(19)
(11)EP 4 047 186 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
15.11.2023 Bulletin 2023/46

(21)Application number: 22155648.3

(22)Date of filing:  08.02.2022
(51)International Patent Classification (IPC): 
F01D 9/00(2006.01)
F01D 25/30(2006.01)
F01D 9/02(2006.01)
F01D 5/12(2006.01)
(52)Cooperative Patent Classification (CPC):
F01D 25/30; F01D 9/00; F01D 9/02; F05D 2220/30; F05D 2240/12; F05D 2240/24; F01D 5/12

(54)

GAS EXPANDER

GASEXPANDER

DÉTENDEUR DE GAZ


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 18.02.2021 JP 2021024191

(43)Date of publication of application:
24.08.2022 Bulletin 2022/34

(73)Proprietor: Mitsubishi Heavy Industries Compressor Corporation
Tokyo 108-0014 (JP)

(72)Inventor:
  • IWATA, Fumihiko
    Hiroshima, 733-8553 (JP)

(74)Representative: Studio Torta S.p.A. 
Via Viotti, 9
10121 Torino
10121 Torino (IT)


(56)References cited: : 
WO-A1-2017/138035
JP-A- 2016 003 584
CN-B- 105 909 319
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION


    Field of the Invention



    [0001] The present disclosure relates to a gas expander.

    Description of Related Art



    [0002] A device called a gas expander is known as a kind of rotating machine. The gas expander converts thermal energy of a working fluid having high temperature and high pressure into rotational energy by rotating an impeller and a rotating shaft with the working fluid.

    [0003] In PCT International Publication No. WO2017/138835, a configuration is disclosed, which includes a diffuser having a flow path in which a gas expanded through an impeller (turbine wheel) flows in a rotational axis direction of the impeller, and a vortex prevention plate for partitioning the flow path of the diffuser in a circumferential direction. The vortex prevention plate suppresses a vortex flow generated in the gas that has passed through the turbine wheel and reached the diffuser.

    [0004] Other prior art documents CN 105 909 319 B and JP 2016 003584 A.

    [0005] However, in the configuration described in PCT International Publication No. WO2017/138835, the vortex flow may not be sufficiently suppressed. Then, the vortex flow collides with the vortex prevention plate, and thus, a flow component reflected on the impeller side is generated, and a non-uniform flow velocity distribution occurs in the flow path in the diffuser. As a result, an exciting force acts on the impeller and the rotating shaft, which may cause vibration.

    SUMMARY OF THE INVENTION



    [0006] The present invention provides a gas expander capable of equalizing a flow velocity distribution of a gas flow in a flow path on a downstream side of an impeller and effectively suppressing the exciting force acting on the impeller and the rotating shaft.

    [0007] According to an aspect of the present disclosure, there is provided a gas expander as set forth in claim 1.

    [0008]  According to the gas expander of the present disclosure, it is possible to equalize the flow velocity distribution of the gas flow in the flow path on the downstream side of the impeller and effectively suppressing the exciting force acting on the impeller and the rotating shaft.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0009] 

    FIG. 1 is a diagram showing a schematic configuration of a gas expander according to an embodiment of the present disclosure.

    FIG. 2 is a cross-sectional view showing a scroll casing, an impeller, a diffuser, and a vortex preventer of the gas expander.

    FIG. 3 is a perspective view of the vortex preventer.


    DETAILED DESCRIPTION OF THE INVENTION



    [0010] Hereinafter, a mode for carrying out the gas expander according to the present invention will be described with reference to the accompanying drawings. However, the present disclosure is not limited to embodiments.

    (Configuration of Gas Expander)



    [0011] As shown in FIGS. 1 and 2, a gas expander 1 as a centrifugal rotating machine according to the present embodiment mainly includes a rotor 3, a scroll casing 2 (refer to FIG. 2), a diffuser 5, and a vortex preventer 6 (refer to FIG. 2).

    (Rotor Configuration)



    [0012] The rotor 3 includes a rotating shaft 30 and an impeller 40.

    [0013] As shown in FIG. 1, the rotating shaft 30 extends in an axial direction Da. The rotating shaft 30 is rotatably supported around a central axis O by a pair of journal bearings 12. The pair of journal bearings 12 are disposed at distances in the axial direction Da. The rotating shaft 30 is restrained from moving in the axial direction Da by a pair of thrust bearings 17. The pair of thrust bearings 17 are disposed between a second-stage impeller 40B described below, and the journal bearing 12 on the second-stage impeller 40B side with respect to a pinion gear 15. The pair of thrust bearings 17 may be disposed at positions separated from each other on both sides in the axial direction Da with respect to the pinion gear 15.

    [0014] The rotating shaft 30 is connected to an external drive target (not shown) via a deceleration transmission unit 11. The deceleration transmission unit 11 includes the pinion gear 15 and a bull gear 16.

    [0015] The pinion gear 15 is fixed to the rotating shaft 30 between the pair of journal bearings 12. The bull gear 16 meshes with the pinion gear 15. The bull gear 16 rotationally drives the external drive target. The bull gear 16 has an outer diameter larger than that of the pinion gear 15. Therefore, a rotation speed of the bull gear 16 is lower than a rotation speed of the rotating shaft 30 having the pinion gear 15. The deceleration transmission unit 11 decelerates the rotation speed of the rotating shaft 30 via the pinion gear 15 and the bull gear 16 and transmits the decelerated rotation speed to the external drive target.

    [0016] The impeller 40 is fixed to the rotating shaft 30. The gas expander 1 of the present embodiment includes the impellers 40 at both end portions of the rotating shaft 30 in the axial direction Da. As shown in FIG. 2, each impeller 40 of the present embodiment includes a disk 41 and a blade 42.

    [0017] The disk 41 is formed in a disk shape and is fixed to the end portion of the rotating shaft 30. The disk 41 has a first surface 41a formed on one surface side of the axial direction Da and a second surface 41b formed on the other surface side of the axial direction Da. The second surface 41b of the disk 41 faces a side of the pinion gear 15 in the axial direction Da. The first surface 41a of the disk 41 faces a side opposite to the side of the pinion gear 15. That is, directions of the disks 41 of the first-stage impeller 40A provided at a first end of the rotating shaft 30 and the second-stage impeller 40B provided at a second end of the rotating shaft 30 are opposite to each other in the axial direction Da.

    [0018] In the following description, in each impeller 40, a side facing the first surface 41a of the disk 41 is referred to as a first side Da1 in the axial direction Da, and a side facing the second surface 41b is referred to as a second side Da2 in the axial direction Da. For example, in the first-stage impeller 40A and the second-stage impeller 40B, the first side Da1 in the axial direction Da and the second side Da2 in the axial direction Da are opposite to each other.

    [0019] As shown in FIG. 2, the first surface 41a of the disk 41 has a curved surface formed in a concave shape of which an outer diameter gradually expands from the first side Da1 to the second side Da2 in the axial direction Da. A gas, which is a working fluid, flows from an outside Dro toward an inside Dri in a radial direction Dr and from the second side Da2 (second surface 41b side) in the axial direction Da to the first side Da1 (first surface 41a side) in the axial direction Da, with respect to the disk 41 of the impeller 40.

    [0020] The blade 42 is provided on the first surface 41a of the disk 41 facing the first side Da1 in the axial direction Da. A plurality of the blades 42 are disposed in a circumferential direction Dc around the central axis O.

    (Configuration of Scroll casing)



    [0021] The scroll casing 2 is made of metal and is formed so as to cover the rotating shaft 30 and the impeller 40. The scroll casing 2 has a shaft labyrinth portion 21 through which the rotating shaft 30 is inserted. The scroll casing 2 includes an expansion portion 22, an gas supply flow path 23, and a discharge portion 24.

    [0022] The expansion portion 22 is formed so as to cover the impeller 40. The expansion portion 22 has an impeller facing surface 22f formed at a distance on the first side Da1 in the axial direction Da with respect to the first surface 41a of the disk 41 of the impeller 40. The impeller facing surface 22f is continuously formed in the circumferential direction Dc so as to cover the plurality of blades 42.

    [0023] An expansion flow path 25 is formed between the impeller facing surface 22f of the expansion portion 22 and the disk 41. The expansion flow path 25 has an inlet flow port 25i and an exhaust flow port 25o. The inlet flow port 25i opens toward the outside Dro of the impeller 40 in the radial direction Dr. The exhaust flow port 25o opens toward the first side Da1 in the axial direction Da on the inside Dri of the radial direction Dr of the first surface 41a side of the disk 41.

    [0024] The gas supply flow path 23 is formed on the outside Dro in the radial direction Dr of the inlet flow port 25i of the expansion flow path 25. The gas supply flow path 23 has a spiral shape that is continuous in the circumferential direction Dc. A high-temperature and high-pressure gas sent from a turbine, a boiler, or the like outside the scroll casing 2 is supplied from the inlet flow port 25i to the expansion flow path 25 through the gas supply flow path 23.

    [0025] The discharge portion 24 is open toward the first side Da1 in the axial direction Da. The discharge portion 24 defines the exhaust flow port 25o of the expansion flow path 25 on the inside Dri of the radial direction Dr. The discharge portion 24 discharges the gas discharged from the exhaust flow port 25o toward the first side Da1 in the axial direction Da.

    [0026] According to the impeller 40 and the scroll casing 2 having the above configuration, the high-temperature and high-pressure gas sent from the turbine, boiler, or the like outside the scroll casing 2 is supplied from the inlet flow port 25i to the expansion flow path 25 through the gas supply flow path 23. While the gas supplied to the expansion flow path 25 expands in the process of flowing through the inside of the expansion flow path 25 from the outside Dro toward the inside Dri in the radial direction Dr, the gas rotationally drives the impeller 40 to a first side Dc1 in the circumferential direction Dc around the central axis O. The gas after being used for the rotation of the impeller 40 is discharged from the discharge portion 24 (exhaust flow port 25o) to the first side Da1 in the axial direction Da. In this case, the discharged gas includes a vortex flow Fs that is directed to the first side Da1 in the axial direction Da and swirls to the first side Dc1 in the circumferential direction Dc by the rotation around the central axis O of the impeller 40.

    (Configuration of Diffuser)



    [0027] The diffuser 5 mainly recovers a static pressure of the gas discharged from the discharge portion 24. The diffuser 5 is attached to the discharge portion 24 of the scroll casing 2. The diffuser 5 includes a diffuser main body 5A and the vortex preventer 6. The diffuser main body 5A has a tubular shape extending from the discharge portion 24 to the first side Da1 in the axial direction Da. The diffuser main body 5A forms a flow path 50 of gas discharged from the impeller 40 to the first side Da1 in the axial direction Da. The diffuser main body 5A is formed so that an inner diameter of the flow path 50 gradually increases from the second side Da2 toward the first side Da1 in the axial direction Da.

    (Configuration of Vortex preventer)



    [0028] The vortex preventer 6 rectifies the vortex flow Fs by canceling a swirling component contained in the vortex flow Fs flowing through the flow path 50. The vortex preventer 6 is provided in the flow path 50, which is the internal space of the diffuser main body 5A. The vortex preventer 6 is disposed at a distance on the first side Da1 in the axial direction Da with respect to the impeller 40.

    [0029] As shown in FIGS. 2 and 3, the vortex preventer 6 includes a cylinder portion 60 and a plurality of rectifying blades 61. The cylinder portion 60 extends along the central axis O. The cylinder portion 60 has a circular cross section when viewed from the axial direction Da. The plurality of rectifying blades 61 are disposed on the outside Dr of the radial direction Dr of the cylinder portion 60 at distances in the circumferential direction Dc. In the present embodiment, a case where four rectifying blades 61 are provided at equal distances in the circumferential direction Dc is shown. The number of rectifying blades 61 is not limited in any way, and may be, for example, two, three, five or more.

    [0030] Each rectifying blade 61 integrally includes a profile rectifying blade portion 62 and a plate rectifying blade portion 63. The profile rectifying blade portion 62 is formed on the second side Da2 in the axial direction Da with respect to the plate rectifying blade portion 63, that is, on a side closer to the impeller 40. The plate rectifying blade portion 63 is formed continuously on the first side Da1 in the axial direction Da with respect to the profile rectifying blade portion 62.

    [0031] The plate rectifying blade portion 63 of the plurality of rectifying blades 61 is formed in a flat plate shape extending radially along the radial direction Dr from the cylinder portion 60 toward the outside Dro in the radial direction Dr. The plate rectifying blade portion 63 of each rectifying blade 61 formed in a flat plate shape overlaps the central axis O over the entire area of the axial direction Da when viewed from the outside Dro in the radial direction Dr.

    [0032] The profile rectifying blade portion 62 is curved or inclined to be gradually positioned from the first side Da1 toward the second side Da2 in the axial direction Da and from a position of the plate rectifying blade portion 63 to the second side Dc2 in the circumferential direction Dc. In the present embodiment, a case is shown in which the profile rectifying blade portion 62 is curved to be positioned from the first side Da1 toward the second side Da2 in the axial direction Da and from a position of the plate rectifying blade portion 63 to the second side Dc2 in the circumferential direction Dc.

    [0033] For example, the above-described profile rectifying blade portion 62 can be formed by bending a vortex preventer forming material P having a flat plate shape into a two-dimensional shape toward the second side Dc2 in the circumferential direction Dc from the first side Da1 toward the second side Da2 in the axial direction Da. When these profile rectifying blade portions 62 have a two-dimensional shape, when each profile rectifying blade portion 62 is viewed from the outside Dro in the radial direction Dr, positions in the circumferential direction Dc are the same at the same position in the axial direction Da. That is, the profile rectifying blade portion 62 curved into a two-dimensional shape is not formed so as to be twisted around the central axis O. The profile rectifying blade portion 62 of the present embodiment is formed in a shape of an arc in cross section formed with a constant radius of curvature.

    [0034] It is also possible to add the profile rectifying blade portion 62 to the existing plate rectifying blade portion 63.

    [0035] Preferably, an inclination angle θ1 of a blade leading edge portion 62a of the profile rectifying blade portion 62 on the second side Da2 (impeller 40 side) in the axial direction Da with respect to the central axis O is set based on a swirling angle of the vortex flow Fs of the gas discharged from the impeller 40. For example, when the gas flows at a maximum flow rate in the gas expander 1, the inclination angle θ1 may be equal to an inclination angle θ2 with respect to the axial direction Da of the vortex flow Fs discharged from the discharge portion 24 (exhaust flow port 25o). Here, since the profile rectifying blade portion 62 is curved in the present embodiment, the inclination angle θ1 is an angle between a tangent line at the blade leading edge portion 62a and the central axis O.

    [0036] In the vortex preventer 6, the vortex flow Fs of the gas discharged from the impeller 40 to the first side Da1 in the axial direction Da flows along the blade leading edge portion 62a of the profile rectifying blade portion 62. Therefore, the vortex flow Fs does not collide violently with the vortex preventer 6 unlike in a case where an angle difference between the inclination angle θ1 at the blade leading edge portion 62a and the swirling angle of the vortex flow Fs is large. Then, the circumferential component of the vortex flow Fs is gradually reduced toward the first side Da1 by the profile rectifying blade portion 62. Further, the gas that has passed through the profile rectifying blade portion 62 flows along the plate rectifying blade portion 63, and thus, the gas flows along the axial direction Da toward the first side Da1 in the axial direction Da.

    (Action effect)



    [0037] In the gas expander 1 having the above configuration, the vortex preventer 6 has a profile rectifying blade portion 62.

    [0038] According to the configuration, the vortex flow Fs of the gas discharged from the impeller 40 to the first side Da1 in the axial direction Da is rectified by flowing along the profile rectifying blade portion 62. Since the profile rectifying blade portion 62 is curved or inclined from the first side Da1 toward the second side Da2 in the axial direction Da and to the second side Dc2 in the circumferential direction Dc, the vortex flow Fs of the gas smoothly flows along the profile rectifying blade portion 62. As a result, it is possible to suppress occurrence of turbulence in the gas flow in the flow path 50 on a downstream side of the impeller 40. In this way, a flow velocity distribution of the gas flow in the flow path 50 on the downstream side of the impeller 40 can be made uniform, and an exciting force acting on the impeller 40 and the rotating shaft 30 can be effectively suppressed.

    [0039] Further, the vortex preventer 6 has the plate rectifying blade portion 63.

    [0040] As a result, the gas flow through the profile rectifying blade portion 62 can be rectified so as to be directed toward the first side Da1 in the axial direction Da. Therefore, it is possible to suppress swirling of the vortex flow Fs of the gas swirling to the first side Dc1 in the circumferential direction Dc.

    [0041] Further, the vortex preventer 6 is disposed at a distance in the axial direction Da with respect to the impeller 40.

    [0042] As a result, a swirling speed of the vortex flow Fs is reduced before the gas discharged from the impeller 40 to the first side Da1 in the axial direction Da reaches the vortex preventer 6. Therefore, a rectifying effect of the vortex preventer 6 can be more effectively exerted, and the vortex flow Fs of the gas discharged from the impeller 40 to the first side Da1 in the axial direction Da can be effectively suppressed.

    [0043] The profile rectifying blade portion 62 is formed by bending or inclining the vortex preventer forming material P having a flat plate shape into a two-dimensional shape.

    [0044] Thereby, the profile rectifying blade portion 62 can be manufactured easily and at low cost.

    [0045] Further, the diffuser 5 is formed so that the diameter dimension gradually increases from the second side Da2 toward the first side in the axial direction Da.

    [0046] As a result, as the gas flows to the first side Da1 in the axial direction Da in the diffuser 5, the swirling speed of the vortex flow Fs discharged from the impeller 40 is reduced. Therefore, the rectifying effect of the vortex preventer 6 can be more effectively exerted, and the vortex flow Fs of the gas discharged from the impeller 40 to the first side Da1 in the axial direction Da can be effectively suppressed.

    (Other Embodiments)



    [0047] As described above, the embodiment of the present invention is described in detail with reference to the drawings. However, the specific configurations are not limited to the embodiment, and include a design modification or the like within a scope which does not depart from the appended claims of the present invention.

    [0048] In the above embodiment, the profile rectifying blade portion 62 is curved in a two-dimensional shape. However, the present invention is not limited to this, and for example, the profile rectifying blade portion 62 may be curved in a three-dimensional shape.

    [0049] Further, in the above embodiment, the impellers 40 are provided at both end portions of the rotating shaft 30 in the axial direction Da, but the present invention is not limited to this. The impeller 40 may be provided only on one side of the axial direction Da of the rotating shaft.

    [0050]  According to the gas expander of the present disclosure, the flow velocity distribution of the gas flow in the flow path on the downstream side of the impeller can be made uniform, and the exciting force acting on the impeller and the rotating shaft can be effectively suppressed.

    EXPLANATION OF REFERENCES



    [0051] 

    1: gas expander

    2: scroll casing

    3: rotor

    5: diffuser

    5A: diffuser main body

    6: vortex preventer

    11: deceleration transmission unit

    12: journal bearing

    15: pinion gear

    16: bull gear

    17: thrust bearing

    21: shaft labyrinth portion

    22: expansion portion

    22f: impeller facing surface

    23: gas supply flow path

    24: discharge portion

    25: expansion flow path

    25i: inlet flow port

    25o: exhaust flow port

    30: rotating shaft

    40: impeller

    40A: first-stage impeller

    40B: second-stage impeller

    41: disk

    41a: first surface

    41b: second surface

    42: blade

    50: flow path

    60: cylinder portion

    61: rectifying blade

    62: profile rectifying blade portion

    62a: blade leading edge portion

    63: plate rectifying blade portion

    Da: axial direction

    Da1: first side

    Da2: second side

    Dc: circumferential direction

    Dc1: first side

    Dc2: second side

    Dr: radial direction

    Dri: inside

    Dro: outside

    Fs: vortex flow

    O: central axis

    P: vortex preventer forming material

    01, θ2: inclination angle




    Claims

    1. A gas expander (1) comprising:

    a scroll casing (2) configured to send gas inside;

    an impeller (40) accommodated in the scroll casing (2) and configured to be rotationally driven to a first side (Dc1) in a circumferential direction around a central axis (O) by the gas flowing while expanding from an outside to an inside in a radial direction (Dr);

    a diffuser (5) disposed on a first side (Da1) in an axial direction in which the central axis (O) extends with respect to the scroll casing (2) and forming a flow path of the gas discharged from the impeller (40) to the first side (Da1) in the axial direction and swirling to the first side in the circumferential direction; and

    a vortex preventer (6) disposed in the diffuser (5),

    wherein the impeller (40) is configured to generate a vortex flow which swirls the gas discharged to the first side (Da1) in the axial direction to the first side in the circumferential direction,

    the vortex preventer (6) includes a profile rectifying blade portion (62), which is curved to a second side (Da2) in the circumferential direction from the first side toward a second side in the axial direction, at least in a portion of the second side in the axial direction, and characterized by a plate rectifying blade portion (63) continuously formed to the first side (Da1) in the axial direction from the profile rectifying blade portion (62) and having a flat plate shape extending in the axial direction (O),

    the plate rectifying blade portion (63) is formed so as to overlap the central axis (O) over the entire area of the axial direction when viewed in the radial direction (Dr), and

    the profile rectifying blade portion (62) is curved so as to move away from a position of the plate rectifying blade portion (63) in the circumferential direction toward a position away from the plate rectifying blade portion (63) toward the second side (Da2) in the circumferential direction as it approaches the impeller (40) from the second straightening blade portion and so as to approach the impeller (40) from the plate rectifying blade portion (63) in the axial direction, when viewed in the radial direction.


     
    2. The gas expander (1) according to claim 1,
    wherein the vortex preventer (6) is disposed at a distance in the axial direction with respect to the impeller (40).
     
    3. The gas expander (1) according to claim 1 or 2,
    wherein the profile rectifying blade portion (62) is formed by bending or inclining a vortex preventer forming material having a flat plate shape into a two-dimensional shape to the second side in the circumferential direction from the first side (Da1) toward the second side (Da2) in the axial direction.
     
    4. The gas expander (1) according to any one of claims 1 to 3,
    wherein the diffuser (5) is formed so that an inner diameter of the flow path gradually increases from the second side (Da2) toward the first side (Da1) in the axial direction.
     


    Ansprüche

    1. Gasexpander (1), der Folgendes umfasst:

    ein Spiralgehäuse (2), das konfiguriert ist, Gas nach innen zu schicken;

    ein Laufrad (40), das in das Spiralgehäuse (2) aufgenommen ist und konfiguriert ist, durch das Gas, das strömt, während es sich von einer Außenseite zu einer Innenseite in einer radialen Richtung (Dr) ausbreitet, zu einer ersten Seite (Dc1) in einer Umfangsrichtung um eine zentrale Achse (O) rotatorisch angetrieben zu werden;

    einen Diffusor (5), der auf einer ersten Seite (Da1) in einer axialen Richtung, in der die zentrale Achse (O) in Bezug auf das Spiralgehäuse (2) verläuft, angeordnet ist und einen Strömungsweg des Gases bildet, das vom Laufrad (40) zur ersten Seite (Da1) in der axialen Richtung abgegeben wird und zur ersten Seite in der Umfangsrichtung verwirbelt wird; und

    einen Wirbelverhinderer (6), der im Diffusor (5) angeordnet ist, wobei

    das Laufrad (40) konfiguriert ist, einen Wirbelstrom zu erzeugen, der das Gas, das zur ersten Seite (Da1) in der axialen Richtung abgegeben wird, zur ersten Seite in der Umfangsrichtung verwirbelt,

    der Wirbelverhinderer (6) ein Profilrichtflügelabschnitt (62) enthält, der mindestens in einem Abschnitt der zweiten Seite in der axialen Richtung zu einer zweiten Seite (Da2) in der Umfangsrichtung von der ersten Seite zu einer zweiten Seite in der axialen Richtung gekrümmt ist und gekennzeichnet ist durch einen Plattenrichtflügelabschnitt (63), der vom Profilrichtflügelabschnitt (62) zur ersten Seite (Da1) in der axialen Richtung kontinuierlich gebildet ist und eine flache Plattenform aufweist, die in der axialen Richtung (O) verläuft,

    der Plattenrichtflügelabschnitt (63) derart gebildet ist, dass er mit der zentralen Achse (O) über den gesamten Bereich der axialen Richtung aus der radialen Richtung (Dr) gesehen überlappt, und

    der Profilrichtflügelabschnitt (62) aus der radialen Richtung gesehen derart gekrümmt ist, dass er sich von einer Position des Plattenrichtflügelabschnitts (63) in der Umfangsrichtung weg zu einer Position weg vom Plattenrichtflügelabschnitt (63) zur zweiten Seite (Da2) in der Umfangsrichtung bewegt, während er sich dem Laufrad (40) vom zweiten Richtflügelabschnitt nähert, und dass er sich dem Laufrad (40) vom Plattenrichtflügelabschnitt (63) in der axialen Richtung nähert.


     
    2. Gasexpander (1) nach Anspruch 1, wobei
    der Wirbelverhinderer (6) in der axialen Richtung in einer Entfernung in Bezug auf das Laufrad (40) angeordnet ist.
     
    3. Gasexpander (1) nach Anspruch 1 oder 2, wobei
    der Profilrichtflügelabschnitt (62) durch Biegen oder Neigen eines den Wirbelverhinderer bildenden Materials, das eine flache Plattenform aufweist, in eine zweidimensionale Form zur zweiten Seite in der Umfangsrichtung von der ersten Seite (Da1) zur zweiten Seite (Da2) in der axialen Richtung gebildet ist.
     
    4. Gasexpander (1) nach einem der Ansprüche 1 bis 3, wobei
    der Diffusor (5) derart gebildet ist, dass ein Innendurchmesser des Strömungswegs von der zweiten Seite (Da2) zur ersten Seite (Da1) in der axialen Richtung allmählich zunimmt.
     


    Revendications

    1. Détendeur de gaz (1) comprenant :

    un carter de volute (2) configuré pour envoyer du gaz à l'intérieur ;

    une roue (40) accueillie dans le carter de volute (2) et configurée pour être entraînée en rotation jusqu'à un premier côté (De1) dans une direction circonférentielle autour d'un axe central (0) par le gaz s'écoulant tout en se détendant de l'extérieur vers l'intérieur dans une direction radiale (Dr) ;

    un diffuseur (5) disposé sur un premier côté (Da1) dans une direction axiale dans laquelle l'axe central (0) s'étend par rapport au carter de volute (2) et formant un trajet d'écoulement du gaz évacué de la roue (40) jusqu'au premier côté (Da1) dans la direction axiale et tourbillonnant jusqu'au premier côté dans la direction circonférentielle ; et

    un dispositif antivortex (6) disposé dans le diffuseur (5),

    dans lequel la roue (40) est configurée pour générer un écoulement en vortex qui fait tourbillonner le gaz évacué jusqu'au premier côté (Da1) dans la direction axiale jusqu'au premier côté dans la direction circonférentielle,

    le dispositif antivortex (6) comporte une portion de lame de redressement de profil (62), qui est courbée jusqu'à un second côté (Da2) dans la direction circonférentielle du premier côté vers un second côté dans la direction axiale, au moins dans une portion du second côté dans la direction axiale, et caractérisé par une portion de lame de redressement de plaque (63) formée en continu jusqu'au premier côté (Da1) dans la direction axiale à partir de la portion de lame de redressement de profil (62) et ayant une forme de plaque plate s'étendant dans la direction axiale (0),

    la portion de lame de redressement de plaque (63) est formée de manière à chevaucher l'axe central (0) sur toute la zone de la direction axiale lorsqu'elle est vue dans la direction radiale (Dr), et

    la portion de lame de redressement de profil (62) est courbée de manière à s'éloigner d'une position de la portion de lame de redressement de plaque (63) dans la direction circonférentielle vers une position éloignée de la portion de lame de redressement de plaque (63) vers le second côté (Da2) dans la direction circonférentielle lorsqu'elle s'approche de la roue (40) à partir de la seconde portion de lame de redressage et de manière à s'approcher de la roue (40) à partir de la portion de lame de redressement de plaque (63) dans la direction axiale, lorsqu'elle est vue dans la direction radiale.


     
    2. Détendeur de gaz (1) selon la revendication 1,
    dans lequel le dispositif antivortex (6) est disposé à une distance dans la direction axiale par rapport à la roue (40).
     
    3. Détendeur de gaz (1) selon la revendication 1 ou 2,
    dans lequel la portion de lame de redressement de profil (62) est formée par courbage ou inclinaison d'un matériau formant un dispositif antivortex ayant une forme de plaque plate en une forme bidimensionnelle jusqu'au second côté dans la direction circonférentielle du premier côté (Da1) vers le second côté (Da2) dans la direction axiale.
     
    4. Détendeur de gaz (1) selon l'une quelconque des revendications 1 à 3, dans lequel le diffuseur (5) est formé de sorte qu'un diamètre intérieur du trajet d'écoulement augmente progressivement du second côté (Da2) vers le premier côté (Da1) dans la direction axiale.
     




    Drawing














    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description