Thermal Analysis Of The Feeder System For The Central Solenoid Magnet Coils Of ITER

The CS1U feeder system is the connection between the central solenoid magnet coil system and the systems outside the Dewar. The systems outside the Dewar include the cooling system, the power supply system and the diagnostic control system. The components, such as the superconducting busbar and supercritical helium tube, inside the feeder system are at extreme high vacuum and4.5K low temperature. The thermal shield is set to reduce the radiation from the300K room temperature to the4.5K low temperature components. The thermal shield is set at80K temperature.The main work of this paper is to analyze the heat transfer of the CS1U feeder system. Main works of this article are as follows.(1) Chinese energy problems are investigated. The fusion energy is put forward as one of the important ways to solve the energy problems. The basic principle of nuclear fusion, the basic situation of ITER and the current status of the feeder system are presented in this paper.(2) The CS1U feeder system is designed. The CS1U feeder system is composed of the ICF, Gimbal and CFT. Both the ICF and the CFT consist of the busbar, supercritical helium tube, data transmission cable pipe, intermediate plate, busbar supports, helium tube supports and active cooling structure, etc. It is discussed how the busbar supports, helium tube supports and active cooling structure distribute in the ICF and CFT(3) The thermal resistances are calculated in two cases for four components. The components are the busbar support, helium tube support, cold mass support and active cooling. One case is that there is contact between the busbar/helium tube and their supports. Another case is that there is not contact between the busbar/helium tube and their supports. The cross sections of LINK33element for the supports and active cooling are calculated by the thermal resistances. The cross sections of LINK33are used to simplify the finite element model of the feeder system CS1U.(4) The effect of the Gimbal on the heat transfer between ICF and CFT is analyzed by ANSYS workbench sortware. The analysis results show that the total heat flow is range from4.0914×10-12W/m2to1.76×10-7W/m2, close to zero. The heat transfer effect of Gimbal between the ICF and CFT can be ignored.(5) The heat transfer effects of three facts are analyzed on the CS1U feeder system. The facts are active cooling, thermal intercept and support contact types. Analysis results are obtained including the temperature distribution of the CS1U feeder system and the peak temperature of ICF and CFT In-Duct pipes. According to the analysis results, active cooling, thermal intercept and contact resistance can help reduce the busbar and supply helium pipe heat load. Active cooling is at the expense of an increase in the return pipe heat load. The temperature of the In-Duct pipes can be maintained below50K with thermal intercept and active cooling. A great part of the heat load is brought by radiation from the thermal shield.