Method and apparatus for compressing gaseous fuel in a turbine engine

Abstract

A gas turbine engine includes a rotatable impeller having a plurality of vanes with inlet and outlet ends. A plurality of diffuser channels are spaced apart radially beyond the outlet ends. A movable source of gaseous fuel is positioned adjacent the inlet ends of the vanes. The movable source of gaseous fuel is movable as a function of the rotational speed of the impeller, whereby the flow of gaseous fuel injected from the movable source is ejected from the outlet ends of the vanes into a selected one of the plurality of diffuser channels to facilitate combustion.

What is claimed is:  
     
         1 . A gas turbine engine comprising: 
 a rotatable impeller having a plurality of vanes with inlet and outlet ends;    a plurality of diffuser channels spaced apart radially beyond said outlet ends;    a movable source of gaseous fuel positioned adjacent said inlet ends of said vanes for injecting gaseous fuel into the inlet ends so that the fuel will be compressed with air in the impeller and ejected into a selected one of said plurality of diffuser channels;    wherein said movable source of gaseous fuel is movable as a function of the rotational speed of the impeller, whereby the flow of gaseous fuel injected from said movable source is always directed into said selected one of the plurality of diffuser channels to facilitate combustion.    
     
     
         2 . The gas turbine engine of  claim 1 , wherein said movable source of gaseous fuel comprises a movable source of natural gas.  
     
     
         3 . The gas turbine engine of  claim 1 , further comprising a cylinder having a movable piston connected to said movable source, said cylinder being in fluid communication with said outlet ends to receive compressed impeller exhaust to move said movable piston, thereby adjusting the position of the movable source based upon exhaust pressure of the rotating impeller.  
     
     
         4 . The gas turbine engine of  claim 1 , further comprising a servomotor operatively connected with said movable source for moving said movable source.  
     
     
         5 . A method of compressing gaseous fuel in a gas turbine engine comprising: 
 a) rotating an impeller about an impeller axis of the gas turbine engine, wherein the impeller includes inlet and outlet portions at opposing ends of a plurality of vanes;    b) injecting gaseous fuel from a movable source of gaseous fuel into said inlet portions such that the fuel travels along said vanes and through the respective outlet portions to a selected one of a plurality of diffuser channels spaced apart radially beyond said outlet portions; and    c) adjusting the position of said movable source with respect to the impeller axis based upon the rotational speed of the impeller to ensure that the injected gaseous fuel enters said selected one of the diffuser channels as the rotational speed of the impeller is varied.    
     
     
         6 . The method of  claim 5 , wherein said adjusting step comprises rotating the movable source about said impeller axis.  
     
     
         7 . The method of  claim 5 , wherein said adjusting step comprises receiving pressurized air from the impeller in a cylinder having a piston connected to the movable source, thereby moving the movable source in response to exhaust pressure changes of the impeller.  
     
     
         8 . The method of  claim 5 , wherein said injecting step comprises injecting natural gas.