1. VENTILATION PRINCIPLE FOR THE DRIVE BEAM TUNNEL M Nonis – EN/CV – 28/7/2009 Already presented by C. Martel/ J Inigo Golfin on15 th October 2008 CLIC WORKSHOP - 2008

2. Agenda CLIC WORKSHOP - 2008 - Ventilation functions - Heat dissipation levels - HVAC principles - Tunnel section - Safety considerations - Equipment issues

3. - Fresh air for people and ventilation (obligation). - Requested ambient conditions (T°C and humidity). - Remove heat loads in air. - Prevent from any air stratification, condensation. - Purge before access. - Smoke or gas extraction (obligation). - Overpressure control linked to radiation (obligation). - Safety of people, fire brigade access, fire fighting issues. Tunnel ventilation functions CLIC WORKSHOP - 2008

4. 90 kW 250 kW 200 kW Heat dissipation in the air Heat dissipation in the tunnel: 250 kW / DB sector 1250 kW between two shafts CLIC WORKSHOP - 2008 Drive Beam sector = 250 kW UTRA cavern = 200 kW Loop = 90 kW Heat dissipation in the Loops & UTRA: 290 kW / DB sector 1450 kW between two shafts

5. CLIC WORKSHOP - 2008 200 kW 90 kW UTRA Loop Local cooling production

6. Tunnel Air flow rate considerations 250 kW 1250 kW 500 kW DB sector Intershafts Heat dissipation in the tunnel 75 000 m 3 /h 370 000 m 3 /h 150 000 m 3 /h Air flow rate 1.73 m 2 8.56 m 2 3.3 m 2 Air duct section 1.48 m 3.3 m 2 m Air duct Diameter Intershafts* Hypothesis: Delta Temperature (Extraction – Supply) = 28 – 18 = 10°C CLIC WORKSHOP - 2008 To be Optimised … Tunnel section = 20 m 2 DB sector volume =17 000 m 2 Inter shaft volume = 90 000 m 3 Input data Limit

7. Air handling from the surface CLIC WORKSHOP - 2008 Air supply Extraction Air supply Extraction

8. Semi transversal principle SHAFT POINT Extraction Air supply NEXT SHAFT POINT Extraction Air supply Optimisation of the air flow rate Low air speed in the tunnel Optimisation of the gradient temperature Reversible and redundant operation possible Energy recovery possible, recycling of air CLIC WORKSHOP - 2008

9. Semi transversal principle SHAFT POINT Extraction Air supply NEXT SHAFT POINT Extraction Air supply Possible fire resistance sectors with two emergency exits per sector 1 Smoke extraction trap per sector 1 supply and extraction grille per 30 mtrs.

10. Safety considerations SHAFT POINT Extraction Air supply Extraction Air supply Possible fire resistant sectors, with emergency exit. Control of the pressure from both ends of a sector. Control of the pressure (overpressure in safe area, and extraction in the critical area). Fire detection via cable compatible (sensibility with temperature increase) to fire fighting via water mist. CLIC WORKSHOP - 2008

11. Tunnel section principle CLIC WORKSHOP - 2008

12. Not standard industrial fans High pressure fans Adapted products Not standard equipment

13. CLIC WORKSHOP - 2008 Special design: Fan in specific concrete section Concrete air ducts Direct driven fans (no belts) Fan in specific concrete section Concrete sound attenuation Extraction unit Supply unit

14. CLIC WORKSHOP - 2008 Lower maintenance need Sealed Fire resistant Modulated Compressed air control Smoke extraction trap Supply/ extraction grille

15. CLIC WORKSHOP - 2008 Conclusions - Heat dissipation in tunnel air to optimize - Heat dissipations in Exp. caverns, linac to be defined ? - Air duct section to optimize - Integration of ventilation in the tunnel section to finalize HVAC criteria shall be specified for each structure: Detailed definition of the structure (fire volumes, partition, and shielding, plug on head of shaft) Required ambient conditions: temperature and humidity Radiation levels in the various areas Description of accessible and non accessible areas Detailed heat dissipation level in the air (when water cooling not possible) Presence of gas, which gas ? Other

16. Longitudinal principle SHAFT POINT Air supply NEXT SHAFT POINT Extraction Large air flow rate High speed Temperature gradient CLIC WORKSHOP - 2008 Base: 150 000 m3/h 1250 kW Delta T°C = 24 = (41-17) Air speed = 2 m/s