Power plants – Combustion products used as motive fluid – Multiple fluid-operated motors
Reexamination Certificate
1997-09-17
2001-04-17
Kim, Ted (Department: 3746)
Power plants
Combustion products used as motive fluid
Multiple fluid-operated motors
C060S039465
Reexamination Certificate
active
06216441
ABSTRACT:
TECHNICAL FIELD
This invention relates to fuel systems for gas turbine or combined cycle power plants and, more particularly, to a system where process gases used to fuel the gas turbine combustor are subjected to an initial clean-up system for the removal of inert gases.
BACKGROUND
Fuels used in gas turbines are typically hydrocarbons in the form of oil, or natural gas. The fuel to be used in any particular stationary plant is generally determined by economics and fuel availability. Industrial processes often create combustible by-product streams. Examples include sugar mill refuse; petroleum coke from oil refineries; steel mill blast furnace gases; sawmill wastes and so on, which also can be converted into gas turbine fuels. All fuels can be characterized by a heating value in terms of BTU's per pound. The heating value may be defined as the energy available in the products of combustion when being cooled back to a reference temperature, and typically runs about 18,500 BTU's per pound for a light fuel oil.
The form and quality of the by-product fuels available from industrial processes varies and may require further processing to be suitable for use in a gas turbine. For example, petroleum coke or refinery bottoms can be gasified to produce a mixture of CO and H
2
suitable for a gas turbine while allowing environmentally harmful contaminants (e.g., sulfur) to be removed. Even gaseous by-product fuels such as blast furnace gas need to be compressed to meet the needs of a gas turbine.
DISCLOSURE OF THE INVENTION
The present invention relates to the enrichment of by-product fuel gas such as blast furnace gas from a steel mill for combustion in a gas turbine, or gas turbine combined cycle plant. Even more specifically, the present invention relates to the removal of inert gases such as CO
2
from the by-product gas prior to, or part-way through, compression for combustion in a gas turbine or gas turbine combined cycle plant for fuel heating value enrichment, compression power reduction, and possibly gas clean-up system size reduction if located upstream. Thus, in addition to the usual gas clean-up system which removes dust, ash, sulfur, etc. from the process gas prior to introduction into the gas turbine combustion system, the present invention utilizes another clean-up system, located downstream or upstream of the conventionally located clean-up system, for the purpose of inert gas removal. The specific inert gas removal technique may be any of several commercially available systems. By removing inert gas from the by-product fuel gas, the heating value and flammability characteristics of the by-product fuel gas are significantly improved. Conventional practice has been to blend natural gas with the by-product gas to increase its heating value (enrich) and improve combustion characteristics.
Accordingly, in a first exemplary embodiment of the invention, the invention relates to a method of operating a gas turbine wherein by-product process gases are used as fuel in the gas turbine, an improvement comprising the steps of:
a) removing inert gases from the process gas;
b) raising the process gas to a minimum pressure if required; and
c) feeding the process gas to the gas turbine combustor.
In another aspect, the invention relates to a gas turbine or gas turbine combined cycle plant including one or more gas turbines, a supply of process gas to be used as fuel in the gas turbine(s); a gas enrichment station for removing inert gas from the process gas prior to or part-way through fuel gas compression; a gas clean-up station located upstream or downstream of the gas enrichment station; optionally, a heat recovery steam generator fed by the gas turbine exhaust to generate steam for a steam turbine; means for conducting exhaust gas from the gas turbine to the heat recovery steam generator, and a steam turbine. The bottoming portion of the gas turbine combined cycle may optionally employ a working fluid other than steam, such as the Kalina cycle using a mixture of NH
3
and H
2
O.
Other objects and advantages of the subject invention will become apparent from the detailed description which follows.
REFERENCES:
patent: 3853498 (1974-12-01), Bailie
patent: 3868817 (1975-03-01), Marion et al.
patent: 3930367 (1976-01-01), Gasaporli
patent: 4199327 (1980-04-01), Hempill et al.
patent: 4202167 (1980-05-01), Suggitt et al.
patent: 4285917 (1981-08-01), Knight
patent: 4524581 (1985-06-01), Cascone et al.
patent: 4631915 (1986-12-01), Frewer et al.
patent: 5104419 (1992-04-01), Funk
patent: 5268019 (1993-12-01), Rathbone
patent: 5517818 (1996-05-01), Leithner
patent: 5682737 (1997-11-01), Schmidli
patent: 2 442 216 (1980-06-01), None
Anand Ashok K.
Jandrisevits Michael
Luessen Hans Peter
Stats David Andrew
General Electric CO
Kim Ted
Nixon & Vanderhye
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