Evaluating the distribution of water hammer pressure in the pressure penstock and checking conditions to ensure stable adjustment of the hydropower unit by Transient numerical simulation

Abstract

     This study uses the Transient numerical simulation software to analyze and evaluate the distribution of water hammer pressure in the pressure pipeline of Nam Mo 2 Hydropower Station. From the above results, the authors have proposed solutions to improve the project exploitation efficiency. At the same time, the study also provides the conditions to ensure stable adjustment for the unit related to the nozzle opening and closing process, the limit of the turbine's working zone and the reasonable value of the momentum torque. In this study, we have studied and applied the method of characteristic curve system of water hammer wave transmission equations, modelized the diagrams, elementalized, and set up the program in Visual basic language. The calculation program includes the torque and flow characteristics of the turbine, the unit control system, the hydraulic and geometrical properties of all the details of the pressure system, the elasticity of the water and the pipe shell. Compared with the theoretical and experienced results, the numerical simulation results by this software are reliable and have been widely applied in practice.