Presenter: Dr. Jing Dong
Co-author(s): Dr. Songlin Han, Prof. Zhibing Jiang
Organisation: Changjiang River Scientific Research Institute
Sub-theme
5. Establishing Sustainable Water Infrastructures
Topic
5-5. Joint operation and regulation of water projects
Body
In order to achieve the "double carbon" goal, energy transformation and development become the future trend. Among many energy storage methods, pumped-storage has obvious advantages and has become a kind of energy storage method that can provide large storage capacity at the grid level. Considering of the limitation of geological conditions or comprehensive costs, curved water conveyance tunnels are often used to connect the side inlet or outlet with the generator unit in the design of pumped storage power stations. However, due to the curvature effect, Dean vortices are likely to be generated in the curved tunnel, which will cause uneven distribution of the flow velocity field and pressure field in the tunnel and affect the internal hydraulic characteristics of the inlet or outlet. This paper focus on the horizontal curved water conveyance tunnel that is common in the pumped storage project and uses numerical simulation and model experiment to study the influence of straight section length of the curved tunnel downstream, the size of the slope and the location of the slope change on the internal hydraulic characteristics of the inlet or outlet. The results show that, compared with the straight tunnel, the curved tunnel will cause the flow distribution at the inlet or outlet and the velocity distribution at the section of trash rack uneven; The Increasing of straight section length of the curved tunnel downstream can make the flow distribution of the inlet or outlet more uniform. However, it does not necessarily improve the uniformity of the flow velocity distribution at the trash rack section, which is caused by the different development status of Dean vortex downstream of the curved tunnel; The uniformity of the flow distribution inside the inlet or outlet and the velocity distribution at the section of trash rack can be effectively improved with a large slope or adopts a suitable slope changing position.