1. Update on UT cooling specifications and status of activities LHCb CO2 cooling meeting 24/9/2015 Simone Coelli For the Milano UT group INFN Milano 1 Istituto Nazionale di Fisica Nucleare Sezione di Milano

2. Many peoples helping in this activity that I need to mention Carlo Gesmundo Andrea Capsoni Mauro Monti Ennio Viscione From design & mechanical dpt. Alessandro Andreani Fabrizio Sabatini Mauro Citterio Powering and DAQ systems Andrea Merli Labview software And all the people involved at CERN and other Institutes in the collaboration Aknowledgements 2

3. Summary DETECTOR COOLING TEST SCOPE TEST SETUP DESCRIPTION LHCb UT central stave “C” actual configuration  Boundary conditions, box insulation  Snake mechanical drawing and geometrical data  Stave Powering  Sensors position STAVE FLUIDO-DYNAMIC CHARACTERIZATION  Thermo-dynamic previsions, COBRA simulation  From 0 to nominal power and back to 0 power behavior in nominal flow condition  Pressure sensors systematic error measurement, no flow  Description of the measurement, steady-states  Stave pressure drop vs mass flowrate  Temperatures, Dry-out DETECTOR CO2 COOLING DISTRIBUTION and DESIGN PROPOSAL  INLET PIPING, design choice: orifice or capillary, test in progress, bonding capillaries with glue, then welding prototyping OUTLET PIPING, design choice: 2/2,5 S.S., pipe procurement, welding prototyping COOLING REQUIREMENTS DOCUMENTS, last comments from Bart COOLING CALCULATIONS AND TEST DOCUMENTS, work in progress 3

4. DETECTOR COOLING TEST SCOPE DETECTOR COOLING TEST (a “big picture” I’ve been asked to give) USING: PROTOTYPES OF THE PROPOSED COOLING COMPONENTS, I.E. SNAKE PIPE, CONNECTION PIPING, ETC. MEASUREMENTS ON A SINGLE STAVE TYPE A, B, C USING THE TRACI COOLING SYSTEM IS A SMALL SCALE FINAL COOLING SYSTEM, HAVING THE SAME WORKING PRINCIPLES AND OPERATING VONDITIONS TO DEMONSTRATE THE OPERATION OF THE CIRCUIT COMPONENTS IN REALISTIC OPERATIVE CONDITIONS TO VARY CONDITIONS, COLING FLOWRATE, PRESSURE, TEMPERATURE, STAVE POWERING FLOW DIRECTION COULD BE CHENGED I.E. TO MOUNT INLET / OUTLET DISTRIBUTION PIPING ROPOSED DESIGN SYSTEMS MAKING THERMAL AND FLUIDO-DYMNAMICAL CHARACTERIZARION AT NOMINAL AND OTHER IMPORTANT POINTS TO HAVE THE FIGURES NEEDED TO DRIVE THE COOLING SYSTEM DESIGN TO SET AND CHECK POINTS IN THE SIMULATION SOFTWARES I.E. COBRA 4

5. TEST SET-UP Boundary conditions. In the actual test the cold circuit is insulated using Armaflex The dummy stave is closed during the test into 3*25 mm Armaflex layers each side. Future test can be envisaged using a cold box dummy: covering with 5 mm Policarbonate+sealing volume and fluxing dryed air; + covering external surfaces with expanded Polystirene, thickness 20mm /40 mm All these materials already procured. THE MEANING OF THIS OPTION IS TO SEE AMBIENT POWER EFFECTS, but the actual is more “pure” test 5

6. TEST SET-UP Experiment instrumentation 6

7. TEST SET-UP Experiment instrumentation 7

8. TEST SET-UP Experiment instrumentation 8

9. TEST SET-UP Experiment instrumentation TRACI V1 DAQ Data acquisition TRACI V1 Mass flowrate measurement By Coriolis flowmeter 9

10. Stave SNAKE PIPE GEOMETRY «C» central stave 8 on a total of 68 staves under test Pipe Length 3 m Heated length = 16 * ~85 mm = 1,36 m 10 Titanium C.P. 2 I.D. 2,025 mm O.D. 2,275 mm

11. Stave SNAKE PIPE GEOMETRY Identical for the «A» «B» staves All the other detector stave apart the 8 central staves Pipe Length 2,82 m Heated length = 14 * ~85 mm = 1,19 m The only different region is the central part of the snake pipe 11

12. Powering the stave with heaters 12

13. at 15 bar ABS Hentalpy liquid (X=0) Hentalpy vapour (X=100%) CO2 physical properties calculated exhaust vapour fraction Xout Xout = (h out-h in)/delta h L-V (h out-h in)= Power/F F= mass flowrateg/s Power= elctrical heaters powerW => Xout = ( Power/F)/ delta h L-V delta h L-V @15 bar ABS300J/g Xout = 75 / (300 * F)W/(J/g*g/s)=1 delta h L-V @15 bar ABS300J/g Set point on TRACIv1: Accumulator pressure P = 15 bar ABS / T saturation= - 28,5 °C 13

14. Pressures steady-state Nominal power and flux one of the measurement points …. Only some data are posted here …. 14

15. Temperatures steady-state Nominal power and flux 16/09/2015 pset15bar POWER75W FLOWRATE0,9g/s DA FILE:2015-09-16-Pset15bar-75W-F09GS-t.txt milli °C TF1TF2T1T2T3T4T5T6T7T8T9T11T12T13T14T15T16T17T18T19T20 -26.413-26.852-26.196-26.156-26.192-24.088-23.325-23.291-22.776-23.687-23.579-21.881-22.913-25.248-24.831-23.893-25.072-24.402-23.827-26.284-26.647 -26.415-26.850-26.213-26.162-26.189-24.083-23.335-23.308-22.788-23.706-23.577-21.889-22.931-25.265-24.835-23.903-25.092-24.404-23.832-26.278-26.634 -26.418-26.850-26.213-26.162-26.189-24.083-23.335-23.308-22.788-23.706-23.577-21.889-22.931-25.265-24.835-23.903-25.092-24.404-23.832-26.278-26.634 -26.418-26.852-26.209-26.151-26.189-24.063-23.333-23.298-22.774-23.698-23.582-21.873-22.926-25.254-24.831-23.907-25.075-24.413-23.850-26.291-26.657 -26.418-26.852-26.209-26.151-26.189-24.063-23.333-23.298-22.774-23.698-23.582-21.873-22.926-25.254-24.831-23.907-25.075-24.413-23.850-26.291-26.657 -26.417-26.851-26.203-26.166-26.201-24.072-23.336-23.321-22.795-23.712-23.590-21.896-22.938-25.259-24.854-23.905-25.093-24.416-23.828-26.277-26.642 -26.414-26.850-26.203-26.166-26.201-24.072-23.336-23.321-22.795-23.712-23.590-21.896-22.938-25.259-24.854-23.905-25.093-24.416-23.828-26.277-26.642 Fluid temperature in/out difference is less than 0,5 °C NEAR ISOTHERMAL STAVE OPERATION, very good condition …. Only some data are posted here …. -26.634MEAN CHANNEL TEMPERATURE 15

16. «C» stave full power pressure drop flow relation 16

17. COBRA simulation for the nominal power and flux case Note: horyzontal pipe, Angle = 0, to run Using full length 3 m (more correct for friction calculation) Consistent with the Calculated Xout=28% 17

18. COBRA simulation for the nominal power and flux case Note: horyzontal pipe, Angle = 0, to run Using heated length 1,36 m (more correct for heat exchange) Consistent with the Calculated Xout=28% 18

19. «C» stave TEST transients at nominal flowrate: power from 0 to nominal and viceversa Initial Mass flowrate F fixed = 0,9 g/s 1.OFF Power = 0 2.ON Power = 75 w 3.OFF Power = 0 when power is switched on Flow-rate decreases from ~0,9 to ~0,8 g/s Increase in the channel pressure drop due to evaporation Viceversa the flow come back to initial value when switched off 19

20. Work in progress Powering 0-25-50-75-100-125-150 % making measurement at different flowrates Build curves channel DeltaP vs Flow **** Inlet piping pressure drop assesment we like to have ~ 5 times 0,3 bar =1,5 bar STAVE INLET DELTAP for distribution stability purposes Mounting new components on the experiment line. OPTION 1: Using swagelok orifice 0,254 mm and other; easy to change VCR Measurement of the pressure drop on the orifice in realistic operation conditions, nominal power and flow and other points OPTION 2: Using 1/16 inch swagelok pipe, starting with 6m measurement Production of pipe fittings and gluing with araldite 2011 in progress Measurement of the pressure drop on the orifice in realistic operation conditions, nominal power and flow and other points 20

21. STAVE INLET CO2 CONNECTION Calibrated orifices option 21 ONE RESCTRICTION FOR EACH STAVE

22. STAVE INLET CO2 CONNECTION PIPE capillary pipe option Using 1/16 inch swagelok pipe, starting with 6m measurement Production of pipe fittings and gluing with araldite 2011 in progress 22

23. STAVE OUTLET CO2 CONNECTION PIPE OUTLET PIPING, design choice: 2 mm ID =no diameter restriction 2,5 mm OD 0,25 mm thickness= minimum commercial available Weldable, Pdesign 100 bar ok factor ~ 5 S.S. AISI 304L annealed (and post-bending annealing foreseen in final system) If ok pipe procurement We buy 30 m = 15 pipes 2 m long min quantity From “Castiglioni” company If ok welding prototyping We’re asking offer to “Real –Vacuum” company To produce prototyp MICRO TIG welded Swagelok 1/8 inch VCR fitting – pipe stave interface Welded to the manifold (no disconnection on manifold side) No more present! 23

24. Design in progress 24 Study stars from 2 staves.. Study need to be completed on updated geometry This will be based on comments received on the proposals made COOLING CONNECTION DESIGN

25. Back up slides 25

26. UT DETECTOR ONE HALF-PANEL USING ONE LONG CAPILLARY/MINIPIPE THAT IS A DISTRIBUTED PRESSURE DROP CONNECTING EACH STAVE PIPE INLET; EXTERNAL MANIFOLD DISTRIBUTED DELTAP 26

27. COOLING REQUIREMENTS DOCUMENTS, last comments from Bart Page 9: >In the stave cooling tube, the evaporation temperature will decrease >along the path due to the pressure drop, so when the condition of CO2 >temperature is set, all the components from inlet to outlet will have a lower temperature. This is not phrased properly, we fix in general the outlet pressure and the inlet temperature. If there is significant pressure drop this means that the pressure of the inlet increases. As the inlet has a controlled temperature this means it becomes single phase and the temperature along the pipe will go up first. When it boils the temperature goes down following the saturation in the tube. So pressure drop is in our system a wrong word in fact as we can only increase the pressure upstream. page 13 >The cooling shall be reduced to maintain the temperature stable near as >possible to the nominal cold operation, to avoid thermal detector >cycles. For electronics testing of digital readout (and perhaps also analog readout) and slow control. What do you mean with the statement "the cooling should be reduced"? The temperature is that same, so a reduced cooling (I guess you mean less massflow) does not change anything in your stave. The inlet condition (=saturated liquid) will be the same, the outlet quality will vary due to the load differences, but your stave will not see these differences. So I consider to do nothing for this special half power case. Another question I have about the partial powering: Does this means half of the staves are on, or are all chips half powered? (I think the 2nd as I read, but I want to be sure as this has lead to some confusion in the past) Table 3 page 14 says: TOTAL POWER LOAD4103.6W/UTpartial load I guess the partial load comment is an error. A comment about warm operation: It is stated at multiple places that the ambient operation temperature is 20'C, I would rather bring that back to 15'C. There is a big difference between 15 and 20 as the system needs a small amount of heat always to run in saturation, the ambient heat leak is generally sufficient. If you really want 20'C we can set it to the required 57 bar, but the system will generally become liquid and stays around 15'C anyway, only switching on the detector makes it to go to 20'C, we can do that as well in the plant if you insist but I think unnecessary. The most important for commissioning is that we stay above the dewpoint. 15'C is therefore generally okay to use and easy to generate, it also lowers the maximum temperature of the sensors when powered on. Typical detectors have gradients of about 10'C, meaning the detector is between 15 and 25'C during commissioning, a very pleasant temperature range in general. 27

28. In addition to my previous mail about the requirement document I would like to discuss the inclusion of a few paragraphs more stating the following subjects: 1.) For the design of the cooling system it is not only important what the power and temperatures are, but as well the required flow and pressure drop. Simone is now working on this, so it might not yet be available. When available I propose we include this in a next version as it is a requirement from the UT towards the cooling, like this we create 1 common document stating all the important input to the cooling system design. Can you already include this chapter? Perhaps Simone can already include preliminary numbers. 2.) For detector testing at the surface we are designing together with CMS a dedicated cooling system in the order of 1kW. We got some preliminary numbers from Burkhard, but it would be nice if we can officialize the required conditions for surface testing in the same requirement document. Can you add a chapter for this in the document as well? Please explain the surface cooling requirements by the segmentation of the parts of the detector you want to test in 1 go. 28