Power plants – Combustion products used as motive fluid
Reexamination Certificate
1997-12-02
2001-01-23
Casaregola, Louis J. (Department: 3746)
Power plants
Combustion products used as motive fluid
Reexamination Certificate
active
06176075
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to gas turbine engines and more particularly to improved methods and apparatus for cooling the combustor and combustion gases of a gas turbine engine.
It is important to provide cooling for the combustor and combustion gases of a gas turbine engine in order to maintain the combustor, turbine, and combustion gas conduits of the engine below the temperature at which thermal failure occurs and to also limit the formation of nitric oxide (NO
x
). Various methods and apparatus have been utilized in the past to achieve combustor and combustion gas cooling including passage of cooling air over and through the combustor, the injection of steam into the combustor cooling air, the injection of a water spray into the combustor cooling air, and various combinations of these methodologies and apparatuses. Whereas these prior art methodologies are useful in lowering the temperature of the combustor and combustion gases, the cooling is achieved through losses in the overall engine system since the work required to deliver the primary coolant, air, is excessive, and the quantity of energy recoverable with the small steam and/or water injection rates permitted is negligible.
SUMMARY OF THE INVENTION
This invention is directed to the provision of an improved gas turbine engine assembly.
More specifically, this invention is directed to the provision of an improved combustor for a gas turbine engine assembly.
Yet more specifically, this invention is directed to the provision of an improved method and apparatus for cooling the combustor and combustion gases of a gas turbine engine assembly.
The invention discloses a method of cooling the combustor and combustion gases of a gas turbine engine assembly of the type including a turbine and a combustor arranged to receive a fuel/air mixture and generate products of combustion within the combustor for delivery to the turbine.
According to the invention, a fluid is delivered to the combustor by a pump and is placed in heat exchange relation with the combustion products within the combustor so that thermal energy is absorbed from the combustion products by the fluid, and the fluid is thereafter injected into the combustion products for delivery with the combustion products to the turbine. This methodology allows combustor cooling to be achieved with a minimum of energy loss in the total system, thereby maximizing the overall efficiency of the total system.
In one embodiment of the invention, liquid is delivered to the combustor where it is placed in heat exchange relation with the combustion products before being injected into the combustion gases as liquid.
In a further embodiment of the invention, liquid id delivered to the combustor where it is placed in heat exchange relation with the combustion products before being injected into the combustion gases as gas or vapor.
In a further embodiment of the invention, gas or vapor is delivered to the combustor where it is placed in heat exchange relation with the combustion products before being injected into the combustion gases as gas or vapor.
According to a further feature of the invention methodology, the combustor has a central combustion chamber for containing the combustion products and an annular cooling chamber in surrounding relation to the central combustion chamber and having apertures communicating with the central combustion chamber; the step of placing the fluid in heat exchange relation with the combustion gases comprises delivering the fluid to the annular cooling chamber in its low energy liquid phase; condition; the conversion of the fluid to a higher level of energy occurs in the annular cooling chamber; and the step of injecting the fluid into the combustor comprises passing the fluid in its relatively high energy condition through the apertures and into the central combustion chamber.
According to a further feature of the invention, the turbine engine assembly includes a shaft driven by the turbine engine assembly includes a shaft driven by the turbine and a pump driven by the shaft and the fluid is delivered to the combustor by the pump.
The invention also provides an improved combustor for generating combustion products for delivery to a gas turbine. The improved combustor includes a central combustion chamber defining a central axis; a burner positioned to deliver products of combustion to one end of the chamber; a discharge at the other end of the chamber for delivering the combustion products to the turbine; and annular cooling chamber in surrounding relation to the central combustion chamber; an entry opening in the cooling chamber for receipt of a cooling liquid; and a plurality of apertures communicating the cooling chamber with the central combustion chamber. This combustor construction allows the cooling fluid to be placed in heat exchange relation to the combustor so that thermal energy is absorbed from the combustion products within the combustor before the fluid is injected in to the combustor through the apertures interconnecting the cooling chamber and central combustion chamber.
According to a further feature of the invention, the combustor is positioned with its central axis generally vertical; the burner is proximate the lower end of the combustion chamber; the discharge is proximate the upper end of the combustion chamber; and the entry opening in the cooling chamber is proximate the lower end of the combustion chamber. This specific arrangement and orientation of the combustor facilitates the placement of the cooling fluid in heat exchange relation to the combustion chamber.
The invention also provides an improved gas turbine engine assembly. The improved gas turbine engine assembly includes a turbine driving a shaft; a combustor operative to generate products of combustion for delivery to the turbine; a source of cooling liquid; and a pump driven by the turbine shaft, having an inlet connected to the liquid source, and having an outlet connected to the combustor. This arrangement allows a cooling liquid to be delivered to the combustor by a pump driven by the turbine, to improve the overall efficiency of the assembly.
According to a further feature of the invention, the combustor includes a central combustion chamber and an annular cooling chamber in surrounding relation to the central combustion chamber and connected to the combustion chamber by a plurality of apertures; the pump outlet is connected to the cooling chamber of the combustor by conduit means; and the assembly further includes a heat exchanger in the conduit means the heat exchanges receiving the discharge of the turbine. This arrangement allows the energy content of the cooling fluid to be increased by utilizing the waste products of the turbine.
According to a further feature of the invention, the assembly further includes means for delivering further energy to the fluid flowing through the conduit means. In the disclosed embodiment of the invention, the energy delivery means comprises a boiler arranged in the conduit interconnecting the pump to the cooling chamber of the combustor.
REFERENCES:
patent: 864017 (1907-08-01), Miller
patent: 1828784 (1931-10-01), Perrin
patent: 2168313 (1939-08-01), Bichowsky
patent: 2322987 (1943-06-01), West
patent: 2523656 (1950-09-01), Goddard
patent: 2636345 (1953-04-01), Zoller
patent: 2770097 (1956-11-01), Walker
patent: 3101592 (1963-08-01), Robertson et al.
patent: 3238719 (1966-03-01), Harslem
patent: 3359723 (1967-12-01), Bohensky et al.
patent: 3369361 (1968-02-01), Craig
patent: 4041699 (1977-08-01), Schelp
patent: 4527514 (1985-07-01), Niggemann
patent: 5055030 (1991-10-01), Schirmer
patent: 5461854 (1995-10-01), Griffin
patent: 1476902 (1969-10-01), None
patent: 316132A (1989-05-01), None
patent: 271706 (1927-05-01), None
patent: 283290 (1928-01-01), None
1991 ASME Cogen-Turbo, vol. 6, A Study on Modified Gas Turbine Systems with Steam Injection or Evaporative Regeneration, K. Annerwall and G. Svedberg, Sep. 1991.
A Novel Heat-Recovery Process for Improving the Thermal Efficiency of Gas Turbines in Elect
Casaregola Louis J.
Harness Dickey & Pierce PLC
LandOfFree
Combustor cooling for gas turbine engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Combustor cooling for gas turbine engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Combustor cooling for gas turbine engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2521372