Design method for bell-shaped water inlet flow channel of bidirectional flow channel pump device

Abstract

The invention discloses a hydraulic design method for a bell-shaped water inlet runner of a bidirectional runner pump device. The method is realized through the following steps: firstly, determining a proper axial flow pump type and model; then geometric modeling is carried out, a water inlet flow channel model comprising a horn tube, a water guide cone, a partition pier and a gate is constructed, a horn tube type line is divided into three sections of section lines, and the length, the width, the height and the diameter of each part are determined; and establishing a rectangular coordinate system to carry out molded line design, determining curvature molded lines of the first curve section of the flare tube and the water guide cone by establishing an equation of a meridian line of the first curve section of the flare tube and the water guide cone and a distance between the first curve section of the flare tube and the water guide cone, and respectively making curvature molded lines of the second curve section of the flare tube and the straight line section. According to the method, parameterization design of the section curvature molded lines of the horn tube and the water guide cone is achieved, specific execution steps and a parameterization design formula are provided, the research and development period is shortened, and the hydraulic performance and stability are improved.

Description

Technical Field

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

[0002] As a common pump station equipment, the bidirectional flow channel pump device has been widely promoted and applied in most parts of the country. Its design and application can be regarded as a major innovation in the field of water pump technology and pump station engineering in China. It is widely used in various water conservancy projects and urban infrastructure construction with the characteristics of compact structure, stable operation and convenient maintenance. However, there are still two major problems with the bidirectional flow channel pump devices currently built in my country. One is the low operating efficiency of the pump device, and the other is the unstable operation of the pump device, which will produce large vibration and noise. The bell-shaped water inlet flow channel has a relatively simple structure and is easy to construct. It can not only significantly improve the water inlet conditions of the bidirectional flow channel pump device, but also reduce the construction cost. This has a high economic value for low-lift bidirectional pump stations. The use of a bidirectional bell-shaped water inlet flow channel is of great significance in a bidirectional flow channel pump station and is an economical and reasonable choice.

[0003] In the Chinese patent "A design method for a bell-shaped water inlet flow channel for a pump station" with application number CN106897512A published on February 17, 2017, a series of geometric parameter formulas are used to determine the main dimensions of the bell-shaped water inlet flow channel, including flow channel height, suction chamber rear wall distance, inlet width, flow channel length, bell tube height, water guide cone bottom diameter, inlet section top tapered angle, lower edge line inclination, bell tube outlet diameter, water guide cone height and bell tube inlet diameter. The bell-shaped water inlet flow channel using this design method can improve the water inlet flow pattern, reduce hydraulic loss, and improve the operating stability and efficiency of the pump station. This method reduces the collision loss between the inlet section and the bell tube by adjusting the parameters such as the width, height, top tapered angle and lower edge line inclination of the inlet section, and optimizes the geometric dimensions of the water guide cone and the bell tube to reduce eddy currents and hydraulic losses along the way, thereby improving the overall performance of the pump station. The invention introduces in detail the design method of various parameters in the bell-shaped water inlet channel. However, the invention does not mention the curved line design of the trumpet tube and the water guide cone. The use of appropriate curved line design can further reduce eddy currents and hydraulic losses along the way, thereby improving the fluid flow state and improving the stability and efficiency of the water inlet channel.

[0004] In the Chinese patent "A Method for Designing the Bell Mouth of the Inlet Flow Channel of a Bidirectional Pumping Station" with application number CN113704850A published on August 27, 2021, a method for designing the bell mouth of the inlet flow channel of a bidirectional pumping station is proposed. By using quadratic equations to solve the set of equations for the inlet profile, the parametric design of the profile of the bell mouth is realized, and the geometric parameters and profile of the bell mouth are optimized. The improved design makes the transition of the profile smoother, improves the stability of the inlet flow state, and reduces hydraulic losses, thereby improving the efficiency and operational stability of the pumping station. The invention introduces in detail the design formula for the profile of the bell-shaped inlet flow channel bell mouth, but ignores the other parameters of the water guide cone profile and the inlet flow channel, which is unreasonable for the overall design of the bidirectional flow channel pump device.

[0005] In the Chinese patent "A square box type two-way water inlet flow channel design method" with application number CN108757571A published on May 25, 2018, an accurate formula design method is used to design the main geometric parameters of a square box type two-way water inlet flow channel for a pump station, including the width of the inlet section of the water inlet flow channel, the inlet height, the height of the bell tube, etc. The reliability of the pump station operation is improved, the hydraulic loss through the water inlet flow channel of the pump station is reduced, and the service life of the pump and the maintenance cycle of the pump station are extended. In addition, this technology is more conducive to the use in combination with computers, making parametric design possible. The water inlet flow channel structure in this invention is a square box type. Compared with the bell-shaped water inlet flow channel, its geometric shape is prone to uneven water flow distribution and greater flow resistance, especially at the corners of the flow channel, it is easy to form dead water areas and vortices, affecting the efficiency and stability of the pump station; and the complex structure of the square box type water inlet flow channel increases the cost and difficulty of design, manufacturing and maintenance, and is relatively poor in space utilization efficiency and adaptability.

[0006] In the Chinese patent "A Bidirectional Elbow Inlet Flow Channel and Pumping Station" with application number CN116837790A filed on July 26, 2023, a bidirectional elbow-type water inlet flow channel and pumping station are proposed, aiming to solve the limitation that the existing elbow-type water inlet flow channel can only run in one direction. The elbow-type water inlet flow channel includes a first elbow and a second elbow-type water inlet flow channel, which share a rotatable elbow section, so that the elbow-type water inlet flow channel can be suitable for bidirectional pumping operations of a bidirectional pumping station. The rotation of the elbow section is controlled by a rotating assembly and a driving mechanism to achieve a flexible connection between the elbow section and the straight section, so that the water supply flow channel can be selected according to the pumping demand, thereby improving the operating efficiency and reliability of the pumping station, reducing the head loss and cavitation risk, and significantly improving the adaptability and economy. The focus of the invention is to design a bidirectional elbow-type water inlet flow channel and its structural design for use in a pumping station to achieve the bidirectional pumping function of the elbow-type water inlet flow channel. However, the invention seems to ignore the reliability and stability of the device operation, which is a crucial aspect in the design of pumping station equipment. In practical applications, in addition to structural design, factors such as material selection, sealing performance, stability of the operation control system, and equipment durability need to be considered to ensure long-term stable operation of the equipment and reduce maintenance costs.

[0007] All of the above patents are designed for part of the parameters or profiles of the water inlet channel of the two-way flow channel pump device, or for the patent design of the mechanical structure and processing and manufacturing process of the water inlet channel. There is a lack of parametric design and hydraulic optimization design of the water inlet channel profile of the two-way flow channel pump device. The advantages of using a bell-shaped water inlet channel in a two-way flow channel pump device are very significant: first, it effectively reduces hydraulic losses through optimized streamline design, improves the fluidity and stability of pump water, and reduces the generation of vortices and turbulence, thereby improving the energy efficiency and operation efficiency of the pump station; second, good water flow conditions help reduce pump wear and damage, extend the service life of the equipment, and reduce maintenance costs and downtime; finally, the design of the bell-shaped water inlet channel is highly adaptable and can maintain stability under different flow rates and operating conditions, providing reliable protection for the operation of the pump station. For a two-way flow channel pump station, the design of the water inlet channel is crucial to the pump station, which directly affects the operating efficiency, energy efficiency and reliability of the pump station. An excellent water inlet channel design can reduce hydraulic losses, improve the stability and flow characteristics of the water flow, and thus improve the overall performance of the pump station. Good design can effectively reduce the generation of eddies and turbulence, reduce pump vibration and noise, extend the service life of equipment, and reduce energy consumption. In addition, the design of the water inlet flow channel must also consider preventing cavitation, reducing the possibility of blockage, and adapting to stable operation under different flow rates and operating conditions. In summary, the water inlet flow channel based on the flow channel centerline design can not only improve the efficiency and reliability of the pump station, but also reduce operating costs, which is of great significance for ensuring the long-term stable operation of the pump station. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a hydraulic design method for a bell-shaped water inlet channel of a bidirectional flow channel pump device. The design method is based on the Dean vortex theory, which divides the profile line of the bell mouth into a first curved segment, a second curved segment and a straight segment, respectively designs the curvature change of the meridian in each segmented area, and gives the width change law of each section of the bell tube, and uses spline curves to connect each point to form a complete profile. The innovation of the present invention lies in using the Dean vortex theory to guide the hydraulic design of the water inlet channel to reduce the generation of vortices and turbulence, thereby improving the energy efficiency and operation efficiency of the bidirectional pump station; providing a parametric design method for the water inlet channel, improving the original design method of the elliptical bell tube and the water guide cone profile image of the water inlet channel of the bidirectional flow channel pump device, and making up for the shortcomings of the current unstable hydraulic performance of the water inlet channel and incomplete hydraulic design parameters.

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

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

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

[0012] Segmentation: dividing the cross-section line of the bell mouth into three segments, namely a first curved segment, a second curved segment, and a straight segment;

[0013] Dimension calculation: According to the design parameters of the bidirectional flow channel pump device, the geometric dimensions of the water inlet flow channel are calculated, including the length X of the bell-shaped water inlet flow channel. L , the width of the bell-shaped water inlet channel X B , height of bell-shaped water inlet channel X H , bell-shaped water inlet channel bottom diameter D1, water guide cone bottom diameter D0, bell-shaped water inlet channel outlet diameter d1, water guide cone outlet diameter d0, bell-shaped water inlet channel height h1, water guide cone height h0;

[0014] Establishing a rectangular coordinate system: establishing a rectangular coordinate system xoy on the longitudinal section of the bell-shaped water inlet flow channel, wherein the coordinate origin o of the rectangular coordinate system xoy is located on the extension line of the impeller axis below the bell-shaped water inlet flow channel, and the x-axis of the rectangular coordinate system xoy extends along the radial direction of the bell mouth, and the y-axis extends along the axial direction of the bell mouth;

[0015] Profile design: establish the meridian curvature profile equation of the first curved segment of the trumpet tube and the water guide cone, and draw the meridian curvature profile of the first curved segment of the trumpet tube and the water guide cone; calculate the variation law of the width b between the first curved segment of the trumpet tube and the water guide cone, make a line segment with a length of b at each point on the meridian curvature profile of the first curved segment of the trumpet tube and the water guide cone, the line segment is perpendicular to the tangent of the corresponding intersection of the first curved segment of the trumpet tube and the meridian curvature profile of the water guide cone, and the corresponding intersection is the midpoint of the line segment; use spline curves to connect the endpoints of each line segment respectively, that is, obtain the curvature profile of the first curved segment and the second curved segment of the trumpet tube; establish the equation of the second curved segment and the straight segment of the trumpet tube, and draw the profile 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 water guide cone are coaxial, and the central axis of the water guide cone and the trumpet tube is the rotation axis of the impeller of the pump device; the curvature profile of the trumpet tube is a concave curve connecting a straight line written upward. The curvature profile of the water guide cone is concave; the bottom of the water guide cone is parallel to the bottom of the trumpet tube; the bottom diameter of the water guide cone is the same as the bottom diameter of the trumpet tube; the tangent line at the outlet of the trumpet tube and the water guide cone is perpendicular to the outlet of the bell-shaped water inlet channel; the partition pier is perpendicular to the bottom surface of the bell-shaped water inlet channel, and one end thereof is located in the concave area of ​​the bell-shaped water inlet channel.

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

[0018]

[0019] Wherein, D is the impeller diameter of the pump type selected by the pump device; n is the design speed of the pump type selected by the pump device; H is the design head of the pump type selected by the pump device;

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

[0021]

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

[0023]

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

[0025]

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

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

[0028] Furthermore, in the step of establishing a rectangular coordinate system, the coordinate 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 radial direction of the bottom surface of the horn tube of the rectangular coordinate system xoy is the x-axis, and the axial direction of the horn tube is the y-axis. The xy plane of the rectangular coordinate system is on the transverse section of the bell-shaped water inlet channel.

[0029] Furthermore, in the profile design step, the equation of the meridian curvature profile of the first curved section of the bell tube of the bell-shaped water inlet channel and the water guide cone is:

[0030]

[0031] In the formula, h0 is the height of the water guide cone; h1 is the height of the bell tube; D0 is the bottom diameter of the water guide cone m; d0 is the outlet diameter of the water 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 water inlet channel.

[0032] Furthermore, in the profile design step, the curvature equation of the first curved section of the bell tube of the bell-shaped water inlet channel and the meridian profile of the water guide cone is:

[0033]

[0034] Furthermore, in the profile design step, the distance b between the first curved section of the bell tube of the bell-shaped water inlet channel and the water guide cone is expressed as:

[0035]

[0036] Furthermore, in the profile design step, the distance A between the first curved section of the bell tube of the bell-shaped water inlet channel and the water guide cone is 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 tube of the bell-shaped water inlet channel is:

[0039] y=(x-D1) 2 +Z-h1+h2.

[0040] The beneficial effects of the present invention are:

[0041] The present invention improves the design method of the elliptical trumpet tube and the curvature profile of the water guide cone of the original bidirectional flow channel pump device, realizes the smooth transition of the curvature profile of the water inlet channel trumpet tube and the water guide cone, and improves the head and efficiency of the bidirectional flow channel pump device. The hydraulic design method of the bell-shaped water inlet channel of the bidirectional flow channel pump device provided by the present invention significantly improves the hydraulic performance and stability, and solves the problems of unstable hydraulic performance and incomplete design parameters in the prior art. By optimizing geometric modeling and precise dimensional calculation, the smoothness and efficiency of the water flow are achieved, adapting to a variety of working conditions, reducing head losses, reducing cavitation risks, and improving the operational reliability and efficiency of the pump station. This design method improves the flexibility and economy of the pump station, and significantly reduces energy consumption and maintenance costs. The present invention also realizes the parametric design of the curvature profile of the trumpet tube and the water guide cone section, provides the specific execution steps and parametric design formulas of the design, takes the hydraulic efficiency of the two-way flow channel pump device as the optimization goal, and can use computer modeling, grid division and numerical simulation software and optimization algorithms to realize automatic optimization of the two-way flow channel pump device, greatly shortening the research and development cycle of the hydraulic model of the efficient and reliable two-way flow channel pump device.

[0042] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 Design a flow chart for the bell-shaped water inlet channel of a bidirectional flow channel pump device;

[0045] Figure 2 It is a structural diagram of the bell-shaped water inlet channel of a bidirectional flow channel pump device;

[0046] Figure 3 It is a side view of the bell-shaped water inlet channel of the bidirectional channel pump device;

[0047] Figure 4 The bell-shaped water inlet channel section A of the bidirectional flow channel pump device r , C r Design schematics;

[0048] Figure 5It is a schematic diagram of the design of the curvature profile of the bell-shaped water inlet flow channel of the bidirectional flow channel pump device;

[0049] Figure 6 This paper compares the external characteristics of a bidirectional pump station based on the elliptical profile design method and the traditional design method.

[0050] The figure marks of the above drawings are: 1. bell mouth; 2. water guide cone; 3. partition pier; 4. gate; 5. first curved section of bell pipe; 6. second curved section of bell pipe; 7. straight section of bell pipe. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

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

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

[0055] Geometric modeling: The bidirectional 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 on 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 pier.

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

[0057] Segmentation: Divide the section line of the trumpet into three segments: a first curved segment 5, a second curved segment 6, and a straight segment 7.

[0058] Dimension calculation: According to the design parameters of the two-way flow channel pump device, the geometric dimensions of the water inlet flow channel are calculated, including the length X of the bell-shaped water inlet flow channel. L , the width of the bell-shaped water inlet channel X B , height of bell-shaped water inlet channel X H , bell-shaped water inlet channel bell tube bottom diameter D1, water guide cone bottom diameter D0, bell tube outlet diameter d1, water guide cone outlet diameter d0, bell tube height h1, water guide cone height h0.

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

[0060]

[0061] Wherein, D is the impeller diameter of the pump type selected by the pump device, m; n is the design speed of the pump type selected by the pump device, r / min; H is the design head of the pump type selected by the pump device, m;

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

[0063]

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

[0065]

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

[0067]

[0068] The bottom diameter D0 of the water guide cone of the bell-shaped water inlet flow channel is D1, the outlet diameter d1 of the trumpet pipe of the bell-shaped water inlet flow channel is the impeller diameter D of the pump type selected for the pump device; the outlet diameter d0 of the water guide cone of the bell-shaped water inlet flow channel is the impeller hub diameter d of the pump type selected for 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 flow channel, the coordinate origin o of the rectangular coordinate system xoy is located on the extension line of the impeller axis below the bell-shaped water inlet flow channel, and the x-axis of the rectangular coordinate system xoy extends along the radial direction of the bell mouth, and the y-axis extends along the axial direction of the bell mouth.

[0070] Among them, the coordinate 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 radial direction of the bottom surface of the trumpet tube of the rectangular coordinate system xoy is the x-axis, and the axial direction of the trumpet tube is the y-axis. The xy plane of the rectangular coordinate system xoy is on the transverse section of the bell-shaped water inlet channel.

[0071] Profile design: establish the meridian curvature profile equation of the first curved segment 5 of the trumpet tube and the water guide cone 2, and draw the meridian curvature profile 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 make a line segment with a length of 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 of 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; use spline curves to connect the endpoints of each line segment respectively, and obtain the curvature profile of the first curved segment 5 of the trumpet tube and the water guide cone 2; establish the equation of the second curved segment 6 of the trumpet tube and the straight segment 7, and draw the profile of the second curved segment 6 of the trumpet tube and the straight segment 7.

[0072] The equation of the meridian curvature profile of the first curved section 5 of the bell-shaped water inlet channel and the water guide cone 2 is:

[0073]

[0074] In the formula, h0 is the height of the water guide cone, m; h1 is the height of the bell tube, m; D0 is the bottom diameter of the water guide cone, m; d0 is the outlet diameter of the water 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 water inlet channel, m.

[0075] The curvature equation of the first curved section 5 of the bell-shaped water inlet channel and the meridian line of the water guide cone 2 is:

[0076]

[0077] The distance b between the first curved section 5 of the bell-shaped water inlet channel and the water guide cone 2 is expressed as:

[0078]

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

[0080]

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

[0082] y=(x-D1) 2 +Z-h1+h0.

[0083] Example:

[0084] like Figure 1 As shown, the method for designing a bell-shaped water inlet channel of a bidirectional flow channel pump according to the present invention comprises the following steps:

[0085] The type and model of the appropriate axial flow pump is determined according to the local hydrological conditions and specific engineering requirements. The design parameters of the selected axial flow pump are:

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

[0087] Establish as Figure 2 The schematic diagram of the structure of the bell-shaped water inlet flow channel of the bidirectional flow channel pump device shown in FIG. 1 includes a trumpet pipe 1, a water guide cone 2, a partition pier 3, and a gate 4. The side cross-sectional view of the water inlet flow channel is shown in FIG. Figure 3 shown.

[0088] The cross-section line of the bell mouth is divided into three sections: a first curved section 5 , a second curved section 6 , and a straight section 7 .

[0089] According to the above geometric relationship, the length X of the bell-shaped water inlet channel is obtained. L =13.6m, the width of the bell-shaped water inlet channel X B =8.72m, the width of the bell-shaped water inlet channel X H =4.53m.

[0090] According to the above geometric relationship, the bottom diameter of the bell-shaped water inlet channel is D1 = 6.22m, the bottom diameter of the water guide cone 2 of the bell-shaped water inlet channel is D0 = 6.22m, the outlet diameter of the bell-shaped water inlet channel is d1 = 3.15m, and the outlet diameter of the water guide cone 2 of the bell-shaped water inlet channel is d0 = 1.03m.

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

[0092] According to Dean vortex theory, Ar and Cr on the inlet flow section of a bidirectional pumping station are as follows: Figure 4 As shown in Figure 2, the parameters on the cross section are as follows: Figure 5 shown.

[0093] The equation of the first curved section 5 of the bell-shaped water inlet channel and the meridian curvature profile of the water guide cone is:

[0094]

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

[0096] The curvature equation of the first curved section 5 of the bell-shaped water inlet channel and the meridian line of the water guide cone 2 is:

[0097]

[0098] The distance b between the first curved section 5 of the bell-shaped water inlet channel and the water guide cone 2 is expressed as:

[0099] b(x)=1.06e 0.366(x-1.06) .

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

[0101] A r =2.12πxe 0.366(x-2.12) .

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

[0103] y=(x-6.22) 2 +Z-h1+h2,

[0104] Where h0 is the height of the water cone; h1 is the height of the bell tube.

[0105] A line segment with a length of b is made 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 of 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; the endpoints of each line segment are connected respectively using a spline curve 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 draw 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) simulation can be used to perform a detailed analysis of the flow field in the flow channel to ensure that the flow channel design can achieve the expected hydraulic performance.

[0107] According to the simulation results and actual engineering requirements, the design parameters are fine-tuned to achieve the optimal flow channel design. Figure 6By comparing the external characteristics of the bidirectional pump station based on the elliptical line design method and the traditional design method, it can be seen that, under the premise of ensuring that the pump head is not much different, the pump operation efficiency designed based on this method is greater than the operation efficiency under the traditional method. Therefore, the embodiment of the present invention not only provides a more efficient water inlet flow channel design method, but also provides an important theoretical basis and technical support for the design and transformation of the pump station.

[0108] Combine simulation results with actual engineering requirements and fine-tune design parameters to achieve the best flow channel design effect. Figure 6 The external characteristics of the bidirectional flow channel pump device with the bidirectional flow channel inlet based on the traditional elliptical line design and the bidirectional flow channel inlet based on the Dean vortex design method are compared. The results show that when the pump head difference is not large, the operating efficiency of the pump designed based on this method is significantly higher than that of the traditional method. Therefore, the present invention not only provides an efficient water inlet flow channel design method, but also provides an important theoretical basis and technical support for the design and transformation of pump stations.

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

[0110] In the description of the present invention, it is necessary to understand that the terms "lateral", "upper", "lower", "front", "rear", "top", "bottom", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0111] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0112] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device, characterized in that: The following steps are involved: Geometric modeling: The bell-shaped water inlet channel comprises a trumpet pipe (1), a water guide cone (2), a partition pier (3) and a gate (4); the surface of the water guide cone (2) is concave on the top surface of the partition pier (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 pier (3); Segmentation: dividing the cross-section line of the bell tube (1) 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 water inlet channel according to the design parameters of the two-way flow channel pump device. L , the width of the bell-shaped water inlet channel X B , the height of the bell-shaped water inlet channel is X H , the bell-shaped water inlet channel has a bottom diameter of the trumpet pipe D1, a bottom diameter of the water guide cone D0, a trumpet outlet diameter d1, a water guide cone outlet diameter d0, a trumpet height h1, and a water guide cone height h0; Establishing a rectangular coordinate system: establishing a rectangular coordinate system xoy on the longitudinal section of the bell-shaped water inlet flow channel, wherein the origin o of the coordinate system is located on the extension line of the impeller axis below the bell-shaped water inlet flow channel; Profile design: Based on the Dean vortex theory, the curvature ratio and width ratio of the bidirectional pump station in the geometric coordinate system are defined respectively, and the mathematical model of the geometric shape of the water inlet flow channel with respect to the curvature ratio and width ratio is established. r is the curvature ratio, A r The invention relates to a method for obtaining a meridian curvature profile line equation of the first curved section (5) of the bell tube and the water guide cone (2) based on the width ratio, and drawing the meridian curvature profile line equation of the first curved section (5) of the bell tube and the water guide cone (2); calculating the variation law of the width b between the first curved section (5) of the bell tube and the water guide cone (2), and calculating the meridian curvature profile line C of the first curved section (5) of the bell tube and the water guide cone (2) based on the variation law. r With A r , according to C r With A r The curvature profile of the first curved segment (5) and the water guide cone (2) of the bell tube is obtained by following the changing law; the equation of the second curved segment and the straight segment of the bell tube is established, and the profile of the second curved segment (6) and the straight segment (7) of the bell tube is drawn.

2. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 1, characterized in that: In the geometric modeling step, the bell tube (1) and the water guide cone (2) are coaxial, the central axis of the water guide cone (2) and the bell tube (1) is the rotation axis of the impeller of the pump device; the curvature profile of the bell tube (1) is a concave curve connecting a straight line that is inclined upward, and the curvature profile of the water guide cone (2) is concave; the bottom of the water guide cone (2) is parallel to the bottom of the bell tube (1); the bottom diameter of the water guide cone (2) is the same as the bottom diameter of the bell tube (1); the tangent line at the outlet of the bell tube (1) and the water guide cone (2) is perpendicular to the outlet of the bell-shaped water inlet channel; the partition pier (3) is perpendicular to the bottom surface of the bell-shaped water inlet channel, and one end thereof is located in the concave area of ​​the bell-shaped water inlet channel; the gate (4) is arranged on the outside of the water guide cone (3).

3. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 1, characterized in that: In the size calculation step, the length of the bell-shaped water inlet flow channel of the two-way flow channel pump device is X L The calculation formula is: Wherein, D is the impeller diameter of the pump type selected by the pump device; n is the design speed of the pump type selected by the pump device; H is the design head of the pump type selected by the pump device; The width of the bell-shaped water inlet channel of the bidirectional flow channel pump device is X B The calculation formula is: Height X of bell-shaped water inlet channel of bidirectional flow channel pump device H The calculation formula is: The calculation formula for the bottom diameter D1 of the bell-shaped water inlet channel is: The bottom diameter of the water guide cone of the bell-shaped water inlet channel is D0=D1; The diameter d1 of the bell-shaped water inlet channel's trumpet outlet is the impeller diameter D of the pump type selected by the pump device; the diameter d0 of the water guide cone outlet of the bell-shaped water inlet channel is the impeller hub diameter d of the pump type selected by the pump device.

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

5. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 1, characterized in that: In the profile design step, the equation of the meridian profile of the first curved section (5) of the bell-shaped water inlet channel and the water guide cone (2) is: In the formula, h0 is the height of the water guide cone; h1 is the height of the bell tube; D0 is the bottom diameter of the water guide cone; d0 is the outlet diameter of the water 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 water inlet flow channel.

6. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 5, characterized in that: In the profile design step, the curvature equation of the first curved section (5) of the bell-shaped water inlet channel and the meridian profile of the water guide cone (2) is:

7. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 6, characterized in that: In the profile design step, the distance b between the first curved section (5) of the bell-shaped water inlet channel and the water guide cone (2) is expressed as:

8. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 7, characterized in that: In the profile design step, the distance A between the first curved section (5) of the bell-shaped water inlet channel and the water guide cone (2) is r The expression is:

9. The method for hydraulic design of a bell-shaped water inlet channel of a bidirectional flow channel pump device according to claim 8, characterized in that: In the profile design step, the profile equation of the second curved section (6) of the bell-shaped water inlet channel is: y=(x-D1) 2 +Z-h1+h2。

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