CN102012263B - Method for identifying turbine unit rotor vibration in-phase component stability in real time - Google Patents

Abstract

The invention discloses a method for real-time identification of the smoothness of the same-phase component of the rotor vibration of a steam turbine unit in the technical field of vibration state monitoring and fault diagnosis of rotating machinery, which is used for real-time automatic online monitoring and analysis of the smoothness of the same-phase component of the rotor vibration. Including setting duration and step length; when each step is a length, obtain the shaft relative vibration data of the supporting bearings on both sides of the rotor, the rotor speed signal and the key phase signal; calculate the in-phase component of the relative vibration of the supporting shafts on both sides of the rotor Amplitude and phase and store the amplitude and phase; when the set duration is reached, verify the amplitude ratio entropy mean value of the in-phase component and the phase difference value of the same-phase component; and verify the amplitude ratio entropy mean value of the same-phase component and the phase of the same-phase component by judging Whether all the difference values pass through determines whether the same-phase component of the rotor vibration of the steam turbine unit is stable. The invention utilizes shaft relative vibration amplitude and phase data to analyze and obtain fault diagnosis conclusions, thereby providing guarantee for the safe operation of the rotor of the steam turbine unit.

Description

Real-time Identification Method of Stationarity of In-Phase Component of Rotor Vibration of Steam Turbine Unit

technical field

The invention belongs to the technical field of vibration state monitoring and fault diagnosis of rotating machinery, and in particular relates to a method for real-time identification of the stability of the same-phase component of rotor vibration of a steam turbine unit.

Background technique

The safety and reliability of the steam turbine generator set is one of the most important issues in the design, manufacture and operation of the equipment. Unit vibration is an important indicator of unit safety and reliability. Units with deteriorating vibration conditions often run at reduced load, or shut down for treatment, or are forced to shut down in an emergency. Improper handling of vibration or sudden vibration may cause partial or overall serious failure of the unit.

The steam turbine generator set operates at a working speed for a long time, and has high requirements for vibration stability. If the first-order critical speed vibration of the turbogenerator rotor is too large, it will have a great impact on the working speed, and there is a large in-phase vibration component at the working speed.

The identification of the stability of the in-phase component of the shafting rotor vibration of a turbogenerator needs to be completed by experts with certain experience in on-site vibration fault diagnosis, which is highly dependent on the subjectivity of experts and poor in objectivity. Therefore, it is very important to propose a real-time identification method for the stationarity of the in-phase component of the rotor vibration of the steam turbine unit.

The method for real-time identification of the stability of the same-phase component of the rotor vibration of the steam turbine unit provided by the present invention performs real-time automatic online monitoring, analysis, and discrimination on the change of the same-phase component of the vibration of the shaft rotor of the steam turbine unit, and improves the identification efficiency and accuracy of the stability of the same-phase component of the rotor vibration.

Contents of the invention

The purpose of the present invention is to provide a real-time identification method for the stability of the same-phase component of the rotor vibration of a steam turbine unit, which is used for real-time automatic on-line monitoring, analysis, and discrimination of the change of the same-phase component of the shaft rotor vibration of the unit, and to improve the stability of the same-phase component of the rotor vibration recognition efficiency and accuracy.

The technical solution is a real-time identification method for the stability of the in-phase component of the rotor vibration of a steam turbine unit, which is characterized in that it includes the following steps:

Step 1: Set the duration T and the step length t;

Step 2: Obtain the shaft relative vibration data of the supporting bearings on both sides of the rotor, the rotor speed signal and the key phase signal;

Step 3: According to the shaft relative vibration data of the supporting bearings on both sides of the rotor, calculate the amplitude and phase of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor and store the amplitude and phase;

Step 4: Determine whether the set duration T is reached, and if so, go to step 5; otherwise, go to step 6;

Step 5: After stepping for a length t, return to Step 2;

Step 6: According to the magnitude and phase of the same-phase component of the relative vibration of the rotor support shafts stored on both sides of the rotor each time a length t is stepped, verify the amplitude ratio entropy mean value of the same-phase component and the phase difference of the same-phase component;

Step 7: Judging and verifying whether the amplitude ratio entropy mean of the same-phase component and the phase difference of the same-phase component are all passed. If yes, it is determined that the same-phase component of the rotor vibration of the steam turbine unit is stable; otherwise, it is determined that the same-phase component of the rotor vibration of the steam turbine unit is not stable.

The step 3 specifically includes:

Step 101: According to the shaft relative vibration data of the supporting bearings on both sides of the rotor, using the fast Fourier transform spectrum analysis method, real-time synchronously calculate the relative vibration amplitude and phase of the supporting bearings on both sides of the rotor; The frequency vibration amplitude is recorded as a ^ra , the phase is recorded as p ^ra ; the relative vibration amplitude of the supporting bearing on the other side of the rotor is recorded as a ^rb , and the phase is recorded as p ^rb ;

的实部A^real和虚部A^imagi；利用公式B^real＝a^rb×cos(p^rb)和B^imagi＝a^rb×sin(p^rb)计算转子另一侧支持轴承的轴振工频振动矢量

的实部B^real和虚部B^imagi；Step 102: Using the formulas A ^real =a ^ra ×cos(p ^ra ) and A ^imagi =a ^ra ×sin(p ^ra ), calculate the shaft vibration power frequency vibration vector of the supporting bearing on the rotor side

The real part A ^real and the imaginary part A ^imagi ; use the formulas B ^real ＝a ^rb ×cos(p ^rb ) and B ^imagi ＝a ^rb ×sin(p ^rb ) to calculate the axial vibration power frequency vibration vector of the supporting bearing on the other side of the rotor

The real part B ^real and the imaginary part B ^imagi ;

计算出转子两侧支持轴承的轴振工频振动的同相分量

Step 103: Using the formula

Calculate the in-phase component of the shaft vibration power frequency vibration of the supporting bearings on both sides of the rotor

的实部S^real和虚部S^imagi，再利用公式计算转子两侧支持轴相对振动同相分量的幅值，利用公式S^phase＝(180/π)×arctan(S^real/S^imagi)计算出转子两侧支持轴相对振动同相分量的相位。Step 104: Using S ^real =1/2×(A ^real +B ^real ) and S ^imagi =1/2×(A ^imagi +B ^imagi ), calculate the in-phase component

The real part S ^real and the imaginary part S ^imagi , and then use the formula Calculate the amplitude of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor, and use the formula S ^phase =(180/π)×arctan(S ^real /S ^imagi ) to calculate the phase of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor.

The verification in-phase component amplitude ratio entropy mean value is specifically:

的幅值

与振幅合格量值S^std的比值

Step 201: Calculate the in-phase component for each step of a length t

the magnitude of

Ratio to amplitude qualified value S ^std

计算比值

的熵均值E_mean，式中

并且规定当

时，

Step 202: Using the formula

Calculate the ratio

The entropy mean value E _mean , where

and stipulates that when

hour,

The phase difference value of the verification in-phase component is specifically:

中的相位最大值

与相位最小值

差值的绝对值

其中

Calculate all the in-phase components stored during each step of a length t in the entire set time length T

The phase maximum in

and phase minimum

absolute value of difference

in

The said judgment verifies whether the amplitude ratio entropy mean value of the in-phase component is passed specifically, judges whether E _mean is greater than or equal to 0, if yes, then verifies the amplitude ratio entropy mean value of the same phase component passes; otherwise, verifies the amplitude ratio entropy mean value of the same phase component does not pass .

中的相位最大值

与相位最小值

差值的绝对值是否小于等于设定值D，如果是，则验证同相分量相位差值通过；否则，验证同相分量相位差值不通过。The verification of whether the phase difference of the in-phase component is passed is specifically to determine whether all the stored in-phase components

The phase maximum in

and phase minimum

Whether the absolute value of the difference is less than or equal to the set value D, if yes, verify that the phase difference of the same-phase component passes; otherwise, verify that the phase difference of the same-phase component fails.

The set duration T=900 seconds.

The length of the step is t=0.1 seconds.

The amplitude qualified value S ^std =50um.

The set value D=5°.

The effect of the present invention is that the real-time identification method for the stability of the in-phase component of the rotor vibration of the steam turbine unit uses the relative shaft vibration amplitude and phase data of the rotor during the operation of the unit, and obtains a fault diagnosis conclusion through calculation, analysis and judgment, which provides a guarantee for the safe operation of the rotor of the steam turbine unit .

Description of drawings

Figure 1 is a schematic diagram of the real-time identification of the stationarity of the same-phase component of the rotor vibration of the steam turbine unit;

Fig. 2 is a flow chart of the real-time identification method for the stationarity of the in-phase component of the rotor vibration of the steam turbine unit;

Fig. 3 is a flow chart of calculating the amplitude and phase of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor.

Detailed ways

The preferred embodiments will be described in detail below in conjunction with the accompanying drawings. It should be emphasized that the following description is only exemplary and not intended to limit the scope of the invention and its application.

Example

The shaft-relative vibration data, rotor speed signal and key-phase signal of the turbogenerator set required by the real-time identification method can be obtained from the monitoring instrument (TSI) equipped with the turbogenerator set or from professional vibration data acquisition and conditioning equipment. In this embodiment, the shaft-relative vibration signal of the steam turbine generator set and the key-phase signal required for analysis and processing of the vibration signal are obtained from professional vibration data acquisition and conditioning equipment connected to the vibration sensor. Figure 1 is a schematic diagram of the real-time identification of the stability of the in-phase component of the rotor vibration of a steam turbine unit. In Figure 1, the high-speed data acquisition card is inserted into the slot provided by the industrial microcomputer (IPC). According to the requirements of the high-speed data acquisition card, professional vibration data acquisition and conditioning The equipment processes the shaft-relative vibration signal of the turbo-generator set and the key-phase signal required for vibration signal analysis and processing, and the processed shaft-relative vibration signal of the turbo-generator set and the key-phase signal required for vibration signal analysis and processing are input into the high-speed data acquisition in the IPC Card. The above technologies are common knowledge of those skilled in the art. Afterwards, according to the method provided by the present invention, a specific computer real-time identification program for the stability of the same-phase component of the shafting rotor vibration of the unit is designed, and the real-time identification program is installed in an industrial microcomputer (IPC).

Fig. 2 is a flow chart of the real-time identification method for the stability of the in-phase component of the rotor vibration of the steam turbine unit. Before implementing the method of the present invention, it is possible to set the amplitude qualified value S ^std =50um and the set value D=5°. In Figure 2, the real-time identification method for the stationarity of the same-phase component of the rotor vibration of the steam turbine unit includes:

Step 1: Set the duration T and the step length t.

In this embodiment, the duration T=900 seconds is set, and the length of the step is t=0.1 seconds, then the number of cycles Second-rate.

Step 2: Obtain the shaft relative vibration data of the supporting bearings on both sides of the rotor, the rotor speed signal and the key phase signal.

As mentioned above, the shaft relative vibration data of the supporting bearings on both sides of the rotor, the rotor speed signal and the key phase signal are obtained and processed through the vibration data acquisition and conditioning equipment, and the processed shaft relative vibration signal and vibration The key-phase signal required for signal analysis and processing is input to the high-speed data acquisition card in the IPC.

Step 3: According to the shaft relative vibration data of the supporting bearings on both sides of the rotor, calculate the amplitude and phase of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor and store the amplitude and phase.

Fig. 3 is a flow chart of calculating the amplitude and phase of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor. In Fig. 3, the process of calculating the magnitude and phase of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor is:

Step 101: According to the shaft relative vibration data of the supporting bearings on both sides of the rotor, using the fast Fourier transform spectrum analysis method, real-time synchronously calculate the relative vibration amplitude and phase of the supporting bearings on both sides of the rotor; The frequency vibration amplitude is recorded as a ^ra , and the phase is recorded as p ^ra ; the relative vibration amplitude of the supporting bearing on the other side of the rotor is recorded as a ^rb , and the phase is recorded as p ^rb .

的实部A^real、虚部A^imagi，计算时采用公式(1)、(2)计算。Step 102: Calculate the shaft vibration power frequency vibration vector of the supporting bearing on one side of the rotor

The real part A ^real and the imaginary part A ^imagi are calculated using formulas (1) and (2).

A ^real ＝a ^ra ×cos(p ^ra ) (1)

A ^imagi ＝a ^ra ×sin(p ^ra ) (2)

Then, calculate the shaft vibration power frequency vibration vector of the supporting bearing on the other side of the rotor The real part B ^real and the imaginary part B ^imagi are calculated using formulas (3) and (4).

B ^real ＝a ^rb ×cos(p ^rb ) (3)

B ^imagi ＝a ^rb ×sin(p ^rb ) (4)

计算时使用公式

Step 103: Calculate the in-phase component of the shaft vibration power frequency vibration of the supporting bearings on both sides of the rotor

Use formulas when calculating

的实部S^real、虚部S^imagi。Step 104: Calculate the in-phase component using formulas (5) and (6) respectively

The real part S ^real and the imaginary part S ^imagi .

S ^real ＝1/2×(A ^real +B ^real ) (5)

S ^imagi ＝1/2×(A ^imagi +B ^imagi ) (6)

Then use formulas (7) and (8) to calculate the amplitude S ^amp (unit: μm) and phase S ^phase (unit: °, ie angle unit) of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor.

${\mathrm{<span\; class="notranslate">\; S</span>}}^{\mathrm{<span\; class="notranslate">\; amp</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{\mathrm{<span\; class="notranslate">\; real</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; S</span>}}^{\mathrm{<span\; class="notranslate">\; imagi</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

S ^phase ＝(180/π)×arctan(S ^real /S ^imagi ) (8)

的幅值S^amp及相位。After the calculation, store the in-phase component of the shaft vibration power frequency vibration on both sides of the rotor

The amplitude S ^amp and phase.

Step 4: Determine whether the set duration of 900 seconds is reached, and if so, go to step 6; otherwise, go to step 5.

Step 5: Step by a length t, that is, step by 0.1 second. Then return to step 2.

Step 6: According to the amplitude and phase of the in-phase component of the relative vibration of the supporting shaft on both sides of the rotor stored at each step of a length (0.1 second), verify the amplitude ratio entropy mean of the in-phase component and the phase difference of the in-phase component.

Verify that the mean value of the in-phase component amplitude ratio entropy (Shannon) is:

的幅值

与振幅合格量值S^std的比值

0≤i≤9000。本实施例中，设定的振幅合格量值S^std＝50um。Step 201: Calculate the in-phase component when each step takes a length of t=0.1 second

the magnitude of

Ratio to amplitude qualified value S ^std

0≤i≤9000. In this embodiment, the set amplitude qualified value S ^std =50um.

的熵(Shannon)均值E_mean，式中n＝9000，并且规定当时，

Step 202: Using the formula Calculate the ratio

The mean value of entropy (Shannon) E _mean , where n=9000, and it is stipulated that when hour,

Verify that the phase difference of the in-phase component is:

中的相位最大值

与相位最小值

差值的绝对值其中0≤i≤9000。Calculate all the in-phase components stored in the entire set time length T=900 seconds, when each step is a length of t=0.1 seconds

The phase maximum in

and phase minimum

absolute value of difference where 0≤i≤9000.

Step 7: Judging and verifying whether the amplitude ratio entropy mean of the in-phase component and the phase difference of the in-phase component are all passed.

Judging and verifying whether the mean value of the amplitude ratio entropy (Shannon) of the in-phase component is passed, specifically, judging whether E _mean is greater than or equal to 0, if yes, then verifying that the mean value of the amplitude ratio entropy of the same-phase component is passed; otherwise, verifying that the mean value of the amplitude ratio entropy of the same-phase component is not pass.

中的相位最大值

与相位最小值

差值的绝对值是否小于等于设定值D＝5°，如果是，则验证同相分量相位差值通过；否则，验证同相分量相位差值不通过。Judging and verifying whether the phase difference of the in-phase component is passed or not, specifically, judging all stored in-phase components

The phase maximum in

and phase minimum

Whether the absolute value of the difference is less than or equal to the set value D=5°, if yes, the verification of the phase difference of the same-phase component is passed; otherwise, the verification of the phase difference of the same-phase component is not passed.

If it is verified whether the amplitude ratio entropy mean of the same-phase component and the phase difference of the same-phase component pass, it is determined that the same-phase component of the rotor vibration of the steam turbine unit is stable; otherwise, it is determined that the same-phase component of the rotor vibration of the steam turbine unit is not stable.

The method for real-time identification of the stability of the same-phase component of the rotor vibration of the steam turbine unit provided by the present invention performs real-time automatic online monitoring, analysis, and discrimination on the change of the same-phase component of the vibration of the shaft rotor of the steam turbine unit, and improves the identification efficiency and accuracy of the stability of the same-phase component of the rotor vibration.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (5)

1. A real-time identification method for the stability of the same-phase component of the rotor vibration of a steam turbine unit, characterized in that it comprises the following steps: Step 1: Set the duration T and the step length t; Step 2: Obtain the shaft relative vibration data of the supporting bearings on both sides of the rotor, the rotor speed signal and the key phase signal; Step 3: According to the shaft relative vibration data of the supporting bearings on both sides of the rotor, calculate the amplitude and phase of the relative vibration of the supporting shafts on both sides of the rotor and store the amplitude and phase; the calculation of the relative vibration of the supporting shafts on both sides of the rotor is in phase The magnitude and phase of the components specifically include: Step 101: According to the shaft relative vibration data of the supporting bearings on both sides of the rotor, using the fast Fourier transform spectrum analysis method, real-time synchronously calculate the relative vibration amplitude and phase of the supporting bearings on both sides of the rotor; The frequency vibration amplitude is recorded as a ^ra , the phase is recorded as p ^ra ; the relative vibration amplitude of the supporting bearing on the other side of the rotor is recorded as a ^rb , and the phase is recorded as p ^rb ; Step 102: Using the formulas A ^real =a ^ra ×cos(p ^ra ) and A ^imagi =a ^ra ×sin(p ^ra ), calculate the shaft vibration power frequency vibration vector of the supporting bearing on the rotor side

The real part A ^real and the imaginary part A ^imagi ; use the formulas B ^real ＝a ^rb ×cos(p ^rb ) and B ^imagi ＝a ^rb ×sin(p ^rb ) to calculate the axial vibration power frequency vibration vector of the supporting bearing on the other side of the rotor The real part B ^real and the imaginary part B ^imagi ; Step 103: Using the formula

Calculate the in-phase component of the shaft vibration power frequency vibration of the supporting bearings on both sides of the rotor

Step 104: Using S ^real =1/2×(A ^real +B ^real ) and S ^imagi =1/2×(A ^imagi +B ^imagi ), calculate the in-phase component

The real part S ^real and the imaginary part S ^imagi , and then use the formula

Calculate the amplitude of the same-phase component of the relative vibration of the supporting shafts on both sides of the rotor, and use the formula S ^phase = (180/π) × arctan (S ^real /S ^imagi ) to calculate the phase of the relative vibration of the supporting shafts on both sides of the rotor; Step 4: Determine whether the set duration T is reached, and if so, go to step 5; otherwise, go to step 6; Step 5: After stepping for a length t, return to Step 2; Step 6: According to the magnitude and phase of the same-phase component of the relative vibration of the rotor support shafts stored on both sides of the rotor each time a length t is stepped, verify the amplitude ratio entropy mean value of the same-phase component and the phase difference of the same-phase component; Wherein, the verification in-phase component amplitude ratio entropy mean is specifically: Step 201: Calculate the in-phase component for each step of a length t the magnitude of

Ratio to amplitude qualified value S ^std

Step 202: Using the formula

Calculate the ratio

The entropy mean value E _mean , where

and stipulates that when

hour,

The phase difference value of the verification in-phase component is specifically: Calculate all the in-phase components stored during each step of a length t in the entire set time length T

The phase maximum in

and phase minimum

absolute value of difference

in Step 7: Judging and verifying whether the amplitude ratio entropy mean of the same-phase component and the phase difference of the same-phase component are all passed, if yes, it is determined that the same-phase component of the rotor vibration of the steam turbine unit is stable; otherwise, it is determined that the same-phase component of the rotor vibration of the steam turbine unit is not stable; Wherein, said judging and verifying whether the in-phase component amplitude ratio entropy mean value is passed is specifically, judging whether E _mean is greater than or equal to 0, if yes, then verifying the in-phase component amplitude ratio entropy mean value passing; otherwise, verifying the in-phase component amplitude ratio entropy mean value Fail; The verification of whether the phase difference of the in-phase component is passed is specifically to determine whether all the stored in-phase components

The phase maximum in

and phase minimum

Whether the absolute value of the difference is less than or equal to the set value D, if yes, verify that the phase difference of the same-phase component passes; otherwise, verify that the phase difference of the same-phase component fails. 2. A real-time identification method for the stability of the in-phase component of the rotor vibration of a steam turbine unit according to claim 1, characterized in that the set time length T=900 seconds. 3. A method for real-time identification of the stability of the in-phase component of rotor vibration of a steam turbine unit according to claim 1, characterized in that the length of the step is t=0.1 second. 4. A method for real-time identification of the stability of the in-phase component of rotor vibration of a steam turbine unit according to claim 1, characterized in that the qualified value of the amplitude S ^std = 50 microns. 5. A method for real-time identification of the stationarity of the in-phase component of rotor vibration of a steam turbine unit according to claim 1, characterized in that the set value D=5°. the

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