System and method for turbocharging an engine

Abstract

A turbocharger system, in certain embodiments, includes a compressor, a turbine, a shaft coupling the compressor to the turbine, and a turbo casing configured to improve pressure recovery, wherein the turbo casing includes a non symmetrical geometry configured to improve flow towards an exhaust outlet.

1 . A turbocharger, comprising:
 a compressor comprising compressor blades;   a turbine comprising turbine blades;   a shaft coupling the compressor to the turbine; and   an exhaust diffuser disposed downstream from the turbine blades, wherein the exhaust diffuser comprises a bell mouth configured to reduce backpressure and improve an exhaust flow downstream;   a turbo-casing disposed downstream from the exhaust diffuser, wherein the turbo-casing comprises a torus-shaped chamber leading to an exhaust outlet disposed on and centered on a second side opposite from a first side, the torus-shaped chamber has a cross-sectional area that progressively increases by at least about 40 percent from a center of the first side in about the first 90 degrees in an annular direction toward the exhaust outlet in the second side.   
   
   
       2 . The turbocharger of  claim 1 , wherein the progressive increase in cross-sectional area is represented by an area ratio of the cross-sectional area of the torus-shaped chamber divided by a diffuser area of the bell mouth, and the area ratio is taken through planes at circumferential locations in a counterclockwise annular direction between about 60 and about 300 degrees relative to a vertical plane centered through the exhaust outlet in the second side, wherein the area ratio varies between about 0.42 and about 1.15. 
   
   
       3 . The turbocharger of  claim 1 , wherein a ratio of a length of the bell mouth in an axial direction to a turbine bucket height in direction generally crosswise to the bell mouth length is about 1.4 to about 3.4. 
   
   
       4 . The turbocharger of  claim 1 , comprising the turbo casing configured to improve pressure recovery, wherein the turbo casing expands in volume in a circumferential direction of flow through an annular chamber to an exhaust outlet. 
   
   
       5 . The turbocharger of  claim 1 , wherein an angle of an interior wall of the second side of the turbo casing is oriented at about 75 to 80 degrees relative to an axis through the shaft. 
   
   
       6 . The turbocharger of  claim 1 , wherein the bell mouth extends about 30-50% of the distance of the width of the turbo casing in a direction parallel to an axis of the shaft. 
   
   
       7 . The turbocharger of  claim 1 , comprising an engine coupled to the turbocharger system. 
   
   
       8 . The turbocharger of  claim 1 , wherein the turbine is configured to create a cavity within the turbo casing with a non symmetrical geometry. 
   
   
       9 . The turbocharger system of  claim 1 , wherein the turbo casing comprises a torus shaped cavity. 
   
   
       10 . A turbocharger, comprising:
 a compressor;   a turbine;   a shaft coupling the compressor to the turbine; and   a turbo casing configured to improve pressure recovery, wherein the turbo casing includes a non symmetrical geometry configured to improve flow towards an exhaust outlet.   
   
   
       11 . The turbocharger of  claim 10 , wherein the turbo casing comprises a torus shaped cavity, wherein a cross sectional area of the torus shaped cavity increases in a direction of exhaust flow towards an exhaust outlet, thereby reducing a flow separation. 
   
   
       12 . The turbocharger of  claim 11 , wherein an angle of an interior wall of the turbo casing is oriented at about 75 to 80 degrees relative to an axis through the shaft. 
   
   
       13 . The turbocharger system of  claim 10 , comprising an exhaust diffuser comprising a bell mouth, wherein the bell mouth and the turbine are configured to improve pressure recovery and enhance exhaust flow through a turbo casing. 
   
   
       14 . The turbocharger of  claim 13 , wherein a ratio of a length of the bell mouth in an axial shaft direction to a turbine bucket height in direction generally crosswise to the bell mouth length is about 1.4 to about 3.4. 
   
   
       15 . The turbocharger of  claim 13 , wherein the bell mouth extends about 30-50% of the distance of the width of the turbo casing in a direction parallel to an axis of the shaft. 
   
   
       16 . A method, comprising:
 flowing exhaust through an exhaust diffuser having a bell mouth configured to improve pressure recovery within a turbo machine; and   flowing the exhaust through an annular torus shaped chamber of a turbo casing having a cross sectional area that expands in a circumferential direction toward an exhaust outlet.   
   
   
       17 . The method of  claim 16 , comprising wherein flowing the exhaust through an annular torus shaped chamber comprises flowing the exhaust through a non symmetrical geometry of the turbo casing. 
   
   
       18 . The method of  claim 16 , wherein flowing the exhaust through an annular torus shaped chamber comprises flowing the exhaust through the chamber wherein a first area ratio at a portion of the chamber opposite the exhaust port is about 30-50% less than a second area ratio of the chamber at a circumferential location about 90 degrees relative to the first cross sectional area. 
   
   
       19 . The method of  claim 16 , wherein flowing the exhaust through an annular torus shaped chamber comprises flowing the exhaust through the chamber wherein an angle of an interior wall of the torus shaped chamber is oriented at about 75 to 80 degrees relative to an axis through a turbine shaft. 
   
   
       20 . The method of  claim 16 , wherein the bell mouth extends about 30-50% of the distance of the width of the turbo casing in a direction parallel to an axis of a turbine shaft