Research And Design KTX Vacuum Chamber Baking System For Degassing

Continue baking chamber is to improve the performance of magnetic confinement fusion devices vacuum important way to improve the quality of plasma. In this paper, we fully self-developed advanced reversed field pinch device KTX (Keda Torus eXperiment), designed and developed induction heating vacuum chamber baking sys-tem. Reversed Field Pinch device KTX vacuum chamber made of stainless steel lining, insulation materials composite outer stabilization copper shell and constitute there be-tween. This paper proposes the use of toroidal field coils KTX device as a primary winding, induction heating method of heating and stainless steel vacuum chamber, to avoid duplication of investment extra baking system, taking into account the difficulties inter layer insulating material for temperature control.In this paper, electromagnetic field theory with long straight column configuration are analyzed in a vacuum chamber baking conditions, the use of flat-shaped bits, as well as a good conductor approximation, given the attenuation characteristics of the electromagnetic field inside the vacuum chamber wall. Numerical simulation of the ring-shaped lower position in given due effect to bring the ring and the coil current distribution uneven distribution, the vacuum chamber wall around the current distri-bution of the magnetic field distribution of the magnetic field in the vacuum chamber wall attenuation. When the frequency of the maximum heating efficiency obtained at800Hz time.In tablet position calculated shape when it reaches thermal equilibrium, theoretical calculations of the vacuum chamber and the temperature distribution of the heat insu-lating layer. Come in at30KW heating power, different thermal convection temperature coefficient and surface exchange coefficients constant surface radiation situation of the vacuum chamber. The case of calculating a greater natural convective heat exchange coefficient, to bake the vacuum chamber150℃power required and the time required to reach that temperature. Shows30kW heating power vacuum chamber can be baked to150℃.Frequency induction heating power supply using thyristor H bridge inverter circuit 4is a series LC resonant circuit is powered, change the power by adjusting the firing angle of thyristor rectifier, rectifier output voltage change. The frequency tracking technology to track LC resonance frequency changes H bridge trigger frequency, as far as possible so that circuit in a resonant state. In order to improve the inverter output current signal, theoretical calculation using PWM technique, the output current characteristics obtained. Simulation feature rectifier circuit and an inverter circuit by simulink. Ensure the correctness of the experiment.By1/4segment of the vacuum chamber and toroidal field coils6cake, bake table vacuum chamber experiments, in the end rectified voltage to500V, current adjusted200A rapidly when the temperature was raised to200℃, later adjusted current inverter50A can be maintained at a temperature200℃, and the measuring point distribution image obtained in different time temperature space temperature changes with time. It demonstrates the correctness of the choice of baking program.