JP3476330B2 - Inspection plan support equipment for plant equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant equipment inspection plan support apparatus for formulating a plant equipment inspection plan.

[0002]

2. Description of the Related Art For example, a power plant facility is regularly inspected at intervals of 2 or 4 years, but the number of facilities to be inspected is enormous, and it is difficult to formulate inspection plans. It takes a lot of work. In addition, it is necessary to take measures such as temporarily stopping the plant during the inspection period. Therefore, how to reduce the frequency of inspections while ensuring the reliability of equipment is an issue for cost reduction.
In particular, in recent years, there has been a tendency for the intervals between periodic inspections of power plant equipment to be extended, so it is necessary to enhance the inspection plan support equipment for objectively determining the inspection time in order to ensure stable operation of the plant. Is desired.

As one method of supporting the inspection plan, the probability density function of the life of the equipment is calculated by analyzing the data of the past inspection and the data of the similar plant, and the inspection is performed from the possibility of deviating from the reliability interval. There are probabilistic methods for estimating the time. FIG. 13 is an explanatory diagram of such a conventional stochastic method for estimating the inspection time.

The characteristic curve S1 in FIG. 13 shows the probability density f (t) of the life of the equipment with respect to the time t elapsed from the start of operation as a result in another plant. Area S2 in FIG. 13 is the integration of the section from 0 to a at time t, and is considered to be the probability that the equipment cannot be continuously operated by time a due to a failure or the like. The characteristic curve S3 in FIG. 13 is the reliability with which the equipment can be continuously operated, and is represented by the following equation (1) as a function R (t) of time t.

[0005]

[Equation 1]

The reliability R (t) is compared with a threshold value at any time, and when the reliability R (t) falls below the threshold value, it is determined that the inspection should be performed.

[0007]

However, such a conventional method cannot determine an accurate inspection time when the past inspection data is small. Further, when utilizing data in similar plants, it is difficult to clearly understand how much the influence of the difference in operating conditions is, and for example, the probability density f (t) of the characteristic curve S1 in FIG.
Will not be the same as the target plant.

In other words, if an attempt is made to create the probability density f (t) using only the data of the target plant, there is a problem that if the available data are few, a probabilistically meaningful test cannot be performed. Further, even when the occurrence of a defect or the occurrence of a new equipment replacement or the like is experienced in the process of accumulating the operation results of the target plant, the conventional method uses the probability density f obtained by using the actual result data obtained at any time. Since the iterative correction technology of (t) has not been developed,
An accurate probability density f (t) cannot be obtained.

Therefore, in recent years, a Bayesian reliability analysis method has attracted attention as a method for solving the problem.
Equation (1) is the probability of failure during the subsequent minute time dt under the condition that the failure has not occurred until time t.
Can be written in the form of (t) dt (Masahiro Ichikawa, Structural Reliability Engineering,
Kaibundo). This λ (t) is called a failure rate, and when these are used to express the equation (1), the following equation (2) is obtained.

[0010]

[Equation 2]

A feature of the Bayesian reliability analysis method is that λ (t) itself is defined as an appropriate random variable based on past experience, and λ (t) is corrected with data obtained thereafter as needed. . By this Bayesian reliability analysis method,
Research has been conducted on a method of predicting the service life from the decreasing tendency of the reliability by utilizing the data after the start of operation and sequentially correcting the reliability.

However, at present, there is no precedent for an apparatus for formulating an inspection plan by sequentially correcting the reliability as the inspection data is accumulated. In particular, in a two-year or four-year periodic inspection at a large-scale plant such as a power plant, support for deciding whether to include individual equipment in the inspection plan or not perform inspection until the next inspection time. There has been no researched purpose.

An object of the present invention is to use the inspection data of a huge amount of plant equipment constituting a plant as subjective prediction information of the Bayesian reliability analysis method to support the formulation of an inspection plan based on the tendency of decreasing reliability. It is to provide an inspection plan support device for plant equipment.

[0014]

According to a first aspect of the present invention, there is provided a reliability function holding unit for holding a change process of a probability that a plant equipment, which is an inspection plan object, operates normally as a reliability function, and a reliability function holding unit. The reliability estimation parameter holding unit that holds the reliability estimation parameter as the existence probability of the reliability function and the equipment whose inspection result is in an abnormal state with the reliability estimation parameter before inspection held in the reliability estimation parameter holding unit as the prior density And the reliability estimation parameter calculation means for calculating the reliability estimation parameter of the posterior density from the number of facilities in the normal state using the Bayesian reliability analysis method and updating the data held in the reliability estimation parameter holding unit, and the reliability. The reliability function is calculated by reflecting the inspection data from the reliability estimation parameter of the posterior density updated by the reliability estimation parameter calculation means. That the reliability function calculating means and the reliability function correcting unit consisting, characterized by comprising a reporting unit for reporting a reliability function modification reliability function and the reliability is corrected in unit estimated parameter.

In the first aspect of the present invention, the reliability function holding unit holds the change process of the probability that the plant equipment to be inspected to operate normally with respect to the operating time as a reliability function, and the reliability estimation parameter. The holding unit holds the reliability estimation parameter as the existence probability of the reliability function. The reliability function correction unit calculates the posterior density reliability estimation parameter using the Bayesian reliability analysis method from the prior density reliability estimation parameter and inspection data stored in the reliability estimation parameter storage unit, and then A reliability function corrected by reflecting inspection data from the reliability estimation parameter of density is calculated. The reliability function and the reliability estimation parameter modified by the reliability function modifying unit are reported by the reporting unit.

[0016]

Then, the reliability estimation parameter calculation means of the reliability function correction unit uses the reliability estimation parameter before inspection held in the reliability estimation parameter storage unit as the prior density, and the equipment with an inspection result in an abnormal state and The reliability estimation parameter of posterior density is calculated using the Bayesian reliability analysis method from the number of equipment in the normal state, and the data stored in the reliability estimation parameter storage unit is updated. Further, the reliability function calculation unit of the reliability function correction unit calculates the reliability function which is modified by reflecting the inspection data from the reliability estimation parameter of the posterior density updated by the reliability estimation parameter calculation unit.

According to a second aspect of the present invention, in the first aspect of the present invention, an inspection time holding unit that holds the inspection time over a period of continuous operation of the plant equipment, and reliability for each inspection time after the inspection time. When there is a time when the reliability change amount calculation unit that calculates the change amount of the reliability function in a time series and a period when the numerical value of the reliability change amount exceeds the threshold value exist and the threshold value is exceeded Is an inspection plan support device for plant equipment additionally provided with an inspection timing validity determination unit for outputting to the notification unit that the reliability of the inspection plan is insufficient.

According to the invention of claim 2, in addition to the operation of the invention of claim 1, the inspection time holding unit holds the inspection time over the period of continuous operation of the plant equipment, and the reliability change amount calculation unit Calculates the amount of change in the reliability function after the inspection time in time series for each inspection time, and the inspection time validity judgment unit determines whether there is a period in which the numerical value of the amount of change in reliability exceeds the threshold value. When there is a time when the threshold value is exceeded, the fact that the reliability is insufficient in the inspection plan is output to the notification unit.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the reliability function held in the reliability function holding unit is the time when the plant equipment is replaced with new equipment. This is a plant equipment inspection planning support device in which the axis is corrected so that the time when the equipment is replaced becomes the time when the operation starts.

According to the invention of claim 3, in addition to the effect of the invention of claim 1 or claim 2, when the plant equipment is replaced with new equipment, the reliability function held in the reliability function holding unit Modify the time axis so that the time of facility replacement is the start of operation.

According to a fourth aspect of the present invention, in the second or third aspect of the invention, the inspection timing validity determination unit calculates each inspection timing so that the reliability change amount becomes equal to the threshold value, It is an inspection plan support device for plant equipment that reports the inspection time as the longest inspection interval schedule.

According to the invention of claim 4, in addition to the operation of the invention of claim 2 or claim 3, the inspection timing validity determining unit sets each inspection timing so that the reliability change amount becomes equal to the threshold value. Calculate and report the inspection time as the longest inspection interval schedule.

According to a fifth aspect of the invention, in the invention of the fourth aspect, the maximum value of the interval between the inspection time and the next inspection time is held in advance as the inspection interval maximum side limit value in the inspection time holding unit. The inspection timing validity determination unit is an inspection plan support device for plant equipment that corrects the inspection timing to the maximum inspection interval side limit value when the calculated inspection timing exceeds the inspection interval maximum side limit value.

According to the invention of claim 5, in addition to the operation of the invention of claim 4, the maximum value of the interval between the inspection time and the next inspection time is held as the inspection interval maximum side limit value in the inspection time holding part, and the inspection time is held. When the inspection time calculated by the time validity determining unit exceeds the inspection interval maximum side limit value, the inspection interval maximum side limit value is corrected.

According to a sixth aspect of the present invention, in the second or fourth aspect of the present invention, the inspection time holding unit holds an inspection interval reference value that presets a period between the inspection and the next inspection, and the reliability change amount. The calculation unit calculates a time series of the reliability change amount starting from each inspection time determined by the inspection interval reference value, and the inspection time validity determination unit has a period in which the reliability change amount exceeds the threshold value. It is an inspection plan support device for plant equipment, which judges whether or not there is a time when the threshold value is exceeded and outputs the fact that the reliability is insufficient in the inspection plan to the notification unit.

According to the invention of claim 6, in addition to the operation of the invention of claim 2 or claim 4, the period between the inspection and the next inspection is held as only one inspection interval reference value in the inspection time holding unit, and the reliability is improved. The degree-of-change calculation unit calculates the time series of the amount of change in reliability starting from each inspection time determined by the inspection interval reference value, and the inspection-timing validity determination unit calculates the period during which the amount of change in reliability exceeds the threshold value. If there is a time when the threshold value is exceeded, it is notified that the reliability is insufficient in the inspection plan.

According to a seventh aspect of the present invention, in the second to sixth aspects of the invention, when the reliability change amount calculation unit sets an entire facility including a plurality of inspection target components as an inspection target, The reliability change amount for each component is calculated from the reliability function according to the characteristics of the component, the reliability estimation parameter and the inspection result, and the product of the reliability change amount for each component is calculated as the reliability change amount for the entire equipment. When there is a time when the amount of change in the reliability of the entire equipment exceeds the threshold, the inspection timing validity determination unit outputs to the notification unit that the reliability is insufficient in the inspection plan. This is an inspection planning support device for plant equipment.

According to the invention of claim 7, in addition to the effects of the inventions of claims 2 to 6, the entire facility composed of a plurality of parts to be inspected is inspected The reliability change amount for each part is calculated from the reliability function and the reliability estimation parameter according to the characteristics of and the inspection result, and the product of the reliability change amount of each component is calculated as the reliability change amount of the entire equipment. When there is a time when the reliability change amount of the entire equipment exceeds the threshold value, the inspection timing validity determination unit reports that the reliability is insufficient in the inspection plan.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing the first embodiment of the present invention.

First, the reliability function holding unit 11 holds the reliability function R (t). Reliability function holding unit 11
Then, the changing process of the probability that the equipment targeted for the inspection plan operates normally with respect to the operating time t is held as the reliability function R (t). In the first embodiment, the accidental failure is targeted. That is, the failure rate λ (t) is set to a constant value λ. The value of λ is given from a slight experience in the past, and is defined here as a constant value, but it is not definitive and is a value that should be corrected from future inspection data. Here, R (t) of the following equation (3) is held as a reliability function.

R (t) = exp {-λt} (3) t: period from the start of plant operation to the scheduled decommissioning period. In this case, it is conceivable to adopt, for example, the following expression (4) as the reliability function.

[0033]

[Equation 3]

Next, the reliability estimation parameter holding unit 12 holds the reliability estimation parameter as the existence probability of the reliability function according to the Bayesian reliability analysis method. That is, the reliability estimation parameter is the likelihood that λ will be in the range of x ≦ λ ≦ x + dx, and can be expressed as the following equation (5).

Pr [x≤λ≤x + dx] (5) The probability density of the equation (5) does not yet reflect the actual results of future inspection results. When the equation (5) is described as the following equation (6), fλ0 (x) is called a prior density.

Pr [x ≦ λ ≦ x + dx] = fλ 0 (x) (6) In the first embodiment, the reliability estimation parameter holding unit 12 is a value indicating a constant density for the time being, as shown in FIG. Will be held at.

Next, the reliability function correction unit 13 uses the Bayesian reliability analysis method from the reliability estimation parameter of the prior density and the inspection data stored in the reliability estimation parameter storage unit 12 to calculate the reliability of the posterior density. The estimated parameter is calculated, and the reliability function corrected by reflecting the inspection data from the reliability estimated parameter of the posterior density is calculated.

First, in the reliability estimation parameter calculation means 14 of the reliability function modification unit 13, the inspection result is in an abnormal state with the reliability estimation parameter before inspection held in the reliability estimation parameter holding unit 12 as the prior density. Bayesian reliability analysis method is used to calculate the reliability estimation parameter of the posterior density from the number of the equipment and the equipment of normal vision, and the reliability estimation parameter stored in the reliability estimation parameter storage unit 12 is updated. . That is, the posterior density is calculated according to Bayes' theorem by reflecting the actual events that have occurred.
The posterior density is calculated by the following equation (7) assuming that the event E with λ as the condition occurs.

[0039]

[Equation 4]

In the first embodiment, an event E is considered in which the target equipment can be safely used until t = TI. In this case, the following expression (8) is established. By substituting the equation (8) into the equation (7), the equation (9) is obtained.

Pr [E | λ = x] = exp {−x · T1} (8) fλ1 (x) = T1 · exp {−T1 · x} (9) The calculation result by the equation (9) is relied on. Hold in the degree estimation parameter. The shapes of fλ0 (x) and fλ1 (x) are shown in FIG.
In the first embodiment, since the failure does not occur for a certain period of time, the numerical value in the region where the failure rate x is small is corrected to be higher in the posterior distribution fλ1 (x) than in the prior distribution fλ0 (x). .

Next, the reliability function calculating means 15 calculates the reliability function reflecting the inspection data from the reliability estimation parameter of the posterior density. Now, let p be the value calculated by the following equation (10).

[0043]

[Equation 5]

Since the larger λ is, the smaller the reliability is, the reliability R1 is calculated by using λp0 determined by the above equation (10).
When (t) is obtained, the equation (11) is obtained.

R1 (t) = exp {−λp0 · t} (11) Then, the probability that the true reliability R (t) is smaller than R1 (t) is determined as the following expression (12). Become.

Pr [R1 (t) ≧ R (t)] = Pr [λ ≧ λp0] = p (12) That is, the expression (12) indicates the reliability of the reliability in advance. Thus, the posterior λp1 with respect to λp0 in Eq. (10)
Becomes the equation (13) from the equation (9), and the lower limit R1 (t) of the reliability that becomes the equation (14) is determined.

Λp1 = −logp / T1 (13) R1 (t) = exp {(logp / T1) · t} (14) That is, the true reliability R (t) is not less than R1 (t). In particular, you will have a certainty of (1-p). This R1
The value (t) is held in the reliability function holding unit 11. Report department 1
At 6, the modified confidence function and confidence estimation parameters are reported.

In the first embodiment, the case where the failure does not occur for a fixed period is dealt with, but the same procedure can be applied to the following cases, for example. (1) When inspection data of other similar equipment can be used, if equation (3) is placed as equation (15), it can be handled similarly. ki is a parameter that takes into consideration the difference in shape or the like for each equipment. As a result, equation (8) becomes equation (16), and equation (7) becomes equation (17).

[0049]

[Equation 6]

That is, since T1 in the equation (8) is replaced by ΣTi, the operation history of one equipment and the operation history of some similar equipment may have the same effect. (2) When the actual results of damage can be used Consider the case where the data that any one of i = 1 to m in the formula (15) is actually damaged is obtained. Here, it is assumed that the equipment with i = 1 was damaged at t = T1, and the other equipment was safe until t = Ti (j = 2, 3, ..., M). In that case, equation (16) is changed to (1)
Since equation (8) is obtained, equation (17) becomes equation (19). If a uniform distribution is considered as the prior density, the equation (20) is obtained.

[0051]

[Equation 7]

The shapes of equations (20) and (17) are shown in comparison with FIG. Compared to the posterior distribution S11 of the equation (17) that reflects the result of no failure for a certain period of time, the posterior distribution S12 of the equation (20) that experienced a failure has a higher numerical value in a region where the failure rate x is large. . As in this example, equation (2
By the method of calculating the reliability using 0) as the reliability parameter, it becomes possible to reflect the data at the time of failure in the reliability.

As described above, according to the plant equipment inspection plan support apparatus in the first embodiment of the present invention, even when the data based on the inspection record is small in the new plant, it is possible to determine the subjectivity by experience in other plants. It is possible to support the inspection plan by holding the specific reliability function and reliability estimation parameter. Further, the accuracy can be successively improved by correcting the reliability function and the reliability estimation parameter as the actual data regarding the presence or absence of a failure due to inspection or the like is obtained. Further, it is possible to improve the accuracy by utilizing the data in the similar plant.

Next, a second embodiment of the present invention will be described. FIG. 5 is a block diagram showing the second embodiment of the present invention. The second embodiment differs from the first embodiment shown in FIG. 1 in that an inspection time holding unit 17 that holds an inspection time during the period of continuous operation of plant equipment,
For each inspection time, there is a reliability change amount calculation unit 18 that calculates the change amount of the reliability function after the inspection time in time series, and whether there is a period in which the numerical value of the reliability change amount exceeds the threshold value. If there is a time in which the threshold value is exceeded and the threshold value is exceeded, an inspection time validity determination unit 19 is additionally provided to notify that the reliability is insufficient in the inspection plan. This makes it possible to determine whether or not the numerical value of the reliability is equal to or higher than the threshold value at the scheduled inspection time. Since other configurations are the same as those of the first embodiment shown in FIG. 1, the same reference numerals are given to the same elements, and the description thereof will be omitted.

First, as in the case of the first embodiment,
Based on the inspection data, the reliability function R as shown in equation (11)
1 (t) is obtained. On the other hand, in the inspection time holding unit 17,
As shown in FIG. 6, the inspection time is maintained during the continuous operation of the equipment. Further, the reliability change amount calculation unit 18
Then, for each inspection time of the inspection time holding unit 17,
The change amount of the reliability function R1 (t) after the inspection time is calculated in time series.

FIG. 7 shows a calculation example in that case. As shown in FIG. 7, the reliability function R1 (t) after the inspection data is reflected
From the characteristic curve S1 of FIG. 3, the reliability change amount after each inspection time at the first inspection, the second inspection, and the third inspection after the start of operation is obtained. That is, the reliability change amount after the first inspection time is ΔR1, the reliability change amount after the second inspection time is ΔR2, and the reliability change amount after the third inspection time is ΔR3.

Next, the inspection timing validity judging section 19 judges whether or not there is a period in which the numerical value of the reliability change amount ΔR exceeds the threshold value ΔRr, and when there is a timing in which the threshold value ΔRr is exceeded. Outputs to the notification unit 16 that the reliability is insufficient in the inspection plan.

As described above, according to the plant equipment inspection plan support apparatus of the second embodiment of the present invention, not the reliability itself, but the reliability variation amount ΔR within the inspection period is determined. Since it is used as an index, it is possible to perform operations that restore the reliability by conducting inspections.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is an explanatory diagram of a reliability function stored in the reliability function storage unit 11 according to the third embodiment of the present invention. The third embodiment is the same as the first embodiment shown in FIG. 1 or the second embodiment shown in FIG. 5, when the plant equipment is replaced with new equipment, the reliability function holding is performed. The time axis of the reliability function R1 (t) held in the unit 11 is corrected so that the time of facility replacement is the time of starting operation.

In FIG. 8, it is assumed that the reliability function holding unit 11 holds the characteristic curve S11 as the reliability function R1 (t). The reliability change amount calculation unit 18 calculates the change amounts of the reliability function (characteristic curve S1) as ΔR1, ΔR2, and ΔR3 at each of the time points T1, T2, and T3 after the transportation of the plant according to the inspection plan.

Here, at time T3, the reliability function R1
It is assumed that the plant equipment has been replaced with new equipment due to a decrease in (t) or the like. In this case, in the third embodiment, the reliability function holding unit 11 stores the reliability function (characteristic curve S1 ′) with the time T3 as the operation start time.
After time T4, the updated reliability function (characteristic curve S1 ′) is used to calculate the reliability change amounts ΔR1 ′ and ΔR2 ′.

As described above, according to the plant equipment inspection plan support apparatus in the third embodiment of the present invention, the time axis of the reliability function is corrected so that the equipment replacement time becomes the operation start time. Therefore, it is possible to avoid an excessive inspection plan equivalent to that of the old facility and formulate an inspection plan that reflects the reliability of the new facility.

Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 9 is an explanatory diagram of the inspection timing determination function in the inspection timing validity determination unit 19 according to the fourth embodiment of the present invention. In the fourth embodiment, the inspection timing validity determining unit 19 of the second embodiment shown in FIG. 5 determines that the inspection execution timing is the time when the reliability change amount ΔR falls below a certain value. It is a plan to be prepared.

In FIG. 9, the characteristic curve S1 is the reliability function R1 (t) held by the reliability function holding unit 11,
In the inspection timing validity determination section 19, each inspection timing T is set so that the reliability change amount ΔR becomes equal to the threshold value ΔRr.
Calculate 1, T2, T3. That is, the reliability change amounts ΔR1, ΔR at the respective inspection times T1, T2, T3.
2. Make ΔR3 equal to the threshold value ΔRr. Inspection times T1 and T in the fourth embodiment
As a result, 2 and T3 become the longest inspection interval schedule, and the notification unit 16 outputs that effect and notifies the operator.

As described above, according to the plant equipment inspection plan support apparatus of the fourth embodiment of the present invention, the maximum inspection interval for which the reliability is guaranteed can be grasped, and the smooth inspection plan can be obtained. Can be considered.

Next explained is the fifth embodiment of the invention. FIG. 10 is an explanatory diagram of the inspection time determination function in the inspection time validity determination unit 19 according to the fifth embodiment of the present invention. In the fifth embodiment, the inspection interval maximum side limit value ΔTmax is set in advance so that the inspection time can be set within a certain period even when the reliability change amount ΔR is small in the fourth embodiment. The inspection interval is set so as not to exceed the maximum value ΔTmax for the inspection interval.

The inspection time holding unit 17 holds in advance the inspection interval maximum side limit value ΔTmax which means the maximum value of the interval between the inspection time and the next inspection time. ΔT in FIG.
max corresponds to the inspection interval maximum side limit value. In the case where the inspection timing validity determination unit 19 determines that the inspection timing calculated from the characteristic curve S1 of the reliability function R1 (t) and the threshold value ΔRr of the reliability change amount exceeds the inspection interval maximum side limit value ΔTmax. , Check interval, check interval maximum side limit value ΔTma
Correct to x. In the fifth embodiment, T1 in FIG. 10, which is the first inspection time, exceeds ΔTmax. Therefore, T1 is corrected to T1 ′ having the same value as ΔTmax. T2 and T3, which are the inspection time after the second time, are T
1'is regarded as the first inspection time and is calculated sequentially.

As described above, according to the plant equipment inspection plan support apparatus of the fifth embodiment of the present invention, the inspection time is set within a certain period even when the reliability change amount is small. Therefore, even when a cause of deterioration due to a sudden factor that cannot be predicted from the Bayesian reliability analysis method may occur, the inspection plan can be secured at the minimum cycle.

Next, a sixth embodiment of the present invention will be described. FIG. 11 is an explanatory diagram of the inspection timing validity determination function in the inspection timing validity determination unit 19 according to the sixth embodiment of the present invention. This sixth embodiment is similar to the second embodiment shown in FIG.
In the case where a regular inspection period is defined by the inspection timing validity determination unit 19 of the embodiment of the above, depending on whether or not the reliability change amount exceeds the threshold value when the inspection period is set to the length. The validity of the inspection period is evaluated.

The inspection time holding unit 17 holds the inspection interval reference value ΔTc in FIG. 11 in advance. This inspection interval reference value ΔTc is the only inspection interval reference value that determines the period between the inspection and the next inspection. Reliability change amount calculation unit 18
Then, the time series ΔR1, ΔR2, ΔR3 of the reliability change amount starting from each inspection time (T1, T2, T3 in the figure) determined by the inspection interval reference value ΔTc is calculated. In the inspection timing validity determination unit 19, the reliability change amounts ΔR1, ΔR2, ΔR3
Is compared with the threshold value ΔRr to determine whether or not there is a period in which the threshold value ΔRr is exceeded, and if there is a time in which the threshold value ΔRr is exceeded, the fact that the reliability is insufficient in the inspection plan is reported. .

As described above, according to the plant equipment inspection plan support apparatus of the sixth embodiment of the present invention, when the periodic inspection period is set, the reliability change amount is based on the reliability change amount. Therefore, the validity of the inspection period can be evaluated.

Next, a seventh embodiment of the present invention will be described. FIG. 12 is a functional explanatory diagram of the seventh embodiment of the present invention. In the case where an inspection plan is formulated from the change in reliability when the entire equipment including a plurality of inspection target parts is the inspection target. It is a thing.

The seventh embodiment is applied, for example, to the case where the pipes forming the pipeline are individually connected in series. In this case, if any of the pipes becomes defective, the entire pipe line will not function. Therefore, in the seventh embodiment, the product of the reliability of the individual pipes forming the pipeline is treated as the reliability of the entire pipeline.

In the reliability change amount calculating section 18, as shown by the characteristic curves S1, S2 and S3 in FIG. 12, the reliability of each component is calculated from the reliability function corresponding to the characteristic of the component, the reliability estimation parameter and the inspection result. Degree change amount ΔR11, ΔR12, ΔR
13 is calculated, and the product ΔR11 of the reliability change amount of each component is calculated.
-Calculate ΔR12 and ΔR13 as the reliability change amount ΔR of the entire equipment. When there is a time when the reliability change amount of the entire equipment exceeds the threshold value ΔRr, the inspection time validity determination unit 19 reports that the reliability is insufficient in the inspection plan.

As described above, according to the plant equipment inspection plan support apparatus in the seventh embodiment of the present invention, when the entire equipment including a plurality of inspection target parts is to be inspected, Also, it becomes possible to evaluate the validity of the inspection period based on the amount of change in reliability.

[0076]

As described above, according to the present invention, the inspection data of a huge amount of plant equipment constituting a plant is used as the subjective prediction information of the Bayesian reliability analysis method to reduce the reliability. Implement an inspection plan support device for plant equipment that supports the formulation of an inspection plan based on the above.

That is, by applying the Bayesian reliability analysis method, it becomes possible to make up for the lack of data by subjective prediction even when there is a small amount of data used as the material for determining the inspection time, and the inspection data It is possible to improve the analysis accuracy step by step with the accumulation of. Therefore, it is possible to properly support the inspection plan.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a prior density stored in a reliability estimation parameter storage unit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a prior density and a posterior density held in a reliability estimation parameter holding unit according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of posterior density reflecting the failure data held in the reliability estimation parameter holding unit in the first embodiment of the present invention.

FIG. 5 is a block configuration diagram showing a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of an inspection time held by an inspection time holding unit according to the second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a reliability change amount calculated by a reliability change amount calculation unit according to the second embodiment of the present invention.

FIG. 8 is an explanatory diagram of a reliability function stored in a reliability function storage unit according to the third embodiment of the present invention.

FIG. 9 is an explanatory diagram of an inspection time determination function in an inspection time validity determination unit according to the fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram of an inspection timing determination function in an inspection timing validity determination unit according to the fifth embodiment of the present invention.

FIG. 11 is an explanatory diagram of an inspection timing validity determining function in an inspection timing validity determining unit according to the sixth embodiment of the present invention.

FIG. 12 is an explanatory diagram of functions of the seventh embodiment of the present invention.

FIG. 13 is an explanatory diagram of an inspection time estimation method based on reliability intervals in the related art.

[Explanation of symbols]

11 Reliability function holding unit 12 Reliability estimation parameter storage unit 13 Reliability function modification unit 14 Reliability estimation parameter calculation means 15 Reliability function calculation means 16 Report Department 17 Inspection time holder 18 Reliability Change Calculation Unit 19 Inspection time validity judgment section

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-276470 (JP, A) JP-A-4-265425 (JP, A) Takafumi Fukuda 1 person, inspection using Kalman filter and Bayes theorem Surveillance technology, measurement and control, Japan, Japan Society for Instrument and Control Engineers, August 1996, Vol. 35, No. 8, p. 581-584 (58) Fields surveyed (Int.Cl. ⁷ , DB name) G05B 23 / 00-23 / 02

Claims (7)

(57) [Claims] 1. A reliability function holding unit that holds, as a reliability function, a changing process of a probability that a plant equipment to be inspected to be operated normally operates with respect to an operating time, and a reliability estimation parameter as an existence probability of the reliability function And a reliability estimation parameter holding unit for holding the reliability estimation parameter holding unit, and the reliability estimation parameter before inspection held in the reliability estimation parameter holding unit is a prior density, and the inspection result is the Bayesian The reliability estimation parameter calculation means for calculating the reliability estimation parameter of the posterior density using the reliability analysis method and updating the data held in the reliability estimation parameter holding part and the reliability estimation parameter calculation means The reliability function for calculating the corrected reliability function by reflecting the inspection data from the reliability estimation parameter of the posterior density An inspection plan support for plant equipment, comprising: a reliability function modifying unit including a calculating unit; and a reporting unit for reporting the reliability function and the reliability estimation parameter modified by the reliability function modifying unit. apparatus. 2. An inspection time holding unit for holding an inspection time over a period of continuous operation of the plant equipment, and a change amount of a reliability function after the inspection time for each inspection time is calculated in time series. The reliability change amount calculation unit determines whether or not there is a period in which the numerical value of the reliability change amount exceeds the threshold value, and if there is a time period in which the threshold value is exceeded, the reliability in the inspection plan is The inspection plan support apparatus for plant equipment according to claim 1, further comprising: an inspection timing validity determination unit that outputs a notification to the notification unit that there is a shortage. 3. The reliability function stored in the reliability function storage unit is modified so that, when the plant equipment is replaced with new equipment, the time axis of the equipment is replaced with the equipment replacement time. The inspection plan support apparatus for plant equipment according to claim 1 or 2, wherein the inspection plan support apparatus is provided. 4. The inspection timing validity determining unit calculates each inspection timing so that the reliability change amount becomes equal to a threshold value, and reports the inspection timing as a longest inspection interval schedule. Claim 2 or Claim 3 characterized by
Inspection planning support device for plant equipment described in. 5. The inspection time holding unit holds in advance the maximum value of the interval between the inspection time and the next inspection time as the inspection interval maximum side limit value, and the inspection time validity judging unit calculates The inspection plan support for plant equipment according to claim 4, wherein the inspection timing is corrected to the maximum inspection interval side limit value when the inspection time exceeds the inspection interval maximum side limit value. apparatus. 6. The inspection time retention unit retains an inspection interval reference value that predetermines a period between an inspection and the next inspection, and the reliability change amount calculation unit determines each inspection determined by the inspection interval reference value. The time series of the reliability change amount calculated from the time point is calculated, and the inspection timing validity determination unit determines whether or not there is a period in which the reliability change amount exceeds the threshold value and determines when the threshold value is exceeded. 5. The inspection plan support apparatus for plant equipment according to claim 2 or 4, wherein when there is such a problem, the fact that the reliability is insufficient in the inspection plan is output to the notification unit. 7. The reliability change amount calculation unit, when the entire equipment including a plurality of inspection target parts is an inspection target, the reliability function and the reliability estimation according to the characteristics of the component parts. The reliability change amount of each component is calculated from the parameters and the inspection result, and the product of the reliability change amount of each component is calculated as the reliability change amount of the entire equipment. 7. When there is a time when the amount of change in the overall reliability exceeds the threshold value, the fact that the reliability is insufficient in the inspection plan is output to the notification unit. Inspection planning support device for the described plant equipment.