The optimal power generation operation of a hydropower station for improving fish shelter area of low TDG level

Abstract

Supersaturated TDG problem has become a serious potential threat to aquatic life on dammed rivers. With the aim to mitigate the impact of supersaturated TDG and improve the fish shelter area, the optimal power generation operation of a hydropower station was explored. In order to consider the TDG mixing process of the tailwater and the spill discharge, a two-dimensional supersaturated TDG transport diffusion model was established. The simulation result of the model was validated by the monitored field data of Xiangjiaba (XJB) hydropower project. Different scheduling schemes of the power generation and spill of Xiluodu (XLD) (upstream of XJB project) and XJB projects were simulated to investigate the TDG distribution downstream of XJB. Based on the simulation results, fish shelter areas of different scheduling schemes were analyzed. Simulation results showed that the generation scheduling of XJB could be optimized in order to expand the fish shelter area. First of all, the powerhouses on both sides for XJB project are recommended to operated as far as possible. In the event of the powerhouse alternatives have to be made between the left powerhouse and right powerhouse, the powerhouse on the right side is recommended due to minor low TDG area. The results show the high significance and practical value of identifying the fish shelter area against the impact of supersaturated TDG under different schemes of power generation and provide vital information for fish protection downstream of a high dam.