Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology A temperature controlled mechanical test facility to ensure safe materials performance

Copyright © TWI Ltd 2007World Centre for Materials Joining Technology

A temperature controlled A temperature controlled mechanical test facility to mechanical test facility to

ensure safe materials ensure safe materials performance in hydrogen at performance in hydrogen at

1000 bar1000 barR.I. HammondR.I. Hammond

R.J. PargeterR.J. Pargeter

([email protected])([email protected])


Safe storageSafe storage

• Liquid / solid / gasLiquid / solid / gas

• Need materials which are resistant Need materials which are resistant to gaseous hydrogen for allto gaseous hydrogen for all

• Hydrogen embrittlement.Hydrogen embrittlement.


Hydrogen embrittlementHydrogen embrittlement

• Below 100°C with no Below 100°C with no straining generally no straining generally no problemproblem

• But strain in the But strain in the presence of hydrogen presence of hydrogen leads to Hydrogen leads to Hydrogen Environment Environment Embrittlement (HEE)Embrittlement (HEE)

• HEE affects low cycle HEE affects low cycle fatigue, tensile, fatigue, tensile, toughness.toughness.


Testing in high pressure Testing in high pressure hydrogenhydrogen

• Most data available are statically Most data available are statically loadedloaded

• HEE only observed if strain in HEE only observed if strain in hydrogenhydrogen

• HEE affected byHEE affected by– Strain rateStrain rate– TemperatureTemperature– Pressure.Pressure.


Design and build of new Design and build of new facilityfacility

• 1000 bar1000 bar• 99.9999% 99.9999%

hydrogenhydrogen• -150°C to +85°C-150°C to +85°C• MeasureMeasure

– LCFLCF– TensileTensile– ToughnessToughness

• Current vesselCurrent vessel– 500 bar500 bar– 99.9999% hydrogen99.9999% hydrogen– Ambient to +85°CAmbient to +85°C


Four strands to projectFour strands to project

• Equipment designEquipment design• Physical protectionPhysical protection• System designSystem design• Operating procedures.Operating procedures.


Equipment designEquipment design

• Pressure Pressure vesselvessel– National National

codescodes– Materials.Materials.


Physical protectionPhysical protection• Plexiglas roofPlexiglas roof• Reinforced wallsReinforced walls• Test cell: spark freeTest cell: spark free• Blast doorsBlast doors• Hydrogen sensorsHydrogen sensors


System design (1)System design (1)

• PLC PLC – Purge and pressurisation cyclesPurge and pressurisation cycles– Safety: never a flammable mixtureSafety: never a flammable mixture– Purity: 0.000 001% contaminantsPurity: 0.000 001% contaminants



• InterlocksInterlocks– Prevent pressurisationPrevent pressurisation– Trigger automatic shut-downTrigger automatic shut-down

• Test cell door closedTest cell door closed• Pressure vessel closedPressure vessel closed• Hydrogen detectorsHydrogen detectors• Fire detectorsFire detectors• Emergency stop buttonsEmergency stop buttons



• Hydrogen detectorsHydrogen detectors– Low: 400 ppm (alert operators)Low: 400 ppm (alert operators)– High: 1000 ppm (triggers shut-down)High: 1000 ppm (triggers shut-down)

• Automatic shut-downAutomatic shut-down– High hydrogenHigh hydrogen– Fire alarmFire alarm– Emergency stop buttonEmergency stop button– Power cut (UPS keep safety systems Power cut (UPS keep safety systems

running)running)



• Shut downShut down– Stop boosterStop booster– Close valves on Close valves on

bottlesbottles

• Shut down and Shut down and ventvent– VentsVents– Purge vesselPurge vessel Solenoid

valves



• AutodiallersAutodiallers

• Safety aspects regarding hydraulicsSafety aspects regarding hydraulics

• Pneumatics: compressed air run in Pneumatics: compressed air run in thin plastic tubes around lab, thin plastic tubes around lab, designed to melt if there is a fire. designed to melt if there is a fire. Low air pressure will trigger shut-Low air pressure will trigger shut-down.down.


Operating proceduresOperating procedures

• Checklist for routine operationChecklist for routine operation• Unusual operation needs special Unusual operation needs special

risk assessmentsrisk assessments

• Skilled operatorsSkilled operators– Compressed gasesCompressed gases– Flammable/explosiveFlammable/explosive– Servo-hydraulic equipment.Servo-hydraulic equipment.


ConclusionsConclusions

• For a safe hydrogen economyFor a safe hydrogen economy

– Need safe, economical materials and Need safe, economical materials and fabrication methodsfabrication methods

– TWI already has facility to carry out TWI already has facility to carry out mechanical tests at 500 bar but are mechanical tests at 500 bar but are extending this to 1000 bar over a extending this to 1000 bar over a temperature range of -150°C to +85°Ctemperature range of -150°C to +85°C

Documents

Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology A temperature controlled mechanical test facility to ensure safe materials performance