JP2007240421A - Torsional rigidity arithmetic unit for rotor, prime mover output arithmetic unit, and methods therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely calculate torsional rigidity, and to precisely find a prime mover output, based on torsional rigidity calculated precisely. <P>SOLUTION: A torsional angle of a rotor in a position in the vicinity of a load is measured in a plant for driving the load connected to an end part of the rotor driven by a plurality of prime movers, by a torsional angle measuring instrument 22, the first torsional rigidity calculating means 24 calculates the torsional rigidity of the rotor in the position in the vicinity of the load, based on the torsional angle of the rotor in the position in the vicinity of the load, a transverse elasticity modulus calculating means 25 calculates a transverse elasticity modulus, based on the torsional rigidity of the rotor in the position in the vicinity of the load. The second torsional rigidity calculating means 26 calculates the torsional rigidity of the rotor in a position between the prime movers, using the transverse elasticity modulus of the rotor calculated by the transverse elasticity modulus calculating means 25. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a torsional rigidity calculating device for a rotating body that obtains torsional rigidity of a rotating body that is given a rotational force by a plurality of prime movers to drive a load, and based on the torsional rigidity calculated by the torsional rigidity calculating device for the rotating body The present invention relates to a prime mover output calculation device for obtaining an output and a method thereof.

  In a thermal power plant or a nuclear power plant, when individually measuring the output of a turbine that is a prime mover, the turbine output (load output) is calculated by measuring the torsion of a drive shaft (rotating body) that drives the turbine. For example, in order to calculate the turbine output by measuring the torsion of the rotating body, a pair of reflectors are provided at different positions in the axial direction of the rotating body, and both reflectors are irradiated with laser light and reflected from both reflectors. The light is detected, the rotation period of the rotating body is obtained based on the periodic strength of the reflected light, and the torque of the rotating body is detected based on the delay time of the reflected light from both reflectors (torsion of the rotating body). (For example, refer to Patent Document 1).

  FIG. 4 is a block configuration diagram of an example of a turbine output device that calculates the turbine output by measuring the torsion of the rotating body. The laser beam output from the laser beam output device 11 is applied to the surface of the rotating body 13 via the optical transceiver 12. A pair of reflectors 14a and 14b are provided on the surface of the rotator 13 at intervals in the axial direction, and the laser light emitted from the optical transceiver 12 is reflected by a predetermined reflection pattern. The reflectors 14a and 14b have, for example, a reflection pattern in which a portion that reflects laser light and a portion that absorbs laser light are formed in a bar code shape, and follows the reflection pattern when irradiated with laser light. Reflected light is generated. The reflected light reflected by the surface of the rotating body 13 including the reflecting plates 14a and 14b is received by the optical transmission / reception device 12, and the reflected light intensity is detected by the light detection devices 15a and 15b and input to the twist angle calculation unit 16. .

The torsion angle calculation unit 16 calculates the torsion angle θ by the equation (1) based on the delay time t _d of the reflected light from both reflectors. T in the equation (1) is the rotation period of the rotating body.

And the torque calculation part 17 calculates torque (tau) by (2) Formula from the torsion angle (theta) calculated | required by (1) Formula, and the torsional rigidity K of a rotary body.

Further, the output calculation unit 18 calculates the turbine output W _T by the equation (3) from the torque τ obtained by the equation (2) and the rotational speed N of the rotating body 13.

Thus, to obtain the turbine output W by measuring the torsion of the rotating body, the torsional rigidity K of the rotating body is required as shown in Equation (3). The torsional rigidity K of the rotating body is obtained by examining the rotating body (turbine drive shaft) by taking it out of the power plant or by computer analysis. In the computer analysis, for example, the torsional rigidity K of the rotating body is obtained by FEM analysis (finite element method).
JP 2002-22564 A

  However, when examining the torsional rigidity K of the rotating body by taking out the rotating body (turbine drive shaft), it takes time and costs because the turbine is disassembled. On the other hand, when it is obtained by computer analysis, there is a problem in terms of accuracy.

The torsional rigidity K of the rotating body is expressed by the equation (4) when the rotating body is a cylinder. (4) modulus of transverse elasticity, Z _P is the second moment of the rotary body, L is a torsion measurement section length of G is the rotation materials in the formula (distance between both reflector), d is the diameter of the rotary body .

  That is, in order to calculate the torsional rigidity K, the transverse elastic coefficient G specific to the material of the rotating body (turbine drive shaft) is required, but it is difficult to accurately grasp the transverse elastic coefficient G. This is because the transverse elastic modulus G varies depending on, for example, a minute difference in the component ratio, a difference in quenching time, and the like even if the same stainless steel is used.

FIG. 5 is a graph of the power plant output W _c calculated by the torsional rigidity K obtained by computer analysis and the power plant output W _g measured by the generator output detector. In Figure 5, start taking the load from time t1, shows a case where a rated output P _R at time t2. As can be seen from FIG. 5, there is an error between the power plant output W _c calculated by the torsional stiffness K obtained by computer analysis and the power plant output W _g measured by the generator output detector. This error is considered to be an error of torsional rigidity K due to an error of the lateral elastic modulus G.

  An object of the present invention is to obtain a motor output with high accuracy based on a torsional rigidity computing device capable of calculating torsional rigidity with high accuracy and a torsional stiffness calculated by the torsional stiffness computing device of the rotating body. A prime mover output computing device and methods thereof are provided.

  The torsional rigidity calculating device for a rotating body according to the invention of claim 1 is the rotation of a position in the vicinity of the load of a plant that applies a rotational force to the rotating body by a plurality of prime movers and drives a load connected to an end of the rotating body. A torsion angle measuring instrument for measuring a torsion angle of the body, and a first torsional rigidity for calculating the torsional rigidity of the rotating body at the position near the load based on the torsion angle of the rotating body at the position near the load measured by the torsion angle measuring instrument. Rigidity calculation means; lateral elastic coefficient calculation means for calculating a transverse elastic coefficient of the rotating body near the load based on the torsional rigidity of the rotating body near the load calculated by the first torsional rigidity calculating means; and Second torsional rigidity calculating means for calculating the torsional rigidity of the rotating body at the position between the prime movers using the transverse elastic coefficient of the rotating body at the position near the load calculated by the lateral elastic modulus calculating means. It is characterized in.

  According to a second aspect of the present invention, there is provided a prime mover output computing device comprising: a rotating body torsional stiffness computing device, wherein a plurality of prime movers apply a rotational force to a rotating body to drive a load connected to an end of the rotating body. A first torsion angle measuring instrument for measuring a torsion angle of a rotating body in the vicinity of the load; a second torsion angle measuring instrument for measuring a torsion angle of a rotating body at a position between any of the plurality of prime movers; First torsional rigidity calculating means for calculating the torsional rigidity of the rotating body at the position near the load based on the torsional angle of the rotating body at the position near the load measured by the first torsion angle measuring instrument; Based on the torsional rigidity of the rotating body at the position near the load calculated by the torsional rigidity calculating means, the lateral elastic coefficient calculating means for calculating the transverse elastic coefficient of the rotating body at the position near the load, and calculated by the transverse elastic coefficient calculating means negative A second torsional rigidity calculating means for calculating the torsional rigidity of the rotating body at the position between the prime movers using the transverse elastic coefficient of the rotating body at a nearby position; and the rotation of the position between the prime movers measured by the second torsion angle measuring instrument. A prime mover output calculating means for calculating the output of the former prime mover at the position between the prime movers based on the torsional angle of the body and the torsional rigidity of the rotating body at the prime mover position calculated by the second torsional stiffness calculation means; It is characterized by.

  According to a third aspect of the present invention, there is provided a method for calculating torsional rigidity of a rotating body, wherein a plurality of prime movers apply rotational force to the rotating body to drive a load connected to an end of the rotating body at a position near the load. Measure the torsional angle of the body, calculate the torsional rigidity of the rotating body near the load based on the measured torsional angle of the rotating body near the load, and load based on the calculated torsional rigidity of the rotating body near the load The transverse elastic coefficient of the rotating body at the vicinity position is calculated, and the torsional rigidity of the rotating body at the position between the prime movers is calculated using the calculated lateral elasticity coefficient of the rotating body at the load vicinity position.

  According to a fourth aspect of the present invention, there is provided a prime mover output calculation method in which a rotational force is applied to a rotating body by a plurality of prime movers to drive a load connected to an end of the rotating body. The torsional rigidity of the rotating body at the position near the load is measured based on the measured twist angle of the rotating body at the position near the load. Calculate the transverse elastic coefficient of the rotating body at the position near the load based on the torsional rigidity of the rotating body at the calculated position near the load, and use the calculated lateral elasticity coefficient of the rotating body at the position near the load at the position between the prime movers. Calculate the torsional rigidity of the rotating body, and determine the position before the prime mover based on the measured torsional angle of the rotating body at the position between the prime movers and the calculated torsional rigidity of the rotational body at the position between the prime movers. And calculates the output of the prime mover.

  According to the present invention, the torsional rigidity of the rotating body at the position near the load is accurately calculated based on the load output of the plant measured accurately and the torsion angle of the rotating body at the position near the load. Since the transverse elastic modulus of the rotating body at the position near the load is calculated based on the torsional rigidity of the rotating body, a highly accurate lateral elastic coefficient can be obtained. And since the torsional rigidity of the rotating body at the position between the prime movers is calculated using the lateral elastic modulus of the rotating body at the position near the load with good accuracy, the torsional rigidity of the rotating body at the calculated position between the prime movers also improves the accuracy. . Further, since the output of the prime mover at the preceding stage of the position between the prime movers is calculated using the torsional rigidity of the rotating body with high accuracy, the accuracy of the calculated prime mover output is also improved.

  As a result, the accuracy of performance management of the plant is improved and accurate maintenance is possible, and furthermore, fuel can be reduced by improving efficiency.

(First embodiment)
FIG. 1 is a block diagram of a torsional rigidity calculating device for a rotating body according to the first embodiment of the present invention. FIG. 1 shows a power plant in which the prime mover is a steam turbine and the load is a generator. The steam turbine includes one high-pressure turbine 19 and three low-pressure turbines 20a, 20b, and 20c, and is configured to drive the generator 21 with these.

The left end drive shaft of the high-pressure turbine 19 is referred to as one axis, the right end drive shaft is referred to as two axes, and similarly, the left end drive shaft of the low pressure turbine 20a is referred to as three axes, the right end drive shaft is referred to as four axes, and so on. The drive shaft at the right end of the low-pressure turbine 20c has eight axes. The eight axes are the axes closest to the generator 21 that is a load, and a torsion angle measuring device 22 is provided on the eight axes. The torsion angle measuring instrument 22 measures the eight-axis torsion angle θ ₈ that drives the generator, and is arranged with an interval in the axial direction of the surface of the rotating body (drive shaft) 13 as described above. Based on the delay time t _d of the reflected light from the pair of reflectors, the eight-axis torsion angle θ ₈ is calculated by the equation (1).

8 torsional angle theta ₈ of obtained in twist angle meter 22 is input to the first torsional rigidity calculation means 24 of the processor 23, the rigidity K ₈ is required twisting in 8 shaft. The first torsional rigidity calculating means 24 inputs the eight-axis torsion angle θ ₈ obtained by the torsion angle measuring device 22, the rotational speed (turbine rotational speed) N of the drive shaft, and the generator output W, (3) the twist angle theta ₈ of 8 axes formula theta, (3) by substituting the power generator output W as the output of the 8 axis W _T of the equation to calculate the torsional rigidity K ₈ of 8 axes. The rotational speed (turbine rotational speed) N of the drive shaft is constant at N regardless of the position of each axis (1 to 8 axes). The eight-axis torsional rigidity K ₈ calculated by the first torsional rigidity calculating means 24 is expressed by equation (5).

Torsional rigidity K ₈ of 8 axes calculated by the first torsional rigidity calculation means 24 to have good accuracy. This is because the generator output W is accurately measured by the output detector, and the 8-axis torsion angle θ ₈ is measured in the vicinity of the generator 21, so there is little error, and the 8-axis torsional rigidity. This is because K ₈ is calculated by using the generator output W and the eight-axis torsion angle θ ₈ with less error.

Next, torsional rigidity K ₈ of 8 axes calculated by the first torsional rigidity calculation means 24 is inputted to the transverse elasticity coefficient calculation means 25, a modulus of transverse elasticity G ₈ is calculated in the eight axes. The lateral elastic modulus calculating means 25 is configured to calculate the eight-axis torsional rigidity K ₈ calculated by the first torsional rigidity calculating means 24, the drive shaft sectional secondary moment Z _{P8 at} the eight axes, and the eight-axis torsion measurement section length ( The transverse elastic modulus G ₈ for the eight axes is calculated by substituting the distance d L ₈ between both reflectors and the diameter d ₈ of the drive shaft for the eight axes into the equation (4). The eight-axis lateral elastic modulus G ₈ calculated by the lateral elastic coefficient calculating means 25 is expressed by equation (6).

The eight-axis lateral elastic modulus G ₈ calculated by the lateral elastic coefficient calculating means 25 is highly accurate. This is because the calculation is performed using the 8-axis torsional rigidity K ₈ with high accuracy calculated by the first torsional rigidity calculating means 24.

The eight-axis lateral elastic modulus G ₈ calculated by the lateral elastic modulus calculating means 25 is input to the second torsional rigidity calculating means 26. Second torsional rigidity calculation means 26, which determine the torsional rigidity of the drive shaft in the turbine between a position, for example, determine the torsional rigidity K ₃ of 3 axes between the high pressure turbine 19 and the low-pressure turbine 12a.

3-axis torsional rigidity K ₃ of the shear modulus of the shaft G _3, 3 a second moment of the drive shaft in the axis Z _P3, 3 twist in the axial measurement interval length (distance between both reflector) L _3, When the diameter of the drive shaft in the three axes is d ₃ and these are substituted into the equation (4), the equation (7) is obtained.

Here, since the turbine drive shafts (1 to 8 shafts) are manufactured from the same material, the transverse elastic modulus G is substantially the same at any position of the 1 to 8 shafts. That is, since the 8-axis lateral elastic modulus G ₈ and the 3-axis lateral elastic modulus G ₃ are substantially the same, substitute G ₈ for G ₃ in the equation (7), and further change the equation (4) to G _8. When substituted, the triaxial torsional stiffness K ₃ is expressed by equation (8).

The triaxial torsional stiffness K ₃ is obtained by calculating the sectional moment of inertia Z _P3 of the drive shaft in the three axes, the torsion measurement section length in the three axes (distance between both reflectors) L ₃ , as shown in the equation (8). Diameter d ₃ of the drive shaft at 8, sectional moment of inertia Z _P8 of drive shaft at 8 axes, torsion measurement section length (distance between both reflectors) L ₈ at 8 axes, drive shaft diameter d _{8 at} 8 axes, generator It is obtained by calculation from the output W, the rotational speed N of the drive shaft, and the twist angle θ ₈ of the eight axes. Since these various quantities can be measured and calculated with _high accuracy, the torsional rigidity K3 of the three axes can also be calculated with high accuracy. The triaxial torsional stiffness K ₃ calculated by the second torsional stiffness calculating means 26 is output to an output device 27 such as a display device or a printer.

According to the first embodiment, accurately measured the generator output and the generator vicinity of the turbine drive shaft torsional rigidity K ₈ (8 axes) to accurately calculate, twisting of 8 axial good accuracy Since the transverse elastic modulus G of the turbine drive shaft is calculated based on the rigidity K ₈ , it is possible to obtain an accurate lateral elastic modulus G. Then, using a good shear modulus G of accuracy, since the calculated torsional stiffness K ₃ of the drive shaft at the other positions on the turbine drive shaft (e.g., three axes) of three axes calculated torsional rigidity K ₃ Can also be calculated accurately.

(Second Embodiment)
FIG. 2 is a block diagram of a prime mover output arithmetic apparatus according to the second embodiment of the present invention. A second torsional angle measuring device 28 is added to the rotating body torsional rigidity calculating device of the first embodiment shown in FIG. 1, and a prime mover output calculating means 29 is added to the arithmetic processing device 23. And providing a prime mover output arithmetic unit. The same elements as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

The prime mover output calculating means 29 of the arithmetic processing unit 23 includes a triaxial torsion angle θ ₃ measured by the second torsion angle measuring instrument 28, and a triaxial torsional rigidity K calculated by the second torsional rigidity calculating means 26. ₃ , the rotational speed N of the turbine drive shaft is input, and the output W _HP of the high-pressure turbine 11, which is the preceding turbine of the three shafts, is calculated by equation (9)

Output W _HP of the high pressure turbine 11, (9) As can be seen from the equation, the second moment Z _P3 of the drive shaft in the three axes, 3 twist in the axial measurement section length (distance between both reflector) L _3, triaxial Diameter d ₃ of the drive shaft at 8, sectional moment of inertia Z _P8 of drive shaft at 8 axes, torsion measurement section length (distance between both reflectors) L ₈ at 8 axes, drive shaft diameter d _{8 at} 8 axes, generator It is obtained by calculation from the output W, the rotational speed N of the drive shaft, the twist angle θ _{8 of the eight} axes, and the twist angle θ ₃ of the three axes.

Since these various quantities can be measured and calculated with high accuracy, the output W _HP of the high-pressure turbine 11 can also be calculated with high accuracy. Then, the output W _HP of the high pressure turbine 11 calculated by the prime mover output calculation means 29 is output to an output device 27 such as a display device or a printer.

FIG. 3 is a graph of the power plant output W _c obtained in the second embodiment of the present invention and the power plant output W _g measured by the generator output detector. In Figure 3, start taking the load from time t1, shows a case where a rated output P _R at time t2. As can be seen from FIG. 3, the power plant output W _c obtained in the second embodiment and the power plant output W _g measured by the generator output detector have almost the same characteristics, and the error of the lateral elastic modulus G The influence of the error of torsional rigidity K due to can be greatly suppressed.

According to the second embodiment, since the output W _HP of the three-stage upstream high-pressure turbine 11 is calculated using the torsional rigidity K ₃ of the rotating body with high accuracy, the calculated output of the high-pressure turbine 11 is calculated. W _HP also improves accuracy. As a result, the accuracy of performance management of the plant is improved and accurate maintenance is possible, and further, fuel can be reduced by improving efficiency.

The block block diagram of the torsional rigidity calculation apparatus of the rotary body concerning the 1st Embodiment of this invention. The block block diagram of the motor | power_engine output calculating apparatus concerning the 2nd Embodiment of this invention. Graph of the power plant output W _g measured by the second and the power plant output W _c obtained in Embodiment generator output detector of the present invention. The block block diagram of an example of the turbine output device which calculates a turbine output by torsion measurement of a rotary body. Graph of the power plant output W _g measured by the power plant output W _c calculated by the torsional rigidity K determined by conventional computer analysis generator output detector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Laser beam output apparatus, 12 ... Optical transmission / reception apparatus, 13 ... Rotating body, 14 ... Reflector, 15 ... Optical detection apparatus, 16 ... Torsion angle calculation part, 17 ... Torque calculation part, 18 ... Output calculation part, 19 ... High pressure turbine, 20 ... Low pressure turbine, 21 ... Generator, 22 ... Torsion angle measuring device, 23 ... Arithmetic processing device, 24 ... First torsional rigidity calculating means, 25 ... Lateral elastic modulus calculating means, 26 ... Second torsion Rigidity calculation means, 27 ... output device

Claims (4)

  A torsion angle measuring instrument for measuring a torsion angle of a rotating body at a position near the load of a plant that applies a rotational force to a rotating body by a plurality of prime movers and drives a load connected to an end of the rotating body; and the torsion angle A first torsional rigidity calculating means for calculating a torsional rigidity of the rotating body in the vicinity of the load based on a torsion angle of the rotating body in the vicinity of the load measured by the measuring instrument and a load output of the plant; A lateral elastic coefficient calculating means for calculating a transverse elastic coefficient of the rotating body at the position near the load based on the torsional rigidity of the rotating body at the position near the load calculated by the rigidity calculating means; and a load calculated by the transverse elastic coefficient calculating means. And a second torsional rigidity calculating means for calculating the torsional rigidity of the rotating body at the position between the prime movers using the transverse elastic coefficient of the rotating body at a nearby position. Jiri rigidity calculation device.   A first torsion angle measuring device for measuring a torsion angle of a rotating body at a position in the vicinity of the load of a plant that applies a rotational force to the rotating body by a plurality of prime movers and drives a load connected to an end of the rotating body; A second torsion angle measuring device for measuring a torsion angle of a rotating body at a position between any of the plurality of prime movers, and a torsion angle of a rotating body at a position in the vicinity of a load measured by the first torsion angle measuring instrument; And a first torsional rigidity calculating means for calculating the torsional rigidity of the rotating body at a position near the load based on the load output of the plant, and a torsion of the rotating body at the position near the load calculated by the first torsional rigidity calculating means. A lateral elastic coefficient calculating means for calculating a lateral elastic coefficient of the rotating body at a position near the load based on the rigidity, and a driving force using the lateral elastic coefficient of the rotating body at the position near the load calculated by the lateral elastic coefficient calculating means. Second torsional rigidity calculating means for calculating the torsional rigidity of the rotating body at the intermediate position; and the torsional angle of the rotating body at the position between the prime movers measured by the second torsion angle measuring instrument and the second torsional rigidity calculating means A prime mover output calculation device comprising: a prime mover output calculation means for calculating an output of a prime mover at a preceding stage of the position between the prime movers based on the torsional rigidity of the rotating body at the prime mover position calculated in (1).   A rotating body at a position near the load is measured by measuring a torsion angle of the rotating body at a position near the load of the plant that applies a rotational force to the rotating body by a plurality of prime movers and drives a load connected to an end of the rotating body. The torsional rigidity of the rotating body at the position near the load is calculated based on the torsion angle of the plant and the load output of the plant, and the lateral elastic modulus of the rotating body at the position near the load is calculated based on the torsional rigidity of the rotating body at the calculated position near the load. A method for calculating torsional rigidity of a rotating body, wherein the torsional rigidity of the rotating body at a position between prime movers is calculated using the calculated lateral elastic modulus of the rotating body at a position near the load. Measure the torsion angle of the rotating body in the vicinity of the load of the plant driving the load connected to the end of the rotating body by applying rotational force to the rotating body with a plurality of prime movers, and one of the plurality of prime movers Measure the torsion angle of the rotating body at the position between the prime movers, calculate the torsional rigidity of the rotating body at the position near the load based on the measured torsion angle of the rotating body at the position near the load and the load output of the plant, and calculate the vicinity of the load Calculate the lateral elastic modulus of the rotating body at the position near the load based on the torsional rigidity of the rotating body at the position, and calculate the torsional rigidity of the rotating body at the position between the prime movers using the calculated lateral elastic modulus of the rotating body at the position near the load. The output of the prime mover before the prime mover position is calculated based on the measured torsion angle of the rotary body at the prime mover position and the calculated torsional rigidity of the rotary body at the prime mover position. Motor output calculation method which is characterized in that output.

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