0-D thermo-hydraulic approach for predicting pressure and temperature along HELIOS SHe closed loop under pulsed loads

Cryogenic systems for future large superconducting tokamaks (e.g. JT-60SA or ITER) are expected to cope with large pulsed heat loads due to cycling plasma operation. Their superconducting magnets are cooled down with forced flow supercritical helium.The aim of this paper is to verify to what extent a 0-D thermo-hydraulic model can well reproduce in space and time, the variations of pressure and temperature along a supercritical helium closed loop, subjected to pulsed heat loads.A 0-D model has been developed and the paper will present the corresponding equations and assumptions will also be justified. A pulsed heat load tokamak relevant scenario has been tested and the resulting variations of pressure and temperature have been compared with experimental data. The results of the 0-D model demonstrate the relevance of such approach for predicting transient behaviors in response of pulsed heat loads in a closed loop.This simple approach is also a justification to use process modeling codes where dynamics of the cryogenic circuits can be simulated with cryogenics components.

► Test facility to study the cryogenic circuits of JT-60SA tokamak.
► Analytical model applied to transient behavior resulting from pulsed load operation.
► Use of superposition principle to add transient evolution to steady state behavior.