Dependence of critical temperature of a ''quasiwarm'' superconductor on the degree of external irreversibility

Ways of decreasing specific power consumption spent in an inverse thermodynamical cycle under superconductor cooling are considered. The superconductor with critical temperature at the level of helium temperatures with equilibrium expulsion of thermal flux and its compensations by inverse thermodynamical cycle at power consemption for keeping superconducting state are equivalent to the superconductor with cryostating at the expense of helium boiling with higher critical temperature and it may be called ''quasiwarm'' superconductor. Development of rotor thermal flow-sheet of a superconducting turbogenerator KTG-20 with 20 MW capacity is based on a regularity expressing dependence of energy equivalence of superconductors on external irreversibility. There are coolants with spiral channels on the cylindrical surface in the ends of the rotor of this turbogenerator. Superheated helium vapors escape through the channels in the coolants carrying away heat getting on the level of low temperatures through design elements (thermal bridges) of the rotor. The thermodynamical analysis, experience-design developments and conducted experimental investigations of the first superconducting turbogenerator KTG-20 permitted to reveal dependence of energy equivalence of superconductors with different critical temperatures on the degree of external irreversibility. The obtained regularity has revealed that the superconductor with low critical temperature, for example, at the level of helium temperatures, is energetically equivalent to a ''quasiwarm'' superconductor with higher critical temperature, for example, at the level of nitrogen temperatures