Hydrogen-Oxygen MHD Generator Applied to Pulsed Power Required in Nuclear Fusion Research

摘要

Designs of large test facilities of nuclear fusion research succeeding the current large Tokamaks such as TFTR, JET and JT-60 show that huge pulsed power is required to operate the new test facilities ; 700 MW for 10 s to excite poloidal coils. The present paper proposes three steps of application of MHD power generation to fusion to provide such large pulsed power. The first step is to design and construct a small scale MHD generator which excites the Demo poloidal superconducting magnet (SCM) coil being under construction in JAERI. The operating current is 30 kA with the stored energy of 40 MJ. As the working gas of MHD generator, H2-O2 combustion product is selected, seeded with 5 w/o K. The second and third steps are to construct an intermediate MHD channel of 100 MWe and a large channel of 800 MWe. Much improved designs are obtained in the present study, compared with the previous designs. For the large 800 MW generator, the maximum magnetic field becomes 3.5 T with the load current of about 100 kA, while the stored energy in the MHD magnet is estimated to be less than 0.5 GJ which is much smaller than 58 GJ of planned poloidal coils. The small MHD channel designed for the Demo poloidal coil is 4 m long with the peak field of 1.8 T. The cryogenic magnet can be self-excited within 20 s. The Demo poloidal coil is charged in about 4 s.