System and method for combining compressor bleed air and throughflow air in a gas turbine engine

Abstract

The present invention is entitled "System and method for combining compressor bleed air and ventilation air flows of a gas turbine engine". The present invention provides a flow combiner (12) for a gas turbine engine (50). The flow combiner (12) includes an outlet duct (14), a compressor bleed air inlet duct (16) coupled to the outlet duct (14), and a ventilation air inlet duct (18) coupled to the outlet duct (14). The compressor bleed air inlet duct (16) is configured to receive a bleed air flow (28) from a compressor (56) of the gas turbine engine (50). The ventilation air inlet duct (18) is configured to receive a ventilation air flow (36) from an enclosure (54) surrounding the gas turbine engine (50). The bleed air flow (28) and the ventilation air flow (36) are combined into an outlet flow through the outlet duct (14).

Description

Background Art

[0001] The subject matter disclosed herein relates to gas turbine engines and, more particularly, to systems and methods for combining compressor bleed and vent flows of a gas turbine engine.

[0002] A gas turbine engine typically includes a compressor, a combustor, and a turbine. The combustor burns fuel using compressed air from the compressor and provides hot combustion gases to the turbine to drive a load (such as a generator). A gas turbine engine can discharge multiple streams (e.g., exhaust stream, vent stream, compressor bleed stream, etc.) through separate flow paths (such as a stack). Unfortunately, each stack requires space and increases the cost of the gas turbine engine. Each stack may also include various internal components, such as muffler baffles. Therefore, a gas turbine engine may have repeated parts (e.g., stacks, muffler baffles, etc.) to handle multiple streams. Summary of the Invention

[0003] The following summarizes certain embodiments that are comparable in scope to the initially claimed invention. These embodiments are not intended to limit the scope of the claimed invention, but rather, these embodiments are intended only to provide a brief overview of possible forms of the invention. In fact, the present invention may include various forms that may be similar or different from the embodiments set forth below.

[0004] In a first embodiment, a system includes a flow combiner in which a bleed flow and a vent flow are combined into an outlet flow through an outlet duct. The flow combiner includes the outlet duct, a compressor bleed air inlet duct coupled to the outlet duct, wherein the compressor bleed air inlet duct is configured to receive the bleed flow from a compressor of a gas turbine engine, and a vent inlet duct coupled to the outlet duct, wherein the vent inlet duct is configured to receive the vent flow from an enclosure surrounding the gas turbine engine.

[0005] In a second embodiment, a method includes receiving a bleed air flow from a compressor of a gas turbine engine into a compressor bleed air inlet duct coupled to an outlet duct of a flow combiner; and receiving a ventilation air flow from an enclosure surrounding the gas turbine engine into a ventilation air inlet duct coupled to the outlet duct, wherein the bleed air flow and the ventilation air flow are combined into an outlet flow through the outlet duct.

[0006] In a third embodiment, a system includes a flow combiner in which a high-energy flow and a low-energy flow are combined into an outlet flow through an outlet duct. The flow combiner includes the outlet duct; a first inlet duct coupled to the outlet duct, wherein the first inlet duct is configured to receive the high-energy flow and includes an adjustable valve; and a second inlet duct coupled to the outlet duct, wherein the second inlet duct is configured to receive the low-energy flow and includes at least one fan. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0008] Figure 1 is a schematic block diagram of an embodiment of a gas turbine system having a flow combiner configured to combine different flows (e.g., a vent flow and a compressor discharge flow);

[0009] Figure 2 yes Figure 1 A perspective view of an embodiment of a stream combiner;

[0010] Figure 3 yes Figure 2 a side view of an embodiment of a stream combiner;

[0011] Figure 4 yes Figure 2 A front view of an embodiment of a stream combiner;

[0012] Figure 5 Yes Figure 1 and Figure 3 a perspective view of an embodiment of a backflow suppressor of the flow combiner, further illustrating an embodiment of multiple conduits of the backflow suppressor;

[0013] Figure 6 is connected to Figure 1 a schematic cross-sectional side view of a flow combiner of a compressor of a gas turbine system showing a compressor bleed air inlet duct having a variable bleed air valve configured to adjust the compressor bleed air flow entering the flow combiner; and

[0014] Figure 7 is used Figures 1 to 6 A flow chart of an embodiment of a method of operating a gas turbine system in different modes with a flow combiner. DETAILED DESCRIPTION

[0015] One or more specific embodiments of the present invention will be described below. In order to provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may vary from implementation to implementation. In addition, it should be understood that such development work may be complex and time-consuming, but it is still a routine task for ordinary technicians who benefit from this disclosure to design, fabricate and manufacture.

[0016] When introducing elements of various embodiments of the present invention, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0017] As discussed in more detail below, the present embodiment described herein provides an efficient ventilation system that combines a ventilation flow from a package disposed around a gas turbine engine and a bleed flow from a compressor of the gas turbine engine via a flow combiner. Without the disclosed flow combiner, the gas turbine engine may include many duplicate sections (e.g., separate stacks and separate muffler assemblies) for various exhaust flows (such as ventilation flow, compressor bleed flow, and other flows). These duplicate sections result in greater space consumption, greater installation costs, and greater maintenance costs. Unfortunately, the various exhaust flows of the gas turbine engine may have significantly different flow rates, pressures, temperatures, and / or other characteristics during various operating phases of the gas turbine engine (e.g., startup, steady state, shutdown, part load, full load, etc.).

[0018] Therefore, the system described herein is a combined ventilation system and silencer to attenuate noise from the combined ventilation and bleed flows. By combining the flows and using a single silencer assembly, the ventilation system described herein can reduce component and maintenance costs, thereby improving the efficiency of the gas turbine system. In order to effectively combine the flows, the bleed flow and ventilation flow can be adjusted based on the various operating modes of the gas turbine system. For example, during startup mode, the bleed flow can be increased but set to a low flow rate, while the ventilation flow can be operated at full flow. During full load mode, the bleed flow can be closed, while the ventilation flow can be operated at full flow. At the same time, during normal shutdown mode, the bleed flow can be operated at a medium flow rate, while the ventilation flow can be operated at full flow. In addition, during emergency shutdown or load reduction mode, the bleed flow can be operated at maximum flow rate, while the ventilation flow can be operated at a reduced flow rate. Combining the ventilation and bleed flows involves continuously or periodically adjusting the flow rate of each flow to meet the specific operating requirements of each mode. The flow combiner that enables mixing the bleed flow and ventilation flow includes two different channels. One channel can be designated as the inlet for the ventilation flow to enter the flow combiner, while another channel can be designated as the inlet for the exhaust flow to enter the flow combiner. After both the ventilation flow and the exhaust flow have entered the flow combiner through their respective channels, both flows can be combined within the flow combiner. Specifically, the ventilation flow channel can include a collection of conduits that help suppress backflow and help disperse the ventilation flow within the flow combiner.

[0019] Figure 1 1 is a schematic block diagram of a gas turbine system 10 having a flow combiner 12 configured to combine different flows. The different flows may have significantly different flow rates, pressures, temperatures, and fluid compositions. In the illustrated embodiment, the different flows may correspond to a compressor bleed flow and a ventilation flow. Specifically, as discussed in detail below, the flow combiner 12 includes an outlet duct 14, a first inlet duct 16 coupled to the outlet duct 14 (e.g., a compressor bleed air inlet duct), and a second inlet duct 18 coupled to the outlet duct 14 (e.g., a ventilation air inlet duct).

[0020] As shown, the first inlet duct 16 and the second inlet duct 18 are coupled to a common duct portion 20 of the outlet duct 14. In some embodiments, the common duct portion 20 may include a flow combining (or mixing) section 22 having one or more flow mixers 24 (e.g., backflow inhibitors, flow baffles, flow separators, flow conduits, etc.). For example, the one or more flow mixers 24 may include a backflow inhibitor 32 having a plurality of conduits 34 (e.g., a bundle of conduits) that converge in the downstream flow direction of the fluid flows (e.g., compressor bleed air flow 28 and vent air flow 36) from the first inlet duct 16 and the second inlet duct 18. The backflow inhibitor 32 (e.g., conduits 34) is configured to inhibit backflow of the fluid flows (e.g., from the first inlet duct 16 to the second inlet duct 18, or vice versa). The backflow inhibitor 32 may also be configured to cause mixing of the fluid flows (e.g., 28, 36) in the common duct portion 20. The first inlet conduit 16 may include or be fluidly coupled to a variable valve 26 (e.g., a variable bleed valve) configured to vary a fluid flow 28 (e.g., a compressor bleed flow) entering the first inlet conduit 16. The variable valve 26 may be adjusted between an open position and a closed position (e.g., to increase or decrease flow rate, pressure, etc.) to help control the intake of the fluid flow 28 into the flow combiner 12, reduce backflow of the fluid flow 28 into the second inlet conduit 18, and improve mixing in the outlet conduit 14. For example, the variable valve 26 may include a plurality of adjustable valve elements 30 (e.g., rotatable gates or flaps).

[0021] The second inlet duct 18 may include a damper 31 configured to open in response to a fluid flow 36 (e.g., a ventilation flow) and close in response to a cessation of the fluid flow 36. The damper 31 may be a gravity damper configured to close one or more pivoting doors (e.g., 1, 2, 3, 4, 5, or more hinged damper doors) by gravity when the fluid flow 36 ceases. Alternatively, the damper 31 may be a spring-loaded damper configured to bias the pivoting doors toward a closed position such that when the force of the fluid flow 36 is sufficient to overcome the spring force, the fluid flow 36 opens the pivoting doors. The damper 31 may also be configured to inhibit backflow of the fluid flow 28 against the incoming fluid flow 36 into the second inlet duct 18. The second inlet duct 18 may also include at least one fan 38 (e.g., 1, 2, or 3 fans) configured to force the fluid flow 36 into the second inlet duct 18. Damper 31 may be configured to open in response to operation of fan 38 (i.e., fan on) and close when fan 38 ceases operation (i.e., fan off). The speed of fan 38 may be adjustable (e.g., increased or decreased) to help control the induction of fluid stream 36, reduce backflow of fluid stream 28 against fluid stream 36, and improve mixing of fluid streams 28 and 36 in outlet duct 14.

[0022] Fluid streams 28 and 36 are combined into a combined fluid stream 40 in the stream combining section 22, and the combined fluid stream 40 then passes through a muffler section 42 in the outlet duct 14. The muffler section 42 may include a plurality of muffler baffles 44 (e.g., parallel muffler baffles) extending in a downstream direction of the combined fluid stream 40. The muffler baffles 44 are configured to reduce noise associated with the fluid streams 28, 36, and 40 passing through the stream combiner 12. For example, each muffler baffle 44 may include an outer enclosure (e.g., a perforated wall) and an inner sound-absorbing structure (e.g., sound-absorbing material, chambers, passages, baffles, etc.). Each muffler baffle 44 may be elongated in the downstream direction and may include an aerodynamic shape (e.g., an airfoil shape). The outlet duct 14 and the muffler section 42 (e.g., the muffler baffles 44) may be designed to handle the maximum loads (e.g., flow rate, pressure, temperature, noise, etc.) expected for both the compressor bleed flow 28 and the vent flow 36.

[0023] In the illustrated embodiment, the flow combiner 12 is used to combine two different flows (e.g., flows having different energy levels) from the gas turbine system 10. In some embodiments, the flow combiner 12 can be configured to combine any number (e.g., 2, 3, 4, 5, 6, or more) of different flows from the gas turbine system 10 or any other system that generates different flows (e.g., different flow rates, pressures, etc.). For example, the different flows can be described as a high energy flow and a low energy flow, where the high energy flow has a relatively higher pressure, a relatively higher temperature, and / or a relatively higher flow rate than the low energy flow. In the illustrated embodiment, the compressor bleed flow 28 can be described as a high energy flow, while the ventilation flow 36 can be described as a low energy flow. Therefore, the use of "high energy" and "low energy" with respect to flows (e.g., high energy flow and low energy flow) can be used only as a relative comparison of the flows. For example, the pressure, temperature, and / or flow rate of the high energy flow may be greater than those of the low energy flow by a certain percentage or multiplication factor (e.g., 1.1, 1.2, 1.3, 1.4, 1.5, 2, 2.5, 3, 4, 5, 10, 20, 30, 40, 50, or more). If additional flows are combined in the flow combiner 12, the flow combiner 12 may include additional inlet ducts similar to the inlet ducts 16 and 18. However, in the following discussion, the flow combiner 12 is described in the context of two combined flows from the gas turbine system 10, and more specifically, the compressor bleed flow as fluid flow 28 and the vent flow as fluid flow 36.

[0024] The gas turbine system 10 includes a gas turbine engine 50 coupled to a load 52, such as a generator. The gas turbine system 10 can be stationary or mobile, such as a trailer-mounted power plant (e.g., a generator 52 driven by the gas turbine engine 50). The gas turbine system 10 also includes a housing or enclosure 54 disposed around the gas turbine engine 50, such that a plenum or volume is disposed within the enclosure 54 around the gas turbine engine 50. The gas turbine engine 50 includes a compressor section or compressor 56 having one or more compressor stages (e.g., any number from 1 to 30 stages), a combustor section 58 having one or more combustors 60, and a turbine section or turbine 62 having one or more turbine stages (e.g., any number from 1 to 30 stages). Each compressor stage of the compressor 56 includes a plurality of compressor blades configured to compress intake air. Each combustor 60 includes one or more fuel nozzles 64 configured to supply fuel and compressed air 66 from the compressor 56 to a combustion chamber 68, where the fuel is combusted to generate hot combustion gases 70. The hot combustion gases flow through the turbine 62, driving one or more turbine stages to rotate a shaft 72 (e.g., one or more shafts) coupled to the turbine 62, the compressor 56, and the load 52. Each turbine stage of the turbine 62 includes a plurality of turbine blades driven by the hot combustion gases 70. Ultimately, the turbine 62 discharges the hot combustion gases 70 as exhaust gas 74 into an exhaust section 76, such as an exhaust duct and / or an exhaust stack.

[0025] The gas turbine system 10 directs intake air 80 into the enclosure 54 and the compressor 56 through an intake system 82. In the illustrated embodiment, the intake system 82 includes a filter section 84 having one or more air filters 86, an air inlet duct 88 (e.g., a ventilation intake duct) coupled to the enclosure 54, and an air inlet duct 90 (e.g., a compressor intake duct) coupled to the compressor 56. The air inlet duct 88 is coupled to an air inlet or opening 92 in the enclosure 54 and may include one or more fans 94 (e.g., electric motor-driven fans) configured to help force a ventilation air flow 96 through the enclosure 54. Ultimately, the ventilation flow 96 enters the second inlet duct 18 (e.g., the ventilation inlet duct) of the flow combiner 12 as the fluid flow 36.

[0026] The air inlet duct 90 is coupled to (or extends through) an air inlet or opening 92 in the enclosure 54, and the air inlet duct 90 extends internally into the enclosure 54 and is coupled to a compressor inlet 102 of the compressor 56. The air inlet duct 90 is configured to supply a compressor inlet airflow 104 to the compressor 56, which then compresses air for use throughout the gas turbine engine 50. For example, the compressed air 66 may be used for combustion and cooling in the combustor section 58, cooling in the turbine 62, and cooling elsewhere in the gas turbine engine 50. In certain embodiments, the compressed air 66 used for cooling may be bled from the compressor 56 at any suitable location (e.g., a compressor bleed airflow at various stages of the compressor 56). Additionally, the compressor bleed airflow may be discharged from the gas turbine system 10 via the flow combiner 12.

[0027] In the illustrated embodiment, the first inlet duct 16 (e.g., a compressor bleed air inlet duct) of the flow combiner 12 is coupled to a compressor bleed air portion 110 of the compressor 56. Specifically, the first inlet duct 16 may include a compressor bleed air intake conduit 112 that is coupled to an outer wall 114 of the compressor 56 at the compressor bleed air portion 110. For example, the compressor bleed air intake conduit 112 may extend circumferentially at least partially or completely around the outer wall 114 of the compressor 56, such as at least 180 degrees, 240 degrees, 300 degrees, or 360 degrees around the compressor 56. The compressor bleed air intake conduit 112 may include compressor openings 116 configured to fit around the outer wall 114 of the compressor 56. In certain embodiments, the outer wall 114 of the compressor 56 may include one or more compressor bleed air openings configured to enable compressor bleed air flow into the first inlet duct 16. As discussed above, the first inlet conduit 16 includes a variable valve 26 (e.g., a variable bleed valve (VBV)) having one or more adjustable valve elements 30 (e.g., a door or flap) configured to adjust the compressor bleed flow when the fluid stream 28 enters the flow combiner 12. The variable valve 26 may include one or more electric actuators, such as a common electric actuator or individual electric actuators for each of the plurality of adjustable valve elements 30.

[0028] The gas turbine system 10 (including the variable valve 26, the fan 38, the fan 94, the fuel injection through the fuel nozzle 64, and other operating parameters) can be controlled by a control system 120 having a monitoring system 122 coupled to a controller 124. The monitoring system 122 includes a plurality of sensors 126 (indicated by S) distributed throughout the gas turbine system 10 to monitor various operating conditions. For example, the sensors 126 can measure environmental conditions external to the gas turbine system 10 (e.g., humidity, temperature, etc.). The sensors 126 can measure intake air conditions in the intake system 82 (e.g., flow rate, temperature, pressure). The sensors 126 can measure compressor conditions (e.g., flow rate, temperature, and pressure of the compressed air 66 from the compressor 56 and the compressor bleed air flow 28). The sensors 126 can measure ventilation conditions (e.g., flow rate, temperature, and pressure of the ventilation air flow 96 in the enclosure 54 and the ventilation air flow 36 in the flow combiner 12). The sensors 126 may measure combustion conditions (e.g., fuel flow, fuel temperature, fuel pressure, fuel composition, Wobbe index, fuel-air ratio, flame temperature or intensity, combustion dynamics, and pollutants such as NO X 、SO X , CO2, CO, particulate matter, etc.). The sensors 126 can measure turbine conditions (e.g., flow rate, temperature, and pressure of the combustion gases 70 in the turbine 62). The sensors 126 can also measure rotational speed, clearances between the rotating blades and the walls of the compressor 56 and the turbine 62, and vibrations of the gas turbine engine 50. The sensors 126 can measure the load on the gas turbine engine 50, such as a partial load or full load condition of the gas turbine engine 50. The sensors 126 can monitor the operating state of the gas turbine engine 50, such as a startup condition, a steady-state condition, or a shutdown condition. The sensors 126 can monitor generator parameters (e.g., power output), conditions on the power grid, output power from the turbine 62, etc.

[0029] The sensors 126 may include various types of sensors to measure the aforementioned parameters. For example, the sensors 126 may include temperature sensors, such as thermocouples, thermistors, etc., disposed in the flow combiner 12 and throughout the gas turbine system 10. The sensors 126 may also include flow sensors, such as flow meters (e.g., differential pressure flow meters, velocity flow meters, mass flow meters, positive displacement flow meters, open channel flow meters) and level sensors, such as continuous level transmitters, ultrasonic transducers, laser level transmitters, etc., disposed in the flow combiner 12 and throughout the gas turbine system 10. Additionally, the sensors 126 may include pressure sensors, such as piezoresistive pressure sensors, differential pressure sensors, optical pressure sensors, etc., included in the flow combiner 12 and throughout the gas turbine system 10. Fuel properties may be sensed and / or otherwise provided to the controller 124, for example, via a human operator interface in the flow combiner 12 and the gas turbine system 10. Fuel characteristics may include water content, carbon content, chemical composition, specific gravity, ambient temperature, energy content, certain "numbers" (e.g., Wobbe index, cetane number, octane number, etc.), or combinations thereof. Exhaust emissions may be measured by emission sensors such as NO X Sensors, SO X Sensors, CO2 sensors and CO sensors are used for measurement.

[0030] The controller 124 is configured to receive and process measurement inputs from the sensors 126 and control operations of the gas turbine system 10, including the fluid flows 28, 36, and 40 through the flow combiner 12. The controller 124 includes one or more processors 128, a memory 130, and instructions 132 stored on the memory 130 and executable by the processor 128 to control the operation of the gas turbine system 10. The processor 128 may include one or more "general purpose" microprocessors, one or more special purpose microprocessors, and / or one or more application specific integrated circuits (ASICs), or some combination thereof. For example, the processor 128 may include one or more reduced instruction set computing (RISC) processors. The memory 130 may store information (such as control software, lookup tables, configuration data, etc.). The memory 130 may include tangible, non-transitory, machine-readable media, such as volatile memory (e.g., random access memory (RAM)) and / or non-volatile memory (e.g., read-only memory (ROM), flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage media, or a combination thereof). The memory 130 may store a variety of information, which may be suitable for various purposes. For example, the memory 130 may store machine-readable and / or processor-executable instructions 132 (eg, firmware or software) for execution by the processor.

[0031] The controller 124 may be communicatively coupled to an operator interface 134 (e.g., a human-machine interface (HMI)) and one or more actuators suitable for controlling components of the gas turbine system 10. For example, actuators (e.g., electric actuators) may be coupled to or integrated with each of the variable valve 26, the fan 38, the fan 94, the fuel supply to the combustion section 58, and other portions of the gas turbine engine 50. The controller 124 may also be coupled to valves, switches, positioners, pumps, etc. suitable for controlling various components of the gas turbine engine 50. The controller 124 may receive data from sensors 126 and may be used to control the compressor 56, the combustor 60, the turbine 62, the load 52, and the flow through the flow combiner 12. As discussed in further detail below, the controller 124 is configured to control the fluid flows 28, 36, and 40 through the flow combiner 12 based on various sensor feedback and the operating mode of the gas turbine system 10 (e.g., startup mode, steady-state mode, shutdown mode, emergency mode, full-load mode, part-load mode, etc.). In each of these modes, controller 124 may adjust variable valve 26 to adjust (e.g., increase or decrease) compressor bleed airflow 28, adjust one or both of fans 38 and 94 to adjust (e.g., increase or decrease) ventilation airflow 36, or a combination thereof.

[0032] Figure 2 、 Figure 3 and Figure 4 yes Figure 1 Detailed view of an embodiment of the stream combiner 12. Specifically, Figure 2 yes Figure 1 A perspective view of an embodiment of the stream combiner 12 is shown. Figure 3 yes Figure 2 A side view of an embodiment of a stream combiner. Figure 4 yes Figure 2 Now refer to Figures 2 to 4 Additional details of stream combiner 12 are described.

[0033] like Figure 2 and Figure 3As shown, the inlet ducts 16 and 18 are shown converging toward each other and the outlet duct 14 in a Y-shaped configuration 138. For example, the inlet ducts 16 and 18 may converge at an angle 140 (such as 10 to 120 degrees, 20 to 90 degrees, or 30 to 60 degrees). The inlet duct 16 may turn from the compressor bleed air intake duct 112 toward the common duct portion 20 of the outlet duct 14. For example, the compressor bleed air intake duct 112 may be substantially parallel to the outlet duct portion 14. The inlet duct 18 may turn from a fan housing portion 142 (e.g., an upstream duct portion having an inlet 144) toward the common duct portion 20 of the outlet duct 14. For example, the fan housing portion 142 may be substantially perpendicular to the outlet duct portion 14. The flow combiner 12 may further include an intermediate duct portion 150 (e.g., a diverging duct portion) between the compressor bleed air inlet duct 112 and the common duct portion 20, and an intermediate duct portion 152 (e.g., a diverging duct portion) between the fan case portion 142 and the common duct portion 20. These intermediate duct portions 150 and 152 (e.g., diverging duct portions) may define the angle of convergence 140 of the inlet ducts 16 and 18.

[0034] A diverging duct portion 150 of the first inlet duct 16 (e.g., a compressor bleed air inlet duct) and a diverging duct portion 152 of the second inlet duct 18 (e.g., a vent inlet duct) may help control the combination of the fluid flows 26 and 38 into the common duct portion 20. In the illustrated embodiment, the diverging duct portion 150 has diverging duct walls 154 and a cross-sectional flow area 156 that expands or increases in the downstream direction of the fluid flow 28. Similarly, the diverging duct portion 152 has diverging duct walls 158 and a cross-sectional flow area 160 that expands or increases in the downstream direction of the fluid flow 36. However, in some embodiments, the cross-sectional flow areas 156 and 158 of the inlet ducts 16 and 18, respectively, may be completely or partially constant, diverging, and / or converging in the downstream direction of the fluid flows 28 and 36, respectively. Additionally, the first minimum value of the cross-sectional flow area 156 of the inlet duct 16 can be equal to, greater than, or less than the second minimum value of the cross-sectional flow area 158 of the inlet duct 18 (e.g., if the fluid flow 28 is a higher energy flow than the fluid flow 36, the first minimum value can be greater than the second minimum value). Similarly, the first maximum value of the cross-sectional flow area 156 of the inlet duct 16 can be equal to, greater than, or less than the second maximum value of the cross-sectional flow area 158 of the inlet duct 18 (e.g., if the fluid flow 28 is a higher energy flow than the fluid flow 36, the first maximum value can be greater than the second maximum value). In some embodiments, the divergence of the duct wall 154 and / or the expansion of the cross-sectional flow area 156 can be the same as or different from the divergence of the duct wall 158 and / or the expansion of the cross-sectional flow area 160 (e.g., greater for higher energy flows).

[0035] like Figure 2 and Figure 3 As further shown in FIG, the cross-sectional flow area 162 of the common duct portion 20 of the outlet duct 14 may be greater than both the cross-sectional flow area 156 of the inlet duct 16 and the cross-sectional flow area 160 of the inlet duct 18. The common duct portion 20 may include a flow combining section 22 having a plurality of flow mixers 24 (e.g., conduits, channels, baffles, etc. to help direct the flows to be mixed together). For example, the flow mixers 24 may include a backflow inhibitor 32 having a plurality of conduits 34 that converge in the downstream flow direction of the fluid flows (e.g., 28, 36), thereby helping to inhibit backflow while combining and mixing the fluid flows in the common duct portion 20. hereinafter referred to as Figure 5 Details of the backflow suppressor 32 are discussed in further detail. The outlet duct 14 may also include a diverging duct portion 164 that diverges in the downstream direction of the combined fluid flow 40. The muffler section 42 may be disposed within a uniform duct portion 166 having a constant cross-sectional flow area 168 in the downstream direction of the combined fluid flow 40. The outlet duct 14 may include a discharge section 170 having oppositely oriented turning duct portions 172 and 174 that help disperse the combined flow 40 discharged to the atmosphere. Figure 4 As shown, turning duct sections 172 and 174 may include internal turning vanes or baffles 176 and 178, respectively. Baffles 176 and 178 are configured to split the combined fluid flow 40 and direct the split flows outwardly through turning duct sections 172 and 174.

[0036] As discussed above, the flow combiner 12 may include various flow control components that are configured to control the ratio of the fluid flow 28 relative to the fluid flow 36, thereby facilitating improved combining of the fluid flows 28 and 36 without causing undesirable backflow and / or overloading the muffler section 42. Specifically, the illustrated embodiment includes a variable valve 26 (e.g., a variable bleed valve (VBV)) having a plurality of adjustable valve elements 30 (e.g., doors or flaps that open and close) circumferentially spaced about a compressor opening 116, which is configured to extend about an outer wall 114 of the compressor 56, as shown. Figure 1As shown. The adjustable valve element 30 may include an actuator (e.g., an electric actuator) coupled to a controller 124 so that the controller 124 can adjust the position of the adjustable valve element 30 based on sensor feedback to help improve the flow combination in the flow combiner 12. The adjustable valve element 30 can be configured to rotate and / or move axially between an open position and a closed position. The illustrated embodiment also includes a plurality of fans 38 in the inlet duct 18. The controller 124 is configured to selectively operate (i.e., turn on or off) each of the fans 38 based on sensor feedback and to adjust the speed of each of the fans (e.g., increase or decrease its speed) independently or in combination with each other to help improve the flow combination in the flow combiner 12. The illustrated embodiment includes three fans 38 arranged in parallel in the inlet duct 18. However, embodiments of the flow combiner 12 may have any number of fans 38 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) arranged in series, in parallel, or in a combination thereof. By adjusting the variable valve 26 and / or the fan 38, the controller 124 can help achieve successful combining of the fluid flows 28 and 36 in the flow combiner 12 without causing backflow (e.g., backflow of the fluid flow 28 into the inlet duct 18) or overloading the flow combiner 12. The inlet duct 18 also includes a damper 31 that is configured to open in response to the fluid flow 36 and close in response to the cessation of the fluid flow 36.

[0037] Using the above-described features, the flow combiner 12 combines or mixes two different types of flows, for example, the compressor bleed flow 28 (e.g., a variable bleed valve (VBV) flow) extracted or bleed from the compressor 56 and the vent flow 36, 96 from the enclosure 54 surrounding the gas turbine engine 50. In one embodiment, the compressor bleed flow 28 can be a high-energy, variable flow, compared to the vent flow 36 (which can be a continuous, low-energy flow). For example, depending on the extraction point on the compressor 56, the compressor bleed flow 28 can have a pressure range of 15 psi to 40 psi, or any other suitable pressure range. In contrast, the vent flow 36 can have a pressure range of 10 psi to 15 psi, or any other suitable pressure range for ventilating the enclosure 54. In another embodiment, the compressor bleed flow 28 can be a high-temperature flow, compared to the vent flow 36, which can be a low- to medium-temperature flow. For example, the compressor bleed flow 28 can have a temperature range of 260°F to 300°F. In contrast, the vent flow 36 can have a temperature range of 120°F to 200°F. In another embodiment, the compressor bleed flow 28 may be operated as a discrete flow during specific time intervals, which may range from 1 second to 10 seconds in duration or any other suitable duration. On the other hand, the ventilation flow 36 may be operated as a continuous flow. Although the compressor bleed flow 28 and the ventilation flow 36 may have significantly different characteristics (e.g., noise levels, continuous versus intermittent, and energy levels based on pressure, temperature, and flow rate), the flow combiner 12 is able to successfully combine the flows 28 and 36 using the variable valve 26, the fan 38, the damper 31, and the backflow inhibitor 32 while using a common muffler section 42. In order to improve the processing of both the compressor bleed flow 28 and the ventilation flow 36 in the flow combiner 12, the controller 124 may control the flow rates of both flows 28 and 36 based on the specific operating mode of the gas turbine system 10. The various operating modes of the gas turbine system 10 will be described in more detail below.

[0038] Figure 5 Yes Figure 1 and Figure 3A perspective view of an embodiment of a backflow suppressor 32 of the flow combiner 12 is shown, further illustrating an embodiment of a plurality of conduits 34 of the backflow suppressor 32. As discussed above, the plurality of conduits 34 are configured to facilitate merging and mixing the fluid streams 28 and 36 from the first inlet duct 16 and the second inlet duct 18, while suppressing backflow from one inlet duct to the other (e.g., from the first inlet duct 16 into the second inlet duct 18 and into the enclosure 54). As shown, each conduit 34 has a cross-sectional flow area 180 that contracts or decreases in the downstream flow direction. For example, each conduit 34 may have a tapered geometry 182, such as conduit walls 184 that are angled toward each other in the downstream flow direction of the fluid streams (e.g., 28 and 36). In certain embodiments, each conduit 34 may include a tapered conduit, a tapered square conduit, or a tapered polygonal conduit. The backflow suppressor 32 may include any number of the plurality of conduits 34 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, or more). The conduits 34 may include two or more conduits of the same size and shape, two or more conduits of different sizes, two or more conduits of different shapes, or any combination thereof.

[0039] Each conduit 34 includes an inlet 186 and an outlet 188 having a downstream edge 190. Each conduit 34 has a first dimension 192 at the inlet 186 and a second dimension 194 at the outlet 188. Dimensions 192 and 194 may comprise the width, diameter, or cross-sectional flow area of the conduit 34. Dimension 194 of the outlet 188 is smaller than dimension 192 of the inlet 186 by a certain percentage or factor to help inhibit backflow. For example, dimension 194 may be less than or equal to approximately 10%, 20%, 30%, 40%, 50%, 60%, 70%, or 80% of dimension 192. In certain embodiments, dimension 192 may correspond to the largest dimension of the conduit 34, while dimension 194 may correspond to the smallest dimension of the conduit 34. The outlet 188 may also define a throat or restricted orifice that regulates fluid flow (e.g., 28 and 36) and inhibits backflow. In addition, dimensions 192 and 194 can be selected to restrict or regulate fluid flow (e.g., 28 and 36) from inlet ducts 16 and 18 to outlet duct 14 of flow combiner 12 while also inhibiting backflow of fluid flow (e.g., compressor bleed air flow 28 into inlet duct 18). For example, dimensions 192 and 194 can be increased to increase fluid flow (e.g., 28 and 36), or dimensions 192 and 194 can be decreased to decrease fluid flow (e.g., 28 and 36). The size, shape, number, and rate of convergence (or angle of convergence) of conduits 34 from inlet 186 to outlet 188 can also be varied to help regulate fluid flow (e.g., 28 and 36) and inhibit backflow. The downstream edge 190 of outlet 188 can be a smooth edge or a variable edge (e.g., a serrated or toothed edge having a plurality of teeth 196). The variable edge with teeth 196 may be configured to help spread the fluid flows (eg, 28 and 36 ) into the flow combiner 12 while also adding additional surface area to inhibit backflow.

[0040] Figure 6 is connected to Figure 1 FIG2 is a schematic cross-sectional side view of a flow combiner 12 of a compressor 56 of a gas turbine system 10, showing a compressor bleed air inlet duct 112 having a variable valve 26 (e.g., a variable bleed valve (VBV)) configured to adjust the compressor bleed air flow 28 entering the flow combiner 12. The compressor bleed air inlet duct 112 can be an integral part (i.e., a single piece) of the inlet duct 16 of the flow combiner 12, or the compressor bleed air inlet duct 112 can be a separate piece that is removably or fixedly coupled to the inlet duct 16. The compressor 56 is disposed within the compressor bleed air inlet duct 112 along a compressor opening 116. As shown, the compressor opening 116 is annular and, therefore, fits around an outer wall 114 (e.g., an annular wall) of the compressor 56. However, the compressor opening 116 and the outer wall 114 can have other shapes at the connection between the compressor bleed air inlet duct 112 and the compressor 56.

[0041] The compressor bleed air intake duct 112 includes a variable valve 26 having a plurality of adjustable valve elements 30 (e.g., doors or flaps) circumferentially arranged around the compressor opening 116. The adjustable valve elements 30 help regulate the compressor bleed air flow 28 in the inlet duct 16 and, therefore, in the flow combiner 12. In some embodiments, the adjustable valve elements 30 can be a collection of circumferentially spaced valves, doors, or flaps that are configured to rotate or move axially between an open position and a closed position. The adjustable valve elements 30 can vary in size, shape, and number. There can be uniform or uneven circumferential gaps between the adjustable valve elements 30. For example, each of the adjustable valve elements 30 can be separated from each other by a circumferential gap having a regularly spaced size, such as 6 inches, 1 foot, or any other suitable distance. In order to regulate the compressor bleed air flow 28 in the inlet duct 16 and in the flow combiner 12, the opening and closing of the adjustable valve elements 30 can be adjusted via a driver 200. The adjustable valve element 30 may be opened and closed simultaneously or periodically to adjust the compressor bleed air flow 28 .

[0042] In certain embodiments, driver 200 may include an electric driver, a fluid driver (e.g., a hydraulic driver and / or a pneumatic driver), or a combination thereof. Driver 200 may be coupled to an energy source 202 and one or more actuators 204 coupled to the adjustable valve element 30. For example, the energy source 202 may include a power source and / or a fluid supply (e.g., a pressurized fluid tank, a compressor, or a pump). Driver 200 is configured to move actuator 204, which in turn moves the adjustable valve element 30 between an open position and a closed position. Therefore, actuator 204 may include a mechanical linkage, a rotary joint, a piston-cylinder assembly, or a transmission assembly configured to transfer force from driver 200 to the adjustable valve element 30. In a fluid-driven embodiment, driver 200 (e.g., a fluid driver) uses a pressurized fluid (e.g., liquid or gas) from an energy source 202 (e.g., a fluid supply) to provide force to regulate the opening and closing of the adjustable valve element 30. For example, the actuator 200 (e.g., a fluid actuator) may include a piston-cylinder assembly driven by pressurized fluid from the energy source 202. Additionally, the actuator 200 may be controlled by the controller 124 to adjust the position of the adjustable valve element 30 and, thereby, vary the flow of the compressor bleed air flow 28 through the flow combiner 12.

[0043] As previously described, to improve the combination of fluid flow 28 (eg, compressor bleed flow) and fluid flow 36 (eg, vent flow), the flow rate associated with each fluid flow may be controlled based on the operating mode of the gas turbine system 10 . Figure 7 is used Figures 1 to 6FIG3 is a flow chart of an embodiment of a method 350 for operating the gas turbine system 10 in different modes using the flow combiner 12 of FIG3 . The modes of operation may not be limited to the modes described herein, but are used as examples. The flow rates associated with the compressor bleed air flow 28 and the vent air flow 36 may be continuously or periodically monitored by the controller 124 via a control algorithm. In the illustrated embodiment, the method 350 includes monitoring the operation of the gas turbine system 10 as indicated by box 360, and changing the operating mode of the gas turbine system 10 based on the monitored conditions as indicated by box 362. The method 350 may then query the operating mode, as indicated by box 364, and proceed to make changes based on the operating mode.

[0044] For example, if query block 364 indicates startup mode 366, method 350 may control variable valve 26 to adjust compressor bleed flow 28 (e.g., variable bleed valve (VBV) flow) to a relatively low and / or increased level as gas turbine engine 12 accelerates, as indicated by block 374. Additionally, during startup mode 366, method 350 may control fans 38 and / or 94 to adjust ventilation flows 36, 96 to full flow (e.g., ventilation at full flow), as indicated by block 382. During startup mode 366, compressor bleed flow 28 may increase but still operate at a low flow rate, while ventilation flow 36 may operate at full flow. During startup mode 366, the rotational speed of the compressor blades increases to achieve a threshold speed for gas turbine engine 50. Thus, when gas turbine engine 50 starts or begins to spin up, compressor bleed flow 28 may operate at a low flow rate. However, as the rotational speed of the compressor blades increases and the gas turbine engine 50 moves toward full load operation, the compressor bleed airflow 28 may increase, but still operate at a lower flow rate than the maximum flow rate. Simultaneously, the vent airflow 36 may operate at full flow.

[0045] If query block 364 indicates full load mode 368, method 350 may control variable valve 26 to adjust compressor bleed flow 28 (e.g., VBV flow) to fully closed (or nearly closed) when gas turbine engine 12 is operating at full load, as indicated by block 376. Additionally, in full load mode 368, method 350 may control fans 38 and / or 94 to adjust ventilation flows 36, 96 to full flow (e.g., ventilation at full flow), as indicated by block 384. During full load mode 368, compressor bleed flow 28 may be closed, while ventilation flow 36 may be operated at full flow. When gas turbine engine 50 is operating in full load mode, gas turbine engine 50 may release a maximum amount of heat. Thus, ventilation flow 36, operating at full flow, may be used to cool gas turbine engine 50 and spaces within enclosure 54.

[0046] If query block 364 indicates a normal shutdown mode 370, method 350 may control variable valve 26 to adjust the compressor bleed flow 28 (e.g., VBV flow) to open at a medium flow rate when gas turbine engine 12 is shut down in a normal manner, as indicated by block 378. The medium flow rate of compressor bleed flow 28 may be an intermediate flow rate between no flow and maximum flow rate. Additionally, in normal shutdown mode 370, method 350 may control fans 38 and / or fans 94 to adjust ventilation flows 36, 96 to full flow (e.g., ventilation at full flow rate), as indicated by block 386. During normal shutdown mode 370, gas turbine engine 50 may be gradually slowed down (rather than rapidly or rapidly) due to an unexpected event or emergency. Consequently, variable valve 26 may be opened such that compressor bleed flow 28 may be operated at a medium flow rate, while ventilation flow 36 may be operated at a full flow rate.

[0047] If query block 364 indicates emergency shutdown and / or load reduction mode 372, method 350 may control variable valve 26 to adjust compressor bleed flow 28 (e.g., VBV flow) to open at maximum flow, as indicated by block 380, when the gas turbine engine 12 may be rapidly shut down in an emergency manner and / or unexpectedly load-shedded. Additionally, in mode 372, method 350 may control fans 38 and / or 94 to adjust ventilation flows 36, 96 to a reduced or partial flow rate (e.g., ventilation at a reduced flow rate less than full flow), as indicated by block 388. During emergency shutdown and / or load reduction mode 372, compressor bleed flow 28 may operate at maximum flow, while ventilation flow 36 may operate at a reduced flow rate. Compressor bleed flow 28 may operate at full capacity to reduce the likelihood of gas turbine engine 50 surging or stalling. Compressor bleed flow 28 may operate at full capacity for a short period of time, such as 5 seconds, 10 seconds, or any other suitable period of time. Because the compressor bleed air flow 28 may be operated at full flow for a reduced amount of time, the flow rate of the vent air flow 36 may also be reduced.

[0048] As mentioned above Figures 1 to 6 The stream combiner 12 is configured to Figure 7 The method 350 provides the aforementioned controls to combine the fluid streams 28 and 36, thereby helping to reduce the possibility of backflow and avoid overloading the muffler section 42 and other portions of the flow combiner 12. Although the method 350 is shown with some specific operating modes and corresponding adjustments to the fluid streams 28 and 36, other operating modes and adjustments to the fluid streams 28 and 36 may be used to help combine the flows through the flow combiner 12.

[0049] The technical effects of the present invention include a flow combiner 12 for combining a compressor bleed flow 28 and a ventilation flow 36. Specifically, the flow combiner 12 may include a shared or common muffler section 42 to attenuate noise from the combined flow 40 (i.e., the combination of the compressor bleed flow 28 and the ventilation flow 36). In order to effectively combine the flows, the controller 124 may continuously or periodically adjust the flow rates associated with the compressor bleed flow 28 and the ventilation flow 36 based on various operating modes of the gas turbine system 10. The flow combiner 12 that enables mixing the compressor bleed flow 28 and the ventilation flow 36 includes two different inlet ducts 16 and 18. The inlet duct 16 may be designated as the inlet for allowing the bleed flow 28 to enter the flow combiner 12, while the inlet duct 18 may be designated as the inlet for allowing the ventilation flow 36 to enter the flow combiner 12. After the ventilation flow 36 and the compressor bleed flow 28 have both entered the flow combiner 12 from their respective inlet ducts 16 and 18 (e.g., through the backflow suppressor 32), both flows may be combined within the flow combiner 12. Specifically, the inlet duct 16 may include an adjustable valve element 30 that adjusts the volume of the compressor bleed airflow 28 via a driver 200 and an actuator 204. Simultaneously, the inlet duct 18 may include one or more fans 38 and dampers 31 to regulate the vent airflow 36 and inhibit backflow of the compressor bleed airflow 28 through the inlet duct 18.

[0050] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any combined methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If such other examples have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims, such other examples are intended to be within the scope of the claims.

Claims

1. A system comprising: A single-piece flow combiner (12), the flow combiner comprising: outlet pipe (14); a compressor bleed air inlet duct (16) coupled to the outlet duct (14), wherein the compressor bleed air inlet duct (16) is configured to receive a bleed air flow (28) from a compressor (56) of a gas turbine engine (50); and a ventilation inlet duct (18) coupled to the outlet duct (14), wherein the ventilation inlet duct (18) is configured to receive a ventilation flow (36) from an enclosure (54) surrounding the gas turbine engine (50), wherein the exhaust gas flow (28) and the ventilation gas flow (36) are combined into an outlet flow through the outlet duct (14), wherein the compressor bleed air inlet duct (16) and the vent inlet duct (18) are coupled to a common duct portion (20) of the outlet duct (14), and wherein the common duct portion (20) includes a backflow inhibitor (32) having a plurality of parallel conduits (34) with decreasing cross-sectional flow areas in a downstream flow direction.

2. The system of claim 1 , wherein the compressor bleed air inlet duct (16) includes a compressor opening (116) configured to extend circumferentially around an outer wall (114) of the compressor (56), wherein the compressor bleed air inlet duct (16) includes a variable bleed air valve (26).

3. The system of claim 1, wherein the outlet duct (14) includes a diverting duct portion (172, 174) coupled to the common duct portion (20).

4. The system of claim 1 , wherein the vent inlet duct (18) includes a damper (31) configured to open in response to the vent flow (36), and wherein the compressor bleed air inlet duct (16) includes a plurality of adjustable valve elements (30) to regulate the bleed flow (28) within the flow combiner (12).

5. The system of claim 1, wherein the outlet duct (14) includes one or more muffler baffles (44).

6. A method comprising: receiving a bleed air flow (28) from a compressor (56) of a gas turbine engine (50) into a compressor bleed air inlet duct (16) coupled to an outlet duct (14) of a one-piece flow combiner (12); and receiving a vent flow (36) from an enclosure (54) surrounding the gas turbine engine (50) into a vent inlet duct (18) coupled to the outlet duct (14), wherein the bleed flow (28) and the vent flow (36) are combined into an outlet flow through the outlet duct (14), wherein the compressor bleed air inlet duct (16) and the vent inlet duct (18) are coupled to a common duct portion (20) of the outlet duct (14), and wherein the common duct portion (20) includes a backflow inhibitor (32) having a plurality of parallel conduits (34) with decreasing cross-sectional flow areas in a downstream flow direction.

7. The method of claim 6, comprising adjusting the bleed air flow (28) or the vent air flow (36) via a controller (124) based on one or more operating parameters of the gas turbine system (10).

8. The method of claim 7, wherein the one or more operating parameters include an operating mode of the gas turbine system (10), wherein the operating mode of the gas turbine system (10) includes one of a startup mode (366), a full load mode (368), a normal shutdown mode (370), or an emergency shutdown / load reduction mode (372).

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