JP7794632B2 - Lifetime prediction system, lifetime prediction program, lifetime prediction device, lifetime notification system, and lifetime prediction method - Google Patents

Description

The present invention relates to a life prediction system, a life prediction program, a life prediction device, and a life prediction method for predicting the life of steam control valve components that make up a steam turbine, as well as a life notification system for notifying the life of the aforementioned components.

Technology for monitoring and evaluating the state of valves that make up a steam turbine and changing the operating conditions of the valve being evaluated based on the evaluation results is known as prior art. For example, Patent Document 1 discloses a technology for determining whether or not there is a possibility of valve corrosion based on steam temperature, chemical composition of steam, etc., and changing the valve's operating parameters based on the determination results. Specifically, feature quantities related to friction between the spindle and guide elements (guide bushings, etc.) are calculated from steam temperature, etc., and the calculation results are used to determine whether or not there is a possibility of valve corrosion. The spindle and guide elements are both components that make up the valve.

Patent No. 6801112 specification

As mentioned above, the technology disclosed in Patent Document 1 takes into account the friction of the components that make up the valve when assessing the possibility of valve corrosion, but does not take into account the degree of deterioration of the components that make up the valve (how much the components that make up the valve have deteriorated). As a result, the technology disclosed in Patent Document 1 does not have sufficient accuracy in assessing the possibility of valve corrosion, in other words, in predicting the lifespan of the components that make up the valve, and it is not possible to change the valve operating parameters at the appropriate time.

One aspect of the present invention was made in consideration of the above-mentioned problems, and aims to accurately predict the lifespan of valves that make up a steam turbine.

To solve the above problem, a life prediction system according to one aspect of the present invention includes a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that constitutes a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that constitutes the steam control valve, and a prediction unit that predicts the life of the component using the deterioration index calculated by the calculation unit.

To solve the above problem, a life prediction device according to one aspect of the present invention includes a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that constitutes a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that constitutes the steam control valve, and a prediction unit that predicts the life of the component using the deterioration index calculated by the calculation unit.

To solve the above-mentioned problems, one aspect of the present invention provides a lifespan notification system that includes a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that constitutes a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that constitutes the steam control valve, a prediction unit that predicts the lifespan of the component using the deterioration index calculated by the calculation unit, and a notification unit that notifies a user of the prediction result of the prediction unit.

In order to solve the above-mentioned problems, a life prediction method according to one aspect of the present invention includes a calculation step of acquiring temperature information indicating the temperature of steam supplied to a steam control valve that constitutes a steam turbine and calculating a deterioration index that is an index indicating the degree of deterioration of a component that constitutes the steam control valve, and a prediction step of predicting the life of the component using the deterioration index calculated in the calculation step.

One aspect of the present invention makes it possible to accurately predict the lifespan of components that make up a steam control valve.

1 is a block diagram showing an example of a configuration of a main part of a life prediction system according to an embodiment of the present invention; 1 is a front view showing the state of the main parts of the steam control valve before the control valve cover thermally expands. FIG. Reference numeral 301 is a side view showing the state of the main part of the steam control valve shown in Fig. 2. Reference numeral 302 is an enlarged view of the carbon packing and its surroundings of the steam control valve shown by reference numeral 301. 3 is a flowchart illustrating an example of processing performed in a lifespan prediction system according to an embodiment of the present invention. FIG. 10 is a diagram showing a calculation model of the load acting on the valve stem. 1 is a graph showing an example of a wear life curve of a carbon packing. 1 is a graph showing an example of a bulk specific gravity reduction rate curve of a carbon packing. 1 is a graph showing a life function, a life slope line, and a design wear limit line of a carbon packing.

[Configuration of life prediction system and main structure of steam control valve]
The configuration of a life prediction system 100 according to one embodiment of the present invention and the structure of a main part of a steam control valve 30 will be described with reference to Figures 1 to 3. As shown in Figure 1, the life prediction system 100 includes an information processing device 1 and a server 2. The information processing device 1 and the server 2 are configured to be able to communicate with each other via a network such as the Internet.

In FIG. 1, the lifespan prediction system 100 is configured with one information processing device 1 and one server 2, but multiple information processing devices 1 can be included in the lifespan prediction system 100. Similarly, multiple servers 2 can be included in the lifespan prediction system 100. Note that the lifespan prediction system 100 also functions as a lifespan notification system according to one aspect of the present invention, since the information processing device 1 is equipped with a display unit 13, which will be described later.

The life prediction system 100 is a system for predicting the life of parts (hereinafter referred to as "components") that make up the steam control valve 30 in the steam turbine 3. In this specification, the "life of a component" refers to the period of time until the component's functionality deteriorates due to aging or other factors to a level that interferes with the operation of the steam control valve 30, and until the component's functionality cannot be restored to the point where the steam control valve 30 can operate without any problems, even if the component is repaired or reinforced.

For example, if an association or other organization to which a component manufacturer belongs specifies a lifespan in its guidelines, the lifespan specified in those guidelines may be used as the component's lifespan. Also, if a manufacturer specifies a warranty period, that warranty period may be used as the component's lifespan. Furthermore, if a component has a statutory useful life, the point at which that useful life has elapsed may be used as the component's lifespan.

The steam turbine 3 is an external combustion engine that converts the thermal energy of steam into rotational power via a blade row and an axle (both not shown) and transmits the rotational power to a driven machine such as a generator. The steam turbine 3 is not limited to specific applications, and can be used for any purpose, including power generation, industrial use, and marine use. The steam turbine 3 may also be, for example, an impulse turbine or a reaction turbine.

The steam control valve 30 is a device that constitutes the steam turbine 3, and is a valve that controls the amount of steam supplied to the steam turbine 3 to adjust the output of the steam turbine 3. In Figures 2 and 3, a nozzle shut-off speed control type (multi-valve type) steam control valve is shown as an example of the steam control valve 30, but the steam control valve 30 may also be of a throttle speed control type. The following explanation will be given assuming that the steam control valve 30 is of the nozzle shut-off speed control type.

In this embodiment, the life prediction system 100 predicts the life of a component, namely, the carbon packing 31 (packing) shown in Figures 2 and 3. The carbon packing 31 is a sealing part that covers the entire wall surface of the valve stem through hole 321 of the control valve cover 32, as indicated by reference numeral 302 in Figure 3. The control valve cover 32 is a cover that forms the upper part of the valve housing 33, as indicated by reference numeral 302 in Figure 3. Specifically, as indicated by reference numeral 302 in Figure 3, the carbon packing 31 comes into contact with the side surface of the valve stem 34 that passes through the valve stem through hole 321, thereby sealing the gap formed between the wall surface of the valve stem through hole 321 and the side surface of the valve stem 34. The gap formed between the wall surface of the valve stem through hole 321 and the side surface of the valve stem 34 is called the "gland."

The valve stem 34 is a component that transmits the operating force, which is converted from the driving force from the hydraulic servo 35 (shown as 301 in Figure 3) via the lever 36, to the valve disc 37. The valve stem 34 reciprocates up and down within the valve stem through-hole 321, transmitting the aforementioned operating force to the valve disc 37. The valve disc 37 reciprocates integrally with the valve stem 34, and controls the amount of steam flowing out of the valve hole 39 by moving toward and away from the valve seat 38.

A bushing 311, through which the valve stem 34 passes, is provided at the lower end of the carbon packing 31. The bushing 311 is a bearing that supports the load of the valve stem 34 and also functions as a sliding tube for the valve stem 34. In this way, the steam control valve 30 is a gland packing type steam control valve that has the carbon packing 31 and the bushing 311.

The steam control valve 30 is not limited to a gland packing type, but may be a gland bush type in which a bush is installed where the carbon packing 31 is installed. Furthermore, the steam control valve 30 may be sealed with a packing made of a different material than the carbon packing 31, instead of the carbon packing 31. In other words, a packing made of a different material than the carbon packing 31 may be the prediction target of the life prediction system 100. Furthermore, the life prediction system 100 may also predict components other than the carbon packing 31, such as the bush 311.

When the steam control valve 30 is a gland bush type, a vacuum device (not shown) sucks out steam passing through the gland to prevent high-temperature, high-pressure steam from passing through the gland from the inside of the steam control valve 30 and leaking to the outside (the atmosphere or the turbine chamber (not shown)). Specifically, a through-hole (not shown) that penetrates the valve stem through-hole 321 is formed in the control valve cover 32, and this through-hole is connected to piping (not shown). This piping is also connected to a vacuum device. When the vacuum device is activated, steam passing through the gland passes through the through-hole and piping and is sucked out into the vacuum device. When the steam control valve 30 is a gland bush type, the gland is sealed in this way.

<Configuration of information processing device>
In this embodiment, the information processing device 1 is a desktop personal computer. The information processing device 1 may be, for example, a tablet terminal or a control panel installed in the steam turbine 3. As shown in Fig. 1 , the information processing device 1 includes a communication unit 11, an input unit 12, a display unit 13 (alert unit), a storage unit 14, and a control unit 15.

The communication unit 11 is a unit that enables the information processing device 1 to communicate with the server 2 (and possibly with an external communication device other than the server 2). The input unit 12 accepts user input operations on the information processing device 1. The memory unit 14 is a storage device that stores various data used by the information processing device 1.

The display unit 13 is a display device that displays various images. The display unit 13 also displays the prediction results of the lifespan prediction device 50 (described below) and the replacement information (described below). In other words, the display unit 13 also functions as a notification unit that notifies the user of the prediction results of the lifespan prediction device 50 through a screen display. However, it is not essential that the display unit 13 display the prediction results of the lifespan prediction device 50. In this case, for example, if the information processing device 1 is equipped with a speaker, the speaker may function as a notification unit by outputting the prediction results of the lifespan prediction device 50 as audio. Furthermore, for example, the lifespan prediction system 100 may include a printer that prints the prediction results of the lifespan prediction device 50 on paper. In this example, the printer also functions as a notification unit. Furthermore, the lifespan prediction system 100 need not have a device that functions as a notification unit.

The control unit 15 is, for example, a CPU, and performs overall control of each unit of the information processing device 1. The control unit 15 has a lifespan prediction device 50. In this embodiment, the lifespan prediction device 50, one of the devices that make up the lifespan prediction system 100, predicts the lifespan of the carbon packing 31. In FIG. 1, the lifespan prediction device 50 is built into the control unit 15, but the lifespan prediction device 50 may be provided outside the control unit 15 within the information processing device 1, or may be provided outside the information processing device 1. The lifespan prediction device 50 has a calculation unit 51 and a prediction unit 52.

The calculation unit 51 acquires temperature information and operation information to calculate the wear amount J and bulk specific gravity reduction rate UR of the carbon packing 31. The temperature information is information indicating the temperature of the main steam MS shown in FIG. 2. The main steam MS is an example of steam supplied to the steam control valve 30, and is supplied to the inside of the valve housing 33 from an inlet 331 formed in the valve housing 33 shown in FIG. 2. In other words, in this embodiment, the steam control valve 30 is a main steam control valve that controls the supply amount of main steam MS.

In this embodiment, the temperature information is the detected value of the temperature of the main steam MS detected by the temperature sensor 41 shown in FIG. 1 . Hereinafter, the temperature of the main steam MS will be referred to as "main steam temperature T ₀ (see equations (2) and (3) below and FIG. 7 )." The temperature sensor 41 is, for example, a known temperature sensor, and is installed near the inlet 331 as shown in FIG. 2 . The calculation unit 51 acquires the temperature information transmitted from the temperature sensor 41 via the communication unit 11.

The operation information is information that indicates the amount of movement D (see equation (1) below) of the valve stem 34 when the valve stem 34 performs the reciprocating motion described above. The amount of movement D is an example of the amount of operation of the steam regulating valve 30, and indicates the total distance traveled by the valve stem 34 from the time the valve stem 34 begins to perform its reciprocating motion until an arbitrary amount of time has elapsed. Here, the "operation" in the "operation amount of the steam regulating valve 30" is a concept that includes not only the operation of the drive portion of the steam regulating valve 30, such as the reciprocating motion of the valve stem 34, but also unintended operation of the entire steam regulating valve 30, such as vibration of the steam regulating valve 30.

It should be noted that it is not necessary to define the amount of movement D as the total distance traveled by the valve stem 34 as described above. For example, the total distance traveled by one reciprocating motion of the valve stem 34 may be defined as the amount of movement D. Alternatively, the total distance traveled by several reciprocating motions of the valve stem 34 may be defined as the amount of movement D. Furthermore, the total distance traveled by one forward motion and the total distance traveled by one return motion of the valve stem 34 may both be defined as the amount of movement D. In these cases, the calculation unit 51 may use the motion information to calculate the sum of the amount of movement D from the point at which the valve stem 34 starts reciprocating until an arbitrary time has elapsed.

In this specification, in one reciprocating motion of the valve stem 34, the motion from top to bottom is referred to as the outgoing motion, and the motion from bottom to top is referred to as the returning motion. Therefore, the total movement distance for one outgoing motion is the distance traveled when the valve stem 34 moves from the uppermost position to the lowermost position. Similarly, the total movement distance for one returning motion is the distance traveled when the valve stem 34 moves from the lowermost position to the uppermost position. The total movement distance for one outgoing motion and the total movement distance for one returning motion are both equal.

In this embodiment, the movement information is the calculated value of the movement amount D calculated using the movement amount D' (see equation (1) below) of the axis 351 of the hydraulic servo 35, indicated by reference numeral 301 in FIG. 3. The movement amount D' of the axis 351 indicates the total movement distance of the axis 351 from the point at which the axis 351 starts its reciprocating motion until an arbitrary time has elapsed, and is measured by the movement meter 42. The movement meter 42 is a measuring device attached to the hydraulic servo 35, as indicated by reference numeral 301 in FIGS. 1 and 3. The movement meter 42 has a communication unit (not shown) for communicating with the information processing device 1 (and possibly the server 2). In other words, the calculation unit 51 obtains the measured value of the movement amount D' of the axis 351 from the movement meter 42 via the communication unit 11, and calculates the movement amount D using the measured value to obtain the movement information. Details of the calculation process of the movement amount D by the calculation unit 51 will be described later.

Note that it is not essential for the calculation unit 51 to use the movement amount D' of the shaft 351 when acquiring the operation information. For example, a known stroke sensor may be provided at a location on the regulator valve cover 32 where the movement amount D can be detected, and the calculation unit 51 may acquire the detection results transmitted from the stroke sensor, thereby acquiring the operation information. In this case, the operation information will be the detection value of the movement amount D detected by the stroke sensor described above.

The wear amount J of the carbon packing 31 (see Equation (5) below) is the amount of wear that occurs in the carbon packing 31 due to the reciprocating motion of the valve stem 34 (operation of the steam control valve). Specifically, the wear amount J refers to the total amount of wear of the valve stem 34 from the time the valve stem 34 starts its reciprocating motion until an arbitrary time has elapsed. The calculation unit 51 uses the temperature information to calculate a load F _h (see Equation (5) below and FIG. 5 ) that acts on the valve stem 34 due to thermal expansion of the carbon packing mounting portion 322 (details of which will be described later). The thermal expansion of the carbon packing mounting portion 322 occurs when the carbon packing mounting portion 322 is exposed to main steam MS supplied from the inlet 331 into the inside of the valve housing 33. Next, the calculation unit 51 calculates the wear amount J using the movement amount D and the load F _h . Details of the calculation process of the wear amount J by the calculation unit 51 will be described later.

The bulk specific gravity reduction rate UR of the carbon packing 31 is the value obtained by dividing the amount of reduction in bulk specific gravity of the carbon packing 31 by the bulk specific gravity of the carbon packing 31 before exposure to the main steam MS, and is an example of a deterioration index. The deterioration index is an index that indicates the degree of deterioration of the carbon packing 31.

When carbon packing 31 is exposed to high-temperature steam such as main steam MS, the carbon oxidizes and vaporizes. When the carbon vaporizes, the portion of the carbon packing 31 where the carbon vaporized becomes a void, reducing the bulk density. Therefore, the "amount of reduction in bulk density of carbon packing 31" refers to the difference between the bulk density of carbon packing 31 before exposure to main steam MS and the bulk density of carbon packing 31 after exposure to main steam MS for a given period of time.

Here, a decrease in bulk density, or the occurrence of voids in the carbon packing 31, can cause a decrease in the sealing performance of the carbon packing 31. For this reason, a decrease in bulk density serves as an indicator of the deterioration of the carbon packing 31. Therefore, the bulk density decrease rate UR, which indicates the rate at which voids have increased compared to before the carbon vaporized, serves as a deterioration indicator of the degree of deterioration of the carbon packing 31.

Whether or not carbon vaporization occurs in the carbon packing 31 depends on the main steam temperature _T0 . Therefore, the calculation unit 51 calculates the bulk specific gravity of the carbon packing 31 after it has been exposed to the main steam MS for a given period of time, using temperature information acquired from the temperature sensor 41. Then, the calculation unit 51 calculates the bulk specific gravity reduction rate UR using the calculated bulk specific gravity of the carbon packing 31. Note that bulk specific gravity is synonymous with general density (= mass/volume).

The prediction unit 52 predicts the life of the carbon packing 31 using the wear amount J and the bulk specific gravity reduction rate UR calculated by the calculation unit 51. Specifically, the prediction unit 52 generates a wear life curve V ₁ (D) (see FIG. 6 ) that indicates the relationship between the wear amount J and the movement amount D. The prediction unit 52 also generates a bulk specific gravity reduction rate curve V ₂ (T ₀ ) (see FIG. 7 ) that indicates the relationship between the bulk specific gravity reduction rate UR and the main steam temperature T _0. The prediction unit 52 then predicts the life of the carbon packing 31 using the generated wear life curve V ₁ (D) and bulk specific gravity reduction rate curve V ₂ (T ₀ ). Details of the life prediction process by the prediction unit 52 will be described later.

<Server configuration>
The server 2 is a device that assists the information processing device 1 (specifically, the lifespan prediction device 50) in performing lifespan prediction processing. As shown in FIG. 1 , the server 2 includes a communication unit 21, an input unit 22, an output unit 23, a storage unit 24, and a control unit 25. The communication unit 21 is a unit that enables the server 2 to communicate with the information processing device 1 (and possibly an external communication device other than the information processing device 1). The input unit 22 accepts user input operations to the server 2. The output unit 23 is a device that outputs various types of information, and examples of such devices include a display device and a printer that prints various types of information on paper media. The control unit 25 is, for example, a CPU, and performs overall control of each unit of the server 2.

The memory unit 24 is a storage device that stores various data used by the server 2. The memory unit 24 has a first DB 241 and a second DB 242. The first DB 241 is a database that records multiple wear life curves _V1 (D) that the prediction unit 52 generated in the past. More specifically, the first DB 241 records not only the multiple wear life curves _V1 (D) but also a data set for each of the multiple wear life curves _V1 (D). This data set is a collection of multiple first data sets (described in detail below) and is composed of multiple wear amounts J and multiple movement amounts D that were used as source data when the prediction unit 52 generated the wear life curves _V1 (D).

The second DB 242 is a database that records multiple bulk gravity reduction rate curves _V2 ( _T0 ) that were previously generated by the prediction unit 52. More specifically, the second DB 242 records not only the multiple bulk gravity reduction rate curves _V2 ( _T0 ), but also a data set for each of the multiple bulk gravity reduction rate curves _V2 ( _T0 ). This data set is a collection of multiple second data sets (details of which will be described later) and is composed of multiple bulk gravity reduction rates UR and multiple main steam temperatures _T0 that were the original data used when the prediction unit 52 generated the bulk gravity reduction rate curve _V2 ( _T0 ).

[Processing flow (prediction of carbon packing life and notification of replacement time)]
2 to 8, a process flow in which the life prediction device 50 predicts the life of the carbon packing 31 and notifies the user of the replacement time will be described. This process corresponds to an example of a life prediction method according to one aspect of the present invention.

<Generation of life wear curve>
4, in step S101, if the calculation unit 51 acquires the measured value of the movement amount D' of the axis 351 from the movement meter 42 (YES), the calculation unit 51 executes the process of step S102. On the other hand, if the calculation unit 51 cannot acquire the above-mentioned measured value (NO), the calculation unit 51 attempts to acquire the above-mentioned measured value again.

In step S102, the calculation unit 51 calculates the movement amount D using the following formula (1):

D=A/B×D'...(1)
In the above-mentioned formula (1), A/B is the lever ratio of the lever 36. A is the shortest distance between the rotation center of the rotation shaft 361 of the lever 36 and the fixed center of the fixed shaft 362, as shown by reference numeral 301 in FIG. 3 . The fixed shaft 362 is an axis that rotatably fixes the lever 36 to the steam control valve 30. B is the shortest distance between the rotation center of the rotation shaft 361 and the fixed center of the fixed shaft 363. The fixed shaft 363 is an axis that rotatably fixes the lever 36 to the hydraulic servo 35. The calculation unit 51 transmits the movement amount D calculated in step S102 to the prediction unit 52.

In step S103, if the calculation unit 51 acquires temperature information (YES), the calculation unit 51 executes the process of step S104. On the other hand, if the calculation unit 51 is unable to acquire temperature information (NO), the calculation unit 51 attempts to acquire temperature information again.

In step S104, the calculation unit 51 calculates the elongation ΔW shown in FIG. 5 using the following equation (2). The elongation ΔW is the elongation in the width direction of the carbon packing mounting portion 322 shown in FIG. 2 caused by thermal expansion of the carbon packing mounting portion 322 (thermal expansion of the regulator valve cover). For the direction of thermal expansion (width direction) of the carbon packing mounting portion 322, please refer to the arrow around the carbon packing mounting portion 322 in FIG. 2. The carbon packing mounting portion 322 is the portion of the regulator valve cover 32 between the widthwise center 323 and the central axis 324 of the valve stem through hole 321 (dimension W).

ΔW=W×(T ₀ −T _r )×α (2)
In the above-mentioned formula (2), W is the width of the carbon packing mounting portion 322. As shown in FIG. 2, the width W corresponds to the shortest distance between the center 323 and the central axis 324. _Tr is room temperature, and in this embodiment, the cold temperature is considered to be room temperature. The cold temperature is the air temperature when the components are assembled and set in the manufacturing process of the steam control valve 30, and is set to 20°C in this embodiment. α is the linear expansion coefficient of the control valve cover 32.

In step S104, the calculation unit 51 calculates the elongation ΔL shown in FIG. 5 using the following equation (3). The elongation ΔL is the elongation in the extension direction of the lid central axis (not shown) that occurs due to thermal expansion of the carbon packing mounting portion 322. The lid central axis is the central axis extending in the front-to-rear direction of the regulator valve lid 32. For the direction of thermal expansion of the carbon packing mounting portion 322 (extension direction of the lid central axis), please refer to the arrow indicated by reference numeral 301 in FIG. 3.

ΔL=L×(T ₀ −T _r )×α (3)
In the above-mentioned formula (3), L is the length in the extension direction of the lid central axis of the carbon packing attachment part 322. As indicated by reference numeral 301 in Fig. 3, the length L corresponds to the shortest distance between the central axis 324 and the side end face 325 of the carbon packing attachment part 322 on the hydraulic servo 35 side.

Here, the lever 36 is exposed to the atmosphere, not the main steam MS, even when the steam control valve 30 is operating. Therefore, the temperature of the lever 36 remains constant at approximately room temperature, and thermal expansion of the lever 36 due to the main steam MS is not taken into account.

In step S105, the calculation unit 51 calculates the load _Fh shown in Fig. 5 using the following equation (4): In the following equation (4), G is the load of the valve stem 34. Furthermore, _H3 is the length of the connecting pinion 326. The connecting pinion 326 connects the valve stem 34 and the lever 36.

F _h =G×√(ΔW ² +ΔL ² )/H ₃ ...(4)
As described above, the carbon packing mounting portion 322 thermally expands due to contact with the main steam MS. This thermal expansion causes elongations ΔW and ΔL as shown in FIG. 5 in the carbon packing mounting portion 322, and the connecting pinion 326 tilts in the direction of each elongation. This tilt causes the load G acting on the connecting pinion 326 to be vector-decomposed, with the point of application of the load G between the valve stem 34 and the connecting pinion 326. Of the components of the vector-decomposed load G, the horizontal component acts in the direction opposite to the direction of each elongation generated in the carbon packing mounting portion 322, pressing the valve stem 34 against the carbon packing 31.

This horizontal component is the load _Fh , and the pressure of the valve stem 34 against the carbon packing 31 due to the load _Fh is one cause of wear on the carbon packing 31. In this embodiment, the life prediction device 50 performs the life prediction process taking into account the wear on the carbon packing 31 due to this pressure.

In step S106, the calculation unit 51 calculates the wear amount J using the following equation (5). In the following equation (5), T is the friction force acting on the carbon packing 31, and K is the specific wear amount. The specific wear amount is the wear volume per unit load and per unit movement amount. The wear volume is the volume of wear occurring in the carbon packing 31. The calculation unit 51 transmits the wear amount J calculated in step S106 to the prediction unit 52.

J=K× _Fh ×D...(5)
In step S107, the calculation unit 51 determines whether the number of calculations of the movement amount D and the wear amount J has reached a first reference number. The first reference number corresponds to the number of first data sets each consisting of the movement amount D and the wear amount J. The first data set is used by the prediction unit 52 to generate the wear life curve _V1 (D). In other words, the calculation process of the movement amount D and the wear amount J by the calculation unit 51 is periodically performed at a predetermined time span (which can be arbitrarily set by the user) until the number of calculations reaches the first reference number. The first reference number is arbitrarily set by the user, for example, and is stored in advance in the storage unit 14 or a memory (not shown) of the calculation unit 51. The same applies to the second reference number, which will be described later.

If it is determined that the number of calculations of the movement amount D and the wear amount J has reached the first reference number (YES), the calculation unit 51 ends the series of processes in steps S101 to S106. On the other hand, if it is determined that the first reference number has not been reached (NO), the calculation unit 51 again executes the series of processes in steps S101 to S106. The series of processes in steps S101 to S107 corresponds to an example of a calculation step in a life prediction method according to one aspect of the present invention.

In step S108, the prediction unit 52 generates the wear life curve _V1 (D) shown in FIG. 6 using multiple (the same number as the first reference number) first data sets. Specifically, the prediction unit 52 plots the wear amount J corresponding to the movement amount D for each of the multiple first data sets on a graph. The prediction unit 52 then generates a curve that most closely resembles the distribution trend of the multiple points plotted on the graph, and sets this as the wear life curve _V1 (D). The prediction unit 52 records the wear life curve _V1 (D) generated in step S108 in the first DB 241. The processing of step S108 corresponds to an example of a prediction step in a life prediction method according to an aspect of the present invention.

Note that the wear life curve V ₁ (D) shown in Figure 6 is merely an example, and wear life curves V ₁ (D) of various shapes can be generated depending on the material of the carbon packing 31, the main steam temperature T ₀ , the speed of the reciprocating movement of the valve stem 34, etc.

<Generation of bulk density reduction rate curve>
In step S201, if the calculation unit 51 acquires temperature information from the temperature sensor 41 (YES), the calculation unit 51 executes the process of step S202. In this case, the calculation unit 51 transmits the acquired temperature information to the prediction unit 52. On the other hand, if the calculation unit 51 cannot acquire the temperature information (NO), the calculation unit 51 attempts to acquire the temperature information again.

In step S202, the calculation unit 51 calculates the bulk specific gravity reduction rate UR using the following formula (6). In the following formula (6), C _mi is the weight of the carbon packing 31 at the operating temperature, and C _m0 is the weight of the carbon packing 31 at the time of manufacturing the steam control valve 30. The operating temperature is the temperature around the carbon packing 31 when the steam control valve 30 is in operation. In this embodiment, the weight of the carbon packing 31 obtained by a carbon packing high-temperature oxidation test is used as the weight of the carbon packing 31 at the operating temperature. The carbon packing high-temperature oxidation test is a test in which the weight per ring of the carbon packing 31 is measured after being held in a furnace for a unit time at each high temperature. The calculation unit 51 transmits the bulk specific gravity reduction rate UR calculated in step S202 to the prediction unit 52.

UR=1- _Cmi / _Cm0 ...(6)
In step S203, the calculation unit 51 determines whether the number of calculations of the bulk gravity reduction rate UR has reached a second reference number. The second reference number corresponds to the number of second data sets each consisting of the bulk gravity reduction rate UR and a detected value (temperature information) of the main steam temperature _T0 . The second data set is used by the prediction unit 52 to generate the bulk gravity reduction rate curve _V2 ( _T0 ). In other words, the calculation unit 51 periodically performs the calculation process of the bulk gravity reduction rate UR at a predetermined time span (which can be arbitrarily set by the user) until the number of calculations reaches the second reference number.

If it is determined that the number of times the bulk specific gravity reduction rate UR has been calculated has reached the second reference number (YES), the calculation unit 51 terminates the processing of steps S201 and S202. On the other hand, if it is determined that the second reference number has not been reached (NO), the calculation unit 51 again executes the processing of steps S201 and S202. The series of processing steps S201 to S203 corresponds to an example of a calculation step in a lifespan prediction method according to one aspect of the present invention.

In step S204, the prediction unit 52 generates the bulk gravity reduction rate curve _V2 ( _T0 ) shown in FIG. 7 using multiple (the same number as the second reference number of times) second data sets. Specifically, the prediction unit 52 plots on a graph the bulk gravity reduction rate UR corresponding to the detected value of the main steam temperature _T0 for each of the multiple second data sets. Then, the prediction unit 52 generates a curve that most closely resembles the distribution trend of the multiple points plotted on the graph, and sets this as the bulk gravity reduction rate curve _V2 ( _T0 ). The prediction unit 52 records the bulk gravity reduction rate curve _V2 ( _T0 ) generated in step S204 in the second DB 242. The processing of step S204 corresponds to an example of a prediction step in a life prediction method according to an aspect of the present invention.

7 is merely an example, and various shapes of bulk specific gravity reduction rate curves _V2 ( _T0 ) can be generated depending on the material of the carbon packing 31, the main steam temperature _{T0, etc. Furthermore} , the calculation unit 51 may execute the series of processes of steps S101 to S107 and the series of processes of steps S201 to S203 simultaneously, or may execute one of the series of processes before the other. Furthermore, the prediction unit 52 may execute the process of step S108 and the process of step S204 simultaneously, or may execute one of the processes before the other.

<Carbon packing life prediction and notification of replacement time>
In step S301, the prediction unit 52 generates a life function f(D, T0) expressed by the following equation (7) using the wear life curve _V1 ( _D ) generated in step S108 and the bulk specific gravity reduction rate curve _V2 ( _T0 ) generated in step S204.

f(D, T ₀ )=V ₁ (D)+V ₂ (T ₀ )...(7)
The abrasion life curve V ₁ (D) is a mechanical characteristic function with the movement amount D as a variable. On the other hand, the bulk specific gravity reduction rate curve V ₂ (T ₀ ) is a chemical characteristic function with the main steam temperature T ₀ as a variable. Therefore, by superimposing the abrasion life curve V ₁ (D) and the bulk specific gravity reduction rate curve V ₂ (T ₀ ), a life function f(D, T ₀ ) is generated that takes into account both the life predicted from the mechanical property aspect and the life predicted from the chemical property aspect. The processing of step S301 corresponds to an example of a prediction step in a life prediction method according to one aspect of the present invention.

In step S302, the prediction unit 52 transforms the life function f(D, T ₀ ) generated in step S301 from the above-mentioned equation (7) to the following equation (8): UR(T ₀ ) is the bulk specific gravity reduction rate at a certain main steam temperature T ₀ , and λ is a correction coefficient.

f(D, T ₀ )=K×(1+λ×UR(T ₀ ))×D×F _h ...(8)
There is a correlation between the bulk specific gravity reduction rate UR and the force with which the carbon packing 31 tightens the valve stem 34 (hereinafter referred to as "tightening force"). Specifically, as the bulk specific gravity reduction rate UR increases, the tightening force decreases. Furthermore, as the tightening force decreases, high-temperature, high-pressure steam is more likely to pass from the inside of the steam control valve 30 through the gland, and thus more likely to leak to the outside. This phenomenon in which high-temperature, high-pressure steam is more likely to leak to the outside due to a decrease in tightening force can be considered equivalent to the phenomenon in which high-temperature, high-pressure steam is more likely to leak to the outside due to wear of the carbon packing 31 caused by the reciprocating movement of the valve stem 34.

Therefore, by regarding the bulk specific gravity reduction rate UR as an increase in the specific wear rate, the life function f(D, T ₀ ) expressed by the above-mentioned equation (7) can be expressed as an equation for the wear rate of the carbon packing 31, as in the above-mentioned equation (8). The processing of step S302 corresponds to an example of a prediction step in a life prediction method according to one aspect of the present invention.

In step S303, the prediction unit 52 uses the above-mentioned equation (8) to calculate the value of f(D, _T0 ) a predetermined number of times n within a period from when the valve stem 34 starts reciprocating to when an arbitrary time has elapsed (hereinafter referred to as the "arbitrary period t _i "). The prediction unit 52 calculates K and _Fh from the wear life curve _V1 (D) and calculates UR( _T0 ) from the bulk specific gravity reduction rate curve _V2 ( _T0 ). The number n of times the value of f(D, _T0 ) is calculated can also be set arbitrarily by the user. The prediction unit 52 then calculates the life function f(D, _T0 ) shown in FIG. 8 from the calculated n values of f(D, _T0 ), and then time-differentiates the life function f(D, _T0 ) to obtain the life slope line df/dt.

The life inclined line df/dt is a line having a slope of df/dt at a point (usually the most recent calculation point) after an arbitrary time has elapsed since the valve stem 34 started to reciprocate, as shown in Fig. 8. This latest calculation point corresponds to the end of an arbitrary period t _i . The life inclined line df/dt is also a tangent line that contacts the life function f(D, T ₀ ) at a point P _i (t _i , J _i ) on the life function f(D, T ₀ ).

As a result, the prediction unit 52 calculates the period _tz from the point at which the valve stem 34 starts reciprocating to the point at which the life inclined line df/dt intersects with the design wear limit line SL, as shown in Fig. 8. The design wear limit line SL is a line that indicates the amount of wear of the carbon packing 31 at the end of its life (hereinafter referred to as "limit wear amount _Jmax "). Specifically, the design wear limit line SL is a line that passes through point _Pz ( _tz , _Jmax ) on the life function f(D, _T0 ) and is parallel to the horizontal axis of the coordinate axes shown in Fig. 8.

The prediction unit 52 defines the design wear limit line SL by calculating the limit wear amount _Jmax prior to calculating the aforementioned period t _z . The prediction unit 52 calculates the limit wear amount _Jmax using the following equation (9). In the following equation (9), _Ds is the maximum amount of movement D, _Yc is the number of years of use of the carbon packing 31 at which replacement of the carbon packing 31 is recommended, and η is the availability rate of the facility in which the steam turbine 3 is installed. In addition, the load _Fh substituted into the following equation (9) is calculated using data (shape, steam conditions, etc.) at the time when use of the steam control valve 30 is planned.

J _max = K x F _h x D _s x Y _c x η x 3.2 x 10 ⁷ ... (9)
The prediction unit 52 determines the above-mentioned period _tz as the life of the carbon packing 31. In other words, the period _tz is the life of the carbon packing 31 predicted by the prediction unit 52, and thus becomes the prediction result of the life prediction device 50. Hereinafter, the period _tz will be referred to as the predicted life _tz . The prediction unit 52 transmits the predicted life _tz to the display unit 13. The processing of step S303 corresponds to an example of a prediction step in a life prediction method according to an aspect of the present invention.

In step S304, the prediction unit 52 calculates an arbitrary period t _i (i: a natural number from 1 to n) from the time when the valve stem 34 starts reciprocating to a certain time when the value of f(D, T ₀ ) is calculated, and then calculates the difference between the predicted life t _z and the arbitrary period t _i . The prediction unit 52 then determines whether the difference is less than six months. Note that six months, which is the period used as the judgment criterion for the prediction unit 52, is just an example and can be changed as desired depending on the target of prediction by the life prediction system 100, etc.

If the answer is NO in step S304, the prediction unit 52 executes the process of step S304 again for the arbitrary period t _i+1 from the time when the valve stem 34 starts reciprocating to the next time when the value of f(D, T ₀ ) is calculated. On the other hand, if the answer is YES in step S304, the prediction unit 52 determines that the arbitrary period t _i is the time to replace the carbon packing 31, and transmits replacement information to the display unit 13 indicating that it is time to replace the carbon packing 31.

In step S305, the display unit 13 displays the predicted life t _z and the replacement information acquired from the prediction unit 52. The replacement information displayed on the display unit 13 functions as a replacement alarm that notifies the user that it is time to replace the carbon packing 31.

When the processing of step S305 is completed, the entire series of processes from when the life prediction device 50 predicts the life of the carbon packing 31 and notifies the user when it is time to replace it is complete. Note that the processes for notifying the user when it is time to replace the carbon packing 31, i.e., the processes of S304 and S305, are not required. The life prediction device 50 only needs to perform the processes up to predicting the life of the carbon packing 31, i.e., the processes of S101 to S303.

[Summary]
The life prediction system 100 differs from conventional life predictions that use only the wear amount of components in that the prediction unit 52 of the life prediction device 50 predicts the life of the carbon packing 31 using the bulk specific gravity reduction rate UR. The wear amount of components is greatly influenced by the structure of the steam control valve, such as the size of the steam control valve and the combination of components. This is because the magnitude of the mechanical force pressing the valve stem against the carbon packing, bushing, etc., varies greatly depending on the structure of the steam control valve.

On the other hand, the degree of deterioration of a component due to the temperature of the steam supplied to the steam control valve largely depends on the composition of the material from which the component is made. Because the composition of the material from which a component is made remains unchanged after the component is completed, the actual measured value and calculated value of the degree of deterioration of the component roughly match. For these reasons, the life prediction system 100, which predicts life using the bulk specific gravity reduction rate UR, which indicates the degree of deterioration of the carbon packing 31, has higher prediction accuracy than conventional life predictions. In other words, the life prediction system 100 produces predictions with less variance than conventional life predictions.

In the life prediction system 100, the prediction unit 52 of the life prediction device 50 predicts the life using not only the bulk specific gravity reduction rate UR but also the wear amount J. This improves the accuracy of the life prediction. Furthermore, in the life prediction system 100, the calculation unit 51 of the life prediction device 50 uses not only the movement amount D but also the load _Fh when calculating the wear amount J. This allows the wear amount J to be calculated with high accuracy, thereby improving the accuracy of the life prediction. Furthermore, the life prediction system 100 targets the carbon packing 31 for life prediction. This makes it possible to accurately predict the life of the carbon packing 31, which deteriorates and wears more severely when exposed to steam in a gland packing-type steam control valve 30, compared to other components. This ultimately makes it possible to prevent shutdowns of the steam turbine 3 with a high probability.

The life prediction system 100 can notify the user of the prediction results of the prediction unit 52, which can accurately predict the life of the carbon packing 31, through a screen display on the display unit 13. This makes it possible to prevent with a high probability the steam turbine 3 from being shut down due to work such as replacing the carbon packing 31 that has reached the end of its life, thereby improving the availability of the steam turbine 3.

[Modification]
The life prediction device 50 may not use the wear amount J to predict the life of the carbon packing 31, and may predict the life using only a deterioration index such as the bulk specific gravity reduction rate UR. In this case, the movement meter 42 is not required, and the calculation unit 51 acquires only temperature information. Furthermore, the prediction unit 52 generates only the bulk specific gravity reduction rate curve _V2 ( _T0 ).

The bulk specific gravity reduction rate UR is merely one example of a deterioration index, and other indexes may be used as the deterioration index. For example, a decrease in the Young's modulus (elastic coefficient) of the carbon packing 31 may be considered to be deterioration of the carbon packing 31, and some index indicating this decrease in Young's modulus may be used as the deterioration index. In this case, if the decrease in Young's modulus is caused by the occurrence of voids in the carbon packing 31, the calculation unit 51 may use temperature information to calculate a deterioration index related to the decrease in Young's modulus. Furthermore, for example, focusing on chemical deterioration of the carbon packing 31, some index indicating this deterioration may be used as the deterioration index. Furthermore, focusing on deterioration of components caused by the quality of steam flowing from the boiler (not shown) of the steam turbine 3 into the steam control valve 30, some index indicating this deterioration may be used as the deterioration index.

The detected value of the main steam temperature _T0 is merely one example of temperature information, and information indicating the temperature of steam other than the main steam MS may also be used as the temperature information. For example, the detected value of the temperature of reheat steam may be used as the temperature information. The temperature of the reheat steam can also be detected by a known temperature sensor such as the temperature sensor 41, as with the main steam temperature _T0 . Here, when the temperature information is the detected value of the temperature of the reheat steam, the steam control valve 30 is an intercept valve (not shown) integrated with a reheat steam shutoff valve. Note that when the steam control valve 30 is this intercept valve, the deterioration index is the bulk specific gravity reduction rate UR of the carbon packing 31, and information indicating the temperature of the steam near the inlet of the reheat steam shutoff valve (not shown) is used as the temperature information.

In other words, the steam control valve 30 is not limited to the main steam control valve of this embodiment, and may be any steam control valve that controls the amount of steam supplied to the steam turbine 3. From this perspective, the aforementioned intercept valve, which is an example of the steam control valve 30, does not necessarily have to be integrated with the reheat steam shutoff valve. If the intercept valve is not integrated with the reheat steam shutoff valve, for example, any reheat turbine could be the steam turbine 3.

The movement amount D is merely one example of operation information, and information indicating an operation amount of the steam control valve 30 other than the movement amount D may also be used as operation information. For example, the detected value of the vibration amount of the steam control valve 30 may be used as operation information. A known vibration sensor, for example, may be used to detect this vibration amount.

Various variations in the configuration of the lifespan prediction system 100 are envisioned. For example, the lifespan prediction device 50 may include only the prediction unit 52, and the server 2 may include the calculation unit 51. Alternatively, the lifespan prediction system 100 may be composed of only the information processing device 1. Furthermore, the control unit 15 may not include the lifespan prediction device 50. In this case, for example, the control unit 15 may include only either the calculation unit 51 or the prediction unit 52, and the control unit 25 may include the other. In other words, it is sufficient that one or more devices constituting the lifespan prediction system 100 include the calculation unit 51 and the prediction unit 52, and there are no limitations on which devices each include the calculation unit 51 and the prediction unit 52.

[Contribution to the SDGs]
The life prediction system 100 can prevent, with a high probability, shutdown of the steam turbine 3 due to component replacement work or the like. Therefore, use of the life prediction system 100 enables stable operation of various plants equipped with the steam turbine 3. In this way, the life prediction system 100 contributes to the development of robust infrastructure, and can therefore contribute to the achievement of Goal 7 of the Sustainable Development Goals (SDGs), which is to "ensure access to affordable and clean energy for all."

[Software implementation example]
The functions of the lifespan prediction device 50 (hereinafter referred to as the "device") can be realized by a program that causes a computer to function as the device, and a program that causes a computer to function as each control block of the device (particularly the calculation unit 51 and the prediction unit 52). This program is an example of a lifespan prediction program according to one aspect of the present invention.

In this case, the aforementioned device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the aforementioned program. By executing the aforementioned program using this control device and storage device, the functions described in the aforementioned embodiment and variations are realized.

The above-mentioned program may be stored non-transitory on one or more computer-readable storage media. These storage media may or may not be included in the above-mentioned device. In the latter case, the above-mentioned program may be supplied to the above-mentioned device via any wired or wireless transmission medium.

Furthermore, some or all of the functions of each of the aforementioned control blocks can be realized by logic circuits. For example, integrated circuits incorporating logic circuits that function as each of the aforementioned control blocks are also included in the scope of the present invention. In addition, the functions of each of the aforementioned control blocks can also be realized by, for example, a quantum computer.

[Additional Notes]
The present invention is not limited to the above-described embodiments and modifications, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the above-described embodiments and modifications are also included in the technical scope of the present invention.

3 Steam turbine 13 Display unit (notification unit)
30 Steam control valve 31 Carbon packing (parts, packing)
32 Regulating valve cover 34 Valve stem 50 Life prediction device 51 Calculation unit 52 Prediction unit 100 Life prediction system (life notification system)
D Displacement _F Load h J Wear amount MS Main steam (steam supplied to the steam control valve)
t _z predicted life (life of parts)
UR bulk density reduction rate

Claims (10)

a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that configures a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that configures the steam control valve;
a prediction unit that predicts a life of the component using the deterioration index calculated by the calculation unit ,
the calculation unit acquires operation information indicating an operation amount of the steam regulating valve and calculates an amount of wear of the component caused by the operation of the steam regulating valve;
the prediction unit predicts a lifespan of the component using the deterioration index and the wear amount of the component calculated by the calculation unit;
The calculation unit
The movement amount of the valve stem when the valve stem reciprocates is acquired as the operation information;
Using the temperature information, a load acting on the valve stem due to thermal expansion of the regulator valve cover is calculated;
A life prediction system that calculates the amount of wear of the component using the amount of movement and the load . a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that configures a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that configures the steam control valve;
a prediction unit that predicts a life of the component using the deterioration index calculated by the calculation unit,
The steam control valve has a packing that contacts the valve stem,
The calculation unit calculates, as the deterioration index, a bulk specific gravity reduction rate obtained by dividing a reduction in the bulk specific gravity of the packing by the bulk specific gravity of the packing before being exposed to the steam,
The prediction unit predicts the life of the packing as the life of the part. The steam control valve has a packing that contacts the valve stem,
the calculation unit calculates the amount of wear of the packing as the amount of wear of the part,
The life prediction system according to claim 1 , wherein the prediction unit predicts the life of the packing as the life of the part. A lifespan prediction program for causing a computer to function as the lifespan prediction system according to claim 1 , the lifespan prediction program causing a computer to function as the calculation unit and the prediction unit. a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that configures a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that configures the steam control valve;
a prediction unit that predicts a life of the component using the deterioration index calculated by the calculation unit ,
the calculation unit acquires operation information indicating an operation amount of the steam regulating valve and calculates an amount of wear of the component caused by the operation of the steam regulating valve;
the prediction unit predicts a lifespan of the component using the deterioration index and the wear amount of the component calculated by the calculation unit;
The calculation unit
The movement amount of the valve stem when the valve stem reciprocates is acquired as the operation information;
Using the temperature information, a load acting on the valve stem due to thermal expansion of the regulator valve cover is calculated;
A life prediction device that calculates the amount of wear of the component using the amount of movement and the load . a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that configures a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that configures the steam control valve;
a prediction unit that predicts a life of the component using the deterioration index calculated by the calculation unit,
The steam control valve has a packing that contacts the valve stem,
The calculation unit calculates, as the deterioration index, a bulk specific gravity reduction rate obtained by dividing a reduction in the bulk specific gravity of the packing by the bulk specific gravity of the packing before being exposed to the steam,
The prediction unit predicts the life of the packing as the life of the part. a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that configures a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that configures the steam control valve;
a prediction unit that predicts a life of the component using the deterioration index calculated by the calculation unit;
a notification unit that notifies a user of a prediction result of the prediction unit ,
the calculation unit acquires operation information indicating an operation amount of the steam regulating valve and calculates an amount of wear of the component caused by the operation of the steam regulating valve;
the prediction unit predicts a lifespan of the component using the deterioration index and the wear amount of the component calculated by the calculation unit;
The calculation unit
The movement amount of the valve stem when the valve stem reciprocates is acquired as the operation information;
Using the temperature information, a load acting on the valve stem due to thermal expansion of the regulator valve cover is calculated;
A lifespan notification system that calculates the amount of wear of the part using the amount of movement and the load . a calculation unit that acquires temperature information indicating the temperature of steam supplied to a steam control valve that configures a steam turbine and calculates a deterioration index that is an index indicating the degree of deterioration of a component that configures the steam control valve;
a prediction unit that predicts a life of the component using the deterioration index calculated by the calculation unit;
a notification unit that notifies a user of a prediction result of the prediction unit,
The steam control valve has a packing that contacts the valve stem,
The calculation unit calculates, as the deterioration index, a bulk specific gravity reduction rate obtained by dividing a reduction in the bulk specific gravity of the packing by the bulk specific gravity of the packing before being exposed to the steam,
The prediction unit predicts the life of the packing as the life of the part. a calculation step of acquiring temperature information indicating the temperature of steam supplied to a steam control valve constituting a steam turbine and calculating a deterioration index which is an index indicating the degree of deterioration of a component constituting the steam control valve;
a prediction step of predicting a life of the component using the deterioration index calculated in the calculation step ,
the calculation step includes acquiring operation information indicating an operation amount of the steam regulating valve, and calculating an amount of wear of the component caused by the operation of the steam regulating valve,
the prediction step includes predicting a lifespan of the component using the deterioration index and the wear amount of the component calculated in the calculation step,
In the calculation step,
The movement amount of the valve stem when the valve stem reciprocates is acquired as the operation information;
Using the temperature information, a load acting on the valve stem due to thermal expansion of the regulator valve cover is calculated;
a wear amount of the component is calculated using the movement amount and the load . a calculation step of acquiring temperature information indicating the temperature of steam supplied to a steam control valve constituting a steam turbine and calculating a deterioration index which is an index indicating the degree of deterioration of a component constituting the steam control valve;
a prediction step of predicting a life of the component using the deterioration index calculated in the calculation step,
The steam control valve has a packing that contacts the valve stem,
The calculation step includes calculating a bulk specific gravity reduction rate as the deterioration index by dividing a reduction in the bulk specific gravity of the packing by the bulk specific gravity of the packing before being exposed to the steam,
A life prediction method, wherein the prediction step includes predicting the life of the packing as the life of the part.