Fluid turbine with ejector shroud

Abstract

A fluid turbine comprises a turbine shroud and an ejector shroud. The turbine shroud has an axial length L M . The ejector shroud has an axial length L E . The ratio of L M to L E is from 0.05 to 2.5. In particular embodiments, the ejector shroud has an axial length L E , an outer diameter D I at the inlet end, and an outer diameter D E at the exhaust end. The ratio of L E to D I is from 0.05 to 3; and the ratio of L E to D E is from 0.05 to 3. The resulting ejector shroud is 30%-50% shorter than ejector shrouds of previous designs.

1 . A fluid turbine comprising a turbine shroud and an ejector shroud;
 wherein the turbine shroud has a front end and a rear end;   wherein the ejector shroud has an inlet end and an exhaust end;   wherein the rear end of the turbine shroud comprises a plurality of mixing lobes along a trailing edge, the mixing lobes extending into the inlet end of the ejector shroud;   wherein the turbine shroud has an axial length L M ;   wherein the ejector shroud has an axial length L E ; and   wherein the ratio of L M  to L E  is from 0.05 to 2.5.   
     
     
         2 . The fluid turbine of  claim 1 , wherein the ratio of L M  to L E  is from 0.16 to 2.1. 
     
     
         3 . The fluid turbine of  claim 1 , wherein the ejector shroud has an outer diameter D I  at the inlet end, and the ratio of L E  to D I  is from 0.05 to 3.0. 
     
     
         4 . The fluid turbine of  claim 1 , wherein the ejector shroud has an outer diameter D E  at the exhaust end, and the ratio of L E  to D E  is from 0.05 to 3.0. 
     
     
         5 . The fluid turbine of  claim 1 , wherein the turbine shroud has an outer diameter D F  at the front end, and the ratio of L M  to D F  is from 0.1 to 2.5. 
     
     
         6 . The fluid turbine of  claim 1 , wherein the turbine shroud has an outer diameter D RO  at the rear end, and the ratio of L M  to D RO  is from 0.1 to 1.25. 
     
     
         7 . The fluid turbine of  claim 1 , wherein the turbine shroud has an inner diameter D RI  at the rear end, and the ratio of L M  to D RI  is from 0.1 to 3.5. 
     
     
         8 . The fluid turbine of  claim 1 , wherein the rear end of the turbine shroud has an inner diameter D RI  and an outer diameter D RO , and the ratio of D RO  to D RI  is from 0.7 to 2. 
     
     
         9 . The fluid turbine of  claim 1 , wherein the fluid turbine has a total axial length L T , and the ratio of L M  to L T  is from 0.05 to 1.0. 
     
     
         10 . The fluid turbine of  claim 1 , wherein the fluid turbine has a total axial length L T , and the ratio of L E  to L T  is from 0.05 to 0.9. 
     
     
         11 . The fluid turbine of  claim 1 , wherein the ejector shroud has a ring airfoil shape and does not have mixing lobes. 
     
     
         12 . The fluid turbine of  claim 1 , wherein the plurality of mixing lobes includes a set of high energy mixing lobes and a set of low energy mixing lobes, the high energy mixing lobes having an angle of about 35° to about 50° relative to a longitudinal axis of the turbine shroud. 
     
     
         13 . A fluid turbine comprising a turbine shroud and an ejector shroud;
 wherein the turbine shroud has a front end and a rear end;   wherein the ejector shroud has an inlet end and an exhaust end;   wherein the rear end of the turbine shroud comprises a plurality of mixing lobes along a trailing edge, the mixing lobes extending into the inlet end of the ejector shroud;   wherein the turbine shroud has an axial length L M ;   wherein the ejector shroud has an axial length L E , an outer diameter D i  at the inlet end, and an outer diameter D E  at the exhaust end;   wherein the ratio of L M  to L E  is from 0.05 to 2.5;   wherein the ratio of L E  to D I  is from 0.05 to 3; and   wherein the ratio of L E  to D E  is from 0.05 to 3.