Wind turbine with mixers and ejectors

Abstract

A Mixer/Ejector Wind Turbine (“MEWT”) system is disclosed which routinely exceeds the efficiencies of prior wind turbines. Unique ejector concepts are used to fluid-dynamically improve many operational characteristics of conventional wind/water turbines for potential power generation improvements of 50% and above. Applicants' preferred MEWT embodiment comprises: an aerodynamically contoured turbine shroud with an inlet; a ring of stator vanes; a ring of rotating blades (i.e., an impeller) in line with the stator vanes; and a mixer/ejector pump to increase the flow volume through the turbine while rapidly mixing the low energy turbine exit flow with high energy bypass wind flow. The MEWT can produce three or more time the power of its un-shrouded counterparts for the same frontal area, and can increase the productivity of wind farms by a factor of two or more. The same MEWT is safer and quieter providing improved wind turbine options for populated areas.

1 . A fluid turbine, comprising:
 a turbine shroud with an inlet, an outlet, and a ring of mixer lobes arranged along a trailing edge;   means for extracting energy from a primary high energy fluid stream, the means for extracting energy being located within the turbine shroud;   an ejector shroud having an inlet and an outlet, the ejector shroud being located downstream of the turbine shroud and coaxial with both the turbine shroud and the turbine stage;   the turbine shroud, means for extracting energy, and ejector shroud being configured for exposure to ambient fluid flow.   
     
     
         2 . The fluid turbine of  claim 1 , wherein the inlet of the ejector shroud is downstream of the trailing edge of the turbine shroud. 
     
     
         3 . The fluid turbine of  claim 1 , wherein the inlet of the ejector shroud is separated from the trailing edge of the turbine shroud by a horizontal gap. 
     
     
         4 . The fluid turbine of  claim 1 , wherein the cross-sectional area ratio of the ejector shroud outlet and the turbine shroud outlet is between 1.5 and 3.0. 
     
     
         5 . The fluid turbine of  claim 1 , wherein the turbine shroud has between 6 and 14 mixer lobes. 
     
     
         6 . The fluid turbine of  claim 1 , wherein each mixer lobe has inner and outer trailing edge angles of between 5 and 25 degrees. 
     
     
         7 . The fluid turbine of  claim 1 , wherein the height-to-width ratio of the lobe channels of the mixer lobes is between 0.5 and 4.5. 
     
     
         8 . The fluid turbine of  claim 1 , wherein the length to distance (L/D) of the turbine is between 0.5 and 1.25. 
     
     
         9 . A horizontal axis fluid turbine supported by a vertical support shaft, the wind turbine comprising:
 a turbine shroud with an inlet, an outlet, and a ring of mixer lobes arranged along a trailing edge;   means for extracting energy from a primary high energy fluid stream, the means for extracting energy being positioned within the turbine shroud; and   an ejector shroud having an inlet and an outlet, the ejector shroud inlet being located downstream of the trailing edge of the turbine shroud;   wherein the turbine shroud defines (i) the primary high energy fluid stream that passes though the means for extracting energy and (ii) a secondary fluid stream that bypasses the means for extracting energy and enters the ejector shroud inlet.   
     
     
         10 . The fluid turbine of  claim 9 , wherein the inlet of the ejector shroud is downstream of the trailing edge of the turbine shroud. 
     
     
         11 . The fluid turbine of  claim 9 , wherein the inlet of the ejector shroud is separated from the trailing edge of the turbine shroud by a horizontal gap. 
     
     
         12 . A horizontal axis fluid turbine supported by a vertical support shaft, the wind turbine comprising:
 a turbine shroud comprising a ring of alternating mixer lobes arranged along a trailing edge, the trailing edge defining an outlet of the turbine shroud;   mounted within the turbine shroud, means for extracting energy from a primary high energy fluid stream flowing through the turbine shroud; and   an ejector shroud having an inlet and an outlet, the ejector shroud being located downstream of and coaxial with the turbine shroud;   wherein the turbine shroud defines (i) the primary fluid stream that passes though the means for extracting energy and (ii) a secondary fluid stream that bypasses the means for extracting energy and enters the ejector shroud inlet.   
     
     
         13 . The fluid turbine of  claim 12 , wherein the inlet of the ejector shroud is downstream of the trailing edge of the turbine shroud. 
     
     
         14 . The fluid turbine of  claim 12 , wherein the inlet of the ejector shroud is separated from the trailing edge of the turbine shroud by a horizontal gap. 
     
     
         15 . An axial flow fluid turbine comprising:
 a turbine shroud with an inlet, an outlet, and a ring of mixer lobes arranged along a trailing edge;   a single turbine stage mounted within the turbine shroud that is configured for exposure to ambient fluid flow; and   an ejector shroud downstream of and coaxial with the turbine shroud, the ejector shroud having an inlet and an outlet.   
     
     
         16 . The fluid turbine of  claim 15 , wherein the inlet of the ejector shroud is downstream of the trailing edge of the turbine shroud. 
     
     
         17 . The fluid turbine of  claim 15 , wherein the inlet of the ejector shroud is separated from the trailing edge of the turbine shroud by a horizontal gap. 
     
     
         18 . An axial flow fluid turbine, comprising:
 a contoured turbine shroud having an outlet, an inlet for receiving a primary fluid stream, and a ring of mixer lobes arranged around a trailing edge;   a single turbine stage within the primary duct that is configured for exposure to ambient fluid flow; and   an ejector shroud having an inlet and an outlet, the ejector shroud being downstream of the turbine shroud.   
     
     
         19 . The fluid turbine of  claim 18 , wherein the inlet of the ejector shroud is downstream of the trailing edge of the turbine shroud. 
     
     
         20 . The fluid turbine of  claim 18 , wherein the inlet of the ejector shroud is separated from the trailing edge of the turbine shroud by a horizontal gap. 
     
     
         21 . A method of increasing energy extraction from a fluid stream, comprising:
 receiving a fluid turbine comprising:
 a turbine shroud, the turbine shroud having an inlet, an outlet, and a ring of mixer lobes arranged along a trailing edge, and the turbine shroud defining a (i) primary high energy fluid stream that passes through the turbine shroud inlet and (ii) a secondary high energy fluid stream that passes around the turbine shroud; and 
 an ejector shroud having an inlet and an outlet; 
   placing the fluid turbine in a fluid stream;   extracting energy from the primary high energy fluid stream to form a primary low energy fluid stream;   directing the secondary high energy fluid stream and the primary low energy fluid stream into the ejector shroud inlet to be mixed together and increase the flow of the primary high energy fluid stream through the turbine shroud and increase energy extraction.   
     
     
         22 . The method of  claim 21 , wherein the mixer lobes direct the primary low energy fluid stream away from a central axis and direct the secondary high energy fluid stream towards the central axis.