System and method for determining gas turbine fuel splits for head-end temperature control - Patents.com

Abstract

To provide methods for controlling a temperature of a first combustion zone of a combustor of a gas turbine engine using a digital simulation.SOLUTION: A method of controlling an operating temperature of a first combustion zone of a combustor of a rotary machine includes determining a current operating temperature and a target operating temperature of a first combustion zone using a digital simulation. The method further includes determining a derivative of the current operating temperature with respect to a current fuel split using the digital simulation. The fuel split apportions a total flow of fuel to the combustor between the first combustion zone and a second combustion zone. The method also includes calculating a calculated fuel split that results in a calculated operating temperature approaching the target operating temperature. The method further includes channeling a first flow of fuel to the first combustion zone and a second flow of fuel to the second combustion zone.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The field of the disclosure relates generally to control of gas turbine engines, and more specifically, to controlling fuel splits in gas turbine engines to achieve a predetermined head end temperature of a combustor. [Background technology]

[0002] In at least some known rotary machines, energy extracted from a gas stream in a turbine is used to power a mechanical load. Specifically, the rotary machine includes a compressor section, a combustor section, and a turbine section arranged in a serial flow arrangement. The compressor section compresses air for combustion with a fuel in the combustor section, and the turbine section extracts energy from combustion gases generated in the combustor section. At least some known combustor sections include an axial fuel staging (AFS) technique that includes axial (sequential) staging of combustion in at least two zones. More specifically, the combustor section can include a plurality of first stage fuel nozzles positioned upstream of a plurality of second stage fuel nozzles. A first fuel stream is directed to the combustor by the first stage fuel nozzles, and a second fuel stream is directed to the combustor by the second stage fuel nozzles. The temperature in the combustor of the combustion gases generated by combustion of the first fuel streams is T 3.5 is the temperature. T 3.5 Controlling the temperature allows the operator to control the emissions and dynamics profile of the combustor, allowing for greater operating flexibility of the rotating machine.

[0003] T 3.5 Temperature is typically not measured directly due to the high temperatures in the combustor. Rather, combustor inlet temperature, first and second fuel flows, and other known parameters are used to determine T 3.5 Used to model or approximate temperature, and T 3.5 More specifically, in at least some known rotating machines, T 3.5The temperature is controlled using a proportional-integral (PI) controller to control the fuel split to the first and second stage nozzles. The PI controller uses alternative parameters to control the fuel split to the first and second stage nozzles, and then T 3.5 Indirectly controls temperature. However, the PI controller controls T 3.5 Tuning a rotating machine to precisely control temperature can be time consuming and expensive. In addition, if the PI controller gains are not set correctly, the PI controller will 3.5 The temperature cannot be adequately controlled, which can lead to temperature oscillations and / or combustor blowouts. Summary of the Invention

[0004] In one aspect, a method of controlling an operating temperature of a first combustion zone of a combustor of a rotary machine is provided. The combustor includes a first combustion zone and a second combustion zone. The method includes determining a current operating temperature of the first combustion zone using a digital simulation of the rotary machine. The method also includes determining a target operating temperature of the first combustion zone. The method further includes determining a derivative of the current operating temperature of the first combustion zone with respect to a current fuel split using the digital simulation. The fuel split apportions a total flow of fuel to the combustor between the first combustion zone and the second combustion zone. The method also includes calculating a calculated fuel split using the determined derivative that results in a calculated operating temperature of the first combustion zone that approaches the target operating temperature. The method further includes directing a first fuel flow to the first combustion zone and a second fuel flow to the second combustion zone. The first fuel flow and the second fuel flow are determined in response to the calculated fuel split. The method also includes repeating steps i through v until the calculated fuel split is equal to the target fuel split, the target fuel split being the fuel split that results in the target operating temperature.

[0005] In another aspect, a rotary machine is provided. The rotary machine includes a compressor configured to compress a flow of intake air, a combustor, and a computing device. The combustor includes a first combustion zone, a second combustion zone, at least one first fuel nozzle, and at least one second fuel nozzle. The at least one first fuel nozzle is configured to direct a first fuel flow to the first combustion zone, and the at least one second fuel nozzle is configured to direct a second fuel flow to the second combustion zone. The combustor is configured to receive the flow of intake air. The fuel split is a percentage of a total flow of fuel that is directed to the second combustion zone. The computing device includes a digital simulation of the rotary machine. The computing device is configured to determine a current operating temperature of the first combustion zone using the digital simulation. The computing device is also configured to determine a target operating temperature of the first combustion zone. The computing device is further configured to simultaneously determine a derivative of the current operating temperature of the first combustion zone with respect to the current fuel split using the digital simulation. The computing device is also configured to calculate, using a numerical method, a calculated fuel split that results in a calculated operating temperature of the first combustion zone. The computing device is further configured to direct a first fuel flow to the first combustion zone and a second fuel flow to the second combustion zone. The first fuel flow and the second fuel flow are determined by the calculated fuel split. The computing device is also configured to iterate until the calculated fuel split is equal to a target fuel split, the target fuel split being a fuel split that results in the target operating temperature.

[0006] These and other features, aspects, and advantages of the present disclosure will become better understood from the following detailed description when taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts throughout. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic diagram of an exemplary rotating machine. [Figure 2A] 2 is a flow diagram of an exemplary method for controlling a temperature of a first combustion zone of a combustor of the rotary machine shown in FIG. 1 . [Figure 2B] 2B is a continuation of the flow diagram of the exemplary method for controlling a temperature of a first combustion zone of a combustor of the rotary machine shown in FIG. 2A. [Diagram 3] 3 is a control diagram illustrating a method of controlling the temperature of a first combustion zone of a combustor of the rotary machine shown in FIG. 2. [Figure 4] 1 is a first graph of the relationship between T3.5 temperature and fuel split and the numerical method used to determine the target fuel split, and a second graph of the corresponding transient response of fuel split over time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Unless otherwise specified, the drawings provided herein are meant to illustrate the features of the embodiments of the present disclosure. These features are believed to be applicable in a wide variety of systems that include one or more embodiments of the present disclosure. Thus, the drawings are not meant to include all of the conventional features known to those skilled in the art that are required for the practice of the embodiments disclosed herein.

[0009] In the following specification and claims, reference will be made to a number of terms that shall be defined to have the following meanings.

[0010] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0011] Unless otherwise specified, approximation terms such as "generally," "substantially," and "approximately" used herein indicate that the modified term may only be applied to an approximate degree as recognized by a person skilled in the art, and not to an absolute or complete degree. Thus, values ​​modified with terms such as "approximately," "about," and "substantially" are not limited to the exact value specified. In at least some instances, approximation terms may correspond to the precision of an instrument for measuring the value. Range limits may be specified here and throughout the specification and claims. Such ranges are combinable and / or interchangeable, and include all subranges contained herein, unless otherwise specified by the context or language. In addition, unless otherwise specified, terms such as "first," "second," and the like are used herein merely as labels, and are not intended to impose any order, position, or hierarchical requirements on the items to which they refer. Further, for example, a reference to a "second" item does not require or exclude the presence of, for example, a "first" or lower-numbered item, or a "third" or higher-numbered item.

[0012] As used herein, the terms "axial" and "axially" refer to directions and orientations that extend substantially parallel to the longitudinal axis of the rotary machine. Additionally, the terms "radial" and "radially" refer to directions and orientations that extend substantially perpendicular to the longitudinal axis of the rotary machine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations that extend in an arc about the longitudinal axis of the rotary machine. Additionally, as used herein, the term "upstream" refers to the forward or inlet end of the rotary machine, and the term "downstream" refers to the aft or exhaust end of the rotary machine. When describing the flow of fluid through a component, the direction from which the fluid flows is described as "upstream" and the direction from which the fluid flows is described as "downstream."

[0013] The methods and systems described herein relate to a method for controlling a temperature of a first combustion zone of a combustor of a gas turbine engine using a digital simulation. More specifically, the combustor includes a first combustion zone, a second combustion zone, at least one first fuel nozzle, and at least one second fuel nozzle. The at least one first fuel nozzle directs a first fuel flow to the first combustion zone, and the at least one second fuel nozzle directs a second fuel flow to the second combustion zone. The fuel split is a percentage of the total fuel flow that is directed to the second combustion zone. The digital simulation simultaneously determines a current operating temperature of the first combustion zone, a target operating temperature of the first combustion zone, and a derivative of the current operating temperature of the first combustion zone with respect to the current fuel split. A computing device then uses a numerical method to calculate a calculated fuel split that results in a calculated operating temperature of the first combustion zone. The first and second fuel flows are determined by a calculated fuel split, with the first fuel flow being directed to the first combustion zone and the second fuel flow being directed to the second combustion zone. The method is repeated until the calculated fuel split is equal to a target fuel split that results in a target operating temperature. Thus, the systems and methods described herein control the temperature of the first combustion zone without the use of traditional feedback controllers, such as PID controllers, reducing the time and cost of regulating a rotating machine.

[0014] FIG. 1 is a schematic diagram of an exemplary rotary machine 100, i.e., a turbomachine, and more specifically, a turbine engine. In the exemplary embodiment, the rotary machine 100 is a gas turbine engine. Alternatively, the rotary machine may be any other turbine engine and / or rotary machine, including, but not limited to, a steam turbine engine, a gas turbofan aircraft engine, other aircraft engines, a wind turbine, a compressor, and a pump. In the exemplary embodiment, the gas turbine engine 100 includes an intake section 102, a compressor section 104 coupled downstream of the intake section 102, a combustor section 106 coupled downstream of the compressor section 104, a turbine section 108 coupled downstream of the combustor section 106, and an exhaust section 110 coupled downstream of the turbine section 108. The turbine section 108 is coupled to the compressor section 104 via a rotor shaft 112.

[0015] It should be noted that, as used herein, the term "couple" is not limited to a direct mechanical, thermal, electrical, and / or flow communication connection between components, but can also include an indirect mechanical, thermal, electrical, and / or flow communication connection between multiple components. In the exemplary embodiment, combustor section 106 includes multiple combustors 114. Combustor section 106 is coupled to compressor section 104 such that each combustor 114 is in flow communication with compressor section 104. Rotor shaft 112 is further coupled to a load 116, such as, but not limited to, a generator and / or a mechanical drive application. In the exemplary embodiment, compressor section 104 and turbine section 108 each include at least one rotor assembly 118 coupled to rotor shaft 112.

[0016] In this embodiment, the intake section 102 includes at least one inlet guide vane 103 controlled by an inlet guide vane controller 105. The inlet guide vane 103 controls the flow of intake air 120 that the intake section 102 directs from the atmosphere to the compressor section 104. Specifically, the inlet guide vane 103 may include a variable or fixed airfoil 107 that directs the intake air 120 to the compressor section 104. The inlet guide vane 103 changes the angle of the flow of the intake air 120 to increase the efficiency of the compressor section 104. In addition, the airfoil 107 of the inlet guide vane 103 may be variable, or the angle of the airfoil 107 relative to the compressor section 104 may be changed to change the angle of the flow of the intake air 120 to increase the efficiency of the compressor section 104 during different operating conditions.

[0017] In the exemplary embodiment, the combustor 114 includes an axial fuel staging (AFS) technique that includes axial (sequential) staging of combustion in at least two zones. Specifically, the combustor 114 is an axially staged combustor that includes a first combustion zone 115, a second combustion zone 117, at least one first fuel nozzle 119, and at least one second fuel nozzle 121, each of which includes a first combustion zone 115, a second combustion zone 117, at least one first fuel nozzle 119, and at least one second fuel nozzle 121. The at least one first fuel nozzle 119 is positioned upstream of the at least one second fuel nozzle 121 and directs a first fuel flow into the first combustion zone 115, which is correspondingly upstream of the second combustion zone 117. The at least one second fuel nozzle 121 is positioned downstream of the at least one first fuel nozzle 119 and the first combustion zone 115 and directs a second fuel flow into the second combustion zone 117. The first and second combustion zones 115, 117 stage the combustion of the total flow of fuel to the combustor in order to control combustion dynamics within the combustor 114. In the exemplary embodiment, a single first fuel nozzle 119 and a single second fuel nozzle 121 are shown in FIG. 1 . However, the combustor 114 may include multiple first fuel nozzles 119 and / or multiple second fuel nozzles 121.

[0018] The rotary machine 100 also includes a fuel supply system 130 including at least one valve 132 that controls a fuel split of the total flow of fuel. The fuel split corresponds to an allocation of the total fuel flow to the combustor between a first flow and a second flow. In an exemplary embodiment, the fuel split is expressed as a percentage of the total fuel flow that is directed to the at least one second fuel nozzle 121 (i.e., the second fuel flow divided by the sum of the first and second fuel flows). Alternatively, the fuel split may be expressed in any suitable manner. Specifically, the fuel supply system 130 directs the total flow of fuel to the combustor 114. More specifically, the fuel supply system 130 directs the total flow of fuel to the first fuel nozzle 119 and the second fuel nozzle 121, which in turn direct the total flow of fuel to the first combustion zone 115 and the second combustion zone 117, respectively. Valve 132 divides the total fuel flow into a first fuel stream and a second fuel stream according to a selected fuel split. As will be described in more detail below, controlling the fuel split allows the T 3.5 The temperature is controlled, which in turn controls the combustion dynamics in the combustor 114 .

[0019] Rotary machine 100 further includes a computing device 134 that controls at least one operating parameter of rotary machine 100. More specifically, in the exemplary embodiment, computing device 134 controls the fuel split of the total flow of fuel to combustor 114 by controlling valve 132. In addition, computing device 134 may also control inlet guide vane controller 105 and / or directly control inlet guide vanes 103 to control the flow of intake air 120 that is directed to combustor 114. Thus, computing device 134 controls the stoichiometry of the combustion reaction in combustor 114 by controlling both the fuel split and the flow of intake air 120 to combustor 114.

[0020] The computing device 134 is also programmed to perform a digital simulation of the rotating machine 100 that accurately determines at least one temperature within the combustor 114. More specifically, the digital simulation determines the T 3.5 and T 3.9 Accurately determine temperature. T 3.5 The temperature is the temperature in the combustor 114 axially upstream of the second fuel nozzle 121 and the second combustion zone 117, in the first combustion zone 115. 3.9 The temperature is within the combustor 114 axially downstream of the second fuel nozzle 121, within the second combustion zone 117. As described in more detail below, the computing device 134 uses digital simulations to calculate T 3.5 To control the temperature, the fuel split and the flow of intake air 120 to the combustor 114 are controlled.

[0021] During operation, the intake section 102 directs the intake air 120 towards the compressor section 104. The computing device 134 and / or the inlet guide vane controller 105 controls the inlet guide vanes 103 to control the flow of the intake air 120. The compressor section 104 compresses the intake air 120 to a higher pressure and then discharges the compressed air 122 towards the combustor section 106. The compressed air 122 is directed to the combustor section 106 where it is mixed with fuel (not shown) and combusted to generate hot combustion gases 124. The computing device 134 uses digital simulations to calculate the T 3.5The combustor section 106 and the turbine section 108 are often referred to as the hot gas section of the turbine engine 100. The exhaust gases 128 are then discharged through the exhaust section 110 to the surrounding atmosphere or to a steam turbine (not shown) if the rotary machine 100 is a gas turbine that is part of a combined cycle power plant.

[0022] 2 is a flow diagram of an exemplary method 200 for controlling the temperature of the first combustion zone 115 of the combustor 114 of the rotary machine 100. FIG. 3 is a control diagram 300 illustrating the method 200 for controlling the temperature of the first combustion zone 115 of the combustor 114 of the rotary machine 100 shown in FIG. 2. The method 200 uses a digital simulation of the rotary machine 100 to calculate a current operating temperature T of the first combustion zone 115. 3.5 The digital simulation includes step 202 of determining the temperature in the combustor 114. The digital simulation is a model of the rotating machine 100. Specifically, the digital simulation is a model that accurately determines the operating conditions of multiple operating parameters within the rotating machine 100 in real time during operation of the rotating machine 100 based on control inputs to the computing device 134 and / or feedback from appropriate sensors (not shown) positioned throughout the rotating machine 100. More specifically, the digital simulation is a thermodynamic and fluid dynamic model that accurately determines the operating conditions of multiple operating parameters within the rotating machine 100 in real time during operation of the rotating machine 100. The multiple operating parameters that the digital simulation determines include, among many other parameters, the T 3.5 and T 3.9 Thus, the digital simulation can be performed to measure the T 3.5 and T 3.9In an exemplary embodiment, the digital simulation is an existing simulation used to model the rotary machine 100. In an alternative embodiment, the digital simulation is a new digital simulation of the rotary machine 100 or a new simulation of only the combustor 114.

[0023] The method 200 also includes a target action T 3.5 In an exemplary embodiment, the step of determining 204 the temperature is 3.5 The step of determining temperature 204 uses the outlet temperature of the compressor section 104 and the combustor mode to determine the target operating temperature T 3.5 The method includes determining 204 a temperature. As described above, the combustor 114 may include a plurality of first fuel nozzles 119 and a plurality of second fuel nozzles 121. The arrangement of the plurality of first fuel nozzles 119 and the plurality of second fuel nozzles 121 (i.e., which nozzles of the plurality of first fuel nozzles 119 and / or the plurality of second fuel nozzles 121 are flowing at a given time) at least partially determines the combustor mode. Thus, the target operating temperature T 3.5 The temperatures are determined at least in part by the compressor section 104 exit temperature and the combustor mode. At least some combustion modes are configured for low load conditions and other combustion modes are configured for high load conditions. Each operating mode has a different ideal T 3.5 In some embodiments, the target action T 3.5 The temperature is T 3.5 Determined by at least one compressor exit temperature to temperature schedule, in some embodiments, each combustor mode has its own schedule.

[0024] In an exemplary embodiment, the target motion T 3.5 The step of determining temperature 204 uses a digital simulation and / or a computing device 134 to determine a target operating temperature T using the outlet temperature of the compressor section 104 and the combustor mode. 3.5The digital simulation and / or computing device 134 iteratively calculates a target operating temperature T 3.5 For example, a target operating temperature T may be determined for the rotating machine 100 to meet load and emissions requirements. 3.5 The conditions that require a temperature update may change. For example, the requirements on the load 116 may increase or decrease, and thus the operating conditions of the rotating machine 100 may change to accommodate the changing requirements on the load 116. Specifically, the target T 3.5 The operating temperature may vary. In an alternative embodiment, the target operating temperature T 3.5 The temperature may be determined by an operator or by some other method other than by digital simulation, and / or may not be updated repetitively every control cycle.

[0025] The method 200 is 3.5 Temperature and target operation T 3.5 The step 206 further includes comparing the temperatures. 3.5 Temperature and target operation T 3.5 If the temperatures are different, the computing device 134 may determine the current operating temperature T 3.5 Target temperature T 3.5 Controls fuel split to change with temperature.

[0026] The method 200 also uses a digital simulation to determine the T for the current fuel split. 3.5 In an exemplary embodiment, the digital simulation includes determining 208 a derivative of the temperature. In an exemplary embodiment, the digital simulation includes determining 202 the temperature of the first combustion zone 115 using a digital simulation of the rotating machine 100 to determine the T 3.5 The derivative of temperature can be determined. In addition, small perturbations in the fuel split can be used to determine the T 3.5The derivative of temperature can be modeled. Thus, T for the current fuel split 3.5 An additional digital simulation module to determine the derivative of temperature is not required. Additionally, in an exemplary embodiment, the digital simulation simulates small changes in the current fuel split and, via the digital simulation, the simulated T 3.5 T for the current fuel split by evaluating the corresponding change that results in 3.5 Determine the derivative of temperature. Alternatively, the digital simulation can determine T for the current fuel split in any suitable manner. 3.5 Determine the derivative of temperature.

[0027] The method 200 uses the determined derivative to calculate the target motion T 3.5 Calculated behavior approaching temperature T 3.5 The method further includes a step 210 of calculating a calculated fuel split, which results in a temperature 414, i.e., the calculated operation T 3.5 Temperature 414 is the current operating temperature T 3.5 Target operation T rather than temperature 3.5 In the exemplary embodiment, the computing device 134 determines (210) the calculated fuel split using a numerical method on the output from the digital simulation. 3.5 4 includes a first graph 400 that includes a graphical representation 402 of the relationship between temperature and fuel split, with an additional dashed line indicating the numerical method used to determine the calculated fuel split. FIG. 4 also includes a second graph 401 that includes a corresponding graphical representation 418 of the transient response of the fuel split over time. 3.5 The illustration in FIG. 4 of the graphical representation 402 of the relationship between temperature and fuel split as a smooth curve is for convenience of illustration only. 3.5 The actual relationship between temperature and fuel split may be a more complicated relationship.

[0028] Calculated Operation T 3.5Determining 210 the calculated fuel split corresponding to the temperature includes using a numerical method to determine the calculated fuel split. For example, as shown in FIG. 4 and described above, a digital simulation may be performed to determine the calculated fuel split for the current operating temperature T 3.5 The temperature 404, the current fuel split 406, and the T 3.5 Determine the derivative 408 of the temperature. For example, as described above, the derivative 408 is the change in the simulated T due to a small change δ in the current fuel split. 3.5 The computing device 134 determines the current operation T 3.5 The temperature 404, the current fuel split 406, and the T 3.5 Take the derivative of temperature 408, T 3.5 A second relationship 410 between temperature and fuel split is derived. T 3.5 The second relationship 410 between temperature and fuel split is a linear extension of the derivative 408 from the current fuel split 406, i.e., T 3.5 has a slope equal to the derivative of temperature 408 and has an x-axis coordinate equal to the current fuel split 406 and the current operation T 3.5 4 as a line intersecting a point having a y-axis coordinate equal to temperature 404. 3.5 A second relationship 410 between temperature and fuel split is used to determine the target operation T 3.5 Calculated behavior approaching temperature 416 T 3.5 4. Solving the calculated fuel split 412 to yield temperature 414. More specifically, in the exemplary embodiment, computing device 134 solves second relationship 410 and target operation T 3.5 The temperature 416 intersection point is determined and the calculated fuel split 412 is set as the x-axis coordinate of that intersection point. The point on the graphical representation 402 with the calculated fuel split 412 corresponds to the calculated operating T 3.5 The y-axis coordinate determines the temperature 414. In an exemplary embodiment, due to the nature of the derivative 208, the calculated motion T 3.5The temperature 414 is typically the current operating temperature T 3.5 Target operation temperature T 3.5 Close to temperature.

[0029] Therefore, the target action T 3.5 Calculated behavior approaching temperature 416 T 3.5 Current behavior changes with temperature T 3.5 The step 210 of determining the calculated fuel split, which results in the temperature, T 3.5 The method may include deriving 212 a second relationship 410 between temperature and fuel split. 3.5 Calculated behavior approaching temperature 416 T 3.5 The step 210 of determining the calculated fuel split, which results in the temperature, T 3.5 The target operation T may include step 214 of assuming that the second relationship 410 between temperature and fuel split is a linear relationship. 3.5 Calculated behavior approaching temperature 416 T 3.5 The step 210 of determining the calculated fuel split, which results in a temperature, is 3.5 Based on the temperature derivative 208, T 3.5 The method may further include determining 216 a slope of a second relationship 410 between temperature and fuel split. 3.5 Calculated behavior approaching temperature 416 T 3.5 The step 210 of determining the calculated fuel split, which results in a temperature, also determines the current operating temperature T 3.5 Based on the temperature 404 and the current fuel split 406, T 3.5 The method may include determining 218 at least one point of a second relationship 410 between temperature and fuel split 412. 3.5 Calculated behavior approaching temperature 416 T 3.5 The step 210 of determining the calculated fuel split, which results in the temperature, is performed by comparing the second relationship 410 with the target operation T 3.5 Operation T calculated according to the intersection of temperature 416 3.5 The method may further include calculating 220 a calculated fuel split 412 , which results in a temperature 414 .

[0030] After the computing device 134 determines the calculated fuel split 412, the computing device 134 controls the valve 132 to adjust the total flow of fuel to the first fuel stream and the second fuel stream according to the calculated fuel split 412. After the valve 132 adjusts the fuel split, the operating conditions of the combustor 114 and the rotary machine 100 change and the digital simulation calculates the target operating T 3.5 The method 200 is repeated as necessary to achieve the temperature 416 .

[0031] More specifically, as shown in graph 400, T 3.5 Because the second relationship 410 between temperature and fuel split 412 is only a linear approximation of the complex graphical representation 402, the calculated fuel split 412 is typically initially set to the target operating temperature T 3.5 Temperature 416 does not result in a change in the current fuel split 406 to the calculated fuel split 412. Rather, changing the current fuel split 406 to the calculated fuel split 412 results in a change in the target operation T 3.5 Calculated behavior approaching but different from temperature 416 T 3.5 4. Thus, in an exemplary embodiment, the computing device 134 is programmed to continuously iterate or repeat the above steps of the method 200. In an alternative embodiment, the computing device 134 may be programmed to iterate or repeat the above steps of the method 200. 3.5 Temperature 414 is the target operating temperature T 3.5 Until the temperature becomes equal to the target operating temperature T 3.5 The above steps of method 200 are repeated or programmed to be repeated until the temperature 416 converges to within a functionally sufficient distance.

[0032] Below graph 400 is graph 401, which includes a corresponding graphical representation 418 of the transient response of fuel split over time without a time lag, and a corresponding graphical representation 419 of the transient response of fuel split over time with a time lag. Like graph 400, graph 401 has an x-axis that represents fuel split, but in contrast to graphical representation 402, graph 401 has a y-axis that represents time away from graph 400. Graph 401 is positioned relative to graph 400 such that the x-axis values ​​of current fuel split 406 and calculated fuel split 412 are aligned on both graph 400 and graph 401.

[0033] As shown in the graphical representation 418, the calculated fuel split 412 is first calculated based on the target operating time T 3.54. The fuel split 412 may overshoot the target fuel split 420, which represents the fuel split that actually results in the temperature 416, and then approach and become substantially equal to the target fuel split 420 as the method 200 iterates. However, in some embodiments, the sudden change in fuel split may destabilize the operation of the combustor 114 and the rotating machine 100. Therefore, in some embodiments, a first-order lag time constant is set by an operator to delay the fuel split response to the method 200. Specifically, to prevent the fuel split from instantly jumping to the calculated fuel split 412 in a stepwise manner, the first-order lag time constant is set to smoothly change the fuel split from the current fuel split 406 to the calculated fuel split 412. More specifically, the first-order lag slows down the rate at which the valve 132 changes the fuel split from the current fuel split 406 to the calculated fuel split 412. Additionally, because the valve 132 does not change the fuel split instantly, the method 200 may iterate multiple times before the fuel split applied by the valve 132 during a given iteration reaches the specified calculated fuel split 412. The selection of the first order lag time constant explicitly defines the response time of the control, whereas a traditional PI regulator leaves the time response characteristics determined by analysis, making tuning the time response more intuitive and easier. Thus, the calculated fuel split 412 is continually refined and changed as the valve 132 changes the fuel split. Thus, as shown in the graphical representation 419, the fuel split gradually changes from the current fuel split 406 to the target fuel split 420 as the first order lag slows down the rate at which the valve 132 changes the fuel split from the current fuel split 406 to the calculated fuel split 412. In some embodiments, by the time an iteration is reached where the valve 132 successfully changes the fuel split from the current fuel split 406 to the specified calculated fuel split 412 for that iteration, the calculated fuel split 412 becomes equal to the target fuel split 420.Therefore, the method 200 may also include setting 222 a primary delay to delay the valve 132 changing the fuel split from the current fuel split 406 to the calculated fuel split 412 .

[0034] Additionally, the computing device 134 and the digital simulation may also control the inlet guide vanes 103 to control the flow of intake air 120 and the stoichiometry of the combustor 114. Furthermore, the computing device 134 and the digital simulation may further control the total flow of fuel to the combustor 114 to further control the stoichiometry of the combustor 114. As a result, the computing device 134 and the digital simulation may control the stoichiometry of the combustor 114 by controlling the total flow of fuel to the combustor 114 and / or by controlling the inlet guide vanes 103 that control the flow of intake air 120. Thus, the method 200 may also include controlling 224 at least one of the inlet guide vanes 103 that control the total flow of fuel to the combustor 114 and / or the flow of intake air 120 to the combustor 114 to control the stoichiometry of the combustor 114.

[0035] Additionally, the computing device 134 is programmed to continuously repeat or iterate (226) the above steps of the method 200. In an alternative embodiment, the computing device 134 may be programmed to iterate (226) the calculated operation T 3.5 Temperature 414 is the target operating temperature T 3.5 Until the temperature becomes equal to the target operating temperature T 3.5 The method is programmed to repeat or iterate (226) the above steps of the method 200 until the temperature 416 converges to within a functionally sufficient distance.

[0036] The above-mentioned system relates to a method for controlling a temperature of a first combustion zone of a combustor of a gas turbine engine using a digital simulation. More specifically, the combustor includes a first combustion zone, a second combustion zone, at least one first fuel nozzle, and at least one second fuel nozzle. The at least one first fuel nozzle directs a first fuel flow to the first combustion zone, and the at least one second fuel nozzle directs a second fuel flow to the second combustion zone. The fuel split is a percentage of the total fuel flow that is directed to the second combustion zone. The digital simulation simultaneously determines a current operating temperature of the first combustion zone, a target operating temperature of the first combustion zone, and a derivative of the current operating temperature of the first combustion zone with respect to the current fuel split. A computing device then uses a numerical method to calculate a calculated fuel split that results in a calculated operating temperature of the first combustion zone. The first and second fuel flows are determined by a calculated fuel split, with the first fuel flow being directed to the first combustion zone and the second fuel flow being directed to the second combustion zone. The method is repeated until the calculated fuel split is equal to a target fuel split that results in a target operating temperature. Thus, the systems and methods described herein control the temperature of the first combustion zone without the use of traditional feedback controllers, such as PID controllers, reducing the time and cost of regulating a rotating machine.

[0037] Additionally, example technical effects of the systems and methods described herein include at least one of: (a) controlling a temperature of a first combustion zone of a combustor; (b) directing a first fuel flow to the first combustion zone based on a calculated fuel split; (c) directing a second fuel flow to the second combustion zone based on a calculated fuel split; (d) controlling combustion dynamics of the combustor; and (e) controlling emissions of the combustor.

[0038] Exemplary embodiments of systems and methods for controlling the temperature of a first combustion zone of a combustor of a gas turbine engine using digital simulation are described above in detail. The methods and systems are not limited to the specific embodiments described herein, but rather, the system components and / or method steps may be utilized independent and separate from other components and / or steps described herein. For example, the methods may be used in combination with other rotary machines and are not limited to being practiced solely with the gas turbine engine described herein. Rather, the exemplary embodiments may be implemented and utilized in connection with many other rotary machine applications.

[0039] Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in others, this is for convenience only, and in accordance with the principles of the embodiments of the present disclosure, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.

[0040] This specification uses examples to disclose embodiments of the present disclosure, including the best mode, and to enable any person skilled in the art to practice the embodiments of the present disclosure, including making and using any device or system and performing any incorporated methods. The patentable scope of the embodiments described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims. [Explanation of symbols]

[0041] 100 Rotating machines, gas turbine engines 102 Intake section 103 Inlet guide vane 104 Compressor Section 105 Inlet Guide Vane Controller 106 Combustor Section 107 Airfoil 108 Turbine Section 110 Exhaust Section 112 rotor shaft 114 Combustor 115 First Combustion Zone 116 Load 117 Second Combustion Zone 118 Rotor Assembly 119 First Fuel Nozzle 120 Intake 121 Second Fuel Nozzle 122 Compressed Air 124 Hot Combustion Gases 126 Longitudinal Axis 128 Exhaust Gas 130 Fuel Supply System 132 Valve 134 Computing Devices 200 ways 300 Control Diagram 400 First Graph 401 Second Graph 402 Graph display 404 Current Operation 3.5 temperature 406 Current Fuel Split 408 Derivatives 410 Second Relation 412 Calculated Fuel Split 414 Calculated Action T 3.5 temperature 416 Target motion T 3.5 temperature 418 Graph display 419 Graph display 420 Target Fuel Split

Claims

1. A method (200) for controlling an operating temperature of a first combustion zone (115) of a combustor (106) of a rotary machine (100), the combustor (106) including the first combustion zone (115) and a second combustion zone (117), comprising: i) determining (202) a current operating temperature (404) of the first combustion zone (115) using a digital simulation of the rotating machine (100); ii) determining (204) a target operating temperature (416) for the first combustion zone (115); iii) using the digital simulation to determine (208) a derivative (408) of the current operating temperature (404) of the first combustion zone (115) with respect to a current fuel split (406), the fuel split (406) apportioning a total flow of fuel to the combustor (106) between the first combustion zone (115) and the second combustion zone (117); iv) using the determined derivative (408) to calculate (210) a calculated fuel split (412) that results in a calculated operating temperature (414) of the first combustion zone (115) that approaches the target operating temperature (416); v) directing a first fuel stream to the first combustion zone (115) and a second fuel stream to the second combustion zone (117), the first fuel stream and the second fuel stream being determined as a function of the calculated fuel split (412); vi) repeating steps i-v until the calculated fuel split (412) is equal to a target fuel split (420), the target fuel split (420) being the fuel split (420) that results in the target operating temperature (416); The method (200).

2. The method (200) of claim 1, further comprising the step of comparing (206) the current operating temperature (404) and the target operating temperature (416).

3. 2. The method of claim 1, wherein using a numerical method to calculate a calculated fuel split that results in a calculated operating temperature of the first combustion zone includes deriving a second relationship between the operating temperature and the fuel split.

4. 4. The method of claim 3, wherein using a numerical method to calculate a calculated fuel split (412), which results in a calculated operating temperature (414) of the first combustion zone (115), includes assuming (214) that the second relationship (410) between the operating temperature (416) and the fuel split (412) is a linear relationship.

5. 5. The method of claim 4, wherein using a numerical method to calculate a calculated fuel split (412), which results in a calculated operating temperature (414) of the first combustion zone (115), includes determining a slope (216) of the second relationship (410) between the operating temperature (416) and the fuel split (412) based on the derivative (408) of the current operating temperature (404) of the first combustion zone (115) with respect to the current fuel split (406).

6. 6. The method (200) of claim 5, wherein using a numerical method to calculate (210) a calculated fuel split (412), which results in a calculated operating temperature (414) of the first combustion zone (115), includes determining (218) at least one point of the second relationship (410) between the operating temperature (416) and the fuel split (412) based on the current operating temperature (404) and the current fuel split (406).

7. 7. The method of claim 6, wherein using a numerical method to calculate a calculated fuel split that results in a calculated operating temperature of the first combustion zone includes calculating the calculated fuel split that results in the calculated operating temperature based on the second relationship between the operating temperature and the fuel split.

8. 2. The method of claim 1, further comprising setting a first order time constant to delay the change in fuel split from the current fuel split to the calculated fuel split.

9. The method (200) of any preceding claim, further comprising controlling (224) a total flow of fuel to the combustor (106) to control a stoichiometry of the combustor (106).

10. The method (200) of any preceding claim, further comprising controlling (224) a flow of inlet air to the combustor (106) to control a stoichiometry of the combustor (106).

11. 2. The method (200) of claim 1, wherein determining (204) a target operating temperature (416) of the first combustion zone (115) is performed simultaneously with determining (202) a current operating temperature (404) of the first combustion zone (115) using a digital simulation of the rotating machine (100) by the digital simulation.

12. 2. The method (200) of claim 1, wherein the step (208) of determining a derivative (408) of the current operating temperature (404) of the first combustion zone (115) with respect to a current fuel split (406) using the digital simulation is performed simultaneously with the step (202) of determining the current operating temperature (404) of the first combustion zone (115) using a digital simulation of the rotating machine (100) by the digital simulation.

13. A rotary machine (100), comprising: a compressor (104) configured to compress a flow of intake air; a combustor (106) comprising a first combustion zone (115), a second combustion zone (117), at least one first fuel nozzle (119), and at least one second fuel nozzle (121), the at least one first fuel nozzle (119) configured to direct a first fuel flow into the first combustion zone (115), the at least one second fuel nozzle (121) configured to direct a second fuel flow into the second combustion zone (117), the combustor (106) configured to receive a flow of the intake air, and a fuel split being a percentage of a total fuel flow that is directed to the second combustion zone (117); A computing device (134) comprising a digital simulation of the rotating machine (100), the computing device (134) comprising: determining (202) a current operating temperature (404) of the first combustion zone (115) using the digital simulation; determining (204) a target operating temperature (416) for the first combustion zone (115); using the digital simulation to simultaneously determine (208) a derivative (408) of the current operating temperature (404) of the first combustion zone (115) with respect to a current fuel split (406); Calculating (210) a calculated fuel split (412) using a numerical method, which results in a calculated operating temperature (414) of said first combustion zone (115); directing the first fuel stream to the first combustion zone (115) and the second fuel stream to the second combustion zone (117), the first fuel stream and the second fuel stream being determined by the calculated fuel split (412); iterating (226) until the calculated fuel split (412) is equal to a target fuel split (420), the target fuel split (420) being the fuel split (420) that results in the target operating temperature (416); A computing device (134) configured to A rotary machine (100).

14. The rotary machine (100) of claim 13, further comprising a fuel supply system (130) configured to direct a total flow of the fuel to the first combustion zone (115) and the second combustion zone (117).

15. 15. The rotary machine (100) of claim 14, wherein the fuel supply system (130) comprises at least one valve (132) configured to split a total flow of the fuel into the first fuel stream and the second fuel stream.

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