A method for evaluating pump hydraulic performance based on blade tip erosion

Abstract

The present invention discloses a method for evaluating the hydraulic performance of a pump based on blade tip erosion, which overcomes the problem in the prior art that the blade tip erosion amount cannot be accurately and comprehensively evaluated, resulting in the inability to accurately evaluate the life of hydraulic components. The method comprises: obtaining hydraulic performance results of different erosion amounts under a uniform blade tip erosion state based on a finite element CFD analysis method; dividing the open impeller blade tip area into N sub-areas according to the area, and obtaining the erosion amount of each sub-area; calculating the hydraulic performance of each area after erosion and determining the proportion of the influence of the erosion of each sub-area on the hydraulic performance of the pump based on a finite element CFD analysis method; obtaining the total influence of each sub-area on the pump head performance, and calculating the heavy metal pump head. Finite element analysis is used to evaluate the proportion of the influence of the blade tip area on the hydraulic performance; at the same time, based on life tests, the erosion amount of different blade tip areas is collected to comprehensively and accurately evaluate the hydraulic performance of the pump.

Description

Technical Field

[0001] The present invention relates to the technical field of pump hydraulic performance evaluation, and in particular to a pump hydraulic performance evaluation method based on blade tip abrasion. Background Art

[0002] Heavy metal pumps are primarily used in metallurgy, chemical engineering, machining, and new energy. Impellers, as high-speed components, are required to operate safely and reliably over extended periods of time in environments characterized by high temperatures, high pressures, corrosion, and radiation. Because repairing and replacing hydraulic components in heavy metal pumps is a cumbersome and expensive task, extending the life of these pumps' impellers is crucial for extending pump lifespan and reducing costs while increasing efficiency. Accurately assessing impeller tip erosion and its impact on hydraulic performance is crucial for hydraulic design.

[0003] Regarding the problem of hydraulic performance degradation caused by blade tip abrasion in heavy metal medium open impellers, the current industry generally assumes that the blade tips are synchronously worn. By changing the blade tip clearance, a numerical simulation of a heavy metal pump based on Fluent is conducted to investigate the effect of blade tip abrasion on the hydraulic performance of the heavy metal pump. This method can, to a certain extent, reflect the effect of blade tip abrasion on the hydraulic performance of the heavy metal pump and can roughly evaluate the hydraulic life of the impeller. However, this method ignores (1) the phenomenon of uneven abrasion in different areas of the blade tip; (2) the fact that different areas of the blade tip have different effects on the hydraulic performance. The amount of blade tip abrasion has a great impact on the hydraulic head of the impeller, especially for high-flow, low-head pumps. If the amount of blade tip abrasion cannot be accurately and comprehensively evaluated, a large error will be generated when calculating the head of the heavy metal pump, and the life of the hydraulic components cannot be accurately evaluated. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the impeller erosion assessment method in the prior art cannot accurately and comprehensively assess the amount of blade tip abrasion, resulting in the inability to accurately assess the life of hydraulic components. A pump hydraulic performance assessment method based on blade tip abrasion is provided, which uses finite element analysis to assess the proportion of the influence of the blade tip area on the hydraulic performance; at the same time, based on life tests, the abrasion amount of different areas of the blade tip is collected to comprehensively and accurately assess the hydraulic performance of the pump.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for evaluating pump hydraulic performance based on blade tip erosion comprises the following steps:

[0007] S1: Based on the finite element CFD analysis method, the hydraulic performance results of the blade tip under the condition of uniform erosion and different erosion amounts are obtained;

[0008] S2: Divide the open impeller blade tip area into N sub-areas according to the area, and obtain the abrasion amount of each sub-area;

[0009] S3: Based on the finite element CFD analysis method, calculate the hydraulic performance of each sub-area after abrasion and determine the proportion of the impact of abrasion in each sub-area on the hydraulic performance of the pump;

[0010] S4: Obtain the total impact of each sub-area on the pump head performance and calculate the pump head.

[0011] The method of this invention not only considers the abrasion state of different blade tip regions but also rationally assesses the degree to which each region affects hydraulic performance. Finite element analysis is used to assess the relative impact of each region on hydraulic performance. Simultaneously, based on life testing, the amount of abrasion in different blade tip regions is collected. By combining these analysis results with test data fitting, a comprehensive and accurate assessment of the pump's hydraulic performance is achieved.

[0012] Preferably, in step S2, the open impeller blade tip area is divided into N sub-areas according to the area, including: evenly dividing the open impeller blade tip area along the circumferential direction; taking the frontmost part of the blade tip and dividing it equally along the vertical edge, and drawing blade profile parallel lines through the equal division points; based on the circumferential bisector and the blade profile parallel lines, the blade tip area is divided into N sub-areas.

[0013] Preferably, in step S2, obtaining the abrasion amount of each sub-region includes: selecting a reference point, performing a three-dimensional scan on the impeller, and obtaining the three-dimensional coordinates of N sub-regions of the blade tip in the initial state; performing a long-period abrasion life test, and after the test, performing a three-dimensional scan on the impeller after abrasion again to obtain the three-dimensional coordinates of N sub-regions of the blade tip after abrasion, calculating the abrasion amount of the center of each sub-region, and treating the abrasion amount as the abrasion amount of the sub-region.

[0014] Preferably, the step S1 comprises: fitting a relevant abrasion-lift curve according to a finite element analysis result, and obtaining a blade tip abrasion-lift function by polynomial fitting.

[0015] Preferably, the tip abrasion-head function includes: the pump head corresponding to the tip abrasion is the sum of the products of the nth power of the impeller tip abrasion and the corresponding coefficients fitted according to the hydraulic performance analysis results of different impeller tip abrasion.

[0016] Preferably, the step S3 includes: calculating the individual abrasion X of the Nth region of the blade tip N mm after the head change, calculate the impeller is not abraded initial head and the blade tip uniform abrasion X N The difference in pump head corresponding to the change in mm is calculated, and the proportion of the impact of abrasion in each sub-area on the hydraulic performance of the pump is calculated according to the ratio of the change in amount to the difference.

[0017] Preferably, in step S4, the pump head is the difference between the initial head of the impeller without abrasion and the total impact of each sub-region on the pump head performance.

[0018] Preferably, the finite element CFD analysis method includes: determining the initial hydraulic flow channel structure and dividing the blade tip area; establishing a fluid model and performing meshing; calculating hydraulic characteristic results, modifying the impeller geometry according to the mode state, and returning to the previous step to establish the fluid model.

[0019] Preferably, after the long-term wear life test is completed, the impeller after wear is three-dimensionally scanned again when the reference point is consistent with that in the first three-dimensional scan.

[0020] As a preference, the total impact of each sub-region on the pump head performance is the abrasion of each sub-region of the blade tip X N The sum of the changes in head after mm.

[0021] Therefore, the present invention has the following beneficial effects: using finite element analysis to evaluate the influence of the blade tip area on the hydraulic performance; at the same time, based on life tests, collecting the abrasion amount of different areas of the blade tip; by means of fitting the analysis results and test data, comprehensively and accurately evaluating the hydraulic performance of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a flow chart of the overall steps of the method for evaluating pump hydraulic performance based on blade tip erosion in the present invention.

[0023] Figure 2 This is the blade tip abrasion-lift curve in Example 1.

[0024] Figure 3 Schematic diagram of the division of the open impeller blade top sub-area in Example 1.

[0025] Figure 4 Schematic diagram of blade tip three-dimensional scanning measurement points in Example 1.

[0026] Figure 5 Schematic diagram of the finite element CFD analysis process in Example 1.

[0027] Figure 6 This is the blade tip abrasion-lift curve of a lead-bismuth medium axial flow pump in Example 2.

[0028] Figure 7 This is a schematic diagram of the impact of abrasion in different areas of the impeller tip on the hydraulic performance of a lead-bismuth medium axial flow pump in Example 2. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0030] Example 1:

[0031] This embodiment provides a method for evaluating pump hydraulic performance based on blade tip erosion. Figure 1 As shown, the operation process is as follows: Step 1, based on the finite element CFD analysis method, the hydraulic performance results of different abrasion amounts under the condition of uniform blade tip abrasion are obtained; Step 2, the open impeller blade tip area is divided into N sub-areas according to the area, and the abrasion amount of each sub-area is obtained; Step 3, based on the finite element CFD analysis method, the hydraulic performance of each sub-area after abrasion is calculated and the proportion of the influence of abrasion of each sub-area on the hydraulic performance of the pump is determined; Step 4, the total influence of each sub-area on the pump head performance is obtained, and the pump head is calculated.

[0032] The head of a water pump refers to the height to which the pump can lift water, also known as the water lifting height of the water pump, that is, the highest point to which the pump can deliver water from the water inlet of the water pump. It is usually represented by the symbol H, and the unit is meter (m). The head is a key performance parameter used to measure the ability of a water pump to transport liquids. Specifically, it represents the energy or height difference added to the liquid from the inlet to the outlet of the water pump when the water pump does work on the liquid, that is, the head describes the ability of the water pump to lift water from a low place to a high place. For example, if the head of a water pump is 10 meters, it means that the water pump can lift water to a vertical height of 10 meters from its starting position.

[0033] This embodiment provides a method for evaluating pump hydraulic performance based on blade tip erosion. It addresses the degradation of hydraulic performance caused by blade tip erosion in open impellers operating in heavy metal media. It rationally assesses the impact of erosion on hydraulic performance in different blade tip regions. Finite element analysis is used to assess the contribution of the blade tip region to hydraulic performance. Furthermore, based on life testing, erosion measurements are collected from different blade tip regions. By combining analytical results with test data fitting, a comprehensive and accurate assessment of the pump's hydraulic performance is achieved.

[0034] The following further illustrates the technical solutions and technical effects of the present invention through specific examples and specific application scenarios. The following examples are intended to explain the present invention, but the present invention is not limited to the following examples.

[0035] This embodiment provides a method for evaluating pump hydraulic performance based on tip erosion. This method is an evaluation method for the impact of tip erosion on the hydraulic performance of an open impeller and is an important basis for hydraulic design. It mainly includes: (1) considering the erosion conditions in different regions of the impeller tip; (2) considering the impact of erosion in different regions of the impeller tip on the hydraulic performance of the impeller. Based on the above two assumptions, the hydraulic performance of the impeller is evaluated under the condition of uneven tip erosion.

[0036] The technical problem to be solved is this: For heavy metal pump open impellers, tip erosion leads to a decline in hydraulic performance, ultimately failing to meet pump head efficiency requirements. Furthermore, tip erosion of open impellers is non-uniform; the amount of erosion varies at different locations on the tip, impacting hydraulic performance in varying ways. If the impeller tip erosion cannot be accurately and comprehensively assessed, the hydraulic performance and impeller life estimates derived from this assessment will inevitably be subject to significant errors. Therefore, a reasonable method for evaluating open impeller tip erosion is essential for accurately assessing the impeller's hydraulic life and guiding the design and development of hydraulic components.

[0037] A method for evaluating pump hydraulic performance based on blade tip erosion specifically comprises the following steps:

[0038] Step 1: Based on the finite element CFD analysis method, obtain the hydraulic performance results of different abrasion amounts under the condition of uniform blade tip abrasion.

[0039] Finite element CFD analysis is a numerical analysis method used to solve complex engineering problems, particularly those involving multiple physical fields. This method combines the principles of finite element analysis and computational fluid dynamics (CFD). It divides the computational domain into a series of small cells and applies an approximation function to each cell to solve the problem, demonstrating its strong adaptability and flexibility.

[0040] In this embodiment, based on the finite element CFD analysis method, the hydraulic performance results of different abrasion amounts are shown in the following table:

[0041] Table 1 Hydraulic performance data

[0042] Blade tip abrasion <![CDATA[X1]]> <![CDATA[X2]]> … <![CDATA[X N ]]> Lift <![CDATA[h(X1)]]> <![CDATA[h(X2)]]> … <![CDATA[h(X N )]]>

[0043] According to the finite element CFD analysis method, the relevant abrasion amount-lift curve is fitted, such as Figure 2 As shown, the pump head decreases as the abrasion of the open-top impeller increases.

[0044] The open impeller blade tip abrasion-head function is obtained through polynomial fitting. The pump head corresponding to the blade tip abrasion is the sum of the product of the impeller blade tip abrasion to the power of n and its corresponding coefficient obtained by fitting the hydraulic performance analysis results of different impeller blade tip abrasion, which can be expressed as follows:

[0045] h(X)=a n X n +a n-1 X n-1 +a n-2 X n-2 +…+a1X+a0.

[0046] Where X represents the amount of impeller tip erosion in mm; h(x) represents the pump head corresponding to the amount of impeller tip erosion in m; n represents the polynomial order; a n 、a n-1 、a n-2 ,…,a1,a0 respectively represent the coefficients obtained by fitting the hydraulic performance analysis results of different impeller tip abrasion amounts.

[0047] Step 2: Divide the open impeller tip area into N sub-areas according to the area, and obtain the abrasion amount of each sub-area.

[0048] The sub-region division method used in this embodiment is:

[0049] Step (2.1.1): Evenly divide the open impeller tip area along the circumferential direction;

[0050] Step (2.1.2): Take the front edge of the leaf and divide it into equal parts along the vertical edge. Draw a line parallel to the leaf shape through the dividing point.

[0051] Step (2.1.3): Based on the circumferential bisector and the blade profile parallel line, the blade tip area is divided into N sub-areas.

[0052] The sub-region division results are as follows Figure 3 shown.

[0053] In this embodiment, the steps for obtaining the abrasion amount of each sub-region are:

[0054] Step (2.2.1): Install a special impeller for abrasion testing on the verification prototype to restore the actual operating environment as much as possible.

[0055] Step (2.2.2): Before the impeller is abraded, a reference point is selected and the impeller is scanned in three dimensions to obtain the three-dimensional coordinates of N sub-regions of the blade tip in the initial state.

[0056] Step (2.2.3): Conduct a long-term abrasion life test, and the life time is determined according to actual requirements.

[0057] Step (2.2.4): After the test is completed, the eroded impeller is scanned again in three dimensions, ensuring that the reference point is consistent with the first three-dimensional scan, and the three-dimensional coordinates of the N sub-areas of the impeller tip after abrasion are obtained.

[0058] Step (2.2.5): By processing the three-dimensional scanning data before and after the life test, the abrasion amount at the center of each sub-area can be obtained, and this abrasion amount can be regarded as the actual abrasion state that can be used to evaluate the impeller blade tip.

[0059] This embodiment utilizes 3D laser scanning technology, a highly accurate and efficient measurement method that can rapidly acquire data about 3D entities. The basic principle is that a scanner emits a laser beam, which strikes the surface of an object and reflects back. By measuring the time it takes for the laser beam to reflect back, the distance from the surface point to the scanner is calculated, thereby obtaining the object's 3D coordinates.

[0060] Step 3: Based on the finite element CFD analysis method, calculate the hydraulic performance of each sub-area after abrasion and determine the proportion of the impact of abrasion in each sub-area on the hydraulic performance of the pump.

[0061] Specifically:

[0062] Based on the finite element CFD analysis method, the hydraulic performance of each area after abrasion is calculated separately. The analysis process is as follows: Figure 5 Shown, including:

[0063] Step (3.1): Determine the initial hydraulic flow channel structure and divide the impeller tip area.

[0064] Step (3.2): Establish a fluid model and perform meshing.

[0065] Further, including:

[0066] Step (3.2.1): Import / create geometry: Import the geometry file created by the 3D modeling software into ICEM, or use the functions of ICEM itself to create geometry.

[0067] Step (3.2.2): Repair the geometry: Fix errors and discontinuities in the imported model to ensure the accuracy of the model.

[0068] Step (3.2.3): Grid division: Select unstructured grid or structured grid for division as needed, and set global and local grid parameters.

[0069] Step (3.2.4): Set boundary conditions and initial conditions: Set the boundary conditions of the fluid domain such as inlet, outlet, and wall according to the simulation purpose.

[0070] Step (3): Run the simulation, solve the calculation, and output the hydraulic characteristics results.

[0071] Step (4): Determine whether all sub-areas have been calculated. If not, modify the impeller geometry according to the abrasion state and return to step (3). If all sub-areas have been calculated, output the calculation results, summarize the results, and perform data post-processing.

[0072] Through a lot of analysis, the hydraulic performance of each sub-area after impeller blade abrasion was calculated, and the influence of blade abrasion in each sub-area on the hydraulic performance of the heavy metal pump was obtained as follows: P1, P2, P3, ..., P N , where P N It represents the proportion of the influence of blade tip erosion in the Nth sub-region on the hydraulic performance of the heavy metal pump. It can be expressed as:

[0073]

[0074] in, Indicates the abrasion of the Nth area of ​​the blade tip X N mm after the head change, the unit is m; H0 is the impeller is not abraded initial head, the unit is m; h(X N ) indicates uniform abrasion of blade tip X N The pump head corresponding to mm is in m.

[0075] Step 4: Obtain the total impact of each sub-area on the pump head performance and calculate the pump head.

[0076] The hydraulic performance of the pump is affected by the amount of abrasion in each area of ​​the blade tip. According to the finite element analysis, the abrasion of the Nth area of ​​the blade tip is X. N The change in head after mm is ΔH N The total impact of each area on the pump head performance is shown in the following formula:

[0077] After considering the change in abrasive head in each area, the actual head H of the pump is obtained as shown in the following formula:

[0078]

[0079] From the third step, the influence ratio of blade abrasion in each sub-region on the hydraulic performance of heavy metal pump can be deduced to calculate the individual abrasion X of blade tip Nth region. N mm The change in head ΔH N As shown in the following formula:

[0080]

[0081] Abrade the Nth area of ​​the blade tip separately by X N mm The change in head ΔH N Substituting the formula into the calculation formula of the actual pump head H, we can get:

[0082] H=H0-ΔH

[0083] =H0-(P1×(H0-h(X1))+P2×(H0-h(X2))+…+P N ×(H0-h(XN )))

[0084] =H0-(P1×H0+P2×H0+…+P N ×H0-P1×h(X1)-P2×h(X2)-…-F N ×h(X N ))

[0085] =H0-(P1+P2+…+P N )×H0+(P1×h(X1)+P2×h(X2)+…+P N ×h(X N )).

[0086] In the above formula, the sum of the influence of each area of ​​the blade tip on the hydraulic performance of the pump is P1+P2+…+P N =1, so the above formula can be simplified to obtain the following formula:

[0087] H=P1×h(X1)+P2×h(X2)+P3×h(X3)+……+P N ×h(X N ).

[0088] Wherein, H represents the impeller head obtained by equivalent calculation considering the abrasion and influence ratio of different areas on the impeller tip, and the unit is m.

[0089] This embodiment provides a method for evaluating pump hydraulic performance based on tip erosion. This method is applicable to evaluating the erosion of open impellers, such as axial-flow and mixed-flow impellers, using media such as lead-based alloys and cadmium alloys. By assessing the erosion of open impeller tips, the hydraulic performance of the pump can be evaluated.

[0090] This embodiment provides a method for evaluating pump hydraulic performance based on blade tip erosion, which has the following beneficial effects: it not only considers the erosion state of different blade tip regions but also rationally assesses the degree of influence of different blade tip regions on hydraulic performance. Finite element analysis is used to assess the contribution of the blade tip region to hydraulic performance; Abrasion measurements from different blade tip regions are also collected based on life testing. By combining analytical results with test data fitting, a comprehensive and accurate assessment of the pump's hydraulic performance is achieved.

[0091] Example 2:

[0092] This embodiment provides a pump hydraulic performance evaluation method based on blade tip erosion, which is brought into a specific application scenario to verify the feasibility of the pump hydraulic performance evaluation method based on blade tip erosion provided in Example 1.

[0093] Specifically:

[0094] This embodiment uses the solution in Example 1 to investigate the influence of the abrasion amount in different areas of the impeller tip of a lead-bismuth medium axial flow pump on the hydraulic performance, thereby verifying the feasibility of the solution.

[0095] Step 1: Based on finite element CFD analysis, the hydraulic performance results of the lead-bismuth medium axial flow pump impeller with different abrasion amounts under the condition of uniform abrasion on the impeller tip are obtained.

[0096] According to the finite element analysis results, the relevant abrasion amount-head curve is fitted, and the impeller tip abrasion amount-head curve of the lead-bismuth medium axial flow pump is obtained as follows Figure 6 As shown in FIG, it can be seen from the tip erosion-lift curve that the lift of the lead-bismuth medium axial flow pump decreases with the increase of the tip erosion of the impeller of the lead-bismuth medium axial flow pump, and decreases in a downward parabola-like manner.

[0097] By fitting the relevant data to the function of blade tip wear-lift, the following formula is obtained:

[0098] h(X)=0.1357X 2 -0.1913X+0.4579.

[0099] This formula is the actual calculation result of the formula in the first step of Example 1. That is, in this embodiment, the polynomial order is 2, and the coefficients obtained by fitting the hydraulic performance analysis results based on different impeller tip abrasion amounts are a2 = 0.1357, a1 = -0.1913, and a0 = 0.4579.

[0100] Step 2: Divide the open impeller tip area into N sub-areas according to the area, obtain the abrasion amount of each sub-area and determine the proportion of the impact of the abrasion of each sub-area on the hydraulic performance of the pump.

[0101] In this embodiment, the open impeller blade tip area is evenly divided along the circumferential direction, the front edge of the blade tip is divided equally along the vertical edge, and a blade profile parallel line is drawn through the dividing point. Based on the circumferential equidivision line and the blade profile parallel line, the blade tip area is divided into 15 sub-areas.

[0102] Effect of abrasion on hydraulic performance of different regions of impeller tip of lead-bismuth medium axial flow pump P1, P2, P3, ...P 15 like Figure 7 As shown, P1=0, P2=1.82%, P3=3.64%, P4=0, P5=1.82%, P6=3.64%, P7=41.82%, P8=0, P9=1.82%, P 10 =0,P 11 =1.82%, P 12 =9.1%, P 13 =14.5%, P 14 =18.2%, P15 =1.82%.

[0103] By conducting an impeller life test, the impeller abrasion condition within a certain life cycle can be obtained. By performing a three-dimensional scan of the life test impeller, the abrasion amount at the center of each sub-area can be measured. This abrasion amount is regarded as the abrasion amount of the sub-area, and this abrasion amount can be used to evaluate the actual abrasion state of the impeller tip.

[0104] Specifically:

[0105] A special impeller for abrasion testing is installed on the verification prototype to restore the real operating environment as much as possible.

[0106] Before the impeller is abraded, a reference point is selected and a three-dimensional scan is performed on the impeller to obtain the three-dimensional coordinates of N sub-regions of the blade tip in the initial state.

[0107] A long-term abrasion life test is conducted, with the lifespan determined based on actual requirements. After the test is completed, the impeller is scanned again after abrasion, ensuring that the reference points are consistent with those in the initial 3D scan. The 3D coordinates of N sub-regions on the blade tip after abrasion are obtained.

[0108] By processing the two 3D scanning data before and after the test, the abrasion amount of the center of each sub-area can be obtained, and the abrasion amount is regarded as the abrasion amount of the sub-area, which are X1, X2, X3, ...X N .

[0109] In this embodiment, the method of determining the three-dimensional coordinates of the leaf top sub-region through three-dimensional scanning includes:

[0110] Step (1): Determine the scanning range and site.

[0111] Before scanning begins, determine the scanning range and reference points based on the impeller sub-areas and their characteristics. The selection of these ranges and reference points requires consideration of several factors, such as the object's shape, size, surface material, and reflectivity. Furthermore, the scanner's measurement accuracy, resolution, and speed must also be considered.

[0112] Step (2): Install and calibrate the scanner.

[0113] After determining the reference points, the scanner needs to be installed at the site and calibrated to eliminate the scanner's own errors and improve measurement accuracy. During the calibration process, the scanner needs to be placed on a standard sphere with known position and orientation. By measuring the distance from each point on the standard sphere to the scanner, the scanner's error value is calculated and corrected in subsequent measurements.

[0114] Step (3): Collect data.

[0115] Following a preset scanning path and speed, the system emits laser light and receives the reflected signal, calculates the distance between the point on the object's surface and the scanner, and stores the data in a computer. In this embodiment, multiple scanning stations are required around the target entity, and the data from different stations are spliced ​​and fused to improve scanning accuracy.

[0116] Step (4): Data processing and modeling

[0117] The collected data is preprocessed, such as removing noise, filling missing data, optimizing data accuracy, etc. A three-dimensional model is established based on the processed data to determine the three-dimensional coordinates.

[0118] Step 3: Based on the finite element CFD analysis method, calculate the hydraulic performance of each sub-area after abrasion.

[0119] Based on the finite element CFD analysis method, the hydraulic performance of each area after abrasion is calculated separately. Through a large number of analyses and calculations, the hydraulic performance of each area after abrasion is obtained, and the influence of abrasion on the hydraulic performance of the pump in each sub-area is calculated as P1, P2, P3, ...P N .

[0120] Step 4: Obtain the total impact of each sub-area on the pump head performance and calculate the pump head.

[0121] The hydraulic performance of the pump is affected by the amount of abrasion in each area of ​​the blade tip. According to the finite element analysis, the abrasion of the Nth area of ​​the blade tip is X. N The change in head after mm is ΔH N .

[0122] After considering the change in abrasive head of each area, the real head H of the lead-bismuth medium axial flow pump is obtained. In addition, the sum of the influence of each area of ​​the blade tip on the hydraulic performance of the pump is P1+P2+…+P N =1, the impeller head obtained by equivalent calculation considering the abrasion and influence ratio of different regions of the simplified impeller tip is:

[0123] H=P1×h(X1)+P2×h(X2)+P3×h(X3)+……+P 15 ×h(X 15 ).

[0124] By combining the above formula and the fitted blade tip wear-lift function obtained in the first step, the lift of the lead-bismuth medium axial flow pump impeller in the abrasion cycle in this embodiment can be obtained, as shown in the following formula:

[0125] H=0×h(X1)+0.0182×h(X2)+0.0364×h(X3)+0×h(X4)+0.0182×h(X5)+0.0364×h(X6)+0.4182×h(X7)+0.0182×h(X9)+0×h(X 10 )+0.0182×h(X 11 )+0.091×h(X 12 )+0.145×h(X 13 )+0.182×h(X 14 )+0.0182×h(X 15 ).

[0126] This embodiment provides a method for evaluating the hydraulic performance of a pump based on blade tip erosion. By rationally evaluating the blade tip erosion of a split impeller, it is possible to accurately evaluate the hydraulic life of the impeller and guide the design and development of hydraulic components. It takes into account the uneven abrasion of various regions of the blade tip and the proportion of the impact of each region on the hydraulic performance, and comprehensively and accurately evaluates the hydraulic performance of the pump.

[0127] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A method for evaluating pump hydraulic performance based on blade tip erosion, characterized in that: include: S1: Based on the finite element CFD analysis method, the hydraulic performance results of the blade tip under the condition of uniform erosion and different erosion amounts are obtained; S2: Divide the open impeller blade tip area into N sub-areas according to the area, and obtain the abrasion amount of each sub-area; S3: Based on the finite element CFD analysis method, calculate the hydraulic performance of each sub-area after abrasion and determine the proportion of the impact of abrasion in each sub-area on the hydraulic performance of the pump, and calculate the abrasion X of the Nth area of ​​the blade tip. N mm after the head change, calculate the impeller is not abraded initial head and the blade tip uniform abrasion X N mm, and calculate the proportion of the impact of abrasion in the Nth sub-region on the hydraulic performance of the pump according to the ratio of the change to the difference. S4: Obtain the total impact of each sub-area on the pump head performance and calculate the pump head. The pump head is the sum of the product of the proportion of the impact of each blade tip sub-area on the pump hydraulic performance and the pump head corresponding to the uniform abrasion of the blade tip in this sub-area.

2. A pump hydraulic performance evaluation method based on blade tip erosion according to claim 1, characterized in that: In step S2, the open impeller blade tip area is divided into N sub-areas according to the area, including: evenly dividing the open impeller blade tip area along the circumferential direction; taking the frontmost part of the blade tip and dividing it equally along the vertical edge, and drawing blade profile parallel lines through the equal division points; based on the circumferential bisector and the blade profile parallel lines, the blade tip area is divided into N sub-areas.

3. A pump hydraulic performance evaluation method based on blade tip erosion according to claim 1 or 2, characterized in that: In step S2, obtaining the abrasion amount of each sub-region includes: selecting a reference point, performing a three-dimensional scan on the impeller, and obtaining the three-dimensional coordinates of N sub-regions of the blade tip in the initial state; performing a long-term abrasion life test, and after the test, performing a three-dimensional scan on the impeller after abrasion again to obtain the three-dimensional coordinates of the N sub-regions of the blade tip after abrasion, calculating the abrasion amount of the center of each sub-region, and treating the abrasion amount as the abrasion amount of the sub-region.

4. A pump hydraulic performance evaluation method based on blade tip erosion according to claim 1 or 2, characterized in that: The step S1 includes: fitting a relevant abrasion-lift curve according to the finite element analysis result, and obtaining a blade tip abrasion-lift function by polynomial fitting.

5. The method for evaluating pump hydraulic performance based on blade tip erosion according to claim 4, characterized in that: The tip abrasion-head function includes: the pump head corresponding to the tip abrasion is the sum of the products of the impeller tip abrasion to the power of n and the corresponding coefficients fitted according to the hydraulic performance analysis results of different impeller tip abrasion.

6. A pump hydraulic performance evaluation method based on blade tip erosion according to claim 1 or 2, characterized in that: In step S4, the pump head is the difference between the initial head of the impeller without abrasion and the total impact of each sub-area on the pump head performance.

7. A pump hydraulic performance evaluation method based on blade tip erosion according to claim 1 or 2, characterized in that: In step S3, calculating the hydraulic performance of each sub-region after abrasion includes: determining the initial hydraulic flow channel structure and dividing the blade tip area; establishing a fluid model and performing meshing; calculating the hydraulic performance results, modifying the impeller geometry according to the mode state, and returning to the previous step to establish the fluid model.

8. The method for evaluating pump hydraulic performance based on blade tip erosion according to claim 3, characterized in that: After the long-term erosion life test is completed, the eroded impeller is scanned again in three dimensions, with the reference points consistent with those in the first three-dimensional scan.

9. The method for evaluating pump hydraulic performance based on blade tip erosion according to claim 6, characterized in that: The total impact of each sub-region on the pump head performance is the abrasion of each sub-region of the blade tip X N The sum of the changes in head after mm.

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