A printed circuit steam generator (PCSG) is being considered as the component for pressurized water reactor (PWR) type small modular reactor (SMR) that can further reduce the physical size of the system. Since a steam generator in many PWR-type SMR generates superheated steam, it is expected that dryout front oscillation can potentially cause thermal fatigue failure due to cyclic thermal stresses induced by the transition in boiling regimes between convective evaporation and film boiling. To investigate the fatigue issue of a PCSG, a reference PCSG is designed in this study first using an in-house PCSG design tool. For the stress analysis, a finite element method analysis model is developed to obtain the temperature and stress fields of the designed PCSG. Fatigue estimation is performed based on ASME Boiler and pressure vessel code to identify the major parameters influencing the fatigue life time originating from the dryout front oscillation. As a result of this study, the limit on the temperature difference between the hot side and cold side fluids is obtained. Moreover, it is found that the heat transfer coefficient of convective evaporation and film boiling regimes play an essential role in the fatigue life cycle as well as the temperature difference.

印刷电路蒸汽发生器 (PCSG) 被视为压水堆 (PWR) 型小型模块化反应堆 (SMR) 的组件，可进一步减小系统的物理尺寸。由于许多 PWR 型 SMR 中的蒸汽发生器产生过热蒸汽，预计干涸前沿振荡可能会由于对流蒸发和薄膜沸腾之间的沸腾状态转变引起的循环热应力而导致热疲劳失效。为了研究 PCSG 的疲劳问题，本研究首先使用内部 PCSG 设计工具设计了参考 PCSG。对于应力分析，开发了有限元方法分析模型，以获得设计 PCSG 的温度场和应力场。基于 ASME 锅炉和压力容器规范进行疲劳估计，以确定影响源自干涸前沿振荡的疲劳寿命的主要参数。作为这项研究的结果，获得了热侧和冷侧流体之间温差的极限。此外，发现对流蒸发和薄膜沸腾状态的传热系数在疲劳寿命周期和温差中起着至关重要的作用。