DE2047648A1 - Axial disk type gas turbine - Google Patents

Description

(The priority of the USA-Stamraa. Application Serial Ko. 861 977 dated Sept. 29, 1969 is claimed)

The invention relates to an axial gas turbine of the Scheibenba.ua.rt, with a duct system for supplying the cooling air to the first rotor disk and its rotor blades, consisting of one axially extending annular channel in the outer circumferential area of the rotor and an adjoining, essentially radially extending Annular space within which the cooling air is conveyed to the inlet channels of the blade roots of the first rotor blade ring and with an annular gap between the outer circumference of the rotor and the inner surface of the annular stator walls surrounding the rotor.

Such a gas turbine is known (German patent specification 953 205). In this case, the ring channel inside the channel serving to supply the cooling air to the first rotor disk and its rotor blades Channel system formed by an annular gap between the outer circumference of the rotor and the inner circumference of the stationary, the Rotor surrounding stator ring walls is located. The invention works based on the consideration that the acceleration of the cooling air flowing from the stator to the rotor to the peripheral speed of the rotor is afflicted with losses, which should be avoided with consideration of the increased material utilization in gas turbines and improved cooling of the rotor blades and rotor disks is desirable. The invention is based on the object of providing the axial gas turbine with such a cooling system, that for the cooling gas on its way from the cooling gas source to the points of the rotor blades and rotor disk to be cooled no unnecessary flow resistances have to be accepted and thus the flow rate and flow speed dea cooling gas is intensified in the area of the places to be cooled.

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The task at hand is for an axial door turbine of the disk type of the type mentioned at the outset, according to the invention, in that an axial region of the annular gap is connected to a source of cooling air connected transition ring chamber formed and the Rotor in the axial area of the transition ring chamber with a ring of Inlet openings is provided that the channel system for supplying the cooling air to the first rotor disk through a with the rotor rotating baffle is completed towards the annular gap and the inlet openings open into this Kanalsystera and that in the In the area of the transition ring chamber, air guide means are arranged through which the inlet openings into the rotor duct system incoming cooling air has a tangential speed coraponent is pressed, which corresponds essentially to the peripheral speed of the rotor and in conjunction with the Pressure gradient-dependent speed components pointing in the conveying direction one rotating in the ring channel of the rotor with the latter, conveyed in the axial direction of the radial annular space Cooling air vortex results.

The advantages that can be achieved by the invention are primarily to be seen in the fact that the cooling efficiency for the carriers and blades is very cheap, especially because of the high cooling air flow rate, so that the dilution of the hot Ireibgases in the step room by the secondary air is relative is low. This increases the useful power or the power loss can be kept lower.

The air guiding means can be used for smaller cooling capacities than rotating ones Vortex generator be designed, which as a hollow, blade-like passage body on the outer circumference of the rotor in openings its baffle are used, at its inlet end with the transfer ring cam and at its outlet end with the rotor ring channel communicate, with the forming the outlet opening Wall parts of the vortex generator in the sense of granting the taugential Velocity components are inclined with regard to the thermosetting cooling air.

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For greater cooling capacities, the air guiding means are expediently formed by a locking ring of nozzles arranged within the transfer ring chamber, which is opposed by a ring of inlet openings at the outer circumference of the rotor, the axes of the nozzles in the sense of achieving a tangential speed component corresponding to the circumferential speed of the inlet openings of the cooling air are inclined by the angle Q 'to the respective circumferential rod.

Two exemplary embodiments are described below with reference to the drawing of the invention described and its mode of operation explained. It shows:

Pig. 1 shows a fragmentary longitudinal section of the inflow section of a gas turbine of the axial type, specifically the one above the rotor axis lying half, the lower half being designed accordingly;

Mg, 2 the cooling system from FIG. 1 enlarged in detail;

Pig. 3 a single vortex generator in perspective in a cutout for the embodiment according to Pig. 1 and 2;

Pig. 4 shows a section along the section plane IV-IV from Pig. 2;

Pig. 5 is a view in detail according to the section plane V-V from Pig. 2 in an enlarged view;

Pig. 6 shows a second embodiment in a Pig. 2 corresponding Mode of representation and

Pig. 7 is an enlarged view of the section along the section plane VII-VII from Pig. 6th

Pig. 1 shows an axial gas turbine of the disk type, consisting of / * 109821/1258

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from an essentially hollow-cylindrical outer housing 11, a likewise hollow-cylindrical or ring-shaped inner housing 12 and a rotor 14, which is rotatably mounted within the inner housing 12 in a suitable manner, not shown in detail. The rotor 14 consists of a carrier disk package, of which only the first two carrier disks located in the upper gradient area 16 and 18 are shown. The carriers are clamped together by tie rods 19 distributed over the circumference, with only a tie rod can be seen. The rings of rotor blades on the outer circumference of the rotor disks 16, 18 are denoted by 20 and 22, respectively. The associated guide vanes 23, 25 of a first and a second guide vane ring are located on the inner circumference of the inner housing 12 and other guide vane rings, not shown and designated, attached. The blades 20, 22 are of shroudless design and each have a blade 28, a base part 29 and a blade root or a blade root 30, the blades with their blade root on the outer circumference of the rotor disks 16, 18 in corresponding receiving grooves are attached. A so-called Christmas tree attachment is shown sart, whereby between the blade root teeth and the walls of the associated Aufnahraenuten substantially axially running cooling channels remain free, through which cooling air can be passed. The blade is in the case of the guide vanes 23, 25 with 32, the foot part with 33 and a cover band on the inner circumference with 34, which latter is used for the step seal.

The hot propellant, in particular compressed combustion gases, is in a plurality of combustion chambers distributed in the circumferential direction 36 generated, only one of which is shown. The combustion chambers 36 have transfer pipe bodies 37, and the latter form with their downstream side Ends arcuate outlet openings 38. The outlet openings together form an annular outlet channel, which the propellant feeds to the first guide vane ring 23. As indicated by the arrows, the propellant flows in the direction of the itself widening voltage channel through the guide and rotor blades

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wreaths 23, 20, 25, 22 axially therethrough in order to ^{drive the rotor 14 (axis of rotation EE 1} ).

The combustion chambers 36 are arranged in an annular pressure chamber 40, wherein compressed air is introduced into the combustion chambers for the purpose of mixing with the fuel (not shown).

Is braced with the rotor 14 or the carriers 16, 18 Via the axially extending tie rods 19, the hollow-cylindrical shaft piece 42 serving for torque transmission, the latter is flanged together with a shaft 43 by means of bolts 44. The shaft shaft 43 in turn is in drive connection with the eotor of an air compressor (not shown).

The shaft piece 42 and the shaft shaft 43 are made of an annular stator wall 45 with Ringpa.lt s, the stator ring wall 45 forming the inner wall of the pressure chamber 40.

The annular manifold attached to the outer housing 11 has one or more outlet pipes 48, only one of which is shown. The outlet pipes 48, which are led around the respective combustion chamber, have a connection end directed radially inward attached to the stator ring wall 45 and open into corresponding passage bores 48a of this ring wall. On the inner circumference the annular wall 45 are mounted labyrinth sealing rings 46 in order to reduce cooling air leaks towards the annular gap a to a minimum .

Like it especially Pig. 2 shows, comprises a tubular baffle 49, the shaft piece 42 to form a rotor channel system 60, Ia connection to its tubular part, the baffle 49 has a disk-shaped,., Radially outwardly extending ring flange 50, which on.his outer circumference with an annular collar 16a of the rotor disk 16 via an annular seal 52. The baffle 49 is placed on the outer circumference 'of the shaft piece 42, for. B. shrunk so that the baffle together with the

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INSPECTED

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Shaft piece 42, the shaft shaft 43 and the other parts of the rotor " 14 rotates.

The cooling air pipe 48 opens into a through hole 48a Überleitringka.mmer 56, which is formed by the stator ring wall 45, the labyrinth seals 46 and the rotor guide wall 49. The guide wall 49 has in the axial area of the transition ring chamber a ring of radial inlet openings 58 which communicate with the transition ring chamber 56. The guide wall 49 and that Shaft piece 42 are arranged with an annular gap to one another, so that an axially extending intermediate space in the form of an annular channel 60 is formed, w.elcher with the inlet openings 58 communicates.

As FIG. 4 in particular shows, vortex generators 62 are in the form of hollow, blade-like passage bodies on the outer circumference of the rotor used in openings of its guide wall 49. The vortex producers 62 are radial 'in the area of the inlet openings 58 in the guide wall 49 inserted and over its circumference to form a wreath distributed regularly. On the inlet side, the vortex generators 62 communicate with the transfer ring chamber. · 56 and on the outlet side with the Rotor ring channel 60.. ·

The vortex generators or passage bodies 62 have (see ^{FIG. 1, in} particular FIGS. 3, 5) an essentially hollow-cylindrical shape and have an outlet region 63, in which part of the wall has been removed to form an outlet opening 64. A central region 65 with a reduced external diameter adjoins the outlet region and an inlet region 67 with an even further reduced external diameter joins the central region with the formation of corresponding gradations. 69 is the concavely curved inner wall of the passage body. The outlet and middle regions 67, 65 are inserted in a form-fitting manner into corresponding recesses 68 in the rotor guide wall 49 (see FIG. 2), so that the passage bodies 62 are held by centrifugal forces.

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The ring channel 60, which extends axially, ends in a radial channel extending annulus 70, see Pig. 2, which from the ring flangeEch 50 and the rotor disk 60 "is limited. A wreath of fan blade 71 is arranged within the annular space 70, wherein the fan blades 71 are expediently attached to the annular flange 50 are. In principle, the running disk 16 could also be used in addition or serve solely to fasten the fan blades. The annular space 70 stands via radial cooling air bores 74 in the annular collar 16a of the rotor disk 16 in connection with an annular, continuous cooling chamber 75, which the cooling channels 30a the blade root 30 is connected upstream and by an annular Cover plates of order 16b is sealed to the step room. The cooling can also extend beyond a blade root cooling the entire blades extend, for which purpose cooling ducts (not shown) would have to be provided in the blade area.

The mode of action results from today's scientific The principle is as follows: The effectiveness of the heat dissipation through the coolant depends on its temperature and the temperature that is passed through Lot. The amount of heat dissipated can be increased by lowering the temperature or increasing the throughput rates of the coolant. The embodiment described improves the cooling effect by reducing the pressure loss and structure a pressure gradient in the direction of flow of the coolant.

The coolant, preferably air, is generally pretreated, in adaptation to local conditions. In particular, the air can be cooled, filtered and its flow rate measured before it is fed into the manifold loop 47. When the coolant flows from the outlet pipe 48 into the transfer ring chamber 56 and accumulates in this ring chamber, results in a pressure difference between the annular chamber and the annular channel 60, which is required so that the air is passed through the inlet openings 58.

The vector diagram according to FIG. 5 shows the speed components in more detail a single gas particle of the coolant, which

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enters the vortex generator 62. That in'den Wirbei producer Entering Ga.Beilch.en is deflected by the concave wall 69, which with the same angular velocity ω as the rotor 14 running around. The vortex generator 62 fulfills two functions: On the one hand, it presses an axial velocity component on the gas particle Vftcj on. This results when added to the smaller axial component V.p, which is dependent on the pressure difference, the total axial speed ility V., which enables the gas particle to flow downstream in the axial direction along the annular channel 60. Second a tangential velocity corapo- " nent V φ given, which is essentially the tangential velocity of the ring channel 60 corresponds. This makes it possible that the gas particle reaching the radial annular space 70 on a higher pressure level is raised when it is conveyed radially outwards by the radial fan according to the centrifugal force will.

The most favorable angle θ that the resulting speed V _{R forms} with the rotor axis RR ¹ can be determined experimentally depending on the size and shape of the outlet opening 64 and the radius of curvature of the vortex generator 62. The puncture of the vortex generator 62 can also , can be fulfilled by flat metal sheets oriented according to the desired deflection angle f> , even if the embodiment shown is particularly favorable.

To achieve the pressure increase within the annular space 70, the blades 71 rotate at the same angular speed as the rotor and thus act as a radial fan or centrifugal pump. The cooling air conveyed by the blades 71 is therefore raised to a higher pressure level corresponding to the distance from the axis of rotation RR ¹ .

Without the cooling air vortex within the annular channel 60, the

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Cooling air between the fan compartment on a 71 with a small amount) Peripheral speed than the fan blade speed occur, which would result in insufficient utilization of the radial fan. There. however the coolant has the same Tangential-Geschwindigke.it V ^ as the leading edges of the fan blades 71 has, the cooling air can with the fan blades with the same Circumferential speed without the occurrence of a rebound effect. It can be shown that the pressure increase in radial direction along the radial space or the Lufterschaufelη is proportional to the square of the circumferential speed of the gas particles at a given radial distance from the rotor axis. With the achieved increase in the circumferential speed of the cooling air is an important part of the gate.

When entering the axial channels 77 or the through-bores 74, the cooling air has practically the same tangential speed like this one, so that because of the elimination of speed differences, the entry losses are reduced to a minimum. As mentioned, some of the cooling air can also be passed through the axial channels 77 of the carrier disk 16 so that it can be used for the Cooling of the next following running disk 18 and the associated one Blades (l'ig. 1) can be used. This results in better utilization of the coolant.

The second embodiment according to Pig. 6 differs in this respect from first embodiment, when the cooling air line 78 opens into an enlarged inlet ring channel 79. The outlet area 80 of the annular channel 79 merges into 'a nozzle ring 82, which accordingly with the stator ring wall 83 is fixed. The nozzle ring 82 is attached to a supporting wall part of the stator ring wall 83. The ring wall 83 has annular grooves 84 and the nozzle ring 82 has protrusions 85 that fit into these grooves. It can also be of a threaded or bayonet ring type Fixing can be chosen. A plurality of labyrinth Oichtungürir-gerj 05a are also in associated recesses the ring wall 03 is mounted. The rotor baffle is here

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denoted by 86. The transition ring chamber'87 is here from the nozzle ring 82, the labyrinth sealing rings 85a and the baffle 86 formed. A ring of radial inlet openings 88 is in the guide wall 86 in the axial area of the transition ring chamber 87 arranged. The inlet openings 88 communicate on the one hand with the annular chamber 87 »on the other hand with the annular channel 89.

Fig. 7 shows that the nozzle ring 82 has a ring of nozzle channels 90, this ring being shown only in sections in a quadrant. The nozzle channels 90 have an enlarged inlet channel part 91 communicating with the cooling air annular space 79 and an outlet channel part 92 which is narrowed in comparison and opens into the transition ring chamber 87. The two channel parts 91, 92 are arranged concentrically or co-axially with respect to the nozzle axis LL ¹ .

The nozzle channels 90 are arranged at the same distance from one another in the circumference s rieh tu ng "and an angle of inclination ^ ', where Q" is the angle between the nozzle axis LL ¹ and the tangent TT' laid on three nozzle outlet 92 all open into the transition ring chamber 87 at practically the same angle of inclination Θ '. The latter is dimensioned so that the coolant blown through the nozzle channels 90 is given a tangential velocity which corresponds to that of the entrance opening 88.

The advantages of the second embodiment are that a larger amount of cooling air at lower temperatures the blades can be forwarded. It is therefore particularly suitable for such cases, if not only the blade root, but the entire one Shovel is to be cooled.

There is no speed difference between that in the inlet openings 88 incoming cooling air and these openings are ventilated, very high flow rates of the coolant can be achieved, wooei these flow values or coefficients in this embodiment

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Example are even larger than in the first, because there the cooling air no ta.ngentia.le velocity component before entering the vortex generator has, whereas here it has the same peripheral speed as the passage openings.

Another advantage of the nozzle ring arrangement is that due to the practically negligible difference in speed between the gas particles and the circumferential openings practically no friction occurs with a negligible increase in temperature of the coolant. The low pressure drop, which is required to accelerate the coolant along the nozzle channels can, if desired, be compensated for.

11 claims
7 mg.

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Claims (11)

VPA 70/8935 - 12 - Pate ntanaprüch e (1.) Axial gas turbine of the disc type, with a duct system Consisting, within which up to the inlet channels of the blade roots promoted \ ^ for supplying the cooling air to the first rotor disk and its blades, an axially extending annular channel in the outer peripheral portion of the rotor and an adjoining, substantially radially extending Ringrautn the cooling air of the first rotor blade ring is, and with an annular gap between the outer surface of the rotor and the inner circumference of the Stafcor ring walls surrounding the rotor, characterized in that an axial area of the annular gap (a) is formed as a transfer ring chamber (56; 87) connected to a cooling air source and the The rotor (14) in the axial area of the transfer ring chamber (56; 87) is provided with a ring of inlet openings (58, 88) that the channel system (60, 70) for supplying the cooling air to the first Lauferscheibc (16) through a with the Rotor (H) rotating Leitwa.nd (49, 50; 86) to the annular gap (s) is closed and in this channel system the Inlet openings (58; 88) and that. in the area of the transition ring chamber (56; 87) air guide means (62; 8k, 90) are arranged, through which a tangential velocity component (Vm) is imposed on the cooling air entering the rotor duct system (60, 70) through the inlet openings (58, 88) which essentially corresponds to the circumferential speed of the rotor (14) and, in conjunction with the pressure gradient-dependent speed component pointing in the direction of advance, results in a cooling air vortex that is circulating in the annular channel of the rotor with the latter and is conveyed in the axial direction to the radial annular space (70) « 2. Gas turbine according to claim 1, characterized in that the air guiding means have rotating vortex generators (62) which are designed as hollow ", blade-like passage bodies on the outer circumference the rotor is inserted into openings (68) in its guide wall, at her inviting end (67) with the transition ring chamber (56) and 109821/1258 - 13 - bath YPA 70/8935 - 13 - communicate at their outlet end (63) with the Eotorringkanal (60), the wall parts (63) of the vortex generators (62) forming the outlet opening (64) in the sense of providing the ta.ngentia.len velocity component (Ym) with respect to the flowing through cooling air are inclined. 3. Gas turbine according to claim 2, characterized in that the passage body (62) has a substantially hollow cylindrical Have inlet and central region (67), which with projections can be inserted into corresponding recesses (68) in the rotor guide wall and which form the outlet openings (64) Wall parts of an outlet area (63) so curved concavely are that the exit speed of the cooling air, axial and ta.ugentia.le components (V ^, V ^) having to the rotor axis is inclined by the angle ^. 4. Gas turbine according to claim 1, characterized in that the radial annular space (70) between the first running disk (16) and the rotor guide wall (50 j 86) from an annular flange (50) of the guide wall arranged at an axial distance from the rotor disk (16) is limited and in the annular space (70) the blades (71) of a radial fan are arranged that the annular space (70) via bores (74) arranged in an annular collar (16a) of the carrier disk (16) with to the blade root channels (30a) leading cooling chambers (75), the blades (71) of the radial fan being arranged so that the tangential component of the cooling air outflow speed on its outer circumference of the circumferential speed of the radial bores (74) corresponds. 5. Gas turbine according to claim 4 »characterized in that the Blades (71) of the radial fan on the annular flange (50) dor Rotor baffle (49, 50; 86) are attached. 6. Gastui'bine according to claim 4 or 5 »characterized in that that the blades (71) of the radial fan with Abetand for 109821/1258 VPA 70/8935 -H- first rotor disk (16) are arranged and thereby formed continuous Ringrau rateil (70) except in the Hadialbohrungen (74) arranged on its outer circumference in axial channels (77) leading through the carrier disk (16) and which are used to convey part of the cooling air to the downstream second running disk (18) and their Serving blades (22). 7. Gas turbine according to claim 1, characterized in that the air guiding means are formed by a fixed ring of nozzles (90) arranged within the transfer ring cam, which faces a ring of inlet openings (88) on the outer circumference of the rotor (H), the Axes of the nozzles in the sense of achieving a tangential speed component of the cooling air corresponding to the circumferential speed of the inlet openings (88) run inclined by the angle & 'to the respective circumferential rod (TT ¹ ). 8. Gas turbine according to claim 7, characterized in that the nozzle ring of an inclined nozzle channels (91, 92) having ring (82) is formed, which by means of projections (85) in corresponding recesses (84) of a supporting wall part (83) the stator ring walls is attached. 9. Gas turbine according to claim 8, characterized in that the DUsenkanäle an enlarged, with a cooling air annulus (79) the inlet channel part communicating with the stator ring walls (91) and one, constricted on the other hand, into the transition ring chamber (87) have opening outlet channel part (92). 1Q. Gas turbine according to claim 1 or one of the following claims, daduroh characterized in that the transfer ring chamber (87) for remaining, axially adjoining annular gap on both sides (b) is sealed by labyrinth seals (85a). 11. Gas turbine according to claim 1, characterized in that the rotor guide wall (49 ₁ 50; 86) on the outer circumference einea Ro- 109821/1258 '_ ₁₅ _ VPA 70/8935 - 1S - tor-shaft piece (42) is attached; what the latter
A torque-transmitting toothing (Z) with the first carrier disc (16) by means of tie rods (a), with between the outer circumferential area of the Loitwand ring flange (50) and the opposite annular collar (16a) of the first carrier disc (16 ) a sealing ring (52) is inserted. 109821/1258