Design method for integrated impeller of high-speed centrifugal pump

Abstract

The invention provides a design method for an integrated impeller of a high-speed centrifugal pump, and belongs to the technical field of centrifugal pump impeller design. The method comprises the steps that the integrated impeller is designed according to the working conditions of the high-speed centrifugal pump; carrying out grid division on the designed integrated impeller by utilizing a grid generation tool, and carrying out grid independence test to obtain an integrated impeller grid; performing numerical simulation according to the integrated impeller grid to obtain simulation steady data and cavitation data of the integrated impeller; according to the simulated steady data and cavitation data of the integrated impeller, whether the working conditions are met or not is judged, if not, the integrated impeller is optimized through the numerical control programming tool based on the grey wolf algorithm, grid division and judgment of meeting the working conditions are conducted again, if yes, the integrated impeller is output, and design of the integrated impeller of the high-speed centrifugal pump is completed. The anti-cavitation capacity and the lift of the high-speed centrifugal pump are improved, and safe and stable operation of the high-speed centrifugal pump is kept.

Description

Technical Field

[0001] The invention belongs to the technical field of centrifugal pump impeller design, and in particular relates to a high-speed centrifugal pump integrated impeller design method. Background Art

[0002] The integrated impeller is a structural design that combines the inducer and the centrifugal impeller. This design has significant advantages in improving the performance and efficiency of the pump. First, the design of the integrated impeller can increase the inlet pressure of the impeller and ensure higher anti-cavitation characteristics. Due to the effect of the inducer blades, the fluid is pre-pressurized before entering the centrifugal impeller, which helps to improve the anti-cavitation performance of the entire pump. In addition, the integrated design avoids the connection and matching problems between traditional split impellers, reduces energy loss, and thus greatly improves the efficiency of the impeller. Secondly, the structure of the integrated impeller is more compact, which allows the overall size of the pump to be reduced, thereby saving space and material costs. At the same time, due to the reduction in the number of components, this design also helps to reduce the manufacturing and maintenance costs of the pump.

[0003] There is a close relationship between cavitation and impeller profile. The design of the impeller profile directly affects the flow state of the fluid in the impeller, and then affects the occurrence and development of cavitation; the design of the impeller profile determines the flow path and velocity distribution of the fluid in the impeller; reasonable profile design can make the fluid flow more smoothly in the impeller, reduce the occurrence of flow separation and vortex phenomena; the geometric parameters of the impeller profile, such as the shape, angle, and number of blades, will affect the cavitation characteristics. For example, the backward rake angle of the blade is one of the important parameters affecting the cavitation performance; studies have shown that increasing the backward rake angle of the blade within a certain range can improve the cavitation performance of the high-speed centrifugal pump. This is because the increase in the backward rake angle can change the flow state at the blade inlet, making the angle of attack when the fluid enters the impeller more reasonable, reducing the occurrence of cavitation; however, when the backward rake angle exceeds a certain range, the cavitation performance will decrease instead; the design of the impeller profile will also affect the distribution and development of cavitation.

[0004] The integrated profile structure helps to reduce the inlet flow velocity of the fluid, increase the inlet pressure, and enhance the pump's anti-cavitation characteristics; in terms of fluid dynamics performance, the integrated impeller also performs well. Its complex profile design can achieve multi-stage pressurization of the fluid and stable flow channel. This design can also effectively reduce the flow loss of the fluid in the impeller, further improving the performance of the pump.

[0005] However, the impeller of the prior art high-speed centrifugal pump has the problems of low anti-cavitation ability and low head of the high-speed centrifugal pump. Therefore, designing a suitable integrated impeller design method is of great significance to the stable operation of the high-speed centrifugal pump against cavitation. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for designing an integrated impeller for a high-speed centrifugal pump, which solves the problems of low cavitation resistance and low head of the existing high-speed centrifugal pump.

[0007] In order to achieve the above objectives, the technical solution adopted by the present invention is: a method for designing an integrated impeller of a high-speed centrifugal pump, comprising the following steps:

[0008] S1. According to the working conditions of the high-speed centrifugal pump, the integrated impeller is preliminarily designed;

[0009] S2. Use a mesh generation tool to mesh the designed integrated impeller and perform a mesh independence test to obtain an integrated impeller mesh;

[0010] S3. Perform numerical simulation using fluid mechanics calculation tools based on the integrated impeller grid to obtain simulated steady data and cavitation data of the integrated impeller;

[0011] S4. According to the simulated steady-state data and cavitation data of the integrated impeller, determine whether it meets the working conditions. If not, optimize the integrated impeller using the CNC programming tool based on the Grey Wolf algorithm and return to step S2. If so, output the integrated impeller to complete the design of the integrated impeller of the high-speed centrifugal pump.

[0012] The beneficial effects of the present invention are as follows: the present invention achieves better external characteristics and anti-cavitation characteristics by initially designing a universal integrated impeller, and by numerically simulating the initially designed integrated impeller, and quantifies the blade profile and long and short blades of the integrated impeller, adopts different combination types for different working conditions, and uses a grid independence test to reduce the amount of calculation, making the calculation of the method of the present invention more accurate and faster, thereby improving the anti-cavitation capability of the high-speed centrifugal pump and the head of the high-speed centrifugal pump, and maintaining the safe and stable operation of the high-speed centrifugal pump.

[0013] Furthermore, the S1 comprises the following steps:

[0014] S101. Design the long blades of the integrated impeller according to the working conditions of the high-speed centrifugal pump, design the inlet flow coefficient of the long blades, the tip diameter of the long blades, the inlet liquid flow angle of the long blades, the inlet long blade installation angle, the outlet long blade installation angle, the outlet width of the long blades, the number of long blades, the tip angle of the long blades and the thickness of the long blades, and complete the initial design of the long blades of the integrated impeller;

[0015] S102. Design the short blades of the integrated impeller according to the working conditions of the high-speed centrifugal pump, design the short blade inlet liquid flow angle, the short blade inlet installation angle, the short blade outlet installation angle, the short blade outlet width and the short blade thickness, and complete the design of the short blades of the integrated impeller;

[0016] S103. Combine the integrated impeller long blade design and the integrated impeller short blade design to obtain a preliminary designed integrated impeller.

[0017] Furthermore, the S101 includes the following steps:

[0018] S1011. According to the working conditions of the high-speed centrifugal pump, the inlet flow coefficient of the long blade is obtained by using a cavitation coefficient calculation formula, and the tip diameter of the long blade is obtained according to the inlet flow coefficient of the long blade;

[0019] S1012. According to the inlet flow coefficient of the long blade, a variable pitch design method is used to design the inlet liquid flow angle of the long blade, the inlet long blade installation angle, the outlet long blade installation angle and the outlet width of the long blade;

[0020] S1013, designing the integrated impeller as a tapered impeller, setting the long blade inlet hub ratio and the taper angle, and selecting the number of long blades of the integrated impeller based on the long blade inlet hub ratio and the taper angle to obtain the impeller consistency;

[0021] S1014, calculating the pitch according to the number of long blades and the tip diameter of the long blades, and calculating the outer diameter of the long blade inlet leading edge according to the long blade inlet hub ratio and the long blade tip diameter;

[0022] S1015. Define the leading edge wrap angle of the long blade, determine the total wrap angle of the long blade by using the integrated impeller blade expansion length and axial length calculation formula, combined with the blade consistency and pitch, and calculate the tip wrap angle of the long blade;

[0023] S1016. Set a first thickness at the leading edge of the long blade, and set a second thickness at 30% to 40% of the blade chord length. Obtain the thickness of the long blade based on the first thickness and the second thickness of the long blade, and complete the initial design of the integrated impeller long blade.

[0024] Furthermore, the calculation formula of the cavitation coefficient of the long blade is as follows:

[0025]

[0026] Where σ represents the cavitation coefficient of the long blade, represents the inlet flow coefficient of the long blade, β in Indicates the installation angle of the inlet long blade, α in It represents the angle of attack of the liquid flow at the inlet of the long blade;

[0027] The calculation formula for the long blade outlet width is as follows:

[0028]

[0029] R=0.25(1+Rin )D i

[0030] Among them, b out Indicates the long blade outlet width, n s represents the specific speed of the integrated impeller, H represents the head of the integrated impeller, n represents the speed of the integrated impeller, R represents the outer diameter of the leading edge of the long blade inlet, R in Indicates the long blade inlet hub ratio, D i Indicates the tip diameter of the long leaf.

[0031] Furthermore, the calculation formula of the total wrap angle of the long blade is as follows:

[0032] θ t =θ-θ q

[0033]

[0034]

[0035] Among them, θ t represents the tip wrap angle of the long blade, θ represents the total wrap angle of the long blade, θ q represents the leading edge wrap angle of the long blade, τ represents the leaf density, t represents the pitch, l represents the unfolded length of the long blade, and D i represents the tip diameter of the long leaf, z represents the number of long leaves, Indicates that β in Indicates the installation angle of the inlet long blade, β out It represents the installation angle of the outlet long blade, and L represents the axial length.

[0036] Furthermore, the integrated impeller long blade design is specifically as follows:

[0037] The inlet flow coefficient of the long blade is 0.05-0.1, the tip diameter of the long blade is 40mm-72mm, the inlet liquid flow angle of the long blade is 0°-5°, the outlet long blade installation angle is 40°-60°, the inlet hub ratio of the long blade is 0.13-0.3, the taper angle is 10°-15°, the number of long blades is 2 or 3, the leading edge wrap angle of the long blade is 40°-160°, the first thickness of the leading edge of the long blade is 0.3mm-0.5mm, and at the position of 30%-40% of the blade chord length, the second thickness is 1.5mm-2.5mm;

[0038] The integrated impeller short blade design is specifically as follows:

[0039] The liquid flow angle at the inlet of the short blade is 5° to 15°, the installation angle at the inlet of the short blade is 15° to 25°, the installation angle at the outlet of the short blade is 40° to 60°, and the thickness of the short blade is 1.5mm to 2.5mm;

[0040] The calculation formula for the short blade outlet width is as follows:

[0041]

[0042] Among them, b out ′ represents the outlet width of the short blade, n s represents the specific speed of the integrated impeller, H represents the head of the integrated impeller, and n represents the speed of the integrated impeller.

[0043] The beneficial effect of the above further scheme is: the present invention designs a design method for a universal integrated impeller, by quantifying the blade profile and long and short blades of the integrated impeller, adopting different combination types for different working conditions, calculating the important parameters of the blades of the integrated impeller, and obtaining an initial integrated impeller design with improved centrifugal pump efficiency and strong anti-cavitation performance.

[0044] Furthermore, the S3 is specifically:

[0045] The integrated impeller mesh is imported into the fluid mechanics calculation tool, and according to the operating conditions of the high-speed centrifugal pump, the fluid mechanics calculation tool is used to set the inlet and outlet boundary conditions of the high-speed centrifugal pump, and numerical simulation is performed to obtain the simulated steady data and cavitation data of the integrated impeller.

[0046] The beneficial effect of the above further scheme is that the present invention adopts a numerical simulation method to evaluate the external characteristics of the integrated impeller, which facilitates the estimation of the performance of the designed integrated impeller and reduces the experimental workload.

[0047] Furthermore, in S4, the specific steps of optimizing the integrated impeller using a numerical control programming tool are as follows:

[0048] Using a numerical control programming tool to edit, obtain multiple tool bodies, and form a tool body group, prioritize and mark the tool body group, and obtain a preprocessed tool body group;

[0049] Taking the integrated impeller as the target body, according to the preprocessed tool body group, the preprocessed tool bodies are used to surround the target body, and iterative optimization is performed to obtain the position vector of each tool body and the position vector of the target body, and the distance between the position of each tool body and the position of the target body is obtained by calculation;

[0050] In each iteration process, the three best tool bodies in the current tool body group are retained as the optimal tool bodies, and the positions of the tool bodies other than the optimal tool bodies are updated to obtain the position information of the current candidate tool bodies;

[0051] In response to reaching the maximum number of iterations, the optimal target body is obtained according to the position information of the current candidate tool body, and the optimal integrated impeller is output to complete the optimization of the integrated impeller.

[0052] Furthermore, the mathematical model expression of the iterative optimization is as follows:

[0053] X(t+1)=X p (t)-A*D

[0054] D=C*X p (txt)

[0055] A=2a*r 1 -a, C = 2r 2

[0056] Where t represents the current iteration number, X(t+1) represents the position vector of the tool body at the t+1th iteration, and X p (t) represents the position vector of the target body at the tth iteration, X(t) represents the position vector of the tool body at the tth iteration, * represents the Hadamard product, A and C both represent the coordination coefficient vector, D represents the distance between the tool body position and the target body position, a represents the convergence factor, which decreases linearly from 2 to 0, and r 1 and r 2 represents a random vector in [0,1].

[0057] Furthermore, the mathematical model expression for updating the position of the tool body is as follows:

[0058] X(t+1)=(X 1 +X 2 +X 3 ) / 3

[0059] X 1 =X α -A 1 *D α , X 2 =X β -A 2 *D β , X 3 =X δ -A 3 *D δ

[0060] D α =C 1 *X α -X,D β =C 2 *X β -X,D δ =C 3 *X δ-X

[0061] Among them, X(t+1) represents the position vector of the tool body at the t+1th iteration, X 1 Represents the position vector of target 1, X 2 represents the position vector of target 2, X 3 represents the position vector of target 3, X α represents the position vector of the first optimal tool body α, D α represents the distance between the first optimal tool body α and the candidate tool body, X β represents the position vector of the second optimal tool body β, D β represents the distance between the second optimal tool body β and the candidate tool body, X δ represents the position vector of the third optimal tool body δ, D δ represents the distance between the third optimal tool body δ and the candidate tool body, A 1 , A 2 , A 3 and C 1 , C 2 , C 3 Both represent the coordination coefficient vector, and X represents the position vector of the candidate tool body.

[0062] The beneficial effect of the above further scheme is: the present invention adopts the Grey Wolf algorithm to optimize the integrated impeller blades, so that the blade optimization effect is better, the optimization speed is faster, and the optimization index is more directed, thereby obtaining an integrated impeller that improves the anti-cavitation ability of the high-speed centrifugal pump and the head of the high-speed centrifugal pump, and maintains the safe and stable operation of the high-speed centrifugal pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 The present invention is a flow chart of the method. DETAILED DESCRIPTION

[0064] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0065] Before describing this embodiment, the following terms are explained:

[0066] TurboGrid: a professional turbine blade channel meshing software;

[0067] CFD: computational fluid dynamics;

[0068] CFX: software tools for computational fluid dynamics;

[0069] Hadamard product operation: Hadamard product operation.

[0070] Example

[0071] like Figure 1 As shown, the present invention provides a method for designing an integrated impeller for a high-speed centrifugal pump, and the implementation method is as follows:

[0072] S1. According to the working conditions of the high-speed centrifugal pump, the integrated impeller is preliminarily designed, specifically:

[0073] S101. According to the working conditions of the high-speed centrifugal pump, the long blades of the integrated impeller are designed, and the inlet flow coefficient, the tip diameter of the long blades, the inlet liquid flow angle of the long blades, the inlet long blade installation angle, the outlet long blade installation angle, the outlet width of the long blades, the number of long blades, the tip angle of the long blades and the thickness of the long blades are designed to complete the initial design of the long blades of the integrated impeller, specifically:

[0074] S1011. According to the working conditions of the high-speed centrifugal pump, the inlet flow coefficient of the long blade is obtained by using a cavitation coefficient calculation formula, and the tip diameter of the long blade is obtained according to the inlet flow coefficient of the long blade;

[0075] S1012. According to the inlet flow coefficient of the long blade, a variable pitch design method is used to design the inlet liquid flow angle of the long blade, the inlet long blade installation angle, the outlet long blade installation angle and the outlet width of the long blade;

[0076] S1013, designing the integrated impeller as a tapered impeller, setting the long blade inlet hub ratio and the taper angle, and selecting the number of long blades of the integrated impeller based on the long blade inlet hub ratio and the taper angle to obtain the impeller consistency;

[0077] S1014, calculating the pitch according to the number of long blades and the tip diameter of the long blades, and calculating the outer diameter of the long blade inlet leading edge according to the long blade inlet hub ratio and the long blade tip diameter;

[0078] S1015. Define the leading edge wrap angle of the long blade, determine the total wrap angle of the long blade by using the integrated impeller blade expansion length and axial length calculation formula, combined with the blade consistency and pitch, and calculate the tip wrap angle of the long blade;

[0079] S1016, setting a first thickness of the leading edge of the long blade, and setting a second thickness at a position of 30% to 40% of the blade chord length, and obtaining the thickness of the long blade according to the first thickness and the second thickness of the long blade, thereby completing the initial design of the long blade of the integrated impeller;

[0080] S102. Design the short blades of the integrated impeller according to the working conditions of the high-speed centrifugal pump, design the short blade inlet liquid flow angle, the short blade inlet installation angle, the short blade outlet installation angle, the short blade outlet width and the short blade thickness, and complete the design of the short blades of the integrated impeller;

[0081] S103. Combine the integrated impeller long blade design and the integrated impeller short blade design to obtain a preliminary designed integrated impeller.

[0082] In this embodiment, according to the existing working conditions of the high-speed centrifugal pump, the integrated impeller is preliminarily designed, and a design of 3 long blades + 3 short blades or 2 long blades + 4 short blades is adopted, as follows:

[0083] Integrated impeller long blade design: In order to ensure that the integrated impeller has better cavitation performance, the cavitation coefficient σ of the long blade in the integrated impeller should be a smaller value. Therefore, according to the cavitation coefficient calculation formula of the long blade, the inlet flow coefficient of the long blade is taken And according to the inlet flow coefficient of the long blade The tip diameter of the long blade is D i =40mm~72mm;

[0084] The cavitation coefficient calculation formula of the long blade is as follows:

[0085]

[0086] Where σ represents the cavitation coefficient of the long blade, represents the inlet flow coefficient of the long blade, β in Indicates the installation angle of the inlet long blade, α in It represents the angle of attack of the liquid flow at the inlet of the long blade;

[0087] The long blades adopt the variable pitch design method, and the long blade inlet flow angle α in =0°~5°, inlet long blade installation angle β in According to the formula and the inlet flow coefficient of the long blade, the installation angle of the outlet long blade is 40°≤β out ≤60°, long blade outlet width b out It is calculated based on the integrated impeller specific speed, the integrated impeller specific speed and the integrated impeller speed;

[0088] The calculation formula for the long blade outlet width is as follows:

[0089]

[0090] Among them, b out Indicates the long blade outlet width, n srepresents the specific speed of the integrated impeller, H represents the head of the integrated impeller, and n represents the speed of the integrated impeller;

[0091] The integrated impeller is designed as a conical impeller, and the long blade inlet hub is larger than R in =0.13~0.3, the cone angle γ is 10°~15°; when the integrated impeller has 2 long blades, the blade consistency τ=2; when the integrated impeller has 3 long blades, the blade consistency τ=3; the leading edge wrap angle θ of the long blade q =40°~160°, the total wrap angle of the long blade of the integrated impeller is calculated by the formula of the unfolded length and axial length of the integrated impeller blade, combined with the blade consistency and pitch, the first thickness of the leading edge of the long blade is 0.3mm~0.5mm, and the second thickness is set to 1.5mm~2.5mm at the position of 30%~40% of the blade chord length;

[0092] The calculation formula of the outer diameter of the leading edge of the long blade inlet is as follows:

[0093] R=0.25(1+R in )D i

[0094] R represents the outer diameter of the leading edge of the long blade inlet, R in Indicates the long blade inlet hub ratio, D i represents the tip diameter of the long leaf;

[0095] The calculation formula of the total wrap angle of the long blade is as follows:

[0096] θ t =θ-θ q

[0097]

[0098] Among them, θ t represents the tip wrap angle of the long blade, θ represents the total wrap angle of the long blade, θ q represents the leading edge wrap angle of the long blade, τ represents the leaf density, t represents the pitch, l represents the unfolded length of the long blade, and D i represents the tip diameter of the long leaf, z represents the number of long leaves, Indicates that β in Indicates the installation angle of the inlet long blade, β out It indicates the installation angle of the outlet long blade, and L indicates the axial length;

[0099] In this embodiment, the integrated impeller short blade design:

[0100] The liquid flow angle at the inlet of the short blade is 5° to 15°, the installation angle at the inlet of the short blade is 15° to 25°, the installation angle at the outlet of the short blade is 40° to 60°, and the thickness of the short blade is 1.5mm to 2.5mm;

[0101] The calculation formula for the short blade outlet width is as follows:

[0102]

[0103] Among them, b out ′ represents the outlet width of the short blade, n s represents the specific speed of the integrated impeller, H represents the head of the integrated impeller, and n represents the speed of the integrated impeller.

[0104] S2. Use the mesh generation tool to mesh the designed integrated impeller and perform a mesh independence test to obtain the integrated impeller mesh.

[0105] In this embodiment, a grid generation tool, TurboGrid, is used to mesh the designed integrated impeller, and a grid independence test is performed to obtain an integrated impeller mesh.

[0106] S3. According to the integrated impeller grid, numerical simulation is performed using fluid mechanics calculation tools to obtain the simulated steady data and cavitation data of the integrated impeller, specifically:

[0107] The integrated impeller mesh is imported into the fluid mechanics calculation tool, and according to the operating conditions of the high-speed centrifugal pump, the fluid mechanics calculation tool is used to set the inlet and outlet boundary conditions of the high-speed centrifugal pump, and numerical simulation is performed to obtain the simulated steady data and cavitation data of the integrated impeller.

[0108] In this embodiment, a CFD flow field numerical simulation is performed, the integrated impeller mesh is imported into the fluid mechanics calculation tool, CFX software, and according to the operating conditions of the high-speed centrifugal pump, the fluid mechanics calculation tool CFX software is used to set the inlet and outlet boundary conditions of the high-speed centrifugal pump, complete the numerical simulation, and obtain the simulated steady-state data and cavitation data of the integrated impeller.

[0109] S4, judging whether the working condition is met according to the simulated steady data and cavitation data of the integrated impeller, if not, optimizing the integrated impeller by using the numerical control programming tool based on the Grey Wolf algorithm, and returning to step S2, if yes, outputting the integrated impeller, and completing the design of the integrated impeller of the high-speed centrifugal pump;

[0110] The specific steps of optimizing the integrated impeller using the numerical control programming tool are as follows:

[0111] Using a numerical control programming tool to edit, obtain multiple tool bodies, and form a tool body group, prioritize and mark the tool body group, and obtain a preprocessed tool body group;

[0112] Taking the integrated impeller as the target body, according to the preprocessed tool body group, the preprocessed tool bodies are used to surround the target body, and iterative optimization is performed to obtain the position vector of each tool body and the position vector of the target body, and the distance between the position of each tool body and the position of the target body is obtained by calculation;

[0113] In each iteration process, the three best tool bodies in the current tool body group are retained as the optimal tool bodies, and the positions of the tool bodies other than the optimal tool bodies are updated to obtain the position information of the current candidate tool bodies;

[0114] In response to reaching the maximum number of iterations, the optimal target body is obtained according to the position information of the current candidate tool body, and the optimal integrated impeller is output to complete the optimization of the integrated impeller.

[0115] In this embodiment, according to the simulated steady data and cavitation data of the integrated impeller, it is judged whether the working condition is met. If not, the integrated impeller is optimized by using the numerical control programming tool based on the Gray Wolf algorithm, and the process returns to step S2. If yes, the integrated impeller is output to complete the design of the integrated impeller of the high-speed centrifugal pump.

[0116] Integrated impeller optimization process:

[0117] Use CNC programming tools to edit, obtain multiple tool bodies, and form a tool body group, divide the tool body priority, and mark them as α, β, δ, ω from top to bottom. Among them, α represents the best working body, followed by β tool body and δ tool body, and the worst tool body is ω. The optimization process is guided by tool bodies α, β, and δ, and ω only obeys other high-level tool bodies to obtain a pre-processed tool body group;

[0118] The integrated impeller is taken as the target body, and iterative optimization of the tool body surrounding the target body is performed. The mathematical model expression of the iterative optimization is as follows:

[0119] X(t+1)=X p (t)-A*D

[0120] D=C*X p (txt)

[0121] A=2a*r 1 -a

[0122] C=2r 2

[0123] Where t represents the current iteration number, X(t+1) represents the position vector of the tool body at the t+1th iteration, and X p(t) represents the position vector of the target body at the tth iteration, X(t) represents the position vector of the tool body at the tth iteration, * represents the hadamard product operation, A and C both represent the coordination coefficient vector, D represents the distance between the tool body position and the target body position, a represents the convergence factor, and r 1 and r 2 represents a random vector in [0,1]. In the process of constructing the optimization target, the decrease of a value will cause the value of A to fluctuate. a decreases linearly from 2 to 0 during the iteration process.

[0124] In each iteration, the three best tool bodies in the current tool body group are retained, and the first best tool body α 1 , the second best tool body β 1 、The third optimal tool body δ 1 , update the position of tool bodies other than the optimal tool body to obtain the position information of the current candidate tool body;

[0125] In response to reaching the maximum number of iterations, an optimal target body is obtained according to the position information of the current candidate tool body, an optimal integrated impeller is output, and the integrated impeller is optimized;

[0126] The mathematical model expression for updating the position of the tool body is as follows:

[0127] X(t+1)=(X 1 +X 2 +X 3 ) / 3

[0128] X 1 =X α -A 1 *D α , X 2 =X β -A 2 *D β , X 3 =X δ -A 3 *D δ

[0129] D α =C 1 *X α -X,D β =C 2 *X β -X,D δ =C 3 *X δ -X

[0130] Among them, X(t+1) represents the position vector of the tool body at the t+1th iteration, X 1Represents the position vector of target 1, X 2 represents the position vector of target 2, X 3 represents the position vector of target 3, X α represents the position vector of the tool body α, D α represents the distance between tool body α and the optimal tool body, X β represents the position vector of the tool body β, D β represents the distance between tool body β and the optimal tool body, X δ represents the position vector of the tool body δ, D δ represents the distance between the tool body δ and the optimal tool body, A 1 , A 2 , A 3 and C 1 , C 2 , C 3 All represent the coordination coefficient vector, X represents the position vector of the candidate tool body;

[0131] When |A|>1, the tool bodies try to disperse in various areas and search for the target body. When |A|<1, the tool bodies will focus on searching for the target body in one or some areas. When A is in the interval [-1,1], the next moment position of the search agent can be anywhere between the current tool body and the target body.

[0132] In this embodiment, the integrated induced impeller designed by the present invention has obvious advantages in improving the efficiency, anti-cavitation performance, compact structure and processing accuracy of the pump, and is a high-efficiency pump impeller design worthy of promotion.

Claims

1. A method for designing an integrated impeller for a high-speed centrifugal pump, characterized in that: The following steps are involved: S1. According to the working conditions of the high-speed centrifugal pump, the integrated impeller is preliminarily designed; S2. Use a mesh generation tool to mesh the designed integrated impeller and perform a mesh independence test to obtain an integrated impeller mesh; S3. Perform numerical simulation using fluid mechanics calculation tools based on the integrated impeller grid to obtain simulated steady data and cavitation data of the integrated impeller; S4. According to the simulated steady-state data and cavitation data of the integrated impeller, determine whether it meets the working conditions. If not, optimize the integrated impeller using the CNC programming tool based on the Grey Wolf algorithm and return to step S2. If so, output the integrated impeller to complete the design of the integrated impeller of the high-speed centrifugal pump.

2. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 1, characterized in that: The S1 comprises the following steps: S101. Design the long blades of the integrated impeller according to the working conditions of the high-speed centrifugal pump, design the inlet flow coefficient of the long blades, the tip diameter of the long blades, the inlet liquid flow angle of the long blades, the inlet long blade installation angle, the outlet long blade installation angle, the outlet width of the long blades, the number of long blades, the tip angle of the long blades and the thickness of the long blades, and complete the initial design of the long blades of the integrated impeller; S102. Design the short blades of the integrated impeller according to the working conditions of the high-speed centrifugal pump, design the short blade inlet liquid flow angle, the short blade inlet installation angle, the short blade outlet installation angle, the short blade outlet width and the short blade thickness, and complete the design of the short blades of the integrated impeller; S103. Combine the integrated impeller long blade design and the integrated impeller short blade design to obtain a preliminary designed integrated impeller.

3. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 2, characterized in that: The S101 includes the following steps: S1011. According to the working conditions of the high-speed centrifugal pump, the inlet flow coefficient of the long blade is obtained by using a cavitation coefficient calculation formula, and the tip diameter of the long blade is obtained according to the inlet flow coefficient of the long blade; S1012. According to the inlet flow coefficient of the long blade, a variable pitch design method is used to design the inlet liquid flow angle of the long blade, the inlet long blade installation angle, the outlet long blade installation angle and the outlet width of the long blade; S1013, designing the integrated impeller as a tapered impeller, setting the long blade inlet hub ratio and the taper angle, and selecting the number of long blades of the integrated impeller based on the long blade inlet hub ratio and the taper angle to obtain the impeller consistency; S1014, calculating the pitch according to the number of long blades and the tip diameter of the long blades, and calculating the outer diameter of the long blade inlet leading edge according to the long blade inlet hub ratio and the long blade tip diameter; S1015. Define the leading edge wrap angle of the long blade, determine the total wrap angle of the long blade by using the integrated impeller blade expansion length and axial length calculation formula, combined with the blade consistency and pitch, and calculate the tip wrap angle of the long blade; S1016. Set a first thickness at the leading edge of the long blade, and set a second thickness at 30% to 40% of the blade chord length. Obtain the thickness of the long blade based on the first thickness and the second thickness of the long blade, and complete the initial design of the integrated impeller long blade.

4. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 3, characterized in that: The cavitation coefficient calculation formula of the long blade is as follows: Where σ represents the cavitation coefficient of the long blade, represents the inlet flow coefficient of the long blade, β in Indicates the installation angle of the inlet long blade, α in It represents the angle of attack of the liquid flow at the inlet of the long blade; The calculation formula for the long blade outlet width is as follows: R=0.25(1+R in )D i Among them, b out Indicates the long blade outlet width, n s represents the specific speed of the integrated impeller, H represents the head of the integrated impeller, n represents the speed of the integrated impeller, R represents the outer diameter of the leading edge of the long blade inlet, R in Indicates the long blade inlet hub ratio, D i Indicates the tip diameter of the long leaf.

5. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 4, characterized in that: The calculation formula of the total wrap angle of the long blade is as follows: i t =θ-θ q Among them, θ t represents the tip wrap angle of the long blade, θ represents the total wrap angle of the long blade, θ q represents the leading edge wrap angle of the long blade, τ represents the leaf density, t represents the pitch, l represents the unfolded length of the long blade, and D i represents the tip diameter of the long leaf, z represents the number of long leaves, Indicates that β in Indicates the installation angle of the inlet long blade, β out It represents the installation angle of the outlet long blade, and L represents the axial length.

6. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 3, characterized in that: The integrated impeller long blade design is specifically as follows: The inlet flow coefficient of the long blade is 0.05-0.1, the tip diameter of the long blade is 40mm-72mm, the inlet liquid flow angle of the long blade is 0°-5°, the outlet long blade installation angle is 40°-60°, the inlet hub ratio of the long blade is 0.13-0.3, the taper angle is 10°-15°, the number of long blades is 2 or 3, the leading edge wrap angle of the long blade is 40°-160°, the first thickness of the leading edge of the long blade is 0.3mm-0.5mm, and at the position of 30%-40% of the blade chord length, the second thickness is 1.5mm-2.5mm; The integrated impeller short blade design is specifically as follows: The liquid flow angle at the inlet of the short blade is 5° to 15°, the installation angle at the inlet of the short blade is 15° to 25°, the installation angle at the outlet of the short blade is 40° to 60°, and the thickness of the short blade is 1.5mm to 2.5mm; The calculation formula for the short blade outlet width is as follows: Among them, b out ′ represents the outlet width of the short blade, n s represents the specific speed of the integrated impeller, H represents the head of the integrated impeller, and n represents the speed of the integrated impeller.

7. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 1, characterized in that: The S3 is specifically: The integrated impeller mesh is imported into the fluid mechanics calculation tool, and according to the operating conditions of the high-speed centrifugal pump, the fluid mechanics calculation tool is used to set the inlet and outlet boundary conditions of the high-speed centrifugal pump, and numerical simulation is performed to obtain the simulated steady data and cavitation data of the integrated impeller.

8. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 1, characterized in that: In S4, the specific steps of optimizing the integrated impeller using the numerical control programming tool are as follows: Using a numerical control programming tool to edit, obtain multiple tool bodies, and form a tool body group, prioritize and mark the tool body group, and obtain a preprocessed tool body group; Taking the integrated impeller as the target body, according to the preprocessed tool body group, the preprocessed tool bodies are used to surround the target body, and iterative optimization is performed to obtain the position vector of each tool body and the position vector of the target body, and the distance between the position of each tool body and the position of the target body is obtained by calculation; In each iteration process, the three best tool bodies in the current tool body group are retained as the optimal tool bodies, and the positions of the tool bodies other than the optimal tool bodies are updated to obtain the position information of the current candidate tool bodies; In response to reaching the maximum number of iterations, the optimal target body is obtained according to the position information of the current candidate tool body, and the optimal integrated impeller is output to complete the optimization of the integrated impeller.

9. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 8, characterized in that: The mathematical model expression of the iterative optimization is as follows: X(t+1)=X p (t)-A*D D=C*X p (t)-X(t) A=2a*r1-a,C=2r2 Where t represents the current iteration number, X(t+1) represents the position vector of the tool body at the t+1th iteration, and X p (t) represents the position vector of the target body at the t-th iteration, X(t) represents the position vector of the tool body at the t-th iteration, * represents the Hadamard product, A and C both represent the coordination coefficient vectors, D represents the distance between the tool body position and the target body position, a represents the convergence factor, which decreases linearly from 2 to 0, and r1 and r2 represent random vectors in [0,1].

10. The method for designing an integrated impeller for a high-speed centrifugal pump according to claim 8, characterized in that: The mathematical model expression for updating the position of the tool body is as follows: X(t+1)=(X1+X2+X3) / 3 X1=X α -A1*D α ,X2=X β -A2*D β ,X3=X δ -A3*D δ D α =C1*X α -X,D β =C2*X β -X,D δ =C3*X δ -X Where X(t+1) represents the position vector of the tool body at the t+1th iteration, X1 represents the position vector of target body 1, X2 represents the position vector of target body 2, X3 represents the position vector of target body 3, and X α represents the position vector of the first optimal tool body α, D α represents the distance between the first optimal tool body α and the candidate tool body, X β represents the position vector of the second optimal tool body β, D β represents the distance between the second optimal tool body β and the candidate tool body, X δ represents the position vector of the third optimal tool body δ, D δ represents the distance between the third optimal tool body δ and the candidate tool body, A1, A2, A3 and C1, C2, C3 all represent coordination coefficient vectors, and X represents the position vector of the candidate tool body.

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