CN106248007A - A kind of rotor of turbogenerator set jack-up height on-line measurement device and method - Google Patents

Abstract

The invention discloses a kind of rotor of turbogenerator set jack-up height on-line measurement device and method, by vibration signal being inputted computer, thus calculating rotor jack-up height at bearing according to the variable quantity of vibration signal voltage.The present invention is easy for installation.The present invention need not set up at each bearing dial gauge, but uses the vibration probe of Turbo-generator Set itself, only vibration signal need to access collecting device, plug and play；Certainty of measurement of the present invention is high, and device certainty of measurement can reach 1 μm；The present invention will not produce mechanical displacement, and data reliability is high；The present invention saves manpower compared with traditional approach, avoids artificial error in reading simultaneously.

Description

Device and method for measuring jacking height of rotor of steam turbine generator unit on line

Technical Field

The invention relates to a steam turbine generator unit, in particular to an on-line measuring device and method for the jacking height of a rotor of the steam turbine generator unit.

Background

The steam turbine and the generator are main equipment in a thermal power plant, play a role in converting heat energy into electric energy, and have important significance for the power plant in safe operation. For a steam turbine generator unit provided with a top shaft oil system, according to different types of the steam turbine generator unit, the rotor jacking height of the steam turbine generator unit is generally 0.02-0.08 mm, the measurement of the rotor jacking height in the adjustment process of the top shaft oil system of the steam turbine generator unit is an essential process, and the accuracy and the size of the measured value are related to the safe operation of the rotor, a bearing bush and the whole steam turbine generator unit, so that the steam turbine generator unit top shaft oil system is the basis for the normal adjustment of the top shaft oil system of the steam turbine generator unit.

At present, in the adjusting process of a jacking shaft oil system, the jacking height of a rotor of a steam turbine generator unit is measured by erecting dial indicators at bearings, and the method mainly has the following defects:

a, the dial indicator is difficult to erect. Most turbo generator unit manufacturers have the problems that due to the consideration of safety and other factors, the exposed part of the rotor is very short, the part close to the bearing is narrow, and a dial indicator can be erected only when a worker is close to the bearing rotor;

and B, the installation error is large. Because the place of the erection position is limited, workers are inconvenient to adjust when erecting the dial indicator, the sight is easy to block in the process of adjusting the dial indicator, and the adjusting force and direction are difficult to accurately judge, so that the installation error is large;

and C, reading errors are easy to generate. Because the pointer type dial plate reads, the reading can generate certain deviation due to different visual angles;

d, mechanical displacement of the dial gauge during measurement may cause distortion of the readings. In the measuring process, because the dial indicator has more connecting parts, displacement is easily generated among all the parts, and the measured data is distorted.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the device and the method for measuring the jacking height of the rotor of the steam turbine generator unit on line solve the problems of high meter installation difficulty, low measurement precision and reading distortion in the conventional measurement of the jacking height of the rotor of the steam turbine generator unit, provide accurate data for adjusting a jacking oil system and provide favorable conditions for safe operation of the steam turbine generator unit.

The technical scheme of the invention is as follows: the utility model provides a turbo generator set rotor jack-up height on-line measuring device, includes vibration sensor, and vibration sensor is located the plane of perpendicular to rotor axis, and distributes on cutting the straight line with the rotor cross-section mutually, and vibration sensor links to each other with the TSI fastener, and the TSI fastener links to each other with data acquisition equipment, and data acquisition equipment links to each other with the computer.

Further, the straight line of the vibration sensor passes through the axis of the rotor, or the straight line of the vibration sensor is perpendicular to the surface of the rotor.

An on-line measuring method for the jacking height of a rotor of a steam turbine generator unit comprises the following steps:

step 1), before a jacking oil pump is started, recording an original voltage value of a vibration signal of a bearing rotor: u shape_i0；

Step 2) starting the top shaft oil pump, adjusting the oil pressure of the top shaft, and recording the voltage value U of the vibration signal at the moment when the oil pressure changes_i1Calculating Δ U_i，

ΔU_i＝U_i1-U_i0；

Step 3) calculating the jacking height h of the rotor at each bearing_i,

h_i＝kcΔU_i

Where k is a sensor coefficient and c is an angle coefficient.

The angular coefficient c is defined as: the secant value of the angle theta between the line on which the vibration sensor is located and the direction perpendicular to the plane (the plane perpendicular to the rotor axis), i.e. c ═ sec theta.

Typically, there are two vibration sensors of the steam turbine generator set, and the vibration sensors are assumed to be located in a cartesian plane coordinate system perpendicular to the rotor axis and arranged on the x-axis and the y-axis, i.e., the x-direction vibration sensor and the y-direction vibration sensor, respectively, while the origin of the cartesian plane coordinate system is located in the rotor section. The x-direction vibration sensor and the y-direction vibration sensor are connected with a TSI (monitoring protection system) clamping piece, the TSI (monitoring protection system) clamping piece is connected with data acquisition equipment, and the data acquisition equipment is connected with a computer.

Under the assumed condition, the method for measuring the jacking height of the rotor of the steam turbine generator unit on line comprises the following steps:

step 1), before a jacking oil pump is started, recording an original voltage value of a vibration signal of a bearing rotor:i represents a bearing number, two sensors are arranged at each bearing, x represents an x-direction vibration sensor, and y represents a y-direction vibration sensor;

step 2) starting the top shaft oil pump, adjusting the oil pressure of the top shaft, and recording the voltage value of the vibration signal at the moment when the oil pressure changesAs shown in equation (1), respectively calculating

${\mathrm{\ΔU}}_i^x=U_{i1}^x-U_{i0}^x$

Step 3) calculating the jacking height of the rotor at each bearingAs shown in the formula (2),

$h_i^x={\mathrm{kc}}_x{\mathrm{\ΔU}}_i^x$

where k is the sensor coefficient, c_x、c_yIs an angle coefficient, an angle coefficient c_x、c_yThe calculation formula is shown in formula (3).

c_x＝secθ_x

c_y＝secθ_yFormula (3);

in the formula, theta_x、θ_yThe angle between the vibration sensor and the rotor in the vertical direction is the straight line which is located in the Cartesian coordinate plane and passes through the origin in the vertical direction.

The x-direction vibration sensor measures the distance between the x-direction vibration sensor and the rotor, and the y-direction vibration sensor measures the distance between the y-direction vibration sensor and the rotor. Wherein,the displacement variation of the rotor in the vertical direction is deduced according to the distance variation between the sensor and the rotor measured by the x-direction vibration sensor;the displacement variation of the rotor in the vertical direction is deduced according to the distance variation between the sensor and the rotor measured by the y-direction vibration sensor. It should be noted that the above-derived displacement variation is an approximate value close to the actual jacking height of the bearing, but the two are considered equal because the difference is negligibly small. According to unit vibration during actual measurementAnd (4) determining the value closest to the actual jacking height by the sensor installation condition.

The device and the method can replace the traditional device and method for measuring the jacking height of the rotor of the steam turbine generator unit, and more accurate data can be obtained more conveniently. Compared with the traditional mode, the method has the following beneficial effects:

and A, the installation is convenient. The invention does not need to erect dial indicators at each bearing, but uses the vibration probe of the turbo generator set, and only needs to connect the vibration signal into the acquisition equipment, namely, the vibration probe can be used after being assembled;

and B, the measurement precision is high. The invention utilizes the vibration sensor, the measurement precision can reach 1 μm, and the measurement precision of the traditional dial indicator is 10 μm;

and C, mechanical displacement cannot be generated, and the data feasibility is high. The vibration probe of the steam turbine generator unit is strictly checked in the installation process and is fixed by screws, so that fewer parts are adopted, the sliding between mechanical parts is avoided, and the measured data has higher feasibility;

and D, manpower is saved. The invention can realize the monitoring of the jacking height of the rotor at all the bearings by one person, and the traditional measuring mode needs more than six persons to realize the simultaneous monitoring of the jacking height of all the bearings, thereby saving the manpower compared with the traditional mode and avoiding the artificial reading error.

Drawings

FIG. 1 is a schematic view of the connection of an on-line measuring device according to the present invention;

FIG. 2 is a schematic view of a vibration sensor at a 45 degree angle to the vertical;

FIG. 3 is a diagram showing an angle θ between the vibration sensor and the vertical direction_x、θ_ySchematic representation.

Detailed Description

1) The utility model provides a turbo generator set rotor jack-up height on-line measuring device, vibration sensor totally two is located two straight lines that pass the rotor axle center respectively, and two vibration sensors distribute in the both sides of crossing the perpendicular line in rotor axle center. The vibration sensors are assumed to be located in a cartesian plane coordinate system perpendicular to the rotor axis and arranged on the x-axis and the y-axis, respectively, i.e., the x-direction vibration sensor and the y-direction vibration sensor, while the origin of the cartesian plane coordinate system coincides with the rotor axis. The x-direction vibration sensor and the y-direction vibration sensor are connected with a TSI (monitoring protection system) clamping piece, the TSI (monitoring protection system) clamping piece is connected with data acquisition equipment, and the data acquisition equipment is connected with a computer. As shown in fig. 2, the straight line of the vibration sensor passes through the axis of the rotor, and a coordinate system is established with the axis of the cross section of the rotor as an origin. As shown in fig. 1, a bearing rotor vibration signal to be measured by the steam turbine generator unit is connected to a data acquisition device, and the signal not only refers to a buffer output interface on a TSI card, but also includes all interfaces using a monitoring probe of the steam turbine generator unit as a signal source;

2) the data acquisition equipment is connected with the computer and transmits a vibration signal of the bearing rotor into the computer;

3) before starting the jacking oil pump, recording the original voltage value of the vibration signal of the bearing rotor:i represents a bearing number, two sensors are arranged at each bearing, x represents an x-direction vibration sensor, and y represents a y-direction sensor;

4) starting the top shaft oil pump, adjusting the oil pressure of the top shaft, and recording the voltage value of the vibration signal when the oil pressure changesAs shown in equation (1), respectively calculating

${\mathrm{\ΔU}}_i^x=U_{i1}^x-U_{i0}^x$

5) Calculating the jacking height of the rotor at each bearingSee formula (2);

$h_i^x={\mathrm{kc}}_x{\mathrm{\ΔU}}_i^x$

where k is the sensor coefficient, c_x、c_yFor the angle coefficient, as shown in FIG. 2, if the angle of the sensor to the vertical is 45, the angle coefficient c isAngle coefficient c_x、c_yThe calculation formula is shown in formula (3).

c_x＝secθ_x

c_y＝secθ_yFormula (3)

Wherein, as shown in FIG. 3, θ_x、θ_yIs the included angle between the vibration sensor and the vertical direction of the rotor.

Claims (3)

1. The utility model provides a turbo generator set rotor jack-up height on-line measuring device, includes vibration sensor, its characterized in that: the vibration sensor is positioned in a plane vertical to the axis of the rotor and distributed on a straight line cutting the section of the rotor, the vibration sensor is connected with the TSI clamping piece, the TSI clamping piece is connected with the data acquisition equipment, and the data acquisition equipment is connected with the computer.

2. The device for measuring the jacking height of the rotor of the steam turbine generator unit according to claim 1, is characterized in that: the straight line of the vibration sensor passes through the axle center of the rotor.

3. The method for measuring the jacking height of the rotor of the steam turbine generator unit on line is characterized by comprising the following steps of:

step 1), before a jacking oil pump is started, recording an original voltage value of a vibration signal of a bearing rotor: u shape_i0；

Step 2) starting the top shaft oil pump, adjusting the oil pressure of the top shaft, and recording the voltage value U of the vibration signal at the moment when the oil pressure changes_i1Calculating Δ U_i，

ΔU_i＝U_i1-U_i0；

Step 3) calculating the jacking height h of the rotor at each bearing_i,

h_i＝kcΔU_i

Where k is a sensor coefficient and c is an angle coefficient.