SAFETY FOLLOW-UPHL-LHC PROJECT

WP17 – Infrastructures meetingS. La Mendola, Jose Gascon DGS/SEE 09 July 2015

• RF System– HV converters (TE-EPC): capacitors at 10kV (no liquid insulation) or 40kV

(oil insulation)– Control racks: PLC, cables, PCBs, etc. - classical combustible material– Tetrodes: no identified combustible

• Power Converters – No oil insulation – Use of small electro-chemical capacitors – Classical combustible materials: cables, PCBs and plastics for capacitors– Mainly copper and metallic component– All components will be in a metallic enclosure not tight

– For capacitors some data will be sent to assess impact

FIRE LOADS ASSESSMENT (Ongoing)

• Electrical distribution– UPS Batteries– Heating Cables in X cable trays– Dry Transformers

• Cryogenics– Compressors???– Control racks

• Cooling & ventilation– Fans, motors???– Cables– Control racks

FIRE LOADS ASSESSMENT (Ongoing)

• Transport– Electrical motors???– Batteries (special vehicles)??– Control racks

• Others???

FIRE LOADS ASSESSMENT (Ongoing)

Burning of electronic cabinets and cable trays

Main failure modes:1. Overheating;2. Short circuit and ground fault;3. Arcing

Protection measures for cabinetsInterior and exterior fire protection (for example according to DIN 4102-11 “Fire behaviour of building materials and building components”)

Similar cabinet used for R2E project

Protection measures for cabinetsTypically suppression systems are made up of either of the following suppression agents:• CO2

• Foam• Water• Powder• Etc.

System already in place in ATLAS, ALICE, LHCb and CMS, using different control systems (5 kg bottles CO2) for 52U standard racks.They are based on thermocable and smoke detection.See EDMS 867968 “Options for the use of the MiniMax System”

Protection measures for cable trays

• Tested against EN 1366-11 “Fire resistance tests for service installationsPart 11: Fire protective systems for cable systems and associated components”• Classified against EN 13501-3, e.g. EI-S 120 (ve ho i↔o), whereE = IntegrityI = InsulationS = smoke leakage, less than 200 m3/(m2∙h)120 = duration of fire resistance in minutes

Smoke hazard characterizationLiterature review

• Calorimetric fire experiments on electronic cabinets, J. Mangs et Al.• Characterization of closed-doors electrical cabinet fires in compartments,

W. Plumecocq et Al.• Characterization of the fire environments in central offices of the

telecommunications industry, A. Tewardson• Energy balance in a confined fire compartment to assess the heat release

rate of an electrical cabinet fire, M. Coutin et Al.• Risk analysis of the LHC underground area at CERN – Fire risk due to

faulty electrical equipment, A. Harrison• Modelling of electrical cabinet fires based on the CARMELA experimental

program

Combustion of electronic cabinetsExperimental apparatus, results and models

Growth phase

Decay phase

Fire Modelling Tools:Quick method to Calculate Fire Load of Cable Trays and Ladders.F. Corsanego DGS/SEE/XP, EDMS 1405658

Fire Modelling Tools:Characterization of burning behaviour of a stack of horizontal cable trays – unconstrained fireF. Corsanego DGS/SEE/XP, EDMS 1357073

Combustion of cable trays, available models

Simplified calculation of necessary smoke extraction flow rate

Reference smoke extraction flow rate for the tunnel of 18000 m3/h.

See for example Enclosure Fire Dynamics, Karlsson and Quintiere

Definition of smoke extraction concept with EN/CV

• Organization of the underground volumes in «smoke compartments».• Extraction ducts dimensioned for one compartment (18000 m3/h).• Natural fresh air intake from the access shaft (openings in surface building)• Use of smoke curtains (EN 12101-1) to define the compartment limits.

• Use of fire rated smoke extraction ducts (EI-S 120 ve ho ) for multiple compartments (EN 12101-7).

• Higher smoke extraction flow rate for the cryo cavern. One additional smoke extraction duct.

Evacuation of occupants• Evacuation of occupants can be simulated (e.g. agent based

software, analytical calculations) taking into account the smoke dynamics (production, propagation, extraction)

• Tenability thresholds are established (visibility, temperature, etc.);

• tRSET < tASET (ISO 16738 “Fire safety engineering – Evaluation of behavior and movement of people)

RSET = Required Safe Egress Time

ASET = Available Safe Egress Time

Possible ground for cooperation with universities• Contact with Lund university established• Possible collaborations in fire and evacuation modeling for HL-LHC

Questions?