Rotary kinetic fluid motors or pumps – With diversely oriented inlet or additional inlet for...
Reexamination Certificate
1999-01-07
2001-05-01
Look, Edward K. (Department: 3745)
Rotary kinetic fluid motors or pumps
With diversely oriented inlet or additional inlet for...
C415S176000, C415S177000
Reexamination Certificate
active
06224329
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to the field of cooling of parts that are subjected to a high temperature environment; and more particularly to the cooling of those portions of a combustion or gas turbine that are exposed to hot combustion gases.
BACKGROUND OF THE INVENTION
Modern combustion turbine engines are being designed to operate at increasingly high combustion gas temperatures in order to improve the efficiency of the engines. Combustion temperatures of over 1,000 degrees C. necessitate the use of new superalloy materials, thermal barrier coatings, and improved component cooling techniques. It is known in the art to utilize a portion of the compressed air generated by the compressor as cooling air for convective cooling of selected portions of the turbine. However, the use of compressed air for this purpose decreases the efficiency of the engine, and therefore, designs that minimize the amount of such cooling air are desired. A typical prior art turbine may have a cooling path formed therein for the passage of cooling air from the compressor. However, as the air flows through the cooling path and removes heat energy from the component, the temperature of the cooling fluid rises. As a result, the effectiveness of the cooling air is higher at the inlet end of the cooling path and lower at the outlet end. This temperature gradient can generate additional stress loading within the component. To provide adequate cooling at the outlet end of the cooling flow path it is necessary to provide a flow rate through the flow path which is higher than necessary for the inlet end. As a result, an excessive quantity of cooling fluid is used and the component may be excessively cooled at the inlet end.
U.S. Pat. No. 5,100,291 issued on Mar. 31, 1992 to Glover discloses a cooling technique that addresses this problem. Glover describes a manifold for providing cooling air to a plurality of radial locations in a turbine, and for providing an immediate exit path for the spent cooling air away from the component being cooled. This approach distributes the cooling capacity more evenly throughout the component, but it requires the installation of additional hardware in the turbine to function as the inlet and exit flow paths.
U.S. Pat. No. 5,472,316 issued on Dec. 5, 1995, to Taslim et al discloses the use of turbulator ribs disposed on at least one side wall of a cooling path in order to promote heat transfer efficiency at selected locations along the flow path. The improvement of heat transfer efficiency results from both the turbulence effect and from the acceleration of the cooling fluid flow rate caused by the reduction in the cross sectional area of the flow path. The use of such turbulators will change the rate of temperature rise of a cooling fluid along a cooling flow path. It does not, however, solve the problem of an unacceptable increase in the temperature of the cooling fluid at the outlet end of the cooling path, nor the resulting excess cooling at the inlet end when the flow rate of the cooling fluid is increased to counteract this temperature rise.
Accordingly, it is an object of this invention to provide a method of cooling a portion of a combustion turbine engine that minimizes the amount of cooling air required and that avoids excessive levels of cooling at the inlet end of a cooling path. It is a further object of this invention to provide a method of cooling a portion of a combustion turbine engine that results in a minimum peak level of stress in the component.
SUMMARY
In order to achieve these and other objects of the invention, a method for cooling a portion of a turbine is provided having the steps of: providing a component for the turbine; forming a first cooling path through the component, the first cooling path having an inlet end and an outlet end; forming a second cooling path through the component, the second cooling path having an inlet end and an outlet end, the second cooling path outlet end being fluidly connected to the first cooling path at a junction point disposed between the inlet end and the outlet end of the first cooling path; providing a first cooling fluid to the inlet end of the first cooling path and directing the first cooling fluid along the first cooling path; providing a second cooling fluid at the inlet end of the second cooling path and directing the second cooling fluid along the second cooling path to join the first cooling fluid at the junction point; directing the first and the second cooling fluids to the outlet end of the first cooling path.
A further method according to this invention includes the additional steps of determining a peak design temperature for the surface of the component; and determining the location of the junction point and the flow rates of the first and the second cooling fluids such that no point on the surface exceeds the peak design temperature during the operation of the turbine, and such that the sum of the flow rates of the first and said second cooling fluids is minimized.
REFERENCES:
patent: 3689174 (1972-09-01), Rahaim et al.
patent: 3864056 (1975-02-01), Gabriel et al.
patent: 3880435 (1975-04-01), Thornbald
patent: 4180373 (1979-12-01), Moore et al.
patent: 4214851 (1980-07-01), Tuley et al.
patent: 4230436 (1980-10-01), Davison
patent: 4232527 (1980-11-01), Reider
patent: 4317646 (1982-03-01), Steel et al.
patent: 4526226 (1985-07-01), Hsia et al.
patent: 4551064 (1985-11-01), Pask
patent: 5039562 (1991-08-01), Liang
patent: 5081843 (1992-01-01), Ishibashi et al.
patent: 5100291 (1992-03-01), Glover
patent: 5273396 (1993-12-01), Albrecht et al.
patent: 5472313 (1995-12-01), Quinones et al.
patent: 5472316 (1995-12-01), Taslim et al.
patent: 5581994 (1996-12-01), Reiss et al.
patent: 5816777 (1998-10-01), Hall
patent: 43 26 801 (1995-02-01), None
patent: 0 690 205 (1996-01-01), None
Look Edward K.
McDowell Liam
Siemens Westinghouse Power Corporation
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