Fluid injection and injection method

Information

  • Patent Grant
  • 6802178
  • Patent Number
    6,802,178
  • Date Filed
    Thursday, September 12, 2002
    22 years ago
  • Date Issued
    Tuesday, October 12, 2004
    20 years ago
Abstract
There are provided an injector and an associated method for injecting and mixing gases, comprising a carbonaceous fuel and oxygen, in a combustion chamber of a combustion device. The injector has jets, which can be used to separately inject different combustion fuels. The injector is compatible with combustion devices that inject only gases, for example, a reheater that provides initial combustion in a power generation cycle or a reheater that recombusts a discharged gas from a gas generator and turbine. Further, the injector defines an annular space through which a recycle gas can be injected into the combustion chamber to lower the combustion temperature.
Description




BACKGROUND OF THE INVENTION




This invention relates generally to apparatuses and methods for injecting fluids and more specifically to an injector and associated method for injecting combustion fluids into a combustion chamber.




DESCRIPTION OF RELATED ART




The combustion of carbon-based compounds, or carbonaceous fuels, is widely used for generating kinetic and electrical power. In one typical electric generation system, a carbonaceous fuel such as natural gas is mixed with an oxidizer and combusted in a combustion device called a gas generator. The resulting combusted gas is discharged to, and used to rotate, a turbine, which is mechanically coupled to an electric generator. The combusted gas is then discharged to one or more additional combustion devices, called reheaters, where the combusted gas is mixed with additional fuel and/or oxidizer for subsequent combustion. The reheaters, which typically generate pressures lower than those found in the gas generator, discharge the reheated gas to one or more turbines, which are also coupled to the electric generator.




The combustion in the gas generator and reheaters results in high temperatures and pressures. In some low-emission systems, pure oxygen is used as the oxidizer to eliminate the production of nitric oxides (NOx) and sulfur oxides (SOx) that typically result from combustion with air. Combustion of carbonaceous gases with pure oxygen can generate combustion temperatures in excess of 5000° F. Such extreme conditions increase the stress on components in and around the combustion chambers, such as turbine blades and injectors. The stress increases the likelihood of failure and decreases the useful life of such components.




Injectors are used to inject the combustion components of fuel and oxidizer into the gas generator and the combusted gas, fuel, and/or oxidizer into the reheaters. Because of their position proximate to the combustion chamber, the injectors are subjected to the extreme temperatures of the combustion chamber. The injectors may also be heated by the passage of preheated combustion components therethrough. Failure of the injectors due to the resulting thermal stress caused by overheating increases operating costs, increases the likelihood of machine downtime, and presents an increased danger of worker injury and equipment damage.




One proposed injector design incorporates a mixer for combining a coolant with the fuel before the fuel is combusted. For example, U.S. Pat. No. 6,206,684 to Mueggenburg describes an injector assembly 10 that includes two mixers 30, 80. The first mixer 30 mixes an oxidizer with a fuel, and the second mixer 80 mixes coolant water with the prior mixed fuel and oxidizer. The mixture then flows through a face 121 to a combustion chamber 12 for combustion. The coolant water reduces the temperature of combustion of the fuel and, thus, the stress on system components. One danger presented by such a design is the possibility of “flash back,” or the combustion flame advancing from the combustion chamber into the injector. Flash back is unlikely in an injector outlet that has a diameter smaller than the mixture's “quenching distance.” Thus, flash back can be prevented by limiting the size of the injectors. Undesirably, however, a greater number of small injectors is required to maintain a specified flow rate of the combustion mixture. The increased number of injectors complicates the assembly. Small injectors are also typically less space-efficient because the small injectors require more space on the face than would a lesser number of large injectors that achieve the same flow rate. Space on the face is limited, so devoting more space to the injectors leaves less space for other uses, such as for mounting other components. The small injectors are also subject to further complications due to their size. For example, small passages and outlets in the injectors can become blocked by particulates present in the fuel, oxidizer, or coolant. Thus, the reactants must be carefully filtered before passing through the injector. Moreover, typical reheaters are not designed to accommodate liquids, so the coolant water cannot be used in them.




In another proposed oxygen-fed combustion cycle, the gas generator is eliminated and gaseous combustion components are provided for initial combustion in a gas turbine combustor. The gas turbine combustor, sometimes also called a reheater, is similar to the reheater of the conventional cycle described above in that all of the inputs are in gaseous form. Cooling is achieved by diluting the combustion components with recirculated flue gas comprising steam and carbon dioxide. The flue gas dilutes the oxygen content in the combustion device and thus the combustion temperature. One such cycle, described as “Combined Cycle Fired with Oxygen,” is discussed in “New Concepts for Natural Gas Fired Power Plants which Simplify the Recovery of Carbon Dioxide,” by Bolland and Saether, Energy Conversion Management, Vol. 33, No. 5-8, pp. 467-475 (1992). Advantageously, this cycle effectively reduces combustion temperatures, and the elimination of the gas generator simplifies the system. No special turbines are required for receiving hot gases from a gas generator, and the gas turbine combustor can discharge to a turbine that is designed for use with a conventional reheater. However, the gas turbine combustor is incompatible with the injectors designed for conventional gas generators, which provide inadequate flow rates and do not provide recirculated gases to the combustion chamber. Further, injectors for gas generators are typically designed to operate at the higher operating pressures found in a gas generator and are inoperable or inefficient when used in a lower pressure gas turbine combustor or reheater. Nor is the gas turbine combustor compatible with injectors designed for conventional reheaters, because the gas turbine combustor requires a lower pressure drop across the injectors than that provided in conventional reheaters.




Moreover, as the availability and price of various combustion fuels change, it is sometimes desirable to change the type of combustion fuel that is used. However, because different combustion fuels have different characteristics, such as heating values, conventional injectors must be adjusted or replaced in order to provide efficient service with the different fuels. Thus, changing the type of fuel that is combusted in a system requires servicing the injectors and thereby interrupting service, reducing output, and increasing costs.




Thus, there exists a need for an apparatus and method for injecting fluid components of combustion into a combustion chamber of a combustion device. The apparatus and method should provide for injection of a recirculated gas to limit the temperature of the injector to decrease thermal stress, likelihood of failure, and operating costs. The injectors should be compatible with combustion devices that inject gaseous coolants, including reheaters, and should provide efficient injection and mixture of combustion gases of various types and heating values.




BRIEF SUMMARY OF THE INVENTION




The present invention provides an injector and an associated method for injecting and mixing gases, comprising a carbonaceous fuel and oxygen, into a combustion chamber of a combustion device. The injector may have an annular space proximate to its perimeter, through which a recycled mixture of steam and carbon dioxide can be injected to limit the combustion temperature, thereby decreasing thermal stress on components in and around the combustion chamber. Further, the injector has different jets, which can be used to separately inject different combustion fuels. Thus, the same injector can permit different combustion fuels to be alternatingly injected, each under the proper conditions. The injector is compatible with combustion devices that inject only gaseous fluids, including a reheater. The injector can be used in a reheater that recombusts a combusted gas that is discharged from a gas generator and turbine. Alternatively, the injectors can be used in a reheater that is the initial combustion device in a power generation cycle.




According to one aspect of the present invention, there is provided an injector for injecting combustion fluids into a combustion chamber. The injector includes an injector body that defines an injector face facing the combustion chamber, a main bore, and at least one main jet extending from the injector face to the main bore. A first plurality of fuel jets extend from the injector face and are fluidly connected to a first fuel inlet, typically by means of a first fuel manifold. Similarly, a second plurality of fuel jets extend from the injector face and are fluidly connected to a second fuel inlet, typically by means of a second fuel manifold. The central axis of each of the fuel jets defines a converging angle relative to one of the main jets such that fluid flowing from the fuel manifolds into the combustion chamber through the fuel jets impinges on a stream of fluid flowing from the respective main jet. The converging angle may be between about 10° and 45° such that convergence occurs in the combustion chamber. According to other aspects of the invention, a center of each of the main jets is located at least about 4 inches from the centers of the other main jets, and each of the main jets has a diameter of at least about 1 inch.




The main bore may be fluidly connected to a source of oxidizing fluid substantially free of nitrogen and sulfur, the first fuel manifold may be fluidly connected to a first source of fuel, including hydrogen and carbon monoxide, and the second fuel manifold may be fluidly connected to a second source of fuel, including methane. Each of the first and second manifolds comprise an annular space that extends circumferentially around at least one of the main jets. In another embodiment, each of the second fuel jets may be smaller in cross sectional area than each of the first fuel jets. As such the fuel jets may be tailored to the delivery requirements necessary for the particular type of fuel to be injected via the fuel jets.




In one advantageous embodiment, the injector also includes a first sleeve that defines an interior space. The injector body is positioned in the interior space such that a first annular space is defined between the injector body and the first sleeve. In one aspect of the invention, the first annular space is fluidly connected to a source of a recycle gas comprising steam and carbon dioxide. In another aspect, the injector includes a recycle gas inlet and a second sleeve which defines a second annular space between the first and second sleeves. The first sleeve defines at least one first sleeve aperture fluidly connecting the first annular space to the second annular space, and the second sleeve defines at least one second sleeve aperture fluidly connecting the second annular space to the recycle gas inlet. In a further aspect, the injector includes a circumferential passage that extends along the perimeter of the second sleeve and fluidly connects the second annular space to the recycle gas inlet so that gas enters the recycle gas inlet and flows generally in a first direction in the second annular space and a second, generally opposite, direction in the first annular space. According to another aspect of the invention, the injector body also defines a coolant chamber that is configured to receive and circulate a coolant fluid.




The present invention also provides a method of injecting combustion fluids into a combustion chamber. At least one stream of oxidizing fluid, including oxygen and substantially free of nitrogen and sulfur, is injected into the combustion chamber. The oxidizing fluid may be injected in streams located with at least about 4 inches between their centers, and each stream may have a diameter of at least about 1 inch. A first combustion fuel and a second combustion fuel are alternatingly injected through fuel jets into the combustion chamber and impinged on the stream of oxidizing fluid. The fuel can be injected through a manifold defining an annular space that extends circumferentially around at least one of the main jets, and can be injected at a converging angle between about 10° and 45° relative to the stream of oxidizing fluid such that convergence occurs in the combustion chamber. The method also includes combusting the fuel with the oxygen. In one aspect of the present invention, a recycle gas including steam and carbon dioxide is injected into the combustion chamber through a first annular space at an inside perimeter of the combustion chamber, for example, to limit the combustion temperature to about 4000° F. In another aspect, a coolant fluid is circulated through at least one coolant chamber in an injector body.




Thus, the present invention provides an injector and method for injecting combustion fluids, for example, into a gas generator or reheater, through a first and second plurality of fuel jets. Different combustion fluids can be injected through fuel jets and combusted efficiently, thereby increasing the versatility of the injector and decreasing the necessity of replacing or modifying the injector. Additionally, the injector and method limit the temperature of the injector and decrease the thermal stress on the components, thereby decreasing the likelihood of failure and the operating costs.











BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)




Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:





FIG. 1

is a partial cut-away isometric view of an injector according to the present invention;





FIG. 2

is another partial cut-away isometric view of the injector of

FIG. 1

;





FIG. 3

is an elevation view of the injector of

FIG. 1

;





FIG. 4

is a partial cross-sectional view of the injector of

FIG. 3

as seen from line


4


-


4


; and





FIG. 5

is a schematic of a power generation cycle that is compatible with the injector of the present invention.











DETAILED DESCRIPTION OF THE INVENTION




The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.




There is shown in

FIG. 1

an injector


10


according to the present invention, which is used to inject fluids into a combustion chamber


100


. The injector


10


has an injector body


14


with an injector face


12


that is oriented towards the combustion chamber


100


. The injector body


14


also includes a plurality of jets


20


,


32


,


52


that are fluidly connected to one or more inlets


18


,


34


,


54


as discussed further below. The fluids enter the injector body


14


through the inlets


18


,


34


,


54


and are injected into the combustion chamber through the jets


20


,


32


,


52


. A first sleeve


80


, which is generally shown as a hollow cylindrical tube, surrounds the injector body


14


and defines part of the combustion chamber


100


. A first annular space


82


is defined between the outside of the injector body


14


and the inside of the first sleeve


80


. A recycle gas inlet


84


, which is fluidly connected to the first annular space


82


, supplies a recycle gas through the annular space


82


to the inside perimeter of the first annular space


82


and the combustion chamber


100


.




The combustion that results in the combustion chamber


100


is a combustion of a fuel and oxygen. The fuel can be, for example, a carbonaceous gas such as methane, ethane, propane, or a mixture of hydrocarbons and may be derived from crude oil or a biomass fuel. Two advantageous carbonaceous fuels are methane and a synthesis gas, or syngas, which includes hydrogen and carbon monoxide. The carbonaceous fuel can be in liquid, gaseous, or combined phases. The oxygen is supplied in an oxidizing fluid. In one advantageous embodiment of the invention, the carbonaceous fuel and the oxygen are supplied in gaseous form and substantially free of nitrogen and sulfur. In the context of this patent, the phrase “substantially free of nitrogen and sulfur” indicates a combined content of less than 0.1 percent nitrogen and sulfur by weight and preferably less than 0.01 percent. Oxygen can be separated from atmospheric air according to methods known in the art and may include trace gases, such as argon.




The combustion of fuel and oxygen in the combustion chamber


100


generates a combusted gas and causes an increase in temperature and gas volume and a corresponding increase in pressure. The combusted gas is discharged to a power take-off device, such as a turbine, and useful energy is generated for use or storage. For example, the turbine can be coupled to an electric generator, which is rotated to generate electricity.




As shown in

FIG. 2

, the oxidizing fluid is supplied through the main inlet


18


to a main bore


16


of the injector body


14


. The oxidizing fluid flows from the main bore


16


through the injector face


12


and into the combustion chamber


100


via a plurality of main jets


20


. Six main jets


20


are shown in the illustrated embodiment, but any number of jets


20


may be provided. The diameter of the main jets


20


is chosen so that predetermined flow rates of oxidizing fluid through the main jets


20


can be achieved by supplying the oxidizing fluid to the main inlet


18


at predetermined pressures higher than the pressure in the combustion chamber


100


. In one advantageous embodiment, each of the main jets


20


has a diameter at the injector face


12


of at least about 1 inch, and a center of each of the main jets


20


is at least about 4 inches from the centers of the other main jets


20


. The oxidizing fluid flows into the combustion chamber


100


as streams emitted from the main jets


20


, which, in the illustrated embodiment, are generally oriented parallel to a central axis that extends lengthwise through the main bore


16


of the injector body


14


.




A first fuel enters the first fuel inlet


34


and flows through a first fuel downcomer


38


to a first fuel manifold


30


. The first fuel manifold


30


is an interior space defined by the injector body


14


that fluidly connects the downcomer


38


, and hence the first fuel inlet


34


, to the first fuel jets


32


. As shown in

FIGS. 2 and 4

, the first fuel manifold


30


of the illustrated embodiment comprises both an annular chamber


42


that extends circumferentially around the main jets


18


and a central chamber


40


located central to the main jets


18


. The central chamber


40


and the annular chamber


42


are fluidly connected by tunnels (not shown) that are generally perpendicular to the main jets


18


. It is appreciated that there are numerous alternative configurations of the first fuel manifold


30


, the downcomer


38


, and the first fuel inlet


34


for fluidly connecting the first fuel source to the first fuel jets


34


.




The first fuel is discharged from the first fuel jets


32


into the combustion chamber


100


. In the illustrated embodiment, 24 first fuel jets are provided, with 4 located at spaced intervals around each of the main jets


20


, though any number of first fuel jets


32


can be provided. Each of the first fuel jets


32


is configured such that a central axis of each first fuel jet


32


converges with a central axis of the respective main jet


20


in the combustion chamber


100


so that fuel discharged from the first fuel jets


32


impinges on the stream of oxidizing fluid flowing from the respective main jet


20


.




Similar to the first fuel, a second fuel enters the second fuel inlet


54


and flows through a second fuel downcomer (not shown) to a second fuel manifold


50


. The second fuel manifold


50


is an interior space defined by the injector body


14


that fluidly connects the second fuel downcomer, and hence the second fuel inlet


54


, to the second fuel jets


52


. As shown in

FIG. 4

, the second fuel manifold


50


of the illustrated embodiment comprises


6


annular chambers, each extending circumferentially around one of the main jets


20


. The annular chambers are fluidly connected to one another by tunnels (not shown) that extend in a direction generally perpendicular to the main jets


20


. In the illustrated embodiment, 24 second fuel jets are provided, with 4 located at spaced intervals around each of the main jets


20


. Each of the second fuel jets


52


is also configured such that a central axis of each second fuel jet


52


converges with the central axis of the respective main jet


20


in the combustion chamber


100


so that fuel discharged from each of the second fuel jets


52


into the combustion chamber


100


impinges on the stream of oxidizing fluid flowing from the respective main jet


20


.




The converging angle between each of the fuel jets


32


,


52


and the respective main jet


20


affects the extent to which the fuel is mixed with the oxidizing fluid as well as the location in the combustion chamber


100


at which the fuel and oxidizing fluid are sufficiently mixed for combustion to occur. The distance between each of the fuel jets


32


,


52


and the respective main jet


20


also affects the mixing of the fuel and oxidizing fluid. If the mixing and the combustion of the fuel and oxidizing fluid occur close to the injector face


12


, the injector face


12


and the injector


10


may be more subject to the heat generated by the combustion and require additional cooling. In one advantageous embodiment of the present invention, each of the first and second fuel jets


32


,


52


defines a converging angle relative to one of the main jets


20


of between about 10° and 45°. In another embodiment, the fuel jets are configured such that fuel flowing from the fuel jets


32


,


52


impinges on the stream of oxidizing fluid flowing from the respective main jet


20


in a region located within about 2 inches of the injector face


12


. Thus, the fuel that is discharged through the jets


32


,


52


mixes with the oxidizing fluid and facilitates a uniform combustion of the fuel. However, the fuel is not mixed and combusted so close to the jets


20


,


32


,


52


that the combustion occurs in the injector


10


.




The arrangement of the first and second fuel jets


32


,


52


is shown in FIG.


3


. It is appreciated that any number of first and second fuel jets


32


,


52


can be provided, including a single first and second jet


32


,


52


for each main jet


20


. Preferably, the first and second jets


32


,


52


are arranged symmetrically about the main jets


20


, but asymmetric arrangements are also possible. Also, while jets


32


,


52


in the illustrations have a round cross section, other shapes are also possible. For example, one or both of the first and second fuel jets


32


,


52


can be a single jet that defines a slot extending circumferentially around all or part of the main jets


20


. Further,

FIG. 3

illustrates the difference in cross-sectional size between the first fuel jets


32


and the second fuel jets


52


. Although any size of jets


32


,


52


can be used, the size of the jets


32


,


52


preferably is chosen in consideration of the heating value of the fuels, the operating pressure, and the number of jets


32


,


52


. For example, the diameters of the jets


32


,


52


can be calculated according to the required mass flow rate of fuel for the desired combustion and the necessary momentum of the fuel into the combustion chamber


100


for proper mixing with the oxidizing fluid. The required mass flow rate of different fuels may vary according to the heating values of the fuels, though it may be desirable to inject the different fuels with similar momentum to ensure proper mixing of each fuel with the oxidizing fluid. Thus, the differently sized jets


32


,


52


allow the use of different fuels while still maintaining the same rate of heat generation and the same momentums of the fuels. For example, in the embodiment shown in

FIG. 3

, the first fuel jets


32


are approximately three times the diameter of the second fuel jets


52


. Thus, if the first fuel jets


32


are used for a first fuel that has a heating value of approximately one-third of the heating value of the second fuel, the amount of heat generated by the two fuels will be similar if the two fuels have equivalent densities and are injected at similar momentums.




The relative sizes of the injector


10


and jets


20


,


32


,


52


are also shown in FIG.


3


. In one embodiment, the diameter of the injector


10


is about 12.5 inches wide, and the diameters of the fuel jets


32


,


52


are at least about 0.1 inch. The main jets


20


are about one inch in diameter at the injector face


12


, and a center of each of the main jets


20


is at least about 4 inches from the centers of the other main jets


20


.




In one advantageous embodiment, the second fuel jets


52


are used to inject natural gas, which is approximately 90 percent methane. The first fuel jets


32


are used to inject a synthesis comprising carbon monoxide, hydrogen, and carbon dioxide. The synthesis gas can be generated by using steam and oxygen for the gasification of petcoke, which is about 90 percent solid carbon by weight, moisture, and ash. The first fuel and the second fuel can be injected simultaneously, but according to one advantageous embodiment of the present invention, only one of the first and second gases is injected at a time. Thus, fuel gas that is used for combustion can be changed without changing the injector


10


and can be chosen according to other criteria such as availability, price, and efficiency. Additionally, it is understood that additional jets can be provided to further improve the versatility of the injector


10


. For example, the injector


10


can include a third set of fuel jets (not shown) with a corresponding fuel manifold and inlet, thus allowing a third fuel source to be independently supplied to the combustion chamber


100


. The configuration of each of the first and second plurality of fuel jets


32


,


52


, and any additional fuel jets, can be tailored to inject a particular type of gas under particular conditions. For example, the number and size of the first fuel jets


32


and the spacing and angle between the first jets


32


and the main jets


20


can be tailored specifically for the injection of a particular file through the first jets


32


, for example, a synthesis gas comprising hydrogen and carbon monoxide. Similarly, the second fuel jets


52


, and any additional sets of fuel jets, can be configured for other fuels such as methane or natural gas.




As shown in

FIGS. 1 and 2

, a second sleeve


90


circumferentially surrounds the first sleeve


80


, defining a second annular space


94


between the two sleeves


80


,


90


. The second annular space


94


is fluidly connected to a circumferential passage


86


, which extends around the second sleeve


90


, and to a diluent gas inlet


84


. The diluent gas inlet


84


is fluidly connected to a source of diluent gas (not shown). Thus, the diluent gas enters the diluent gas inlet


84


and flows through the circumferential passage


86


and into the second annular space


94


through the second sleeve apertures


92


. The diluent gas flows through the second annular space


94


in a direction that is generally opposite to the direction of the oxidizing fluid and the fuel in the jets


20


,


32


,


52


. From the second annular space


94


, the diluent gas flows through a plurality of first sleeve apertures


88


that fluidly connect the second annular space


94


and the first annular space


82


. Once in the first annular space


82


, the diluent gas reverses its direction of flow and flows toward the combustion chamber


100


, where it is then mixed with and becomes part of the combustion gas in the combustion chamber


100


. The diluent gas dilutes the combustion gas and moderates the temperature of the combustion. Although liquid diluents can also be used, a gaseous diluent is preferred. Various diluent gases can be used including, in one advantageous embodiment, a recycle gas from a turbine in which the combustion gas from the combustion chamber


100


is expanded. The recycle gas comprises steam and carbon dioxide. The degree of cooling that is provided by the recycle gas depends on the combustion temperature, the flow rate of the gases into the combustion chamber


100


, the temperature of the recycle gas, and the composition of the recycle gas. Preferably, the temperature in the combustion chamber


100


is reduced to at least about 4000° F., and most preferably to about 2000° F.




The injector


10


can also be cooled by a coolant fluid such as water that flows through a coolant chamber (not shown). The coolant chamber is an interior gap defined by the injector body


10


, which is fluidly connected to a coolant inlet


72


and a coolant outlet


74


. Coolant fluid is pumped into the coolant inlet


72


and discharged from the coolant outlet


74


. It will be appreciated that various configurations of coolant chambers can be used as are known in the art.




In one advantageous embodiment of the present invention, the injector


10


is used to inject gases into a combustion chamber


100


that is compatible only with gases. For example, the injector


10


can be used to inject a carbonaceous gas, gaseous oxygen, and a mixture of steam and carbon dioxide into a reheater that is used to combust gases in an electricity generation plant. The reheater can recombust an exhaust gas that is discharged from a gas generator and turbine, as discussed in U.S. Patent Application No. [ . . . ], titled “LOW-EMISSION, STAGED-COMBUSTION POWER GENERATION,” filed concurrently herewith and the entirety of which is incorporated herein by reference. Alternatively, the reheater can be the initial combustion device in a power generation cycle as shown, for example, in FIG.


5


.




The power generation cycle shown in

FIG. 5

includes a reheater


140


that receives oxygen and a carbonaceous gas, for example, a synthesis gas, for combustion. The oxygen is generated in an air separation unit


110


, which removes at least most of the nitrogen from the air and discharges the oxygen substantially free of nitrogen and sulfur. The nitrogen can be removed using a cryogenic process, as will be understood by one of ordinary skill in the art. In that case, the cryogenic nitrogen that is derived from the process can be sold or used in subsequent cooling processes in the power generation cycle. In other embodiments, the oxidizing fluid can be derived from sources other than the air separation unit


110


, for example, from a storage tank, delivery pipeline, or other oxygen generation apparatuses that are known in the art.




In the illustrated embodiment of

FIG. 5

, the synthesis gas, or syngas, is generated in a syngas generator


120


. The syngas generator


120


is shown for illustrative purposes only, and it is understood that syngas can be obtained by other processes known in the art. Further, combustion gases other than syngas can be used. For example, the combustion gas can comprise methane, ethane, propane, or a mixture of hydrocarbons and may be derived from crude oil or a biomass fuel.




The oxidizing fluid is compressed by compressors


112


,


114


and delivered to the reheater


140


and the syngas generator


120


. The syngas generator


120


includes a gasifier


126


that also receives water and petroleum coke, or petcoke, from water and petcoke sources


122


,


124


. The petcoke is gasified in the gasifier


126


to form an exhaust gas that includes the syngas, as known in the art. The syngas comprises hydrogen, carbon monoxide, and carbon dioxide, and in this embodiment specifically comprises about 50 percent carbon monoxide, 34.2 percent hydrogen, and 15.8 percent carbon dioxide. The syngas is passed through a high temperature heat recoverer


128


and a low temperature heat recoverer


130


, both of which are thermally coupled to a heat recovery steam generator


150


, described below.




The syngas is then discharged to the reheater


140


. The syngas enters the reheater


140


through the injectors


10


, as do the oxygen and a diluent. The diluent is a recycle gas that includes steam and carbon dioxide. The diluent dilutes the oxygen in the reheater, limiting the temperature in the reheater


140


. The product gas is combusted in the combustion chamber


100


of the reheater


140


to form a combusted gas or combustion product, which is discharged to a primary turbine


142


. The combustion product is expanded in the primary turbine


142


and energy is generated by rotating an electric generator


146


that is mechanically or hydraulically coupled to the primary turbine


142


. The combustion product from the primary turbine


142


is discharged to the heat recovery steam generator


150


where the combustion product is cooled. The heat recovery steam generator


150


acts as a heat exchanger by using thermal energy of the combustion product discharged from the primary turbine


142


to heat an intermediate exhaust gas from the high temperature heat recoverer


128


. The intermediate exhaust gas is then discharged to a first turbine


160


. The intermediate exhaust gas is discharged from the first turbine


160


to the heat recovery steam generator


150


where it is reheated and discharged to a second turbine


162


and then a third turbine


164


. The intermediate exhaust gas is expanded in the turbines


160


,


162


,


164


, and the temperature and pressure of the intermediate exhaust gas arc decreased. The operating pressures of the turbines


160


,


162


,


164


decrease consecutively so that the second turbine


162


operates at a pressure that is lower than that of the first turbine


160


and higher than that of the third turbine


164


. The turbines


160


,


162


,


164


are coupled to an electric generator


166


, which is rotated by the turbines


160


,


162


,


164


and generates electricity. Subsequently, the intermediate exhaust gas is discharged to a condenser


168


and a pump


170


, which returns the condensed exhaust to the syngas generator


120


.




The combustion product is cooled in the heat recovery steam generator


150


. A first portion of the combustion product is recycled from the heat recovery steam generator


150


to a compressor


144


, which compresses the combustion product and discharges the combustion product as the diluent to the reheater


140


. Bleed lines


148


connect the compressor


144


to the primary turbine


142


. The compressor


144


can be driven by a shaft that also couples the primary turbine


142


to the electric generator


146


. Although not shown, a single drive shaft may be driven by all of the turbines


142


,


160


,


162


,


164


, and the same shaft may also drive the compressor


144


. In the embodiment of

FIG. 5

, the diluent comprises approximately 67 percent steam and 33 percent carbon dioxide, though the actual proportions can vary.




A second portion of the combustion product is discharged to a high pressure compressor


172


where it is compressed to liquefy the carbon dioxide in the combustion product. The carbon dioxide is then discharged via a carbon dioxide outlet


174


and water is discharged through a water outlet


176


. The carbon dioxide and water may be recycled for use in other parts of the generation cycle or discharged.




Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.



Claims
  • 1. An injector for injecting combustion fluids into a combustion chamber, comprising:an injector body defining a first annular space between the injector body and a first sleeve, said injector body comprising an injector face facing the combustion chamber, and defining a main bore, at least one main jet extending from the injector face to the main bore, a first plurality of fuel jets opening through the injector face, a first fuel inlet fluidly connected to the first plurality of fuel jets, a second plurality of fuel jets opening through the injector face, and a second fuel inlet fluidly connected to the second plurality of fuel jets, wherein each of the second plurality of fuel jets has a smaller cross sectional area than each of the first plurality of fuel jets.
  • 2. An injector according to claim 1 wherein the first annular space is fluidly connected to a source of a recycle gas comprising steam and carbon dioxide.
  • 3. An injector according to claim 1 further comprising a recycle gas inlet and a second sleeve, the second sleeve defining an interior side and positioned to define a second annular space between the interior side of the second sleeve and an outer surface of the first sleeve, and wherein the first sleeve defines at least one first sleeve aperture fluidly connecting the first annular space to the second annular space and the second sleeve defines at least one second sleeve aperture fluidly connecting the second annular space to the recycle gas inlet.
  • 4. An injector according to claim 3 further comprising a circumferential passage extending about the perimeter of the second sleeve and wherein the circumferential passage fluidly connects the second annular space to the recycle gas inlet such that gas enters the recycle gas inlet and generally flows in a first direction in the second annular space and a second direction in the first annular space, the second direction opposite to the first direction.
  • 5. An injector according to claim 1 wherein the main bore is fluidly connected to a source of oxidizing fluid substantially free of nitrogen and sulfur.
  • 6. An injector according to claim 1 wherein the first fuel inlet is fluidly connected to a first source of fuel.
  • 7. An injector according to claim 6 wherein the first source of fuel comprises a synthesis gas of hydrogen and carbon monoxide.
  • 8. An injector according to claim 1 wherein the injector body further defines a first fuel manifold fluidly connected to the first plurality of fuel jets.
  • 9. An injector according to claim 8 wherein the first fuel manifold comprises an annular fuel space that extends circumferentially around at least one of the main jets and a central chamber between the main jets and fluidly connected to the annular fuel space.
  • 10. An injector according to claim 1 wherein the central axis of each of the first plurality of fuel jets defines a converging angle of between about 10° and 45° relative to the central axis of one of the at least one main jets such that fluid flowing from the injector body into the combustion chamber through each of the first plurality of fuel jets impinges on a stream of fluid flowing from the respective main jet in the combustion chamber.
  • 11. An injector according to claim 1 wherein the injector body defines at least one coolant chamber configured to receive and circulate a coolant fluid for cooling the injector body.
  • 12. An injector according to claim 1 wherein a center of each of the main jets is located at least about 4 inches from centers of the other main jets.
  • 13. An injector according to claim 1 wherein each of the main jets has a diameter of at least about 1 inch at the injector face.
  • 14. An injector according to claim 1 wherein the injector body further defines a second fuel manifold fluidly connected to the plurality of fuel jets.
  • 15. An injector according to claim 14 wherein the fuel manifold defines at least one annular space that extends circumferentially around at least one of the main jets.
  • 16. An injector according to claim 1 wherein the second fuel inlet is fluidly connected to a second source of fuel.
  • 17. An injector according to claim 16 wherein the second source of fuel comprises methane.
  • 18. An injector according to claim 1 wherein the central axis of each of the second plurality of fuel jets defines a converging angle of between about 10° and 45° relative to the central axis of one of the at least one main jets such that fluid flowing from the injector body into the combustion chamber through each of the second plurality of fuel jets impinges on a stream of fluid flowing from the respective main jet in the combustion chamber.
  • 19. An injector according to claim 1 wherein the main bore is fluidly connected to a source of gaseous oxygen, at least one of the first and second fuel inlets is fluidly connected to a source of gaseous fuel, and the first annular space is fluidly connected to a source of a recycle gas comprising steam and gaseous carbon dioxide.
  • 20. An injector for injecting combustion fluids into a combustion chamber, comprising:an injector body defining a first annular space between the injector body and a first sleeve, said injector body comprising an injector face facing the combustion chamber, and defining a main bore, at least one main jet extending from the injector face to the main bore, a first plurality of fuel jets opening through the injector face, a first fuel inlet fluidly connected to the first plurality of fuel jets, a second plurality of fuel jets opening through the injector face, and a second fuel inlet fluidly connected to the second plurality of fuel jets, wherein a respective one of the fuel jets defines a converging angle relative to a respective main jet such that fluid flowing from the injector body into the combustion chamber through the respective fuel jet impinges on a stream of fluid flowing from the respective main jet in the combustion chamber.
  • 21. An injector according to claim 20 wherein the first annular space is fluidly connected to a source of a recycle gas comprising steam and carbon dioxide.
  • 22. An injector according to claim 20 further comprising a recycle gas inlet and a second sleeve, the second sleeve defining an interior side and positioned to define a second annular space between the interior side of the second sleeve and an outer surface of the first sleeve, and wherein the first sleeve defines at least one first sleeve aperture fluidly connecting the first annular space to the second annular space and the second sleeve defines at least one second sleeve aperture fluidly connecting the second annular space to the recycle gas inlet.
  • 23. An injector according to claim 22 further comprising a circumferential passage extending about the perimeter of the second sleeve and wherein the circumferential passage fluidly connects the second annular space to the recycle gas inlet such that gas enters the recycle gas inlet and generally flows in a first direction in the second annular space and a second direction in the first annular space, the second direction opposite to the first direction.
  • 24. An injector according to claim 20 wherein the main bore is fluidly connected to a source of oxidizing fluid substantially free of nitrogen and sulfur.
  • 25. An injector according to claim 20 wherein the first fuel inlet is fluidly connected to a first source of fuel.
  • 26. An injector according to claim 25 wherein the first source of fuel comprises a synthesis gas of hydrogen and carbon monoxide.
  • 27. An injector according to claim 20 wherein the injector body further defines a first fuel manifold fluidly connected to the first plurality of fuel jets.
  • 28. An injector according to claim 27 wherein the first fuel manifold comprises an annular fuel space that extends circumferentially around at least one of the main jets and a central chamber between the main jets and fluidly connected to the annular fuel space.
  • 29. An injector according to claim 20 wherein the central axis of each of the first plurality of fuel jets defines a converging angle of between about 10° and 45° relative to the central axis of one of the at least one main jets such that fluid flowing from the injector body into the combustion chamber through each of the first plurality of fuel jets impinges on a stream of fluid flowing from the respective main jet in the combustion chamber.
  • 30. An injector according to claim 20 wherein the injector body defines at least one coolant chamber configured to receive and circulate a coolant fluid for cooling the injector body.
  • 31. An injector according to claim 20 wherein a center of each of the main jets is located at least about 4 inches from centers of the other main jets.
  • 32. An injector according to claim 20 wherein each of the main jets has a diameter of at least about 1 inch at the injector face.
  • 33. An injector according to claim 20 wherein the injector body further defines a second fuel manifold fluidly connected to the second plurality of fuel jets.
  • 34. An injector according to claim 33 wherein the second fuel manifold defines at least one annular space that extends circumferentially around at least one of the main jets.
  • 35. An injector according to claim 20 wherein the second fuel inlet is fluidly connected to a second source of fuel.
  • 36. An injector according to claim 35 wherein the second source of fuel comprises methane.
  • 37. An injector according to claim 20 wherein the central axis of each of the second plurality of fuel jets defines a converging angle of between about 10° and 45° relative to the central axis of one of the at least one main jets such that fluid flowing from the injector body into the combustion chamber through each of the second plurality of fuel jets impinges on a stream of fluid flowing from the respective main jet in the combustion chamber.
  • 38. An injector according to claim 20 wherein the main bore is fluidly connected to a source of gaseous oxygen, at least one of the first and second fuel inlets is fluidly connected to a source of gaseous fuel, and the first annular space is fluidly connected to a source of a recycle gas comprising steam and gaseous carbon dioxide.
US Referenced Citations (82)
Number Name Date Kind
2636778 Michelsen Apr 1953 A
2785926 Lataste Mar 1957 A
2857204 Gross Oct 1958 A
2930532 Johnson Mar 1960 A
3056559 Orr Oct 1962 A
3093315 Tachiki et al. Jun 1963 A
3121639 Bauer et al. Feb 1964 A
3430863 Canavan et al. Mar 1969 A
3603092 Paine et al. Sep 1971 A
3610537 Nakagawa et al. Oct 1971 A
3729285 Schwedersky Apr 1973 A
3779212 Wagner Dec 1973 A
3837788 Craig et al. Sep 1974 A
3850569 Alquist Nov 1974 A
3923011 Pfefferle Dec 1975 A
3928961 Pfefferle Dec 1975 A
4021186 Tenner May 1977 A
4021188 Yamagishi et al. May 1977 A
4054407 Carrubba et al. Oct 1977 A
4102125 Schelp Jul 1978 A
4173118 Kawaguchi Nov 1979 A
4216908 Sakurai et al. Aug 1980 A
4271664 Earnest Jun 1981 A
4288408 Guth et al. Sep 1981 A
4297093 Morimoto et al. Oct 1981 A
4316580 Bodai Feb 1982 A
4356698 Chamberlain Nov 1982 A
4407450 Chegolya et al. Oct 1983 A
4504211 Beardmore Mar 1985 A
4566268 Hoffeins et al. Jan 1986 A
4575332 Oppenberg et al. Mar 1986 A
4773596 Wright et al. Sep 1988 A
4783008 Ikeuchi et al. Nov 1988 A
4784600 Moreno Nov 1988 A
4801092 Webber et al. Jan 1989 A
4893468 Hines Jan 1990 A
4912931 Joshi et al. Apr 1990 A
4936088 Bell Jun 1990 A
4955191 Okamoto et al. Sep 1990 A
4958488 Wilkes et al. Sep 1990 A
4989549 Korenberg Feb 1991 A
5025631 Garbo Jun 1991 A
5029557 Korenberg Jul 1991 A
5042964 Gitman Aug 1991 A
5103630 Correa Apr 1992 A
5158445 Khinkis Oct 1992 A
5161379 Jones et al. Nov 1992 A
5222357 Eddy et al. Jun 1993 A
5224333 Bretz et al. Jul 1993 A
5247791 Pak et al. Sep 1993 A
5259184 Borkowicz et al. Nov 1993 A
5285628 Korenberg Feb 1994 A
5288021 Sood et al. Feb 1994 A
5361578 Donlan Nov 1994 A
RE35061 Correa Oct 1995 E
5462430 Khinkis Oct 1995 A
5467926 Idleman et al. Nov 1995 A
5675971 Angel et al. Oct 1997 A
5680765 Choi et al. Oct 1997 A
5680766 Joshi et al. Oct 1997 A
5709077 Beichel Jan 1998 A
5713205 Sciocchetti et al. Feb 1998 A
5715673 Beichel Feb 1998 A
5743081 Reynolds Apr 1998 A
5778676 Joshi et al. Jul 1998 A
5806298 Klosek et al. Sep 1998 A
5833141 Bechtel, II et al. Nov 1998 A
5894720 Willis et al. Apr 1999 A
5906094 Yang et al. May 1999 A
5906806 Clark May 1999 A
5934064 Newby et al. Aug 1999 A
5950417 Robertson, Jr. et al. Sep 1999 A
5956937 Beichel Sep 1999 A
5966937 Graves Oct 1999 A
5970702 Beichel Oct 1999 A
6065281 Shekleton et al. May 2000 A
6076745 Primdahl Jun 2000 A
6082112 Shekleton Jul 2000 A
6148602 Demetri Nov 2000 A
6162266 Wallace et al. Dec 2000 A
6170264 Viteri et al. Jan 2001 B1
6206684 Mueggenburg Mar 2001 B1
Foreign Referenced Citations (2)
Number Date Country
1 013 990 Jun 2000 EP
WO 0043712 Jul 2000 WO
Non-Patent Literature Citations (2)
Entry
O. Bolland and S. Saether, New Concepts For Natural Gas Fired Power Plants Which Simplify The Recovery Of Carbon Dioxide; Energy Convers. Mgmt, 1992, pp. 467-475, vol. 33, No. 5-8, Pergamon Press Ltd, Great Britain.
Olav Bolland and Philippe Mathieu, Comparison Of Two CO2 Removal Options In Combined Cycle Power Plants, Energy Convers. Mgmt, 1998, pp. 1653-1663, vol. 39, No. 16-18, Elsevier Science Ltd, Great Britian.