Simulation and validation of a CO2-based pumped loop cooling system.

In high physics applications, silicon trackers form the innermost layer of particle detectors. These trackers require a complex active cooling system: tight space constraints, stringent requirements of low mass, a radioactive environment and the need for very stable evaporation temperatures complicate the cooling system design. Cooling systems based on Two-Phase Accumulator Controlled Loops have proven to be excellent in dealing with these challenges. In such systems, the liquid refrigerant is mechanically pumped and cooling is achieved through flow boiling inside the evaporator. A two-phase accumulator is used to control the evaporation temperature. In this study, a component library has been developed in EcosimPro to model such cooling systems. This library is used to simulate the complex startup and temperature step change dynamics of a test plant at CERN. The simulation results are compared against measured data. The results show that the library is able to predict well the transients considered.