JP5736650B2 - Axial compressor and gas turbine engine - Google Patents

Description

  The present invention relates to an axial flow compressor that is used as, for example, a component of a gas turbine engine and compresses and conveys gas in an axial direction.

  A general axial compressor includes a cylindrical compressor case as a base, and the compressor case extends in the axial direction. An annular gas flow path is formed inside the compressor case.

  In the compressor case, a plurality of stages of compressor stators are provided along the axial direction. The compressor stator at each stage includes a plurality of stationary blades arranged at equal intervals in the circumferential direction, and each stationary blade is located in the gas flow path.

  In the compressor case, a plurality of stages of compressor rotors are provided alternately with the plurality of stages of compressor stators along the axial direction. The compressor rotor at each stage includes a disk provided in the compressor case so as to be rotatable about the axis, and the outer peripheral surface of the disk is a part of the wall surface on the radially inner side of the gas flow path. It constitutes. Further, a plurality of blades are provided at equal intervals on the outer peripheral surface of the disk in the compressor rotor of each stage, and each blade is located in the gas flow path.

  Therefore, by rotating the multi-stage compressor rotor, the multi-stage compressor rotor and the multi-stage compressor stator cooperate with each other, and the gas taken into the gas flow path is compressed and conveyed in the axial direction. be able to.

  On the other hand, various developments have been made to expand the operating range of an axial compressor, and the applicant of the present application has applied for an axial compressor with an expanded operating range and has already obtained a patent ( Patent Document 1). In the axial compressor according to this prior art, in addition to the configuration of the general axial compressor described above, the outlet side cross-sectional area (outlet cross-sectional area) of any compressor rotor is the inlet side cross-sectional area (inlet cross-section). It is configured to be larger than (area). As a result, the axial flow velocity (axial flow velocity) of the gas is reduced in any compressor rotor, and considering the velocity triangle of the moving blade, the work of the moving blade can be performed without increasing the warpage of the moving blade. It can be secured sufficiently. In other words, it is possible to reduce the pressure difference between the pressure surface and the suction surface of the moving blade by sufficiently reducing the warping of the moving blade while sufficiently securing the work of the moving blade. Therefore, it is possible to reduce the clearance flow from the pressure surface side to the suction surface side of the moving blade, thereby suppressing the stall of the axial flow compressor and expanding the operating range of the axial flow compressor to the low flow rate side.

Japanese Patent No. 3743415

  By the way, in recent years, in the field of jet engines, not only expansion of the operating range of axial compressors, but also the demand for higher pressure ratio and higher efficiency of axial compressors has become stronger, expanding the operating range. Above, development of the axial flow compressor which can aim at a high pressure ratio and high efficiency has become urgent.

  Accordingly, an object of the present invention is to provide an axial flow compressor having a novel configuration capable of further expanding the operating range by improving the axial flow compressor according to the above-described prior art.

As a result of repeating trial and error in order to solve the above-mentioned problems, the inventor of the present invention has determined that the outlet side sectional area (outlet sectional area) of any compressor rotor is larger than the inlet side sectional area (inlet sectional area). And the hub side portions of the leading and trailing edges of each blade are swept so as to retreat from the hub side toward the tip side (tip side) (see FIG. 3). In the case of the new compressor rotor shown in (a), when the hub side portions of the leading and trailing edges of each blade are not swept (in the case of the comparative compressor rotor shown in FIG. 3B) In comparison, as shown in FIGS. 4A, 4B, and 4C, the deceleration of the gas in the vicinity of the hub is suppressed, and the deceleration state of the gas is brought close to the uniform deceleration state over the entire span of the moving blade. As shown in FIGS. 5 (a) and 5 (b), near the exit of the moving blade That it is possible to reduce the large area of the energy loss, it is possible to obtain novel findings, the present invention has been completed.

  Here, FIG. 3A is a schematic side sectional view showing a new compressor rotor having characteristics relating to new knowledge, and FIG. 3B is a compressor for comparison with the new compressor rotor. 4A is a schematic side sectional view showing the rotor, and FIG. 4A shows the relationship between the flow coefficient near the leading edge of the moving blade and the span ratio of the moving blade for a new compressor rotor and a comparative compressor rotor. FIG. 4B is a diagram showing the relationship between the flow coefficient of the 50% code of the moving blade and the span ratio of the moving blade for the new compressor rotor and the comparative compressor rotor, and FIG. ) Shows the relationship between the flow coefficient near the trailing edge of the moving blade and the span ratio of the moving blade for the new compressor rotor and the comparative compressor rotor, and FIG. 5A shows the new compressor rotor. FIG. 5 (a schematic rear view showing a large energy loss region in the vicinity of the rotor blade exit for the rotor, ) Is a rear view showing a region of large energy loss in the vicinity of the rotor blade outlet for the compressor rotor for comparison, and these relations were obtained by three-dimensional steady viscosity CFD (Computational Fluid Dynamics) analysis. Is. Further, in the new compressor rotor shown in FIG. 3A, the radial position (the radial position) of the tip of each blade is the same from the leading edge to the trailing edge, and the trailing edge of the blade The hub side part of the blade is swept back from the hub side toward the tip side (tip side), and the sweep angle of the hub side part of the leading edge of the moving blade is the hub side part of the trailing edge of the moving blade Is the same as the sweep angle.

According to a first aspect of the present invention, there is provided an axial compressor that compresses and conveys gas in an axial direction, and that extends in the axial direction and has a cylindrical compressor case having an annular gas flow path formed therein. And a plurality of compressor stators provided in the compressor case along the axial direction, provided with a plurality of stationary blades disposed at equal intervals in the circumferential direction and located in the gas flow path, The compressor case is provided alternately with the compressor stator of a plurality of stages along the axial direction in the compressor case, and the outer peripheral surface constitutes a part of the radially inner wall surface of the gas flow path and rotates around the axis. And a plurality of compressor rotors provided with a plurality of moving blades provided at equal intervals on the outer peripheral surface of the disk and positioned in the gas flow path, Rotor outlet side cross section (outlet cross section) is inlet side cross section (inlet cross section) The front side and the rear end of each rotor blade in any one of the compressor rotors are swept (curved) so as to recede from the hub side toward the tip side. A portion (base end side portion) and a tip side portion that is continuous with the hub side portion and is all the tip side of the hub side portion and is perpendicular to the main flow direction. The gist.

  In addition, the said axial flow compressor is not restricted to the compressor used as a component apparatus of gas turbine engines, such as a jet engine.

  According to the first feature, the gas introduced into the gas flow path by rotating the plurality of stages of the compressor rotors so that the plurality of stages of the compressor rotors and the plurality of stages of the compressor stators cooperate with each other. Can be transported compressed in the axial direction.

  In addition, since the outlet side cross-sectional area of any one of the compressor rotors is configured to be larger than the inlet side cross-sectional area, the warp of the moving blade can be prevented while sufficiently ensuring the work of the moving blade. By reducing the pressure, the pressure difference between the pressure surface and the suction surface of the moving blade can be reduced.

And the outlet side cross-sectional area of any one of the compressor rotors is configured to be larger than the inlet-side cross-sectional area, and the hub side of the leading edge and the trailing edge of each rotor blade in any of the compressor rotors Since the part is swept so as to be retracted from the hub side toward the tip side, when the above-described novel knowledge is applied, the hub side part of the leading edge and the trailing edge of each blade is not swept (FIG. 3 ( Compared to the case of the comparative compressor rotor shown in b), the gas deceleration near the hub is suppressed to bring the gas deceleration state closer to the uniform deceleration state over the entire span of the blade. In addition, the region where the energy loss is large in the vicinity of the outlet of the moving blade can be reduced.

  The gist of the second feature of the present invention is that the gas turbine engine includes the axial flow compressor having the first feature.

  According to the feature of the second feature, the same effect as that of the first feature is achieved.

  According to the present invention, since the warpage of the moving blade can be reduced and the pressure difference between the pressure surface and the suction surface of the moving blade can be reduced, the pressure surface side of the moving blade from the pressure surface side to the suction surface side can be reduced. The operating range of the axial flow compressor can be expanded to the low flow rate side while reducing the clearance flow and suppressing the stall of the axial flow compressor.

  Further, since the gas deceleration state can be brought close to a uniform deceleration state over the entire span of the moving blade, the static pressure of the gas is sufficiently increased over the entire span of the moving blade, and the compression is performed. The pressure ratio of the machine rotor, in other words, the pressure ratio of the axial compressor can be increased.

  Furthermore, since the region of large energy loss in the vicinity of the outlet of the moving blade can be reduced, the efficiency of the compressor rotor, in other words, the efficiency of the axial compressor (compressor efficiency) can be increased. .

  Therefore, it is possible to achieve a high pressure ratio and high efficiency of the axial flow compressor while expanding the operating range of the axial flow compressor.

It is a typical sectional side view which shows the principal part of the axial flow compressor which concerns on embodiment of this invention. It is the typical figure which looked at a part of compressor rotor in the axial flow compressor concerning the embodiment of the present invention from the diameter direction outside. FIG. 3A is a schematic side sectional view showing a new compressor rotor having characteristics relating to new knowledge, and FIG. 3B shows a compressor rotor for comparison with the new compressor rotor. It is a typical sectional side view. FIG. 4A is a diagram showing the relationship between the flow coefficient near the leading edge of the moving blade and the span ratio of the moving blade for the new compressor rotor and the comparative compressor rotor, and FIG. FIG. 4 (c) shows the relationship between the flow rate coefficient of the 50% code of the moving blade and the span ratio of the moving blade for the new compressor rotor and the comparative compressor rotor. FIG. It is a figure which shows the relationship between the flow coefficient near the trailing edge of a moving blade, and the span ratio of a moving blade about the compressor rotor for high pressure. FIG. 5 (a) is a schematic rear view showing a large energy loss region in the vicinity of the rotor blade outlet for a new compressor rotor, and FIG. It is a rear view which shows the area | region where the energy loss is large near the exit of the wing. It is a figure which shows the relationship between a flow coefficient and a pressure ratio about the compressor rotor (new compressor rotor) which concerns on embodiment of this invention, and the compressor rotor for a comparison. It is a figure which shows the relationship between a flow coefficient and efficiency about the compressor rotor which concerns on embodiment of this invention, and the compressor rotor for a comparison. It is a figure which shows the relationship between the sweep angle of a moving blade, and an efficiency improvement coefficient about the compressor rotor which concerns on embodiment of this invention.

  An embodiment of the present invention will be described with reference to FIGS. In the figure, “F” indicates the forward direction (upstream direction), and “R” indicates the backward direction (downstream direction).

  As shown in FIGS. 1 and 2, an axial flow compressor 1 according to an embodiment of the present invention is used as a compressor that is a component device of a jet engine (an example of a gas turbine engine), and gas (implementation of the present invention). In the form, air is compressed in the axial direction (rearward direction) and conveyed. And the specific structure of the axial flow compressor 1 which concerns on embodiment of this invention is as follows.

  The axial flow compressor 1 includes a cylindrical compressor case 3 as a base, and the compressor case 3 extends in the axial direction (front-rear direction). An annular gas flow path 5 is formed inside the compressor case 3.

  In the compressor case 3, a plurality of stages (only two stages are shown in FIG. 1) of compressor stators 7 are provided along the axial direction. The compressor stator 7 at each stage includes a plurality of stationary blades 9 arranged (aligned) at equal intervals in the circumferential direction, and each stationary blade 9 is located in the gas flow path 5. Yes.

  In the compressor case 3, a plurality of stages of compressor rotors 11 (only one stage is shown in FIG. 1) are provided alternately with the plurality of stages of compressor stators 7 along the axial direction. The machine rotor 11 is integrally connected to a plurality of stages of turbine rotors (not shown) in a turbine (not shown) which is a component device of the jet engine. The compressor rotor 11 at each stage includes a disk 13 provided in the compressor case 3 so as to be rotatable around an axis, and the outer peripheral surface of the disk 13 is radially inward of the gas flow path 5. Part of the wall surface 5s. Further, a plurality of moving blades 15 are provided at equal intervals on the outer peripheral surface of the disk 13 in each stage of the compressor rotor 11, and each moving blade 15 is located in the gas flow path 5.

  Then, the principal part of embodiment of this invention is demonstrated.

  The outlet side cross-sectional area (outlet cross-sectional area) of any of the compressor rotors 11 (referred to as the compressor rotor 11 shown in the drawing and hereinafter simply referred to as the compressor rotor 11) is the inlet-side cross-sectional area (inlet cross-sectional area). ) Is configured to be larger than. The radial position (the radial position) of the tip 15t of each rotor blade 15 in the compressor rotor 11 is the same from the front edge 15a to the rear edge 15b. The radial position of the tip 15t of each rotor blade 15 in the compressor rotor 11 may change from the front edge 15a to the rear edge 15b.

  The front edge 15a of each rotor blade 15 in the compressor rotor 11 is swept (curved) so as to recede from the hub side toward the tip side (tip side) (in other words, to move downstream). It has a side portion (base end side portion) 15ah and a tip side portion (tip side portion) 15at which is continuous to the hub side portion 15ah and perpendicular to the main flow direction. The hub side portion 15ah is formed in a linear shape, but may be formed in a curved shape such as an arc shape or may be connected to the outer peripheral surface of the disk 13 with a fillet radius. Further, the entire chip side portion 15at is continuous to the hub side portion 15ah and is a vertical portion perpendicular to the main flow direction. However, a part of the chip side portion 15at is a vertical portion, and other than the chip side portion 15at. You may sweep so that the part of retreats.

  The sweep angle (curvature angle) α of the leading edge 15a of the moving blade 15 is preferably 4 to 38 degrees. The reason why the sweep angle α of the leading edge 15a of the moving blade 15 is set to 4 degrees or more is that when the sweep angle α of the leading edge 15a of the moving blade 15 is less than 4 degrees, as shown in FIG. This is because it has been found that the efficiency improvement coefficient cannot be increased by 10% or more. On the other hand, the sweep angle α of the leading edge 15a of the moving blade 15 is set to 38 degrees or less even if the sweep angle α of the leading edge 15a of the moving blade 15 exceeds 38 degrees, as shown in FIG. This is because it has been found that the efficiency improvement coefficient of the machine rotor 11 does not improve, and the stress concentration on the hub side of the rotor blade 15 only increases.

  Here, as described above, FIG. 8 is a diagram showing the relationship between the sweep angle α of the leading edge 15a of the moving blade 15 and the efficiency improvement coefficient for the compressor rotor 11 according to the embodiment of the present invention, This relationship is obtained by three-dimensional steady viscosity CFD analysis.

  The hub side portion 15bh of the trailing edge 15b of each rotor blade 15 in the compressor rotor 11 is swept so as to retreat from the hub side toward the tip side (tip side). The sweep angle β is the same as the sweep angle α of the leading edge 15 a of the rotor blade 15. In the compressor rotor 11, the tip side portion 15 bt of the trailing edge 15 b of each rotor blade 15 is also swept back, or the sweep angle β of the trailing edge 15 b of the rotor blade 15 is swept by the leading edge 15 a of the rotor blade 15. It may be different from the angle α. Further, the meridional surface shape (side cross-sectional shape) of the outer peripheral surface 13 of the disk in the compressor rotor 11 may transition from a convex first curve to a concave second curve in the downstream direction.

  Then, the effect | action and effect of embodiment of this invention are demonstrated.

  A turbine is driven by the expansion of combustion gas from a combustor (not shown) in a jet engine to rotate a multi-stage turbine rotor, whereby a multi-stage compressor rotor 11 is rotated integrally with the multi-stage turbine rotor. Let Thereby, the multistage compressor rotor 11 and the multistage compressor stator 7 can cooperate with each other, and the gas taken into the gas flow path 5 can be compressed and conveyed in the axial direction.

  In addition, since the compressor rotor 11 outlet side cross-sectional area is configured to be larger than the inlet side cross-sectional area, the warp of the rotor blade 15 can be reduced while ensuring sufficient work of the rotor blade 15, The pressure difference between the pressure surface 15p and the suction surface 15n of the blade 15 can be reduced.

The compressor rotor 11 is configured such that the outlet side cross-sectional area is larger than the inlet side cross-sectional area, and the hub side portion 15ah of the leading edge 15a of each rotor blade 15 and the hub side of the trailing edge 15b in the compressor rotor 11 are configured. since the portion 15bh is swept so as to retract toward the hub side to the tip side, applying novel finding described above, the hub portion 15ah and the front edge 15a of each blade 15 shown in FIG. 5 (b) Compared with the case where the hub side portion 15bh of the trailing edge 15b is not swept (in the case of the comparative compressor rotor shown in FIG. 3B), as shown in FIG. , The gas deceleration state can be brought close to a uniform deceleration state over the entire span of the rotor blade 15, and a large energy loss region in the vicinity of the outlet of the rotor blade 15 can be reduced. .

  Therefore, according to the embodiment of the present invention, the warp of the moving blade 15 can be reduced, and the pressure difference between the pressure surface 15p and the suction surface 15n of the moving blade 15 can be reduced. The clearance flow from the 15p side to the suction surface 15n side can be reduced, and the operating area of the axial compressor 1 can be expanded to the low flow rate side while the stall of the axial compressor 1 is suppressed.

  Further, since the deceleration state of the gas can be brought close to a uniform deceleration state over the entire span of the rotor blade 15, the static pressure of the gas is sufficiently increased over the entire span of the rotor blade 15, and FIG. As shown in FIG. 4, it has been found that the pressure ratio of the compressor rotor 11, in other words, the pressure ratio of the axial compressor 1 is increased.

  Furthermore, since the region where the energy loss is large in the vicinity of the outlet of the moving blade 15 can be reduced, the efficiency of the compressor rotor 11, in other words, the efficiency of the axial compressor 1 (compressor) as shown in FIG. It has been found that efficiency) can be increased. In particular, since the sweep angle α of the leading edge 15a of the moving blade 15 is 4 to 38 degrees, the efficiency of the compressor rotor 11 can be sufficiently increased.

  Therefore, according to the embodiment of the present invention, it is possible to achieve a high pressure ratio and high efficiency of the axial compressor 1 while expanding the operating range of the axial compressor 1.

  Here, as described above, FIG. 6 shows the compressor rotor (the new compressor rotor shown in FIG. 3A) 11 and the comparative compressor rotor (the comparison shown in FIG. 3) according to the embodiment of the present invention. FIG. 7 is a diagram showing a relationship between a flow coefficient and a pressure ratio for a compressor rotor for use in the present invention, and FIG. These relationships are obtained by three-dimensional steady viscosity CFD analysis. The examples in FIGS. 6 and 7 are analysis results for the compressor rotor 11 according to the embodiment of the present invention, and the comparative examples in FIGS. 6 and 7 are for the compressor rotor for comparison. This is the analysis result.

  The present invention is not limited to the description of the above-described embodiment, but can be applied in various modes, such as applying the axial flow compressor 1 used as a component device of a gas turbine engine to other axial flow compressors. It can be implemented. The scope of rights encompassed by the present invention extends not only to the axial flow compressor 1 but also to a gas turbine engine equipped with the axial flow compressor 1.

α Sweep angle of leading edge of rotor blade β Sweep angle of trailing edge of rotor blade 1 Axial compressor 3 Compressor case 5 Gas flow path 5s Wall surface 7 Compressor stator 9 Stator blade 11 Compressor rotor 13 Disc 15 Rotating blade 15p Positive pressure surface 15n Negative pressure surface 15a Front edge 15ah Front edge hub side portion 15at Front edge tip side portion 15b Rear edge 15bh Rear edge hub side portion 15bt Rear edge tip side portion 15t Tip

Claims (5)

In an axial compressor that compresses and transports gas in the axial direction,
A cylindrical compressor case that extends in the axial direction and has an annular gas passage formed inside;
A plurality of compressor stators provided in the compressor case along the axial direction and provided with a plurality of stationary blades disposed at equal intervals in the circumferential direction and located in the gas flow path;
The compressor case is provided alternately with the compressor stator of a plurality of stages along the axial direction in the compressor case, and the outer peripheral surface constitutes a part of the radially inner wall surface of the gas flow path and rotates around the axis. And a plurality of compressor rotors provided with a plurality of rotor blades provided at equal intervals on the outer peripheral surface of the disk and positioned in the gas flow path,
The outlet side cross-sectional area of any of the compressor rotors is configured to be larger than the inlet side cross-sectional area,
A leading edge and a trailing edge of each rotor blade in any one of the compressor rotors are continuous with the hub side portion sweeping so as to recede from the hub side toward the tip side, and the hub side portion and An axial flow compressor comprising: a tip side portion that is all of the tip side of the hub side portion and is perpendicular to the main flow direction.   2. The axial flow compressor according to claim 1, wherein a radial position of a tip of each rotor blade in any one of the compressor rotors is the same from a leading edge to a trailing edge.   The axial flow compressor according to claim 1 or 2, wherein a sweep angle of a leading edge of the moving blade in any one of the compressor rotors is 4 to 38 degrees.   The sweep angle of the trailing edge of the moving blade in any one of the compressor rotors is the same as the sweep angle of the leading edge of the moving blade. An axial flow compressor given in any 1 paragraph. Gas turbine engine characterized by comprising the axial compressor according to any one of claims 1 to 4.

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