A design method of a bell-shaped water inlet flow channel of a bidirectional flow channel pump device

Abstract

The application discloses a hydraulic design method for a clock-shaped water inlet flow channel of a bidirectional flow channel pump device. The method is realized through the following steps: firstly, determining a suitable axial flow pump type and model; then, performing geometric modeling, constructing a water inlet flow channel model comprising a horn pipe, a guide vane, a partition pier and a gate, and dividing the horn pipe profile line into three sectional lines and determining the length, width, height and diameter of each part; establishing a rectangular coordinate system for profile line design, determining the curvature profile line of the horn pipe first curve section and the guide vane through the equation of the distance between the horn pipe first curve section and the meridian of the guide vane and the distance between the horn pipe first curve section and the guide vane, and respectively making the curvature profile line of the horn pipe second curve section and the straight line section. The application realizes the parametric design of the horn pipe and the guide vane sectional curvature profile line, provides specific execution steps and parametric design formula, shortens the research and development cycle, and improves the hydraulic performance and stability.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to a hydraulic design method for a bell-shaped inlet flow channel of a bidirectional flow channel pump device based on Dean's vortex theory. Background Technology

[0002] Bidirectional flow channel pump units, as a common type of pumping station equipment, have been widely promoted and applied in most parts of China. Their design and application represent a significant innovation in China's pump technology and pumping station engineering fields. With their compact structure, stable operation, and convenient maintenance, they are widely used in various water conservancy projects and urban infrastructure construction. However, two major problems still exist in the bidirectional flow channel pump units currently built in my country: low operating efficiency and unstable operation, resulting in significant vibration and noise. The bell-shaped inlet flow channel structure is relatively simple and convenient to construct. It not only significantly improves the water intake conditions of bidirectional flow channel pump units but also reduces construction costs, which has high economic value for low-head bidirectional pumping stations. Adopting a bidirectional bell-shaped inlet flow channel is of great significance in bidirectional flow channel pumping stations and is an economically reasonable choice.

[0003] Chinese patent application CN106897512A, published on February 17, 2017, entitled "Design Method of Bell-Shaped Inlet Channel for Pumping Stations," determines the main dimensions of the bell-shaped inlet channel through a series of geometric parameter formulas. These dimensions include channel height, distance from the rear wall of the suction chamber, inlet width, channel length, trumpet tube height, bottom diameter of the guide cone, top taper angle of the inlet section, bottom edge inclination angle, trumpet tube outlet diameter, guide cone height, and trumpet tube inlet diameter. The bell-shaped inlet channel designed using this method improves the inlet flow pattern, reduces hydraulic losses, and enhances the operational stability and efficiency of the pumping station. This method reduces collision losses between the inlet section and the trumpet tube by adjusting parameters such as the width, height, top taper angle, and bottom edge inclination angle of the inlet section, optimizing the geometric dimensions of the guide cone and trumpet tube to reduce eddies and friction losses, thereby improving the overall performance of the pumping station. This invention details the design methods for various parameters in the bell-shaped inlet channel. However, the invention does not mention the curved profile design of the horn tube and the guide cone. Using an appropriate curved profile design can further reduce eddies and hydraulic losses along the flow path, thereby improving the fluid flow pattern and enhancing the stability and efficiency of the inlet channel.

[0004] Chinese patent application CN113704850A, published on August 27, 2021, entitled "A Design Method for the Bell-Shaped Inlet Channel of a Bidirectional Pumping Station," proposes a design method for the bell-shaped inlet channel of a bidirectional pumping station. This method uses quadratic equations to solve the equations of the inlet profile, achieving parametric design of the bell-shaped channel profile and optimizing its geometric parameters and profile. The improved design results in smoother profile transitions, improved stability of the inlet flow, and reduced hydraulic losses, thereby enhancing the efficiency and operational stability of the pumping station. While this invention details the design formula for the bell-shaped inlet channel profile, it neglects the guide cone profile and other parameters of the inlet channel, which is unreasonable for the overall design of a bidirectional pumping unit.

[0005] Chinese patent application CN108757571A, published on May 25, 2018, entitled "A Design Method for a Box-Type Bidirectional Inlet Channel," employs a precise formula design method to design the main geometric parameters of a box-type bidirectional inlet channel for pumping stations, including the width of the inlet section, the inlet height, and the height of the bell pipe. This improves the reliability of pumping station operation, reduces hydraulic losses through the inlet channel, extends pump lifespan and pumping station maintenance cycles, and is more conducive to computer integration, enabling parametric design. The box-type inlet channel structure in this invention, compared to a bell-shaped inlet channel, is prone to uneven water flow distribution and greater flow resistance, especially at channel corners where dead zones and vortices can easily form, affecting pumping station efficiency and stability. Furthermore, the complex structure of the box-type inlet channel increases the cost and difficulty of design, manufacturing, and maintenance, while also being relatively less efficient in terms of space utilization and adaptability.

[0006] Chinese Patent Application No. CN116837790A, filed on July 26, 2023, entitled "A Bidirectional Elbow-Type Inlet Channel and Pumping Station," proposes a bidirectional elbow-type inlet channel and pumping station, aiming to overcome the limitation of existing elbow-type inlet channels that can only operate in one direction. This elbow-type inlet channel includes a first elbow-type and a second elbow-type inlet channel, sharing a rotatable elbow bend section, enabling the elbow-type inlet channel to be suitable for bidirectional pumping operations in a bidirectional pumping station. By controlling the rotation of the elbow bend section through a rotating component and a drive mechanism, flexible connection between the elbow bend section and the straight section is achieved, allowing selection of the water supply channel according to pumping demand. This improves the operating efficiency and reliability of the pumping station, reduces head loss and cavitation risk, and significantly enhances adaptability and economy. The focus of this invention is on the design of the bidirectional elbow-type inlet channel and its structural design for application in a pumping station, realizing the bidirectional pumping function of the elbow-type inlet channel. However, the invention seems to neglect the reliability and stability of the device operation, which is a crucial aspect in pumping station equipment design. In practical applications, in addition to structural design, factors such as material selection, sealing performance, stability of the operation and control system, and equipment durability need to be considered to ensure that the equipment operates stably for a long time and reduce maintenance costs.

[0007] The aforementioned patents all focus on the design of specific parameters or profiles of the inlet channel of a bidirectional flow channel pump, or on the mechanical structure and manufacturing process of the inlet channel. They lack parametric design and hydraulic optimization design for the inlet channel profile of the bidirectional flow channel pump. The advantages of using a bell-shaped inlet channel in a bidirectional flow channel pump are significant: First, its optimized streamline design effectively reduces hydraulic losses, improves the flowability and stability of the pump water, and reduces the generation of eddies and turbulence, thereby improving the energy efficiency and operating efficiency of the pumping station. Second, favorable flow conditions help reduce pump wear and damage, extend equipment lifespan, and reduce maintenance costs and downtime. Finally, the bell-shaped inlet channel design is highly adaptable, maintaining stability under different flow rates and operating conditions, providing reliable assurance for pumping station operation. For bidirectional flow channel pumping stations, the inlet channel design is crucial, directly affecting the pumping station's operating efficiency, energy efficiency, and reliability. An excellent inlet channel design can reduce hydraulic losses, improve the stability and flow characteristics of the water flow, thereby enhancing the overall performance of the pumping station. A well-designed inlet channel can effectively reduce the generation of eddies and turbulence, decrease pump vibration and noise, extend equipment lifespan, and reduce energy consumption. Furthermore, the design of the inlet channel must consider preventing cavitation, reducing the possibility of blockage, and ensuring stable operation under different flow rates and operating conditions. In conclusion, an inlet channel designed based on the centerline not only improves the efficiency and reliability of the pumping station but also reduces operating costs, which is of great significance for ensuring the long-term stable operation of the pumping station. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a hydraulic design method for a bell-shaped inlet channel of a bidirectional flow channel pump device. This method, based on Dean's vortex theory, divides the cross-section of the bell-shaped tube into a first curved segment, a second curved segment, and a straight segment. It designs the curvature variation of the meridian in each segment and provides the width variation law for each segment of the bell-shaped tube. Spline curves are used to connect the points to form a complete profile. The innovation of this invention lies in using Dean's vortex theory to guide the hydraulic design of the inlet channel, thereby reducing the generation of eddies and turbulence and improving the energy efficiency and operating efficiency of the bidirectional pump station. It also provides a parametric design method for the inlet channel, improving upon the original design method of the elliptical bell-shaped tube and guide cone cross-section of the bidirectional flow channel pump device, and overcoming the shortcomings of unstable hydraulic performance and incomplete hydraulic design parameters in current inlet channels.

[0009] The present invention achieves the above-mentioned technical objectives through the following solutions:

[0010] This invention provides a hydraulic design method for a bell-shaped inlet flow channel of a bidirectional flow channel pump device based on Dean's vortex theory, comprising the following design steps:

[0011] Geometric modeling: The water inlet channel includes a trumpet pipe, a guide cone, a partition, and a gate. The surface of the guide cone is concave to the top surface of the partition. The trumpet pipe is sleeved on the outside of the guide cone, and the gate is located on the outside of the partition.

[0012] Segmentation: The cross-section of the horn tube is divided into three segments: the first curved segment, the second curved segment, and the straight segment.

[0013] Dimension Calculation: Calculate the geometric dimensions of the inlet channel based on the design parameters of the bidirectional flow channel device, including the length X of the bell-shaped inlet channel. L Width of bell-shaped inlet channel X B Height X of the bell-shaped water inlet channel H The bell-shaped inlet channel has the following parameters: bottom diameter D1 of the horn tube, bottom diameter D0 of the guide cone, outlet diameter d1 of the horn tube, outlet diameter d0 of the guide cone, height h1 of the horn tube, and height h0 of the guide cone.

[0014] Establish a rectangular coordinate system: Establish a rectangular coordinate system xoy on the longitudinal section of the bell-shaped water inlet channel. The origin o of the rectangular coordinate system xoy is located on the extension line of the impeller axis below the bell-shaped water inlet channel, and the x-axis of the rectangular coordinate system xoy extends along the radial direction of the trumpet tube, and the y-axis extends along the axial direction of the trumpet tube.

[0015] Profile Design: Establish the equations for the meridional curvature profiles of the first curved segment of the trumpet tube and the guide cone, and draw the meridional curvature profiles of the first curved segment of the trumpet tube and the guide cone; calculate the variation law of the width b between the first curved segment of the trumpet tube and the guide cone, and draw a line segment of length b at each point on the meridional curvature profile of the first curved segment of the trumpet tube and the guide cone. The line segment is perpendicular to the tangent at the corresponding intersection point on the meridional curvature profile of the first curved segment of the trumpet tube and the guide cone, and the corresponding intersection point is the midpoint of the line segment; use spline curves to connect the endpoints of each line segment to obtain the curvature profiles of the first curved segment and the second curved segment of the trumpet tube; establish the equations for the second curved segment and the straight segment of the trumpet tube, and draw the profiles of the second curved segment and the straight segment of the trumpet tube.

[0016] Furthermore, in the geometric modeling step, the trumpet tube and the guide cone are coaxial, and the central axis of the guide cone and the trumpet tube is the rotation axis of the pump impeller; the curvature profile of the trumpet tube is a concave curve connected to an upward straight line. The curvature profile of the guide cone is concave; the bottom of the guide cone is parallel to the bottom of the trumpet tube; the bottom diameter of the guide cone is the same as the bottom diameter of the trumpet tube; the tangent at the outlet of the trumpet tube and the guide cone is perpendicular to the outlet of the bell-shaped inlet channel; the partition is perpendicular to the bottom surface of the bell-shaped inlet channel, and one end of it is located in the concave area of ​​the bell-shaped inlet channel.

[0017] Furthermore, in the size calculation step, the length X of the bell-shaped inlet channel of the bidirectional flow channel pump device is... L The calculation formula is:

[0018] ;

[0019] In the formula, D is the impeller diameter of the pump type selected in the pump unit; n is the design speed of the pump type selected in the pump unit; and H is the design head of the pump type selected in the pump unit.

[0020] Width X of the bell-shaped inlet channel of the bidirectional flow channel pump unit B The calculation formula is:

[0021] ;

[0022] Height X of the bell-shaped inlet channel of the bidirectional flow channel pump unit H The calculation formula is:

[0023] ;

[0024] The formula for calculating the bottom diameter D1 of the bell-shaped inlet channel is:

[0025] ;

[0026] Furthermore, the bottom diameter of the guide cone of the bell-shaped water inlet channel is D0=D1.

[0027] Furthermore, the diameter d1 of the bell-shaped inlet channel's horn-shaped outlet is the impeller diameter D of the pump type selected for the pump device; the diameter d0 of the bell-shaped inlet channel's guide cone outlet is the impeller hub diameter d of the pump type selected for the pump device.

[0028] Furthermore, in the step of establishing a rectangular coordinate system, the origin o of the rectangular coordinate system xoy is located below the bottom surface of the bell-shaped water inlet channel, and the distance between it and the bottom surface of the bell-shaped water inlet channel is Z. The rectangular coordinate system xoy is the x-axis along the radial direction of the bottom surface of the trumpet tube and the y-axis along the axial direction of the trumpet tube. The rectangular coordinate system xy plane is located on the transverse cross-section of the bell-shaped water inlet channel.

[0029] Furthermore, in the profile design step, the equations for the first curved segment of the bell-shaped inlet channel and the meridional curvature profile of the guide cone are as follows:

[0030] ;

[0031] In the formula, h0 is the height of the guide cone; h1 is the height of the bell tube; D0 is the bottom diameter of the guide cone (m); d0 is the outlet diameter of the guide cone; D1 is the bottom diameter of the bell tube (m); d1 is the outlet diameter of the bell tube (m); Z is the distance between the x-axis of the rectangular coordinate system and the bottom surface of the bell-shaped inlet channel.

[0032] Furthermore, in the profile design step, the curvature equations for the first curved segment of the bell-shaped inlet channel and the meridional profile of the guide cone are:

[0033] .

[0034] Furthermore, in the profile design step, the expression for the distance b between the first curved segment of the bell-shaped inlet channel and the guide cone is:

[0035] .

[0036] Furthermore, in the profile design step, the first curved section of the bell-shaped inlet channel and the guide cone are A... r The expression is:

[0037] .

[0038] Furthermore, in the profile design step, the equation for the curvature profile of the second curved segment of the bell-shaped inlet channel is:

[0039] .

[0040] The beneficial effects of this invention are as follows:

[0041] This invention improves the design method of the elliptical trumpet tube and guide cone curvature profile of the inlet channel of the original bidirectional flow channel pump device, achieving a smooth transition between the curvature profiles of the inlet channel trumpet tube and guide cone, thus improving the head and efficiency of the bidirectional flow channel pump device. The bell-shaped inlet channel hydraulic design method for bidirectional flow channel pump devices provided by this invention significantly improves hydraulic performance and stability, solving the problems of unstable hydraulic performance and incomplete design parameters in existing technologies. Through optimized geometric modeling and precise dimensional calculations, it achieves smooth and efficient water flow, adapts to various operating conditions, reduces head loss, lowers the risk of cavitation, and improves the operational reliability and efficiency of the pump station. This design method improves the flexibility and economy of the pump station, significantly reducing energy consumption and maintenance costs. This invention also realizes the parametric design of the curvature profile of the trumpet tube and the guide cone, and provides the specific execution steps and parametric design formulas. With the hydraulic efficiency of the bidirectional flow channel pump device as the optimization target, the automatic optimization of the bidirectional flow channel pump device can be realized with the help of computer modeling, mesh generation and numerical simulation software and optimization algorithms, which greatly shortens the development cycle of the hydraulic model of the efficient and reliable bidirectional flow channel pump device.

[0042] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 Flow diagram for the design of the bell-shaped inlet flow channel of a two-way flow channel pump device;

[0045] Figure 2 This is a structural diagram of the bell-shaped inlet flow channel of a two-way flow channel pump device;

[0046] Figure 3 Side view of the bell-shaped inlet flow channel of a two-way flow channel pump unit;

[0047] Figure 4 Section A of the bell-shaped inlet flow channel of the bidirectional flow channel pump device r C r Design schematic diagram;

[0048] Figure 5A schematic diagram of the curvature profile design of the bell-shaped inlet channel of a two-way flow channel pump device;

[0049] Figure 6 This study compares the external characteristics of bidirectional pumping stations based on the elliptical line design method with those based on traditional design methods.

[0050] The reference numerals in the above figures are as follows: 1. Trumpet pipe; 2. Guide cone; 3. Divider; 4. Gate; 5. First curved section of trumpet pipe; 6. Second curved section of trumpet pipe; 7. Straight section of trumpet pipe. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] It should be noted that in the description of this invention, the terms "first," "second," etc., are used only for descriptive purposes and to distinguish similar objects; there is no order between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0053] Combination Figure 1-6 As shown, this embodiment discloses a hydraulic design method for a bell-shaped inlet flow channel of a bidirectional flow channel pump device, including the following design steps:

[0054] Determine the pump type: Based on local hydrological conditions and specific engineering requirements, determine the appropriate type and model of axial flow pump to meet operational and economic requirements.

[0055] Geometric modeling: The bidirectional bell-shaped water inlet channel includes a trumpet pipe 1, a guide cone 2, a partition 3, and a gate 4. The surface of the guide cone 2 is concave to the top surface of the partition 3; the trumpet pipe 1 is fitted onto the outside of the guide cone 2; and the gate 4 is located on the outside of the partition.

[0056] The horn tube 1 and the guide cone 2 are coaxial, and the central axis of the guide cone 2 and the horn tube 1 is the rotation axis of the pump impeller. The curvature profile of the horn tube 1 is a concave curve connected to an upward straight line. The curvature profile of the guide cone is concave. The bottom of the guide cone 2 is parallel to the bottom of the horn tube 1. The bottom diameter of the guide cone 2 is the same as the bottom diameter of the horn tube 1. The tangent at the outlet of the horn tube 1 and the guide cone 2 is perpendicular to the outlet of the bell-shaped inlet channel. The partition 3 is perpendicular to the bottom surface of the bell-shaped inlet channel, and one end of it is located in the concave area of ​​the bell-shaped inlet channel.

[0057] Segmentation: Divide the cross-section of the horn tube into three segments: the first curved segment 5, the second curved segment 6, and the straight segment 7.

[0058] Dimension Calculation: Calculate the geometric dimensions of the inlet channel based on the design parameters of the bidirectional flow channel pump unit, including the length X of the bell-shaped inlet channel. L Width of bell-shaped inlet channel X B Height X of the bell-shaped water inlet channel H The bell-shaped inlet channel has the following parameters: bottom diameter D1 of the bell-shaped tube, bottom diameter D0 of the guide cone, outlet diameter d1 of the bell-shaped tube, outlet diameter d0 of the guide cone, height h1 of the bell-shaped tube, and height h0 of the guide cone.

[0059] Among them, the length X of the bell-shaped inlet channel of the bidirectional flow channel pump device L The calculation formula is:

[0060] ;

[0061] In the formula, D is the impeller diameter of the selected pump type, in meters; n is the design speed of the selected pump type, in r / min; and H is the design head of the selected pump type, in meters.

[0062] Width X of the bell-shaped inlet channel of the bidirectional flow channel pump unit B The calculation formula is:

[0063] ;

[0064] Height X of the bell-shaped inlet channel of the bidirectional flow channel pump unit H The calculation formula is:

[0065] ;

[0066] The formula for calculating the bottom diameter D1 of the bell-shaped inlet channel is:

[0067] .

[0068] The bottom diameter of the guide cone of the bell-shaped inlet channel is D0=D1, the outlet diameter of the bell-shaped inlet channel is d1, which is the impeller diameter D of the pump type selected by the pump device; the outlet diameter of the guide cone of the bell-shaped inlet channel is d0, which is the impeller hub diameter d of the pump type selected by the pump device.

[0069] Establish a rectangular coordinate system: Establish a rectangular coordinate system xoy on the longitudinal section of the bell-shaped water inlet channel. The origin o of the rectangular coordinate system xoy is located on the extension line of the impeller axis below the bell-shaped water inlet channel, and the x-axis of the rectangular coordinate system xoy extends along the radial direction of the trumpet tube, and the y-axis extends along the axial direction of the trumpet tube.

[0070] In this system, the origin o of the rectangular coordinate system xoy is located below the bottom surface of the bell-shaped water inlet channel, and the distance between the origin o and the bottom surface of the bell-shaped water inlet channel is Z. The rectangular coordinate system xoy is radially along the bottom surface of the trumpet tube and axially along the horn tube. The xy plane of the rectangular coordinate system xoy is located on the transverse cross-section of the bell-shaped water inlet channel.

[0071] Profile Design: Establish the equations for the meridional curvature profiles of the first curved segment 5 of the trumpet tube and the water guide cone 2, and draw the meridional curvature profiles of the first curved segment 5 of the trumpet tube and the water guide cone 2; calculate the variation law of the width b between the first curved segment 5 of the trumpet tube and the water guide cone 2, and draw a line segment of length b at each point on the meridional curvature profile of the first curved segment 5 of the trumpet tube and the water guide cone 2. The line segment is perpendicular to the tangent at the corresponding intersection point on the meridional curvature profile of the first curved segment 5 of the trumpet tube and the water guide cone 2, and the corresponding intersection point is the midpoint of the line segment; use spline curves to connect the endpoints of each line segment to obtain the curvature profiles of the first curved segment 5 of the trumpet tube and the water guide cone 2; establish the equations for the second curved segment 6 of the trumpet tube and the straight segment 7, and draw the profiles of the second curved segment 6 of the trumpet tube and the straight segment 7.

[0072] The equations for the first curved segment 5 of the bell-shaped inlet channel and the meridian curvature profile of the guide cone 2 are as follows:

[0073] ;

[0074] In the formula, h0 is the height of the guide cone, m; h1 is the height of the bell tube, m; D0 is the bottom diameter of the guide cone, m; d0 is the outlet diameter of the guide cone, m; D1 is the bottom diameter of the bell tube, m; d1 is the outlet diameter of the bell tube, m; Z is the distance between the x-axis of the rectangular coordinate system and the bottom surface of the bell-shaped inlet channel, m.

[0075] The curvature equations for the first curved segment 5 of the bell-shaped inlet channel and the meridional profile of the guide cone 2 are as follows:

[0076] .

[0077] The expression for the distance b between the first curved segment 5 of the bell-shaped inlet pipe and the guide cone 2 is:

[0078] .

[0079] Between the first curved section 5 of the bell-shaped inlet channel and the guide cone 2, A r The expression is:

[0080] .

[0081] Furthermore, in the profile design step, the equation for the curvature profile of the second curved segment 6 of the bell-shaped inlet channel is:

[0082] .

[0083] Example:

[0084] like Figure 1 As shown, the bidirectional flow channel pump bell-shaped inlet flow channel design method of the present invention includes the following steps:

[0085] The appropriate type and model of axial flow pump are determined based on local hydrological conditions and specific engineering requirements. The design parameters of the selected axial flow pump are as follows:

[0086] The impeller diameter D = 3.15m, the impeller hub diameter d = 1.03m, the impeller design speed n = 125r / min, and the design head H = 3.6m for the bidirectional flow channel pump device.

[0087] Establish as Figure 2 The schematic diagram of the bell-shaped inlet channel of the bidirectional flow channel pump device shown includes a bell-shaped pipe 1, a guide cone 2, a baffle 3, and a gate 4. A side cross-sectional view of the inlet channel is shown below. Figure 3 As shown.

[0088] The cross-section of the horn tube is divided into three segments: the first curved segment 5, the second curved segment 6, and the straight segment 7.

[0089] Based on the above geometric relationships, the length X of the bell-shaped inlet channel is obtained. L =13.6m, the width of the bell-shaped inlet channel X B =8.72m, the width of the bell-shaped inlet channel X H =4.53m.

[0090] Based on the above geometric relationships, the bottom diameter of the bell-shaped inlet pipe 1 is D1 = 6.22m, the bottom diameter of the guide cone 2 is D0 = 6.22m, the outlet diameter of the bell-shaped inlet pipe 1 is d1 = 3.15m, and the outlet diameter of the guide cone 2 is d0 = 1.03m.

[0091] Create a rectangular coordinate system and list the parametric design equations for the profile:

[0092] According to Dean's vortex theory, Ar and Cr in the inlet flow channel profile of a bidirectional pumping station, such as Figure 4 As shown, the parameters on the cross-section are as follows: Figure 5 As shown.

[0093] The equations for the first curved segment 5 of the bell-shaped inlet channel and the meridian curvature profile of the guide cone are as follows:

[0094] .

[0095] In the formula, h0 is the height of the water guide cone 2 (m); h1 is the height of the trumpet tube 1.

[0096] The equations for the curvature of the first curved segment 5 of the bell-shaped inlet channel and the meridian profile of the guide cone 2 are as follows:

[0097] .

[0098] The expression for the distance b between the first curved segment 5 of the bell-shaped inlet pipe and the guide cone 2 is:

[0099] .

[0100] Between the first curved section 5 of the bell-shaped inlet channel and the guide cone 2, section A r The expression is:

[0101] .

[0102] The equation for the curvature profile of the second curved segment 6 of the bell-shaped inlet channel is:

[0103] ;

[0104] In the formula, h0 is the height of the guide cone; h1 is the height of the bell pipe.

[0105] Draw a line segment of length b at each point on the meridian curvature profile of the first curved segment 5 of the trumpet tube and the water guide cone 2. The line segment is perpendicular to the tangent at the corresponding intersection point on the meridian curvature profile of the first curved segment 5 of the trumpet tube and the water guide cone 2, and the corresponding intersection point is the midpoint of the line segment. Connect the endpoints of each line segment using spline curves to obtain the curvature profile of the first curved segment 5 of the trumpet tube and the water guide cone 2.

[0106] Computer-aided design (CAD) software is used to create a three-dimensional model of the flow channel based on the calculated parameters, and a detailed fluid dynamics analysis is performed to verify the rationality and effectiveness of the design. During the model verification phase, computational fluid dynamics (CFD) simulations can be used to analyze the flow field within the channel in detail, ensuring that the channel design achieves the expected hydraulic performance.

[0107] Based on the simulation results and actual engineering requirements, the design parameters are fine-tuned to achieve the optimal flow channel design. Figure 6A comparison of the external characteristics of bidirectional pumping stations based on the elliptical curve design method and the traditional design method shows that, under the premise that the pump head difference is not significant, the pump operating efficiency designed using this method is greater than that under the traditional method. Therefore, the embodiments of this invention not only provide a more efficient inlet channel design method, but also provide important theoretical basis and technical support for the design and renovation of pumping stations.

[0108] By combining simulation results with actual engineering requirements, design parameters are fine-tuned to achieve the best flow channel design effect. Figure 6 This paper compares the external characteristics of two-way flow channel pump units with inlets based on a traditional elliptical inlet design and those based on the Dean vortex design method. The results show that, with minimal difference in pump head, the pump designed using this method has significantly higher operating efficiency than the traditional method. Therefore, this invention not only provides an efficient inlet flow channel design method but also offers important theoretical foundations and technical support for the design and modification of pump stations.

[0109] It should be understood that although this specification describes various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0110] In the description of this invention, it should be understood that the terms "lateral", "upper", "lower", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0111] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included within the scope of protection of the present invention.

[0112] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A hydraulic design method for a bell-shaped inlet flow channel of a bidirectional flow channel pump device, characterized in that, Includes the following steps: Geometric modeling: The bell-shaped water inlet channel includes a trumpet pipe (1), a water guide cone (2), a partition (3) and a gate (4); the surface of the water guide cone (2) is concave to the top surface of the partition (3); the trumpet pipe (1) is sleeved on the outside of the water guide cone (2), and the gate (4) is located on the outside of the partition (3); Segmentation: The cross-sectional line of the horn tube (1) is divided into a first curved segment (5), a second curved segment (6), and a straight segment (7). Size calculation: Calculate the length X of the bell-shaped inlet channel based on the design parameters of the bidirectional flow channel pump device. L The width of the bell-shaped inlet channel X B The height X of the bell-shaped water inlet channel H The bell-shaped inlet channel has a bottom diameter of D1, a bottom diameter of D0, an outlet diameter of d1, an outlet diameter of d0, a height of h1, and a height of h0. Establish a rectangular coordinate system: Establish a rectangular coordinate system xoy on the longitudinal section of the bell-shaped water inlet channel, with the origin o of the coordinate system located on the extension line of the impeller axis below the bell-shaped water inlet channel; Profile Design: Based on Dean's vortex theory, the curvature ratio and width ratio of the bidirectional pump station in the geometric coordinate system are defined respectively. A mathematical model of the inlet channel geometry with respect to the curvature ratio and width ratio is established. C r As the curvature ratio, A r Given the width ratio; establish the meridian curvature profile equations of the first curved segment (5) of the trumpet tube and the water guide cone (2), and draw the meridian curvature profiles of the first curved segment of the trumpet tube and the water guide cone (2); calculate the variation law of the width b between the first curved segment (5) of the trumpet tube and the water guide cone (2), and obtain the C of the meridian profile of the first curved segment (5) of the trumpet tube and the water guide cone (2) through the above variation law. r With A r According to C r With A r Based on the changing pattern, the curvature profiles of the first curved segment (5) of the trumpet tube and the guide cone (2) are obtained; the equations of the second curved segment and the straight segment of the trumpet tube are established, and the profiles of the second curved segment (6) and the straight segment (7) of the trumpet tube are drawn; The curvature equations of the meridional profiles of the first curved segment (5) of the bell-shaped inlet channel and the guide cone (2) are as follows: ； The first curved section (5) of the bell-shaped inlet channel and the guide cone (2) are located between A r The expression is: 。 2. The hydraulic design method for the bell-shaped inlet flow channel of the bidirectional flow channel pump device according to claim 1, characterized in that, In the geometric modeling step, the trumpet tube (1) and the guide cone (2) are coaxial, and the central axis of the guide cone (2) and the trumpet tube (1) is the rotation axis of the pump impeller; the curvature profile of the trumpet tube (1) is a concave curve connected to a straight line sloping upward; the curvature profile of the guide cone (2) is concave; the bottom of the guide cone (2) is parallel to the bottom of the trumpet tube (1); the bottom diameter of the guide cone (2) is the same as the bottom diameter of the trumpet tube (1); the tangent at the outlet of the trumpet tube (1) and the guide cone (2) is perpendicular to the outlet of the bell-shaped water inlet channel; the partition (3) is perpendicular to the bottom surface of the bell-shaped water inlet channel, and one end of it is located in the concave area of ​​the bell-shaped water inlet channel; the gate (4) is located outside the partition (3).

3. The hydraulic design method for the bell-shaped inlet flow channel of the bidirectional flow channel pump device according to claim 1, characterized in that, In the dimensional calculation step, the length X of the bell-shaped inlet channel of the bidirectional flow channel pump device is... L The calculation formula is: ； In the formula, D is the impeller diameter of the pump type selected in the pump unit; n is the design speed of the pump type selected in the pump unit; and H is the design head of the pump type selected in the pump unit. Width X of the bell-shaped inlet channel of the bidirectional flow channel pump unit B The calculation formula is: ； Height X of the bell-shaped inlet channel of the bidirectional flow channel pump unit H The calculation formula is: ； The formula for calculating the bottom diameter D1 of the bell-shaped inlet channel is: ； The bottom diameter of the guide cone of the bell-shaped water inlet channel is D0=D1; The bell-shaped inlet channel has a horn-shaped outlet diameter d1 that is the impeller diameter D of the pump type selected for the pump device; the bell-shaped inlet channel has a guide cone outlet diameter d0 that is the impeller hub diameter d of the pump type selected for the pump device.

4. The hydraulic design method for the bell-shaped inlet flow channel of the bidirectional flow channel pump device according to claim 1, characterized in that, In the step of establishing a rectangular coordinate system, the origin o of the rectangular coordinate system xoy is located below the bottom surface of the bell-shaped water inlet channel, and the distance between it and the bottom surface of the bell-shaped water inlet channel is Z. The rectangular coordinate system xoy is the x-axis along the radial direction of the bottom surface of the trumpet tube (1) and the y-axis along the axial direction of the trumpet tube (1). The rectangular coordinate system xy plane is located on the transverse section of the bell-shaped water inlet channel.

5. The hydraulic design method for the bell-shaped inlet flow channel of the bidirectional flow channel pump device according to claim 1, characterized in that, In the profile design step, the equations for the meridional profiles of the first curved segment (5) of the bell-shaped inlet channel and the guide cone (2) are as follows: ； In the formula, h0 is the height of the guide cone; h1 is the height of the bell tube; D0 is the bottom diameter of the guide cone; d0 is the outlet diameter of the guide cone; D1 is the bottom diameter of the bell tube; d1 is the outlet diameter of the bell tube; Z is the distance between the x-axis of the rectangular coordinate system and the bottom surface of the bell-shaped inlet channel.

6. The hydraulic design method for the bell-shaped inlet flow channel of the bidirectional flow channel pump device according to claim 1, characterized in that, In the profile design step, the expression for the distance b between the first curved segment (5) of the bell-shaped inlet channel and the guide cone (2) is: 。 7. The hydraulic design method for the bell-shaped inlet flow channel of the bidirectional flow channel pump device according to claim 5, characterized in that, In the profile design step, the equation for the profile of the second curved segment (6) of the bell-shaped inlet channel is: 。

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