Power plants – Combustion products used as motive fluid – Combustion products generator
Reexamination Certificate
1999-06-15
2001-02-27
Thorpe, Timothy S. (Department: 3746)
Power plants
Combustion products used as motive fluid
Combustion products generator
Reexamination Certificate
active
06192670
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
FIELD OF THE INVENTION
This invention relates generally to the field of turbines and power systems. Fuel fired internal combustion engines such as gas turbine engines utilize a working fluid, namely an air/fuel mixture, which changes composition during combustion to drive the turbine with hot expanded gases. A conventional gas turbine engine includes a compressor, a combustion chamber and a turbine made up of an arrangement of stators and rotors. Each of the rotors includes blades and a supporting disk. Ideally, for the optimum extraction of energy, the combustion process should occur at about 4000° Fahrenheit. However, as a practical matter due to metallurgical concerns, the components of a turbine must operate at considerably lower temperatures. Cooling of the stationary housing and stators in combustion chamber walls is relatively straightforward by any of a number of means; however the rotors, due to their high rotational speed, present many problems for conventional cooling.
Various approaches have been proposed for utilizing internal fluid cooling to more effectively cool engine parts such as combustion chamber walls, turbine rotors and stators. In the case of rotor blades, some approaches have involved the internal use of a vaporizable cooling fluid that travels from the root of the rotor out through the tip of the rotor blade. Another approach has been to utilize a closed cycle cooling system in which a cooling fluid occupies only a portion of an internal cavity in the blade and circulates as a heat exchange medium. The physical properties of the cooling fluid are such that it is vaporized in certain regions of the cavity by virtue of the operating temperature prevailing in those regions during normal operation of the engine. Applicant has previously obtained a patent, U.S. Pat. No. 5,299,418, which describes one particularly advantageous structure for closed circulation of a vaporizable liquid phase coolant within the cavity of a turbine blade. The improvement claimed in that patent involves a geometry for distributing coolant fairly uniformly over the inner surface of a blade in an axial-flow gas turbine so as to achieve a distributed cooling effect for the entire blade.
While that patent illustrates an axial flow turbine with its characteristic blade shape, other forms of turbine have a configuration entirely different and pose different challenges to implementing effective coolant circulation. Thus, for example, in a relatively common turbine architecture utilizing a centrifugal compressor with an annular combustion chamber to feed a radial flow turbine, the foregoing construction would find no application. Similarly, in the case of smaller turbines where a regenerative loop architecture is used to enhance heat efficiency of a radial flow turbine, the aforesaid patented construction would not apply.
Accordingly, it would be desirable to provide a system and construction for cooling the blades of a radial flow turbine so that the combustion process may be operated at higher temperatures without impairing the structural integrity of the turbine itself.
In general, it is an object of the invention to provide an internal combustion engine wherein higher combustion temperatures can be achieved while maintaining material temperatures at levels at least as low as those associated with known turbine engines.
Another object of the invention is to provide a radial flow gas turbine engine utilizing closed cycled evaporative cooling for the moving parts of the engine.
Still another object is to provide a rotor or rotor blade for use in a turbine of such an engine.
SUMMARY OF THE INVENTION
One or more of the above desirable objects are achieved in accordance with the present invention by a system including a radial flow turbine having an arrangement of one or more stators and rotors in which each of the rotors defines an internal cavity that includes a vaporization section and a condensation section. The condensation section is disposed radially inward toward the shaft and the vaporization section extends over the rotor in thermal proximity to the blades. The vaporization section includes a series of pockets or passages for dispersing the cooling fluid proximate to heated surfaces of each blade, and a cascaded series of catchment channels or protruding shelves to distribute coolant to the pockets. A working system includes a centrifugal compressor which feeds a compressed air/fuel mixture to an annular combustion chamber that, in turn, provides hot gases along a radial direction to impinge on the surface of a radial flow rotor. Optionally, the system is a regenerative system including a heat exchange sub-assembly which couples heat from the exhaust stream to a position between the compressor and combustion chamber.
REFERENCES:
patent: 2667326 (1954-01-01), Ledinegg
patent: 2737366 (1956-03-01), Ledinegg
patent: 2744723 (1956-05-01), Roush
patent: 2812157 (1957-11-01), Turunen et al.
patent: 2849210 (1958-08-01), Turunen et al.
patent: 2952441 (1960-09-01), Jones
patent: 3738771 (1973-06-01), Delarbre et al.
patent: 3842596 (1974-10-01), Gray
patent: 3902820 (1975-09-01), Amos
patent: 3963368 (1976-06-01), Emmerson
patent: 4022542 (1977-05-01), Barbeau
patent: 4118145 (1978-10-01), Stahl
patent: 4179240 (1979-12-01), Kothmann
patent: 4302153 (1981-11-01), Tubbs
patent: 4314794 (1982-02-01), Holden et al.
patent: 4330235 (1982-05-01), Araki
patent: 4422229 (1983-12-01), Sadler et al.
patent: 4437810 (1984-03-01), Pearce
patent: 4440834 (1984-04-01), Aubert et al.
patent: 4498301 (1985-02-01), Tsubouchi
patent: 4506634 (1985-03-01), Kerrebrock
patent: 4507051 (1985-03-01), Lesgourgues et al.
patent: 4522562 (1985-06-01), Glowacki et al.
patent: 4529358 (1985-07-01), Papell
patent: 4604031 (1986-08-01), Moss et al.
patent: 4648799 (1987-03-01), Brown et al.
patent: 4668162 (1987-05-01), Cederwall et al.
patent: 4898514 (1990-02-01), McCracken
patent: 5299418 (1994-04-01), Kerrebrock
Engellenner Thomas J.
Falkoff Michael I.
Nutter & McClennen & Fish LLP
Rodriguez William
Thorpe Timothy S.
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