Symmetrical steel bifurcated pipe spiral flow state elimination composite guide plate device

Abstract

The utility model provides a symmetrical steel branch pipe spiral flow state elimination composite guide plate device, a spiral flow state elimination composite guide plate unit comprises four spiral flow state elimination composite guide plate subunits, and each spiral flow state elimination composite guide plate subunit comprises a composite guide plate and a plurality of parallel guide plates; the composite flow guide plate and the parallel flow guide plates are sequentially arranged in the direction from near to far away from the datum line; and moreover, the front ends of the composite flow guide plate and each parallel flow guide plate and the tail end of the crescent rib plate are kept on the same horizontal line vertical to the datum line. According to the device, the vortex eliminating effect of the guide plate in the pipe is utilized to cut the pressurized water flow in the incoming flow direction so as to eliminate vortexes in the pressurized water flow, so that the vortexes in the pressurized hydraulic pipeline are effectively eliminated or weakened on the basis of not changing the external structure of the branch pipe and not influencing the efficiency, and finally small head loss is contributed to the whole hydroelectric generation system; and the efficiency and the operation safety of the hydroelectric generation system are improved.

Description

Technical Field

[0001] This utility model relates to a flow guide plate device, specifically a composite flow guide plate device for eliminating spiral flow in a symmetrical steel branch pipe. Background Technology

[0002] With the implementation of the "energy conservation and emission reduction" policy, hydropower has become the preferred renewable energy source. A hydropower station is an engineering project consisting of a series of structures and equipment. Pressurized hydraulic pipelines are an indispensable part of a hydropower station. To save costs, these pipelines need to be symmetrically branched before connecting to the turbine to complete the entire hydropower system. When high-pressure water flows through symmetrical branched components, the complex flow patterns inside the pipes easily generate vortices. Specifically, the internal flow of symmetrical branched components is a complex three-dimensional turbulent flow. When high-speed water flows through these components within the pressurized hydraulic pipeline, due to technical limitations and the material of the ribs, the main pipe and branch pipes cannot perfectly fit together. Small protrusions appear at the ends of the ribs, causing the water flow to impact these protrusions and generate vortices. Subsequent water flow continues forward, increasing the risk of these vortices being propelled into the turbine, leading to low turbine efficiency, turbine damage, and even plant failure.

[0003] Therefore, how to reduce or eliminate vortices in pressurized hydraulic pipelines and improve the efficiency and operational safety of hydropower systems is a problem that needs to be solved. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a symmetrical steel branch pipe spiral flow elimination composite guide plate device, which can effectively solve the above problems.

[0005] The technical solution adopted in this utility model is as follows:

[0006] This utility model provides a symmetrical steel branch pipe spiral flow elimination composite guide plate device, including a symmetrical steel branch pipe and a spiral flow elimination composite guide plate unit; the symmetrical steel branch pipe includes a main pipe (1), a branch pipe (2) and a crescent rib plate (3); one end of the main pipe (1) is connected to two left and right symmetrical branch pipes (2), and the crescent rib plate (3) is provided on the inner wall of the connection between the two branch pipes (2);

[0007] The spiral flow elimination composite guide plate unit includes four spiral flow elimination composite guide plate sub-units, which are respectively arranged on the upper left, upper right, lower left and lower right sides inside the symmetrical steel branch pipe. With the symmetry line of the symmetrical steel branch pipe as the reference line (6), the sub-units on the upper left and lower left sides are vertically symmetrical, the sub-units on the upper right and lower right sides are vertically symmetrical, the sub-units on the upper left and upper right sides are horizontally symmetrical, and the sub-units on the lower left and lower right sides are horizontally symmetrical.

[0008] Each of the spiral flow elimination composite guide plate sub-units includes a composite guide plate (5) and several parallel guide plates (4); the composite guide plate (5) and each of the parallel guide plates (4) are arranged sequentially in the direction from near to far from the baseline (6); and the front ends of the composite guide plate (5) and each of the parallel guide plates (4) are kept on the same horizontal line (7) perpendicular to the baseline (6) as the end of the crescent rib (3).

[0009] Preferably, each of the spiral flow elimination composite guide plate sub-units has 3 to 4 of the parallel guide plates (4) and 1 of the composite guide plate (5).

[0010] Preferably, the contraction angle of each of the parallel guide vanes (4), that is, the angle formed by the rear extension line of the parallel guide vane (4) and the reference line (6), is 6-15 degrees.

[0011] Preferably, for the sequentially arranged composite guide plate (5) and each of the parallel guide plates (4), the distance between two adjacent guide plates is 0.15 to 0.2 times the diameter D of the main pipe (1).

[0012] Preferably, the lengths of each of the parallel guide plates (4) are equal and are 0.1 times the diameter D of the main pipe (1); the length of the composite guide plate (5) is 0.1 times the length of the parallel guide plates (4).

[0013] Preferably, the thickness of the composite guide plate (5) and each of the parallel guide plates (4) is 0.8-1.5 times the thickness of the crescent rib (3).

[0014] Preferably, in the circumferential direction, the arrangement area of ​​the composite guide plate (5) and each of the parallel guide plates (4) covers the protruding part of the crescent rib (3) and has a margin of 8 to 15 degrees.

[0015] The symmetrical steel branch pipe spiral flow elimination composite guide plate device provided by this utility model has the following advantages.

[0016] This device utilizes the vortex-eliminating effect of the guide plate inside the pipe to cut the pressurized water flow in the incoming direction, thereby eliminating vortices. Therefore, without changing the external structure of the branch pipe or affecting efficiency, it effectively eliminates or weakens vortices in the pressurized hydraulic pipeline, ultimately contributing a smaller head loss to the entire hydropower system and improving the efficiency and operational safety of the hydropower system. Attached Figure Description

[0017] Figure 1A perspective view of a composite guide plate device for eliminating spiral flow in a symmetrical steel branch pipe, provided by this utility model;

[0018] Figure 2 A top view of a symmetrical steel fork pipe spiral flow elimination composite guide plate device provided by this utility model;

[0019] Figure 3 A top view of the spiral flow elimination composite guide plate subunit provided by this utility model;

[0020] Figure 4 A cross-sectional view of the main pipe provided by this utility model at the location of the spiral flow elimination composite guide plate unit.

[0021] Wherein: 1-Main pipe; 2-Branch pipe; 3-Crescent rib; 4-Parallel guide plate; 5-Composite guide plate; 6-Baseline; 7-Horizontal line. Detailed Implementation

[0022] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0023] This utility model relates to a vortex elimination technology in large-scale water transmission pipeline systems such as hydropower stations, particularly a vortex elimination technology for large-sized symmetrical branch pipes in high-head power stations. The spiral flow elimination composite guide plate device mainly includes: symmetrical steel branch pipes used in the power station's water transmission system, and crescent-shaped ribs, parallel guide plates, and composite guide plates inside the symmetrical steel branch pipes. This device utilizes the vortex elimination effect of the guide plates inside the pipe to cut the pressurized water flow in the incoming direction, thereby eliminating vortices. Therefore, without changing the external structure of the branch pipe or affecting efficiency, it effectively eliminates or weakens vortices in pressurized hydraulic pipelines, ultimately contributing less head loss to the entire hydropower system and improving the efficiency and operational safety of the hydropower system.

[0024] See Figures 1-4 This utility model provides a symmetrical steel branch pipe spiral flow elimination composite guide plate device, including a symmetrical steel branch pipe and a spiral flow elimination composite guide plate unit; the symmetrical steel branch pipe includes a main pipe 1, branch pipes 2 and crescent ribs 3, all of which are made of steel plates; one end of the main pipe 1 is connected to two left and right symmetrical branch pipes 2, and the crescent ribs 3 are provided on the inner wall at the connection of the two branch pipes 2;

[0025] The spiral flow elimination composite guide plate unit includes four spiral flow elimination composite guide plate sub-units, which are respectively arranged on the upper left, upper right, lower left and lower right sides inside the symmetrical steel branch pipe. With the symmetry line of the symmetrical steel branch pipe as the reference line 6, the sub-units on the upper left and lower left sides are vertically symmetrical with respect to the reference line 6, the sub-units on the upper right and lower right sides are vertically symmetrical, the sub-units on the upper left and upper right sides are horizontally symmetrical, and the sub-units on the lower left and lower right sides are horizontally symmetrical.

[0026] Each of the spiral flow elimination composite guide plate sub-units includes a composite guide plate 5 and several parallel guide plates 4, all made of steel plates. The composite guide plate 5 and each of the parallel guide plates 4 are arranged sequentially from near to far from the baseline 6. Furthermore, the front ends of the composite guide plate 5 and each of the parallel guide plates 4 are aligned with the end of the crescent-shaped rib 3 on the same horizontal line 7 perpendicular to the baseline 6. The end of the crescent-shaped rib 3 is the rib tip. In this invention, the horizontal line 7 serves as an explanation of the arrangement of the crescent-shaped rib 3, parallel guide plates 4, and composite guide plate 5.

[0027] In this application, the front ends of the composite guide plate 5 and each of the parallel guide plates 4 are kept on the same horizontal line 7 as the end of the crescent rib plate 3. Therefore, the composite guide plate 5 and each of the parallel guide plates 4 can prevent water from scattering when cutting the incoming flow, making the flow smoother.

[0028] For each spiral flow elimination composite guide plate sub-unit, its structural parameters are as follows:

[0029] Each spiral flow elimination composite guide plate subunit has 3 to 4 parallel guide plates 4 and 1 composite guide plate 5. Figure 1 In the middle, there are 3 parallel guide plates 4 and 1 composite guide plate 5; therefore, for the 4 spiral flow elimination composite guide plate sub-units, there are a total of 12 parallel guide plates 4 and 4 composite guide plates 5.

[0030] refer to Figure 3 The contraction angle of each of the parallel guide vanes 4, that is, the angle formed by the rear extension line of the parallel guide vane 4 and the reference line 6, is 6-15 degrees.

[0031] For the composite guide plate 5 and each of the parallel guide plates 4 arranged in sequence, the distance between two adjacent guide plates is 0.15 to 0.2 times the diameter D of the main pipe 1, so as to maintain the effect of eliminating water vortices.

[0032] The lengths of each of the parallel guide vanes 4 are equal and are 0.1 times the diameter D of the main pipe 1; the length of the composite guide vane 5 is 0.1 times the length of the parallel guide vanes 4. The thickness of the composite guide vane 5 and each of the parallel guide vanes 4 is 0.8-1.5 times the thickness of the crescent rib 3.

[0033] In the circumferential direction, i.e., within the arrangement range of the parallel guide plates 4 and the composite guide plates 5, the arrangement area of ​​the composite guide plates 5 and each of the parallel guide plates 4 covers the protruding portion of the crescent-shaped rib 3, with a margin of 8 to 15 degrees. Specifically, because the crescent-shaped rib 3 has thickness, and the water flow generates vortices and harmful flow patterns at the protrusion of the crescent-shaped rib 3, the design of the parallel guide plates 4 and the composite guide plates 5 must cover the protruding portion of the crescent-shaped rib 3, i.e. Figure 4 The dotted line area is completely covered, with an additional 8 to 15 degrees, to prevent water flow from leaking out and spreading to the outer channel of the guide plate, forming an unfavorable flow pattern. Under the premise of ensuring circumferential arrangement, the starting position of the composite guide plate 5 is determined according to the situation, and then each parallel guide plate 4 is arranged at a distance of 0.15 to 0.2 times the diameter of the main pipe 1.

[0034] The device operates as follows:

[0035] Utilizing Bernoulli's principle, the pressure and velocity within the same flow beam are conserved overall. The composite guide plate 5 alters the effective flow area of ​​the channel, allowing for flexible conversion between velocity and local pressure, achieving stable flow and further reducing drastic pressure changes. When vortices appear in the incoming water flow as it passes the crescent-shaped rib 3, the parallel guide plate 4 inside the pipe cuts the water flow, weakening or eliminating the vortices. The composite guide plate 5 further eliminates any remaining weak vortices, preventing them from entering the turbine unit, reducing harm, improving the efficiency of the hydroelectric power generation system, and facilitating high efficiency and energy saving. This device meets the requirements under four-machine operating conditions, significantly reducing vortex phenomena and improving the stability of the flow within the pressurized hydraulic pipeline.

[0036] Therefore, this invention, based on simulation studies of flow patterns within pipes, focuses on the vortices generated by different flow patterns inside branch pipes. It conducts three-dimensional flow numerical calculations of steel branch pipes, closely approximating engineering realities. For various typical unit combinations under power generation operation conditions, it analyzes the flow pattern distribution on typical cross-sections and flow surfaces inside the branch pipe, including internal flow smoothness, flow smoothness in all directions, and vortex distribution. Ultimately, this achieves the elimination of vortices generated by complex flow patterns inside the branch pipe.

[0037] This invention eliminates or reduces vortices by adding guide plates inside the branch pipe, ultimately contributing less head loss to the entire system, improving system operating efficiency, and avoiding unnecessary losses.

[0038] After analysis and quantitative verification, this utility model is effective and feasible, taking into account the actual operability in engineering.

[0039] In summary, this utility model relates to a symmetrical branch pipe component used inside a high-pressure hydraulic pipeline water conveyance system in a hydroelectric power station. It is a composite guide plate device for eliminating spiral flow in symmetrical branch pipes. This device, by installing guide plates in the branch pipe, cuts the pressurized water flow in the direction of incoming water, effectively eliminating vortices generated within the pipe due to complex flow patterns. This device is low-cost and highly efficient, eliminating the hazards of vortices without altering the external structure of the branch pipe, thus improving water conveyance capacity and ultimately increasing power generation efficiency.

[0040] The following description, using a hydropower station project that employs the technical solution of this utility model as an example, is further illustrated with reference to the accompanying drawings:

[0041] A hydroelectric power station project uses crescent-ribbed steel branch pipes, forming a symmetrical Y-shape. The main pipe (1) has a diameter of 8.0m and a wall thickness of 66mm; the branch pipe (2) has a diameter of 5.7m and a wall thickness of 66mm; the crescent rib plate (3) is 130mm thick. The maximum common tangent sphere radius of this branch pipe is 4560mm, and the bifurcation angle is 70°. The rated power generation flow rate is 207.55m³. 3 / s. According to the three-dimensional flow field analysis, the internal flow pattern of the main pipe 1 is stable and smooth, which meets the design requirements of the flow angle; however, due to the coupling flow factors of the branch pipe configuration, a spiral flow phenomenon is generated inside the branch pipe 2. This not only causes a high head loss, but also generates hydraulic vibration, which has a negative impact on the entire hydraulic system and ultimately affects the operating efficiency and safety of the entire power station. At the same time, in terms of the force on the crescent rib 3, the water-induced force on the crescent rib 3 is high under some operating conditions. It is recommended to take measures to avoid such flow phenomena.

[0042] Therefore, the symmetrical steel branch pipe spiral flow elimination composite guide plate device of this utility model is adopted in this project:

[0043] Four symmetrical spiral flow elimination composite guide vane sub-units are set up, one on the left and one on the right, and one on the top and bottom. In each spiral flow elimination composite guide vane sub-unit, the number of parallel guide vanes 4 is set to 3, and the number of composite guide vanes 5 is set to 1. The front ends of the parallel guide vanes 4 and the composite guide vanes 5 are kept on the same horizontal line as the end of the crescent rib 3 (i.e., the tip of the rib). The contraction angle of the parallel guide vanes 4, that is, the angle formed by the extension line of the rear end of the parallel guide vanes 4 and the reference line 6, is set to 10°. The distance between adjacent guide vanes is 1600mm. The parallel guide vanes 4 and the composite guide vanes 5 are arranged circumferentially. The length of the parallel guide vanes 4 is 800mm, and the length of the composite guide vanes 5 is 80mm and the thickness is 130mm.

[0044] Overall, the optimized main and branch pipes exhibit smooth and stable internal flow patterns, meeting the design requirements for flow angle. Hydraulic losses are significantly reduced compared to the unoptimized system. The spiral flow phenomenon and its potential for higher head losses, hydraulic vibrations, and their negative impact on the entire hydraulic system have been largely eliminated.

[0045] The above-mentioned technical solution disclosed in this utility model solves the problem of spiral flow phenomenon caused by the coupling flow factor of the branch pipe configuration, reduces head loss, avoids hydraulic vibration, reduces the negative impact of the flow state on the entire hydraulic system, and solves the problem of high water-induced force on the rib plate in some working conditions.

[0046] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A composite guide plate device for eliminating spiral flow in symmetrical steel branch pipes, characterized in that, It includes a symmetrical steel branch pipe and a spiral flow elimination composite guide plate unit; the symmetrical steel branch pipe includes a main pipe (1), a branch pipe (2) and a crescent rib plate (3); one end of the main pipe (1) is connected to two left and right symmetrical branch pipes (2), and the crescent rib plate (3) is provided on the inner wall of the connection between the two branch pipes (2); The spiral flow elimination composite guide plate unit includes four spiral flow elimination composite guide plate sub-units, which are respectively arranged on the upper left, upper right, lower left and lower right sides inside the symmetrical steel branch pipe. With the symmetry line of the symmetrical steel branch pipe as the reference line (6), the sub-units on the upper left and lower left sides are vertically symmetrical, the sub-units on the upper right and lower right sides are vertically symmetrical, the sub-units on the upper left and upper right sides are horizontally symmetrical, and the sub-units on the lower left and lower right sides are horizontally symmetrical. Each of the spiral flow elimination composite guide plate sub-units includes a composite guide plate (5) and several parallel guide plates (4); the composite guide plate (5) and each of the parallel guide plates (4) are arranged sequentially in the direction from near to far from the baseline (6); and the front ends of the composite guide plate (5) and each of the parallel guide plates (4) are kept on the same horizontal line (7) perpendicular to the baseline (6) as the end of the crescent rib (3).

2. The composite guide plate device for eliminating spiral flow in a symmetrical steel branch pipe according to claim 1, characterized in that, Each of the spiral flow elimination composite guide plate sub-units has 3 to 4 of the parallel guide plates (4) and 1 of the composite guide plates (5).

3. The symmetrical steel branch pipe spiral flow elimination composite guide plate device according to claim 1, characterized in that, The contraction angle of each of the parallel guide vanes (4), that is, the angle formed by the extension line of the rear end of the parallel guide vane (4) and the reference line (6), is 6-15 degrees.

4. The composite guide plate device for eliminating spiral flow in a symmetrical steel branch pipe according to claim 1, characterized in that, For the composite guide plate (5) and each of the parallel guide plates (4) arranged in sequence, the distance between two adjacent guide plates is 0.15 to 0.2 times the diameter D of the main pipe (1).

5. The composite guide plate device for eliminating spiral flow in a symmetrical steel branch pipe according to claim 1, characterized in that, The lengths of each of the parallel guide plates (4) are equal and are 0.1 times the diameter D of the main pipe (1); the length of the composite guide plate (5) is 0.1 times the length of the parallel guide plates (4).

6. The composite guide plate device for eliminating spiral flow in a symmetrical steel branch pipe according to claim 1, characterized in that, The thickness of the composite guide plate (5) and each of the parallel guide plates (4) is 0.8-1.5 times the thickness of the crescent rib (3).

7. The composite guide plate device for eliminating spiral flow in a symmetrical steel branch pipe according to claim 1, characterized in that, In the circumferential direction, the arrangement area of ​​the composite guide plate (5) and each of the parallel guide plates (4) covers the protruding part of the crescent rib (3) and has a margin of 8 to 15 degrees.

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