Performance Study And Optimization Design Of GDC Electrode Cooling Runner System

With the development of human society and economy,non-renewable resources such as oil,coal,and natural gas will gradually become exhausted until they are exhausted.In response to the energy crisis that the world may face in the future,tokamak device is proposed.Compared with the nuclear fission reaction technology used in traditional nuclear power plants,tokamak device uses nuclear fusion reactions with higher efficiency,less radioactive pollution,less environmental pollution,and renewable energy.As a sub-project of the tokamak device,Glow Discharge Cleaning(GDC)electrodes are designed to remove nuclear fuel particles and other impurity particles from the first wall surface,provideing a clean and recyclable first wall for high-constrained performance plasma.Since the GDC tip portion directly faces the plasma wall,a large thermal load is received,resulting in an excessively high temperature of the electrode body,causing excessive thermal stress,destroying the stability of the structure.Therefore,it is necessary to drill a flow channel inside the electrode body,and circulating a coolant therein to ensure that the GDC electrode satisfies the requirements of GDC regarding the maximum temperature of the electrode body,the temperature difference between the inlet and outlet of the coolant,the pressure drop,and the average flow rate of the coolant.In this paper,for the GDC electrode,through the commercial computational fluid dynamics software Fluent and the Static Structural module in the finite element analysis software ANSYS Workbench,a variety of GDC electrode cooling runner systems with different structures are designed,and simulated the temperature and stress of cooling runner system under different design conditions.According to the analysis result,it is determined that there are four regional flow channels,the first regional flow channel is 12 rows,the second regional flow channel is 7 rows,and the third regional flow channel is double row cooling channel design with better heat dissipation in the research range and meet the requirements of GDC for each parameter.On this basis,the influence of the structure size of each region on the heat transfer effect of the GDC electrode cooling runner system is further studied by numerical simulation.The analysis results show that the thickness and width of the cooling channel in the first region are reduced,and the radius of the top edge of the outermost wall of the electrode body is increased.The diameter of the second,third and fourth regions can reduce the maximum temperature and average temperature of the GDC electrode.The reduction of the thickness,width and the diameter of the cooling channel in the first region increases the pressure drop and the average flow velocity of the coolant inlet and outlet,and has little influence on the temperature difference between the inlet and outlet of the cooling water,and the electrode body is enlarged.The radius of the top edge of the outermost wall has little effect on these types of parameters.Based on these influencing factors,the structure of the cooling runner system is optimized,and the maximum temperature and average temperature of the GDC electrode are effectively reduced under the premise of ensuring sufficient safety margin.Aiming at the optimized GDC electrode cooling runner system design,the influence of the heat load and the cooling water inlet temperature on the parameters of the electrode body under different working conditions was studied by numerical simulation.The numerical simulation results show that the maximum heat flux density of the GDC electrode cooling channel system that can withstand the neutron heat is 17MW/m~3,and the maximum heat flux density that can withstand the radiation and charge exchange heat is 0.525MW/m~2 during the plasma operation period.Increasing the radiation and charge exchange heat has a greater effect on the maximum temperature rise of the GDC electrode.The GDC electrode cooling runner system can withstand a maximum cooling water inlet temperature of 170℃.During the baking period,the GDC electrode cooling runner system has a maximum heat flux that can withstand radiant heat of 3100W.The GDC electrode cooling runner system can withstand a maximum cooling water inlet temperature of 240℃.