29th Symposium on Fusion Technology (SOFT 2016)

P4.162 Dynamic model of ITER cryo-pumps cryogenic distribution system: torus pumping and regeneration scenarios

8 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 162

Poster H. Fuel Cycle and Breeding Blankets P4 Poster session

Speaker

Silvio Giors (Plant Engineering Department)

Description

The ITER vacuum system, one of the largest and most complex vacuum systems ever to be built, will use first of a kind cryopumps to provide high vacuum conditions to the torus vessel, cryostat vessel, and neutral beam injectors. In order to evacuate the high gas flows required by the plasma scenarios, the cryopumps will need sequential regenerations with unprecedented high frequencies. The Front-End Cryogenic Distribution System (FECDS), made of 12 cold valve boxes (CVB) and 1 Warm Regeneration Box (WRB), will provide helium to each of the cryopumps at the required pressure, temperature and mass flowrate, in order to control the pumps behaviour during operation and regeneration. Such CVBs and WRB will operate in parallel, with dynamic synchronization to satisfy the cryopumps requirements. A model of the FECDS and cryopumps system is being developed within EcosimPro/Cryolib simulation environment, with the purpose of simulating the cryogenic process in dynamic scenarios and optimize the final design and the control of the system. This paper presents the dynamic model of the torus subsystem, made of 6 torus CVBs and the connected cryopumps, during operation and 100K regeneration scenarios, which will imply the staggered dynamic transition of the system components between several states during plasma pulses. The preliminary simulation results will be presented, giving useful information for a refined setting of parameters like pressures, mass flow rates, and valves control. These results are suitable to be used to optimize the FECDS final design and operation.