JPH0518209A - Measuring device of steam turbine packing gap - Google Patents

Abstract

PURPOSE:To eliminate dispersion of the results of human measuring, and improve work efficiency by inputting in form of an image the thickness of a molded part whose gap is measured calculating the thickness of the part thereof, by means of a presonal computer and judging whether the gap is a proper value or not. CONSTITUTION:A lead wire 8 sandwiched between a packing and a steam turbine rotor is brought in pressure-contact and molded. After that, the steam turbine rotor is hung up, and the lead wire 8 is taken out. The lead wire 8 is put on an image scanner 4, and the image of the lead wire 8 is inputted by the image scanner 4. The image is transfered to a personal computer 7 through a telecommunication line 5. Calculation process of the input image thereof is carried out by the personal computer 7, and the calculated value is presented as a practically measured value. The design value of a packing gap is inputted into the personal computer 7 beforehand, and the value is compared with the practically measured value, so that it is judged whether the practically measured gap is suitable or not, and secular change is suitable or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gap measuring method and a device used therefor when measuring a gap composed of a plurality of parts such as a packing part of a steam turbine.

[0002]

2. Description of the Related Art A packing for a steam turbine is provided in a portion where an axle of the turbine penetrates a passenger compartment or a partition plate in order to maintain airtightness. The packing is usually used to prevent steam leakage, and the low pressure packing of the condensing turbine is
It is used to prevent air ingress and is one of the important parts of a steam turbine, and the packing gap is measured during regular inspections.

To measure the packing gap, first, the steam turbine rotor is lifted, a soft lead wire having a diameter of about 2 to 3 mm is placed on the packing portion of the steam turbine casing, and the steam turbine rotor is returned on the lead wire to return the packing gap. The lead wire is pressed into contact with the teeth to make a pattern. After that, the lead wire is taken out and the tooth portion of the packing is measured with a dial gauge or a caliper.

The measured value thus obtained is compared with the design value, and the change over time is investigated to determine whether the turbine maintenance is good or bad.

[0005]

According to the measurement by the above-mentioned conventional method, there is a problem of variation in measured values due to individual differences, so that the operator is required to have a considerable degree of skill. In addition, since the data management of the record requires a great deal of labor, a large amount of time and labor are required especially for a large steam turbine having a large number of packings.

An object of the present invention is to provide an automatic measuring device which eliminates the variation in human measurement by using an image input device.

It is another object of the present invention to provide an apparatus capable of calculating the influence on the performance of the steam turbine from the measured value of the packing gap and determining whether or not the packing gap needs to be corrected.

[0008]

SUMMARY OF THE INVENTION The present invention is a steam turbine packing gap measuring device, which is a device constituted by at least an image input device and a personal computer, and which is a part of a mold (lead wire) where the gap is measured. The thickness of the part is input as an image, the thickness of that part is calculated by a personal computer, and the calculated value is compared with the design value to determine whether the gap is appropriate or not. Is.

[0009]

[Function] The mold (the lead wire) whose gap is measured is input by an image scanner or the like to input an image, and then the data is transferred to a personal computer.

The personal computer scans the image and measures the thickness. Since the lead wire portion of the packing gap has a change in thickness, the calculation display is performed as a portion having a large change amount in the thickness. Further, since the planned value of the packing gap is not inputted in advance and can be compared with the calculated actual value, it is possible to judge whether or not the actual gap is appropriate.

Further, the steam leak amount and the turbine performance deterioration amount of the packing part are calculated from the packing gap measurement value,
It is possible to judge whether or not the packing gap measurement value needs to be corrected.

[0012]

EXAMPLES Examples of the present invention will be described below with reference to FIGS.
3 and FIG.

FIG. 1 is a sectional view showing a specific structure of a steam turbine and an auxiliary device according to the present invention.

Reference numeral 1 is a steam turbine rotor, and 2 is a steam turbine casing. FIG. 2 is an explanatory view of a detailed portion of the A packing of FIG. 1, and 3 is a packing, which is incorporated in the steam turbine casing 2.

After hoisting the steam turbine rotor 1,
A lead wire having a diameter equal to or larger than the packing gap size is placed on the packing portion 3 of the steam turbine casing 2, and the steam turbine rotor 1 is lowered.

By this work, the lead wire sandwiched between the packing 3 and the steam turbine rotor 1 can be pressed into contact with the die for molding.

Then, the steam turbine rotor 1 is lifted again to take out the lead wire. The lead wire is the image scanner 4
Then, the image of the lead wire is input by the image scanner 4. The image is transferred to the personal computer 7 via the communication line 5. The input image is calculated by the personal computer 7, and the measured value is obtained. Further, the design value of the packing gap is input to the personal computer 7 in advance, and it is compared with the actual measurement value to determine whether the actual measurement gap is appropriate or the secular change is appropriate.

According to such a method, it is possible to eliminate variations in human measurement and perform mechanical measurement and judgment.

Referring to FIG. 4, the packing gap (δ ₁ ...
An example of the method of measuring δ _N ) and the method of determining the quality of the packing gap will be described.

The cross-sectional shape of the lead wire taken from the packing No. A is shown in FIG. 4 (b). The thickness of the lead wire is input to an image by an image scanner, and the image is shown in FIG. In FIG. 4C, the valleys (δ ₁ ... δ _N ) show the measured values of the packing gap.

The relationship between the axial packing position and the packing gap can be grasped by taking out only the dimension of the valley portion. Separately from this, an example in which the packing gap design value input to the personal computer in advance is displayed by being superimposed on the actual measurement value is shown in FIG.
It shows in (d). According to this figure, it is possible to compare the measured value and the design value for each packing group unit.

Further, the vapor leak amount G of the packing portion is calculated from the packing gap δ _i by using the equations 1 and 2, and the relational diagram between the leak amount of the packing portion and the performance deterioration amount inputted in advance (FIG. 4). By plotting in (e)), it becomes possible to judge whether the leak amount of the packing portion is good or bad.

[0023]

[Equation 1]

[0024]

[Equation 2]

D: packing diameter, V: packing steam flow rate G: packing steam leak amount, N: packing number δ _i : packing gap actual measurement value, δ: packing gap average value

[0026]

Since the present invention is constructed in this way, it has the following effects.

For example, for the work of measuring the packing gap of the steam turbine, which is carried out at the time of periodic inspection of the power plant,
A technique requiring skill is not required, and a large number of packings can be measured at the same time, and it is possible to easily determine whether or not the measurement value needs to be corrected, so that work efficiency is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a steam turbine and an auxiliary device.

FIG. 2 is an explanatory view showing a detailed view of a steam turbine packing part.

FIG. 3 is a block diagram showing a measurement system that calculates a packing gap from a lead wire.

FIG. 4 is an explanatory view showing steps for measuring a packing gap.

[Explanation of symbols]

1 ... Steam turbine rotor, 2 ... Steam turbine casing, 3 ... Packing, 4 ... Image scanner, 5 ... Communication line, 6 ... CRT, 7 ... Personal computer, 8 ... Lead wire.

Claims (3)

[Claims] 1. A steam turbine packing gap measuring device, which is a device including an image input device and a personal computer, wherein an image is input for the thickness of a mold part where the gap is measured, and the thickness of the part is measured. A steam turbine packing gap measuring device characterized in that analysis and calculation are performed by the personal computer. 2. A function according to claim 1, comprising a function of comparing the measured value with a planned value, determining whether the measured value is appropriate, or managing a secular change of the measured value. Measuring device. 3. A function for determining whether or not the packing gap measurement value needs to be corrected by calculating a steam leak amount of the packing portion from the packing gap measurement value and further calculating an influence on turbine performance. A measuring device for the steam turbine packing gap.