United Kingdom
H21- Hydrogen Boilers Installed in Demonstration Houses
Nov 2020
Publication
Hydrogen boilers have been developed by Worcester Bosch and Baxi and are being trialled in demonstration houses. They look and feel just like the boilers we use today. Hydrogen produces no carbon when used and a hydrogen gas network could provide the least disruptive route to a net zero carbon future.
The Effect of Tube Internal Geometry on the Propensity to Spontaneous Ignition in Pressurized Hydrogen Release
Sep 2013
Publication
Spontaneous ignition of compressed hydrogen release through a length of tube with different internal geometries is numerically investigated using our previously developed model. Four types of internal geometries are considered: local contraction local enlargement abrupt contraction and abrupt enlargement. The presence of internal geometries was found to significantly increase the propensity to spontaneous ignition. Shock reflections from the surfaces of the internal geometries and the subsequent shock interactions further increase the temperature of the combustible mixture at the contact region. The presence of the internal geometry stimulates turbulence enhanced mixing between the shock-heated air and the escaping hydrogen resulting in the formation of more flammable mixture. It was also found that forward-facing vertical planes are more likely to cause spontaneous ignition by producing the highest heating to the flammable mixture than backward-facing vertical planes.
Ia-HySafe Standard Benchmark Exercise Sbep-V21- Hydrogen Release and Accumulation within a Non-Ventilated Ambient Pressure Garage at Low Release Rates
Sep 2011
Publication
The successful Computational Fluid Dynamics (CFD) benchmarking activity originally started within the EC-funded Network of Excellence HySafe (2004-2009) continues within the research topics of the recently established “International Association of Hydrogen Safety” (IA-HySafe). The present contribution reports the results of the standard benchmark problem SBEP-V21. Focus is given to hydrogen dispersion and accumulation within a non-ventilated ambient pressure garage both during the release and post-release periods but for very low release rates as compared to earlier work (SBEP-V3). The current experiments were performed by CEA at the GARAGE facility under highly controlled conditions. Helium was vertically released from the centre of the 5.76 m (length) x 2.96 m (width) x 2.42 m (height) facility 22 cm from the floor from a 29.7 mm diameter opening at a volumetric rate of 18 L/min (0.027 g/s equivalent hydrogen release rate compared to 1 g/s for SBEP-V3) and for a period of 3740 seconds. Helium concentrations were measured with 57 catharometric sensors at various locations for a period up to 1.1 days. The simulations were performed using a variety of CFD codes and turbulence models. The paper compares the results predicted by the participating partners and attempts to identify the reasons for any observed disagreements.
A Dynamic Performance Diagnostic Method Applied to Hydrogen Powered Aero Engines Operating under Transient Conditions
Apr 2022
Publication
At present aero engine fault diagnosis is mainly based on the steady-state condition at the cruise phase and the gas path parameters in the entire flight process are not effectively used. At the same time high quality steady-state monitoring measurements are not always available and as a result the accuracy of diagnosis might be affected. There is a recognized need for real-time performance diagnosis of aero engines operating under transient conditions which can improve their condition-based maintenance. Recent studies have demonstrated the capability of the sequential model-based diagnostic method to predict accurately and efficiently the degradation of industrial gas turbines under steady-state conditions. Nevertheless incorporating real-time data for fault detection of aero engines that operate in dynamic conditions is a more challenging task. The primary objective of this study is to investigate the performance of the sequential diagnostic method when it is applied to aero engines that operate under transient conditions while there is a variation in the bypass ratio and the heat soakage effects are taken into consideration. This study provides a novel approach for quantifying component degradation such as fouling and erosion by using an adapted version of the sequential diagnostic method. The research presented here confirms that the proposed method could be applied to aero engine fault diagnosis under both steady-state and dynamic conditions in real-time. In addition the economic impact of engine degradation on fuel cost and payload revenue is evaluated when the engine under investigation is using hydrogen. The proposed method demonstrated promising diagnostic results where the maximum prediction errors for steady state and transient conditions are less than 0.006% and 0.016% respectively. The comparison of the proposed method to a benchmark diagnostic method revealed a 15% improvement in accuracy which can have great benefit when considering that the cost attributed to degradation can reach up to $702585 for 6000 flight cycles of a hydrogen powered aircraft fleet. This study provides an opportunity to improve our understanding of aero engine fault diagnosis in order to improve engine reliability availability and efficiency by online health monitoring.
Scottish Hydrogen Assessment
Dec 2020
Publication
During 2020 the Scottish Government in partnership with Highlands and Islands Enterprise and Scottish Enterprise commissioned Arup and E4Tech to carry out a hydrogen assessment to deepen our evidence base in order to inform our policies on hydrogen going forward. The assessment aims to investigate how and where hydrogen may fit within the evolving energy system technically geographically and economically. To assist in this consideration a key part of the Hydrogen Assessment is the development of distinct viable scenarios for hydrogen deployment in Scotland and the economic assessment of those scenarios.<br/>From our assessment it is clear that hydrogen is not just an energy and emissions reduction opportunity; it could also have an important role in generating new economic opportunities in Scotland. The assessment forms an important part of the evidence base that informed the development of the Hydrogen Policy Statement.
Materials Aspects Associated with the Addition of up to 20 mol% Hydrogen into an Existing Natural Gas Distribution Network
Sep 2019
Publication
The introduction of hydrogen into the UK natural gas main has been reviewed in terms of how materials within the gas distribution network may be affected by contact with up to 80% Natural Gas : 20 mol% hydrogen blend at up to 2 barg. A range of metallic polymeric and elastomeric materials in the gas distribution network (GDN) were assessed via a combination of literature review and targeted practical test programmes.
The work considered:
The work considered:
- The effect of hydrogen on metallic materials identified in the network
- The effect of hydrogen on polymeric materials identified in the network
- The effect of hydrogen exposure on polyethylene pipeline techniques (squeeze off and collar electrofusion)
Hydrogen Bubble Dispersion and Surface Bursting Behaviour
Sep 2013
Publication
In many processes where hydrogen may be released from below a liquid surface there has been concern regarding how such releases might ultimately disperse in an ullage space. Knowledge of the extent and persistence of any flammable volume formed is needed for hazardous area classification as well as for validation of explosion modelling or experiments. Following an initial release of hydrogen the overall process can be subdivided into three stages (i) rise and possible break-up of a bubble in the liquid (ii) formation and bursting of a thin gas-liquid-gas interface at the liquid surface and (iii) dispersion of the released gas. An apparatus based on a large glass sided water tank has been constructed which employs two synchronised high-speed imaging systems to record the behaviour of hydrogen bubble release and dispersion. A high-speed digital video system records the rising of the bubbles and the formation and bursting of the gas-liquid-gas interface at the liquid surface. An additional schlieren system is used to visualise the hydrogen release as bubbles burst at the liquid surface. The bubble burst mechanism can clearly be described from the results obtained. Following the nucleation of a hole surface tension causes the liquid film to peel back rapidly forming a ring/torus of liquid around the enlarging hole. This process lasts only a few milliseconds. Although some hydrogen can be seen to be expelled from the bubble much seems to remain in place as the film peels away. To assess the extent of the flammable plume following a bubble burst the apparatus was modified to include an electric-arc igniter. In order to identify plumes coincident in space with the igniter a schlieren system was built capable of recording simultaneously in two orthogonal directions. This confirmed that clouds undetected by the schlerien imaging could not be ignited with the electric arc igniter.
Operation of UK Gas Appliances with Hydrogen Blended Natural Gas
Sep 2019
Publication
The HyDeploy project has undertaken a programme of work to assess the effect of hydrogen addition on the safety and performance of gas appliances and installations. A representative set of eight appliances have been assessed in laboratory experiments with a range of test gases that explored high and low Wobbe Number and hydrogen concentrations up to 28.4 % mol/mol. Tests have demonstrated that the addition of hydrogen does not affect the key hazard areas of CO production light back flame out or the operation of flame failure devices. It was identified that for some designs of gas fire appliances the operation of the oxygen depletion sensors may be affected by the addition of hydrogen and further studies in this area are planned. A laboratory based study was supported by an onsite testing programme where 133 installations were assessed for gas tightness appliance combustion safety and operation against normal line natural gas G20 reference gas and two hydrogen blended gases. Where installations were gas tight for natural gas analysis showed that no additional leakage occurred with hydrogen blended gases. There were also no issues identified with the combustion performance of appliances and onsite results were in line with those obtained in the laboratory testing programme.
Annual Science Review 2020
Mar 2020
Publication
HSE maintains a national network of doctors appointed doctors and approved medical examiners of divers who are appointed to deliver certain vital functions under our regulatory framework.1 Over the last year or so we have been reaching out to them and offering training and networking opportunities so that we can learn from each other. Their intelligence from real workplaces helps ensure that our medical approach is grounded by what actually happens and this helped us ensure that our health and work strategy took account of their views. I think that it is increasingly important to share our approaches and our research outcomes on the global stage in an attempt to learn from other researchers around the world. A good example is the work described in this report on the artificial stone issue. I have been lucky enough to work with the Australian research group who identified an epidemic of silicosis from this exposure in their country and helped to facilitate some cross-comparison of materials with our hygienists and measurement scientists. The dialogue continues and I hope that by doing so we can help to prevent such an epidemic from occurring in the UK.<br/>All HSE research findings are published as soon as we are able to do this and this demonstrates both my and Andrew Curran’s commitment to ensure that we publish the evidence we generate to make workplaces healthier for all.
Gas Detection of Hydrogen/Natural Gas Blends in the Gas Industry
Sep 2019
Publication
A key element in the safe operation of a modern gas distribution system is gas detection. The addition of hydrogen to natural gas will alter the characteristics of the fuel and therefore its impact on gas detection must be considered. It is important that gas detectors remain sufficiently sensitive to the presence of hydrogen and natural gas mixtures and that they do not lead to false readings. This paper presents analyses of work performed as part of the Office for Gas and Energy Markets (OFGEM) funded HyDeploy project on the response of various natural gas industry detectors to blended mixtures up to 20 volume percent (vol%) of hydrogen in natural gas. The scope of the detectors under test included survey instruments and personal monitors that are used in the gas industry. Four blend ratios were analysed (0 10 15 and 20 vol% hydrogen in natural gas). The laboratory testing undertaken investigated the following:
- Flammable response to blends in the ppm range (0-0.2 vol%);
- Flammable response to blends in the lower explosion limit range (0.2-5 vol%);
- Flammable response to blends in the volume percent range (5-100 vol%);
- Oxygen response to blends in the volume percent range (0-25 vol%); and
- Carbon monoxide response to blends in the ppm range (0-1000 ppm).
Simulation of Hydrogen Dispersion under Cryogenic Release Conditions
Sep 2013
Publication
The use of hydrogen as fuel should always be accompanied by a safety assessment in case of an accidental release. To evaluate the potential hazards in a spill accident both experiments and simulations are performed. In the present work the CFD code ADREA-HF is used to simulate the liquefied hydrogen (LH2) spill experiments (test 5 6 7) conducted by the Health and Safety Laboratory (HSL). In these tests LH2 was spilled at a fixed rate of 60lt/min in several directions and for several durations. The factors that influence the vapor dispersion under cryogenic release conditions that were examined in this study are: the air humidity the wind direction and the slip effect of droplets formed by both the cryogenic liquid and the condensation of air humidity. The numerical results were compared with the experimental measurements and the effect of each abovementioned factors in the vapor dispersion is being discussed.
A New Sustainable Hydrogen Clean Energy Paradigm
Feb 2018
Publication
We analyze the feasibility of a novel hydrogen fuel cell electric generator to provide power with zero noise and emissions for myriad ground based applications. The hydrogen fuel cell electric generator utilizes a novel scalable apparatus that safely generates 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 sodium hydroxide (NaOH) byproduct of the hydrogen producing reaction is collected within the apparatus for later reprocessing by electrolysis to recover the Na reactant. The detailed analysis shows that the novel hydrogen fuel cell electric generator will be capable of meeting the clean power requirements for residential and commercial buildings including single family homes and light commercial establishments under a wide range of geographic and climatic conditions.
Flow Loop Test for Hydrogen
Jul 2020
Publication
National Grid (NG) needs to understand the implications that a hydrogen rich gas mix may have on the existing pipeline network. The primary network consists extensively of X52 steel pipe sections welded together using girth welds. Different welding specifications that have been used in the past 40 years and girth welds with different specifications may behave differently when coming into contact with hydrogen gas.
The aim of the flow loop test programme is to begin to evaluate the durability of pipeline materials in the context of future proofing of gas grid service where the gas mix may include a significant proportion of hydrogen. One specific objective is to investigate the resistance to hydrogen embrittlement of a conventional steel (X52) with commonly used girth welds. The primary concern is that the phenomenon of hydrogen embrittlement may cause unexpected or early failure mechanisms especially in older pipe sections with less stringent girth weld specifications.
This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.
The aim of the flow loop test programme is to begin to evaluate the durability of pipeline materials in the context of future proofing of gas grid service where the gas mix may include a significant proportion of hydrogen. One specific objective is to investigate the resistance to hydrogen embrittlement of a conventional steel (X52) with commonly used girth welds. The primary concern is that the phenomenon of hydrogen embrittlement may cause unexpected or early failure mechanisms especially in older pipe sections with less stringent girth weld specifications.
This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.
Numerical Simulation of Diverging Detonation in Hydrogen Air Mixtures
Oct 2015
Publication
Propagation and stability of diverging cylindrical detonation in hydrogen air mixture is numerically simulated and the mechanism of the transverse waves is analysed. For the numerical modelling a new solver based on compressible transient reactive Navier–Stokes equations is developed which can the simulate detonation propagation and extinction in hydrogen-air mixture. A single step reaction mechanism is tuned to ensure the detonation and deflagration properties (in case of detonation failure) can be simulated accurately. The solver is used for modelling various detonation scenarios in particular cylindrical diverging-detonations because most of accidental industrial detonations start from a spark and then a diverging-detonation propagates outwards. The diverging detonation its cellular structure and adoption with the increased surface area at the detonation front as well as interactions with obstacles leading to detonation failure and re-initiation are studied.
Hydrogen and Fuel Cell Stationary Applications: Key Findings of Modelling and Experimental Work in the Hyper Project
Sep 2009
Publication
Síle Brennan,
A. Bengaouer,
Marco Carcassi,
Gennaro M. Cerchiara,
Andreas Friedrich,
O. Gentilhomme,
William G. Houf,
N. Kotchourko,
Alexei Kotchourko,
Sergey Kudriakov,
Dmitry Makarov,
Vladimir V. Molkov,
Efthymia A. Papanikolaou,
C. Pitre,
Mark Royle,
R. W. Schefer,
G. Stern,
Alexandros G. Venetsanos,
Anke Veser,
Deborah Willoughby,
Jorge Yanez and
Greg H. Evans
"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. "
World Energy Issues Monitor 2019 Managing the Grand Energy Transition
Oct 2019
Publication
This is the tenth consecutive year of the World Energy Council’s (the Council) annual survey of key challenges and opportunities facing energy leaders in managing and shaping Energy Transitions. This year’s Issues Monitor report provides seven global maps six regional maps and fifty national maps.
These maps have been developed by analysing the responses of nearly 2300 energy leaders drawn from across the Council’s diverse and truly global energy community.
The Council’s Issues Monitor identifies the strategic energy landscape of specific countries and regions in the world through an analysis of 42 energy issues and 4 digitalisation-specific issues affecting the energy system. It provides a unique reality check and horizon scanning of persistent and emerging concerns involved in whole energy systems transition. This year’s report welcomes a significant increase in both the participation of global leaders (up over 75% from 1300 to nearly 2300) as well as the participation of 86 countries.
Each Issue Map provides a visual snapshot of the uncertainties and action priorities that energy policymakers CEOs and leading experts strive to address to shape and manage successful Energy
Transitions. Maps can be used in the following ways:
These maps have been developed by analysing the responses of nearly 2300 energy leaders drawn from across the Council’s diverse and truly global energy community.
The Council’s Issues Monitor identifies the strategic energy landscape of specific countries and regions in the world through an analysis of 42 energy issues and 4 digitalisation-specific issues affecting the energy system. It provides a unique reality check and horizon scanning of persistent and emerging concerns involved in whole energy systems transition. This year’s report welcomes a significant increase in both the participation of global leaders (up over 75% from 1300 to nearly 2300) as well as the participation of 86 countries.
Each Issue Map provides a visual snapshot of the uncertainties and action priorities that energy policymakers CEOs and leading experts strive to address to shape and manage successful Energy
Transitions. Maps can be used in the following ways:
- To promote a shared understanding of successful Energy Transitions
- To appreciate and contrast regional variations to better understand differing priorities and areas of concern
- To follow the evolution of specific technology trends related to the energy sector
Benchmark Exercise on Risk Assessment Methods Applied to a Virtual Hydrogen Refuelling Station
Sep 2009
Publication
A benchmarking exercise on quantitative risk assessment (QRA) methodologies has been conducted within the project HyQRA under the framework of the European Network of Excellence (NoE) HySafe. The aim of the exercise was basically twofold: (i) to identify the differences and similarities in approaches in a QRA and their results for a hydrogen installation between nine participating partners representing a broad spectrum of background in QRA culture and history and (ii) to identify knowledge gaps in the various steps and parameters underlying the risk quantification. In the first step a reference case was defined: a virtual hydrogen refuelling station (HRS) in virtual surroundings comprising housing school shops and other vulnerable objects. All partners were requested to conduct a QRA according to their usual approach and experience. Basically participants were free to define representative release cases to apply models and frequency assessments according their own methodology and to present risk according to their usual format. To enable inter-comparison a required set of results data was prescribed like distances to specific thermal radiation levels from fires and distances to specific overpressure levels. Moreover complete documentation of assumptions base data and references was to be reported. It was not surprising that a wide range of results was obtained both in the applied approaches as well as in the quantitative outcomes and conclusions. This made it difficult to identify exactly which assumptions and parameters were responsible for the differences in results as the paper will show. A second phase was defined in which the QRA was determined by a more limited number of release cases (scenarios). The partners in the project agreed to assess specific scenarios in order to identify the differences in consequence assessment approaches. The results of this phase provide a better understanding of the influence of modelling assumptions and limitations on the eventual conclusions with regard to risk to on-site people and to the off-site public. This paper presents the results and conclusions of both stages of the exercise.
Safe Operation of Combined Cycle Gas Turbine and Gas Engine Systems Using Hydrogen Rich Fuels
Oct 2015
Publication
This paper describes work performed by a consortium led by the UK Health and Safety Laboratory(HSL)to identify the safe operating conditions for combined cycle power generating systems running on high hydrogen fuels. The work focuses on hydrogen and high hydrogen syngas and biogas waste-stream fuel mixtures which may prove hazardous in the event of a turbine or engine flame out resulting in a flammable fuel mixture entering the hot exhaust system and igniting. The paper describes the project presenting some initial results from this work including the development of large scale experimental facilities on the550 acre HSL site near Buxton Derbyshire UK. It describes the large scale experimental facility which utilises the exhaust gas from a Rolls-Royce Viper jet-engine (converted to run on butane) feeding into a 12 m long 0.60 m diameter instrumented tube at a pre-combustion velocity of 22 m/s. A variable geometry simulated heat exchanger with a 40 %2blockage ratio is present in the tube. Flammable mixtures injected into the tube close to the Viper outlet together with make-up oxygen are then ignited. Extensive optical ionisation temperature and pressure sensors are employed along the length of the tube to measure the pressures and flame speeds resulting from the combustion event. Some preliminary results from the test programme are discussed including deflagration to detonation transitions at high equivalence ratios.
Hydrogen Transport and Trapping: From Quantum Effects to Alloy Design
Jun 2017
Publication
This discussion session concerned experimental and theoretical investigations of the atomistic properties underlying the energetics and kinetics of hydrogen trapping and diffusion in metallic systems.
This article is a transcription of the recorded discussion of ‘Hydrogen transport and trapping: from quantum effects to alloy design.‘ at the Royal Society Scientific Discussion Meeting Challenges of Hydrogen and Metals 16–18 January 2017. The text is approved by the contributors. Y.-S.C. transcribed the session. H.L. assisted in the preparation of the manuscript.
Link to document download on Royal Society Website
This article is a transcription of the recorded discussion of ‘Hydrogen transport and trapping: from quantum effects to alloy design.‘ at the Royal Society Scientific Discussion Meeting Challenges of Hydrogen and Metals 16–18 January 2017. The text is approved by the contributors. Y.-S.C. transcribed the session. H.L. assisted in the preparation of the manuscript.
Link to document download on Royal Society Website
Hy4Heat Hydrogen Purity - Work Package 2
Feb 2020
Publication
The report makes a recommendation for a minimum hydrogen purity standard to be used by manufacturers developing prototype hydrogen appliances and during their subsequent demonstration as part of the Hy4Heat programme. It makes a recommendation for a hydrogen purity level with the aim that it is reasonable and practicable and considers implications related to hydrogen production the gas network and cost.
This report and any attachment is freely available on the Hy4Heat website here. The report can also be downloaded directly by clicking on the pdf icon above
This report and any attachment is freely available on the Hy4Heat website here. The report can also be downloaded directly by clicking on the pdf icon above
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