RU2241216C2 - Method and monitoring system for controlling condition and emergency protection of blade devices of rotor engines - Google Patents

Abstract

FIELD: turbine devices diagnostics technologies.

SUBSTANCE: method for monitoring vibration state of multiple blades on rotating operation wheel of machine includes measuring angular shaft position in plane of blade device rotation by noncontact impulse locating sensor of shaft angular position generating one impulse with each turn of shaft for 2π/n radians angle, where n - number of blades of operation wheel, concurrently angular positions of peripheral ends of each blade are measured in rotation plane with m noncontact marker sensors placed on body along perimeter of blade device above outer ends of blades with angular step of 2π/m radians, while current values of relative angular oscillations φ_j for each separate j blade is determined from current values of time interval τ between adjacent impulses generated by impulse locating sensor, and time deviation θ_j between matched pairs of impulses from impulse locating sensor and impulses, consecutively along shaft rotation, from m impulse marker sensors from formula φ_j = (2π/n·τ)·θ_j. Also described is system for monitoring vibration state and emergency protection of blade devices of rotor machines.

EFFECT: higher precision and reliability of measurements.

2 cl, 3 dwg

Description

The invention relates to the field of diagnosis of turbomachines and can be used to signal the pre-emergency state of the turbine blade apparatus when there are signs of material fatigue or blade defects.

A known monitoring system for representing the vibrational states of many blades on a rotating impeller [1] (RF patent No. 2125247, MKI G 01 H 1/00; G 07 C 3/00, published January 20, 1999, Bull. No. 2), containing attached the impeller is a sensor connected to a related impulse sensor, which delivers sensory impulses marking the point in time at which the blade passes by the sensor. There is also a marker sensor that generates a marker pulse when the wheel is in a certain zero position and an evaluation device, which includes a module for matching each sensor pulse with allowance for marker pulses to the blade that caused it and converts the flow of sensor pulses from each blade into data characterizing vibrational state of the scapula. The system includes a storage module associated with a random-access drive operating on a cycle, which stores fragments of the received data, and the presentation device selects data from the operational drive.

The known system has the disadvantage that the introduction of a marker sensor that generates a single marker pulse for each revolution of the rotor, with the aim of matching each sensor pulse generated by the pulse sensor, which caused it to the blade of the turbine impeller, does not allow measuring the vibrations of the turbine blade relative to the rotor, and hence the heterogeneity caused by dynamic deformations of the blades.

Known warning device for pre-emergency deformations of turbomachine blades [2] (RF patent No. 2177145, MKI G 01 H 1/08, published on December 20, 2001, Bull. No. 35), containing a non-contact impulse sensor installed in the turbomachine body over the path of peripheral ends blades, comparison circuit, rectangular pulse shaper, clock generator, control unit, time slot to code converter, digital code adder, total code divider by a fixed number corresponding to the number of blades in the wheel Bina, the difference calculation unit, a code generator prefault corresponding pre-fault level deformation of the blades.

The disadvantage of this device is that the measured are the joint oscillations of the rotor and the blade rim of the turbomachine, which do not clearly characterize the heterogeneity of the oscillations caused by the dynamic deformations of the blades themselves. So, in the absence of any heterogeneity of the scapular apparatus, the excitation of torsional vibrations of the rotor itself, on which the turbine is planted, will lead to a false conclusion about the appearance of such heterogeneity. The cause of such angular oscillations of the rotor may be the excitation of one of the torsion resonance forms, grazing in the kinematic pair of the rotor - stator, uneven gas flow through the turbine, etc.

In accordance with this objective of the present invention is to improve the accuracy and reliability of the measurement and monitoring of vibrations that determine the technical condition of the material part of the scapular apparatus relative (with respect to the rotor) vibrations of the blades in the plane of rotation caused by their dynamic deformations, with subsequent diagnosis of the current technical condition as each scapula, and scapular apparatus as a whole.

To achieve the task in a method for monitoring the vibrational state of many blades on a rotating impeller of a machine, in the plane of rotation of a machine’s blade apparatus, measure the angular position of the shaft using a non-contact pulse reference sensor (IRD) of the angular position of the shaft, generating one pulse every time the shaft rotates through angle 2 π / n radian, where n is the number of impeller blades, at the same time measure the angular position of the peripheral ends of each of the blades in the plane of rotation using m non-contact s pulse marker sensors (IPD) disposed on the perimeter body blading over the external ends of vanes with an angular increments of 2 π / m radian, and the current values of the relative angular oscillations φ _j each individual j-of the blade is determined by the current values of the time interval τ between adjacent pulses generated by the IRD, and the time shift θ _j between the matched pairs of pulses from the IRD and the pulses (sequentially in the direction of rotation of the shaft) from m - pieces of IPM according to the formula

φ _j = (2 π / n · τ) · θ _j ,

and the system for monitoring the vibrational state and emergency protection of rotor blade vanes contains non-contact pulse marker sensors (BMD) of the angular position of the peripheral ends of the blades, marking the times of the end of the blade end of the working area of the sensing elements of these sensors, placed symmetrically around the perimeter of the blade apparatus above the peripheral rotation path the ends of the blades with an angular pitch of 2 π / m radians, where m is the number of installed BMI, which determines the frequency d apazone 0 ... f _max oscillation measurement blades, where f _max = f _p · m / 2, f _p - rotor speed; a signal amplifier connected to the output of the IRD loaded onto forming devices generating standard rectangular reference impulses-markers of the “zero” and current angular position of the shaft, and with outputs IMD-signal amplifiers connected to forming devices-generators of standard rectangular marker impulses of the angular position of peripheral ends blades, the identifier block of the blades on the impeller, which in turn is connected to the module for matching pulses from the IRD and pulses from the IMD, (respectively) along the end of each blade in the BMI sensitive elements, a high-frequency generator of standard clock pulses, a measuring module of the current values of the time interval between adjacent pulses from the IRD by the signal from the standard rectangular reference pulse generator from the IRD and the signal from the standard high-frequency generator clock pulses, a module measuring the current values of the time shift between set in accordance with the pairs of standard rectangular reference impu signals from the IRD and marker pulses from the IMD, by a signal from a high-frequency generator of standard clock pulses, connected to a unit for converting the output signals from these modules to codes, a calculator module for calculating the current values of the relative angular oscillations of each impeller blade relative to the rotating shaft using the generated temporal code signals interval and time shift, a measuring module of the current values of the signs of dynamic activity of the impeller blades by their relative angular oscillations, loaded onto the unit for generating commands for emergency protection of the equipment, a unit for displaying information about the current vibrational behavior of the blades, a pulse reference sensor of the current angular position of the shaft located on the housing above the ends of the blades of the impeller, pulse marker sensors placed symmetrically around the perimeter of the blade body above the peripheral rotation path the ends of the blades, the module bringing in the course of the experiment in accordance with the pulses from the IRD and pulses from the BMI, excited sequentially (by the rotation of the shaft) with the end face of each specific impeller blade in the sensitive elements of the sensors; a module for measuring the current values of the time interval between adjacent pulses from the IRD and a module for measuring the current values of the time shift between the matched pairs of pulses from the IRD and pulses from the IMD, a module for calculating the relative angular oscillations of each blade of the impeller, and a measuring module for it current values of signs of relative (relative to the rotating shaft) dynamic activity of the blades.

Figure 1 shows the functional diagram of the proposed system for implementing the method, which shows: shaft 1 with an impeller fixed on it with a blade apparatus 2 located in the housing 3 with contactless pulse pulsed sensors (BMI) mounted on it along the outer perimeter of the blade apparatus 2 ) 4, 5, 6, 7, pulse reference sensor (IRD) 8, 9, 10, 11, structurally including a gear wheel 8 with a ring gear 9, a reference mark 11 of the "zero" angular position of the shaft and a sensing element 10, pulse amplifiers cores 12, 15, 16, 17, 18, a forming device-generator of pulse-markers 13 of the "zero" position of the shaft 1, forming device 14, generating reference pulses of the angular position of the shaft, forming device-generators of marker pulses 19, 20, 21, 22 angular positions of the peripheral ends of the blades, block identifier 23 of the blades, the module 24 matching pulses from the IPD and the pulses from the IRD, the measuring module 25 time intervals between adjacent pulses from the IRD, the measuring module 26 time shifts between the corresponding pulses from IRD and IMD, a high-frequency generator of 27 standard clock pulses, a unit for converting 28 measured time intervals into codes, a calculating module 29 for the relative angular vibrations of each impeller blade 2, and a measuring module 30 for signs of a relative (relative to the rotating shaft) dynamic the activity of the blades, block 31 of the formation of the emergency protection commands of the machine, block 32 display information about the current technical condition of the blade apparatus 2.

To solve this problem, the angular position of the shaft is measured using a non-contact sensitive element 10 of a pulsed reference sensor (IRD) of the angular position of the shaft 1, which generates one pulse at each rotation of the shaft 1 by an angle of 2 π / n radians, where n is the number of impeller blades 2. To mark the pulse corresponding to the accepted “zero” angular position of the shaft, a reference mark 11 is formed mechanically on the ring gear 9 of the gear wheel 8 (for example, by creating a deeper groove between one of the pairs of dnih teeth). Using contactless impulse marker sensors IMD 4, 5, 6, 7 installed on the housing 3 around the perimeter of the blade apparatus 2 (above the outer ends of the blades), placed with an angular pitch of 2 π / m radians, where m is the number of used IMDs, the current angular the position of the peripheral ends of the blades by forming one pulse at each rotation of the end of each blade by an angle of 2 π / m radians, and the current values of the relative angular oscillations φ _{j of} each specific j-th blade are determined by the current values of the time interval τ between adjacent pulses generated by the IRD, and the time shift θ _j between the matched pairs of pulses from the IRD and the pulses (sequentially in the direction of rotation of the shaft) from m - pieces of IPM according to the formula: φ _j - = (2 π / n · τ) · θ _j .

The solution of the problem in the proposed monitoring system of the condition and emergency protection of the blades is achieved by the fact that this system, in contrast to the known, additionally includes an auxiliary non-contact pulse reference sensor (IRD) of the angular position of the shaft, structurally formed from elements 8, 9, 10, 11, generating one marker pulse at each rotation of the shaft by an angle of 2 π / n radians, where n is the number of blades of the controlled blade apparatus of the machine, as well as the main pulse marker sensors (BMI) 4, 5, 6, 7, ma the timing moments of the passage by the ends of the blades of the working zone of the sensitive elements of these sensors, the obligatory condition for the placement of which is their symmetrical location along the perimeter of the casing 3 of the blade apparatus above the rotation path of the peripheral ends of the blades with an angular pitch of 2 π / m radians, where m is the number of installed IMD m, the frequency range 0 .... f _max is determined for measuring the oscillations of the blades, where f _max = f _p · m / 2, f _p is the rotor speed. In addition, the system contains a module 24 for bringing during the experiment the correspondence of pulses from the IRD and pulses from the BMI, excited sequentially (in the direction of rotation of the shaft) with the end face of each concrete blade 2 of the impeller in sensors 4, 5, 6, 7; a module-meter 25 of the current values of the time interval between adjacent pulses from the IRD and a module-meter 26 of the current values of the time shift between the matched in the module 24 pairs of pulses from the IRD and pulses from the IPD 4, 5, 6, 7. Compliance is established during operation rotary machine on the basis of the minimum largest timing advance or delay of the pulse from the IMD relative to the pulse from the IRD. Additionally, a calculating module 29 of the relative angular vibrations of each blade of the impeller 2 and a measuring module 30 of the current values of the signs of relative (relative to the shaft) dynamic activity of the blades are introduced.

The method and system are implemented and operate as follows. When the shaft 1 rotates, the IRD sensing element 10, for example, the eddy current type, generates a sequence of analog pulses in the amount of n per one revolution of the shaft, where n is the number of impeller blades 2 of the rotor machine. A fragment of the analog signal at the output of the IRD sensing element 10 is shown in FIG. 2, where the pulse marker of the “zero” position of the shaft 1 has an obvious distinguishing feature - a voltage dip compared to pulses corresponding to sequential rotations of the shaft by an angle of 2π / n radians.

Similarly, when the shaft 1 is rotated, the m 3 pieces of IMD installed along the perimeter of the casing 3 of the blade apparatus (Fig. 1, for definiteness, shows the option m = 4 of installing 4 sensors 4, 5, 6, 7) also generate sequences of n pulses per revolution shaft 1. Each such sequence of pulses marks the time moments of the ends of the blades of the impeller of the zone of sensitive elements IMD. Next, the pulse signals from the sensor element IRD 10 are fed to the input of the amplifier 12, and from the sensitive elements IMD 4, 5, 6, 7, respectively, to the inputs of the amplifiers 15, 16, 17, 18. The signal from the output of the amplifier 12 is fed to two forming devices: 13, generating standard rectangular pulses corresponding to the “zero” position of the shaft 1, and a device 14 generating standard rectangular pulses corresponding to successive rotations of the shaft 1 by an angle of 27 π / n radians. Similarly, the signals from the outputs of amplifiers 15, 16, 17, 18 are fed respectively to the inputs of forming devices 19, 20, 21, 22, generating standard rectangular pulses corresponding to successive rotations of the ends of the blades 2 of the impeller by an angle of 2 π / n radians. All forming devices 13, 14, 19, 20, 21, 22, which are one of the varieties of the analog comparator, generate rectangular pulses in such a way that their leading edges correspond to the maximum values of the gradients of the pulse signals at the output of amplifiers 12, 15, 16, 17, 18. A sign for the formation in the device 13 of the pulse marking the “zero” position of the shaft is the amplitude value of the corresponding pulse at the output of the amplifier 12.

Figure 3 presents the standard rectangular pulses at the outputs of the forming devices 13 (Fig.3-a), 14 (Fig.3-b) and the forming device corresponding to one of the IMD (Fig.3-c). In this case, the leading edges of each of the standard rectangular pulses correspond to the moment of reaching the maximum by the gradient of rise of the corresponding analog pulse at the outputs of the IRD and IMD. Next, the output signals of the forming devices 13, 14, 19, 20, 21, 22 are fed to the inputs of the identifier block 23 of the blades of the impeller. At known times when the shaft passes its “zero” position, determined by the corresponding pulse markers from the forming device 13, the blades are identified at each rotation of the shaft automatically during the experiment by sequential numbering of the blades, where the first blade is the closest to the “zero” position of the shaft, the course of its rotation, and the latter is closest to the “zero” position of the shaft against the course of its rotation. At the outputs of block 23, the same pulse signals are present as at outputs 19, 20, 21, 22, but with additional indexing of pulses, which determines their binding to the corresponding ends of the blades. These signals simultaneously with the reference pulses from block 14 are fed to the inputs of module 24 automatically during the experiment, which establishes and confirms the correspondence between the pulses from the IRD and the marked pulses from each of the IMD according to the following criterion: the impulse from the IRD corresponds to the impulse from the allocated IMD, if it separates them the shortest time interval in comparison with other pulses from the IMD.

At the outputs of the cast module 24, all pulses from each IMD are marked according to the pulses from the IRD. Next, the reference pulse signal from the forming device 14 and standard clock pulses from the high-frequency generator 27 are supplied to the inputs of the meter module 25. The moments of the arrival times of the leading edges of the pulses from the module 14 are determined and marked in the module 25. The obtained information is then transmitted to one of the inputs of the meter 26. In addition, in the measuring module 25, the current values of the time interval τ between neighboring reference pulses from the IRD are determined. The inputs of the measuring module 26, in addition to the above-mentioned signal from the measuring module 25, are supplied with signals from the module 24, by which the current values of the time shifts θ _j for each j-th blade between the associated pulse pairs from IRD and each IMD. The output signals from the measuring modules 25 and 26 are fed to the inputs of the block 28 for converting the current values of τ and θ _j into codes, which, in turn, are fed to the inputs of the calculating module 29 of the current values of the relative angular position of each j-th blade (1≤ j≤ n) impeller according to the formula

φ _j = (2 π / n · τ) · θ _j radian.

The digitized data from the output of the calculating module 29 is fed to the inputs of the measuring module 30 of the current values of the signs of dynamic activity of both each blade and the blade apparatus as a whole. RMS values of relative angular fluctuations φ _j , “pic to pic” φ _j , maximum deviation φ _j from the average value, etc. can be taken as such signs. Further, the current values of the accepted signs of the dynamic activity of the blade apparatus from the output of the module 30 are supplied to the emergency protection command generation unit 31 of the rotary machine based on the technical condition of its blade apparatus, as well as to the information display unit 32 about the current status of the blade apparatus.

Claims (2)

1. A method for monitoring the vibrational state of many blades on a rotating impeller of a machine, characterized in that, in order to improve the accuracy and reliability of measuring the vibrations of the blades relative to the rotating shaft in the plane of rotation of the blade apparatus of the machine, the angular position of the shaft is measured using a non-contact pulsed reference sensor (IRD) ) the angular position of the shaft that generates one pulse at each rotation of the shaft by an angle of 2 π / n radians, where n is the number of impeller blades, simultaneously measure the angular the position of the peripheral ends of each of the blades in the plane of rotation using m non-contact pulse marker sensors (BMI) located on the housing along the perimeter of the blade apparatus above the outer ends of the blades with an angular pitch of 2 π / m radians, and the current values of the relative angular oscillations φ _{j of} each specific j-blade that is determined by the current values of the time interval τ between successive pulses generated by the IRD and the time shift θ _j maintained between aligned pairs of pulses and pulses from IRD (sequence tionary shaft during the rotation) of m - IPD pieces by the formula φ _j = (2 π / n · τ) · θ _j . 2. A system for monitoring the vibrational state and emergency protection of rotor machine vanes, characterized in that it contains contactless pulse marker sensors (IMD) of the angular position of the peripheral ends of the blades, marking the times of the end of the blade of the working area of the sensitive elements of these sensors, placed symmetrically around the perimeter the casing of the blade apparatus over the trajectory of rotation of the peripheral ends of the blades with an angular pitch of 2 π / m radians, where m is the number of installed BMI, which the frequency range 0-f _max is determined for measuring the oscillations of the blades, where f _max = f _p · m / 2, f _p is the rotor speed; a signal amplifier connected to the output of the IRD loaded onto forming devices generating standard rectangular reference impulses-markers of the “zero” and current angular position of the shaft, and with outputs of the IPM signal amplifiers connected to forming devices-generators of standard rectangular marker pulses of the angular position of the peripheral ends blades, a block identifier of the blades on the impeller connected to the module for matching pulses from the IRD and pulses from the IMD, sequentially given (in the direction of rotation of the shaft) by the end face of each blade in the BMI sensitive elements, a high-frequency generator of standard clock pulses, a measuring module of the current values of the time interval between adjacent pulses from the IRD according to the signal from the standard rectangular clock pulse generator from the IRD and the signal from the high-frequency standard clock generator pulses, a module measuring the current values of the time shift between the matched pairs of standard rectangular reference pulses from the IRD and arker pulses from IMD, by a signal from a high-frequency generator of standard clock pulses, connected to a unit for converting output signals from these modules into codes, a calculator module for calculating the current values of the relative angular oscillations of each impeller blade relative to the rotating shaft using the generated code signals for the time interval and time shift , a module measuring the current values of the signs of dynamic activity of the impeller blades by their relative angular oscillations, loaded on a unit for generating emergency equipment protection commands, a unit for displaying information about the current vibrational behavior of the blades, a pulse reference sensor of the current angular position of the shaft located on the housing above the ends of the blades of the impeller, pulse marker sensors placed symmetrically around the perimeter of the body of the blade apparatus above the rotation path of the peripheral ends of the blades , the module of bringing in the course of the experiment in correspondence of pulses from the IRD and pulses from the BMI, excited sequentially (in the direction of rotation shaft) with the end face of each specific impeller blade in the sensitive elements of the sensors; a module for measuring the current values of the time interval between adjacent pulses from the IRD and a module for measuring the current values of the time shift between the matched pairs of pulses from the IRD and pulses from the IMD, a module for calculating the relative angular oscillations of each blade of the impeller, and a measuring module for it current values of signs of relative (relative to the rotating shaft) dynamic activity of the blades.

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