Modelling and simulation of high-pressure hydrogen jets using notional nozzle theory and open source code OpenFOAM

The Hydrogen and Fuel Cell (H2FC) European research Infrastructure Cyber-laboratory (http://h2fc.eu/cyber-laboratory) is a software suite containing ‘modelling’ and ‘engineering’ tools, encompassing a wide range of H2FC processes and systems. One of the core aims of the H2FC Cyber-laboratory has been the creation of a state-of-the-art hydrogen CFD modelling toolbox. This paper describes the implementation and validation of this new CFD modelling toolbox, in conjunction with a selection of the available ‘Safety’ engineering tools, to analyse a high pressure hydrogen release and dispersion scenario. The experimental work used for this validation was undertaken by Shell and the Health and Safety Laboratory (UK). The overall goal of this work is to provide and make readily available a Cyber-laboratory that will be worth maintaining after the end of the H2FC project for the benefit of both the FCH scientific community and industry. This paper therefore highlights how the H2FC Cyber-laboratory, which is offered as an open access platform, can be used to replicate and analyse real-world scenarios, using both numerical engineering tools and through the implementation of CFD modelling techniques.     

Development of a model evaluation protocol for CFD analysis of hydrogen safety issues the SUSANA project

The “SUpport to SAfety aNAlysis of Hydrogen and Fuel Cell Technologies (SUSANA)” project aims to support stakeholders using Computational Fluid Dynamics (CFD) for safety engineering design and assessment of FCH systems and infrastructure through the development of a model evaluation protocol. The protocol covers all aspects of safety assessment modelling using CFD, from release, through dispersion to combustion (self-ignition, fires, deflagrations, detonations, and Deflagration to Detonation Transition - DDT) and not only aims to enable users to evaluate models but to inform them of the state of the art and best practices in numerical modelling. The paper gives an overview of the SUSANA project, including the main stages of the model evaluation protocol and some results from the on-going benchmarking activities.     

Innovative regions and industrial clusters in hydrogen and fuel cell technology

Regional governments in Europe seem to be playing an increasing role in hydrogen and fuel cell (H2FC) development. A number of regions are supporting demonstration projects and building networks among regional stakeholders to strengthen their engagement in H2FC technology. In this article, we will analyse regions that are highly engaged in H2FC activity, based on three indicators: existing hydrogen infrastructure and production sites, general innovativeness and the presence of industrial clusters with relevance for H2FC. Our finding is that regions with high activity in H2FC development are also innovative regions in general. Moreover, the article highlights some industrial clusters that create favourable conditions for regions to take part in H2FC development. Existing hydrogen infrastructure, however, seems to play only a minor role in a region's engagement. The article concludes that, while further research is needed before qualified policy implications can be drawn, an overall well-functioning regional innovation system is important in the formative phase of an H2FC innovation system.     

On the development of an International Curriculum on Hydrogen Safety Engineering and its implementation into educational programmes

The present paper provides an overview of the development of an International Curriculum on Hydrogen Safety Engineering and its implementation into new educational programmes. The curriculum is being developed as part of the educational and training activities of the European Network of Excellence “Safety of Hydrogen as an Energy Carrier” (HySafe). It has a modular structure consisting of five basic, six fundamental and four applied modules. The reasons for this particular structure are explained. To accelerate the development of teaching materials and their implementation in training/educational programmes, an annual European Summer School on Hydrogen Safety will be held (the first Summer School was from 15–24 August 2006, Belfast, UK), where leading experts deliver keynote lectures to an audience of researchers on topics covering the state-of-the-art in hydrogen safety science and engineering. The establishment of a postgraduate certificate course in hydrogen safety engineering at the University of Ulster (starting in January 2007) as a first step in the development of a worldwide system of hydrogen safety education and training is described.     

Hydrogen in future energy systems: Social acceptance of the technology and its large-scale infrastructure

Hydrogen is regarded as a key component of future low-carbon energy systems. Yet, for the implementation of hydrogen technologies on a large scale it is necessary to consider social acceptance. Studies on acceptance of hydrogen technologies have resulted in neutral to positive evaluations. This paper extends previous studies by focusing on large-scale hydrogen infrastructure. Within the project ELEGANCY, quantitative data on the acceptance was gathered among the German population. The results confirm the positive perception of hydrogen on a general level. However, the high level of acceptance is decreasing when it comes to infrastructure implementation in the own neighbourhood. In this paper, the gap between acceptance of hydrogen technology on a general level and the level of its infrastructural implementation is analysed, focusing on new pipeline infrastructure. The results show that sociodemographic factors, especially the variable age, as well as project-related factors, especially trust in stakeholders, have a high explanatory power.     

Canadian hydrogen safety program

The Canadian hydrogen safety program (CHSP) is a project initiative of the Codes & Standards Working Group of the Canadian transportation fuel cell alliance (CTFCA) that represents industry, academia, government, and regulators. The Program rationale, structure and contents contribute to acceptance of the products, services and systems of the Canadian Hydrogen Industry into the Canadian hydrogen stakeholder community. It facilitates trade through fair insurance policies and rates, effective and efficient regulatory approval procedures and accommodation of the interests of the general public. The Program integrates a consistent quantitative risk assessment methodology with experimental (destructive and non-destructive) failure rates and consequence-of-release data for key hydrogen components and systems into risk assessment of commercial application scenarios. Its current and past six projects include Intelligent Virtual Hydrogen Filling Station (IVHFS), Hydrogen clearance distances, comparative quantitative risk comparison of hydrogen and compressed natural gas (CNG) refuelling options; computational fluid dynamics (CFD) modeling validation, calibration and enhancement; enhancement of frequency and probability analysis, and Consequence analysis of key component failures of hydrogen systems; and fuel cell oxidant outlet hydrogen sensor project. The Program projects are tightly linked with the content of the International Energy Agency (IEA) Task 19 Hydrogen Safety.     

Critical review and analysis of hydrogen safety data collection tools

The wider adoption of hydrogen in multiple sectors of the economy requires that safety and risk issues be rigorously investigated. Quantitative Risk Assessment (QRA) is an important tool for enabling safe deployment of hydrogen fueling stations and is increasingly embedded in the permitting process. QRA requires reliability data, and currently hydrogen QRA is limited by the lack of hydrogen specific reliability data, thereby hindering the development of necessary safety codes and standards [1]. Four tools have been identified that collect hydrogen system safety data: H2Tools Lessons Learned, Hydrogen Incidents and Accidents Database (HIAD), National Renewable Energy Lab's (NREL) Composite Data Products (CDPs), and the Center for Hydrogen Safety (CHS) Equipment and Component Failure Rate Data Submission Form. This work critically reviews and analyzes these tools for their quality and usability in QRA. It is determined that these tools lay a good foundation, however, the data collected by these tools needs improvement for use in QRA. Areas in which these tools can be improved are highlighted, and can be used to develop a path towards adequate reliability data collection for hydrogen systems.     

3D risk management for hydrogen installations

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.     

Hydrogen storage and delivery: Review of the state of the art technologies and risk and reliability analysis

Among all introduced green alternatives, hydrogen, due to its abundance and diverse production sources is becoming an increasingly viable clean and green option for transportation and energy storage. Governments are considerably funding relevant researches and the public is beginning to talk about hydrogen as a possible future fuel. Hydrogen production, storage, delivery, and utilization are the key parts of the Hydrogen Economy (HE). In this paper, hydrogen storage and delivery options are discussed thoroughly. Then, since safety and reliability of hydrogen infrastructure is a necessary enabling condition for public acceptance of these technologies and any major accident involving hydrogen can be difficult to neutralize, we review the main existing safety and reliability challenges in hydrogen systems. The current state of the art in safety and reliability analysis for hydrogen storage and delivery technologies is discussed, and recommendations are mentioned to help providing a foundation for future risk and reliability analysis to support safe, reliable operation.     

Overview of the DOE hydrogen safety,codes and standards program part 2: Hydrogen and fuel cells: Emphasizing safety to enable commercialization

Safety is of paramount importance in all facets of the research, development, demonstration and deployment work of the U.S. Department of Energy's (DOE) Fuel Cell Technologies Program. The Safety, Codes and Standards sub-program (SC&S) facilitates deployment and commercialization of fuel cell and hydrogen technologies by developing and disseminating information and knowledge resources for their safe use. A comprehensive safety management program utilizing the Hydrogen Safety Panel to raise safety consciousness at the project level and developing/disseminating a suite of safety knowledge resources is playing an integral role in DOE and SC&S efforts. This paper provides examples of accomplishments achieved while reaching a growing and diverse set of stakeholders involved in research, development and demonstration; design and manufacturing; deployment and operations. The work of the Hydrogen Safety Panel highlights new knowledge and the insights gained through interaction with project teams. Various means of collaboration to enhance the value of the program's safety knowledge tools and training resources are illustrated and the direction of future initiatives to reinforce the commitment to safety is discussed.     

A systematic literature review of societal acceptance and stakeholders’ perception of hydrogen technologies

This paper presents the results of a systematic review that analysed the literature on factors influencing societal acceptance and stakeholders’ perceptions of hydrogen related technologies. This study found that the most influencing factors include prior knowledge, perceived cost/risks, environmental knowledge, higher education and income, personal and distributive benefits, infrastructure availability and close proximity to hydrogen facilities. There was low hydrogen awareness in more than 60% of the countries analysed in the reviewed studies. Although stakeholders had diverse perceptions, there was agreement that infrastructure availability, affordability, local community engagement, regional skill capability development, preservation of biodiversity, and safety and distributive benefits to the community were essential for a successful hydrogen industry. Future research could examine consumer acceptance at different geographical scales, analyse pre-and post-hydrogen project implementation, and social impact of hydrogen infrastructure on local communities. We also recommend diversifying hydrogen research projects and investigating the policy and regulatory arrangements for community-owned hydrogen projects.     

Safety investigation of hydrogen energy storage systems using quantitative risk assessment

Hydrogen energy storage systems are expected to play a key role in supporting the net zero energy transition. Although the storage and utilization of hydrogen poses critical risks, current hydrogen energy storage system designs are primarily driven by cost considerations to achieve economic benefits without safety considerations. This paper aims to study the safety of hydrogen storage systems by conducting a quantitative risk assessment to investigate the effect of hydrogen storage systems design parameters such as storage size, mass flow rate, storage pressure and storage temperature. To this end, the quantitative risk assessment procedure, which includes data collection and hazard identification, frequency analysis, consequence analysis and risk analysis, was carried out for the hydrogen storage system presented in a previous study [1]. In the consequence analysis, the Millers model and TNO multi-energy were used to model the jet fire and explosion hazards, respectively. The results show that the storage capacity and pressure have the greatest influence on the hydrogen storage system risk assessment. More significantly, the design parameters may affect the acceptance criteria based on the gaseous hydrogen standard. In certain cases of large storage volume or high storage pressure, risk mitigation measures must be implemented since the risk of the hydrogen storage system is unacceptable in accordance with ISO 19880-1. The study highlights the significance of risk analysis conduction and the importance of considering costs associated with risk mitigation in the design of hydrogen storage system.     

Review and analysis of the hydrogen production technologies from a safety perspective

Hydrogen can be produced via many different technologies; however, from a safety standpoint there exists no framework for selecting the right technology. Here, we provide a structured framework for assessment of the most desirable hydrogen production technology based on efficiency, safety, and infrastructure, by using a Multi-Criteria Decision-Making (MCDM) integrated Analytic Hierarchy Process (AHP) and life-cycle index (LInX) approach. We apply this modified MCDM approach to steam methane reforming (SMR), autothermal reforming, partial oxidation, alkaline electrolysis, polymer electrode membrane electrolysis, and solid oxide electrolyzer cell processes. Our results show that SMR is the most desirable technology based on the efficiency, safety, and infrastructure criteria. We employ fuzzy set theory to address subjectivity and uncertainty challenges in the data and found that although the technologies based on electrolysis have an environmental advantage, they exhibit higher uncertainties than non-renewable technologies such as SMR. Overall, this new framework addresses the challenge to find the most desirable and safer technology for hydrogen production.     

工业仓库的消防安全性能设计

以工业仓库为例，采取消防安全性能设计新理念，在保证人员人身安全的前提下，探讨排烟系统性能以及人员疏散问题，利用简单分析与计算机模拟技术相结合的方法定量分析安全疏散时间等相关特性。同时，对火源、排烟条件以及疏散出口等不同条件下的火灾场景进行了研究，并对部分场景进行了三维CFD计算。研究表明，作为现有处方式法规的一种变通，性能设计在一定程度上可达到预先确定的消防安全目标。     

Simulation of hydrogen leak and explosion for the safety design of hydrogen fueling station in Korea

Hydrogen has been used as chemicals and fuels in industries for last decades. Recently, it has become attractive as one of promising green energy candidates in the era of facing with two critical energy issues such as accelerating deterioration of global environment (e.g. carbon dioxide emissions) as well as concerns on the depletion of limited fossil sources. A number of hydrogen fueling stations are under construction to fuel hydrogen-driven vehicles. It would be indispensable to ensure the safety of hydrogen station equipment and operating procedure in order to prevent any leak and explosions of hydrogen: safe design of facilities at hydrogen fueling stations e.g. pressurized hydrogen leak from storage tanks. Several researches have centered on the behaviors of hydrogen ejecting out of a set of holes of pressurized storage tanks or pipes. This work focuses on the 3D simulation of hydrogen leak scenario cases at a hydrogen fueling station, given conditions of a set of pressures, 100, 200, 300, 400 bar and a set of hydrogen ejecting hole sizes, 0.5, 0.7, 1.0 mm, using a commercial computational fluid dynamics (CFD) tool, FLACS. The simulation is based on real 3D geometrical configuration of a hydrogen fueling station that is being commercially operated in Korea. The simulation results are validated with hydrogen jet experimental data to examine the diffusion behavior of leak hydrogen jet stream. Finally, a set of marginal safe configurations of fueling facility system are presented, together with an analysis of distribution characteristics of blast pressure, directionality of explosion. This work can contribute to marginal hydrogen safety design for hydrogen fueling stations and a foundation on establishing a safety distance standard required to protect from hydrogen explosion in Korea being in the absence of such an official requirement.     

Best practice guidelines in numerical simulations and CFD benchmarking for hydrogen safety applications

Correct use of Computational Fluid Dynamics (CFD) tools is essential in order to have confidence in the results. A comprehensive set of Best Practice Guidelines (BPG) in numerical simulations for Fuel Cells and Hydrogen applications has been one of the main outputs of the SUSANA project. These BPG focus on the practical needs of engineers in consultancies and industry undertaking CFD simulations or evaluating CFD simulation results in support of hazard/risk assessments of hydrogen facilities, as well as on the needs of regulatory authorities. This contribution presents a summary of the BPG document. All crucial aspects of numerical simulations are addressed, such as selection of the physical models, domain design, meshing, boundary conditions and selection of numerical parameters. BPG cover all hydrogen safety relative phenomena, i.e. release and dispersion, ignition, jet fire, deflagration and detonation. A series of CFD benchmarking exercises are also presented serving as examples of appropriate modelling strategies.     

Construction of a structural equation model to identify public acceptance factors for hydrogen refueling stations under the provision of risk and safety information

Hydrogen refueling stations (HRSs) are an inevitable infrastructure for the utility of fuel cell vehicles; however, they can raise public safety concerns. The aim of this study is to establish a framework for public acceptance of HRSs in Japan upon the provision of risk and/or safety measure information on HRSs. We executed an in-person interview survey asking the respondents about their acceptance of HRSs and then constructed a structural equation model on HRS acceptance with four endogenous factors. The common factors to determine acceptability were “Dread” and “Independent”. “Balance” was added to the factors for the risk-informed group. If risk information was provided, people tended to judge based on their inherent sense of “Balance”; however, if it was not provided, their judgment was based on their intuitive “Dread” of HRSs or hydrogen. This study reveals risk perception characteristics and attempts to promote improved risk communication prior to HRS installation.     

Blast wave from a hydrogen tank rupture in a fire in the open: Hazard distance nomograms

The nomograms for graphical calculation of hazard distances and zones from a blast wave generated by a stand-alone (stationary) and an onboard (under-vehicle) high-pressure hydrogen tank ruptures in a fire are presented. The nomograms can be used by first responders, hydrogen safety engineers and other stakeholders to determine hazard distances and zones based on a blast wave strength characterised by both overpressure and impulse. The nomograms were built using the validated physical model of a blast wave decay published by the authors and accounting for the contribution of combustion into the blast wave strength. Two types of nomograms are developed: one for on-site use by the first responders, and another for design of hydrogen systems and infrastructure by hydrogen safety engineers. The paper underlines the importance of international regulatory activities to unify harm to people and damage to buildings criteria across different countries.     

A GIS-based assessment of coal-based hydrogen infrastructure deployment in the state of Ohio

Hydrogen infrastructure costs will vary by region as geographic characteristics and feedstocks differ. This paper proposes a method for optimizing regional hydrogen infrastructure deployment by combining detailed spatial data in a geographic information system (GIS) with a technoeconomic model of hydrogen infrastructure components. The method is applied to a case study in Ohio in which coal-based hydrogen infrastructure with carbon capture and storage (CCS) is modeled for two distribution modes at several steady-state hydrogen vehicle market penetration levels. The paper identifies the optimal infrastructure design at each market penetration as well as the costs, CO₂ emissions, and energy use associated with each infrastructure pathway. The results indicate that aggregating infrastructure at the regional-scale yields lower levelized costs of hydrogen than at the city-level at a given market penetration level, and centralized production with pipeline distribution is the favored pathway even at low market penetration. Based upon the hydrogen infrastructure designs evaluated in this paper, coal-based hydrogen production with CCS can significantly reduce transportation-related CO₂ emissions at a relatively low infrastructure cost and levelized fuel cost.