JP6980034B2 - Device life evaluation method - Google Patents

Description

The present invention relates to a device life evaluation method for evaluating a device life for each model of plant equipment, a device life evaluation device, and a device life evaluation program.

As one of the methods for evaluating the quality and reliability of industrial products, there is a method for evaluating the product life. If the product life, that is, the expected period from the start of operation of a certain product to the failure, is known, for example, it can be used by the user of the product when formulating a maintenance plan, or the product can be used. It can be used by the supplier as an index to evaluate the performance of the product.

As a method for evaluating the product life, for example, Japanese Patent Application Laid-Open No. 2008-234572 (Patent Document 1) sets the number of days from the purchase date to the failure date of a product sold through a retail store as the product life. It discloses a technology for estimating the number of products in operation and the life of a product based on the manufacturing data and claim data owned by the manufacturer. This technology solves the problem that it is difficult to specify the start time of operation for consumer products by estimating the start time of operation based on the purchase date information collected at the complaint reception base.

Further, Japanese Patent Application Laid-Open No. 2009-266029 (Patent Document 2) is based on the information of the replacement work including such a case even when the failed component causing the failure of the device is not specified. It discloses a technique for generating a survival curve used for calculating a failure probability. In this technique, in the conventional technique, it is necessary to identify the part that caused the failure in order to generate the survival curve, but it has succeeded in eliminating the necessity.

Japanese Patent Application Laid-Open No. 2008-234572 Japanese Patent Application Laid-Open No. 2009-266029

Here, since the technique of Patent Document 1 is based on the premise that the complaint receiving base is contacted when a failure occurs, the information is collected only when the device falls into an abnormal state. Similarly, the technique of Patent Document 2 also generates a survival curve based on a record of maintenance work performed on a device in which a failure has occurred, and information is collected only when the device falls into an abnormal state. It can be said that it is a thing. As a result, the quality and quantity of information collected to assess device life may be inadequate.

On the other hand, plant equipment used in a plant (for example, a steam trap used in a steam plant) is generally inspected regularly by a manager or a supplier who has expertise. That is, since the plant equipment is inspected regardless of whether or not a failure has occurred, it is possible to obtain information not only about the equipment in an abnormal state but also about the equipment in a normal state.

Therefore, it is required to realize a highly accurate evaluation method of equipment life by utilizing inspections performed on plant equipment.

The device life evaluation method according to the present invention is a device life evaluation method for evaluating the device life of each model of plant equipment, and inspects a plurality of plant devices of the evaluation target model that are operating in the plant. , A diagnostic process for diagnosing whether the operating state of the plant equipment is in a normal state or an abnormal state for each of the plurality of plant equipments based on the results of the inspection, and each of the plurality of plant equipments. With respect to, operation start information regarding the start of operation when the plant equipment starts operation in the plant, inspection timing information regarding the inspection time when the inspection is performed on the plant equipment in the diagnosis process, and In the storage step of accumulating the operating state information regarding the operating state diagnosed in the diagnostic step in the storage device, the operating start information stored in the storage step, the inspection time information, and the operating state information. based on the evaluation possess a calculating step of calculating the target model of the device life, and the diagnosis process is executed multiple times, the interval of the diagnosis process to each other to be executed multiple times, diagnosis a predetermined cycle It is characterized by being within.

According to these configurations, it is possible to realize a highly accurate device life evaluation method by utilizing the inspection performed on the plant equipment. In addition, since inspections and diagnoses are performed on a regular basis, the quality and quantity of information collected is improved, and it is easy to calculate the life of the device with higher accuracy.

Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiments described below.

The device life evaluation method according to the present invention is, as one aspect, calculated in the device life evaluation step of calculating the device life for each of a plurality of evaluation target models and the device life evaluation step by the above-mentioned device life evaluation method. It is preferable to include a comparison step of comparing the device life of each of the plurality of evaluation target models.

According to this configuration, the difference in device life between different models can be appropriately compared and evaluated based on an objective standard.

As one aspect of the device life evaluation method according to the present invention, the survival rate curve of the evaluation target model is calculated in the calculation step, and the horizontal axis of the survival rate curve is the elapsed time from the start of operation. The vertical axis of the survival rate curve is the survival rate representing the ratio of the plant equipment of the evaluation target model that operates in a normal state after the elapsed time has elapsed, and the device life of the evaluation target model is the survival rate curve. It is preferable that the elapsed time is such that the survival rate becomes a predetermined threshold value.

According to this configuration, a highly accurate survival rate curve can be calculated based on the results of inspection and diagnosis of plant equipment. Further, by setting a threshold value suitable for the evaluation purpose, it is possible to calculate the device life according to the purpose.

As one aspect of the device life evaluation method according to the present invention, it is preferable that the survival rate curve is calculated by the Kaplan-Meier method.

According to this configuration, a highly accurate survival rate curve can be calculated by the Kaplan-Meier method, which has abundant application results in the field of survival time analysis method.

As one aspect of the device life evaluation method according to the present invention, the diagnosis cycle is preferably one year or less.

According to this configuration, the device life can be calculated in units of one year or less, so that the calculated device life can be easily used for making a maintenance plan and evaluating the device performance.

As one aspect of the device life evaluation method according to the present invention, it is preferable that the device life can be calculated for each usage condition in which the plant equipment is used.

According to this configuration, it is easy to objectively evaluate the influence of the usage conditions on the life of the device.

Device life evaluation method according to the present invention, as one aspect, the plant equipment, there is the fluid to be handled by the plant therein flows, the conditions of use, the plant equipment applications definitive in the plant , And a fluid physical quantity, which is a physical quantity related to the fluid flowing through the plant equipment, is preferably included.

According to this configuration, it is easy to objectively evaluate the application of the plant equipment and the influence of the temperature, pressure, flow rate, etc. of the fluid flowing through the plant equipment on the life of the equipment.

As one aspect of the device life evaluation method according to the present invention, in the diagnostic step, an inspector visually inspects each of the at least a part of the plant equipment in the inspection of at least a part of the plurality of plant equipment. It is preferable that this is done including.

According to this configuration, the device life can be calculated based on the diagnosis reflecting the result of the accurate visual inspection.

As one aspect of the device life evaluation method according to the present invention, in the diagnosis step, inspection and diagnosis of at least a part of the plurality of plant equipment are detected in advance in each of the at least a part of the plant equipment. It is preferably performed based on the physical quantity of the device, which is the physical quantity detected by the device.

According to this configuration, the device life can be calculated based on the diagnosis reflecting the result of the inspection constantly performed by the detector provided in advance.

As one aspect of the device life evaluation method according to the present invention, in the diagnostic step, when the detector detects a physical quantity of the device that deviates from a predetermined standard range, the plant device provided with the detector is provided. However, the inspector visually inspects the primary diagnosis step for diagnosing the state requiring attention that may be in an abnormal state and the plant equipment diagnosed as being in the state requiring attention in the primary diagnosis step. It is preferable to have a secondary diagnosis step for diagnosing whether the plant equipment is in a normal state or an abnormal state based on the result of the visual inspection.

According to this configuration, it is possible to limit the number of plant equipment that executes the secondary diagnosis step of performing the visual inspection by the inspector, so that it is easy to reduce the man-hours, costs, time, etc. required for calculating the life of the equipment.

As one aspect of the device life evaluation method according to the present invention, when the plant equipment is diagnosed as being in an abnormal state in the secondary diagnosis step, the inspection is accumulated as the inspection timing information in the accumulation step. The time is preferably when the primary diagnostic step is performed.

According to this configuration, since the abnormality is treated as having occurred retroactively when the primary diagnosis step is executed, the accuracy of identifying the time when the abnormality has occurred is improved, and the accuracy of the calculated device life is improved. Cheap.

Further features and advantages of the invention will be further clarified by the following illustration of exemplary and non-limiting embodiments described with reference to the drawings.

Schematic diagram showing a configuration example of the present invention Block diagram showing a configuration example of the present invention Example of survival rate curve according to the present invention Example of survival rate curve for each model according to the present invention Example of survival rate curve for each working pressure according to the present invention Example of survival rate curve for each installation pressure according to the present invention

The device life evaluation method, the device life evaluation device, and the embodiment of the device life evaluation program according to the present invention will be described with reference to the drawings. In the following, the steam trap 1 (an example of plant equipment) operating in a steam plant P (an example of a plant) that uses steam (an example of a fluid) such as a petroleum chemical plant or a thermal power plant will be described in the present embodiment. An example of evaluating the device life of each model of the steam trap 1 by the device life evaluation method according to the present embodiment will be described using the device life evaluation device 10.

Considering the entire steam system such as the steam plant P as one of the important assets, the device life evaluation method, the device life evaluation device, and the device life evaluation program according to the present embodiment are one of the asset management methods. It is applicable as one.

[Device configuration and system configuration]
First, the device life evaluation device 10 according to the present embodiment and the steam trap 1 for which the device life is evaluated using the device life evaluation device 10 will be described. As shown in FIG. 1, in the present embodiment, there are a plurality of steam plants P, and a plurality of steam traps 1 are operating in each steam plant P.

The steam plant P according to the present embodiment includes a turbine, a compressor, a heat exchanger, etc., that is, equipment driven by kinetic energy extracted from steam, equipment that consumes heat energy of steam to heat an object, and the like. Steam utilization equipment that operates by consuming the energy of steam, transportation pipes that transport steam to steam utilization equipment, drain pipes that discharge drain generated from steam utilization equipment, and steam installed in the piping system. It has components such as a trap 1, a control valve, a pump, a filter, a process device such as a separator, a water supply tank, a deaerator, and a steam supply device such as a boiler.

Steam flows through each of these components, and various conditions such as the temperature, pressure, and flow rate of the steam are diverse. Therefore, the conditions for using the steam trap 1 are the site where the steam trap 1 is used in the steam plant P, the purpose for which the steam trap 1 is used, and the temperature, pressure, and amount of steam flowing through the steam plant. , Etc., are specified for each steam trap 1. Here, as the steam trap 1, a model suitable for the usage conditions is selected and installed from a plurality of models distributed on the market.

The device life evaluation device 10 according to the present embodiment includes a portable detector 2 and an arithmetic unit 3 (FIG. 2). The portable detector 2 is configured to be portable by an inspector, and has a detection unit 2a capable of detecting a trap physical quantity (an example of a physical quantity of equipment) which is a physical quantity related to the steam trap 1, and various information by the inspector. Includes an input unit 2b capable of inputting data, and a display unit 2c capable of displaying information necessary for an inspector to perform an inspection.

The arithmetic unit 3 is configured to be able to communicate with the portable detector 2 through the network 4, and receives various information transmitted from the portable detector 2. The arithmetic unit 3 includes a storage unit 3a (an example of a storage device) capable of storing such information, and an arithmetic unit 3b capable of performing various operations based on the information.

[Device life evaluation method]
Next, the device life evaluation method according to the present embodiment, which is performed using the device life evaluation device 10, will be described. The device life evaluation method according to the present embodiment includes a diagnosis step, a storage step, and a calculation step.

(1) Diagnostic step The diagnostic step includes an inspection of the steam trap 1 by an inspector and a diagnosis of the operating state of the steam trap 1 by the inspector. Specifically, the inspector detects the trap physical quantity using the detection unit 2a of the portable detector 2 for each of the plurality of steam traps 1 operating in the steam plant P. The detected trap physical quantity is displayed on the display unit 2c, and the inspector can confirm this sequentially during the inspection work.

Examples of the trap physical quantity detected here include vibration and temperature. If the detected vibration exceeds a predetermined threshold value, it is suspected that steam leakage has occurred in the steam trap 1. If the detected temperature is below a predetermined threshold value, it is suspected that the steam trap 1 is clogged.
In addition to detecting these trap physical quantities, the inspector also performs a visual inspection.

By integrating the detection result of the trap physical quantity and the result of the visual inspection in the above inspection, the inspector diagnoses whether the operating state of each steam trap 1 is a normal state or an abnormal state.

Such a series of diagnostic steps is periodically executed at predetermined diagnostic cycles. In the present embodiment, the diagnosis cycle is one year, and the next diagnosis step is executed within a period not exceeding one year from the execution of the previous diagnosis step.

(2) Accumulation process In the accumulation process, information necessary for evaluating the life of the device is accumulated. First, the inspector first, for each of the plurality of steam traps 1 operating in the steam plant P, as basic information of the steam trap 1, identification information (ID) for identifying the steam trap 1 and a model name of the steam trap 1. , The start of operation when the steam trap starts operation, the part where the steam trap 1 is used in the steam plant P, the purpose for which the steam trap 1 is used, and the physical amount of steam flowing through the steam plant. Information including the vapor physical quantity (an example of the fluid physical quantity) is input to the input unit 2b. The steam physical quantity is, for example, temperature, pressure, distribution amount, and the like. Here, the input of these basic information is omitted if there is no change in the basic information from the previous storage step in the second and subsequent storage steps for the steam trap 1. The basic information input to the input unit 2b is transmitted to the arithmetic unit 3 via the network 4 and stored in the storage unit 3a.

Next, the inspector inputs to the input unit 2b the operating state information regarding the operating state of the steam trap 1 diagnosed in the diagnosis step, that is, whether the operating state of the steam trap 1 is a normal state or an abnormal state. .. The operating status information input to the input unit 2b is transmitted to the arithmetic unit 3 via the network 4 together with the inspection timing information regarding the inspection timing when the inspection on which the operating status information is based is performed, and is stored. It is accumulated in the part 3a.

Table 1 illustrates a part of the information stored in the storage unit 3a in the above storage step. As shown in Table 1, it is stored in the storage unit 3a that the steam traps A to H are model a and the steam traps I to L are model b. Further, for all steam traps, the operation start period (year) and the operation state information in the diagnostic process carried out every year from 2011 to 2017 are stored in the storage unit 3a. In the column of operating status information, the part indicated by a hyphen (-) is about the steam trap because the steam trap did not exist, the diagnosis process of the steam trap was not performed, and so on. It means that the information of the year is not accumulated. In addition, in Table 1, the description related to the part with ID D indicates that the steam trap D1 was replaced with the steam trap D2 of the same model (model a) because an abnormality was found in the diagnostic process in 2015. show.

Table 1: Examples of information accumulated in the accumulation process

(3) Calculation process In the calculation process, the calculation unit 3b calculates the survival rate curve of the evaluation target model, and determines the device life of the evaluation target model based on the survival rate curve. In this embodiment, the survival rate curve is calculated by the Kaplan-Meier method. The specific method will be described below. In the following description, "model a" in Table 1 will be described as a model to be evaluated.

First, as shown in Table 2, the information shown in Table 1 is organized according to the number of years elapsed from the start of operation.
Here, since the model a is the model to be evaluated, the information about the model b is excluded from the calculation target.

For example, steam trap A was confirmed to be in a normal state in 2011, one year after the start of operation in 2010, so it is stated that it was "normal" in the column of the elapsed years "1 year". It is remembered. In addition, steam trap C, whose operation starts in 2011, is in a normal state from 2012 (1 year after the start of operation) to 2016 (5 years after the start of operation), and is in a normal state in 2017 (6 years after the start of operation). ), Since it was confirmed that it was in an abnormal state, it was "normal" in the column of "1 year" to "5 years" and "abnormal" in the column of "6 years". It is remembered that it was.

On the other hand, since the information on the steam trap A after 2012 has not been accumulated, the information on the steam trap A after the elapsed age of 2 years is unknown. In addition, since steam trap D2 has only passed two years since the start of operation in 2015, information after three years has passed is unknown. When the operating state is unknown as in these examples, it is excluded from the calculation target and is indicated by a hyphen (-) in Table 2. Further, the traps G and H whose start of operation is unknown are excluded from the calculation target because the elapsed years cannot be specified.

Table 2: Examples of information organized by the number of years elapsed since the start of operation

Next, as shown in Table 3, based on the information organized in Table 2, the number of steam traps in operation (number of operations) and the number of steam traps in operation are normal for each elapsed year section of each year. The quantity of things in the normal state (normal number) is totaled, and the ratio of things in the normal state (normal rate) is calculated. For example, in Table 2, in the column of the elapsed years "2 years", it is remembered that the 6 steam traps were "normal", so the number of operations is the number of years after installation "1 to 2 years". It is "6", the normal number is "6", and the normal rate is "100%". Similarly, for the installation years "4 to 5 years", the number of operations is "4", the normal number is "3", and the normal rate is "75%".

Table 3: An example of totaling the number of operations, normal numbers, and normal rates for each year after installation.

Further, the normal rate for each number of years after installation as shown in Table 3 is integrated to calculate the survival rate for each elapsed year. For example, the survival rate at the time of 3 years elapsed is 100% (normal rate of 0 to 1 year) x 100% (normal rate of 1 to 2 years) x 80% (normal rate of 2 to 3 years) = 80. Calculated as%. A survival rate curve can be obtained by performing the same calculation for each elapsed year, plotting the horizontal axis as the elapsed years (an example of the elapsed time from the start of operation) and the vertical axis as the survival rate for each elapsed years (Fig.). 3).

Finally, in the survival rate curve, the number of years elapsed when the survival rate reaches a predetermined threshold value is determined as the device life of the model a, which is the model to be evaluated. For example, assuming that the threshold value is 70%, in FIG. 3, the survival rate is 80% at the age of 4 years and 60% at the time of 5 years, so the survival rate is 70 when the age exceeds 4.5 years. It is estimated to be%. Therefore, the device life of model a is determined to be 4.5 years.

In the above, for the sake of simplicity, an example of aggregation based on seven points of information is shown, but the number of steam traps to be aggregated is not limited. It will be appreciated by those skilled in the art that in practice embodiments it is preferable to aggregate a sufficiently large number of steam traps in order to obtain statistically significant statistical results.

The information stored in the storage unit 3a in the storage process and targeted for calculation in the calculation process is not only the information related to the steam trap 1 operating in the specific steam plant P, but also the steam operating in the plurality of steam plants P. Contains information related to trap 1. In the device life evaluation method according to the present embodiment, this is not only to evaluate the life of the steam trap 1 in the specific steam plant P, but also to evaluate the life of the steam trap 1 that flows out from the manufacturer to the market as a general product. This is because the purpose is also to evaluate the life. For the purpose of facilitating the acquisition of a statistically significant sample quantity, it is advantageous to target the steam trap 1 operating in the plurality of steam plants P.

(4) Equipment life evaluation process In the equipment life evaluation process, the above diagnosis process, storage process, and calculation process are executed for a plurality of evaluation target models, and the device life and survival rate curves are obtained for each evaluation target model. It is calculated. In this embodiment, in addition to calculating the device life and survival rate curve of "model a" as described above, the device life and survival rate of "model b" and "model c (not shown in Table 1)" are also calculated. The case where the calculation of the curve is performed will be described as an example.

(5) Comparison step In the comparison step, the calculation unit 3b compares the device life and survival rate curves of each of the plurality of evaluation target models. In the present embodiment, the device life and survival rate curves of the models a to c are compared by plotting the survival rate curves of the models a to c calculated in the device life evaluation process on one graph (Fig.). 4).

Based on the survival rate curves of the models a to c exemplified in FIG. 4, the device life of the model a is 4.5 years as described above, whereas the device life of the model b is 4.3 years. It can be seen that the device life of c is 2.0 years. Further, it can be seen that the performance of the model b is slightly inferior to that of the model a in terms of the numerical value of the device life, but the survival rate when the elapsed years exceed 5 years is significantly inferior to that of the model a.

By calculating and comparing the device life of the models to be evaluated by each of the above steps, it is possible to objectively compare the device life between the models. As a result, the consumer of the steam trap 1 can make a comparison in consideration of the renewal plan based on the device life of each model when selecting the model of the steam trap 1 to be introduced in the steam plant P, and thus the introduction cost. , Maintenance cost, and renewal cost can be comprehensively considered when selecting a model. In addition, the supplier of the steam trap 1 can objectively compare the difference in the device life between the old and new products of the company or between the products of the company and the products of other companies, and evaluate the product performance and the validity of the product design. It can be used in situations such as verification of products, evaluation and management of manufacturing quality.

[Variation example of the above embodiment]
(1) Evaluation of Device Life for Each Use Condition In the above embodiment, an example is described in which the steam trap 1 is uniformly counted without taking into account the difference in the use condition. This embodiment is suitable for evaluating the device life as the performance of the product itself, which is mainly caused by the product design of the steam trap 1 and the product supply system. On the other hand, the same evaluation method can be applied as a method for evaluating the influence of the difference in the conditions in which the steam trap 1 is used on the life of the device.

FIG. 5 shows steam traps of a specific evaluation target model having a circulating steam pressure (hereinafter referred to as working pressure) of 0.5 MPa or less, 0.5 to 1.0 MPa or less, and a steam trap of 0.5 to 1.0 MPa or less, respectively. It is an example of classifying into those of 1.0 to 1.5 MPa or less and calculating the survival rate curve for each classification. When the device life for each working pressure is calculated based on the survival rate curve in FIG. 5, it is used for 9.0 years when the working pressure is 0.5 MPa and 7.3 years when the working pressure is 0.5 to 1.0 MPa. It is 4.8 years when the pressure is 1.0 to 1.5 MPa. In this way, by calculating the survival rate curve and device life for each working pressure, it is possible to evaluate the magnitude of the effect of working pressure on the device life, and whether it is appropriate to select a model for the working pressure. It is possible to evaluate whether or not it is. In addition to the pressure, the steam trap may be classified according to the temperature and flow rate of the circulating steam, that is, according to an arbitrary physical quantity of steam.

FIG. 6 shows the case where the steam trap of a specific evaluation target model is installed without trapping defects, the discharge capacity is not suitable for the installation location (discharge capacity selection error), and the model is not suitable for the installation location. This is an example of calculating the survival rate curve for each classification by classifying into the case of (type selection error) and the case of installation with each trapping defect that is not installed in the correct mounting posture (inappropriate mounting posture). .. When the device life for each installation state is calculated based on the survival rate curve in Fig. 5, it is 9.0 years for the installation state without trapping defects, 0.8 years for the discharge capacity selection error, and the model selection error. Is 5.7 years, and if the mounting posture is inappropriate, it will be 7.2 years. In this way, by calculating the survival rate curve and device life for each installation state, the effect of trapping defects on the device life can be evaluated for each type of trapping defect, and the priority for eliminating trapping defects can be determined. can do.

In addition to the above, the aggregation for each usage condition may be performed for each site (use of the trap) in which the steam trap 1 is used in the steam plant P, for example. For example, if the steam trap is installed in the main pipe, in an iron trace, in a copper trace, etc., the survival curve and device life can be calculated for the steam trap. It is possible to objectively evaluate that the device life differs depending on the site where 1 is installed.

(2) Evaluation of device life using a detector provided in advance in the steam trap In the above embodiment, it is assumed that an inspector goes to the site to inspect and diagnose each of the steam traps 1 to be evaluated. I explained the example. In this embodiment, not only the detection result of the physical quantity of the trap but also the visual inspection result of the inspector is taken into consideration to diagnose whether the steam trap 1 is in a normal state or an abnormal state. This is because the detection result of the physical quantity of the trap can be affected by the operating conditions of the equipment installed around the steam trap 1 to be evaluated and the weather at the time of inspection, and the steam trap 1 is in a normal state. Even if there is, the detection result of the trap physical quantity may be different from the normal time, so it is difficult to judge whether the steam trap 1 is in the normal state or the abnormal state based only on the detection result of the trap physical quantity. ..

Therefore, in the device life evaluation method according to the present invention, instead of detecting the trap physical quantity using the detection unit 2a of the portable detector 2, the trap physical quantity is detected by using the permanent detector provided in the steam trap 1 in advance. It may be configured to do so. In this configuration, the trap physical quantity is constantly monitored by the permanent detector, and when the permanent detector detects the trap physical quantity that deviates from the predetermined standard range in the constant monitoring, the permanent detector is provided. It is diagnosed that the steam trap 1 is in a state requiring attention. Here, the caution state means that the steam trap 1 may be in an abnormal state. The step including the above-mentioned continuous monitoring and diagnosis of the state requiring attention is called a primary diagnosis step.

Subsequently, the inspector performs a visual inspection only on the specific steam trap 1 diagnosed as being in a state of caution in the primary diagnosis step. At the same time as the visual inspection, the detection of the trap physical quantity using the portable detector 2 may be performed again. In this way, at least an inspection by an inspector including a visual inspection is performed, and based on the result, it is finally diagnosed whether the steam trap 1 is in a normal state or an abnormal state. The step including the above-mentioned visual inspection by the inspector and the final diagnosis of the operating state is called a secondary diagnosis step.

By providing the two-step diagnostic step in this way, the number of steam traps 1 that need to be visually inspected can be reduced, and the inspection man-hours of the inspector can be reduced.

Further, when the steam trap 1 is diagnosed as being in an abnormal state in the secondary diagnosis step, the time when the permanent detector detects the trap physical quantity deviating from the predetermined standard range in the primary diagnosis step is input in the accumulation step. It may be the inspection time information to be input to the part 2b. With this configuration, it is possible to eliminate the time lag between when the steam trap 1 actually falls into an abnormal state and when the diagnosis that the steam trap 1 is in an abnormal state is confirmed by the secondary diagnosis step. It is possible to calculate the device life with higher accuracy.

It is not always necessary to provide a permanent detector in all the steam traps 1 of the steam plant P, and a diagnostic step using the permanent detector and a diagnostic step using the portable detector 2 may be appropriately combined.

[Other embodiments]
Finally, other embodiments of the device life evaluation method according to the present invention will be described. The configurations disclosed in each of the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Further, each of the following embodiments will be described as another embodiment of the device life evaluation method according to the present invention, but the same embodiment is also implemented in the device life evaluation device and the device life evaluation program according to the present invention. sell.

In the above embodiment, the configuration in which the plant equipment to be evaluated is the steam trap 1 has been described as an example. However, without being limited to such a configuration, the plant equipment to be evaluated includes turbines, compressors, generators, heat exchangers, transport pipes, drain pipes, control valves, pumps, filters, separators, water supply tanks, etc. It may be a deaerator, a boiler, a revoir, or the like.

In the above embodiment, an example in which the survival rate curve is calculated by the Kaplan-Meier method has been described. However, without being limited to such a configuration, the survival rate curve is calculated by a survival time analysis method assuming known distributions such as Weibull distribution, exponential distribution, lognormal distribution, gamma distribution, and loglogistic distribution. May be.

In the above embodiment, an example in which the diagnosis cycle is one year has been described. However, the diagnostic cycle may be any period. When the diagnosis cycle is short, the accuracy of the calculated device life tends to improve, and when the diagnosis cycle is long, the man-hours and costs required for inspection and diagnosis tend to be reduced. Therefore, the diagnostic cycle should be appropriately determined in view of the required accuracy of device life and the man-hours and costs that can be spent. Here, if the diagnosis cycle is within one year, it is preferable because the device life can be calculated with sufficiently high accuracy for many plant devices.

In the above embodiment, the configuration in which the elapsed years when the survival rate becomes 70% is set as the device life of the model to be evaluated has been described as an example. However, without being limited to such configurations, predetermined thresholds for determining equipment life are the structure, materials, and conditions of use of the plant equipment to be evaluated, as well as the user or user of the plant equipment. Any value can be used depending on the conditions required by the supplier and the like.

It should be understood that with respect to other configurations, the embodiments disclosed herein are exemplary in all respects and the scope of the invention is not limited thereto. Those skilled in the art will be able to easily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, another embodiment modified without departing from the spirit of the present invention is naturally included in the scope of the present invention.

The present invention can be used, for example, to evaluate the life of a steam trap operating in a steam plant.

P: Steam plant 10: Equipment life evaluation device 1: Steam trap 2: Portable detector 2a: Detection unit 2b: Input unit 2c: Display unit 3: Arithmetic unit 3a: Storage unit 3b: Arithmetic unit 4: Network

Claims (11)

It is a device life evaluation method that evaluates the device life for each model of plant equipment.
We inspect multiple plant equipment of the model to be evaluated that are operating in the plant, and based on the results of the inspection, the operating status of the plant equipment is normal for each of the multiple plant equipment. The diagnostic process for diagnosing whether it is in an abnormal state and
For each of the plurality of plant equipment, operation start information regarding the operation start time when the plant equipment starts operation in the plant, and inspection when the inspection is performed on the plant equipment in the diagnostic process. A storage process for accumulating inspection timing information regarding the timing and operating status information regarding the operating status diagnosed in the diagnostic step in a storage device, and
Wherein the operation start timing information stored in the storage step, the test timing information, and, based on the operational status information, have a, a calculation step of calculating a device life of the evaluation target model,
The diagnostic step is executed a plurality of times, and the interval between the diagnostic steps executed a plurality of times is within a predetermined diagnosis cycle . A device life evaluation process for calculating the device life for each of a plurality of evaluation target models by the device life evaluation method according to claim 1.
A device life evaluation method including a comparison step of comparing the device life of each of the plurality of evaluation target models calculated in the device life evaluation step. In the calculation process, the survival rate curve of the evaluation target model is calculated.
The horizontal axis of the survival rate curve is the elapsed time from the start of operation.
The vertical axis of the survival rate curve is the survival rate representing the ratio of the plant equipment of the evaluation target model that operates in a normal state after the elapsed time has elapsed.
The device life evaluation method according to claim 1 or 2, wherein the device life of the evaluation target model is the elapsed time at which the survival rate becomes a predetermined threshold value in the survival rate curve. The device life evaluation method according to claim 3, wherein the survival rate curve is calculated by the Kaplan-Meier method. The device life evaluation method according to any one of claims 1 to 4, wherein the diagnosis cycle is one year or less. The device life evaluation method according to any one of claims 1 to 5 , wherein the device life can be calculated for each usage condition in which the plant equipment is used. The fluid handled in the plant circulates inside the plant equipment.
The device life evaluation method according to claim 6 , wherein the usage condition includes at least one of the application of the plant equipment in the plant and a fluid physical quantity which is a physical quantity related to a fluid flowing through the plant equipment. In any one of claims 1 to 7 , the inspection of at least a part of the plurality of plant equipment in the diagnostic step includes a visual inspection of each of the at least a part of the plant equipment by an inspector. The device life evaluation method described. In the diagnostic step, inspection and diagnosis of at least a part of the plurality of plant equipment are performed based on the physical quantity of the equipment, which is a physical quantity previously detected by a detector provided in each of the at least a part of the plant equipment. The device life evaluation method according to any one of claims 1 to 8. The diagnostic step is
When the detector detects a physical quantity of equipment that deviates from a predetermined standard range, the primary diagnosis that the plant equipment provided with the detector is in a state requiring attention that may be in an abnormal state. Diagnostic steps and
An inspector visually inspects the plant equipment diagnosed as being in the state requiring attention in the primary diagnosis step, and based on the result of the visual inspection, whether the plant equipment is in a normal state or an abnormal state. The device life evaluation method according to claim 9 , further comprising a secondary diagnostic step for diagnosing. When the plant equipment is diagnosed as being in an abnormal state in the secondary diagnosis step, the inspection time stored as the inspection time information in the storage step shall be the time when the primary diagnosis step is executed. The device life evaluation method according to claim 10.

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