Analysis of Energy Dissipation Effect of Fluid-Filled Capacitive Structure in the Water Hammer Process

Abstract Water hammer is a common phenomenon in nuclear engineering piping systems. Water hammer can cause a large fluctuation of fluid pressure, which may threaten system security. It is essential to control and mitigate pressure fluctuations and energy. The fluid-filled capacitive structure is a key component of energy dissipation equipment, and plays an important role in the water hammer mitigation process. The water hammer performance experiment rig was established, and the experiments were carried out. The water hammer theoretical model was established, and the influence of unsteady friction was considered. The model results agreed well with the experimental data. The fluid-filled capacitive structure was added to the pipeline system to analyze the dissipation effects using two analysis methods. The analysis results show that as the fluid-filled capacitive structure moves from upstream to downstream and the cavity volume increases, the fluctuation amplitude of pressure and internal energy decrease, the fluid mass transfer between the capacitive structure and the pipes is enhanced, and the energy dissipation effect increases. The capacitive structure periodically absorbs and releases the energy of the water hammer process to achieve the energy dissipation effect. The research results can provide guidance for the design of water hammer pressure mitigation and energy dissipation equipment in nuclear engineering pipeline systems.