Experimental research on blowout process development of the EAST divertor

Abstract

In the maintenance phase of the Experimental Advanced Superconducting Tokamak (EAST), water in the divertor cooling channel needs be drained to avoid the possible divertor damage. However, the cooling water in the cooling channel of the divertor cannot be drained only by gravity, using pressurized nitrogen is necessary to push the cooling water out. In this paper, establishing an experimental platform to predict the critical blowout parameter for complete drying of the divertor. The research results show that no less than 8.3 kPa of the pressure difference between the inlet and outlet of the divertor can ensure that the water in the cooling channel is completely discharged. Moreover, compare the results of experimental measurements and previous simulation calculations, even though the trends agree with each other reasonably well, there is a substantial difference in the pressure difference required to blow out. Howener, the actual error can not exceed 5% after error analysis, which is in the acceptable range. Therefore, this work can not only provide reliable boundary of critical differential pressure for the drainage and drying design of the plasma-facing components (PFCs), but also provide basis for the research of Tokamak drainage and drying system in the future.