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This report presents the outcomes of the first test campaign for ultra-light carbon fiber structures held on July 18, 2012. The campaign involved thermal tests and evaluations performed by the Bari team. Key setups included circuit assembly, sensor connections, and heater insulation procedures. Results indicate a stable heater temperature across varying flow rates and highlight significant thermal characteristics, including hotspot analysis. Recommendations for system improvements and standardized setups are discussed to enhance thermal performance in future tests.
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Enrico DA RIVA (EN-CV-PJ) Manuel GOMEZ MARZOA (EN-CV-PJ) 18th July 2012 Ultra-light carbon fiber structures: first test campaign WG4 Meeting - 18th July 2012
Outline • Thermal tests done over the structure already tested by the Bari team. WG4 Meeting - 18th July 2012
Setup description WG4 Meeting - 18th July 2012
Setup procedure • Assemble the circuit • Connect the sensors to the Data Acquisition System through ELMB cards • Existing channel configuration used: no need to recalibrate ELMB • Build up the PVSS panel • Connect the circuit bypassing prototype: flush water • Check the reading of the sensors • Connect prototype and flush water • Start measurements • Heater emissivity: ε=0.86 (for thermo camera) • Insulation placed over the PTs and connectors WG4 Meeting - 18th July 2012
Results • Six cases done, corresponding to the experiments done in Bari • An absolute power equal to 11.7 W applied to heater (see Bari presentation): • Rheater = 27.2 Ω • P = I2 R; I= (11.7/27.2)0.5 = 0.65 A • V = I R = 0.65*27.2 = 17.7 V • From case number 3 onwards, insulation was put over the aluminum connectors and the PTs at the piping • Temperature of the heater remains stable even when increasing the flow rate WG4 Meeting - 18th July 2012
Results – Thermal pictures Inlet/outlet Hotspot outside the stave cooling area 7.60 lpm 8.12 lpm 8.22 lpm 11.41 lpm 13.70 lpm 15.8 lpm Silicon WG4 Meeting - 18th July 2012
Results – Thermal pictures (Bari) WG4 Meeting - 18th July 2012
Results – Thermal pictures • Hotspots on the heater: 8.22 lpm Silicon Inlet/outlet • Hottest point is at the heater end, outside the cooled area (silicon) • Heater is supposed to be cooled there by the water at the pipe turn and the stave by thermal conduction along the heater. WG4 Meeting - 18th July 2012
Results – Thermal pictures • Temperature along three lines at the stave: 8.22 lpm Silicon Inlet/outlet T line 1 T line 2 T line 3 WG4 Meeting - 18th July 2012
Results • The first test (@7.6 lpm) can be neglected, the results do not follow the trend of the rest. • Noticeable decrease of silicon maximum temperature when transition to turbulent flow happens (~ 12 lpm). WG4 Meeting - 18th July 2012
Results • Difference in pressure drop with the expected theoretical values is due to the connectors, piping, etc. These losses can be considered as k*1/2*ρ*v2, where k is a constant dependent on the setting and can be calculated. • ΔT wall-water: establishes the margin of improvement by using a better cooling system for this setup: WG4 Meeting - 18th July 2012
Outcome • Experiences can be run fast and reliably. • Uncertainty: big • Sensors (PTs, NTCs, p sensors, flow meter). • Thermo camera: -/+4 oC below 100 oC • Systematic: depends on the setup (assembly of sensors, NTCs over heater). • Thermo camera shooting point: not fixed this time (reflections can appear). • Results qualitatively significant • Standardized setup necessary: • Stave support for quick replacement. • Tripod for thermo camera. • NTCs glued to the heater to enhance local contact. • Evaporative cooling system little improves thermal performance, but could ensure better T distribution. • Water tests can be repeated using the same absolute power as in the Bari experiences (13.7 W corresponding to 0.71 A current) WG4 Meeting - 18th July 2012
Enrico DA RIVA (EN-CV-PJ) Manuel GOMEZ MARZOA (EN-CV-PJ) 18th July 2012 Ultra-light carbon fiber structures: first test campaign WG4 Meeting - 18th July 2012