Multi-step regenerated organic fluid helical screw expander hermetic induction generator system

In an expander powered electrical generator system including a helical screw rotary expander having an expander casing, intermeshed male and female helical screw rotors mounted for rotation within said expander casing and forming with said casing a closed thread expansion chamber and having a high pressure inlet port and a low pressure outlet port at opposite ends of said helical screw rotors, and an electrical induction generator mechanically coupled to one of said rotors of said expander and being driven thereby, said system further comprising a condenser, a boiler, and conduit means carrying a vaporizable working fluid and forming a closed loop circuit including in series, the expander, the condenser and the boiler, said expander casing further including at least one movable slide valve and forming a part of the envelope for said expansion chamber, and motor means for shifting said at least one valve in response to a system operating parameter, and means for pumping the condensate from the condenser to the boiler, means for adding thermal energy to the working fluid within said closed loop at said boiler and for removing thermal energy from said closed loop working fluid at said condenser to effect vaporization of said working fluid within said boiler and condensation of said working fluid within said condenser, the improvement comprising:

• at least one regenerator within the closed loop between the condenser and the boiler and having a regenerator heat exchange coil carrying the working fluid passing from the condenser to the boiler,
• said at least one slide valve including an ejection port open to a closed thread of the expander intermediate of the expander inlet and outlet and being connected to said at least one regenerator for supplying partially expanded working fluid in vapor form to said regenerator for regeneratively heating the condensed working fluid within said regenerator heat exchange coil passing from the condenser to the boiler, and
• means for adding the condensed working fluid within the regenerator to said closed loop downstream of said at least one regenerator and for raising the pressure of said condensed working fluid of said regenerator to that of said closed loop.