System and method for deicing wind turbine rotor blades

Abstract

A system and method for deicing a wind turbine rotor blade includes simultaneously directing heated air through an internal leading edge circulation loop and a separate internal trailing edge circulation loop within the rotor blade.

What is claimed is: 
     
         1 . A rotor blade for a wind turbine with integrated deicing capability, the rotor blade comprising:
 a blade root;   a blade tip;   a leading edge and a trailing edge extending between the blade tip and blade root;   structural members disposed within an internal volume of the rotor blade;   the structural members defining a leading edge fluid circulation loop and a separate trailing edge fluid circulation loop; and   a fluid handling system disposed within the internal volume of the rotor blade and configured with the structural members so as to direct a heated fluid medium through the leading edge and trailing edge fluid circulation loops.   
     
     
         2 . The rotor blade as in  claim 1 , wherein, the structural members define a span-wise extending middle circulation channel that is common to the leading edge and the trailing edge fluid circulation loops. 
     
     
         3 . The rotor blade as in  claim 2 , wherein the structural members comprise a first web disposed proximate to the leading edge and defining a leading edge channel of the leading edge fluid circulation loop, and a second web disposed proximate to the trailing edge and defining a trailing edge channel of the trailing edge fluid circulation loop, the middle circulation channel defined between the first and second webs. 
     
     
         4 . The rotor blade as in  claim 2 , wherein the fluid handling system comprises at least one fan heater disposed within the blade root so as to direct a heated outflow airstream through the leading edge and trailing edge fluid circulation loops. 
     
     
         5 . The rotor blade as in  claim 4 , wherein the fan heater is disposed so as to direct the outflow airstream along the middle circulation channel to adjacent the blade tip where the heated outflow airstream separates into separate return airstreams that flow through the leading edge and the trailing edge channels, respectively, back to the blade root. 
     
     
         6 . The rotor blade as in  claim 4 , wherein the fan heater is disposed so as to direct the outflow airstream as separate streams through the leading edge and trailing edge channels, wherein the separate streams combine adjacent the blade tip into a single return airstream through the middle circulation channel and back to the blade root. 
     
     
         7 . The rotor blade as in  claim 4 , wherein the heated outflow airstream is a single airstream within the middle circulation channel such that the leading edge and the trailing edge fluid circulation loops share a combined outflow portion through the middle fluid circulation channel. 
     
     
         8 . The rotor blade as in  claim 4 , further comprising separating structure within the middle circulation channel such that the leading edge and the trailing edge fluid circulation loops have separate flow portions along at least a portion of the middle circulation channel. 
     
     
         9 . The rotor blade as in  claim 8 , wherein the separating structure extends from the blade tip into the middle circulation channel. 
     
     
         10 . The rotor blade as in  claim 8 , wherein the separating structure extends completely through the middle circulation channel and divides the middle circulation channel into separate flow channels, and further comprising a separate respective fan heater disposed within the blade root for each of the separate flow channels, wherein airflow through the leading edge and the trailing edge fluid circulation loops is independently controllable. 
     
     
         11 . The rotor blade as in  claim 3 , wherein the webs comprise airflow passages defined therethrough along a span-wise portion of the webs adjacent the blade tip. 
     
     
         12 . A method for deicing a wind turbine rotor blade, the method comprising directing heated air through an internal leading edge circulation loop and a separate internal trailing edge circulation loop within the rotor blade. 
     
     
         13 . The method as in  claim 12 , further comprising directing the heated air through a middle circulation channel that is common to the leading edge and the trailing edge circulation loops. 
     
     
         14 . The method as in  claim 13 , wherein the heated air is directed as an outflow airstream from one or more fan heaters disposed in a root area of the rotor blade through the middle circulation channel towards a tip area of the rotor blade, wherein the outflow airstream is directed at the tip area into separate return airstreams through respective leading and trailing edge channels within the rotor blade. 
     
     
         15 . The method as in  claim 14 , wherein the outflow airstream is maintained as a single combined airstream through the middle circulation channel or is maintained as separate airstreams through the middle circulation channel. 
     
     
         16 . The method as in  claim 14 , wherein airflow through the respective leading edge and trailing edge circulation loops is independently controlled. 
     
     
         17 . The method as in  claim 13 , wherein the heated air is directed as separate outflow airstreams from one or more fan heaters disposed in a root area of the rotor blade through respective leading and trailing edge channels within the rotor blade towards a tip area, wherein the outflow airstreams are directed at the tip area through the middle circulation channel back to the root area of the blade. 
     
     
         18 . The method as in  claim 17 , wherein the separate outflow airstreams are combined into a single return airstream in the middle circulation channel. 
     
     
         19 . The method as in  claim 12 , further comprising directing the heated air through a middle circulation channel that is common to the leading edge and the trailing edge circulation loops, and using separating structure that extends from the blade tip at least partially into the middle circulation channel to separate the heated air into separate airstreams. 
     
     
         20 . The method as in  claim 12 , wherein a span-wise extending middle circulation channel is common to the leading edge and the trailing edge fluid circulation loops, the middle circulation channel defined by a first web disposed proximate to the leading edge and a second web disposed proximate to the trailing edge, the method further comprising directing the heated air through airflow passages defined in the first and second webs along a span-wise portion of the webs adjacent the blade tip.