Flow guide and bent duct

Abstract

This flow guide is disposed in a bent flow-path part bent to connect an outlet larger than an inlet in terms of flow path cross-sectional area. The flow guide comprises a plurality of guide parts that are disposed in the bent flow-path part and that guide the flowing direction of a fluid flowing through the bent flow-path part such that the flowing direction bends from a first direction to a second direction. The plurality of guide parts are disposed to be separated from each other in the flowing direction. The plurality of guide parts each have guide paths that are disposed to be separated from each other side by side in an intersecting direction intersecting the flowing direction, and that extend to intersect the first direction. In two of the guide paths adjacent in the second direction, a guide flow path formed in a guide part closer to the outlet has a greater inclined angle with respect to the first direction.

Description

Flow guides and bent ducts

[0001] This application claims priority to Japanese Patent Application No. 2024-111014, filed on July 10, 2024, the contents of which are incorporated herein by reference.

[0002] Flow paths through which fluids such as air and water flow often have curved flow paths that redirect the flow. In such curved flow paths, the flow of the fluid flowing inside cannot follow the curved flow path shape and often separates from the inside of the bend. This separation increases the pressure loss of the flow and increases the deviation in flow velocity between the upstream and downstream positions of the bend.

[0003] Therefore, for example, Patent Document 1 describes a structure in which a plurality of flow straightening members are arranged in a curved flow path to suppress separation. The flow straightening members in Patent Document 1 have a curved upstream end and a tapered downstream end. As a result, in the curved flow path, the fluid passes along the flow straightening members, suppressing separation.

[0004] Japanese Patent Application Laid-Open No. 2000-167347

[0005] In a curved flow path, the cross-sectional area of ​​the outlet where the fluid flows out may be larger than that of the inlet where the fluid flows in. In such a curved flow path, separation occurs not only when the flow bends but also when the cross-sectional area of ​​the flow path expands. Therefore, it is desirable to circulate the fluid while suppressing not only the loss associated with the flow redirection but also the loss associated with the expansion of the cross-sectional area of ​​the flow path.

[0006] The present disclosure has been made to solve the above-mentioned needs, and aims to provide a flow guide and a curved duct that can circulate fluid while suppressing losses associated with turning the flow and increasing the cross-sectional area of ​​the flow path.

[0007] In order to solve the above problems, the flow guide according to the present disclosure is a flow guide that is arranged in a curved flow path portion that curves to connect an inlet portion, through which a fluid flows in toward a first direction, and an outlet portion that is arranged at a position intersecting the inlet portion, through which the fluid flows out toward a second direction intersecting the first direction, and has a flow path cross-sectional area larger than that of the inlet portion, and the flow guide includes a plurality of guide portions that are arranged in the curved flow path portion and guide the flow direction of the fluid flowing through the curved flow path portion to bend from the first direction to the second direction, the plurality of guide portions are arranged at a distance from each other in the flow direction, and the plurality of guide portions are arranged side by side at a distance from each other in a cross direction that intersects the flow direction, and each of the guide portions has a guide flow path that extends crossing the first direction, and of two guide flow paths that are adjacent to each other in the second direction, the guide flow path formed in the guide portion closer to the outlet portion has a larger inclination angle with respect to the first direction.

[0008] In addition, the curved duct according to the present disclosure includes an inlet portion through which a fluid flows in a first direction, an outlet portion that is arranged at a position intersecting the inlet portion and through which the fluid flows out in a second direction intersecting the first direction and has a larger flow path cross-sectional area than the inlet portion, and the curved flow path portion that connects the inlet portion and the outlet portion and in which the flow guide is arranged.

[0009] The flow guide according to the present disclosure is a flow guide provided in a duct body having an inlet portion through which a fluid flows in a first direction, an outlet portion through which the fluid flows out in a second direction intersecting the first direction and which has a larger flow path cross-sectional area than the inlet portion, and a bending portion that connects the inlet portion and the outlet portion and changes the flow direction of the fluid from the first direction to the second direction. The flow guide has a plurality of guide plates that are arranged at intervals in a flow path width direction intersecting the flow direction and guide the fluid, each of the guide plates having a flat plate portion provided within the bending portion and extending from the inlet portion toward the first direction, and a turning plate portion provided within the bending portion and connected to the downstream side of the flat plate portion and extending toward the second direction as it moves toward the first direction. Between adjacent flat plate portions, an enlarged flow path is formed whose flow path cross-sectional area increases toward the downstream side of the flow direction, and between adjacent turning plate portions, a turning flow path is formed that is connected to the enlarged flow path and changes the flow of the fluid from the first direction to the second direction.

[0010] A curved duct according to the present disclosure includes the above-described flow guide and the duct body.

[0011] The flow guide and curved duct of the present disclosure allow fluid to flow while minimizing losses that accompany flow redirection and an increase in the cross-sectional area of ​​the flow path.

[0012] FIG. 1 is a schematic diagram showing a curved duct equipped with a flow guide according to the present embodiment; FIG. 2 is an enlarged view of a main part detailing a flow guide according to a first embodiment; FIG. 3 is an enlarged view of a main part detailing a flow guide according to a second embodiment; FIG. 4 is an enlarged view of a main part detailing a flow guide according to a third embodiment; FIG. 5 is an enlarged view of a main part detailing a flow guide according to a fourth embodiment; FIG. 6 is an enlarged view of a main part detailing a flow guide according to a fifth embodiment; FIG. 7 is a longitudinal sectional view of a curved duct equipped with a flow guide according to a sixth embodiment; FIG. 8 is a longitudinal sectional view of a curved duct equipped with a flow guide according to a seventh embodiment; FIG. 9 is a longitudinal sectional view of a curved duct equipped with a flow guide according to an eighth embodiment; FIG. 10 is a longitudinal sectional view of a curved duct equipped with a flow guide according to a ninth embodiment.

[0013] Hereinafter, embodiments for implementing a flow guide and a curved duct according to the present disclosure will be described with reference to the accompanying drawings, but the present disclosure is not limited to these embodiments.

[0014] First Embodiment (Bending Duct) The bending duct 1 constitutes a part of a flow path through which a fluid flows in a facility such as a plant through which the fluid flows. The bending duct 1 has a flow path formed therein through which the fluid can flow. The bending duct 1 is formed to redirect the flow direction Df of the fluid that has flowed therein and to increase the cross-sectional area of ​​the flow path. Here, the flow direction Df refers to the direction in which the fluid flows in a bending flow path section 13, which will be described later. The flow path cross-sectional area refers to the cross-sectional area of ​​the flow path perpendicular to the flow direction Df of the fluid. In this embodiment, the fluid that flows through the bending duct 1 is, for example, a gas such as air or a process gas. As shown in FIG. 1 , the bending duct 1 of this embodiment includes an inlet section 11, an outlet section 12, a bending flow path section 13, and a flow guide 2.

[0015] The inlet portion 11 is adapted to receive fluid supplied from outside the curved duct 1. The fluid flows into the inlet portion 11 in a first direction D1. The fluid flowing in from the inlet portion 11 flows toward the curved flow path portion 13.

[0016] The outlet section 12 discharges the fluid that has flowed inside the curved duct 1 to the outside. At the outlet section 12, the fluid flows out in the second direction D2. The fluid that has passed through the curved flow path section 13 and the flow guide 2 flows through the outlet section 12. The second direction D2 is a direction that intersects with the first direction D1 (orthogonal in this embodiment). The outlet section 12 is disposed at a position that intersects with the inlet section 11. The outlet section 12 is disposed at a position away from the inlet section 11. The outlet section 12 is formed to have a larger flow path cross-sectional area than the inlet section 11. In other words, the flow path cross-sectional area of ​​the outlet section 12 when viewed from the second direction D2 is larger than the flow path cross-sectional area of ​​the inlet section 11 when viewed from the first direction D1.

[0017] The curved flow path section 13 is curved to connect the inlet section 11 and the outlet section 12. The curved flow path section 13 redirects the flow direction Df of the fluid that flows from the inlet section 11 in the first direction D1 to the second direction D2. The curved flow path section 13 expands the flow path cross-sectional area from the inlet section 11 to the outlet section 12. The curved flow path section 13 includes a first flow path 131 connected to the inlet section 11 and extending in the first direction D1, a second flow path 132 connected to the outlet section 12 and extending in the second direction D2, and a curved flow path 133 connecting the first flow path 131 and the second flow path 132 at a right angle. In other words, the curved flow path 133 is formed so as to be bent at a right angle. Inside the curved flow path 133, a convex curved surface connects the first flow path 131 and the second flow path 132. On the outside of the curved flow path 133, an inclined surface connects the first flow path 131 and the second flow path 132. The curved flow path 133 of this embodiment connects the first flow path 131 and the second flow path 132 by a plurality of inclined surfaces at different angles.

[0018] (Flow Guide) The flow guide 2 is capable of suppressing separation of the fluid when the flow direction Df is turned in the curved flow path section 13. The flow guide 2 is disposed in the curved flow path section 13. The flow guide 2 of this embodiment includes a plurality of guide sections 3 (three in this embodiment).

[0019] The guide portion 3 is disposed in the curved flow path portion 13 and guides the flow direction Df of the fluid flowing through the curved flow path portion 13 so as to bend from the first direction D1 to the second direction D2. Therefore, in the curved flow path portion 13, the flow direction Df coincides with the first direction D1, coincides with the second direction D2, or intersects with the first direction D1 and the second direction D2, depending on the location. The guide portion 3 of this embodiment is disposed in the curved flow path 133. More specifically, the guide portion 3 is disposed at the boundary with the second flow path 132 in the curved flow path 133 so as to be outside the region where the first flow path 131 and the second flow path 132 intersect. The guide portion 3 is disposed in the curved flow path portion 13 at a position away from the first flow path 131 when viewed from the first direction D1. The multiple guide portions 3 are disposed spaced apart from each other in the flow direction Df.

[0020] As shown in FIG. 2 , in this embodiment, the multiple guide portions 3 are spaced apart from one another in the second direction D2. The flow guide of this embodiment includes a first guide portion 31, a second guide portion 32, and a third guide portion 33 as the guide portions 3. The first guide portion 31 is disposed closest to the inlet portion 11 in the second direction D2 among the first guide portion 31, the second guide portion 32, and the third guide portion 33. In other words, the first guide portion 31 is disposed furthest upstream in the second direction D2 among the first guide portion 31, the second guide portion 32, and the third guide portion 33. The third guide portion 33 is disposed closest to the outlet portion 12 in the second direction D2 among the first guide portion 31, the second guide portion 32, and the third guide portion 33. In other words, the third guide portion 33 is disposed furthest downstream in the second direction D2 among the first guide portion 31, the second guide portion 32, and the third guide portion 33. The second guide portion 32D is disposed closer to the outlet portion 12 than the first guide portion 31 in the second direction D2. That is, the second guide portion 32 is disposed downstream of the first guide portion 31 in the second direction D2. Moreover, the second guide portion 32 is disposed closer to the inlet portion 11 than the third guide portion 33 in the second direction D2. That is, the second guide portion 32 is disposed upstream of the third guide portion 33 in the second direction D2.

[0021] The upstream side and downstream side are the upstream side (close to the inlet 11) and downstream side (close to the outlet 12) in the fluid flow direction Df. Therefore, depending on the location of the curved flow path section 13 where the flow guide 2 is arranged, the upstream side and downstream side are the upstream side (close to the inlet 11) and downstream side (close to the outlet 12) in the first direction D1, and the upstream side (close to the inlet 11) and downstream side (close to the outlet 12) in the second direction D2. In the arrangement of the flow guide 2 in this embodiment, the upstream side and downstream side are the upstream side and downstream side in the second direction D2.

[0022] Furthermore, an intersecting flow path 4 through which a fluid can flow is formed between two guide parts 3 that are spaced apart in the second direction D2. The intersecting flow path 4 in this embodiment extends straight in the first direction D1 so as to cross the second flow path 132 between the two guide parts 3. Therefore, an intersecting flow path 4 is formed between the first guide part 31 and the second guide part 32, and between the second guide part 32 and the third guide part 33.

[0023] Furthermore, each guide portion 3 is formed in a flat plate shape that extends perpendicular to the second direction D2. The guide portions 3 have the same thickness in the second direction D2. The guide portions 3 are fixed to the inner circumferential surface of the curved flow path portion 13 so as to cover the curved flow path 133. Furthermore, the guide portion 3 of this embodiment has a plurality of flow path forming portions 5 and a plurality of guide flow paths 6.

[0024] The multiple flow path forming portions 5 are arranged side by side and spaced apart in the intersecting direction Dp so as to form guide flow paths 6 therebetween in the intersecting direction Dp. Here, the intersecting direction Dp is a direction intersecting the flow direction Df. In this embodiment, the intersecting direction Dp is the first direction D1. When viewed from a direction perpendicular to the flow direction Df and the intersecting direction Dp (the depth direction of the paper in FIG. 2 ), the cross-sectional shape of each flow path forming portion 5 is formed into a rectangle. In this embodiment, the cross-sectional shape of the flow path forming portion 5 is formed into a parallelogram or a rectangle.

[0025] The multiple guide flow paths 6 are arranged side by side and spaced apart in a first direction D1, which is the intersecting direction Dp. Each guide flow path 6 extends intersecting the first direction D1. In this embodiment, each guide flow path 6 extends in a direction inclined with respect to the second direction D2 or in the second direction D2. Each guide flow path 6 is formed between a pair of flow path forming portions 5 adjacent to each other in the first direction D1. The multiple guide flow paths 6 formed side by side in the first direction D1 in one guide portion 3 have the same shape. Each guide flow path 6 is formed as a slit penetrating the guide portion 3 in the second direction D2.

[0026] Furthermore, of two guide flow paths 6 adjacent to each other in the second direction D2, the guide flow path 6 formed in the guide section 3 closer to the outlet 12 has a larger inclination angle θ with respect to the first direction D1. In other words, between the guide flow path 6 located downstream in the second direction D2 and the guide flow path 6 located upstream in the second direction D2, the guide flow path 6 located downstream is inclined so as to be closer to perpendicular to the first direction D1 (parallel to the second direction D2). In other words, the inclination angle θ with respect to the intersecting flow path 4 extending in the first direction D1 is larger. The inclination angle θ is the angle between an imaginary center line passing through the center of the guide flow path 6 and an imaginary line extending in the first direction D1.

[0027] Therefore, when comparing the first guide flow path, which is the guide flow path 6 of the first guide portion 31, with the second guide flow path 62, which is the guide flow path 6 of the second guide portion 32, the inclination angle θ (θ2) of the second guide flow path 62 is larger than the inclination angle θ (θ1) of the first guide flow path 61. Furthermore, when comparing the second guide flow path 62 with the third guide flow path 63, which is the guide flow path 6 of the third guide portion 33, the inclination angle θ (θ3) of the third guide flow path 63 is larger than the inclination angle θ (θ2) of the second guide flow path 62. Furthermore, in this embodiment, the inclination angle θ (θ3) of the third guide flow path 63 is 90°. In other words, the third guide flow path 63 extends parallel to the second direction D2. Therefore, among the first guide flow path 61, the second guide flow path 62, and the third guide flow path 63, the inclination angle θ (θ1) of the first guide flow path 61 is smallest, and the inclination angle θ (θ3) of the third guide flow path 63 is largest. Therefore, the first guide flow path 61 extends at the most acute angle with respect to the intersecting flow path 4 .

[0028] In addition, the first guide flow path 61, the second guide flow path 62, and the third guide flow path 63 in this embodiment have a constant flow path cross-sectional area. Specifically, the first guide flow path 61, the second guide flow path 62, and the third guide flow path 63 have a constant flow path cross-sectional area when viewed in a direction perpendicular to the flow direction Df and the intersecting direction Dp. Furthermore, the first guide flow path 61, the second guide flow path 62, and the third guide flow path 63 have a constant opening area (the area of ​​the portion facing the intersecting flow path 4) in the first guide portion 31, the second guide portion 32, and the third guide portion 33. Furthermore, the first guide flow path 61, the second guide flow path 62, and the third guide flow path 63 have a constant interval in the second direction D2. That is, in each guide flow path 6, the interval from the inlet (the opening upstream in the flow direction Df) to the outlet (the opening downstream in the flow direction Df) is constant.

[0029] Furthermore, the relationship between the distance di in the second direction D2 at the inlet and outlet of each stage and the width Hi in the second direction D2 of the intersecting flow path 4 facing the outlet of each stage is preferably di / 2≦Hi≦2di.

[0030] Furthermore, the two guide channels 6 aligned in the second direction D2 are arranged with a shift in the intersecting direction Dp so that an imaginary center line passing through the center of the upstream guide channel 6 intersects with an imaginary center line passing through the center of the downstream guide channel 6 at the inlet of the downstream guide channel 6. Accordingly, the second guide channel 62 is arranged with a shift in the first direction D1 with respect to the first guide channel 61 so that an imaginary center line passing through the center of the first guide channel 61 intersects with an imaginary center line passing through the center of the second guide channel 62 at the inlet of the second guide channel 62. Furthermore, the third guide channel 63 is arranged with a shift in the first direction D1 with respect to the second guide channel 62 so that an imaginary center line passing through the center of the second guide channel 62 intersects with an imaginary center line passing through the center of the third guide channel 63 at the inlet of the third guide channel 63.

[0031] (Operation and Effect) In the flow guide 2 and curved duct 1 of the present embodiment described above, a plurality of first guide portions 31, second guide portions 32, and third guide portions 33 are arranged at intervals in the second direction D2. Therefore, an intersecting flow path 4 through which a fluid can flow in the first direction D1 is formed between two adjacent guide portions 3 in the second direction D2. Then, each time the fluid passes through a guide portion 3, it is diverted into a plurality of guide flow paths 6 and reaches the intersecting flow path 4. By repeating this process as the fluid passes through a plurality of guide portions 3, it is possible to distribute the fluid that flows in from the inlet portion 11, which has a small flow path cross-sectional area, so that the flow rate is uniform throughout the entire length of the fluid until it reaches the outlet portion 12, which has a large flow path cross-sectional area.

[0032] The guide channels 6 extend intersecting the first direction D1. Among the first and second guide channels 61 and 62 adjacent to each other in the second direction D2, the second guide channel 62, which is closer to the outlet 12, has a larger inclination angle θ relative to the first direction D1. That is, the inclination angle θ of the multiple guide channels aligned in the second direction D2 gradually increases from the first direction D1 to the second direction D2 toward the downstream side in the second direction D2. This suppresses flow separation when the fluid flows into the guide channels 6, making it easier for the fluid to conform to the shape of the channel. This allows the fluid to be smoothly redirected while suppressing pressure loss. Additionally, by gradually redirecting the fluid using multiple guide sections 3, the inclination angle θ of each guide channel 6 can be reduced, thereby reducing pressure loss in the guide channels 6. As a result, pressure loss can be suppressed compared to redirecting the fluid all at once using only one guide section 3. This suppresses flow resistance when the fluid flows through the guide channels 6 of each guide section 3, enabling the fluid to be smoothly redirected in the flow direction Df. Therefore, the pressure loss in the curved flow path portion 13 can be reduced.

[0033] These allow the fluid to flow while suppressing losses that accompany the turning of the fluid and the expansion of the cross-sectional area of ​​the flow path.

[0034] Furthermore, by arranging multiple guide portions 3, the dimension of each guide portion 3 in the second direction D2 can be reduced, making the guide portion 3 thinner. This improves the processing accuracy of the slit-shaped guide flow path 6, allowing the guide flow path 6 to be formed with small dimensions. By reducing the dimensions of the guide flow path 6, the representative dimension of the flow velocity deviation at the outlet of the guide flow path 6 can be reduced. Here, as the representative dimension of the flow velocity deviation becomes smaller, the attenuation of the flow velocity deviation becomes faster. In other words, the flow velocity can be reduced more quickly, and the flow velocity distribution of the fluid passing through the guide flow path 6 becomes more uniform more quickly. In this way, by reducing the dimensions of the guide flow path 6, the flow velocity deviation can be reduced.

[0035] The relationship between the distance di in the second direction D2 at the inlet and outlet of each stage and the width Hi in the second direction D2 of the intersecting flow path 4 facing the outlet of each stage is di / 2≦Hi≦2di. Assuming a situation in which the entire amount of fluid passing through the guide flow paths 6 passes through the intersecting flow path 4, even if the fluid arriving at the intersecting flow path 4 from the guide flow paths 6 flows evenly through the intersecting flow path 4 toward both sides in the first direction D1, if the width of the intersecting flow path 4 is too small (e.g., less than half the distance di), the flow rate of the fluid passing through the intersecting flow path 4 will be too fast, resulting in significant loss. Conversely, if the entire amount of fluid arriving at the intersecting flow path 4 from the guide flow paths 6 flows through the intersecting flow path 4 only to one side in the first direction D1, if the width of the intersecting flow path 4 is too large (e.g., more than twice the distance di), the intersecting flow path 4 will not have a deceleration effect, and the fluid will not flow in a spreading manner. As a result, the pressure loss reduction and dynamic pressure recovery effects in the intersecting flow path 4 will not be achieved. In contrast to these, by setting the relationship between the guide flow path 6 and the intersecting flow path 4 to be di / 2≦Hi≦2di, it is possible to efficiently reduce pressure loss in the intersecting flow path 4 and achieve a dynamic pressure recovery effect.

[0036] Furthermore, by arranging the flow guide 2 as described above in the curved flow path section 13, even when the flow direction Df is significantly deflected toward the outlet, which has a larger flow path cross-sectional area than the inlet section 11, the fluid can be circulated while minimizing losses associated with the deflection of the fluid and the expansion of the flow path cross-sectional area.

[0037] Furthermore, the plurality of guide portions are arranged in the curved flow path portion 13 at positions that are offset from the first flow path 131 when viewed from the first direction D1. Therefore, the flow direction Df of the fluid is redirected by the shape of the curved flow path portion 13 itself, and the flow guide 2 efficiently rectifies the flow, allowing the fluid to circulate with reduced pressure loss.

[0038] Second Embodiment Next, a flow guide 2A according to a second embodiment of the present disclosure will be described. In the second embodiment described below, components common to the first embodiment will be denoted by the same reference numerals in the drawings and will not be described again. The flow guide 2A of the second embodiment differs from the first embodiment in the shape of the guide flow path 6A.

[0039] As shown in FIG. 3 , in the flow guide 2A of the second embodiment, the guide flow path 6A located downstream in the second direction D2 has a larger cross-sectional area as well as a larger inclination angle θ. That is, between two adjacent guide flow paths 6A in the second direction D2, the guide flow path 6A formed in the guide section 3A closer to the outlet 12 has a larger cross-sectional area. That is, between the guide flow path 6A located downstream in the second direction D2 and the guide flow path 6A located upstream in the second direction D2, the guide flow path 6A located downstream has a larger cross-sectional area when viewed in a direction perpendicular to the flow direction Df and the intersecting direction Dp. Furthermore, in this embodiment, the cross-sectional area gradually increases from the guide flow path 6A located upstream to the guide flow path 6A located downstream.

[0040] Therefore, when comparing the first guide flow path 61A and the second guide flow path 62A, the flow path cross-sectional area of ​​the second guide flow path 62A is larger than that of the first guide flow path 61A. Furthermore, when comparing the second guide flow path 62A and the third guide flow path 63A, the flow path cross-sectional area of ​​the third guide flow path is larger than that of the second guide flow path 62A. Furthermore, the first guide flow path 61A, the second guide flow path 62A, and the third guide flow path 63A are formed so that the opening areas gradually increase.

[0041] Furthermore, it is preferable that the relationship between the distance di in the second direction D2 at the entrance of the first guide flow path 61A, which is the guide section 3A located upstream in the second direction D2, and the distance di+1 in the second direction D2 at the entrance of the second guide flow path 62A, which is the guide section 3A located one downstream in the second direction D2, is di+1 / di≦2.

[0042] (Effects) In the flow guide 2A of the second embodiment, the second guide flow path 62A has a larger flow path cross-sectional area than the first guide flow path 61A. Furthermore, the third guide flow path 63A has a larger flow path cross-sectional area than the second guide flow path 62A. That is, in the multiple guide flow paths 6A aligned in the second direction D2, the flow path cross-sectional areas of the guide flow paths 6A gradually increase toward the outlet portion 12. By gradually increasing the flow path cross-sectional area of ​​the guide flow paths 6A in this manner, separation of the fluid flow due to the expansion of the flow path can be further suppressed. Furthermore, as the flow path cross-sectional area increases, the fluid decelerates. Therefore, when the fluid flows into the guide flow path 6A located downstream in the second direction D2, the representative dynamic pressure of the fluid decreases, further suppressing pressure loss. Furthermore, by decelerating the fluid, flow separation can be further suppressed, further suppressing pressure loss.

[0043] Furthermore, the relationship between the distance di in the second direction D2 at the inlet of the guide section 3A located upstream in the second direction D2 and the distance di+1 in the second direction D2 at the inlet of the guide section 3A located immediately downstream in the second direction D2 with respect to the first guide passage 61A, such as the second guide passage 62A, is set to be di+1 / di≦2. By increasing the flow path cross-sectional area of ​​the guide passage 6A within this range, the fluid deceleration effect can be obtained with high precision when the fluid bends (redirects) in the guide passage 6A of each stage. Therefore, the flow path cross-sectional area of ​​the guide passage 6A can be increased while maintaining the pressure loss reduction and dynamic pressure recovery effect in the guide passage 6A.

[0044] Third Embodiment Next, a flow guide 2B according to a third embodiment of the present disclosure will be described. In the third embodiment described below, components common to the first and second embodiments are denoted by the same reference numerals in the drawings, and description thereof will be omitted. The flow guide 2B of the third embodiment differs from the first and second embodiments in the shape of the guide flow path 6B.

[0045] As shown in Fig. 4, in the flow guide 2B of the third embodiment, the width of the guide channels 6B gradually increases toward the downstream side in the second direction D2. That is, the spacing between the guide channels 6B in the cross direction Dp increases in the second direction D2 from a position closer to the inlet 11 toward a position closer to the outlet 12. In this embodiment, the spacing between the first guide channels 61B and the second guide channels 62B increases in the second direction D2. On the other hand, the spacing between the third guide channels 63B is constant in the second direction D2. That is, the cross-sectional shape of the channel forming portion 5B of this embodiment is not a parallelogram or a rectangle, but a rectangle with opposing sides having different angles in the second direction D2.

[0046] In the first guide channel 61B, the spacing in the second direction D2 increases from the inlet to the outlet. In addition, the spacing at the inlet of the second guide channel 62B is the same as the spacing at the outlet of the first guide channel 61B. In the second guide channel 62B, the spacing in the second direction D2 increases from the inlet to the outlet. The spacing at the outlet of the second guide channel 62B is the same as the spacing between the inlet and the outlet of the third guide channel 63B.

[0047] (Effects) In the flow guide 2B of the third embodiment, the first guide flow path 61B and the second guide flow path 62B are expanded flow paths that gradually widen from the inlet toward the outlet. That is, the first guide flow path 61B and the second guide flow path 62B function as diffusers, and flow energy (dynamic pressure) can be recovered in the first guide flow path 61B and the second guide flow path 62B. Furthermore, because the first guide flow path 61B and the second guide flow path 62B gradually widen from the inlet toward the outlet, the distance between them is widest at the outlet located closest to the outlet section 12. This reduces the flow velocity of the fluid at the outlet. As a result, pressure loss and flow velocity deviation in the curved flow path section 13 can be further reduced.

[0048] Fourth Embodiment Next, a flow guide 2C according to a fourth embodiment of the present disclosure will be described. In the fourth embodiment described below, components common to the first to third embodiments will be denoted by the same reference numerals in the drawings, and description thereof will be omitted. The flow guide 2C of the fourth embodiment differs from the first to third embodiments in the shape of the flow path forming portion 5C.

[0049] As shown in Fig. 5, in the flow guide 2C of the fourth embodiment, the cross-sectional shape of the flow path forming portion 5C is rectangular when viewed from a direction perpendicular to the flow direction Df and the cross direction Dp. The flow path forming portion 5C has rounded corners (R) located on the upstream side in the second direction D2. Specifically, the flow path forming portion 5C has convex curved surfaces 7 at both corners formed near the inlet portion 11 in the second direction D2. Therefore, the guide flow path 6C of the fourth embodiment is formed so that the inlet is wider than the outlet.

[0050] (Operation and Effect) In the flow guide 2C of the fourth embodiment, of two corners formed near the inlet 11 in the second direction D2 of the flow path forming portion 5C, the corner formed far from the inlet 11 in the first direction D1 has a convex curved surface 7. Therefore, the fluid flowing into the flow guide 2C and the fluid flowing through the intersecting flow path 4 flows along the upstream wall surface of the flow path forming portion 5C in the second direction D2, and then flows along the convex curved surface 7 of the corner formed far from the inlet 11. As a result, the fluid flowing into the guide flow path 6C flows along the side surface of the flow path forming portion 5C that forms part of the guide flow path 6C. In other words, the Coanda effect can be imparted to the fluid flowing into the guide flow path 6C. As a result, the fluid can be attracted to the side surface of the flow path forming portion 5C within the guide flow path 6C. This suppresses separation of the fluid flowing into the guide flow path 6C, thereby suppressing pressure loss.

[0051] Furthermore, of the two corners formed near the inlet portion 11 in the second direction D2 of the flow path forming portion 5C, the corner formed near the inlet portion 11 in the first direction D1 also has a convex curved surface 7. Therefore, when the fluid flowing into the flow guide 2C or the fluid flowing through the intersecting flow path 4 reaches the corner formed near the inlet portion 11, it collides with the convex curved surface 7 and flows so as to branch gently along the convex curved surface 7. This suppresses separation of the fluid flowing into the flow guide 2C or the fluid flowing through the intersecting flow path 4 when they flow into the guide flow path 6C, thereby suppressing pressure loss.

[0052] Fifth Embodiment Next, a flow guide 2D according to a fifth embodiment of the present disclosure will be described. In the fifth embodiment described below, components common to the first to fourth embodiments will be denoted by the same reference numerals in the drawings, and description thereof will be omitted. The flow guide 2D of the fifth embodiment differs from the first to fourth embodiments in the shape of the guide portion 3D.

[0053] As shown in FIG. 6 , the flow guide 2D of the fifth embodiment includes a first guide portion 31D and a second guide portion 32D as guide portions 3D. The first guide portion 31D and the second guide portion 32D include a flow path forming portion 5D. The cross-sectional shape of the flow path forming portion 5D when viewed from a direction perpendicular to the flow direction Df and the intersecting direction Dp is formed in a blade shape. Specifically, the blade shape of the flow path forming portion 5D includes a concave positive pressure surface 81 located near the inlet portion 11 in the first direction D1, and a convex negative pressure surface 82 located farther from the inlet portion 11 than the positive pressure surface 81. Therefore, a guide flow path 6D is formed between a pair of adjacent blade-shaped flow path forming portions 5D in the first direction D1, the guide flow path 6D conforming to the shape of the blade surface.

[0054] Furthermore, in the first guide section 31D and the second guide section 32D, the plurality of flow path forming sections 5, 5B, 5C, and 5D are arranged to form a reducer blade cascade that decelerates the fluid and increases the pressure. Furthermore, in the fifth embodiment, the second guide section 32D is arranged with respect to the first guide section 31D so that the flow direction Df of the fluid that has flowed in from the first guide flow path 61D contacts the positive pressure surface 81. Therefore, the second guide flow path 62D is arranged offset in the first direction D1 with respect to the first guide flow path 61D.

[0055] (Operation and Effect) In the flow guide 2D of the fifth embodiment, the cross-sectional shape of the flow path forming portion 5D is formed in a vane shape in the first direction D1, with the positive pressure surface 81 located closer to the inlet portion 11 and the negative pressure surface 82 located farther from the inlet portion 11. Therefore, when the fluid flowing into the flow guide 2D or the fluid flowing through the intersecting flow path 4 reaches the upstream end of the flow path forming portion 5D, it collides with the leading edge of the vane shape and flows in a gently branching manner along the leading edge. This reduces the collision loss of the fluid when it flows into the guide flow path 6D. Furthermore, by forming the flow path forming portion 5D in a vane shape, the fluid flows along the positive pressure surface 81 and the negative pressure surface 82, resulting in smooth fluid deflection. This suppresses separation of the fluid flowing through the guide flow path 6D and reduces pressure loss.

[0056] Furthermore, by arranging the plurality of flow path forming portions 5D in a reducer blade row, it is possible to recover the dynamic pressure of the fluid and reduce pressure loss.

[0057] Furthermore, the second guide portion 32D is disposed relative to the first guide portion 31D so that the flow direction Df of the fluid flowing in from the first guide flow passage 61D contacts the positive pressure surface 81. Therefore, the fluid flowing in the guide flow passage 61D flows along the negative pressure surface 82. As a result, the fluid with energy flows into a position close to the negative pressure surface 82 of the flow passage forming portion 5D. This suppresses separation of the fluid on the blade surface, reducing pressure loss of the fluid and enabling the fluid to be smoothly turned.

[0058] (Other Embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope that does not deviate from the gist of the present disclosure are also included.

[0059] The shape of the curved duct 1 is not limited to the shape of this embodiment. For example, the curved duct 1 is not limited to a shape in which the first direction D1, which is the direction in which the fluid flows at the inlet 11, and the second direction D2, which is the direction in which the fluid flows at the outlet 12, are perpendicular to each other. The second direction D2 may be inclined with respect to the first direction D1.

[0060] Furthermore, the fluid flowing through the curved duct 1 is not limited to gas, but may be liquid such as water or various solutions.

[0061] The guide portions 3, 3A, 3B, 3C, and 3D are not limited to the arrangement in the above embodiment as long as they are arranged in the curved flow path portion 13. That is, the guide portions 3, 3A, 3B, 3C, and 3D may be arranged in the curved flow path portion 13 at positions that overlap with the first flow path 131 when viewed from the first direction D1.

[0062] Furthermore, it is sufficient that a plurality of guide portions 3, 3A, 3B, 3C, and 3D are arranged, and the number of guide portions 3, 3A, 3B, 3C, and 3D is not limited to the number as in the present embodiment. Therefore, in the first to fourth embodiments, only two guide portions 3, 3A, 3B, and 3C may be arranged, or four or more guide portions 3, 3A, 3B, and 3C may be arranged. Similarly, three or more guide portions 3D may be arranged in the fifth embodiment.

[0063] Furthermore, the shapes of the guide channels 6, 6A, 6B, 6C, and 6D are not limited to those described in the above embodiments. For example, in the first to fourth embodiments, the inclination angle θ of the third guide channels 63, 63A, 63B, and 63C, which are the guide channels 6, 6A, 6B, and 6C arranged at the most downstream side in the second direction D2, is not limited to 90° and extending parallel to the second direction D2. Therefore, the inclination angle θ of the third guide channels 63, 63A, 63B, and 63C may be smaller than 90°. Furthermore, in the third embodiment, the spacing of the third guide channels 63B in the second direction D2 is not limited to being constant. Therefore, the third guide channels may also be formed as enlarged channels.

[0064] Sixth Embodiment Next, a sixth embodiment will be described with reference to Fig. 7. As shown in Fig. 7, a curved duct 200 of this embodiment has a duct body 201 and a plurality of flow guides 240.

[0065] <Duct main body> The duct main body 201 has an inlet section 210, an outlet section 220, and a bending section 230. A fluid supplied from outside the duct main body 201 is introduced into the inlet section 210. The space inside the inlet section 210 is defined as an inlet flow path 211. In the inlet flow path 211, the fluid flows downstream in the first direction D1 (to the left in FIG. 7 ).

[0066] The outlet portion 220 discharges the fluid that has flowed through the duct body 201 to the outside. The space within the outlet portion 220 forms an outlet flow path 221. Within the outlet flow path 221, the fluid flows downstream in a second direction D2 (toward the lower side in FIG. 7 ). The second direction D2 intersects with (is perpendicular to) the first direction D1. The outlet portion 220 (outlet flow path 221) is formed with a larger flow path cross-sectional area than the inlet portion 210 (inlet flow path 211).

[0067] The bending section 230 connects the inlet section 210 and the outlet section 220. The space within the bending section 230 is defined as a curved flow path 231. The fluid that has flowed through the inlet flow path 211 is introduced into the curved flow path 231. The fluid introduced into the curved flow path 231 has its flow direction Df redirected from the first direction D1 to the second direction D2 in the curved flow path 231, and is then discharged to the outlet flow path 221. The cross-sectional area of ​​the curved flow path 231 increases from the inlet flow path 211 toward the outlet flow path 221. Hereinafter, a direction perpendicular to the flow direction Df in a plane including the first direction D1 and the second direction D2 will be referred to as a flow path width direction W.

[0068] Here, the duct main body 201 has an inner casing portion 235 arranged inside the curvature of the curved flow path 231 (hereinafter simply referred to as the "inside of the curvature") and an outer casing portion 236 arranged outside the curvature of the curved flow path 231 (hereinafter simply referred to as the "outside of the curvature"). The inner casing portion 235 and the outer casing portion 236 are plate-shaped and extend in a depth direction in a third direction D3 that is perpendicular to the first direction D1 and the second direction D2. A pair of end plates (not shown) are provided to close the space between the inner casing portion 235 and the outer casing portion 236 from both sides in the third direction D3. This defines the flow paths within the duct main body 201.

[0069] The outer casing portion 236 is composed of an upstream plate portion 236a, a midstream plate portion 236b, and a downstream plate portion 236c. The upstream plate portion 236a is the portion on the inlet portion 210 side, and is a plate-like portion extending linearly in the first direction D1 in a vertical cross-sectional view including the first direction D1 and the second direction D2 (hereinafter simply referred to as "vertical cross-sectional view"). The downstream plate portion 236c is the portion on the outlet side, and is a plate-like portion extending linearly in the second direction D2 in a vertical cross-sectional view. The midstream plate portion 236b is the portion between the upstream plate portion 236a and the downstream plate portion 236c.

[0070] <Flow Guide> Next, a description will be given of the flow guide 240. The flow guide 240 has a plurality of guide plates 250 provided inside the duct body 201.

[0071] <Guide Plates> The multiple guide plates 250 are plate-shaped and extend in the flow direction Df and the third direction D3. The multiple guide plates 250 are arranged at intervals in the flow path width direction W. The upstream end of each guide plate 250 is located at the boundary between the inlet flow path 211 and the curved flow path 231. The downstream end of each guide plate 250 is located at the boundary between the outlet flow path 221 and the curved flow path 231. The guide plates 250 located closer to the inside of the curvature have a shorter dimension in the flow direction Df. The guide plates 250 located closer to the outside of the curvature have a longer dimension in the flow direction Df. Each guide plate 250 is composed of three parts: a flat plate portion 251, a turning plate portion 252, and an extension plate portion 253.

[0072] <Flat Plate Portion> The flat plate portion 251 is an upstream portion of the guide plate 250, and extends linearly in the first direction D1 in a vertical cross-sectional view. In this embodiment, the flat plate portion 251 extends slightly downstream in the second direction D2 as it extends downstream in the first direction D1. The flat plate portion 251 is provided within the curved flow path 231.

[0073] <Turning Plate Portion> The turning plate portion 252 is a portion that continues from the downstream end of the flat plate portion 251. As the turning plate portion 252 extends from the downstream end of the flat plate portion 251 toward the downstream side in the first direction D1, it gradually curves toward the downstream side in the second direction D2, and then extends linearly toward the downstream side in the second direction D2. The turning plate portion 252 is provided within the curved flow path 231.

[0074] <Extension portion> The extension plate portion 253 is a portion that continues to the downstream end portion of the turning plate portion 252. The extension plate portion 253 extends linearly from the downstream end portion of the turning plate portion 252 toward the downstream side in the second direction D2 in a vertical cross section. The extension plate portion 253 is provided in the outlet flow path 221.

[0075] <Expanded flow path> An expanded flow path F1 is formed between adjacent flat plate portions 251 in the flow path width direction W. The expanded flow path F1 is a flow path in which the cross-sectional area of ​​the flow path gradually expands as the adjacent flat plate portions 251 move away from each other in the flow path width direction W toward the downstream side of the flow direction Df.

[0076] In this embodiment, an expanded flow passage F1 is also formed between the flat plate portion 251 of the guide plate 250 located at the outermost side of the curvature and the upstream plate portion 236a of the outer casing portion 236. The upstream end of the expanded flow passage F1 is located at the boundary between the inlet flow passage 211 and the turning flow passage F2. No expanded flow passage F1 is formed between the flat plate portion 251 of the guide plate 250 located at the innermost side of the curvature and the inner casing portion 235.

[0077] The expansion angle of the expanded flow channel F1 in a vertical cross section is set to a range of 1 to 30 degrees, or may be set to a range of 4 to 15 degrees.

[0078] <Turning Flow Path> A turning flow path F2 is formed between the turning plate portions 252 adjacent to each other in the flow path width direction W. The turning flow path F2 is formed to turn the fluid flow from the first direction D1 to the second direction D2. The turning flow path F2 extends so as to be continuous with the downstream side of the expanded flow path F1.

[0079] In this embodiment, a curved flow path 231 is also formed between the turning plate portion 252 of the guide plate 250 located at the outermost side of the curvature and the midstream plate portion 236b of the outer casing portion 236. A curved flow path 231 is also formed between the turning plate portion 252 of the guide plate 250 located at the innermost side of the curvature and the inner casing portion 235. The upstream end of the curved flow path 231 is located at the boundary between the inlet flow path 211 and the curved flow path 231. The downstream end of each curved flow path F2 coincides with the boundary between the curved flow path 231 and the outlet flow path 221.

[0080] <Straightening Flow Channel> A straightening flow channel F3 extending in the second direction D2 is formed between the extension plate portions 253 adjacent to each other in the flow channel width direction W. The straightening flow channel F3 extends so as to be continuous with the downstream side of each curved flow channel 231. The straightening flow channel F3 has a constant flow channel cross-sectional area from the upstream side to the downstream side.

[0081] In this embodiment, a rectifying flow path F3 is also formed between the extension plate portion 253 of the guide plate 250 located on the outermost side of the curvature and the downstream plate portion 236c of the outer casing portion 236. A rectifying flow path F3 is also formed between the extension plate portion 253 of the guide plate 250 located on the innermost side of the curvature and the inner casing portion 235.

[0082] <Effects> Next, the effects of the present embodiment will be described. The fluid introduced into the inlet flow path 211 flows so as to branch into multiple flow paths formed by providing the flow guide 240 inside the duct body 201.

[0083] The flow of fluid flowing into the expanded flow channel F1 is decelerated because the cross-sectional area of ​​the expanded flow channel F1 expands downstream. This allows the dynamic pressure of the flow to be recovered. In addition, the dynamic pressure at the downstream end of the expanded flow channel F1 can be reduced.

[0084] Furthermore, by having the fluid flow through multiple divided expanded channels F1 instead of a single expanded channel F1, the diffusion angle of the expanded channel F1 can be reduced, thereby further reducing pressure loss in the expanded channel F1 and increasing the recoverable dynamic pressure.

[0085] When the expansion angle is smaller than 15°, the pressure loss in the expanded flow path F1 can be reduced compared to a pipe with a constant flow path cross-sectional area. The minimum value of the expansion angle is preferably 4°, which can minimize the pressure loss in the expanded flow path F1.

[0086] In the curved flow path 231, the fluid whose flow has been decelerated by the expanded flow path F1 is introduced, so that the pressure loss when the flow direction Df of the fluid is changed can be reduced.

[0087] In this embodiment, the fluid that has been turned in the curved flow path 231 passes through the flow straightening flow path F3, so the flow of the fluid is straightened and mixing loss due to drift can be reduced.

[0088] Seventh Embodiment Next, a seventh embodiment will be described with reference to Fig. 8. In the seventh embodiment, the same components as those in the sixth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The guide plate 250 of the seventh embodiment does not have an extension plate portion 253, and the configuration of the turning plate portion 252 differs from that of the sixth embodiment.

[0089] That is, the turning plate portion 252 of each guide plate 250 in the seventh embodiment extends from the downstream end of the flat plate portion 251 toward the downstream side in the first direction D1 and then toward the downstream side in the second direction D2. That is, these turning plate portions 252 extend so as to be inclined with respect to both the first direction D1 and the second direction D2 in a vertical cross-sectional view.

[0090] As a result, each turning flow path F2 discharges the fluid in a direction that is inclined toward the downstream side of the second direction D2 as it moves toward the downstream side of the first direction D1. That is, since the turning angle can be made smaller than in the first embodiment, separation and drift of the flow in the turning flow path 231 can be suppressed. As a result, pressure loss can be further reduced.

[0091] Eighth Embodiment Next, an eighth embodiment will be described with reference to Fig. 9. In the eighth embodiment, the same components as those in the seventh embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The guide plate 250 of the eighth embodiment differs from the seventh embodiment in the configuration of the turning plate portion 252.

[0092] That is, in the eighth embodiment, the turning plate portions 252 adjacent to each other in the flow path width direction W extend so as to be spaced apart in the flow path width direction W toward the downstream side. As a result, the flow path cross-sectional area of ​​the turning flow path F2 gradually increases toward the downstream side.

[0093] In this way, by expanding the cross-sectional area of ​​the flow path in the turning flow path F2 as well as the expanding flow path F1, it is possible to further recover dynamic pressure by decelerating the flow, and to reduce pressure loss by reducing the blow-out dynamic pressure. Also, by dividing the region where the flow path expands into two stages, it is possible to prevent the flow path from becoming longer in one direction.

[0094] The region where the flow passage expands may be divided into three or more stages, rather than just two stages, which also makes it possible to further reduce pressure loss.

[0095] Ninth Embodiment Next, a ninth embodiment will be described with reference to Fig. 10. In the ninth embodiment, components similar to those in the eighth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In addition to the configuration of the eighth embodiment, the ninth embodiment further includes a divided guide plate 260.

[0096] The dividing guide plate 260 is a plate-like member provided in the turning flow path F2. Similar to the guide plate 250, the dividing guide plate 260 has a plate shape extending in the flow direction Df and the third direction D3. The dividing guide plate 260 is provided in the downstream portion of the turning flow path F2 and divides the turning flow path F2 in the flow path width direction W. As a result, two small flow paths divided by the dividing guide plate 260 are formed in the downstream portion of the turning flow path F2.

[0097] In this way, by providing the divided guide plate 260 in the downstream portion of the turning flow path F2 where the flow path cross-sectional area is increased, it is possible to suppress the flow drift, thereby further reducing the dynamic pressure at the flow outlet.

[0098] In this embodiment, the divided guide plates 260 are provided only on the two outermost turning flow paths F2 of the curvature, but the divided guide plates 260 may be provided on the other turning flow paths F2. Also, the divided guide plates 260 may be provided on only one of the turning flow paths F2. Furthermore, such divided guide plates 260 may be applied to the seventh and eighth embodiments.

[0099] <Additional Notes> The flow guides 2, 2A, 2B, 2C, and 2D and the curved duct 1 described in each embodiment can be understood, for example, as follows.

[0100] (1) The flow guides 2, 2A, 2B, 2C, and 2D according to a first aspect are arranged in a curved flow path portion 13 that is curved so as to connect an inlet portion 11 through which a fluid flows in a first direction D1, an outlet portion 12 that is arranged at a position intersecting the inlet portion 11 and through which the fluid flows out in a second direction D2 that intersects the first direction D1, and has a flow path cross-sectional area larger than that of the inlet portion 11, and the flow guides 2, 2A, 2B, 2C, and 2D include a plurality of guide portions that are arranged in the curved flow path portion 13 and guide the flow direction Df of the fluid flowing through the curved flow path portion 13 so as to bend the flow direction Df from the first direction D1 to the second direction D2. The guide portions 3, 3A, 3B, 3C, and 3D are arranged at intervals in the flow direction Df, and the guide portions 3, 3A, 3B, 3C, and 3D are arranged side by side at intervals in a cross direction Dp that crosses the flow direction Df, and each of the guide portions 3, 3A, 3B, 3C, and 3D has a guide flow path 6, 6A, 6B, 6C, and 6D that extends crossing the first direction D1, and of two guide flow paths 6, 6A, 6B, 6C, and 6D adjacent to each other in the second direction D2, the guide flow path 6, 6A, 6B, 6C, and 6D formed in the guide portion closer to the outlet portion 12 has a larger inclination angle θ with respect to the first direction D1.

[0101] According to this configuration, the plurality of guide portions 3, 3A, 3B, 3C, and 3D are arranged at intervals in the flow direction Df. Therefore, a flow path through which the fluid can flow in the cross direction Dp is formed between two adjacent guide portions 3, 3A, 3B, 3C, and 3D. Each time the fluid passes through a guide portion 3, 3A, 3B, 3C, or 3D, it is diverted into one of the plurality of guide flow paths 6, 6A, 6B, 6C, and 6D and reaches the corresponding flow path. By repeating this process as the fluid passes through the plurality of guide portions 3, 3A, 3B, 3C, and 3D, the fluid flowing in through the inlet portion 11, which has a small flow path cross-sectional area, can be distributed so that the flow rate is uniform throughout the entire length of the fluid flowing through the inlet portion 11, which has a small flow path cross-sectional area, until it reaches the outlet portion 12, which has a large flow path cross-sectional area.

[0102] The guide channels 6, 6A, 6B, 6C, and 6D extend intersecting the first direction D1. Among two adjacent guide channels in the flow direction Df, the guide channel 6, 6A, 6B, 6C, and 6D closer to the outlet 12 has a larger inclination angle θ with respect to the first direction D1. That is, the inclination angle θ of the guide channels 6, 6A, 6B, 6C, and 6D aligned in the flow direction Df gradually increases from the first direction D1 to the second direction D2 toward the downstream side of the flow direction Df. This suppresses flow separation when the fluid flows into the guide channels 6, 6A, 6B, 6C, and 6D, allowing the fluid to more easily conform to the shape of the channel. This suppresses pressure loss while smoothly redirecting the fluid. In addition, by gradually redirecting the fluid through the multiple guide sections 3, 3A, 3B, 3C, and 3D, the inclination angle θ of each guide channel 6, 6A, 6B, 6C, and 6D can be reduced, reducing pressure loss in the guide channels 6, 6A, 6B, 6C, and 6D. As a result, pressure loss can be reduced compared to when the fluid is redirected all at once using only one guide section 3, 3A, 3B, 3C, and 3D. This reduces flow resistance when the fluid flows through the guide channels 6, 6A, 6B, 6C, and 6D of each guide section 3, 3A, 3B, 3C, and 3D, allowing for smooth redirection of the fluid flow direction Df. Therefore, pressure loss in the curved channel section 13 can be reduced.

[0103] These allow the fluid to flow while suppressing losses that accompany the turning of the fluid and the expansion of the cross-sectional area of ​​the flow path.

[0104] (2) The flow guide 2A according to the second aspect is the flow guide 2, 2A, 2B, 2C, or 2D of (1), and of two adjacent guide flow paths 6A in the second direction D2, the guide flow path 6A formed in the guide portion 3A closer to the outlet portion 12 has a larger flow path cross-sectional area.

[0105] According to this configuration, the guide flow paths 6A closer to the outlet 12 in the flow direction Df have a larger flow path cross-sectional area than the guide flow paths 6A closer to the inlet 11 in the flow direction Df. That is, among the multiple guide flow paths 6A aligned in the flow direction Df, the flow path cross-sectional areas of the guide flow paths 6A gradually increase as they approach the outlet 12. By gradually increasing the flow path cross-sectional area of ​​the guide flow paths 6A in this manner, separation of the fluid flow during expansion of the flow path can be further suppressed. Furthermore, as the flow path cross-sectional area increases, the fluid decelerates. Therefore, when the fluid flows into the guide flow path 6A located downstream in the second direction D2, the representative dynamic pressure of the fluid decreases, further suppressing pressure loss. Furthermore, by decelerating the fluid, flow separation can be further suppressed, further suppressing pressure loss.

[0106] (3) The flow guide 2B according to the third aspect is the flow guide 2, 2A, 2B, 2C, or 2D of (1) or (2), and the spacing of the guide flow paths 6B in the cross direction Dp increases in the flow direction Df from a position close to the inlet portion 11 toward a position close to the outlet portion 12.

[0107] With this configuration, the guide flow path 6B becomes an expanding flow path that gradually widens. In other words, the guide flow path 6B acts as a diffuser, and flow energy (dynamic pressure) can be recovered in the guide flow path 6B. Furthermore, because the guide flow path 6B gradually widens, the gap is widest at the outlet of the guide flow path 6B, which is located closest to the outlet section 12. Therefore, the flow velocity of the fluid at the outlet of the guide flow path 6B is decelerated. As a result, pressure loss and flow velocity deviation in the curved flow path section 13 can be further reduced.

[0108] (4) A flow guide 2C according to a fourth aspect is a flow guide 2, 2A, 2B, 2C, or 2D according to any one of (1) to (3), in which the guide portion 3C has a plurality of flow path forming portions 5C arranged side by side and spaced apart in the intersecting direction Dp so as to form the guide flow path 6C therebetween in the intersecting direction Dp, the cross-sectional shape of the flow path forming portions 5C when viewed from a direction perpendicular to the flow direction Df and the intersecting direction Dp is formed rectangular, and among the corners of the flow path forming portions 5C formed at positions close to the inlet portion 11 in the second direction D2, the corners formed at positions far from the inlet portion 11 in the first direction D1 have a convex curved surface 7.

[0109] With this configuration, the fluid flowing into the flow guide 2C flows along the wall surface on the upstream side of the flow path forming portion 5C in the second direction D2, and then flows along the convex curved surface 7 of the corner formed at a position far from the inlet portion 11. As a result, the fluid flowing into the guide flow path 6C flows along the side surface of the flow path forming portion 5C that forms part of the guide flow path 6C. In other words, the Coanda effect can be imparted to the fluid flowing into the guide flow path 6C. As a result, the fluid can be attracted to the side surface of the flow path forming portion 5C within the guide flow path 6C. This suppresses separation of the fluid flowing into the guide flow path 6C, thereby suppressing pressure loss.

[0110] (5) The flow guide 2C according to the fifth aspect is the flow guide 2C of (4), in which, among the corners formed in the flow path forming portion 5C at a position close to the inlet portion 11 in the second direction D2, the corner formed at a position close to the inlet portion 11 in the first direction D1 has a convex curved surface 7.

[0111] With this configuration, when the fluid flowing into the flow guide 2C reaches the corner formed at a position close to the inlet 11, it collides with the convex curved surface 7 and flows so as to branch gently along the convex curved surface 7. This suppresses separation of the fluid when it flows into the guide flow path 6C, thereby suppressing pressure loss.

[0112] (6) A flow guide 2D according to a sixth aspect is any of the flow guides 2, 2A, 2B, 2C, and 2D of (1) to (5), in which the guide portion 3D has a plurality of flow path forming portions 5D arranged side by side in the intersecting direction Dp at a distance from each other so as to form the guide flow path 6D therebetween in the intersecting direction Dp, and the cross-sectional shape of the flow path forming portion 5D when viewed from a direction perpendicular to the flow direction Df and the intersecting direction Dp is formed in a wing shape in which, in the first direction D1, a concave positive pressure surface 81 is arranged near the inlet portion 11 and a convex negative pressure surface 82 is arranged farther from the inlet portion 11 than the positive pressure surface 81.

[0113] With this configuration, when the fluid flowing into the flow guide 2D reaches the upstream end of the flow path forming portion 5D, it collides with the leading edge of the wing shape and flows so as to branch gently along the leading edge. This reduces the collision loss of the fluid when it flows into the guide flow path 6D. Furthermore, by making the flow path forming portion 5D wing-shaped, the fluid flows along the positive pressure surface 81 and the negative pressure surface 82, which makes the fluid turn smoothly. Therefore, separation of the fluid flowing through the guide flow path 6D is suppressed, and pressure loss can be suppressed.

[0114] (7) The curved duct 1 according to the seventh aspect comprises an inlet section 11 through which a fluid flows in a first direction D1, an outlet section 12 arranged at a position intersecting the inlet section 11 and through which the fluid flows out in a second direction D2 intersecting the first direction D1, and having a larger flow path cross-sectional area than the inlet section 11, and a curved flow path section 13 connecting the inlet section 11 and the outlet section 12 and in which the flow guides 2, 2A, 2B, 2C, and 2D of (1) to (6) are arranged.

[0115] With this configuration, even when the flow direction Df is significantly deflected toward the outlet, which has a larger flow path cross-sectional area than the inlet portion 11, the fluid can be circulated while minimizing losses associated with the deflection of the fluid and the expansion of the flow path cross-sectional area.

[0116] (8) A flow guide 240 according to an eighth aspect is a flow guide 240 provided in a duct body 201, the flow guide 240 having an inlet portion 210 through which a fluid flows in a first direction D1, an outlet portion 220 through which the fluid flows out in a second direction D2 intersecting the first direction D1 and which has a flow path cross-sectional area larger than that of the inlet portion 210, and a bending portion 230 which connects the inlet portion 210 and the outlet portion 220 and turns a flow direction Df of the fluid from the first direction D1 to the second direction D2, the flow guide 240 having a plurality of guide plates 250 arranged at intervals in a flow path width direction W intersecting the flow direction Df and which guide the fluid, and each of the guide plates 250 has a cross-sectional area of ​​the flow path larger than that of the inlet portion 210. The fluid passage has a flat plate portion 251 provided within the bent portion 230 and extending from the inlet portion 210 side toward the first direction D1, and a turning plate portion 252 provided within the bent portion 230 and connected to the downstream side of the flat plate portion 251 and extending toward the second direction D2 as it approaches the first direction D1, and an enlarged flow path F1 is formed between adjacent flat plate portions 251, and the flow path cross-sectional area expands as it approaches the downstream side of the flow direction Df, and a turning flow path F2 is formed between adjacent turning plate portions 252, and is connected to the enlarged flow path F1 and turns the flow of the fluid from the first direction D1 toward the second direction D2.

[0117] This allows the flow to be decelerated in the expanded flow path F1. The decelerated flow is then redirected in the redirecting flow path F2, thereby reducing pressure loss.

[0118] (9) The flow guide 240 according to the ninth aspect is the flow guide 240 of (8), which is provided in the outlet flow path 221, and further has an extension plate portion 253 connected to the turning plate portion 252 and extending in the second direction D2.

[0119] This makes it possible to obtain a rectifying effect.

[0120] (10) The flow guide 240 according to the tenth aspect is the flow guide 240 of (8), in which the turning flow path F2 causes the fluid to flow out in a direction inclined toward the first direction D1 with respect to the second direction D2.

[0121] This allows the turning angle to be shallower, and flow separation and drift can be suppressed.

[0122] (11) The flow guide 240 according to an eleventh aspect is the flow guide 240 of any one of (8) to (10), in which the cross-sectional area of ​​the forward turning flow path F2 increases toward the downstream side.

[0123] This allows the flow to be decelerated in the turning flow path F2 as well, further reducing pressure loss.

[0124] (12) The flow guide 240 according to the twelfth aspect is the flow guide 240 of (11), further comprising a dividing guide plate 260 provided between the adjacent turning flow paths F2 and dividing the turning flow path F2 in the flow path width direction W.

[0125] This makes it possible to suppress drift of the flow on the downstream side.

[0126] (13) A curved duct 200 according to a thirteenth aspect includes the flow guide 240 according to any one of (8) to (12) and the duct body 201.

[0127] REFERENCE SIGNS LIST 1 curved duct 11 inlet portion 12 outlet portion 13 curved flow path portion 131 first flow path 132 second flow path 133 curved flow path 2, 2A, 2B, 2C, 2D flow guide 3, 3A, 3B, 3C, 3D guide portion 31, 31D first guide portion 32, 32D second guide portion 33 third guide portion 4 intersecting flow path 5, 5B, 5C, 5D flow path forming portion 6, 6A, 6B, 6C, 6D guide flow path 61, 61A, 61B, 61C, 61D first guide flow path 62, 62A, 62B, 62C, 62D second guide flow path 63, 63A, 63B, 63C third guide flow path θ inclination angle 7 convex curved surface 81 positive pressure surface 82 negative pressure surface D1 first direction D2 Second direction Df Flow direction Dp Intersecting direction 200 Bent duct 201 Duct body 210 Inlet portion 211 Inlet flow path 220 Outlet portion 221 Outlet flow path 230 Bent portion 231 Bent flow path 235 Inner casing portion 236 Outer casing portion 236a Upstream plate portion 236b Midstream plate portion 236c Downstream plate portion 240 Flow guide 250 Guide plate 251 Flat plate portion 252 Turning plate portion 253 Extension plate portion 260 Divided guide plate F1 Expanded flow path F2 Turning flow path F3 Straightening flow path D1 First direction D2 Second direction D3 Third direction W Flow path width direction Df Flow direction

Claims

1. A flow guide arranged in a curved flow path section that curves to connect an inlet section through which a fluid flows in in a first direction, and an outlet section that is arranged at a position intersecting the inlet section and through which the fluid flows out in a second direction intersecting the first direction and has a flow path cross-sectional area larger than that of the inlet section, the flow guide comprising: a plurality of guide sections that are arranged in the curved flow path section and guide the flow direction of the fluid flowing through the curved flow path section to bend from the first direction to the second direction, the plurality of guide sections are arranged at a distance from each other in the flow direction, and the plurality of guide sections are arranged side by side at a distance from each other in a cross direction that intersects the flow direction, and each of the guide sections has a guide flow path that extends intersecting the first direction, and between two guide flow paths adjacent to each other in the second direction, the guide flow path formed in the guide section closer to the outlet section has a larger inclination angle with respect to the first direction.

2. A flow guide as described in claim 1, wherein, of two guide flow paths adjacent to each other in the second direction, the guide flow path formed in the guide section closer to the outlet section has a larger flow path cross-sectional area.

3. A flow guide according to claim 1 or 2, wherein the spacing between the guide flow paths in the crossing direction increases in the flow direction from a position closer to the inlet portion toward a position closer to the outlet portion.

4. A flow guide as described in claim 1 or 2, wherein the guide section has a plurality of flow path forming sections arranged side by side and spaced apart in the intersecting direction so as to form the guide flow paths therebetween in the intersecting direction, the cross-sectional shape of the flow path forming sections when viewed from a direction perpendicular to the flow direction and the intersecting direction is formed into a rectangular shape, and among the corners formed in the flow path forming sections at positions close to the inlet section in the second direction, the corners formed at positions far from the inlet section in the first direction have a convex curved surface.

5. A flow guide as described in claim 4, wherein, among the corners formed in the flow path forming portion at positions close to the inlet portion in the second direction, the corner formed at a position close to the inlet portion in the first direction has a convex curved surface.

6. A flow guide as described in claim 1 or 2, wherein the guide section has a plurality of flow path forming sections arranged side by side and spaced apart in the intersecting direction so as to form the guide flow path therebetween in the intersecting direction, and the cross-sectional shape of the flow path forming section when viewed from a direction perpendicular to the flow direction and the intersecting direction is formed in a wing shape in which, in the first direction, a concave positive pressure surface is arranged near the inlet section and a convex negative pressure surface is arranged farther from the inlet section than the positive pressure surface.

7. A curved duct comprising: an inlet section through which a fluid flows in a first direction; an outlet section arranged at a position intersecting the inlet section, through which the fluid flows out in a second direction intersecting the first direction, the outlet section having a flow path cross-sectional area larger than that of the inlet section; and a curved flow path section connecting the inlet section and the outlet section, in which the flow guide described in claim 1 or 2 is arranged.

8. A flow guide provided in a duct body having an inlet portion through which a fluid flows in in a first direction, an outlet portion through which the fluid flows out in a second direction intersecting the first direction and which has a larger flow path cross-sectional area than the inlet portion, and a bending portion connecting the inlet portion and which turns the flow direction of the fluid from the first direction to the second direction, the flow guide having a plurality of guide plates arranged at intervals in a flow path width direction intersecting the flow direction and guiding the fluid, each of the guide plates having: a flat plate portion provided within the bending portion and extending from the inlet portion toward the first direction; and a turning plate portion provided within the bending portion and connected to the downstream side of the flat plate portion and extending toward the second direction as it approaches the first direction, wherein an enlarged flow path is formed between adjacent flat plate portions whose flow path cross-sectional area increases as it approaches the downstream side of the flow direction, and a turning flow path is formed between adjacent turning plate portions which is connected to the enlarged flow path and turns the flow of the fluid from the first direction to the second direction.

9. The flow guide according to claim 8, further comprising an extension plate portion disposed within said outlet flow passage, connected to said turning plate portion and extending in said second direction.

10. The flow guide of claim 8, wherein the turning flow passage causes the fluid to exit in a direction inclined toward the first direction relative to the second direction.

11. A flow guide according to any one of claims 8 to 10, wherein the turning flow passage has a flow passage cross-sectional area that increases toward the downstream side.

12. The flow guide according to claim 11, further comprising a dividing guide plate provided between adjacent turning flow paths to divide the turning flow paths in the flow path width direction.

13. A curved duct comprising: a flow guide according to any one of claims 8 to 10; and the duct body.

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