Simulation and Optimization of Hot Nitrogen Gas Baking for HL-2M Divertor

To provide the best vacuum environment for the plasma operation, it is necessary to bake the divertor. According to the heat conduction and the convective heat transfer equations, the baking process of the divertor was simulated and optimized. The results show that the pressure drop increases gradually and the baking temperature of the divertor components increases linearly when the mass flow rate of the hot nitrogen gas is unchanged. Similarly, when the volume flow rate is constant, the baking temperature of the divertor components also increases linearly, but the pressure drop decreases gradually. While the initial conditions are approximate (the equivalent mass flow rate is 3×10^-3 kg/s and the equivalent volume flow rate is 4.8×10^-4 m³/s), the former temperature rise rate is lower than that of the latter slightly, but the maximum temperature difference of all parts in the baking process is lower than 90 ℃.