Analyses of the power generation performance and the non-equilibrium plasma of a disk MHD generator

Abstract

Recently, closed cycle MHD power generation system studies have been focused on improving the isentropic efficiency and the enthalpy extraction ratio. By reducing the crosssection area ratio of the disk MHD generator, it is believed that a high isentropic efficiency can be achieved with the same enthalpy extraction. In this study, the results relating to a plasma state which takes into account the ionization instability of non-equilibrium seeded plasma is added to the theoretical prediction of the relationship between enthalpy extraction and isentropic efficiency. As a result, the electron temperature, which reaches the seed complete ionization state without the growth of ionization instability, can be realized at a relatively high seed fraction condition. However, the upper limit of the power generation performance is suggested to remain lower than the value expected in the low seed fraction condition. It is also suggested that a higher power generation performance may be obtained by implementing the electron temperature range, which reaches the seed complete ionization state at a low seed fraction.