Hydrogen Delivery System – R&D Activities

1. Hydrogen Delivery System – R&D Activities T W Bradshaw M Courthold M Hills J Rochford Daresbury Controls Group etc…

2. Status Buffer Volume:Complete and radiographed, awaiting certification Buffer volume pipework

3. Status Cryostat:50% complete overall

4. Status Cryostat:Condenser and condensing pot complete

5. Status Absorber base plate

6. Status Gas panel:Layouts agreed; fabrication to start as soon as relief valves decided. Delivery of relief valves on critical path. Transfer Line: Complete

7. Metal Hydride Storage Tank Nominal capacity: 2450 g (27 Nm3) H2 Volume of overall storage tank: 250 litres Overall weight: 375 kg Dia 470 Top removable thermal insulation cover Hydrogen connection with shut-off valve and safety valve Hull cooling Water/Glycol Outlet, 1” 1680 1590 Internal cooling Water/Glycol Inlet/Outlet Hull cooling Water/Glycol Inlet, 1”

8. Schedule • Ongoing issues with commissioning the Decay Solenoid and Linde refrigerator have taken effort off this project (MJDC, JHR, MJH) • The H2 R&D team at RAL is still chronically short-staffed, since Yuri Ivaniouschenkov left and Tony Jones moved to other projects; although Alan Ruddell has recently joined the team (25% effort). • Work on the cryostat build is proceeding at AS Scientific (50% complete), but work on the gas panel is awaiting a final decision on choice of safety relief valves and LH2 level detectors. • Graham Charnley and Adrian Oates (DL) have begun attending progress meetings with AS Scientific, in preparation for work on the control system, but Graham will also be leaving the project in the near future. • Initial tests will be conducted with Helium in the Cryogenics Laboratory • to avoid interference with installation of the ventilation system • The schedule is under review, but it looks as though the ventilation system in the hall will not be installed before September

9. Testing Helium Tests Check instrumentation Pump and purge Check relief valve settings and operation Check cryocooler operation at LH2 and LHe temperatures Liquify helium in the cryostat Test emptying sequence Thermally cycle the system, to check for leaks from thermal stresses Hydrogen Tests Check alarms and interlocks Liquify hydrogen in the cryostat Check empty and purge sequence Test effect of using Helium top-up gas to maintain positive pressure Measure H2 desorption rate Measure H2 absorption rate

10. Hydrogen R&D System

11. Gas Panel Bottle Store Venting Vac. Pumps Cryostat Heater/ Chiller Unit Hydrogen Bottle Hydrogen System P&ID

12. Fill/Purge Valves • Pneumatically actuated valves • Arrow indicates position on failure

13. Cryostat Cryocooler and Compressor Nitrogen Jacketing on Pipes Temperature sensors Pressure Transducers Electrical heater for operation of cryocooler with H2 Temperature sensors on base-plate Level Sensors Electrical heating of base-plate Pre-cooling loops

14. Hydrogen R&D System Layout Hydrogen R&D System Test Cryostat

15. END

16. Cryostat Cryocooler and Compressor Nitrogen Jacketing on Pipes Temperature sensors Pressure Transducers Electrical heater for operation of cryocooler with H2 Temperature sensors on base-plate Level Sensors Electrical heating of base-plate Pre-cooling loops

17. Gas Panel and Hood Extraction Hood Fill/Purge Valves Hydride Bed Buffer Volume Absorber Relief Valves Cryostat Relief Valves

18. Fill/Purge Valves • Pneumatically actuated valves • Arrow indicates position on failure

19. Vacuum System • 2 Elements • Purging Pump • for H2 system • Cryostat Vacuum system

20. Venting • Hydrogen detectors in extraction hood, vent line and vacuum exhaust • 2 fans provide redundancy in venting from hood • Flame arrestors used throughout • Helium flow in vent line to dilute leaks Whessoe – Varec Flame Arrestor

21. Control Valves • Ball Valves • Pneumatically actuated • Spring Return Actuators ensure valve returns to default position on failure • Control Valves • Pneumatically Actuated • Large range on throttling • Suitable for use with hydrogen

22. Relief Valves & Bursting Discs • Tyco (AG Series 90) Relief Valves • Too expensive & long delivery • Unsatisfactory • Circle Seal, Tamo, RHPS • Seetru AD2000:A2 / TDR 421 for gas • Media Hydrogen gas • Temperature – minus 80 Deg C • Flow rate – 1000 Ltrs/sec • Set pressure 0.5 BarG • Valve fully open at 0.6 BarG • Reseat at 0.3 BarG • Atex approved • BS&B Low Pressure Reverse Buckling Disc • ±10% tolerance on burst pressure • Vacuum/back pressure resistant • Designed to rupture without fragmentation • Appropriate certification to be obtained for all valves

23. Instrumentation • Temperature Sensors • Platinum Resistance • Fast response time (<0.5s) • Cernox for cooler cold head temp. • Level Sensors • AMI Capacitance Level Transmitter • Useable with Hydrogen • Problem with obtaining ATEX certification • No solution • Ametek Drexilbro, Endress & Hauser, Impress, Omega, Synatel • Pressure and Vacuum Gauges • Leybold can supply capacitance vacuum gauges, which are safe for use with hydrogen. • Explosion proof pressure transducers available from Honeywell • ATEX approved pressure transducers also available from SensorsOne Temperature sensors Pressure Transducers Level Sensors

24. Vacuum System Pumps TRIVAC D40B • Proposal received from Leybold based on combination of rotary vane and turbo-molecular pumps • TRIVAC D40B for hydrogen system purging pump (VP1) • Special Pumpset with active control suggested for cryostat vacuum (VP2) • D25BCS backing pump • Turbo-molecular TMP151C to achieve high vacuum (10-3 mbar) • Both pumps can be operated with purge gas (e.g. He) if pressure rises (indicating a leak) TRIVAC D25BCS TMP151C