Apparatus for preventing axial-flow compressor from stalling by employing casing treatment

Patent metadata

Field	Value
Publication number	US-2016010652-A1
Application number	US-201214772149-A
Country	US
Kind code	A1
Filing date	Dec 18, 2012
Priority date	Dec 18, 2012
Publication date	Jan 14, 2016
Grant date	—

Abstract

An apparatus for preventing an axial-flow compressor from stalling by employing a casing treatment includes an outer casing having an inner wall with a slot formed to face a rotor blade, an inner casing moveable so as to open the slot in an unstable operating region and close the slot of the outer casing in a stable operating region, and a drive means for moving the inner casing along the axial direction of the outer casing. Thus, the apparatus can be applied not only to a casing treatment structure where the slope of a slot does not vary with the rotational position of the rotor, but also to a casing with a variously shaped slot such as a radial slot or an axial skewed slot.

First claim

1 . An apparatus for preventing an axial-flow compressor from stalling by employing a casing treatment, in which the axial-flow compressor comprises an outer casing having a slot formed in an inner wall faced with a rotor, the apparatus comprising:
an inner casing moveable in an axial direction of the outer casing to open or close the slot of the outer casing; and a drive means to move the inner casing in an axial direction of the outer casing.

2 . The apparatus of claim 1 , wherein the outer casing comprises:
a cavity in fluid communication with the slot in the axial direction of the outer casing, and being positioned within the outer casing; and a slot in fluid communication with the cavity in a direction of wall thickness of the outer casing.

3 . The apparatus of claim 2 , wherein the drive means comprises:
a connecting member connected with the inner casing and extended externally through the slot; and a move means to move the connecting member in the axial direction of the outer casing.

4 . The apparatus of claim 3 , wherein the move means comprises:
a cylinder connected with the connecting member, and an interior of which is divided by a partition into a left side and a right side; a first valve and a second valve to control an inflow of a high pressure air at a downstream of the axial-flow compressor into the cylinder; and a third valve and a fourth valve to control an outflow of the high pressure air from the cylinder.

5 . The apparatus of claim 4 , wherein the first valve and the third valve are connected with the left side of the cylinder, and the second valve and the fourth valve are connected with the right side of the cylinder.

6 . The apparatus of claim 2 , wherein an interval in fluid communication between the slot and the cavity of the outer casing corresponds to a thickness of the inner casing.

7 . The apparatus of claim 6 , wherein, at a portion in fluid communication between the slot and the cavity, an airtightness maintaining member is installed between the outer casing and the inner casing.

8 . The apparatus of claim 1 , wherein the inner casing is moved so that the slot is open in an unstable operating region, and is closed in a stable operating region.

9 . An apparatus for preventing an axial-flow compressor from stalling by employing a casing treatment, in which the axial-flow compressor comprises a casing having a plurality of slots formed in an inner wall faced with a rotor, the apparatus comprising:
a plurality of sliders to be slidably inserted into the plurality of slots, respectively; a plurality of first links, one ends of which are connected with the plurality of sliders, respectively, and being rotatable relative to the plurality of sliders; a plurality of second links, one ends of which are connected with the other ends of the plurality of first links, respectively, and being rotatable relative to the other ends of the plurality of first links; and a plurality of rotational shafts fixedly coupled with the other ends of the plurality of second links, respectively.

10 . The apparatus of claim 9 , wherein each of the plurality of sliders and each of the plurality of first links coupled with each other are connected to be rotated relative to each other through a first ring member.

11 . The apparatus of claim 9 , wherein each of the plurality of the first links and each of the plurality of second links coupled with each other are connected to be rotated relative to each other through a second ring member.

12 . The apparatus of claim 9 , wherein a drive force transmitting member is disposed between the plurality of rotational shafts so that the plurality of rotational shafts are rotated in a same direction.

13 . The apparatus of claim 12 , wherein the drive force transmitting member is a gear.

14 . The apparatus of claim 12 , further comprising a drive portion to rotate one of the plurality of rotational shafts as a driving shaft.

15 . The apparatus of claim 14 , wherein the drive portion comprises a fixing member and an actuator, wherein one end of the fixing member is fixed to one of the plurality of rotational shafts and one end of the actuator is connected with the other end of the fixing member with a degree of freedom to rotate the fixing member.

16 . The apparatus of claim 15 , wherein the other end of the actuator is connected with the casing through a third ring member having a ring shape, while having a degree of freedom.

17 . The apparatus of claim 9 , wherein, in an unstable operating region, the plurality of sliders are ascended within the plurality of slots to open the plurality of slots, while in a stable operating region, the sliders are descended within the plurality of slots to close the plurality of slots.

18 . The apparatus of claim 9 , wherein a circle formed by the plurality of rotational shafts has a same center of curvature as that of the casing.

19 . The apparatus of claim 9 , wherein the casing has a plurality of passing holes through which the plurality of first links are passed.

20 . An apparatus for preventing an axial-flow compressor from stalling by employing a casing treatment, in which the axial-flow compressor comprises a casing having a plurality of slots formed in an inner wall faced with a rotor, the apparatus comprising:
a plurality of sliders to be slidably inserted into the plurality of slots, respectively; a plurality of rods connected with the plurality of sliders, respectively; a plurality of rollers connected with one ends of the plurality of rods, respectively, to be rotated relative to the plurality of rods; and an arm on which the plurality of rollers are movably provided, and which is disposed to have a same center of curvature as that of the casing.

21 . The apparatus of claim 20 , wherein the slider of the plurality of sliders and the rod of the plurality of rods, which are connected with each other, are integrally formed with each other.

22 . The apparatus of claim 20 , wherein the arm comprises an upper rail and a lower rail which are connected with each other to form a closed curve, and the plurality of rollers are moved in a rolling motion between the upper rail and the lower rail.

23 . The apparatus of claim 20 , wherein a slope of the plurality of slots is in a direction of radius of the casing.

24 . The apparatus of claim 20 , further comprising a drive portion to drive the arm in the direction of radius of the casing.

25 . The apparatus of claim 20 , wherein the plurality of rollers have a concave portion on an outer circumference in a circumferential direction, and the upper rail and the lower rail each comprise a protrusion to be inserted into the concave portion.

26 . The apparatus of claim 20 , wherein, in an unstable operating region, the plurality of sliders are ascended within the plurality of slots to open the plurality of slots, while in a stable operating region, the sliders are descended within the plurality of slots to close the plurality of slots.

27 . The apparatus of claim 23 , wherein the plurality of rods are constantly aligned in the direction of radius of the casing.

28 . The apparatus of claim 20 , wherein, when the arm is moved to a direction away from the casing, the plurality of rollers are moved so that intervals between the plurality of rollers increase.

29 . The apparatu

Assignees

• Korea Aerospace Res Inst

Inventors

• Lim Byeung Jun
• Park Tae Choon
• Kang Young Seok

Classifications

• F04D27/002 Primary

  by varying geometry within the pumps, e.g. by adjusting vanes · CPC title

• F04D29/522

  especially adapted for elastic fluid pumps · CPC title

• F04D19/002

  Axial flow fans · CPC title

• F04D29/685

  Inducing localised fluid recirculation in the stator-rotor interface · CPC title

• F04D29/526

  Details of the casing section radially opposing blade tips (ducts F04D29/545) · CPC title