US 6,884,021 B2Granted

Single cascade multistage turbine

AssigneeNational Aerospace Laboratory of Japan

InventorYoshio Saito

Life of this patent

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Abstract

This invention provides a single cascade multistage turbine that has a compact turbine structure having only a single cascade, and enables power to be extracted efficiently in the same way as a multistage turbine having multistage rotor vanes. The working fluid supplied through the supply duct 3 flows on one side of the single cascade of rotor vanes 2 to one part of the circumference direction of the rotor vanes 2, and after passing through the rotor vanes 2 it passes through the circulation ducts 4a and 4b and returns to the former side of the rotor vanes 2. The circulation ducts 4a and 4b consist of exhaust duct members 6a and 6b, return duct members 7a and 7b, and inflow duct members 8a and 8b. Using the circulation ducts 4a and 4b this circulation process is repeated at least once whereby the working fluid is again passed through the rotor vanes 2 at a slightly different position in the circumferential direction of the rotor vanes 2. Each time the working fluid is passed through the rotor vanes 2, the energy contained in the fluid can be efficiently extracted as torque of the rotor vanes 2.

Claims5

Dependent claims

A single cascade multistage turbine comprising:

a single cascade of rotor vanes;
two supply ducts for causing a working fluid to flow on one side of said rotor vanes to one part of the circumferential direction of said rotor vanes;
one or more circulation ducts each having an exhaust duct member through which said working fluid that has passed through said rotor vanes is drained out, a return duct member to return said working fluid to the former side of said rotor vanes, and an inflow duct member connected to said return duct member, which supplies said working fluid to said rotor vanes at a slightly different position in the circumferential direction of said rotor vanes;
two exhaust ports to discharge said working fluid that has returned through the last circulation duct of said circulation ducts and passed through said rotor vanes;
wherein said two supply ducts are disposed at 180° intervals in the circumferential direction, and said two exhaust ports are positioned on the opposite side in substantially intermediate positions in the circumferential direction of said supply ducts,
a plurality of said circulation ducts are disposed over the entire circumferential range of said rotor vanes, and
said rotor vanes are attached to the tips of moving vanes, and said moving vanes are driven directly to rotate by said working fluid.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/401,669Filed 31 Mar 2003
Priority: JP 2002-1005412 Apr 2002
Published: US 2003/0185680 A12 Oct 2003
Granted: 26 Apr 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

F02K 3/068
The plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type: being…
F01D 1/12
With stationary working-fluid guiding means and bladed or like rotor, e.g. multi-bladed impulse steam turbines: with repeated action on same blade…
F01D 5/022
Blade-carrying members, e.g. rotors: with concentric rows of axial blades
F01D 15/08
Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby: adaptations for driving, or combinations…