Rapid prediction of water hammer characteristics in liquid hydrogen storage and transportation systems: A theoretical model

A renewable energy liquid hydrogen storage and transportation system is a very complex system, so water hammering due to valve closure cannot be ignored. A theoretical model for the rapid prediction of the water hammer effect in liquid hydrogen pipeline valves was developed in this work. The impact of valve closure characteristics and subcooling on the peak pressure water hammer was analyzed. The results indicate that as the subcooling temperature of liquid hydrogen decreases, the density of subcooled liquid hydrogen increases, leading to larger peak pressures in the water hammer transient. At subcooling temperatures of 14, 16, 18, and 20 K, the maximum instantaneous pressures for the water hammer fluctuation are 51563.02, 50846.76, 50082.40, and 48510.70 Pa, respectively. Under identical boundary conditions, the density of subcooled liquid hydrogen emerges as the primary factor influencing the peak pressure of water hammer. The theoretical model exhibits a significant advantage in terms of computational time cost, saving approximately 9.99 h. However, the accuracy of the theoretical model is slightly inferior to that of the CFD model. The results of the study are expected to provide a technical basis for the design of refueling systems for storage and transportation, as well as densification technology of supercooled renewable liquid hydrogen and safety protection.