Combined cycle power plant with exhaust gas recirculation

Abstract

A combined cycle power plant (100) includes a gas turbine engine (102) having a compressor inlet (106) and a turbine outlet (110) configured to discharge a first exhaust gas stream (120) therefrom. The heat recovery steam generator (112) is configured to receive the first exhaust gas stream (120), extract heat from the first exhaust gas stream (120) to generate steam, and discharge a second exhaust gas stream (122) therefrom. The steam turbine (104) is configured to discharge a steam flow (128) therefrom, the carbon capture system (134) is configured to receive the steam flow (128), the recirculation blower (170) is configured to pressurize a portion of the second exhaust gas flow (122) for recirculation toward the compressor inlet (106), and the air inlet blower (168) is configured to pressurize an air flow (174) directed toward the compressor inlet (1060), such that a pressurized mixed flow stream formed by the portion of the second exhaust gas stream (122) and the air stream (174) is received at the compressor inlet (106).

Description

Background Art

[0001] The present disclosure relates generally to power generation systems and, more particularly, to systems that use pressurized exhaust gas recirculation to increase device output.

[0002] At least some known power generation devices generate energy derived from the combustion of fuels containing carbon and hydrogen, such as coal, oil, peat, waste, biofuels, natural gas, etc. In addition to carbon and hydrogen, such fuels may also contain oxygen, moisture, and / or pollutants. Thus, the combustion of such fuels may result in the production of a gas stream containing pollutants in the form of ash, carbon dioxide (CO2), sulfur compounds (often in the form of sulfur oxides, referred to as "SOx"), nitrogen compounds (often in the form of nitrogen oxides, referred to as "NOx"), chlorine, mercury, and / or trace elements.

[0003] To facilitate the removal of pollutants from the gas stream, at least some known power plants may use a capture system that attempts to capture pollutants before the exhaust gas stream is released into the atmosphere. For example, some known power plants use a carbon capture system that attempts to capture carbon dioxide (CO2) after combustion and store it underground to reduce the amount of CO2 released into the atmosphere. However, due to the power required for the carbon capture process, the carbon capture process may reduce the overall efficiency of the power plant, and / or limit the power production of the power plant. Therefore, at least some of such power plant systems operate with reduced power production. Summary of the invention

[0004] In one aspect, a combined cycle power generation device is provided, comprising a gas turbine engine having a compressor inlet and a turbine outlet from which a first exhaust gas stream is discharged. A heat recovery steam generator is located downstream of the turbine, wherein the heat recovery steam generator is configured to receive the first exhaust gas stream, extract heat from the first exhaust gas stream, and discharge a second exhaust gas stream therefrom. The steam turbine is configured to discharge a steam stream therefrom. A carbon capture system is located downstream of the steam turbine and is oriented to receive a steam stream. A recirculation blower is connected downstream of the heat recovery steam generator and is configured to pressurize a portion of the second exhaust gas stream for recirculation toward the compressor inlet. The air inlet blower is configured to pressurize the air flow directed toward the compressor inlet so that a pressurized mixed flow stream is formed by the portion of the second exhaust gas stream and the air flow before the mixture enters the compressor inlet. The air inlet blower is configured to pressurize the air flow directed toward the compressor inlet so that a pressurized mixed flow stream is formed by the portion of the second exhaust gas stream and the air flow before the mixture enters the compressor inlet.

[0005] In yet another aspect, a combined cycle power generation device is provided, comprising a gas turbine engine having a compressor inlet and a turbine outlet from which a first exhaust gas stream is discharged. A heat recovery steam generator is located downstream of the turbine and is configured to receive the first exhaust gas stream, extract heat from the first exhaust gas stream, and discharge a second exhaust gas stream therefrom. The steam turbine is configured to discharge a steam stream therefrom. The carbon capture system is located downstream of the steam turbine and is oriented to receive the steam stream. The first cooler is located between the heat recovery steam generator and the carbon capture system. The first cooler is configured to facilitate cooling of the second exhaust gas stream directed toward the carbon capture system, thereby defining a third exhaust gas stream. The recirculation blower is configured to pressurize a portion of the third exhaust gas stream for recirculation toward the compressor inlet. The air inlet blower is configured to pressurize the air flow directed toward the compressor inlet so that a pressurized mixed flow stream is formed by the portion of the third exhaust gas stream and the air flow before the mixture enters the compressor inlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of an exemplary combined cycle power plant.

[0007] Figure 2 is a schematic diagram of another exemplary combined cycle power plant.

[0008] Figure 3 is a schematic diagram of another exemplary combined cycle power plant.

[0009] Figure 4 is a schematic diagram of yet another exemplary combined cycle power plant.

[0010] Figure 5 is a schematic diagram of another exemplary combined cycle power plant.

[0011] Figure 6 is a schematic diagram of another exemplary combined cycle power plant. DETAILED DESCRIPTION

[0012] Embodiments described herein relate to power generation systems that use pressurized exhaust gas recirculation to increase device output. The basic idea is to use both pressurized inlet air and pressurized exhaust gas recirculation to increase the gas turbine compressor inlet pressure (i.e., supercharging). The boost provided to the compressor promotes increasing the gas turbine power output to a level sufficient to at least balance the blower fan power consumption and the steam cycle loss from the steam outlet to the carbon capture system. In one embodiment, only fans for inlet air and exhaust gas recirculation pressurization are used, so that the gas turbine exhaust gas and the heat recovery steam generator (HRSG) exhaust gas can be moderately pressurized to reduce the need for additional blower fans to pressurize the feed of the absorber tower located downstream of the HRSG. In alternative embodiments, additional or third fans can be used to pressurize the feed of the carbon capture system, or can be used as an induced draft fan at the exhaust. Therefore, the system described herein promotes the recovery of the device output lost when the exhaust gas is recirculated to the gas turbine inlet.

[0013] Unless otherwise indicated, approximate language as used herein, such as "substantially", "substantially" and "about" indicate that as will be recognized by those of ordinary skill in the art, the terms so modified may apply only to approximate degrees, rather than absolute or perfect degrees. Therefore, the values ​​modified by one or more terms (such as "about", "approximately" and "substantially") are not limited to the specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value. In addition, unless otherwise indicated, the terms "first", "second", etc. are used only as tags in this article, and are not intended to impose order, position or hierarchical requirements on the items to which these terms are related. In addition, for example, a reference to a "second" item does not require or exclude the existence of, for example, a "first" or lower numbered item or a "third" or higher numbered item.

[0014] Figure 1 is a schematic diagram of an exemplary combined cycle power plant 100. In an exemplary embodiment, the power plant 100 includes a gas turbine 102 and a steam turbine 104. The gas turbine 102 includes a compressor 106, a combustor 108, and a turbine 110 coupled together in a series flow relationship. In operation, the combustor 108 receives air from the compressor section 106 and fuel from the fuel supply, and uses the fuel and air to form a fuel-air mixture, which is combusted to generate combustion gases. The combustion gases are directed through the turbine 110 and discharged from the turbine 110. In an exemplary embodiment, the power plant 100 also includes a steam cycle arrangement, which includes a heat recovery steam generator (HRSG) 112 and the steam turbine 104. In some embodiments, the steam cycle arrangement may also include other components, including a condenser 114 and at least one circulating pump 116.

[0015] The HRSG 112 includes an inlet 118 oriented and sized to receive a first exhaust gas stream 120 from the gas turbine 102. Heat is extracted from the first exhaust gas stream 120, and the second exhaust gas stream 122 is discharged via a first outlet 124 at a lower temperature than the temperature of the first exhaust gas stream 120. The HRSG 112 also includes a second outlet 126 that discharges a first steam stream 128. The steam turbine 104 receives the first steam stream 128 and then discharges a circulating stream 130 therefrom. In some embodiments, the steam turbine 104 may include an additional pressure steam turbine located downstream thereof. In an exemplary embodiment, the gas turbine 102 and the steam turbine 104 are each coupled to a generator 132 for generating electricity therefrom.

[0016] In an exemplary embodiment, the power generation device 100 also includes a carbon capture system 134. During operation, the carbon capture system 134 produces a carbon-depleted waste gas stream 140 and a carbon dioxide stream 138. The carbon capture system 134 may include one or more separators, which are used either alone or in combination with other separation processes (such as carbon dioxide selective membrane technology, adsorption processes, diaphragms, etc.). The waste gas stream 140 can be discharged from the carbon capture system 134 into the surrounding environment. In some other embodiments, the waste gas stream 140 is further processed before being discharged to the environment or elsewhere. For example, at least a portion of the carbon dioxide stream 138 can be directed to a supercritical pressure for transportation and / or storage.

[0017] The carbon capture system 134 generally includes an absorber 142, a stripper 144, and a reboiler 146. In operation, a second exhaust gas stream 122 discharged from the HRSG 112 is directed toward the absorber 142. The exhaust gas 122 may be pre-treated to remove particulates and impurities, such as SOx and NOx, before entering the absorber 142. Additionally, in an exemplary embodiment, a first cooler 148 and a booster blower 150 are coupled between the HRSG 112 and the carbon capture system 134. The first cooler 148, such as a quench tower, cools a portion of the exhaust gas stream 122 that is directed toward the carbon capture system 134. The booster blower 150 pressurizes the portion of the stream 122 before it is directed toward the carbon capture system 134 and helps control the pressure within the carbon capture system 134.

[0018] The solvent 152 rich in carbon dioxide is discharged from the bottom of the absorber 142 and then directed to the stripper 144 via a pump 154. The solvent 156 lean in carbon dioxide is also discharged from the bottom of the stripper 144 and directed back to the upper portion of the absorber 142 via a reboiler 146, a pump 166 and a heat exchanger 158. The absorber 142 can be any structure that is generally used to provide gas-liquid contact and absorption. The absorber 142 and the stripper 144 can be combined with a variety of internal components, such as trays, packings and / or carriers. In one embodiment, the absorber 142 absorbs carbon dioxide from the incoming exhaust gas by countercurrent. The stripper 144 removes carbon dioxide from the solvent 152. The absorber 142 and the stripper 144 can be variably sized based on the desired amount of carbon dioxide to be removed, and can be sized based on various engineering design equations. In addition, a single stripper 144 can serve multiple absorbers 142.

[0019] In an exemplary embodiment, the solvent can be a solution or dispersion (typically in water) of one or more absorbent compounds (i.e., compounds that can produce an absorbent fluid in water) that enhances the ability of the absorbent fluid to preferentially remove carbon dioxide from the exhaust gas compared to water alone. For example, the solvent can be, but is not limited to, monoethanolamine (MEA). An inhibitor can be included in the solvent to inhibit degradation of the solvent.

[0020] In an exemplary embodiment, the solvent 152 is preheated relative to the solvent 156 in a countercurrent heat exchanger 158 and is then supplied to the upper portion of the stripper 144. The stripper 144 is a pressurized unit in which carbon dioxide is recovered from the solvent 152. The stripper 144 typically includes a reboiler 146 that receives a portion of the solvent 156 that exits the bottom portion of the stripper 144. The reboiler 146 evaporates the solvent 156 and directs the solvent vapor 160 to the stripper 144 to increase carbon dioxide separation. A single stripper may include more than one reboiler 146. The reboiler 146 receives steam directed from the steam turbine 104 (such as from a recycle stream) to provide a heating duty in the reboiler 146.

[0021] Vapor 162 exiting the top of stripping column 144 is partially condensed in overhead condenser 165. The condensed portion of vapor 162 is returned to stripping column 144 as reflux 164. Reflux 164 may be diverted through an accumulator (not shown) and a pump (not shown) prior to entering stripping column 144. Carbon dioxide gas stream 138 is removed from condenser 165 for transport and / or storage.

[0022] In an exemplary embodiment, the power generation device 100 also includes an air inlet blower 168, a recirculation blower 170, and a controller 172. The air inlet blower 168 pressurizes the air flow 174 directed toward the inlet 176 of the compressor 106. In this embodiment, a portion of the second exhaust gas flow 122 is also recirculated toward the inlet 176 as an exhaust gas recirculation flow 178. The recirculation blower 170 pressurizes the exhaust gas recirculation flow 178 before it enters the inlet 118 of the compressor 106. In some embodiments, the air flow 174 is combined and mixed with the exhaust gas recirculation flow 178 to form a pressurized mixed flow stream (not shown), and then the mixture enters the compressor inlet. Therefore, the boost provided to the compressor inlet helps to increase the power density of the power generation device 100.

[0023] However, the power consumption of the operation of the blowers 150, 168 and 170 may also result in a reduction in the efficiency of the device. Without being bound by any particular theory, it is believed that the pressurization provided at the inlet 118 provides an increase in the output of the power plant 100 that is greater than any reduction in efficiency caused by blower power consumption and steam cycle losses that may result during operation of the power plant 100.

[0024] In an exemplary embodiment, the power plant 100 also includes a controller 172 that monitors and / or controls the operation of the power plant 100. For example, the controller 172 can monitor the power consumption of the blowers 150, 168, and / or 170, and can also determine, for example, steam cycle losses due to the discharge flow 130 toward the carbon capture system 134. The controller 172 can also dynamically determine the power consumption and steam cycle losses and adjust the operation of the power plant 100 accordingly. Therefore, in one embodiment, the operation of the blowers 150, 168, and / or 170 is variably adjusted by the controller 172 to increase the output of the plant to a level that overcomes the power consumption and steam cycle losses, which is a result of the boost pressure provided to the compressor 106. That is, the controller 172 can adjust the flow rate of the exhaust gas recirculation flow 178 and / or the air flow 174 directed to the compressor inlet to provide an increase in the output of the power plant 100 that is greater than any losses caused by the blower power consumption and steam cycle losses. In an exemplary embodiment, the size of the blowers 150, 168, and / or 170 and / or the overall size of the recirculation line are variably selected to provide a predetermined desired mixture at base load (i.e., full boost) with minimal control action. Adjusting the blower speed and / or changing the position of the blower guide vanes (not shown) facilitates managing flow and reducing boost as power is reduced. At and below at least some reduced load, at least one of the blowers 168, 170, 175 (at Figure 5 ) and / or possibly 190 (shown in Figure 6 ) can be de-energized so that recirculation flow control is promoted via a damper in the EGR duct. In an exemplary embodiment, the device output is generally proportional to the total fuel burned, which is subject to the constraints of the gas flow at the compressor inlet. Raising the inlet pressure to above atmospheric pressure using EGR and inlet blower 168 and / or 170 or 175 helps provide a substantially linear increase in the gas flow through the compressor and arriving at the burner, thus resulting in a linear increase in power output. More generally, such action is similar to operating the device at a physically lower altitude, where the air density is higher than the air density at sea level or the actual density at the device location.

[0025] Figure 2 1 is a schematic diagram of another exemplary combined cycle power plant 100. In the exemplary embodiment, the power plant 100 includes an air inlet blower 168 and a recirculation blower 170, but does not include a booster blower 150 (eg, Figure 1 ). Figure 1 In the embodiment shown, the inclusion of blower 150 is dependent upon the designed internal pressure capabilities of the HRSG, GT exhaust ducting and absorber 142 and the ventilation losses through the equipment to discharge clean exhaust gas to the atmosphere at 140. Figure 2 In the embodiment, the exhaust system of the device 100 has been designed to Figure 1 The device 100 shown in FIG. 1 operates at a slightly increased pressure compared to the device 100 shown in FIG. 1 , and thus the blower 150 may be eliminated in order to simplify the system and improve reliability. Figure 2 In the embodiment shown, performance should also generally be slightly better, since the power lost in the turboexpander 110 should be less than the power that would be consumed by including the blower 150. Figure 2 In an embodiment, an increase in power output is facilitated as a result of compressor boost.

[0026] Figure 3 and Figure 4 1 is a schematic diagram of another exemplary combined cycle power plant 100. In an exemplary embodiment, the power plant 100 includes a second cooler 180, such as a quench tower, which facilitates cooling the exhaust gas recirculation stream 178 before it enters the compressor inlet. Providing independent control of the EGR gas temperature via cooler 180 to the inlet 176 and via cooler 148 to the adsorber 142 helps optimize the temperature of each stream. The second cooler 180 can be located between the HRSG 112 and the recirculation blower 170, such as Figure 3 As shown, or alternatively located between the recirculation blower 170 and the compressor inlet, as shown Figure 4As shown. Positioning the second cooler 180 between the recirculation blower 170 and the compressor inlet helps mitigate any temperature increase of the exhaust gas recirculation flow 178 due to the pressurization caused by the recirculation blower 170. Although the additional equipment adds cost and complexity to the device 100, the benefits of including the cooler 180 before or after the blower 170 outweigh these costs because supplying a cooler mixed inlet gas temperature to the compressor 106 is beneficial to power output (e.g., due to denser gas, the required boost pressure is reduced for the same device output). Cooling also helps reduce moisture in the EGR flow through condensation.

[0027] Figure 5 and Figure 6 is a schematic diagram of another exemplary combined cycle power generation device 100. More specifically, Figure 5 In the exemplary embodiment shown, the power generation device 100 pressurizes the exhaust gas recirculation flow 178 and the inlet air flow 174 in a single booster blower or compressor 175 before the combined flow 179 enters the compressor inlet. The use of the blower 175 helps to increase the net device output. In an exemplary embodiment, the inlet air flow 174 flows through the inlet filter 181 before the flow 174 is combined with the exhaust gas recirculation flow 178. Although the additional equipment may increase the complexity of the device 100, the benefits of reducing the number of blowers used by the device 100 outweigh these costs. In addition, a single blower 175 is conducive to the layout flexibility of its position relative to the compressor inlet, including, for example, additional inlet adjustments before the recirculation flow 178 enters the compressor inlet. In addition, depending on the operating conditions of the device 100, a single blower 175 can contribute to cost reduction, maintenance and / or accessibility. In addition, like other blowers used in the device 100 in each embodiment described herein, the blower 175 can be powered off according to the device load requirements. In this embodiment, an exhaust gas recirculation supply connection downstream of cooler 148 facilitates cooling of exhaust gas flow 148 prior to the flow entering absorber 142 and / or turbine inlet via steam 178. This orientation helps reduce and / or simplify the complexity of the exhaust system of device 100.

[0028] exist Figure 6 In the illustrated embodiment, the blower 175 (in Figure 5) has been removed, and a compressor with a shaft-driven booster blower 190 has been included to pressurize convection 179. In one embodiment, the blower 190 includes gears to reduce its speed relative to the drivetrain. Although the blower 190 reduces the options for inlet gas treatment after the blower, the blower 190 does make the device 100 compact compared to other embodiments because the blower 190 is closely coupled to the main compressor inlet 106. In addition, the axial shaft-driven compressor helps to improve overall device efficiency by eliminating motor losses and because its design generally has higher efficiency rights than known independent blowers. In addition, a dedicated shaft-driven booster also promotes increased design flexibility to optimize boost pressure and increase total device power, although it is more difficult to de-energize such a booster at lower device loads when no power boost is required.

[0029] Embodiments described herein relate to power generation systems that use pressurized exhaust gas recirculation to increase device output. The boost provided to the gas turbine compressor inlet pressure by both pressurized inlet air and pressurized exhaust gas recirculation facilitates increased gas turbine power output, the boost being sufficient to at least balance both blower fan power consumption and steam cycle losses from the steam outlet to the carbon capture system. For example, the boost increases the power density of the power generation device, which should provide an improvement on a $ / kW basis. Thus, adjusting the boost provided by the blower described herein provides a knob that can be used to enhance part load performance.

[0030] Other aspects of the disclosure are provided by the subject matter of the following clauses:

[0031] 1. A combined cycle power generation device, comprising: a gas turbine engine, the gas turbine engine including a compressor inlet and a turbine outlet from which a first exhaust gas stream is discharged; a heat recovery steam generator, the heat recovery steam generator being located downstream of the turbine, the heat recovery steam generator being configured to: receive the first exhaust gas stream; extract heat from the first exhaust gas stream to generate steam; and discharge a second exhaust gas stream therefrom; a steam turbine, the steam turbine being oriented to receive steam from the heat recovery steam generator and to discharge a steam stream therefrom; a carbon capture system, the carbon capture system being located downstream of the steam turbine and oriented to receive the steam stream; a recirculation blower, the recirculation blower being coupled downstream of the heat recovery steam generator and being configured to pressurize a portion of the second exhaust gas stream for recirculation toward the compressor inlet; and an air inlet blower, the air inlet blower being configured to pressurize an air stream directed toward the compressor inlet so that a pressurized mixed flow stream is formed by the portion of the second exhaust gas stream and the air stream before the mixture enters the compressor inlet.

[0032] 2. The combined cycle power generation device according to claim 1 further includes a controller configured to: monitor the power consumption of the recirculation blower and the air inlet blower; determine the steam cycle losses caused by discharging the steam flow toward the carbon capture system; and adjust the flow rate of the exhaust gas flow recirculated toward the compressor inlet to facilitate improved operation of the combined cycle power generation device.

[0033] 3. A combined cycle power plant according to any preceding clause, further comprising a first cooler coupled between the heat recovery steam generator and the carbon capture system, the first cooler being configured to facilitate cooling of the second exhaust gas flow directed towards the carbon capture system.

[0034] 4. A combined cycle power plant according to any preceding clause, further comprising a booster blower coupled in fluid communication with the first cooler, the booster blower being configured to pressurize the second exhaust gas flow directed towards the carbon capture system.

[0035] 5. A combined cycle power plant according to any preceding clause, further comprising a second cooler configured to facilitate cooling of the portion of the second exhaust gas flow recirculated towards the compressor inlet.

[0036] 6. A combined cycle power plant according to any preceding clause, wherein the second cooler is located between the heat recovery steam generator and the recirculation blower.

[0037] 7. A combined cycle power plant according to any preceding clause, wherein the second cooler is located between the recirculation blower and the compressor inlet.

[0038] 8. A combined cycle power generation device, comprising: a gas turbine engine, the gas turbine engine including a compressor inlet and a turbine outlet oriented to discharge a first exhaust gas flow therefrom; a heat recovery steam generator, the heat recovery steam generator being located downstream of the turbine, the heat recovery system generator being configured to: receive the first exhaust gas flow; extract heat from the first exhaust gas flow to generate steam; and discharge a second exhaust gas flow therefrom; a recirculation blower, the recirculation blower being located downstream of the heat recovery steam generator and being configured to pressurize a portion of the second exhaust gas flow for recirculation toward the compressor inlet; and an air inlet blower, the air inlet blower being configured to pressurize an air flow directed toward the compressor inlet so that a pressurized mixed flow stream is formed by the portion of the second exhaust gas flow and the air flow before the mixture enters the compressor inlet.

[0039] 9. The combined cycle power plant according to the preceding clause further comprises: a steam turbine configured to discharge a steam flow therefrom; and a carbon capture system located downstream of the steam turbine and oriented to receive the steam flow.

[0040] 10. A combined cycle power generation device according to any of the preceding clauses, further comprising a controller configured to: monitor the power consumption of the recirculation blower and the air inlet blower; determine the steam cycle losses caused by discharging the steam flow toward the carbon capture system; and adjust at least one of the flow rate and temperature of the exhaust gas flow recirculated toward the compressor inlet to facilitate improved operation of the combined cycle power generation device.

[0041] 11. A combined cycle power plant according to any preceding clause, further comprising a first cooler coupled between the heat recovery steam generator and the carbon capture system, the first cooler being configured to facilitate cooling of the second exhaust gas flow directed towards the carbon capture system.

[0042] 12. A combined cycle power plant according to any preceding clause, further comprising a booster blower coupled in fluid communication with the first cooler, the booster blower being configured to pressurize the second exhaust gas flow for directing towards the carbon capture system.

[0043] 13. A combined cycle power plant according to any preceding clause, further comprising a second cooler configured to facilitate cooling of the portion of the second exhaust gas flow recirculated towards the compressor inlet.

[0044] 14. A combined cycle power plant according to any preceding clause, wherein the second cooler is located between the heat recovery steam generator and the recirculation blower.

[0045] 15. A combined cycle power plant according to any preceding clause, wherein the second cooler is located between the recirculation blower and the compressor inlet.

[0046] 16. A combined cycle power generation device, comprising: a gas turbine engine, the gas turbine engine including a compressor inlet and a turbine outlet from which a first exhaust gas stream is discharged; a heat recovery steam generator, the heat recovery steam generator being located downstream of the turbine, the heat recovery system steam generator being configured to: receive the first exhaust gas stream; extract heat from the first exhaust gas stream to generate steam; and discharge a second exhaust gas stream therefrom; a steam turbine, the steam turbine being configured to discharge a steam stream therefrom; a carbon capture system, the carbon capture system being located downstream of the steam turbine and oriented to receive the steam stream; a first cooler, the first cooler being located at the heat recovery steam generator generator and the carbon capture system, the first cooler being configured to facilitate cooling a first portion of the second exhaust gas flow directed toward the carbon capture system, thereby defining a third exhaust gas flow; a recirculation blower connected downstream of the heat recovery steam generator and configured to pressurize a second portion of the second exhaust gas flow for recirculation toward the compressor inlet; and an air inlet blower configured to pressurize an air flow directed toward the compressor inlet, so that a pressurized mixed flow stream is formed by the second portion of the second exhaust gas flow and the air flow before the mixture enters the compressor inlet.

[0047] 17. The combined cycle power generation device according to the preceding clause further includes a controller configured to: monitor the power consumption of the recirculation blower and the air inlet blower; determine the steam cycle losses caused by discharging the steam flow toward the carbon capture system; and adjust one of the flow rate and temperature of the exhaust gas flow recirculated toward the compressor inlet to facilitate increasing the net output of the combined cycle power generation device, wherein the net output exceeds the blower power consumption and the steam cycle losses.

[0048] 18. A combined cycle power plant according to any preceding clause, further comprising a second cooler configured to facilitate cooling of the second portion of the second exhaust gas flow recirculated towards the compressor inlet.

[0049] 19. A combined cycle power plant according to any preceding clause, wherein the second cooler is located between the heat recovery steam generator and the recirculation blower.

[0050] 20. A combined cycle power plant according to any preceding clause, wherein the second cooler is located between the recirculation blower and the compressor inlet.

[0051] The above description is intended to be exemplary only, and those skilled in the art will recognize that changes may be made to the described embodiments without departing from the scope of the disclosed invention. In view of the review of this disclosure, modifications falling within the scope of the invention will be apparent to those skilled in the art, and such modifications are intended to fall within the appended claims.

[0052] Although specific features of various embodiments of the present invention may be shown in some drawings and not in others, this is for convenience only. In addition, reference to "one embodiment" in the above description is not intended to be interpreted as excluding the existence of additional embodiments that also include the described features. In accordance with the principles of the present invention, any feature of a drawing may be referenced and / or claimed in conjunction with any feature of any other drawing.

[0053] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.

Claims

1. A combined cycle power generation device (100), comprising: A gas turbine engine (102) comprising a compressor inlet (106) and a turbine outlet (110) from which a first exhaust gas stream (120) is discharged; A heat recovery steam generator (112) is located downstream of the gas turbine engine (102), the heat recovery steam generator (112) being configured to: receiving the first exhaust gas stream (120); extracting heat from the first exhaust gas stream (120) to generate steam; and discharging a second exhaust gas stream (122) therefrom; a steam turbine (104) oriented to receive steam from the heat recovery steam generator (112) and to discharge a steam flow (128) therefrom; a carbon capture system (134) located downstream of the steam turbine (104) and oriented to receive the steam flow (128); a recirculation blower (170) coupled downstream of the heat recovery steam generator (112) and configured to pressurize a portion of the second exhaust gas stream (122) for recirculation toward the compressor inlet (106); and An air inlet blower (168) is configured to pressurize an air flow (174) directed toward the compressor inlet (106) so that a pressurized mixed flow stream is formed by the portion of the second exhaust gas flow (122) and the air flow (174) before the mixture enters the compressor inlet (106).

2. The combined cycle power generation device (100) according to claim 1, further comprising a controller (172), wherein the controller is configured to: monitoring power consumption of the recirculation blower (170) and the air inlet blower (168); determining steam cycle losses resulting from venting the steam stream (128) toward the carbon capture system (134); and The flow of the exhaust gas stream recirculated toward the compressor inlet (106) is regulated to facilitate improved operation of the combined cycle power plant (100).

3. The combined cycle power plant (100) of claim 1, further comprising a first cooler (148) coupled between the heat recovery steam generator (112) and the carbon capture system (134), the first cooler (148) being configured to facilitate cooling of the second exhaust gas flow (122) directed toward the carbon capture system (134).

4. The combined cycle power plant (100) according to claim 3, further comprising a boost blower (150) coupled to the first cooler (148) in a fluid communication manner, the boost blower (150) being configured to pressurize the second exhaust gas flow (122) directed toward the carbon capture system (134).

5. The combined cycle power plant (100) of claim 1, further comprising a second cooler (180) configured to facilitate cooling the portion of the second exhaust gas flow (122) recirculated toward the compressor inlet (106).

6. The combined cycle power plant (100) according to claim 5, wherein the second cooler (180) is located between the heat recovery steam generator (112) and the recirculation blower (170).

7. The combined cycle power plant (100) according to claim 5, wherein the second cooler (180) is located between the recirculation blower (170) and the compressor inlet (106).

8. A combined cycle power generation device (100), comprising: A gas turbine engine (102) comprising a compressor inlet (106) and a turbine outlet (110) oriented to discharge a first exhaust gas stream (120) therefrom; A heat recovery steam generator (112) is located downstream of the turbine, and the heat recovery steam generator (112) is configured to: receiving the first exhaust gas stream (120); extracting heat from the first exhaust gas stream (120) to generate steam; and discharging a second exhaust gas stream (122) therefrom; a recirculation blower (170) located downstream of the heat recovery steam generator (112) and configured to pressurize a portion of the second exhaust gas stream (122) for recirculation toward the compressor inlet (106); and An air inlet blower (168) is configured to pressurize an air flow (174) directed toward the compressor inlet (106) so that a pressurized mixed flow stream is formed by the portion of the second exhaust gas flow (122) and the air flow (174) before the mixture enters the compressor inlet (106).

9. The combined cycle power generation device (100) according to claim 8, further comprising: a steam turbine (104) configured to discharge a steam flow (128) therefrom; and A carbon capture system (134) is located downstream of the steam turbine (104) and is oriented to receive the steam flow (128).

10. The combined cycle power generation device (100) according to claim 9, further comprising a controller (172), wherein the controller is configured to: monitoring power consumption of the recirculation blower (170) and the air inlet blower (168); determining steam cycle losses resulting from venting the steam stream (128) toward the carbon capture system (134); and At least one of the flow rate and temperature of the exhaust gas stream recirculated toward the compressor inlet (106) is adjusted to facilitate improved operation of the combined cycle power plant (100).

11. The combined cycle power plant (100) of claim 10, further comprising a first cooler (148) coupled between the heat recovery steam generator (112) and the carbon capture system (134), the first cooler (148) being configured to facilitate cooling of the second exhaust gas flow (122) directed toward the carbon capture system (134).

12. The combined cycle power plant (100) of claim 11, further comprising a booster blower (150) fluidically coupled to the first cooler (148), the booster blower (150) being configured to pressurize the second exhaust gas flow (122) for being directed toward the carbon capture system (134).

13. The combined cycle power plant (100) of claim 10, further comprising a second cooler (180) configured to facilitate cooling the portion of the second exhaust gas flow (122) recirculated toward the compressor inlet (106).

14. The combined cycle power plant (100) according to claim 13, wherein the second cooler (180) is located between the heat recovery steam generator (112) and the recirculation blower (170).

15. The combined cycle power plant (100) of claim 13, wherein the second cooler (180) is located between the recirculation blower (170) and the compressor inlet (106).

16. A combined cycle power generation device (100), comprising: A gas turbine engine (102) comprising a compressor inlet (106) and a turbine outlet (110) from which a first exhaust gas stream (120) is discharged; A heat recovery steam generator (112), the heat recovery steam generator being located downstream of the turbine, the heat recovery system steam generator (112) being configured to: receiving the first exhaust gas stream (120); extracting heat from the first exhaust gas stream (120) to generate steam; and discharging a second exhaust gas stream (122) therefrom; a steam turbine (104) configured to discharge a steam flow (128) therefrom; a carbon capture system (134) located downstream of the steam turbine (104) and oriented to receive the steam flow (128); a first cooler (148) located between the heat recovery steam generator (112) and the carbon capture system (134), the first cooler (148) being configured to facilitate cooling a first portion of the second exhaust gas stream (122) directed toward the carbon capture system (134) to define a third exhaust gas stream; a recirculation blower (170) coupled downstream of the heat recovery steam generator (112) and configured to pressurize a second portion of the second exhaust gas stream (122) for recirculation toward the compressor inlet (106); and An air inlet blower (168) is configured to pressurize an air flow (174) directed toward the compressor inlet (106) such that a pressurized mixed flow stream is formed from the second portion of the second exhaust gas flow (122) and the air flow (174) before the mixture enters the compressor inlet (106).

17. The combined cycle power generation device (100) according to claim 16, further comprising a controller (172), wherein the controller is configured to: monitoring power consumption of the recirculation blower (170) and the air inlet blower (168); determining steam cycle losses resulting from venting the steam stream (128) toward the carbon capture system (134); and One of a flow rate and a temperature of the exhaust gas stream recirculated toward the compressor inlet (106) is adjusted to facilitate increasing a net output of the combined cycle power plant (100) that exceeds blower power consumption and steam cycle losses.

18. The combined cycle power plant (100) of claim 16, further comprising a second cooler (180) configured to facilitate cooling the second portion of the second exhaust gas flow (122) recirculated toward the compressor inlet (106).

19. The combined cycle power plant (100) according to claim 18, wherein the second cooler (180) is located between the heat recovery steam generator (112) and the recirculation blower (170).

20. The combined cycle power plant (100) of claim 18, wherein the second cooler (180) is located between the recirculation blower (170) and the compressor inlet (106).

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