hydrogen delivery system – r&d activities

Hydrogen Delivery System – R&D Activities

T W BradshawM CourtholdM HillsJ RochfordDaresbury Controls Group etc…

AS Scientific status

Buffer Volume:Complete and radiographed, awaiting certification

Buffer volume pipework

AS Scientific statusCryostat:50% complete overall

Cryostat:Condenser and condensing pot complete

AS Scientific status

AS Scientific status

Absorber base plate

AS Scientific status

Gas panel:Layouts agreed; fabrication not yet started

Relief valves decided.

Delivery of relief valves on critical path.

Transfer Line: Complete

Hull coolingWater/Glycol Inlet, 1”

Hull coolingWater/Glycol Outlet, 1”

Dia 470

1590

Hydrogen connection with shut-off valve and safety valve

Internal coolingWater/Glycol Inlet/Outlet

Top removable thermal insulation cover

1680

Nominal capacity: 2450 g (27 Nm3) H2

Volume of overall storage tank: 250 litresOverall weight: 375 kg

Metal Hydride Storage Tank

Ventilation & Vacuum Systems

MICE Hall South Wall

Hydrogen Extraction Vents

Proposed Area for Vacuum Pump Enclosure

Conduits for vacuum lines installed during August shutdown

Hall Installation

Ventilation Ducts

Enclosure(containing Gas Panel, Hydride Bed and Buffer Tank)

Heater/Chiller Units for Hydride Bed

Transfer Line

Test Cryostat

Plans & Schedule

•Ongoing issues with commissioning the Decay Solenoid and Linde refrigerator have taken effort off this project (MJDC, JHR, MJH)

•H2 R&D team at RAL still chronically short-staffed, having lost two key team members earlier this year; although Alan Ruddell joined team in May (25% effort). Still no technician effort available.

•Ian Mullacrane (DL) taken over from Graham Charnley, and coordinating DL effort re controls & instrumentation. The work will need to comply with IEC 62508/61511 (Functional Safety), and Safety Integrity Level (SIL) of H2 R&D system will need to be assessed & implemented. Progress is good in this area, thanks to DL team. Some discussion between DL & RAL teams currently re appropriate level of compliance.

•Key members of RAL & DL teams will be trained in December in SIL assessment according to IEC 61508/61511, although consultants still required to ensure system complies with IEC 61508/61511.

•Work on cryostat build at AS Scientific currently very slow (still 50% complete). Work on gas panel not yet stated, although final decision on choice of safety relief valves and LH2 level detectors has now been taken.

Plans & Schedule

•Design of H2 ventilation system and external pump housing well advanced. Mound excavation complete.

•Hydrogen System Control Room has been assigned.

•As much control & instrumentation hardware will be purchased as possible by December, including pumping systems.

•H2 system purging pump, along with backing-pump for cryostat pumping rig, will be housed outside MICE Hall.

•Exact location of turbo-pump for the R&D cryostat pumping rig still to be decided. It needs to be located outside magnetic shielding wall, but its location might differ from that of final system, and it is important not to cut more holes in shielding wall than absolutely necessary.

•Initial tests will be conducted with Helium in Cryogenics Laboratory, to avoid interference with installation of ventilation system

Plans & Schedule

•Schedule has been revised:

•It is anticipated that the ventilation system in the hall will be installed by the end of December.

•It is planned to submit H2 R&D commissioning plan to ISIS/MICE Safety Committee in November.

•HAZOP 2 review will be held as soon as practical in the near future, hopefully Nov/Dec.

•Final Safety Review will follow as soon as possible after HAZOP 2.

Testing

Helium TestsCheck instrumentationPump and purgeCheck relief valve settings and operationCheck cryocooler operation at LH2 and LHe temperaturesLiquify helium in the cryostatTest emptying sequenceThermally cycle the system, to check for leaks from thermal stresses

Hydrogen TestsCheck alarms and interlocksLiquify hydrogen in the cryostatCheck empty and purge sequenceTest effect of using Helium top-up gas to maintain positive pressureMeasure H2 desorption rateMeasure H2 absorption rate

Hydrogen R&D System

TestCryostat

Gas Panel

VacuumSystem

Exhaust

Heater Chiller

Hydride Bed

Storage

Buffer Volume Hydrogen

DeliveryControlSystem

MICE ControlSystem

Extraction Hood / Cabinet

Safety Relief

TestCryostat

Gas Panel

VacuumSystem

Exhaust

Heater Chiller

Hydride Bed

Storage

Buffer Volume Hydrogen

DeliveryControlSystem

MICE ControlSystem

Extraction Hood / Cabinet

Safety Relief

Hydrogen System P&ID

Cryostat

BottleStore

Gas Panel

Venting

Vac. Pumps

Heater/ChillerUnit

HydrogenBottle

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Cryostat

Cryocoolerand Compressor

Level Sensors

Nitrogen Jacketingon Pipes

Electrical heating ofbase-plate Pre-cooling loops

Pressure Transducers

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Electrical heater for operation of cryocooler with H2

Temperature sensors

Temperature sensors on base-plate

Gas Panel and Hood

Hydride BedBuffer Volume

Extraction Hood

Absorber ReliefValves

Cryostat Relief Valves

Fill/Purge ValvesH

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Fill/Purge Valves

• Pneumatically actuated valves• Arrow indicates position on failure

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Vacuum System

2 Elements

• Purging Pump for H2 system

• Cryostat Vacuum system

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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

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

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

Relief Valves & Bursting Discs

• 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

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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

Level SensorsPressure Transducers

Temperature sensors

Vacuum System Pumps

• 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 D40B

TMP151C

TRIVACD25BCS

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