Simulation of the efficiency of hydrogen recombiners as safety devices

Numerical study on the influence of different boundary conditions on the efficiency of hydrogen recombiners inside a car garage

“…The only input parameters required for the calculation are temperature and gas composition at the PAR inlet and the absolute pressure. The model is coupled by means of a data and program flow controlled interface routine to CFX [6]. The stand-alone version of REKO-DIREKT as well as the coupling to CFX has been extensively validated against experimental data [28,29].…”

“…The basic geometry and boundary conditions of the simulation is taken from an early benchmark based on helium distribution experiments performed in the GARAGE facility at CEA [10,30] and are identical to previous analysis [6]. The computational domain has a size of 3 m times 6 m and a ceiling height of 2 m (Fig.…”

“…During active venting scenarios, outflow through vent 3 (lc ¼ 10) is possible. The walls are assumed to have a high heat capacity and thus remain at initial temperature of 18 C. The hydrogen release rate and total amount (0.5 g/s for a duration of 120 s) is identical to the previously analyzed cases in order to be comparable with the previous work [6]. The relevant model definitions are summarized in Fig.…”

“…2, right). A dedicated grid sensitivity study and model validation was performed based on the GARAGE experiments [6]. Based on the investigated scenario the geometry is slightly adapted by e.g.…”

“…In an earlier numerical study [6], the efficiency of the application of a PAR inside a car garage for hydrogen removal from a small leak has been studied. Such a scenario could be prototypical for future hydrogen applications and has been discussed in several recent publications dealing with hydrogen releases inside cars [7,8], private garages [9e16], and public underground parking [17].…”