Hydraulic characteristics of right-angle turn section of surge chamber of pumped storage power station

Under the background of the "double carbon" goal and accelerating the construction of a new energy system, pumped storage is booming with the demand for a large number of new energy sources. As an important regulator and stabilizer for the power system, a pumped storage power station plays an important role in optimizing the power supply structure of the power grid, alleviating the pressure of the power grid regulation. In order to study the complex hydraulic characteristics of the surge chamber in the right-angle turn section, a three-dimensional numerical calculation model of the surge chamber structure in the right-angle turn section was built to analyze the relationship between the flow pattern and pressure characteristics of the surge chamber, the head loss coefficient of shunt/confluence flow and the ratio of split (combined) flow under pumping/power generation conditions. The results show that under constant flow and small disturbance, the fluctuation range of water level in the pressure regulator chamber is relatively stable, the minimum fluctuation range is 0.007, and the unit runs stably. Under different shunt ratios, the hydraulic characteristics of the surge chamber change significantly with the increase of shunt ratio, the coefficient of head loss increases exponentially, and the polynomial of flow coefficient decreases. The coefficient of head loss and the coefficient of discharge show opposite trends before and after the turning point respectively.