France
Sample Scale Testing Method to Prevent Collapse of Plastic Liners in Composite Pressure Vessels
Sep 2017
Publication
Type IV pressure vessels are commonly used for hydrogen on-board stationary or bulk storages. When pressurised hydrogen permeates through the materials and solves into them. Emptying then leads to a difference of pressure at the interface between composite and liner possibly leading to a permanent deformation of the plastic liner called “collapse” or “buckling”. This phenomenon has been studied through French funded project Colline allowing to better understand its initiation and long-term effects. This paper presents the methodology followed using permeation tests hydrogen decompression tests on samples and gas diffusion calculation in order to determine safe operating conditions such as maximum flow rate or residual pressure level.
The Curious Case of the Conflicting Roles of Hydrogen in Global Energy Scenarios
Oct 2019
Publication
As energy systems transition from fossil-based to low-carbon they face many challenges particularly concerning energy security and flexibility. Hydrogen may help to overcome these challenges with potential as a transport fuel for heating energy storage conversion to electricity and in industry. Despite these opportunities hydrogen has historically had a limited role in influential global energy scenarios. Whilst more recent studies are beginning to include hydrogen the role it plays in different scenarios is extremely inconsistent. In this perspective paper reasons for this inconsistency are explored considering the modelling approach behind the scenario scenario design and data assumptions. We argue that energy systems are becoming increasingly complex and it is within these complexities that new technologies such as hydrogen emerge. Developing a global energy scenario that represents these complexities is challenging and in this paper we provide recommendations to help ensure that emerging technologies such as hydrogen are appropriately represented. These recommendations include: using the right modelling tools whilst knowing the limits of the model; including the right sectors and technologies; having an appropriate level of ambition; and making realistic data assumptions. Above all transparency is essential and global scenarios must do more to make available the modelling methods and data assumptions used.
Hydrogen Storage in Pure and Boron-Substituted Nanoporous Carbons—Numerical and Experimental Perspective
Aug 2021
Publication
Nanoporous carbons remain the most promising candidates for effective hydrogen storage by physisorption in currently foreseen hydrogen-based scenarios of the world’s energy future. An optimal sorbent meeting the current technological requirement has not been developed yet. Here we first review the storage limitations of currently available nanoporous carbons then we discuss possible ways to improve their storage performance. We focus on two fundamental parameters determining the storage (the surface accessible for adsorption and hydrogen adsorption energy). We define numerically the values nanoporous carbons have to show to satisfy mobile application requirements at pressures lower than 120 bar. Possible necessary modifications of the topology and chemical compositions of carbon nanostructures are proposed and discussed. We indicate that pore wall fragmentation (nano-size graphene scaffolds) is a partial solution only and chemical modifications of the carbon pore walls are required. The positive effects (and their limits) of the carbon substitutions by B and Be atoms are described. The experimental ‘proof of concept’ of the proposed strategies is also presented. We show that boron substituted nanoporous carbons prepared by a simple arc-discharge technique show a hydrogen adsorption energy twice as high as their pure carbon analogs. These preliminary results justify the continuation of the joint experimental and numerical research effort in this field.
Hydrogen Safety Aspects Related to High Pressure - PEM Water Electrolysis
Sep 2007
Publication
Polymer electrolyte membrane (PEM) water electrolysis has demonstrated its potentialities in terms of cell efficiency (energy consumption ≈ 4.0-4.2 kW/Nm3 H2) and gas purity (> 99.99% H2). Current research activities are aimed at increasing operating pressure up to several hundred bars for direct storage of hydrogen in pressurized vessels. Compared to atmospheric pressure electrolysis high-pressure operation yields additional problems especially with regard to safety considerations. In particular the rate of gases (H2 and O2) cross-permeation across the membrane and their water solubility both increase with pressure. As a result gas purity is affected in both anodic and cathodic circuits and this can lead to the formation of explosive gas mixtures. To prevent such risks two different solutions reported in this communication have been investigated. First the chemical modification of the solid polymer electrolyte in order to reduce cross-permeation phenomena. Second the use of catalytic H2/O2 recombiners to maintain H2 levels in O2 and O2 levels in H2 at values compatible with safety requirements.
Guidelines and Recommendations for Indoor Use of Fuel Cells and Hydrogen Systems
Oct 2015
Publication
Deborah Houssin-Agbomson,
Simon Jallais,
Elena Vyazmina,
Guy Dang-Nhu,
Gilles Bernard-Michel,
Mike Kuznetsov,
Vladimir V. Molkov,
Boris Chernyavsky,
Volodymyr V. Shentsov,
Dmitry Makarov,
Randy Dey,
Philip Hooker,
Daniele Baraldi,
Evelyn Weidner,
Daniele Melideo,
Valerio Palmisano,
Alexandros G. Venetsanos,
Jan Der Kinderen and
Béatrice L’Hostis
Hydrogen energy applications often require that systems are used indoors (e.g. industrial trucks for materials handling in a warehouse facility fuel cells located in a room or hydrogen stored and distributed from a gas cabinet). It may also be necessary or desirable to locate some hydrogen system components/equipment inside indoor or outdoor enclosures for security or safety reasons to isolate them from the end-user and the public or from weather conditions.<br/>Using of hydrogen in confined environments requires detailed assessments of hazards and associated risks including potential risk prevention and mitigation features. The release of hydrogen can potentially lead to the accumulation of hydrogen and the formation of a flammable hydrogen-air mixture or can result in jet-fires. Within Hyindoor European Project carried out for the EU Fuel Cells and Hydrogen Joint Undertaking safety design guidelines and engineering tools have been developed to prevent and mitigate hazardous consequences of hydrogen release in confined environments. Three main areas are considered: Hydrogen release conditions and accumulation vented deflagrations jet fires and including under-ventilated flame regimes (e.g. extinguishment or oscillating flames and steady burns). Potential RCS recommendations are also identified.
Detonation Dynamics in a Curved Chamber for an Argon Diluted Hydrogen-oxygen Mixture
Sep 2019
Publication
The dynamics of detonation transmission from a straight channel into a curved chamber was investigated as a function of initial pressure using a combined experimental and numerical study. Hi-speed Schlieren and *OH chemiluminescense were used for flow visualization; numerical simulations considered the two-dimensional reactive Euler equations with detailed chemistry. Results show the highly transient sequence of events (i.e. detonation diffraction re-initiation attempts and wave reflections) that precede the formation of a steadily rotating Mach detonation along the outer wall of the chamber. An increase in pressure from 15 kPa to 26 kPa expectedly resulted in detonations that are less sensitive to diffraction. Local quenching of the initial detonation occurred for all pressures considered. The location where this decoupling occurred along the inner wall determined the location where transition from regular reflection to a rather complex wave structure occurred along the outer wall. This complex wave structure includes a steadily rotating Mach detonation (stem) an incident decoupled shock-reaction zone region and a transverse detonation that propagates in pre-shocked mixture.
Fire Risk on High-pressure Full Composite Cylinders for Automotive Applications
Sep 2011
Publication
In the event of a fire the TPRD (Thermally activated Pressure Relief Device) prevents the high-pressure full composite cylinder from bursting by detecting high temperatures and releasing the pressurized gas. The current safety performance of both the vessel and the TPRD is demonstrated by an engulfing bonfire test. However there is no requirement concerning the effect of the TPRD release which may produce a hazardous hydrogen flame due to the high flow-rate of the TPRD. It is necessary to understand better the behavior of an unprotected composite cylinder exposed to fire in order to design appropriate protection for it and to be able to reduce the length of any potential hydrogen flame. For that purpose a test campaign was performed on a 36 L cylinder with a design pressure of 70 MPa. The time from fire exposure to the bursting of this cylinder (the burst delay) was measured. The influence of the fire type (partial or global) and the influence of the pressure in the cylinder during the exposure were studied. It was found that the TPRD orifice diameter should be significantly reduced compared to current practice.
The CALIF3S-P2remics Software – An Application to Underexpanded Hydrogen Jet Deflagration
Sep 2019
Publication
To assess explosion hazard the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN) is developing the P2REMICS software (for Partially PREMIxed Combustion Solver) on the basis of the generic CFD solver library CALIF3S (for Components Adaptive Library for Fluid Flow Simulation). Both P2REMICS and CALIF3S are in-house IRSN softwares released under an open-source license. CALIF3S-P2REMICS is dedicated to the simulation of explosion scenarii (explosive atmosphere formation deflagration or detonation and blast waves propagation) for hydrogen as more generally for any explosive gas or gas/dust mixture. It is based on staggered space discretizations and implements fractional-steps time algorithms well suited for massively parallel computations. A wide range of experiments is used for the software validation. Among them we focus here on a free underexpanded hydrogen jet deflagration performed in two steps: first the hydrogen is released in air up to obtain a steady jet (dispersion phase) then the deflagration is triggered. For the dispersion phase simulation a notional nozzle approach is used to get rid of the description of the shocked zone located near the nozzle. Then a so-called turbulent flame velocity approach is chosen for the deflagration simulation. The computations allow to highlight the complex flow structures induced by the inhomogeneity fuel concentration in the jet. A large dispersion of results is observed depending on the chosen correlation for the turbulent flame speed.
Hydrogen Related Risks Within a Private Garage: Concentration Measurements in a Realistic Full Scale Experimental Facility
Sep 2007
Publication
Next generation of hydrogen energy based vehicles is expected to come into widespread use in the near future. Various topics related to hydrogen including production storage and application of hydrogen as an energy carrier have become subjects of discussion in the framework of various European and International projects. Safety information is vital to support the successful introduction into mainstream and public acceptance of hydrogen as an energy carrier. One of such issues which is seeking major attention is related to hydrogen powered vehicles parked inside a confined area (such as in a private garage). It is of utmost importance to predict if uncontrolled release of hydrogen from a vehicle parked inside a confined area can create an explosive atmosphere. Subsequently how the preventive measures can be implied to control these explosive atmospheres if present inside a confined area? There is a little guidance currently developed for confined areas accommodating hydrogen fuelled vehicles. It is essential that mitigation measures for such conditions become established.<br/>Characterization of different scenarios those may arise in a real situation from hydrogen fuelled vehicle parked inside a garage and furthermore the investigation of an optimal ventilation rate for hydrogen risk mitigation are some of the main objectives described in the framework of the present study. This work is an effort to provide detail experimental information’s in view of establishing guidelines for hydrogen powered vehicles parked inside a private garage. The present work is developed in the framework of a European Network of Excellence HySafe and French project DRIVE. Present paper describes a purpose built realistic Garage test facility at CEA to study the dispersion of hydrogen leakage. The studied test cases evaluate the influence of injected volumes of hydrogen and the initial conditions at the leakage source on the dispersion and mixing characteristics inside the free volume of the unventilated garage. The mixing process and build-up of hydrogen concentration is measured for the duration of 24 hours. Due to safety reasons helium gas is used to simulate the hydrogen dispersion characteristics.
Full Scale Experimental Campaign to Determine the Actual Heat Flux Produced by Fire on Composite Storages - Calibration Tests on Metallic Vessels
Oct 2015
Publication
If Hydrogen is expected to be highly valuable some improvements should be conducted mainly regarding the storage safety. To prevent from high pressure hydrogen composite tanks bursting the comprehension of the thermo-mechanics phenomena in the case of fire should be improved. To understand the kinetic of strength loss the heat flux produced by fire of various intensities should be assessed. This is the objective of this real scale experimental campaign which will allow studying in future works the strength loss of composite high-pressure vessels in similar fire conditions to the ones determined in this study. Fire calibration tests were performed on metallic cylinder vessels. These tests with metallic cylinders are critical in the characterization of the thermal load of various fire sources (pool fire propane gas fire hydrogen gas fire) so as to evaluate differences related to different thermal load. Radiant panels were also used as thermal source for reference of pure radiation heat transfer. The retained thermal load might be representative of accidental situations in worst case scenarios and relevant for a standardized testing protocol. The tests performed show that hydrogen gas fires and heptane pool fire allow reaching the target in terms of absorbed energy regarding the results of risk analysis performed previously. Other considerations can be taken into account that will led to retain an hydrogen gas fire for further works. Firstly hydrogen gas fire is the more realistic scenario: Hydrogen is the combustible that we every time find near an hydrogen storage. Secondly as one of the objectives of the project is to make recommendations for standardization issues it’s important to note that gas fires are not too complex to calibrate control and reproduce. Finally due to previous considerations Hydrogen gas fire will be retained for thermal load of composite cylinders in future works.
Defect Assessment on Pipe Used For Transport of Mixture of Hydrogen and Natural Gas
Sep 2009
Publication
The present article indicates the change of mechanical properties of X52 gas pipe steel in presence of hydrogen and its consequence on defect assessment particularly on notch like defects. The purpose of this work is to determine if the transport of a mixture of natural gas and hydrogen in the actual existing European natural gas pipe network can be done with a reasonable low failure risk (i.e. a probability of failure less than 10-6). To evaluate this risk a deterministic defect assessment method has been established. This method is based on Failure Assessment Diagram and more precisely on a Modified Notch Failure Assessment Diagram (MNFAD) which has been proposed for this work. This MNFAD is coupled with the SINTAP failure curve and allows determining the safety factor associated with defect geometry loading conditions and material resistance. The work described in this paper was performed within the NATURALHY work package 3 on ’Durability of pipeline material’.
Hydrogen Effect on Fatigue and Fracture of Pipe Steels
Sep 2009
Publication
Transport by pipe is one the most usual way to carry liquid or gaseous energies from their extraction point until their final field sites. To limit explosion risk or escape to avoid pollution problems and human risks it is necessary to assess nocivity of defect promoting fracture. This need to know the mechanical properties of the pipes steels. Hydrogen is considered to day as a new energy vector and its transport in one of the key problems to extension of its use. Within the European project NATURALHY it has been proposed to transport a mixture of natural gas and hydrogen. 39 European partners have combined their efforts to assess the effects of hydrogen presence on the existing gas network. Key issues are durability of pipeline material integrity management safety aspects life cycle and socio-economic assessment and end-use. The work described in this paper was performed within the NATURALHY work package on ’Durability of pipeline material’. This study makes it possible to emphasize the hydrogen effect on mechanical properties of several pipe steels as X52 X70 or X100 in fatigue and fracture and in two different environments: air and hydrogen electrolytic.
CFD Benchmark Based on Experiments of Helium Dispersion in a 1m3 Enclosure–intercomparisons for Plumes
Sep 2013
Publication
In the context of the French DIMITRHY project ANR-08-PANH006 experiments have been carried out to measure helium injections in a cubic 1 m3 box - GAMELAN in a reproducible and quantitative manner. For the present work we limit ourselves to the unique configuration of a closed box with a small hole at its base to prevent overpressure. This case leads to enough difficulties of modelisations to deserve our attention. The box is initially filled with air and injections of helium through a tube of diameter 20 mm is operated. The box is instrumented with catharometres to measure the helium volume concentration within an accuracy better than 0.1%. We present the CFD (Fluent and CASTEM ANSYS-CFX and ADREA-HF) calculations results obtained by 5 different teams participating to the benchmark in the following situation: the case of a plume release of helium in a closed box (4NL/min). Parts of the CFD simulations were performed in the European co-funded project HyIndoor others were performed in the French ANR-08-PANH006 DimitrHy project.
Material Testing and Design Recommendations for Components Exposed to Hydrogen Enhanced Fatigue – the Mathryce Project
Sep 2013
Publication
The three years European MATHRYCE project dedicated to material testing and design recommendations for components exposed to hydrogen enhanced fatigue started in October 2012. Its main goal is to provide an “easy” to implement methodology based on lab-scale experimental tests under hydrogen gas to assess the service life of a real scale component taking into account fatigue loading under hydrogen gas. Dedicated experimental tests will be developed for this purpose. In the present paper the proposed approach is presented and compared to the methodologies currently developed elsewhere in the world.
Influence of the Location of a Buoyant Gas Release in Several Configurations Varying the Height of the Release and the Geometry of the Enclosure
Sep 2013
Publication
The present work proposes a parametric study on the influence of the height of the release source on the helium dispersion regimes inside a naturally ventilated enclosure. Several configurations were experimentally addressed in order to improve knowledge on dispersion considering conditions close to hydrogen energy systems in terms of operating characteristics and design. Thus the varying parameters of the study were mainly the height of the release and also the releasing flow rate the volume and the geometry of the enclosure. Experimental results were compared to existing analytical models and considered through model improvements allowing a better approach of these specific cases for hydrogen systems risk assessment.
Hydrogen Storage: Recent Improvements and Industrial Prospective
Oct 2015
Publication
Efficient storage of hydrogen is crucial for the success of hydrogen energy markets (early markets as well as transportation market). Hydrogen can be stored either as a compressed gas a refrigerated liquefied gas a cryo-compressed gas or in hydrides. This paper gives an overview of hydrogen storage technologies and details the specific issues and constraints related to the materials behaviour in hydrogen and conditions representative of hydrogen energy uses. It is indeed essential for the development of applications requiring long-term performance to have good understanding of long-term behaviour of the materials of the storage device and its components under operational loads.
European Hydrogen Safety Training Platform for First Responders- Hyresponse Project
Sep 2013
Publication
The paper presents HyResponse project i.e. a European Hydrogen Safety Training Platform that targets to train First responders to acquire professional knowledge and skills to contribute to FCH permitting process as approving authority. The threefold training program is described: educational training operational-level training on mock-up real scale transport and hydrogen stationary installations and innovative virtual training exercises reproducing entire accident scenarios. The paper highlights how the three pilot sessions for European First Responders in a face to face mode will be organized to get a feedback on the training program. The expected outputs are also presented i.e. the Emergency Response Guide and a public website including teaching material and online interactive virtual training.
Probability of Occurrence of ISO 14687-2 Contaminants in Hydrogen: Principles and Examples from Steam Methane Reforming and Electrolysis (Water and Chlor-alkali) Production Processes Model
Apr 2018
Publication
According to European Directive 2014/94/EU hydrogen providers have the responsibility to prove that their hydrogen is of suitable quality for fuel cell vehicles. Contaminants may originate from hydrogen production transportation refuelling station or maintenance operation. This study investigated the probability of presence of the 13 gaseous contaminants (ISO 14687-2) in hydrogen on 3 production processes: steam methane reforming (SMR) process with pressure swing adsorption (PSA) chlor-alkali membrane electrolysis process and water proton exchange membrane electrolysis process with temperature swing adsorption. The rationale behind the probability of contaminant presence according to process knowledge and existing barriers is highlighted. No contaminant was identified as possible or frequent for the three production processes except oxygen (frequent for chlor-alkali membrane process) carbon monoxide (frequent) and nitrogen (possible) for SMR with PSA. Based on it a hydrogen quality assurance plan following ISO 19880-8 can be devised to support hydrogen providers in monitoring the relevant contaminants.
High Pressure Hydrogen Fires
Sep 2009
Publication
Within the scope of the French national project DRIVE and European project HyPER high pressure jet flames of hydrogen were produced and instrumented.<br/>The experimental technique and measurement strategy are presented. Many aspects are original developments like the direct measurement of the mass flow rate by weighing continuously the hydrogen container the image processing to extract the flame geometry the heat flux measurement device the thermocouples arrangement…<br/>Flames were observed from 900 bar down to 1 bar with orifices ranging from 1 to 3 mm. An original set of data is now available about the main flame characteristics and about some thermodynamic aspects of hydrogen releases under high pressure.<br/>A brief comparison of some available models is presented.
Data for the Evaluation of Hydrogen Risks Onboard Vehicles: Outcomes from the French Project Drive
Sep 2011
Publication
From 2006 to 2009 INERIS alongside with CEA PSA PEUGEOT CITROËN and IRPHE were involved in a project called DRIVE. Its objective was to provide data on the whole reaction chain leading to a hydrogen hazard onboard a vehicle. Out of the three types of leakage identified by the consortium (permeation chronic and accidental) the chronic leakage taking place within the engine was judged to be more problematic since it can feature a high probability of occurrence and a significant release flow rate (up to 100 NL/min). Ignition tests carried out within a real and dummy engine compartment showed that pressure effects due to an explosion will be relatively modest provided that the averaged hydrogen concentration in this area is limited to 10% vol/vol which would correspond to a maximum release flow of 10 NL/min. This maximum concentration could be used as a threshold value for detection or as a target while designing the vehicle. Jet fire experiments were also conducted in the frame of the DRIVE project. It was found that pressure-relief devices (PRDs) might be unsuited to protect humans from the explosion of a tank caused by a bonfire. Other solutions are proposed in this paper.
No more items...