Progress at the large scale CO2 system, Contents Progress at the large scale CO2 system, Results of the small scale CO2 system connected to the large scale system.

Possible mass flow rate CO2 - Large scale system Location in 158: Temperature range -27°C to 25 °C, Possible mass flow rate 0.5...12 g/s, Self made accumulator, Measurements with: - CMS 5.5m tube and - CL small scale system. Joao Noite, Lukasz Zwalinski, Jihao Wu, Petra Janickova, Torsten Koettig

CO2 - Large scale system

CO2 - Large scale system

Large scale system in Bldg. 158 at CERN: Test section length: 5.5 m CO2 – CMS 5.5 m tube Large scale system in Bldg. 158 at CERN: Test section length: 5.5 m Jani Turunen and Joao Noite Measurement of the temperature distribution along the tube in dependency of: heat load mass flow comparison of the dependencies vs vapor quality

CO2 - Large scale system

CO2 - Large scale system

5.5 m CMS tube, 1.424 mm diameter, varied heat input and mass flow CO2 - Large scale system 5.5 m CMS tube, 1.424 mm diameter, varied heat input and mass flow Mass flow (g/s) Heat input (W) 1.5 2.1 70 100 120 150

Small scale system in the cryolab CERN: CO2 – Small scale system Small scale system in the cryolab CERN: Test section length: 300 mm, heated part: 150 mm Petra Janickova, Jihao Wu and Torsten Koettig Measurement of the heat transfer coefficient and pressure drop under variation of the following dependencies: Vapor quality x Mass flux G Saturation temperature Tsat

CO2 - Small scale system

CO2 - Small scale system Heat transfer coefficient – Comparison of different supply systems

CO2 - Small scale system Pressure drop – Comparison of different supply systems

CO2 - Small scale system Alternative pressure drop determination: temperature difference T4-T8 in the two phase region => Δp4-8 Δp outlet inlet

CO2 - Small scale system

CO2 - Small scale system

CO2 – Small scale system Heat transfer coefficient - Mass flux dependency G= 502 kg/m2s G= 628 kg/m2s G= 816 kg/m2s G= 1005 kg/m2s

CO2 – Small scale system Pressure drop gradient - Mass flux dependency G= 502 kg/m2s G= 628 kg/m2s G= 816 kg/m2s G= 1005 kg/m2s

Paper is in review process Int. Journal of Heat and Mass Transfer Resume Large scale system in operation, Small scale system is connected to the large scale system, Deviation in heat transfer and pressure drop at different locations, Possible influences of pressure oscillations created by the membrane- pump. Paper is in review process Int. Journal of Heat and Mass Transfer

CO2 - Large scale s. incl. small scale s. Top-lid dismounted and turned CO2 heat exchanger spiral Heat exchanger vessel Small scale system connected via flexible pipes

CO2 - Large scale s. incl. small scale s. Electrical connection box of the heater Corrosion by inleaking water – glykol mixture 3 heater loops - one failed => disconnected Dummy load vessel - view from the bottom