 und Hinterkantenbereich 4 der Schaufel 10, die aus dem Schaufelblatt 1 und dem Schaufelfuss 11 besteht. Die Rippen 7c der druckseitigen Wand sind im Gegensatz zur Fig. 3 so angeordnet, dass ihre Spitze 9c zuerst von der Strömung beaufschlagt wird. Die Rippen sind dabei ebenfalls im Winkel 8 zur Hauptströmungsrichtung des Kühlfluides 20 angewinkelt. Fig. 5 shows the inside of the pressure side wall 6 with cut Front edge area 3 and rear edge area 4 of the blade 10, which from the Blade 1 and the blade root 11 there. The ribs 7c of the In contrast to FIG. 3, the pressure-side wall is arranged so that its tip 9c is first acted upon by the flow. The ribs are also in the Angle 8 angled to the main flow direction of the cooling fluid 20.

Fig. 6 zeigt die saugseitige Wand mit Rippen 7a und angedeuteten Rippen 7c wobei die Rippen 7a entsprechend Fig. 2 an der Saugseite angeordnet sind. Aus konstruktionstechnischen Gründen ist hier natürlich das Verhältnis lokale Rippenhöhe zu lokaler Hohlraumhöhe immer kleiner 50%.6 shows the suction-side wall with ribs 7a and indicated ribs 7c wherein the ribs 7a are arranged according to FIG. 2 on the suction side. Out For technical reasons, the relationship is of course local Rib height to local cavity height always less than 50%.

Durch die Anordnung nach Fig. 6 werden ebenfalls sehr hohe Wärmeübergangszahlen erzielt, welche jedoch gleichförmiger verteilt sind als bei der Anordnung gemäss Fig. 4. Die Wärmeübergangszahlen einer Schaufel gemäss Fig. 6 sind jedoch unterschiedlich an der Druck- und der Saugseite, wodurch diese Anordnung bei unterschiedlicher Wärmebelastung auf der Druckund der Saugseite angewendet wird.6 are also very high Heat transfer numbers achieved, but are more uniformly distributed than in the arrangement according to Fig. 4. The heat transfer coefficients of a blade 6, however, are different on the pressure side and the suction side, whereby this arrangement with different heat loads on the pressure and the suction side is applied.

Selbstverständlich ist die Erfindung nicht auf das gezeigte und beschriebene Ausführungsbeispiel beschränkt. Die V-förmigen Rippen können auch in Schaufeln mit mehreren Kühlluftdurchlässen angeordnet werden, falls in den Randzonen der Kühlluftdurchlässe ein hoher Strömungswiderstand vorherrscht. Of course, the invention is not limited to that shown and described Embodiment limited. The V-shaped ribs can also be in Buckets with several cooling air passages can be arranged if in the Edge zones of the cooling air diffusers have a high flow resistance.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

11
Schaufelblattairfoil
22
Hohlraumcavity
33
VorderkantenbereichLeading edge region
44
HinterkantenbereichTrailing edge region
55
saugseitige Wandsuction side wall
66
druckseitige Wandpressure side wall
77
Ripperib
7a, 7c7a, 7c
Rippe saugseitige WandRib suction side wall
7b7b
Rippe druckseitige WandRib on the pressure side wall
88th
Anstellwinkel RippeAngle of attack rib
9, 9a, 9b9, 9a, 9b
Rippenspitzefin tip
1010
Schaufelshovel
1111
Schaufelfussblade root
1212
Plattformplatform
1313
Ebenelevel
14, 1514, 15
Schenkel der V-förmigen RippenLeg of the V-shaped ribs
2020
Kühlfluidcooling fluid
h, h1, h2h, h1, h2
lokale Rippenhöhelocal rib height
H, H1, H2H, H1, H2
lokale Hohlraumhöhelocal cavity height

Claims (8)

  1. Coolable blade (10), essentially comprising a blade root (11) and a blade body (1), which blade body is composed of a pressure-side wall (6) and a suction-side wall (5), which are connected to one another essentially via a trailing-edge region (4) and a leading-edge region (3) in such a way that at least one hollow space (2) used as a cooling-fluid passage is formed, in which ribs (7) are arranged, and at least one rib (7) being configured in such a way that it has an apex (9) and two legs (14, 15), which legs (14, 15) of the rib are bent at an acute angle (8) relative to a plane (13) which runs parallel to the main direction of flow of the cooling fluid (20), characterized in that the ratio of the local rib height (h) to the local hollow-space height (H) is essentally the same at all points on the rib (7).
  2. Coolable blade according to Claim 1, characterized in that the hollow space (2) is of double triangular shape having acute-angled triangular points in the region of the leading edge (3) and the trailing edge (4).
  3. Coolable blade according to Claim 2, characterized in that the apex (9) of the rib (7) is arranged in the region of the greatest local height (h) of the rib.
  4. Coolable blade according to Claim 3, characterized in that the ratio of local rib height (h) to local hollow-space height (H) is 5-50 %.
  5. Coolable blade according to Claim 3, characterized in that the ratio of local rib height (h) to local hollow-space height (H) increases for ribs (7) arranged one after the other in the main direction of flow of the cooling fluid.
  6. Coolable blade according to Claim 1 or 2, characterized in that the apexes (9) of the ribs (7) on the suction-side wall (5) and the pressure-side wall (6) lie downstream in the main direction of flow of the cooling fluid (20).
  7. Coolable blade according to Claim 1 or 2, characterized in that the apexes (9) of the ribs (7) on the suction-side wall (5) or the pressure-side wall (6) lie downstream and on the opposite wall (5, 6) lie upstream in the main flow direction of the cooling fluid.
  8. Coolable blade according to Claim 1 or 2, characterized in that the legs (14, 15) of the ribs are bent at an angle (8) of 30 to 60° relative to the plane (13).
EP97810493A 1996-08-23 1997-07-15 Coolable blade Expired - Lifetime EP0825332B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19634238A DE19634238A1 (en) 1996-08-23 1996-08-23 Coolable shovel
DE19634238 1996-08-23

Publications (2)

Publication Number Publication Date
EP0825332A1 EP0825332A1 (en) 1998-02-25
EP0825332B1 true EP0825332B1 (en) 2003-02-05

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EP97810493A Expired - Lifetime EP0825332B1 (en) 1996-08-23 1997-07-15 Coolable blade

Country Status (5)

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US (1) US5919031A (en)
EP (1) EP0825332B1 (en)
JP (1) JP4017708B2 (en)
CN (1) CN1105227C (en)
DE (2) DE19634238A1 (en)

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DE50105063D1 (en) * 2000-03-22 2005-02-17 Siemens Ag STEELING AND COOLING STRUCTURE OF A TURBINE BUCKET
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SE526847C2 (en) * 2004-02-27 2005-11-08 Demag Delaval Ind Turbomachine A component comprising a guide rail or a rotor blade for a gas turbine
EP1921269A1 (en) * 2006-11-09 2008-05-14 Siemens Aktiengesellschaft Turbine blade
CN103089335A (en) * 2013-01-21 2013-05-08 上海交通大学 W-shaped rib channel cooling structure suitable for turbine blade backside cooling cavity
JP6036424B2 (en) * 2013-03-14 2016-11-30 株式会社Ihi Cooling promotion structure
KR101501444B1 (en) * 2014-04-30 2015-03-12 연세대학교 산학협력단 Gas Turbine Blade Having an Internal Cooling Passage Structure for Improving Cooling Performance
CN106481366B (en) * 2015-08-28 2019-03-26 中国航发商用航空发动机有限责任公司 Cooling blade and gas turbine
CN106555617B (en) * 2017-01-05 2018-07-10 西北工业大学 A kind of turbo blade for having oblique bottom blowing type film cooling holes
JP6906332B2 (en) 2017-03-10 2021-07-21 川崎重工業株式会社 Turbine blade cooling structure
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CN110748384B (en) * 2019-11-29 2021-11-05 大连理工大学 Turbine blade trailing edge broken line type exhaust split structure
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Also Published As

Publication number Publication date
US5919031A (en) 1999-07-06
EP0825332A1 (en) 1998-02-25
DE19634238A1 (en) 1998-02-26
CN1186150A (en) 1998-07-01
CN1105227C (en) 2003-04-09
JPH1089006A (en) 1998-04-07
JP4017708B2 (en) 2007-12-05
DE59709255D1 (en) 2003-03-13

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