United Kingdom
Techno-economic Assessment of Offshore Wind-to-hydrogen Scenarios: A UK Case Study
Jan 2023
Publication
The installed capacity electricity generation from wind and the curtailment of wind power in the UK between 2011 and 2021 showed that penetration levels of wind energy and the amount of energy that is curtailed in future would continue to rise whereas the curtailed energy could be utilised to produce green hydrogen. In this study data were collected technologies were chosen systems were designed and simulation models were developed to determine technical requirements and levelised costs of hydrogen produced and transported through different pathways. The analysis of capital and operating costs of the main components used for onshore and offshore green hydrogen production using offshore wind including alternative strategies for hydrogen storage and transport and hydrogen carriers showed that a significant reduction in cost could be achieved by 2030 enabling the production of green hydrogen from offshore wind at a competitive cost compared to grey and blue hydrogen. Among all scenarios investigated in this study compressed hydrogen produced offshore is the most cost-effective scenario for projects starting in 2025 although the economic feasibility of this scenario is strongly affected by the storage period and the distance to the shore of the offshore wind farm. Alternative scenarios for hydrogen storage and transport such as liquefied hydrogen and methylcyclohexane could become more cost-effective for projects starting in 2050 when the levelised cost of hydrogen could reach values of about £2 per kilogram of hydrogen or lower.
Methodologies for Representing the Road Transport Sector in Energy System Models
Dec 2013
Publication
Energy system models are often used to assess the potential role of hydrogen and electric powertrains for reducing transport CO2 emissions in the future. In this paper we review how different energy system models have represented both vehicles and fuel infrastructure in the past and we provide guidelines for their representation in the future. In particular we identify three key modelling decisions: the degree of car market segmentation the imposition of market share constraints and the use of lumpy investments to represent infrastructure. We examine each of these decisions in a case study using the UK MARKAL model. While disaggregating the car market principally affects only the transition rate to the optimum mix of technologies market share constraints can greatly change the optimum mix so should be chosen carefully. In contrast modelling infrastructure using lumpy investments has little impact on the model results. We identify the development of new methodologies to represent the impact of behavioural change on transport demand as a key challenge for improving energy system models in the future.
IGEM/TD/1 Edition 6 Supplement 2 - High Pressure Hydrogen Pipelines
Nov 2021
Publication
This Supplement gives additional requirements and qualifications for the transmission of Hydrogen including Natural Gas/Hydrogen blended mixtures (subsequently referred to as NG/H blends) and for the repurposing of Natural Gas (NG) pipelines to Hydrogen service. For the purposes of this document any NG/H blend above 10% MOL is considered to be an equivalence to 100% hydrogen. For blends below 10% MOL there is no evidence to confirm that blends containing up to 10 mol.% hydrogen do not cause material degradation but it is considered that the risk is low.
This Supplement covers the design construction inspection testing operation and maintenance of steel pipelines and certain associated installations in Hydrogen service and the repurposing of NG pipelines to Hydrogen service at maximum operating pressure (MOP) exceeding 7 bar and not exceeding 137.9 bar.
This standard can be purchased here
This Supplement covers the design construction inspection testing operation and maintenance of steel pipelines and certain associated installations in Hydrogen service and the repurposing of NG pipelines to Hydrogen service at maximum operating pressure (MOP) exceeding 7 bar and not exceeding 137.9 bar.
This standard can be purchased here
Future Electricity Series Part 3 - Power from Nuclear
Mar 2014
Publication
This independent cross-party report highlights the key role that political consensus can play in helping to reduce the costs of nuclear power in the UK as well as other low carbon technologies. This political consensus has never been more important than in this ‘defining decade’ for the power sector. The report highlights that an immediate challenge facing the UK’s new build programme is agreeing with the European Commission a regime for supporting new nuclear power. Changing the proposed support package would not be an impossible task if made necessary but maintaining broad political consensus and considering the implications of delay are also important. The State Aid process is an important opportunity for scrutiny with the report demonstrating that shareholders for Hinkley Point C could see bigger returns (19-21%) than those typically expected for PFI projects (12-15%). However it is too early to conclude on the value for money of the Hinkley Point C agreement. Both the negotiation process and the resulting investment contract are important but there has been little transparency over either so far and the negotiations were not competitive. The inquiry calls for more urgency and better coordination in seizing the opportunity to reuse the UK’s plutonium stockpile.
The UK’s stockpile of separated plutonium presents opportunities to tackle a number of national strategic priorities including implementing long term solutions for nuclear waste developing new technologies that could redefine the sector laying the ground for new nuclear power and pursuing nuclear non-proliferation. Government has identified three ‘credible solutions’ for reuse and the report recommends that it now sets clearer criteria against which to assess options and identifies budgetary requirements to help expediate the process. The report also argues that Government should do more on new nuclear technologies that could redefine the sector – such as considering smaller reactors nuclear for industrial heat or hydrogen production and closed or thorium fuel cycles. The Government’s initial response to a review of nuclear R&D a year ago by the then Chief Scientific Advisor Sir John Beddington has been welcome and it needs to build on this. In particular the UK should capitalise upon its existing expertise and past experience to focus efforts where there is most strategic value. Nulcear waste. Having failed to date the Government must urgently revisit plans for finding a site to store nuclear waste underground for thousands of years. Implementing this is a crucial part of demonstrating that nuclear waste is a manageable challenge. Despite being rejected by Cumbria County Council the continuing strong support amongst communities in West Cumbria for hosting a site is a promising sign.
On affordability the report finds that it is not yet clear which electricity generation technologies will be cheapest in the 2020s and beyond. Coal and gas could get more expensive if fossil fuel and carbon prices rise whilst low carbon technologies could get cheaper as technology costs fall with more deployment. This is the main reason for adopting an ‘all of the above’ strategy including nuclear power until costs become clearer and there is broad consensus behind this general approach.
On security of supply the inquiry says that deployment of nuclear power is likely to be influenced more by the economics of system balancing rather than technical system balancing challenges which can be met with greater deployment of existing balancing tools. The cost of maintaining system security is likely to mean that the UK maintains at least some baseload capacity such as nuclear power to limit system costs.
On sustainability the report finds that the environmental impacts of nuclear power are comparable to some generation technologies and favourable to others although the long lived nature of some radioactive nuclear waste and the dual use potential of nuclear technology for civil and military applications create unique sustainability challenges which the UK is a world leader in managing.
It is the final report of the Future Electricity Series an independent and cross party inquiry into the UK power sector sponsored by the Institution of Gas Engineers and Managers
The UK’s stockpile of separated plutonium presents opportunities to tackle a number of national strategic priorities including implementing long term solutions for nuclear waste developing new technologies that could redefine the sector laying the ground for new nuclear power and pursuing nuclear non-proliferation. Government has identified three ‘credible solutions’ for reuse and the report recommends that it now sets clearer criteria against which to assess options and identifies budgetary requirements to help expediate the process. The report also argues that Government should do more on new nuclear technologies that could redefine the sector – such as considering smaller reactors nuclear for industrial heat or hydrogen production and closed or thorium fuel cycles. The Government’s initial response to a review of nuclear R&D a year ago by the then Chief Scientific Advisor Sir John Beddington has been welcome and it needs to build on this. In particular the UK should capitalise upon its existing expertise and past experience to focus efforts where there is most strategic value. Nulcear waste. Having failed to date the Government must urgently revisit plans for finding a site to store nuclear waste underground for thousands of years. Implementing this is a crucial part of demonstrating that nuclear waste is a manageable challenge. Despite being rejected by Cumbria County Council the continuing strong support amongst communities in West Cumbria for hosting a site is a promising sign.
On affordability the report finds that it is not yet clear which electricity generation technologies will be cheapest in the 2020s and beyond. Coal and gas could get more expensive if fossil fuel and carbon prices rise whilst low carbon technologies could get cheaper as technology costs fall with more deployment. This is the main reason for adopting an ‘all of the above’ strategy including nuclear power until costs become clearer and there is broad consensus behind this general approach.
On security of supply the inquiry says that deployment of nuclear power is likely to be influenced more by the economics of system balancing rather than technical system balancing challenges which can be met with greater deployment of existing balancing tools. The cost of maintaining system security is likely to mean that the UK maintains at least some baseload capacity such as nuclear power to limit system costs.
On sustainability the report finds that the environmental impacts of nuclear power are comparable to some generation technologies and favourable to others although the long lived nature of some radioactive nuclear waste and the dual use potential of nuclear technology for civil and military applications create unique sustainability challenges which the UK is a world leader in managing.
It is the final report of the Future Electricity Series an independent and cross party inquiry into the UK power sector sponsored by the Institution of Gas Engineers and Managers
A Review on Ports' Readiness to Facilitate International Hydrogen Trade
Jan 2023
Publication
The existing literature on the hydrogen supply chains has knowledge gaps. Most studies focus on hydrogen production storage transport and utilisation but neglect ports which are nexuses in the supply chains. To fill the gap this paper focuses on ports' readiness for the upcoming hydrogen international trade. Potential hydrogen exporting and importing ports are screened. Ports' readiness for hydrogen export and import are reviewed from perspectives of infrastructure risk management public acceptance regulations and standards and education and training. The main findings are: (1) liquid hydrogen ammonia methanol and LOHCs are suitable forms for hydrogen international trade; (2) twenty ports are identified that could be first movers; among them twelve are exporting ports and eight are importing ports; (3) ports’ readiness for hydrogen international trade is still in its infancy and the infrastructure construction or renovation risk management measures establishment of regulations and standards education and training all require further efforts.
Moving Toward the Low-carbon Hydrogen Economy: Experiences and Key Learnings from National Case Studies
Sep 2022
Publication
The urgency to achieve net-zero carbon dioxide (CO2) emissions by 2050 as first presented by the IPCC special report on 1.5°C Global Warming has spurred renewed interest in hydrogen to complement electrification for widespread decarbonization of the economy. We present reflections on estimates of future hydrogen demand optimization of infrastructure for hydrogen production transport and storage development of viable business cases and environmental impact evaluations using life cycle assessments. We highlight challenges and opportunities that are common across studies of the business cases for hydrogen in Germany the UK the Netherlands Switzerland and Norway. The use of hydrogen in the industrial sector is an important driver and could incentivise large-scale hydrogen value chains. In the long-term hydrogen becomes important also for the transport sector. Hydrogen production from natural gas with capture and permanent storage of the produced CO2 (CCS) enables large-scale hydrogen production in the intermediate future and is complementary to hydrogen from renewable power. Furthermore timely establishment of hydrogen and CO2 infrastructures serves as an anchor to support the deployment of carbon dioxide removal technologies such as direct air carbon capture and storage (DACCS) and biohydrogen production with CCS. Significant public support is needed to ensure coordinated planning governance and the establishment of supportive regulatory frameworks which foster the growth of hydrogen markets.
HyDeploy2: Summary of Procedures for the Trial Network
Jun 2021
Publication
The assessment of appropriate operational procedures to govern the injection of a hydrogen/natural gas blend into Northern Gas Networks’ (NGN) Winlaton gas distribution network was a key requirement of the HyDeploy2 project. To perform this assessment the review was broken down into two areas procedures upstream of the emergency control valve (owned by NGN) and procedures downstream of the Emergency Control Valve (procedures which would be performed by Gas Safe registered individuals). Assessment of the upstream procedures was led by NGN (own and carry out all upstream procedures on NGN’s gas network) and assessment of the downstream procedures was led by Blue Flame Associates (an industry expert on downstream gas procedures).<br/>Methodologies were adopted to be able to highlight procedures that could potentially be used on the Winlaton trial network during the hydrogen blended gas injection period and if they were impacted by the changing of the gas within the network from natural gas to hydrogen blended gas. This method determined that for downstream gas procedures a total of 56 gas procedures required expert review resulting in 80 technical questions to be assessed and for the upstream gas procedures a total of 80 gas procedures required expert review resulting in 266 technical questions to be assessed.<br/>The operational procedures assessment has led to a determination as to whether a change is or is not required for relevant operational procedures where a basis of concern existed with respect to the injection of hydrogen blended gas. Any requirements to modify an existing procedure has been given in this report referencing the source as to where the detailed analysis for the change/no change recommendation has been given.<br/>The assessment took into account the associated experimental and research carried out as part of the HyDeploy and HyDeploy2 projects such as the assessment of gas characteristics materials impact appliance survey of assets on the Winlaton network and impact of hydrogen blended gas on gas detection equipment references to these studies have been given accordingly to associated impacted operational procedures.<br/>The conclusion of the assessment is that for upstream gas procedures there are some operational procedures that are unchanged some that require an increase in the frequency as to how often they are performed and some procedures which require a technical modification. For downstream domestic gas procedures all procedures applicable to a domestic gas installation were deemed to not be detrimentally affected by the introduction of a 20 mol% hydrogen blend.<br/>For upstream gas procedures an appropriate training package will be built off the back of the results presented in this report and disseminated accordingly to all relevant Operatives that will be responsible for the safety operation and maintenance of the Winlaton network during the hydrogen blend injection period. For downstream gas procedures the Gas Safe community have been fully engaged and informed about the trial.<br/>Click on the supplements tab to view the other documents from this report
Comparative Sustainability Study of Energy Storage Technologies Using Data Envelopment Analysis
Mar 2022
Publication
The transition to energy systems with a high share of renewable energy depends on the availability of technologies that can connect the physical distances or bridge the time differences between the energy supply and demand points. This study focuses on energy storage technologies due to their expected role in liberating the energy sector from fossil fuels and facilitating the penetration of intermittent renewable sources. The performance of 27 energy storage alternatives is compared considering sustainability aspects by means of data envelopment analysis. To this end storage alternatives are first classified into two clusters: fast-response and long-term. The levelized cost of energy energy and water consumption global warming potential and employment are common indicators considered for both clusters while energy density is used only for fast-response technologies where it plays a key role in technology selection. Flywheel reveals the highest efficiency between all the fast-response technologies while green ammonia powered with solar energy ranks first for long-term energy storage. An uncertainty analysis is incorporated to discuss the reliability of the results. Overall results obtained and guidelines provided can be helpful for both decision-making and research and development purposes. For the former we identify the most appealing energy storage options to be promoted while for the latter we report quantitative improvement targets that would make inefficient technologies competitive if attained. This contribution paves the way for more comprehensive studies in the context of energy storage by presenting a powerful framework for comparing options according to multiple sustainability indicators.
A Multi-period Sustainable Hydrogen Supply Chain Model Considering Pipeline Routing and Carbon Emissions: The Case Study of Oman
Nov 2022
Publication
This paper presents a mathematical model for a multi-period hydrogen supply chain design problem considering several design features not addressed in other studies. The model is formulated as a mixed-integer program allowing the production and storage facilities to be extended over time. Pipeline and tube trailer transport modes are considered for carrying hydrogen. The model also allows finding the optimal pipeline routes and the number of transport units. The objective is to obtain an efficient supply chain design within a given time frame in a way that the demand and carbon dioxide emissions constraints are satisfied and the total cost is minimized. A computer program is developed to ease the problem-solving process. The computer program extracts the geographical information from Google Maps and solves the problem using an optimization solver. Finally the applicability of the proposed model is demonstrated in a case study from Oman.
Fuel Cell Development for New Energy Vehicles (NEVs) and Clean Air in China
Apr 2018
Publication
This paper reviews the background to New Energy Vehicles (NEV) policies in China and the key scientific and market challenges that need to be addressed to accelerate fuel cells (FCs) in the rapidly developing NEV market. The global significance of the Chinese market key players core FC technologies and future research priorities are discussed.
Technology Roadmaps for Transition Management: The Case of Hydrogen Energy
Oct 2011
Publication
Technology roadmaps are increasingly used by governments to inform and promote technological transitions such as a transition to a hydrogen energy system. This paper develops a framework for understanding how current roadmapping practice relates to emerging theories of the governance of systems innovation. In applying this framework to a case study of hydrogen roadmaps the paper finds that roadmapping for transitions needs to place greater emphasis on ensuring good quality and transparent analytic and participatory procedures. To be most useful roadmaps should be embedded within institutional structures that enable the incorporation of learning and re-evaluation but in practice most transition roadmaps are one-off exercises
Techno-Economic Analysis of Hydrogen Storage Technologies for Railway Engineering: A Review
Sep 2022
Publication
According to the specific requirements of railway engineering a techno-economic comparison for onboard hydrogen storage technologies is conducted to discuss their feasibility and potentials for hydrogen-powered hybrid trains. Physical storage methods including compressed hydrogen (CH2 ) liquid hydrogen (LH2 ) and cryo-compressed hydrogen (CcH2 ) and material-based (chemical) storage methods such as ammonia liquid organic hydrogen carriages (LOHCs) and metal hydrides are carefully discussed in terms of their operational conditions energy capacity and economic costs. CH2 technology is the most mature now but its storage density cannot reach the final target which is the same problem for intermetallic compounds. In contrast LH2 CcH2 and complex hydrides are attractive for their high storage density. Nevertheless the harsh working conditions of complex hydrides hinder their vehicular application. Ammonia has advantages in energy capacity utilisation efficiency and cost especially being directly utilised by fuel cells. LOHCs are now considered as a potential candidate for hydrogen transport. Simplifying the dehydrogenation process is the important prerequisite for its vehicular employment. Recently increasing novel hydrogen-powered trains based on different hydrogen storage routes are being tested and optimised across the world. It can be forecasted that hydrogen energy will be a significant booster to railway decarbonisation.
Optimising Fuel Supply Chains within Planetary Boundaries: A Case Study of Hydrogen for Road Transport in the UK
Jul 2020
Publication
The world-wide sustainability implications of transport technologies remain unclear because their assessment often relies on metrics that are hard to interpret from a global perspective. To contribute to filling this gap here we apply the concept of planetary boundaries (PBs) i.e. a set of biophysical limits critical for operating the planet safely to address the optimal design of sustainable fuel supply chains (SCs) focusing on hydrogen for vehicle use. By incorporating PBs into a mixed-integer linear programming model (MILP) we identify SC configurations that satisfy a given transport demand while minimising the PBs transgression level i.e. while reducing the risk of surpassing the ecological capacity of the Earth. On applying this methodology to the UK we find that the current fossil-based sector is unsustainable as it transgresses the energy imbalance CO2 concentration and ocean acidification PBs heavily i.e. five to 55-fold depending on the downscale principle. The move to hydrogen would help to reduce current transgression levels substantially i.e. reductions of 9–86% depending on the case. However it would be insufficient to operate entirely within all the PBs concurrently. The minimum impact SCs would produce hydrogen via water electrolysis powered by wind and nuclear energy and store it in compressed form followed by distribution via rail which would require as much as 37 TWh of electricity per year. Our work unfolds new avenues for the incorporation of PBs in the assessment and optimisation of energy systems to arrive at sustainable solutions that are entirely consistent with the carrying capacity of the planet.
Estimates of the Decarbonization Potential of Alternative Fuels for Shipping as a Function of Vessel Type, Cargo, and Voyage
Oct 2022
Publication
Fuel transition can decarbonize shipping and help meet IMO 2050 goals. In this paper HFO with CCS LNG with CCS bio-methanol biodiesel hydrogen ammonia and electricity were studied using empirical ship design models from a fleet-level perspective and at the Tank-ToWake level to assist operators technology developers and policy makers. The cargo attainment rate CAR (i.e. cargo that must be displaced due to the low-C propulsion system) the ES (i.e. TTW energy needed per ton*n.m.) the CS (economic cost per ton*n.m.) and the carbon intensity index CII (gCO2 per ton*n.m.) were calculated so that the potential of the various alternatives can be compared quantitatively as a function of different criteria. The sensitivity of CAR towards ship type fuel type cargo type and voyage distance were investigated. All ship types had similar CAR estimates which implies that considerations concerning fuel transition apply equally to all ships (cargo containership tankers). Cargo type was the most sensitive factor that made a ship either weight or volume critical indirectly impacting on the CAR of different fuels; for example a hydrogen ship is weight-critical and has 2.3% higher CAR than the reference HFO ship at 20000 nm. Voyage distance and fuel type could result in up to 48.51% and 11.75% of CAR reduction. In addition to CAR the ES CS and CII for a typical mission were calculated and it was found that HFO and LNG with CCS gave about 20% higher ES and CS than HFO and biodiesel had twice the cost while ammonia methanol and hydrogen had 3–4 times the CS of HFO and electricity about 20 times suggesting that decarbonisation of the world’s fleet will come at a large cost. As an example of including all factors in an effort to create a normalized scoring system an equal weight was allocated to each index (CAR ES CS and CII). Biodiesel achieved the highest score (80%) and was identified as the alternative with the highest potential for a deep-seagoing containership followed by ammonia hydrogen bio-methanol and CCS. Electricity has the lowest normalized score of 33%. A total of 100% CAR is achievable by all alternative fuels but with compromises in voyage distance or with refuelling. For example a battery containership carrying an equal amount of cargo as an HFO-fuelled containership can only complete 13% of the voyage distance or needs refuelling seven times to complete 10000 n.m. The results can guide decarbonization strategies at the fleet level and can help optimise emissions as a function of specific missions.
Assessment of Operability and Inspection, Maintenance and Repair Requirements for Transmission Pipelines and Installations in Hydrogen Service
Apr 2021
Publication
This report has been prepared for Hytechnical work programme to support the technical strategy for repurposing existing transmission pipelines and installations for the transportation and distribution of hydrogen and natural gas / hydrogen blends. The aim of the Hytechnical work programme is to support the implementation of the IGEM supplements to the standards TD/1 TD/13 TD/3 and TD/4.<br/>The report covers a desk study into the requirements for the inspection maintenance operation and repair of above 7 bar natural gas pipelines and installations designed and operated in accordance with the standards existing IGEM/TD/1 and IGEM/TD/13 which are repurposed for hydrogen service.
Experimental Parameters of Ignited Congestion Experiments of Liquid Hydrogen in the PRESLHY Project
Sep 2021
Publication
Liquid hydrogen (LH2) has the potential to form part of the UK energy strategy in the future and therefore could see widespread use due to the relatively high energy density when compared to other renewable energy sources. To study the feasibility of this the European Fuel Cells and Hydrogen Joint Undertaking (FCH JU) funded project PRESLHY undertook pre-normative research for the safe use of cryogenic LH2 in non-industrial settings. Several key scenarios were identified as knowledge gaps and both theoretical and experimental studies were conducted to provide insight into these scenarios. This included experiments studying the effect of congestion on an ignited hydrogen plume that develops from a release of LH2; this paper describes the objectives experimental setup and a summary of the results from these activities. Characterisation of the LH2 release hydrogen concentration and temperatures measurements within the resulting gas cloud was undertaken along with pressure measurements both within the cloud and further afield. Various release conditions and congestion levels were studied. Results showed that at high levels of congestion increased overpressures occurred with the higher flow rates studied including one high order event. Data generated from these experiments is being taken forward to generate and validate theoretical models ultimately to contribute to the development of regulations codes and standards (RCS) for LH2."
Review of IGEM/SR/25 for Use with Hydrogen
Jan 2021
Publication
This report presents the findings of the initial gap analysis and technical review of IGEM/SR/25 undertaken as a collaborative effort between HSE and DNV GL. The review is intended to help understand the steps which would be involved in updating the standard to include data appropriate for installations using H2 or an H2/NG blend. Furthermore the report highlights where additional research and updated data applicable to H2 installations is needed to enable development of an H2-specific supplement to the standard.<br/>A review of alternative approaches for area classification is presented. This review is aimed at determining whether existing standards or guidance provide methodologies which could be used as an alternative to IGEM/SR/25 for area classification of systems using either H2 or H2/NG blends. The review covers IGEM/SR/25 IGE/SR/23 EI15 BCGA guidance BS EN 60079:10:1 (including Quadvent) NFPA 497 API RP 505 and EIGA Doc. 121/14. Some of these are general like the British Standard BS EN 60079-10-1:2015 while others are industry specific like IGEM/SR/25 and EI15.<br/>Consideration is given to the methodology that each area classification approach presents for establishing the zone and zone size with particular focus on how factors such as ventilation and gas buoyancy are accounted for in the methods. The findings of the review indicate that none of the alternative approaches evaluated in the study provide an approach that is suitable for the gas industry for the area classification of gas network installations involving H2 or an H2/NG blend.
Gas Goes Green: Britain's Hydrogen Blending Delivery Plan
Jan 2022
Publication
Britain’s Hydrogen Blending Delivery Plan which sets out how all five of Britain’s gas grid companies will meet the Government’s target for Britain’s network of gas pipes to be ready to deliver 20% hydrogen to homes and businesses from 2023 as a replacement for natural gas.
HydroGenerally - Episode 3: Lift Off for Hydrogen in Aviation
Apr 2022
Publication
In this third episode Steffan Eldred and Hannah Abson from Innovate UK KTN are exploring the scale of the opportunity that hydrogen and aviation present alongside their special guest Katy Milne Head of Industrial Strategy at FlyZero.
The podcast can be found on their website
The podcast can be found on their website
Assessment of Hydrogen Flame Length Full Bore Pipeline Rupture
Sep 2021
Publication
The study aims at the development of a safety engineering methodology for the assessment of flame length after full-bore rupture of hydrogen pipeline. The methodology is validated using experimental data on hydrogen jet flame from full-bore pipeline rupture by Acton et al. (2010). The experimental pressure dynamics in the hydrogen pipeline system is simulated using previously developed adiabatic and “isothermal” blowdown models. The hydrogen release area is taken as equal similar to the experiment to doubled pipeline cross-section as hydrogen was coming out from both sides of the ruptured pipe. The agreement with the experimental pressure decay in the piping system was achieved using discharge coefficient CD=0.26 and CD=0.21 for adiabatic and “isothermal” blowdown model respectively that indicates significant friction and minor pressure losses. The hydrogen flame length was calculated using the dimensionless correlation by Molkov and Saffers (2013). The correlation relies on the density of hydrogen in the choked flow at the pipe exit. The maximum experimental flame length between 92 m and 111 m was recorded at 6 s after the pipe rupture under the ground. The calculated by the dimensionless correlation flame length is 110 m and 120 m for the “isothermal” and adiabatic blowdown model respectively. This is an acceptable accuracy for such a large-scale experiment. It is concluded that the methodology can be applied as an engineering tool to assess flame length resulting from ruptured hydrogen pipelines.
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