Rotor optimization compensation method and system applied to roots vacuum pump

Abstract

The invention relates to the technical field of analog simulation, and discloses a Roots vacuum pump rotor optimization compensation method and system, and the method comprises the steps: S01, collecting the operation indexes of a Roots vacuum pump, S02, collecting the comprehensive optimization parameters of the Roots vacuum pump from the previous monitoring moment to the current monitoring moment, S03, predicting the expansion deformation amount, and S04, calculating the expansion deformation amount of the Roots vacuum pump. S04, constructing a simulation model, and simulating a theoretical compensation amount, S05, eliminating error factors, and calculating a real compensation amount; according to the invention, virtual adjustable analogue simulation operation can be carried out on the Roots vacuum pump at a virtual level, so that the invariability of an entity structure during simulation is avoided, and the simulation model can be ensured to be consistent with the actual operation condition of the Roots vacuum pump during analogue simulation; and meanwhile, factors which cause negative error influences on the thermal expansion deformation of the roots vacuum pump rotor can be effectively eliminated, and the accuracy of subsequent rotor thermal expansion deformation reduction compensation is improved.

Description

Technical Field

[0001] This invention relates to the field of simulation technology, and more specifically, to a method and system for optimizing and compensating the rotor of a Roots vacuum pump. Background Technology

[0002] When a Roots vacuum pump is running, it compresses and discharges low-temperature, low-pressure gas by rotating the rotor, converting it into high-temperature, high-pressure gas. After the Roots vacuum pump has been running for a long time, the gas will continuously rub against the rotor, causing the rotor temperature to rise continuously. This leads to thermal expansion and deformation of the rotor, resulting in excessive friction between rotors and between the rotor and the inner wall of the casing, or even jamming. This reduces the operational stability and reliability of the Roots vacuum pump.

[0003] The patent application with publication number CN118965986A discloses a method for optimizing and compensating the rotor of a Roots vacuum pump, which includes the following specific steps: performing offline measurement on the processed rotor blank to calculate the processing error and actual clearance; optimizing the actual clearance to calculate the first compensation clearance and the second compensation clearance, and establishing an optimized compensation rotor model; and reprocessing the rotor blank according to the optimized compensation rotor model to obtain a rotor workpiece that meets the dimensional accuracy and performance requirements. Existing methods for rotor optimization compensation of Roots vacuum pumps typically only consider the expansion and deformation of the rotor under static or ideal conditions. They fail to fully consider and eliminate the negative impact of dynamic factors such as heat attenuation during heat conduction in the Roots vacuum pump's internal environment and the tensile deformation caused by the rotor's continuous rotation under long-term gravity on the final compensation accuracy. This results in limitations in the optimization compensation analysis process, failing to provide real and accurate data support for the precise suppression of rotor thermal expansion and deformation problems, and consequently making it difficult to ensure the long-term, safe, and stable operation of Roots vacuum pumps.

[0004] In view of this, the present invention proposes a method and system for optimizing compensation of the rotor of a Roots vacuum pump to solve the above problems. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art and to achieve the above objectives, the present invention provides the following technical solution: a method for optimizing and compensating the rotor of a Roots vacuum pump, comprising: S01: By collecting and analyzing the operating parameters of the Roots vacuum pump, including evacuation time and rotor temperature, the operating status of the Roots vacuum pump is identified, and it is determined whether to execute the optimization analysis mode; if the optimization analysis mode is executed, proceed to S02. S02: In the optimization analysis mode, the temperature change time of the Roots vacuum pump is calculated, the previous monitoring time is determined, and the comprehensive optimization parameters of the Roots vacuum pump between the previous monitoring time and the current monitoring time are collected. The comprehensive optimization parameters include pumping volume, vibration amplitude fluctuation value, noise intensity and instantaneous temperature difference dispersion rate. S03: Summarize the comprehensive optimization parameters and operating indicators into expansion deformation parameters, input the expansion deformation parameters into the expansion deformation prediction model, predict the expansion deformation amount, and determine whether to execute the optimization compensation mode; if the optimization compensation mode is executed, proceed to S04. S04: In the optimized compensation mode, a simulation model of the Roots vacuum pump is constructed using mesh reconstruction technology. The aerodynamic parameters, material parameters, and state parameters of the simulation model are initialized, and the theoretical compensation amount of the simulation model is simulated. S05: Eliminate the error factors of the theoretical compensation amount, calculate the actual compensation amount, and optimize the compensation of the rotor of the Roots vacuum pump based on the actual compensation amount.

[0006] Furthermore, the method for determining whether to execute the optimization analysis mode is as follows: When the evacuation time is greater than or equal to the normal time, the evacuation time is recorded as an abnormal indicator; when the rotor temperature is greater than or equal to the normal temperature, the rotor temperature is recorded as an abnormal indicator. If the number of abnormal indicators is 1 or 2, the Roots vacuum pump is in monitoring status, and the optimization analysis mode is executed. If the number of abnormal indicators is 0, the Roots vacuum pump is in normal operating condition, and the optimization analysis mode is not executed.

[0007] Furthermore, the method for calculating the duration of temperature gradual change is as follows: The maximum rotor temperature in the Roots vacuum pump's work log is recorded as the temperature peak value, and work logs with temperature peak values ​​exceeding the calibrated temperature value are recorded as valid logs, resulting in A valid logs; The time when the first calibrated peak value appears in the valid log is recorded as the start time, the time when the first temperature peak value appears is recorded as the end time, and the duration between the start time and the end time is recorded as the temperature change duration. The temperature peak values ​​in A valid logs are subtracted from the calibrated temperature values, and the differences are compared with the corresponding temperature change durations to calculate the A sub-gradual change durations. The average duration is calculated by summing the durations of A sub-gradients. The average duration is then calculated by summing the durations of C sub-gradients that are less than the average duration.

[0008] Furthermore, when determining the previous monitoring time, the previous monitoring time is obtained by counting backwards along the timeline from the current monitoring time as the starting point, after counting backwards for one temperature change duration.

[0009] Furthermore, the method for acquiring the instantaneous temperature difference dispersion is as follows: Find out the time it takes for the rotor of the Roots vacuum pump to rotate one revolution, and record it as the single revolution time. Find out the length between the outlet of the Roots vacuum pump and the infrared temperature sensor, and record it as the exhaust distance value. Divide the exhaust distance value by the exhaust speed to obtain the exhaust duration, and add the single-cycle duration to the exhaust duration to calculate the temperature change duration. Using the previous monitoring time as the starting point and the current monitoring time as the ending point, and using a temperature change duration interval as the standard, mark B temperature change points with equal duration distribution. The rotor temperature at B temperature change points is detected respectively to obtain B point temperatures. The temperature difference is calculated by subtracting the B point temperatures from the calibrated temperature value one by one, and the point temperatures that are less than the preset temperature threshold are recorded as discrete temperatures. According to the chronological order, the temperatures of B points are numbered in ascending order, and the number of discrete temperatures where the previous and next numbers are both point temperatures, and the number of discrete temperatures where the previous two numbers and the next two numbers are both point temperatures are obtained, respectively, to obtain the first discrete value and the second discrete value. The first and second discrete values ​​are assigned corresponding proportional coefficients and then added together. The instantaneous temperature difference dispersion rate is calculated by comparing the sum with the number of temperature points.

[0010] Furthermore, the method for determining the optimized compensation mode is as follows: When the predicted expansion deformation is greater than or equal to the preset expansion deformation threshold, the optimized compensation mode is executed. If the predicted expansion deformation is less than the preset expansion deformation threshold, the optimized compensation mode will not be executed.

[0011] Furthermore, the method for constructing the simulation model is as follows: The point cloud data of all parts is scanned by a laser scanner. After the point cloud data is denoised, filtered and downsampled, the cleaned point cloud data is obtained. The cleaned point cloud data is imported into the same three-dimensional space, the model reference point is selected, the model outline is constructed based on mesh reconstruction technology, and the air inlet pipe on the model outline is simulated to be connected to the vacuum equipment. The control logic and operating permissions of the Roots vacuum pump are retrieved from the database, and simulation logic and permissions consistent with the control logic and operating permissions are simulated on the model outline, thus converting the model outline into a simulation model.

[0012] Furthermore, the simulation method for the theoretical compensation amount is as follows: In CFD software, a basic scene with a trigger window is created, the simulation model is imported into the basic scene, and the trigger window is initialized to a hidden state. Establish scene positions within the basic scene, establish simulation positions and state positions on the simulation model, import aerodynamic parameters into the scene positions, and import material parameters and state parameters into the simulation positions and state positions respectively, thereby upgrading the basic scene into a simulation scene. Configure simulation conditions that match the simulation logic and permissions within the simulation scenario, switch the trigger window from a hidden state to a visible state, and use the completion of a full simulation by the simulation model as the standard to query the simulation results of the simulation scenario and obtain the theoretical compensation amount.

[0013] Furthermore, error factors include thermal conduction attenuation and gravitational rotation stretching; The method for calculating the actual compensation amount is as follows: The rotor temperature at the current monitoring moment is used as the reference temperature. The corresponding heat conduction attenuation coefficient is found. The difference between the reference temperature and the normal temperature is calculated, and the difference is multiplied by the heat conduction attenuation coefficient to calculate the heat conduction attenuation. Find the tensile deformation coefficient of the Roots vacuum pump, subtract the evacuation time at the current monitoring moment from the normal time, and multiply the difference by the tensile deformation coefficient to calculate the gravitational rotation tensile amount. The actual compensation is calculated by adding the theoretical compensation, the thermal conduction attenuation, and the gravitational rotation stretching.

[0014] A rotor optimization compensation system for Roots vacuum pumps is provided to implement a rotor optimization compensation method for Roots vacuum pumps. The system includes a first execution module, a parameter acquisition module, a second execution module, a theoretical compensation module, and a real compensation module. The modules are connected to each other via wired or wireless networks. The first execution module is used to identify the operating status of the Roots vacuum pump by collecting and analyzing its operating indicators, and to determine whether to execute the optimization analysis mode. The parameter acquisition module is used to calculate the temperature gradient duration of the Roots vacuum pump in the optimization analysis mode, determine the previous monitoring time, and acquire the comprehensive optimization parameters of the Roots vacuum pump from the previous monitoring time to the current monitoring time. The second execution module is used to summarize the comprehensive optimization parameters and operating indicators into expansion deformation parameters, input the expansion deformation parameters into the expansion deformation prediction model, predict the expansion deformation amount, and determine whether to execute the optimization compensation mode. The theoretical compensation module is used to construct a simulation model of the Roots vacuum pump using mesh reconstruction technology under optimized compensation mode, initialize the aerodynamic parameters, material parameters and state parameters of the simulation model, and simulate the theoretical compensation amount of the simulation model. The true compensation module is used to eliminate the error factors of the theoretical compensation amount, calculate the true compensation amount, and optimize the compensation of the rotor of the Roots vacuum pump based on the true compensation amount.

[0015] The technical advantages of this invention, which relates to a rotor optimization compensation method and system for Roots vacuum pumps, are as follows: (1): This invention constructs a virtualized simulation model and imports the simulation model into the simulation scene for simulation operation. This not only transforms the physical Roots vacuum pump into a virtual one, but also allows for virtual and adjustable simulation of the Roots vacuum pump at the virtual level. This avoids the inconvenience caused by the physical structure during simulation. Furthermore, by configuring simulation conditions that are compatible with the simulation logic and simulation permissions, it ensures that the simulation model is consistent with the actual operation of the Roots vacuum pump during simulation. This avoids the phenomenon of inaccurate simulation results caused by differences in control logic and simulation permissions, thereby ensuring the simulation reliability of the theoretical compensation amount.

[0016] (2): This invention calculates the thermal conduction attenuation and gravitational rotation stretch of the Roots vacuum pump and combines them with the theoretical compensation amount to calculate the actual compensation amount for optimization compensation. This effectively eliminates the factors that cause negative errors in the thermal expansion deformation of the Roots vacuum pump rotor, ensuring that the obtained actual compensation amount can be used as the final basis for optimizing the compensation of the Roots vacuum pump rotor. This improves the accuracy of subsequent rotor thermal expansion deformation reduction compensation and ensures that the Roots vacuum pump can maintain a long-term and safe operating state. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of a rotor optimization compensation method for a Roots vacuum pump provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of a module for a rotor optimization compensation system for a Roots vacuum pump, provided in Embodiment 2 of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: Please refer to Figure 1 As shown in this embodiment, a rotor optimization compensation method for a Roots vacuum pump includes: S01: By collecting and analyzing the operating indicators of the Roots vacuum pump, the operating status of the Roots vacuum pump is identified, and it is determined whether to execute the optimization analysis mode. Operating indicators are used to represent the multi-dimensional basic operating parameters of a Roots vacuum pump under operating conditions, and serve as the basis for judging whether a Roots vacuum pump can meet the rotor optimization compensation. Since the temperature of the rotor in a Roots vacuum pump is not generated instantaneously but accumulates as the pump continues to operate, by collecting and analyzing operating parameters, it is possible to determine whether the temperature of the rotor in the Roots vacuum pump will cause thermal expansion and deformation, thereby deciding whether to execute subsequent optimization analysis modes.

[0020] Specifically, the operating parameters include evacuation time and rotor temperature; Evacuation time refers to the actual operating time of a Roots vacuum pump in normal evacuation state, which can be used as a factor to judge the real-time operating status of a Roots vacuum pump. In this embodiment, the evacuation time is obtained by using a timer to count the duration during which the Roots vacuum pump operates at its rated power.

[0021] Rotor temperature refers to the temperature value of the rotor in the Roots vacuum pump under evacuation conditions, which can be used as another factor to judge the real-time operating status of the Roots vacuum pump. In this embodiment, the rotor temperature is obtained by detecting an infrared temperature sensor installed on the housing of the Roots vacuum pump.

[0022] The operating status is used to represent the actual operating status of the Roots vacuum pump at the current moment, and serves as a direct basis for determining whether to execute the optimization analysis mode; Specifically, the operating status includes normal status and monitoring status; normal status refers to the Roots vacuum pump being in a state of low operating time and low rotor temperature, while monitoring status refers to the Roots vacuum pump being in a state of high operating time and high rotor temperature.

[0023] Specifically, the method for identifying the running status is as follows: The evacuation time and rotor temperature of the Roots vacuum pump were compared. When the evacuation time is greater than or equal to the normal time, it means that the evacuation time of the Roots vacuum pump at the current moment exceeds the maximum value under normal conditions, and the evacuation time is recorded as an abnormal indicator. The normal time refers to the minimum time for the Roots vacuum pump to perform rotor optimization compensation monitoring operation. The normal time can be set according to actual needs, or it can be obtained by averaging a large amount of historical data. When the rotor temperature is greater than or equal to the normal temperature, it means that the rotor temperature of the Roots vacuum pump at the current moment exceeds the maximum value under normal conditions, and the rotor temperature is recorded as an abnormal indicator. The normal temperature refers to the minimum temperature at which the Roots vacuum pump needs to perform rotor optimization compensation monitoring operations. The normal temperature can be set according to actual needs, or it can be obtained by averaging a large amount of historical data. If the number of abnormal indicators is 1 or 2, it means that the rotor of the Roots vacuum pump needs to be monitored and analyzed at the current moment, and the operating status of the Roots vacuum pump is the monitoring status. If the number of abnormal indicators is 0, it means that the Roots vacuum pump does not need to perform rotor monitoring and analysis at the current moment, and the Roots vacuum pump is in normal operating condition.

[0024] The optimization analysis mode is a working mode used to specifically analyze the optimization compensation operation of the Roots vacuum pump, and provides a prerequisite for a series of subsequent steps and measures. Specifically, the method for determining whether to execute the optimization analysis mode is as follows: When the vacuum pump is in monitoring mode, if the Roots vacuum pump needs to be optimized and compensated, then the optimization analysis mode will be executed. When the vacuum pump is operating in normal mode, no specific analysis of optimization compensation is required for the Roots vacuum pump, so it is determined that the optimization analysis mode will not be executed.

[0025] S02: In the optimization analysis mode, calculate the temperature gradient duration of the Roots vacuum pump, determine the previous monitoring time, and collect the comprehensive optimization parameters of the Roots vacuum pump at the current monitoring time; In the optimization analysis mode, the comprehensive optimization parameters of the Roots vacuum pump can be collected, thereby providing an analytical basis for the specific magnitude of the expansion and deformation of the rotor in the Roots vacuum pump at the current moment. In this embodiment, when collecting comprehensive optimization parameters, it is necessary to first determine the previous monitoring time that is compared and analyzed with the current monitoring time, and then accurately collect and calculate the comprehensive optimization parameters by analyzing the changes in parameters between two adjacent monitoring times.

[0026] When determining the previous monitoring time, it is necessary to calculate the duration between two adjacent monitoring times and record this duration as the temperature gradual change duration, that is, the time required for the rotor temperature change to reach a temperature unit. Specifically, the calculation method for the duration of temperature gradual change is as follows: The database is used to retrieve all the working logs of the Roots vacuum pump. The maximum value of the rotor temperature in the working log is recorded as the temperature peak value, and the working logs with temperature peak values ​​exceeding the calibrated temperature value are recorded as valid logs, thus obtaining A valid logs. The calibrated temperature value is the minimum temperature value that will cause thermal expansion deformation of the Roots vacuum pump rotor, so the valid logs can be accurately filtered out from the working logs. The time when the first calibrated peak value appears in the valid log is recorded as the start time, the time when the first temperature peak value appears is recorded as the end time, and the duration between the start time and the end time is recorded as the temperature change duration. The temperature peak values ​​in A valid logs are subtracted from the calibrated temperature values, and the differences are compared with the corresponding temperature change durations to calculate the A sub-gradual change durations. The formula for calculating the sub-gradient duration is: ; In the formula, The duration of the change is gradual. This represents the peak temperature. To calibrate the temperature value, This refers to the duration of temperature change. The average duration is calculated by summing the durations of A sub-gradients. The average duration is then calculated by summing the durations of C sub-gradients that are less than the average duration.

[0027] After calculating the temperature gradient duration, the previous and next monitoring times can be obtained by working backward or forward at intervals of one temperature gradient duration. In this embodiment, when determining the previous monitoring time, the previous monitoring time is obtained by counting backward along the timeline from the current monitoring time as the starting point, after counting backward by one temperature change duration.

[0028] The comprehensive optimization parameters are multi-dimensional parameters that may affect the rotor expansion and deformation of the Roots vacuum pump at the current monitoring time, so that the comprehensive optimization parameters can maintain a dynamic relationship with the amount of rotor expansion and deformation. Specifically, the comprehensive optimization parameters include air extraction volume, vibration amplitude fluctuation value, noise intensity, and instantaneous temperature difference dispersion rate; Pumping volume refers to the flow rate of gas discharged by the Roots vacuum pump when it is pumping vacuum at the current monitoring time, and serves as the basis for judging whether the pumping efficiency of the Roots vacuum pump has changed. In this embodiment, the pumping volume is obtained by detecting the flow sensor installed at the outlet.

[0029] The vibration amplitude fluctuation value refers to the range of change between the vibration amplitude of the Roots vacuum pump at the current monitoring time and the vibration amplitude at the previous monitoring time. It can represent the vibration situation of the Roots vacuum pump at two monitoring times. When the vibration amplitude fluctuation value is larger, it indicates that the frictional vibration between the rotors and between the rotor and the inner wall of the housing of the Roots vacuum pump is more serious, and the probability of the rotor undergoing thermal expansion deformation is greater. Specifically, when collecting vibration amplitude fluctuation values, the vibration peak values ​​at the previous monitoring time and the current monitoring time are detected by vibration sensors, and the vibration amplitude fluctuation value is calculated by subtracting the vibration peak value at the current monitoring time from the vibration peak value at the previous monitoring time.

[0030] Noise intensity refers to the operating noise of the Roots vacuum pump when it is evacuating at the current monitoring time. The greater the noise intensity, the more severe the frictional vibration between the rotors and between the rotor and the inner wall of the housing, and the greater the probability of thermal expansion and deformation of the rotor. In this embodiment, the noise intensity is obtained by detecting the noise using a sound sensor.

[0031] The instantaneous temperature difference dispersion rate refers to the percentage of times the difference between the real-time gas temperature discharged from the outlet of the Roots vacuum pump and the standard gas temperature is separated between the previous monitoring time and the current monitoring time. It can be used to represent the temperature change of the gas discharged from the Roots vacuum pump when it is evacuating. The larger the instantaneous temperature difference dispersion rate, the lower the probability of the rotor undergoing thermal expansion deformation. The method for collecting the instantaneous temperature difference dispersion is as follows: The time it takes for the rotor of the Roots vacuum pump to rotate one revolution is retrieved from the database and recorded as the single revolution time. The length between the outlet of the Roots vacuum pump and the infrared temperature sensor is retrieved and recorded as the exhaust distance value. Divide the exhaust distance value by the exhaust speed to obtain the exhaust time, and add the single-cycle time to the exhaust time to calculate the temperature change time; Starting from the previous monitoring time and ending at the current monitoring time, and using a temperature change duration interval as the standard, mark B temperature change points with equal duration distribution; The rotor temperature at B temperature change points is detected by infrared sensors to obtain B point temperatures. The temperature difference is calculated by subtracting each of the B point temperatures from the calibrated temperature value. Point temperatures that are less than a preset temperature threshold are recorded as discrete temperatures. The preset temperature threshold is the maximum value of the temperature difference when recorded as discrete temperatures, thereby representing the actual temperature change at each temperature change point. According to the chronological order, the temperatures of B points are numbered in ascending order. The positional relationship between discrete temperatures and point temperatures is observed. The number of discrete temperatures whose previous and next numbers are both point temperatures, and the number of discrete temperatures whose previous two and next two numbers are both point temperatures are obtained, respectively. The first discrete value and the second discrete value are obtained. The first and second discrete values ​​are assigned corresponding proportional coefficients and then added together. The instantaneous temperature difference dispersion rate is calculated by comparing the sum with the number of temperature points. The formula for calculating the instantaneous temperature difference dispersion rate is: ; In the formula, The instantaneous temperature difference dispersion rate, This is the first discrete value. This is the second discrete value. The number of temperature points, , These are the proportionality coefficients for the first discrete value and the second discrete value, respectively. .

[0032] In this embodiment, by observing the positional relationship between point temperature and discrete temperature, the positional distribution of the two can be specifically represented, thereby enabling targeted collection and analysis of exhaust temperature changes between two adjacent monitoring times.

[0033] S03: The comprehensive optimization parameters and operating indicators are summarized into expansion deformation parameters, and the expansion deformation parameters are input into the expansion deformation prediction model to predict the expansion deformation amount of the rotor and determine whether to execute the optimization compensation mode. After obtaining the comprehensive optimization parameters and operating indicators, the comprehensive optimization parameters and operating indicators can be summarized to generate expansion deformation parameters. The summarized expansion deformation parameters are then input into the expansion deformation prediction model to intelligently predict the specific thermal expansion deformation of the rotor of the Roots vacuum pump at the current monitoring time and obtain the expansion deformation amount corresponding to the expansion deformation parameters.

[0034] The expansion deformation prediction model is based on machine learning models in artificial intelligence technology. It combines a large number of expansion deformation parameters and expansion deformation amounts as training data and is obtained after repeated optimization and iterative training. In this embodiment, the expansion deformation amount is used to represent the magnitude of thermal expansion deformation of the rotor in the Roots vacuum pump when the temperature rises; specifically, the expansion deformation amount is obtained by disassembling the rotor and measuring its dimensions.

[0035] When using the expansion deformation prediction model, it needs to be trained first. Specifically, the training method for the expansion deformation prediction model is as follows: Under ideal experimental conditions, multiple sets of comprehensive optimization parameters, operating indicators and expansion deformation amount of the Roots vacuum pump are collected in advance. A set of comprehensive optimization parameters and a set of operating indicators are summarized into a set of expansion deformation parameters, and multiple sets of expansion deformation parameters are converted into multiple sets of feature vectors. The expansion deformation is converted into labels, multiple sets of labels are obtained, and multiple sets of feature vectors are matched one-to-one with multiple sets of labels. One feature vector corresponds to one label, forming a set of training data. Multiple sets of training data constitute a dataset. The labeled training data is divided into a training set and a test set. 70% of the training data is used as the training set, and 30% of the training data is used as the test set. The feature vector is used as the input to the expansion deformation prediction model, and the label corresponding to the feature vector is used as the output of the expansion deformation prediction model. The expansion deformation prediction model is trained using the training set and tested using the test set. An error threshold is preset for the expansion deformation prediction model. When the mean of the prediction errors of all training data in the test set is less than the preset error threshold, the expansion deformation prediction model is obtained.

[0036] After training and obtaining the expansion deformation prediction model, the collected comprehensive optimization parameters and operating indicators can be summarized into expansion deformation parameters and input into the expansion deformation prediction model to predict the expansion deformation amount of the Roots vacuum pump at the current monitoring time.

[0037] The optimized compensation mode is a working mode used to optimize and compensate for the thermal expansion deformation of the rotor when the rotor of the Roots vacuum pump experiences abnormal expansion deformation. In other words, the working state of the rotor of the Roots vacuum pump can be adjusted in the optimized compensation mode. Specifically, the method for determining the optimized compensation mode is as follows: The predicted amount of expansion deformation is compared with the preset expansion deformation threshold. The preset expansion deformation threshold is the critical value for determining the amount of expansion deformation when the optimized compensation mode is executed and when the optimized compensation mode is not executed, thus providing an accurate numerical basis for whether to execute the optimized compensation mode. When the predicted expansion deformation is greater than or equal to the preset expansion deformation threshold, it indicates that the thermal expansion deformation of the rotor of the Roots vacuum pump exceeds the safe range at the current monitoring time, which will cause excessive friction between rotors and between the rotor and the inner wall of the housing, resulting in continuous thermal deformation. In this case, the optimization compensation mode is executed. When the predicted expansion deformation is less than the preset expansion deformation threshold, it means that the thermal expansion deformation of the rotor of the Roots vacuum pump at the current monitoring time has not exceeded the safe range, and will not cause excessive friction between rotors or between the rotor and the inner wall of the housing, resulting in continuous thermal deformation. Therefore, it is determined that the optimization compensation mode will not be executed.

[0038] S04: Under the optimized compensation mode, a simulation model of the Roots vacuum pump is constructed, the model data of the simulation model is initialized, and the theoretical compensation amount of the simulation model is simulated. When executing the optimization compensation mode, it is necessary to optimize and compensate for the thermal expansion deformation of the rotor of the Roots vacuum pump. In order to ensure the accuracy of the optimization compensation operation, the physical structure of the Roots vacuum pump can be converted into a simulation model of a virtual structure, and the specific values ​​for optimizing compensation of the rotor can be calculated by simulating the virtual structure. In this embodiment, the simulation model is a three-dimensional model constructed based on the physical structure and shape of the Roots vacuum pump and combined with model simulation technology.

[0039] Specifically, the method for constructing the simulation model is as follows: With the Roots vacuum pump disassembled, the point cloud data of all parts is scanned by a laser scanner. After noise reduction, filtering and downsampling of the point cloud data, the cleaned point cloud data is obtained. The cleaned point cloud data is imported into the same three-dimensional space. The model reference point is selected, and the model outline is constructed based on mesh reconstruction technology. The air inlet pipe on the model outline is simulated to be connected to the vacuum equipment. The model reference point can lay the positional foundation for the establishment of the simulation model, ensure that other structures of the simulation model can maintain spatial alignment, and avoid the phenomenon of inconsistent center points when the simulation model is constructed. The control logic and operating permissions of the Roots vacuum pump are retrieved from the database, and simulation logic and permissions consistent with the control logic and operating permissions are simulated on the model outline, thus converting the model outline into a simulation model.

[0040] It should be noted that the control logic and operating permissions are the core logic and specific operating permissions for maintaining the normal operation of the Roots vacuum pump, while the simulation logic and simulation permissions are the specific parameters that ensure the simulated operating state of the simulation model is consistent with that of the Roots vacuum pump.

[0041] After the simulation model is built, it can only be consistent with the Roots vacuum pump in terms of structure and form. It cannot be directly used for the simulation of the Roots vacuum pump. The model data of the simulation model needs to be initialized so that the simulation model can be basically consistent with the actual operating state of the Roots vacuum pump. Specifically, the model data includes aerodynamic parameters, material parameters, and state parameters; Aerodynamic parameters refer to the parameters related to the forces acting on gas flow when the simulation model is used, which can represent the aerodynamic performance of the simulation. Specifically, aerodynamic parameters include gas velocity, gas temperature, and gas type; these are used to represent the initial flow velocity, initial flow temperature, and specific gas type of the gas imported into the simulation model.

[0042] Material parameters refer to the material properties of specific parts of the Roots vacuum pump when the simulation model is used for simulation. Specifically, material parameters include rotor material, rotor curvature, and gas compression ratio; that is, they can represent the specific type of material used to manufacture the rotor, the magnitude of the rotor curvature, and the compression ratio of the vacuum gas in the simulation model.

[0043] State parameters refer to the operational performance of the Roots vacuum pump during simulation. State parameters include pumping power and pumping speed; that is, they can represent the working power and rotor speed of the simulation model during the simulation.

[0044] After initializing all model data, the theoretical compensation amount of the simulation model can be simulated in the virtual state, so that the theoretical compensation amount can serve as the data theoretical basis for the rotor of the Roots vacuum pump in subsequent optimization compensation. In this embodiment, the theoretical compensation amount refers to the magnitude of the expansion deformation reduction compensation required for the rotor of the Roots vacuum pump.

[0045] Specifically, the simulation method for the theoretical compensation amount is as follows: In CFD software, a basic scene with trigger windows is created, the simulation model is imported into the basic scene, and the trigger windows are initialized to a hidden state. The trigger window is used to provide the limiting conditions for simulation operations in the simulation scene. Through the trigger window in different states, the simulation in the simulation scene can be started and stopped. The states of the trigger window include hidden state and exposed state. When the state is hidden, no simulation operation is performed, and vice versa. Establish scene positions within the basic scene, establish simulation positions and state positions on the simulation model, import aerodynamic parameters into the scene positions, and import material parameters and state parameters into the simulation positions and state positions respectively, thereby upgrading the basic scene into a simulation scene. Within the simulated scenario, configure simulation conditions that are compatible with the simulation logic and permissions. Switch the trigger window from a hidden state to a visible state. Using a complete simulation run by the simulation model as the standard, query the simulation results of the simulated scenario to obtain the theoretical compensation amount. Simulation conditions refer to simulation passwords that are compatible with the simulation logic and permissions, allowing the simulation conditions to directly affect the trigger window and switch it from a hidden state to a visible state.

[0046] In this embodiment, the simulated theoretical compensation amount can only be used as the value of the rotor expansion deformation reduction under ideal conditions, resulting in a certain gap between the theoretical compensation amount and the actual compensation amount.

[0047] S05: Eliminate the error factors of the theoretical compensation amount, calculate the actual compensation amount, and optimize the compensation of the rotor of the Roots vacuum pump based on the actual compensation amount. Since the theoretical compensation amount is not the direct basis for the expansion, deformation and reduction operation of the rotor of the Roots vacuum pump, it is necessary to optimize and adjust the theoretical compensation amount to eliminate the error factors that affect the theoretical compensation amount, so that the theoretical compensation amount can be reduced to the actual compensation amount. Error factors include thermal conduction attenuation and gravitational rotational stretching. Thermal conduction attenuation is used to represent the continuous effect of rotor temperature rise on the magnitude of expansion deformation, while gravitational rotational stretching is used to represent the continuous effect of rotor rotational stretching on the magnitude of expansion deformation.

[0048] The method for calculating the actual compensation amount is as follows: Use the rotor temperature at the current monitoring moment as the reference temperature, and look up the heat conduction attenuation coefficient corresponding to the reference temperature. The difference between the reference temperature and the normal temperature is calculated, and then the difference is multiplied by the thermal conductivity attenuation coefficient to calculate the thermal conductivity attenuation. The thermal conductivity attenuation coefficient refers to the degree of influence of the rotor of the Roots vacuum pump on the expansion and deformation under continuous temperature changes. The thermal conductivity attenuation coefficient is usually preset and is between 0 and 1. The formula for calculating the thermal conductivity attenuation is: ; In the formula, This is the amount of thermal conduction attenuation. As the reference temperature, At normal temperature The thermal conductivity attenuation coefficient; Find the tensile deformation coefficient of the Roots vacuum pump, subtract the evacuation time at the current monitoring moment from the normal time, and multiply the difference by the tensile deformation coefficient to calculate the amount of gravity rotational stretching. The tensile deformation coefficient multiplication refers to the degree of influence of the rotor of the Roots vacuum pump on the expansion deformation under continuous rotational stretching. The tensile deformation coefficient is usually preset and is between 0 and 1. The formula for calculating the amount of tension due to gravity rotation is: ; In the formula, This represents the amount of stretching due to gravity rotation. The duration of the current monitoring interval. For standard duration, The tensile deformation coefficient; The actual compensation is calculated by adding the theoretical compensation, the thermal conduction attenuation, and the gravitational rotation stretching.

[0049] After calculating the actual compensation amount, this actual compensation amount can be used as the actual numerical basis for the expansion deformation reduction of the rotor of the Roots vacuum pump, thus providing accurate guidance for subsequent optimization compensation of the rotor. Specifically, when optimizing and compensating the rotor of a Roots vacuum pump, it is necessary to cool down the rotor to reduce the extent of expansion and deformation caused by heat, until the rotor temperature returns to below normal. This ensures that the rotor does not expand or deform due to heat, or that the expansion and deformation is minimal, avoiding direct friction between rotors or between the rotor and the inner wall of the casing that would cause thermal expansion and deformation. This achieves the effect of optimizing and compensating the rotor of the Roots vacuum pump.

[0050] Example 2: Please refer to Figure 2 As shown, the parts not described in detail in this embodiment are described in Embodiment 1. A rotor optimization compensation system for Roots vacuum pumps is provided to implement a rotor optimization compensation method for Roots vacuum pumps. The system includes a first execution module, a parameter acquisition module, a second execution module, a theoretical compensation module, and a real compensation module. The modules are connected to each other via wired or wireless networks. The first execution module is used to identify the operating status of the Roots vacuum pump by collecting and analyzing its operating indicators, and to determine whether to execute the optimization analysis mode. The parameter acquisition module is used to calculate the temperature gradient duration of the Roots vacuum pump in the optimization analysis mode, determine the previous monitoring time, and acquire the comprehensive optimization parameters of the Roots vacuum pump from the previous monitoring time to the current monitoring time. The second execution module is used to summarize the comprehensive optimization parameters and operating indicators into expansion deformation parameters, input the expansion deformation parameters into the expansion deformation prediction model, predict the expansion deformation amount, and determine whether to execute the optimization compensation mode. The theoretical compensation module is used to construct a simulation model of the Roots vacuum pump using mesh reconstruction technology under optimized compensation mode, initialize the aerodynamic parameters, material parameters and state parameters of the simulation model, and simulate the theoretical compensation amount of the simulation model. The true compensation module is used to eliminate the error factors of the theoretical compensation amount, calculate the true compensation amount, and optimize the compensation of the rotor of the Roots vacuum pump based on the true compensation amount.

[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing compensation of the rotor of a Roots vacuum pump, characterized in that, include: S01: By collecting and analyzing the operating parameters of the Roots vacuum pump, including evacuation time and rotor temperature, the operating status of the Roots vacuum pump is identified, and it is determined whether to execute the optimization analysis mode; if the optimization analysis mode is executed, proceed to S02. S02: In the optimization analysis mode, the temperature change time of the Roots vacuum pump is calculated, the previous monitoring time is determined, and the comprehensive optimization parameters of the Roots vacuum pump between the previous monitoring time and the current monitoring time are collected. The comprehensive optimization parameters include pumping volume, vibration amplitude fluctuation value, noise intensity and instantaneous temperature difference dispersion rate. S03: Summarize the comprehensive optimization parameters and operating indicators into expansion deformation parameters, input the expansion deformation parameters into the expansion deformation prediction model, predict the expansion deformation amount, and determine whether to execute the optimization compensation mode; if the optimization compensation mode is executed, proceed to S04. S04: In the optimized compensation mode, a simulation model of the Roots vacuum pump is constructed using mesh reconstruction technology. The aerodynamic parameters, material parameters, and state parameters of the simulation model are initialized, and the theoretical compensation amount of the simulation model is simulated. S05: Eliminate the error factors of the theoretical compensation amount, calculate the actual compensation amount, and optimize the compensation of the rotor of the Roots vacuum pump based on the actual compensation amount.

2. The method for optimizing and compensating the rotor of a Roots vacuum pump according to claim 1, characterized in that, The method for determining whether to execute the optimization analysis mode is as follows: When the evacuation time is greater than or equal to the normal time, the evacuation time is recorded as an abnormal indicator; when the rotor temperature is greater than or equal to the normal temperature, the rotor temperature is recorded as an abnormal indicator. If the number of abnormal indicators is 1 or 2, the Roots vacuum pump is in monitoring status, and the optimization analysis mode is executed. If the number of abnormal indicators is 0, the Roots vacuum pump is in normal operating condition, and the optimization analysis mode is not executed.

3. The method for optimizing and compensating the rotor of a Roots vacuum pump according to claim 2, characterized in that, The method for calculating the duration of temperature gradual change is as follows: The maximum rotor temperature in the Roots vacuum pump's work log is recorded as the temperature peak value, and work logs with temperature peak values ​​exceeding the calibrated temperature value are recorded as valid logs, resulting in A valid logs; The time when the first calibrated peak value appears in the valid log is recorded as the start time, the time when the first temperature peak value appears is recorded as the end time, and the duration between the start time and the end time is recorded as the temperature change duration. The temperature peak values ​​in A valid logs are subtracted from the calibrated temperature values, and the differences are compared with the corresponding temperature change durations to calculate the A sub-gradual change durations. The average duration is calculated by summing the durations of A sub-gradients. The average duration is then calculated by summing the durations of C sub-gradients that are less than the average duration.

4. The method for optimizing compensation of the rotor of a Roots vacuum pump according to claim 3, characterized in that, To determine the previous monitoring time, the current monitoring time is used as the starting point, and the previous monitoring time is obtained by counting backwards along the timeline for a temperature change duration.

5. The method for optimizing compensation of a Roots vacuum pump rotor according to claim 4, characterized in that, The method for collecting the instantaneous temperature difference dispersion is as follows: Find out the time it takes for the rotor of the Roots vacuum pump to rotate one revolution, and record it as the single revolution time. Find out the length between the outlet of the Roots vacuum pump and the infrared temperature sensor, and record it as the exhaust distance value. Divide the exhaust distance value by the exhaust speed to obtain the exhaust duration, and add the single-cycle duration to the exhaust duration to calculate the temperature change duration. Using the previous monitoring time as the starting point and the current monitoring time as the ending point, and using a temperature change duration interval as the standard, mark B temperature change points with equal duration distribution. The rotor temperature at B temperature change points is detected respectively to obtain B point temperatures. The temperature difference is calculated by subtracting the B point temperatures from the calibrated temperature value one by one, and the point temperatures that are less than the preset temperature threshold are recorded as discrete temperatures. According to the chronological order, the temperatures of B points are numbered in ascending order, and the number of discrete temperatures where the previous and next numbers are both point temperatures, and the number of discrete temperatures where the previous two numbers and the next two numbers are both point temperatures are obtained, respectively, to obtain the first discrete value and the second discrete value. The first and second discrete values ​​are assigned corresponding proportional coefficients and then added together. The instantaneous temperature difference dispersion rate is calculated by comparing the sum with the number of temperature points.

6. The method for optimizing compensation of a Roots vacuum pump rotor according to claim 5, characterized in that, The method for determining the optimized compensation mode is as follows: When the predicted expansion deformation is greater than or equal to the preset expansion deformation threshold, the optimized compensation mode is executed. If the predicted expansion deformation is less than the preset expansion deformation threshold, the optimized compensation mode will not be executed.

7. The method for optimizing compensation of a Roots vacuum pump rotor according to claim 6, characterized in that, The method for constructing the simulation model is as follows: The point cloud data of all parts is scanned by a laser scanner. After the point cloud data is denoised, filtered and downsampled, the cleaned point cloud data is obtained. The cleaned point cloud data is imported into the same three-dimensional space, the model reference point is selected, the model outline is constructed based on mesh reconstruction technology, and the air inlet pipe on the model outline is simulated to be connected to the vacuum equipment. The control logic and operating permissions of the Roots vacuum pump are retrieved from the database, and simulation logic and permissions consistent with the control logic and operating permissions are simulated on the model outline, thus converting the model outline into a simulation model.

8. The method for optimizing compensation of a Roots vacuum pump rotor according to claim 7, characterized in that, The simulation method for the theoretical compensation amount is as follows: In CFD software, a basic scene with a trigger window is created, the simulation model is imported into the basic scene, and the trigger window is initialized to a hidden state. Establish scene positions within the basic scene, establish simulation positions and state positions on the simulation model, import aerodynamic parameters into the scene positions, and import material parameters and state parameters into the simulation positions and state positions respectively, thereby upgrading the basic scene into a simulation scene. Configure simulation conditions that match the simulation logic and permissions within the simulation scenario, switch the trigger window from a hidden state to a visible state, and use the completion of a full simulation by the simulation model as the standard to query the simulation results of the simulation scenario and obtain the theoretical compensation amount.

9. The method for optimizing compensation of a Roots vacuum pump rotor according to claim 8, characterized in that, Error factors include thermal conduction attenuation and gravitational rotation stretching; The method for calculating the actual compensation amount is as follows: The rotor temperature at the current monitoring moment is used as the reference temperature. The corresponding heat conduction attenuation coefficient is found. The difference between the reference temperature and the normal temperature is calculated, and the difference is multiplied by the heat conduction attenuation coefficient to calculate the heat conduction attenuation. Find the tensile deformation coefficient of the Roots vacuum pump, subtract the evacuation time at the current monitoring moment from the normal time, and multiply the difference by the tensile deformation coefficient to calculate the gravitational rotation tensile amount. The actual compensation is calculated by adding the theoretical compensation, the thermal conduction attenuation, and the gravitational rotation stretching.

10. A rotor optimization compensation system for a Roots vacuum pump, used to implement the rotor optimization compensation method for a Roots vacuum pump as described in any one of claims 1-9, characterized in that, It includes a first execution module, a parameter acquisition module, a second execution module, a theoretical compensation module, and a real compensation module, wherein the modules are connected to each other via wired or wireless network. The first execution module is used to identify the operating status of the Roots vacuum pump by collecting and analyzing its operating indicators, and to determine whether to execute the optimization analysis mode. The parameter acquisition module is used to calculate the temperature gradient duration of the Roots vacuum pump in the optimization analysis mode, determine the previous monitoring time, and acquire the comprehensive optimization parameters of the Roots vacuum pump from the previous monitoring time to the current monitoring time. The second execution module is used to summarize the comprehensive optimization parameters and operating indicators into expansion deformation parameters, input the expansion deformation parameters into the expansion deformation prediction model, predict the expansion deformation amount, and determine whether to execute the optimization compensation mode. The theoretical compensation module is used to construct a simulation model of the Roots vacuum pump using mesh reconstruction technology in the optimized compensation mode, initialize the aerodynamic parameters, material parameters, and state parameters of the simulation model, and simulate the theoretical compensation amount of the simulation model. The real compensation module is used to eliminate the error factors of the theoretical compensation amount, calculate the real compensation amount, and optimize the compensation of the rotor of the Roots vacuum pump based on the real compensation amount.

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