The inlet / outlet shape of the tailwater pipe

Abstract

The present application relates to an inlet / outlet body shape immediately adjacent to a tailwater pipe, wherein the inlet / outlet body shape comprises: a horizontal tunnel section, a bend section, a shaft section, a shaft diffusion section and a diversion section, the tailwater pipe is connected to a horizontal tunnel section, the horizontal tunnel section is connected to a bend section; the bend section is connected to a shaft section, the shaft section is connected to a shaft diffusion section, and the flow channel is divided into an upstream part and a downstream part based on the inverted cone of the shaft diffusion section, and the shaft diffusion section is connected to the diversion section on both the upstream and downstream sides, wherein the design result of the inlet / outlet body shape is determined by the design size of each segment of the inlet / outlet body shape determined by the working parameters, installation parameters and terrain parameters of the target unit and the actual size of each segment obtained by at least one connection constraint preset. The embodiment of the present application can effectively improve the uneven flow state after the tailwater pipe while having good terrain adaptability by combining the water flow characteristics of the side-type and shaft-type inlets / outlets, thereby meeting the requirements of the inlet / outlet of a low-head ground-type powerhouse pumped-storage power station immediately adjacent to the tailwater pipe.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulics of pumped storage power stations and hydraulic structures, and in particular to a water inlet / outlet shape immediately adjacent to a tailwater pipe. Background Art

[0002] Pumped storage will play a key role in ensuring the stability of the new power system, promoting the consumption of new energy, and supporting the realization of the dual carbon goals. Pumped storage power stations have the characteristics of two-way operation and two-way water flow. Their water inlet is also the outlet, and they must meet the requirements of smooth flow, average flow, uniform flow velocity, and small head loss at the same time, which poses a challenge to design optimization. In particular, low-head power stations often adopt the tail open plant development method. The distance between the unit and the lower reservoir is very short, and the tailwater pipe is immediately followed by the inlet / outlet. Affected by the uneven flow state of the elbow section of the tailwater pipe, the flow velocity is easily concentrated and offset during the outflow, which makes it difficult for the flow state evaluation parameters of the trash rack section to meet the regulatory requirements, affecting the safety and efficiency of the power station operation.

[0003] Among the related technologies, the research on the optimization design of inlets and outlets is relatively complete, and a number of technologies have emerged to address undesirable flow patterns, such as the design method of adjusting the layout of diversion piers to achieve uniform diversion of inlets and outlets under different operating conditions, the diffusion section shape optimization method based on the response surface model, and the adjustable vortex-proof beam.

[0004] However, the relevant technologies are only aimed at the inlet / outlet of the conventional layout. For the special layout immediately following the tailwater pipe section, it is difficult to solve the problems of flow velocity concentration and deviation by using the side inlet / outlet. At the same time, its terrain conditions are difficult to meet the height difference requirements of the shaft inlet / outlet, which urgently needs to be improved. Summary of the invention

[0005] The present application provides an inlet / outlet shape immediately adjacent to a tailwater pipe, in order to solve the technical problems in the related art that the side inlet / outlet immediately adjacent to the tailwater pipe section is difficult to solve the problems of flow velocity concentration and deviation, and the vertical shaft inlet / outlet is difficult to adapt to terrain conditions.

[0006] A first aspect of the present application provides an inlet / outlet shape immediately adjacent to a tailwater pipe, the inlet / outlet shape comprising: a horizontal tunnel section, a bend section, a shaft section, a shaft diffuser section and a diversion section, the tailwater pipe is connected to one side of the horizontal tunnel section, and the other side of the horizontal tunnel section is connected to the bend section; the upper part of the bend section is connected to the shaft section, the upper part of the shaft section is connected to the shaft diffuser section, and based on the inverted cone of the shaft diffuser section, the flow channel is divided into an upstream part and a downstream part, and the upstream and downstream sides of the shaft diffuser section are respectively connected to the diversion section, wherein the design result of the inlet / outlet shape is determined by the actual size of the horizontal tunnel section, the bend section, the shaft section, the shaft diffuser section and the diversion section obtained by the design size of each segment of the inlet / outlet shape determined by the working parameters, installation parameters and terrain parameters of the target unit and at least one preset connection constraint.

[0007] Optionally, in one embodiment of the present application, the cross-sections of the horizontal tunnel section, the elbow section, the vertical shaft section, the vertical shaft diffusion section and the diversion section are all rectangular or quasi-rectangular.

[0008] Optionally, in one embodiment of the present application, the floor elevation, minimum surge water level and minimum flooding depth of the tailwater pipe are obtained from the working parameters, installation parameters and terrain parameters; the total elevation of the inlet / outlet body is obtained from the floor elevation, minimum surge water level and minimum flooding depth of the tailwater pipe.

[0009] Optionally, in one embodiment of the present application, the end-section height of the horizontal tunnel section is obtained by the initial section height of the horizontal tunnel section, the length of the horizontal tunnel section and the roof expansion angle.

[0010] Optionally, in one embodiment of the present application, the radius of the bend section, the length of the vertical shaft straight pipe section and the height of the vertical shaft diffusion section are obtained by the total elevation and at least one preset connection constraint; the height difference from the bend section to the vertical shaft diffusion section is obtained by the total elevation and the lowest operating water level of the target unit.

[0011] Optionally, in one embodiment of the present application, the inner diameter of the curved pipe section is a 90° curved pipe of equal diameter, and the curvature of the outer diameter of the curved pipe section is a preset curvature.

[0012] Optionally, in one embodiment of the present application, the inner side of the vertical shaft section is vertical, and the outer side of the vertical shaft section is inclined inward and forms a preset angle with the vertical direction.

[0013] Optionally, in one embodiment of the present application, the diffusion curve of the vertical shaft diffusion section is a 1 / 4 ellipse, wherein the ratio of the major axis to the minor axis of the ellipse is in the interval [3, 5], and the inverted cone of the vertical shaft diffusion section is bullet-shaped, wherein the elevation of the cone head of the inverted cone is lower than the bottom plate of the diversion section.

[0014] Optionally, in one embodiment of the present application, the diversion section divides the flow channel into a plurality of sub-flow channels by a diversion pier, and a trash rack is provided at the end of the diversion pier, wherein the size of the trash rack is obtained by the flow rate of the target unit, and the pier head spacing of the diversion pier is obtained by the starting cross-sectional width of the diversion section.

[0015] Optionally, in one embodiment of the present application, the length of the diverter section, the width of the diverter pier, the initial cross-sectional width of the horizontal tunnel section, the single-unit rated flow and the number of trash rack sections of the target unit are obtained from the working parameters, installation parameters and terrain parameters; the cross-sectional height and width of the trash rack are obtained from the value range of the cross-sectional area of ​​a single trash rack, wherein the value range is obtained from the single-unit rated flow, the number of trash rack sections and the maximum average flow velocity of the trash rack section; the starting cross-sectional width of the diverter section and the rectangular cross-sectional width of the bend section are obtained from the length of the diverter section, the width of the diverter pier, the width of the trash rack, the length of the horizontal tunnel section and the initial cross-sectional width of the horizontal tunnel section, wherein, based on the starting cross-sectional width of the diverter section and the rectangular cross-sectional width of the bend section, the single-hole horizontal diffusion angle of the diverter section, the horizontal diffusion angle of the horizontal tunnel section and the width direction diffusion angle of the shaft section all meet the preset angle conditions.

[0016] The embodiment of the present application can determine the design size of each segment of the inlet / outlet body based on the working parameters, installation parameters and terrain parameters of the target unit, wherein the inlet / outlet body includes a tailwater pipe, a horizontal tunnel section, a bend section, a shaft section, a shaft diffusion section and a diversion section, and the actual size of each segment is obtained according to the design size and at least one preset connection constraint, so as to obtain the design result of the inlet / outlet body that meets the preset terrain conditions according to the actual size, and obtain the tailwater pipe inlet / outlet body with good hydraulic characteristics and able to meet the layout requirements of the low-head ground-type plant pumped storage power station, which effectively improves the uneven flow state behind the tailwater pipe and has good terrain adaptability. Thus, the technical problems in the related art that the side inlet / outlet immediately adjacent to the tailwater pipe section is difficult to solve the problem of flow velocity concentration and deviation, and the shaft inlet / outlet is difficult to adapt to terrain conditions are solved.

[0017] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of the structure of an inlet / outlet body immediately connected to a tailwater pipe provided according to an embodiment of the present application;

[0020] Figure 2 A flow chart of a method for designing the shape of an inlet / outlet of a tailwater pipe provided according to an embodiment of the present application;

[0021] Figure 3 A longitudinal cross-sectional view of a water inlet / outlet body immediately adjacent to a tailwater pipe according to one embodiment of the present application;

[0022] Figure 4 A plan view of the shape of an inlet / outlet of a tailwater pipe provided in accordance with an embodiment of the present application;

[0023] Figure 5 A vector diagram of flow velocity distribution at each cross section of the inlet / outlet of the tailwater pipe provided according to one embodiment of the present application. DETAILED DESCRIPTION

[0024] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0025] The following describes the shape of the water inlet / outlet immediately adjacent to the tailwater pipe in an embodiment of the present application with reference to the accompanying drawings. In view of the technical problems that the side inlet / outlet immediately adjacent to the tailwater pipe section is difficult to solve the problems of flow velocity concentration and deviation, and the shaft inlet / outlet is difficult to adapt to terrain conditions in the related technologies mentioned in the above background technology, the present application provides an inlet / outlet shape immediately adjacent to the tailwater pipe. Based on the inlet / outlet shape, the design size of each segment of the inlet / outlet shape can be determined based on the working parameters, installation parameters and terrain parameters of the target unit, wherein the inlet / outlet shape includes a tailwater pipe, a horizontal tunnel section, a bend section, a shaft section, a shaft diffusion section and a diversion section, and the actual size of each segment is obtained according to the design size and at least one preset connection constraint, so as to obtain the design result of the inlet / outlet shape that meets the preset terrain conditions according to the actual size, and obtain a tailwater pipe inlet / outlet shape with good hydraulic characteristics that can meet the layout requirements of a low-head ground-type plant pumped-storage power station, which effectively improves the uneven flow state after the tailwater pipe while having good terrain adaptability. Thereby, the technical problems in the related art that the side inlet / outlet immediately adjacent to the tailwater pipe section is difficult to solve the problems of flow velocity concentration and deviation, and the vertical shaft inlet / outlet is difficult to adapt to terrain conditions are solved.

[0026] Specifically, Figure 1 As shown, the inlet / outlet body of the tailwater pipe of the embodiment of the present application is adjacent to the tailwater pipe 1, wherein the inlet / outlet body may include: a horizontal tunnel section 2, a bend section 3, a vertical shaft section 4, a vertical shaft diffusion section 5 and a diversion section 6.

[0027] Among them, the tailwater pipe 1 is connected to one side of the horizontal tunnel section 2 at the rear, and the other side of the horizontal tunnel section 2 is connected to the elbow section 3; the upper part of the elbow section 3 is connected to the vertical shaft section 4, and the upper part of the vertical shaft section 4 is connected to the vertical shaft diffuser section 5, and the flow channel is divided into an upstream part and a downstream part based on the inverted cone of the vertical shaft diffuser section 5, and the upstream and downstream sides of the vertical shaft diffuser section 5 are respectively connected to the diversion section 6, wherein the design result of the inlet / outlet body shape is determined by the design size of each segment of the inlet / outlet body shape determined by the working parameters, installation parameters and terrain parameters of the target unit and the actual size of the horizontal tunnel section 2, the elbow section 3, the vertical shaft section 4, the vertical shaft diffuser section 5 and the diversion section 6 obtained by the preset at least one connection constraint.

[0028] In the actual implementation process, the embodiments of the present application can be as follows Figure 2 As shown in the figure, the inlet / outlet shape is designed.

[0029] In step S201, the operating parameters, installation parameters and terrain parameters of the target unit are obtained.

[0030] The embodiment of the present application can obtain parameters such as the installation location, terrain conditions, unit installation elevation, minimum operating water level, unit flow rate, etc. of the target unit, so as to subsequently perform corresponding inlet / outlet body design immediately adjacent to the tailwater pipe.

[0031] In step S202, based on working parameters, installation parameters and terrain parameters, the design dimensions of each segment of the inlet / outlet body are determined, wherein the inlet / outlet body includes a horizontal tunnel section 2, a bend section 3, a vertical shaft section 4, a vertical shaft diffusion section 5 and a diversion section 6.

[0032] Furthermore, the embodiment of the present application can calculate the design dimensions of each segment of the inlet / outlet body shape according to the working parameters, installation parameters and terrain parameters, so as to obtain the inlet / outlet body shape of the tailwater pipe that is suitable for the current terrain and the current unit characteristics, wherein, Figure 1 As shown, the inlet / outlet structure includes a tailwater pipe 1, a horizontal tunnel section 2, a bend section 3, a vertical shaft section 4, a vertical shaft diffuser section 5 and a diversion section 6.

[0033] In step S203, the actual size of each segment is obtained according to the design size and at least one preset connection constraint, so as to obtain a design result of the inlet / outlet shape that meets the preset terrain conditions according to the actual size.

[0034] The embodiment of the present application can obtain the actual size of each segment based on the design dimensions and connection constraints calculated above, such as the hole flow distribution constraints, the specification requirement constraints, the unit single unit rated flow constraints, etc., and then complete the design of the inlet / outlet shape, and obtain the inlet / outlet shape of the tailwater pipe that has good hydraulic characteristics and can meet the layout requirements of the low-head ground-type plant pumped storage power station, while effectively improving the uneven flow state behind the tailwater pipe and having good terrain adaptability.

[0035] It should be noted that the connection constraints and preset terrain conditions can be set accordingly by those skilled in the art according to actual target unit parameters, terrain structure, specification requirements, etc., and no specific restrictions are made here.

[0036] Optionally, in one embodiment of the present application, the cross-sections of the horizontal tunnel section 2, the elbow section 3, the vertical shaft section 4, the vertical shaft diffuser section 5 and the diversion section 6 are all rectangular or quasi-rectangular.

[0037] In some embodiments, the embodiments of the present application adopt a vertical and lateral combined inlet / outlet design, and the tailwater pipe 1 is immediately followed by a diffuse horizontal tunnel section 2, the length of which is determined by the installation position and terrain conditions of the target unit, and the end section and the subsequent sections of the flow channel section are all rectangular or quasi-rectangular, and the horizontal tunnel section 2 is followed by an equal-diameter elbow section 3 with an inner diameter of 90°, and the outer diameter curvature is greater than the inner diameter by an angle γ, and the upper part of the elbow section 3 is connected to a vertical shaft section 4, the inner side is vertical, and the outer side is inclined inward, forming an angle γ with the vertical direction, and the upper part of the vertical shaft section 4 is connected to a vertical shaft diffusion section 5, and the diffusion curve is a 1 / 4 ellipse, and the flow channel is divided into upstream and downstream parts by an inverted cone, and the height difference from the elbow section 3 to the vertical shaft diffusion section 5 is determined by the installation elevation of the unit and the lowest operating water level, and the upstream and downstream sides of the vertical shaft diffusion section 5 are respectively connected to the diversion section 6, which is divided into several flow channels by the diversion pier, and a trash rack is set at the end of the partition pier, and the size is determined by the flow rate of the target unit.

[0038] Optionally, in one embodiment of the present application, the floor elevation, the lowest surge water level and the minimum flooding depth of the tailwater pipe 1 are obtained by working parameters, installation parameters and terrain parameters; the total elevation of the inlet / outlet body is obtained by the floor elevation, the lowest surge water level and the minimum flooding depth of the tailwater pipe 1.

[0039] Among them, the calculation formula for the total elevation H of the inlet / outlet body can be as follows:

[0040] H≤h s -h b -d min ,

[0041] Among them, h s is the minimum surge water level, h b is the bottom plate elevation of tailwater pipe 1, d min The minimum flooding depth can be taken as 2.0m.

[0042] Optionally, in one embodiment of the present application, the end section height of the horizontal tunnel section 2 is obtained by the initial section height of the horizontal tunnel section 2, the length of the horizontal tunnel section 2 and the roof expansion angle.

[0043] Among them, the calculation formula for the end section height D of the horizontal tunnel section 2 can be as follows:

[0044] D=h t +Ltanθ(top plate unilateral expansion),

[0045] or (Bilateral expansion),

[0046] Among them, h t is the initial section height of the horizontal tunnel section 2 (same as the outlet section height of the tailwater pipe 1), L is the length of the horizontal tunnel section 2, which is determined by the installation position and terrain conditions of the target unit, and the top plate expansion angle θ is preferably selected in the range of 1° to 3°.

[0047] Optionally, in one embodiment of the present application, the radius of the bend section 3, the length of the straight pipe section of the shaft and the height of the shaft diffuser section 5 are obtained by the total elevation and at least one preset connection constraint; the height difference from the bend section 3 to the shaft diffuser section 5 is obtained by the total elevation and the lowest operating water level of the target unit.

[0048] Among them, the radius of the curved pipe section 3 R, the length of the vertical shaft straight pipe section h v and the shaft diffuser section 5 height h vd The calculation formula can be as follows:

[0049]

[0050] Among them, R, h v and h vd It can be 1 to 2 times D.

[0051] The height difference from the elbow section 3 to the shaft diffuser section 5 is determined by the installation elevation of the unit, that is, the total elevation and the lowest operating water level of the target unit.

[0052] Optionally, in one embodiment of the present application, the inner diameter of the curved pipe section 3 is a 90° curved pipe with a constant diameter, and the curvature of the outer diameter of the curved pipe section 3 is a preset curvature.

[0053] The horizontal tunnel section 2 is followed by an equal-diameter curved pipe section 3 with an inner diameter of 90°, and the curvature of the outer diameter is greater than the inner diameter by an angle γ, so that the curvature of the outer diameter of the curved pipe section 3 is a certain curvature.

[0054] Optionally, in one embodiment of the present application, the inner side of the vertical shaft section 4 is vertical, and the outer side of the vertical shaft section 4 is inclined inward and forms a preset angle with the vertical direction.

[0055] In the actual implementation process, in order to evenly distribute the outflow on both the upstream and downstream sides, the curvature of the outer side of the elbow section 3 can be increased, and the outer side of the vertical shaft section 4 can also be tilted to a certain extent. The tilt angle γ can be 25° to 35°.

[0056] Optionally, in one embodiment of the present application, the diffusion curve of the vertical shaft diffuser section 5 is a 1 / 4 ellipse, wherein the ratio of the major axis to the minor axis of the ellipse is in the interval [3, 5], and the inverted cone of the vertical shaft diffuser section 5 is bullet-shaped, wherein the elevation of the cone head of the inverted cone is lower than the bottom plate of the diversion section 6.

[0057] In some embodiments, the shaft diffuser section 5 can adopt a 1 / 4 elliptical curve, the ratio of the major axis to the minor axis can be selected in the range of 3 to 5, the inverted cone is bullet-shaped, and the cone head is slightly lower than the bottom plate of the diversion section 6.

[0058] Optionally, in one embodiment of the present application, the diversion section 6 divides the flow channel into several sub-flow channels by a diversion pier, and a trash rack is provided at the end of the diversion pier, wherein the size of the trash rack is obtained by the flow rate of the target unit, and the pier head spacing of the diversion pier is obtained by the starting cross-sectional width of the diversion section 6.

[0059] Among them, the starting section width B of the diversion section 6 is vd The calculation formula for the rectangular section width B of the elbow section 3 can be as follows:

[0060]

[0061]

[0062]

[0063] Among them, b p is the width of the diversion pier, which can be 1m to 1.5m. hd is the length of the diversion section 6, which can be 2 to 3 times the length of the minor semi-axis of the elliptic curve, b t is the initial cross-sectional width of the horizontal tunnel section 2 (same as the cross-sectional width of the tailwater pipe 1 outlet), and the designed B vd , B should ensure that the horizontal diffusion angle Δ of the single hole of the diversion section 6, the horizontal diffusion angle α of the horizontal tunnel and the diffusion angle β in the width direction of the vertical shaft section 4 can all be below 10°.

[0064] In order to make the flow distribution of each hole equal, the embodiment of the present application can appropriately reduce the width b2 of the middle hole flow channel, which can be 0.22 to 0.26 times B vd .

[0065] Optionally, in one embodiment of the present application, the length of the diverter section 6, the width of the diverter pier, the initial cross-sectional width of the horizontal tunnel section 2, the single-unit rated flow and the number of trash rack sections of the target unit are obtained from the working parameters, installation parameters and terrain parameters; the cross-sectional height and width of the trash rack are obtained from the value range of the cross-sectional area of ​​a single trash rack, wherein the value range is obtained from the single-unit rated flow, the number of trash rack sections and the maximum average flow velocity of the trash rack section; the initial cross-sectional width of the diverter section 6 and the rectangular cross-sectional width of the bend section 3 are obtained from the length of the diverter section 6, the width of the diverter pier, the width of the trash rack, the length of the horizontal tunnel section 2 and the initial cross-sectional width of the horizontal tunnel section 2, wherein, based on the initial cross-sectional width of the diverter section 6 and the rectangular cross-sectional width of the bend section 3, the single-hole horizontal diffusion angle of the diverter section 6, the horizontal diffusion angle of the horizontal tunnel section 2 and the width direction diffusion angle of the shaft section 4 all meet the preset angle conditions.

[0066] Furthermore, the embodiment of the present application can design the cross-sectional height h and width b of the trash rack.

[0067] First calculate the cross-sectional area of ​​the trash rack:

[0068]

[0069] Where A is the cross-sectional area of ​​a single trash rack, Q is the rated flow of a single unit, n is the number of trash rack cross-sections, and v max The maximum average flow velocity of the trash rack cross section required by the specification is taken as 1.0m / s.

[0070] Then, the height and width are reasonably designed according to the cross-sectional area of ​​the trash rack: (the height should not be too high, preferably 2m to 5m):

[0071] A=hb.

[0072] Based on the above design results, the embodiment of the present application can also use CFD (Computational Fluid Dynamics) or model test methods to verify the hydraulic characteristics of the inlet / outlet body of the embodiment of the present application and perform parameter optimization design. In summary, compared with the side body or shaft body in the related art, the embodiment of the present application has the following effects:

[0073] 1. The side type is arranged in a horizontal direction. In order to make the water flow smoothly spread from the small area of ​​the tailwater pipe 1 section to the large area of ​​the trash rack section, a long horizontal distance is required, and the space requirement is large, which brings inconvenience to the construction of cofferdams and other projects. The embodiment of the present application can be combined with the characteristics of the shaft type, and the flow channel has two sections, horizontal and vertical, with a longer flow channel in a limited space, which can save space and have better terrain adaptability.

[0074] 2. The water flow of the side-type body only flows in one direction. When it is immediately after the tailwater pipe 1, the outflow is prone to flow concentration and deviation, resulting in turbulent flow state, affecting the safety and efficiency of power station operation. The embodiment of the present application can be combined with the characteristics of the shaft-type body, using the curved pipe section 3 to change the direction of the water flow, and guiding the deviation of the mainstream by adjusting the curvature of the outer side of the curved pipe, that is, when the mainstream deviates to the bottom of the flow channel in the horizontal tunnel, the curvature of the outer side of the curved pipe is increased to make the mainstream return to the inside in the shaft section 4, and the high velocity area on the outside is merged with the low velocity area on the inside, thereby making the cross-sectional flow velocity distribution uniform, solving the problem of velocity concentration and deviation, and also making the outflow on both sides of the upstream and downstream of the diversion section 6 average.

[0075] 3. The shaft type is difficult to be used in a low-head ground-type plant pumped-storage power station due to the large height difference between the horizontal tunnel section 2 and the diversion section 6. The embodiment of the present application can be combined with the side type body characteristics, and the tunnel section adopts a large-area rectangular section, so that the water flow can be fully diffused in the shorter shaft diffusion section 5, thereby reducing the height difference and meeting the layout requirements of the low-head tail open plant pumped-storage power station.

[0076] 4. The shaft-type body adopts radial inlet / outlet flow at the reservoir end. In order to reduce the mutual influence between the inlets / outlets, the adjacent parallel inlets / outlets have a large spacing. The embodiment of the present application can combine the characteristics of the side-type body, and the flow only flows from the upstream and downstream directions in the diversion section 6, so that the mutual influence between the inlets / outlets is small, thereby reducing the spacing between adjacent parallel inlets / outlets and saving space.

[0077] Combination Figure 1 , Figure 3-Figure 5 As shown, the structure and design process of the inlet / outlet body of the tailwater pipe of the embodiment of the present application are described in detail by taking an embodiment as an example.

[0078] Among them, the water inlet / outlet involved in the embodiment of the present application can be as follows Figure 1 , Figure 3 and Figure 4 shown.

[0079] The minimum operating control water level of the lower reservoir of a pumped storage power station is 78.20m, the bottom plate elevation of tailwater pipe 1 is 44.60m, and the outlet of tailwater pipe 1 is a circular section with a diameter of 4.6m. According to the installation position of the unit and the terrain conditions of the lower reservoir, the length of horizontal tunnel section 2 is determined to be 63.6m, and the rated flow of a single unit in power generation condition is 111.41m 3 / s as an example.

[0080] The embodiment of the present application can calculate the size of each segment of the water inlet / outlet.

[0081] (1) Determine the total elevation H of the inlet / outlet

[0082] H=h s -h b -d min ,

[0083] Among them, h s =78.20m,h b =44.60m,d min =2.0m, calculated H=31.6m.

[0084] (2) Design the trash rack cross-sectional height h and width b

[0085] There are 6 trash racks in total. First, calculate the cross-sectional area of ​​the trash racks:

[0086]

[0087] Where, Q = 111.41m 3 / s,n=6,v max =1.0m / s, calculated A≥18.568m 2 .

[0088] Then, the height and width of the trash rack are reasonably designed according to its cross-sectional area:

[0089] A=hb,

[0090] Select h = 3.5m, b = 6.0m, then A = 21.0m 2 , which meets the requirements.

[0091] (3) Determine the end section height D of horizontal tunnel section 2

[0092] Since the outlet of tailwater pipe 1 is a circular section, the horizontal tunnel is a square-circular gradient section, and a double-side expansion form is adopted, D can be calculated by the following formula:

[0093]

[0094] Among them, h t =4.6m, L=63.6m, select θ=1.8°, and calculate D=6.6m.

[0095] (4) Determine the radius R of the curved pipe section 3 and the length h of the vertical shaft straight pipe section v and the shaft diffuser section 5 height h vd

[0096] It can be reasonably designed according to the total elevation of the inlet / outlet:

[0097]

[0098] Among them, H = 31.6m, h = 3.5m, Select R = h v =9m, calculate h vd =7.8m.

[0099] (5) Determine the shaft diffusion section 5 curve

[0100] The shaft diffusion section 5 adopts a 1 / 4 elliptical curve, the ratio of the major axis to the minor axis is 3, the inverted cone is bullet-shaped, and the cone head is 0.7m lower than the bottom plate of the diversion section 6.

[0101] (6) Determine the starting section width B of the diversion section 6 vd and the rectangular section width B of the elbow section 3

[0102]

[0103]

[0104]

[0105] Among them, b p =1m,l hd Take 5.5m, b t =4.6m, take Bvd =15.5m, B=18m, then Δ=6.9°, α=9.8°, β=8.5°, all below 10°, meeting the requirements.

[0106] (7) Determine the outer inclination angle γ of the curved pipe section 3 and the shaft section 4

[0107] Take γ=30°.

[0108] (8) Determine the distance b2 between the diversion pier heads

[0109] The width ratio of each flow channel in the pier head section is b1:b2:b3=0.38:0.24:0.38, at this time b2=4.32m.

[0110] (9) Hydraulic properties verification

[0111] After the new body design is completed, the CFD method is used to verify the hydraulic characteristics of the new body. The commercial software ANSYSFluent is used to calculate and simulate the hydraulic characteristics of this example at the lowest operating control water level and single unit rated power generation flow. Its hydraulic parameters can be shown in Table 1, where Table 1 is a hydraulic parameter table.

[0112] Table 1

[0113]

[0114] In summary, the flow distribution on both sides of the upstream and downstream of this example is even, the maximum flow difference of each hole is 4.06%, which is less than 10%, the maximum average flow velocity of each hole is 0.92m / s, which is less than 1m / s, and the maximum velocity unevenness coefficient is 1.89, which is less than 2, all of which meet the requirements of the specification; the head loss is 0.16, which is relatively small.

[0115] The flow pattern of the water inlet / outlet of the embodiment of the present application can be as follows Figure 5 As shown, after the water flows out of the tailwater pipe 1 during outflow, the flow velocity in the horizontal tunnel finally gathers at the bottom of the flow channel. In the bend section 3, the flow velocity is concentrated on the outer diameter of the flow channel due to the centrifugal force. After adjustment by the bend section 3 and the shaft diffuser section 5, the flow distribution on both the upstream and downstream sides is relatively even, and the outflow velocity distribution is relatively uniform.

[0116] Therefore, the inlet / outlet of the embodiment of the present application has a smooth flow pattern and hydraulic parameters that meet the requirements of the specifications. It can be considered that its hydraulic characteristics are good and the design is reasonable.

[0117] According to the inlet / outlet shape immediately adjacent to the tailwater pipe proposed in the embodiment of the present application, the design size of each segment of the inlet / outlet shape can be determined based on the working parameters, installation parameters and terrain parameters of the target unit, wherein the inlet / outlet shape includes the tailwater pipe, the horizontal tunnel section, the elbow section, the shaft section, the shaft diffusion section and the diversion section, and the actual size of each segment is obtained according to the design size and at least one preset connection constraint, so as to obtain the design result of the inlet / outlet shape that meets the preset terrain conditions according to the actual size, and obtain the tailwater pipe inlet / outlet shape with good hydraulic characteristics and meeting the layout requirements of the low-head ground-type plant pumped storage power station, which effectively improves the uneven flow state behind the tailwater pipe and has good terrain adaptability. Thus, the technical problems in the related art that the side inlet / outlet immediately adjacent to the tailwater pipe section is difficult to solve the problem of flow velocity concentration and deviation, and the shaft inlet / outlet is difficult to adapt to terrain conditions are solved.

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0119] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0120] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0121] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0122] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0123] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0124] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0125] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A water inlet / outlet body immediately adjacent to a tailwater pipe, characterized in that: The inlet / outlet body includes: a horizontal tunnel section, a bend section, a vertical shaft section, a vertical shaft diffusion section and a diversion section. The tailwater pipe is connected to one side of the horizontal tunnel section, and the other side of the horizontal tunnel section is connected to the bend section; the upper part of the bend section is connected to the vertical shaft section, and the upper part of the vertical shaft section is connected to the vertical shaft diffusion section. The inverted cone of the vertical shaft diffusion section is bullet-shaped in longitudinal section, and the cross-sectional shape remains unchanged along the transverse direction. The flow channel is divided into an upstream part and a downstream part based on the inverted cone of the vertical shaft diffusion section. The upstream and downstream sides of the vertical shaft diffusion section are respectively connected to the diversion section, wherein, The design result of the inlet / outlet shape is determined by the actual size of the horizontal tunnel section, the elbow section, the shaft section, the shaft diffusion section and the diversion section obtained by the design size of each segment of the inlet / outlet shape determined by the working parameters, installation parameters and terrain parameters of the target unit and at least one preset connection constraint; The cross-sections of the horizontal tunnel section, the elbow section, the shaft section, the shaft diffusion section and the diversion section are all rectangular or quasi-rectangular; The outer diameter curvature of the curved pipe section is larger than the inner diameter of the curved pipe section, so that the outer diameter curvature of the curved pipe section is a preset curvature; The inner side of the vertical shaft section is vertical, and the outer side of the vertical shaft section is inclined inward and forms a preset angle with the vertical direction.

2. The inlet / outlet shape of the tailwater pipe according to claim 1, characterized in that: The floor elevation, the lowest surge water level and the minimum flooding depth of the tailwater pipe are obtained from the working parameters, the installation parameters and the terrain parameters; The total elevation of the inlet / outlet body is obtained by the floor elevation of the tailwater pipe, the lowest surge water level and the minimum flooding depth.

3. The inlet / outlet shape of the tailwater pipe according to claim 1, characterized in that: The end section height of the horizontal tunnel section is obtained by the initial section height of the horizontal tunnel section, the length of the horizontal tunnel section and the roof expansion angle.

4. The inlet / outlet shape of the tailwater pipe according to claim 2, characterized in that: The radius of the curved pipe section, the length of the vertical shaft straight pipe section and the height of the vertical shaft diffusion section are obtained from the total elevation and the at least one preset connection constraint; The height difference from the elbow section to the shaft diffusion section is obtained by the total elevation and the lowest operating water level of the target unit.

5. The inlet / outlet shape of the tailwater pipe according to claim 1, characterized in that: The inner diameter of the curved pipe section is a 90° curved pipe of equal diameter.

6. The inlet / outlet shape of the tailwater pipe according to claim 1, characterized in that: The diffusion curve of the shaft diffusion section is a 1 / 4 ellipse, wherein the major-minor axis ratio of the ellipse is in the interval [3, 5], and the elevation of the cone head of the inverted cone is lower than the bottom plate of the diversion section.

7. The inlet / outlet shape of the tailwater pipe according to claim 1, characterized in that: The diversion section divides the flow channel into a plurality of sub-flow channels by a diversion pier, and a trash rack is arranged at the end of the diversion pier, wherein the size of the trash rack is obtained by the flow rate of the target unit, and the pier head spacing of the diversion pier is obtained by the starting section width of the diversion section.

8. The inlet / outlet shape of the tailwater pipe according to claim 1, characterized in that: The length of the diversion section, the width of the diversion pier, the initial cross-sectional width of the horizontal tunnel section, the single unit rated flow of the target unit and the number of trash rack cross-sections are obtained from the working parameters, installation parameters and terrain parameters; The height and width of the trash rack section are obtained from the value range of the cross-sectional area of ​​a single trash rack, wherein the value range is obtained from the rated flow of the single machine, the number of trash rack sections and the maximum average flow velocity of the trash rack section; The starting cross-sectional width of the diverter section and the rectangular cross-sectional width of the bend section are obtained by the length of the diverter section, the width of the diverter pier, the width of the trash rack, the length of the horizontal tunnel section and the initial cross-sectional width of the horizontal tunnel section, wherein, based on the starting cross-sectional width of the diverter section and the rectangular cross-sectional width of the bend section, the single-hole horizontal diffusion angle of the diverter section, the horizontal diffusion angle of the horizontal tunnel section and the width direction diffusion angle of the vertical shaft section all meet the preset angle conditions.

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