A high-temperature molten salt pump rotor dynamics test system based on mechanical sensors

Abstract

The present invention discloses a high-temperature molten salt pump rotor dynamics test system based on mechanical sensors, which relates to the fields of new energy and mechanical engineering technology. The system includes a multi-source data acquisition module, which collects raw state signals in real time through sensors designed for high-temperature protection; a data preprocessing module, which generates and stores structured time series data after performing data preprocessing on the raw state signals; a rotor dynamics analysis module, which obtains dynamic parameters and generates stability evaluation results based on the structured time series data; a dynamic operating condition control module, which adjusts the motor speed and outlet valve opening according to the stability evaluation results; and a specification generation output module, which generates standardized specification documents. The present invention adapts to corrosive environments through a multi-level high-temperature protection design, realizes precise analysis of rotor dynamics parameters, graded stability evaluation, and dynamic simulation of variable operating conditions, and improves the accuracy and efficiency of high-temperature molten salt pump rotor dynamics testing.

Description

Technical Field

[0001] The present invention relates to the field of new energy and mechanical engineering technology, and in particular to a high-temperature molten salt pump rotor dynamics testing system based on a mechanical sensor. Background Art

[0002] The performance of high-temperature molten salt pumps, a core component of solar thermal power generation, directly impacts system stability and efficiency. As the heart of a solar thermal power generation system, high-temperature molten salt pumps must operate continuously in high-temperature and highly corrosive environments. Their rotor dynamics are a key factor limiting equipment reliability.

[0003] Currently, my country relies heavily on imports for key technologies related to high-temperature molten salt pumps, and existing testing methods face significant bottlenecks. These bottlenecks include: Traditional sensors and testing systems struggle to withstand the high temperatures and corrosive nature of molten salt, which can easily lead to signal distortion and even equipment damage, and their adaptability to high-temperature environments is insufficient. A comprehensive testing specification for high-temperature molten salt pumps is lacking, and methods for measuring rotor dynamic parameters under variable speed and flow rates are not yet standardized, leading to a lack of standardized testing procedures. Existing systems lack control loops, making it difficult to assess rotor stability in real time and dynamically adjust operating conditions. This results in low testing efficiency, insufficient data reliability, and weak dynamic analysis capabilities. A standardized process for high-temperature molten salt pump performance testing has not yet been established in China, hindering breakthroughs in domestically produced technologies and industry adoption, leaving a gap in the regulatory framework. Therefore, a testing system that adapts to high-temperature corrosive environments, possesses the capabilities for precise parameter measurement and dynamic operating condition simulation, is urgently needed to fill this technological gap and promote the independent development of CSP equipment. To this end, a high-temperature molten salt pump rotor dynamics testing system based on mechanical sensors is proposed. Summary of the Invention

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

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

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

[0007] The multi-source data acquisition module is used to collect the original state signal of the high-temperature molten salt pump rotor in real time through the sensor designed for high-temperature protection;

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

[0009] The rotor dynamics analysis module is used to obtain rotor system dynamic parameters based on structured time series data and generate stability evaluation results accordingly;

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

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

[0012] Preferably, the sensors designed for high temperature protection 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 accelerometer, eddy current displacement sensor, piezoelectric force sensor, and platinum resistance temperature sensor are coated with alumina ceramic and equipped with a double-layer air-cooled heat shield with nitrogen as the cooling gas. The sensor interface is sealed with a metal bellows, thereby achieving a high-temperature protection design to adapt to high temperature and molten salt corrosive environments.

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

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

[0016] Deploy IEPE triaxial piezoelectric accelerometers in the X, Y, and Z directions of the rotor bearings of the high-temperature molten salt pump rotor to collect vibration acceleration in real time.

[0017] The eddy current displacement sensor is Installed on the pump shaft of the high-temperature molten salt pump rotor to collect vortex displacement in real time;

[0018] Deploy a piezoelectric force sensor on the rotor support structure of the high-temperature molten salt pump rotor to collect axial and radial forces in real time;

[0019] Platinum resistance temperature sensors are embedded in the bearings and shaft seals of the high-temperature molten salt pump rotor to collect bearing and shaft seal temperatures in real time.

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

[0021] The original state signal is denoised using the Daubechies5 wavelet basis, the denoised original state signal is filtered using a Butterworth low-pass filter, and the filtered original state signal is normalized and mapped to the [0, 1] interval, thereby obtaining structured time series data including time-series vibration acceleration, time-series eddy 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 wavelet basis function commonly used in wavelet analysis, and the normalization process adopts the minimum and maximum normalization method.

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

[0023] The time series vibration acceleration in the structured time series data is analyzed by fast Fourier transform to obtain the vibration acceleration spectrum. The vibration acceleration spectrum is calculated by the significant peak frequency formula to obtain the natural frequency. , and the natural frequency The critical speed is calculated by the critical speed formula. ;

[0024] The significant peak frequency formula is:

[0025] ;

[0026] in, is the natural frequency, is the acceleration spectrum;

[0027] The critical speed formula is:

[0028] 60;

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

[0030] The time series eddy displacement in the structured time series data is processed by the logarithmic decay method to obtain the damping ratio , for the damping ratio The damping coefficient is calculated by the damping coefficient formula to obtain the damping coefficient , the logarithmic decay method is an important method for analyzing the damping characteristics in a damped vibration system;

[0031] The damping coefficient formula is:

[0032] ;

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

[0034] The time series eddy displacement, time series axial force and time series radial force in the structured time series data are calculated by the stiffness coefficient formula to obtain the preliminary stiffness coefficient , and the preliminary stiffness coefficient The time series bearing temperature and time series shaft seal temperature in the structured time series data are calculated through the stiffness temperature compensation formula, and the stiffness correction processing is performed to obtain the stiffness coefficient , which includes the natural frequency , critical speed , stiffness coefficient and damping coefficient Dynamic parameters of the rotor system;

[0035] The stiffness coefficient formula is:

[0036] ;

[0037] in, is the temporal eddy displacement, is the sequential axial force, is the temporal radial force, is the preliminary stiffness coefficient;

[0038] The stiffness temperature compensation formula is:

[0039] ;

[0040] in, is the sequential bearing temperature, is the timing 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 dynamics analysis module, the process of generating stability assessment results is as follows:

[0042] For natural frequency , critical speed , stiffness coefficient and damping coefficient The comprehensive stability index is calculated by the stability fusion formula ;

[0043] The stability fusion formula is:

[0044] ;

[0045] in, 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 damping coefficient safety threshold, is the safety threshold of the stiffness coefficient, is the design speed, is the minimum frequency of the natural frequency safety range, is the maximum frequency of the natural frequency safety range, It is a comprehensive stability index;

[0046] Comprehensive stability index Compare with the preset multi-level threshold of stability index. , then the stability assessment result is a stable state;

[0047] like , the stability assessment result is critical;

[0048] like , the stability evaluation result is unstable.

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

[0050] If the stability evaluation result is stable, the current motor speed of the high temperature molten salt pump is maintained. and outlet valve opening , and allow and by A small adjustment of the value of is used to explore higher comprehensive stability indicators ;

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

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

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

[0054] Based on the Jinja2 template engine, the rotor system dynamic parameters, stability assessment results, motor speed, and outlet valve opening 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 also includes a closed-loop feedback mechanism, specifically: after the dynamic working condition control module dynamically adjusts the motor speed and the molten salt pump outlet valve opening, the multi-source data acquisition module synchronously collects new original state signals to form a closed-loop test process.

[0057] Due to the adoption of the above technical solution, the present invention has the following technical advancements compared to the prior art:

[0058] The present invention solves the problem of insufficient adaptability of traditional sensors in high-temperature molten salt environments through a multi-level high-temperature protection design, ensuring the stable acquisition of signals such as vibration acceleration; with the help of Daubechies5 wavelet basis denoising, Butterworth filtering and normalization processing, combined with spectrum analysis and logarithmic decay method, dynamic parameters such as natural frequency are accurately calculated to improve data reliability; based on stability evaluation, the motor speed and valve opening are dynamically adjusted, and new signals are collected in real time through closed-loop feedback, constructing a full-process dynamic test closed loop to improve the efficiency of variable working condition evaluation; in addition, the Jinja2 template engine is used to generate LaTe or Word standardized specification documents, filling the gap in domestic high-temperature molten salt pump testing specifications and promoting the independent development of solar thermal power generation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0060] Figure 1 Schematic diagram of the system function modules of the present invention. DETAILED DESCRIPTION

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0062] Examples, such as Figure 1 The high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor includes a multi-source data acquisition module, a data preprocessing module, a rotor dynamics analysis module, a dynamic operating condition control module, and a specification generation and output module;

[0063] Multi-source data acquisition module, used to collect the original status signal of the high-temperature molten salt pump rotor in real time through sensors designed for high-temperature protection;

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

[0065] The rotor dynamics analysis module is used to obtain the rotor system dynamic parameters based on structured time series data and generate stability assessment results based on them;

[0066] The dynamic operating condition control module is used to dynamically adjust the motor speed and outlet valve opening of the high-temperature molten salt pump based on the stability assessment results to simulate variable operating condition scenarios;

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

[0068] Furthermore, the working principle of the present invention is described below by way of examples:

[0069] For a high-temperature molten salt pump in a solar thermal power station, model CSP-1000, with a rated speed of 1800 r / min and an operating temperature of 550°C, a sensor group with high-temperature protection design is deployed to collect the rotor's original state signals, including vibration acceleration, eddy displacement, axial force, radial force, bearing temperature and shaft seal temperature, in real time. The sensor housing of the high-temperature protection sensor group is coated with an alumina ceramic coating and is equipped with a double-layer nitrogen air-cooled insulation cover with an inlet temperature of 25°C and a flow rate of 5L / min. The interface is sealed with a 316L stainless steel bellows, achieving 500 hours of continuous trouble-free operation in a high temperature of 550°C and molten salt corrosion environment. The IEPE triaxial piezoelectric accelerometers of the high-temperature protection sensor group are deployed in the X, Y and Z directions of the bearings, with a sampling frequency of 10kHz and a range of ±50g. The measured root mean square values ​​of vibration acceleration are: X=20g, Y=18g and Z=22g; the eddy current displacement sensor is installed at 90° to the radial direction of the pump shaft, with a measurement range of 0 to 2mm, an accuracy of ±1μm, and a measured eddy displacement of 1μm; the piezoelectric force sensor is installed on the rotor support structure, with an axial force range of 0 to 5kN, measured to be 2000N, and a radial force range of 0 to 10kN, measured to be 5000N; the platinum resistance temperature sensor is embedded in the bearing and shaft seal, and the bearing temperature is measured to be 520℃ and the shaft seal temperature is 530℃.

[0070] The Daubechies5 wavelet basis is used to remove high-frequency noise from the original state signal. For example, the vibration acceleration noise is reduced from 20g to 0.5g, and the signal-to-noise ratio of the eddy displacement is improved from 20dB to 30dB. The denoised original state signal is filtered through a Butterworth low-pass filter to remove mechanical noise and power supply interference. Then, using the minimum-maximum normalization method, the vibration acceleration and eddy displacement signals are mapped to the [0,1] interval to facilitate subsequent dynamic analysis. This generates structured time series data containing time-series vibration acceleration, eddy displacement, axial force, radial force, bearing temperature, and shaft seal temperature, which is stored in a database for access by the analysis module.

[0071] Based on structured time series data, perform FFT spectrum analysis on time series vibration acceleration and extract peak frequency is 25Hz, and the critical speed is calculated by the critical speed formula to obtain the critical speed is 1500r / min; the damping ratio O is obtained by logarithmic decay method 0.03, combined with the rotor equivalent mass The damping coefficient is 50kg, and the damping coefficient is calculated by the damping coefficient formula. is 94.25N·s / m; the time-series eddy displacement, time-series axial force and time-series radial force are calculated by the stiffness coefficient formula Calculate and obtain the preliminary stiffness coefficient 5.385×10 6N / m, and at the same time, the preliminary stiffness coefficient The time series bearing temperature and time series shaft seal temperature in the structured time series data are calculated using the stiffness temperature compensation formula to obtain the stiffness coefficient About 5.32×10 6 N / m, where the stiffness temperature compensation formula for , is 20℃. Based on this, the stability fusion formula is used to calculate S, which is 0.65. 100N・s / m, 5×10 6 N / m, 1800r / min, is 20Hz, is 30Hz, due to , assessed as critical.

[0072] According to the evaluation results, the motor speed was reduced from 1800r / min to 1620r / min, and the outlet valve opening was reduced from 70% to 59.5%. After the adjustment, the original state signal was collected again and calculated by the data preprocessing module and the rotor dynamics analysis module. is 28Hz, The speed was 1680 r / min, S was 0.72, and the evaluation results indicated a stable state. The vibration acceleration dropped to 15g, the vortex displacement was reduced to 0.6μm, the bearing temperature was 515°C, and the shaft seal temperature was 525°C. Furthermore, calculations showed that this system completed operating condition optimization within 15 minutes through closed-loop feedback.

[0073] Based on the Jinja2 template engine, LaTeX templates are used to generate standardized specification documents, including dynamic parameters, stability assessment results, and real-time operating data including motor speed and outlet valve opening.

[0074] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor, characterized in that ,include: Multi-source data acquisition module, used to collect the original status signal of the high-temperature molten salt pump rotor in real time through sensors designed for high-temperature protection; The data preprocessing module is used to preprocess the original state signals of the multi-source data acquisition module, generate structured time series data, and store the structured time series data in the database; The rotor dynamics analysis module is used to obtain the rotor system dynamic parameters based on structured time series data and generate stability assessment results based on them; The dynamic operating condition control module is used to dynamically adjust the motor speed and outlet valve opening of the high-temperature molten salt pump based on the stability assessment results to simulate variable operating condition scenarios; A specification generation and output module is used to automatically generate a standardized specification document containing rotor system dynamic parameters, stability assessment results, motor speed, and outlet valve opening, and output the standardized specification document to the user; In the data preprocessing module, the process of performing data preprocessing on the original state signal of the multi-source data acquisition module: The original state signal is denoised using the Daubechies5 wavelet basis, filtered using a Butterworth low-pass filter, and normalized before being mapped to the [0,1] interval. This yields structured time series data including time-series vibration acceleration, time-series eddy 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 wavelet basis function commonly used in wavelet analysis; In the rotor dynamics analysis module, the process of obtaining the rotor system dynamic parameters based on structured time series data is as follows: The time series vibration acceleration in the structured time series data is analyzed by fast Fourier transform to obtain the vibration acceleration spectrum. The vibration acceleration spectrum is calculated by the significant peak frequency formula to obtain the natural frequency f n , and the natural frequency f n The critical speed Ω is calculated by the critical speed formula. critical ; The time series eddy displacement in the structured time series data is processed by the logarithmic decay method to obtain the damping ratio ζ, and the damping ratio ζ is calculated by the damping coefficient formula to obtain the damping coefficient c; The time series eddy displacement, time series axial force and time series radial force in the structured time series data are calculated by the stiffness coefficient formula to obtain the preliminary stiffness coefficient k measured , and the initial stiffness coefficient k measured The time series bearing temperature and time series shaft seal temperature in the structured time series data are calculated by the stiffness temperature compensation formula, and the stiffness correction processing is performed to obtain the stiffness coefficient k correct , based on which we get the natural frequency f n , critical speed Ω critical , stiffness coefficient k correct and the rotor system dynamic parameters of the damping coefficient c; The logarithmic decay method is an important method for analyzing the damping characteristics of a damped vibration system.

2. A high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor according to claim 1, characterized in that: The sensors designed for high temperature protection include IEPE triaxial piezoelectric acceleration sensor, eddy current displacement sensor, piezoelectric force sensor and platinum resistance temperature sensor; The sensor housings of the IEPE triaxial piezoelectric accelerometer, eddy current displacement sensor, piezoelectric force sensor, and platinum resistance temperature sensor are coated with alumina ceramic and equipped with a double-layer air-cooled heat shield with nitrogen as the cooling gas. The sensor interface is sealed with a metal bellows, thereby achieving a high-temperature protection design to adapt to high temperature and molten salt corrosive environments.

3. A high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor according to claim 2, characterized in that: In the multi-source data acquisition module, the process of real-time acquisition of the original state signal of the high-temperature molten salt pump rotor is as follows: The original state signals include vibration acceleration, eddy displacement, axial force, radial force, bearing temperature and shaft seal temperature; Deploy IEPE triaxial piezoelectric accelerometers in the X, Y, and Z directions of the rotor bearings of the high-temperature molten salt pump rotor to collect vibration acceleration in real time. The eddy current displacement sensor is installed at 90 degrees on the pump shaft of the high-temperature molten salt pump rotor to collect eddy displacement in real time; Deploy a piezoelectric force sensor at the rotor support structure of the high-temperature molten salt pump rotor to collect axial force and radial force in real time; Embed a platinum resistance temperature sensor at the bearings and shaft seals of the high-temperature molten salt pump rotor to collect bearing temperature and shaft seal temperature in real time.

4. A high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor according to claim 3, characterized in that: In the rotor dynamics analysis module, the process of generating the stability evaluation result: For the natural frequency f n , critical speed Ω critical , stiffness coefficient k correct The comprehensive stability index S is calculated by the stability fusion formula using the damping coefficient c; Compare the comprehensive stability index S with the preset multi-level threshold of the stability index. If S≥0.7, the stability evaluation result is a stable state; If 0.5≤S<0.7, the stability evaluation result is a critical state; If 0.5<S, the stability evaluation result is an unstable state.

5. A high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor according to claim 4, 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 evaluation result is stable, the current motor speed of the high temperature molten salt pump is maintained at Ω current and outlet valve opening Q current , and allows for Ω current and Q current A small adjustment of ±0.05 is used to explore a higher comprehensive stability index S; If the stability evaluation result is critical, adjust the current high temperature molten salt pump motor speed to 0.9Ω current and the outlet valve opening is 0.85Q current ; If the stability evaluation result is unstable, adjust the current high temperature molten salt pump motor speed to 0.15Ω current and the outlet valve opening is 0.1Q current .

6. A high-temperature molten salt pump rotor dynamics test system based on a mechanical sensor according to claim 5, 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 dynamics parameters, stability evaluation results, motor speed and outlet valve opening degree into a preset template to generate a standardized specification document, and the preset template is a LaTeX template or a Word template; The Jinja2 template engine is a template engine written in Python.

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

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