Bode diagram signal processing method and device in nuclear turbine starting process and medium

Abstract

The invention relates to a Bode diagram signal processing method and device in the starting process of a nuclear turbine and a medium. The method comprises the following steps: acquiring a vibration signal and a key phase signal in a steam turbine starting process; determining a key phase starting moment according to the key phase signal, and calculating a rotating speed frequency based on the key phase starting moment; performing full-period interception processing and zero-phase band-pass filtering processing on the vibration signal in sequence, and determining the position of a local maximum point of the filtered vibration signal; calculating an absolute phase according to the key phase starting moment and the position of the local maximum point of the filtered vibration signal; fourier transform is carried out on the vibration signal after the whole-period interception processing so as to obtain a corresponding frequency domain signal and a frequency spectrum signal; calculating an index correction value according to the rotating speed frequency and the spectrum signal; performing amplitude correction on the frequency domain signal based on the index correction value to obtain a corrected amplitude; and drawing and displaying a corresponding Bode diagram according to the absolute phase and the corrected amplitude.

Description

Technical Field

[0001] The present invention relates to the technical field of rotating machinery vibration analysis, and in particular to a Bode diagram signal processing method, device and medium in a nuclear power steam turbine startup process. Background Art

[0002] The purpose of rotating machinery vibration analysis is to monitor and evaluate the health of the machinery and prevent failures. As one of the analysis tools, Bode plot can show the relationship between the amplitude and phase of vibration and the speed change, which is crucial for identifying problems such as imbalance, misalignment, friction, rotor instability and resonance of rotating machinery. However, the current technologies for Bode plot processing of nuclear power turbines have shortcomings such as slow processing speed and inaccurate analysis. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a Bode diagram signal processing method, device and medium for the nuclear power steam turbine startup process.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a Bode diagram signal processing method for a nuclear power steam turbine startup process, the method comprising the following steps:

[0005] S1, obtaining the vibration signal and key phase signal of the steam turbine startup process;

[0006] S2, determining a key phase start time according to the key phase signal, and calculating a rotational speed frequency based on the key phase start time;

[0007] S3, performing whole-cycle interception processing and zero-phase bandpass filtering processing on the vibration signal in sequence, and determining the position of the local maximum point of the filtered vibration signal;

[0008] S4, calculating the absolute phase according to the key phase start time and the position of the local maximum point of the filtered vibration signal;

[0009] S5, performing Fourier transform on the vibration signal after the whole cycle interception process to obtain the corresponding frequency domain signal and spectrum signal;

[0010] S6. Calculate an index correction amount according to the rotation speed frequency and the spectrum signal;

[0011] S7, performing amplitude correction on the frequency domain signal based on the index correction amount to obtain a corrected amplitude;

[0012] S8. Draw a corresponding Bode diagram according to the absolute phase and the corrected amplitude and display it.

[0013] Further, in the Bode diagram signal processing method of the present invention, the steam turbine includes a high-pressure cylinder, a first low-pressure cylinder, and a second low-pressure cylinder, and step S1 includes:

[0014] Select two measuring points at the two ends of the bearing seat of the high-pressure cylinder, the two ends of the bearing seat of the first low-pressure cylinder, the two ends of the bearing seat of the second low-pressure cylinder, and the two ends of the bearings of the connecting extension shaft between the cylinders;

[0015] During the steam turbine startup process, the vibration signal and the key phase signal are acquired through the signal detection module on the measuring point.

[0016] Further, in the Bode diagram signal processing method of the present invention, the step S2 of calculating the rotational speed frequency based on the key phase start time includes:

[0017] Normalizing the key phase start time, and calculating the rotation speed frequency according to the normalized key phase start time;

[0018] Step S4 includes:

[0019] The absolute phase is calculated based on the normalized key phase start time and the position of the local maximum point of the filtered vibration signal.

[0020] Further, in the Bode diagram signal processing method of the present invention, step S2 comprises:

[0021] Determine the local maximum point of the key phase signal, and use the corresponding time as the key phase start time;

[0022] The instantaneous rotational speed frequency is calculated based on the time difference between the local maximum value points of the key phase signal;

[0023] The average rotational speed frequency is obtained according to the instantaneous rotational speed frequency.

[0024] Further, in the Bode diagram signal processing method of the present invention, step S3 comprises:

[0025] Performing full-cycle interception processing on the vibration signal according to the key phase start time, and performing zero-phase bandpass filtering on the intercepted vibration signal according to the rotation speed frequency;

[0026] The position of the local maximum point of the filtered vibration signal is calculated by a preset local maximum point search function.

[0027] Further, in the Bode diagram signal processing method of the present invention, the rotational speed frequency is an average rotational speed frequency, and step S6 includes:

[0028] The corresponding index number is determined from the frequency spectrum signal according to the average rotation speed frequency, and the index correction amount is calculated according to the index number, the average rotation speed frequency, the sampling frequency and the number of vibration signal points.

[0029] Further, in the Bode diagram signal processing method of the present invention, step S6 comprises:

[0030] The index correction amount Δk is calculated according to the following formula:

[0031]

[0032] Among them, k is the index number, f 0 is the average speed frequency, f s is the sampling frequency, and N is the number of vibration signal points.

[0033] Further, in the Bode diagram signal processing method of the present invention, step S7 includes:

[0034] The corrected amplitude A is calculated according to the following formula:

[0035]

[0036] Where Δk is the index correction amount, A k is the modulus of the spectrum signal corresponding to the index number k in the spectrum signal, and N is the number of vibration signal points.

[0037] In addition, the present invention also provides a Bode diagram signal processing device for a nuclear power steam turbine startup process, comprising:

[0038] An acquisition unit, used for acquiring a vibration signal and a key phase signal during the steam turbine startup process;

[0039] A first calculation unit, configured to determine a key phase start time according to the key phase signal, and calculate a rotation speed frequency based on the key phase start time;

[0040] A signal processing unit, used to perform whole-cycle interception processing and zero-phase bandpass filtering processing on the vibration signal in sequence, and determine the position of the local maximum point of the filtered vibration signal;

[0041] A second calculation unit is used to calculate the absolute phase according to the key phase start time and the position of the local maximum point of the filtered vibration signal;

[0042] A transform unit, used for performing Fourier transform on the vibration signal after the whole cycle interception process, so as to obtain a corresponding frequency domain signal and spectrum signal;

[0043] A third calculation unit, configured to calculate an index correction amount according to the rotation speed frequency and the spectrum signal;

[0044] an amplitude correction unit, configured to perform amplitude correction on the frequency domain signal based on the index correction amount to obtain a corrected amplitude;

[0045] A drawing unit is used to draw and display a corresponding Bode diagram according to the absolute phase and the corrected amplitude.

[0046] In addition, the present invention also provides a computer-readable storage medium, which stores a computer program, and the computer program is suitable for loading by a processor to execute the steps of the Bode diagram signal processing method for the nuclear power turbine startup process as described above.

[0047] The Bode diagram signal processing method, device and medium for the nuclear power turbine startup process of the present invention have the following beneficial effects: the present invention can draw a more accurate Bode diagram, which is conducive to more accurate identification and analysis of problems such as imbalance, misalignment, friction, rotor instability and resonance during the startup of rotating machinery such as turbines, and improves the analysis and processing speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0049] Figure 1 It is a flow chart of a Bode diagram signal processing method for a nuclear power steam turbine startup process provided by an embodiment of the present invention;

[0050] Figure 2 is a schematic diagram of measuring point arrangement provided by an embodiment of the present invention;

[0051] Figure 3 is a schematic diagram of an absolute phase processing flow provided by an embodiment of the present invention;

[0052] Figure 4 is a schematic diagram of an amplitude processing flow provided by an embodiment of the present invention;

[0053] Figure 5 This is the ideal rotor vibration Bode diagram of a steam turbine in a power plant;

[0054] Figure 6 It is a Bode diagram of a steam turbine startup process of a power plant provided by an embodiment of the present invention;

[0055] Figure 7 It is a structural schematic diagram of a Bode diagram signal processing device for a nuclear power steam turbine startup process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0057] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0058] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0059] refer to Figure 1 In one of the embodiments provided by the present invention, the Bode diagram signal processing method of the nuclear power steam turbine startup process of this embodiment includes the following steps:

[0060] S1. Obtain the vibration signal and key phase signal of the steam turbine startup process. It can be understood that the vibration signal of this embodiment is a radial vibration signal. Specifically, the steam turbine includes a high-pressure cylinder, a first low-pressure cylinder and a second low-pressure cylinder. In this step, two measuring points are selected at both ends of the bearing seat of the high-pressure cylinder, both ends of the bearing seat of the first low-pressure cylinder, both ends of the bearing seat of the second low-pressure cylinder, and both ends of the bearings of the connecting extension shaft between the cylinders. During the startup of the steam turbine, the vibration signal and key phase signal are obtained by the signal detection module on the measuring point.

[0061] It can be understood that each measuring point is equipped with a signal detection module in a direction at a 90-degree angle to the horizontal direction, thereby obtaining a radial vibration signal and / or a key phase signal. Alternatively, the radial vibration signal and the key phase signal can be obtained by detecting the same signal detection module with two signal detection functions (integrable) on the measuring point, or by detecting different signal detection modules on the measuring point. Optionally, the signal detection module can be a vibration signal sensor. The working principle of the vibration signal sensor can refer to the prior art and will not be repeated here.

[0062] Figure 2 The following is a schematic diagram of the measurement point arrangement of an optional embodiment. The vibrations in different directions of the steam turbine often correspond to different sources. The measurement point location is closely related to the acquisition of the vibration signal. In order to comprehensively analyze the vibration causes of the rotating equipment, the measurement point arrangement needs to consider the following factors:

[0063] 1) Bearing support of the high-pressure cylinder and two low-pressure cylinders. Select two radial vibrations (installed at a horizontal angle of 90 degrees) on the bearing seats at both ends of each cylinder. The absolute vibration signal of the bearing seat can be effectively and truly collected. By collecting the radial vibration of these two measuring points, the working status of the bearings at both ends of the high-pressure cylinder, low-pressure cylinder No. 1, and low-pressure cylinder No. 2 can be monitored. For example, whether there are bearing failures, rotor balance, shaft misalignment and other problems.

[0064] 2) Select two radial vibration measurement points on the bearings at both ends of the high-pressure cylinder, No. 1 low-pressure cylinder, and No. 2 low-pressure cylinder connected to the extended shaft (installed at a horizontal angle of 90 degrees). Through the collection of vibration data, the working status of the bearings and the extended shaft can be monitored, such as whether there are bearing failures, loose foundations, etc. It can be understood that the number in the box in the figure is the probe code of the vibration signal sensor.

[0065] It should be noted that, in the embodiment of the present invention, each measuring point collects a radial vibration signal and a key phase signal, and a radial vibration signal generates a Bode diagram corresponding to the signal. Figure 2 Taking the high-pressure cylinder as an example, there are four radial measuring points at both ends of the bearing seat of the high-pressure cylinder, and four corresponding Bode diagrams will be drawn accordingly.

[0066] S2, determining the key phase start time according to the key phase signal, and calculating the rotational speed frequency based on the key phase start time. Specifically, in this step, the key phase start time can be normalized, and the rotational speed frequency can be calculated based on the normalized key phase start time.

[0067] In some embodiments, step S2 may specifically include:

[0068] Determine the local maximum point of the key phase signal, and use the corresponding time as the key phase start time. Calculate the instantaneous speed frequency based on the time difference between the local maximum points of the key phase signal. Calculate the average speed frequency based on the instantaneous speed frequency.

[0069] S3, the vibration signal is subjected to full cycle interception processing and zero phase bandpass filtering processing in sequence, and the position of the local maximum point of the filtered vibration signal is determined. Specifically, in this step, the vibration signal can be subjected to full cycle interception processing according to the key phase start time, and the intercepted vibration signal can be subjected to zero phase bandpass filtering according to the rotational speed frequency. The position of the local maximum point of the filtered vibration signal is calculated by a preset local maximum point search function.

[0070] S4, calculate the absolute phase according to the key phase start time and the position of the local maximum point of the filtered vibration signal. Specifically, in this step, the absolute phase can be calculated according to the normalized key phase start time and the position of the local maximum point of the filtered vibration signal.

[0071] S5. Perform Fourier transform on the vibration signal after the whole cycle interception process to obtain the corresponding frequency domain signal and spectrum signal. It can be understood that the amplitude in the Bode diagram is the amplitude corresponding to the rotational speed frequency. When calculating the amplitude, the vibration time domain signal is converted into a frequency domain signal through Fourier transform. The frequency domain signal is a complex signal. The modulus of the frequency domain signal corresponding to the rotational frequency is the amplitude.

[0072] S6. Calculate the index correction amount according to the rotational speed frequency and the spectrum signal. In some embodiments, the rotational speed frequency is the average rotational speed frequency, and this step includes: determining the corresponding index number from the spectrum signal according to the average rotational speed frequency, and calculating the index correction amount according to the index number, the average rotational speed frequency, the sampling frequency and the number of vibration signal points.

[0073] S7, based on the index correction amount, the frequency domain signal is amplitude corrected to obtain a corrected amplitude. Specifically, in this step, the frequency domain signal can be amplitude corrected according to the index correction amount and the spectrum modulus function of the window function used in Fourier transform to obtain a corrected amplitude.

[0074] S8. Draw a corresponding Bode diagram based on the absolute phase and the corrected amplitude and display it.

[0075] This embodiment can draw a more accurate Bode diagram, which is conducive to more accurate identification and analysis of problems such as imbalance, misalignment, friction, rotor instability and resonance during the startup of rotating machinery such as a steam turbine, and improves the analysis and processing speed.

[0076] It should be noted that the present invention preferably uses a Bode diagram data processing method based on Python, focusing on how to use Python and its related libraries to realize rapid processing and accurate analysis of Bode diagram data. Python is an open source programming language that is extremely flexible and not restricted by platforms. It is not only comprehensive but also easy to use, so it has won wide application and solid support. As an interpreted language that supports dynamic input, Python is particularly suitable for interactive operations and rapid prototyping of scripts and one-time programs. In addition, it also has an excellent ability to develop large-scale applications, making Python a leader in the field of programming.

[0077] SciPy (Scientific Python) is an open source Python algorithm library and mathematical toolkit. SciPy contains modules for optimization, linear algebra, integration, interpolation, special functions, fast Fourier transform, signal processing, image processing, solving ordinary differential equations and other calculations commonly used in scientific computing. SciPy provides a series of tools and techniques for analyzing and processing vibration signals generated by the operation of rotating machinery. SciPy provides a fast Fourier transform (FFT) function that can perform spectral analysis on signals. SciPy provides a variety of digital filter functions that can be used to smooth, denoise or extract specific frequency components of signals. SciPy provides tools for waveform analysis and processing, such as peak detection, waveform recognition, waveform synthesis, etc., which can perform various professional analyses on vibration time domain signals.

[0078] The Bode plot is mainly used to display the vibration data of the turbine startup or shutdown process. During the startup / shutdown transient process, the vibration vector between the startup speed and the operating speed of the turbine is collected in small speed increments. The Bode plot consists of two rectangular coordinate systems, with the vibration amplitude and phase plotted on the two coordinate graphs respectively, and the horizontal axis of the rectangular coordinate graph represents the speed (or frequency).

[0079] When the rotor rotates, the angular position of the unbalanced vector is defined as the focus. When the rotor rotates, the angular position where the rotor bends and deforms under the action of the unbalanced force is called the high point. According to the theory of rotor dynamics, when the rotor rotates at a speed lower than the resonance, the focus and the high point are in phase, that is, the phase lag angle is 0°. At this time, the vibration vector will point in the direction of the focus. When the rotor rotates at the resonant speed, the amplitude of the vibration will reach a maximum value, and the high point will lag the focus by about 90°. When the rotor rotates at a speed much higher than the resonant speed, the rotor vibration amplitude will drop to a constant value, and the high point will lag the focus by about 180°, such as Figure 5 As shown in Figure 1, the Bode diagram can be used to determine the critical speed of the rotor system through the amplitude-frequency diagram and the phase-frequency diagram. In the amplitude-frequency diagram, the peak of the vibration vector amplitude will indicate the critical speed. At the same time, the sharp change of phase in the phase-frequency diagram (usually greater than 70°) can also help identify the critical speed. For example, Figure 5 The figure shows the ideal rotor vibration Bode diagram of a steam turbine in a power plant. The critical speed of the steam turbine in the power plant can be determined by the amplitude-frequency diagram and phase-frequency diagram of the Bode diagram. 1500rpm is the first-order critical speed. The Bode diagram can be used for the balance analysis of the steam turbine, and can also identify and analyze the resonance. From the image of the Bode diagram, it can be seen that the key to drawing the Bode diagram is to calculate the phase and amplitude corresponding to the speed frequency.

[0080] Combination Figure 3 , which is a schematic diagram of the absolute phase processing flow based on Python in a specific embodiment of the present invention. The relative time between two events in different signals is called phase. In the vibration analysis of rotating machinery, the phase is divided into relative phase and absolute phase. Relative phase refers to the phase difference of the same event on different vibration signals. Absolute phase compares the time of an event on a vibration signal with different types of reference signals, which can be generated by a "once per revolution" marking device on the shaft. The phase used in the Bode diagram of the steam turbine in the present invention is absolute phase, which is defined as the time from the start of the key phase signal to the highest point of the rotation frequency signal.

[0081] The first step is to calculate the bond phase information: load the bond phase signal and use the find_peaks function provided by the SciPy package to find the local maximum point of the bond phase signal. The time corresponding to the local maximum point is the bond phase start time, recorded as K = [K 0 ,K 1 ,...,K n ]. Normalize the start time of the bond phase:

[0082]

[0083] K i This is the normalized bond phase start time.

[0084] The time difference between the local maxima is the time for one rotation, from which the instantaneous rotation frequency f can be calculated i :

[0085]

[0086] In the formula, f s is the sampling frequency.

[0087] After averaging the calculated instantaneous rotational frequencies, the average rotational frequency of the device can be obtained, that is, the rotational frequency of the device, which is recorded as f 0 :

[0088]

[0089] The second step is to calculate the phase information: load the vibration signal. Since the key phase signal and the vibration signal are sampled synchronously, the vibration signal can be intercepted for a whole cycle according to the key phase start time. Use the filtfilt function provided by the SciPy package to perform zero-phase bandpass filtering on the intercepted signal. It can be understood that this embodiment needs to filter out the interference generated by the measurement data, and the interference is mainly caused by the rotation speed. Zero-phase filtering can avoid phase distortion introduced by the filtering operation, and the frequency range of the bandpass is [f 0 ―1,f 0 +1]. Use the find_peaks function to calculate the location of the local maximum point of the filtered signal, denoted as X = [X 0 ,X 1 ,...,X n ].

[0090] Absolute Phase It can be calculated according to the following formula:

[0091]

[0092] Combination Figure 4 , which is a schematic diagram of the amplitude processing flow based on Python in a specific embodiment of the present invention. The amplitude in the Bode diagram is the amplitude corresponding to the frequency conversion. When calculating the amplitude, the vibration time domain signal is generally converted into a frequency domain signal through Fourier transform. The frequency domain signal is a complex signal. The modulus of the frequency domain signal corresponding to the frequency conversion is the amplitude. However, during the time-to-frequency transformation, the spectrum peak becomes smaller due to the energy leakage caused by the time domain truncation, so the spectrum must be corrected.

[0093] The first step is to calculate the key phase information, and the calculation process is consistent with the absolute phase calculation process. It should be noted that in the amplitude correction process, it is not necessary to calculate the key phase information and the vibration signal full cycle interception process again, that is, directly use the relevant information obtained in the absolute phase processing process.

[0094] The second step is to calculate the amplitude: load the vibration signal, and intercept the entire cycle of the vibration signal according to the start time of the key phase. Use the fft function provided by the SciPy package to perform Fourier transform on the vibration signal. According to the rotation frequency calculated using the key phase signal, the index number closest to the rotation frequency in the spectrum signal can be found. Assuming that the index correction amount is Δk, it can be calculated according to the following formula:

[0095]

[0096] Among them, k is the index number, f 0 is the average speed frequency, fs is the sampling frequency, and N is the number of vibration signal points.

[0097] Next, the corrected amplitude can be calculated based on the index correction amount Δk and the spectrum modulus function of the window function used in Fourier transform. Specifically, the corrected amplitude A can be calculated based on the following Hanning window amplitude correction formula:

[0098]

[0099] Among them, A k is the modulus of the spectrum signal corresponding to the index number k in the spectrum signal.

[0100] like Figure 6 As shown, the Bode diagram signal processing method of the present invention is used to process the data during the startup process of a steam turbine in a power plant, and the processing results are displayed. It can be seen from the figure that as the speed increases, the amplitude of the vibration gradually increases, and when the resonance point of the unit is reached, the amplitude reaches the maximum. The phase of the vibration increases slowly at low speeds, and near the resonance point, the phase changes significantly. Although the relationship between phase and amplitude is not completely consistent with the theoretical value, this phenomenon is caused by the influence of rotor anisotropic stiffness, structural resonance and multi-modal distortion. From the results, the accuracy of the Bode diagram data calculation algorithm of the present invention is verified.

[0101] refer to Figure 7 In another embodiment of the present invention, the Bode diagram signal processing device for the nuclear power steam turbine startup process of this embodiment includes:

[0102] The acquisition unit is used to acquire the vibration signal and key phase signal of the steam turbine startup process.

[0103] The first calculation unit is used to determine the key phase start time according to the key phase signal, and calculate the rotation speed frequency based on the key phase start time.

[0104] The signal processing unit is used to perform whole-cycle interception processing and zero-phase bandpass filtering processing on the vibration signal in sequence, and determine the position of the local maximum point of the filtered vibration signal.

[0105] The second calculation unit is used to calculate the absolute phase according to the key phase start time and the position of the local maximum point of the filtered vibration signal.

[0106] The transform unit is used to perform Fourier transform on the vibration signal after the whole cycle interception process to obtain the corresponding frequency domain signal and spectrum signal.

[0107] The third calculation unit is used to calculate the index correction amount according to the rotation speed frequency and the spectrum signal.

[0108] The amplitude correction unit is used to perform amplitude correction on the frequency domain signal based on the index correction amount to obtain a corrected amplitude.

[0109] The drawing unit is used for drawing and displaying the corresponding Bode diagram according to the absolute phase and the corrected amplitude.

[0110] This embodiment can draw a more accurate Bode diagram, which is conducive to more accurate identification and analysis of problems such as imbalance, misalignment, friction, rotor instability and resonance during the startup of rotating machinery such as a steam turbine, and improves the analysis and processing speed.

[0111] In another embodiment of the present invention, a computer-readable storage medium of this embodiment stores a computer program, and the computer program is suitable for a processor to load to execute the steps of the Bode diagram signal processing method of the nuclear power turbine startup process as in the above-mentioned embodiment.

[0112] This embodiment can draw a more accurate Bode diagram, which is conducive to more accurate identification and analysis of problems such as imbalance, misalignment, friction, rotor instability and resonance during the startup of rotating machinery such as a steam turbine, and improves the analysis and processing speed.

[0113] The computer-readable storage medium of the present invention can be any computer-readable storage medium that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disk.

[0114] The processor of the present invention is used to provide computing and control capabilities to support the operation of the Bode diagram signal processing device of the entire nuclear power steam turbine startup process. It should be understood that in the embodiment of the present application, the processor can be a central processing unit (CPU), and the processor can also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0115] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0116] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0117] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A Bode diagram signal processing method for a nuclear power steam turbine startup process, characterized in that: The method comprises the following steps: S1, obtaining the vibration signal and key phase signal of the steam turbine startup process; S2, determining a key phase start time according to the key phase signal, and calculating a rotational speed frequency based on the key phase start time; S3, performing whole-cycle interception processing and zero-phase bandpass filtering processing on the vibration signal in sequence, and determining the position of the local maximum point of the filtered vibration signal; S4, calculating the absolute phase according to the key phase start time and the position of the local maximum point of the filtered vibration signal; S5, performing Fourier transform on the vibration signal after the whole cycle interception process to obtain the corresponding frequency domain signal and spectrum signal; S6. Calculate an index correction amount according to the rotation speed frequency and the spectrum signal; S7, performing amplitude correction on the frequency domain signal based on the index correction amount to obtain a corrected amplitude; S8. Draw a corresponding Bode diagram according to the absolute phase and the corrected amplitude and display it.

2. The Bode diagram signal processing method according to claim 1, characterized in that: The steam turbine includes a high-pressure cylinder, a first low-pressure cylinder and a second low-pressure cylinder, and step S1 includes: Select two measuring points at the two ends of the bearing seat of the high-pressure cylinder, the two ends of the bearing seat of the first low-pressure cylinder, the two ends of the bearing seat of the second low-pressure cylinder, and the two ends of the bearings of the extended shaft connecting the cylinders; During the steam turbine startup process, the vibration signal and the key phase signal are acquired through the signal detection module on the measuring point.

3. The Bode diagram signal processing method according to claim 1, characterized in that: The step S2 of calculating the rotational speed frequency based on the key phase start time includes: Normalizing the key phase start time, and calculating the rotation speed frequency according to the normalized key phase start time; Step S4 includes: The absolute phase is calculated based on the normalized key phase start time and the position of the local maximum point of the filtered vibration signal.

4. The Bode diagram signal processing method according to claim 3, characterized in that: Step S2 includes: Determine the local maximum point of the key phase signal, and use the corresponding time as the key phase start time; The instantaneous rotational speed frequency is calculated based on the time difference between the local maximum value points of the key phase signal; The average rotational speed frequency is obtained according to the instantaneous rotational speed frequency.

5. The Bode diagram signal processing method according to claim 1, characterized in that: Step S3 includes: Performing full-cycle interception processing on the vibration signal according to the key phase start time, and performing zero-phase bandpass filtering on the intercepted vibration signal according to the rotation speed frequency; The position of the local maximum point of the filtered vibration signal is calculated by presetting the local maximum point search function.

6. The Bode diagram signal processing method according to claim 1, characterized in that: The rotation speed frequency is an average rotation speed frequency, and step S6 includes: The corresponding index number is determined from the frequency spectrum signal according to the average rotation speed frequency, and the index correction amount is calculated according to the index number, the average rotation speed frequency, the sampling frequency and the number of vibration signal points.

7. The Bode diagram signal processing method according to claim 6, characterized in that: Step S6 includes: The index correction amount Δk is calculated according to the following formula: Among them, k is the index number, f0 is the average speed frequency, f s is the sampling frequency, and N is the number of vibration signal points.

8. The Bode diagram signal processing method according to claim 1, characterized in that: Step S7 includes: The corrected amplitude A is calculated according to the following formula: Where Δk is the index correction amount, A k is the modulus of the spectrum signal corresponding to the index number k in the spectrum signal, and N is the number of vibration signal points.

9. A Bode diagram signal processing device for a nuclear power steam turbine startup process, characterized in that: include: An acquisition unit, used for acquiring a vibration signal and a key phase signal during the steam turbine startup process; A first calculation unit, configured to determine a key phase start time according to the key phase signal, and calculate a rotation speed frequency based on the key phase start time; A signal processing unit, used to perform whole-cycle interception processing and zero-phase bandpass filtering processing on the vibration signal in sequence, and determine the position of the local maximum point of the filtered vibration signal; A second calculation unit is used to calculate the absolute phase according to the key phase start time and the position of the local maximum point of the filtered vibration signal; A transform unit, used for performing Fourier transform on the vibration signal after the whole cycle interception process, so as to obtain a corresponding frequency domain signal and spectrum signal; A third calculation unit, configured to calculate an index correction amount according to the rotation speed frequency and the spectrum signal; an amplitude correction unit, configured to perform amplitude correction on the frequency domain signal based on the index correction amount to obtain a corrected amplitude; A drawing unit is used to draw and display a corresponding Bode diagram according to the absolute phase and the corrected amplitude.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded by a processor to execute the steps of the Bode diagram signal processing method for the nuclear power steam turbine startup process as described in any one of claims 1 to 8.

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