KR20110029395A - Method and system for predicting life of steam turbine - Google Patents

Abstract

PURPOSE: A system and method for predicting the service life of a steam turbine are provided to improve the stability of a power plant by predicting the damage rate and the residual service life by measuring the tensile properties of the damaged part using a potable indentation test device. CONSTITUTION: A system for predicting the service life of a steam turbine comprises follows. An indentation test device measures the tensile properties of a casing and rotor of a generating station steam turbine. The tensile properties of a casing and rotor of a generating station steam turbine are measured. The damage rate of corresponding localized region is calculated. Eaged and Haged is the elastic modulus and hardness of the rotor and casing after operation in the corresponding localized region. Evirgin and Hvirgin is the elastic modulus and hardness of the rotor and casing before the operation in the corresponding localized region.

Description

METHOD AND SYSTEM FOR PREDICTING LIFE OF STEAM TURBINE

The present invention relates to a method and system for accurately predicting the damage rate and the service life even in the local area of a power plant steam turbine degraded by long time operation.

Steam turbine facilities of industrial plants, such as power plants, need to be effectively maintained and managed because their strength deteriorates with deterioration over a long period of time. Therefore, life evaluation of steam turbine facilities is important. In order to accurately evaluate the life of steam turbines, it is necessary to accurately measure the degree of degradation of material properties due to mechanical or thermal loads. However, there is no method of directly evaluating the degree of strength drop in the area where damage occurs.

However, to date, conventional life assessment methods include operating conditions for steam turbine equipment, modeling of the equipment, theoretical analysis method through temperature and stress analysis, and evaluation of deterioration of microstructures by replicating plant structure, hardness test, and non-destruction. By comprehensively evaluating methods such as testing, the remaining life of the steam turbine installation could be evaluated.

In particular, in the field test, the hardness test can be easily performed through a portable hardness tester, but there are fundamental limitations such as an indirect strength prediction method as well as errors due to data imperfections, errors in interpretation, and test incompleteness. .

The present invention has been made to solve the above-mentioned conventional problems, in evaluating the life of the thermal power plant turbine equipment, the tensile properties of the local area where the damage is mainly measured by using a portable indentation tester, and It aims to provide a method and system for improving the safety of power generation facilities by predicting the damage rate and remaining life.

In order to achieve the object of the present invention as described above, and to perform the characteristic functions of the present invention described below, features of the present invention are as follows.

According to an aspect of the present invention, the tensile properties (E _aged , H _aged , E _virgin , H _virgin , δ _y , δ _u ) were measured using a indentation tester on the rotor and casing of the power plant steam turbine. Thereafter, a life prediction method is provided which calculates the damage rate D _total of the local area by inputting the following equation (1).

..... 식 (1)

..... Formula (1)

Here, E _{aged and} H _aged are the elastic modulus and hardness measured in the corresponding localized area after driving the rotor and the casing, and E _virgin and H _virgin are the elastic modulus measured in the localized area before operating the rotor and the casing. Hardness, wherein δ _y is the yield strength measured in the localized region before operation, δ _u is the tensile strength measured in the localized region after operation, and α, β are assigned to the rotor and the casing material according to characteristics Represents a variable value.

Also, using the damage rate (D _total = D) calculated by Equation (1) and the input operation time (t _op ) of operating the power plant steam turbine, the rotor and the casing remain as shown in Equation (2) below. Further methods are provided for calculating the lifetime t _r .

..... 식 (2)

..... equation (2)

Further, according to another aspect of the present invention, by measuring the at least one of the elastic modulus, hardness, yield strength, tensile strength before and after operation using the indentation tester for the rotor and the casing local region of the power plant steam turbine A life prediction system is provided that includes a tensile property measurement module and a damage rate calculation module that calculates a damage rate (D _total ) of the local area by using information of the tensile property measured in the tensile property measurement module.

Here, the damage rate calculation module calculates the damage rate (D _total ) of the local area by inputting the tensile property information into the following equation (1).

..... 식 (1)

..... Formula (1)

The E _{aged and} H _aged are the elastic modulus and hardness measured in the corresponding local area after the rotor and the casing are operated, and the E _virgin and the H _virgin are the elastic modulus and hardness measured in the local area before the rotor and the casing are operated. Δ _y is the yield strength measured in the localized region before operation, δ _u is the tensile strength measured in the localized region after operation, and α, β are variable values given according to the properties of the rotor and the casing material Indicates.

In addition, the life prediction system uses the damage rate (D _total = D) calculated by Equation (1) and the input operating time (t _op ) of operating the power plant steam turbine. t _r ), further comprising: a remaining life calculation module for calculating a remaining life calculation module and an information display module for displaying the measured tensile properties, the calculated damage rate, and the result of the remaining life in a user-friendly interface according to a user's request or a result of performing a module. do.

In addition, the residual life calculation module may calculate the residual life (t _r ) of the rotor and the casing as shown in Equation (2) below.

..... 식 (2)

..... equation (2)

According to the present invention, it is possible to accurately calculate the damage rate and the remaining life according to the insulation state and predict the remaining life even in the localized region where the steam turbine is not easily measured, thereby improving the safety of the power generation equipment and reducing the operating cost. Is achieved.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention are different, but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be embodied in other embodiments without departing from the spirit and scope of the invention with respect to one embodiment. In addition, it is to be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. Like reference numerals in the drawings refer to the same or similar functions throughout the several aspects.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

1 is a view showing the overall configuration for predicting the remaining life of the steam turbine according to an embodiment of the present invention by way of example.

As shown in FIG. 1, the overall configuration for estimating the remaining life of a steam turbine according to an embodiment of the present invention is a power plant steam that is not subject to insulation degradation before operation or to which insulation degradation occurs during operation. The indentation tester 200 as a tool for measuring the tensile properties of the local area 300 of the rotor and the casing of the turbine and the local area 300 and the tensile property information measured by the indentation test 200 are used. And a life expectancy system 100 that calculates a damage rate for determining the degree of damage of the rotor or casing local area and a residual life.

Here, although the rotor and the casing including the local region are mentioned, the shape of the rotor may be represented as shown in FIG. 2 as a specific example.

FIG. 2 is a diagram illustrating a rotor and a local region as a measuring object of the present invention as an example. The rotor, which is the measuring object of the present invention, is divided into three local regions 310, 320, and 330 to be measured. The local region 310 is a high pressure inlet portion, and a deterioration phenomenon occurs when the steam turbine is in operation. The second and third local regions 320 and 330 are respectively a high pressure outlet portion and a coupling region portion of the turbine. In other words, it refers to a portion where deterioration does not occur before the steam turbine is operated, that is, before the steam turbine is used. In the present invention, the first to third local areas 310, 320, and 330 are exemplarily used as measurement target areas.

3 is a schematic diagram illustrating in more detail the system 100 for predicting the life of a steam turbine according to an embodiment of the present invention.

As shown in Figure 3, the life prediction system 100 according to an embodiment of the present invention is a tensile property measurement module 110, damage rate calculation module 120, remaining life calculation module 130, information display Module 140, control module 150, and information database 160.

First, referring to the tensile property measurement module 110, the tensile property measurement module 110 of the present invention targets the indentation tester 200 to the local region (310, 320, 330) of the rotor and the casing of the power plant steam turbine. It performs the function of measuring at least one of the elastic modulus, hardness, yield strength, tensile strength before and after operation. Here, the information on the tensile properties measured using the indentation tester 200 is the operation of the rotor and the casing after the operation of the elastic modulus (E _aged ) and the hardness (H _aged ) measured in the local region 310, the rotor and the casing The elastic modulus (E _virgin ) and the hardness (H _virgin ) measured in the corresponding local regions (320, 330) before, the yield strength (δ _y ) measured in the local regions (320, 330) before the operation, after the operation The tensile strength (δ _u ) measured in the corresponding local region 310 and the variable values (α, β) assigned to the rotor and the casing material according to their properties may correspond to this. The tensile property information thus obtained is stored in the information database 160.

Next, the damage rate calculation module 120 of the present invention uses the tensile property information measured by the tensile property measurement module 110 or the tensile property information stored in the information database 160 to determine the damage rate of the local area ( D _total ) function. That is, the damage rate calculation module 120 of the present invention calculates the damage rate (D _total ) of the local area by inputting the tensile property parameter measured by the tensile property measurement module 110 as a corresponding variable value in Equation (1) below. Will be done.

..... 식 (1)

..... Formula (1)

The parameters E _aged , H _aged , E _virgin , H _virgin , δ _y , δ _u , α, and β in Equation (1) were previously mentioned in the tensile property measurement module 110, and thus are omitted here. The local area 310 is a site where deterioration occurs a lot as described above, and is a confirmed result area according to a test result, and the local areas 320 and 330 before the operation have no heat exchange phenomenon as described above. A site or a less frequently occurring site can be fully understood to be a result site confirmed by the test results as well. The damage rate information thus obtained is stored in the information database 160.

Next, the residual life calculation module 130 of the present invention inputs the damage rate (D _total = D) calculated by Equation (1) and the operating time (t _op ) input from the user while operating the power plant steam turbine. to when using the operation time (t _op) there is performed the function for calculating the remaining service life of the rotor and the casing (t _r), the remaining service life of the rotor and the casing as in the following formula (2) (t _r) Can be calculated.

..... 식 (2)

..... equation (2)

As described above, in this embodiment, the indentation tester 200 is used to measure the tensile properties of the local area during and before operation, and the damage rate of the local area where the deterioration phenomenon occurs a lot in the steam turbine is used. By calculating the remaining life quickly, the management safety of the power plant can be greatly achieved. The remaining life information thus obtained is stored in the information database 160.

Next, the information display module 140 of the present invention is a tensile property measurement module 110, the damage rate calculation module 120, the residual life calculation module 130 of the tensile properties, damage rate and residual life obtained respectively The function displays the result on the screen. The results of the tensile properties, the damage rate, and the remaining life are automatically displayed on the screen by the user's request or the result of the module execution. At this time, when the results of the tensile properties, damage rate and the remaining life is displayed at the request of the user, it is obvious that the tensile properties, damage rate and the remaining life information is stored in the information database 160.

Finally, the control module 150 of the present invention is the data between the tensile property measurement module 110, damage rate calculation module 120, remaining life calculation module 130, information display module 140 and information database 160 The function of controlling the flow, and the information database 160, as mentioned above, is a place for storing the performance results of each module. This information database 160 refers not only to a database of consultation, but also to a database in a broad sense including a file system-based data record and the like, and if a simple set of logs can be retrieved to extract data, It can be included in the talking database.

Hereinafter, a menu environment linked with the information display module 140 will be described.

4 to 7 are diagrams exemplarily illustrating a user-friendly menu linked to the information display module 140 according to an embodiment of the present invention.

First, the user-friendly menu of FIG. 4 uses the indentation tester 200 to input basic information necessary for the press test of the local region of the steam turbine or basic information necessary to predict the damage rate and the remaining life. The material characteristic information of the power plant, location information, operating condition information (temperature, pressure, etc.), operation time information, and the like may be input by the user.

The user-friendly menu of FIG. 5 shows an environment in which the tensile properties of the local area can be started and stopped at the request of the user according to the location of the local area of the rotor described with reference to FIGS. 2 and 3, and can be stopped. The user-friendly menu shows an environment in which data of tensile properties measured by the tensile property measurement module 110 is loaded and analyzed, and sometimes a correction result can be input.

The user-friendly menu of FIG. 7 is a menu configuration for evaluating the final remaining life of the rotor and the casing of the steam turbine, and the damage rate calculation module 120 and the remaining life calculation module 130 are performed by a user request or automatically. As a result, the calculation results of the damage rate and the remaining life are shown. As such, the user-friendly menu related to the prediction of the remaining life of the steam turbine rotor and the casing 300A is implemented as described above, so that the safety of the power generation facility can be quickly confirmed.

1 is a view showing the overall configuration for predicting the remaining life of the steam turbine according to an embodiment of the present invention by way of example.

2 is a diagram illustrating an example of a rotor and a local region, which is a measurement object of the present invention.

3 is a schematic diagram illustrating in more detail the system 100 for predicting the life of a steam turbine according to an embodiment of the present invention.

4 to 7 are diagrams exemplarily illustrating a user-friendly menu linked to the information display module 140 according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: life prediction system 110: tensile property measurement module

120: damage rate calculation module 130: remaining life calculation module

140: information display module 150: control module

160: Information Davies 200: Indentation Tester

300: local area of the loader and casing

Claims (7)

Tensile properties (E _aged , H _aged , E _virgin , H _virgin , δ _y , δ _u ) were measured using the indentation tester on the rotor and casing of the power plant steam turbine, and then the following equation (1) Lifetime prediction method for calculating the damage rate (D _total ) for a given local area by typing in.

..... Formula (1) The E _{aged and} H _aged are the elastic modulus and hardness measured in the corresponding local area after the rotor and the casing are operated, and the E _virgin and the H _virgin are the elastic modulus and hardness measured in the local area before the rotor and the casing are operated. Δ _y is the yield strength measured in the localized region before operation, δ _u is the tensile strength measured in the localized region after operation, and α, β are variable values given according to the properties of the rotor and the casing material Indicates. The method of claim 1, Using the damage rate (D _total = D) calculated by Equation (1) and the input operation time (t _op ) of operating the power plant steam turbine, the remaining lifespan of the rotor and the casing (Equation 2) t _r ).

..... equation (2) The method of claim 2, The local area after the operation is a site where many deterioration occurs. The local region before the operation represents a site without a thermal ring phenomenon. Tensile property measurement module for measuring at least one of the elastic modulus, hardness, yield strength, tensile strength before and after operation using the indentation tester for the rotor and casing of the power plant steam turbine, and Damage rate calculation module for calculating the damage rate (D _total ) of the local area by using the information of the tensile properties measured in the tensile property measurement module Life prediction system comprising a. The method of claim 4, wherein The damage rate calculation module, And calculating the damage rate (D _total ) of the local area by inputting the tensile property information into the following equation (1).

..... Formula (1) The E _{aged and} H _aged are the elastic modulus and hardness measured in the corresponding local area after the rotor and the casing are operated, and the E _virgin and the H _virgin are the elastic modulus and hardness measured in the local area before the rotor and the casing are operated. Δ _y is the yield strength measured in the localized region before operation, δ _u is the tensile strength measured in the localized region after operation, and α, β are variable values given according to the properties of the rotor and the casing material Indicates. The method of claim 5, The life prediction system, Residual life, which calculates the residual life (t _r ) of the rotor and casing using the damage rate (D _total = D) calculated by Equation (1) and the input operating time (t _op ) of operating the power plant steam turbine Calculation module, Information display module for displaying the results of the measured tensile properties, the damage rate and the remaining life in the user-friendly interface according to the user's request or the module execution result It further comprises a system. The method of claim 6, The remaining life calculation module, A system for calculating the residual life (t _r ) of the rotor and the casing as in the following equation (2).

..... equation (2)

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