Systems and methods for operating a turbocharged gas turbine engine

Abstract

The present invention is entitled "System and method for operating a turbocharged gas turbine engine." The present invention provides a power generation system (100) comprising a combustion system (102), a turbocharger (106), and a heat recovery system (104). The combustion system (102) is configured to combust fuel with an air flow. The combustion system (102) is further configured to produce an exhaust flow. The turbocharger (106) is configured to compress a compressed air flow and direct the compressed air flow to the combustion system (102). The combustion system (102) is configured to combust fuel with the compressed air flow and an additional air flow. The heat recovery system (104) is configured to recover heat from the exhaust flow and drive the turbocharger (106). The heat recovery system (104) uses a supercritical working fluid to absorb heat from the exhaust flow and drive the turbocharger (106).

Description

Background Art

[0001] The field of the present disclosure relates generally to gas turbine engines and, more particularly, to systems and methods for operating a turbocharged gas turbine engine.

[0002] A gas turbine engine typically includes at least one compressor, at least one burner, and at least one turbine arranged in a series flow configuration. Typically, the compressor directs compressed air to the burner, where it is mixed with a fuel stream and combusted, forming a high-temperature combustion gas stream that is directed to the turbine before being discharged from the gas turbine engine. However, at high altitudes or high ambient temperatures, where the air has a lower density than at low altitudes or low ambient temperatures, less air is compressed, and because the lower-density air burns less fuel, the gas turbine engine produces less power.

[0003] To overcome the shortages encountered at higher altitudes and in areas with high ambient temperatures, at least some known gas turbine engines include turbochargers to increase the volume of compressed air directed to the burners. However, turbochargers use the power generated by the gas turbine engine to compress the additional air for combustion, thereby reducing the efficiency of the gas turbine engine. To partially offset the energy consumed by the turbocharger, at least some known gas turbine engines include heat recovery systems that recover heat from the gas turbine engine's exhaust gas directed to the turbocharger. Heat recovery systems typically use water and / or steam as a working fluid, but such systems typically consume large amounts of water during operation. Furthermore, the water used as the working fluid undergoes impurity treatment to prevent oxidation and scaling in the heat recovery system. Consequently, heat recovery systems using water and / or steam as a working fluid typically require a water treatment system. Therefore, if such turbines are located in areas without sufficient water to support the heat recovery system, the use of turbochargers in higher altitudes, high ambient temperatures, and / or arid locations may be limited. Therefore, it is desirable to provide a gas turbine engine having a turbocharger that includes a heat recovery system that uses a fluid other than water as a working fluid. Summary of the Invention

[0004] In one aspect, a power generation system is provided. The power generation system includes a combustion system, a turbocharger, and a heat recovery system. The combustion system is configured to combust fuel with an air flow. The combustion system is further configured to produce an exhaust flow. The turbocharger is configured to compress a compressed air flow and direct the compressed air flow to the combustion system. The combustion system is configured to combust fuel with the compressed air flow and an additional air flow. The heat recovery system is configured to recover heat from the exhaust flow and drive the turbocharger. The heat recovery system uses a supercritical working fluid to absorb heat from the exhaust flow and drive the turbocharger.

[0005] In another aspect, a method for generating electricity using a power generation system is provided. The power generation system includes a combustion system, a heat recovery system, and a turbocharger. The method includes using the combustion system to combust a fuel with an air flow to generate electricity and an exhaust flow. The method also includes directing the exhaust flow from the combustion system to the heat recovery system. The method also includes using the exhaust flow to heat a supercritical working fluid within the heat recovery system. The method also includes using the supercritical working fluid to drive a turbocharger. The method also includes compressing a compressed air flow using the turbocharger. The method also includes combusting the fuel with the compressed air flow and an additional air flow to generate electricity and an exhaust flow.

[0006] In another aspect, a heat recovery system for a power generation system is provided. The heat recovery system includes at least one heat exchanger configured to receive an exhaust flow from a combustion system. The at least one heat exchanger is configured to transfer heat from the exhaust flow to a supercritical working fluid. The heat recovery system also includes at least one turbine coupled to at least one turbocharger. The at least one turbine is configured to receive the supercritical working fluid from the at least one heat exchanger. The at least one turbine is configured to extract useful work from the supercritical working fluid to drive the at least one turbocharger. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters refer to like parts throughout, and in which:

[0008] Figure 1 is a block flow diagram of an exemplary power generation system;

[0009] Figure 2 It can be with Figure 1 A schematic diagram of an exemplary combustion system for use with the power generation system shown;

[0010] Figure 3 It is a block flow diagram of an alternative power generation system;

[0011] Figure 4 is a block flow diagram of another alternative power generation system; and

[0012] Figure 5 is used Figure 1 、 Figure 3 and Figure 4 A flow chart of an exemplary method of generating electricity using a power generation system is shown.

[0013] Unless otherwise indicated, the drawings provided herein are intended to illustrate features of the embodiments of the present disclosure. It is believed that these features are applicable to a variety of systems including one or more embodiments of the present disclosure. Therefore, the drawings are not intended to include all conventional features required for practicing the embodiments disclosed herein that are known to those of ordinary skill in the art. DETAILED DESCRIPTION

[0014] In the following description and claims, reference will be made to a number of terms which shall be defined to have the following meanings.

[0015] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0016] Unless otherwise indicated, approximate language as used herein, such as "substantially," "substantially," and "about," indicates that as one of ordinary skill in the art will recognize, the terms so modified may apply only to an approximate degree, rather than an absolute or perfect degree. Therefore, values modified by one or more terms (such as "about," "approximately," and "substantially") are not limited to the exact values specified. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range limitations may be identified. Unless otherwise indicated by the context or language, these ranges may be combined and / or interchanged and include all subranges contained therein. In addition, unless otherwise indicated, the terms "first," "second," and the like are used herein merely as labels and are not intended to impose order, position, or hierarchical requirements on the items to which these terms relate. Furthermore, for example, a reference to a "second" item does not require or exclude the presence of, for example, a "first" or lower numbered item or a "third" or higher numbered item. As used herein, the term "coupled" is not limited to direct mechanical, thermal, electrical, and / or fluidic connections between components, but may also include indirect mechanical, thermal, electrical, and / or fluidic connections between multiple components.

[0017] As used herein, the terms "axial" and "axially" refer to directions and orientations that extend substantially parallel to the longitudinal axis of a rotary machine. Additionally, the terms "radial" and "radially" refer to directions and orientations that extend substantially perpendicular to the longitudinal axis of a rotary machine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations that extend in an arc around the longitudinal axis of a rotary machine. Further, as used herein, the term "upstream" refers to the front end or inlet end of a rotary machine, and the term "downstream" refers to the rear end or outlet end of a rotary machine.

[0018] The systems described herein relate to power generation systems that can be used in areas with high altitudes and / or high ambient temperatures. Specifically, each power generation system described herein includes a gas turbine engine, a heat recovery system, a turbocharger, and a generator. The gas turbine engine combusts fuel and produces an exhaust stream. The exhaust stream is directed to the heat recovery system, where heat is recovered from the exhaust stream to power a turbocharger. The turbocharger directs a compressed air stream to the gas turbine engine, where the compressed air stream is mixed with fuel and combusted to increase power output and gas turbine engine efficiency.

[0019] In an exemplary embodiment, the power generation system is located at a high altitude and / or high ambient temperature. Consequently, the air used by the gas turbine engine to combust fuel has a lower density than air at lower altitudes or in areas with lower ambient temperatures. Due to the lower air density, the gas turbine engine produces less power than a gas turbine engine at a lower altitude or in areas with lower ambient temperatures. The turbocharger increases the air flow entering the gas turbine engine for combustion, thereby increasing the gas turbine engine's overall power generation. Furthermore, because the heat recovery system utilizes heat recovered from the exhaust gas flow to drive the turbocharger, the power generated by the power generation system is increased without compromising efficiency. Furthermore, in an exemplary embodiment, the working fluid, i.e., the fluid used to convert heat into usable energy, is supercritical CO2, and therefore, the heat recovery system is not water-intensive. Therefore, when the power generation system is located at higher altitudes and / or in arid areas, the power generation system improves the power generation and efficiency of the gas turbine engine while reducing water consumption.

[0020] Figure 1 1 is a block flow diagram of an exemplary power generation system 100 including a gas turbine engine 102, a heat recovery system 104, a turbocharger 106, and a generator 108. In the exemplary embodiment, the gas turbine engine 102 generates electricity by combusting fuel to produce an exhaust stream 110. The exhaust stream 110 is directed to the heat recovery system 104, and the heat recovery system 104 recovers heat from the exhaust stream 110 to power the turbocharger 106. The turbocharger 106 directs a compressed air stream 112 to the gas turbine engine 102, and the gas turbine engine 102 combusts the compressed air stream 112 with fuel to increase the power output and efficiency of the gas turbine engine 102.

[0021] In the exemplary embodiment, gas turbine engine 102 is a gas turbine engine. Alternatively, gas turbine engine 102 may be any other turbine engine and / or rotary machine, including but not limited to a steam turbine engine, a gas turbofan aircraft engine, other aircraft engines, a wind turbine, a compressor, and / or a pump. Figure 2is an enlarged schematic diagram of gas turbine engine 102. In the exemplary embodiment, gas turbine engine 102 includes an intake section 202, a compressor section 204 downstream of intake section 202, a combustor section 206 downstream of compressor section 204, a turbine section 208 downstream of combustor section 206, and an exhaust section 210 downstream of turbine section 208. Turbine section 208 is coupled to compressor section 204 via a rotor shaft 212.

[0022] In the exemplary embodiment, combustor section 206 includes a plurality of combustors 214 and a plurality of fuel nozzles (not shown). Combustor section 206 is coupled to compressor section 204 such that each combustor 214 is in fluid communication with compressor section 204. Rotor shaft 212 is also coupled to a load 216, such as, but not limited to, a generator and / or a mechanical drive application. In the exemplary embodiment, each compressor section 204 and each turbine section 208 includes at least one rotor assembly 218 coupled to rotor shaft 212.

[0023] In operation, the intake section 202 directs air 220 from the atmosphere and air 112 from the turbocharger 106 toward the compressor section 204. The compressor section 204 compresses the inlet air 220 to a higher pressure and then discharges the compressed air 222 toward the combustor section 206. The compressed air 222 from the compressor section 204 is mixed with the compressed air 112 from the turbocharger 106, and the mixture is directed to the combustor section 206, where it is mixed with fuel and combusted to produce high-temperature combustion gases 224. More specifically, the fuel is directed to the fuel nozzles at high pressure. The fuel nozzles atomize the fuel, causing the atomized fuel to mix with the compressed air 222. The combustion gases 224 are directed downstream toward the turbine section 208 and impinge on turbine blades (not shown), thereby converting thermal energy into mechanical rotational energy used to drive the rotor assembly 218 about the longitudinal axis 226. The combustor section 206 and the turbine section 208 are generally referred to as the hot gas section of the gas turbine engine 102. The exhaust gas flow 110 is then discharged to the heat recovery system 104 through the exhaust portion 210. The rotor assembly 218 is coupled to the generator 108, which produces electricity.

[0024] During operation of the power generation system 100, exhaust gas stream 110 from the gas turbine engine 102 is directed to the heat recovery system 104. Once the gas turbine engine 102 has reached a minimum operating load, the turbocharger 106 begins generating and directing compressed air 112 to the gas turbine engine 102. That is, once the temperature of the exhaust gas is high enough to power the turbocharger 106, the turbocharger 106 begins compressing and directing the air to the gas turbine engine 102. The gas turbine engine 102 then begins generating additional power at a higher efficiency.

[0025] like Figure 1 As shown, heat recovery system 104 includes a heat exchanger 114, a turbine 116, a heat exchanger 118, a cooler 120, and a compressor 122. Turbine 116 is coupled to turbocharger 106 and compressor 122 via shaft 124. In an alternative embodiment, turbine 116 may be coupled to turbocharger 106 and compressor 122 via shaft 124 and at least one gearbox 125, the gearbox being configured to control the speed of turbocharger 106 and / or compressor 122. Furthermore, in another alternative embodiment, turbine 116 may be coupled to turbocharger 106 and compressor 122 via different shafts 124. Heat exchanger 114, turbine 116, heat exchanger 118, cooler 120, and compressor 122 form a closed loop circuit 126 that enables a working fluid to be directed around closed loop circuit 126 to provide power to turbocharger 106. More specifically, the closed loop circuit 126 (1) transfers heat from the exhaust stream 110 to the working fluid, (2) utilizes the heat in the working fluid to drive the turbine 116 , and (3) utilizes the turbine 116 to drive the turbocharger 106 .

[0026] Heat exchanger 114 transfers heat from exhaust stream 110 to a working fluid to drive turbine 116. Heat exchanger 114 includes at least one heat exchanger that transfers heat from exhaust stream 110 to the working fluid. In alternative embodiments, heat exchanger 114 includes multiple heat exchangers that transfer heat from exhaust stream 110 to the working fluid. In an exemplary embodiment, heat exchanger 114 includes a shell and tube heat exchanger. In alternative embodiments, heat exchanger 114 can be any other type of heat exchanger that enables heat recovery system 104 to operate as described herein, including but not limited to a plate and frame heat exchanger and / or a double pipe heat exchanger.

[0027] Turbine 116 extracts energy from exhaust flow 110 to drive turbocharger 106 and compressor 122. More specifically, turbine 116 extracts energy from exhaust flow 110 to drive shaft 124, which in turn drives turbocharger 106 and compressor 122. Turbine 116 includes at least one turbine that extracts heat from exhaust flow 110. In alternative embodiments, turbine 116 includes multiple turbines that extract heat from exhaust flow 110. In an exemplary embodiment, turbine 116 includes any rotating machine that extracts energy from a fluid and converts the extracted energy into useful work. In alternative embodiments, turbine 116 can be any device that enables heat recovery system 104 to operate as described herein.

[0028] Heat exchanger 118 transfers heat from exhaust 128 of turbine 116 to exhaust 130 of compressor 122 to recover additional heat from the working fluid and improve the efficiency of power generation system 100. In an exemplary embodiment, heat exchanger 118 includes at least one heat exchanger that transfers heat from exhaust 128 of turbine 116 to exhaust 130 of compressor 122. In an alternative embodiment, heat exchanger 118 includes a plurality of heat exchangers that transfer heat from exhaust 128 of turbine 116 to exhaust 130 of compressor 122. In an exemplary embodiment, heat exchanger 118 includes a shell and tube heat exchanger. In alternative embodiments, heat exchanger 118 can be any other type of heat exchanger that enables heat recovery system 104 to operate as described herein, including but not limited to a plate and frame heat exchanger and / or a double pipe heat exchanger.

[0029] Cooler 120 transfers heat from the working fluid to cool the working fluid before being compressed by compressor 122. Cooler 120 includes at least one heat exchanger that cools the working fluid. In an alternative embodiment, cooler 120 includes a plurality of heat exchangers that cool the working fluid. In an exemplary embodiment, cooler 120 includes a shell and tube heat exchanger that exchanges heat from the working fluid to the cooling fluid. In an alternative embodiment, cooler 120 can be any other type of heat exchanger that enables heat recovery system 104 to operate as described herein, including but not limited to a plate and frame heat exchanger and a double-pipe heat exchanger. In an exemplary embodiment, the cooling fluid is water, air, a combination of water and air, and / or any other cooling fluid that enables cooler 120 to operate as described herein.

[0030] Compressor 122 increases the pressure of the working fluid to provide motive force to guide the working fluid around closed loop 126. Compressor 122 includes at least one compressor that increases the pressure of the working fluid. In an alternative embodiment, compressor 122 includes multiple compressors that increase the pressure of the working fluid. In an exemplary embodiment, compressor 122 includes any rotating machine that increases the pressure of the fluid, including a centrifugal compressor. In an alternative embodiment, compressor 122 can be any other device that enables heat recovery system 104 to operate as described herein.

[0031] In an exemplary embodiment, the working fluid is a supercritical fluid. More specifically, in an exemplary embodiment, the working fluid is supercritical carbon dioxide (sCO2). In an alternative embodiment, the working fluid can be any other supercritical fluid that enables the heat recovery system 104 to operate as described herein. In addition, the working fluid can be any other fluid that enables the heat recovery system 104 to operate as described herein, including but not limited to steam, air and / or liquid water. In an exemplary embodiment, a supercritical fluid is a substance whose temperature and pressure are higher than the critical point of the substance. When a substance is a supercritical fluid, the distinction between the vapor phase and the liquid phase of the substance disappears, and the density of the substance generally increases. In addition, when a substance is a supercritical fluid, slight changes in temperature and pressure can cause the density of the substance to change significantly, thereby being able to adjust the properties of the substance. As described above, in an exemplary embodiment, the working fluid is sCO2. The density of sCO2 is approximately three times that of steam, and therefore, a unit volume of sCO2 absorbs more heat than steam. Therefore, the equipment within heat recovery system 104, including heat exchanger 114, turbine 116, heat exchanger 118, chiller 120, and compressor 122, is more compact than equipment using steam as the working fluid, and heat recovery system 104 is not water-intensive. Accordingly, when power generation system 100 is located at higher altitudes and / or in arid regions, sCO2 can be advantageously used to increase power generation and efficiency of gas turbine engine 102, reduce the size of equipment within heat recovery system 104, and reduce water consumption by heat recovery system 104.

[0032] Turbocharger 106 compresses air and directs the compressed air to gas turbine engine 102 to provide additional air for combustion and improve the efficiency of gas turbine engine 102. Turbocharger 106 includes at least one compressor that compresses air and directs the compressed air to gas turbine engine 102. In alternative embodiments, turbocharger 106 includes multiple compressors that compress air and direct the compressed air to gas turbine engine 102. In the exemplary embodiment, turbocharger 106 includes any rotating machine that compresses air, including a centrifugal compressor. In alternative embodiments, turbocharger 106 may be any other device that enables power generation system 100 to operate as described herein.

[0033] Generator 108 generates electricity from the rotational energy provided by gas turbine engine 102. More specifically, generator 108 includes a rotor (not shown) including a plurality of magnets (not shown), a stator (not shown) surrounding the rotor, and a plurality of windings (not shown). The rotation of the rotor induces current in the windings, thereby generating electricity. Generator 108 includes at least one generator that generates electricity. In alternative embodiments, generator 108 includes multiple generators that generate electricity. In alternative embodiments, generator 108 can be any device that enables power generation system 100 to operate as described herein.

[0034] During operation of power generation system 100, gas turbine engine 102 combusts fuel and air from compressor section 204 and turbocharger 106 to rotate generator 108, thereby generating electricity. Exhaust gas stream 110 is directed from gas turbine engine 102 to heat exchanger 114. Heat exchanger 114 transfers heat from exhaust gas stream 110 to a working fluid and directs the working fluid to turbine 116. Turbine 116 extracts energy from the working fluid and drives turbocharger 106 and compressor 122. Exhaust 128 of turbine 116 is directed to heat exchanger 118, where heat exchanger 118 transfers heat from exhaust 128 of turbine 116 to exhaust 130 of compressor 122. The working fluid is then directed to cooler 120, which cools the working fluid before compression by compressor 122. The working fluid is then directed to compressor 122, which compresses the working fluid and directs it to heat exchanger 118. Heat exchanger 118 transfers heat from exhaust 128 of turbine 116 to exhaust 130 of compressor 122. Ultimately, the working fluid is directed back to heat exchanger 114 to complete closed loop circuit 126. Turbocharger 106 compresses air and directs the compressed air to gas turbine engine 102, where it is combusted to generate electricity.

[0035] Thus, power generation system 100 generates electricity in a compact footprint and using a non-water-intensive system at higher altitudes and / or in regions with higher ambient temperatures. More specifically, when power generation system 100 is located at higher altitudes and / or in regions with higher ambient temperatures, the air used by gas turbine engine 102 to combust fuel has a lower density than air at lower altitudes and / or in regions with lower ambient temperatures. Turbocharger 106 increases the air flow entering gas turbine engine 102 for combustion, thereby increasing the overall power generation of gas turbine engine 102. Furthermore, because heat recovery system 104 utilizes heat recovered from exhaust gas stream 110 to power turbocharger 106, the power generated by power generation system 100 is increased without reducing turbine efficiency. Furthermore, the working fluid is supercritical CO2, and therefore heat recovery system 104 is not water-intensive. Therefore, when power generation system 100 is located at higher altitudes and / or in arid regions, power generation system 100 improves the power generation and efficiency of gas turbine engine 102 and reduces water consumption by heat recovery system 104.

[0036] Figure 3 FIG2 is a block flow diagram of another exemplary power generation system 300. Power generation system 300 is substantially similar to power generation system 100, except that power generation system 300 further includes an auxiliary generator 302 coupled to shaft 124. In the exemplary embodiment, shaft 124 drives turbocharger 106, compressor 122, and auxiliary generator 302. Consequently, turbine 116 extracts more useful work from the working fluid, and this useful work generates electricity that supplements the electricity generated by gas turbine engine 102. Furthermore, in situations where the flow rate of compressed air 112 that can be injected into gas turbine engine 102 is limited due to mechanical limitations of gas turbine engine 102, heat absorbed from the exhaust of gas turbine engine 102 is directly converted into additional electrical output on the same shaft 124. Thus, auxiliary generator 302 increases the total power generated by power generation system 300 and improves the efficiency of power generation system 300.

[0037] Figure 4 is a block flow diagram of another exemplary power generation system 400. Power generation system 400 is substantially similar to power generation system 100, except that power generation system 400 includes at least one first turbine 402, at least one second turbine 404, and a heat exchanger 406 coupled to exhaust section 110 of gas turbine engine 102. In an exemplary embodiment, power generation system 400 may include a plurality of first turbines 402 and a plurality of second turbines 404. In the illustrated embodiment, power generation system 400 includes a single first turbine 402 and two second turbines 404. However, power generation system 400 may include any number of turbines 402 and turbines 404 that enables power generation system 400 to operate as described herein.

[0038] The first turbine 402 is a rotary machine that combines the functions of the turbocharger 106, the turbine 116, the compressor 122, and the auxiliary generator 302. That is, the first turbine 402 includes the turbocharger 106, the turbine 116, the compressor 122, and the auxiliary generator 302 in a single unit. Because the first turbine 402 includes the turbocharger 106, its primary function is to drive the turbocharger 106 using the turbine 116. Therefore, in an alternative embodiment, the first turbine 402 may include only the turbocharger 106 and the turbine 116 in a single unit. In another alternative embodiment, the first turbine 402 may include only the turbocharger 106, the turbine 116, and the auxiliary generator 302 in a single unit. In yet another alternative embodiment, the first turbine 402 may include only the turbocharger 106, the turbine 116, and the compressor 122 in a single unit.

[0039] Second turbine 404 is a rotary machine that combines the functions of turbine 116, compressor 122, and auxiliary generator 302. That is, second turbine 404 includes turbine 116, compressor 122, and auxiliary generator 302 in a single unit. Since second turbine 404 does not include turbocharger 106, its primary function is to use turbine 116 to drive compressor 122 and convert the net excess energy into electrical output. Therefore, in an alternative embodiment, second turbine 404 may also include only turbocharger 106 and compressor 122 in a single unit. Heat exchanger 406 is directly coupled to exhaust section 210 of gas turbine engine 102, thereby improving the efficiency of heat exchanger 406 and reducing the footprint of power generation system 400.

[0040] Power generation system 400 has an efficiency greater than that of power generation system 100 because heat exchanger 406 is directly coupled to exhaust section 110 of gas turbine engine 102, and first turbine 402 drives turbocharger 106, while second turbine 404 drives compressor 122. Separating the driving of turbocharger 106 and compressor 122 increases the efficiency of power generation system 400. Consequently, first turbine 402 and second turbine 404 extract more useful work from the working fluid, thereby increasing the efficiency of power generation system 400. Thus, the orientation of heat exchanger 406, first turbine 402, and second turbine 404 facilitates increasing the total power generated by power generation system 400 and facilitates improving the efficiency of power generation system 400.

[0041] Figure 5 Is the use of power generation system ( Figure 1Flowchart of an exemplary method 500 for generating electricity (as shown). The power generation system includes a combustion system, a heat recovery system, and a turbocharger. The method 500 includes combusting 502 a mixed fuel to generate electricity and an exhaust flow. In addition, the method 500 also includes directing 504 the exhaust flow from the combustion system to the heat recovery system. In addition, the method 500 also includes using the exhaust flow to heat 506 a supercritical working fluid within the heat recovery system. In addition, the method 500 also includes driving 508 a turbocharger using the supercritical working fluid. The method 500 also includes compressing 510 a compressed air flow using the turbocharger. The method 500 also includes directing 512 the compressed air flow to the combustion system. Finally, the method 500 also includes combusting 514 a fuel using the compressed air flow and at least one additional air flow to generate electricity and an exhaust flow.

[0042] The above-described power generation system can be effectively used in areas with higher altitudes and / or higher ambient temperatures. Specifically, each power generation system described herein includes a gas turbine engine, a heat recovery system, a turbocharger, and a generator. The gas turbine engine combusts fuel and produces an exhaust gas stream. The exhaust gas stream is directed to the heat recovery system, where heat is recovered from the exhaust gas stream to power the turbocharger. The turbocharger directs a compressed air stream to the gas turbine engine, where the compressed air stream is mixed with fuel and combusted to increase power output and gas turbine engine efficiency.

[0043] In an exemplary embodiment, the power generation system is located at a high altitude and / or a higher ambient temperature. Consequently, the air used by the gas turbine engine to combust fuel has a lower density than air at lower altitudes and / or lower ambient temperatures. Because the air is less dense, the gas turbine engine produces less power than a gas turbine engine at a lower altitude and / or lower ambient temperature. The turbocharger increases the air flow entering the gas turbine engine for combustion, thereby increasing the gas turbine engine's overall power generation. Furthermore, because the heat recovery system utilizes heat recovered from the exhaust gas flow to drive the turbocharger, the power generated by the power generation system is increased without compromising efficiency. Furthermore, in an exemplary embodiment, the working fluid (i.e., the fluid used to convert heat into usable energy) is supercritical CO2, and therefore, the heat recovery system is not water-intensive. Therefore, when the power generation system is located at higher altitudes, higher temperatures, and / or in arid regions, the power generation system improves the power generation and efficiency of the gas turbine engine while reducing water consumption.

[0044] Among other things, exemplary technical effects of the systems and methods described herein include at least one of: (a) using turbine power to drive a turbocharger via a supercritical working fluid; (b) using a heat recovery system to recover heat from an exhaust stream; and (c) using compressed air from a turbocharger to operate a combustion system.

[0045] Exemplary embodiments of systems and methods for power generation are described above in detail. The systems and methods are not limited to the specific embodiments described herein, but rather, components of the systems and / or steps of the methods can be used independently and separately from other components and / or steps described herein. For example, the methods can also be used in conjunction with other power generation systems and are not limited to practice with only the other power generation systems described herein. Rather, the exemplary embodiments can be implemented and used in conjunction with many other power generation applications.

[0046] Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the embodiments of the present disclosure, any feature of a drawing may be referenced and / or claimed in conjunction with any feature of any other drawing.

[0047] This written description uses examples to disclose embodiments of the present disclosure, including the best mode, and also to enable any person skilled in the art to practice the embodiments of the present disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the embodiments described herein is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A power generation system (100), comprising: a combustion system (102) configured to combust a fuel with an air flow, the combustion system (102) further configured to produce an exhaust flow; a turbocharger (106) configured to compress a compressed air flow and direct the compressed air flow to the combustion system (102), wherein the combustion system (102) is configured to combust the fuel with the compressed air flow and an additional air flow; and A heat recovery system (104) is configured to recover heat from the exhaust flow and drive the turbocharger (106), wherein the heat recovery system (104) uses a supercritical working fluid to absorb heat from the exhaust flow before the heated supercritical working fluid drives the turbocharger (106).

2. The power generation system (100) of claim 1, wherein the combustion system (102) comprises a gas turbine engine (102).

3. The power generation system (100) of claim 1, further comprising a generator (108) coupled to the combustion system (102), wherein the generator (108) is configured to generate electricity.

4. The power generation system (100) of claim 1, wherein the heat recovery system (104) comprises: at least one heat exchanger (114) configured to receive the exhaust stream exhausted from the combustion system (102), the at least one heat exchanger (114) configured to transfer heat from the exhaust stream to the supercritical working fluid; and At least one turbine (116) is coupled to the turbocharger (106), the at least one turbine (116) being configured to receive the supercritical working fluid from the at least one heat exchanger (114), wherein the at least one turbine (116) is further configured to extract useful work from the supercritical working fluid to drive the turbocharger (106).

5. The power generation system (100) of claim 4, wherein the heat recovery system (104) further comprises at least one compressor (122) coupled to the at least one turbine (116), the at least one compressor (122) being configured to compress the supercritical working fluid.

6. The power generation system (100) of claim 5, wherein the heat recovery system (104) further comprises at least one heat exchanger (118) configured to transfer heat from an exhaust port of the at least one turbine (116) to an exhaust port of the at least one compressor (122).

7. The power generation system (100) of claim 6, the heat recovery system (104) further comprising at least one cooler (120) configured to cool the exhaust port of the at least one turbine (116).

8. A method (500) of generating electricity using a power generation system (100), the power generation system (100) comprising a combustion system (102), a heat recovery system (104), and a turbocharger (106), the method (500) comprising: combusting (502) a fuel with an air flow using the combustion system (102) to generate electricity and an exhaust flow; directing (504) the exhaust gas flow from the combustion system (102) to the heat recovery system (104); heating (506) a supercritical working fluid within the heat recovery system (104) using the exhaust stream; driving (508) the turbocharger (106) using the heated supercritical working fluid; compressing (510) a compressed air flow using the turbocharger (106); and The fuel is combusted (514) with the compressed air flow and the additional air flow to generate electricity and the exhaust gas flow.

9. The method (500) of claim 8, wherein combusting (514) the fuel with the air flow using the combustion system (102) to generate electricity and the exhaust flow comprises combusting the fuel with the air flow using a gas turbine engine (102) to generate electricity and the exhaust flow.

10. The method (500) of claim 8, wherein heating (506) the supercritical working fluid within the heat recovery system (104) using the exhaust stream comprises transferring heat from the exhaust stream to the supercritical working fluid using at least one heat exchanger (114).

11. The method (500) of claim 8, wherein driving (508) the turbocharger (106) using the supercritical working fluid comprises extracting useful work from the supercritical working fluid using a turbine (116) to drive the turbocharger (106).

12. The method (500) of claim 11, further comprising cooling an exhaust of the turbine (116) using at least one cooler (120).

13. The method (500) of claim 11, further comprising compressing the supercritical working fluid using a compressor (122) coupled to the turbine (116).

14. The method (500) of claim 13, further comprising transferring heat from an exhaust of the turbine (116) to an exhaust of the compressor (122) using at least one heat exchanger (118).

15. The method (500) of claim 11, further comprising generating electricity from an auxiliary generator (108) coupled to the turbine (116).

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