Session: 08-05: Computational Fluid Dynamics (CFD) and Applications - V

Paper Number: 135113

135113 - Numerical Simulation and Analysis of Condensation-Induced Water Hammer in Heat Exchangers for Residual Heat Removal System in Nuclear Power Plant 

Abstract: 

Condensation-induced water hammer, a phenomenon triggered by the abrupt condensation of steam within pipelines, presents a notable concern as it can give rise to pressure surges capable of causing damage to critical system components. The primary objective of this research is to delve into the potential occurrence of water hammer phenomena during the condensation process, with a particular focus on understanding the risks involved and the substantial damage it may inflict upon the heat exchanger and its surrounding components.

To accomplish this objective, We employed FLUENT to simulate an abnormal transient in the heat exchangers for waste heat discharge system using a hybrid heat transfer model. The simulation process involves the application of a sophisticated hybrid heat transfer model, thoughtfully designed to incorporate the constraints posed by both the Lee model and the hybrid heat transfer coefficient (HTC) model during its development. This comprehensive approach ensures a thorough and precise understanding of the intricate dynamics associated with water hammer during the steam condensation process.

The simulation results showed that when the cooling water and hot steam came into direct contact and condensation occurred, the liquid level in the pipe rose rapidly, leading to an unstable gas-liquid interface. A liquid bridging structure was formed near the pipe wall, which may induce slug flow and lead to gas pocket collapse water hammer, causing significant pressure fluctuations and posing a safety hazard to the stable operation of the system.

In addition to the simulation efforts, this comprehensive study extended its focus to the real-time monitoring of key water hammer parameters. This holistic approach not only enhances the theoretical foundation for engineering design considerations but also serves as a proactive means to prevent and mitigate potential accidents associated with water hammer. Monitoring critical parameters allows for the development of early warning systems, facilitating timely interventions and adjustments to ensure the system's safe and efficient operation.

The theoretical insights gained from this study offer valuable guidance for engineering design, helping refine strategies to mitigate water hammer risks. Furthermore, the monitored parameters provide a wealth of data for developing predictive models and improving the accuracy of risk assessments. By gaining a deeper understanding of the intricate mechanisms behind condensation-induced water hammer and actively monitoring critical parameters, this study contributes significantly to the development of effective engineering strategies. These strategies, in turn, bolster the long-term safe operation of industrial piping systems, ensuring not only efficiency but also the safety of the entire operational environment. This research plays a pivotal role in advancing the knowledge and practices surrounding water hammer phenomena in complex industrial settings, fostering a safer and more resilient industrial landscape.

Presenting Author: Jie Li China Nuclear Power Engineering Co.,Ltd. Beijing,China

Presenting Author Biography: Jie Li is a senior engineer, in charge of nuclear reactor process system, equipment and layout design, including engineering safety system, nuclear auxiliary system, severe accident mitigation system and steam generator secondary side system, and its associated equipment and arrangement.

Authors:

Jie Li China Nuclear Power Engineering Co.,Ltd. Beijing,China
Feng Xiong North China Electric Power University,Beijing,China
Jiaqi Pan China Nuclear Power Engineering Co.,Ltd. Beijing,China
Ruiyang Tu North China Electric Power University,Beijing,China
Pei Yu China Nuclear Power Engineering Co.,Ltd. Beijing,China
Jiaming Zhao China Nuclear Power Engineering Co.,Ltd. Beijing,China
Zhengyu Chen North China Electric Power University,Beijing,China
Zihao Zhang North China Electric Power University,Beijing,China
Wentao Guo North China Electric Power University,Beijing,China
Shengfei Wang North China Electric Power University,Beijing,China