A method and an apparatus for producing power from a heat source
comprising a nonane heater/vaporizer, an intermediate fluid vapor turbine
mounted on a shaft that receives and expands the vaporized nonane, an
organic fluid vaporizer that receives the expanded vaporized nonane for
supplying heat to liquid organic working fluid present in said organic
fluid vaporizer and vaporizes said liquid organic working fluid with heat
from the expanded vaporized nonane to form vaporized organic working
fluid and a nonane condensate, a seal of said shaft being cooled using
the nonane condensate by cooling and condensing hot pressurized vapor
near the seal, and liquid containing such condensed hot pressurized vapor
being supplied to a condensate drain vessel, the drained condensate being
supplied to a line connected to a cycle pump of the nonane intermediate
cycle, and an organic vapor turbine that expands the vaporized organic
working fluid.