Novel diversion trash rack for water intake of hydropower station

Abstract

The utility model discloses a novel diversion trash rack for a water intake of a hydropower station, relates to the field of water conservancy and hydropower engineering, and aims to reduce hydraulic loss after water flows through the water intake of the hydropower station and is preliminarily filtered. According to the technical scheme, the novel hydropower station water intake flow guide trash rack comprises an annular frame body and a plurality of flow guide plates fixedly installed on the frame body, the plate faces of the flow guide plates are parallel to one another and are perpendicular to the corresponding plane of the frame body, the flow guide plates are in a streamline shape, the outer contours of the flow guide plates on the first section are isosceles trapezoids, and the outer contours of the flow guide plates on the second section are isosceles trapezoids. The first section is parallel to the plate surface of the flow guide plate and passes through the center of the flow guide plate, the sides, corresponding to the upper bottom, of the two waists of the isosceles trapezoid are upstream faces, the side, corresponding to the lower bottom, of the isosceles trapezoid is a downstream face, diagonal planes are arranged between the upstream faces and the two plate surfaces, and chamfers are arranged on the plate surface of the flow guide plate and corner angles between the upstream faces and the diagonal planes respectively. The device is used for being arranged at the water intake of the hydropower station to guide and filter water flow.

Description

Technical Field

[0001] The utility model relates to the field of water conservancy and hydropower engineering, in particular to a structure arranged at a water intake of a hydropower station and having the functions of guiding and filtering water flow. Background Art

[0002] The water supply system of a hydropower station includes technical water supply, fire fighting water supply and domestic water supply. In order to prevent large-sized and large-diameter solid impurities from entering the water supply system through the water intake of the hydropower station, a trash rack is generally installed at the water intake to perform preliminary filtration of the water. The existing trash rack includes a frame and a plurality of round steels fixedly installed on the frame. Each round steel is in the same plane, parallel to each other and arranged at equal intervals. The main factors to be considered for preliminary filtration of water bodies by using round steel are manufacturing cost, material strength and trash interception effect. The hydraulic loss caused by the round steel is not considered or is insufficiently considered. For the water entering the water supply system, it is also necessary to use a water pump to pump it to different elevations. Due to the hydraulic loss caused by the round steel of the trash rack, the head requirement of the water pump is relatively high, and the energy consumption of the water pump is relatively high. Utility Model Content

[0003] The utility model provides a novel guide trash rack for a water intake of a hydropower station, aiming at reducing the hydraulic loss of water after the water body flows through the water intake of the hydropower station for preliminary filtration.

[0004] The technical scheme adopted by the utility model is: a novel water intake diversion trash rack of a hydropower station, comprising an annular frame and a plurality of guide plates fixedly mounted on the frame, the plate surfaces of the guide plates are parallel to each other and perpendicular to the plane corresponding to the frame, the guide plates are streamlined, the outer contour of the guide plates on the first section is an isosceles trapezoid, the first section is parallel to the plate surface of the guide plates and passes through the center of the guide plates, the two waists and the upper bottom of the isosceles trapezoid correspond to the side of the water-facing surface, the lower bottom of the isosceles trapezoid corresponds to the side of the water-receiving surface, beveled surfaces are arranged between the water-facing surface and the two plate surfaces, and chamfers are arranged at the edges and corners between the plate surface of the guide plate, the water-facing surface and the beveled surface.

[0005] Furthermore: on the second cross-section of the guide plate, a chamfer is set between the two beveled surfaces, or the water-facing surfaces corresponding to the two sides of the isosceles trapezoid and the water-facing surface corresponding to the upper bottom are both planes, a chamfer is set between the beveled surface and the water-facing surface, and the second cross-section is perpendicular to the plane corresponding to the frame and to the board surface of the guide plate.

[0006] Specifically: the distance between the two board surfaces of a single guide plate is 15 mm, the dihedral angle between the chamfered surface and the board surface is 165°, the chamfer radius is 30 mm, the chamfer radius between the chamfered surface and the water-facing surface is 2 mm, and the width of the projection of the chamfered surface on the first section is 20 mm.

[0007] Furthermore, the angle formed by the waist of the isosceles trapezoid and the lower base is 15°, the chamfer radius is 5 mm, the chamfer radius between the waist of the isosceles trapezoid and the upper base is 300 mm, and the height of the isosceles trapezoid is 50 mm.

[0008] Furthermore, the spacing between each guide plate is equal. For example, the distance between the first cross sections of two adjacent guide plates is 70 mm.

[0009] Specifically: the frame is in a circular ring shape, and the two ends of the guide plate are welded to the frame.

[0010] In order to improve the connection strength of the guide plate on the frame, further: a groove is set at the position of the inner angle formed by the back water surface of the guide plate and the frame and welded. For example, the dihedral angle between the slope surface corresponding to the groove and the plate surface of the guide plate is 45°, and the width of the projection of the slope surface on the first section is 5 mm.

[0011] The beneficial effects of the utility model are as follows: from the perspective of flow resistance loss in fluid mechanics, the utility model designs the guide plate to be streamlined, thereby maximally improving the flow state of water flowing through the water intake, making the flow field change uniform and stable, and reducing the hydraulic loss of water flowing through the water intake, which is not only beneficial to improving the reliability of the water supply system and the water intake efficiency, but also can reduce the head of the water pump of the water supply system and reduce the energy loss during the operation period of the hydropower station. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The utility model is a structural schematic diagram of a novel diversion trash rack at a water intake of a hydropower station.

[0013] Figure 2 yes Figure 1 Side view of the illustrated embodiment.

[0014] Figure 3 yes Figure 1 The structure diagram of the guide plate in the first cross section in the embodiment shown.

[0015] Figure 4 yes Figure 1 The structure diagram of the guide plate in the second cross section in the embodiment shown.

[0016] Figure 5 It is a schematic diagram of the flow field of water flowing through the guide plate in the utility model.

[0017] Reference numerals: frame 1 , guide plate 2 , plate surface 21 , water-facing surface 22 , water-receiving surface 23 , chamfered surface 24 , slope surface 25 . Figure 3 and Figure 4 The lengths in the table are marked in mm. Figure 3 and Figure 4 The unit of the radius marking is mm. DETAILED DESCRIPTION

[0018] The utility model will be further described below in conjunction with the accompanying drawings.

[0019] like Figure 1 and Figure 2 As shown, the utility model is a new type of water intake diversion trash rack for a hydropower station, including an annular frame 1 and a plurality of guide plates 2 fixedly mounted on the frame 1. The frame 1 is generally in the shape of a circular ring, but may also be other polygonal frames, such as a square frame. In order to ensure the strength of the utility model, the material of the frame 1 and the guide plates 2 is preferably metal, generally steel. The guide plates 2 are fixedly connected to the frame 1, generally by welding. For example, the frame 1 is in the shape of a circular ring, and the two ends of the guide plates 2 are welded to the frame 1. Each guide plate 2 has two plate surfaces 21, and the two plate surfaces 21 are parallel to each other. The plate surfaces 21 of each guide plate 2 are parallel to each other and perpendicular to the plane corresponding to the frame 1. In order to achieve the purpose of effectively diverting and filtering the water flow, the spacing between each guide plate 2 is equal, for example, the spacing between two adjacent guide plates 2 is 70 mm.

[0020] The guide plate 2 is streamlined to reduce the hydraulic loss of water after flowing through the guide plate 2. The guide plate 2 is described in detail below. Figure 3 As shown, the outer contour of the guide plate 2 on the first section is an isosceles trapezoid. The first section is parallel to the plate surface 21 of the guide plate 2 and passes through the center of the guide plate 2. The side corresponding to the two waists and the upper base of the isosceles trapezoid is the water-facing surface 22, and the side corresponding to the lower base of the isosceles trapezoid is the water-repelling surface 23. In order to prevent the edges and corners on the guide plate 2 from affecting the flow field of the water flow, chamfers are set at the edges and corners between the plate surface 21, the water-facing surface 22 and the chamfered surface 24 of the guide plate 2. For example, the angle formed by the waist of the isosceles trapezoid and the lower base is 15°, the chamfer radius is 5mm, the chamfer radius between the waist of the isosceles trapezoid and the upper base is 300mm, and the height of the isosceles trapezoid is 50mm. Figure 3 As shown. The water-facing surface 22 can be a three-segment plane or a three-segment curved surface. When the water-facing surface 22 is a three-segment plane, the water-facing surface 22 corresponding to the upper base of the isosceles trapezoid is perpendicular to the direction of the water flow, and the water-facing surfaces 22 corresponding to the two sides of the isosceles trapezoid are oblique to the direction of the water flow. Beveled surfaces 24 are provided between the water-facing surface 22 and the two plate surfaces 21, and the beveled surfaces 24 mainly play the role of reducing the hydraulic loss of the water flow. The edges and corners of the back surface 23 of the guide plate 2 have little effect on the flow field of the water flow, so the edges and corners of the back surface 23 can be chamfered or not.

[0021] The shape of the guide plate 2 on the second cross section is as follows: Figure 4As shown, the second cross section is perpendicular to the plane corresponding to the frame 1 and perpendicular to the board surface 21 of the guide plate 2. The water-facing surfaces 22 corresponding to the two waists of the isosceles trapezoid and the water-facing surface 22 corresponding to the upper base are both planes, and a chamfer is set between the beveled surface 24 of the guide plate 2 and the board surface 21. In order to ensure the function of the guide plate 2, the dihedral angle between the beveled surface 24 and the board surface 21 is close to a straight angle, for example, the dihedral angle between the beveled surface 24 and the board surface 21 is 165°, and the chamfer radius is 30mm; chamfers are set between the two beveled surfaces 24 of the guide plate 2 and the water-facing surface 22, for example, the chamfer radius between the beveled surface 24 and the water-facing surface 22 is 2mm. Figure 4 In order to further reduce the resistance of the water-facing surface 22, the two chamfered surfaces 24 of the guide plate 2 can be directly connected by chamfering, and the curved surface formed by the chamfering is the water-facing surface 22. The thickness of the guide plate 2 is calculated and determined according to the strength requirements. For example, the distance between the two plate surfaces 21 of a single guide plate 2 is 15 mm, that is, the thickness of the guide plate 2 is 15 mm, and the maximum width of the guide plate 2 is 50 mm, wherein the width of the projection of the chamfered surface 24 on the first section is 20 mm.

[0022] The guide plate 2 can be fixed on any side of the corresponding plane of the frame 1, but each guide plate 2 is located on the same side of the frame 1. For example, see Figure 1 and Figure 2 , the water flows through the guide plate 2 first. In order to improve the connection strength of the guide plate 2 on the frame 1, a groove is set at the position of the inner angle formed by the back surface 23 of the guide plate 2 and the frame 1 and welded. Figure 4 The dihedral angle between the slope 25 corresponding to the groove and the plate surface 21 of the guide plate 2 is 45°, and the width of the projection of the slope 25 on the first section is 5 mm.

Claims

1. A novel water intake diversion trash rack for a hydropower station, comprising an annular frame (1) and a plurality of guide plates (2) fixedly mounted on the frame (1), characterized in that: The plate surfaces (21) of each guide plate (2) are parallel to each other and perpendicular to the plane corresponding to the frame (1); the guide plate (2) is streamlined; the outer contour of the guide plate (2) on a first section is an isosceles trapezoid; the first section is parallel to the plate surface (21) of the guide plate (2) and passes through the center of the guide plate (2); the two sides and the upper base of the isosceles trapezoid correspond to a water-facing surface (22); the lower base of the isosceles trapezoid corresponds to a water-receiving surface (23); chamfered surfaces (24) are arranged between the water-facing surface (22) and the two plate surfaces (21); and chamfers are arranged at the edges and corners between the plate surface (21), the water-facing surface (22) and the chamfered surface (24) of the guide plate (2).

2. A new type of water intake guide trash rack for a hydropower station as claimed in claim 1, characterized in that: On the second cross section of the guide plate (2), a chamfer is provided between the two oblique cut surfaces (24), or the water-facing surfaces (22) corresponding to the two sides of the isosceles trapezoid and the water-facing surface (22) corresponding to the upper base are both planes, a chamfer is provided between the oblique cut surface (24) and the water-facing surface (22), and the second cross section is perpendicular to the plane corresponding to the frame (1) and perpendicular to the plate surface (21) of the guide plate (2).

3. A new type of water intake guide trash rack for a hydropower station as claimed in claim 2, characterized in that: The distance between the two plate surfaces (21) of the single guide plate (2) is 15 mm, the dihedral angle between the chamfered surface (24) and the plate surface (21) is 165°, the chamfer radius is 30 mm, the chamfer radius between the chamfered surface (24) and the water-facing surface (22) is 2 mm, and the width of the projection of the chamfered surface (24) on the first section is 20 mm.

4. A new type of water intake guide trash rack for a hydropower station as claimed in claim 1, characterized in that: The angle formed by the waist of the isosceles trapezoid and the lower base is 15°, the chamfer radius is 5 mm, the chamfer radius between the waist of the isosceles trapezoid and the upper base is 300 mm, and the height of the isosceles trapezoid is 50 mm.

5. A new type of water intake guide trash rack for a hydropower station as claimed in any one of claims 1 to 4, characterized in that: The spacing between each guide plate (2) is equal.

6. A new type of water intake guide trash rack for a hydropower station as claimed in claim 5, characterized in that: The distance between the first cross sections of two adjacent guide plates (2) is 70 mm.

7. A new type of water intake guide trash rack for a hydropower station as claimed in any one of claims 1 to 4, characterized in that: The frame (1) is in the shape of a circular ring, and the two ends of the guide plate (2) are welded to the frame (1).

8. A novel water intake guide trash rack for a hydropower station as claimed in claim 6, characterized in that: A groove is provided at the position of the inner angle formed by the back-water surface (23) of the guide plate (2) and the frame (1) and the two are welded together.

9. A novel water intake guide trash rack for a hydropower station as claimed in claim 7, characterized in that: The dihedral angle between the slope surface (25) corresponding to the groove and the plate surface (21) of the guide plate (2) is 45°, and the width of the projection of the slope surface (25) on the first section is 5 mm.

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