Patent ID: 7354245
Filing Date: 2008-04-08
Classification: F03D,F05B,Y02B,Y02E,Y10S

Abstract:
1. A wind power generation device comprising: a substaiitially cylindrical duct; an impeller having a plurality of blades protruding outward, said impeller being rotatable around a duct axis; and a nacelle that constitutes a streamlined pencil body together with said impeller and houses a generator that uses a torque of said impeller, wherein said duct has a side wall with a wing-shaped cross section, so as to be able to produce a reduced pressure area at a rear of said duct and prevent generation of swirl at the rear of said duct, wherein said pencil body is provided such that a forward end thereof is disposed inside of said duct and a rear end thereof protrudes outwardly from a rear end of said duct, so as to be close to a tip of the reduced pressure area produced at the rear of said duct, wherein blades of said impeller are provided in a maximum wind speed area in said duct, wherein a chord of said wing-shaped cross section of said side wall of said duct is inclined at a predetermined angle to the duct axis, and wherein a protruding length of the rear end of said pencil body from the rear of said duct is adjusted according to a position of the tip of said reduced pressure area, which changes depending on said predetermined angle, wherein said predetermined angle is a positive angle such that a leading edge of said chord at the front end of said duct is separated a greater distance from said duct axis than a trailing edge of said chord at the rear end of said, and wherein said predetermined angle is 2° to 12°, and the protruding length of said pencil body from the rear of said duct is 0.1 to 0.4 times a length of said duct.