Publications

In the long term the key to the development of a hydrogen economy is a full infrastructure to support it which include means for the delivery and storage of hydrogen at the point of use eg at hydrogen refuelling stations for vehicles. As an interim measure to allow the development of refuelling stations and rapid implementation of hydrogen distribution to them liquid hydrogen is considered the most efficient and cost effective means for transport and stora Read More

On April 7 2021 OIES with and the Kuwait Foundation for the Advancement of Sciences (KFAS) held the annual OIES-KFAS Workshop on Energy Transition Post-Pandemic in the Gulf. During the hydrogen session a paper titled “Opportunity and Cost of Green Hydrogen in Kuwait: A Preliminary Assessment” co-authored by Dr. Manal Shehabi was presented.Like others states in the GCC Kuwait is seeking to explore hydrogen as part of its energy transition projects. T Read More

This White Paper has been commissioned by the UK Hydrogen and Fuel Cell (H2FC) SUPERGEN Hub to examine the roles and potential benefits of hydrogen and fuel cell technologies within each sector of future energy systems and the transition infrastructure that is required to achieve these roles. The H2FC SUPERGEN Hub is an inclusive network encompassing the entire UK hydrogen and fuel cells research community with around 100 UK-based acade Read More

Hydrogen combustion in a noble gas atmosphere increases the combustion chamber temperature and the high specific heat ratio of the gas increases the thermal efficiency. In this study nitrogen was replaced by argon as the intake air along with pure oxygen to supply the engine. The objectives of this study are to determine the effects of different engine parameters on combustion and to analyse the emissions from hydrogen combustion in an argon-oxyg Read More

Computational Fluid Dynamics (CFD) is applied to investigate the near exit jet behavior of high pressure hydrogen release into quiescent ambient air through different types of orifices. The size and geometry of the release hole can affect the possibility of auto-ignition. Therefore the effect of release geometry on the behavior and development of hydrogen jet issuing from non-axisymmetric (elliptical) and expanding orifices is investigated and compared with Read More

In the present study the phenomena of blast wave and fireball generated by high pressure (35 MPa) hydrogen tank (72 l) rupture have been investigated numerically. The realizable k-ε turbulence model was applied. The simulation of the combustion process is based on the eddy dissipation model coupled with the one step chemical reaction mechanism. Simulation results are compared with experimental data from a stand-alone hydrogen fuel tank raptu Read More

The formation of hydrogen jets from pressurized sources and its ignition when hitting hot devices has been studied by many projects. The transient jets evolve with high turbulence depending on the configuration of the nozzle and especially the pressure in the hydrogen reservoir. In addition the length of the jets and the flames generated by ignition at a hot surface varies. Parameters to be varied were initial pressure of the source (2.5 10 20 and 40 MP Read More

Experiments in an obstructed semi-confined vertical combustion channel with a height of 6 m (cross-section 0.4 × 0.4 m) inside a safety vessel of the hydrogen test center HYKA at the Karlsruhe Institute of Technology (KIT) are reported. In the work homogeneous hydrogen-air-mixtures as well as mixtures with different well-defined H2-concentration gradients were ignited either at the top or at the bottom end of the channel. The combustion charact Read More

The thermal behaviour of several commercial hydrogen tanks has been studied during high pressure (70-84 MPa) hydrogen cycling. The temperature of the gas at different points inside the tank the temperature at the bosses and the tank outer wall temperature have been measured under different filling and emptying conditions. From the experimental results the effect of the filling rate (1.5-4 g/s) and the influence of the liner material in the thermal be Read More

The present work proposes improvements on a model developed by Linden to predict the concentration distribution in a 2 vented cavities. Recent developments on non constant entrainment coefficient from Carazzo et al as well as a non constant pressure distribution at the vents-the vents being vertical-are included in the Linden approach. This model is compared with experimental results from a parametric study on the influence of the he Read More

This paper shows the numerical investigation on the self-ignition behavior of high pressure hydrogen released from the tube. The present study aims to clarify the effect of parameters on the behavior and duration of self-ignition outside the tube using two-dimensional axisymmetric numerical simulation with detailed chemistry. The parameters in this study are release pressure tube diameter and tube length. The strength of the spherical shock wave to Read More

Deflagration-to-Detonation Transition Ratio (DDTR) is an important parameter in measuring the hazard of hydrogen detonation at given thermodynamic conditions. It’s among the major tasks to evaluate DDTR in the study of hydrogen safety in a nuclear containment. With CFD tools detailed distribution of thermodynamic parameters at each instant can be simulated with considerable reliability. Then DDTR can be estimated using related CFD output. Read More

Clean energy and fuel storage is often required for both stationary and automotive applications. Some of the clean energy and fuel storage technologies currently under extensive research and development are hydrogen storage direct electric storage mechanical energy storage solar-thermal energy storage electrochemical (batteries and supercapacitors) and thermochemical storage. The gravimetric and volumetric storage capacity energy storage de Read More

Consequence modelling of high potential risks of usage and transportation of cryogenic liquids yet requires substantial improvements. Among the cryogenics liquid hydrogen (LH2) needs especial treatments and a comprehensive understanding of spill and spread of liquid and dispersion of vapor. Even though many of recent works have shed lights on various incidents such as spread dispersion and explosion of the liquid over land less focus was given on spill a Read More

This paper aims to improve prediction capability of the vent sizing correlation presented in the form of functional dependence of the dimensionless deflagration overpressure on the turbulent Bradley number similar to our previous studies. The correlation is essentially upgraded based on recent advancements in understanding and modelling of combustion phenomena relevant to hydrogen-air vented deflagrations and unique large-scale te Read More

For refuelling on-board hydrogen tanks table-based or formula based protocols are commonly used. These protocols are designed to achieve a tank filling close to 100% SOC (State of Charge) in s safe way: without surpassing temperature (-40°C to 85°C) and pressure limits (125% Nominal Working Pressure NWP). The ambient temperature the initial pressure and the volume category of the (compressed hydrogen storage system CHSS are used as inp Read More

Sustainable electricity generation is gaining importance across the globe against the backdrop of ever- diminishing resources and to achieve significant reductions in CO2 emissions. One of the challenges is storing excess energy generated from wind and solar power. Siemens developed an electrolysis system based on proton exchange membrane (PEM) technology enabling large volumes of energy to be stored through the conversion of electrical energ Read More

Successful transition to a hydrogen economy calls for a deep understanding of the risks associated with its widespread use. Accidental ignition of hydrogen by hot surfaces is one of such risks. In the present study we investigated the effect that rotation has on the reported ignition thresholds by numerically determining the minimum surface temperature required to ignite stoichiometric hydrogen-air using a hot horizontal cylinder rotating at various an Read More

Previous studies have demonstrated that while blowdown pressure is reproduced well by both adiabatic and isothermal analytical models the dynamics of temperature cannot be predicted well by either model. The reason for the last is heat transfer to cooling during expansion gas from the vessel wall. Moreover when exposed to an external fire the temperature inside the vessel increases i.e. when a thermally activated pressure relief device (TPRD) is still c Read More

The course is an introduction to the procedures for safe handling of hydrogen flammable and toxic gases by small users working in the field of hydrogen and fuel cells. Theoretical and practical aspects are emphasized aiming at identifying the main hazards and reduce the risks associated with the use of these gases. Topics: 1. Market hydrogen production fuel cells and energy storage; 2. International System of Units Comparison between the ideal gas an Read More

Although many studies have looked at safety issues relating to hydrogen fuelling stations few studies have analyzed the security risks such as deliberate attack of the station by threats such as terrorists and disgruntled employees. The purpose of this study is to analyze security risks for a hydrogen fuelling station with an on-site production of hydrogen from methylcyclohexane. We qualitatively conducted a security risk analysis using American Petrole Read More

Hydrogen embrittlement (HE) together with the hydrogen transport behaviour in hydrogen-charged type 304 stainless steel was investigated by combined tension and outgassing experiments. The hydrogen release rate and HE of hydrogen-charged 304 specimens increase with the hydrogen pressure for hydrogen-charging (or hydrogen content) and almost no HE is observed below the hydrogen content of 8.5 mass ppm. Baking at 433 K for 48 h ca Read More

Laboratory measurements were made on the concentration and temperature fields of cryogenic hydrogen jets. Images of spontaneous Raman scattering from a pulsed planar laser sheet were used to measure the concentration and temperature fields from varied releases. Jets with up to 5 bar pressure with near-liquid temperatures at the release point were characterized in this work. This data is relevant for characterizing unintended leaks from piping Read More

The growing number of hydrogen fillings stations and cars increases the need for accurate models to determine risk. The effect on hydrogen flame length was measured by varying the diameter of the spouting nozzle downstream from the chocked nozzle upstream. The results was compared with an existing model for flame length estimations. The experimental rig was setup with sensors that measured accurately temperature mass flow heat radiation Read More

GASFLOW is a finite-volume computer code that solves the time-dependent two-phase homogeneous equilibrium model compressible Navier–Stokes equations for multiple gas species with turbulence. The fluid-dynamics algorithm is coupled with conjugate heat and mass transfer models to represent walls floors ceilings and other internal structures to describe complex geometries such as those found in nuclear containments and facilities. Recent ap Read More