Numerical simulation and optimization on valve-induced water hammer characteristics for parallel pump feedwater system
Title of Paper:
Numerical simulation and optimization on valve-induced water hammer characteristics for parallel pump feedwater system
Summary:
In this study, the Method Of Characteristic line(MOC) was adopted to evaluate the valve-induced water hammer behaviors for a Parallel Pumps Feedwater System(PPFS) during the alternate startup process of parallel pumps. Based on closed physical and mathematical equations supplied with suitable boundary conditions, a code was developed to compute the transient behaviors including the pressure wave, the flow velocity and the slamming of the check valve disc etc.. Some interesting results were obtained and it was showed that severe slamming between the valve disc and valve seat occurred during the alternate startup of parallel pumps. The induced maximum pressure vibration amplitude is up to 5.0MPa which occurs under high-high speed startup condition. The scheme of appending a damping spring to the check valve disc was also numerically performed to eliminate the water hammer for optimum design purpose. The adoption of damping spring enlarges the closing time of check valve and has been approved to be an effective approach. The computation results are expected to be instructive for the optimum design of the PPFS in NPPs so as to eliminate the damage potential induced by water hammer.
Co-author:
Wenxi Tian, G.H. Su, Gaopeng Wang, Suizheng Qiu
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