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Picture: LHCb-VELO evaporator. Nikhef Activities on CO 2 Cooling. Bart Verlaat, Nikhef Introduction meeting with FOM director W. Van Saarloos. 1. CO 2 cooling @ Nikhef (1). Evaporative CO 2 cooling is very promising for detectors:
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Picture: LHCb-VELO evaporator Nikhef Activities on CO2 Cooling Bart Verlaat, Nikhef Introduction meeting with FOM director W. Van Saarloos 1
CO2 cooling @ Nikhef (1) Evaporative CO2 cooling is very promising for detectors: Need small tubing (5-10x lower mass than conventional cooling systems) Excellent heat transfer properties (5-10x higher than conventional systems) Due to high system pressure more design freedom (pressure losses not significant) CO2 is very safe and clean to work with. Since 10 years Nikhef is developing CO2 cooling systems. 2 have been build: AMS-TTCS and LHCb-VTCS. CO2 cooling becomes the standard for the Atlas and CMS inner detector upgrade. Other applications are interested
CO2 cooling @ Nikhef (2) Nikhef has developed a new cooling principle called 2PACL. (2-Phase Accumulator Controlled Loop) The 2PACL concept is a mix of technologies from different “kitchens” (Space, refrigeration, central heating and fire fighting) CO2 fire extinguisher Central heating system Satellite thermal control Refrigeration system
CO2 systems in HEP • 2 CO2 cooling systems have been developed for HEP detectors so far. • AMS-TTCS (Tracker Thermal Control System) • Q= 150 watt • T=+15ºC to -20ºC • LHCb-VTCS (Velo Thermal Control System) • Q=1500 Watt • T= +8ºC to -30ºC • Both systems are based on the 2PACL principle invented at Nikhef
From central heating to 2PACL cooling 100ºC • What we actually do: • Replace the burner heat by the detector heat. • Place all the hardware in the “heated room” away from the detector • Place the radiator in a refrigerator • Replace water by CO2 to boil at sub-zero temperatures • Introduce a heat exchanger between the supply and return line, to make the CO2 boiling. • Replace the expansion vessel by a more sophisticated accumulator from satellite cooling systems. • Varying the pressure in the accumulator and let the CO2 boil at any temperature you want. Central heating system Result: 2PACL is an easy to control cooling principle which is accurate, low mass and passive in the detector 2PACL Cooling system HX
The AMS-Tracker Thermal Control System (AMS-TTCS) Component box on satellites exterior Evaporator tube Evaporator section Pump Heat exchanger Accumulator TTCS Space radiator AMS
The LHCb-Velo Thermal Control System (LHCb-VTCS) Evaporator Velo Module with cooling block CO2 rack The VTCS cooling plant
LHCb-VTCS The cooling tube temperature is: • Easy to control • Very stable • Independent of primary cooler temperature Accumulator temperature = Cooling tube temperature Temperature of the chiller 0 -10 -20 -30 Temperature of space radiator Temperature (ºC) Time 1 orbit (~1.5h) AMS-TTCS
CO2 developments for future HEP experiments The Dutch C1O2 flu is becoming pandemic; The whole world is getting infected…………. Blow system in SLAC 2PACL system in Nikhef Compressor plant in CERN-Cryolab Blow-system in IPN-Lyon Blow system in CERN-DT 2PACL system in RWTH-Aachen Atlas CMS Blow-system in Karlsruhe
CO2 2PACL Lab Cooler 2PACL with PLC Test box with experiment • Supplies: • Massflow • Enthalpy • Pressure • Supplies: • Cold Cryostat • Supplies: • Power • Supplies: • Temperature • Pressure • Voltage • Demand for: • Mass flow • Enthalpy • Pressure Power supply • Demand for: • Temperature • Demand for: • Power • Supplies data: • HTC • Pressure drop • CHF • Dry out PC with PVSS to control the cooler and experiment 10
Conclusions • CO2 cooling works very well in AMS and LHCb. • It has a promising future to become a HEP detector default. Auke-Pieter’s Mantra adopted in CMS