High-temperature molten salt pump rotor dynamic test system based on mechanical sensor

Abstract

The invention discloses a high-temperature molten salt pump rotor dynamic test system based on a mechanical sensor, and relates to the technical field of new energy and mechanical engineering, and the system comprises a multi-source data collection module which collects an original state signal in real time through a sensor designed through high-temperature protection; the data preprocessing module carries out data preprocessing on the original state signal to generate structured time sequence data and store the structured time sequence data; the rotor dynamics analysis module is used for obtaining dynamics parameters and generating a stability evaluation result based on the structured time sequence data; the dynamic working condition control module adjusts the rotating speed of a motor and the opening degree of an outlet valve according to a stability evaluation result; and the specification generation and output module is used for generating a standardized specification document. The device adapts to the corrosive environment through the multi-level high-temperature protection design, precise analysis of kinetic parameters of the rotor, stability grading evaluation and variable-working-condition dynamic simulation are achieved, and the accuracy and efficiency of kinetic testing of the high-temperature molten salt pump rotor are improved.

Description

Technical Field

[0001] The present invention relates to the technical fields of new energy and mechanical engineering, and particularly relates to a rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor. Background Technique

[0002] The performance of the high-temperature molten salt pump, which is the core equipment of solar thermal power generation, directly affects the system stability and efficiency. As the heart of the solar thermal power generation system, the high-temperature molten salt pump needs to operate continuously in a high-temperature and strong-corrosion environment, and its rotor dynamics characteristics are the key factors restricting the reliability of the equipment.

[0003] At present, the key technologies of high-temperature molten salt pumps in China rely on imports, and there are significant bottlenecks in existing testing methods, specifically manifested as follows: traditional sensors and testing systems are difficult to withstand the high temperature and corrosiveness of molten salt, which easily leads to signal distortion and even equipment damage, and the adaptability to high-temperature environments is insufficient; there is a lack of full-condition testing specifications for high-temperature molten salt pumps, and the measurement methods for rotor dynamics parameters under variable rotational speeds and flows have not been unified, and the standardization of the testing process is lacking; existing systems cannot achieve a control closed-loop, it is difficult to evaluate the rotor stability in real time and dynamically adjust the working conditions, resulting in low testing efficiency and insufficient data reliability, and weak dynamic analysis capabilities; there is no standardized process for testing the performance of high-temperature molten salt pumps in China, which restricts the breakthrough of domestic technologies and the industry promotion, and the specification system is blank. Therefore, there is an urgent need to develop a testing system that can adapt to high-temperature corrosion environments and has the capabilities of accurate parameter measurement and dynamic working condition simulation to fill the domestic technical gap and promote the process of independent development of solar thermal power generation equipment. For this reason, a rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor is proposed herein. Summary of the Invention

[0004] The purpose of the present invention is to provide a rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor to solve the problems raised in the above background technique.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor includes a multi-source data acquisition module, a data preprocessing module, a rotor dynamics analysis module, a dynamic working condition control module, and a specification generation and output module;

[0007] The multi-source data acquisition module is used to collect the original state signals of the rotor of the high-temperature molten salt pump in real time through sensors with high-temperature protection design;

[0008] The data preprocessing module is used to preprocess the original state signals of the multi-source data acquisition module to generate structured time-series data, and store the structured time-series data in a database;

[0009] The rotor dynamics analysis module is used to obtain the rotor system dynamics parameters based on the structured time-series data, and generate a stability evaluation result accordingly;

[0010] The dynamic operating condition control module is used to dynamically adjust the motor speed and the opening degree of the outlet valve of the high-temperature molten salt pump according to the stability evaluation result, and simulate the variable operating condition scenario;

[0011] The specification generation and output module is used to automatically generate a standardized specification document containing the rotor system dynamics parameters, the stability evaluation result, the motor speed and the opening degree of the outlet valve, and output the standardized specification document to the user.

[0012] Preferably, the sensors with high-temperature protection design include IEPE triaxial piezoelectric acceleration sensors, eddy current displacement sensors, piezoelectric force sensors and platinum resistance temperature sensors;

[0013] The sensor housings of the IEPE triaxial piezoelectric acceleration sensors, eddy current displacement sensors, piezoelectric force sensors and platinum resistance temperature sensors are coated with alumina ceramic coatings, and a double-layer air-cooled heat insulation cover with nitrogen as the cooling gas is configured. At the same time, the sensor interfaces are sealed with metal bellows, thereby realizing the high-temperature protection design and being used to adapt to the high-temperature and molten salt corrosive environment.

[0014] Preferably, in the multi-source data acquisition module, the process of real-time collecting the original state signals of the high-temperature molten salt pump rotor is as follows:

[0015] The original state signals include vibration acceleration, whirling displacement, axial force, radial force, bearing temperature and shaft seal temperature;

[0016] The IEPE triaxial piezoelectric acceleration sensors are deployed in the X, Y and Z directions of the rotor bearing of the high-temperature molten salt pump rotor to collect vibration acceleration in real time;

[0017] The eddy current displacement sensors are installed on the pump shaft of the high-temperature molten salt pump rotor to collect whirling displacement in real time;

[0018] The piezoelectric force sensors are deployed at the rotor support structure of the high-temperature molten salt pump rotor to collect axial force and radial force in real time;

[0019] The platinum resistance temperature sensors are embedded in the bearing and shaft seal positions of the high-temperature molten salt pump rotor to collect bearing temperature and shaft seal temperature in real time.

[0020] Preferably, in the data preprocessing module, the process of preprocessing the original state signals of the multi-source data acquisition module is as follows:

[0021] The original state signal is denoised by the Daubechies5 wavelet basis, the denoised original state signal is filtered by a Butterworth low-pass filter, and the original state signal after filtering is subjected to signal normalization processing to map the original state signal after filtering to the interval [0,1], thereby obtaining structured time-series data including time-series vibration acceleration, time-series whirling displacement, time-series axial force, time-series radial force, time-series bearing temperature, and time-series gland seal temperature. The Daubechies5 wavelet basis is a commonly used wavelet basis function in wavelet analysis, and the normalization processing is performed using the min-max normalization method.

[0022] Preferably, in the rotor dynamics analysis module, the process of obtaining the rotor system dynamics parameters based on the structured time-series data:

[0023] Perform spectral analysis on the time-series vibration acceleration in the structured time-series data through fast Fourier transform to obtain a vibration acceleration spectrogram, and calculate the vibration acceleration spectrogram through the significant peak frequency formula to obtain the natural frequency , and for the natural frequency Calculate through the critical speed formula to obtain the critical speed ;

[0024] The significant peak frequency formula is:

[0025] ;

[0026] where is the natural frequency, is the acceleration spectrogram;

[0027] The critical speed formula is:

[0028] 60;

[0029] where is the natural frequency, is the critical speed;

[0030] Process the time-series whirling displacement in the structured time-series data through the logarithmic decrement method to obtain the damping ratio , and calculate the damping ratio through the damping coefficient formula to obtain the damping coefficient , and the logarithmic decrement method is an important method for analyzing the damping characteristics in a damped vibration system;

[0031] The damping coefficient formula is:

[0032] ;

[0033] where is the damping coefficient, is the damping ratio, is the natural frequency, is the equivalent mass of the rotor;

[0034] The temporal whirling displacement, temporal axial force, and temporal radial force in the structured temporal data are calculated through the stiffness coefficient formula to obtain the preliminary stiffness coefficient , and the preliminary stiffness coefficient and the temporal bearing temperature and temporal shaft seal temperature in the structured temporal data are calculated through the stiffness temperature compensation formula for stiffness correction processing to obtain the stiffness coefficient , and based on this, the rotor system dynamic parameters including the natural frequency , critical speed , stiffness coefficient and damping coefficient are obtained;

[0035] The stiffness coefficient formula is:

[0036] ;

[0037] where, is the temporal whirling displacement, is the temporal axial force, is the temporal radial force, is the preliminary stiffness coefficient;

[0038] The stiffness temperature compensation formula is:

[0039] ;

[0040] where, is the temporal bearing temperature, is the temporal shaft seal temperature, is the material temperature coefficient, is the room temperature, is the preliminary stiffness coefficient, is the stiffness coefficient.

[0041] Preferably, in the rotor dynamic analysis module, the process of generating the stability evaluation result:

[0042] For the natural frequency , critical speed , stiffness coefficient and damping coefficient are calculated through the stability fusion formula to obtain the comprehensive stability index ;

[0043] The stability fusion formula is:

[0044] ;

[0045] Among them, is 0.3, is 0.3, is 0.2, is 0.2, is the natural frequency, is the critical speed, is the stiffness coefficient, is the damping coefficient, is the safety threshold of the damping coefficient, is the safety threshold of the stiffness coefficient, is the design speed, is the minimum frequency of the safe range of the natural frequency, is the maximum frequency of the safe range of the natural frequency, is the comprehensive stability index;

[0046] Compare the comprehensive stability index with the preset multi-level threshold of the stability index. If , the stability evaluation result is the stable state;

[0047] If , the stability evaluation result is the critical state;

[0048] If , the stability evaluation result is the unstable state.

[0049] Preferably, in the dynamic working condition control module, the process of dynamically adjusting the motor speed and the opening of the outlet valve of the high-temperature molten salt pump:

[0050] If the stability evaluation result is the stable state, then keep the current motor speed of the high-temperature molten salt pump and the opening of the outlet valve , and allow to and to be adjusted with a small amplitude of for exploring a higher comprehensive stability index ;

[0051] If the stability evaluation result is the critical state, then adjust the current motor speed of the high-temperature molten salt pump to and the opening of the outlet valve to ;

[0052] If the stability evaluation result is the unstable state, then adjust the current motor speed of the high-temperature molten salt pump to and the opening of the outlet valve to .

[0053] Preferably, in the specification generation and output module, the process of generating a standardized specification document is as follows:

[0054] Based on the Jinja2 template engine, the dynamic parameters of the rotor system, the stability evaluation results, the motor speed, and the opening degree of the outlet valve are dynamically filled into a preset template to generate a standardized specification document. The preset template is a LaTeX template or a Word template;

[0055] The Jinja2 template engine is a high-performance, flexible, and secure template engine written in Python.

[0056] Preferably, a high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor further includes a closed-loop feedback mechanism, specifically: after the multi-source data acquisition module synchronously acquires new original state signals after the dynamic condition control module dynamically adjusts the motor speed and the opening degree of the molten salt pump outlet valve, it is used to form a closed-loop test process.

[0057] Due to the adoption of the above technical solution, the technical progress achieved by the present invention compared with the prior art is:

[0058] The present invention solves the problem of insufficient adaptability of traditional sensors in a high-temperature molten salt environment through a multi-level high-temperature protection design, ensuring the stable acquisition of signals such as vibration acceleration; by means of Daubechies5 wavelet basis denoising, Butterworth filtering, and normalization processing, combined with spectrum analysis and logarithmic decrement method, accurately calculate dynamic parameters such as natural frequencies to improve data reliability; dynamically adjust the motor speed and valve opening degree based on stability evaluation, and collect new signals in real time through closed-loop feedback to construct a full-process dynamic test closed-loop to improve the variable condition evaluation efficiency; in addition, use the Jinja2 template engine to generate LaTe or Word standardized specification documents, fill the domestic gap in high-temperature molten salt pump test specifications, and promote the process of independent development of solar thermal power generation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0060] Figure 1 It is a schematic diagram of the system function module of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0062] An embodiment, such as Figure 1 described, a rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor, comprising a multi-source data acquisition module, a data preprocessing module, a rotor dynamics analysis module, a dynamic working condition control module, and a specification generation and output module;

[0063] The multi-source data acquisition module is used to collect the original state signals of the rotor of the high-temperature molten salt pump in real time through sensors with high-temperature protection design;

[0064] The data preprocessing module is used to preprocess the original state signals of the multi-source data acquisition module to generate structured time-series data and store the structured time-series data in a database;

[0065] The rotor dynamics analysis module is used to obtain the dynamic parameters of the rotor system based on the structured time-series data and generate a stability evaluation result accordingly;

[0066] The dynamic working condition control module is used to dynamically adjust the motor speed and the opening of the outlet valve of the high-temperature molten salt pump according to the stability evaluation result to simulate a variable working condition operation scenario;

[0067] The specification generation and output module is used to automatically generate a standardized specification document containing the dynamic parameters of the rotor system, the stability evaluation result, the motor speed, and the opening of the outlet valve, and output the standardized specification document to the user.

[0068] Further, the working principle of the present invention will be described below through embodiments:

[0069] For a high-temperature molten salt pump in a certain solar thermal power plant with a model of CSP-1000, a rated speed of 1800 r / min, and an operating temperature of 550 °C, a sensor group with a high-temperature protection design is deployed to collect in real time the original state signals of the rotor, including vibration acceleration, whirling displacement, axial force, radial force, bearing temperature, and shaft seal temperature. The sensor housing of the sensor group with a high-temperature protection design is coated with an alumina ceramic coating, and a double-layer air-cooled heat insulation cover with an intake air temperature of 25 °C and a flow rate of 5 L / min is configured. The interface is sealed with a 316L stainless steel bellows to achieve continuous operation for 500 hours without failure under the high temperature of 550 °C and the molten salt corrosion environment. The IEPE triaxial piezoelectric acceleration sensors of the sensor group with a high-temperature protection design are deployed in the X, Y, and Z directions of the bearing, with a sampling frequency of 10 kHz and a measuring range of ±50 g. The measured root mean square value of vibration acceleration is: X = 20 g, Y = 18 g, and Z = 22 g; the eddy current displacement sensor is installed radially on the pump shaft at 90°, with a measuring range of 0 to 2 mm and an accuracy of ±1 μm. The measured whirling displacement is 1 μm; the piezoelectric force sensor is installed on the rotor support structure, with an axial force measuring range of 0 to 5 kN and a measured value of 2000 N, and a radial force measuring range of 0 to 10 kN and a measured value of 5000 N; the platinum resistance temperature sensor is embedded in the bearing and shaft seal, and the measured bearing temperature is 520 °C and the shaft seal temperature is 530 °C.

[0070] Daubechies5 wavelet basis is used to remove high-frequency noise from the original state signals. For example, the vibration acceleration noise is reduced from 20 g to 0.5 g, and the signal-to-noise ratio of the whirling displacement is increased from 20 dB to 30 dB. After denoising the original state signals, mechanical noise and power interference are filtered out through a Butterworth low-pass filter. Then, through the min-max normalization method, signals such as vibration acceleration and whirling displacement are mapped to the [0,1] interval for subsequent dynamic analysis. Based on this, structured time series data containing time series vibration acceleration, whirling displacement, axial force, radial force, bearing temperature, and shaft seal temperature are generated and stored in the database for the analysis module to call.

[0071] Based on the structured time series data, FFT spectrum analysis is performed on the time series vibration acceleration to extract the peak frequency which is 25 Hz, and through the critical speed formula calculation, the critical speed is obtained as 1500 r / min; the O damping ratio is obtained through the logarithmic decrement method as 0.03. Combining with the equivalent mass of the rotor which is 50 kg, through the damping coefficient formula calculation, the damping coefficient is obtained as 94.25 N·s / m; for the time series whirling displacement, time series axial force, and time series radial force, through the stiffness coefficient formula calculation, the preliminary stiffness coefficient is obtained as 5.385×10 6N / m. Meanwhile, the preliminary stiffness coefficient and the sequential bearing temperature and sequential shaft seal temperature in the structured sequential data are calculated through the stiffness temperature compensation formula to obtain the stiffness coefficient which is approximately 5.32×10 6 N / m. Among them, in the stiffness temperature compensation formula is , is 20°C. Based on this, through the stability fusion formula calculation, S is obtained as 0.65. Among them, in the stability fusion formula is 100 N·s / m, is 5×10 6 N / m, is 1800 r / min, is 20 Hz, is 30 Hz. Due to , it is evaluated as a critical state.

[0072] According to the evaluation results, the motor speed is reduced from 1800 r / min to 1620 r / min, and the outlet valve opening is reduced from 70% to 59.5%. After adjustment, the original state signals are collected again, and through the data preprocessing module and the rotor dynamics analysis module in sequence, it is calculated that is 28 Hz, is 1680 r / min, S is 0.72, the evaluation result is a stable state, the vibration acceleration is reduced to 15 g, the whirling displacement is reduced to 0.6 μm, the bearing temperature is 515°C, and the shaft seal temperature is 525°C. At the same time, through measurement, this system completes the working condition optimization within 15 minutes through closed-loop feedback.

[0073] Based on the Jinja2 template engine, the LaTeX template is selected to generate a standardized specification document, including dynamic parameters, stability evaluation results, and real-time working condition data including motor speed and outlet valve opening.

[0074] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application.

Claims

1. A rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor, characterized in that , including: A multi-source data acquisition module for real-time collecting the original state signals of the rotor of a high-temperature molten salt pump through sensors with high-temperature protection design; A data preprocessing module for preprocessing the original state signals of the multi-source data acquisition module to generate structured time-series data and storing the structured time-series data in a database; A rotor dynamics analysis module for obtaining the dynamic parameters of the rotor system based on the structured time-series data and generating a stability evaluation result accordingly; A dynamic operating condition control module for dynamically adjusting the motor speed and the opening degree of the outlet valve of the high-temperature molten salt pump according to the stability evaluation result to simulate a variable operating condition scenario; A specification generation and output module for automatically generating a standardized specification document including the dynamic parameters of the rotor system, the stability evaluation result, the motor speed, and the opening degree of the outlet valve and outputting the standardized specification document to the user.

2. The high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor according to claim 1, characterized in that The sensors with high-temperature protection design include IEPE triaxial piezoelectric acceleration sensors, eddy current displacement sensors, piezoelectric force sensors, and platinum resistance temperature sensors; The sensor housings of the IEPE triaxial piezoelectric acceleration sensors, eddy current displacement sensors, piezoelectric force sensors, and platinum resistance temperature sensors are coated with alumina ceramic coatings, and a double-layer air-cooled heat insulation cover with nitrogen as the cooling gas is configured. At the same time, the sensor interfaces are sealed with metal bellows, thereby realizing the high-temperature protection design to adapt to high-temperature and molten salt corrosive environments.

3. A rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor according to claim 2, characterized in that In the multi-source data acquisition module, the process of real-time collecting the original state signals of the rotor of the high-temperature molten salt pump is as follows: The original state signals include vibration acceleration, whirling displacement, axial force, radial force, bearing temperature, and shaft seal temperature; Deploy the IEPE triaxial piezoelectric acceleration sensors in the X, Y, and Z directions of the rotor bearing of the high-temperature molten salt pump rotor to collect vibration acceleration in real time; The eddy current displacement sensor is arranged as installed on the pump shaft of the rotor of the high-temperature molten salt pump to collect the whirling displacement in real time; Deploy the piezoelectric force sensors at the rotor support structure of the high-temperature molten salt pump rotor to collect axial force and radial force in real time; Embed the platinum resistance temperature sensors at the bearing and shaft seal positions of the high-temperature molten salt pump rotor to collect bearing temperature and shaft seal temperature in real time.

4. A rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor according to claim 3, characterized in that, In the data preprocessing module, the process of preprocessing the original state signals of the multi-source data acquisition module is as follows: Denoise the original state signals through the Daubechies5 wavelet basis, filter the denoised original state signals through a Butterworth low-pass filter, and normalize the filtered original state signals, mapping the filtered original state signals to the [0, 1] interval, thereby obtaining structured time-series data including time-series vibration acceleration, time-series whirling displacement, time-series axial force, time-series radial force, time-series bearing temperature, and time-series shaft seal temperature; The Daubechies5 wavelet basis is a commonly used wavelet basis function in wavelet analysis.

5. The rotor dynamics test system of a high-temperature molten salt pump based on a mechanical sensor according to claim 4, characterized in that In the rotor dynamics analysis module, the process of obtaining the dynamic parameters of the rotor system based on the structured time-series data is as follows: Perform spectral analysis on the time-series vibration acceleration in the structured time-series data through fast Fourier transform to obtain the vibration acceleration spectrogram, and calculate the vibration acceleration spectrogram through the significant peak frequency formula to obtain the natural frequency , and calculate the natural frequency through the critical speed formula to obtain the critical speed ; The time-series vortex displacement in the structured time-series data is processed by the logarithmic decay method to obtain the damping ratio , and the damping ratio is calculated through the damping coefficient formula to obtain the damping coefficient ; The time-varying eddy displacement, time-varying axial force, and time-varying radial force in the structured time-series data are calculated through the stiffness coefficient formula to obtain the preliminary stiffness coefficient , and the preliminary stiffness coefficient , as well as the time-varying bearing temperature and time-varying shaft seal temperature in the structured time-series data, are calculated through the stiffness temperature compensation formula for stiffness correction processing to obtain the stiffness coefficient . Based on this, the dynamic parameters of the rotor system including the natural frequency , critical speed , stiffness coefficient , and damping coefficient are obtained; The logarithmic decrement method is an important method for analyzing the damping characteristics in a damped vibration system.

6. The rotor dynamics test system of a high-temperature molten salt pump based on a mechanical sensor according to claim 5, characterized in that In the rotor dynamics analysis module, the process of generating a stability evaluation result is as follows: For the natural frequency , critical speed , stiffness coefficient and damping coefficient , the comprehensive stability index is calculated through the stability fusion formula ; Compare with the multi-level thresholds of the preset stability index for the comprehensive stability index If , the stability evaluation result is a stable state; If , the stability assessment result is in a critical state; If , the stability assessment result is in an unstable state.

7. The rotor dynamics test system of a high-temperature molten salt pump based on a mechanical sensor according to claim 6, characterized in that, In the dynamic operating condition control module, the process of dynamically adjusting the motor speed and the opening degree of the outlet valve of the high-temperature molten salt pump: If the stability assessment result is in a stable state, maintain the current motor speed of the high-temperature molten salt pump and the opening of the outlet valve , and allow for and to be adjusted with a small amplitude of for exploring higher comprehensive stability indicators ; If the stability assessment result is in a critical state, adjust the motor speed of the current high-temperature molten salt pump to and the opening degree of the outlet valve to ; If the stability assessment result is in an unstable state, adjust the motor speed of the current high-temperature molten salt pump to and the opening degree of the outlet valve to .

8. A rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor according to claim 7, characterized in that, In the specification generation and output module, the process of generating a standardized specification document: Based on the Jinja2 template engine, dynamically fill the rotor system dynamic parameters, stability evaluation results, motor speed, and the opening degree of the outlet valve into a preset template to generate a standardized specification document. The preset template is a LaTeX template or a Word template; The Jinja2 template engine is a template engine written in Python.

9. A rotor dynamics test system for a high-temperature molten salt pump based on a mechanical sensor according to claim 1, characterized in that, It also includes a closed-loop feedback mechanism, specifically: after the multi-source data acquisition module dynamically adjusts the motor speed and the opening degree of the molten salt pump outlet valve in the dynamic operating condition control module, it synchronously acquires new original state signals for forming a closed-loop test process.

Images