France

The lay-out requirements developed for hydrogen systems operated in industrial environment are not suitable for the operating conditions specific to hydrogen refuelling stations (service pressure of up to 95 MPa facility for public use). A risk informed rationale has been developed to define and substantiate separation distance requirements in ISO 20100 Gaseous hydrogen – refuelling stations [1]. In this approach priority is given to preventing escalation of small incidents into majors ones with a focus on critical exposures such as places of occupancy (fuelling station retail shop) while optimizing use of the available space from a risk perspective a key objective for being able to retrofit hydrogen refuelling in existing stations.

PEM water electrolysis offers an efficient and flexible way to produce “green-hydrogen” from renewable (intermittent) energy sources. Most research papers published in the open literature on the subject are addressing performances issues and to date very few information is available concerning the mechanisms of performance degradation and the associated consequences. Results reported in this communication have been used to analyze the failure mechanisms of PEM water electrolysis cells which can ultimately lead to the destruction of the electrolyzer. A two-step process involving firstly the local perforation of the solid polymer electrolyte followed secondly by the catalytic recombination of hydrogen and oxygen stored in the electrolysis compartments has been evidenced. The conditions leading to the onset of such mechanism are discussed and some preventive measures are proposed to avoid accidents.

We present an experimental investigation of the different concentration build-up regimes encountered during a release of helium/air mixture in an empty enclosure without ventilation. The release is a vertical jet issuing from a nozzle located near the floor. The nozzle diameter the flow rate and the composition of the injected mixture have been varied such that the injection Richardson number ranges from 6 × 10−6 to 190. The volume Richardson number which gives the ability of the release to mix the enclosure content ranges from 2 × 10−3 to 2 × 104. This wide range allowed reaching three distinct regimes: stratified stratified with a homogeneous upper layer and homogenous.

This paper is devoted to a benchmarking exercise of the EUROPLEXUS code against several large scale deflagration and detonation experimental data sets in order to improve its hydrogen combustion modeling capabilities in industrial settings. The code employs an algorithm for the propagation of reactive interfaces RDEM which includes a combustion wave as an integrable part of the Reactive Riemann problem propagating with a fundamental flame speed (being a function of initial mixture properties as well as gas dynamics parameters). An improvement of the combustion model is searched in a direction of transient interaction of flames with regions of elevated vorticity/shear in obstacle-laden channels and vented enclosures.

"This paper summarises the modelling and experimental programme in the EC FP6 project HYPER. A number of key results are presented and the relevance of these findings to installation permitting guidelines (IPG) for small stationary hydrogen and fuel cell systems is discussed. A key aim of the activities was to generate new scientific data and knowledge in the field of hydrogen safety and where possible use this data as a basis to support the recommendations in the IPG. The structure of the paper mirrors that of the work programme within HYPER in that the work is described in terms of a number of relevant scenarios as follows: 1. high pressure releases 2. small foreseeable releases 3. catastrophic releases and 4. the effects of walls and barriers. Within each scenario the key objectives activities and results are discussed.<br/>The work on high pressure releases sought to provide information for informing safety distances for high-pressure components and associated fuel storage activities on both ignited and unignited jets are reported. A study on small foreseeable releases which could potentially be controlled through forced or natural ventilation is described. The aim of the study was to determine the ventilation requirements in enclosures containing fuel cells such that in the event of a foreseeable leak the concentration of hydrogen in air for zone 2 ATEX is not exceeded. The hazard potential of a possibly catastrophic hydrogen leakage inside a fuel cell cabinet was investigated using a generic fuel cell enclosure model. The rupture of the hydrogen feed line inside the enclosure was considered and both dispersion and combustion of the resulting hydrogen air mixture were examined for a range of leak rates and blockage ratios. Key findings of this study are presented. Finally the scenario on walls and barriers is discussed; a mitigation strategy to potentially reduce the exposure to jet flames is to incorporate barriers around hydrogen storage equipment. Conclusions of experimental and modelling work which aim to provide guidance on configuration and placement of these walls to minimise overall hazards is presented. "

With regard to the goals of the European HySafe Network research facilities are essential for the experimental investigation of relevant phenomena for testing devices and safety concepts as well as for the generation of validation data for the various numerical codes and models. The integrating activity ‘Integration of Experimental Facilities (IEF)’ has provided basic support for jointly performed experimental work within HySafe. Even beyond the funding period of the NoE HySafe in the 6th Framework Programme IEF represents a long lasting effort for reaching sustainable integration of the experimental research capacities and expertise of the partners from different research fields. In order to achieve a high standard in the quality of experimental data provided by the partners emphasis was put on the know-how transfer between the partners. The strategy for reaching the objectives consisted of two parts. On the one hand a documentation of the experimental capacities has been prepared and analysed. On the other hand a communication base has been established by means of biannual workshops on experimental issues. A total of 8 well received workshops has been organised covering topics from measurement technologies to safety issues. Based on the information presented by the partners a working document on best practice including the joint experimental knowledge of all partners with regard to experiments and instrumentation was created. Preserving the character of a working document it was implemented in the IEF wiki website which was set up in order to provide a central communication platform. The paper gives an overview of the IEF network activities over the last 5 years.

Natural ventilation is an efficient and well-known way to mitigate a hydrogen build-up in the case of an accidental release in confined enclosures. However for some hydrogen energy applications natural ventilation is not possible or is not efficient enough to reach defined safety strategy. Thus mechanical or forced ventilation can be interesting means to avoid critical concentration of hydrogen considering degraded operation and associated potential hazardous events. To better understand the impact of mechanical ventilation on the hydrogen build-up and distribution a dedicated study was led. First accidental release scenarios were experimentally simulated with helium in a 1-m3 enclosure. Several configurations of release and ventilation modes were tested and are presented in this study. Secondly analytical and numerical – Computational Fluid Dynamics – calculation approaches were applied and adjusted to propose a simplified methodology taking into account mechanical ventilation for assessment of hydrogen accumulation and for design optimization of the applications.

Hydrogen Infrastructures are currently being built up to support the initial commercialization of the fuel cell vehicle by multiple automakers. Three primary markets are presently coordinating a large build up of hydrogen stations: Japan; USA; and Europe to support this. Hydrogen Fuelling Station General Safety and Performance Considerations are important to establish before a wide scale infrastructure is established.

This document introduces the ISO Technical Report 19880-1 and summarizes main elements of the proposed standard. Note: this ICHS paper is based on the draft TR 19880 and is subject to change when the document is published in 2015. International Standards Organisation (ISO) Technical Committee (TC) 197 Working Group (WG) 24 has been tasked with the preparation of the ISO standard 19880-1 to define the minimum requirements considered applicable worldwide for the hydrogen and electrical safety of hydrogen stations. This report includes safety considerations for hydrogen station equipment and components control systems and operation. The following systems are covered specifically in the document as shown in Figure 1:

• H2 production / supply delivery system
• Compression
• Gaseous hydrogen buffer storage;
• Pre-cooling device;
• Gaseous hydrogen dispensers.
• Hydrogen Fuelling Vehicle Interface

The draft TR 19880-1 (and current plan for the standard) also gives guidance for the fueling validation with safety considerations relevant to the interaction between the hydrogen station and hydrogen road vehicles (during fuelling).. Through a cross-industry risk assessment carried out between OEMs Hydrogen Suppliers and existing vehicle fuelling station providers & operators (e.g. oil and industrial gas companies) the hydrogen fueling protocol SAE J2601 and associated dispenser hardware was evaluated."

Hydrogen can be used as a buffer for storing intermittent electricity produced by solar plants and/or wind farms. The MYRTE project in Corsica France aims to operate and test a large scale hydrogen facility for regulating the electricity produced by a 560 kWp photovoltaic plant.

Due to the large quantity of hydrogen and oxygen produced and stored (respectively 333 kg and 2654 kg) this installation faces safety issues and safety regulations constraints that can lead to extra costs. These extra costs may concern detectors monitoring barrier equipments that have to be taken into account for evaluating the system‘s total cost.

Relying on the MYRTE example that is an R&D platform the present work consists in listing the whole environmental and safety regulations to be applied in France on both Hydrogen and Oxygen production and storage. A methodology has been developed [1] [2] for evaluating safety extra costs. This methodology takes into account various hydrogen storage technologies (gaseous and solid state) and is applicable to other ways of storage (batteries etc.) to compare them. Results of this work based on a forecast of the operating platform over 20 years can be used to extrapolate and/or optimize future safety costs of next large scale hydrogen systems for further PV or wind energy storage applications.

A new route for making steel from iron ore based on the use of hydrogen to reduce iron oxides is presented detailed and analyzed. The main advantage of this steelmaking route is the dramatic reduction (90% off) in CO2 emissions compared to those of the current standard blast-furnace route. The first process of the route is the production of hydrogen by water electrolysis using CO2-lean electricity. The challenge is to achieve massive production of H2 in acceptable economic conditions. The second process is the direct reduction of iron ore in a shaft furnace operated with hydrogen only. The third process is the melting of the carbon-free direct reduced iron in an electric arc furnace to produce steel. From mathematical modeling of the direct reduction furnace we show that complete metallization can be achieved in a reactor smaller than the current shaft furnaces that use syngas made from natural gas. The reduction processes at the scale of the ore pellets are described and modeled using a specific structural kinetic pellet model. Finally the differences between the reduction by hydrogen and by carbon monoxide are discussed from the grain scale to the reactor scale. Regarding the kinetics reduction with hydrogen is definitely faster. Several research and development and innovation projects have very recently been launched that should confirm the viability and performance of this breakthrough and environmentally friendly ironmaking process.