Advancement of the sonar fluorocarbon mixture analyzer for C2F6/C3F8 evaporative cooling development Greg Hallewell Centre de Physique des Particules de Marseille Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 1 Development of sonar fluorocarbon mixture analyzer for C2F6/C3F8 evaporative cooling development People involved: Michele Battistin, Jan Godlewski, Elena Perez Rodriguez (CERN) Greg Hallewell, Dirk Hoffmann, Michel Mathieu & Sasha Rozanov (CPPM) Jose Botelho Direito (Univ. Coimbra/CERN) Lukasz Zwalinski (Crackow Institute of Technology/CERN) Richard Bates & Alex Bitadze (Glasgow) Kirill Egorov (Indiana) Danilo Giugni (Milano) Keita Hanawa & Koichi Nagai (Nagoya Univ.) Rusty Boyd (Oklahoma State) Sergei Katunin (St Petersberg) Martin Doubek, Vic Vacek & Michal Vitek (CTU, Prague) Steve Mcmahon (RAL/STFC) 2 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 But why does ATLAS silicon need C2F6/C3F8 evaporative cooling? Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 3 Current as-built ATLAS tracker C3F8 evaporative cooling system Condensation @ ~50 C Hot water H.Ex. 17.0 10.0 ) Liquid abs Mixed Phase Zone Zone Evaporation @ ~-25 C 1.07 Pressure (bar Pressure 0.90 Pressure drop(mainly capillary) Cooling capacity followed by J.T. expansion ~75 J/g Vapour Zone 175 200 225 250 275 300 Enthalpy (kJ/kg) SameLooking principle at blending as A/C, C2 F(but6 with 324 C parallel3F8 to raise channels: evaporation 60kW): pressure (7) piston and compressorat exploiting reliability 92m poorATLAS & d pitP in depth compressor to eliminate aspiration compressors lines too high Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 4 Advantages of a modest C2F6 admixture (1) Full thermodynamic cycle simulation C3F8/C2F6 PC-SAFT equation of state molecular simulations At -25ºC in 10%C2F6/90%C3F8 median evaporation pressure is around 2barabs Pressure drop problem in exhaust tubing mitigated Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 5 Advantages of a modest C2F6 admixture (2) Full thermodynamic cycle simulation C3F8/C2F6 PC-SAFT equation of state molecular simulations At -25ºC in 20%C2F6/80%C3F8 median evaporation pressure is around 3barabs Pressure drop problem in exhaust tubing mitigated Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 6 Why sonar analysis of gas mixtures? - Velocity of sound in a binary gas mixture at known temperature & pressure is a unique function of their relative molar concentrations; - Sonar gas analyzer is an in-line/on-line instrument in the gas delivery circuit, instantaneous response well adapted to updating cursor display without the delay inherent in (e.g.) gas extraction to a gas chromatograph; - Depending on the difference in molecular weight of the components, mixture measurement precision to 10-5 is possible - Already considerable experience & success with the technique for Cherenkov radiator refractivity monitoring (SLDDELPHI COMPASS LHCb etc.) However it is a binary device; for mixing multiple gases an additional cell is needed after each stage of mixing (eg. 2 cells for Anesthesia trimix…) 7 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 First sonar binary gas analysis use for C5F12/N2 radiator refractivity analysis: SLAC-SLD CRID (1988) Later adopted in DELPHI, COMPASS, LHCb… Vs T P Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 8 SLAC SLD Barrel CRID Radiator Vessel Still using these transducers in the present project One of 12 45 kHz Polaroid ultrasonic transducers (Ø= 44mm): 6 pairs at three different heights, North and South of central -80KV drift tube cathode/potential degrader 9 SLD CRID C5F12/N2 (short: DH ~ 1.5m) thermosyphon recirculator (A) C5F12 Condenser (cooled with GN2) (B) C5F12 storage tank and N2 separator LN2 conditioner (Chills GN2 in counterflow with LN2 DH from liquid argon calorimeter source) (C) C5F12 Evaporator Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201010 Sonar in the SLD CRID C5F12/N2 (short: DH ~ 1.5m) thermosyphon recirculator A Low temperature N2 gas-induced condensation of C5F12/N2 radiator gas followed by electric re-evaporation B (1-1.5m below condenser liq. level) Cold N2 gas (‘conditioned’ by D counterflow with boil-off LN2 from liquid argon calorimeter) C Sonar analyses C5F12/N2 after N2 admixture and before entry into Cherenkov radiator vessel Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201011 Also SLD CRID combined sonar mixture analyzer/flowmeter: sends sound alternately in both (u,d) directions for flow measurement… L ~ 50 cm Flange Ø ~ 10cm Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201012 Principle of combined ultrasonic flowmeter/ gas analyzer Flowmetry: measure d(transit time) up(down) stream in fluid flow: Most general case, sound injected angle at j to the fluid flow tdown = L / (c + v cosΦ) , tup = L / (c - v cosΦ); Gas flow velocity v (m/s): v =L/2cosΦ * ((tu – td)/ tu* td) ; Sound velocity c (m/s): c = L/2 * ((tu + td)/ tu* td); Volume flow n (m3/s) : n = v * A Note: knowledge of gas temperature not necessary Analysis: use average d(transit time) up(down) and abs temp and use some theory: NEED TEMPERATURE Tempting but only really valid for ideal gases (monatomics, He, Ne, Ar, Kr, Xe) Sometimes OK for N2, O2… 13 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201014 Sonar flowmeter/analyzer mechanical structure The following slides adapted from presentation & images created by Jose Botelho Direito (EN/CV/DC), who has designed the mechanical structure for the sonar gas mixture analyzer The first sonar flowmeter/analyzers foreseen for installation in the USA15 thermosyphon and in a new mixed fluid circulation system at SR1, which will allow cooling studies using C3F8/C2F6 mixtures Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201015 Sonar installations foreseen in thermosyphon surface plant (return to condenser and degassing tank) 16 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Detailed Overview (without Flanges) Sonar Flow meter/ Analyzer 10 Overview 9 8 5 6 4 (1) Tube DN40 (2) Reduction DN65 to DN40 3 (3) Sensor (4) Spider (sensor holder) 2 (5) PEEK Cone (6) Tube extension DN65 with 2 welded metric 10/8mm and 6/4mm tubes (7) Schrader valve (8) VCR Male Nut SS-8-VCR-4 7 (9) VCR glands 6LV-8-VCR-3-10MTB7 1 (10) VCR Female Nut SS-8-VCR-1 29/04/2010 Sonar Flowmeter/Analyser 18 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 General Drawing (No External Pipe Flanges) 29/04/2010 Sonar Flowmeter/Analyser 19 19 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Sonar analyzer to be built using components (including flares, CF UHV 152/100 Flanges etc.) readily available in CERN stores 29/04/2010 Sonar Flowmeter/Analyser 20 20 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 General Drawing 29/04/2010 Sonar Flowmeter/Analyser Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 21 21 Detailed Overview (showing flanges) Design follows 40/60 max. service/ test specification for all thermosyphon components 2 3 4.a 1 4. 6 b 7 5 (1) Reduction DN65 to DN50 (Connection to plant) (2) Bolts DIN EN 24014 M8x55 (3) Washers ISO 7089 M8 (4) (4.a & 4.b) CF UHV Rotatable Flange CERN SCEM Code 18.60.18.365.2 (5) Tube DN65 (6) CF UHV Flange CERN SCEM Code 18.60.18.015.1 (7) Nuts DIN EN 24032 M8 29/04/2010 Sonar Flowmeter/Analyser 22 22 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Overview CF UHV Flanges 152/100 Total weight = 12.2 kg 29/04/2010 Sonar Flowmeter/Analyser 23 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201023 44mm transducer attachment & centering via PEEK deflector cone (similar annular area to circular cross section between transducers) ; wire routing toward electrical feed-through, port for evacuation & periodic calibration with reference gas (e.g. Xe) 24 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Multipin connector (transducers + temperature sensors) for sonar analyzer/ flowmeter – to be screwed into spoolpieces for 2 * VCR tube extensions (to be designed) CS-MS-A-J-9-BCR-SS 25 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Sonar analyzer/flowmeter; new electronics development Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 201026 Basic ultrasonics functionality (one of two directions shown) 50 KHz sound clock, 40 MHz transit clock Also analog inputs: - Temperature sensors; -Pressure sensor And analog outputs: -4-20mA DAC drive signal to PLC controlling C2F6 mass flow controller for on-line correction of C2F6 /C3F8 mix ratio Digital communication: - via RS232 to PVSS GUI – CAN in production version 27 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Sensitive to first sound peak and successive zero crossings 50 kHz , 5 pulses, Air , length: ~ 557 mm: repeatability ~ 50ns in ~ 1.6ms @ fixed T, P 28 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Sonar test stand in SR1 – May 2010 : 56 cm tube 29 Sonar fluorocarbon analyzer: ATLAS ID Thermosyphon Workshop, CERN, May 28, 2010 Sound Velocity/ concentration look up tables A sonar analyzer compares measured sound velocity at known T&P for comparison with a stored look-up table fit to (Vs vs % concentration A in B) at known T&P. This look up table can be established theoretically using an equation of state, mixing rules and thermodynamic data for fluorocarbons or else from measurements with calibration mixtures as was necessary at SLD in the 1980s Calibration equation can be shifted from the calibration temperature to the sonar tube temperature using √(T1abs/T2abs), providing this is not so far as to substantially affect (Cp/Cv) in the components.