Coupled Modeling of Flow−Sediment Transport and Power Generation in the Xiaolangdi Reservoir

As the controlling reservoir that possesses a large storage capacity in Yellow River, the operation of Xiaolangdi Reservoir (XLD) is of great importance to the reservoir maintenance and the downstream channel shaping. Considering the integrated economical profit of power generation and sediment discharge, an operation model of XLD was established by coupling the calculations of water-sediment balances with the calculation of power generation. There were two types of optimization objectives: the maximum of power generation and the maximum of integrated profits. The hydrographs of water level, discharge and turbine output were constrained according to the regulation rules during the late sediment-retaining period of the XLD Reservoir. The model was solved by the dynamic programming, and was adopted to obtain different operation schemes under different optimization objectives in a typical dry year of 2015 and a typical high flood year of 2012. The results showed that: 1) with the power generation as the optimization objective, the operation scheme could to energy outputs of 7.130×109 kW·h in 2015 and 10.215×109 kW·h in 2012; 2) with the integrated profits as the optimization objective, an annual power outputs of 7.017×109 kW·h and 9.524×109 kW·h could be achieved in 2015 and 2012 respectively, along with sediment discharges of 31×106 t and 166×106 t; 3) when comparing these two schemes with different optimization objectives, it could be found that both schemes would finally achieve an increase in the integrated profits, whereas the latter would result in a larger increase by sacrificing part of the power generation in exchange for a silting reduction in the reservoir; 4) optimization schemes in both typical years would produce an increase in power generation and integrated profits, with a larger increase being obtained for the typical high flow year. Furthermore, some suggestions were also proposed for improving the current operation schemes in some typical years. © 2021, Editorial Department of Advanced Engineering Sciences. All right reserved.