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7. 2.2 Thermal studies

7. 2.2 Thermal studies. EUCARD-WP7-HFM collaboration meeting. Slawomir Pietrowicz, Bertrand Baudouy CEA/IRFU/SACM March 22, 2011, Grenoble. Outline. Modeling of thermal process in the magnet during ramp rate – 2 D steady state model Geometry and physical model;

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7. 2.2 Thermal studies

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  1. 7.2.2 Thermal studies EUCARD-WP7-HFM collaboration meeting Slawomir Pietrowicz, Bertrand Baudouy CEA/IRFU/SACM March 22, 2011, Grenoble

  2. Outline • Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  3. Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  4. Modeling of thermal process in the magnet during ramping process – 2 D steady state model • Physical model • model of heat transfer used during simulations (steady state): • Assumptions • Two types of boundary conditions: • Constant temperature on walls (red lines); • Symmetry (yellow lines); • Thermal conductivity as function of temperature; • Perfect contact between solid elements; • 1 W, 5 W and 10 Wdissipated in conductors. For those values the homogenous spreadsof heat sources are used; • Calculations are carried out for CUDI model (AC loss due to ISCC losses, non-homogenous spread) as well; • Calculations are performed for two bath (helium) temperature 1.9 K and 4.2 K Geometry and boundary conditions applied during simulations

  5. Modeling of thermal process in the magnet ramp rate – 2 D steady state model The temperature contour map of central part and localization of maximum temperature rise 4.2 K 1.9 K 1 W Homogenous spread of heat dissipation 5 W 10 W CUDI Model average 0.2 W

  6. Modeling of thermal process in the magnet during ramp rate – 2 D steady state model Maximum temperature difference in magnet at different bath temperature and heat load LHC Upgrade CUDI Model Temperature rise in the magnet as a function of heat load

  7. Outline • Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 Kto 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  8. Modeling of cool-down process – 2 D transient model – indirect cooling • Assumptions: • 8cooling elements (tubes) for magnet are proposed (2 per quarter) on external shell; • Cpand kare function of temperature, Cp(T), k(T); • Helium is treated as solid domain; • The cooling tubes are replaced by temperature evolution in time according to thefollowing graph; • 4scenarios (1.5, 2, 3 and 4 days) of cool-down from 300 K to 20 K are considered; • The details of cooling scenarios • I II III IV • Cooling step 300 K to 80 K 3 days 2 days 1days 0,5 day • Electrical integrity test at 80 K 6 hour 6 hour 6 hour 6 hour • Cooling step 80 K to 20 K 12 hour 12 hour 12 hour 12 hour • Electrical integrity test at 20 K 6 hour 6 hour 6 hour 6 hour • Total 4 days 3 days 2 days 1,5 day Evolution of temperature on the cooling elements

  9. Modeling of cool-down process – 2 D transient model - indirect cooling Animation of 4 days cool-down

  10. Modeling of cool-down process – 2 D transient model - indirect cooling Evolution of maximum DT within the magnet structure

  11. Outline • Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  12. Modeling of cool-down process – 2 D transient model - direct cooling from 20 K to 4.2 K After indirect cool-down to 20 K via external tubes, direct cooling method from 20 K to 4.2 K is applied e.g. helium is flowing directly to the structure from the bottom of magnet (vertical configuration). The first type of boundary conditions is used e.g. the temperature on the walls (read lines). The temperature changes in time according to graph. Geometry and boundary conditions applied during simulations

  13. Modeling of cool-down process – 2 D transient model - direct cooling Evolution of maximum DT in the magnet structure during direct cool-down

  14. Outline • Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  15. Modeling of cool-down process – 2 D transient model – mass flow rate of cooling helium The total heat which has to be removed from whole magnet during cool-down via cooling tubes.

  16. Outline • Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  17. Modeling of thermal process in the magnet with quench heaters – 2 D unsteady state model • Assumptions • Two types of boundary conditions: • Constant temperature on walls; • Symmetry; • Thermal conductivity and heat capacity as a function of temperature; • Perfect contact between solid elements; • Temperature 4.2 K • Heating power of quench heaters 50 W/cm2 Heaters The evolution of heat flux in quenchheater Details of heater, localization and mesh

  18. Modeling of thermal process in the magnet with quench heaters – 2 D unsteady state model Contours of temperature for selected time during heating process Heating Changes of temperature rise at the center of heaters

  19. Modeling of thermal process in the magnet with quench heaters – 2 D unsteady state model Evolution of temperature rise at selected points 6 ms Block 1 Block 2 Block 3 6 ms Block 4 left central right Localization of selected points

  20. Outline • Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  21. Thermal test of TGPAP - DETD The numbers and thicknesses of tested samples Assembled “drum” apparatus in the cryostat Sample glued to the holderflange

  22. Experimental results Temperature rise for sample D2 (28,9 mm) at different bath temperature Total resistance of samples as a function of bath temperature and thicknesses

  23. Modeling of thermal process in the magnet during ramp rate – 2 D steady state model • Geometry and physical model; • Results - maximum temperature rise as a function of heat load. • Modeling of cool-down process – 2 D transient model • Indirect method from 300 k to 20 K – cool-down through cooling tubes • Assumptions and scenarios of cool-down used during calculations; • Results – maximum temperature rise as a function of time; • Direct method from 20 K to 4.2 K – direct filling with helium; • Scenario of cool-down used during calculations; • Results - maximum temperature rise as a function of time; • Maximum cooling power. • Modeling of thermal process with quench heaters • The conception of quench heaters localization • Results – the temperature rise at selected points • The thermal test of TGPAP – DETD insulation - Experimental set-up; - Results. • Summary Numerical calculations Experiment

  24. Summary • 2D numerical model based on FVM (Finite Volume Method) has been developed in ANSYS CFX Software. The steady and unsteady simulations have been performed. • For steady simulations: the maximum temperature rises in conductors are smaller than critical temperature. • For transient simulations: • The simulations show that maximum temperature differences in magnet structure are varying from 10 K to 60 K. • The most critical time during cool-down is first 14 hours (by the reason of mechanical constraints). • The maximum temperature rise during direct cool-down is relatively small 0,45 K in comparison with indirect cool-down method. • The required power of cryogenics system is changing from 17,2 kW for 1,5 days of cool-down to 3,2 kW for 4 days; • The calculations with quench heaters have been performed at 4.2 K.

  25. Summary Numericalmodeling tasks: • Update the simulation for new geometry- June 2011 • Extend the simulation to 3 D geometry – July 2011 Experiment task: • Measurement of new samples - the cyanateesther (under delivering) – May 2011 Future plan

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