Barbara Lowesmith Loughborough University

Transcription

1 EC Naturalhy Project The Effect on Safety of Adding Hydrogen to the Natural Gas System Barbara Lowesmith Loughborough University NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD)

2 Naturalhy Project Aim is to assess the possibility of using the existing natural gas pipeline network for conveying natural gas/hydrogen mixtures Provides greener fuel if burned directly H 2 can be separated out for use in fuel cells Provides a means of introducing and developing the Hydrogen economy at an earlier stage Provides opportunity to make use of H 2 produced as by-product eg bio-gas or from industrial processes NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 2

3 Naturalhy Project Naturalhy Project is 17m with 39 partners Effect on durability and integrity of pipeline network Effect on safety of the public Separating the Hydrogen from the mixture Using the mixture in existing appliances Socio-economic aspects NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 3

4 Safety Work Package Aim is to assess the change in risk to the public caused by adding hydrogen to the pipeline network Considers all network from transmission to use of gas in the home RISK = LIKELIHOOD x CONSEQUENCE Likelihood: Increased failure probability? Increased ignition probability? Consequence (Hazard): Increased explosion severity? Change in fire behaviour? Change in gas accumulation behaviour? NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 4

5 Summary of Work Package Consequences (Hazard): Large scale experiments to gather data on gas build up, fire and explosion hazards Laboratory scale experiments to assess burning velocity data Modifying i mathematical ti models to cope with H 2 /NG mixtures Likelihood: Assessing change in failure frequency and ignition probability Risk: Develop risk assessment method for transmission pipelines and apply to networks Assess risk of explosions in domestic properties NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 5

6 Assessing the Hazard: Gas Build Up Experiments conducted in domestic sized room and dlarge industrial ti enclosure Behaviour similar to natural gas in terms of nature and location of accumulation Additional buoyancy of accumulations formed by NG/H 2 releases results in additional buoyancy driven ventilation which helps to limit the concentrations produced No separation of hydrogen out of mixture NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 6

7 Assessing the Hazard: Confined Vented Explosions Vented explosions with and without t internal congestion Measured overpressure and flame speed Little difference in overpressure for methane/hydrogen mixture containing 20% H 2, but significant increase when mixture contained 50% H 2, especially when congestion present NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 7

8 Comparison of CH4 and 50:50 Rear ignition, No Pipes CH4 50:50 NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 8

9 Assessing the Hazard: VCEs Vapour Cloud Explosions in a compact and also in a long congested region Transition to Detonation observed in compact region with 100% Hydrogen but not with mixtures Transition to Detonation observed in long congested region with 50:50 CH 4 :H 2 mixture in some circumstances NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 9

10 Assessing the Hazard: VCEs 80:20 50:50 NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 10

11 Assessing the Hazards: Fires High pressure jet fires and underground pipeline ruptures Assessed flame size and radiation hazard NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 11

12 Key Results of Hazard Studies Additional buoyancy driven ventilation produced during gas build-up up beneficial in limiting gas concentrations produced, although may still be higher Explosion severity increases slightly for <30% hydrogen but significantly for >40%, with increased risk of DDT in some circumstances Little change to fire hazard for up to 25% hydrogen NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 12

13 Assessing the Likelihood of Pipeline Failures Identified database information for failure frequency of transmission pipelines operating with natural gas Information from studies within Durability and Integrity areas of Naturalhy has identified effect of hydrogen on failure frequency Potential for increased failures from fatigue crack growth in some circumstances NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 13

14 Risk Screening Tool - LURAP Objective to provide simple screening tool capable of considering the effect of adding hydrogen and provide comparative risk profiles Can input pipeline network Calculates individual risk with distance from pipeline ppe eand dsoceta societal risk NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 14

15 Individual Risk -Example Individual id lrisk with Distance Risk (p per yr) 6.00E E E E E E E+00 NG 75:25 Mix Distance (m) NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 15

16 Naturalhy Project Finishes October 2009 Wealth of information on the effect of adding hydrogen to the natural gas infra- structure t Visit for more information NATURALHY is an Integrated Project funded by the European Commission s Sixth Framework Programme ( ) for research, technological development and demonstration (RTD) 16