David S Little

US Patent:

6691519, Feb 17, 2004

Filed:

Jan 25, 2001

Appl. No.:

09/769973

Inventors:

David Allen Little - Oviedo FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

F02C 720

US Classification:

60798, 60805, 415912

Abstract:

A combustion turbine power plant includes a modular compressor assembly structured to enclose multiple configurations of vanes and blades, a modular combustor assembly structured to be disengagably coupleable to a fuel source, a modular first turbine assembly structured to enclose multiple configurations of vanes and blades, a modular diffuser, a modular second turbine unit, a work unit, and a modular heat exchange system. A work unit shaft is structured to have two ends that are disengagably coupleable to the modular second turbine unit and the work unit. A compressor turbine shaft is structured to have two ends that are disengagably coupleable to the modular compressor assembly and the modular compressor turbine assembly.

US Patent:

6796130, Sep 28, 2004

Filed:

Nov 7, 2002

Appl. No.:

10/289573

Inventors:

David Allen Little - Chuluota FL
Thomas E. Lippert - Murrysville PA

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

F02C 100

US Classification:

60782, 60723, 60805

Abstract:

A gas turbine combustion system and method used for generating electrical power includes a compressor that receives and compresses air. A first stage turbine nozzle is flowise connected to the compressor and receives a portion of the compressed air from the compressor within a first air flow. A torus configured combustion chamber is positioned around the first stage turbine nozzle and receives a portion of the compressed air from the compressor within a second air flow that is passed through the combustion chamber where air and fuel are mixed and combusted. The air is discharged at the first stage turbine nozzle to mix with the first air while achieving a dry low NOx combustion.

US Patent:

6968696, Nov 29, 2005

Filed:

Sep 4, 2003

Appl. No.:

10/654747

Inventors:

David Allen Little - Chuluota FL, US

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

F02C007/12

US Classification:

60772, 60782, 60806

Abstract:

Aspects of the invention relate to a turbine engine configuration and method for overcoming a turbine blade tip clearance problem that can arise when the turbine inlet temperature is maintained at a high level during part load operation of the turbine. Aspects of the invention relate to reducing rotor cooling air to a temperature below the design temperature level by using, for example, additional heat extraction devices or by reconfiguring or resizing existing heat exchanger devices. Upon exposure to the cooled air, the discs and blades of the turbine will shrink so as to provide a clearance between the blade tips and surrounding stationary support structure. The design rotor cooling air temperature can be from about 350 degrees Fahrenheit to about 480 degrees Fahrenheit. Aspects of the present invention can be used to decrease the rotor cooling air to about 150 degrees Fahrenheit at about 70 percent load.

US Patent:

7086233, Aug 8, 2006

Filed:

Nov 26, 2003

Appl. No.:

10/722977

Inventors:

Abdullatif Chehab - Oviedo FL, US
David A. Little - Chuluota FL, US

Assignee:

Siemens Power Generation, Inc. - Orlando FL

International Classification:

F02C 1/00

US Classification:

60772, 60782, 415116

Abstract:

Aspects of the invention relate to a turbine engine system and method for actively managing blade tip clearances during part load operation of the engine. Aspects of the invention relate to extracting a portion of the combustion gases from the combustor section of the engine and routing these heated gases to the blade rings or other stationary structure surrounding the turbine blades. Upon exposure to the combustion gases, which can be mixed with compressor exit air, the stationary structure will thermally expand, causing blade tip clearances to increase. Thus, concerns of blade tip rubbing are minimized. Once the engines achieves steady state operation, the flow of the combustion gases to the blade rings can be substantially restricted so that only compressor exit air is supplied to the stationary structure. Consequently, the stationary structure will contract and the blade tip clearances will decrease, thereby increasing the efficiency of the turbine.

US Patent:

7096673, Aug 29, 2006

Filed:

Oct 8, 2003

Appl. No.:

10/681397

Inventors:

David A. Little - Chuluota FL, US
Gerry McQuiggan - Orlando FL, US

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

F02C 7/18

US Classification:

60782, 785806

Abstract:

Aspects of the invention relate to methods and assemblies for improving the efficiency of a turbine engine through active management of blade tip clearances. In some designs, a portion of compressor exit air is routed to the rotor and discs of the turbine section. Aspects of the invention relate to treating the compressor exit air in light of the operating conditions of the engine. For instance, under base load or substantially steady state operation, a portion of compressor exit air can be routed to the rotor and discs without reducing the temperature of the compressor exit air. In such case, blade tip clearances will reduce, allowing for improved engine efficiency. Under part load or substantially transient operating conditions, a portion of compressor exit air can be cooled before it is supplied to the rotor and discs. As a result, the blade tip clearances increase, minimizing concerns of blade tip rubbing. Routing of the compressor exit air for cooling and bypass can be controlled by a valve.

US Patent:

7107773, Sep 19, 2006

Filed:

Sep 4, 2003

Appl. No.:

10/654748

Inventors:

David Allen Little - Chuluota FL, US

Assignee:

Siemens Power Generation, Inc. - Orlando FL

International Classification:

F02C 9/26

US Classification:

60773, 60746, 60776

Abstract:

Aspects of the invention relate to a method for facilitating the reduction of carbon monoxide emissions during part load operation of a turbine engine by holding high combustor temperatures. The combustor section of the turbine engine includes a plurality of combustors, each combustor having a pilot nozzle, a plurality of main nozzles circumferentially surrounding the pilot nozzle, and a premix ring. According to one aspects of the invention, a first pair of combustors are selected. Fuel can be substantially restricted from being supplied to the main nozzles and the premix ring of the selected combustors, while fuel continues to be supplied to the pilot nozzles of the selected combustors. Additional combustors can be selected and the supply of fuel can be selectively restricted as described above. The process can continue until there is substantially zero net power out of the engine.

US Patent:

7784261, Aug 31, 2010

Filed:

May 25, 2006

Appl. No.:

11/440838

Inventors:

David A. Little - Chuluota FL, US

Assignee:

Siemens Energy, Inc. - Orlando FL

International Classification:

F02C 3/16
F02C 6/18

US Classification:

60 39182, 60735

Abstract:

A combined cycle power plant () that is optimized to reduce total life cycle cost rather than only thermal efficiency. A steam bottoming cycle () is fed with exhaust gas () from a gas turbine topping cycle (). The topping cycle incorporates multiple stages of combustion in order to maintain a desired high temperature of the exhaust gas being delivered to the bottoming cycle while at the same time avoiding peak combustion temperatures that would produce undesirable levels of NOx emissions. Accordingly, no post-combustion exhaust gas treatment is needed. In one embodiment, an aspirated compressor () provides compressed air to a torus-configured combustion chamber () that is integrated with a first stage of vanes (), and a plurality of stages of in-situ reheat combustion () are utilized. In other embodiments, torus-configured combustion chambers may be utilized for more than one of the stages of combustion.

US Patent:

8075256, Dec 13, 2011

Filed:

Apr 29, 2009

Appl. No.:

12/432061

Inventors:

David A. Little - Chuluota FL, US

Assignee:

Siemens Energy, Inc. - Orlando FL

International Classification:

F01D 25/24

US Classification:

4151737, 4151731, 4151735, 415180, 415230

Abstract:

A seal assembly limits gas leakage from a hot gas path to one or more disc cavities in a gas turbine engine. The seal assembly includes a seal apparatus associated with a blade structure including a row of airfoils. The seal apparatus includes an annular inner shroud associated with adjacent stationary components, a wing member, and a first wing flange. The wing member extends axially from the blade structure toward the annular inner shroud. The first wing flange extends radially outwardly from the wing member toward the annular inner shroud. A plurality of regions including one or more recirculation zones are defined between the blade structure and the annular inner shroud that recirculate working gas therein back toward the hot gas path.