A GAS TURBINE ARRANGEMENT

Description

[0001] The present invention relates to a gas turbine arrangement.

[0002] More particularly the present invention relates to a gas turbine arrangement comprising: a passage, annular in cross section, for conveying combustion gases; located in the passage, turbine blading to be driven by the combustion gases; a diffuser, annular in form, for diffusing the combustion gases following their passage through the turbine blading; and a collector for collecting the combustion gases diffused by the diffuser, the collector comprising an annular main part, and, located at a position around the annular main part, a neck exit, in use of the gas turbine arrangement, combustion gases collected by the collector being conveyed around the annular main part of the collector in opposite senses so as to arrive at the neck exit of the collector travelling in opposed directions.

[0003] One known such gas turbine arrangement is disclosed in US3120374 and is also shown in Figs 1 to 4 of the accompanying drawings. Another prior art arrangement is disclosed in JP 54064204.
Fig 1 is a cut away perspective view of the arrangement, Fig 2 is a partial longitudinal cross section of the arrangement, Fig 3 is a schematic diagram illustrating the passage of combustion gases through the arrangement, and Fig 4 is a cross section on the line IV-IV in Fig 3.

[0004] Referring to Figs 1 to 4, the gas turbine arrangement comprises: a passage 1, annular in cross section, for conveying combustion gases; located in the passage 1, turbine blading 3 to be driven by the combustion gases; a diffuser 5, annular in form, for diffusing the combustion gases following their passage through the turbine blading 3; and a collector 7 for collecting the combustion gases diffused by the diffuser 5, the collector 7 comprising an annular main part 9, and, located at a position around the annular main part 9, a neck exit 11.

[0005] In use of the gas turbine arrangement, combustion gases travel along passage 1, drive turbine blading 3, are diffused by diffuser 5, and are collected by collector 7. The combustion gases on leaving the diffuser 5 form within the collector 7 first and second opposite sense vortical flows 13a, 13b, see Fig 4. These vortical flows 13a, 13b are formed by virtue of the combustion gas flow separating off the shroud rim 15 of the diffuser 5, and rolling up, see arrows 17 in Fig 3. The flow is then convected around the annular main part 9 of the collector 7, forming the first and second opposite sense vortical flows 13a, 13b. These flows 13a, 13b meet at the top neck exit 11 of the collector 7 travelling in opposed directions.

[0006] The separation of the combustion gas flow off the shroud rim 15, and the meeting of the vortical flows 13a, 13b in the neck exit 11, result in the production of significant entropy in the flow. This is detrimental to the efficiency of the gas turbine arrangement.

[0007] According to the present invention there is provided a gas turbine arrangement having the features of claim 1 comprising: a passage, annular in cross section, for conveying combustion gases; located in the passage, turbine blading to be driven by the combustion gases; a diffuser, annular in form, for diffusing the combustion gases following their passage through the turbine blading; and a collector for collecting the combustion gases diffused by the diffuser, the collector comprising an annular main part, and, located at a position around the annular main part, a neck exit, wheren in use of the gas turbine arrangement, combustion gases collected by the collector are conveyed around the annular main part of the collector in opposite senses so as to arrive at the neck exit of the collector travelling in opposed directions, characterized ind that the neck exit of the collector includes a partition device whereby the opposed direction flows at the neck exit are kept substantially separates, wherein the turbine blading rotates about a centre line of the gas turbine arrangement, and the partition device runs parallel to the centre line, and extends radially from the centre line, wherein the diffuser has a mouth whereby combustion gases leave the diffuser and enter the collector, the partition device comprises a first portion that extends over the mouth and a second portion that extends to one side of the mouth, and the second portion extends radially inward to a position closer to the centre line than the mouth.

[0008] In an arrangement according to the preceding paragraph, it is preferable that the side of the first portion that faces radially inwardly increases in distance from the centre line as the distance from the second portion increases.

[0009] In an arrangement according to any one of the preceding two paragraphs, it is preferable that the partition device comprises a flat plate.

[0010] In an arrangement according to any one of the preceding three paragraphs, it is preferable that the diffuser has a curved shroud rim whereat combustion gases leave the diffuser and enter the collector, the shroud rim has an extension operative to increase pressure recovery in the gas turbine arrangement, and the extension comprises a flat rim extension that is generally planar in form and forms a discontinuity with the curved shroud rim.

[0011] Alternatively to the arrangement according to the preceding paragraph, it is preferable that the diffuser has a curved shroud rim whereat combustion gases leave the diffuser and enter the collector, the shroud rim has an extension operative to increase pressure recovery in the gas turbine arrangement, and the extension comprises a spiral rim extension that continues or extends the curve of the curved shroud rim so as to form a spiral.

[0012] The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig 1, already referred to, is a cut away perspective view of a known gas turbine arrangement;

Fig 2, also already referred to, is a partial longitudinal cross section of the arrangement of Fig 1;

Fig 3, also already referred to, is a schematic diagram illustrating the passage of combustion gases through the arrangement of Fig 1;

Fig 4, also already referred to, is a cross section on the line IV-IV in Fig 3;

Fig 5 is a cut away perspective view of a gas turbine arrangement in accordance with the present invention;

Fig 6 is a partial longitudinal cross section of the arrangement of Fig 5;

Fig 7 is a schematic diagram illustrating the passage of combustion gases through the arrangement of Fig 5;

Fig 8 is a cross section on the line VIII-VIII in Fig 7;

Fig 9 illustrates in greater detail the form and location of a splitter plate of the arrangement of Fig 5;

Fig 10 illustrates alternative splitter plates to the splitter plate of Fig 9;

Fig 11 illustrates possible extensions to a shroud rim of the arrangement of Fig 5;

Figs 12, 13 and 14 illustrate respectively combustion gas flow in three gas turbine arrangements;

Figs 15, 16 and 17 are plan views corresponding respectively to Figs 12, 13 and 14;

Figs 18, 19 and 20 are side views corresponding respectively to Figs 12, 13 and 14;

Figs 21 and 22 are perspective views corresponding respectively to Figs 13 and 14; and

Fig 23 illustrates an alternative form of partition device to the flat plates of earlier Figs.

[0013] In Figs 5 to 23, the same elements as appearing in Figs 1 to 4 are labelled with the same reference numerals.

[0014] Referring to Figs 5 to 8, the arrangement of Figs 5 to 8 is the same as that of Figs 1 to 4 with the exception that the neck exit 11 of the collector 7 includes a partition device in the form of a splitter plate 19 whereby the opposed direction vortical flows 13a, 13b at the neck exit 11 are kept substantially separate, i.e. the splitter plate 19 isolates the vortical flows 13a, 13b one from the other. The splitter plate 19 runs parallel to the centre line A of the gas turbine arrangement, and extends radially from the centre line A.

[0015] Preventing meeting of the vortical flows 13a, 13b, reduces entropy production in the flow of combustion gases through the gas turbine arrangement, consequently improving the efficiency of the arrangement. The splitter plate 19 has the advantage that it is simple in design, and can be retrofitted to current gas turbine arrangement collectors.

[0016] Fig 9 illustrates the precise shape and location of the splitter plate 19 in the arrangement of Figs 5 to 8. The diffuser 5 has a mouth 35 whereby combustion gases leave the diffuser 5 and enter the collector 7. The splitter plate 19 comprises a first portion 37 that extends over the mouth 35 and a second portion 39 that extends to one side of the mouth 35. It can be seen from Fig 9 that the second portion 39 extends radially inward to a position 41 closer to the centre line A than the mouth 35. It can also be seen from Fig 9 that the side 43 of the first portion 37 that faces radially inwardly progressively increases in distance from the centre line A as the distance from the second portion 39 increases.

[0017] Fig 10 illustrates the precise shape of three alternative splitter plates 21, 23, 25. It is to be noted that the two last alternative splitter plates (23,25) do not fall within the scope of the claims. Plate 21 is the same as plate 19 except that the side 45 of plate 21 corresponding to side 43 of plate 19 remains at a constant distance from the centre line A. Plate 23 may be derived from plate 21 by removing that portion of plate 21 which is radially nearer to the centre line A than side 45 of plate 21. Plate 25 may be derived from plate 23 by removing a further radially inner portion of plate 23. It is to be noted that in the case of both plates 23, 25, the sides 47 of the plates 23, 25 that face radially inwardly remain at a constant distance from the centre line A. It is also to be noted that the sides 47 are radially further from the centre line A than the mouth 35 of the diffuser 5.

[0018] Fig 11 illustrates two possible extensions 29, 31 to the shroud rim 15 of the diffuser 5 of the arrangement of Figs 5 to 8. The extensions 29, 31 operate to increase the pressure recovery in the gas turbine arrangement, over and above that obtained using a splitter plate alone. The extensions 29, 31 diffuse the combustion gas flow in a more controlled manner, weakening the vortices formed in the collector 7. Extension 29 comprises a flat rim extension, and is generally planar in form, and forms a discontinuity with the shroud rim 15. Extension 31 comprises a spiral rim extension, and continues or extends the curve of the shroud rim 15 so as to form a spiral.

[0019] Fig 12 illustrates combustion gas flow in the diffuser 5 and collector 7 of the known gas turbine arrangement of Figs 1 to 4. It is to be noted that strong vortices occur in the annular main part 9 of the collector 7, and mixing of the vortical flows 13a, 13b occurs in the neck exit 11 of the collector 7.

[0020] Fig 13 illustrates combustion gas flow in the diffuser 5 and collector 7 of a gas turbine arrangement including a splitter plate 19 only, i.e. not including an extension 29, 31 to the shroud rim 15 as shown in Fig 11. It is to be noted that strong vortices still occur in the annular main part 9 of the collector 7, but no mixing of the vortical flows 13a, 13b occurs in the neck exit 11 of the collector 7.

[0021] Fig 14 illustrates combustion gas flow in the diffuser 5 and collector 7 of a gas turbine arrangement including a splitter plate 19 and a flat rim extension 29. It is to be noted that only weak vortices occur in the annular main part 9 of the collector 7, and, in addition, no mixing of the vortical flows 13a, 13b occurs in the neck exit 11 of the collector 7.

[0022] Figs 15, 16 and 17 are views taken from above in Figs 12, 13 and 14 respectively. Splitter plate 19 is to be noted in Figs 16 and 17. Flat rim extension 29 is to be noted in Fig 17.

[0023] Figs 18, 19 and 20 are views taken from the left side in Figs 12, 13 and 14 respectively. Splitter plate 19 is to be noted in Figs 19 and 20. Flat rim extension 29 is to be noted in Fig 20.

[0024] Figs 21 and 22 are perspective views corresponding respectively to Figs 13 and 14. Splitter plate 19 is to be noted in Figs 21 and 22. Flat rim extension 29 is to be noted in Fig 22.

[0025] In the above description, the partition device in the neck exit 11 of the collector 7 takes the form of a flat plate. It is to be realised that the partition device could take other forms that achieve the required separation of the opposed direction vortical flows 13a, 13b in the neck exit 11. Fig 23 shows an example of an alternative partition device 33, comprising an upper flat plate part 51 and a lower substantially triangular cross section part 53 having concave sides. It is to be noted that the cross section shown in Fig 23 corresponds to second portion 39 in Fig 9, and that the first portion 37 in Fig 9 remains as it is, i.e. a flat plate. The upper and lower parts 51, 53 of the partition device 33 meet at a height corresponding to the height of the obtuse angle 55 in Fig 9.

Claims

1. A gas turbine arrangement comprising: a passage (1), annular in cross section, for conveying combustion gases; located in the passage (1), turbine blading (3) to be driven by the combustion gases; a diffuser (5), annular in form, for diffusing the combustion gases following their passage (1) through the turbine blading (3); and a collector (7) for collecting the combustion gases diffused by the diffuser (5), the collector (7) comprising an annular main part (9), and, located at a position around the annular main part (9), a neck exit (11), wherein in use of the gas turbine arrangement, combustion gases collected by the collector (7) are conveyed around the annular main part (9) of the collector (7) in opposite senses so as to arrive at the neck exit (11) of the collector (7) travelling in opposed directions, characterized in that the neck exit (11) of the collector (7) includes a partition device (19) whereby the opposed direction flows at the neck exit (11) are kept substantially separate, wherein the turbine blading (3) rotates about a centre line (A) of the gas turbine arrangement, and the partition device (19) runs parallel to the centre line (A), and extends radially from the centre line (A), wherein the diffuser (5) has a mouth (35) whereby combustion gases leave the diffuser (5) and enter the collector (7), the partition device (19) comprises a first portion (37) that extends over the mouth (35) and a second portion (39) that extends to one side of the mouth (35), and the second portion (39) extends radially inward to a position (41) closer to the centre line (A) than the mouth (35).

2. An arrangement according to claim 1, wherein the side of the first portion (37) that faces radially inwardly increases in distance from the centre line (A) as the distance from the second portion (39) increases.

3. An arrangement according to any one of the preceding claims wherein the partition device (19) comprises a flat plate.

4. An arrangement according to any one of the preceding claims, wherein the diffuser (5) has a curved shroud rim (15) whereat combustion gases leave the diffuser (5) and enter the collector (7), the shroud rim (15) has an extension (29) operative to increase pressure recovery in the gas turbine arrangement, and the extension (29) comprises a flat rim extension that is generally planar in form and forms a discontinuity with the curved shroud rim (15).

5. An arrangement according to any one of claims 1 to 3 wherein the diffuser (5) has a curved shroud rim (15) whereat combustion gases leave the diffuser (5) and enter the collector (7), the shroud rim (15) has an extension (31) operative to increase pressure recovery in the gas turbine arrangement, and the extension (31) comprises a spiral rim extension that continues or extends the curve of the curved shroud rim (15) so as to form a spiral.

Ansprüche

1. Gasturbinenanordnung, die Folgendes umfasst: einen Kanal (1) mit ringförmigem Querschnitt zum Leiten von Verbrennungsgasen, eine Turbinenbeschaufelung (3) in dem Kanal (1), die von den Verbrennungsgasen angetrieben wird, einen ringförmigen Diffusor (5) zum Abbremsen der Verbrennungsgase nach ihrem Durchlauf durch die Turbinenbeschaufelung (3) und einen Kollektor (7) zum Sammeln der vom Diffusor (5) abgebremsten Verbrennungsgase, wobei der Kollektor (7) einen ringförmigen Hauptteil (9) und einen in einer Position um den ringförmigen Hauptteil (9) liegenden Halsausgang (11) umfasst, wobei beim Benutzen der Gasturbinenanordnung vom Kollektor (7) gesammelte Verbrennungsgase in entgegengesetzten Richtungen um den ringförmigen Hauptteil (9) des Kollektors (7) geleitet werden, so dass sie in entgegengesetzten Richtungen strömend am Halsausgang (11) des Kollektors (7) eintreffen,
dadurch gekennzeichnet, dass der Halsausgang (11) des Kollektors (7) eine Trennvorrichtung (19) aufweist, durch die die in entgegengesetzten Richtungen fließenden Ströme am Halsausgang (11) im Wesentlichen voneinander getrennt gehalten werden, wobei die Turbinenbeschaufelung (3) um eine Mittellinie (A) der Gasturbinenanordnung rotiert und die Trennvorrichtung (19) parallel zur Mittellinie (A) radial von dieser weg verläuft, wobei der Diffusor (5) eine Öffnung (35) aufweist, über die die Verbrennungsgase den Diffusor (5) verlassen und in den Kollektor (7) eintreten, wobei die Trennvorrichtung (19) einen ersten Abschnitt (37) umfasst, der sich über die Öffnung (35) erstreckt, und einen zweiten Abschnitt (39), der sich bis zu einer Seite der Öffnung (35) erstreckt und radial nach innen zu einer Position (41) verläuft, die näher an der Mittellinie (A) liegt als die Öffnung (35).

2. Anordnung nach Anspruch 1, bei der sich die Seite des ersten Abschnitts (37), die radial nach innen zeigt, mit zunehmendem Abstand vom zweiten Abschnitt (39) immer weiter von der Mittellinie (A) entfernt.

3. Anordnung nach einem der vorhergehenden Ansprüche, bei der die Trennvorrichtung (19) eine flache Platte umfasst.

4. Anordnung nach einem der vorhergehenden Ansprüche, bei der der Diffusor (5) einen gekrümmten Deckbandrand (15) aufweist, an dem Verbrennungsgase aus dem Diffusor (5) aus- und in den Kollektor (7) eintreten, wobei der Deckbandrand (15) eine Verlängerung (29) aufweist, die eine verstärkte Druckerholung in der Gasturbinenanordnung bewirkt, und die Verlängerung (29) eine flache Randverlängerung umfasst, die allgemein eben ist und eine Unregelmäßigkeit zum gekrümmten Deckbandrand (15) bildet.

5. Anordnung nach einem der Ansprüche 1 bis 3, bei der der Diffusor (5) einen gekrümmten Deckbandrand (15) aufweist, an dem Verbrennungsgase aus dem Diffusor (5) aus- und in den Kollektor (7) eintreten, wobei der Deckbandrand (15) eine Verlängerung (31) aufweist, die eine verstärkte Druckerholung in der Gasturbinenanordnung bewirkt, und die Verlängerung (31) eine spiralförmige Randverlängerung umfasst, die die Krümmung des gekrümmten Deckbandrandes (15) so weiterführt oder verlängert, dass eine Spirale gebildet wird.

Revendications

1. Système de turbine à gaz comprenant : un passage (1), de section transversale annulaire, pour transporter des gaz de combustion ; disposées dans le passage (1), des aubes de turbine (3) destinées à être entraînées par les gaz de combustion ; un diffuseur (5), de forme annulaire, pour diffuser les gaz de combustion après leur passage (1) à travers les aubes de turbine (3) ; et un collecteur (7) pour collecter les gaz de combustion diffusés par le diffuseur (5), le collecteur (7) comprenant une partie principale annulaire (9) et, occupant une position périphérique à la partie principale annulaire (9), un col de sortie (11), dans lequel, lors de l'utilisation du système de turbine à gaz, les gaz de combustion collectés par le collecteur (7) sont transportés autour de la partie principale annulaire (9) du collecteur (7) dans des directions opposées, de manière à parvenir au niveau du col de sortie (11) du collecteur (7) en se déplaçant dans des directions opposées, caractérisé en ce que le col de sortie (11) du collecteur (7) inclut un dispositif de séparation (19), grâce à quoi les écoulements dans des directions opposées au niveau du col de sortie (11) sont maintenus essentiellement séparés, dans lequel les aubes de turbine (3) tournent autour d'un axe (A) du système de turbine à gaz et le dispositif de séparation (19) s'étend parallèlement à l'axe (A) et s'étend radialement par rapport à l'axe (A), dans lequel le diffuseur (5) est pourvu d'une embouchure (35), grâce à quoi les gaz de combustion quittent le diffuseur (5) et entrent dans le collecteur (7), le dispositif de séparation (19) comprend une première partie (37) qui s'étend au-dessus de l'embouchure (35) et une seconde partie (39) qui s'étend sur un côté de l'embouchure (35) et la seconde partie (39) s'étant radialement vers l'intérieur, vers une position (41) plus proche de l'axe (A) que l'embouchure (35).

2. Système selon la revendication 1, dans lequel le côté de la première partie (37) qui est tourné radialement vers l'intérieur a une distance par rapport à l'axe (A) qui augmente à mesure que la distance par rapport à la seconde partie (39) augmente.

3. Système selon l'une quelconque des revendications précédentes, dans lequel le dispositif de séparation (19) comprend une plaque plate.

4. Système selon l'une quelconque des revendications précédentes, dans lequel le diffuseur (5) comprend un rebord d'anneau courbe (15) au niveau duquel les gaz de combustion quittent le diffuseur (5) et entrent dans le collecteur (7), le rebord d'anneau (15) possède une extension (29) fonctionnelle pour augmenter le rendement en pression du système de turbine à gaz, et l'extension (29) comprend une extension de bord plate qui a une forme généralement plane et forme une discontinuité avec le rebord d'anneau courbe (15).

5. Système selon l'une quelconque des revendications 1 à 3, dans lequel le diffuseur (5) comprend un rebord d'anneau courbe (15) au niveau duquel les gaz de combustion quittent le diffuseur (5) et entrent dans le collecteur (7), le rebord d'anneau (15) possède une extension (31) fonctionnelle pour augmenter le rendement en pression du système de turbine à gaz, et l'extension (31) comprend une extension de bord en spirale qui poursuit ou prolonge la courbe du rebord d'anneau courbe (4) de manière à former une spirale.

Drawing