Numerical Study on the Effect of Upstream Piping Configuration on Flow Diverter Performance

Liquid hydrogen, a cryogenic fluid with extremely low density and viscosity, plays a crucial role in zero-carbon energy strategies. It has become a prominent research focus in the field of new energy strategy. In most processes within the liquid hydrogen industry chain, liquid hydrogen flow measurement is involved. This paper focuses on the study of the flow diverter, a key component of the liquid hydrogen flow standard device. Aiming at the high thermal insulation requirement of liquid hydrogen, the straight piping in the conventional flow standard device is optimized. A combined coiled-vertical piping with key equipment is enclosed in a vacuum cold box for centralized thermal insulation. Fluid flow during diverter switching under four piping configurations was simulated using ANSYS Fluent for both water and liquid hydrogen. The influence of piping structure on flow error during the switching of the diverter is systematically studied. From the simulation results, it can be concluded that the U-shaped piping effectively avoids the inertia and overshoot effects during fluid switching, which helps to reduce errors caused by commutation.