Sensible heat storage is an effective way to solve the instability and fluctuation of solar thermal utilization. The common water medium was used as the medium material of sensible heat energy storage

and the heat storage tank device was used to realize the application of solar energy heat storage and release. The basic shape of the initially selected water tank was cylindrical. The conical structure of the tank bottom was optimized

and the respective heat storage change characteristics of the heat storage water tank under the three working conditions of 40°

45° and 50° cone bottom angles were explored. Based on the unsteady laminar heat transfer model

the volume average temperature change and the maximum volume temperature change of the heat storage device were simulated by using the Fluent numerical software. The results showed that

when the cone bottom angle was 50°

the overall heat charging and discharging performance of the heat storage tank was better. When the average temperature of the heat storage tank body was 308.612 K under this parameter

the average temperature of the heat storage tank body was 0.202% and 0.053% higher than that of the heat storage tank body with a cone bottom angle of 40° and 45°

respectively. On this basis

the dynamic change law of heat storage and heat release of 50° tank was further analyzed

and the distribution characteristics of key indicators such as volume fraction and velocity field in the process of water storage and drainage inside the tank were studied. This research can provide some reference for the optimal design and engineering application of solar energy thermal storage system.