Final Report on the Joint U.S.--U.S.S.R. Test of the U.S. MHD Electrode System in the U-02Facility. Phase II (September 21--September 27, 1976).

摘要

The second (Phase II) joint U.S.-U.S.S.R. test of U.S. electrode materials was carried out in Moscow between September 21and September 27, 1976in the Soviet U-02MHD Facility. The test procedure followed closely a predetermined work plan designed to test five different electrode materials,different leadouts and attachments,and the cathode and anode electrode walls under MHD operating conditions. The materials which were selected were Graded CeO sub 2 /ZrO sub 2 ; 50CeO sub 2 -50ZrO sub 2 ; 75MgAl sub 2 O sub 4 -25Fe sub 3 O sub 4 ; 75FeAl sub 2 O sub 4 -25Fe sub 3 O sub 4 ;and 95 LaCrO sub 3 -5Mg. The materials were arranged into modules of five electrodes apiece each with its own heat sink. Opposing electrodes on the anode and cathode were of the same material. The cathode and anode wall had six modules apiece. The opposing electrodes were separately loaded to various assigned current densities during the experiment which lasted a total of 131hours with 75hours under MHD power operational conditions. There were four main phases in the test schedule: (1) Start-up of the channel over a specific heating period. No K sub 2CO sub 3seed introduction. (2) Electrophysical tests of the electrodes at operating temperature with seed and magnetic field. (3) Operating life test of electrodes at various assigned current densities. (4) Shut-down of the channel over a specific cool down period. Extensive pre-and post-test materials characterizations were made to determine the effect of the MHD environment on the electrodes and insulators. Pre-test measurements were made to determine:thermal diffusivity,thermal expansion,chemical composition,microstructure,electrical conductivity,phase composition,closed and open porosity and pore size distribution. (ERA citation 04:006118)