Roundness deviation control method and system for bending of heat exchanger u-tubes

Abstract

The application discloses a roundness deviation control method and system for U-shaped tube bending of a heat exchanger, relates to the related field of size and shape measurement, and comprises the following steps: determining a pipe material blank of a U-shaped tube and bending target input control center analysis; controlling a first side bending arm bending of the U-shaped tube by using a bending machine with first bending parameter control, starting a laser scanning device to scan along the pipe section at 360 degrees; performing bending detection of each section based on a continuous scanning data sequence, performing bending deviation prediction and correction, and generating first real-time correction parameters; continuing bending control, performing opposite side influence checking of a second side bending arm with opposite side interaction information after the first control is completed, and then performing bending deviation prediction and correction of the second side bending arm according to second bending parameter control. The application solves the technical problem that the existing roundness deviation control cannot effectively control the roundness deviation, resulting in unstable bending quality, and achieves the technical effect of effectively controlling the roundness deviation and improving the bending quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of size and shape measurement, in particular to a roundness deviation control method and system for bending of U-shaped tube of heat exchanger. BACKGROUND

[0002] In the field of heat exchanger manufacturing, the roundness deviation control of U-shaped tube is crucial to ensure the heat exchange efficiency and service life of the heat exchanger. If the roundness deviation is too large, it will seriously affect the performance and reliability of the heat exchanger. At present, the main method to solve the problem of roundness deviation control of U-shaped tube is to bend according to the preset parameters during bending, and to perform quality evaluation after bending is completed through simple detection means. The current method lacks real-time and accurate roundness deviation detection and correction mechanism during bending, and does not fully consider the mutual influence between the two bending arms during bending, which leads to difficulty in effectively controlling the roundness deviation, unstable bending quality, and low product qualification rate.

[0003] In the related art, the roundness deviation control for bending of U-shaped tube of heat exchanger has the technical problem of difficulty in effectively controlling the roundness deviation, resulting in unstable bending quality. SUMMARY

[0004] The present application provides a roundness deviation control method and system for bending of U-shaped tube of heat exchanger. The method includes inputting the pipe material blank and bending target of the U-shaped tube of heat exchanger into the bending machine control center, determining the twice bending parameters and the opposite side mutual influence information, controlling the bending machine to bend the first side bending arm according to the first bending parameter, simultaneously scanning along the pipe cross section 360° with a laser scanning device to generate a scanning data sequence, detecting the bending based on the scanning data sequence, predicting and correcting the bending deviation of the first side bending arm, generating real-time correction parameters, after the first bending is completed, verifying according to the opposite side mutual influence information, and if the verification is passed, predicting and correcting the bending deviation of the second side bending arm according to the second bending parameter. The present application solves the technical problem of difficulty in effectively controlling the roundness deviation in the existing roundness deviation control for bending of U-shaped tube of heat exchanger, resulting in unstable bending quality, and achieves the technical effect of effectively controlling the roundness deviation and improving the bending precision and product quality.

[0005] The application provides a roundness deviation control method for U-shaped tube bending of a heat exchanger, comprising the following steps: determining a pipe material blank of a U-shaped tube of the heat exchanger and a control center of a bending target input bending machine, analyzing, determining first bending parameters and second bending parameters, and mutual influence information of opposite sides; controlling the bending machine to perform first side bending arm bending control on the U-shaped tube by using the first bending parameters, and starting a laser scanning device to perform 360° scanning along a pipe section to generate a continuous scanning data sequence; performing roundness detection of each section based on the continuous scanning data sequence, performing roundness deviation prediction and correction of the first side bending arm by using a continuous roundness detection result, and generating first real-time correction parameters; continuing to perform bending control by using the first real-time correction parameters, performing opposite side influence checking of a second side bending arm by using the mutual influence information of opposite sides after the first control is completed, and performing roundness deviation prediction and correction of the second side bending arm according to the second bending parameters after the checking is passed.

[0006] In a possible implementation, the pipe material blank of the U-shaped tube of the heat exchanger and the control center of the bending target input bending machine are determined, the first bending parameters and the second bending parameters and the mutual influence information of opposite sides are determined, and the following processing is performed: the first bending target of the first side bending arm and the second bending target of the second side bending arm are extracted based on the bending target; the pipe material blank is combined with the first bending target and the second bending target in sequence and input into the control center for analysis to obtain first side initial bending parameters and second side initial bending parameters; the first side initial bending parameters and the second side initial bending parameters are corrected by mutual influence analysis of roundness of opposite sides in combination with the pipe material blank to generate the first bending parameters and the second bending parameters and the mutual influence information of opposite sides.

[0007] In a possible implementation, the first side initial bending parameters and the second side initial bending parameters are corrected by mutual influence analysis of roundness of opposite sides in combination with the pipe material blank, and the following processing is performed: material attribute information is collected based on the pipe material blank; a bending finite element model is constructed based on modeling data collected based on the material attribute information; residual stress and deformation distribution analysis of the pipe material based on the first side initial bending parameters is performed under a first condition by using the bending finite element model to generate first roundness mutual influence information; residual stress and deformation distribution analysis of the pipe material based on the second side initial bending parameters is performed under a second condition by using the bending finite element model to generate second roundness mutual influence information; the first roundness mutual influence information and the second roundness mutual influence information are used to generate the mutual influence information of opposite sides, and mutual influence coupling correction of the first side initial bending parameters and the second side initial bending parameters is performed to generate the first bending parameters and the second bending parameters.

[0008] In a possible implementation, the following processing is performed: the first condition is that the second side bending arm is configured to be in an original state without bending, and the first-time bending process is simulated; and the second condition is that the first side bending arm is configured to be in a bending state, and the second-time bending process is simulated.

[0009] In a possible implementation, based on the continuous scanning data sequence, the curvature detection of each section is performed, the curvature deviation prediction and correction of the first side bending arm are performed based on the continuous curvature detection result, the first real-time correction parameter is generated, and the following processing is performed: the full-section shape sequence is reconstructed based on the continuous scanning data sequence; the roundness change sequence of each section is calculated according to the full-section shape sequence; the roundness deviation prediction of the uncontrolled process is performed by taking the roundness change sequence and the controlled process parameter as training data, to generate a first full-stage roundness change sequence; it is judged whether the first full-stage roundness change sequence satisfies a preset roundness range, and if not, an abnormal deviation sequence is located; the time when the deviation first occurs is judged according to the abnormal deviation sequence, and the selection of the uncontrolled process parameter correction or the local springback correction is performed, to determine the first real-time correction parameter.

[0010] In a possible implementation, the time when the deviation first occurs is judged according to the abnormal deviation sequence, and the selection of the uncontrolled process parameter correction or the local springback correction is performed, to determine the first real-time correction parameter, and the following processing is performed: if the time when the deviation first occurs belongs to the uncontrolled process, the control deviation relationship is analyzed according to the first full-stage roundness change sequence; the abnormal deviation sequence is corrected based on the control deviation relationship, to generate the first real-time correction parameter.

[0011] In a possible implementation, the first real-time correction parameter is determined, and the following processing is further performed: if the time when the deviation first occurs belongs to the controlled process, the deviation in the abnormal deviation sequence that belongs to the uncontrolled process is corrected, and the roundness deviation is detected in real time after the bending of the first side bending arm is completed; the roundness deviation is input into a multi-roller straightening mapping relationship for local correction parameter matching, to generate a multi-roller straightening parameter; and the multi-roller straightening machine is controlled by using the multi-roller straightening parameter to perform local correction on the first side bending arm.

[0012] In a possible implementation, the opposite-side mutual influence information is used to perform opposite-side influence verification of the second side bending arm, and the following processing is performed: before the second side bending arm starts to be bent, the second side bending arm is detected first, to evaluate the actual influence of the bending of the first side bending arm on the second side bending arm; the actual influence is consistently analyzed with corresponding information in the opposite-side mutual influence information, and if the consistency satisfies a preset requirement, the opposite-side influence verification is passed.

[0013] In a possible implementation, the following processing is performed: if the opposite side influence check fails, the second bending parameter is re-optimized with the actual influence.

[0014] The application also provides a roundness deviation control system for U-shaped tube bending of a heat exchanger, comprising: a center analysis module for determining a tube material blank of a U-shaped tube of the heat exchanger and a control center of a bending target input bending machine to perform analysis, determining a first bending parameter and a second bending parameter and opposite side mutual influence information; a first side bending control module for controlling the bending machine to bend the U-shaped tube at a first side bending arm with the first bending parameter, and starting a laser scanning device to scan along a tube section at 360° to generate a continuous scanning data sequence; a first side correction module for performing bending detection of each section based on the continuous scanning data sequence, performing roundness deviation prediction and correction of the first side bending arm with a continuous bending detection result to generate a first real-time correction parameter; a second side bending control and correction module for continuing bending control with the first real-time correction parameter, performing opposite side influence check of a second side bending arm with the opposite side mutual influence information after the first control is completed, and performing roundness deviation prediction and correction of the second side bending arm according to the second bending parameter after the check is passed.

[0015] The roundness deviation control method and system for U-shaped tube bending of a heat exchanger provided in the application first determine a tube material blank of a U-shaped tube of the heat exchanger and a control center of a bending target input bending machine to perform analysis, determine a first bending parameter and a second bending parameter and opposite side mutual influence information, then control the bending machine to bend the U-shaped tube at a first side bending arm with the first bending parameter, and start a laser scanning device to scan along a tube section at 360° to generate a continuous scanning data sequence, then perform bending detection of each section based on the continuous scanning data sequence, perform roundness deviation prediction and correction of the first side bending arm with a continuous bending detection result to generate a first real-time correction parameter, and finally continue bending control with the first real-time correction parameter, perform opposite side influence check of a second side bending arm with the opposite side mutual influence information after the first control is completed, and perform roundness deviation prediction and correction of the second side bending arm according to the second bending parameter after the check is passed. The technical effect of effectively controlling roundness deviation, improving bending precision and product quality is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments of the present application will be briefly introduced below, and the flowcharts are used to illustrate the operations performed by the system according to the embodiments of the present application in the present application. It should be understood that the foregoing or the following operations are not necessarily performed in sequence. On the contrary, various steps can be processed in reverse order or simultaneously according to needs. Meanwhile, other operations can be added to these processes, or one or more steps of operations can be removed from these processes.

[0017] Figure 1 The flowchart of the roundness deviation control method for U-shaped tube bending of a heat exchanger provided by the embodiments of the present application is shown.

[0018] Figure 2 The structural diagram of the roundness deviation control system for U-shaped tube bending of a heat exchanger provided by the embodiments of the present application is shown.

[0019] Legend: center analysis module 10, first side bending control module 20, first side correction module 30, second side bending control and correction module 40. DETAILED DESCRIPTION

[0020] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described.

[0021] In order to make the purposes, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings, and the described embodiments should not be regarded as limiting the present application, all other embodiments obtained by those skilled in the art without making creative labor belong to the scope of protection of the present application.

[0022] In the following description, "some embodiments" are referred to, which describe a subset of all possible embodiments, but it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict, and the term "first\second" referred to only distinguishes similar objects, and does not represent a specific order for the objects. The terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or server including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or modules not clearly listed or inherent to these processes, methods, products or devices. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by those skilled in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application.

[0023] The embodiments of the present application provide a roundness deviation control method for U-shaped tube bending of a heat exchanger, as shown in Figure 1 The method comprises the following steps:

[0024] In step S100, the pipe material blank of the U-shaped tube of the heat exchanger and the bending target are input into the control center of the pipe bending machine for analysis to determine the first bending parameter and the second bending parameter and the mutual influence information of the opposite side.

[0025] Specifically, the specifications (such as diameter, wall thickness, material properties, etc.) of the pipe material blank and the bending target (such as bending radius, bending angle, etc.) are input into the control center of the pipe bending machine using a data input interface (such as a USB interface, a network interface, etc.). For example, the pipe diameter is 25mm, the wall thickness is 2mm, the material is stainless steel, the bending radius is 100mm, and the bending angle is 180°. The control center analyzes the input pipe material blank and bending target through a built-in calculation model (such as a finite element analysis model). For example, the calculation model determines the first bending parameter (such as bending speed, bending force, bending angle, etc.) and the second bending parameter according to the material properties of the pipe and the bending requirements. At the same time, the mutual influence information of the opposite side is analyzed, which refers to the influence information on the roundness of the other side when bending one side of the pipe arm. For example, due to the elastic deformation of the material, the roundness of the other side may change when one side is bent. For example, through simulation calculation, it is determined that the influence coefficient of the roundness of the other side when one side is bent is 0.05 (which means that for every 1° of bending, the roundness deviation of the other side increases by 0.05mm).

[0026] In one possible implementation, the determination of the pipe material blank of the heat exchanger U-shaped tube and the bending target input to the control center of the pipe bending machine is analyzed to determine the first bending parameter and the second bending parameter and the mutual influence information between the opposite sides, and step S100 further includes step S110 of extracting a first bending target of the first side bending arm and a second bending target of the second side bending arm based on the bending target. Specifically, the control center extracts the specific bending targets of the first side and the second side bending arm according to the input bending target (such as the bending radius, the bending angle, etc.) through the built-in geometric model. For example, the bending target is a U-shaped tube, and the total bending angle is 180°, and the control center divides the total bending angle into two parts, the first side bending target is 90°, and the second side bending target is 90°.

[0027] Step S120, the pipe material blank is combined with the first bending target and the second bending target in sequence and input to the control center for analysis to obtain the first side initial bending parameter and the second side initial bending parameter. Specifically, the control center combines the specifications (such as the diameter, the wall thickness, the material properties, etc.) of the pipe material blank with the first side bending target and the second side bending target respectively, and analyzes through the built-in calculation model (such as the finite element analysis model). For example, the pipe diameter is 25 mm, the wall thickness is 2 mm, the material is stainless steel, the first side bending target is 90°, and the second side bending target is 90°. The control center obtains the first side initial bending parameter (such as the bending speed 5 mm / s, the bending force 100 N) and the second side initial bending parameter (such as the bending speed 5.5 mm / s, the bending force 105 N) through the calculation model.

[0028] Step S130, in combination with the pipe material blank, the first side initial bending parameter and the second side initial bending parameter are analyzed and corrected for the mutual influence of the roundness between the opposite sides to generate the first bending parameter and the second bending parameter and the mutual influence information between the opposite sides. Specifically, the control center analyzes the mutual influence of the roundness between the opposite sides for the first side and the second side initial bending parameter in combination with the material properties of the pipe material blank. For example, through simulation calculation, it is predicted that the influence coefficient of one side bending on the roundness of the other side is 0.05 (indicating that for every 1° of bending, the roundness deviation of the other side increases by 0.05 mm). According to the analysis result of the mutual influence of the roundness between the opposite sides, the initial bending parameter is corrected to generate the final first bending parameter and the second bending parameter. For example, the first side initial bending parameter is adjusted to be the bending speed 5.2 mm / s and the bending force 102 N; the second side initial bending parameter is adjusted to be the bending speed 5.7 mm / s and the bending force 107 N. At the same time, the mutual influence information between the opposite sides is generated for the subsequent verification of the mutual influence between the opposite sides. This implementation can more accurately control the bending process and reduce the bending deviation by extracting the bending target and analyzing the initial bending parameter in steps and correcting in combination with the mutual influence analysis of the roundness between the opposite sides.

[0029] In a possible implementation, in combination with the pipe blank, the first side initial bending parameter and the second side initial bending parameter are subjected to opposite roundness mutual influence analysis correction, and step S130 further includes step S131 of collecting material attribute information based on the pipe blank. Specifically, the material testing equipment (such as a tensile testing machine, a hardness tester, etc.) is used to test the pipe blank, and the elastic modulus, yield strength, Poisson's ratio and other attribute information of the material are collected. For example, the stainless steel pipe is tested, and the elastic modulus is 200 GPa, the yield strength is 250 MPa, and the Poisson's ratio is 0.3.

[0030] Step S132, based on the material attribute information, collecting modeling data to construct a bending finite element model. Specifically, the finite element analysis software (such as ANSYS, ABAQUS, etc.) is used to construct a bending finite element model according to the collected material attribute information and the geometric size of the pipe. For example, according to the pipe diameter of 25 mm, the wall thickness of 2 mm, and the material attribute (elastic modulus of 200 GPa, yield strength of 250 MPa, and Poisson's ratio of 0.3), a bending finite element model is constructed.

[0031] Step S133, performing residual stress and deformation distribution analysis of the pipe based on the first side initial bending parameter under the first condition by using the bending finite element model, to generate first roundness mutual influence information; and step S134, performing residual stress and deformation distribution analysis of the pipe based on the second side initial bending parameter under the second condition by using the bending finite element model, to generate second roundness mutual influence information. The first condition is to configure the second side bending arm to be in an original state without bending, to simulate the first bending process; and the second condition is to configure the first side bending arm to be in a bending state, to simulate the second bending process.

[0032] Specifically, the first condition is defined as configuring the second side bending arm to be in an original state without bending, to simulate the first bending process. The first side initial bending parameter (such as a bending speed of 5 mm / s and a bending force of 100 N) is set in the bending finite element model, and simulation analysis is performed. The simulation result shows the residual stress distribution and deformation distribution of the pipe after the first side bending, especially the influence on the second side roundness. For example, the simulation result shows that the opposite roundness deviation is 0.2 mm after the first side bending, and the first roundness mutual influence information is generated.

[0033] The second condition is defined as configuring the first side bending arm to a bending state, simulating the second bending process. The second side initial bending parameters (such as bending speed 5.5 mm / s, bending force 105 N) are set in the bending finite element model for simulation analysis. The simulation results show the residual stress distribution and deformation distribution of the pipe after the second side bending, especially the influence on the first side roundness. For example, the simulation results show that after the second side bending, the side roundness deviation is 0.3 mm, and the second roundness mutual influence information is generated.

[0034] In step S135, the first roundness mutual influence information and the second roundness mutual influence information are used to generate the side mutual influence information, and mutual influence coupling correction of the first side initial bending parameters and the second side initial bending parameters is performed to generate the first bending parameters and the second bending parameters. Specifically, the goal of mutual influence coupling correction is to adjust the initial bending parameters of the first side and the second side according to the first roundness mutual influence information and the second roundness mutual influence information, to reduce the side roundness deviation and ensure that the roundness after bending on both sides meets the design requirements. According to the first roundness mutual influence information and the second roundness mutual influence information, the side mutual influence information is generated. For example, the side mutual influence information shows that the influence coefficient of the first side bending on the second side roundness is 0.05, and the influence coefficient of the second side bending on the first side roundness is 0.06. The first side initial bending parameters and the second side initial bending parameters are coupled and corrected to generate the final first bending parameters and the second bending parameters. For example, for the correction of the first side bending parameters: the corrected first bending parameters = the first side initial bending parameters - the second side roundness deviation x the influence coefficient of the second side on the first side. For the correction of the second side bending parameters: the corrected second bending parameters = the second side initial bending parameters - the first side roundness deviation x the influence coefficient of the first side on the second side. This implementation can more accurately predict the residual stress and deformation distribution through simulation analysis of the finite element model, so as to more accurately correct the bending parameters.

[0035] In step S200, the first bending parameters are used to control the bending of the first side bending arm of the pipe bending machine, and the laser scanning device is started to scan along the pipe cross section at 360° to generate a continuous scanning data sequence.

[0036] Specifically, the control center controls the bending arm of the bending machine to perform the bending operation on the first side according to the first bending parameters through the motor driving system. For example, the control motor bends at a set speed (e.g., 5 mm / s) and force (e.g., 100 N) until a set bending angle (e.g., 90°) is reached. The laser scanning device is started, and the device scans 360° along the pipe cross section. For example, the laser scanning device scans the pipe cross section at a frequency of 100 times per second to generate a continuous scanning data sequence. The scanning data includes coordinate information of each point of the pipe cross section for bend detection. For example, the scanning data sequence contains multiple data points, such as point 1 coordinates (0, 0), point 2 coordinates (10, 0), point 3 coordinates (10, 10), point 4 coordinates (0, 10), and so on.

[0037] At step S300, the bend of each cross section is detected based on the continuous scanning data sequence, and the bend deviation of the bending arm on the first side is predicted and corrected with the continuous bend detection result to generate the first real-time correction parameters.

[0038] Specifically, the control center receives the continuous scanning data sequence generated by the laser scanning device and detects the bend of each cross section through the built-in bend detection algorithm. For example, the detection algorithm calculates the ellipticity of the pipe cross section (i.e., the difference between the maximum diameter and the minimum diameter) according to the scanning data. For example, the detection result shows that the ellipticity of a certain cross section is 0.5 mm. The control center predicts the bend deviation according to the bend detection result in combination with the pre-set deviation threshold (e.g., the ellipticity threshold is 0.3 mm). For example, if the detected ellipticity exceeds the threshold, it is predicted that there is a bend deviation. The control center corrects by adjusting the bending parameters (e.g., adjusting the bending force or the bending speed) according to the prediction result to generate the first real-time correction parameters for subsequent bending control. For example, if the ellipticity exceeds the threshold, the control center increases the bending force by 5 N to reduce the ellipticity.

[0039] In one possible implementation, the bend of each cross section is detected based on the continuous scanning data sequence, and the bend deviation of the bending arm on the first side is predicted and corrected with the continuous bend detection result to generate the first real-time correction parameters, and step S300 further includes step S310 of reconstructing a full-section shape sequence based on the continuous scanning data sequence. Specifically, the continuous scanning data sequence generated by the laser scanning device is used to reconstruct the full-section shape sequence through a data processing algorithm (e.g., an interpolation algorithm). For example, the scanning data sequence contains coordinate points of multiple cross sections, and the complete shape of each cross section is reconstructed through the interpolation algorithm.

[0040] Step S320, calculate the roundness variation sequence of each section according to the full-section shape sequence. Specifically, for the reconstructed full-section shape sequence, calculate the roundness variation of each section. The roundness variation can be represented by calculating the difference between the maximum diameter and the minimum diameter of the section. For example, calculate the ellipticity (the difference between the maximum diameter and the minimum diameter) of each section.

[0041] Step S330, perform roundness deviation prediction of the uncontrolled process using the roundness variation sequence and the controlled process parameters as training data, and generate a first full-stage roundness variation sequence. Specifically, use the roundness variation sequence and the controlled process parameters as training data to train a machine learning model (such as a linear regression model or a neural network). For example, the training data includes the roundness variation of each section and the corresponding bending parameters (such as bending speed, bending force). Use the trained model to predict the roundness deviation of the uncontrolled process and generate a first full-stage roundness variation sequence.

[0042] Step S340, determine whether the first full-stage roundness variation sequence meets the preset roundness range, and if not, locate the abnormal deviation sequence. Specifically, according to the preset roundness range (such as the roundness deviation being less than 0.1mm), determine whether the first full-stage roundness variation sequence meets the requirements. For example, the preset roundness range is 0.1mm, if the roundness deviation of a certain section exceeds 0.1mm, then locate the section as an abnormal deviation sequence.

[0043] Step S350, determine the time when the deviation first occurs according to the abnormal deviation sequence, select uncontrolled process parameter correction or local springback correction, and determine the first real-time correction parameter. Specifically, analyze the abnormal deviation sequence to determine the time when the deviation first occurs. For example, by analyzing the roundness variation sequence, it is determined that the deviation first occurs at the 10th section. According to the time when the deviation first occurs, select uncontrolled process parameter correction or local springback correction. According to the selected correction method, determine the first real-time correction parameter. For example, select uncontrolled process parameter correction, adjust the bending speed to 5.2mm / s and the bending force to 102N. This implementation can more accurately control the bending process and reduce the roundness deviation through real-time monitoring and correction.

[0044] In a possible implementation, the first real-time correction parameter is determined according to the abnormal deviation sequence and the moment when the deviation first occurs, and step S350 further includes step S351: if the moment when the deviation first occurs belongs to the uncontrolled process, the control deviation relationship is analyzed according to the first full-stage roundness change sequence. Specifically, the abnormal deviation sequence is analyzed to determine the specific moment when the deviation first occurs. If the deviation first occurs in the uncontrolled process stage, the relationship between the control parameter (such as bending speed and bending force) and the roundness deviation in the uncontrolled process is analyzed according to the first full-stage roundness change sequence. For example, by analyzing the roundness change sequence, it is determined that the deviation first occurs at the 10th cross section, and the moment belongs to the uncontrolled process stage. By regression analysis or machine learning model, the relationship between the bending speed and the roundness deviation is found out.

[0045] Step S352: the deviation of the abnormal deviation sequence is corrected according to the control deviation relationship to generate the first real-time correction parameter. Specifically, the abnormal deviation sequence is corrected according to the control deviation relationship. Specifically, the control parameter in the uncontrolled process is adjusted to reduce the roundness deviation. For example, according to the control deviation relationship, the bending speed and the bending force that need to be adjusted are calculated. According to the above adjustment, the first real-time correction parameter is generated for subsequent bending control. This implementation can more accurately control the bending process and reduce the roundness deviation through real-time monitoring and correction.

[0046] In a possible implementation, the first real-time correction parameter is determined, and step S350 further includes step S353: if the moment when the deviation first occurs belongs to the controlled process, the deviation in the uncontrolled process in the abnormal deviation sequence is corrected, and the roundness deviation is detected in real time after the first side bending arm bending is completed. Specifically, the abnormal deviation sequence is analyzed to determine the specific moment when the deviation first occurs. If the deviation first occurs in the controlled process stage, the deviation in the uncontrolled process in the abnormal deviation sequence is corrected. Specifically, similar analysis methods as steps S351-352 are used to analyze the deviation data in the uncontrolled process and the control deviation relationship, and to correct the deviation. For example, by analyzing the roundness change sequence, it is determined that the deviation first occurs at the 10th cross section, and the moment belongs to the controlled process stage. The deviation data belonging to the uncontrolled process after the 10th cross section is analyzed and corrected. After the first side bending arm bending is completed, the roundness deviation is detected in real time by using a laser scanning device.

[0047] Step S354, input the roundness deviation into the multi-roll straightening mapping relationship for local correction parameter matching to generate multi-roll straightening parameters. Specifically, using the pre-established multi-roll straightening mapping relationship, input the roundness deviation into the mapping relationship for local correction parameter matching. For example, the multi-roll straightening mapping relationship is a function based on experimental data and simulation results, describing the relationship between roundness deviation and straightening parameters. According to the real-time detected roundness deviation, the corresponding multi-roll straightening parameters are calculated through the mapping relationship. The multi-roll straightening parameters include the adjustment parameters of each straightening roll.

[0048] Step S355, control the multi-roll straightening machine to perform local correction on the first side bending arm using the multi-roll straightening parameters. Specifically, use the calculated multi-roll straightening parameters to control the multi-roll straightening machine to perform local correction on the first side bending arm. For example, adjust the position and pressure of each straightening roll according to the multi-roll straightening parameters to perform local correction on the first side bending arm. This implementation can more accurately control the bending process and reduce the roundness deviation through real-time monitoring and correction.

[0049] Step S400, continue bending control using the first real-time correction parameters, perform opposite side influence verification of the second side bending arm after the first control is completed, and then perform roundness deviation prediction and correction of the second side bending arm according to the second bending parameters.

[0050] Specifically, the control center continues to bend the first side bending arm using the first real-time correction parameters until the first bending is completed. After the first side bending is completed, the opposite side influence verification of the second side bending arm is performed according to the opposite side mutual influence information. The opposite side influence verification refers to verifying whether the roundness deviation of the other side is consistent with the prediction after one side bending is completed to ensure the accuracy of the bending process. For example, the control center predicts the roundness deviation of the second side bending arm according to the opposite side mutual influence information and compares it with the actual scanning data. If the actual deviation is consistent with the predicted deviation (e.g., the error is within the allowed range), the verification is passed. For example, the predicted second side roundness deviation is 0.2 mm, and the actual scanning result is 0.21 mm, the error is within the allowed range (e.g., ±0.05 mm), and the verification is passed. After the verification is passed, the bending of the second side bending arm is performed according to the second bending parameters, and the laser scanning device is simultaneously started to scan 360° along the pipe cross section to generate a continuous scanning data sequence. Based on the continuous scanning data sequence, the roundness detection of each cross section is performed, and the roundness deviation prediction and correction of the second side bending arm are performed based on the continuous roundness detection results, i.e., by detecting the roundness (e.g., ovality) of the pipe cross section to determine whether there is a deviation, and by adjusting the bending parameters (e.g., bending force, bending speed) to correct it, the second real-time correction parameters are generated. The second real-time correction parameters are used for bending control of the second side until the second side bending is completed, ensuring that the bent pipe meets the design requirements.

[0051] In a possible implementation, the step S400 of performing the cross-side influence check of the second bending arm based on the cross-side mutual influence information further includes a step S410 of detecting the second bending arm before the second bending arm starts bending, to evaluate the actual influence of the bending of the first bending arm on the second bending arm. Specifically, the second bending arm is detected using a laser scanning device or a high-precision measuring tool, to obtain the current shape and size data of the second bending arm. For example, the laser scanning device is used to perform a 360° scanning along the tube section of the second bending arm, to generate a continuous scanning data sequence. According to the scanning data, the roundness change of the second bending arm is calculated, to evaluate the actual influence of the bending of the first bending arm on the second bending arm. For example, the ovality (the difference between the maximum diameter and the minimum diameter) of the second bending arm is calculated, to evaluate the roundness deviation thereof.

[0052] The step S420 includes a step of consistent analysis of the actual influence and the corresponding information in the cross-side mutual influence information, and if the consistency meets the preset requirement, the cross-side influence check is passed. Specifically, the actually detected roundness deviation is compared and analyzed with the predicted value in the cross-side mutual influence information. According to the design requirement, an allowed error range (for example, ±0.05 mm) is set. If the consistency of the actual influence and the predicted value meets the preset requirement (i.e., the error is within the allowed range), the cross-side influence check is passed. For example, the preset error range is ±0.05 mm, the actual deviation 0.21 mm and the predicted value 0.2 mm have an error of 0.01 mm, which meets the preset requirement, and the cross-side influence check is passed. This implementation can more accurately evaluate the influence of the first bending on the second side through actual detection and consistent analysis, to ensure the accuracy of the second bending.

[0053] In one possible implementation, step S400 further includes step S430, whereby if the counter-influence verification fails, the second bending parameters are optimized again based on the actual influence. Specifically, if the consistency between the actual influence and the predicted value in the counter-influence information does not meet a preset requirement (i.e., the error exceeds the allowable range), the counter-influence verification fails. For example, if the preset error range is ±0.05mm, the error between the actual deviation of 0.26mm and the predicted value of 0.2mm is 0.06mm, which exceeds the preset range, and the verification fails. Based on the actual influence, the second bending parameters are adjusted to reduce the counter-influence roundness deviation. For example, the adjustment formula is: adjusted bending speed = bending speed in the second bending parameters − Δ roundness × a, adjusted bending force = bending force in the second bending parameters − Δ roundness × b, where Δ roundness represents the difference between the actual roundness deviation and the predicted roundness deviation, and a and b are regression coefficients obtained through experiments or simulations. Based on the above adjustments, optimized second bending parameters are generated for subsequent bending control. This implementation method, through side influence verification and parameter optimization, can effectively reduce the impact of the first side bending on the second side and improve the overall quality of the U-shaped tube.

[0054] This application employs a method where the tube blank and bending target of the heat exchanger U-tube are input into the control center of the tube bending machine to determine the bending parameters for two bending operations and the mutual influence information of the opposite sides. The tube bending machine is controlled to bend the first side bending arm according to the first bending parameters. Simultaneously, a laser scanning device scans the tube cross-section 360° to generate a scanning data sequence. Based on the scanning data sequence, the curvature is detected, the curvature deviation of the first side bending arm is predicted and corrected, and real-time correction parameters are generated. After the first bending is completed, the mutual influence information of the opposite sides is used for verification. After the verification is passed, the curvature deviation of the second side bending arm is predicted and corrected according to the second bending parameters. This method solves the technical problem of the difficulty in effectively controlling the roundness deviation in the existing roundness deviation control for heat exchanger U-tube bending, which leads to unstable bending quality. It achieves the technical effect of effectively controlling the roundness deviation, improving bending accuracy and product quality.

[0055] In the above text, refer to Figure 1 A method for controlling the roundness deviation of U-shaped tubes in heat exchangers according to an embodiment of the present invention is described in detail. Next, reference will be made to... Figure 2 A roundness deviation control system for bending U-tubes in heat exchangers according to an embodiment of the present invention is described.

[0056] The roundness deviation control system for U-tube bending of heat exchangers according to embodiments of the present invention solves the technical problem of existing roundness deviation control methods for U-tube bending of heat exchangers, which are difficult to effectively control roundness deviation, leading to unstable bending quality. The system achieves the technical effect of effectively controlling roundness deviation and improving bending accuracy and product quality. The roundness deviation control system for U-tube bending of heat exchangers includes: a center analysis module 10, a first side bending control module 20, a first side correction module 30, and a second side bending control and correction module 40.

[0057] The central analysis module 10 is used to determine the tube blank and bending target of the heat exchanger U-tube and input them into the control center of the tube bending machine for analysis, determining the first bending parameters, the second bending parameters, and the mutual influence information of the opposite side; the first side bending control module 20 is used to control the tube bending machine to perform the first side bending arm control of the U-tube with the first bending parameters, and start the laser scanning equipment to scan along the tube cross section 360° to generate a continuous scanning data sequence; the first side correction module 30 is used to perform bending detection at each cross section based on the continuous scanning data sequence, and to predict and correct the bending deviation of the first side bending arm with the continuous bending detection results, generating the first real-time correction parameters; the second side bending control and correction module 40 is used to continue bending control with the first real-time correction parameters. After the first control is completed, the mutual influence information of the opposite side is used to perform the mutual influence verification of the second side bending arm. After the verification is passed, the bending deviation of the second side bending arm is predicted and corrected according to the second bending parameters.

[0058] The specific configuration of the central analysis module 10 will be described in detail below. As mentioned above, the tube blank and bending target of the heat exchanger U-tube are determined and input into the control center of the tube bending machine for analysis to determine the first bending parameters, the second bending parameters, and the mutual influence information of the opposite side. The central analysis module 10 may further include: a bending target extraction unit for extracting the first bending target of the first side bending arm and the second bending target of the second side bending arm based on the bending target; an initial bending parameter acquisition unit for combining the tube blank with the first bending target and the second bending target in sequence and inputting them into the control center for analysis to obtain the first side initial bending parameters and the second side initial bending parameters; and a mutual influence analysis and correction unit for the opposite side roundness for performing mutual influence analysis and correction on the first side initial bending parameters and the second side initial bending parameters in combination with the tube blank to generate the first bending parameters, the second bending parameters, and the mutual influence information of the opposite side.

[0059] The opposite roundness mutual influence analysis correction unit can further include: a material attribute information acquisition subunit configured to acquire material attribute information based on the pipe blank; a bending finite element model construction subunit configured to construct a bending finite element model based on the material attribute information acquisition modeling data; a first roundness mutual influence information generation subunit configured to execute residual stress and deformation distribution analysis of the pipe based on the first side initial bending parameter in a first condition with the bending finite element model to generate first roundness mutual influence information; a second roundness mutual influence information generation subunit configured to execute residual stress and deformation distribution analysis of the pipe based on the second side initial bending parameter in a second condition with the bending finite element model to generate second roundness mutual influence information; and a mutual influence coupling correction subunit configured to generate the opposite mutual influence information with the first roundness mutual influence information and the second roundness mutual influence information, and execute mutual influence coupling correction of the first side initial bending parameter and the second side initial bending parameter to generate the first time bending parameter and the second time bending parameter.

[0060] The opposite roundness mutual influence analysis correction unit can further include: the first condition is to configure the second side bending arm to be in an original state without bending, simulating the first bending process; and the second condition is to configure the first side bending arm to be in a bending state, simulating the second bending process.

[0061] In the following, the specific configuration of the first side correction module 30 will be described in detail. As described above, the bending detection of each cross section is performed based on the continuous scanning data sequence, and the bending deviation prediction and correction of the first side bending arm are performed with the continuous bending detection result to generate the first real-time correction parameter. The first side correction module 30 can further include: a full-section cross-sectional shape sequence reconstruction unit configured to reconstruct a full-section cross-sectional shape sequence based on the continuous scanning data sequence; a roundness change sequence calculation unit configured to calculate a roundness change sequence of each cross section according to the full-section cross-sectional shape sequence; a roundness deviation prediction unit configured to execute roundness deviation prediction of an uncontrolled process with the roundness change sequence and the controlled process parameter as training data to generate a first full-stage roundness change sequence; an abnormal deviation sequence positioning unit configured to judge whether the first full-stage roundness change sequence satisfies a preset roundness range, and if not, position an abnormal deviation sequence; and a first real-time correction parameter determination unit configured to determine the first real-time correction parameter according to the time when the abnormal deviation sequence first appears.

[0062] The first real-time correction parameter determination unit can further include: a control deviation relationship analysis subunit configured to, if the time when the deviation first occurs belongs to an uncontrolled process, analyze a control deviation relationship according to the first full-stage roundness variation sequence; and a deviation correction subunit configured to perform deviation correction on the abnormal deviation sequence according to the control deviation relationship, to generate the first real-time correction parameter.

[0063] The first real-time correction parameter determination unit can further include: a roundness deviation detection subunit configured to, if the time when the deviation first occurs belongs to a controlled process, correct the deviation that belongs to the uncontrolled process according to the abnormal deviation sequence, and detect a roundness deviation in real time after the first side bending arm bending is completed; a local correction parameter matching subunit configured to input the roundness deviation into a multi-roll straightening mapping relationship to perform local correction parameter matching, to generate a multi-roll straightening parameter; and a local correction subunit configured to control a multi-roll straightening machine to perform local correction on the first side bending arm according to the multi-roll straightening parameter.

[0064] Next, the specific configuration of the second side bending control and correction module 40 will be described in detail. As described above, the second side bending arm is subjected to opposite side influence checking according to the opposite side mutual influence information, and the second side bending control and correction module 40 can further include: an actual influence evaluation unit configured to, before the second side bending arm starts bending, first detect the second side bending arm to evaluate the actual influence of the bending of the first side bending arm on the second side bending arm; and a consistency analysis unit configured to perform consistency analysis on the actual influence and corresponding information in the opposite side mutual influence information, and if the consistency meets a preset requirement, the opposite side influence checking is passed.

[0065] The second side bending control and correction module 40 can further include: a re-optimization unit configured to, if the opposite side influence checking is not passed, re-optimize the second bending parameter according to the actual influence.

[0066] The roundness deviation control system for U-shaped tube bending of a heat exchanger provided in the embodiments of the present application can perform the roundness deviation control method for U-shaped tube bending of a heat exchanger provided in any of the embodiments of the present application, and has the corresponding function modules and beneficial effects of the execution method.

[0067] Although the present application makes various references to certain modules in the system according to the embodiments of the present application, however, any number of different modules can be used and run on the user terminal and / or server, the various units and modules are only divided according to the functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific name of each functional unit is only for the convenience of mutual differentiation, and does not serve to limit the protection scope of the present application.

[0068] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. In some cases, the actions or steps described in the present application can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are possible or can be advantageous.

Claims

1. A method for controlling the roundness deviation in the bending of U-shaped tubes for heat exchangers, characterized in that, include: The tube blank and bending target of the heat exchanger U-tube are determined and input into the control center of the tube bending machine for analysis to determine the first bending parameters, the second bending parameters, and the mutual influence information on the opposite side. The bending machine is controlled to perform the first side bending arm bending control on the U-shaped tube using the first bending parameters, and the laser scanning equipment is started to scan along the tube cross-section 360° to generate a continuous scanning data sequence; Based on the continuous scanning data sequence, the curvature detection of each section is performed, and the curvature deviation of the first side bending arm is predicted and corrected based on the continuous curvature detection results, generating the first real-time correction parameter. The bending control continues with the first real-time correction parameter. After the first control is completed, the opposite side influence verification of the second side bending arm is performed with the opposite side mutual influence information. After the verification is passed, the bending deviation of the second side bending arm is predicted and corrected according to the second bending parameter. The tube blank and bending target of the heat exchanger U-tube are input into the control center of the tube bending machine for analysis to determine the first bending parameters, the second bending parameters, and the mutual influence information on both sides, including: Based on the bending target, extract the first bending target of the first side bending arm and the second bending target of the second side bending arm; The tube blank is sequentially combined with the first bending target and the second bending target and input into the control center for analysis to obtain the initial bending parameters of the first side and the initial bending parameters of the second side. Based on the pipe blank, the initial bending parameters of the first side and the initial bending parameters of the second side are analyzed and corrected for mutual influence of roundness on opposite sides, thereby generating the first bending parameters, the second bending parameters, and the mutual influence information on opposite sides; The step of performing the contralateral influence verification of the second side bending arm using the contralateral mutual influence information includes: Before the bending of the second side bending arm begins, the second side bending arm is inspected to assess the actual impact of the bending of the first side bending arm on the second side bending arm. The actual impact is analyzed to ensure consistency with the corresponding information in the mutual impact information on the opposite side. If the consistency meets the preset requirements, the impact verification on the opposite side is passed.

2. The method for controlling the roundness deviation of U-shaped tubes in heat exchangers as described in claim 1, characterized in that, Based on the aforementioned pipe blank, a mutual influence analysis and correction of the roundness of the first side's initial bending parameters and the second side's initial bending parameters is performed, including: Material property information is collected based on the pipe blank; A bending finite element model is constructed based on the material property information collected and modeled. The residual stress and deformation distribution of the pipe based on the initial bending parameters of the first side are analyzed using the bending finite element model under the first condition to generate the first roundness interaction information. Using the bending finite element model, an analysis of the residual stress and deformation distribution of the pipe based on the initial bending parameters of the second side is performed under the second condition to generate second roundness interaction information; The first roundness mutual influence information and the second roundness mutual influence information are used to generate the opposite side mutual influence information, and the mutual influence coupling correction of the first side initial bending parameters and the second side initial bending parameters is performed to generate the first bending parameters and the second bending parameters. The first condition is to configure the second side bending arm in its unbent original state to simulate the first bending process; the second condition is to configure the first side bending arm in a bent state to simulate the second bending process.

3. The method for controlling the roundness deviation of U-shaped tubes in heat exchangers as described in claim 1, characterized in that, Based on the continuous scan data sequence, bend detection is performed at each cross-section. The bend deviation of the first side bending arm is predicted and corrected using the continuous bend detection results, and first real-time correction parameters are generated, including: Reconstruct the full cross-sectional shape sequence based on the continuous scan data sequence; Calculate the roundness variation sequence of each section based on the overall cross-sectional shape sequence; Using the roundness change sequence and the controlled process parameters as training data, roundness deviation prediction of the uncontrolled process is performed to generate the first full-stage roundness change sequence. Determine whether the first full-stage roundness change sequence meets the preset roundness range; if not, locate the abnormal deviation sequence. Based on the abnormal deviation sequence, determine the moment when the deviation first occurs, select between uncontrolled process parameter correction or local rebound correction, and determine the first real-time correction parameter.

4. The method for controlling the roundness deviation of U-shaped tubes in heat exchangers as described in claim 3, characterized in that, Based on the abnormal deviation sequence, determine the time of the first occurrence of the deviation, select between uncontrolled process parameter correction and local rebound correction, and determine the first real-time correction parameter, including: If the first occurrence of the deviation occurs during an uncontrolled process, the relationship between the control deviation and the first full-stage roundness change sequence is analyzed. The abnormal deviation sequence is corrected using the control deviation relationship to generate the first real-time correction parameter.

5. The method for controlling the roundness deviation of U-shaped tubes in heat exchangers as described in claim 4, characterized in that, Determining the first real-time correction parameter further includes: If the first occurrence of the deviation is within a controlled process, correction is performed based on the deviations in the abnormal deviation sequence that belong to the uncontrolled process. After the first side bending arm is completed, the roundness deviation is detected in real time. The roundness deviation is input into the multi-roller straightening mapping relationship for local correction parameter matching to generate multi-roller straightening parameters; The multi-roller straightening machine is controlled by the multi-roller straightening parameters to perform local correction on the first side-bent arm.

6. The method for controlling the roundness deviation of U-shaped tubes in heat exchangers as described in claim 1, characterized in that, If the side effect verification fails, the second bending parameters will be optimized again based on the actual effect.

7. A roundness deviation control system for U-tube bending in heat exchangers, characterized in that, The system is used to implement the roundness deviation control method for U-tube bending of heat exchangers as described in any one of claims 1-3, and the system comprises: The central analysis module is used to determine the tube blank and bending target of the heat exchanger U-tube and input them into the control center of the tube bending machine for analysis, to determine the first bending parameters, the second bending parameters, and the mutual influence information on the opposite side; The first side bending control module is used to control the pipe bending machine to perform first side bending arm control on the U-shaped pipe according to the first bending parameters, and to start the laser scanning device to scan along the pipe cross section 360° to generate a continuous scanning data sequence. The first side correction module is used to perform curvature detection at each section based on the continuous scan data sequence, predict and correct the curvature deviation of the first side bending arm based on the continuous curvature detection results, and generate the first real-time correction parameters. The second side bending control and correction module is used to continue bending control with the first real-time correction parameters. After the first control is completed, the opposite side influence verification of the second side bending arm is performed with the opposite side mutual influence information. After the verification is passed, the bending deviation of the second side bending arm is predicted and corrected according to the second bending parameters.

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