A circulating pump hydraulic model construction method, a construction system, a terminal and a medium

Abstract

This invention discloses a method, system, terminal, and medium for constructing a hydraulic model of a circulating pump, relating to the field of hydraulic model construction technology for circulating pumps. Its main technical solution involves incorporating casting shrinkage deformation, casting residual stress, machining allowance, machining stress deformation, and structural residual stress into the model construction. This reproduces the geometric distortions caused by the entire casting and machining process, making the impeller blade profile, volute, and flow channel more realistically geometric. This improves the accuracy of fluid-structure interaction simulation in predicting the flow field, stress distribution, and deformation displacement within the pump body. Simultaneously, before prototype manufacturing, fluid-structure interaction simulation is conducted based on the blank theoretical model to extract theoretical hydraulic performance values, correct the original hydraulic model structural parameters, and reproduce the casting and machining deformation effects, allowing for selection during the simulation stage. This reduces the number of troubleshooting attempts during prototype trial production, thereby effectively reducing the R&D and debugging costs of circulating pumps and shortening the equipment development iteration cycle.

Description

Technical Field

[0001] This invention relates to the field of circulating pump hydraulic model construction technology, specifically to a circulating pump hydraulic model construction method, construction system, terminal, and medium. Background Technology

[0002] The circulating pump in an alkylation unit is a core piece of equipment ensuring the transport of process media and the stable and continuous production of the unit. It operates under harsh and complex conditions, including frequent adjustments to wide loads, scouring by highly corrosive media, and significant fluctuations in operating conditions. The pump's hydraulic forming accuracy, rotor force balance stability, cavitation resistance, and overall operational reliability directly determine the safety level and energy consumption control efficiency of the entire alkylation unit. Therefore, building a high-precision hydraulic simulation model capable of physical closed-loop calibration is a key technological step to improve the circulating pump's adaptability to wide operating conditions, enhance overall operational stability, and reduce equipment failure frequency.

[0003] Current coupled simulations of circulating pumps only consider dynamic elastic loads such as fluid pressure and temperature, failing to adequately account for inherent geometric deviations and residual stresses generated during equipment casting and machining. This makes it difficult to achieve coupled superposition analysis of manufacturing deformation and operational deformation. Consequently, simulation results of the pump's internal flow field distribution, structural stress characteristics, hydraulic load characteristics, and cavitation performance deviate from actual operating conditions, hindering accurate reproduction of the prototype's true operating state and performance. Furthermore, current equipment optimization is mostly a reactive, post-implementation approach, only addressing issues such as hydraulic parameter deviations, excessive vibration amplitudes, and cavitation failures observed during prototype testing. This not only increases equipment R&D and debugging costs and prolongs the development cycle but also exacerbates on-site operational safety hazards, increases maintenance load and costs, and is detrimental to the long-term stable, safe, and efficient operation of the equipment and facilities. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, terminal, and medium for constructing a hydraulic model of a circulating pump. This invention addresses the current issues where the simulation results of the circulating pump's internal flow field distribution, structural stress characteristics, hydraulic load characteristics, and cavitation performance deviate from actual operating conditions, making it difficult to accurately reproduce the prototype's true operating state and actual performance. It also addresses the problems that current equipment optimization methods increase equipment R&D and debugging costs and prolong the R&D iteration cycle.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] Firstly, a method for constructing a hydraulic model of a circulating pump is provided, including the following operations:

[0007] S1, obtain the original hydraulic model of the circulating pump, the material properties of the pump body, the casting process parameters, and the machining cutting parameters;

[0008] S2. Based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters, construct a theoretical model of the circulating pump blank.

[0009] S3, use the theoretical model of the circulating pump blank to perform coupled simulation on the preset load data to obtain simulation data;

[0010] S4. Based on the simulation data, generate theoretical values ​​for the hydraulic performance indicators;

[0011] S5, determine whether the theoretical value of the hydraulic performance index meets the performance index threshold; if yes, then record the original hydraulic model as the target hydraulic model; if no, then adjust the structural parameters of the original hydraulic model and cycle from S2 to S4 until the theoretical value of the hydraulic performance index meets the performance index threshold, and record the original hydraulic model with the last adjusted structural parameters as the target hydraulic model.

[0012] S6. Based on the target hydraulic model, manufacture a circulating pump prototype and obtain the measured values ​​of the hydraulic performance indicators of the circulating pump prototype.

[0013] S7. Based on the measured values ​​and theoretical values ​​of the hydraulic performance indicators, a correction coefficient is generated, and the theoretical model of the circulating pump blank is corrected using the correction coefficient.

[0014] A further approach involves constructing a theoretical model of the circulating pump blank based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters. This process includes:

[0015] S21, the original hydraulic model, pump body material properties and casting process parameters are coupled and simulated to obtain the casting blank temperature field and casting blank residual thermal stress field; wherein, the casting blank temperature field is used to characterize the temperature distribution of all grid nodes of the pump body at each casting time, and the casting blank residual thermal stress field is used to characterize the internal tensile residual stress and compressive residual stress distribution of all grid nodes of the pump body during the casting cooling stage.

[0016] S22, Based on the temperature field of the cast blank and the residual thermal stress field of the cast blank, generate the global solidification shrinkage deformation vector data of the pump body;

[0017] S23, the original hydraulic model is reconstructed by offsetting the grid nodes using the global solidification shrinkage deformation vector data to obtain the theoretical model of the circulating pump casting blank;

[0018] S24, Perform coupled simulation of the cutting process between the theoretical model of the circulating pump casting blank and the machining cutting parameters to obtain the cutting plastic deformation displacement field;

[0019] S25, the cutting plastic deformation displacement field is superimposed on the theoretical model of the circulating pump casting blank to obtain the theoretical model of the circulating pump blank.

[0020] A further approach is that the process of generating the global solidification shrinkage deformation vector data of the pump body includes:

[0021] S211, extract the temperature gradient parameters and triaxial residual stress parameters corresponding to each grid node from the temperature field and residual thermal stress field of the casting blank, respectively.

[0022] S212, calculate the temperature gradient correction coefficient and thermal stress constraint correction coefficient for each grid node based on the temperature gradient parameters and triaxial residual stress parameters of each grid node.

[0023] S213, based on the temperature gradient correction coefficient, thermal stress constraint correction coefficient and pump body material properties, calculate the differential solidification shrinkage per grid node;

[0024] S214. Based on the differentiated solidification shrinkage of each grid node, the triaxial coordinate offset of each grid node is solved separately. The triaxial coordinate offsets of all grid nodes are integrated to obtain the global solidification shrinkage deformation vector data of the pump body.

[0025] A further approach is as follows: the process of solving the triaxial coordinate offset of each grid node based on the differentiated solidification shrinkage of each grid node includes:

[0026] A local coordinate system is established with the geometric center of the original hydraulic model as the reference point;

[0027] Based on the differential solidification shrinkage of each grid node and the spatial orientation vector of the grid node relative to the reference point, the differential solidification shrinkage is distributed to the X-axis, Y-axis and Z-axis directions in a vector decomposition manner to obtain the three-axis coordinate offset of the grid node.

[0028] A further approach is to: before superimposing the cutting plastic deformation displacement field onto the theoretical model of the circulating pump casting blank, further include: performing smoothing filtering on the cutting plastic deformation displacement field to reduce numerical oscillations and singularities generated in the coupled simulation of the cutting process.

[0029] A further approach is to adjust the structural parameters of the original hydraulic model, including: based on the deviation between the theoretical value of the hydraulic performance index and the threshold value of the performance index, using a gradient optimization algorithm or a response surface optimization algorithm to iteratively correct at least one of the structural parameters of the original hydraulic model, namely the impeller blade angle, blade wrap angle, and volute cross-sectional area.

[0030] Secondly, a construction system is provided, the construction system being applicable to the circulating pump hydraulic model construction method as described in the first aspect, the construction system comprising:

[0031] The acquisition module is used to execute S1 to acquire the original hydraulic model of the circulating pump, the material properties of the pump body, the casting process parameters, and the machining cutting parameters.

[0032] The construction module is used to execute S2 to construct a theoretical model of the circulating pump blank based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters.

[0033] The coupling module is used to execute S3, which uses the theoretical model of the circulating pump blank to perform coupled simulation on the preset load data to obtain simulation data.

[0034] A generation module is used to execute S4 to generate theoretical values ​​of hydraulic performance indicators based on the simulation data.

[0035] The judgment module is used to execute S5 to determine whether the theoretical value of the hydraulic performance index meets the performance index threshold; if yes, the original hydraulic model is recorded as the target hydraulic model; if no, the structural parameters of the original hydraulic model are adjusted, and S2 to S4 are repeated until the theoretical value of the hydraulic performance index meets the performance index threshold, and the original hydraulic model with the last adjusted structural parameters is recorded as the target hydraulic model.

[0036] The processing module is used to execute S6, manufacture a circulating pump prototype based on the target hydraulic model, and obtain the measured values ​​of the hydraulic performance indicators of the circulating pump prototype.

[0037] The correction module is used to execute S7, generate correction coefficients based on the measured values ​​and theoretical values ​​of the hydraulic performance indicators, and use the correction coefficients to correct the theoretical model of the circulating pump blank.

[0038] Thirdly, a terminal is provided, including a processor and a memory, the memory being used to store processor-executable instructions; wherein the processor is configured to invoke the instructions stored in the memory to execute the circulating pump hydraulic model construction method as described in the first aspect.

[0039] Fourthly, a computer-readable storage medium is provided, on which computer program instructions are stored, which, when executed by a processor, implement the circulating pump hydraulic model construction method as described in the first aspect.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] By incorporating inherent geometric deviations and structural residual stresses from manufacturing processes such as casting shrinkage deformation, casting residual stress, machining allowances, and machining stress deformation into the model construction, the geometric distortions of flow components resulting from the entire casting and machining process are reproduced. This enables coupled and superimposed analysis of manufacturing deformation and operational deformation, resulting in more realistic impeller blade profiles, volutes, and flow channels. This aims to improve the accuracy of fluid-structure interaction (FSI) simulation in predicting the flow field, stress distribution, and deformation displacement within the pump body. Simultaneously, before prototype manufacturing, FSI simulations are conducted based on the blank theoretical model to extract theoretical hydraulic performance values. The original hydraulic model's structural parameters are iteratively corrected through optimized algorithms to reproduce casting and machining deformation effects, allowing for performance compliance iteration and screening during the simulation phase. The goal is to significantly reduce the number of prototype trial failures requiring rectification, thereby effectively reducing the R&D and debugging costs of circulating pumps and shortening the equipment development iteration cycle. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating a method for constructing a circulating pump hydraulic model in this embodiment. Detailed Implementation

[0043] The invention will now be further described with reference to the accompanying drawings.

[0044] Example 1: This example provides a method for constructing a hydraulic model of a circulating pump, such as... Figure 1 As shown, the following operations are included:

[0045] S100. Obtain the original hydraulic model of the circulating pump, the material properties of the pump body, the casting process parameters, and the machining cutting parameters;

[0046] For example, in implementation, the original hydraulic model of the circulating pump is an ideal three-dimensional hydraulic model of the circulating pump design. This original hydraulic model includes the geometric dimensions of core flow components such as the impeller, volute, flow channel, and inlet / outlet. The material properties of the circulating pump body include the casting's elastic modulus, Poisson's ratio, coefficient of thermal expansion, and yield strength. The casting process parameters of the circulating pump include pouring temperature, cooling rate, mold constraints, and casting shrinkage parameters. The machining parameters of the circulating pump include cutting allowance, machining stress, clamping constraints, and cutting deformation parameters.

[0047] S200. Based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters, construct a theoretical model of the circulating pump blank;

[0048] For example, during implementation, based on the original hydraulic model geometry, the shrinkage deformation and residual stress deformation brought about by casting are superimposed, and the machining removal of allowance and the deformation induced by machining stress are superimposed. The flow channel contour, impeller blade profile, and volute cross-sectional dimensions of the flow components are corrected to obtain a theoretical model of the circulating pump blank that includes the deformation of the entire process of casting and machining, so as to simulate and restore the real geometric shape of the flow components after the actual machining of the circulating pump blank.

[0049] S300. Use the theoretical model of the circulating pump blank to perform coupled simulation on the preset load data to obtain simulation data;

[0050] For example, during implementation, the theoretical model of the circulating pump blank is imported into the simulation solver, and preset load data such as fluid hydraulic load, casting residual stress load, and machining residual stress load are input to carry out fluid-structure interaction simulation calculations, so as to simulate and output simulation data such as velocity field, pressure field, stress distribution, component deformation displacement, flow rate-head, etc. in the flow channel.

[0051] S400. Based on the simulation data, generate theoretical values ​​for the hydraulic performance indicators;

[0052] For example, during implementation, theoretical values ​​of hydraulic performance indicators such as head, flow rate, efficiency, net positive suction head (NPSH), and power under rated operating conditions are extracted based on simulation data. These theoretical values ​​include performance deviations caused by geometric deformation resulting from casting and machining.

[0053] S500. Determine whether the theoretical value of the hydraulic performance index meets the performance index threshold; if yes, then record the original hydraulic model as the target hydraulic model; if no, then adjust the structural parameters of the original hydraulic model and cycle from S200 to S400 until the theoretical value of the hydraulic performance index meets the performance index threshold, and record the original hydraulic model with the last adjusted structural parameters as the target hydraulic model.

[0054] In this embodiment, the process of adjusting the structural parameters of the original hydraulic model includes: based on the deviation between the theoretical value of the hydraulic performance index and the threshold value of the performance index, using a gradient optimization algorithm or a response surface optimization algorithm to iteratively correct at least one of the structural parameters of the original hydraulic model, namely the impeller blade angle, blade wrap angle, and volute cross-sectional area.

[0055] For example, during implementation, the theoretical values ​​of hydraulic performance indicators are compared with preset performance indicator thresholds. If the theoretical values ​​of the hydraulic performance indicators meet the preset performance indicator thresholds, the current original hydraulic model is used as the target hydraulic model. If the theoretical values ​​of the hydraulic performance indicators do not meet the preset performance indicator thresholds, a gradient optimization algorithm or response surface optimization algorithm is used to iteratively correct at least one of the structural parameters of the original hydraulic model, such as blade placement angle, blade thickness, volute base circle diameter, flow channel cross-sectional area, and impeller inlet / outlet diameter. After adjusting the structural parameters, the process returns to S200, regenerates the blank theoretical model, and repeats the preset load data coupling simulation and recalculates the theoretical values ​​of the hydraulic performance indicators. This process iterates from S200 to S400 until the theoretical values ​​of the hydraulic performance indicators meet the preset performance indicator thresholds. At this point, the original hydraulic model after the last round of structural parameter adjustments is determined as the target hydraulic model.

[0056] Based on the original hydraulic model iteration, each iteration reproduces the casting and machining deformation effects to reduce the error between the ideal simulation and the actual product.

[0057] S600. Based on the target hydraulic model, manufacture a circulating pump prototype and obtain the measured values ​​of the hydraulic performance indicators of the circulating pump prototype;

[0058] For example, during the implementation process, the target hydraulic model obtained through iteration is used to carry out prototype casting and machining to manufacture a circulating pump prototype, and performance testing is conducted on the prototype to collect measured values ​​of hydraulic performance indicators such as head, flow rate, efficiency, net positive suction head, and power under different operating conditions.

[0059] S700. Based on the measured values ​​and theoretical values ​​of the hydraulic performance indicators, a correction coefficient is generated, and the theoretical model of the circulating pump blank is corrected using the correction coefficient.

[0060] For example, during implementation, the measured values ​​of the hydraulic performance indicators of the circulating pump prototype are compared with the theoretical values ​​of the hydraulic performance indicators output by simulation. Deviations in flow rate, head, efficiency, net positive suction head (NPSH), and power under different operating conditions are calculated, and correction coefficients related to the operating conditions are generated based on these deviations. These correction coefficients are then used to correct the geometric boundaries and deformation compensation of the circulating pump blank theoretical model to complete the blank theoretical model calibration, resulting in a corrected circulating pump blank theoretical model, thereby improving the accuracy of simulation predictions.

[0061] The circulating pump hydraulic model construction method in this embodiment, on the one hand, incorporates inherent geometric deviations and structural residual stresses from manufacturing processes, such as casting shrinkage deformation, casting residual stress, machining allowances, and machining stress deformation, into the model construction. This reproduces the geometric distortions of flow components caused by the entire casting and machining process, achieving coupled superposition analysis of manufacturing deformation and operational deformation, making the impeller blade profile, volute, and flow channel more realistically geometric. The aim is to improve the accuracy of fluid-structure interaction simulation in predicting the flow field, stress distribution, and deformation displacement within the pump body. On the other hand, before prototype manufacturing, fluid-structure interaction simulation is conducted based on the blank theoretical model to extract theoretical hydraulic performance values. Gradient optimization / response surface optimization algorithms are used to iteratively correct the structural parameters of the original hydraulic model, reproducing the casting and machining deformation effects, thus completing performance compliance iteration and screening during the simulation phase. This aims to significantly reduce the number of prototype trial production failures and rectifications, thereby effectively reducing the R&D and debugging costs of the circulating pump and shortening the equipment R&D iteration cycle.

[0062] In this embodiment, the process of constructing a theoretical model of the circulating pump blank based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters includes:

[0063] S201. Perform coupled simulation of the casting process on the original hydraulic model, pump body material properties and casting process parameters to obtain the casting blank temperature field and casting blank residual thermal stress field; wherein, the casting blank temperature field is used to characterize the temperature distribution of all grid nodes of the pump body at each casting time, and the casting blank residual thermal stress field is used to characterize the internal tensile residual stress and compressive residual stress distribution of all grid nodes of the pump body during the casting cooling stage.

[0064] For example, during implementation, the mesh geometry of the original hydraulic model, the material properties of the pump body, and the casting process parameters are input into the casting simulation solution module, and a multi-physics coupled simulation of casting temperature and stress is performed to output the temperature field and residual thermal stress field of the casting blank. The temperature field of the casting blank records the temperature distribution of all mesh nodes of the pump body at each time step throughout the casting process, reflecting the cooling rate and solidification sequence of different parts of the pump body. The residual thermal stress field of the casting blank records the distribution of residual tensile and compressive stresses at all mesh node positions of the pump body after cooling, characterizing the residual stress state inside the pump body after casting cooling.

[0065] S202. Generate global solidification shrinkage deformation vector data of the pump body based on the temperature field and residual thermal stress field of the cast blank;

[0066] For example, during implementation, the temperature field and residual thermal stress field of the cast blank are used as inputs. Based on the constitutive relationship of material thermal expansion and contraction and phase transformation shrinkage, the displacement direction and displacement amount are calculated for each grid node in the entire pump body, generating global solidification shrinkage deformation vector data. The global solidification shrinkage deformation vector data is a three-dimensional deformation vector corresponding to each grid node, containing the magnitude and direction of the offset in the X, Y, and Z directions, characterizing the shrinkage and warping deformation of the pump body impeller, volute, flow channel, and other parts caused by solidification and cooling.

[0067] S203. The original hydraulic model is reconstructed by offsetting the grid nodes using the global solidification shrinkage deformation vector data to obtain the theoretical model of the circulating pump casting blank.

[0068] For example, during implementation, the coordinates of all grid nodes of the original hydraulic model are read, the global solidification shrinkage deformation vector data is mapped to the corresponding grid nodes of the original hydraulic model, the coordinates of each grid node are offset according to the deformation vector, the model grid is reconstructed and updated, and the flow components, blade profiles, volute flow channel cross sections, and impeller profiles undergo geometric changes following the node offsets, resulting in a theoretical model of the circulating pump casting blank that includes casting solidification shrinkage and thermal stress warping.

[0069] S204. Perform coupled simulation of the cutting process on the theoretical model of the circulating pump casting blank and the machining cutting parameters to obtain the cutting plastic deformation displacement field;

[0070] For example, in the implementation process, the theoretical model of the circulating pump casting blank is used as the simulation geometry object. Machining cutting parameters are imported, and coupled simulation of the cutting process is carried out to simulate the material removal process and the plastic deformation caused by the cutting force, so as to obtain the cutting plastic deformation displacement field. Among them, the cutting plastic deformation displacement field includes the plastic displacement of each grid node on the casting blank after machining, which characterizes the local deformation of the pump body caused by the cutting force and clamping stress.

[0071] S205. The cutting plastic deformation displacement field is superimposed on the theoretical model of the circulating pump casting blank to obtain the theoretical model of the circulating pump blank.

[0072] For example, during implementation, the three-dimensional displacements of each mesh node in the cutting plastic deformation displacement field are superimposed onto the corresponding mesh nodes of the circulating pump casting blank theoretical model, updating the coordinates of all mesh nodes and completing the geometric reconstruction to obtain the circulating pump blank theoretical model. This circulating pump blank theoretical model integrates both casting solidification shrinkage and warping deformation, as well as the plastic deformation caused by machining, thus better reflecting the geometric state of the actual flow-through components of the circulating pump after both casting and machining processes.

[0073] The circulating pump hydraulic model construction method in this embodiment obtains the three-dimensional solidification shrinkage deformation vector of each grid node by solving the temperature field and residual thermal stress field. This can reflect the non-uniform shrinkage and local warping at different locations of the volute and impeller, and can capture the local distortion of key hydraulic components such as blades and flow channels. The aim is to reduce the risk that the overall scaled model cannot adequately represent local irregular deformations, thereby making the circulating pump blank theoretical model more closely resemble the actual blank shape after casting.

[0074] In this embodiment, the process of generating global solidification shrinkage deformation vector data of the pump body includes:

[0075] S2011. Extract the temperature gradient parameters and triaxial residual stress parameters corresponding to each grid node from the temperature field and residual thermal stress field of the casting blank, respectively.

[0076] For example, during implementation, all grid nodes of the casting blank temperature field and the casting blank residual thermal stress field are traversed. For each grid node, temperature data of that grid node and its surrounding neighboring grid nodes are extracted, and the temperature gradient parameter of that grid node is calculated. The temperature gradient parameter characterizes the cooling rate and the degree of temperature change at the location of that grid node. Simultaneously, the triaxial residual stress parameters in the X, Y, and Z directions of that grid node are extracted. These triaxial residual stress parameters reflect the internal constraint stress state experienced by different parts during the casting cooling process.

[0077] S2012. Calculate the temperature gradient correction coefficient and thermal stress constraint correction coefficient for each grid node based on the temperature gradient parameters and triaxial residual stress parameters of each grid node.

[0078] For example, during implementation, the temperature gradient parameter of a single grid node is used as input, and the temperature gradient correction coefficient corresponding to that grid node is calculated by combining the material's phase change cooling characteristics. The temperature gradient correction coefficient characterizes the effect of cooling rate on the actual shrinkage: locations with large temperature gradients cool faster, resulting in different phase change solidification processes, and the actual shrinkage will deviate from the material's inherent theoretical shrinkage rate.

[0079] Using the triaxial residual stress parameters of the mesh node as input, the thermal stress constraint correction coefficient is calculated. The thermal stress constraint correction coefficient characterizes the constraint effect of internal residual stress on free solidification shrinkage: when the node is subjected to residual compressive stress, it will inhibit shrinkage; when it is subjected to residual tensile stress, it will aggravate deformation. The thermal stress constraint correction coefficient reflects the inhibition / amplification effect of stress constraint on shrinkage behavior.

[0080] S2013. Based on the temperature gradient correction coefficient, thermal stress constraint correction coefficient and pump body material properties, calculate the differential solidification shrinkage per grid node;

[0081] For example, during implementation, the material properties of the pump body are retrieved, and for each grid node, the inherent theoretical solidification shrinkage of the material is multiplied by the temperature gradient correction coefficient and the thermal stress constraint correction coefficient of that node to calculate the differential solidification shrinkage of that grid node.

[0082] S2014. Based on the differentiated solidification shrinkage of each grid node, the triaxial coordinate offset of each grid node is solved separately, and the triaxial coordinate offset of all grid nodes is integrated to obtain the global solidification shrinkage deformation vector data of the pump body.

[0083] For example, during implementation, based on the differentiated solidification shrinkage of each grid node and combined with the dominant local stress direction of the grid node, the three-axis coordinate offsets in the X, Y, and Z directions are calculated; the three-axis coordinate offset of a single grid node constitutes the three-dimensional deformation vector of that grid node. By traversing all grid nodes of the pump body, the three-axis coordinate offsets of all grid nodes are summarized and integrated to form solidification shrinkage deformation vector data covering the entire solidification shrinkage deformation of the pump body's flow-through components and main structure.

[0084] The circulating pump hydraulic model construction method in this embodiment introduces temperature gradient correction coefficients and thermal stress constraint correction coefficients for each grid node to incorporate cooling rate and internal stress constraints into the shrinkage calculation. This aims to improve the precision of solving non-uniform solidification shrinkage.

[0085] In this embodiment, the process of calculating the triaxial coordinate offset of each grid node based on the differentiated solidification shrinkage of each grid node includes:

[0086] A local coordinate system is established with the geometric center of the original hydraulic model as the reference point;

[0087] For example, during implementation, a local coordinate system for the original hydraulic model is constructed using the geometric center of the original hydraulic model as the reference point. This local coordinate system corresponds to the three-dimensional geometry of the original hydraulic model, with the reference point being the geometric center of the impeller-volute assembly. This reference point is also used as the unified reference origin for calculating the spatial orientation of all mesh nodes.

[0088] Based on the differential solidification shrinkage of each grid node and the spatial orientation vector of the grid node relative to the reference point, the differential solidification shrinkage is distributed to the X-axis, Y-axis and Z-axis directions in a vector decomposition manner to obtain the three-axis coordinate offset of the grid node.

[0089] For example, during implementation, for each grid node on the pump body, the spatial orientation vector of the grid node relative to the reference point is calculated. The spatial orientation vector represents the spatial pointing and positional relationship of the current grid node relative to the geometric center reference point. The spatial orientation vector includes the orientation components of the grid node in the X, Y, and Z directions in the local coordinate system.

[0090] By traversing all grid nodes of the pump body, each grid node completes the triaxial decomposition of the differential solidification shrinkage based on its spatial orientation vector relative to the reference point. The triaxial coordinate offsets of all grid nodes are summarized and integrated to obtain the global solidification shrinkage deformation vector data of the pump body.

[0091] The circulating pump hydraulic model construction method in this embodiment establishes a local coordinate system based on the geometric center of the original hydraulic model. It performs vector decomposition using the spatial orientation vectors of the grid nodes relative to the reference point to simulate the phenomenon of material shrinking towards the overall geometric center during casting cooling and solidification. This aims to make the deformation direction more closely match the actual casting process.

[0092] In actual implementation, the coupled simulation of the cutting process is affected by mesh discretization, instantaneous changes in cutting load, and numerical errors in the contact algorithm. In the obtained cutting plastic deformation displacement field, some local mesh nodes exhibit singularities with abrupt displacement changes and abnormal jumps, as well as high-frequency numerical oscillations. These singularities and high-frequency oscillations are not actual physical cutting deformations but rather simulation artifacts. Directly superimposing the displacement field containing numerical oscillations and singularities onto the theoretical model of the circulating pump casting blank will cause local mesh distortion and element twisting, leading to false burrs and abnormal unevenness in the blade profiles and volute flow channels of the flow components, damaging the model's geometric quality and affecting the convergence and computational accuracy of subsequent fluid-structure interaction simulations. Therefore, in this embodiment, before superimposing the cutting plastic deformation displacement field onto the theoretical model of the circulating pump casting blank, the process further includes: smoothing and filtering the cutting plastic deformation displacement field to reduce the numerical oscillations and singularities generated in the coupled simulation of the cutting process.

[0093] For example, during implementation, the cutting plastic deformation displacement field output by the coupled simulation of the cutting process is obtained. This cutting plastic deformation displacement field stores the plastic deformation displacement components in the X, Y, and Z directions of each grid node. A neighborhood smoothing filtering algorithm is selected. For each grid node, the triaxial displacement components of the surrounding neighboring grid nodes are read, and the X, Y, and Z displacements of the grid node are calculated by neighborhood weighted averaging to complete the smoothing filtering process for that grid node. The smoothing filtering process is completed by traversing all grid nodes. During the filtering process, the overall deformation change trend of the cutting plastic deformation displacement field is preserved, the true plastic deformation gradient in the cutting load area is preserved, and only local discrete singularities and high-frequency numerical oscillations are filtered out to retain the true macroscopic plastic deformation brought about by machining.

[0094] After filtering, the noise-reduced cutting plastic deformation displacement field is obtained. Then, the noise-reduced cutting plastic deformation displacement field is superimposed on the theoretical model of the circulating pump casting blank, and the mesh node coordinates are updated to obtain the theoretical model of the circulating pump blank.

[0095] The circulating pump hydraulic model construction method in this embodiment uses smoothing filtering to eliminate singular points and numerical oscillations in the cutting plastic deformation displacement field. This aims to reduce the risk of introducing simulation numerical errors into the geometric model, thereby reducing the risk of false local deformations in the blades and volute flow channels, and ultimately ensuring that the theoretical model of the circulating pump casting blank more closely matches the actual physical state after machining.

[0096] Example 2: This embodiment provides a construction system applicable to the circulating pump hydraulic model construction method described in Example 1. The construction system includes an acquisition module, a construction module, a coupling module, a generation module, a judgment module, a processing module, and a correction module.

[0097] The acquisition module executes step S100 to acquire the original hydraulic model, pump body material properties, casting process parameters, and machining parameters of the circulating pump. The construction module executes step S200 to construct a theoretical model of the circulating pump blank based on the original hydraulic model, pump body material properties, casting process parameters, and machining parameters. The coupling module executes step S300 to perform coupled simulation on preset load data using the theoretical model of the circulating pump blank to obtain simulation data. The generation module executes step S400 to generate theoretical values ​​of hydraulic performance indicators based on the simulation data. The judgment module executes step S500 to determine whether the theoretical values ​​of the hydraulic performance indicators meet the requirements. If the performance index threshold is met, the original hydraulic model is designated as the target hydraulic model; otherwise, the structural parameters of the original hydraulic model are adjusted, and S200 to S400 are repeated until the theoretical value of the hydraulic performance index meets the performance index threshold. The original hydraulic model with the last adjusted structural parameters is then designated as the target hydraulic model. The processing module executes S600 to manufacture a circulating pump prototype based on the target hydraulic model and obtains the measured values ​​of the hydraulic performance index of the circulating pump prototype. The correction module executes S700 to generate correction coefficients based on the measured values ​​and theoretical values ​​of the hydraulic performance indexes, and uses the correction coefficients to correct the theoretical model of the circulating pump blank.

[0098] In this embodiment, a terminal is also provided, including a processor and a memory, wherein the memory is used to store processor-executable instructions; wherein the processor is configured to invoke the instructions stored in the memory to execute the circulating pump hydraulic model construction method as described in Embodiment 1.

[0099] In this embodiment, a computer-readable storage medium is also provided, on which computer program instructions are stored, which, when executed by a processor, implement the circulating pump hydraulic model construction method as described in Embodiment 1.

[0100] Although the invention has been described herein with reference to several illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter arrangement within the scope of the disclosure, drawings, and claims. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A method for constructing a hydraulic model of a circulating pump, characterized in that, Includes the following operations: S1, obtain the original hydraulic model of the circulating pump, the material properties of the pump body, the casting process parameters, and the machining cutting parameters; S2. Based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters, construct a theoretical model of the circulating pump blank. S3, use the theoretical model of the circulating pump blank to perform coupled simulation on the preset load data to obtain simulation data; S4. Based on the simulation data, generate theoretical values ​​for hydraulic performance indicators; S5, determine whether the theoretical value of the hydraulic performance index meets the performance index threshold; if yes, then record the original hydraulic model as the target hydraulic model; if no, then adjust the structural parameters of the original hydraulic model and cycle from S2 to S4 until the theoretical value of the hydraulic performance index meets the performance index threshold, and record the original hydraulic model with the last adjusted structural parameters as the target hydraulic model. S6. Based on the target hydraulic model, manufacture a circulating pump prototype and obtain the measured values ​​of the hydraulic performance indicators of the circulating pump prototype. S7. Based on the measured values ​​and theoretical values ​​of the hydraulic performance indicators, a correction coefficient is generated, and the theoretical model of the circulating pump blank is corrected using the correction coefficient.

2. The method for constructing a circulating pump hydraulic model according to claim 1, characterized in that, The process of constructing a theoretical model of a circulating pump blank based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters includes: S21, the original hydraulic model, pump body material properties and casting process parameters are coupled and simulated to obtain the casting blank temperature field and casting blank residual thermal stress field; wherein, the casting blank temperature field is used to characterize the temperature distribution of all grid nodes of the pump body at each casting time, and the casting blank residual thermal stress field is used to characterize the internal tensile residual stress and compressive residual stress distribution of all grid nodes of the pump body during the casting cooling stage. S22, Based on the temperature field of the cast blank and the residual thermal stress field of the cast blank, generate the global solidification shrinkage deformation vector data of the pump body; S23, the original hydraulic model is reconstructed by offsetting the grid nodes using the global solidification shrinkage deformation vector data to obtain the theoretical model of the circulating pump casting blank; S24, Perform coupled simulation of the cutting process between the theoretical model of the circulating pump casting blank and the machining cutting parameters to obtain the cutting plastic deformation displacement field; S25, the cutting plastic deformation displacement field is superimposed on the theoretical model of the circulating pump casting blank to obtain the theoretical model of the circulating pump blank.

3. The method for constructing a circulating pump hydraulic model according to claim 2, characterized in that, The process of generating global solidification shrinkage deformation vector data of the pump body includes: S211, extract the temperature gradient parameters and triaxial residual stress parameters corresponding to each grid node from the temperature field and residual thermal stress field of the casting blank, respectively. S212, calculate the temperature gradient correction coefficient and thermal stress constraint correction coefficient for each grid node based on the temperature gradient parameters and triaxial residual stress parameters of each grid node. S213, based on the temperature gradient correction coefficient, thermal stress constraint correction coefficient and pump body material properties, calculate the differential solidification shrinkage per grid node; S214. Based on the differentiated solidification shrinkage of each grid node, the triaxial coordinate offset of each grid node is solved separately. The triaxial coordinate offsets of all grid nodes are integrated to obtain the global solidification shrinkage deformation vector data of the pump body.

4. The method for constructing a circulating pump hydraulic model according to claim 3, characterized in that, The process of calculating the triaxial coordinate offset of each grid node based on the differentiated solidification shrinkage of each grid node includes: A local coordinate system is established with the geometric center of the original hydraulic model as the reference point; Based on the differential solidification shrinkage of each grid node and the spatial orientation vector of the grid node relative to the reference point, the differential solidification shrinkage is distributed to the X-axis, Y-axis and Z-axis directions in a vector decomposition manner to obtain the three-axis coordinate offset of the grid node.

5. The method for constructing a circulating pump hydraulic model according to claim 2, characterized in that, Before superimposing the cutting plastic deformation displacement field onto the theoretical model of the circulating pump casting blank, the method further includes: performing smoothing filtering on the cutting plastic deformation displacement field to reduce numerical oscillations and singularities generated in the coupled simulation of the cutting process.

6. The method for constructing a circulating pump hydraulic model according to claim 1, characterized in that, The process of adjusting the structural parameters of the original hydraulic model includes: based on the deviation between the theoretical value of the hydraulic performance index and the threshold value of the performance index, using a gradient optimization algorithm or a response surface optimization algorithm to iteratively correct at least one of the structural parameters of the original hydraulic model, namely the impeller blade angle, blade wrap angle, and volute cross-sectional area.

7. A construction system, characterized in that, The construction system is applicable to the circulating pump hydraulic model construction method as described in any one of claims 1-6, and the construction system includes: The acquisition module is used to execute S1 to acquire the original hydraulic model of the circulating pump, the material properties of the pump body, the casting process parameters, and the machining cutting parameters. The construction module is used to execute S2, which constructs a theoretical model of the circulating pump blank based on the original hydraulic model, pump body material properties, casting process parameters, and machining cutting parameters. The coupling module is used to execute S3, which uses the theoretical model of the circulating pump blank to perform coupled simulation on the preset load data to obtain simulation data. A generation module is used to execute S4 to generate theoretical values ​​of hydraulic performance indicators based on the simulation data. The judgment module is used to execute S5 to determine whether the theoretical value of the hydraulic performance index meets the performance index threshold; if yes, the original hydraulic model is recorded as the target hydraulic model; if no, the structural parameters of the original hydraulic model are adjusted, and S2 to S4 are repeated until the theoretical value of the hydraulic performance index meets the performance index threshold, and the original hydraulic model with the last adjusted structural parameters is recorded as the target hydraulic model. The processing module is used to execute S6, manufacture a circulating pump prototype based on the target hydraulic model, and obtain the measured values ​​of the hydraulic performance indicators of the circulating pump prototype. The correction module is used to execute S7, generate correction coefficients based on the measured values ​​and theoretical values ​​of the hydraulic performance indicators, and use the correction coefficients to correct the theoretical model of the circulating pump blank.

8. A terminal, characterized in that, include: A processor and a memory, wherein the memory is used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the circulating pump hydraulic model construction method as described in any one of claims 1-6.

9. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the circulating pump hydraulic model construction method as described in any one of claims 1-6.

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