Exhaust duct for a gas turbine engine

Abstract

An exhaust duct (1) for a gas turbine engine (50) is disclosed, the exhaust duct (1) comprising a silencer section (12). At least two plate-shaped silencer baffles (20) are provided inside the silencer section (12). At least one of the plate-shaped silencer baffles is configured as a heat exchanging device, as it comprises at least one internal chamber (22) adapted to receive a heat exchanging fluid and being leak-tight with respect to the inside of the exhaust duct, wherein the at least one internal chamber is fluidly connected to the outside of the exhaust duct at an inlet port and an outlet port (23, 24). The device can be used to recover exhaust heat from the exhaust gases of a gas turbine engine without the need to provide the costs and additional space required for a heat recovery steam generator.

Description

Technical Field

[0001] This disclosure relates to an exhaust pipe for a gas turbine engine. Background Technology

[0002] In modern gas turbine engines, under high component loads and full-load conditions, the exhaust gas remains several hundred degrees Celsius after leaving the expander turbine, typically ranging from 500°C to 600°C. Therefore, the large enthalpy flow added to the combustion fuel before expansion in the expander turbine is released into the atmosphere and loses its technical utility. This enthalpy loss adversely affects efficiency.

[0003] It is known in the art to recover the exhaust enthalpy of a gas turbine engine in a heat recovery steam generator and use the resulting steam in the steam turbine to generate electricity. The steam can also be used for industrial purposes. However, constructing a combined-cycle power plant in which the steam turbine acts as the bottom cycle to utilize the exhaust energy from the gas turbine engine requires significant capital investment, making this technology, despite its excellent overall efficiency, only economically attractive if the power plant can essentially operate as a baseload power plant, for example, for more than 5,000 hours per year and with a high power output, for example, at least 75% of rated power output. Furthermore, numerous components within the exhaust piping generate additional pressure losses, thus reducing the efficiency and power output of the gas turbine engine itself. Moreover, the space required for a heat recovery steam generator may not always be available. In particular, installing a heat recovery steam generator may not be an option for adding to existing single-cycle gas turbine engine power plants.

[0004] US 2013 / 0327052 teaches how to connect multiple gas turbine engines to a common flue and arrange heat exchangers in that common flue. The document also teaches how to place heat exchangers in a common flue and improve heat transfer from exhaust gas to the heat exchanger by introducing non-laminar flow through the common exhaust flue and further by applying dew point control.

[0005] US 8,069,660 discloses a heat recovery system integrated into a silencing chamber. According to the teachings of this document, the exhaust flow first enters a first silencing chamber and is then split into two localized flows. A first localized flow is conveyed from the first silencing chamber to a second silencing chamber, and from the second silencing chamber to a third silencing chamber. A second localized flow bypasses the second silencing chamber and is directed directly to the third silencing chamber. The second localized flow thus flows through a duct arranged around the silencing chamber in a heat recovery flow path formed between the inner shell and the outer heat recovery shell. A heat transfer fluid is guided through the heat recovery flow path to exchange heat with the exhaust gas in the silencing chamber through the inner wall, and with the second localized flow of exhaust gas flowing through the duct, wherein the heat transfer fluid flows around the duct. The teachings of this document do not specifically relate to use in conjunction with a gas turbine engine.

[0006] US 3,235,001 teaches a combined muffler and heat exchanger assembly suitable for attachment to an outlet or inlet of an internal combustion engine. The combined muffler and heat exchanger assembly includes a housing. At the front of the housing, a front panel partially closes the housing and opens a front inlet formed between the front panel and an outer panel of the housing. At the rear of the housing, the interior of the housing is connected to an engine inlet, thereby forming a rear inlet around a conduit connecting the interior of the housing to the engine inlet and the outer panel of the housing. Thus, fluid flow can enter the interior of the housing through the rear and front inlets and deflect radially inward to the center of the housing and from the center of the housing to the engine inlet. A heat exchanger assembly is disposed inside the housing, wherein the heat exchanger assembly includes tubes with square fins on their exterior to improve heat exchange between the flow around the tubes and the tubes. Summary of the Invention

[0007] The purpose of this disclosure is to provide a device that enables the recovery of exhaust heat from a gas turbine engine. A more specific objective of the subject matter disclosed herein is to provide an exhaust manifold for a gas turbine engine of the type initially mentioned. In one aspect, an exhaust manifold for a gas turbine engine will be provided that enables the recovery of waste heat from exhaust gases without the need for additional components inside the exhaust manifold that would result in pressure loss. In another aspect, a heat exchange device should be integrated into components already present in the exhaust manifold. In yet another aspect, a heat exchange device should be provided that requires minimal additional capital investment.

[0008] This is achieved through the topics described below.

[0009] Whether or not explicitly stated, the further effects and benefits of the disclosed subject matter will become apparent from the disclosure provided below.

[0010] Therefore, the present invention discloses an exhaust duct for a gas turbine engine, the exhaust duct including a muffler section having an inlet and an outlet, and a flow direction from the inlet to the outlet. This flow direction can be determined by geometry, aerodynamic design, etc. It should be understood that the inlet is configured to be arranged closer to the exhaust outlet of the gas turbine engine than the outlet of the muffler section. At least two plate-shaped muffler baffles are disposed within the muffler section and arranged parallel to each other. Each muffler baffle extends from an upstream edge to a downstream edge along the flow direction of the muffler section. Each of the at least two plate-shaped muffler baffles has a side surface extending from the upstream edge to the downstream edge along the flow direction of the muffler section. The upstream edge may be particularly rounded and forms the so-called "outer radius" of the baffle for aerodynamic reasons. The side surfaces of the muffler baffles also extend over the entire flow cross-section of the muffler section. The two side surfaces of two adjacent plate-shaped muffler baffles are arranged facing each other and form an exhaust flow passage between them. At least one of the plate-shaped muffler baffles is configured as a heat exchange device because it includes at least one internal chamber adapted to receive heat exchange fluid. Those skilled in the art will understand that the internal chamber adapted to receive the heat exchange fluid is leak-proof relative to the interior of the exhaust duct. At least one internal chamber is fluidly connected to the exterior of the exhaust duct at inlet and outlet ports. In particular, the inlet and outlet ports extend through one or more sidewalls of the exhaust duct.

[0011] In the following text, the baffle configured as a heat exchange device may also be referred to as a heat exchange baffle or a heat exchange silencer baffle.

[0012] It should be noted that, within the framework of this disclosure, the use of the indefinite article "a" or "an" does not prescribe singularity, nor does it exclude the existence of multiple named components or features. Therefore, it should be interpreted in the sense of "at least one" or "one or more".

[0013] In one embodiment, at least one internal chamber may be provided as at least one internal pipe fluidly connected to the exterior of the exhaust duct (i.e., through the wall of the exhaust duct). In an exemplary embodiment, at least one internal pipe extends adjacent to and along the leading edge of at least one plate-shaped muffler baffle and may extend from an inlet port to an outlet port. Similarly, it may be provided that at least one internal pipe extends in a spiral shape inside at least one muffler baffle and may extend from an inlet port to an outlet port.

[0014] In an exemplary embodiment disclosed herein, at least one side surface of a muffler baffle is disposed on a sidewall, wherein each sidewall is provided as a hollow body having two sheets with a space between them, each of the sheets being perforated by a plurality of openings, and the openings on the sheets of the sidewall are connected by a tube bridging the space so as to fluidly connect the two opposite sides of the sidewall through the tube. The tube does not necessarily have a circular cross-section. The connection between the tube and the sheet is hermetically sealed with respect to the respective sheet. Thus, a chamber suitable for receiving heat exchange fluid is formed inside the sidewall within the space between the sheets and outside the tube.

[0015] In an exemplary embodiment further disclosed herein, all internal chambers suitable for receiving heat exchange fluid, having all silencer baffles (i.e., configured as heat exchange devices) of the internal chambers, are connected to two common manifolds, wherein each internal chamber for heat exchange fluid is fluidly connected to the two common manifolds. Given that the internal chambers are intended for the flow of heat exchange fluid, the manifolds may be referred to as inlet manifolds and outlet manifolds.

[0016] The present invention also discloses a gas turbine engine in which the exhaust side of an expansion turbine is connected to an exhaust pipe of the type described above. The present invention also discloses a power plant comprising at least one of the disclosed gas turbine engines, i.e., wherein the expansion turbine is connected to an exhaust pipe of the type described above.

[0017] In addition to the gas turbine engine, the power plant may also include a compressed air energy storage (CAES) system, wherein the inlet port of a muffler baffle configured as a heat exchange device is fluidly connected to a CAES tank, and the outlet port of a muffler baffle configured as a heat exchange device is fluidly connected to a CAES expansion turbine.

[0018] In another embodiment, the power plant can be substantially the type of power plant disclosed in US 2019 / 0195131. In addition to the gas turbine engine, the power plant also includes a turbocharging device, which includes at least one low-pressure compressor, at least one high-pressure compressor, and at least one turbine for driving said compressors. Each compressor can be arranged on a common shaft with a separate turbine and driven by that separate turbine. The turbocharging device can then include at least one low-pressure turbocharger and one or more high-pressure turbochargers, wherein the compressor of the low-pressure turbocharger delivers fluid to the high-pressure compressor. It is possible that multiple low-pressure turbochargers are arranged parallel to each other and in series with a single high-pressure turbocharger to, for example, use the same turbocharger while taking into account the different volumetric flow rates in the high-pressure and low-pressure compressors. In other embodiments, it can be provided that one or more high-pressure compressors and one or more low-pressure compressors are fluidly arranged such that the compressor of the low-pressure turbocharger delivers fluid to the high-pressure compressor, while being arranged on a common shaft having, in particular, a single turbine for driving the compressors. The compressor outlet of at least one low-pressure compressor is fluidly connected to the inlet port of a muffler baffle configured as a heat exchange device and the compressor inlet of at least one high-pressure compressor. An intercooler may be fluidly inserted between the compressor outlet of at least one low-pressure compressor and the compressor inlet of at least one high-pressure compressor. The outlet port of the muffler baffle configured as a heat exchange device is fluidly connected to the turbine inlet of at least one turbine of the turbocharger. The turbine outlet of at least one turbine of the turbocharger is fluidly connected to a back pressure control device, and the compressor outlet of at least one high-pressure compressor is connected to the working fluid flow path of the gas turbine engine downstream of the compressor and upstream of the combustor, i.e., fluidly connected to the combustor. Therefore, the waste heat recovered in the heat exchange baffle can be used to drive an external compressor to supply additional air to the combustor of the gas turbine engine, and thus enhance the turbine output of the gas turbine engine and / or reduce the flow through the compressor of the gas turbine engine, thereby reducing the power consumption of the compressor of the gas turbine engine. A back pressure valve is used to control the discharge pressure of the high-pressure compressor of the turbocharger.

[0019] In other embodiments of the power plant disclosed herein, a muffler baffle, configured as a heat exchange device, is fluidly inserted between the compressor and burner of the gas turbine engine via its inlet and outlet ports, thereby being configured to receive at least a portion of the fluid flow from the compressor to the burner. In a more specific embodiment, the compressor is a supplementary compressor, distinct from the gas turbine engine compressor, and specifically, the compressor is motor-driven. During partial load operation, the compressor can charge a battery, which, during periods of high power demand, is used to power the motor driving the supplementary compressor and enhance the power output of the gas turbine engine.

[0020] In the power plant embodiments disclosed herein, the gas turbine engine is equipped with an intake preheating circuit that includes an intake preheating heat exchanger disposed upstream of the compressor of the gas turbine engine. An exemplary, specific, and non-limiting embodiment of a gas turbine engine equipped with an intake preheating heat exchanger is disclosed in US 2018 / 0135467. A muffler baffle configured as a heat exchange device is incorporated into the intake preheating circuit through its inlet and outlet ports to allow fluid contained in the intake preheating circuit to flow through an internal chamber for providing heat exchange fluid within the heat exchange muffler baffle. This application can be found to improve the part-load efficiency of the gas turbine engine, or may otherwise allow the gas turbine engine to operate in normal operating mode at a low percentage of its ISO rated power output.

[0021] In other embodiments of the power plant disclosed herein, the gas turbine engine is equipped with a fuel preheating circuit, wherein the fuel preheating circuit includes a fuel preheating heat exchanger disposed upstream of the combustor of the gas turbine engine in the fuel flow path. A muffler baffle configured as a heat exchange device is connected to the fuel preheating circuit through its inlet and outlet ports to allow fluid contained in the fuel preheating circuit to flow through an internal chamber for providing heat exchange fluid within the heat exchange muffler baffle.

[0022] In other embodiments of the power plant disclosed herein, the compressor of the gas turbine engine includes a vent port downstream of the compressor inlet and upstream of the compressor outlet. A first line extends from the vent port to a low-pressure inlet port of an external compressor, thereby fluidly connecting the vent port to the low-pressure inlet port of the external compressor. A second line connects to the high-pressure outlet port of the external compressor and fluidly connects the high-pressure outlet port of the external compressor to the inlet port of a muffler baffle configured as a heat exchange device. A third line connects to at least one of the high-pressure outlet of the gas turbine engine compressor and the burner of the gas turbine engine, and fluidly connects the outlet port of the muffler baffle configured as a heat exchange device to the high-pressure outlet of the gas turbine engine compressor and / or the burner of the gas turbine engine.

[0023] It should be understood that the features and embodiments disclosed above can be combined with each other. It should also be understood that other embodiments, which are obvious to a person skilled in the art, can be conceived within the scope of this disclosure and the claimed subject matter. Attached Figure Description

[0024] The subject matter of this disclosure will be explained in more detail with reference to the selected exemplary embodiments shown in the accompanying drawings. The drawings illustrate...

[0025] Figure 1 A perspective view of an exemplary embodiment of the exhaust pipe of a gas turbine engine;

[0026] Figure 2 A cross-sectional view of the muffler section of the exhaust pipe of a gas turbine engine with a rectangular cross-section;

[0027] Figure 3 A cross-sectional view of a first exemplary embodiment passing through a heat exchange muffler baffle;

[0028] Figure 4 A cross-sectional view of a second exemplary embodiment of a heat exchange muffler baffle;

[0029] Figure 5 A perspective view of a third exemplary embodiment of a heat exchange muffler baffle;

[0030] Figure 6 for Figure 5 Another sectional view of the baffle depicted in the image;

[0031] Figure 7 An isometric view of a portion of the heat exchange muffler section of the exhaust duct, depicting the connection between the heat exchange baffle and the inlet and outlet manifolds;

[0032] Figure 8This is a schematic diagram of an implementation scheme for a power plant that includes a gas turbine engine and a compressed air energy storage device. The power plant uses a heat exchange muffler section of the gas turbine engine's exhaust pipe to preheat the working fluid of the compressed air energy storage device.

[0033] Figure 9 A schematic diagram of an implementation scheme for a power plant with turbocharger-driven air injection, wherein the power plant uses a heat exchange muffler section of the exhaust pipe of a gas turbine engine to supply energy for driving the turbocharger;

[0034] Figure 10 This is a schematic diagram of an implementation scheme for a power plant with an externally driven booster compressor, which uses a heat exchange muffler section of the exhaust pipe of a gas turbine engine to preheat air from the external compressor.

[0035] Figure 11 This is a schematic diagram of an implementation scheme for a power plant with gas turbine inlet preheating, where the power plant uses a heat exchange muffler section of the exhaust pipe of the gas turbine engine to provide heat to the inlet preheater; and

[0036] Figure 12 This is a schematic diagram of another embodiment of a gas turbine power plant, which uses a heat exchange muffler section of the exhaust pipe of a gas turbine engine to preheat the air discharged from the compressor of the gas turbine engine.

[0037] It should be understood that the accompanying drawings are highly schematic, and details not necessary for illustrative purposes may be omitted for ease of understanding and depiction. It should also be understood that the drawings show only selected exemplary embodiments, and embodiments not shown are still fully within the scope of the subject matter disclosed and / or claimed herein. Detailed Implementation

[0038] Those skilled in the art will better understand the subject matter described herein through the exemplary embodiments shown in the accompanying drawings and summarized below. It should be understood that these exemplary embodiments are shown for illustrative purposes only to provide a better understanding of the subject matter described herein and should not be construed as limiting the subject matter outlined in the claims.

[0039] Figure 1 An example of an exhaust pipe 1 for a gas turbine engine is shown. The exhaust pipe 1 includes a flue 10. The exhaust pipe transition section 11 is configured to connect to the downstream end of the gas turbine engine 50 (in...). Figures 8 to 12(Illustrated schematically). The muffler section 12 of the exhaust duct includes a muffler baffle 20 visible in the sectional view of this section. In the depicted example, the flue 10 and the muffler section 12 have circular cross-sections, while the exhaust duct transition section 11 is shown as having a rectangular cross-section. However, it is quite possible that either the flue 10 or the muffler section 12 may exhibit a rectangular cross-section, and the exhaust duct transition section 11 may be specified to exhibit a circular or round cross-section. Similarly, although the muffler section 12 is exemplarily shown arranged in a vertical section of the exhaust duct 1, the muffler section 12 may also be arranged in a horizontal section of the exhaust duct 1. These facts are readily apparent to those skilled in the art.

[0040] For example, Figure 2 A cross-sectional view of a muffler section 12 with a rectangular cross-section is depicted. The exhaust duct 1 is defined by a duct wall 13. It should be understood that the exhaust gas flow in the muffler section 12 is perpendicular to the plane of the drawing. A plurality of muffler baffles 20 are arranged on the cross-section of the exhaust duct 1 and are substantially parallel to each other, thereby forming a flow channel between two adjacent muffler baffles 20. According to the subject matter disclosed herein, at least one of the muffler baffles 20, and in some embodiments, each of the muffler baffles 20, is configured as a heat exchange device or a heat-exchange muffler baffle, as will be described in more detail below.

[0041] Generally, the muffler baffle 20 is configured as a heat exchange device because it includes at least one internal chamber adapted to receive heat exchange fluid. Those skilled in the art will understand that the internal chamber for receiving the heat exchange fluid is leak-proof relative to the interior of the exhaust pipe 1, such that no heat exchange fluid can leak from the internal chamber of the muffler baffle 20 into the exhaust pipe 1. At least one internal chamber is fluidly connected to the outside of the exhaust pipe 1. Figure 3A cross-sectional view is shown through a first exemplary embodiment of a muffler baffle 20 configured as a heat exchange device, with the cross-section perpendicular to the side surfaces 25 and 26 of the baffle. The side surfaces span the exhaust duct 1 in the muffler section 12 and extend from the upstream edge 21 to the downstream edge along the flow direction of the muffler section 12. The flow of exhaust gas will be shown from left to right in the figure. In a particular embodiment, the upstream edge 21 of the muffler baffle 20 is rounded to form a so-called outer rounded corner section of the muffler baffle 20 in order to reduce aerodynamic drag and thus reduce pressure loss in the muffler baffle section 12. In the illustrated embodiment, an internal chamber 22 adapted to receive heat exchange fluid is provided as a duct that extends along the leading edge (or upstream) 21 of the muffler baffle 20 in the outer rounded corner section of the muffler baffle 20. The conduit 22 extends along the entire span width of the muffler baffle 20 and has an open end with a port that extends through the wall of the exhaust duct 1 when the baffle 20 is installed in the muffler section 12, providing fluid communication between the conduit 22 and the outside of the exhaust duct 1. Although the ports are not shown in this description, they will be apparent to those skilled in the art. Downstream of the outer rounded corner section, the baffle 20 is hollow between sidewalls 250 and 260. Side surfaces 25 and 26 are located on the outer sides of sidewalls 250 and 260, respectively.

[0042] Figure 4 A second embodiment of the muffler baffle 20, configured as a heat exchange device, is shown in a cross-section taken parallel to the main surface of the baffle 20. In this exemplary embodiment, the internal chamber 22 is configured as a conduit meandering within the baffle between side surfaces 25 and 26. The conduit 22 is fluidly connected to ports 23 and 24, which may be referred to as the inlet port and outlet port, respectively. Figure 4 The heat exchange pipe exemplarily shown in the example can also be arranged in the lining of the exhaust flue wall 13, such as those described above. Figure 2 Or as cited below Figure 7 As shown in the diagram. Although the ducts inside the exhaust flue wall are not explicitly shown, they will be obvious to those skilled in the art based on this disclosure.

[0043] It should be understood that Figure 3 and Figure 4 The two types of pipes shown can be combined in a single baffle 20.

[0044] exist Figure 5 and Figure 6In the illustrated embodiment, the sidewalls 250 and 260 of the baffle 20 (sidewall 250 is shown in more detail) are provided as hollow bodies formed between sheets 251 and 252, with spaces provided between the sheets. Although only one hollow body sidewall 250 is depicted, those skilled in the art will readily understand that sidewall 260 can be identical. The sidewall 250 comprises sheets 251 and 252 spaced apart from each other, such that the sidewall 250 itself constitutes a hollow body. The side surface 25 of the baffle 20 is disposed on the outer side of the sheet 251.

[0045] Figure 6 The sidewall 250 is shown in the figure. Figure 5 The "VI-VI" designation indicates a cross-sectional view along the viewing direction. Each of the sheets 251 and 252 is perforated with multiple openings, and the openings on the two sheets 251 and 252 of the sidewall 250 are aligned with each other. Each pair of oppositely arranged openings is connected by a tube 27 bridging the space between the sheets 251 and 252. Thus, the tube 27 fluidly connects the two opposite sides of the sidewall 250. In addition, the tube 27 is hermetically sealed to the corresponding sheets 251 and 252 to form a chamber 22 suitable for receiving heat exchange fluid in the space between the two sheets 251 and 252 and outside the tube 27.

[0046] Figure 7 An isometric view is shown of a portion of the heat exchange muffler section 12 of the exhaust duct 1, and this isometric view also shows the fluid connection of the heat exchange baffle 20. As described above, the baffle 20 is arranged in a portion of the exhaust duct 1 formed by the duct wall 13. Outside the exhaust duct, manifolds 28 and 29 are connected to the feed and return lines. Ports 23 and 24 extend through the duct wall 13 and are connected to the manifolds 28 and 29 to an internal chamber 22 for receiving heat exchange fluid within the baffle 20. As will be readily understood, in particular, one port 23 and one port 24 may be associated with each heat exchange baffle 20. It goes without saying that the number of heat exchange baffles 20 and the number of ports 23 and 24 may differ from those shown in the exemplary embodiment. Thus, the heat exchange baffles 20 are connected to the feed manifold 28 and the return manifold 29.

[0047] The gas turbine engine 50 (in which the exhaust side of the expansion turbine 53 is fluidly connected to a heat exchange muffler section 12 comprising one or more heat exchange muffler baffles 20 of any type described above) can be effectively applied to a number of applications, some of which will be outlined in more detail below. It should be understood that the exemplary applications mentioned below are not exhaustive and are shown only by way of example.

[0048] Figure 8A first exemplary embodiment using the above-described subject matter is depicted in a power plant. The power plant includes a gas turbine engine 50 and a compressed air energy storage (CAES) device 100. The gas turbine engine 50 includes a compressor 51, a burner 52, and an expansion turbine 53, and is arranged to drive a generator 54. Exhaust gas 61 from the expansion turbine 53 is discharged through a flue 10. In the flow path of the exhaust gas 61, a muffler section 12 of the exhaust duct is arranged upstream of the flue 10. The muffler baffle 20 inside the muffler section 12 is configured as a heat exchange device as described above.

[0049] CAES device 100 includes a compressed air tank 101, a main air heater 102, an expansion turbine 103, and a generator 104 driven by the expansion turbine 103. A heat exchange baffle 20 of a silencer section 12 is fluidly inserted between the compressed air tank 101 and the main air heater 102. This is because the inlet port of the heat exchange silencer baffle 20 inside the silencer section 12 is fluidly connected to the compressed air tank 101, while the outlet port of the heat exchange silencer baffle 20 is fluidly connected to the expansion turbine 103 via the main air heater 102. Therefore, air discharged from the compressed air tank 101 flows through the internal chamber 22 before being fed to the main air heater 102 to receive heat exchange fluid within the baffle 20 of the silencer section 12.

[0050] Therefore, when the gas turbine engine 50 and the CAES equipment 100 operate simultaneously, the air discharged from the compressed air tank 101 passes through the heat exchange baffle 20 inside the muffler section 12 and is heated by heat exchange with the gas turbine engine exhaust gas 61 before entering the main air heater 102, thereby cooling the gas turbine engine exhaust gas 61. This results in less energy required to heat the air to a specific temperature in the main air heater 102, while reducing heat loss associated with the exhaust gas flow 61 through the flue 10, thereby improving the overall power plant efficiency. Based on the thermal power requirements of the CAES equipment 100, the heat exchange capacity of the heat exchange muffler section 12 and the required inlet temperature of the CAES expansion turbine 103 are matched with the temperature to which the heat exchange muffler section 12 can heat the air discharged from the compressed air tank 101. The heat exchange muffler section 12 can be used as the main air heater of the CAES equipment, and therefore the heater 102 can be omitted. However, it should be noted that in the arrangement without CAES heater 102, the operation of CAES device 100 depends entirely on the operation of gas turbine engine 50, while in the presence of CAES heater 102, CAES device 100 can operate independently of gas turbine engine 50.

[0051] A second exemplary example of a power plant utilizing the heat exchange muffler arrangement disclosed herein is a gas turbine power plant with turbocharger-driven air injection, as basically described in US 2019 / 0195131 and... Figure 9 As shown in the illustration. In addition to the gas turbine engine 50, the power plant also includes a turbocharging device, which, in the depicted exemplary embodiment, includes a low-pressure turbocharger 70 and a high-pressure turbocharger 75. The exemplary embodiment shows three low-pressure turbochargers and one high-pressure turbocharger. As will become apparent below, on the one hand, the mass flow through the compressor of the low-pressure turbocharger 70 is higher than the mass flow through the high-pressure turbocharger 75. Furthermore, due to the compression of air in the compressor 71 of the low-pressure turbocharger 70, even at the same mass flow, the inlet flow rate of the compressor 76 of the high-pressure turbocharger 75 is less than the inlet mass flow rate of the compressor 71 of the low-pressure turbocharger 70. Taking into account these effects of adjusting the number of low-pressure turbochargers, it is permissible in principle for the high-pressure turbocharger 75 and the low-pressure turbocharger 70 to use the same type of turbocharger.

[0052] The gas turbine engine 50 discharges exhaust gas from the expansion turbine 53 through the transition section 11 into the exhaust duct 1. The exhaust gas then passes through the heat exchange muffler section 12 and enters the flue 10. During operation, intake air 65 is compressed by the low-pressure compressor 71 and discharged as low-pressure compressed air 66. The compressor outlet of the low-pressure compressor 71 is fluidly connected to the inlet port of the heat exchange muffler baffle 20 arranged inside the heat exchange muffler section 12 and the compressor inlet of the high-pressure compressor 76. Therefore, the low-pressure compressed air 66 is divided into a first partial flow flowing into the heat exchange muffler baffle 20 of the heat exchange muffler section 12, while a second partial flow is supplied to the inlet of the high-pressure compressor 76 via the intercooler 73. The outlet port of the heat exchange muffler baffle 20 arranged inside the heat exchange muffler section 12 is fluidly connected to the turbine inlet of the expansion turbine 72 of the low-pressure turbocharger 70 and the turbine inlet of the expansion turbine 77 of the high-pressure turbocharger 75. Therefore, heated low-pressure compressed air 67 from the heat exchange muffler section 12 is delivered to expansion turbines 72 and 77 to expand in the turbines and be discharged as exhaust air 69. During the expansion of the heated low-pressure compressed air, expansion turbines 72 and 77 generate power to drive compressors 71 and 76.

[0053] The compressor outlet of the high-pressure compressor 76 is fluidly connected to the combustor 52 of the gas turbine engine 50. Therefore, high-pressure compressed air 68 from the high-pressure compressor 76 is delivered to the combustor 52, thereby increasing the mass flow delivered to the combustor 52 by the compressor 51 of the gas turbine engine. Consequently, the mass flow that the expansion turbine 53 of the gas turbine engine can expand is greater than the mass flow delivered by the compressor 51. This configuration enhances the mechanical power output from the expansion turbine 53 and / or reduces the power consumption of the compressor 51, resulting in more power available to drive the generator 54 to generate electrical energy. The turbine outlet of the high-pressure expansion turbine 77 is fluidly connected to a back pressure control device 78, thereby allowing control of the pressure of the high-pressure compressed air 68.

[0054] Another exemplary example of a power plant in conjunction with the topics discussed in this article is... Figure 10 As shown, an external motor drives an external compressor 111 to increase the power output of the gas turbine engine 50. Such applications can be found to be useful during both low and peak grid power demand periods. For example, during low grid power demand, the battery is charged using electricity generated by a generator driven by the gas turbine engine 50. During peak grid power demand, the stored electrical energy can be used to drive the motor, which in turn drives the external compressor 111. Generally, the external compressor 111 compresses the intake air 65 and supplies the resulting additional compressed air substantially downstream of or at the outlet of the compressor 51 into the gas turbine engine or into the combustor 52. In either case, the outlet of the external compressor 111 is in fluid communication with the combustor 52.

[0055] In the embodiment shown herein, the expansion turbine 53 of the gas turbine engine 50 discharges exhaust gas into an exhaust duct having a heat exchange muffler section 12, which includes a heat exchange muffler baffle 20. The heat exchange muffler baffle 20 is fluidly inserted between the external compressor 111 and the combustor 52 through its inlet and outlet ports, and is configured to receive at least a portion of the fluid flow delivered from the external compressor 111 to the combustor 52. Therefore, compressed air 81 from the external compressor 111 flows through the heat exchange muffler baffle 20 and is fed as heated compressed air 82 to the gas turbine engine 50 downstream of the compressor 51.

[0056] Temperature sensor 115 senses the temperature of the heated compressed air 82 and forwards this temperature to controller 116. Controller 116 controls the mass flow of compressed air 81 through heat exchange muffler baffle 20 via control valve 113, adapting the mass flow of compressed air 81 to available heat to achieve the desired target temperature of the heated compressed air. If external compressor 111 is not operating, stop valve 112 can close the line of compressed air 81. Due to heat exchange with the exhaust gas of gas turbine engine 50, compressed air 82 is introduced into gas turbine engine 50 at an elevated temperature, thus reducing the temperature rise of the portion of the gas turbine engine working fluid flow through combustor 52. Therefore, heating the supplementary air 82 fed to gas turbine engine 50 by external compressor 111 reduces the fuel consumption of gas turbine engine 50.

[0057] Figure 11 Another exemplary example of a power plant in which a gas turbine engine with a heat exchange muffler section of the type described herein is used to improve efficiency is shown. As described above, an exemplary, specific, and non-limiting embodiment of a gas turbine engine equipped with an intake preheating heat exchanger is disclosed in US 2018 / 0135467. The gas turbine engine 50 is equipped with an intake preheating circuit including an intake preheating heat exchanger 56 disposed in an inlet housing 55, upstream of the compressor 51 of the gas turbine engine 50 in the working fluid flow of the gas turbine engine 50. While intake preheating increases the power consumption of the compressor 51 of the gas turbine engine 50, it is known to be an effective means when the gas turbine engine 50 is operated at very low loads. By changing the temperature of the intake air 60, as is well known to those skilled in the art, the relative power output of the gas turbine engine 50 can be changed with a constant megawatt power output. Therefore, the operating point can be shifted to achieve better overall efficiency and improved emissions.

[0058] The heat exchange muffler baffle 20 is integrated into the intake preheating circuit via its inlet and outlet ports to allow fluid contained in the intake preheating circuit to flow through an internal chamber for providing heat exchange fluid within the heat exchange muffler baffle 20. In a manner commonly known to those skilled in the art, the intake preheating circuit includes a pump 117 that delivers fluid from a tank 118. Fluid is typically fed from the pump through the heat exchange muffler baffle 20, which is disposed within the heat exchange muffler section 12 of the exhaust duct.

[0059] During operation of the gas turbine engine, exhaust gas from the expander turbine 53 flows through the heat exchange muffler section 12. Therefore, the fluid delivered by pump 117 and flowing through the heat exchange baffle 20 is heated during heat exchange with the exhaust gas from the gas turbine engine 50, flows through the intake preheating heat exchanger 56, heats the intake air 60 flowing through the compressor 51 during heat exchange with water, and returns to tank 118. In the intake preheating circuit, downstream of the heat exchange muffler baffle 20, a temperature sensor 115 is arranged and connected to a controller 116. The controller 116 acts on a three-way control valve 114, which controls the flow of water through a bypass line that bypasses the heat exchange baffle 20 to control the temperature of the fluid entering the intake heat exchanger 56. It should be noted that the temperature sensor 115 can be arranged in the flow of heated intake air 60 from the intake heat exchanger 56 to the compressor 51 of the gas turbine engine 50. This allows for direct control of the intake air temperature. Furthermore, in the exemplary embodiment shown herein, the intake preheating circuit includes a stop valve 112 for completely shutting off the fluid flow in the intake preheating circuit to prevent final thermally driven convection that could occur even if pump 117 is turned off.

[0060] Exhaust heat recovery can be applied to the heat exchange muffler baffle 20 using a very similar arrangement for fuel preheating. In this case, the intake preheating heat exchanger 56 would simply be replaced by a fuel preheating heat exchanger through which fuel is fed instead of intake air.

[0061] exist Figure 12 Another exemplary embodiment of a gas turbine power plant is illustrated, which utilizes the exhaust duct with a heat exchange muffler section as described herein. A portion of the compressed air is vented from the compressor 51 of the gas turbine engine 50 at vent ports downstream of the compressor inlet and upstream of the compressor outlet, and is further compressed by an external compressor 111. The high-pressure outlet port of the external compressor 111 is fluidly connected to the inlet port of the heat exchange muffler baffle 20. Therefore, compressed air from the external compressor 111 flows through the heat exchange baffle 20.

[0062] Additional piping connects to at least one of the high-pressure outlet of compressor 51 and the combustor 52 of gas turbine engine 50, and thus fluidly connects the outlet port of heat exchange muffler baffle 20 to the combustor of gas turbine engine. Exhaust heat from gas turbine engine 50 is thus recovered and reintroduced into the gas turbine engine process. Temperature sensor 115 senses the temperature of compressed air downstream of heat exchange muffler baffle 20. The sensed temperature is forwarded to controller 116, which in turn controls three-way control valve 114. By means of three-way valve 114, a portion of compressed air from external compressor 111 can bypass heat exchange baffle 20, thereby allowing control of the temperature of compressed air downstream of heat exchange muffler baffle 20. A stop valve 112 arranged in the flow path of the vented air allows the external flow path from the vent port through heat exchange muffler baffle 20 to the combustor 52 of gas turbine engine 50 to be closed.

[0063] While the subject matter of this disclosure has been explained through exemplary embodiments, it should be understood that these are in no way intended to limit the scope of the claimed invention. It should be understood that the claims cover embodiments not expressly shown or disclosed herein, and embodiments deviating from those disclosed in exemplary models of carrying out the teachings of this disclosure will still be covered by the claims.

Claims

1. An exhaust duct (1) for a gas turbine engine (50), the exhaust duct including a muffler section (12) having an inlet and an outlet and a flow direction from the inlet to the outlet; in, At least two plate-shaped muffler baffles (20) are disposed inside the muffler section (12) and arranged parallel to each other, wherein each muffler baffle extends from the upstream edge (21) to the downstream edge along the flow direction of the muffler section. Each of the at least two plate-shaped muffler baffles has a side surface (25, 26) extending from the upstream edge (21) to the downstream edge along the flow direction of the muffler section, wherein the two side surfaces of two adjacent plate-shaped muffler baffles are arranged facing each other and form an exhaust flow channel therebetween. At least one of the plate-shaped muffler baffles is also configured as a heat exchange device, since at least one of the plate-shaped muffler baffles includes at least one internal chamber (22) adapted to receive heat exchange fluid, wherein the at least one internal chamber is fluidly connected to the outside of the exhaust pipe at an inlet port and an outlet port (23, 24), wherein the side surfaces (25, 26) of at least one muffler baffle are provided on side walls (250, 260), wherein each side wall is configured as a hollow body having two sheets (251, 252), wherein there is a space between the two sheets, wherein each of the sheets is perforated by a plurality of openings, and each pair of aligned openings on the sheets (251, 252) of the side wall is connected by a tube (27) bridging the space and hermetically sealed to the corresponding sheet, so as to fluidly connect the two opposite sides of the side wall through the tube, such that the internal chamber (22) adapted to receive heat exchange fluid is formed in the space between the two sheets and outside the tube.

2. The exhaust pipe according to claim 1, wherein, The at least one internal chamber is provided as at least one internal conduit fluidly connected to the outside of the exhaust conduit.

3. The exhaust pipe according to claim 2, wherein, At least one internal duct is adjacent to and extends along the upstream edge (21) of at least one plate-shaped muffler baffle (20).

4. The exhaust pipe according to claim 2 or 3, wherein, At least one internal conduit extends in a spiral shape inside at least one muffler baffle.

5. The exhaust pipe according to any one of claims 1-3, wherein, All internal chambers (22) adapted to receive heat exchange fluids configured as all muffler baffles (20) of a heat exchange device are connected to two common manifolds (28, 29), wherein each internal chamber for heat exchange fluids is fluidly connected to the two common manifolds.

6. A gas turbine engine (50), wherein, The exhaust side of the expansion turbine (53) is connected to the exhaust pipe (1) according to any one of the preceding claims 1-5.

7. A power plant comprising at least one gas turbine engine (50) according to claim 6, and further comprising a compressed air energy storage (CAES) system (100), wherein, The inlet port of the muffler baffle (20), which is configured as a heat exchange device, is fluidly connected to the compressed air tank (101), and the outlet port of the muffler baffle, which is configured as a heat exchange device, is fluidly connected to the expansion turbine (103).

8. A power plant comprising at least one gas turbine engine (50) according to claim 6, and further comprising a turbocharger, wherein, The turbocharger includes at least one low-pressure compressor (71), at least one high-pressure compressor (76), and at least one turbine (72, 77) for driving the low-pressure compressor and the high-pressure compressor, wherein: The compressor outlet of the at least one low-pressure compressor (71) is fluidly connected to the inlet port of the silencer baffle (20), which is configured as a heat exchange device, and the compressor inlet of the at least one high-pressure compressor (76). The outlet port of the muffler baffle (20), configured as a heat exchange device, is fluidly connected to the turbine inlet of at least one turbine (72, 77) of the turbocharger. The turbine outlet of at least one turbine of the turbocharger is fluidly connected to the back pressure control device (78), and The compressor outlet of the at least one high-pressure compressor (76) is fluidly connected to the burner (52) of the gas turbine engine.

9. A power plant comprising at least one gas turbine engine (50) according to claim 6, wherein, The muffler baffle (20), configured as a heat exchange device, is fluidly inserted between the external compressor (111) and the combustor (52) of the gas turbine engine through its inlet and outlet ports, thereby enabling the muffler baffle, configured as a heat exchange device, to receive at least a portion of the fluid flow delivered from the compressor to the combustor.

10. The power plant according to claim 9, wherein, The external compressor (111) is a supplementary compressor, different from the compressor (51) of the gas turbine engine (50), and the compressor is motor driven.

11. A power plant comprising at least one gas turbine engine according to claim 6, wherein, The gas turbine engine is equipped with an intake preheating circuit, wherein the intake preheating circuit includes an intake preheating heat exchanger (56) disposed upstream of the compressor (51) of the gas turbine engine (50), wherein the muffler baffle (20) configured as a heat exchange device is connected to the intake preheating circuit through its inlet port and outlet port so that fluid contained in the intake preheating circuit flows through the internal chamber for heat exchange fluid disposed inside the muffler baffle configured as a heat exchange device.

12. A power plant comprising at least one gas turbine engine (50) according to claim 6, wherein, The gas turbine engine is equipped with a fuel preheating circuit, wherein the fuel preheating circuit includes a fuel preheating heat exchanger disposed upstream of the combustor of the gas turbine engine in the fuel flow path, wherein the muffler baffle (20) configured as a heat exchange device is connected to the fuel preheating circuit through its inlet port and outlet port so that fluid contained in the fuel preheating circuit flows through the internal chamber for heat exchange fluid disposed inside the muffler baffle configured as a heat exchange device.

13. A power plant comprising at least one gas turbine engine (50) according to claim 6, wherein, The compressor (51) of the gas turbine engine includes a vent port downstream of the compressor inlet and upstream of the compressor outlet, wherein a first line extends from the vent port to a low-pressure inlet port of an external compressor (111), thereby fluidly connecting the vent port to the low-pressure inlet port of the external compressor, wherein a second line is further connected to a high-pressure outlet port of the external compressor (111) and fluidly connects the high-pressure outlet port of the external compressor to the inlet port of the muffler baffle (20) configured as a heat exchange device, and a third line is connected to at least one of the high-pressure outlet of the compressor (51) of the gas turbine engine and the burner (52) of the gas turbine engine, and fluidly connects the outlet port of the muffler baffle (20) configured as a heat exchange device and the high-pressure outlet of the compressor of the gas turbine engine and the burner of the gas turbine engine.

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