CFD analysis of filling process for a hydrogen energy storage system

Abstract

Hydrogen is a clean energy source and can be generated from renewable energy resources [1]. In this research a 3D dynamics simulation for stationary hydrogen storage is performed by using COMSOL Multiphysics computational software. The development of a model according to information collected from different references is described as follows. This time dependent model is based on the Laminar Flow and Heat Transfer in Fluids modules. Laminar Flow is used to compute the velocity and pressure fields for the flow of a single-phase fluid. The equations solved by Laminar Flow are the Navier-Stokes equation for conservation of momentum and the continuity equation for conservation of mass. Heat Transfer solves the Navier-Stokes equation together with an energy balance [15]. In the current model, one node implemented was the Inlet, in which a velocity field was used. The flow direction was assumed to be uniform through the injection pipe in the direction of the cylinder axis. Results show various conditions of velocity and pressure fields along with temperature in different locations inside the storage tube produced through the inflow of hydrogen gas. According to the Bernoulli equation, where the velocity field is zero, the pressure is at maximum value. This fact is seen in the results of this simulation in the right half of the tank where the stagnation plane is created. Zero-dimensional modeling has also been carried out to compare with the results. This model shows qualitative agreement with the COMSOL results.