FCC Refrigeration cost vs magnet temperature Laurent Tavian CERN, ATS-DO 15 February 2016

Contents Refrigeration need for magnet cooling vs – shaft elevation and cryoplant location – Operating magnet temperature Optimum cutting temperature between ground and underground refrigeration – Cryogenic architecture proposal CAPEX and OPEX for magnet cooling vs operating magnet temperature CAPEX and OPEX for FCC cooling

FCC-hh cryogenic layout 10 cryoplants 6 technical sites Sector length ~8 km

Cooling scheme He II cooling He I cooling

Exergy load Carnot eff: 0.29

Exergy efficiency T0= 290 K, h= 0 m

Cryoplant size Depending on the cryoplant location (surface or underground), the entropic size increase from 20 to 25 %  the cryoplant must be partially located underground.

Contents Refrigeration need for magnet cooling vs – shaft elevation and cryoplant location – Operating magnet temperature Optimum cutting temperature between ground and underground refrigeration – Cryogenic architecture proposal CAPEX and OPEX for magnet cooling vs operating magnet temperature CAPEX and OPEX for FCC cooling

Cutting temperature Shaft elevation impacts the hydrostatic head ( .g.h) and the enthalpy (g.h) variations: The relative variation strongly depends on the operating temperature. 40 K is a good compromise compatible with the Nelium cycle producing the refrigeration capacity down to 40 K and which has to be located at the surface for limiting the Neon inventory (cost). h= 400 m

Cryoplant architecture

Process flow diagram

Contents Refrigeration need for magnet cooling vs – shaft elevation and cryoplant location – Operating magnet temperature Optimum cutting temperature between ground and underground refrigeration – Cryogenic architecture proposal CAPEX and OPEX for magnet cooling vs operating magnet temperature CAPEX and OPEX for FCC cooling

4.5 K cryoplant cost Tmag = 4.5 K Tmag = 1.9 K Extra cost (4.5  1.9 K): 10 to 18 MCHF per sector  100 to 180 MCHF for FCC

Cold compression cost Extra cost (4.5  1.9 K): 7 MCHF per sector  70 MCHF for FCC

Operation cost (for magnet cooling) T magnet 4.5 K1.9 K Power to refrigerator [W/m] Power to refrigerator [MW/sector] FCC energy consumption over 10 y, 6000 h/y [TW.h] FCC energy cost over 10 y [MCHF] Extra cost (4.5  1.9 K): 20 MCHF per sector  200 MCHF for FCC

Extra cryo-cost 1.9 K vs 4.5 K CAPEX: – Cryoplant extra cost: 100 to 180 MCHF – Cold compression extra cost:70 MCHF – Total CAPEX extra cost:170 to 250 MCHF OPEX – Operation extra cost (10 y)200 MCHF Total extra cost 370 to 450 MCHF (CAPEX + OPEX(10 y))

Contents Refrigeration need for magnet cooling vs – shaft elevation and cryoplant location – Operating magnet temperature Optimum cutting temperature between ground and underground refrigeration – Cryogenic architecture proposal CAPEX and OPEX for magnet cooling vs operating magnet temperature CAPEX and OPEX for FCC cooling

Nelium cycle and BS circulators

CL cooling m1  85 g/s (50 g/s per MA)  exergy load: 154 kW per sector m2  9 g/s  exergy load: 61 kW Total exergy load: 215 kW  equi K Total power to refrigerator: 746 kW per sector

FCC Refrigerator cost [MCHF] OPEX [MCHF] ( h/y] T mag 4.5 KT mag 1.9 K MW/sectorOPEXMW/sectorOPEX BS-TS cooling Magnet cooling CL cooling Total CAPEX [MCHF]T mag 4.5 KT mag 1.9 K BS-TS coolingX ? Magnet cooling CL cooling Total194 + X (+X) Without overcapacity margin

Comparison with Linde publication CAPEX C 4.5K (12 kW) =12 MCHF (see slide 12) C 1.9K (12 kW) =35-43 MCHF (see slide 19) C 1.9K (12 kW)/C 4.5K (12 kW)= L. Decker In good agreement !

Comparison with Linde publication OPEX C 4.5K (12 kW) = 9.5 MCHF (220 W/W) C 1.9K (12 kW) = 35 MCHF (see slide 19) C 1.9K (12 kW)/C 4.5K (12 kW)= 3.7 L. Decker Factor ~2 difference !

Comparison with Linde publication OPEX C 4.5K (12 kW) = 9.5 MCHF (220 W/W  2.6 MW) if C 1.9K (12 kW)/C 4.5K (12 kW)= 7.5 i.e. C 1.9K (12 kW)  19.5 MW of electrical consumption i.e. a COP 1.9K = 1620 W/W i.e. a Carnot efficiency of about 10 % (very small!) L. Decker

Other impacts 1.9 K vs 4.5 K Coldmass diameter: – impact on cooldown time and LN2 consumption (OPEX for 4.5 K). – Impact on tunnel integration and or tunnel diameter (CAPEX for 4.5 K) – Helium inventory (OPEX for 4.5 K) Pumping line: Higher diameter i.e. tunnel integration and or tunnel diameter (CAPEX for 1.9 K) Size of cryoplants: increase of building surface and cavern volume (CAPEX for 1.9 K).