2. The device of claim 1 wherein said rotor exit nozzles are arranged to discharge tangentially backward and said nozzles are sized and shaped to provide for highest attainable exit velocity from said nozzles for said heating fluid, for the pressure differential between the entry and exit ends of said nozzles.

3. The device of claim 1 wherein said rotor exit nozzles arranged to discharge said heating fluid at highest attainable exit velocity for the pressure differential available between the entry and exit ends of said nozzles; and wherein a secondary rotor is provided with suitable vanes to convert the kinetic energy available in the heating fluid stream to power; with said secondary rotor being supported by shaft and bearings and being rotatably mounted and with means for passing said power to external load.

4. The device of claim 1 wherein said heating fluid radial velocity within said rotor cavity is maintained at less than 200 feet per second.

5. The device of claim 1 wherein said heating fluid enters said rotor as a gas, and wherein said heating fluid is condensed within said rotor cavity with the heat of vaporization of said heating fluid being passed to said working fluid being circulated within said heat exchanger.

6. The device of claim 1 wherein said heating fluid enters said rotor as a gas and wherein said heating fluid leaves said rotor nozzles as a gas, with minor amounts of liquid, if any.

7. The device of claim 1 wherein said heating fluid is a gaseous fluid with a low specific heat at constant pressure; with said specific heat being less than 1.2 British thermal units per pound.

8. The device of claim 1 wherein said heating fluid a halogenated hydrocarbon.

9. The device of claim 1 wherein said working fluid is water.

10. The device of claim 1 wherein said working fluid is a halogenated hydrocarbon.

11. The device of claim 1 wherein said rotor is provided with thermal insulation within said rotor near the periphery of said rotor, and wherein said rotor walls are in cantact with said heating fluid in the areas near the rotor center; the thermal insulation to reduce the loss of strength of said rotor construction material due to high temperatures.

12. The device of claim 1 wherein said heating fluid is supplied to said rotor from an external stationary heat exchanger, and is also passed from said device back to said external heat exchanger for the purpose of adding heat to said heating fluid, with said heating fluid being circulated in a closed loop.

13. The device of claim 1 wherein said heating fluid is ambient air.

14. The device of claim 1 wherein said heating fluid is provided with means, external to said device, for adding heat from water, at its natural temperature, to said heating fluid, with said heating fluid being circulated through said means.

15. The device of claim 1 wherein said flow of said working fluid is arranged within said heat exchanger to be outward from the center of said rotor toward rotor periphery thus having the said working fluid in parallel flow with said heating fluid during the period when heat is transferred from said heating fluid to said working fluid; said working fluid then being returned back to said rotor center directly from said rotor periphery.

16. The device of claim 1 wherein said heating fluid and the amount of heat removed from said heating fluid is selected to provide for a sufficiently high exit velocity from said rotor exit nozzles to generate sufficient work to overcome all rotor work losses and to make the work input to said rotor shaft during normal operation nil.