Roundness deviation control method and system for bending U-shaped pipe of heat exchanger

Abstract

The invention discloses a roundness deviation control method and system for bending a U-shaped pipe of a heat exchanger, and relates to the related field of size and shape measurement, and the method comprises the steps: determining a pipe blank of the U-shaped pipe and a bending target, and inputting the pipe blank and the bending target into a control center for analysis; controlling a pipe bending machine to perform bending control on a first side bending arm of the U-shaped pipe according to the first bending parameter, and starting laser scanning equipment to perform 360-degree scanning along the section of the pipe; performing camber detection on each section based on the continuous scanning data sequence, performing camber deviation prediction and correction, and generating a first real-time correction parameter; and the bending control is continued, after the first control is completed, the opposite-side influence verification of the second-side bending arm is executed according to the opposite-side mutual influence information, and after the opposite-side influence verification passes, the bending deviation prediction and correction of the second-side bending arm are carried out according to the second-time bending parameters. The technical problem that in existing roundness deviation control, the roundness deviation is difficult to effectively control, and consequently the bending quality is unstable is solved, and the technical effects that the roundness deviation is effectively controlled, and the bending quality is improved are achieved.

Description

Technical Field

[0001] The present application relates to the field of size and shape measurement, and in particular to a method and system for controlling roundness deviation of U-shaped tubes used in heat exchanger bending. Background Art

[0002] In the field of heat exchanger manufacturing, controlling the roundness deviation of U-shaped tubes is crucial to ensuring 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 controlling the roundness deviation of U-shaped tubes is to bend them according to preset parameters during the bending process and perform quality assessment after the bending is completed through simple detection methods. The current method lacks a real-time and accurate roundness deviation detection and correction mechanism during the bending process, and does not fully consider the mutual influence between the bending arms on both sides during the bending process. As a result, it is difficult to effectively control the roundness deviation, the bending quality is unstable, and the product qualification rate is low.

[0003] In the current related technologies, there is a technical problem in that it is difficult to effectively control the roundness deviation of the U-shaped tube used for bending heat exchangers, resulting in unstable bending quality. Summary of the Invention

[0004] The present application provides a roundness deviation control method and system for bending U-shaped tubes of heat exchangers. The method adopts the method of inputting the tube blank and bending target of the heat exchanger U-shaped tube into the tube bending machine control center, determining the bending parameters of two times and the mutual influence information of the opposite sides, controlling the tube bending machine to bend the first side bending arm according to the first bending parameters, and simultaneously using a laser scanning device to scan 360° along the tube cross section to generate a scanning data sequence. The curvature is detected based on the scanning data sequence, 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 curvature deviation is predicted and corrected according to the mutual influence information of the opposite side. After the verification is passed, the curvature deviation of the second side bending arm is predicted and corrected according to the second bending parameters. The present application solves the technical problem of the difficulty in effectively controlling the roundness deviation of the existing roundness deviation control for bending U-shaped tubes of heat exchangers, which leads to unstable bending quality, and achieves the technical effect of effectively controlling the roundness deviation and improving the bending accuracy and product quality.

[0005] The present application provides a roundness deviation control method for bending a U-shaped tube of a heat exchanger, comprising: determining a tube blank and a bending target of the U-shaped tube of the heat exchanger, inputting the tube blank and the bending target into a control center of a tube bending machine for analysis, and determining a first bending parameter, a second bending parameter, and opposite-side mutual influence information; controlling the tube bending machine to perform first-side bending arm bending control on the U-shaped tube with the first bending parameter, and starting a laser scanning device to scan 360° along the tube cross section to generate a continuous scanning data sequence; performing curvature detection of each cross section based on the continuous scanning data sequence, predicting and correcting the curvature deviation of the first-side bending arm with the continuous curvature detection result, and generating a first real-time correction parameter; continuing bending control with the first real-time correction parameter, and after the first control is completed, performing opposite-side influence verification of the second-side bending arm with the opposite-side mutual influence information, and after the verification passes, predicting and correcting the curvature deviation of the second-side bending arm according to the second bending parameter.

[0006] In a possible implementation, 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, the first bending parameters, the second bending parameters and the opposite side mutual influence information are determined, and the following processing is performed: based on the bending target, the first bending target of the first side bending arm and the second bending target of the second side bending arm are extracted; the tube blank is combined with the first bending target and the second bending target in turn and input into the control center for analysis to obtain the first side initial bending parameters and the second side initial bending parameters; in combination with the tube blank, the opposite side roundness mutual influence analysis and correction are performed on the first side initial bending parameters and the second side initial bending parameters to generate the first bending parameters, the second bending parameters and the opposite side mutual influence information.

[0007] In a possible implementation, in combination with the tube blank, the first-side initial bending parameters and the second-side initial bending parameters are subjected to opposite-side roundness mutual influence analysis correction, and the following processing is performed: material property information is collected based on the tube blank; modeling data is collected based on the material property information to construct a bending finite element model; residual stress and deformation distribution analysis of the tube based on the first-side initial bending parameters is performed under a first condition using the bending finite element model to generate first roundness mutual influence information; residual stress and deformation distribution analysis of the tube based on the second-side initial bending parameters is performed under a second condition using the bending finite element model to generate second roundness mutual influence information; opposite-side mutual influence information is generated using the first roundness mutual influence information and the second roundness 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.

[0008] In a possible implementation, the following processing is performed: the first condition is to configure the second side bending arm to an unbent original state, simulating the first bending process; the second condition is to configure the first side bending arm to a bent state, simulating the second bending process.

[0009] In a possible implementation, curvature detection of each section is performed based on the continuous scanning data sequence, and the curvature deviation of the first side bending arm is predicted and corrected based on the continuous curvature detection result to generate a first real-time correction parameter, and the following processing is performed: a full-segment cross-sectional shape sequence is reconstructed based on the continuous scanning data sequence; a roundness change sequence of each section is calculated based on the full-segment cross-sectional shape sequence; the roundness change sequence and the controlled process parameters are used as training data to perform roundness deviation prediction of the uncontrolled process to generate a first full-stage roundness change sequence; the first full-stage roundness change sequence is judged to determine whether it meets the preset roundness range, and if not, the abnormal deviation sequence is located; the moment when the deviation first occurs is determined based on the abnormal deviation sequence, and the uncontrolled process parameter correction or the local rebound correction is selected to determine the first real-time correction parameter.

[0010] In a possible implementation, the moment when the deviation first occurs is determined based on the abnormal deviation sequence, and the uncontrolled process parameter correction or local rebound correction is selected to determine the first real-time correction parameter, and the following processing is performed: if the moment when the deviation first occurs belongs to the uncontrolled process, the control deviation relationship is analyzed based on the first full-stage roundness change sequence; the abnormal deviation sequence is corrected with 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 also performed: if the moment when the deviation first occurs belongs to a controlled process, correction is performed according to the deviation belonging to an uncontrolled process in the abnormal deviation sequence, and after the first side bending arm is bent, 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 with the multi-roller straightening parameters to perform local correction on the first side bending arm.

[0012] In a possible implementation, the contralateral influence check of the second-side bending arm is performed using the contralateral mutual influence information, and the following processing is performed: before the second-side bending arm starts to bend, the second-side bending arm is first detected to evaluate the actual influence of the bending of the first-side bending arm on the second-side bending arm; the actual influence is analyzed for consistency with the corresponding information in the contralateral mutual influence information. If the consistency meets the preset requirements, the contralateral influence check passes.

[0013] In a possible implementation, the following processing is performed: if the contralateral impact check fails, the second bending parameters are optimized again based on the actual impact.

[0014] The present application also provides a roundness deviation control system for bending U-shaped tubes of heat exchangers, comprising: a center analysis module, configured to determine the tube blank and bending target of the heat exchanger U-shaped tube, input them into the control center of the tube bender for analysis, and determine the first bending parameters, the second bending parameters, and the opposite-side mutual influence information; a first-side bending control module, configured to control the tube bender to bend the U-shaped tube with the first bending parameters, and start a laser scanning device to scan 360° along the tube cross section to generate a continuous scanning data sequence; a first-side correction module, configured to perform curvature detection of each cross section based on the continuous scanning data sequence, predict and correct the curvature deviation of the first-side bending arm with the continuous curvature detection results, and generate a first real-time correction parameter; a second-side bending control and correction module, configured to continue bending control with the first real-time correction parameter, and after the first control is completed, perform opposite-side influence verification of the second-side bending arm with the opposite-side mutual influence information, and after the verification passes, predict and correct the curvature deviation of the second-side bending arm with the second bending parameters.

[0015] The proposed roundness deviation control method and system for bending U-shaped tubes for heat exchangers first determines the tube material and bending target for the heat exchanger U-shaped tube and inputs them into the control center of the tube bender for analysis. First, first and second bending parameters, as well as opposite-side interaction information, are determined. The tube bender then uses the first bending parameters to control the first bending arm of the U-shaped tube. A laser scanning device is activated to scan 360° along the tube cross section, generating a continuous scan data sequence. Curvature detection is then performed at each cross-section based on the continuous scan data sequence. The curvature deviation of the first bending arm is predicted and corrected using the continuous curvature detection results, generating a first real-time correction parameter. Finally, bending control continues using the first real-time correction parameter. After the first control is completed, the opposite-side interaction information is used to perform opposite-side effect verification on the second bending arm. Once verification passes, the curvature deviation of the second bending arm is predicted and corrected based on the second bending parameters. This method effectively controls roundness deviation, improving bending accuracy and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention are briefly introduced below. Flowcharts are used in this application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in precise order. Instead, various steps may be processed in reverse order or simultaneously as needed. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0017] Figure 1 A schematic flow chart of a method for controlling roundness deviation in bending U-shaped tubes of a heat exchanger provided in an embodiment of the present application.

[0018] Figure 2 A schematic structural diagram of a roundness deviation control system for bending U-shaped tubes in a heat exchanger provided in an embodiment of the present application.

[0019] Description of reference numerals: 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 an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below.

[0021] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0022] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict, and the terms “first\second” involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. The terms “including” and “having” and any variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or modules that are not clearly listed or that are inherent to these processes, methods, products or devices. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein are for the purpose of describing the embodiments of this application only.

[0023] The embodiment of the present application provides a method for controlling roundness deviation of a U-shaped tube bending of a heat exchanger, such as Figure 1 As shown, the method includes: Step S100: Determine the tube material and bending target of the heat exchanger U-tube and input them into the control center of the tube bender for analysis to determine the first bending parameters, the second bending parameters and the mutual influence information of the opposite side.

[0024] Specifically, the tube blank specifications (such as diameter, wall thickness, and material properties) and bending targets (such as bend radius and bend angle) are input into the tube bender's control center using a data input interface (such as a USB port or network interface). For example, a tube with a diameter of 25 mm, a wall thickness of 2 mm, stainless steel material, a bend radius of 100 mm, and a bend angle of 180° is input. The control center analyzes the input tube blank and bending targets using a built-in computational model (such as a finite element analysis model). For example, the computational model determines the first bending parameters (such as bending speed, bending force, and bending angle) and the second bending parameters based on the tube's material properties and bending requirements. The control center also analyzes the opposite-side interaction information, which refers to the impact of bending one tube arm on the roundness of the other tube arm. For example, when bending one tube arm, the elastic deformation of the material may cause the roundness of the other tube arm to change. For example, through simulation calculations, it was determined that the influence coefficient of 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 0.05mm).

[0025] In one possible implementation, the tube stock and bending target for a heat exchanger U-shaped tube are input into the tube bender's control center for analysis. First and second bending parameters, as well as information on the interaction between the opposite sides, are determined. Step S100 further includes step S110, where a first bending target for the first bending arm and a second bending target for the second bending arm are extracted based on the bending targets. Specifically, the control center uses a built-in geometric model to extract specific bending targets for the first and second bending arms based on the input bending targets (such as bend radius and bend angle). For example, if the bending target is a U-shaped tube with a total bend angle of 180°, the control center divides the total bend angle into two parts: a first bending target of 90° and a second bending target of 90°.

[0026] In step S120, the tube blank is sequentially combined with the first and second bending targets and input into the control center for analysis, obtaining initial bending parameters for the first and second sides. Specifically, the control center combines the tube blank specifications (such as diameter, wall thickness, and material properties) with the first and second bending targets, respectively, and analyzes them using a built-in computational model (such as a finite element analysis model). For example, if the tube has a diameter of 25 mm, a wall thickness of 2 mm, and is made of stainless steel, the first and second bending targets are 90° and 90°, respectively. The control center uses the computational model to obtain initial bending parameters for the first and second sides (e.g., a bending speed of 5 mm / s and a bending force of 100 N) and 5.5 mm / s and a bending force of 105 N).

[0027] In step S130, the first and second side initial bending parameters are analyzed and corrected for opposite-side roundness interactions based on the tube blank, generating the first and second bending parameters, as well as opposite-side interaction information. Specifically, the control center performs opposite-side roundness interaction analysis on the first and second side initial bending parameters, taking into account the material properties of the tube blank. For example, through simulation calculations, the influence coefficient of one side's bending on the other side's roundness is predicted to be 0.05 (indicating that for every 1° of bending, the other side's roundness deviation increases by 0.05mm). Based on the opposite-side interaction analysis results, the initial bending parameters are corrected to generate the final first and second bending parameters. For example, the first side initial bending parameters are adjusted to a bending speed of 5.2 mm / s and a bending force of 102 N; the second side initial bending parameters are adjusted to a bending speed of 5.7 mm / s and a bending force of 107 N. Simultaneously, opposite-side interaction information is generated for subsequent opposite-side interaction verification. This implementation method extracts the bending target and analyzes the initial bending parameters in steps, combined with the analysis and correction of the mutual influence of the roundness of the opposite sides, which can more accurately control the bending process and reduce bending deviation.

[0028] In one possible implementation, the first-side initial bending parameters and the second-side initial bending parameters are analyzed and corrected for the mutual influence of opposite-side roundness on the tube blank. Step S130 further includes step S131, where material property information is collected based on the tube blank. Specifically, the tube blank is tested using material testing equipment (such as a tensile testing machine or a hardness tester) to collect material property information such as elastic modulus, yield strength, and Poisson's ratio. For example, testing of a stainless steel tube yields an elastic modulus of 200 GPa, a yield strength of 250 MPa, and a Poisson's ratio of 0.3.

[0029] Step S132: Construct a bending finite element model based on the collected modeling data based on the material property information. Specifically, a finite element analysis software (such as ANSYS or ABAQUS) is used to construct the bending finite element model based on the collected material property information and the pipe's geometric dimensions. For example, a bending finite element model is constructed based on a pipe with a diameter of 25 mm, a wall thickness of 2 mm, and material properties (elastic modulus of 200 GPa, yield strength of 250 MPa, and Poisson's ratio of 0.3).

[0030] In step S133, the bending finite element model is used to perform a residual stress and deformation distribution analysis of the pipe based on the initial bending parameters of the first side under a first condition, generating first roundness interaction information. In step S134, the bending finite element model is used to perform a residual stress and deformation distribution analysis of the pipe based on the initial bending parameters of the second side under a second condition, generating second roundness interaction information. The first condition is to place the second-side bending arm in its original, unbent state, simulating the first bending process; the second condition is to place the first-side bending arm in its bent state, simulating the second bending process.

[0031] Specifically, the first condition is defined by arranging the second-side bending arm in its original, unbent state to simulate the first bending process. Initial bending parameters for the first side (e.g., a bending speed of 5 mm / s and a bending force of 100 N) are set in the bending finite element model, and a simulation analysis is performed. The simulation results demonstrate the residual stress and deformation distribution of the tube after the first side bends, particularly its impact on the roundness of the second side. For example, the simulation results show that after the first side bends, the roundness deviation of the opposite side is 0.2 mm, generating information on the first roundness interaction.

[0032] The second condition defines the configuration of the bending arm on the first side into a bent state, simulating the second bending process. Initial bending parameters for the second side (e.g., a bending speed of 5.5 mm / s and a bending force of 105 N) were set in the bending finite element model, and a simulation analysis was performed. The simulation results reveal the residual stress and deformation distribution of the tube after the second bending, particularly its impact on the roundness of the first side. For example, the simulation results show that after the second bending, the roundness deviation of the opposite side is 0.3 mm, generating information on the interaction effect of the second roundness.

[0033] Step S135: Generate the opposite-side mutual influence information using the first and second roundness mutual influence information, and perform mutual influence coupling correction on the first and second side initial bending parameters to generate the first and second bending parameters. Specifically, the goal of the mutual influence coupling correction is to adjust the initial bending parameters of the first and second sides based on the first and second roundness mutual influence information to reduce the opposite-side roundness deviation and ensure that the roundness of both sides after bending meets the design requirements. Generate the opposite-side mutual influence information based on the first and second roundness mutual influence information. For example, the opposite-side mutual influence information indicates 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. Couple correction is performed on the first and second side initial bending parameters to generate the final first and second bending parameters. For example, when correcting the bending parameters on the first side, the corrected first bending parameter = initial bending parameter on the first side - roundness deviation on the second side × influence coefficient of the second side on the first side. For correcting the bending parameters on the second side, the corrected second bending parameter = initial bending parameter on the second side - roundness deviation on the first side × influence coefficient of the first side on the second side. This implementation method, through finite element model simulation analysis, enables more accurate prediction of residual stress and deformation distribution, leading to more precise correction of bending parameters.

[0034] Step S200: controlling the tube bender to perform first side bending arm bending on the U-shaped tube using the first bending parameters, and starting a laser scanning device to scan 360° along the tube cross section to generate a continuous scanning data sequence.

[0035] Specifically, the control center controls the bending arm of the pipe bender through the motor drive system to perform the first side bending operation based on the first bending parameters. For example, the motor is controlled to bend at a set speed (such as 5mm / s) and force (such as 100N) until the set bending angle (such as 90°) is reached. The laser scanning device is started and 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, generating a continuous scan data sequence. The scan data includes the coordinate information of each point on the pipe cross section for curvature detection. For example, the scan data sequence contains multiple data points, such as point 1 with coordinates of (0,0), point 2 with coordinates of (10,0), point 3 with coordinates of (10,10), point 4 with coordinates of (0,10), and so on.

[0036] Step S300 , performing curvature detection of each cross section based on the continuous scanning data sequence, predicting and correcting the curvature deviation of the first side bending arm using the continuous curvature detection results, and generating a first real-time correction parameter.

[0037] Specifically, the control center receives a continuous sequence of scan data generated by the laser scanning device and uses a built-in curvature detection algorithm to detect the curvature of each cross-section. For example, the detection algorithm calculates the ovality of the tube cross-section (i.e., the difference between the maximum and minimum diameters) based on the scan data. For example, the detection results may indicate an ovality of 0.5mm for a particular cross-section. The control center uses the curvature detection results, combined with a pre-set deviation threshold (e.g., an ovality threshold of 0.3mm), to predict the curvature deviation. For example, if the detected ovality exceeds the threshold, a curvature deviation is predicted. Based on the prediction results, the control center adjusts the bending parameters (such as the bending force or bending speed) to make corrections, generating first real-time correction parameters for subsequent bending control. For example, if the ovality exceeds the threshold, the control center will increase the bending force by 5N to reduce the ovality. In one possible implementation, curvature detection is performed at each cross-section based on the continuous scan data sequence. The curvature deviation of the first side bending arm is predicted and corrected using the continuous curvature detection results to generate first real-time correction parameters. Step S300 further includes step S310 of reconstructing a full cross-sectional shape sequence based on the continuous scan data sequence. Specifically, the full cross-sectional shape sequence is reconstructed using a data processing algorithm (e.g., an interpolation algorithm) using the continuous scan data sequence generated by the laser scanning device. For example, if the scan data sequence contains coordinate points for multiple cross-sections, the complete shape of each cross-section is reconstructed using the interpolation algorithm.

[0038] Step S320 calculates a sequence of roundness changes for each cross-section based on the full cross-sectional shape sequence. Specifically, for the reconstructed full cross-sectional shape sequence, the roundness change for each cross-section is calculated. The roundness change can be represented by calculating the difference between the maximum and minimum diameters of the cross-section. For example, the ellipticity of each cross-section (the difference between the maximum and minimum diameters) is calculated.

[0039] Step S330 uses the roundness variation sequence and the controlled process parameters as training data to predict the roundness deviation of the uncontrolled process, generating a first full-stage roundness variation sequence. Specifically, a machine learning model (such as a linear regression model or a neural network) is trained using the roundness variation sequence and the controlled process parameters as training data. For example, the training data includes the roundness variation of each cross-section and the corresponding bending parameters (such as bending speed and bending force). The trained model is used to predict the roundness deviation of the uncontrolled process, generating the first full-stage roundness variation sequence.

[0040] Step S340 determines whether the first full-stage roundness variation sequence meets a preset roundness range. If not, an abnormal deviation sequence is identified. Specifically, the first full-stage roundness variation sequence is determined to meet the requirements based on a preset roundness range (e.g., a roundness deviation of less than 0.1 mm). For example, if the preset roundness range is 0.1 mm, and the roundness deviation of a certain section exceeds 0.1 mm, the section is identified as having an abnormal deviation sequence.

[0041] Step S350, judging the moment when the deviation first occurs according to the abnormal deviation sequence, selecting uncontrolled process parameter correction or local rebound correction, and determining the first real-time correction parameter. Specifically, analyze the abnormal deviation sequence to determine the moment when the deviation first occurs. For example, by analyzing the roundness change sequence, determine that the deviation first occurs in the 10th section. According to the moment when the deviation first occurs, select uncontrolled process parameter correction or local rebound 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 method can more accurately control the bending process and reduce roundness deviation through real-time monitoring and correction.

[0042] In one possible implementation, the moment when the deviation first occurs is determined based on the abnormal deviation sequence, and either uncontrolled process parameter correction or local rebound correction is selected to determine the first real-time correction parameter. 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 based on 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 parameters (such as bending speed and bending force) in the uncontrolled process and the roundness deviation is analyzed based on the first full-stage roundness change sequence. For example, by analyzing the roundness change sequence, it is determined that the deviation first appears in the 10th section and that this moment belongs to the uncontrolled process stage. Regression analysis or a machine learning model is used to find the relationship between the bending speed and the roundness deviation.

[0043] Step S352: Correct the abnormal deviation sequence using the control deviation relationship to generate the first real-time correction parameter. Specifically, the abnormal deviation sequence is corrected based on the control deviation relationship. Specifically, the control parameters during the uncontrolled process are adjusted to reduce roundness deviation. For example, the required bending speed and bending force are calculated based on the control deviation relationship. Based on these adjustments, the first real-time correction parameter is generated for subsequent bending control. This implementation method, through real-time monitoring and correction, enables more precise control of the bending process and reduces roundness deviation.

[0044] In one possible implementation, the first real-time correction parameter is determined, and step S350 further includes step S353, if the moment when the deviation first appears belongs to the controlled process, correction is performed based on the deviation belonging to the uncontrolled process in the abnormal deviation sequence, and after the bending of the first side bending arm is completed, the roundness deviation is detected in real time. Specifically, the abnormal deviation sequence is analyzed to determine the specific moment when the deviation first appears. If the deviation first appears in the controlled process stage, correction is performed based on the deviation belonging to the uncontrolled process in the abnormal deviation sequence. Specifically, an analysis method similar to steps S351-352 is used to analyze the deviation data in the uncontrolled process and the control deviation relationship, and deviation correction is performed. For example, by analyzing the roundness change sequence, it is determined that the deviation first appears in the 10th section, and this moment belongs to the controlled process stage, and the deviation data belonging to the uncontrolled process after the 10th section is analyzed and corrected. After the bending of the first side bending arm is completed, the roundness deviation is detected in real time using a laser scanning device.

[0045] In step S354, the roundness deviation is input into a multi-roller straightening mapping relationship for local correction parameter matching, generating multi-roller straightening parameters. Specifically, a pre-established multi-roller straightening mapping relationship is used to input the roundness deviation into the mapping relationship for local correction parameter matching. For example, the multi-roller straightening mapping relationship is a function based on experimental data and simulation results that describes the relationship between roundness deviation and straightening parameters. Based on the real-time roundness deviation, the corresponding multi-roller straightening parameters are calculated using the mapping relationship. These multi-roller straightening parameters include the adjustment parameters for each straightening roller.

[0046] In step S355, the multi-roller straightening machine is controlled using the multi-roller straightening parameters to perform local correction on the first side bending arm. Specifically, the calculated multi-roller straightening parameters are used to control the multi-roller straightening machine to perform local correction on the first side bending arm. For example, the position and pressure of each straightening roller are adjusted based on the multi-roller straightening parameters to perform local correction on the first side bending arm. This implementation method, through real-time monitoring and correction, enables more precise control of the bending process and reduces roundness deviation.

[0047] In step S400, bending control is continued with the first real-time correction parameters. After the first control is completed, the contralateral influence verification of the second side bending arm is performed with the contralateral mutual influence information. After the verification passes, the curvature deviation of the second side bending arm is predicted and corrected according to the second bending parameters.

[0048] Specifically, the control center continues bending the first bending arm using the first real-time correction parameters until the first bend is completed. After the first bending is completed, the second bending arm undergoes a contralateral effect check based on the contralateral mutual influence information. This contralateral effect check verifies that the roundness deviation of the second bending arm is consistent with the prediction after one bending is completed, ensuring the accuracy of the bending process. For example, the control center predicts the roundness deviation of the second bending arm based on the contralateral mutual influence information and compares it with the actual scan data. If the actual deviation is consistent with the predicted deviation (i.e., within the allowable error range), the check passes. For example, if the predicted roundness deviation of the second side is 0.2mm and the actual scan result is 0.21mm, the error is within the allowable error range (i.e., ±0.05mm), and the check passes. After the check passes, the second bending arm is bent according to the second bending parameters, and the laser scanning equipment is simultaneously activated to scan 360° along the tube cross section, generating a continuous scan data sequence. Based on a continuous scanning data sequence, curvature detection is performed at each cross-section. The results of these continuous curvature detections are used to predict and correct the curvature deviation of the second-side bending arm. This involves detecting the curvature (e.g., ovality) of the tube cross-section to determine if any deviation exists. Correction is then made by adjusting bending parameters (e.g., bending force and speed), generating second real-time correction parameters. These second real-time correction parameters are used to control the bending of the second side until the bending is complete, ensuring that the bent tube meets design requirements.

[0049] In one possible implementation, the contralateral influence verification of the second bending arm is performed using the contralateral mutual influence information. Step S400 further includes step S410: before the second bending arm begins bending, the second bending arm is inspected to assess the actual impact of the bending of the first bending arm on the second bending arm. Specifically, the second bending arm is inspected using a laser scanning device or a high-precision measurement tool to obtain its current shape and size data. For example, a laser scanning device is used to perform a 360° scan along the cross-section of the second bending arm to generate a continuous sequence of scan data. Based on the scan data, the roundness change of the second bending arm is calculated to assess the actual impact of the bending of the first bending arm on the second bending arm. For example, the ovality of the second bending arm (the difference between the maximum and minimum diameters) is calculated to assess its roundness deviation.

[0050] In step S420, the actual influence is analyzed for consistency with the corresponding information in the opposite-side mutual influence information. If the consistency meets the preset requirements, the opposite-side influence verification is passed. Specifically, the actually detected roundness deviation is compared and analyzed with the predicted value in the opposite-side mutual influence information. According to the design requirements, an allowable error range (such as ±0.05mm) is set. If the consistency between the actual influence and the predicted value meets the preset requirements (that is, the error is within the allowable range), the opposite-side influence verification is passed. For example, the preset error range is ±0.05mm, the actual deviation of 0.21mm and the predicted value of 0.2mm have an error of 0.01mm, which meets the preset requirements, and the opposite-side influence verification is passed. This implementation method can more accurately evaluate the influence of the first side bending on the second side through actual detection and consistency analysis, thereby ensuring the accuracy of the second side bending.

[0051] In one possible implementation, step S400 further includes step S430: If the contralateral influence verification fails, the second bending parameters are re-optimized based on the actual influence. Specifically, if the consistency between the actual influence and the predicted value in the contralateral mutual influence information does not meet preset requirements (i.e., the error exceeds the allowable range), the contralateral influence verification fails. For example, if the preset error range is ±0.05 mm, the error between the actual deviation of 0.26 mm and the predicted value of 0.2 mm is 0.06 mm, which exceeds the preset range and the verification fails. Based on the actual influence, the second bending parameters are adjusted to reduce the contralateral 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 these adjustments, optimized second bending parameters are generated for subsequent bending control. This implementation method can effectively reduce the impact of the first side bending on the second side through side impact verification and parameter optimization, thereby improving the overall quality of the U-shaped tube.

[0052] The embodiment of the present application adopts the method of inputting the tube blank and bending target of the heat exchanger U-shaped tube into the tube bending machine control center, determining the two bending parameters and the mutual influence information of the opposite sides, controlling the tube bending machine to bend the first side bending arm according to the first bending parameters, and simultaneously using a laser scanning device to scan 360° along the tube cross section to generate a scanning data sequence, detecting the curvature based on the scanning data sequence, predicting and correcting the curvature deviation of the first side bending arm, generating real-time correction parameters, and after the first bending is completed, verifying according to the mutual influence information of the opposite side, and predicting and correcting the curvature deviation of the second side bending arm according to the second bending parameters after the verification is passed. These technical means solve the technical problem of the difficulty in effectively controlling the roundness deviation and resulting in unstable bending quality in the existing roundness deviation control for bending U-shaped tubes of heat exchangers, and achieve the technical effect of effectively controlling the roundness deviation and improving the bending accuracy and product quality.

[0053] In the above, refer to Figure 1 The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to an embodiment of the present invention is described in detail. Figure 2 A roundness deviation control system for bending a U-shaped tube of a heat exchanger according to an embodiment of the present invention is described.

[0054] The roundness deviation control system for bending U-shaped tubes for heat exchangers according to an embodiment of the present invention addresses the technical issues of existing U-shaped tube bending systems, which suffer from difficulty effectively controlling roundness deviation and resulting in unstable bending quality. This system effectively controls roundness deviation, improving bending precision and product quality. The roundness deviation control system for bending U-shaped tubes for 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.

[0055] A central analysis module 10 is configured to determine the tube material and bending target of the heat exchanger U-shaped tube and input them into the control center of the tube bender for analysis, thereby determining the first bending parameters, the second bending parameters, and the opposite-side mutual influence information. A first-side bending control module 20 is configured to control the tube bender to bend the U-shaped tube with the first bending parameters, and to activate a laser scanning device to scan 360° along the tube cross section to generate a continuous scanning data sequence. A first-side correction module 30 is configured to perform curvature detection on each cross section based on the continuous scanning data sequence, predict and correct the curvature deviation of the first-side bending arm based on the continuous curvature detection results, and generate a first real-time correction parameter. A second-side bending control and correction module 40 is configured to continue bending control based on 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 based on the opposite-side mutual influence information. After the verification passes, the curvature deviation of the second-side bending arm is predicted and corrected based on the second bending parameters.

[0056] The specific configuration of the central analysis module 10 will be described in detail below. As described above, the tube blank and bending target of the heat exchanger U-shaped tube are determined and input into the control center of the tube bender for analysis, and the first bending parameters, second bending parameters, and opposite-side mutual influence information are determined. The central analysis module 10 may further include: a bending target extraction unit for 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; 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 an opposite-side roundness mutual influence analysis correction unit for combining the tube blank and performing opposite-side roundness mutual influence analysis correction on the first side initial bending parameters and the second side initial bending parameters to generate the first bending parameters, the second bending parameters, and the opposite-side mutual influence information.

[0057] Wherein, in combination with the tube blank, the first side initial bending parameters and the second side initial bending parameters are subjected to opposite side roundness mutual influence analysis correction, and the opposite side roundness mutual influence analysis correction unit may further include: a material attribute information acquisition subunit for acquiring material attribute information based on the tube blank; a bending finite element model construction subunit for acquiring modeling data based on the material attribute information to construct a bending finite element model; a first roundness mutual influence information generation subunit for executing the residual stress and shape analysis of the tube based on the first side initial bending parameters under the first condition using the bending finite element model. The second roundness mutual influence information generating subunit is used to perform residual stress and deformation distribution analysis of the pipe based on the second side initial bending parameters under the second condition with the bending finite element model to generate second roundness mutual influence information; the mutual influence coupling correction subunit is used to generate the opposite side mutual influence information with the first roundness mutual influence information and the second roundness mutual influence information, and perform mutual influence coupling correction of the first side initial bending parameters and the second side initial bending parameters to generate the first bending parameters and the second bending parameters.

[0058] Among them, the contralateral roundness mutual influence analysis and correction unit can further include: the first condition is to configure the second side bending arm to the original unbent state, simulating the first bending process; the second condition is to configure the first side bending arm to the bent state, simulating the second bending process.

[0059] The specific configuration of the first side correction module 30 will be described in detail below. As described above, based on the continuous scan 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 to generate a first real-time correction parameter. The first side correction module 30 may further include: a full-segment cross-sectional shape sequence reconstruction unit for reconstructing the full-segment cross-sectional shape sequence based on the continuous scan data sequence; a roundness change sequence calculation unit for calculating the roundness change sequence of each section based on the full-segment cross-sectional shape sequence; a roundness deviation prediction unit for performing roundness deviation prediction of the uncontrolled process using the roundness change sequence and the controlled process parameters as training data to generate a first full-stage roundness change sequence; an abnormal deviation sequence locating unit for determining whether the first full-stage roundness change sequence meets a preset roundness range, and if not, locating the abnormal deviation sequence; and a first real-time correction parameter determination unit for determining the moment when the deviation first occurs based on the abnormal deviation sequence, selecting between uncontrolled process parameter correction or local rebound correction, and determining the first real-time correction parameter.

[0060] Among them, the moment when the deviation first occurs is judged according to the abnormal deviation sequence, and the uncontrolled process parameter correction or local rebound correction is selected to determine the first real-time correction parameter. The first real-time correction parameter determination unit may further include: a control deviation relationship analysis subunit for analyzing the control deviation relationship according to the first full-stage roundness change sequence if the moment when the deviation first occurs belongs to the uncontrolled process; a deviation correction subunit for performing deviation correction on the abnormal deviation sequence with the control deviation relationship to generate the first real-time correction parameter.

[0061] Among them, the first real-time correction parameter is determined, and the first real-time correction parameter determination unit may further include: a roundness deviation detection subunit is used to correct the deviation belonging to the uncontrolled process in the abnormal deviation sequence if the moment when the deviation first appears belongs to the controlled process, and detect the roundness deviation in real time after the bending of the first side bending arm is completed; a local correction parameter matching subunit is used to input the roundness deviation into the multi-roller straightening mapping relationship to perform local correction parameter matching and generate multi-roller straightening parameters; the local correction subunit is used to control the multi-roller straightening machine to perform local correction on the first side bending arm with the multi-roller straightening parameters.

[0062] The specific configuration of the second-side bending control and correction module 40 will be described in detail below. As described above, the contralateral influence verification of the second-side bending arm is performed using the contralateral mutual influence information. The second-side bending control and correction module 40 may further include: an actual influence evaluation unit for testing the second-side bending arm before the second-side bending arm begins bending 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 for analyzing the consistency of the actual influence with the corresponding information in the contralateral mutual influence information. If the consistency meets preset requirements, the contralateral influence verification passes.

[0063] The second side bending control and correction module 40 may further include: a re-optimization unit configured to re-optimize the second bending parameters based on the actual impact if the side impact verification fails.

[0064] The roundness deviation control system for bending a U-shaped tube of a heat exchanger provided in an embodiment of the present invention can execute the roundness deviation control method for bending a U-shaped tube of a heat exchanger provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0065] Although the present application makes various references to certain modules in the system according to the embodiments of the present application, any number of different modules may be used and run on the user terminal and / or server, and the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other and are not used to limit the scope of protection of the present invention.

[0066] The above specific embodiments do not constitute a limitation to the scope of protection of this application. It should be understood by those skilled in the art that various modifications, combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of this application should be included in the scope of protection of this application. In some cases, the actions or steps recorded in this application can be performed in an order different from that in the embodiments and can still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for controlling roundness deviation of a U-shaped tube bend in a heat exchanger, characterized in that: include: Determine the tube material and bending target of the heat exchanger U-tube and input them into the control center of the tube bending machine for analysis, determine the first bending parameters, the second bending parameters and the mutual influence information on the opposite sides; Controlling the tube bender to perform first side bending arm bending on the U-shaped tube using the first bending parameters, and starting a laser scanning device to scan 360° along the tube cross section to generate a continuous scanning data sequence; Performing curvature detection of each cross section based on the continuous scanning data sequence, predicting and correcting the curvature deviation of the first side bending arm using the continuous curvature detection results, and generating a first real-time correction parameter; Continue to perform bending control with the first real-time correction parameter. After the first control is completed, perform contralateral influence verification of the second side bending arm with the contralateral mutual influence information. After the verification passes, predict and correct the curvature deviation of the second side bending arm according to the second bending parameter.

2. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 1, characterized in that: Determine the tube material and bending target of the heat exchanger U-tube and input them into the control center of the tube bending machine for analysis. Determine the first bending parameters, the second bending parameters, and the mutual influence information on the opposite sides, including: 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; Combining the tube blank with the first bending target and the second bending target in sequence and inputting them into a control center for analysis to obtain initial bending parameters of the first side and initial bending parameters of the second side; In combination with the tube blank, the first side initial bending parameters and the second side initial bending parameters are subjected to opposite side roundness mutual influence analysis and correction to generate the first bending parameters, the second bending parameters and the opposite side mutual influence information.

3. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 2, characterized in that: In combination with the tube blank, performing a mutual influence analysis and correction of the roundness of opposite sides on the initial bending parameters of the first side and the initial bending parameters of the second side, including: collecting material attribute information based on the tube blank; Acquiring modeling data based on the material property information to construct a bending finite element model; performing residual stress and deformation distribution analysis of the pipe based on the initial bending parameters of the first side under the first condition using the bending finite element model to generate first roundness interaction information; performing residual stress and deformation distribution analysis of the pipe based on the initial bending parameters of the second side under the second condition using the bending finite element model to generate second roundness interaction information; The opposite-side mutual influence information is generated using the first roundness mutual influence information and the second roundness mutual influence information, and mutual influence coupling correction is performed on the first-side initial bending parameters and the second-side initial bending parameters to generate the first bending parameters and the second bending parameters.

4. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 3, characterized in that: The first condition is to configure the second side bending arm to an unbent original state to simulate the first bending process; the second condition is to configure the first side bending arm to a bent state to simulate the second bending process.

5. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 1, characterized in that: Performing curvature detection of each cross section based on the continuous scanning data sequence, predicting and correcting the curvature deviation of the first side bending arm based on the continuous curvature detection results, and generating a first real-time correction parameter, including: reconstructing a full-segment cross-sectional shape sequence based on the continuous scanning data sequence; Calculating a roundness variation sequence of each cross section based on the full cross section shape sequence; Using the roundness variation sequence and the controlled process parameters as training data, performing roundness deviation prediction of the uncontrolled process to generate a first full-stage roundness variation sequence; Determine whether the first full-stage roundness change sequence meets a preset roundness range, and if not, locate the abnormal deviation sequence; The time when the deviation first occurs is determined according to the abnormal deviation sequence, and an uncontrolled process parameter correction or a local rebound correction is selected to determine the first real-time correction parameter.

6. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 5, characterized in that: Determining the time when the deviation first occurs according to the abnormal deviation sequence, selecting uncontrolled process parameter correction or local rebound correction, and determining the first real-time correction parameter includes: If the moment when the deviation first occurs belongs to an uncontrolled process, the control deviation relationship is analyzed based on the first full-stage roundness change sequence; Deviation correction is performed on the abnormal deviation sequence using the control deviation relationship to generate the first real-time correction parameter.

7. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 6, characterized in that: Determining the first real-time correction parameter further includes: If the moment when the deviation first occurs belongs to a controlled process, correction is performed based on the deviation belonging to an uncontrolled process in the abnormal deviation sequence, and after the bending of the first side bending arm is completed, the roundness deviation is detected in real time; Inputting the roundness deviation into a multi-roller straightening mapping relationship to perform local correction parameter matching to generate multi-roller straightening parameters; The multi-roller straightening machine is controlled by using the multi-roller straightening parameters to perform local correction on the first side bending arm.

8. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 1, characterized in that: Performing a contralateral influence check of the second side bending arm using the contralateral mutual influence information includes: Before the second side bending arm begins to bend, the second side bending arm is first tested to evaluate the actual effect of the bending of the first side bending arm on the second side bending arm; The actual impact is analyzed for consistency with the corresponding information in the opposite-side mutual impact information. If the consistency meets the preset requirements, the opposite-side impact verification passes.

9. The roundness deviation control method for bending a U-shaped tube of a heat exchanger according to claim 8, characterized in that: If the contralateral impact check fails, the second bending parameters are optimized again based on the actual impact.

10. A roundness deviation control system for U-shaped tube bending in heat exchangers, characterized in that: The system is used to implement the roundness deviation control method for bending a U-shaped tube of a heat exchanger according to any one of claims 1 to 9, 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 bender for analysis, to determine the first bending parameters, the second bending parameters and the mutual influence information of the opposite side; a first side bending control module, configured to control the tube bender to perform first side bending arm bending control on the U-shaped tube using the first bending parameters, and to start a laser scanning device to scan 360° along the tube cross section to generate a continuous scanning data sequence; a first side correction module, configured to perform curvature detection of each cross section based on the continuous scanning data sequence, predict and correct the curvature deviation of the first side bending arm using the continuous curvature detection results, and generate a first real-time correction parameter; 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 contralateral influence verification of the second side bending arm is performed with the contralateral mutual influence information. After the verification is passed, the curvature deviation of the second side bending arm is predicted and corrected according to the second bending parameters.

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