Diapositive 1

7.2.2 Thermal studiesSlawomir Pietrowicz, Bertrand BaudouyCEA/IRFU/SACMMarch 22, 2011, Grenoble1EUCARD-WP7-HFM collaboration meeting 1OutlineModeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.Summary

2Numerical calculationsExperiment3Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperimentModeling of thermal process in the magnet during ramping process 2 D steady state model4Geometry and boundary conditions applied during simulationsPhysical modelmodel of heat transfer used during simulations (steady state):

AssumptionsTwo 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 W dissipated in conductors. For those values the homogenous spreads of 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

Modeling of thermal process in the magnet ramp rate 2 D steady state model5The temperature contour map of central part and localization of maximum temperature rise1.9 K4.2 K1 W5 W10 WCUDI Modelaverage 0.2 WHomogenous spread of heat dissipation

Modeling of thermal process in the magnet during ramp rate 2 D steady state model6Temperature rise in the magnet as a function of heat loadHeat loadNameUnitValueCritical temperature riseTotalW0,21,05,010,0UnitW/m0,10,52,65,3VolumetricW/m34,321,8108,9217,7Maximum temperature rise@ 1,9K0,2311,0532,9063,9516,1@ 4,2K0,0660,3541,3442,1973,8CUDI ModelHomogenous modelMaximum temperature difference in magnet at different bath temperature and heat loadLHC UpgradeCUDI Model

6Outline7Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperimentModeling of cool-down process 2 D transient model indirect cooling8Assumptions:8 cooling elements (tubes) for magnet are proposed (2 per quarter) on external shell;Cp and k are 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 the following graph;

4 scenarios (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 IVCooling step 300K to 80K 3 days 2 days 1days 0,5 dayElectrical integrity test at 80K 6 hour 6 hour 6 hour 6 hourCooling step 80K to 20K 12 hour 12 hour 12 hour 12 hourElectrical integrity test at 20K 6 hour 6 hour 6 hour 6 hour Total 4 days 3 days 2 days 1,5 dayEvolution of temperature on the cooling elements

9Modeling of cool-down process 2 D transient model - indirect cooling

Animation of 4 days cool-down Modeling of cool-down process 2 D transient model - indirect cooling10Evolution of maximum DT within the magnet structureOutline11Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperiment12Geometry and boundary conditions applied during simulationsAfter 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.Modeling of cool-down process 2 D transient model - direct cooling from 20 K to 4.2 K

13Evolution of maximum DT in the magnet structure during direct cool-downModeling of cool-down process 2 D transient model - direct coolingOutline14Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperimentModeling of cool-down process 2 D transient model mass flow rate of cooling heliumThe total heat which has to be removed from whole magnet during cool-down via cooling tubes.Time of total cool-down processMaximum heat (required power of cryogenic system)DaykW1.517.129.134.743.2Outline16Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperiment

Modeling of thermal process in the magnet with quench heaters 2 D unsteady state model17AssumptionsTwo 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 KHeating power of quench heaters 50 W/cm2

HeatersDetails of heater, localization and meshThe evolution of heat flux in quench heater18Modeling of thermal process in the magnet with quench heaters 2 D unsteady state model

Heating

Changes of temperature rise at the center of heatersContours of temperature for selected time during heating process 19Modeling of thermal process in the magnet with quench heaters 2 D unsteady state modelEvolution of temperature rise at selected points

Block 1Block 2Block 3Block 4Localization of selected points6 ms 6 ms leftcentralrightOutline20Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperimentThermal test of TGPAP - DETD21

SampleD1D2D3D4mmmmmmmmThickness (average value)16,028,940,061,1Assembled drum apparatus in the cryostatSample glued to the holder flangeThe numbers and thicknesses of tested samples

Experimental results22Temperature rise for sample D2 (28,9 mm) at different bath temperatureTotal resistance of samples as a function of bath temperature and thicknesses23Modeling of thermal process in the magnet during ramp rate 2 D steady state modelGeometry and physical model;Results - maximum temperature rise as a function of heat load.Modeling of cool-down process 2 D transient modelIndirect 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 heatersThe conception of quench heaters localizationResults the temperature rise at selected points

The thermal test of TGPAP DETD insulation- Experimental set-up;- Results.

Summary

Numerical calculationsExperimentSummary2D 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.

24SummaryNumerical modeling tasks:Update the simulation for new geometry - June 2011Extend the simulation to 3 D geometry July 2011

Experiment task:Measurement of new samples - the cyanate esther (under delivering) May 201125Future plan