Inlet air heating system for gas turbine systems

Abstract

To provide an inlet air heating system for a gas turbine system.SOLUTION: An inlet air heating system for a gas turbine system (10) includes an inlet heat exchanger (52) configured to be positioned upstream of a compressor (16) of the gas turbine system (10). The inlet air heating system also includes a heating loop (56) fluidly coupled to the inlet heat exchanger (52). The heating loop (56) is configured to provide heating fluid (58) to the inlet heat exchanger (52), and the inlet heat exchanger (52) is configured to facilitate transfer of heat from the heating fluid (58) to an airflow into the compressor (16). Furthermore, the inlet air heating system includes a heat transfer assembly configured to receive cooling tower fluid (48) from a fluid pathway (44) extending between a steam condenser (39) and a cooling tower. The heat transfer assembly is configured to facilitate transfer of heat from the cooling tower fluid (48) to the heating fluid (58).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The subject matter disclosed herein relates to an intake air heating system for a gas turbine system. [Background technology]

[0002] A gas turbine system typically includes at least one gas turbine engine having a compressor, a combustor, a turbine, and a fuel source. Particular gas turbine systems have an intake air heating system configured to increase the temperature of air entering the compressor. The intake air heating system may operate during particular operating conditions (e.g., lower working gas volumes of the gas turbine system) and / or ambient air conditions (e.g., lower ambient air temperatures) to increase the efficiency of the gas turbine system. Particular intake air heating systems are configured to facilitate the transfer of heat from condensate derived from a low-pressure economizer to the ambient air, thereby increasing the temperature of the ambient air. Unfortunately, transferring heat from the condensate to the ambient air reduces the heat / energy in the fluid that ultimately drives the steam turbine of the steam turbine system, thereby reducing the power output of the steam turbine system. Summary of the Invention

[0003] Certain embodiments commensurate with the claims at the time of filing are summarized below. These embodiments are not intended to limit the scope of the claimed subject matter; rather, these embodiments are merely intended to provide a brief outline of possible forms of the claimed subject matter. Indeed, the claimed subject matter may encompass a variety of forms that may be similar to or different from the embodiments set forth below.

[0004] According to one embodiment of the present disclosure, an intake air heating system for a gas turbine system includes an inlet heat exchanger configured to be positioned upstream of a compressor of the gas turbine system. The intake air heating system also includes a heating loop fluidly coupled to the inlet heat exchanger. The heating loop is configured to provide a heating fluid to the inlet heat exchanger, the inlet heat exchanger being configured to facilitate transfer of heat from the heating fluid to an airflow entering the compressor. The intake air heating system further includes a heat transfer assembly configured to receive cooling tower fluid from a fluid path extending between a steam condenser and a cooling tower. The heat transfer assembly is configured to facilitate transfer of heat from the cooling tower fluid to the heating fluid.

[0005] These and other features, aspects, and advantages of the present disclosure will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which like characters represent like parts throughout. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram of an embodiment of a gas turbine system having an embodiment of an intake air heating system in accordance with an aspect of the present disclosure. [Figure 2] FIG. 2 is a block diagram of the gas turbine system of FIG. 1 having another embodiment of an inlet air heating system according to an aspect of the present disclosure. [Figure 3] FIG. 2 is a block diagram of the gas turbine system of FIG. 1 having a further embodiment of an intake air heating system according to an aspect of the present disclosure. [Figure 4] FIG. 2 is a block diagram of the gas turbine system of FIG. 1 having another embodiment of an inlet air heating system according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] One or more specific embodiments of the present disclosure are described below. While an effort is made to provide a concise description of these embodiments, it is possible that not all features of an actual implementation may be described herein. It should be understood that, as in any engineering or design project, the development of any such actual implementation will require many implementation-specific decisions to be made in order to achieve the developer's specific goals, including compliance with system- and business-related constraints that may vary from implementation to implementation. Moreover, it should be appreciated that such a development effort may be complex and time-consuming, but would nevertheless be considered a routine undertaking of design, fabrication, and manufacture for those of ordinary skill in the art having the benefit of this disclosure.

[0008] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the element. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and / or environmental conditions do not exclude other parameters / conditions of the disclosed embodiments.

[0009] In certain embodiments, an intake air heating system for a gas turbine system includes an inlet heat exchanger configured to be positioned upstream of a compressor of the gas turbine system. Additionally, the intake air heating system includes a heating loop fluidly coupled to the inlet heat exchanger. The heating loop is configured to provide a heating fluid to the inlet heat exchanger, which is configured to facilitate the transfer of heat from the heating fluid to an airflow entering the compressor. The intake air heating system also includes a heat transfer assembly (e.g., a heat transfer assembly including a heat exchanger) configured to receive a cooling tower fluid from a fluid path extending between a steam condenser and a cooling tower. The heat transfer assembly is configured to facilitate the transfer of heat from the cooling tower fluid to the heating fluid. Because the intake air heating system uses heat from the cooling tower fluid to heat the airflow to the compressor, heat within a steam turbine system configured to utilize combustion gases from a gas turbine system to generate steam for driving rotation of the steam turbine can be increased compared to utilizing an intake air heating system that uses only heat from the steam turbine system to heat the airflow to the compressor. As a result, energy transfer to a load / generator coupled to the steam turbine can be increased, thereby increasing the power output of the steam turbine system.

[0010] Referring now to the drawings, Figure 1 is a block diagram of an embodiment of a gas turbine system 10 having an inlet air heating system 12. In the illustrated embodiment, the gas turbine system 10 includes a gas turbine engine 14, which includes a compressor 16, a combustor 18, and a turbine 20. As shown, the combustor 18 receives compressed air from the compressor 16 and fuel from a fuel source. The fuel source may provide liquid fuel and / or syngas, such as natural gas and / or a gaseous fuel produced from a gasification system (e.g., a gasifier that produces syngas from a feedstock such as coal). The combustor 18 ignites and combusts the fuel with the compressed air from the compressor 16, thereby producing hot, pressurized combustion gases (e.g., exhaust) 21.

[0011] The turbine blades within the turbine 20 are coupled to a shaft 22 of the gas turbine engine 14, which may in turn be coupled to several other components throughout the gas turbine system 10. As combustion gases 21 flow against and between the turbine blades of the turbine 20, the turbine blades are driven to rotate, thereby rotating the shaft 22. Ultimately, the combustion gases 21 exit the gas turbine engine 14 through an exhaust. Furthermore, in the illustrated embodiment, the shaft 22 is coupled to a load 24 that is powered via the rotation of the shaft 22. The load 24 may be any suitable device that produces power via the rotational output of the gas turbine engine 14, such as an electrical generator or other load.

[0012] The compressor 16 of the gas turbine engine 14 includes compressor blades. The compressor blades within the compressor 16 are coupled to a shaft 22 and rotate when the shaft 22 is driven to rotate by the turbine 20, as described above. As the compressor blades rotate within the compressor 16, the compressor 16 compresses air 26 received from an intake to produce compressed air. The compressed air is then delivered to the combustor 18. The compressed air and fuel enter the combustor 18 and are combusted to drive the rotation of the turbine 20.

[0013] In the illustrated embodiment, the combustion gases 21 are channeled to a steam turbine system 28. The steam turbine system 28 is configured to facilitate the transfer of heat from the combustion gases 21 to water, thereby generating steam that is used to drive the rotation of a steam turbine. The steam turbine may be coupled to a load, such as an electrical generator, and the rotational energy of the steam turbine may be transferred to the load (e.g., to facilitate the generation of electrical power). In the illustrated embodiment, the steam turbine system 28 includes a low-pressure (LP) evaporator 30 and an LP economizer 32. The LP evaporator 30 and the LP economizer 32 are configured to facilitate the transfer of heat from the combustion gases 21 to the feedwater.

[0014] As shown, cooler feedwater 33 enters LP economizer 32, which raises the temperature of the feedwater, thereby producing hotter feedwater 34. The hotter feedwater 34 then enters LP evaporator 30 via LP drum 36. Heat from combustion gases 21 is transferred to the hotter feedwater 34, thereby producing LP steam 38. LP steam 38 flows to the LP steam turbine, driving it to rotate. The LP steam turbine may be coupled to a load, such as an electrical generator, and the rotational energy of the LP steam turbine may be transferred to the load (e.g., to facilitate the generation of electrical power).

[0015] In the illustrated embodiment, the LP evaporator 30 is positioned upstream of the LP economizer 32 with respect to the flow of the combustion gases 21. Thus, the feedwater in the LP evaporator 30 may be exposed to higher combustion gas temperatures than the feedwater in the LP economizer 32. While the LP evaporator 30 and the LP economizer 32 are in the flow path of the combustion gases 21 in the illustrated embodiment, in other embodiments the LP economizer 32 may be omitted and / or additional heat exchangers (e.g., a high-pressure evaporator, an intermediate-pressure evaporator, etc.) may be positioned in the flow path of the combustion gases 21.

[0016] In the illustrated embodiment, the lower temperature feedwater 33 is provided by a steam condenser 39. Thus, the lower temperature feedwater 33 includes condensate from the steam condenser 39. In the illustrated embodiment, a pump 40 drives the lower temperature feedwater / condensate from the steam condenser 39 to flow to the LP economizer 32. Additionally, the steam condenser 39 receives a flow of higher temperature feedwater 34 from the LP economizer 32. As illustrated, a first portion of the higher temperature feedwater 34 flows from the LP economizer 32 to the LP drum 36, and a second portion of the higher temperature feedwater 34 flows to the steam condenser 39. The steam condenser 39 may also receive steam and / or higher temperature water from other sources, such as an LP steam turbine, an LP drum, an intermediate-pressure steam turbine, a high-pressure steam turbine, other suitable sources, or a combination thereof. The steam condenser 39 is configured to condense the received steam into condensate (e.g., water) and reduce the temperature of the condensate and / or the received warmer water. In the illustrated embodiment, the steam condenser 39 includes a heat exchanger 42 configured to transfer heat from the received steam / warmer water to the cooling tower fluid (e.g., water).

[0017] As shown, a first fluid path 44 extends between the steam condenser 39 and a cooling tower (not shown) in a direction away from the steam condenser 39. Additionally, a second fluid path 46 extends between the cooling tower and the steam condenser 39 in a direction toward the steam condenser 39. A cooling tower fluid (e.g., water) 48 flows from the cooling tower to the steam condenser 39 through the second fluid path 46, and heated cooling tower fluid 48 flows from the steam condenser 39 to the cooling tower through the first fluid path 44. In the illustrated embodiment, a pump 50 disposed along the second fluid path 46 drives the cooling tower fluid 48 from the cooling tower to the steam condenser 39.

[0018] Within the steam condenser 39, a heat exchanger 42 facilitates the transfer of heat from the steam / hotter water to a cooling tower fluid, thereby condensing the steam into condensate, lowering the temperature of the hotter water, and increasing the temperature of the cooling tower fluid 48. After receiving heat from the steam / hotter water, the heated cooling tower fluid 48 flows to the cooling tower via a first fluid path 44. The cooling tower facilitates the transfer of heat from the heated cooling tower fluid 48 to the environment, thereby producing cooling tower fluid 48 that flows through a second fluid path 46 to the steam condenser 39.

[0019] In the illustrated embodiment, the gas turbine system 10 includes an inlet air heating system 12 configured to increase the temperature of the airflow entering the compressor 16. The inlet air heating system 12 may be activated / utilized during certain operating and / or ambient air conditions to increase the efficiency of the gas turbine system 10. For example, while the gas turbine system 10 is operating at a lower ambient air temperature and with a lower gas amount, the inlet air heating system 12 may be activated / utilized to increase the temperature of the airflow entering the compressor 16, thereby increasing the operating efficiency of the gas turbine system 10.

[0020] In the illustrated embodiment, the intake air heating system 12 includes an inlet heat exchanger 52 positioned upstream of the compressor 16 along an air flow path 54 from the ambient environment to the compressor 16. The inlet heat exchanger 52 is configured to receive ambient air and transfer heat to the air, thereby establishing the heated airflow 26 entering the compressor 16. Additionally, the intake air heating system 12 includes a heating loop 56 fluidly coupled to the inlet heat exchanger 52. The heating loop 56 is configured to provide a heating fluid 58 (e.g., water, a water / propylene glycol solution, a water / ethylene glycol solution, etc.) to the inlet heat exchanger 52, and the inlet heat exchanger 52 is configured to facilitate the transfer of heat from the heating fluid 58 to the airflow entering the compressor 16. In the illustrated embodiment, the intake air heating system 12 includes a heat transfer assembly 60 (e.g., first heat transfer assembly 60) configured to receive heated cooling tower fluid (e.g., water) 48 from a first fluid path 44 extending from the steam condenser 39 to the cooling tower. The heat transfer assembly 60 is configured to facilitate the transfer of heat from the cooling tower fluid 48 to the heating fluid 58 .

[0021] In the illustrated embodiment, the heat transfer assembly 60 includes a heating loop heat exchanger 62 configured to facilitate the transfer of heat from the heated cooling tower fluid 48 to the heating fluid 58. As shown, a first portion of the heated cooling tower fluid (e.g., water) 48 flows from the steam condenser 39 to the cooling tower via the first fluid path 44, and a second portion of the heated cooling tower fluid (e.g., water) 48 flows from the steam condenser 39 to the heating loop heat exchanger 62 via the first fluid path 44 and the first fluid passage 64. Within the heating loop heat exchanger 62, heat is transferred from the heated cooling tower fluid 48 to the heating fluid 58, thereby increasing the temperature of the heating fluid 58 and decreasing the temperature of the cooling tower fluid 48. The cooler cooling tower fluid 48 returns to the first fluid path 44 via the second fluid passage 66. The cooling tower fluid 48 then mixes with the first portion of the cooling tower fluid 48 and flows to the cooling tower.

[0022] Additionally, the heated heating fluid 58 flows from the heating loop heat exchanger 62 to the inlet heat exchanger 52, where heat is transferred from the heating fluid 58 to the airflow entering the compressor 16. The transfer of heat from the heating fluid 58 to the airflow reduces the temperature of the heating fluid 58, and the cooler heating fluid 58 flows back to the heating loop heat exchanger 62. Because the inlet air heating system 12 uses heat from the cooling tower fluid 48 to heat the airflow to the compressor 16, increased heat can be generated in the steam turbine system 28 compared to utilizing an inlet air heating system that uses only heat from the steam turbine system 28 (e.g., heat from a higher temperature feedwater) to heat the airflow to the compressor 16. As a result, increased energy can be transferred to a load / generator coupled to the steam turbine, thereby increasing the power output of the steam turbine system 28.

[0023] In the illustrated embodiment, the intake air heating system 12 includes a second heat transfer assembly 68 configured to receive the higher temperature feedwater 35 (e.g., condensate) from the LP economizer 32. The second heat transfer assembly 68 is configured to facilitate heat transfer from the higher temperature feedwater 35 to the heating fluid 58 in the heating loop 56. For example, under certain operating and / or environmental conditions, the first heat transfer assembly 60 may not be able to provide sufficient heat to the heating fluid 58. Thus, the second heat transfer assembly 68 may be utilized (e.g., in conjunction with the first heat transfer assembly 60) to provide sufficient heat to the heating fluid 58 to effectively heat the airflow 26 to the compressor 16.

[0024] In the illustrated embodiment, the second heat transfer assembly 68 includes a second heating loop heat exchanger 70 configured to facilitate the transfer of heat from the higher temperature feedwater 35 (e.g., condensate) to the heating fluid 58. As shown, the second heating loop heat exchanger 70 is positioned along the flow path of the higher temperature feedwater 35 from the LP economizer 32 to the steam condenser 39. In the illustrated embodiment, a first LP flow path 72 fluidly couples the LP economizer 32 to the LP drum 36, and a second LP flow path 74 fluidly couples the first LP flow path 72 to the second heating loop heat exchanger 70. Thus, the higher temperature feedwater 35 flows through the second LP flow path 74 from the first LP flow path 72 to the second heating loop heat exchanger 70. Additionally, a third LP flow path 76 fluidly couples the second heating loop heat exchanger 70 to the steam condenser 39. This causes the higher temperature feedwater 35 to flow through the second heating loop heat exchanger 70 to the steam condenser 39. Within the second heating loop heat exchanger 70, heat is transferred from the higher temperature feedwater 35 to the heating fluid 58. In the illustrated embodiment, the intake air heating system 12 includes a second heat transfer assembly 68, although in other embodiments, the second heat transfer assembly 68 may be omitted. Additionally, in certain embodiments, another suitable heat transfer assembly capable of receiving heat from another suitable source (e.g., feedwater for the high-pressure evaporator, feedwater for the intermediate-pressure evaporator, etc.) may be utilized to heat the heating fluid 58.

[0025] In the illustrated embodiment, the intake air heating system 12 includes a heating loop pump 78 disposed along the heating loop 56. The heating loop pump 78 is configured to drive the heating fluid 58 around the heating loop 56, thereby facilitating heat transfer from the first heat transfer assembly 60 and / or the second heat transfer assembly 68 to the inlet heat exchanger 52. In the illustrated embodiment, the intake air heating system 12 includes a single heating loop pump, but in other embodiments, the intake air heating system 12 may include more or fewer heating loop pumps (e.g., 0, 2, 3, 4, or more). For example, in certain embodiments, the heating loop pump 78 may be omitted.

[0026] Additionally, in the illustrated embodiment, the intake air heating system 12 includes a heat transfer assembly pump 80 disposed along the first fluid passage 64. The heat transfer assembly pump 80 is configured to drive the heated cooling tower fluid 48 (e.g., water) through the first heat transfer assembly 60, thereby facilitating heat transfer from the heated cooling tower fluid 48 to the heating fluid 58. In the illustrated embodiment, the intake air heating system 12 includes a single heat transfer assembly pump, however, in other embodiments, the intake air heating system may include additional heating loop pumps (e.g., one, two, three, four, or more additional pumps). Additionally, in the illustrated embodiment, the heat transfer assembly pump 80 is disposed along the first fluid passage 64, however, in other embodiments, the heat transfer assembly pump 80 may be disposed along the second fluid passage 66, or one or more heat transfer assembly pumps may be disposed along the first fluid passage 64 and / or along the second fluid passage 66.

[0027] In the illustrated embodiment, the intake air heating system 12 includes a first valve 82 configured to control the flow rate of the heated cooling tower fluid 48 through the first heat transfer assembly 60. As shown, the first valve 82 is disposed along the first fluid passage 64. Additionally, the intake air heating system 12 includes a second valve 84 configured to control the flow rate of the higher temperature feedwater 35 (e.g., condensate) through the second heat transfer assembly 68. In the illustrated embodiment, the second valve 84 is disposed along the second LP flow path 74. Furthermore, the intake air heating system 12 includes a third valve 86 configured to control the flow rate of the heating fluid 58 through the heating loop 56. As shown, the third valve 86 is disposed along the heating loop 56.

[0028] In the illustrated embodiment, the first valve 82 is positioned along the first fluid passage 64, although in other embodiments the first valve 82 may be positioned at any other suitable location to facilitate control of the flow rate of the heated cooling tower fluid 48 through the first heat transfer assembly 60, such as along the second fluid passage 66. Furthermore, in the illustrated embodiment, the second valve 84 is disposed along the second LP flow path 74, although in other embodiments the second valve 84 may be positioned at any other suitable location to facilitate control of the flow rate of the higher temperature feedwater 35 through the second heat transfer assembly 68, such as along the third LP flow path 76.

[0029] In the illustrated embodiment, first valve 82, second valve 84, and third valve 86 are communicatively coupled to a controller 88 configured to control the positions of the valves. In certain embodiments, controller 88 is an electronic controller having electrical circuitry configured to control first valve 82, second valve 84, and third valve 86. In the illustrated embodiment, controller 88 includes a processor, such as the illustrated microprocessor 90, and a memory device 92. Controller 88 may also include one or more memory devices and / or other suitable components.

[0030] Processor 90 may be used to execute software, such as software for controlling first valve 82, second valve 84, and third valve 86. Additionally, processor 90 may include multiple microprocessors, one or more "general-purpose" microprocessors, one or more special-purpose microprocessors, and / or one or more application-specific integrated circuits (ASICs), or a combination thereof. For example, processor 90 may include one or more reduced instruction set (RISC) processors.

[0031] The memory device 92 may include volatile memory, such as random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM). The memory device 92 can store a variety of information and can be used for a variety of purposes. For example, the memory device 92 can store processor-executable instructions (e.g., firmware or software) for execution by the processor 90, such as instructions for controlling a valve. The storage device (e.g., non-volatile storage) can include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The storage device can store data, instructions (e.g., software or firmware for controlling a valve), and any other suitable data.

[0032] In certain embodiments, the controller 88 is configured to control the first valve 82 to establish a target temperature of the airflow 26 entering the compressor 16. In the illustrated embodiment, a first temperature sensor 94 is positioned along the airflow path 54 to the compressor 16 and is communicatively coupled to the controller 88. The first temperature sensor 94 is configured to output a first sensor signal indicative of the temperature of the airflow 26 downstream of the inlet heat exchanger 52 (e.g., entering the compressor 16). In certain embodiments, the controller 88 is configured to control the position (e.g., between an open position and a closed position) of the first valve 82 to control the flow rate of the heated cooling tower fluid 48 through the first heat transfer assembly 60, thereby controlling the temperature of the heating fluid 58. Because heat is transferred from the heating fluid 58 via the inlet heat exchanger 52 to the airflow entering the compressor 16, controlling the temperature of the heating fluid 58 controls the temperature of the airflow 26 entering the compressor 16. Thus, the controller 88 can control the position of the first valve 82 to control the temperature of the airflow 26 entering the compressor 16. Under certain operating conditions, the second valve 84 may be closed while the controller 88 controls the position of the first valve 82 to control the temperature of the airflow 26 entering the compressor 16.

[0033] Further, in certain embodiments, the controller is configured to enable opening of the second valve 84 in response to determining that the position of the first valve 82 is equal to or greater than the threshold position for more than a first threshold duration. For example, the threshold position may be 50% open, 60% open, 70% open, 80% open, 90% open, or 95% open, among other suitable positions. Further, the first threshold duration may be 15 seconds, 30 seconds, 45 seconds, 60 seconds, 75 seconds, or 90 seconds, among other suitable durations. While the second valve 84 is enabled to open, the controller 88 is configured to control the second valve 84 to establish a target temperature for the airflow 26 entering the compressor 16.

[0034] For example, as the first valve 82 approaches the fully open position, heat transfer between the heated cooling tower fluid 48 and the heating fluid 58 in the first heat transfer assembly 60 approaches a maximum. When the first heat transfer assembly 60 is providing maximum heat transfer and operating and / or environmental conditions result in a decrease in ambient temperature, the heating fluid 58 may not be able to provide enough heat to the inlet heat exchanger 52 to maintain the target temperature of the airflow 26 entering the compressor 16. Therefore, as the first valve 82 approaches the fully open position, the controller 88 allows the second valve 84 to open, thereby enabling the controller 88 to control the second valve 84 to establish the target temperature of the airflow 26 entering the compressor 16. With the second valve 84 open, the hotter feedwater 35 (e.g., condensate) flows through the second heat transfer assembly 68, thereby increasing the temperature of the heating fluid 58. As a result, the heating fluid 58 can provide sufficient heat to the inlet heat exchanger 52 to substantially maintain the target temperature of the air flow 26 to the compressor 16 (e.g., while the first valve 82 is in the fully open position).

[0035] Furthermore, in certain embodiments, the controller 88 is configured to instruct the second valve 84 to close and prevent its opening in response to determining that the position of the first valve 82 is less than the threshold position for more than a second threshold duration. The second threshold duration may be 15 seconds, 30 seconds, 45 seconds, 60 seconds, 75 seconds, or 90 seconds, among other suitable durations.

[0036] Because the second valve 84 can only open in response to the first valve 82 approaching its fully open position, heat transfer from the heated cooling tower fluid (e.g., water) 48 to the heating fluid 58 is prioritized over heat transfer from the higher temperature feedwater 35 (e.g., condensate) to the heating fluid 58. Thus, heat is transferred from the higher temperature feedwater 35 to the heating fluid 58 only when the heat provided by the heated cooling tower fluid 48 is insufficient or nearly insufficient to maintain the airflow 26 entering the compressor 16 at a target temperature. As a result, heat losses within the steam turbine system 28 can be substantially reduced compared to utilizing an inlet air heating system that uses only heat from the steam turbine system 28 (e.g., heat from the higher temperature feedwater) to heat the airflow to the compressor 16. As a result, energy transfer to the load / generator coupled to each steam turbine can be increased, thereby increasing the power output of the steam turbine system 28.

[0037] In certain embodiments, the controller 88 is configured to determine a temperature difference (e.g., a first temperature difference) between the heated cooling tower fluid (e.g., water) 48 entering the first heat transfer assembly 60 and the heating fluid 58 flowing from the inlet heat exchanger 52. In the illustrated embodiment, the second temperature sensor 96 is positioned along the first fluid passage 64 upstream of the first heat transfer assembly 60, and the third temperature sensor 98 is positioned along the heating loop 56 downstream (e.g., immediately downstream) of the inlet heat exchanger 52. As shown, the second and third temperature sensors 96, 98 are communicatively coupled to the controller 88.

[0038] The second temperature sensor 96 is configured to output a second sensor signal indicative of the temperature of the heated cooling tower fluid 48 entering the first heat transfer assembly 60, and the third temperature sensor 98 is configured to output a third sensor signal indicative of the temperature of the heating fluid 58 flowing from the inlet heat exchanger 52. The controller 88 is configured to determine a temperature difference between the heated cooling tower fluid (e.g., water) 48 entering the first heat transfer assembly 60 and the heating fluid 58 flowing from the inlet heat exchanger 52 based on the second and third sensor signals.

[0039] In certain embodiments, the controller 88 is configured to instruct the first valve 82 to close while the second valve 84 is allowed to open and in response to determining that the temperature difference between the heated cooling tower fluid (e.g., water) 48 entering the first heat transfer assembly 60 and the heating fluid 58 flowing from the inlet heat exchanger 52 is less than or equal to the threshold temperature difference for more than a third threshold duration. For example, the threshold temperature difference may be 0.25°F, 0.5°F, 0.75°F, or 1.0°F, among other suitable temperature differences. Further, the third threshold duration may be 15 seconds, 30 seconds, 45 seconds, 60 seconds, 75 seconds, or 90 seconds, among other suitable durations. The controller 88 is configured to instruct the first valve 82 to close under the conditions disclosed above, since during such conditions the first heat transfer assembly 60 is providing a substantially insignificant amount of heat to the heating fluid 58. Although the control of the valves is based on first, second, and third threshold durations in the embodiments disclosed above, in other embodiments, at least one valve control action may be performed substantially instantaneously in response to a detected condition / parameter / value.

[0040] In certain embodiments, the controller 88 is configured to determine a second temperature difference between the temperature of the heating fluid 58 entering the inlet heat exchanger 52 and the temperature of the heating fluid 58 exiting the inlet heat exchanger 52. In the illustrated embodiment, a fourth temperature sensor 100 is positioned upstream (e.g., immediately upstream) of the inlet heat exchanger 52 along the heating loop 56. As shown, the fourth temperature sensor 100 is communicatively coupled to the controller 88. Additionally, the fourth temperature sensor 100 is configured to output a fourth sensor signal indicative of the temperature of the heating fluid 58 entering the inlet heat exchanger 52. The controller 88 is configured to determine the second temperature difference between the heating fluid 58 entering the inlet heat exchanger 52 and the heating fluid 58 flowing out of the inlet heat exchanger 52 based on the third sensor signal from the third temperature sensor 98 and the fourth sensor signal from the fourth temperature sensor 100.

[0041] Further, in certain embodiments, the controller 88 is configured to determine a third temperature difference between the target temperature of the airflow 26 entering the compressor 16 and the temperature of the airflow entering the inlet heat exchanger 52. In the illustrated embodiment, a fifth temperature sensor 102 is positioned upstream of the inlet heat exchanger 52 along the airflow path 54 from the ambient environment to the compressor 16. As shown, the fifth temperature sensor 102 is communicatively coupled to the controller 88. Additionally, the fifth temperature sensor 102 is configured to output a fifth sensor signal indicative of the temperature of the airflow entering the inlet heat exchanger 52. The controller 88 is configured to determine the third temperature difference between the target temperature of the airflow 26 entering the compressor 16 and the temperature of the airflow entering the inlet heat exchanger 52 based on the fifth sensor signal and the target temperature of the airflow 26 entering the compressor 16. The target temperature may be determined by the controller 88, received from a remote electronic device, received from a user interface, or a combination thereof.

[0042] In certain embodiments, the controller 88 is configured to control the third valve 86 so that the second temperature difference is less than the third temperature difference multiplied by the first adjustment factor and greater than or equal to the third temperature difference multiplied by the second adjustment factor. The first adjustment factor is greater than the second adjustment factor. For example, the first adjustment factor may be 1.0, and the second adjustment factor may be 0.9. However, in other embodiments, the first adjustment factor may be greater or less than 1.0 (but still greater than the second adjustment factor) and / or the second adjustment factor may be greater or less than 0.9 (but still less than the first adjustment factor). Controlling the third valve 86 in the manner disclosed above establishes substantially equal heat capacity ratios (e.g., the product of mass flow rate and specific heat) for the air flow through the inlet heat exchanger 52 and the heating fluid flow through the inlet heat exchanger 52, thereby improving the efficiency of the intake air heating system 12.

[0043] In the illustrated embodiment, the intake air heating system 12 includes three controlled valves, although in other embodiments, the intake air heating system 12 may include more or fewer controlled valves configured to control the flow of each fluid. Additionally, in the illustrated embodiment, the higher temperature feedwater 35 (e.g., heated fluid) from the LP economizer 32 is provided to the second heat transfer assembly 68, although in other embodiments, the second heat transfer assembly 68 may receive the heating fluid from another suitable source, such as the LP drum 36, an intermediate-pressure economizer, an intermediate-pressure drum, or an intermediate-pressure evaporator, among other suitable sources or combinations of sources. Additionally, in the illustrated embodiment, the first heat transfer assembly 60 transfers heat from the cooling tower fluid (e.g., water) 48 to the heating fluid, although in other embodiments, the first heat transfer assembly 60 may be configured to transfer heat to the heating fluid 58 (e.g., alone or in combination with cooling tower fluid) from other suitable sources, such as generator cooling fluid or fluid from an oil cooling system, among other suitable sources or combinations of sources.

[0044] 2 is a block diagram of the gas turbine system 10 of FIG. 1 with another embodiment of an inlet air heating system 104. In the illustrated embodiment, the inlet air heating system 104 includes an inlet heat exchanger 52 positioned upstream of the compressor 16 along an airflow path 54 from the ambient environment to the compressor 16. As previously described, the inlet heat exchanger 52 is configured to receive ambient air and transfer heat to the air, thereby establishing the heated airflow 26 entering the compressor 16. Additionally, the inlet air heating system 104 includes a heating loop 56 fluidly coupled to the inlet heat exchanger 52. The heating loop 56 is configured to provide a heating fluid 58 to the inlet heat exchanger 52, which is configured to facilitate the transfer of heat from the heating fluid 58 to the airflow entering the compressor 16. Furthermore, the inlet air heating system 104 includes a first heat transfer assembly 60 having a heating loop heat exchanger 62. As previously mentioned, a portion of the heated cooling tower fluid (e.g., water) 48 flows from the steam condenser 39 through a first fluid passage 64 to the heating loop heat exchanger 62. Within the heating loop heat exchanger 62, heat is transferred from the heated cooling tower fluid 48 to the heating fluid 58, thereby increasing the temperature of the heating fluid 58 and decreasing the temperature of the cooling tower fluid 48.

[0045] In the illustrated embodiment, the intake air heating system 104 includes a second heat transfer assembly 106 configured to receive the higher temperature feedwater 35 (e.g., condensate) from the LP economizer 32. The second heat transfer assembly 106 is configured to facilitate heat transfer from the higher temperature feedwater 35 to the heating fluid 58 in the heating loop 56. For example, under certain operating and / or environmental conditions, the first heat transfer assembly 60 may not be able to provide sufficient heat to the heating fluid 58. Thus, the second heat transfer assembly 106 may be utilized (e.g., in conjunction with the first heat transfer assembly 60) to provide sufficient heat to the heating fluid to effectively heat the airflow to the compressor 16.

[0046] In the illustrated embodiment, the second heat transfer assembly 106 includes a fluid inlet passage 108 and a fluid outlet passage 110. As shown, the fluid inlet passage 108 and the fluid outlet passage 110 are fluidly coupled to the heating loop 56. Additionally, the fluid inlet passage 108 is fluidly coupled to the second LP flow path 74, and the fluid outlet passage 110 is fluidly coupled to the third LP flow path 76. Thus, the second LP flow path 74 and the fluid inlet passage 108 are configured to transfer the higher temperature feedwater 35 (e.g., condensate) from the LP economizer 32 to the heating fluid 58 in the heating loop 56. Additionally, the fluid outlet passage 110 and the third LP flow path 76 are configured to receive the higher temperature feedwater 35 (e.g., a combination of the higher temperature feedwater 35 and the heating fluid 58) from the heating fluid 58 and transfer the fluid to the steam condenser 39. Within the second heat transfer assembly 106, the hotter feedwater 35 mixes with the heating fluid 58, thereby transferring heat from the hotter feedwater 35 to the heating fluid 58. As a result, the temperature of the heating fluid 58 within the heating loop increases.

[0047] The inlet heat exchanger 52 is positioned along the heating loop 56 downstream of the fluid inlet passage 108 and upstream of the fluid outlet passage 110 so that the hotter heating fluid 58 flows through the inlet heat exchanger 52 before exiting the fluid outlet passage 110 and flowing toward the steam condenser. In the illustrated embodiment, the fluid outlet passage 110 is positioned downstream of the first heat transfer assembly 60, although in other embodiments, the fluid outlet passage may be positioned upstream of the first heat transfer assembly 60 and downstream of the inlet heat exchanger 52. Because the hotter feedwater 35 mixes with the heating fluid 58 in the heating loop 56, water can be used as both the feedwater and the heating fluid. Thus, the illustrated second heat transfer assembly 106 can be used in gas turbine systems operating in warmer environments (e.g., environments with a lower likelihood of freezing).

[0048] In the illustrated embodiment, the second valve 84 is configured to control the flow rate of the higher temperature feedwater 35 (e.g., condensate) through the second heat transfer assembly 106. Additionally, as previously mentioned, the first valve 82, the second valve 84, and the third valve 86 are communicatively coupled to the controller 88. The controller 88 may control the valves in the manner disclosed above with reference to FIG.

[0049] FIG. 3 is a block diagram of the gas turbine system 10 of FIG. 1 with a further embodiment of an inlet air heating system 112. In the illustrated embodiment, the steam condenser 39 includes a direct contact system 114 configured to mix the cooling tower fluid 48, which is water in the illustrated embodiment, with the received steam / hotter water, thereby generating the cooler feedwater 33. Because the received steam / hotter water is mixed with the cooler cooling tower water, the temperature of the cooler feedwater 33 is lower than the temperature of the received steam / hotter water. In certain embodiments, the direct contact system 114 sprays the cooling tower water onto the received steam / hotter water, thereby generating the cooler feedwater 33. As previously mentioned, the pump 40 drives the cooler feedwater from the steam condenser 39 to the LP economizer 32. Because the received steam / hotter water mixes with the cooling tower water, the cooling tower includes a substantially sealed heat exchanger to substantially maintain the purity of the water used in the steam turbine system 28. For example, a cooling tower may include a heat exchanger that facilitates the transfer of heat from the cooling tower water to the surrounding air.

[0050] In the illustrated embodiment, a pump 50 disposed along first fluid path 44 drives cooling tower water from steam condenser 39 to the cooling tower. Within the cooling tower, the temperature of the cooling tower water is reduced. The cooler cooling tower water then flows back to steam condenser 39 via second fluid path 46. While in the illustrated embodiment, a pump is disposed along first fluid path 44, in other embodiments, a pump may be disposed along the second fluid path (e.g., alone or in combination with pump 50 disposed along the first fluid path), or pump 50 may be omitted.

[0051] Further, in the illustrated embodiment, the intake air heating system 112 includes an inlet heat exchanger 52 positioned upstream of the compressor 16 along the airflow path 54 from the ambient environment to the compressor 16. As previously described, the inlet heat exchanger 52 is configured to receive ambient air and transfer heat to the air, thereby establishing the heated airflow 26 entering the compressor 16. Additionally, the intake air heating system 112 includes a heating loop 56 fluidly coupled to the inlet heat exchanger 52. The heating loop 56 is configured to provide a heating fluid 58 to the inlet heat exchanger 52, which is configured to facilitate the transfer of heat from the heating fluid 58 to the airflow entering the compressor 16.

[0052] In the illustrated embodiment, the inlet air heating system 112 includes a first heat transfer assembly 116 configured to receive heated cooling tower water from the steam condenser 39. The first heat transfer assembly 116 is configured to facilitate heat transfer from the heated cooling tower water 48 to the heating fluid 58 in the heating loop 56. In the illustrated embodiment, the first heat transfer assembly 116 includes a fluid inlet passage 118 and a fluid outlet passage 120. As shown, the fluid inlet passage 118 and the fluid outlet passage 120 are fluidly coupled to the heating loop 56. Additionally, the fluid inlet passage 118 is fluidly coupled to the first fluid passage 64, and the fluid outlet passage 120 is fluidly coupled to the second fluid passage 66. Thus, the first fluid passage 64 and the fluid inlet passage 118 are configured to transport the heated cooling tower water from the first fluid path 44 to the heating fluid 58 in the heating loop 56. Additionally, the fluid outlet passage 120 and the second fluid passage 66 are configured to receive cooling tower water from the heating fluid 58 (e.g., a combination of the cooling tower water and the heating fluid 58) and transfer the fluid to the first fluid path 44, which directs the fluid to the cooling tower.

[0053] Within the first heat transfer assembly 116, the hotter cooling tower water mixes with the heating fluid 58, thereby transferring heat from the hotter cooling tower water to the heating fluid 58. As a result, the temperature of the heating fluid 58 within the heating loop increases. Because the inlet heat exchanger 52 is positioned along the heating loop 56 downstream of the fluid inlet passage 118 and upstream of the fluid outlet passage 120, the hotter heating fluid 58 flows through the inlet heat exchanger 52 before exiting the fluid outlet passage 120 and flowing toward the first fluid path 44. Because the heated cooling tower water mixes with the heating fluid 58 within the heating loop 56, water can be used as both the cooling tower fluid and the heating fluid. Thus, the illustrated first heat transfer assembly 116 can be used in gas turbine systems operating in warmer environments (e.g., environments with a lower probability of freezing).

[0054] Additionally, in the illustrated embodiment, the inlet air heating system 112 includes a second heat transfer assembly 106 configured to receive the higher temperature feedwater 35 (e.g., condensate) from the LP economizer 32. As previously described, the second heat transfer assembly 106 is configured to facilitate heat transfer from the higher temperature feedwater 35 to the heating fluid 58 in the heating loop 56. For example, under certain operating and / or environmental conditions, the first heat transfer assembly 116 may not be able to provide sufficient heat to the heating fluid 58. Thus, the second heat transfer assembly 106 may be utilized (e.g., in conjunction with the first heat transfer assembly 116) to provide sufficient heat to the heating fluid to effectively heat the airflow to the compressor 16.

[0055] In the illustrated embodiment, the hotter feedwater 35 mixes with the heating fluid 58 in the second heat transfer assembly 106, thereby transferring heat from the hotter feedwater 35 to the heating fluid 58. As a result, the temperature of the heating fluid 58 in the heating loop increases. While in the illustrated embodiment, the hotter feedwater 35 mixes with the heating fluid 58 in the second heat transfer assembly 106, in other embodiments, the second heat transfer assembly 106 may include a second heating loop heat exchanger, such as disclosed above with reference to FIG. 1 , configured to facilitate the transfer of heat from the hotter feedwater to the heating fluid 58 without mixing the fluids.

[0056] In the illustrated embodiment, the first valve 82 is configured to control the flow rate of cooling tower water through the first heat transfer assembly 116. Additionally, as previously mentioned, the first valve 82, the second valve 84, and the third valve 86 are communicatively coupled to the controller 88. The controller 88 may control the valves in the manner disclosed above with reference to FIG.

[0057] 4 is a block diagram of the gas turbine system 10 of FIG. 1 with another embodiment of an inlet air heating system 122. In the illustrated embodiment, the steam condenser 39 includes a direct contact system 114 configured to mix the cooling tower fluid 48, which in the illustrated embodiment is water, with the received steam / hotter water, thereby producing the cooler feedwater 33, as described above with reference to FIG.

[0058] Further, in the illustrated embodiment, the intake air heating system 122 includes an inlet heat exchanger 52 positioned upstream of the compressor 16 along the airflow path 54 from the ambient environment to the compressor 16. As previously described, the inlet heat exchanger 52 is configured to receive ambient air and transfer heat to the air, thereby establishing the heated airflow 26 entering the compressor 16. Additionally, the intake air heating system 122 includes a heating loop 56 fluidly coupled to the inlet heat exchanger 52. The heating loop 56 is configured to provide a heating fluid 58 to the inlet heat exchanger 52, which is configured to facilitate the transfer of heat from the heating fluid 58 to the airflow entering the compressor 16.

[0059] In the illustrated embodiment, the inlet air heating system 122 includes a first heat transfer assembly 124 configured to receive heated cooling tower water from the steam condenser 39. The first heat transfer assembly 124 is configured to facilitate heat transfer from the heated cooling tower water to the heating fluid 58 in the heating loop 56. In the illustrated embodiment, the first heat transfer assembly 124 includes a fluid inlet passage 126 and a fluid outlet passage 128. As shown, the fluid inlet passage 126 and the fluid outlet passage 128 are fluidly coupled to the heating loop 56. Additionally, the fluid inlet passage 126 is fluidly coupled to the first fluid passage 64, and the fluid outlet passage 128 is fluidly coupled to the second fluid passage 66.

[0060] In the illustrated embodiment, the heating loop 56 has an inlet 130 and an outlet 132. The inlet 130 of the heating loop 56 is fluidly coupled to the fluid inlet passage 126 of the first heat transfer assembly 124, and the outlet 132 of the heating loop 56 is fluidly coupled to the fluid outlet passage 128. Thus, the first fluid passage 64 and the fluid inlet passage 126 are configured to transport heated cooling tower water from the first fluid path 44 to the heating loop 56 via the heating loop inlet 130. The cooling tower water flows through the heating loop 56 from the inlet 130 to the outlet 132. Thus, the heating fluid 58 and the cooling tower water are the same fluid. However, while the fluid is within the heating loop, the fluid is referred to as a heating fluid. Thus, the first fluid passage 64 and the fluid inlet passage 126 are configured to transport the heated cooling tower water from the first fluid path 44 to the heating fluid 58 in the heating loop 56, thereby facilitating heat transfer from the heated cooling tower water to the heating fluid 58. Additionally, the fluid outlet passage 128 and the second fluid passage 66 are configured to receive cooling tower water from the heating fluid 58 at the outlet 132 of the heating loop 56 and transfer the cooling tower water to the first fluid path 44, which directs the cooling tower water to the cooling tower.

[0061] In the first heat transfer assembly 124, the hotter cooling tower water enters the heating loop 56 as the heating fluid 58. Because the inlet heat exchanger 52 is positioned along the heating loop 56 downstream of the fluid inlet passage 126 and upstream of the fluid outlet passage 128, the heating fluid 58 flows through the inlet heat exchanger 52 before exiting the fluid outlet passage 128 and flowing toward the first fluid path 44. Because the cooling tower water and the heating fluid are the same fluid in the illustrated embodiment, water can be used as both the cooling tower fluid and the heating fluid. Thus, the illustrated first heat transfer assembly 124 can be used in gas turbine systems operating in warmer environments (e.g., environments with a lower probability of freezing).

[0062] Additionally, in the illustrated embodiment, the inlet air heating system 122 includes a second heat transfer assembly 106 configured to receive the higher temperature feedwater 35 (e.g., condensate) from the LP economizer 32. As previously described, the second heat transfer assembly 106 is configured to facilitate heat transfer from the higher temperature feedwater 35 to the heating fluid 58 in the heating loop 56. For example, under certain operating and / or environmental conditions, the first heat transfer assembly 124 may not be able to provide sufficient heat to the heating fluid 58. Thus, the second heat transfer assembly 106 may be utilized (e.g., in conjunction with the first heat transfer assembly 124) to provide sufficient heat to the heating fluid 58 to effectively heat the airflow to the compressor 16.

[0063] In the illustrated embodiment, the hotter feedwater 35 mixes with the heating fluid 58 in the second heat transfer assembly 106, thereby transferring heat from the hotter feedwater 35 to the heating fluid 58. As a result, the temperature of the heating fluid 58 in the heating loop 56 increases. While in the illustrated embodiment, the hotter feedwater 35 mixes with the heating fluid 58 in the second heat transfer assembly 106, in other embodiments, the second heat transfer assembly 106 may include a second heating loop heat exchanger, such as disclosed above with reference to FIG. 1 , configured to facilitate the transfer of heat from the hotter feedwater to the heating fluid 58 without mixing the fluids.

[0064] In the illustrated embodiment, the first valve 82 is configured to control the flow rate of cooling tower water through the first heat transfer assembly 124. Additionally, as previously mentioned, the first valve 82, the second valve 84, and the third valve 86 are communicatively coupled to the controller 88. The controller 88 may control the valves in the manner disclosed above with reference to FIG.

[0065] Because the cooling tower water flows through the heating loop 56 from the inlet 130 to the outlet 132, the heat transfer assembly pump 80 can establish a sufficient flow of fluid through the heating loop 56. As a result, in certain embodiments, the heating loop pump (e.g., 78 shown in FIG. 3 ) may be omitted. Furthermore, while in the embodiment disclosed above with reference to FIGS. 2-4 , the second heat transfer assembly 106 is configured to mix the higher temperature feedwater 35 with the heating fluid 58, in other embodiments, the second heat transfer assembly 106 can transfer the higher temperature feedwater 35 to the heating loop as the heating fluid 58. The second heat transfer assembly 106 can also receive the heating fluid 58 from the heating loop 56 and direct the fluid as feedwater toward the steam condenser 39.

[0066] Additionally, although in the embodiments disclosed above with reference to Figures 1-4, each intake air heating system includes a second heat transfer assembly, in certain embodiments, the second heat transfer assembly may be omitted. Furthermore, any variations in the gas turbine system including the intake air heating system disclosed with reference to the embodiment of Figure 1 may be applied to the gas turbine system disclosed above with reference to the embodiment of Figures 2-4.

[0067] While each of the embodiments of the intake air heating system disclosed with reference to Figures 1-4 includes a single inlet heat exchanger, in other embodiments, the intake air heating system can include multiple inlet heat exchangers (e.g., positioned along the air flow path to the compressor). For example, a first inlet heat exchanger can be fluidly coupled to a first heating loop, and a first heat transfer assembly (e.g., the first heat transfer assembly of any of the embodiments disclosed above) can be disposed along the first heating loop. Additionally, a second inlet heat exchanger can be fluidly coupled to a second heating loop, and a second heat transfer assembly (e.g., the second heat transfer assembly of any of the embodiments disclosed above) can be disposed along the second heating loop.

[0068] Furthermore, in certain embodiments, the intake air heating system can include a single inlet heat exchanger with two independent coils. For example, a first coil can be fluidly coupled to a first heating loop, and a first heat transfer assembly (e.g., the first heat transfer assembly of any of the embodiments disclosed above) can be disposed along the first heating loop. Additionally, a second coil can be fluidly coupled to a second heating loop, and a second heat transfer assembly (e.g., the second heat transfer assembly of any of the embodiments disclosed above) can be disposed along the second heating loop.

[0069] Additionally, in certain embodiments, a third LP flow path can fluidly couple the second heat transfer assembly to the first LP flow path. In such embodiments, a pump can be disposed along the third LP flow path to drive feedwater from the second heat transfer assembly to the first LP flow path. Thus, higher temperature feedwater can flow from the first LP flow path through the second LP flow path to the second heat transfer assembly, and then the feedwater can flow from the second heat transfer assembly through the third LP flow path back to the first LP flow path (e.g., at a location downstream of the intersection of the first and second LP flow paths).

[0070] This specification uses examples to disclose the present subject matter, including the best mode, and also to enable any person skilled in the art to practice the presently disclosed subject matter, including making and using any devices or systems and performing any integrated methods. The patentable scope of the present subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are 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 that do not differ substantially from the literal language of the claims.

[0071] The techniques presented and claimed herein are applied to tangible objects and specific examples of a practical nature that clearly improve the art, and are therefore not abstract, intangible, or purely theoretical. Furthermore, if any claim appended to the end of this specification contains one or more elements designated as "means for [performing] [function]" or "steps for [performing] [function]," it is intended that such elements be construed under 35 U.S.C. §112(f). However, in the case of any claim containing elements designated in any other manner, it is not intended that such elements be construed under 35 U.S.C. §112(f). [Explanation of symbols]

[0072] 10 Gas Turbine System 12 Intake air heating system 14 Gas turbine engine 16 Compressor 18 Combustor 20 Turbine 21 Combustion gas 22 shaft 24 Load 26 Air, air flow 28 Steam Turbine System 30 Low-pressure evaporator, LP evaporator 32 LP Economizer 33 Lower temperature water supply 34 Higher temperature supply water 35 Higher temperature supply water 36 LP drums 38 LP vapor 39 Steam condenser 40 Pump 42 Heat exchanger 44 First fluid path 46 Second fluid path 48 Cooling tower fluid, cooling tower water 50 pump 52 Inlet heat exchanger 54 Air flow path 56 Heating Loop 58 Heating fluid 60 First heat transfer assembly 62 Heating Loop Heat Exchanger 64 first fluid passage 66 second fluid passage 68 Second Heat Transfer Assembly 70 Second heating loop heat exchanger 72 First LP flow path 74 Second LP flow path 76 Third LP flow path 78 Heating Loop Pump 80 Heat Transfer Assembly Pump 82 First Valve 84 Second Valve 86 Third Valve 88 Controller 90 Microprocessors, Processors 92 Memory Device 94 First temperature sensor 96 Second temperature sensor 98 Third Temperature Sensor 100 Fourth temperature sensor 102 5th temperature sensor 104 Intake Air Heating System 106 Second Heat Transfer Assembly 108 Fluid inlet passage 110 Fluid outlet passage 112 Intake Air Heating System 114 Direct Contact Systems 116 First Heat Transfer Assembly 118 Fluid inlet passage 120 Fluid outlet passage 122 Intake Air Heating System 124 First Heat Transfer Assembly 126 Fluid inlet passage 128 Fluid outlet passage 130 inlet, heating loop inlet 132 Exit

Claims

1. An intake air heating system (12, 104, 112, 122) for a gas turbine system (10), comprising: an inlet heat exchanger (52) configured to be positioned upstream of a compressor (16) of the gas turbine system (10); a heating loop (56) fluidly coupled to the inlet heat exchanger (52), the heating loop (56) configured to provide a heating fluid (58) to the inlet heat exchanger (52), the inlet heat exchanger (52) configured to facilitate the transfer of heat from the heating fluid (58) to an airflow entering the compressor (16); a first heat transfer assembly (60, 116, 124) configured to receive cooling tower fluid (48) from a fluid path (44) extending between a steam condenser (39) and a cooling tower, the first heat transfer assembly (60, 116, 124) configured to facilitate transfer of heat from the cooling tower fluid (48) to the heating fluid (58); a second heat transfer assembly (68, 106) configured to receive a heated fluid from a steam turbine system (28), the second heat transfer assembly (68, 106) configured to facilitate transfer of heat from the heated fluid to the heating fluid (58); An intake air heating system (12, 104, 112, 122) comprising:

2. 2. The intake air heating system of claim 1, wherein the first heat transfer assembly comprises a heating loop heat exchanger configured to facilitate the transfer of heat from the cooling tower fluid to the heating fluid.

3. 2. The intake air heating system of claim 1, wherein the first heat transfer assembly includes a fluid inlet passage and a fluid outlet passage, the fluid inlet passage and the fluid outlet passage being fluidly coupled to the heating loop, the fluid inlet passage configured to transfer the cooling tower fluid from the fluid path to the heating fluid, and the fluid outlet passage configured to receive the cooling tower fluid from the heating fluid and transfer the cooling tower fluid to the fluid path.

4. 2. The intake air heating system of claim 1, wherein the second heat transfer assembly comprises a second heating loop heat exchanger configured to facilitate the transfer of heat from the heated fluid to the heating fluid.

5. 2. The intake air heating system of claim 1, wherein the second heat transfer assembly includes a second fluid inlet passage and a second fluid outlet passage, the second fluid inlet passage and the second fluid outlet passage being fluidly coupled to the heating loop, the second fluid inlet passage configured to transfer the heated fluid from the steam turbine system to the heating fluid, and the second fluid outlet passage configured to receive the heated fluid from the heating fluid and transfer the heated fluid to the steam condenser.

6. a first valve (82) configured to control a first flow rate of the cooling tower fluid (48) through the first heat transfer assembly (60, 116, 124); a second valve (84) configured to control a second flow rate of the heated fluid through the second heat transfer assembly (68, 106); a third valve (86) configured to control a third flow rate of the heating fluid (58) through the heating loop (56); a controller (88) including a memory (92) and a processor (90), the controller (88) communicatively coupled to the first valve (82), the second valve (84), and the third valve (86), and configured to control the first valve (82), the second valve (84), and the third valve (86); The intake air heating system (12, 104, 112, 122) of claim 1, comprising:

7. 7. The intake air heating system of claim 6, wherein the controller is configured to control the first valve to establish a target temperature of the airflow to the compressor.

8. 7. The intake air heating system of claim 6, wherein the controller is configured to allow the second valve to open in response to determining that the position of the first valve is equal to or greater than a threshold position for greater than a first threshold duration, and the controller is configured to instruct the second valve to close and disable opening in response to determining that the position of the first valve is less than the threshold position for greater than a second threshold duration.

9. 10. The intake air heating system of claim 8, wherein the controller is configured to control the second valve to establish a target temperature for the airflow entering the compressor while the second valve is allowed to open, and the controller is configured to command the first valve to close in response to determining that a temperature difference between the cooling tower fluid entering the first heat transfer assembly and the heating fluid flowing from the inlet heat exchanger is less than or equal to a threshold temperature difference while the second valve is allowed to open and for more than a third threshold duration, or a combination thereof.

10. 7. The intake air heating system of claim 6, wherein the controller is configured to control the third valve such that a first temperature difference is less than a second temperature difference multiplied by a first adjustment factor and is greater than or equal to the second temperature difference multiplied by a second adjustment factor, the first adjustment factor being greater than the second adjustment factor, the first temperature difference corresponding to a difference between a temperature of the heating fluid entering the inlet heat exchanger and a temperature of the heating fluid exiting the inlet heat exchanger, and the second temperature difference corresponding to a difference between a target temperature of the airflow entering the compressor and a temperature of a second airflow entering the inlet heat exchanger.

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