Dual-use radial turbomachine

1. A method of constructing a turbine for use in a rankine cycle system having in serial flow relationship a pump, a boiler, a turbine and a condenser, comprising the steps of:

providing a volute for receiving a vapor medium from the evaporator and for conducting said vapor radially inwardly;

providing a plurality of nozzles circumferentially spaced and disposed around the inner periphery of said valuate for receiving a flow of vapor therefrom and conducting it radially inwardly; and

providing an impeller disposed radially within said nozzles such that the radial inflow of vapor from said nozzles impinges on a plurality of circumferentially spaced blades of said impeller to cause rotation of said impeller; wherein, the angle of said impeller blades is chosen according to the degree of lift for the intended application, such that for relatively low-lift application, the impeller blades are back swept, for intermediate-lift applications, the blades are radially disposed, and for relatively high-lift applications, the impeller blades are forward swept.

2. A method as set forth in claim 1 wherein said diffuser is a vaned diffuser.

3. A method as set forth in claim 2 wherein said diffuser is a pipe diffuser.

4. A method as set forth in claim 1 wherein said vapor is an organic refrigerant.

5. A method as set forth in claim 4 wherein said vapor is R-245fa.

6. A method as set forth in claim 1 wherein each of said plurality of nozzles has its radially inner and outer boundaries defined by R 1 and R 2 , respectively, and wherein R 2 /R 1 >1.25.

7. An organic rankine cycle system of the type having in serial flow relationship a pump, an evaporator, a turbine and a condenser, wherein said turbine comprises:

an arcuately disposed volute for receiving an organic refrigerant vapor medium from the evaporator and for conducting the flow of said vapor radially inwardly;

a plurality of nozzles circumferentially spaced and disposed around the inner periphery of said volute for receiving a flow of vapor therefrom and conducting it radially inwardly; and

an impeller disposed radially within said nozzles such that the radial inflow of vapor from said nozzles impinges on the plurality of circumferentially spaced blades on said impeller to cause rotation of said impeller; and

discharge flow means for conducting the flow of vapor from said turbine to the condenser;

wherein, said impeller blades are either back swept or forward swept

and further wherein each of said nozzles has its radially inner and outer boundaries defined by radii R 1 and R 2 , respectively, and wherein R 2 /R 1 >1.25.

8. An organic rankine cycle system as set forth in claim 7 wherein the application is for a relatively low lift application and further wherein said impeller blades are back swept.

9. An organic rankine cycle system as set forth in claim 7 wherein the application is for a relatively high lift application and further wherein said impeller blades are forward swept.

10. An organic rankine cycle system as set forth in claim 7 wherein said plurality of nozzles are of the vane type.

11. An organic rankine cycle system as set forth in claim 10 wherein said nozzles are each comprised of a frustro-conical passageway.

12. An organic rankine cycle system as set forth in claim 7 wherein the pressure of a vapor entering said volute is in the range of 180-330 psia.

13. An organic rankine cycle system as set forth in claim 7 wherein the saturation temperature of the vapor entering the volute is in the range of 210-270□F.

14. An organic rankine cycle system as set forth in claim 7 wherein the evaporator receives heat from an internal combustion engine.

15. An organic rankine cycle system as set forth in claim 14 wherein the heat derived from said internal combustion engine is derived from the exhaust thereof.

16. An organic rankine cycle system as set forth in claim 15 wherein the heat derived from said internal combustion engine is derived from its liquid coolant being circulated within said internal combustion engine.

17. An organic rankine cycle system as set forth in claim 7 wherein. said condenser is of the water cooled type.

18. An organic rankine cycle system as set forth in claim 7 wherein said organic refrigerant is R-245fa.