A new diversion and trash screen for water intake of hydropower station

Abstract

The application discloses a novel diversion and trash rack for a water intake of a hydropower station and relates to the field of water conservancy and hydropower engineering, aiming to reduce the hydraulic loss of water after the water is filtered through the water intake of the hydropower station. The technical scheme adopted by the application is as follows: the novel diversion and trash rack for the water intake of the hydropower station comprises a ring-shaped frame body and a plurality of diversion plates fixedly installed on the frame body, the plate surfaces of the diversion plates are parallel to each other and perpendicular to the corresponding planes of the frame body, the diversion plates are streamline-shaped, the outer contour of the diversion plates on a first section is isosceles trapezoidal, the first section is parallel to the plate surfaces of the diversion plates and passes through the center of the diversion plates, one side of the isosceles trapezoid corresponding to the upper base is a water-facing surface, one side of the isosceles trapezoid corresponding to the lower base is a backwater surface, the water-facing surface and the two plate surfaces are all provided with inclined surfaces, and the corners between the plate surfaces, the water-facing surface and the inclined surfaces are all provided with chamfers. The application is arranged at the water intake of the hydropower station and plays a role in guiding and filtering the water flow.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering, specifically a structure arranged at the water intake of a hydropower station to guide and filter water flow. Background Technology

[0002] The water supply system of a hydropower station includes technical water supply, fire-fighting water supply, and domestic water supply. To prevent large-sized, large-particle solid impurities from entering the water supply system through the hydropower station's intake, a trash rack is generally installed at the intake for preliminary filtration of the water. Existing trash racks consist of a frame and multiple round steel bars fixed to the frame, all on the same plane, parallel to each other and evenly spaced. The primary considerations for using round steel bars for preliminary filtration are manufacturing cost, material strength, and trash-blocking effectiveness; the hydraulic losses caused by the round steel bars are not considered or are insufficiently considered. For the water entering the water supply system, pumps are needed to pump it to different elevations. Due to the hydraulic losses caused by the round steel bars of the trash rack, the required pump head is too high, resulting in high pump energy consumption. Summary of the Invention

[0003] This invention provides a novel guide rail for the intake of a hydropower station, which aims to reduce hydraulic losses after water flows through the intake of the hydropower station and undergoes preliminary filtration.

[0004] The technical solution adopted in this invention is: a novel guide rail for a hydropower station intake, comprising an annular frame and multiple guide plates fixedly installed on the frame. The surfaces of each guide plate are parallel to each other and perpendicular to the corresponding plane of the frame. The guide plates are streamlined, and the outer contour of the guide plate on the first cross section is an isosceles trapezoid. The first cross section is parallel to the surface of the guide plate and passes through the center of the guide plate. The two sides and the upper base of the isosceles trapezoid are the water-facing side, and the lower base of the isosceles trapezoid is the water-repellent side. A chamfer is provided between the water-facing side and the two plate surfaces. Chamfers are provided at the corners of the guide plate surface, the water-facing side, and the chamfer.

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

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

[0007] Furthermore, the isosceles trapezoid has an angle of 15° between its legs and lower base, a chamfer radius of 5mm, a chamfer radius of 300mm between its legs and upper base, and a height of 50mm.

[0008] Furthermore, the spacing between each deflector is equal. For example, the distance between the first cross-section of any two adjacent deflectors is 70 mm.

[0009] Specifically: The frame is circular, and the two ends of the baffle are welded to the frame.

[0010] To further enhance the connection strength of the guide vane to the frame, a bevel is provided at the internal angle formed between the backwater surface of the guide vane and the frame, and the connection is then welded. For example, the dihedral angle between the beveled surface and the surface of the guide vane is 45°, and the width of the projection of the beveled surface onto the first section is 5mm.

[0011] The beneficial effects of this invention are as follows: From the perspective of flow resistance loss in fluid mechanics, this invention designs the guide plate as a streamlined shape, which improves the flow state of the water flowing through the water intake to the greatest extent, making the flow field change uniform and stable, and reducing the hydraulic loss of the water flowing through the water intake. This not only helps to improve the reliability of the water supply system and improve the water intake efficiency, but also reduces the head of the water pump in the water supply system and reduces the energy loss of the hydropower station during operation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a novel water intake guide and debris barrier for a hydropower station according to the present invention.

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

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

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

[0016] Figure 5 This is a schematic diagram of the flow field as water flows through the guide plate in this invention.

[0017] Attached reference numerals: Frame 1, Guide plate 2, Plate surface 21, Water-facing surface 22, Water-repelling surface 23, Inclined surface 24, Slope 25. Figure 3 and Figure 4 The unit for length annotations in the text is mm. Figure 3 and Figure 4 The unit for the radius designation is mm. Detailed Implementation

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] like Figure 1 and Figure 2 As shown, this invention discloses a novel water intake guide and debris barrier for a hydropower station, comprising an annular frame 1 and multiple guide plates 2 fixedly installed on the frame 1. The frame 1 is generally annular, but can also be other polygonal shapes, such as a square frame. To ensure the strength of the invention, both the frame 1 and the guide plates 2 are preferably made of metal, generally steel. The guide plates 2 are fixedly connected to the frame 1, generally by welding. For example, the frame 1 is annular, and the two ends of the guide plates 2 are welded to the frame 1. Each guide plate 2 has two surfaces 21, which are parallel to each other, and the surfaces 21 of each guide plate 2 are parallel to each other and perpendicular to the corresponding plane of the frame 1. To achieve effective water flow guidance and filtration, 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 vane 2 is streamlined to reduce hydraulic losses as water flows past it. The guide vane 2 is described in detail below. Figure 3 As shown, the outer contour of the guide plate 2 on the first cross-section is an isosceles trapezoid. The first cross-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 are the water-facing side 22, and the side corresponding to the lower base is the water-repelling side 23. To avoid the sharp edges on the guide plate 2 from affecting the flow field, chamfers are provided at the corners between the plate surface 21, the water-facing side 22, and the oblique section 24 of the guide plate 2. For example, the angle formed by the sides and the lower base of the isosceles trapezoid is 15°, the chamfer radius is 5mm, the chamfer radius between the sides 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 three plane segments or three curved surfaces. When the water-facing surface 22 is three plane segments, the water-facing surface 22 corresponding to the upper base of the isosceles trapezoid is perpendicular to the water flow direction, and the water-facing surfaces 22 corresponding to the two legs of the isosceles trapezoid are oblique to the water flow direction. An oblique tangent surface 24 is provided between the water-facing surface 22 and both plate surfaces 21. The oblique tangent surface 24 mainly serves to reduce hydraulic losses in the water flow. The corners of the back surface 23 of the guide plate 2 have little impact on the flow field; therefore, the corners of the back surface 23 can be chamfered or not.

[0021] The shape of the guide vane 2 on the second section is as follows Figure 4As shown, the second section is perpendicular to the plane corresponding to the frame 1 and to the plate surface 21 of the guide plate 2. The water-facing surfaces 22 corresponding to the two sides and the upper base of the isosceles trapezoid are both planes. A chamfer is provided between the oblique cut surface 24 and the plate surface 21 of the guide plate 2. To ensure the function of the guide plate 2, the dihedral angle between the oblique cut surface 24 and the plate surface 21 is close to a straight angle; for example, the dihedral angle between the oblique cut surface 24 and the plate surface 21 is 165°, and the chamfer radius is 30mm. Chamfers are provided between the two oblique cut surfaces 24 and the water-facing surfaces 22 of the guide plate 2; for example, the chamfer radius between the oblique cut surface 24 and the water-facing surfaces 22 is 2mm. Figure 4 As shown. To further reduce the resistance of the water-facing surface 22, the two oblique surfaces 24 of the guide plate 2 can be directly connected by a chamfer, and the curved surface formed by the chamfer is the water-facing surface 22. The thickness of the guide plate 2 is determined according to the strength requirements. For example, if the distance between the two plates 21 of a single guide plate 2 is 15mm, that is, the thickness of the guide plate 2 is 15mm, and the maximum width of the guide plate 2 is 50mm, of which the width of the projection of the oblique surface 24 on the first section is 20mm.

[0022] The deflector 2 can be fixed to either side of the corresponding plane of the frame 1, but all deflectors 2 are located on the same side of the frame 1. For example, see... Figure 1 and Figure 2 The water flow first passes through the guide plate 2. To improve the connection strength of the guide plate 2 to the frame 1, a bevel is provided at the internal angle formed between the back surface 23 of the guide plate 2 and the frame 1, and the two are welded together. See, for example... Figure 4 The dihedral angle between the slope surface 25 corresponding to the bevel 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 5mm.

Claims

1. A novel guide rail for a hydropower station intake, comprising an annular frame (1) and multiple guide plates (2) fixedly installed on the frame (1), wherein the spacing between the guide plates (2) is equal, characterized in that: The 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 the first section is an isosceles trapezoid. The first section is parallel to the surface (21) of the guide plate (2) and passes through the center of the guide plate (2). The two sides of the isosceles trapezoid and the side corresponding to the upper base are the water-facing side (22). The side corresponding to the lower base of the isosceles trapezoid is the water-repelling side (23). The water-facing side (22) and the two surfaces (21) are provided with oblique cut surfaces (24). The corners between the surface (21), the water-facing side (22) and the oblique cut surfaces (24) of the guide plate (2) are respectively provided with chamfers. The angle formed by the waist and the lower base of the isosceles trapezoid is 15° and the chamfer radius is 5mm. The chamfer radius between the waist and the upper base of the isosceles trapezoid is 300mm. The height of the isosceles trapezoid is 50mm. On the second section of the guide plate (2), a chamfer is set between the two oblique surfaces (24), or the water-facing surfaces (22) corresponding to the two sides of the isosceles trapezoid and the water-facing surfaces (22) corresponding to the upper base are both planes. A chamfer is set between the oblique surface (24) and the water-facing surface (22). The distance between the two plate surfaces (21) of the guide plate (2) is 15mm. The dihedral angle between the oblique surface (24) and the plate surface (21) is 165° and the chamfer radius is 30mm. The chamfer radius between the oblique surface (24) and the water-facing surface (22) is 2mm. The width of the projection of the oblique surface (24) on the first section is 20mm. The second section is perpendicular to the plane corresponding to the frame (1) and perpendicular to the plate surface (21) of the guide plate (2). The frame (1) is circular. The two ends of the guide plate (2) are welded to the frame (1). The backwater surface (23) of the guide plate (2) and the frame (1) form a bevel and are welded together. The dihedral angle between the slope surface (25) corresponding to the bevel and the plate surface (21) of the guide plate (2) is 45°. The width of the projection of the slope surface (25) on the first section is 5mm.

2. A novel water intake guide rail for a hydropower station as described in claim 1, characterized in that: The distance between the first cross section of two adjacent guide plates (2) is 70mm.

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