Fluid machinery

Abstract

To provide a fluid machine which suppresses lowering of water turbine efficiency.SOLUTION: At an axial flow runner (30) provided at a fluid machine, a vane part (50) is provided which includes a front edge part (50a) positioned on the front side of the rotation direction of a rotary shaft (40), a rear edge part (50b) positioned at the back of the rotation direction of the rotary shaft (40), and an outer edge part (50c) along an inner peripheral surface of a cylindrical part (21). A first end part (51a) which is an end part inside the radial direction of the front edge part (50a) is positioned further on the upstream side in the flow direction of a fluid than a second end part (51b) inside the radial direction of the rear edge part (50b). At the vane part (50), a curved part (80) is formed which curves in such a manner that at least part of the outer edge part (50c) goes toward the opposite direction from the flow direction of the fluid.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a fluid machine.

Background Art

[0002] The axial flow hydraulic machine disclosed in Patent Document 1 has a runner vane formed for the purpose of suppressing an increase in the amount of fluid leaking from the gap between the tip end of the runner vane and the discharge ring and suppressing the occurrence of cavitation. Thereby, the flow velocity distribution of the fluid at the outlet of the runner vane is optimized to improve the performance of the waterwheel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even with the shape of the runner vane disclosed in Patent Document 1, when the runner rotates, the fluid is deflected and flows toward the outer peripheral side of the blade due to centrifugal force, so it cannot be said that the leakage of the fluid in the gap between the tip end of the runner vane and the discharge ring is sufficiently suppressed. Therefore, there is room for considering the shape of the runner vane for suppressing a decrease in waterwheel efficiency.

[0005] An object of the present disclosure is to provide a fluid machine that suppresses a decrease in waterwheel efficiency.

Means for Solving the Problems

[0006] The first aspect is a fluid machine including a cylindrical cylinder portion (21) and an axial flow runner (30) disposed in the cylinder portion (21), wherein fluid in the cylinder portion (21) flows to the axial flow runner (30), the axial flow runner (30) is The rotating shaft (40) extends in the direction of the cylindrical axis of the cylindrical portion (21), The rotating shaft (40) has a plurality of wing portions (50) that extend radially outward from the outer circumferential surface of the cylindrical portion (21) and are arranged in the circumferential direction of the rotating shaft. The wing portion (50) is The leading edge portion (50a) located in the forward direction of rotation of the rotation axis (40), The trailing edge portion (50b) located behind the rotational axis (40) in the direction of rotation, The cylindrical portion (21) has an outer edge portion (50c) that is along the inner circumferential surface, The first end (51a), which is the radially inward end of the leading edge (50a), is located upstream in the fluid flow direction of the second end (51b), which is the radially inward end of the trailing edge (50b). The blade portion (50) has a curved portion (80) formed such that at least a part of the outer edge portion (50c) curves in the direction opposite to the direction of fluid flow. It is a fluid machine.

[0007] In the first embodiment, the formation of a curved portion (80) in the blade portion (50) reduces the influence of the centrifugal force of the fluid flowing inside the cylindrical portion (21) on the flow direction. As a result, meandering of the fluid flow on the blade surface is suppressed, and leakage of fluid from the gap between the outer edge portion (50c) of the blade portion (50) and the inner surface of the cylindrical portion (21) is suppressed, thereby suppressing a decrease in turbine efficiency.

[0008] A second aspect is, in the first aspect, When viewing the cross-section of the axial flow runner (30) passing through the axis of the rotation shaft (40) from the front in the direction of rotation, The curved portion (80) includes a third end (E1), which is the radially outer end of the wing portion (50). The straight line passing through the third end (E1) and the fourth end (E2), which is the radially inward end of the blade portion (50), extends from the fourth end (E2) to the third end (E1) toward the upstream side in the flow direction.

[0009] In the second embodiment, the same effect as in the first embodiment can be improved by inclining the straight line connecting the third end (E1) and the fourth end (E2) of the blade (50) upstream with respect to the direction of fluid flow.

[0010] A third aspect is, in the second aspect, Viewed from the axial direction of the aforementioned rotating shaft (40), Let θ be the angle between a first straight line extending from the axis of the rotation axis (40) to the first end (51a) of the leading edge (50a) and a second straight line obtained by rotating the first straight line in the counter-rotational direction of the rotation axis (40) around the axis of the rotation axis (40). When viewing the cross-section passing through the axis of the rotation shaft (40) from the front in the direction of rotation, and defining the first angle as the angle formed by the straight line passing through the first end (51a) and the second end (51b) and the tangent line at the third end (E1), In the range where θ is zero or greater, the first angle decreases as θ increases.

[0011] In a third embodiment, the same effect as in the first embodiment can be improved by designing the system so that the distribution of the first angle decreases as θ increases in the range where θ is greater than or equal to zero.

[0012] A fourth aspect is, in the third aspect, When θ is zero, the first angle is 10° or more and 30° or less.

[0013] In the fourth embodiment, the same effect as in the first embodiment can be improved by designing the first angle to be 10° or more and 30° or less when θ is zero.

[0014] A fifth aspect is a third or fourth aspect, When the cross section of the axial flow runner (30) passing through the axis of the rotation axis (40) is viewed from the front in the direction of rotation, the second angle is defined as the angle between the straight line passing through the third end (E1) and the fourth end (E2) and the straight line extending from the fourth end (E2) in a direction perpendicular to the longitudinal direction of the rotation axis (40), In the range where the said θ is zero or more, the said second angle decreases as the said θ increases.

[0015] The fifth aspect is that in the range where θ is zero or more, by designing so that the distribution of the second angle decreases as θ increases, the effect similar to the first aspect can be improved.

[0016] The sixth aspect is in the fifth aspect, when the said θ is zero, the said second angle is 5° or more.

[0017] In the sixth aspect, by designing the second angle to be 5° or more when θ is zero, the effect similar to the first aspect can be improved.

[0018] The seventh aspect is in any one of the first to sixth aspects, the said cylindrical portion (21) is formed from the upstream end to the downstream end in the said flow direction of the said wing portion (50).

[0019] In the seventh aspect, it is possible to suppress an increase in the amount of fluid leakage between the inner surface of the cylindrical portion (21) and the outer edge portion (50c) of the wing portion (50) from the upstream end to the downstream end of the cylindrical portion (21).

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of the hydraulic power generation device of the present embodiment. [Figure 2] FIG. 2 is a view of the axial flow hydraulic machine seen from above. The figure within the dashed line frame is an enlarged view of a part of the axial flow hydraulic machine. [Figure 3] FIG. 3 is a view of the axial flow runner seen from the front. [Figure 4] FIG. 4 is a view when a cross-section passing through the axis of the axial flow runner is seen from the front in the rotational direction. [Figure 5] FIG. 5 is a graph showing the relationship between θ and the first angle in the axial flow runner. [Figure 6]Figure 6 is a graph showing the relationship between θ and the second angle in an axial flow runner. [Figure 7A] Figure 7A shows the fluid flow on the wing surface of an airfoil with a curved section. [Figure 7B] Figure 7B shows the fluid flow on the wing surface of an wing section without a curved surface. [Figure 8] Figure 8 is a graph showing the relationship between the first angle and turbine efficiency in an axial flow runner. [Figure 9] Figure 9 is a graph showing the relationship between the second angle and turbine efficiency in an axial flow runner. [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, the embodiments, modifications, and other examples described below can be combined or partially replaced to the extent that the present invention is implementable.

[0022] (1) Hydroelectric power generation equipment As shown in Figure 1, the fluid machine (10) of this embodiment is applied to a hydroelectric power generation device (1). The hydroelectric power generation device (1) recovers the head energy of the fluid water as electricity. The hydroelectric power generation device (1) has an axial flow hydraulic machine (10) and a generator (100).

[0023] The axial flow hydraulic machine (10) is an example of a fluid machine (10). The axial flow hydraulic machine (10) is placed in the middle of a flow path (4) through which water, which is a fluid, flows. The flow path (4) can be any flow path through which water flows, and may be, for example, a water supply pipeline that forms between a water tank and a water supply target such as a house or building. The axial flow hydraulic machine (10) converts the energy of water into rotational energy. The axial flow hydraulic machine (10) rotates due to the action of water flowing through the flow path.

[0024] The generator (100) is positioned above the axial-flow hydraulic machine (10). The generator (100) is driven by the axial-flow hydraulic machine (10). The generator (100) is connected to the axial-flow hydraulic machine (10) by a drive shaft (11) that extends vertically. The drive shaft is fixed to the rotation shaft (40) of the axial-flow hydraulic machine (10), which will be described later. As the axial-flow hydraulic machine (10) rotates, the drive shaft rotates. The generator (100) generates electricity using the rotational energy from the rotation of the drive shaft. The electricity generated by the generator (100) is supplied to a predetermined power grid.

[0025] (2) Axial flow hydraulic machinery As shown in Figures 1 to 3, the axial flow hydraulic machine (10) comprises a casing (20) and an axial flow runner (30).

[0026] (2-1) Casing The casing (20) is installed in the middle of the water flow path. The casing (20) has an inlet (not shown) through which water flows from the flow path toward the axial flow runner (30), and an outlet (not shown) through which water that has passed through the axial flow runner (30) flows back into the flow path.

[0027] The casing (20) has a cylindrical section (21). The axial direction of the section (21) is vertical. Water flowing into the casing (20) flows from top to bottom within the section (21). Hereinafter, the direction from top to bottom within the section (21) may be simply referred to as the direction of water flow. Also, the radial direction of the section (21) may be simply referred to as the radial direction. Note that the radial direction is not limited to the direction perpendicular to the axial direction, but may also include directions inclined with respect to the axial direction.

[0028] (2-2) Axial flow runner The axial flow runner (30) is positioned within the cylindrical portion (21). The axial flow runner (30) has a rotating shaft (40) extending in the direction of the cylindrical axis of the cylindrical portion (21), and a plurality of blade portions (50) provided on the outer circumferential surface of the rotating shaft (40). In this embodiment, the axial flow runner (30) has five blade portions (50).

[0029] The rotating shaft (40) extends vertically. The axis of the rotating shaft (40) coincides with the axis of the cylindrical portion (21). The rotating shaft (40) is connected to the generator (100) via a drive shaft. The rotating shaft (40) rotates as the flowing water inside the cylindrical portion (21) acts on the blade portion (50). The rotation of the rotating shaft (40) causes the drive shaft to rotate. The rotating shaft (40) has a boss portion (41) to which the blade portion (50) is connected. The boss portion (41) is formed in a cylindrical shape. Hereinafter, the axial direction of the rotating shaft (40) may be simply referred to as the axial direction, and the direction of rotation of the rotating shaft may be simply referred to as the direction of rotation. In this embodiment, the direction of rotation is counterclockwise in Figure 2.

[0030] The wing sections (50) extend radially outward from the outer surface of the rotation axis (40) toward the cylindrical section (21). Specifically, the wing sections (50) are connected to the outer surface of the boss section (41). The five wing sections (50) are arranged in the circumferential direction of the rotation axis (40). The five wing sections (50) are arranged so as not to overlap when viewed from the axial direction of the rotation axis (40).

[0031] The wing portion (50) has a leading edge portion (50a), a trailing edge portion (50b), and an outer edge portion (50c). The leading edge portion (50a) is located in front of the rotational direction of the rotation axis (40). The trailing edge portion (50b) is located behind the rotational direction of the rotation axis (40). The outer edge portion (50c) forms an edge along the inner circumferential surface of the cylindrical portion (21). The outer edge portion (50c) connects the radially outward ends of the leading edge portion (50a) and the trailing edge portion (50b).

[0032] (3) Detailed structure of the wing The wing portion (50) has a base portion (51) and a feather portion (52).

[0033] The base (51) is formed on the boss (41). The vane portion (52) is fixed to the boss (41) via the base (51). The base (51) constitutes the wing root of the wing portion (50). The wing root may also refer to the connection portion between the base (51) and the boss (41) (the dashed line portion in Figure 4).

[0034] As shown in Figure 3, when the axial flow runner (30) is viewed from the front, the base (51) is formed as a projection that extends vertically above the boss (41). Specifically, the base (51) extends inclined with respect to the direction of water flow. More specifically, the first end (51a), which is the end of the base (51), is located forward in the rotational direction of the rotation axis (40) and above the second end (51b), which is the other end of the base (51). In other words, the first end (51a) is located upstream in the direction of water flow than the second end (51b).

[0035] The first end (51a) is the radially inward end of the leading edge (50a) of the wing portion (50). The first end (51a) may be part or all of the leading edge portion located forward in the rotational direction of the base (51). The first end (51a) may be the radially inward end or the radially outward end of the leading edge portion located forward in the rotational direction of the base (51).

[0036] The second end (51b) is the radially inward end of the trailing edge (50b) of the wing portion (50). The second end (51b) may be part or all of the trailing edge portion located forward of the base (51) in the rotational direction. The second end (51b) may be the radially inward end or the radially outward end of the trailing edge portion located forward of the base (51) in the rotational direction.

[0037] As shown in Figures 2 to 4, the vane portion (52) is connected to the base portion (51). The vane portion (52) is fixed to the boss portion (41) via the base portion (51). The vane portion (52) extends radially outward from the base portion (51). The vane portion (52) has a leading edge portion (52a) located in front of the rotational direction of the rotation axis (40) and a trailing edge portion (52b) located behind it. The vane portion (52) has an outer edge portion formed to connect the radially outward ends of the leading edge portion (52a) and the trailing edge portion (52b) of the vane portion (52). The outer edge portion of the vane portion (52) is the same as the outer edge portion (50c) of the wing portion (50).

[0038] The first end (51a) of the base (51) and the leading edge portion (52a) of the vane portion (52), located in front of the rotational direction of the rotation axis (40), constitute the leading edge portion (50a) of the wing portion (50). The second end (51b) of the base (51) and the trailing edge portion (52b) of the vane portion (52), located behind the rotational direction of the rotation axis (40), constitute the trailing edge portion (50b) of the wing portion (50). The outer edge portion (50c) of the wing portion (50) constitutes the wingtip of the wing portion (50).

[0039] As shown in Figure 2, when viewed from the direction of the rotation axis (40), the leading edge portion (52a) of the vane (52) curves so as to bulge forward in the direction of rotation. Specifically, the leading edge portion (52a) of the vane (52) curves forward in the direction of rotation from the base (51) to a predetermined position P1 radially outward, and then curves backward in the direction of rotation from the predetermined position P1 to the outer edge portion (50c). The predetermined position P1 is located closer to the wingtip than the wing root in the leading edge portion (52a) of the vane (52). In other words, the predetermined position P1 is located closer to the outer edge portion (50c) than the base (51) in the leading edge portion (50a) of the wing portion (50).

[0040] Viewed from the direction of the axis of rotation (40), the trailing edge portion (52b) of the vane (52) curves so as to bulge outward in the direction of rotation. Specifically, the trailing edge portion (52b) of the vane (52) curves outward radially from the base to a predetermined position P2, and then curves forward in the direction of rotation from the predetermined position P2 to the outer edge portion (50c). The predetermined position P2 is formed in the trailing edge portion (52b) of the vane (52) at the center between the base and the tip, or closer to the tip. In other words, the predetermined position P2 is formed in the trailing edge portion (50b) of the wing (50) at the center between the base (51) and the outer edge portion (50c), or closer to the outer edge portion (50c).

[0041] As shown in Figure 3, when the axial flow runner (30) is viewed from the front, the outer edge (50c) of the blade (50) is inclined with respect to the direction of water flow (vertical direction). Specifically, at the outer edge (50c), the front end in the direction of rotation is located upstream (above) in the direction of water flow than the rear end in the direction of rotation. Also, when the axial flow runner (30) is viewed from the front, the degree of inclination of the outer edge (50c) of the blade with respect to the vertical direction (direction of water flow) is greater than the degree of inclination of the base (51) with respect to the vertical direction (direction of water flow).

[0042] As shown in Figure 3, the wing portion (50) has a curved portion (80) formed on it, where the outer edge portion (50c) curves in the direction opposite to the direction of water flow. The curved portion (80) is formed to bend smoothly. The curved portion (80) will be described below.

[0043] The radially outward end of the wing section (50) is defined as the third end (E1). The third end (E1) is part of the outer edge (50c) of the wing section (50). Because the vane section (52) is thick, the third end (E1) is midway between the upper end (H1) and lower end (L1) in the thickness direction of the outer edge (50c) of the wing section (50). The radially inward end of the wing section (50) is defined as the fourth end (E2). The fourth end (E2) is the connection point between the base (51) and the boss section (41). The fourth end (E2) is midway between the upper end (H1) and lower end (L2) of the base (51).

[0044] The curved section (80) includes the third end (E1). The curved section (80) is formed such that a straight line D1 passing through the third end (E1) and the fourth end (E2) extends upstream (upward) in the flow direction from the fourth end (E2) to the third end (E1).

[0045] Let me explain the shape of the curved portion (80) in more detail.

[0046] As shown in Figure 2, when viewed from the axial direction of the rotation axis (40), the straight line K1 is defined as the straight line extending from the axis of the rotation axis (40) to the first end (51a) at the leading edge (50a) of the wing portion (50). The straight line K2 is defined as the straight line passing through the axis of the rotation axis (40) and located in the counter-rotation direction of the rotation axis relative to the first straight line K1. Let θ be the angle between the first straight line K1 and the second straight line K2 in the counter-rotation direction of the rotation axis. In this embodiment, the first straight line K1 passes through the point at the rearmost position in the rotation direction of the first end (51a). In other words, the first straight line K1 passes through the point at the rearmost position in the rotation direction of the leading edge (50a).

[0047] As shown in Figure 4, the first angle α is defined as the angle between the straight line D1 passing through the third end (E1) and the fourth end (E2) and the tangent line D2 at the third end (E1). The tangent line D2 is the tangent at the third end (E1) to the line D4 drawn from the base to the tip of the wing, passing through the middle of the thickness direction of the wing section (50), as shown by the dashed line in Figure 4. In other words, the tangent line D2 is a straight line drawn radially outward so as to connect smoothly with line D4 at the third end (E1). The second angle β is defined as the angle between the straight line D1 passing through the third end (E1) and the fourth end (E2) and the straight line D3 extending from the fourth end (E2) in a direction perpendicular to the longitudinal direction of the axis of rotation (40).

[0048] As shown in Figure 5, the wing section (50) was formed such that the first angle α decreases as θ increases in the range where θ is greater than or equal to zero. Specifically, when θ is zero, the first angle α was set to be between 10° and 30°.

[0049] As shown in Figure 6, the wing section (50) was formed such that the second angle β decreases as θ increases in the range where θ is greater than or equal to zero. Specifically, when θ is zero, the second angle β was set to 5° or more.

[0050] Figure 7A shows the water flow on the wing surface of the wing portion (50) without the curved portion (80) of this embodiment, indicated by white lines. As shown within the dashed lines in Figure 7A, it can be seen that near the outer edge (50c) of the wing portion (50), the water flows more radially than circumferentially (indicated by the arrows in Figure 7A). In other words, the water is flowing in a directional direction.

[0051] Figure 7B shows the water flow on the wing surface of the wing section (50) having the curved section (80) of this embodiment, indicated by white lines. As shown within the dashed lines in Figure 7B, it can be seen that near the outer edge (50c) of the wing section (50), the water flows more in the circumferential direction than in the radial direction (indicated by the arrows in Figure 7B). In other words, it is shown that water drift is suppressed compared to the wing section (50) without the curved section (80).

[0052] (4) Features (4-1) Feature 1 In this embodiment, the blade portion (50) of the axial flow hydraulic machine (10) has a curved portion (80) formed on it such that at least a part of the outer edge portion (50c) is curved in the direction opposite to the direction of water flow.

[0053] By forming a curved section (80) on the blade section (50), the influence of the centrifugal force of the fluid flowing inside the cylindrical section (21) on the flow direction can be reduced. As a result, meandering of the fluid flow on the blade surface is suppressed, and leakage of fluid from the gap between the outer edge (50c) of the blade section (50) and the inner surface of the cylindrical section (21) can be suppressed, thereby suppressing a decrease in turbine efficiency.

[0054] (4-2) Feature 2 In the axial flow hydraulic machine (10) of this embodiment, when viewing the cross-section of the axial flow runner (30) passing through the axis of the rotating shaft (40) from the front in the direction of rotation, the curved portion (80) includes the third end (E1), which is the radially outer end of the blade portion (50), and the straight line passing through the third end (E1) and the fourth end (E2), which is the radially inner end of the blade portion (50), extends from the fourth end (E2) to the third end (E1) toward the upstream side in the direction of water flow.

[0055] By forming a curved section (80) such that the straight line connecting the third end (E1) and the fourth end (E2) of the blade section (50) is inclined upstream with respect to the direction of fluid flow, leakage of fluid from the gap between the outer edge (50c) of the blade section (50) and the inner surface of the cylindrical section (21) can be suppressed, thereby suppressing a decrease in turbine efficiency.

[0056] (4-3) Feature 3 In the axial-flow hydraulic machine (10) of this embodiment, when viewed from the axial direction of the rotating shaft (40), the first straight line K1 extending from the axis of the rotating shaft (40) to the first end (51a) of the leading edge (50a) is defined as the angle θ between the first straight line K1 and the second straight line K2 obtained when the first straight line K1 is rotated in the counter-rotational direction of the rotating shaft (40) around the axis. When viewed from the front in the rotational direction of the cross section passing through the axis of the rotating shaft (40), the first angle α is defined as the angle between the straight line D1 passing through the first end (51a) and the second end (51b) and the tangent line at the third end (E1). In the range where θ is zero or greater, the first angle α decreases as θ increases.

[0057] In this way, by designing the shape of the blade (50) such that the first angle α decreases as θ increases in the range where θ is greater than or equal to zero, it is possible to suppress fluid leakage from the gap between the outer edge (50c) of the blade (50) and the inner surface of the cylinder (21), thereby suppressing a decrease in turbine efficiency.

[0058] (4-4) Feature 4 In this embodiment, when θ is zero, the first angle α is 10° or more and 30° or less.

[0059] As shown in Figure 8, it was found that the turbine efficiency exceeds 71% by designing the first angle α to be between 10° and 30° when θ is zero. Thus, it was demonstrated that the blade section (50) of this embodiment can suppress the decrease in turbine efficiency. Turbine efficiency is determined based on the kinetic energy generated in the turbine shaft and the energy of the flowing water. For example, turbine efficiency can be determined based on output / (gravitational acceleration × head × flow rate). Output is the load.

[0060] (4-5) Feature 5 In this embodiment, when viewing a cross-section of the axial flow runner (30) passing through the axis of the rotation axis (40) from the front in the direction of rotation, the second angle β is defined as the angle between a straight line D1 passing through the third end (E1) and the fourth end (E2) and a straight line D3 extending from the fourth end (E2) in a direction perpendicular to the longitudinal direction of the rotation axis (40). In the range where θ is zero or greater, the second angle β decreases as θ increases.

[0061] By designing the shape of the blade (50) such that the second angle β decreases as θ increases in the range where θ is greater than or equal to zero, it is possible to suppress fluid leakage from the gap between the outer edge (50c) of the blade (50) and the inner surface of the cylinder (21), thereby suppressing a decrease in turbine efficiency.

[0062] (4-6) Feature 6 In this embodiment, when θ is zero, the second angle β is 5° or greater.

[0063] As shown in Figure 9, it was found that the turbine efficiency exceeds 70% by designing the second angle β to be 5° or more when θ is zero. Thus, it was demonstrated that the blade section (50) of this embodiment can suppress the decrease in turbine efficiency.

[0064] (4-7) Feature 7 In this embodiment, the cylindrical portion (21) is formed from the upstream end to the downstream end of the blade portion (50) in the flow direction. This makes it possible to suppress an increase in the amount of fluid leakage between the inner surface of the cylindrical portion (21) and the outer edge portion (50c) of the blade portion (50) from the upstream end to the downstream end of the cylindrical portion (21).

[0065] (5) Other embodiments The above embodiment may also have the following configuration.

[0066] The curved portion (80) does not have to be formed over the entire outer edge portion (50c) of the wing portion (50), but may be formed only in a part of it.

[0067] The curved portion (80) only needs to be curved such that its outer edge (50c) is curved in the direction opposite to the direction of water flow, and the wing portion (50) does not need to be formed such that the straight line D1 extends from the fourth end (E2) to the third end (E1) toward the upstream side in the direction of water flow.

[0068] The wing section (50) is formed such that a straight line D1 extends from the fourth end (E2) to the third end (E1) toward the upstream side in the direction of water flow, and the first angle α does not have to decrease as θ increases in the range where θ is greater than or equal to zero. The first angle α may increase as θ increases in the range where θ is greater than or equal to zero.

[0069] If the first angle α is 10° or greater and 30° or less, the range of the second angle β does not need to be limited. Also, if the second angle β is 10° or greater and 30° or less, the range of the first angle α does not need to be limited.

[0070] The wing portion (50) does not necessarily have a base portion (51). A member corresponding to the vane portion (52) may be connected to the boss portion (41) or the rotating shaft (40).

[0071] The first straight line K1 only needs to pass through the axis of rotation (40) and the first end (51a) of the base (51). In other words, the first straight line K1 only needs to pass through the leading edge portion of the base (51) in the direction of rotation.

[0072] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, these embodiments and modifications may be combined or substituted as appropriate, as long as they do not impair the functions of the subject matter of this disclosure. The terms “First,” “Second,” etc., used above are used to distinguish the phrases to which these terms are attached, and do not limit the number or order of such phrases. [Industrial applicability]

[0073] As explained above, this disclosure is useful for fluid machinery. [Explanation of Symbols]

[0074] 10 Fluid machinery (axial flow hydraulic machinery) 21 Cylinder part 30 Axial flow runner 40 Rotation axis 50 Wings 50a Leading edge 50b Trailing edge 50c outer edge 51a First end 51b Second end 80 Curved section E1 3rd end E2 4th end

Claims

1. A fluid machine comprising a cylindrical section (21) and an axial flow runner (30) disposed within the cylindrical section (21), wherein the fluid in the cylindrical section (21) flows to the axial flow runner (30), The aforementioned axial flow runner (30) The rotating shaft (40) extends in the direction of the cylindrical axis of the cylindrical portion (21), The rotating shaft (40) has a plurality of wing portions (50) that extend radially outward from the outer circumferential surface of the cylindrical portion (21) and are arranged in the circumferential direction of the rotating shaft. The wing portion (50) is The leading edge portion (50a) located in front of the rotational direction of the rotational shaft (40), The trailing edge portion (50b) located behind the rotational axis (40) in the direction of rotation, The cylindrical portion (21) has an outer edge portion (50c) that is along the inner circumferential surface, The first end (51a), which is the radially inward end of the leading edge (50a), is located upstream in the fluid flow direction of the second end (51b), which is the radially inward end of the trailing edge (50b). The wing portion (50) has a curved portion (80) formed on the trailing edge (50b) side of the leading edge (50a) such that at least a part of the outer edge (50c) curves in the direction opposite to the direction of fluid flow. Fluid machinery.

2. When the first straight line is defined as the straight line extending from the axis of the rotation axis (40) and passing through the point on the leading edge portion (50a) that is located furthest back in the direction of rotation, The curved portion (80) is formed at the position through which the first straight line passes. The fluid machine according to claim 1.

3. A fluid machine comprising a cylindrical tube (21) and an axial flow runner (30) disposed within the cylindrical tube (21), wherein the fluid in the cylindrical tube (21) flows to the axial flow runner (30), The aforementioned axial flow runner (30) The rotating shaft (40) extends in the direction of the cylindrical axis of the cylindrical portion (21), The rotating shaft (40) has a plurality of wing portions (50) that extend radially outward from the outer circumferential surface of the cylindrical portion (21) and are arranged in the circumferential direction of the rotating shaft. The wing portion (50) is The leading edge portion (50a) located in front of the rotational direction of the rotational shaft (40), The trailing edge portion (50b) located behind the rotational axis (40) in the direction of rotation, The cylindrical portion (21) has an outer edge portion (50c) that is along the inner circumferential surface, The first end (51a), which is the radially inward end of the leading edge (50a), is located upstream in the fluid flow direction of the second end (51b), which is the radially inward end of the trailing edge (50b). The blade portion (50) has a curved portion (80) formed therein, in which at least a part of the outer edge portion (50c) is curved in the direction opposite to the direction of fluid flow. When viewing the cross-section of the axial flow runner (30) passing through the axis of the rotation shaft (40) from the front in the direction of rotation, The curved portion (80) includes a third end (E1), which is the radially outward end of the wing portion (50). The straight line passing through the third end (E1) and the fourth end (E2), which is the radially inward end of the blade portion (50), extends from the fourth end (E2) to the third end (E1) toward the upstream side in the flow direction. Fluid machinery.

4. A fluid machine comprising a cylindrical tube (21) and an axial flow runner (30) disposed within the cylindrical tube (21), wherein the fluid in the cylindrical tube (21) flows to the axial flow runner (30), The aforementioned axial flow runner (30) The rotating shaft (40) extends in the direction of the cylindrical axis of the cylindrical portion (21), The rotating shaft (40) has a plurality of wing portions (50) that extend radially outward from the outer circumferential surface of the cylindrical portion (21) and are arranged in the circumferential direction of the rotating shaft. The wing portion (50) is The leading edge portion (50a) located in front of the rotational direction of the rotational shaft (40), The trailing edge portion (50b) located behind the rotational axis (40) in the direction of rotation, The cylindrical portion (21) has an outer edge portion (50c) that is along the inner circumferential surface, The first end (51a), which is the radially inward end of the leading edge (50a), is located upstream in the fluid flow direction of the second end (51b), which is the radially inward end of the trailing edge (50b). The blade portion (50) has a curved portion (80) formed therein, in which at least a part of the outer edge portion (50c) is curved in the direction opposite to the direction of fluid flow. When viewing the cross-section of the axial flow runner (30) passing through the axis of the rotation shaft (40) from the front in the direction of rotation, The curved portion (80) includes a third end (E1), which is the radially outward end of the wing portion (50). The straight line passing through the third end (E1) and the fourth end (E2), which is the radially inward end of the blade portion (50), extends from the fourth end (E2) to the third end (E1) toward the upstream side in the flow direction. Viewed from the axial direction of the aforementioned rotating shaft (40), Let θ be the angle between a first straight line extending from the axis of the rotation axis (40) to the first end (51a) of the leading edge (50a) and a second straight line obtained by rotating the first straight line in the counter-rotational direction of the rotation axis (40) about the axis of the rotation axis (40). When viewing the cross-section passing through the axis of the rotation shaft (40) from the front in the direction of rotation, and defining the first angle as the angle formed by the straight line passing through the first end (51a) and the second end (51b) and the tangent line at the third end (E1), In the range where θ is zero or greater, the first angle decreases as θ increases. Fluid machinery.

5. When θ is zero, the first angle is 10° or more and 30° or less. The fluid machine according to claim 4.

6. When the cross section of the axial flow runner (30) passing through the axis is viewed from the front in the direction of rotation, the second angle is defined as the angle between the straight line passing through the third end (E1) and the fourth end (E2) and the straight line extending from the fourth end (E2) in a direction perpendicular to the longitudinal direction of the rotation axis (40), In the range where θ is zero or greater, the second angle decreases as θ increases. The fluid machine according to claim 4 or 5.

7. When θ is zero, the second angle is 5° or greater. The fluid machine according to claim 6.

8. The cylindrical portion (21) is formed from the upstream end to the downstream end of the wing portion (50) in the flow direction. A fluid machine according to any one of claims 1 to 4.

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