KR102371924B1 - Real-time fatigue damage evaluation method for high-temperature structures and real-time damage monitoring method and system having the same - Google Patents

Abstract

A real-time fatigue damage evaluation method for a high-temperature structure is disclosed. The real-time fatigue damage evaluation method for a high-temperature structure according to an exemplary embodiment of the present invention is a method for real-time evaluation of fatigue damage to a high-temperature structure in operation, and divides the entire operation cycle into a plurality of unit cycles according to the operation cycle to do; determining whether the unit cycle is an end cycle in which operation is terminated or a current cycle in which operation is in progress; evaluating the fatigue damage with respect to the end cycle among the unit cycles; and evaluating the fatigue damage with respect to the current cycle among the unit cycles.

Description

Real-time fatigue damage evaluation method for high-temperature structures, and real-time damage monitoring method and system including the same

The present invention relates to a real-time fatigue damage evaluation method for a high-temperature structure, and a real-time damage monitoring method and system including the same, and more particularly, to a real-time fatigue damage evaluation method for a high-temperature structure that can be applied to a heat transfer system in a high-temperature nuclear power plant. And, it relates to a real-time damage monitoring method and system including the same.

In general, when a load is repeatedly applied to a structure, damage to the structure is caused even if the magnitude of the load is small, which is called fatigue damage. In particular, in a power plant that is operated for a long time in a high-temperature environment, fatigue damage may occur to equipment, structures, and piping depending on operating load, operating time, and temperature conditions, which may ultimately cause leakage and breakage of vulnerable parts.

In addition, in a sodium-cooled fast reactor (SFR) that uses liquid sodium (sodium, Na) as a core coolant, the coolant temperature of the primary heat transfer system that directly cools the core is about 550°C, and the turbine is driven The temperature of the steam supplied for this purpose reaches about 500 °C. Since such a temperature condition is a temperature range that causes creep deformation in the structure, not only fatigue damage due to repeated driving loads but also creep damage may occur in the structure.

In general, creep damage and fatigue damage of high-temperature structures are aggravated by interaction, so damage evaluation is necessary considering this. However, although the fatigue monitoring system (NuFMS) is applied to domestic commercial nuclear power plants (nuclear power plants) as a means to ensure safe operation, most commercial nuclear power plants operate at low operating temperatures without considering creep damage. It is difficult to apply to nuclear power plants operating under high-temperature conditions, such as sodium-cooled high-speed reactors, because only the fatigue damage accumulated in the monitoring target is evaluated quantitatively.

One embodiment of the present invention is to provide a real-time damage monitoring method and system for a high-temperature structure that can evaluate damage based on an arbitrary specific time point for a high-temperature structure in operation.

An embodiment of the present invention is to provide a real-time damage monitoring method and system for a high-temperature structure, which can more accurately predict the remaining lifespan according to operation.

An embodiment of the present invention is to provide a real-time damage monitoring method and system for a high-temperature structure that can more comprehensively evaluate the damage of a high-temperature structure in consideration of the interaction between fatigue damage and creep damage.

According to one aspect of the present invention, there is provided a method for evaluating fatigue damage to a high-temperature structure in operation in real time, the method comprising: dividing an entire operating cycle into a plurality of unit cycles according to the operating cycle; determining whether the unit cycle is an end cycle in which operation is terminated or a current cycle in which operation is in progress; A real-time fatigue damage evaluation method for a high-temperature structure is provided, comprising: evaluating the fatigue damage with respect to the end cycle of the unit cycle; and evaluating the fatigue damage with respect to the current cycle of the unit cycle.

In this case, the evaluating of the fatigue damage with respect to the current cycle among the unit cycles may include subdividing the current cycle into a plurality of local cycles; Calculating the fatigue damage usage factor for each local cycle and adding up the fatigue damage usage factor calculated for each local cycle.

In this case, the step of subdividing the current cycle into a plurality of local cycles may include dividing the current cycle into a plurality of local cycles based on a point at which a temperature rise or fall starts.

In this case, the step of calculating the fatigue damage use factor for each local cycle is calculated as a ratio of the actual number of occurrences of the local cycle to the maximum number of cycles allowed for each local cycle, and when calculating the actual number of occurrences, one local Cycles can be counted as 0.5 occurrences.

According to another aspect of the present invention, there is provided a method for monitoring damage to a high-temperature structure in operation in real time, the method comprising: dividing an entire operation cycle into a plurality of unit cycles according to the operation period; determining whether the unit cycle is an end cycle in which operation is terminated or a current cycle in which operation is in progress; evaluating the fatigue damage and creep damage for the end cycle among the unit cycles; evaluating the fatigue damage and creep damage with respect to the current cycle among the unit cycles; adding up the fatigue damage and creep damage evaluation results of the end cycle and the current cycle, respectively, and comprehensively evaluating damage to the high-temperature structure, wherein the fatigue damage for the current cycle among the unit cycles and evaluating creep damage may include: subdividing the current cycle into a plurality of local cycles; A real-time damage monitoring method for a high-temperature structure is provided, comprising the steps of calculating the fatigue damage usage factor for each local cycle and adding the fatigue damage usage factor calculated for each local cycle.

In this case, the step of subdividing the current cycle into a plurality of local cycles may include dividing the current cycle into a plurality of local cycles based on a point at which a temperature rise or fall starts.

In this case, the step of calculating the fatigue damage use factor for each local cycle is calculated as a ratio of the actual number of occurrences of the local cycle to the maximum number of cycles allowed for each local cycle, and when calculating the actual number of occurrences, one local Cycles can be counted as 0.5 occurrences.

In this case, the step of evaluating the fatigue damage and creep damage with respect to the end cycle among the unit cycles may include: subdividing the end cycle for each type of transient operation; The method may include calculating a fatigue damage usage coefficient for each type of transient operation and adding up the fatigue damage usage coefficient calculated for each type of excessive operation.

In this case, the step of evaluating the fatigue damage and creep damage with respect to the end cycle of the unit cycle and the step of evaluating the fatigue damage and the creep damage with respect to the current cycle of the unit cycle are, respectively, the end cycle or subdividing the load history of the current cycle into time sections at regular intervals; It may include calculating the creep damage usage coefficient for each time section and adding the creep damage usage factor calculated for each time section.

In this case, the calculating of the creep damage usage coefficient for each time section may be applied by relaxing stress compared to the immediately preceding time section for a plurality of consecutive time sections while the temperature is kept constant.

In this case, in the step of comprehensively evaluating the damage to the high-temperature structure, it may be determined whether the high-temperature structure is safe in consideration of the correlation between the fatigue damage and the creep damage.

According to another aspect of the present invention, there is provided a system for monitoring damage to a high-temperature structure in operation in real time, which is installed in the high-temperature structure to obtain at least one of temperature data, pressure data, and flow rate data of a coolant inside the high-temperature structure. A load history collection device that collects in real time and converts it into a digital signal, and a damage evaluation device that analyzes the digital signal received from the load history collection device to evaluate whether the high-temperature structure is damaged and delivers the damage information to the user And, the damage evaluation device divides the entire driving cycle into a plurality of unit cycles according to the driving cycle, and a driving cycle classification unit for determining whether the unit cycle is an end cycle in which operation is completed or a current cycle in which operation is in progress ; an end cycle evaluation unit for evaluating the fatigue damage and creep damage with respect to the end cycle among the unit cycles; A current cycle evaluation unit that evaluates the fatigue damage and creep damage with respect to the current cycle among the unit cycles, and sums the fatigue damage and creep damage evaluation results of the end cycle and the current cycle to determine damage to the high-temperature structure A real-time damage monitoring system for a high-temperature structure is provided, including a comprehensive evaluation unit that comprehensively evaluates it.

At this time, the current cycle evaluation unit subdivides the current cycle into a plurality of local cycles, calculates a fatigue damage usage factor for each local cycle, and adds the fatigue damage usage factor calculated for each local cycle to the fatigue damage can be evaluated.

In this case, when the current cycle is subdivided into a plurality of local cycles, the current cycle evaluator may divide the current cycle into a plurality of local cycles based on a point at which an increase or decrease in temperature starts.

The real-time fatigue damage evaluation method for a high-temperature structure according to an embodiment of the present invention divides the current cycle into a plurality of local cycles and calculates the fatigue damage usage coefficient for each local cycle, so that the load history up to the current operation point can be reflected. Reliable fatigue damage evaluation results can be obtained.

The real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention performs a creep damage assessment together with the fatigue damage assessment result up to the present time, and by taking this comprehensively into consideration, a more effective damage assessment for a high-temperature structure results can be obtained.

In an embodiment of the present invention, the real-time damage monitoring system for a high-temperature structure includes a load history collection device and a damage evaluation device, so that damage to a load can be automatically evaluated and related information can be delivered to a user in real time.

1 is a flowchart of a real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention.
2 is a diagram illustrating a real-time damage monitoring system for a high-temperature structure according to an embodiment of the present invention.
3 is a block diagram illustrating a real-time damage monitoring system for a high-temperature structure according to an embodiment of the present invention.
FIG. 4 is a flowchart showing subdivided steps of assessing impairment for the end cycle of FIG. 1 .
5 is a graph illustrating an example of an end cycle of a high temperature structure.
FIG. 6 is a graph illustrating subdivision of the end cycle shown in FIG. 5 by types of transient driving.
7 is a graph showing the subdivision of the load history into time sections at regular intervals.
FIG. 8 is a flowchart showing subdivided steps of evaluating damage with respect to the current cycle of FIG. 1 .
9 is a graph illustrating an example of a current cycle of a high temperature structure.
FIG. 10 is a graph illustrating subdivision of the current cycle shown in FIG. 9 into a local cycle.
11 is a graph showing an example of a correlation between fatigue damage and creep damage.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification is present, and one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

1 is a flowchart of a real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention. 2 is a diagram illustrating a real-time damage monitoring system for a high-temperature structure according to an embodiment of the present invention. 3 is a block diagram illustrating a real-time damage monitoring system for a high-temperature structure according to an embodiment of the present invention. FIG. 4 is a flow chart subdivided into the steps of assessing impairment for the end cycle of FIG. 1 . 5 is a graph illustrating an example of an end cycle of a high temperature structure. FIG. 6 is a graph illustrating subdivision of the end cycle shown in FIG. 5 by types of transient driving. 7 is a graph showing the subdivision of the load history into time sections at regular intervals.

The real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention is a method of monitoring the stability of a high-temperature structure in real time by analyzing the load history of the high-temperature structure and then comprehensively evaluating fatigue damage and creep damage am.

At this time, each step of the real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention may be performed by the real-time damage monitoring system 100 for a high-temperature structure according to an embodiment of the present invention.

Hereinafter, each step of the real-time damage monitoring method (hereinafter, 'damage monitoring method') for a high-temperature structure according to an embodiment of the present invention will be mainly described, but the damage monitoring method in the real-time damage monitoring system 100 for a high-temperature structure The subject performing each of the above steps will also be described.

First, the real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention includes the step of collecting the load history for the high-temperature structure by using the load history collecting device 10 (S10).

At this time, the high-temperature structure to which the damage monitoring method for the high-temperature structure according to an embodiment of the present invention is applied may be a high-temperature pipe through which a high-temperature thermal fluid is moved, such as an intermediate heat transfer system (IHTS) of a sodium-cooled high-speed reactor. However, it should be noted that the application of the damage monitoring method according to an embodiment of the present invention is not limited thereto.

Meanwhile, referring to FIG. 2 , the load history collecting device 10 may include a temperature sensor 11 , a pressure sensor 12 , a flow rate sensor 13 and the like installed in a high-temperature structure. From this, the load history collecting device 10 can collect the temperature data, pressure data, or flow velocity data of the internal fluid in real time of the high-temperature structure and convert it into a digital signal, which is ultimately related to the load history acting on the structure. information can be organized.

Here, the load history may mean a load (pressure, etc.) applied to the high-temperature structure over time. Such a load history can be illustrated by indicating the time temperature or stress of the high-temperature structure over time as shown in FIGS. 5 and 9 . In this specification, the load history shown in this way is defined as a driving cycle.

Next, the damage monitoring method according to an embodiment of the present invention includes dividing the entire driving cycle into a plurality of unit cycles by the driving cycle classification unit 31 of the damage evaluation device 30 (S20).

In more detail, when the above-described load history is shown for the entire operating time of the high-temperature structure, it can be confirmed that the driving cycle repeats the rising and falling according to the operating cycle, and a similar shape is repeated. For example, in the case of nuclear power generation using a sodium-cooled high speed reactor, an operation cycle may be generated according to a fuel exchange cycle.

At this time, referring to FIG. 5 , when the fuel exchange time of the entire driving cycle is a segmentation point, the entire driving cycle may be divided into a plurality of pieces. In this way, the individual pieces of the driving cycle divided according to the time of fuel exchange are defined as a unit cycle.

In an embodiment of the present invention, the driving cycle classification unit 31 of the damage evaluation device 30 may perform an operation of dividing the entire driving cycle having such a repetitive shape into a plurality of unit cycles. In this case, the above operation may be performed by automatically analyzing the load history, or based on information according to the fuel exchange time input in advance. Through this, fatigue damage or creep damage, which will be described later in unit cycle units, can be evaluated.

The damage monitoring method according to an embodiment of the present invention includes determining whether this is an end cycle or a current cycle for each of the divided unit cycles. (S30)

More specifically, some of the unit cycles may be past end cycles in which operation has already ended based on the monitoring time point. For example, as shown in FIG. 5 , the termination cycle is a cycle in which the initial temperature is raised through a new fuel exchange and then falls back to the initial temperature after the operation is finished, and may be ended with the next fuel exchange.

Alternatively, the unit cycle may be a current cycle in which operation is still in progress based on the monitoring time point. That is, the unit cycle may be a cycle in which the temperature drop is not yet finished even after time passes as shown in FIG. 9 .

The step (S30) of determining whether it is the end cycle or the current cycle may also be automatically performed by the driving cycle classifying unit 31 .

Thereafter, the damage monitoring method according to an embodiment of the present invention may perform the step (S40) of evaluating fatigue damage and creep damage with respect to the end cycle of the unit cycle. The above step may be performed by the end cycle evaluation unit 32 of the real-time damage evaluation device 30 .

)에 대한 실제 과도운전 횟수(

)의 비율로 계산되는 값(

)으로 정해질 수 있다. 이 때, 과도운전 유형별 허용가능한 최대횟수(

)는 고온 구조물의 특성에 따라 미리 정해진 값일 수 있다.First, looking at fatigue damage evaluation, if a load is repeatedly applied to a structure, it causes damage to the structure even if the magnitude of the load is small, which can be referred to as fatigue damage. Such fatigue damage can be evaluated by calculating the fatigue damage usage factor, where the fatigue damage usage factor is the maximum allowable number of times (

) for the actual number of overruns (

) calculated as a ratio of (

) can be determined. At this time, the maximum allowable number of times (

) may be a predetermined value according to the characteristics of the high-temperature structure.

In more detail, referring back to FIG. 5, one end cycle may perform a normal operation to maintain a normal temperature by design, but various types of transient operation (in the case of FIG. 5, S1, S2, S3) may be included. In particular, when the transient operation returns to the first position after passing through the peak and valley values from the normal operation, it can be regarded as a one-time operation and specified.

Such transient operation can be subdivided by type in consideration of operating temperature, operating time, and load range. (S41) Among these, transient operation forming the largest strain range as shown in FIG. 6 (S3 in the case of FIG. 6) It can be evaluated by setting it preferentially, and then setting the cycle independently for the rest of the load and evaluating it. For example, in allocating the total operating time for each transient operation, in order to perform a conservative evaluation, most of the operating time is allocated to S3 that can form the largest strain range as shown in FIG. 6 , and other S2 and S3 In the case of , it will be possible to allocate the operation time based on the start and end points of the transient operation.

)로 나누어 개별 피로손상 사용계수를 산출할 수 있다.(S42) 그리고 산출된 개별 피로손상 사용계수를 최종적으로 합산할 경우, 특정 종료 사이클에 대한 피로손상 사용계수를 얻을 수 있다.(S43)After that, by counting the number of occurrences for each type of transient operation, it is calculated as the maximum allowable number (

) to calculate individual fatigue damage usage factors. (S42) And when the calculated individual fatigue damage usage factors are finally added up, the fatigue damage usage factor for a specific end cycle can be obtained (S43).

Next, the step of evaluating the creep damage of the end cycle with reference to FIGS. 4 and 7 is as follows.

)에 대한 운전시간의 비율로 계산할 수 있다.The creep phenomenon is the increase in deformation when the load is maintained for a certain period of time in a high temperature environment. At this time, the creep damage usage factor is the minimum allowable time for rupture (

) can be calculated as the ratio of operating time to

)으로 구획하고 각 구간의 하중을 적용하여 크리프손상을 평가할 수 있다.(S44)To this end, the end cycle evaluation unit 32 of the real-time damage evaluation device 30, as shown in FIG.

) and apply the load in each section to evaluate creep damage. (S44)

)을 계산하고, 파단허용최소시간(

)에 대한 실제 시간구간(

)의 비율(

)이 해당 시간구간에서의 크리프손상 사용계수가 될 수 있다. (S45) 또한 각 구간에서 계산한 사용계수들을 모두 합한 값이 총 크리프손상 사용계수가 될 수 있다. (S46)And, the allowable minimum time to fracture for the stress in each time section (

), and the minimum allowable break time (

) for the actual time interval (

) of the ratio (

) can be the creep damage usage factor in the corresponding time period. (S45) In addition, the sum of the use factors calculated in each section may be the total creep damage use factor. (S46)

에서 시작되는 첫번째 손상평가 시점인

에서는 [

,

] 구간의 시간 동안에 작용하는 하중에 대한 크리프손상을 계산한다. 그러나, 두번째 구간인 에서는 [

,

] 구간에 대하여 크리프손상을 평가함에 있어서는

시점의 응력이

시간동안 완화된 값을 사용한다. 이와 같이 온도가 일정하게 유지되면서 연속되는 복수의 시간구간에 대해서는 응력완화를 고려함으로써 과도한 보수적 평가를 완화할 수 있다.At this time, referring back to FIG. 7, time

The first damage assessment point starting from

In [

,

] Calculate the creep damage for the load acting during the time of the section. However, in the second interval [

,

] In evaluating creep damage for the section,

the stress at the time

Use a relaxed value for time. In this way, excessive conservative evaluation can be alleviated by considering stress relaxation for a plurality of consecutive time sections while the temperature is kept constant.

FIG. 8 is a flowchart showing subdivided steps of evaluating damage with respect to the current cycle of FIG. 1 . 9 is a graph illustrating an example of a current cycle of a high temperature structure. FIG. 10 is a graph illustrating subdivision of the current cycle shown in FIG. 9 into a local cycle. 11 is a graph showing an example of a correlation between fatigue damage and creep damage.

The damage monitoring method according to an embodiment of the present invention may perform the step (S50) of evaluating fatigue damage and creep damage even for a current cycle among unit cycles. Such a step may be performed by the current cycle evaluation unit 33 of the real-time damage evaluation device 30 .

In relation to fatigue damage evaluation, in the case of the current cycle, since the operation has not yet been completed, there is a problem in that it is difficult to evaluate the fatigue damage using the same method as the fatigue damage evaluation method of the end cycle described above. The current cycle does not have a specific shape like the end cycle, but the cycle shape is updated every minute according to the evaluation time, so that the transient operation that forms the largest strain range can be continuously changed. In this way, when the maximum transient operation is continuously changed, it directly affects the calculation of the fatigue damage usage factor due to the previous excessive operation, causing a problem in the amount of calculation.

In order to solve such a problem, the damage monitoring method according to an embodiment of the present invention may apply the concept of a local cycle in evaluating fatigue damage with respect to a current cycle.

Specifically, in the case of the end cycle, where transient driving could be clearly classified by type, when returning to the first position after passing through peak and valley values, it was considered as a one-time operation, in the case of the current cycle, it is By dividing the cycle, one such divided cycle can be defined as a local cycle. That is, it can be divided into a plurality of local cycles based on the point at which the temperature rise or fall starts. (S51)

)까지 운전이 진행되고 있는데, 이 사이클은 정상운전 상태의 정상온도(

)를 유지하도록 운전이 진행된다. 하지만 실제 운전에는 설계단계에서 예상했거나 또는 예상하지 못한 다양한 과도운전이 발생할 수 있음은 이미 살펴본 바와 같다. 이 때, 현재 사이클은 현재시간(

)까지 운전이 진행되면서 상승과 하강을 반복하며 CT-1에서 CT-5까지 국부 사이클들이 발생되었고, CT-6는 현재 진행중임을 알 수 있다. In more detail, taking the graph shown in FIG. 10 as an example, the shown current cycle is the current time (

), and this cycle is at the normal temperature (

), the operation proceeds to maintain However, as we have already seen, various transient operations that were expected or unexpected at the design stage may occur in actual operation. At this time, the current cycle is the current time (

), ascending and descending repeatedly, local cycles from CT-1 to CT-5 occurred, and it can be seen that CT-6 is currently in progress.

,

]이지만

시점에서 온도가

까지 상승하여 온도하중범위는 [

,

]로 증가된다. 그래서 CT-1은 [

,

] 범위에서 온도가 상승하는 국부 사이클로 결정된다. CT-2는 온도가 감소하는 하강선도 국부사이클인데,

에서 온도가 다시 증가하므로 [

,

] 구간으로 결정된다. CT-3의 과도운전으로

가 발생하지만 앞에서 발생한

보다 작아서 현재 사이클 중 가장 큰 변형률 범위를 형성하는 과도운전에 영향을 주지 않으므로 CT-3의 온도구간은 [

,

]로 결정된다. CT-4는 [

,

]의 온도구간을 가지는 하강선도 사이클이다.In one embodiment of the present invention, the temperature range is [

,

]as

temperature at the time

The temperature load range is [

,

] is increased. So CT-1 is [

,

] is determined by the local cycle in which the temperature rises in the range. CT-2 is a local cycle of descending curve with decreasing temperature.

As the temperature increases again at [

,

] is determined by the section. CT-3's overdrive

occurs, but occurred before

The temperature section of CT-3 is [

,

] is determined. CT-4 is [

,

A descending line with a temperature section of ] is also a cycle.

시점까지 운전이 진행되면서 현재 사이클에서 가장 높은 온도는

인데, 이후에 보다 높은 온도(

)의 과도운전이 발생한다. 최고 온도가 에서

로 바뀜에 따라 국부 사이클 CT-5는 온도범위가 [

,

]인 상승선도로 결정된다. 이는 번째 운전사이클의 최대 온도하중범위가

까지는 [

,

]였지만 이후에는 [

,

]로 증가된 것을 반영하기 위함이다.

As the operation progresses up to this point, the highest temperature in the current cycle is

, but later at a higher temperature (

) overdrive occurs. the highest temperature in

As the local cycle CT-5 changes to [

,

] is determined by the upward trend. This means that the maximum temperature load range of the th operation cycle is

Until [

,

], but after [

,

] to reflect the increase.

The reason for setting the local cycle in this way to evaluate the fatigue damage is to evaluate in real time even if a new maximum load occurs during the operation process without affecting the calculation result for the local cycle that has already been calculated.

)를 카운트하여 이를 해당 과도운전 유형의 허용가능한 최대횟수(

)로 나누어 개별 피로손상 사용계수를 산출하고(S52), 이들 개별 피로손상 사용계수를 최종적으로 합산함으로써, 특정 현재 사이클에 대한 피로손상 사용계수를 산출하는 것(S53)도 종료 사이클의 적용과 동일하므로 중복되는 설명은 피하도록 한다.Transient operation expressed as such a subdivided local cycle can be classified by type in consideration of operating temperature, operating time, and load range, just like when evaluating fatigue damage of the end cycle. And, the number of occurrences for each type of transient operation (

) is counted and this is the maximum permissible number of times (

) to calculate individual fatigue damage usage factors (S52), and finally summing these individual fatigue damage usage factors by calculating the fatigue damage usage factors for a specific current cycle (S53) is the same as the application of the end cycle Therefore, duplicate explanations are avoided.

However, the difference compared to the application of the end cycle is that each local cycle is a diagram showing only one aspect of rising or falling, so in counting the number of occurrences, it is calculated as 0.5 occurrences instead of one. By counting in this way, the accuracy of evaluation can be improved, and conservatism can be relaxed more.

)으로 구획하고 각 구간의 하중을 적용하여 크리프손상을 평가할 수 있다. 이와 관련된 설명은 종료 사이클에 대한 설명과 중복되므로, 생략하기로 한다.In one embodiment of the present invention, the creep damage may be evaluated together with the fatigue damage evaluation for the current cycle. (S54 to S56) In this case, the method for evaluating the creep damage for the current cycle is for the end cycle. In the same way as evaluating creep damage, the load history over time is analyzed at regular time intervals (((

) and applying the load in each section to evaluate creep damage. Since the description related thereto overlaps with the description of the end cycle, it will be omitted.

On the other hand, the damage monitoring method according to an embodiment of the present invention comprises the steps of adding the fatigue damage evaluation result and the creep damage evaluation result of the end cycle and the current cycle through the comprehensive evaluation unit 34 of the damage evaluation device 30, respectively. (S60) Through this, the damage monitoring method according to an embodiment of the present invention continuously accumulates the load history for the entire operating time, and the degree of accumulated damage at the time of evaluation can be checked in real time. As described above, the damage monitoring method according to an embodiment of the present invention performs fatigue damage and creep damage evaluation for the current cycle as well as the end cycle and adds them up, so that the damage level of the high-temperature structure is monitored more realistically and accurately. There are advantages to doing.

And the damage monitoring method according to an embodiment of the present invention includes the step of comprehensively evaluating the summed fatigue damage evaluation result and the creep damage evaluation result, respectively. (S70) The above step also includes the comprehensive evaluation unit 34 It is, of course, carried out through

As described above, especially in high-temperature structures, fatigue damage and creep damage do not produce independent results, but may affect each other. Therefore, in one embodiment of the present invention, it is possible to determine whether a high-temperature structure is safe by considering the correlation between the calculated fatigue damage and creep damage evaluation results, rather than separately analyzing the results.

As an example, as shown in FIG. 11 , an evaluation table in the form of a straight line comprehensive line in which the above-described correlation is considered may be used. If fatigue damage and creep damage have a simple linear relationship, each (0.5, 0.5) may be acceptable, but when using the table in the form of a straight line comprehensive diagram in Fig. X, (0.5, 0.5) is no longer safe. It does not, and the safe range is greatly reduced and will be allowed up to the point (0.3, 0.3).

On the other hand, in an embodiment of the present invention, information related to damage to the high-temperature structure derived by the damage evaluation device 30 may be automatically transmitted to the user. For example, as shown in FIG. 2 , it may be transmitted to the display device 50 using a wireless or wired communication means and delivered to the user.

Meanwhile, the damage evaluation apparatus 30 of the real-time damage monitoring system according to an embodiment of the present invention may include at least one processor, a computer readable storage medium, and a communication bus. The processor may cause the impairment assessment device 30 to operate according to the exemplary embodiment described above. For example, the processor may execute one or more programs stored in a computer-readable storage medium. The one or more programs may include one or more computer-executable instructions, which, when executed by a processor, may be configured to cause the impairment assessment apparatus to perform operations according to an exemplary embodiment. Here, the computer-readable storage medium may be configured to store computer-executable instructions or program code, program data, and/or other suitable form of information. A program stored in a computer-readable storage medium may include a set of instructions executable by a processor. In one embodiment, the computer-readable storage medium includes memory (volatile memory, such as random access memory, non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices. , other types of storage media that can be accessed by the computing device and can store desired information, or a suitable combination thereof.

As described above, the real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention can improve the accuracy of evaluation by considering all current cycles up to the evaluation point even for the high-temperature structure in operation. In addition, the real-time damage monitoring method for a high-temperature structure according to an embodiment of the present invention is evaluated for damage to a high-temperature pipe through which a high-temperature thermal fluid is moved, such as an intermediate heat transfer system (IHTS) of a sodium-cooled high-speed reactor, up to creep damage. By comprehensively considering them together, the reliability of the evaluation can be improved.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , changes, deletions, additions, etc. may easily suggest other embodiments, but this will also fall within the scope of the present invention.

10 Load history collection device 11 Temperature sensor
12 Pressure sensor 13 Flow sensor
30 Real-time damage assessment device 50 Display device
100 real-time damage monitoring system
S10 Step of collecting load history
Step of dividing the S20 operation cycle into a plurality of unit cycles
S30 Determining whether the unit cycle is the end cycle or the current cycle
Steps to Assess the Damage of the S40 End Cycle
Steps to assess the damage of the S50 current cycle
The step of summing the damage assessment of the S60 end cycle and the current cycle
Step to comprehensively evaluate the damage to the S70 high-temperature structure

Claims (16)

As a method for real-time evaluation of fatigue damage to high-temperature structures in operation,
dividing the entire driving cycle into a plurality of unit cycles according to the driving cycle;
determining whether the unit cycle is an end cycle in which operation is terminated or a current cycle in which operation is in progress;
evaluating the fatigue damage with respect to the end cycle among the unit cycles; and
and evaluating the fatigue damage with respect to the current cycle among the unit cycles, and
The step of evaluating the fatigue damage with respect to the current cycle among the unit cycles,
subdividing the current cycle into a plurality of local cycles;
Calculating a fatigue damage use factor for each local cycle; and
Comprising the step of summing the fatigue damage use coefficient calculated for each local cycle,
The step of subdividing the current cycle into a plurality of local cycles comprises:
Divided into a plurality of local cycles based on the point at which the temperature rise or fall begins,
Calculating the fatigue damage usage coefficient for each local cycle comprises:
Real-time fatigue for high-temperature structures, calculated as the ratio of the actual number of occurrences of the local cycle to the maximum number of cycles allowed for each local cycle, and calculated by considering that one local cycle has occurred 0.5 times when calculating the actual number of occurrences How to assess damage. The method of claim 1,
The real-time fatigue damage evaluation method for a high-temperature structure, wherein the high-temperature structure is a pipe through which a high-temperature thermal fluid is moved. 3. The method of claim 2,
The pipe is an intermediate heat transfer system of a sodium-cooled high-speed reactor, a real-time fatigue damage evaluation method for a high-temperature structure. delete delete delete As a method for real-time monitoring of damage to high-temperature structures in operation,
dividing the entire driving cycle into a plurality of unit cycles according to the driving cycle;
determining whether the unit cycle is an end cycle in which operation is terminated or a current cycle in which operation is in progress;
evaluating fatigue damage and creep damage for the end cycle among the unit cycles;
evaluating the fatigue damage and creep damage with respect to the current cycle among the unit cycles;
summing the fatigue damage and creep damage evaluation results of the end cycle and the current cycle, respectively;
Comprising the step of comprehensively evaluating the damage to the high-temperature structure,
Evaluating the fatigue damage and creep damage with respect to the current cycle among the unit cycles comprises:
subdividing the current cycle into a plurality of local cycles;
Calculating a fatigue damage use factor for each local cycle; and
Comprising the step of summing the fatigue damage use coefficient calculated for each local cycle,
The step of subdividing the current cycle into a plurality of local cycles comprises:
Divided into a plurality of local cycles based on the point at which the temperature rise or fall begins,
Calculating the fatigue damage usage coefficient for each local cycle comprises:
Real-time damage to high-temperature structures, calculated as the ratio of the actual number of occurrences of the local cycle to the maximum number of cycles allowed for each local cycle, and calculated by considering that one local cycle has occurred 0.5 times when calculating the actual number of occurrences monitoring method. delete delete 8. The method of claim 7,
Evaluating the fatigue damage and creep damage for the end cycle of the unit cycle comprises:
subdividing the end cycle for each type of transient operation;
Calculating a fatigue damage usage coefficient for each type of transient operation; and
A real-time damage monitoring method for a high-temperature structure, comprising the step of summing the fatigue damage usage coefficient calculated for each type of transient operation. 8. The method of claim 7,
Evaluating the fatigue damage and creep damage with respect to the end cycle of the unit cycle, and evaluating the fatigue damage and creep damage with respect to the current cycle of the unit cycle, respectively,
subdividing the load history of the end cycle or the current cycle into time sections at regular intervals;
calculating the creep damage usage coefficient for each time period;
A real-time damage monitoring method for a high-temperature structure, comprising the step of summing the creep damage usage coefficient calculated for each time period. 12. The method of claim 11,
The step of calculating the creep damage usage coefficient for each time period comprises:
A real-time damage monitoring method for a high-temperature structure in which a stress is applied to a plurality of consecutive time sections while maintaining a constant temperature compared to the previous time section. 8. The method of claim 7,
The step of comprehensively evaluating the damage to the high-temperature structure,
A real-time damage monitoring method for a high-temperature structure for determining whether the high-temperature structure is safe in consideration of the correlation between the fatigue damage and the creep damage. As a system for real-time monitoring of damage to high-temperature structures in operation,
A load history collecting device installed in the high-temperature structure to collect at least one of temperature data, pressure data, and flow rate data of the coolant inside the high-temperature structure in real time and convert it into a digital signal; and
and a damage evaluation device that analyzes the digital signal received from the load history collecting device to evaluate whether the high-temperature structure is damaged and transmits the damage information to the user,
The damage assessment device,
a driving cycle classification unit dividing the entire driving cycle into a plurality of unit cycles according to the driving cycle, and determining whether the unit cycle is an end cycle in which the driving is finished or a current cycle in which the driving is in progress;
an end cycle evaluation unit for evaluating fatigue damage and creep damage for the end cycle among the unit cycles;
a current cycle evaluation unit for evaluating the fatigue damage and creep damage with respect to the current cycle among the unit cycles; and
Comprising a comprehensive evaluation unit for comprehensively evaluating the damage to the high-temperature structure by summing the fatigue damage and creep damage evaluation results of the end cycle and the current cycle,
The current cycle evaluation unit,
After subdividing the current cycle into a plurality of local cycles, calculating the fatigue damage usage factor for each local cycle, summing the fatigue damage usage factor calculated for each local cycle to evaluate the fatigue damage,
The current cycle evaluation unit,
When the current cycle is subdivided into a plurality of local cycles, the current cycle is divided into a plurality of local cycles based on the point at which the temperature rise or fall starts,
When the fatigue damage use factor is calculated for each local cycle, it is calculated as the ratio of the actual number of occurrences of the local cycle to the maximum number of cycles allowed for each local cycle, and when calculating the actual number of occurrences, one local cycle is 0.5 times A real-time damage monitoring system for high-temperature structures that counts as occurring. delete delete

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