JPH11173490A - Heat fatigue prevention method for pipe or the like - Google Patents
Heat fatigue prevention method for pipe or the likeInfo
- Publication number
- JPH11173490A JPH11173490A JP34103097A JP34103097A JPH11173490A JP H11173490 A JPH11173490 A JP H11173490A JP 34103097 A JP34103097 A JP 34103097A JP 34103097 A JP34103097 A JP 34103097A JP H11173490 A JPH11173490 A JP H11173490A
- Authority
- JP
- Japan
- Prior art keywords
- pipe
- stress
- thermal fatigue
- analysis
- distribution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Protection Of Pipes Against Damage, Friction, And Corrosion (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、発電プラントや化
学プラントにおける、温度変動のある流体が内部を流れ
る配管やノズルの、熱疲労損傷を防止する方法に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing thermal fatigue damage of pipes and nozzles in a power plant or chemical plant through which a fluid having a temperature fluctuation flows.
【０００２】[0002]
【従来の技術】熱疲労を受ける配管や配管類似部材の熱
疲労損傷を防止する方法としては、例えば、特願平1−4
0103号出願や、M. Hayashi et. at.‘Fatigue monitori
ngsystem for BWR reactor pressure vessel’11th int
ernational conference and exhibits on NDE in the n
uclear pressure vessel industries にあるように、プ
ラント機器の疲労損傷の発生が予想される部位の近傍に
流体の温度，流体の流速，機器の温度を測定できるセン
サーを設けて、温度や流速をプラントの稼働中に計測
し、これらのデータを用いて機器のひずみ履歴を解析
し、熱疲労損傷の程度を評価して、熱疲労の蓄積が大き
くなったときに運転を停止したり、熱疲労を受けた機器
を交換する方法が考えられてきた。2. Description of the Related Art As a method for preventing thermal fatigue damage of a pipe or a pipe-like member subjected to thermal fatigue, for example, Japanese Patent Application No. Hei.
No. 0103 application and M. Hayashi et. At.'Fatigue monitori
ngsystem for BWR reactor pressure vessel'11th int
ernational conference and exhibits on NDE in the n
As in uclear pressure vessel industries, a sensor that can measure fluid temperature, fluid flow rate and equipment temperature is installed near the site where fatigue damage of plant equipment is expected to occur, and the temperature and flow rate of the plant are operated. During the measurement, the strain history of the equipment was analyzed using these data, and the degree of thermal fatigue damage was evaluated. Methods for replacing equipment have been considered.
【０００３】[0003]
【発明が解決しようとする課題】従来の技術を用いれ
ば、配管や配管類似部材において発生する熱疲労損傷を
監視し、機器の寿命を適切に判断してプラントの運転を
停止したり機器を交換することが可能である。しかし、
熱疲労損傷の監視にとどまるため、熱疲労損傷を防止、
あるいは低減させる方法を与えるものではない。熱疲労
損傷を起こらなくする、あるいは熱疲労損傷の程度を低
減させる方法が望まれていた。According to the conventional technique, thermal fatigue damage occurring in a pipe or a pipe-like member is monitored, the life of the equipment is appropriately determined, and the operation of the plant is stopped or the equipment is replaced. It is possible to But,
Prevents thermal fatigue damage by monitoring thermal fatigue damage only,
Or, it does not provide a method for reducing it. There has been a demand for a method for preventing thermal fatigue damage or reducing the degree of thermal fatigue damage.
【０００４】[0004]
【課題を解決するための手段】上記従来技術の課題を解
決するために、高温の流体を流通させる配管やそれに類
似する部材において、配管の温度分布の計測値と配管外
周のひずみの計測値とから配管の応力分布を解析で求
め、応力分布の解析結果に基づいて配管の内周における
引張り応力が最小となるように、配管外周に設置した複
数のヒーターの出力を制御することによって、配管等の
熱疲労を防止できるようにする。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems in the prior art, in a pipe through which a high-temperature fluid flows or a member similar to the pipe, a measured value of a pipe temperature distribution and a measured value of a strain of a pipe outer periphery are used. From the analysis of the stress distribution of the piping from the analysis, based on the analysis results of the stress distribution, by controlling the output of multiple heaters installed on the outer periphery of the piping so as to minimize the tensile stress on the inner circumference of the piping, To prevent thermal fatigue.
【０００５】即ち、本発明の方法を適用すれば、流体が
流通しており流体との相互作用によって疲労損傷が特に
大きくなると予想される配管内面の発生応力を、配管の
拘束条件も考慮して、応力解析によって求めることがで
きる。配管内面の発生応力が引張り応力の場合に、その
引張り応力を最小とする配管外周からの加熱条件を解析
で求め、その加熱条件を実現するように配管の外周部に
設けたヒーターの加熱を行い、配管内面に発生する引張
り応力を小さく抑えることができ、配管内面の熱疲労損
傷を防止することができる。That is, if the method of the present invention is applied, the stress generated on the inner surface of a pipe, which is expected to cause particularly large fatigue damage due to the interaction of the fluid with the fluid, is considered in consideration of the constraint conditions of the pipe. Can be determined by stress analysis. When the stress generated on the inner surface of the pipe is a tensile stress, the heating conditions from the outer circumference of the pipe that minimize the tensile stress are obtained by analysis, and the heater provided on the outer circumference of the pipe is heated to realize the heating condition. Further, the tensile stress generated on the inner surface of the pipe can be suppressed to be small, and the thermal fatigue damage of the inner surface of the pipe can be prevented.
【０００６】また本発明によれば、実際に配管内面に発
生していた応力の発生履歴を高精度に予測することがで
き、その応力の発生履歴予測に基づいて疲労累積損傷係
数を計算することができ、疲労累積損傷係数の計算結果
に基づいて構造物の余寿命予測をすることができる。Further, according to the present invention, it is possible to accurately predict the occurrence history of the stress actually generated on the inner surface of the pipe, and to calculate the fatigue cumulative damage coefficient based on the prediction of the occurrence history of the stress. It is possible to predict the remaining life of the structure based on the calculation result of the fatigue cumulative damage coefficient.
【０００７】[0007]
【発明の実施の形態】図１から図６を用いて、本発明に
よる配管等の熱疲労防止方法の実施例を説明する。図１
及び図２は、熱疲労防止方法の装置構成を示した図であ
る。配管１の内部には、プラントの運転中に流体２が流
れている。流体２は、プラントの運転の状態に応じて、
低温の状態や高温の状態、あるいは高温の流体と低温の
流体が混合した状態となっている。例えば、配管１にお
いて下部を低温の流体が流れ、上部を高温の流体が流れ
ると、配管１は、その下部が低温，上部が高温となり、
高温の上部が低温の下部よりも膨張するために配管に曲
げモーメントが発生する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for preventing thermal fatigue of a pipe or the like according to the present invention will be described with reference to FIGS. FIG.
FIG. 2 is a diagram showing an apparatus configuration of a thermal fatigue prevention method. The fluid 2 flows inside the pipe 1 during operation of the plant. Fluid 2 depends on the state of operation of the plant,
The state is a low temperature state, a high temperature state, or a state in which a high temperature fluid and a low temperature fluid are mixed. For example, when a low-temperature fluid flows through the lower portion of the pipe 1 and a high-temperature fluid flows through the upper portion, the lower portion of the pipe 1 has a lower temperature and the upper portion has a high temperature.
A bending moment is generated in the pipe because the hot upper part expands more than the cold lower part.
【０００８】配管１は、プラントの配管系によって拘束
されているため、その拘束力との兼ね合いで配管１には
熱応力が発生する。配管１の内部には流体２が流れてお
り、配管１の内周部３では、熱応力と流体２との相互作
用で、配管１の外周部４よりも比較的大きな熱疲労損傷
を受ける可能性がある。配管１には、その周方向および
軸方向の数ヵ所に、熱電対５を埋め込んでおく。Since the pipe 1 is restrained by the piping system of the plant, thermal stress is generated in the pipe 1 in consideration of the restraining force. The fluid 2 flows inside the pipe 1, and the inner peripheral portion 3 of the pipe 1 may be subjected to relatively larger thermal fatigue damage than the outer peripheral portion 4 of the pipe 1 due to the interaction between the thermal stress and the fluid 2. There is. Thermocouples 5 are embedded in the pipe 1 at several locations in the circumferential and axial directions.
【０００９】各位置には、配管１の厚さ方向の温度の違
いも測定できるように、埋め込み深さを変えて、熱電対
５を複数本埋め込んでおく。熱電対５の出力は、計測ア
ンプ８で増幅して、その信号を計測，解析及び制御用コ
ンピュータ１０に入力する。また、配管１の外周部４に
は、周方向及び軸方向の複数の箇所に、ひずみゲージを
貼付しておく。ひずみゲージの出力は、計測アンプ８で
増幅して、計測，解析及び制御用コンピュータ１０に入
力する。At each position, a plurality of thermocouples 5 are buried at different burying depths so that the temperature difference in the thickness direction of the pipe 1 can be measured. The output of the thermocouple 5 is amplified by the measurement amplifier 8 and the signal is input to the measurement, analysis and control computer 10. In addition, strain gauges are attached to the outer peripheral portion 4 of the pipe 1 at a plurality of locations in the circumferential direction and the axial direction. The output of the strain gauge is amplified by the measurement amplifier 8 and input to the computer 10 for measurement, analysis and control.
【００１０】また、配管１の外周部にはヒーター７を周
方向及び軸方向の数ヵ所に設置しておく。計測，解析及
び制御用コンピュータ１０からの制御信号により、ヒー
ター制御装置９がヒーター７に電力を供給し、ヒーター
７は加熱される。計測，解析及び制御用コンピュータ１
０には、余寿命評価用コンピュータ１１が接続されてい
る。プラント運転中に配管１中を流れる流体２の温度は
変化し、流体２の温度変動によって配管１には温度分布
が形成される。On the outer periphery of the pipe 1, heaters 7 are installed at several places in the circumferential direction and the axial direction. The heater control device 9 supplies electric power to the heater 7 according to a control signal from the measurement, analysis and control computer 10, and the heater 7 is heated. Measurement, analysis and control computer 1
0 is connected to the remaining life evaluation computer 11. During operation of the plant, the temperature of the fluid 2 flowing in the pipe 1 changes, and a temperature distribution of the fluid 1 is formed in the pipe 1 due to the temperature fluctuation of the fluid 2.
【００１１】配管１の周方向及び軸方向に複数設置され
た熱電対５で温度を計測すると、図３及び図４に示すよ
うな温度分布が求められる。図３及び図４中のΘは、配
管１の周方向の位置を示し、ｘは配管軸方向の位置を、
Ｌは配管の長さを示す。ここで、例えばΘ＝０°は、配
管１の上部方向を示し、このとき、図３及び図４の温度
分布は、配管１の上部で温度が高く、配管１の下部で温
度が低い例である。When the temperature is measured by a plurality of thermocouples 5 installed in the circumferential direction and the axial direction of the pipe 1, a temperature distribution as shown in FIGS. 3 and 4 is obtained. 3 and 4 indicate the position in the circumferential direction of the pipe 1, x indicates the position in the pipe axial direction,
L indicates the length of the pipe. Here, for example, Θ = 0 ° indicates the upper direction of the pipe 1, and at this time, the temperature distribution in FIGS. 3 and 4 is an example in which the temperature is higher at the upper part of the pipe 1 and lower at the lower part of the pipe 1. is there.
【００１２】図５は、配管１の応力解析モデルの例３０
である。熱応力評価点３５の熱応力を基準に、本発明に
よる熱疲労防止方法を適用する。ひずみ計測点４０〜４
５の位置の、ひずみの解析値と実測値を比較し、本発明
による熱疲労防止方法を適用する。加熱領域５０〜５５
は、それぞれ個別にヒーターを設置してある領域であ
る。拘束による軸力６０と拘束による曲げモーメント６
５は、配管１の両端部に図５のように作用しているもの
とする。FIG. 5 shows an example 30 of a stress analysis model of the pipe 1.
It is. The thermal fatigue prevention method according to the present invention is applied based on the thermal stress at the thermal stress evaluation point 35. Strain measurement point 40-4
The strain analysis value and the measured value at the position 5 are compared, and the thermal fatigue prevention method according to the present invention is applied. Heating area 50-55
Are areas where heaters are individually installed. Axial force 60 due to constraint and bending moment 6 due to constraint
5 acts on both ends of the pipe 1 as shown in FIG.
【００１３】図６は、本発明による熱疲労防止方法のフ
ローを示す図である。はじめに温度分布計測ステップ７
０において、図１及び図２に示す装置を用いて配管１の
温度を測定し、図３及び図４に示すような温度分布を求
める。次に、応力，ひずみ分布の解析ステップ７１にお
いて、温度分布計測ステップ７０で取得した温度分布を
初期条件として、計測，解析及び制御用コンピュータ１
０を用いて、配管１の応力及びひずみ分布を解析する。FIG. 6 is a diagram showing a flow of a thermal fatigue prevention method according to the present invention. Introduction temperature distribution measurement step 7
At 0, the temperature of the pipe 1 is measured using the apparatus shown in FIGS. 1 and 2, and the temperature distribution as shown in FIGS. 3 and 4 is obtained. Next, in a stress / strain distribution analysis step 71, the measurement, analysis and control computer 1 is set using the temperature distribution acquired in the temperature distribution measurement step 70 as an initial condition.
Using 0, the stress and strain distribution of the pipe 1 is analyzed.
【００１４】次に、周方向のひずみ平均値の比較ステッ
プ７２で、図５のひずみ計測点４０〜４５の各軸方向位
置における周方向平均ひずみを実測値と解析値で比較す
る。周方向のひずみ平均値の比較ステップ７２において
実測値と解析値が大きく異なる場合には拘束による軸力
７０が作用していると判断し、次に軸力の設定ステップ
７３で軸力を設定する。軸力を設定したら、この軸力を
境界条件として、応力，ひずみ分布の解析ステップ７１
で再び応力分布及びひずみ分布を解析する。Next, at a circumferential average strain value comparison step 72, the average circumferential strain at each axial position of the strain measurement points 40 to 45 in FIG. 5 is compared with the actually measured value and the analysis value. If the measured value is significantly different from the analysis value in the circumferential average strain value comparison step 72, it is determined that the axial force 70 due to the constraint is acting, and then the axial force is set in the axial force setting step 73. . After the axial force is set, the stress and strain distribution analysis step 71 is performed using the axial force as a boundary condition.
The stress distribution and the strain distribution are analyzed again.
【００１５】一方、周方向のひずみ偏差比較ステップ７
４において、図５のひずみ計測点４０〜４５の各軸方向
位置において周方向平均ひずみからの偏差ひずみを実測
値と解析値で比較する。周方向のひずみ偏差比較ステッ
プ７４において実測値と解析値が大きく異なる場合には
拘束による曲げモーメント６５が作用していると判断
し、次に曲げモーメントの設定ステップ７５で曲げモー
メントを設定する。曲げモーメントを設定したら、この
曲げモーメントを境界条件として、応力，ひずみ分布の
解析ステップ７１で再び応力分布及びひずみ分布を解析
する。On the other hand, a circumferential strain deviation comparing step 7
In step 4, the deviation from the circumferential average strain at each axial position of the strain measurement points 40 to 45 in FIG. 5 is compared with the actually measured value and the analysis value. If the measured value and the analysis value are significantly different from each other in the circumferential strain deviation comparing step 74, it is determined that the bending moment 65 due to the constraint is acting, and then the bending moment is set in the bending moment setting step 75. After setting the bending moment, the stress distribution and the strain distribution are analyzed again in the stress / strain distribution analysis step 71 using the bending moment as a boundary condition.
【００１６】以上の、軸力の設定ステップ７３と曲げモ
ーメントの設定ステップ７５を、周方向のひずみ平均値
比較ステップ７２と周方向のひずみ偏差比較ステップ７
４において実測値と解析値が大きく異ならないようにな
るまで繰り返す。応力解析ステップ７６では、温度分布
の計測結果と最終的に求められた軸力及び曲げモーメン
トを初期条件及び境界条件として、例えば有限要素法に
より解析を行う。The above-described axial force setting step 73 and bending moment setting step 75 are made up of a circumferential strain average value comparing step 72 and a circumferential strain deviation comparing step 7.
This is repeated until the actual measurement value and the analysis value do not greatly differ in step 4. In the stress analysis step 76, analysis is performed by, for example, a finite element method using the measurement result of the temperature distribution and the finally obtained axial force and bending moment as initial conditions and boundary conditions.
【００１７】次に、内周部の引張り応力比較ステップ７
７において、応力解析ステップ７６で配管１の内周部３
に引張り応力が発生していると解析された場合には、そ
の引張り応力と配管１の材料の疲労限との比較を行う。
内周部の引張り応力比較ステップ７７において、配管１
の内周部３の引張り応力が疲労限よりも大きいと判断さ
れた場合には、次の外周部の加熱条件の設定ステップ７
８において、配管１の内周部３の引張り応力ができるだ
け小さくなるように、配管外周部の加熱条件を設定す
る。この配管外周部の加熱条件を境界条件として与え、
再び応力解析ステップ７９で有限要素法等により応力解
析を行う。Next, a step 7 for comparing the tensile stress of the inner peripheral portion is performed.
7, in the stress analysis step 76, the inner peripheral portion 3 of the pipe 1
When it is analyzed that a tensile stress is generated in the pipe 1, the tensile stress is compared with the fatigue limit of the material of the pipe 1.
In the tensile stress comparison step 77 of the inner peripheral portion, the pipe 1
If it is determined that the tensile stress of the inner peripheral portion 3 is larger than the fatigue limit, the next heating condition setting step 7 of the outer peripheral portion is performed.
At 8, the heating condition of the outer peripheral portion of the pipe 1 is set so that the tensile stress of the inner peripheral portion 3 of the pipe 1 becomes as small as possible. The heating condition of the outer periphery of the pipe is given as a boundary condition,
The stress analysis is performed again by the finite element method or the like in the stress analysis step 79.
【００１８】次に、内周部の引張り応力比較ステップ８
０において、再び内周部の引張り応力と疲労限の比較を
行う。内周部の引張り応力比較ステップ８０において、
まだ内周部の引張り応力が疲労限よりも大きいと判断さ
れた場合には、外周部加熱条件の設定ステップ７８に戻
って、再度、外周部加熱条件の設定を行う。この外周部
加熱条件の設定フローを繰り返し、内周部の引張り応力
比較ステップ８０において、内周部の引張り応力が疲労
限よりも小さくなったら、ヒーターによる加熱ステップ
８１にて、配管１の外周部４をヒーターで加熱する。Next, a tensile stress comparing step 8 of the inner peripheral portion is performed.
At 0, the tensile stress of the inner peripheral portion and the fatigue limit are compared again. In the tensile stress comparing step 80 of the inner peripheral portion,
If it is determined that the tensile stress in the inner peripheral portion is still larger than the fatigue limit, the process returns to the outer peripheral portion heating condition setting step 78 to set the outer peripheral portion heating condition again. This setting flow of the outer peripheral portion heating conditions is repeated, and in the tensile stress comparing step 80 of the inner peripheral portion, when the tensile stress of the inner peripheral portion becomes smaller than the fatigue limit, in the heating step 81 by the heater, the outer peripheral portion of the pipe 1 is heated. 4 is heated with a heater.
【００１９】また、内周部の引張り応力比較ステップ７
７において、内周部の引張り応力が疲労限よりも小さい
と判断された場合には、ヒーターによる加熱ステップ８
１は実施しない。内周部の引張り応力比較ステップ７７
または８０において内周部の引張り応力が疲労限よりも
小さいと判断されたときの応力を用いて、累積疲労損傷
係数の計算ステップ８２において余寿命評価用コンピュ
ータ１１を用いて、累積疲労損傷係数を計算する。この
累積疲労損傷係数に基づいて、余寿命評価ステップ８３
で、配管１の余寿命を評価する。Further, a step 7 for comparing the tensile stress of the inner peripheral portion
In step 7, when it is determined that the tensile stress of the inner peripheral portion is smaller than the fatigue limit, the heating step 8
1 is not performed. Inner peripheral tensile stress comparison step 77
Alternatively, the cumulative fatigue damage coefficient is calculated by using the remaining life evaluation computer 11 in the step 82 of calculating the cumulative fatigue damage coefficient using the stress when it is determined that the tensile stress of the inner peripheral portion is smaller than the fatigue limit in 80. calculate. Based on the cumulative fatigue damage coefficient, the remaining life evaluation step 83
Then, the remaining life of the pipe 1 is evaluated.
【００２０】[0020]
【発明の効果】本発明により、配管及び配管類似部材の
熱疲労を低減、あるいは防止することができる。According to the present invention, thermal fatigue of piping and piping-like members can be reduced or prevented.
【図１】本発明の実施例である熱疲労防止装置の構成を
示す図である。FIG. 1 is a diagram showing a configuration of a thermal fatigue prevention device according to an embodiment of the present invention.
【図２】図１の配管部分を軸方向から見た断面図であ
る。FIG. 2 is a cross-sectional view of the pipe portion of FIG. 1 as viewed from an axial direction.
【図３】図２の配管の温度と軸方向位置との関係を示す
特性図である。FIG. 3 is a characteristic diagram showing a relationship between a temperature of a pipe in FIG. 2 and an axial position.
【図４】配管の温度の周方向分布と温度との関係を示す
特性図である。FIG. 4 is a characteristic diagram showing a relationship between a circumferential distribution of a pipe temperature and a temperature.
【図５】配管の応力解析のモデルの例を示す図である。FIG. 5 is a diagram showing an example of a model for stress analysis of piping.
【図６】熱疲労防止方法を適用するためのフローを示す
フローチャートである。FIG. 6 is a flowchart showing a flow for applying the thermal fatigue prevention method.
１…配管、２…流体、３…内周部、４…外周部、５…熱
電対、６…ひずみゲージ、７…ヒーター、８…計測アン
プ、９…ヒーター制御装置、１０…計測，解析及び制御
用コンピュータ、１１…余寿命評価用コンピュータ、２
０…温度分布（Θ＝０°）、２１…温度分布（Θ＝９０
°）、２２…温度分布(Θ＝１８０°)、２５…温度分布
（ｘ＝Ｌ／２）、３０…配管の解析モデルの例、３５…
応力評価点、４０〜４５…ひずみ計測点、５０〜５５…
外周部加熱領域、６０…拘束による軸力、６５…拘束に
よる曲げモーメント、７０…温度分布計測ステップ、７
１…応力，ひずみ分布の解析ステップ、７２…周方向の
ひずみ平均値比較ステップ、７３…軸力の設定ステッ
プ、７４…周方向のひずみ偏差比較ステップ、７５…曲
げモーメントの設定ステップ、７６…応力解析ステッ
プ、７７…内周部の引張り応力比較ステップ、７８…外
周部加熱条件の設定ステップ、７９…応力解析ステッ
プ、８０…内周部の引張り応力比較ステップ、８１…ヒ
ーターによる加熱ステップ、８２…累積疲労損傷係数の
計算ステップ、８３…余寿命評価ステップ。DESCRIPTION OF SYMBOLS 1 ... piping, 2 ... fluid, 3 ... inner peripheral part, 4 ... outer peripheral part, 5 ... thermocouple, 6 ... strain gauge, 7 ... heater, 8 ... measuring amplifier, 9 ... heater control device, 10 ... measurement, analysis and Control computer, 11 ... Computer for remaining life evaluation, 2
0: temperature distribution (Θ = 0 °), 21: temperature distribution (Θ = 90)
°), 22: Temperature distribution (Θ = 180 °), 25: Temperature distribution (x = L / 2), 30: Example of analysis model of piping, 35:
Stress evaluation point, 40-45 ... Strain measurement point, 50-55 ...
Outer peripheral heating area, 60: axial force due to restraint, 65: bending moment due to restraint, 70: temperature distribution measurement step, 7
1 ... Stress and strain distribution analysis step, 72 ... Circumferential strain average value comparison step, 73 ... Axial force setting step, 74 ... Circumferential strain deviation comparison step, 75 ... Bending moment setting step, 76 ... Stress Analysis step, 77: inner peripheral tensile stress comparison step, 78: outer peripheral heating condition setting step, 79: stress analysis step, 80: inner peripheral tensile stress comparison step, 81: heater heating step, 82: Calculation step of cumulative fatigue damage coefficient, 83 ... remaining life evaluation step.
Claims (9)
する部材において、配管の温度分布の計測値と配管外周
のひずみの計測値とから配管の応力分布を解析で求め、
応力分布の解析結果に基づいて配管の内周における引張
り応力が最小となるように、配管外周に設置した複数の
ヒーターの出力を制御する配管等の熱疲労防止方法。1. In a pipe through which a high-temperature fluid flows or a member similar thereto, a stress distribution of the pipe is obtained by analysis from a measured value of a temperature distribution of the pipe and a measured value of a strain on the outer circumference of the pipe,
A method for preventing thermal fatigue of a pipe or the like that controls the output of a plurality of heaters installed on the outer circumference of the pipe so that the tensile stress on the inner circumference of the pipe is minimized based on the analysis result of the stress distribution.
するために、複数の熱電対をその周方向と軸方向に複数
設置し、配管の管肉厚部の温度分布を計測できるように
したことを特徴とする配管等の熱疲労防止方法。In order to carry out the method for preventing thermal fatigue of a pipe or the like according to the first aspect, a plurality of thermocouples are provided in the circumferential direction and the axial direction, and a temperature distribution in a pipe thick portion of the pipe can be measured. A method for preventing thermal fatigue of piping and the like, characterized in that:
分布を初期条件として配管の応力分布とひずみ分布を解
析し、解析により得た配管外周のひずみ分布と実測され
た配管外周のひずみ分布の差から、配管を外部から拘束
している力学的条件を予測する方法であることを特徴と
する配管等の熱疲労防止方法。3. Analyzing the stress distribution and strain distribution of the pipe with the temperature distribution of the pipe measured by the thermocouple of claim 2 as an initial condition, and analyzing the strain distribution of the pipe outer circumference obtained by the analysis and the actually measured pipe outer circumference. A method for preventing thermal fatigue of a pipe or the like, which is a method of predicting a mechanical condition for restricting the pipe from the outside from a difference in strain distribution.
施するために、配管外周のひずみ分布を計測できるよう
に配管の外周部の周方向と軸方向にひずみゲージを貼付
した配管であることを特徴とする配管等の熱疲労防止方
法。In order to carry out the method of predicting mechanical constraint conditions according to claim 3, a pipe having strain gauges attached in a circumferential direction and an axial direction of an outer peripheral portion of the pipe so as to measure a strain distribution on the outer circumference of the pipe. A method for preventing thermal fatigue of piping and the like, characterized in that:
た配管において、実測された配管の温度分布と請求項３
の方法で予測した力学的拘束条件とを初期条件及び境界
条件として応力解析を行い、配管の応力分布を予測する
方法であることを特徴とする配管等の熱疲労防止方法。5. A pipe provided with the measuring member according to claim 2 and claim 4, wherein the measured temperature distribution of the pipe and the pipe are provided.
A method for performing stress analysis using the mechanical constraint conditions predicted by the method (1) as initial conditions and boundary conditions, and predicting the stress distribution of the pipes.
布のうち、流体との相互作用によって損傷の発生が著し
くなると予測される配管内周において発生する応力の分
布において、その応力分布に引張り応力が存在する場合
に、配管外周の加熱条件を種々仮定して与えて応力解析
を実行し、配管内面の引張り応力が最小となるような配
管外周の加熱条件を求め、その加熱条件に従って配管外
周を加熱して配管内面の引張り応力を最小にし、配管内
面の熱疲労を防止する方法であることを特徴とする配管
等の熱疲労防止方法。6. A distribution of stresses generated in the inner circumference of a pipe, which is predicted to cause significant damage due to interaction with a fluid, among stress distributions of the pipe predicted by the method of claim 5. In the case where there is tensile stress, the stress analysis is performed by giving various heating conditions on the outer periphery of the pipe, and the heating conditions of the outer circumference of the pipe are determined so that the tensile stress on the inner surface of the pipe is minimized. A method for preventing thermal fatigue of a pipe or the like, which is a method of heating a pipe outer periphery to minimize a tensile stress on a pipe inner surface and prevent thermal fatigue of the pipe inner surface.
施するために、配管外周の複数の部位にヒーターを設け
た配管であることを特徴とする配管等の熱疲労防止方
法。7. A method for preventing thermal fatigue of a pipe or the like, wherein the pipe is provided with heaters at a plurality of locations on the outer periphery of the pipe in order to carry out the method for preventing thermal fatigue of the inner surface of the pipe according to claim 6.
用するために実施する応力解析によって評価される、解
析の時間遅れとヒーターの加熱時間のための遅れによっ
てわずかに発生する引張り応力も含めた配管内面の応力
履歴から、疲労累積損傷係数を計算し、疲労累積損傷係
数に基づいて疲労損傷の進行状態と配管の余寿命を評価
する、配管の余寿命評価方法であることを特徴とする配
管等の熱疲労防止方法。8. A tensile stress slightly generated by a time delay of the analysis and a delay due to a heating time of the heater, which is evaluated by a stress analysis performed to apply the method for preventing thermal fatigue of a pipe inner surface according to claim 6. It is a remaining life evaluation method for pipes that calculates the cumulative fatigue damage coefficient from the stress history of the pipe inner surface, including the pipe, and evaluates the progress of fatigue damage and the remaining life of the pipe based on the cumulative fatigue damage coefficient. To prevent thermal fatigue of pipes.
求項８の配管の余寿命評価方法を実施するために、請求
項２の熱電対と請求項４のひずみゲージとそれら計測セ
ンサーのためのアンプ、及び請求項７のヒーターとヒー
ター制御装置、及び応力解析用コンピュータと余寿命評
価用コンピュータを備え、請求項６の熱疲労防止方法と
請求項８の余寿命評価方法を実施できるように構成した
熱疲労防止及び余寿命評価システムであることを特徴と
する配管等の熱疲労防止方法。9. A thermocouple according to claim 2, a strain gauge according to claim 4, and a sensor for measuring them for implementing the method for preventing thermal fatigue of the inner surface of the pipe and the method for evaluating the remaining life of the pipe according to claim 8. And a computer for stress analysis and a computer for remaining life evaluation, and can implement the thermal fatigue prevention method of claim 6 and the remaining life evaluation method of claim 8. A method for preventing thermal fatigue of a pipe or the like, which is a thermal fatigue prevention and remaining life evaluation system configured as described above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34103097A JPH11173490A (en) | 1997-12-11 | 1997-12-11 | Heat fatigue prevention method for pipe or the like |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34103097A JPH11173490A (en) | 1997-12-11 | 1997-12-11 | Heat fatigue prevention method for pipe or the like |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11173490A true JPH11173490A (en) | 1999-06-29 |
Family
ID=18342584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34103097A Pending JPH11173490A (en) | 1997-12-11 | 1997-12-11 | Heat fatigue prevention method for pipe or the like |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11173490A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011158362A (en) * | 2010-02-01 | 2011-08-18 | Kyushu Electric Power Co Inc | Thermal fatigue evaluation method |
-
1997
- 1997-12-11 JP JP34103097A patent/JPH11173490A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011158362A (en) * | 2010-02-01 | 2011-08-18 | Kyushu Electric Power Co Inc | Thermal fatigue evaluation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4599250B2 (en) | High-frequency induction heating outer surface temperature control method and control device | |
| Robinson et al. | Experimental investigation of the high-temperature performance of high-strength steel suspension bridge wire | |
| KR101403347B1 (en) | Apparatus of steam generator tube plugging analysis using pressure drop and heat-transfer performance | |
| EP0165675B1 (en) | Apparatus for measuring thermal stress of pressure-tight tube | |
| JPH11173490A (en) | Heat fatigue prevention method for pipe or the like | |
| JP2008134095A (en) | Lifetime evaluation device of high temperature apparatus, and lifetime evaluation method of high temperature apparatus | |
| JP4579749B2 (en) | Pipe thinning prediction apparatus and pipe thinning prediction method | |
| US6116094A (en) | Method for determining the axial load on an elongated member | |
| Law et al. | Finite element analysis of creep using Theta projection data | |
| JPH06222053A (en) | Deterioration diagnostic method for ferrite based heat-resistant steel | |
| Rezaie et al. | Probabilistic fracture assessment of snake laid pipelines under high pressure/high temperature conditions by engineering critical assessment | |
| CN111811687A (en) | Pipeline temperature monitoring system | |
| JPS59128429A (en) | Life monitoring method for pressure resisting parts | |
| JP2627925B2 (en) | Remaining life evaluation method for metallic materials | |
| EP4273524A1 (en) | System and method for non-invasive determining of a fluid temperature | |
| Maslov et al. | Strain-measurement-based calculation and experimental determination of stresses on equipment internal surfaces | |
| JPH09145578A (en) | Apparatus for determining development of crack in pipe | |
| JP5688352B2 (en) | Heat treatment method for piping | |
| JPH09324900A (en) | Method and apparatus for monitoring thermal fatigue damage in piping or the like | |
| JPH0159402B2 (en) | ||
| JPH0772725B2 (en) | Method and apparatus for evaluating temperature cracks in concrete | |
| Schulz et al. | Failure Modes of the Primary System of PWR | |
| CN118375533A (en) | Reliability test method and system for thrust chamber of liquid rocket engine | |
| JP5479985B2 (en) | Heat treatment method for piping | |
| JPS6327732A (en) | Method for forecasting life of cylindrical metal machinery |