压力容器2024，Vol.41Issue(2)：43-48,80,7.DOI:10.3969/j.issn.1001-4837.2024.02.006
T型三通管道冷热流体混合作用下循环热疲劳评估方法
An assessment method of thermal cycling induced fatigue of T-shaped junctions under combined action of hot and cold fluid
王明毓 1刘锐 2李春锦3
作者信息
- 1. 通用核能国际有限公司,英国伦敦 SW1Y4PE
- 2. 生态环境部核与辐射安全中心,北京 102442
- 3. 深圳中广核工程设计有限公司,广东深圳 518172
- 折叠
摘要
Abstract
With regards to T-shaped junctions commonly used for mixing hot and cold fluid in nuclear power stations,the previous studies mostly focused on the flow characteristics and temperature distribution of fluid mixture.A simplified assessment method for thermal fatigue was raised herein.The advantages and disadvantages of the JSME guideline for thermal fatigue assessment were analyzed.Furthermore,the mixing characteristics of the fluid were summarized through the laboratory tests.The tests show that temperature fluctuation strength increases with the increase of momentum ratio,the maximum normalized RMS temperature difference is 0.26;The temperature difference between hold and cold fluid has limited influence on temperature fluctuation strength,which is only 5%.Meanwhile,the tests show that there is no typical dominant frequency for the mixed fluid in the range of 0.05～2 Hz.Based on the above results,a simplified assessment method was obtained and proposed to simplify T-shaped junction as the axial symmetric pipe model,and simplify a series of sinusoidal thermal loads,the fluctuating temperature difference was defined as 75%of the nominal temperature difference.The tee junction with cracks found in the inspection of RHR system of a PWR nuclear station was analyzed.The accumulative running time of this component was evaluated to be about 726 h under the combined action of the hot and cold fluid with the temperature difference of more than 150℃,whereas the corresponding effective operation time is 450 h stipulated in the common RHR system operation guideline,so its fatigue risk can be well controlled;The fatigue life according to JSME guideline was 1 190 h,which is not conservative enough for this case;The fatigue life estimated by the method of this study was 587 h,which can better predict the fatigue life in this case,and further effectively identify thermal fatigue risk and guide operation and overhaul.关键词
T型管道/冷热流体混合/循环热疲劳/JSME导则Key words
T-shapes junction/cold and hot fluid mixing/thermal cycling induced fatigue/JSME guidance分类
机械制造引用本文复制引用
王明毓,刘锐,李春锦..T型三通管道冷热流体混合作用下循环热疲劳评估方法[J].压力容器,2024,41(2):43-48,80,7.
