1. CO 2 as a potential cooling medium for detector cooling at CERN

2. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 2 Abstract:  Project conception  CO 2 overview  Reverse Rankine Cycle  Components  Calculations / dimensioning  Heat transmission  Perspective

3. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 3 Project definition  Today’s state of the art  Existing applications and look for trends  CO 2 as cooling medium  Laboratory and test facility design  Correlations for CERN Project conception

4. CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 4 Project structure Project conception

5. CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 5 Timetable Project conception

6. CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 6 CO 2 overview  CO 2 sublimates under ambient pressure direct from solid to steam and reaches a temperature of -78,5°C.  CO 2 is color- and odorless, good soluble in water and not soluble with mineral oil.  CO 2 has a critical point at 31,06°C and 73,83 bar.  CO 2 is non flammable, non explosive, non corrosive and does not corrode sealant and lubricant.  30vol.% (300'000 ppm) of CO 2 in the air are lethal. CO 2 overview

7. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 7 Reverse Rankine Cycle

8. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 8 Components of the laboratory CO 2 cycle Compressor (Bock) Expansion valve CondenserEvaporator Components

9. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 9 CO 2 compressor Technical data:  2-cylinder, semi-hermetic compressor  Limitation of use:  Operation point: Condensing temperature: 0°C Evaporation temperature: -40°C  Cooling capacity at operation point: 6058 W  Attachment: continuous speed control Components HGX12P/60-4 CO2

10. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 10 Components  Condenser  Evaporator  Throttle valve  Reservoir All elements will be appointed over one company. Components

11. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 11 CO 2 Reverse Rankine Cycle in the T,s-diagram Calculation / dimensioning 1-2: Isentropic compaction 2-3: Isobar condensation 3-4: Isenthalpe choke 4-1: Isobar evaporation

12. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 12 Calculation result Input based on operation point: Cooling capacity6058 W Isentrope efficiency49% Evaporation temperature-40°C Condensing temperature0°C Calculation / dimensioning CO 2 Reverse Rankine Cycle1 – 2 – 3 – 41 – 2‘ – 3 – 41 – 2“ – 3 – 4 Mass flow25,78 g/sec25,74 g/sec Rejected heat flow-7476 W-8226 W-8952 W Compressor power consumption1418 W2890 W Coefficient of performance4,2722,1  It is a obvious difference to the ideal process expected.  The compressor don’t work isentropic.  The condenser has to provide a minimum heat flow of 9 kW.  The evaporator has to provide a minimum heat flow of 6,5 kW.

13. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 13 Detector cooling with CO 2 cycle  Pilot study  Test state Liquid CO 2 through thin and heated capillary tubes Measuring of heat transmission characteristics  Identify the formula coherences  Correlate formula with the measured data Heat transmission

14. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 14 Flow Boiling Heat transmission

15. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 15 Correlations  Heat transmission separated into two independent rates: ConvectiveHeat transmission heat transmissionin nucleate boiling Heat transmission

16. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 16 Yoon  Horizontal microtubes Critical quality  Constant heat flux below x cr above x cr

17. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 17 Steiner - Horizontal  Horizontal thick-walled tubes  Constant heat flux  Start of nucleate boiling:

18. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 18 Steiner - Horizontal  Convective  Nucleate boiling Heat transmission

19. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 19 Steiner - Vertical Heat transmission  Convective  Nucleate boiling no mass flux no quality

20. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 20 Steffen Grohmann – Horizontal microtubes  Working fluid: Argon  No mass flux and quality dependence in microtubes Strong influence of surface tension in microtubes  Phase seperation occures less likely  α B based on VDI-Wärmeatlas correlations for vertical tubes

21. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 21 Options for future work Perspective  Ordering the components (condenser, evaporator).  Setup and launch of the cooling machine in the laboratory.  Tests regarding the heat transmission and conventional cycle.  Calculation of the cycle based on the measured data.  Optimization of the cooling machine.

22. Project conception CO2 overview Reverse Rankine Cycle Components Calculations / dimensioning Heat transmission Perspective CO 2 as a potential cooling medium for detector cooling at CERN 16.01.2009 Project Tutor: Prof. Dr.-Ing. W. Czarnetzki M. Renner, S. Erhardt, S. Feghelm, J. Bürkle 22 Future collaboration with CERN Experiments on heat transmission:  with several tubes types  in a evaporation temperature range from -25°C to -50°C  in a pressure range from 7bar to 40bar Correlation of the measurements Perspective