Investigation on the Relation of CICC Stability Margin to Mass Flow Rate and Operating Temperature of Helium

To circulate supercritical helium, a differential pressure between inlet and outlet has to be applied. A differential pressure can be generated by a refrigerating compressor which forces the coolant through cooling channels. A differential pressure corresponds to a constant flow rate in a constant length. The coolant flow rate was set at different values from 0.2 to 2.8 g/s. The numerical simulation was performed using the 1-D mathematical model (Gandalf). The results of the experiment and simulation show that the larger the coolant flow rate, the higher the stability margin is. It is also showed that the shorter the cooling channel, the higher the stability margin is with the same coolant flow rate. Meanwhile, we also introduce the influence of temperature and pressure on the stability margin of CICC.