JP2008293106A - Maintenance plan making method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily calculate a value as the scale of a damage or defect probability (lifetime consumption rate) by operating digitization and weighting processing in performing an RBM method. <P>SOLUTION: This is a method for making a maintenance plan by operating the risk assessment of equipment with the matrix of the scale and defect probability of a damage. This method includes operating the hierarchization and sub-dividing processing of the factor of the scale of the damage, and operating weighting and digitization processing by comparing a pair of the sub-division factors in each hierarchy, and calculating the scale of the damage by operating the addition processing of the scale of the damage of individual apparatus whose digitization processing has been operated. Then, this method includes setting the shortest lifetime and longest lifetime of each apparatus, and specifying the likelihood of the occurrence of the damage as a primary formula with respect to the years of use, and extracting items affecting the lifetime of each apparatus, and operating weighting and digitization processing by comparing a pair of the extracted items, and operating the selection processing of the extracted items under the apparatus use conditions of each extracted item, and setting and deciding the inclination of the individual lifetime line of each apparatus between the longest and shortest lifetime lines. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plan for efficiently performing maintenance of facility equipment. For example, the present invention relates to a maintenance plan planning method suitable for efficiently performing maintenance of air conditioning equipment in a nuclear power plant.

  A method called RBM (Risk Based Maintenance) is known for maintenance of plants and equipment. This is to evaluate the “risk” from the magnitude of damage when a failure occurs and the likelihood of the failure (damage probability or lifetime consumption rate), and to manage the plant and equipment according to the magnitude. To do. As shown in FIG. 9, for example, the horizontal axis indicates the magnitude of damage as “small”, “medium”, “large”, and “serious”, and the vertical axis indicates the damage probability (lifetime consumption rate) as “fine” and “ Set low, medium, and high. On the resulting matrix, a table is created in which “I”, “II”, “III”, and “IV” are evaluated in order from the smallest risk. For each facility device, the magnitude of damage and the probability of damage are obtained and risk assessment is performed, and maintenance is started from a device with a high risk (Patent Document 1). In the above RBM method, in order to manage the risk of the target device, values such as the magnitude of damage and damage probability must be set. For this evaluation, general evaluation factors as shown in FIG. 10 are used. Do it. If the evaluation item is the magnitude of damage, factors such as impact on environmental pollution, explosive poisons, personal injury and economic loss are factors, and the first two are based on the material characteristics and the amount of leakage. This will be determined as an evaluation factor. In the case of personal injury, the degree of injury and the number of people, and in the case of economic loss, the stoppage period and repair costs of the plant and equipment are the evaluation factors.

On the other hand, the damage probability on the vertical axis is an evaluation factor based on the service life or years of use of each device. As a method for obtaining this, there is a method of confirming the degree of damage by measuring the wall thickness by inspection and predicting the lifetime consumption rate (Patent Document 2). However, inspections are not so frequently performed on static equipment (eg, ducts, dampers, etc.) among air conditioning equipment. One of the reasons is that there is no simple and quantitative inspection method. Furthermore, there is a method of obtaining the probability by taking statistics of failure of the same model that has been shipped so far, without directly inspecting (Patent Document 3). However, this makes it impossible to evaluate the characteristics of individual devices. Since the usage environment is not the same, in a nuclear power plant, it is impossible to correctly determine the lifetime consumption rate of equipment.
JP 2005-122525 A JP 2003-302021 A JP 2003-182465 A

  However, even if risk management is attempted using the above-described evaluation factors, the concept of the general evaluation factor shown in FIG. 9 is an abstract and wide group. However, there was a disadvantage that there was no individual specificity and it was difficult to determine the magnitude of the damage. In addition, since the experience value of the field manager is not incorporated in the evaluation factor, the experience value cannot be used, and there is a problem that the risk management is not integrated with the field knowledge. In addition, in the case of damage probability, equipment equipment, etc., checks the degree of damage and predicts the lifetime consumption rate. Among air conditioning equipment, static equipment (eg, ducts, dampers, etc.) However, since simple and quantitative inspection cannot be performed, it is difficult to predict the lifetime consumption rate. In addition, there is a method for obtaining the damage probability by taking the statistics of the failure of the same type of equipment shipped so far, but it is not possible to evaluate the characteristics in the individual use environment. Therefore, there is a problem that the RBM method cannot be used properly because the life consumption rate cannot be determined especially in the air conditioner of a nuclear power plant.

  The present invention pays attention to the above-mentioned conventional problems, and when performing the RBM method, values such as the magnitude of damage and damage probability (lifetime consumption rate) are numerically processed and weighted so that they can be easily determined. The purpose is to provide a maintenance planning method.

  In order to achieve the above object, a maintenance plan planning method according to the present invention is a method for planning a maintenance plan by evaluating a risk of equipment with a matrix of damage magnitude and damage probability, The factors are hierarchized into subdivisions, and a paired comparison of the subdivision factors in each layer is performed, weighted and digitized, and the amount of damage is added to each digitized individual device. It is characterized by determining the magnitude of damage.

  The maintenance planning method according to the present invention is a method for making a maintenance plan by evaluating the risk of equipment with a matrix of damage magnitude and damage probability, and setting the shortest life and the longest life of each device. In addition to prescribing the likelihood of damage as a linear expression for the years of service, extract items that affect the life of each device, perform weighting by paired comparison for each extracted item, and perform numerical processing. The extraction item is selected according to device usage conditions, and the inclination of the individual life line of each device is set between the longest and shortest life lines to make a determination.

  Further, the present invention is a method of making a maintenance plan by evaluating the risk of equipment with a matrix of damage magnitude and damage probability, and subdividing the damage factor into a hierarchical process, A pairwise comparison of subdivision factors in each hierarchy is performed, weighted and digitized, and the magnitude of damage is determined by adding the magnitude of damage for each digitized individual device. Set the shortest life and the longest life of the equipment, specify the probability of damage as a primary expression for the years of use, extract the items that affect the life of each equipment, and weight the values by paired comparison for each extracted item In addition, the extraction item is selected and processed according to the device usage conditions of each extraction item, and the slope of the individual life line of each device is set between the longest and shortest life lines to make a determination. It is made as.

  According to the above configuration, the factor that determines the magnitude of damage is divided into layers and subdivided, and the work that is weighted by pairwise comparison of the factors in each layer is performed to the minimum subdivision unit, thereby Knowledge can be gathered and maintenance can be performed by making the most of the opinions of the site. In addition, regarding the probability of damage (lifetime consumption rate), the inclination of each line of the longest life and the shortest life is obtained for each of the equipments, the influence factors on the life are determined, and similarly, a pair comparison is made and weighted. Since the extracted items are selected by integrating the components from “0” to “1” depending on the usage environment, risk determination according to the usage environment of the device can be performed. By calculating the damage magnitude and damage probability as described above, in the present invention, when performing the RBM method, values such as damage magnitude and damage probability (lifetime consumption rate) are numerically processed and weighted. The effect that it can be easily determined.

  Hereinafter, specific embodiments of a maintenance planning method according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a method for quantifying the magnitude of damage in an RBM to which a maintenance planning method according to an embodiment is applied. This is to be applied to a maintenance plan for air conditioning equipment in a nuclear power plant.

  This embodiment is a method for drafting a maintenance plan for an air conditioner equipment in a nuclear power plant using an RBM method that performs risk assessment of the equipment with a matrix of damage magnitude and damage probability. The size factor is hierarchized into subdivisions, paired comparisons of subdivision factors in each hierarchy are performed, weighted and digitized, and the amount of damage is added to each digitized device The amount of damage is determined by processing.

For this reason, a factor 10 for determining the magnitude of damage is listed in the highest hierarchy, and a numerical value of the maximum value “1.00” is given thereto. This is to make it easier to display the percentage of each factor hierarchized as a range of maximum one. In the second tier, the magnitude of damage is divided into repair costs 12 and equipment failure-caused damage 14. Since the repair cost 12 is a substantial amount, it cannot be further subdivided. On the other hand, the damage due to equipment failure 14 can be subdivided into a system 16, a model 18, and a stop period 20, such as what model of which system it is and how long the stop period is. This is the third layering process. Next, the system 16 is subdivided into A system 16 ₁ , B system 16 ₂ , C system 16 ₃ , D system,. The fourth hierarchy. Similarly, the model 18 is subdivided into minimum parts such as a damper 18 ₁ , an isolation valve 18 ₂ , and a coil 18 ₃ . Then, weighting is performed by making a pairwise comparison between the segmentation factors in each layer.

  As shown in FIG. 2, when the items to be compared are distributed between the system 16, the model 18, and the stop period 20, as shown in FIG. 2, in the comparison between the system 16 and the model 18, for example, “system is important ”,“ Somewhat system is important ”,“ Both are equally important ”,“ Somewhat model is important ”,“ Model is important ”. If it is determined that the system has five times the weight of the model, it is determined. In this example, the determination is made as a five-level evaluation, but various evaluations can be set in this evaluation stage. For example, there are a four-level evaluation and a six-level evaluation. Thus, based on the stage evaluation according to importance, each subdivision factor is compared with each other and weighted numerical values are given as shown in FIG. In this table, comparison targets are arranged in the horizontal direction. For example, “system” at the top of the column is equivalent to “1” for the same “system” in the row direction, “1” for the model, and “5” times the weight when the model is “1”. However, if the stop period is “1”, it is determined that there is a weight “5” times. This may be determined based on the opinions of field workers. As a result, on-site knowledge is collected into weighted numerical values. After weighting in this way, the geometric average of each subdivision factor is obtained. In the case of the system, the geometrical average is 3√ (1 × 5 × 5) = 2. Because the system is 1 for the pair “system”, 5 for the pair “model”, and 5 for the pair “stop period”. Similarly, the geometrical average value of the model and the stop period is 1.30. The weight of the system is (2.92) / (2.92 + 1.30 + 1.30) = 0.53. Based on this weight, the upper layer weight is allocated.

In the embodiment, the weight of the damage due to equipment failure 14 in the two layers and the repair cost 12 is an example in which the former is 5/6 = 0.83 and the latter is 1/6 = 0.17 as a six-level evaluation. Show. The system 16, model 18, and stop period 20 which are factors that subdivide the equipment failure-caused damage 14 are 53% (0.53) and 24% (0) of 0.83, respectively, based on the weight values described above. .24), 24% (0.24), the weight of system 16 is 0.44, the weight of model 18 is 0.20, and the weight of stop period 20 is 0.20. In the same manner, A system 16 ₁ , B system 16 ₂ , C system 16 ₃ , etc., which are factors that subdivide system 16, and damper 18 ₁ , isolation valve 18 ₂ , coil 18 ₃ that subdivides model 18. ... etc. are also prioritized by paired comparison, and weighted numerical values for each subdivision factor are obtained.

但し、Ｈは被害の大きさ、Ｐ_Ｕは系統ウェイト、Ｕは対象機器の系統ポイント、Ｕ_maxは最重要系統ポイント、Ｐ_Ｓは機種ウェイト、Ｓは対象機器の機種ポイント、Ｓ_maxは最重要機種ポイント、Ｐ_Ｋは停止期間ウェイト、Ｋは停止期間（日）、Ｋ_maxは最大停止期間、Ｐ_Ｃは修理費用ウェイト、Ｃは修理費用（Ｍ￥）、Ｃ_maxは最大修理費用（Ｍ￥）である。 In this way, evaluation factors that determine the magnitude of damage are hierarchized and subdivided, each factor is weighted and digitized, and then the weight of each factor is used as a coefficient to determine the damage magnitude. The height H is obtained by the following equation.

However, H is the magnitude of the damage, P _U is system weight, U is the system point of the target device, U _max is the most important system point, P _S the model weight, S is the model point of the target device, S _max is the most important model point, _{P K} stop period weights, K is the stop period (day), K _max is the maximum suspension period, _{P C} repair cost weights, C is the repair cost (M ¥), C _max is the maximum repair cost (M ¥ ).

  Therefore, the damage magnitude position on the RBM can be easily set by obtaining the damage magnitude H based on the mathematical formula 1 for each subdivided equipment component device.

  In this way, the factor 10 that determines the magnitude of damage is hierarchized to subdivide it to such a level that it cannot be further subdivided, and a pairwise comparison of the factors in each layer is weighted by the experience value of the field worker By performing up to the smallest subdivision unit, it is possible to consolidate on-site work knowledge. Therefore, it is possible to perform maintenance of the air conditioning equipment of the nuclear power plant based on the risk assessment that makes the best use of the opinions of the site.

  Next, means for quantifying the damage probability (lifetime consumption rate), which is the other axis of the RBM that makes a maintenance plan for nuclear plant equipment, is performed as follows. In other words, the shortest life and the longest life of each device are set to specify the likelihood of damage as a linear expression with respect to the number of years of use, and items that affect the life of each device are extracted and weighted by pairwise comparison for each extracted item The extraction items are selected and processed according to the device usage conditions of each extraction item, and the inclination of the individual life line of each device is set between the longest and shortest life lines for determination. ing.

  Specifically, for each facility device, first, the design life of the device is set as the longest life. In addition, the breakage life of the device actually used is set as the shortest life. For example, in the case of the damper shown in FIG. 4, the design life is set to 15 years, but the shortest life of the damper actually used is 7 years. Until the breakage, minor damage, low-level damage, medium-level damage, and high-level damage are passed. If this is the vertical axis and the horizontal axis is the number of years, it starts from “0” year when the service started. Thus, using the upper end of the vertical axis as the damaged area, a linear expression with 15 years and 7 years at the top can be drawn. As a result, the longest life line (minimum slope α) as a primary expression up to 15 years of the longest life year is obtained, and similarly, the shortest life line (maximum slope β) up to 7 years of the shortest life year is obtained. The target damper is defined as falling within this range.

  Next, the determinants of the degradation rate of the equipment are determined from the viewpoint of equipment factors and prevention measures. For example, the damper is mounted in the air path and has functions such as air volume adjustment and backflow prevention. The impact items that cause the breakage include, for example, “corrosive environment (a1)”, “material improvement (a2)”, “high air volume (a3)”, “strength improvement (a4)”, “damper with current plate (a5) ) "Or the like. Then, a pairwise comparison is made as to which of these items is important, and finally, weighting is performed to perform numerical processing. The total value of all items is “1”. This chart is shown in FIG.

  For these factors, for example, b1 = 1 is set if it is installed in an environment that directly contacts outside air with respect to the corrosive environment of a1, and b1 = 0 is set otherwise. Next, with respect to material improvement, b2 = 0 is set when the material is improved, and b2 = 1 is set when the material is not improved.

これにより、図４中に該当ダンパの寿命線を描くことができ、現時点の年数から損傷の起こり易さを数値表現できる。 Similarly, for each factor, “0” is set for an evaluation that extends the life, and “1” is set for an evaluation that shortens the life, and processing based on the following equation is performed.

Thereby, the life line of the corresponding damper can be drawn in FIG. 4, and the ease of damage can be expressed numerically from the current number of years.

このようにして原子力プラントの空調設備機器の各々について求めた寿命線を設定することができる。損傷の起こり易さを０〜１の範囲に割り振ることで、全ての機器について同じ評価をすることができる。したがって、使用年数に応じた損傷の起こり易さを数値として求めることができる。 The case of a duct is shown in FIGS. This is obtained in the same manner as for the damper. The slope γ of the design life line (longest life line) is minimum, and the actual shortest life line is a linear expression having the maximum slope θ. When the pair of life influence factors are compared in the same manner as in the case of the damper and weighted, the result is as shown in FIG. 7 (c1 to c4). Similarly, dn = 0 is given for the usage environment above the permissible value, and dn = 1 is given below the permissible value. The extraction item is selected according to the equipment usage conditions of each extraction item, and the duct inclination is determined based on the following equation. After the setting, the inclination of the individual life line of the duct is set between the longest and shortest life lines to make a determination.

In this way, it is possible to set the life line obtained for each of the air conditioning equipment of the nuclear power plant. By assigning the likelihood of damage to a range of 0 to 1, the same evaluation can be made for all devices. Therefore, it is possible to obtain the ease of damage according to the years of use as a numerical value.

  In this way, the damage magnitude and the probability of damage (lifetime consumption rate) as the likelihood of damage can be determined for each device as numerical values, and should be described as a risk assessment for each device in the RBM chart. Can do. This is shown in FIG. 8 as an example. Note that the remaining life on the vertical axis in FIG. 8 is the opposite of the life consumption rate and is an index indicating the remaining life. In this RBM table, the damage probability is changed to the life consumption rate. As a result, risk determination according to the usage environment of the device can be easily performed by performing specific numerical processing.

  It can be used for maintenance of plant equipment.

It is explanatory drawing of the hierarchization process of the maintenance plan planning method which concerns on embodiment of this invention. It is explanatory drawing of the pair comparison of the fragmentation factor of the magnitude | size of damage of an apparatus. It is explanatory drawing of the process of calculating the weight of the fragmentation factor of the magnitude | size of the damage of an apparatus. It is explanatory drawing of the lifetime diagram of a damper. It is a weight processing table of the lifetime influence item of the damper. It is explanatory drawing of the lifetime diagram of a duct. It is a weight processing table of the lifetime influence item of a duct. It is a RBM table concerning an embodiment. It is a conceptual diagram of RBM. It is an example of the evaluation factor of RBM.

Explanation of symbols

10 ......... Factors that determine the magnitude of damage, 12 ... Repair costs, 14 ... Damage caused by equipment failure, 16 ... System, 18 ... Model, 20 ... Stop period.

Claims (3)

  It is a method of making a maintenance plan by evaluating the risk of equipment with a matrix of damage magnitude and damage probability, and subdividing the damage severity factors into hierarchies, and subdividing factors within each hierarchy A maintenance planning method characterized in that a pairwise comparison is performed, a weighting process is performed, a numerical process is performed, and a damage level is calculated by adding a damage level to each of the numerically processed individual devices.   This is a method of making a maintenance plan by assessing the risk of equipment with a matrix of damage magnitude and damage probability, and setting the shortest life and longest life of each equipment, and the likelihood of damage as a primary expression for the years of use In addition to extracting the items that affect the life of each device, performing a quantification process by weighting by paired comparison for each extracted item, selecting the extracted item according to the device usage conditions of each extracted item, A maintenance planning method characterized in that determination is made by setting an inclination of an individual life line of each device between the longest and shortest life lines. It is a method of making a maintenance plan by evaluating the risk of equipment with a matrix of damage magnitude and damage probability,
The damage factor is hierarchized into subdivisions, and a paired comparison of subdivision factors in each hierarchy is made and weighted to quantify the damage. By calculating the amount of damage,
Set the shortest life and the longest life of each device to define the likelihood of damage as a primary expression for the years of use, extract items that affect the life of each device, and give weights by pairwise comparison for each extracted item In addition, the extraction item is selected and processed according to the device usage conditions of each extraction item, and the inclination of the individual life line of each device is set between the longest and shortest life lines to make a determination.
A maintenance planning method characterized by that.

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