CFD model performance benchmark of fast filling simulations of hydrogen tanks with pre-cooling Daniele Melideo, Daniele Baraldi*, Maria Cristina Galassi, Rafael Ortiz Cebolla, Beatriz Acosta Iborra, Pietro Moretto European Commission Joint Research Centre, Institute for Energy and Transport, Westerduinweg 3, P. Box 2, Petten 1755 ZG, Petten, The Netherlands article info Article history: Received 8 November 2013 Received in revised form 16 December 2013 Accepted 28 December 2013 Available online 27 January 2014 Keywords: Hydrogen Safety CFD Storage Fast filling abstract High gas temperatures can be reached inside a hydrogen tank during the filling process because of the large pressure increase (up to 70e80 MPa) and because of the short time (w3 min) of the process. High temperatures can potentially jeopardize the structural integrity of the storage system and one of the strategies to reduce the temperature increase is to pre-cool the hydrogen before injecting it into the tank. Computational Fluid Dynamics (CFD) tools have the capabilities of capturing the flow field and the temperature rise in the tank. The results of CFD simulations of fast filling with pre-cooling are shown and compared with experimental data to assess the accuracy of the CFD model. Copyright ª 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 1. Introduction Nowadays drivers are used to re-fill the vehicle tank in a few minutes with conventional fuel like gasoline or diesel. They have similar expectations towards the new technology of hydrogen powered vehicles. The requirement of a reasonable short filling time introduces a new challenge since the in- crease of temperature due to the quick compression inside the tank, e.g. from low pressure up to 700 bar, could be harmful for the mechanical properties of the tank material. Because of this reason, the maximum allowed temperature inside tanks is set to 85 Ce358 K by the majority of the international standards and regulations (e.g. the European regulation [1], the SAE [2,3], the global technical regulation [4], and the international standard ISO 15869 [5]). Moreover, the higher the temperature is, the lower the gas density is and the smaller the amount of gas that can be filled inside the tank is. The technological solution that was envisaged to tackle the issue of high temperature is to decrease the temperature of the gas going inside the tank by means of a heat exchanger. The process is called pre-cooling and in this work the pre-cooling is investigated both from the experimental and from the nu- merical point of view. Given the importance of the re-fueling issue for the deployment of hydrogen technology in the automotive sector, the number of papers with investigations on the fast filling process that have been published in the last decade has constantly increasing [6e15]. * Corresponding author. E-mail addresses: daniele.baraldi@ec.europa.eu, dbaraldi@gmail.com (D. Baraldi). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 39 (2014) 4389 e4395 0360-3199/$ e see front matter Copyright ª 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijhydene.2013.12.196