FR2699223A1 - Adjustable flow guiding device - Google Patents

Abstract

The invention relates to an adjustable flow guide device. In this device for a rotor of a turbomachine actuated by the exhaust gases of an internal combustion engine, comprising annular inserts (18) arranged between spiral guide channels (2, 3, 4, 5) of the turbomachine and rotor, and flow guide elements, forming a guide grid and located in the inserts (18), the latter are divided into annular sectors with differently arranged sectors (19, 20) in the guide grid so that different guide grids (8) can be loaded simultaneously by the flow circulating in the guide channels. Application in particular to internal combustion turbofan exhaust gas lasers for motor vehicles.

Description

The invention relates to an adjustable flow guiding device for

  a rotor of a turbomachine driven by the exhaust gas of an internal combustion engine, wherein the flow guiding device comprises an annular insert disposed between a plurality of spiral-shaped guide channels of the turbomachine and the rotor, with an at least partly radial direction of flow, and in the annular insert are arranged, in a distributed manner on the periphery of this insert, the flow-guiding elements, which form a guide gate and establish a connection flow between the spiral-shaped guide channels and the rotor of the turbomachine, the annular insert forming part of an adjusting sleeve, which is movable in the

  direction of the longitudinal axis of the rotor.

  According to the Belgian patent 501 076, there is known an adjustable axially displaceable flow guiding device of the type indicated above which is arranged in a radial turbine with several flows comprising a spiral channel extending around a rotor, between the channel and the rotor The flow guiding device has an annular ring of conductive vanes, whose gate parameters are constant on its periphery. The axial displacement of the flow guiding device is effected by means of intermediate of a setting mechanism

operated by a compressor.

  On the other hand, according to the patent application

  German P 42 32 400 9-13 we already know a turbo-

  exhaust fan comprising a radial wheel,

  which is surrounded by a spiral-shaped guiding channel.

  An axially displaceable tubular bush-shaped portion having a conductive grid is disposed between the guide channel and the radial wheel. The axial displacement of the bush-shaped portion can in particular affect the cross-section.

  flow of the spiral-shaped guiding channel.

  Furthermore, according to German Offenlegungsschrift No. 1,011,671, an adjustable flow guiding device is known in which, in a radial turbomachine, gases are fed to a rotor ( radial turbine) via an adjustable guide gate The adjustable guide gate consists of a plurality of guide vane crowns arranged one behind the other and having different dimensions and / or different configurations and is axially displaceable and is manually adjustable The parameters of the grids of the guide vane crowns are constant around their circumference. With regard to the general technological background, reference is also made to DE-OS 26 33 587, DE-OS 28 43 202, German Patent 39 08 286,

  German Patent 39 23 370 and US Patent 4,492,520.

  In the flow guide device of the known type known, which is axially adjustable, in the case of multi-flow turbomachines, the spirals of which open out in an angularly offset manner at the level of the guide gate, only a identical deviation of the flow towards the rotor for all

flows.

  This is a disadvantage especially because of the fact that the possibility of adjusting multi-flow turbomachines using known guiding devices

  flow is relatively strongly limited.

  Another disadvantage of known flow guiding devices occurs when transferring the flow between the tongue-shaped portion of the spiral-shaped guide channel and the associated guide vane. The angle of the tip of the tongue is usually adapted to the angle of flow, which is determined by the spiral-shaped channel flow channels and the spiral-shaped channel outlet nozzle, the spiral-shaped channel being equipped with an outlet nozzle of such a shape as that the mass flow rate for each circumferential angle is discharged as constant as possible over as much of the periphery as possible, but since the tongue must have a finite thickness for technical manufacturing reasons, due to the flow trailing of the tongue, it appears a zone of disturbances sometimes important for the flow, which has the effect that an irregular flow arrives at the n downstream direction and therefore the performance of the

  turbomachine is adversely affected.

  The object of the invention is to develop a flow guiding device of the type indicated, so that for multi-flow turbomachines, a flow guiding device is obtained that is as simple as possible and simultaneously with a very variable use. compared to previously known solutions, while avoiding the disadvantages indicated in the state of the art. This problem is solved in accordance with the invention by virtue of the fact that the insert is divided into annular sectors, with sectors of the directing gate arranged differently so that different guide grids can be simultaneously loaded by the flow flowing in the channels. guiding spiral shape. An advantage of the embodiment according to the invention of the flow guiding device lies in the fact that due to the presence of the annular sectors with differently arranged guide grids, the flow of different flows can be directed simultaneously with a different swirling and a different volume flow, in the direction of the rotor, which allows to obtain a better capacity of adjustment of the turbomachine. A particularly advantageous effect of the embodiment according to the invention of the flow guiding device is obtained by using the different dynamic or discharge behavior in the different flows downstream of the arranged control gates of

different ways.

  For example, in a three-stage turbomachine, in which the mouths of the spiral-shaped ducts are angularly offset at the level of the flow guiding device, it is possible to obtain, in a first flow, a directional grid having a cross-section relatively narrow passage, high dynamic pressure, which can be used

  advantageous for a return of the exhaust gas.

  Simultaneously, for example for operation under partial load, in a second flow a directional grid having a large cross sectional passage can send the exhaust gas stream, in a relatively little constricted way, to the turbine The guide grid for the third stream is set for example

  on a specific operating point of the turbine.

  Thanks to the flow guiding device according to the invention, it is possible to very simply obtain a partial or complete combination of a compound turbine engine device, an exhaust gas return and a register booster charge according to the examples of achievement explained more

far in more detail.

  According to an alternative embodiment, the number of annular sectors is equal to the number of spiral-shaped guide channels, which open into the periphery of the insert, that is to say that each spiral-shaped guide channel is associated an annular sector, and, according to an alternative embodiment of the invention, the annular sectors comprise guide grids arranged axially behind each other and having different profile and gate parameters, and further, according to another variant embodiment, the annular sectors have guide vanes of left shape and, according to another variant embodiment, the annular sectors have hook vanes. A judicious distribution of the guide gates arranged in different ways on an annular sector is obtained when, in because of the axial shift of the annular sectors, respectively another director grid having either parameters very identical is inserted between the spiral-shaped guiding channel and the rotor. Advantageously, this results in a very wide range.

  regulator for the turbomachine.

  According to another variant embodiment, various selected guide vanes of the annular insert and tongue-like portions of the spiral-shaped guide channels, which open at the level of the insert, are fitted together so that a flow-promoting, continuous transition between the tongue-shaped portions and the selected guide vanes respectively, that is, the transition between the apex of the blade and the channel-shaped portion of the channel, appears respectively. The tongue emerges tangentially at the level of the next guide vane, in which case it is necessary to respect a certain minimum gap between the tip of the tongue and the dawn director, for

  facilitate the passage of the axially movable insert.

  The arrangement avoids drag flow of the tongue, since the guide vane forms the continuous extension of the tongue. It is also conceivable that the guide vane located downstream of the tongue differs from the rest of the guide vanes of the tongue.

  guiding grid, especially at the summit of dawn.

  According to another variant embodiment, the annular sectors comprise sleeve elements, by means of which the spiral-shaped guide channels can be closed until only circulators

flows in the form of blades.

  According to another variant embodiment, a cross section of a brake slot for a brake

  motor can be formed by the annular insert.

  According to another variant embodiment, the

  annular sectors have hook blades.

  According to another embodiment, the annular sectors are adjustable according to operating parameters of the internal combustion engine. By means of the last-mentioned arrangements, for example, a variable configuration of the braking slot cross-section for a motor brake is obtained by virtue of the respective cross-section of the flow inlet in the flow guiding device. In one of the previously mentioned embodiments, in which a braking slot cross-section for a motor brake can be formed by the annular insert, specifically the cross-section (braking slot-shaped cross-section), which is necessary for motor brake operation, remains in an end position Therefore, no separate engine braking device

is not necessary.

  A particularly advantageous possibility of producing an engine brake in the case of a compound turbine engine is obtained by using in the compound turbine of this engine a control gate having hook blades. The exhaust gas stream is directed by the guide grid formed by hook blades, in the direction of the guide vanes of the compound turbine so that a delay time is applied to the rotor of the compound turbine, compared to the useful moment of the

turbine engine compound.

  According to another embodiment of the invention, the annular insert is divided axially into annular sectors by cutting surfaces and that the annular sectors can move relative to each other in the direction of the longitudinal axis of the rotor , which greatly increases the flexibility of use of the flow guiding device Thus, particularly in connection with another feature of the invention wherein the annular sectors are adjustable according to operating parameters of the internal combustion engine, also only one flow can be adjusted at will, while keeping the position of the grids constant

guidelines for other flows.

  Other features and benefits of the

  present invention will emerge from the description given

  Hereinafter taken as an example in the case of a three and four-flow case, with reference to the accompanying drawings, in which: Figure 1 shows a radial section of a four-stage turbine stage having guide channels, which have mouths offset to 180 and are in the form of two symmetrical double spirals and a guide grid according to the invention; Figure 2 shows a meridian section of Figure 2; FIG. 3 represents a radial section of a three-stage turbine stage, comprising spiral-shaped guiding channels, which have angularly offset inputs of 120.degree., and another guiding grid according to the invention; FIG. 4 shows a schematic representation of a compound turbine engine with exhaust gas return and equipped with two guide grids in accordance with the invention, each comprising two different sectors; FIG. 5 shows a diagrammatic representation of a compound turbocharger with a supercharger with a register of two exhaust gas turbochargers mounted upstream of the internal combustion engine and comprising guide grids in accordance with the invention; and FIG. 6 shows a compound gas turbine engine with exhaust gas return and register boost of two exhaust gas turbochargers connected in parallel upstream of the internal combustion engine and comprising guide grids in accordance with the invention.

  We will explain in more detail the application

  cation of the invention in the case of the example of exhaust gas turbine and compound with two flows, in some combinations of arrangement of a compound turbine engine, a register supercharger and a return of the gases exhaust. Figures 1 and 2 show a radial section and a meridian section of a four-stage turbine stage comprising a casing 1, which has guide channels 2, 3, 4 and 5 with mouths offset by 80 e and presenting itself in the form of two symmetrical double spirals. In the housing 1 is disposed a rotor 6, which is mounted on a shaft 7 and forms, with a guide gate 8, a turbine stage of a turbomachine not shown in detail and driven by the exhaust gas A

an internal combustion engine.

  The shaft 7 is supported in a bearing housing 9 shown only partially and having bearings 10 also shown only partially. The casing 1 of the turbine stage is connected.

  by flange to bearing housing 9 with screws 11 and 12.

  Between the casing 1 and the rotor 6 is arranged the flow guiding device 14, which is axially displaceable along the longitudinal axis 13 of the rotor and which comprises an annular adjustment sleeve 15, which is constituted by two tubular sleeve elements. 16 and

17 and an annular insert 18.

  The insert 18 has, in accordance with the invention, four differently arranged sectors 19, 20, 21 and 22 of a guide grid, the two sectors 19, 21 and 20, 22, which are respectively axially adjacent and separated respectively. on the other hand by a radial bar 23, form two annular sectors 24 and 25, in which case, in the indicated representation, the flows 2 and 3 open into the annular sector 24 and the flows 4 and 5 open into the sector

annular 25 of the insert 18.

  FIG. 1 shows the sectors 19 and 20, which are staggered differently, of the guide grid, with elements 26 and 27 for guiding the flow. The sectors 21 and 22 of the control gate, which are represented only on the median section of FIG. 2, are arranged in a similar manner to the sectors 19 and 20 of the guide grid, but by

  example with blades with varying angles.

  FIG. 1 shows the two tongue-like portions 28 and 29 of spiral-shaped guide channels 3 and 5, the tongue-like portion 28 being

  ending in a continuous way and favoring the flow of

  at a selected guide vane 30 and similarly, the tongue portion 29 terminating at a selected guide vane 31

insert 18.

  In another exemplary embodiment, there is shown in FIG. 3 a radial section of a three-stage turbine stage comprising a casing 32, which has three inputs, angularly offset by 1200, of spiral-shaped guiding channels 33. 34 and 35 and which open into a guide vane 36 according to the invention comprising three sectors 37, 38 and 39, which simultaneously form three annular sectors 40, 41 and 42. In a manner similar to FIG. 1, it can be seen that the master grid sector associated with each annular sector (for example sector 37 of the master chart associated with annular sector 40) has a different staggering

in the grid.

  In a similar manner to FIG. 1, here also the tab-shaped portions 43, 44 and 45 terminate continuously and by promoting flow at selected guide vanes 46, 47 and 48 of the guide grid 36, which are adapted, at their vertices, to the tongue-shaped portion which is

respectively associated.

  Figure 4 shows the advantageous use

  two guide grids 49 and 50 in accordance with the invention.

  tion and comprising two sectors 64 and 65, in a turbo-

  compound exhaust gas engine, shown schematically. A multi-cylinder internal combustion engine 51, not shown in detail, is connected via exhaust pipes 52 and 53 and

  from a supply air pipe 54 to a turbocharger

  EXHAUST PIPES 55 The exhaust pipes 52 and 53 represent cylinder output channels of the engine of the internal combustion engine 51 grouped into groups of variable size. The variable size of the groups during the assembly of the different fuel pipes. Exhaust work rolls can be obtained for example by means of a control valve not shown. The exhaust gas turbocharger 55 comprises, among its essential components, a compressor 56, which is connected via a shaft 57 to a turbine.

two streams 58.

  A pipe 60 connects the nozzle 59 of the turbine 58 to another compound turbine 61 also with two flows, the shaft 62 is mechanically coupled, in a manner known per se, to the internal combustion engine 51, via a reduction transmission 63 shown schematically The exhaust gas A is sent, via the outlet pipe of the compound turbine 61, into the exhaust system

  represented by the compound turbine engine.

  The internal combustion engine 51 and the exhaust gas turbocharger 55 form, together with the compound turbine 61 and the mechanical coupling between the compound turbine 61 and the combustion engine

  internal 51, a compound turbine engine.

  Between the casing and the spiral-shaped channel at

  two flows of the two turbines 58 and 61, it has been shown that

  respectively one of the guide grids 49, 50 according to the invention, comprising two sectors 64

  and 65 A possible radial section of this grid

  trice is also shown in Figure 1.

  The exhaust pipe 52 connects the outlet side 66 of the internal combustion engine 51 to the manifold

  intake 67 of the first flow of the turbine 58.

  A first portion 68 of the exhaust pipe 53 terminates in a compensation tank 69, from which a second portion 66 of the exhaust pipe 53 leads to an intake manifold 71 of the second flow of the turbine 58. The air The supercharger L is sucked and compressed by the compressor 56 and is driven from an outlet manifold 72 of the compressor 56, in a first portion 73 of the boost air line 54, to a charge air cooler 74. The latter is connected by a second part 75 of the exhaust air duct 54 to the intake side 76 of the combustion engine.

internal combustion 51.

  A pipe 77 for returning exhaust gases

  the compensating reservoir 69 to the second portion 75 of the charge air pipe 54 between the charge air cooler 74 and the

  intake side 76 of the internal combustion engine 51.

  In the exhaust gas return line 77 is arranged a blocking valve 78, by means of which the exhaust gas return flow rate is adjustable, by means of a regulator 79, according to the operating parameters of the engine. Due to the presence of the largely scaled guide grid of the sector 64 in the first flow of the turbine 58, a relatively large amount of the exhaust gas is sent to the twin-flow compound turbine 61 mounted downstream, the flow of supply is adjusted, as shown in the drawing, through the guide gate 50 with two flows, according to the invention Depending on the desired operating behavior of the compound turbine engine, the turbine compound 61 delivers, depending on the guide grid disposed upstream of the rotor of the turbine, a corresponding driving moment or, for example in the case of the use of a grid dawn director hook, a moment of

engine braking.

  At the same time, the relatively dense steerable grid of the sector 65 in the second flow of the turbine 58 can produce a relatively high dynamic pressure in the exhaust pipe 53 equipped with the compensation tank 69. exhaust, the exhaust pressure A in the compensation tank 69 must be greater than the boost air pressure L located in the second portion 75 of the charge air pipe 54 Quantitative control exhaust gases returned A is carried out at

  means of a regulator 79, as described above.

  FIG. 5 shows the guide grid according to the invention for a compound turbine, with a diagrammatic representation of a compound turbine engine with a register boost of two exhaust gas turbochargers 81 and 82 connected in parallel upstream. of the internal combustion engine 51 The same reference numerals characterize components

corresponding figures in Figure 4.

  The two outlet pipes 72 of the two compressors 56 of the exhaust gas turbochargers 81 and 82 are connected to a pipe 83 In the portion 84 of the pipe 83, which arrives from the compressor 56 of the exhaust gas turbocharger 81 is arranged A check valve 85 Between the check valve 85 and the outlet manifold 72 of the compressor 56 of the exhaust gas turbine 82, the charge air pipe 54 extends in a bypass from the line 83 towards the engine intake side 76

internal combustion 51.

  A pipe 86 connects the two outlet pipes 71 of the two turbines 58 of the exhaust gas turbochargers 81 and 82, the exhaust pipe 52 connecting the pipe 86 to the outlet side 66 of the combustion engine

internal 51.

  A first connecting pipe 87 represents a flow connection between the tubing of

  output 59 of the turbine 58 of the exhaust gas turbocharger

  81 A second connecting pipe 89 connects the outlet pipe 59 of the turbine 58 of the exhaust gas turbocharger 82 to an intake manifold 61 and the inlet manifold 88 of the first flow of the dual-flow compound turbine 61. 90 of the second flow of the turbine

compound 61.

  In the provided representation of the guide grid 50 according to the invention, in an annular sector 91 (as for reference 24, see Figure 1), is disposed a socket sector 93, which completely blocks the first flow of the compound turbine 61, apart from blade-shaped flows The socket-shaped sector 93 therefore replaces, for example, the sector 19 of the guide grid of FIG. 1. Under the effect of this blocking, for example in the range of partial loads, the total exhaust gas stream passing through the turbine 58 of the exhaust gas turbocharger 81 is blocked and is deflected towards the turbine 58 of the exhaust gas turbocharger 82 Therefore, this turbocharger is responsible for the delivery The check valve 85 prevents supercharging air from exiting the compressor 56, which

  performs no training, from the exhaust gas turbocharger

  A relatively large, conductive grid of a sector 94 is located in the second annular sector 92 (which is analogous to the reference 25, see FIG. 1), which allows the compound turbine 61 to be charged with the gases. A exhaust that arrives from the turbine 58 of the exhaust gas turbocharger 82 through the second connecting pipe 89, so that the driving moment appearing from the turbine compound 61 contributes through the transmission multiplier 63, to form the moment

  total drive of the compound turbine engine.

  FIG. 6 represents the guide grid according to the invention with a schematic representation of a compound turbine engine with exhaust gas return and register boost of two exhaust gas turbochargers 81 and 82 connected in parallel upstream of the engine. FIG. 6 shows a circuit formed by the combination of the circuits shown in FIGS. 4 and 5 and, in FIGS. 4 and 5 given above, the operation of the illustrated assembly of these combined circuits is obvious, since the same reference numerals have been designated for the same components as in FIGS. 4 and 5. To this is added in this drawing, as another characteristic, only the pipe 96, which shunts, at a location 95, from the second portion 70 of the exhaust pipe 53 and which respectively connects a flow of the

  gas turbine 58 of the two exhaust gas turbochargers

  81 and 82 As a result, an additional increase in the flexibility of current regulation is obtained.

  supply to exhaust gas turbochargers

81 and 82.

  Instead of the guideline grids and fixtures, given by way of example on the given representations, it is of course also possible to use other circuits and other assemblies of guide grids, depending on the desired behavior of

control of the entire system.

Claims (10)

  An adjustable flow guiding device for a rotor of a turbomachine driven by the exhaust gas of an internal combustion engine, wherein the flow guiding device comprises an annular insert (18) disposed between a plurality of channels spiral guide means (2,3,4,5,33,34,35) of the turbomachine and the   rotor, with at least partial flow direction   radially, and in the annular insert (18) are arranged, in a distributed manner on the periphery of this insert, flow guiding elements, which form a guide gate and establish a flow connection between the channels. spiral-shaped guide means and the rotor of the turbomachine, the annular insert (18) forming part of an adjusting sleeve, which is displaceable in the direction of the longitudinal axis of the rotor, characterized in that the insert ( 18) is divided into annular sectors (24, 25,40,41,42), with sectors (19,20,21,22,37,38,39,64,) of the guide grid arranged differently so that different grids (8.36, 49.50) can be simultaneously loaded by the flow flowing in the spiral-shaped guide channels (2, 3, 4, 5, 33, 341 35).   Adjustable flow-guiding device according to Claim 1, characterized in that the number of annular sectors (24, 25, 40, 41, 42) is equal to the number of spiral-shaped guide channels (2, 3, 4 , 5, 33, 34, 35), which open into the periphery of the insert (18).   3 Adjustable flow guiding device   according to one of claims 1 or 2, characterized in that   that the annular sectors (24, 25, 40, 41, 42) comprise guide grids (8, 36, 49, 50) arranged axially one behind the other and having   different profile and grid settings.   4 Adjustable flow guiding device   according to any one of claims 1 to 3,   characterized in that the annular sectors (24, 25, 40,   41, 42) have guide vanes of left form.   Adjustable flow guiding device   according to any one of claims 1 to 4,   characterized in that different selected guide vanes (30, 31, 46, 47, 48) of the annular insert (18) and tongue-shaped portions (28, 29, 43, 44,) of the shape guide channels spiral (2, 3, 4, 5, 33, 34, 35), which open at the level of the insert (18), are adapted to one another so that it appears   respectively a continuous transition, favoring   between the tab-shaped portions (28, 29, 43, 44, 45) and the selected guide vanes (30, 41, 46, 47, 48).   6 Adjustable flow guiding device   according to any one of claims 1 to 5,   characterized in that the annular sectors (24, 25, 40, 41, 42) comprise sleeve elements (16, 17), by means of which the spiral-shaped guide channels can be closed until only circulators flows in the form of blades.   7 Adjustable flow guiding device   according to any one of claims 1 to 6,   characterized in that a braking slot cross-section for a motor brake can be formed by the annular insert (18).   8 Adjustable flow guiding device   according to any one of claims 1 to 7,   characterized in that the annular sectors (24, 25, 40,   41, 42) have hook blades.   9 Adjustable flow guiding device   according to any of claims 1 to 7, characterized   in that the annular sectors (24,25,40,41,42) are adjustable according to operating parameters   of the internal combustion engine (51).   10 Adjustable flow guiding device   according to any one of claims 1 to 9,   characterized in that the annular insert (18) is divided axially into annular sectors (24, 25, 40, 41, 42) by cutting surfaces and that the annular sectors (24, 25, 40, 41, 42) can moving relative to each other in the direction of the longitudinal axis (13) of the rotor.