United States
Hydrogen Monitoring Requirements in the Global Technical Regulation on Hydrogen and Fuel Cell Vehicles
Oct 2015
Publication
The United Nations Economic Commission for Europe Global Technical Regulation (GTR) Number 13 (Global Technical Regulation on Hydrogen and Fuel Cell Vehicles) is the defining document regulating safety requirements in hydrogen vehicles and in particular fuel cell electric vehicles (FCEVs). GTR Number 13 has been formally adopted and will serve as the basis for the national regulatory standards for FCEV safety in North America (led by the United States) Japan Korea and the European Union. The GTR defines safety requirements for these vehicles including specifications on the allowable hydrogen levels in vehicle enclosures during in-use and post-crash conditions and on the allowable hydrogen emissions levels in vehicle exhaust during certain modes of normal operation. However in order to be incorporated into national regulations that is to be legally binding methods to verify compliance with the specific requirements must exist. In a collaborative program the Sensor Laboratories at the National Renewable Energy Laboratory in the United States and the Joint Research Centre Institute for Energy and Transport in the Netherlands have been evaluating and developing analytical methods that can be used to verify compliance with the hydrogen release requirements as specified in the GTR.
State-of-the-Art and Research Priorities in Hydrogen Safety
Sep 2013
Publication
On October 16-17 2012 the International Association for Hydrogen Safety (HySafe) in cooperation with the Institute for Energy and Transport of the Joint Research Centre of the European Commission (JRC IET Petten) held a two-day workshop dedicated to Hydrogen Safety Research Priorities. The workshop was hosted by Federal Institute for Materials Research and Testing (BAM) in Berlin Germany. The main idea of the Workshop was to bring together stakeholders who can address the existing knowledge gaps in the area of the hydrogen safety including identification and prioritization of such gaps from the standpoint of scientific knowledge both experimental and theoretical including numerical. The experience highlighting these gaps which was obtained during both practical applications (industry) and risk assessment should serve as reference point for further analysis. The program included two sections: knowledge gaps as they are addressed by industry and knowledge gaps and state-of-the-art by research. In the current work the main results of the workshop are summarized and analysed.
A Review on Advanced Manufacturing for Hydrogen Storage Applications
Dec 2021
Publication
Hydrogen is a notoriously difficult substance to store yet has endless energy applications. Thus the study of long-term hydrogen storage and high-pressure bulk hydrogen storage have been the subject of much research in the last several years. To create a research path forward it is important to know what research has already been done and what is already known about hydrogen storage. In this review several approaches to hydrogen storage are addressed including high-pressure storage cryogenic liquid hydrogen storage and metal hydride absorption. Challenges and advantages are offered based on reported research findings. Since the project looks closely at advanced manufacturing techniques for the same are outlined as well. There are seven main categories into which most rapid prototyping styles fall. Each is briefly explained and illustrated as well as some generally accepted advantages and drawbacks to each style. An overview of hydrogen adsorption on metal hydrides carbon fibers and carbon nanotubes are presented. The hydrogen storage capacities of these materials are discussed as well as the differing conditions in which the adsorption was performed under. Concepts regarding storage shape and materials accompanied by smaller-scale advanced manufacturing options for hydrogen storage are also presented.
What is an Explosion?
Sep 2013
Publication
We are going to focus our discussion on “Explosions” its definitions from a scientific regulatory and societal perspective. We will point out that as defined these definitions are not consistent and lead to ambiguity. Of particular interest to this work is how this current ambiguity affects the emerging Regulation Codes and Standards (RCS) as applied to hydrogen technologies. While this manuscript has its roots in combustion science with extension to both the standard development and regulatory communities for hazards at large the unique behavior of hydrogen in many configurations motivates examining the relevant definitions and language used in these communities. We will point out the ambiguities how this leads to confusion in supporting definitions and how it leads to overly restrictive RCS for hydrogen applications. We will then suggest terminology which is not ambiguous internally self-consistent and allows appropriate RCS to be promulgated to ensure the safety of the public and capital to ensure the correct response of first responders and allow cost effective development of hydrogen technologies in our infrastructure.
Fundamental Combustion Properties of Oxygen Enriched Hydrogen-air Mixtures Relevant to Safety Analysis Experimental and Simulation Study
Oct 2015
Publication
In order to face the coming shortage of fossil energies a number of alternative methods of energy production are being considered. One promising approach consists in using hydrogen in replacement of the conventional fossil fuels or as an additive to these fuels. In addition to conventional hydro-electric and fission-based nuclear plants electric energy could be obtained in the future using nuclear fusion as investigated within the framework of the ITER project International Thermonuclear Experimental Reactor. However the operation of ITER may rise safety problems including the formation of a flammable dust/hydrogen/air atmosphere. A first step towards the accurate assessment of accidental explosion in ITER consists in better characterizing the risk of explosion in gaseous hydrogen-containing mixtures. In the present study laminar burning speeds ignition delay-times behind reflected shock wave and detonation cell sizes were measured over wide ranges of composition and equivalence ratios. The performances of five detailed reaction models were evaluated with respect to the present data.
Comparison of Two-layer Model for High Pressure Hydrogen Jets with Notional Nozzle Model Predictions and Experimental Data
Oct 2015
Publication
A two-layer reduced order model of high pressure hydrogen jets was developed which includes partitioning of the flow between the central core jet region leading to the Mach disk and the supersonic slip region around the core. The flow after the Mach disk is subsonic while the flow around the Mach disk is supersonic with a significant amount of entrained air. This flow structure significantly affects the hydrogen concentration profiles downstream. The predictions of this model are compared to previous experimental data for high pressure hydrogen jets up to 20 MPa and to notional nozzle models and CFD models for pressures up to 35 MPa using ideal gas properties. The results show that this reduced order model gives better predictions of the mole fraction distributions than previous models for highly underexpanded jets. The predicted locations of the 4% lower flammability limit also show that the two-layer model much more accurately predicts the measured locations than the notional nozzle models. The comparisons also show that the CFD model always underpredicts the measured mole fraction concentrations.
Very Low-cost Visual and Wireless Sensors for Effective Hydrogen Gas Leak Detection
Sep 2013
Publication
Element One Inc. Boulder CO is developing novel hydrogen gas leak indicators to improve the safety and maintenance operations of hydrogen production and chemical processing facilities and hydrogen fueling stations. These technologies can be used to make visual gas leak indicators such as paints decals and conformal plastic films as well as RF sensors for wireless networks. The primary advantage of the Element One hydrogen gas indicators is their low cost and easy deployment which allows them to be used ubiquitously at each and every potential hydrogen leak site. They have the potential to convert safety problems into routine maintenance problems thereby improving overall safety and decreasing operational costs.
Quantifying the Potential Consequences of a Detonation in a Hydrogen Jet Release
Sep 2019
Publication
The unconfined release of high-pressure hydrogen can create a large flammable jet with the potential to generate significant damage. To properly understand the separation distances necessary to protect the immediate surroundings it is important to accurately assess the potential consequences. In these events the possibility for a detonation cannot be excluded and would generally result in the worst case scenario from the standpoint of damaging overpressure. The strong concentration gradients created by a jet release however raises the question of what portion of the flammable cloud should be considered. Often all of the fuel within the limits of fast-flame acceleration or even all of the fuel within the flammability range is considered which typically comprises the majority of the flammable cloud. In this work prior detonation studies are reviewed to illustrate the inherently unstable nature of detonations with a focus on the critical dimensions and concentration gradients that can support a propagating detonation wave. These criteria are then applied to the flammable cloud concentration distributions generated by an unconfined jet release of hydrogen. By evaluating these limits it is found that the portion of the flammable cloud that is likely to participate is significantly reduced. These results are compared with existing experimental data on the ignition of unconfined hydrogen releases and the peak pressures that were measured are consistent with a detonation of a mass of fuel that is equivalent to the model prediction for the mass of fuel within the detonable limits. This work demonstrates how the critical conditions for detonation propagation can be used to estimate the portion of a hydrogen release that could participates in a detonation and how these criteria can be readily incorporated into existing dispersion modelling approaches.
Kinetic Model of Incipient Hydride Formation in Zr Clad under Dynamic Oxide Growth Conditions
Feb 2020
Publication
The formation of elongated zirconium hydride platelets during corrosion of nuclear fuel clad is linked to its premature failure due to embrittlement and delayed hydride cracking. Despite their importance however most existing models of hydride nucleation and growth in Zr alloys are phenomenological and lack sufficient physical detail to become predictive under the variety of conditions found in nuclear reactors during operation. Moreover most models ignore the dynamic nature of clad oxidation which requires that hydrogen transport and precipitation be considered in a scenario where the oxide layer is continuously growing at the expense of the metal substrate. In this paper we perform simulations of hydride formation in Zr clads with a moving oxide/metal boundary using a stochastic kinetic diffusion/reaction model parameterized with state-of-the-art defect and solute energetics. Our model uses the solutions of the hydrogen diffusion problem across an increasingly-coarse oxide layer to define boundary conditions for the kinetic simulations of hydrogen penetration precipitation and dissolution in the metal clad. Our method captures the spatial dependence of the problem by discretizing all spatial derivatives using a stochastic finite difference scheme. Our results include hydride number densities and size distributions along the radial coordinate of the clad for the first 1.6 h of evolution providing a quantitative picture of hydride incipient nucleation and growth under clad service conditions.
The Pressure Peaking Phenomenon: Validation for Unignited Releases in Laboratory-scale Enclosure
Oct 2015
Publication
This study is aimed at the validation of the pressure peaking phenomenon against laboratory-scale experiments. The phenomenon was discovered recently as a result of analytical and numerical studies performed at Ulster University. The phenomenon is characterized by the existence of a peak on the overpressure transient in an enclosure with vent(s) at some conditions. The peak overpressure can significantly exceed the steady-state pressure and jeopardise a civil structure integrity causing serious life safety and property protection problems. However the experimental validation of the phenomenon was absent until recently. The validation experiments were performed at Karlsruhe Institute of Technology within the framework of the HyIndoor project. Tests were carried out with release of three different gases (air helium and hydrogen) within a laboratory-scale enclosure of about 1 m3 volume with a vent of comparatively small size. The model of pressure peaking phenomenon reproduced closely the experimental pressure dynamics within the enclosure for all three used gases. The prediction of pressure peaking phenomenon consists of two steps which are explained in detail. Examples of calculation for typical hydrogen applications are presented.
H-Mat Hydrogen Compatibility of Polymers and Elastomers
Sep 2019
Publication
The H2@Scale program of the U.S. Department of Energy (DOE) Fuel Cell Technologies Office is supporting work on the hydrogen compatibility of polymers to improve the durability and reliability of materials for hydrogen infrastructure. The hydrogen compatibility program (H-Mat) seeks “to address the challenges of hydrogen degradation by elucidating the mechanisms of hydrogen-materials interactions with the goal of providing science-based strategies to design materials (micro)structures and morphology with improved resistance to hydrogen degradation.” This research has found hydrogen and pressure interactions with model rubber-material compounds demonstrating volume change and compression-set differences in the materials. The research leverages state-of-the-art capabilities of the DOE national labs. The materials were investigated using helium-ion microscopy which revealed significant morphological changes in the plasticizer incorporating compounds after exposure as evidenced by time-of-flight secondary ion mass spectrometry. Additional studies using transmission electron microscopy and nuclear magnetic resonance revealed that nanosized inclusions developed after gas decompression in rubber- and plasticizer-only materials; this is an indication of void formation at the nanometer level.
Experimental Investigation of Nozzle Aspect Ratio Effects on Under Expanded Hydrogen Jet Release Characteristics
Sep 2013
Publication
Most experimental investigations of underexpanded hydrogen jets have been limited to circular nozzles in an attempt to better understand the fundamental jet-exit flow physics and model this behaviour with pseudo source models. However realistic compressed storage leak exit geometries are not always expected to be circular. In the present study jet dispersion characteristics from rectangular slot nozzles with aspect ratios from 2 to 8 were investigated and compared with an equivalent circular nozzle. Schlieren imaging was used to observe the jet-exit shock structure while quantitative Planar Laser Rayleigh Scattering was used to measure downstream dispersion characteristics. These results provide physical insight and much needed model validation data for model development.
An Assessment on the Quantification of Hydrogen Releases Through Oxygen Displacement Using Oxygen
Sep 2013
Publication
Contrary to several reports in the recent literature the use of oxygen sensors for indirectly monitoring ambient hydrogen concentration has serious drawbacks. This method is based on the assumption that a hydrogen release will displace oxygen which is quantified using oxygen sensors. Despite its shortcomings the draft Hydrogen Vehicle Global Technical Regulation lists this method as a means to monitor hydrogen leaks to verify vehicle fuel system integrity. Experimental evaluations that were designed to impartially compare the ability of commercial oxygen and hydrogen sensors to reliably measure and report hydrogen concentration changes are presented. Numerous drawbacks are identified and discussed.
IPHE Regulations Codes and Standards Working Group-type IV COPV Round Robin Testing
Oct 2015
Publication
This manuscript presents the results of a multi-lateral international activity intended to understand how to execute a cycle stress test as specified in a chosen standard (GTR SAE ISO EIHP …). The purpose of this work was to establish a harmonized test method protocol to ensure that the same results would be achieved regardless of the testing facility. It was found that accurate temperature measurement of the working fluid is necessary to ensure the test conditions remain within the tolerances specified. Continuous operation is possible with adequate cooling of the working fluid but this becomes more demanding if the cycle frequency increases. Recommendations for future test system design and operation are presented.
Department of Energy Hydrogen Program Plan
Nov 2020
Publication
The Department of Energy (DOE) Hydrogen Program Plan (the Program Plan or Plan) outlines the strategic high-level focus areas of DOE’s Hydrogen Program (the Program). The term Hydrogen Program refers not to any single office within DOE but rather to the cohesive and coordinated effort of multiple offices that conduct research development and demonstration (RD&D) activities on hydrogen technologies. This terminology and the coordinated efforts on hydrogen among relevant DOE offices have been in place since 2004 and provide an inclusive and strategic view of how the Department coordinates activities on hydrogen across applications and sectors. This version of the Plan updates and expands upon previous versions including the Hydrogen Posture Plan and the DOE Hydrogen and Fuel Cells Program Plan and provides a coordinated high-level summary of hydrogen related activities across DOE.
The 2006 Hydrogen Posture Plan fulfilled the requirement in the Energy Policy Act of 2005 (EPACT 2005) that the Energy Secretary transmit to Congress a coordinated plan for DOE’s hydrogen and fuel cell activities. For historical context the original Posture Plan issued in 2004 outlined a coordinated plan for DOE and the U.S. Department of Transportation to meet the goals of the Hydrogen Fuel Initiative (HFI) and implement the 2002 National Hydrogen Energy Technology Roadmap. The HFI was launched in 2004 to accelerate research development and demonstration (RD&D) of hydrogen and fuel cell technologies for use in transportation electricity generation and portable power applications. The Roadmap provided a blueprint for the public and private efforts required to fulfill a long-term national vision for hydrogen energy as outlined in A National Vision of America’s Transition to a Hydrogen Economy—to 2030 and Beyond. Both the Roadmap and the Vision were developed out of meetings involving DOE industry academia non-profit organizations and other stakeholders. The Roadmap the Vision the Posture Plans the 2011 Program Plan and the results of key stakeholder workshops continue to form the underlying basis for this current edition of the Program Plan.
This edition of the Program Plan reflects the Department’s focus on conducting coordinated RD&D activities to enable the adoption of hydrogen technologies across multiple applications and sectors. It includes content from the various plans and documents developed by individual offices within DOE working on hydrogen-related activities including: the Office of Fossil Energy's Hydrogen Strategy: Enabling a Low Carbon Economy the Office of Energy Efficiency and Renewable Energy’s Hydrogen and Fuel Cell Technologies Office Multi-year RD&D Plan the Office of Nuclear Energy’s Integrated Energy Systems 2020 Roadmap and the Office of Science’s Basic Research Needs for the Hydrogen Economy. Many of these documents are also in the process of updates and revisions and will be posted online.
Through this overarching document the reader will gain information on the key RD&D needs to enable the largescale use of hydrogen and related technologies—such as fuel cells and turbines—in the economy and how the Department’s various offices are addressing those needs. The Program will continue to periodically revise the Plan along with all program office RD&D plans to reflect technological progress programmatic changes policy decisions and updates based on stakeholder input and reviews.
The 2006 Hydrogen Posture Plan fulfilled the requirement in the Energy Policy Act of 2005 (EPACT 2005) that the Energy Secretary transmit to Congress a coordinated plan for DOE’s hydrogen and fuel cell activities. For historical context the original Posture Plan issued in 2004 outlined a coordinated plan for DOE and the U.S. Department of Transportation to meet the goals of the Hydrogen Fuel Initiative (HFI) and implement the 2002 National Hydrogen Energy Technology Roadmap. The HFI was launched in 2004 to accelerate research development and demonstration (RD&D) of hydrogen and fuel cell technologies for use in transportation electricity generation and portable power applications. The Roadmap provided a blueprint for the public and private efforts required to fulfill a long-term national vision for hydrogen energy as outlined in A National Vision of America’s Transition to a Hydrogen Economy—to 2030 and Beyond. Both the Roadmap and the Vision were developed out of meetings involving DOE industry academia non-profit organizations and other stakeholders. The Roadmap the Vision the Posture Plans the 2011 Program Plan and the results of key stakeholder workshops continue to form the underlying basis for this current edition of the Program Plan.
This edition of the Program Plan reflects the Department’s focus on conducting coordinated RD&D activities to enable the adoption of hydrogen technologies across multiple applications and sectors. It includes content from the various plans and documents developed by individual offices within DOE working on hydrogen-related activities including: the Office of Fossil Energy's Hydrogen Strategy: Enabling a Low Carbon Economy the Office of Energy Efficiency and Renewable Energy’s Hydrogen and Fuel Cell Technologies Office Multi-year RD&D Plan the Office of Nuclear Energy’s Integrated Energy Systems 2020 Roadmap and the Office of Science’s Basic Research Needs for the Hydrogen Economy. Many of these documents are also in the process of updates and revisions and will be posted online.
Through this overarching document the reader will gain information on the key RD&D needs to enable the largescale use of hydrogen and related technologies—such as fuel cells and turbines—in the economy and how the Department’s various offices are addressing those needs. The Program will continue to periodically revise the Plan along with all program office RD&D plans to reflect technological progress programmatic changes policy decisions and updates based on stakeholder input and reviews.
Deploying Fuel Cell Systems, What Have We Learned
Sep 2013
Publication
The Hydrogen Safety Panel brings a broad cross-section of expertise from the industrial government and academic sectors to help advise the U.S. Department of Energy's (DOE) Fuel Cell Technologies Office through its work in hydrogen safety codes and standards. The Panel's initiatives in reviewing safety plans conducting safety evaluations identifying safety-related technical data gaps and supporting safety knowledge tools and databases cover the gamut from research and development to demonstration. The Panel's recent work has focused on the safe deployment of hydrogen and fuel cell systems in support of DOE efforts to accelerate fuel cell commercialization in early market applications: vehicle refuelling material handling equipment backup power for warehouses and telecommunication sites and portable power devices. This paper summarizes the work and learnings from the Panel's early efforts the transition to its current focus and the outcomes and conclusions from recent work on the deployment of hydrogen and fuel cell systems.
3D Risk Management for Hydrogen Installations (HY3DRM)
Oct 2015
Publication
This paper introduces the 3D risk management (3DRM) concept with particular emphasis on hydrogen installations (Hy3DRM). The 3DRM framework entails an integrated solution for risk management that combines a detailed site-specific 3D geometry model a computational fluid dynamics (CFD) tool for simulating flow-related accident scenarios methodology for frequency analysis and quantitative risk assessment (QRA) and state-of-the-art visualization techniques for risk communication and decision support. In order to reduce calculation time and to cover escalating accident scenarios involving structural collapse and projectiles the CFD-based consequence analysis can be complemented with empirical engineering models reduced order models or finite element analysis (FEA). The paper outlines the background for 3DRM and presents a proof-of-concept risk assessment for a hypothetical hydrogen filling station. The prototype focuses on dispersion fire and explosion scenarios resulting from loss of containment of gaseous hydrogen. The approach adopted here combines consequence assessments obtained with the CFD tool FLACS-Hydrogen from Gexcon and event frequencies estimated with the Hydrogen Risk Assessment Models (HyRAM) tool from Sandia to generate 3D risk contours for explosion pressure and radiation loads. For a given population density and set of harm criteria it is straightforward to extend the analysis to include personnel risk as well as risk-based design such as detector optimization. The discussion outlines main challenges and inherent limitations of the 3DRM concept as well as prospects for further development towards a fully integrated framework for risk management in organizations.
ISO 19880-1, Hydrogen Fueling Station and Vehicle Interface Safety Technical Report
Oct 2015
Publication
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:
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
Design of an Efficient, High Purity Hydrogen Generation Apparatus and Method for a Sustainable, Closed Clean Energy Cycle
Jul 2015
Publication
In this paper we present a detailed design study of a novel apparatus for safely generating hydrogen (H2) on demand according to a novel method using a controlled chemical reaction between water (H2O) and sodium (Na) metal that yields hydrogen gas of sufficient purity for direct use in fuel cells without risk of contaminating sensitive catalysts. The apparatus consists of a first pressure vessel filled with liquid H2O with an overpressure of nitrogen (N2) gas above the H2O reactant and a second pressure vessel that stores solid Na reactant. Hydrogen gas is generated above the solid Na when H2O reactant is introduced using a regulator that senses when the downstream pressure of H2 gas above the solid Na reactant has dropped below a threshold value. The sodium hydroxide (NaOH) byproduct of the hydrogen producing reaction is collected within the apparatus for later reprocessing by electrolysis to recover the Na reactant.
Hydrogen Systems Component Safety
Sep 2013
Publication
The deployment of hydrogen technologies particularly the deployment of hydrogen dispensing systems for passenger vehicles requires that hydrogen components perform reliably in environments where they have to meet the following performance parameters:
The paper will use incident frequency data from NREL’s Technology Validation project to more quantitatively identify safety concerns in hydrogen dispensing and storage systems.
- Perform safely where the consumer will be operating the dispensing equipment
- Dispense hydrogen at volumes comparable to gasoline dispensing stations in timeframes comparable to gasoline stations
- Deliver a fueling performance that is within the boundaries of consumer tolerance
- Perform with maintenance/incident frequencies comparable to gasoline dispensing systems
The paper will use incident frequency data from NREL’s Technology Validation project to more quantitatively identify safety concerns in hydrogen dispensing and storage systems.
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