Flow Characteristics and Resistance Coefficient of Liquid Hydrogen in the Ball Valve at Different Opening Degrees

Hydrogen energy is regarded as an ideal energy source due to its high efficiency, environmental friendliness, and renewability. Liquid hydrogen energy storage is considered a cost-effective method for long-distance transportation and large-volume storage of hydrogen. The liquid hydrogen ball valve regulates flow and directs the liquid hydrogen system. Understanding the flow characteristics in the ball valve is crucial for ensuring the stability and safety of liquid hydrogen storage systems. In this study, computational fluid dynamics (CFD) is used to establish a comprehensive model of the liquid hydrogen ball valve. The distributions of pressure, velocity, and vorticity under varying opening degrees are examined to elucidate the fluid dynamics within the valve. Furthermore, the study investigates the flow resistance coefficient and flow coefficient for the liquid hydrogen ball valve to assess its performance characteristics. Results indicate that with increasing ball opening, the pressure difference between the ball inlet and outlet diminishes, leading to the gradual disappearance of vortex formations within the valve. Quantitatively, the pressure difference remains relatively stable at approximately 10,500 Pa between 20° and 60°, but drops sharply by 80.99% from 60° to 90°. The flow resistance coefficient decreases drastically from 689.057 at 20° to 0.546 at 80°, while the flow coefficient increases from 0.042 to 3.356. Notably, at a ball opening of 80°, vortex formations are nearly eliminated. This investigation contributes valuable research insights and theoretical foundations for the optimal design of valves within liquid hydrogen storage systems.