Rotary kinetic fluid motors or pumps – With passage in blade – vane – shaft or rotary distributor...
Reexamination Certificate
1998-03-16
2001-04-17
Verdier, Christopher (Department: 3401)
Rotary kinetic fluid motors or pumps
With passage in blade, vane, shaft or rotary distributor...
C415S116000, C415S117000, C415S176000, C416S095000, C416S09600A, C060S039010, C060S039780
Reexamination Certificate
active
06217280
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to cooling systems for use with turbine engines. More particularly, the invention relates to pressure changing mechanisms disposed in turbine engines for changing the pressure of a cooling medium that is flowing through the turbine engine. This invention also relates to methods and systems that employ the pressure changing mechanisms.
BACKGROUND OF THE INVENTION
Pressurized air is among the more common cooling mediums used to cool various components in gas turbine engines. Generally in such systems, compressed air is drawn from the combustor shell and traverses a closed loop cooling system in which the air cools components of the turbine engine, e.g., the vanes, the blades and the combustors. Typically, the air is first filtered and cooled before its use as a coolant. After being cooled, the air is directed to the components to be cooled, and then the air is returned to the discharge of the compressor or the combustor shell of the gas turbine engine.
In such a closed loop system, the cooling air must be sufficiently pressurized in order to re-enter the combustor shell or mix with the air discharged from the compressor. Unfortunately, within the cooling circuit, the air generally experiences a pressure loss. This pressure loss is caused by the resistance of bends, orifices and other obstructions. To overcome these pressure drops and increase the pressure of the cooling medium to approximately that of the combustor shell or the discharge of the compressor, the air coolant, in some applications, is routed out of the turbine engine to an external compressor before it is returned to the combustion turbine and eventually the combustor shell. In the external compressor, the air coolant may be compressed about 60 PSI. Significantly, external compressors are expensive components, with costs in the $300,000 range. Other costs are associated with the use of external compressors, e.g., back up compressors, piping, operation, maintenance, floor space and the like. Applicants have recognized that a turbine engine that internally provides the pressurization required for the air coolant to reenter the combustor shell would eliminate the need for external compressors, thereby providing substantial economic benefits.
Thus, there is a need for pressure changing mechanisms that function within turbines and compress the cooling medium and thereby eliminate the need for external compressors. There is also a need for improved systems and methods for using the pressure reducing mechanisms that operate within turbines.
SUMMARY OF THE INVENTION
A cooling circuit for a combustion turbine may include a compressor, a combustor shell, an external cooler, a component of the turbine to be cooled and the pressure changing mechanism of this invention. As is conventional with cooling circuits, a cooling medium flows from the compressor to the combustor shell. From the combustor shell, the cooling medium flows through the external cooler and the component of the turbine to be cooled. After flowing through the component of the turbine to be cooled the pressure of the cooling medium is less than that of the combustor shell. Therefore, in order to return the cooling medium to the combustor shell, the pressure of the cooling medium must be raised. This invention includes a pressure changing mechanism disposed within the combustion turbine and within the cooling circuit of the combustion turbine that increases the pressure of the cooling medium from the pressure at which it exits the component to be cooled to approximately the pressure of the combustor shell.
According to one aspect of this invention, the combustion turbine components that are cooled by the cooling circuit are the rotating blades disposed within the turbine section of the combustion turbine. In order to cool the rotating blades, the cooling circuit further includes a flow path defined within the rotating disks of the combustion turbine. In this type of cooling circuit, the cooling medium flows from the combustor shell through the rotating disks and then through the rotating blades. From the rotating blades, the cooling medium then flows through the pressure changing mechanism.
In a preferred embodiment of this invention the pressure changing mechanism includes a plurality of diffusing vanes that are disposed circumferentially around a torque tube casing of the combustion turbine. A diffusing channel is defined between every two diffusing vanes. The diffusing channels receives cooling medium after it has flowed through the rotating disks and blades of the combustion turbine. Preferably, the geometry of each of these diffusing vanes and channels is such that when it receives the cooling medium from each of the rotating blades and disks it increases the pressure of the cooling medium to approximately that of the combustor shell.
In order to change the pressure of the cooling medium, each diffusing vane is preferably curved and each of the diffusing channels has a portion of which has an increasing cross-sectional area. When the cooling medium enters the channels defined by the diffusing vanes it slows down in this portion of the channel that has an increasing cross sectional area. Because of this deceleration and subsequent decrease in velocity, the static pressure of the cooling medium is increased to approximate that of the combustor shell pressure.
In another preferred embodiment of this invention, the pressure changing mechanism includes a ring disposed within the torque tube casing of the combustion turbine. Defined within the ring are a plurality of diffusing channels. These channels are disposed between the rotating blades and the combustor shell so that the cooling medium flows from the rotating blades through the diffusing channels and into the combustor shell. Each of these diffusing channels has a geometry that causes the pressure of the cooling medium to approximate that of the combustor shell. Preferably, each of these diffusing channels has a receiving end and an exhausting end. The receiving end receives coolant from the rotating disks and blades, and the exhausting end exhausts cooling medium to the combustor shell. The cross-sectional area of the receiving end is preferably smaller than the cross-sectional area of the exhausting end, so that the cooling medium diffuses within the diffusing channel, and the static pressure of the cooling medium is thereby increased to approximately that of combustor shell pressure.
Other features of this invention are described below.
REFERENCES:
patent: 2648519 (1953-08-01), Campini
patent: 3826084 (1974-07-01), Branstrom et al.
patent: 4456427 (1984-06-01), Evans et al.
patent: 4910958 (1990-03-01), Kreitmeier
patent: 5120192 (1992-06-01), Ohtomo et al.
patent: 5226785 (1993-07-01), Narayana et al.
patent: 5269653 (1993-12-01), Evans
patent: 5394687 (1995-03-01), Chen et al.
patent: 5468125 (1995-11-01), Okpara et al.
patent: 5507620 (1996-04-01), Primoschitz et al.
patent: 5593274 (1997-01-01), Carreno et al.
patent: 5611197 (1997-03-01), Bunker
patent: 0 313 826 (1989-05-01), None
patent: 2 042 643 (1980-08-01), None
patent: WO 97/49902 (1997-12-01), None
Eckert Seamans Cherin & Mellott , LLC
Siemens Westinghouse Power Corporation
Verdier Christopher
LandOfFree
Turbine inter-disk cavity cooling air compressor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Turbine inter-disk cavity cooling air compressor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbine inter-disk cavity cooling air compressor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2530171