Influence study on front wall height on intake water temperature in reservoirs

In order to further study the influence of the front wall on the temperature of the water intake, taking Jinchuan Reservoir on Dadu River as the research object, the 3D numerical model was built to simulate the temperature distribution of the water in front of the dam with different height of the front wall. The results show that in January, the reservoir had an inverse stratification structure, with lower temperatures in the surface layer and higher temperatures in the bottom layer. From April to June, the reservoir has a stratified structure, with higher temperatures in the surface layer and lower temperatures in the bottom layer. Increasing the curtain wall height has a diminishing marginal effect on the rise in intake water temperature. Taking into account operational safety at the front wall inlet, power generation efficiency, and the ecological benefits of intake water, the optimal elevation for the front wall for multi-level water withdrawal is 2 235 m. Under this scheme, the average increase in intake water temperature in April, May and June is about 0.34 ℃, 0.28 ℃, and 0.26 ℃, respectively, with a maximum increase of 0.43 ℃ in April.The findings can provide a reference for the design and optimization of multi-level water withdrawal projects utilizing forebay curtain walls.