Experimental study on the phenomenon of gas–liquid flow in divertor and diffuser under blowout condition

Abstract

In the Experimental Advanced Superconducting Tokamak (EAST), the water in the cooling channel of the divertor needs to be pushed out by the blowout system to avoid water leakage, otherwise it will further endanger the safe operation. However, diffusers often used to change the pipe size have an adverse effect on the water discharge in divertors. Therefore, research on the blowout process in the divertor and diffuser is essential to improving the dryness of the blowout system. In this paper, the mutual restriction between divertor and diffuser is proposed by the experiment research, such restriction is an important factor in reducing the dryness of the divertor. According to the experimental results, the larger the resistance loss is in the divertor, the smaller the effective pressure difference will be in the diffuser. Meanwhile, liquid phase water flows rotationally in the diffuser under a small pressure difference, thus reducing the dryness of the divertor. Moreover, the diffuser increases the pressure difference required for complete blowout in the divertor. These results will provide a reference for the design and optimization of the EAST blowout system in the future.