System and method for determining gas turbine fuel split for head-end temperature control

Abstract

The present invention discloses a method (200) for controlling the operating temperature of a first combustion zone (115) of a combustor (106) of a rotary machine (100), the method comprising using digital simulation to determine a current operating temperature and a target operating temperature of the first combustion zone (115). The method (200) further comprises using digital simulation to determine a derivative (408) of the current operating temperature relative to a current fuel split. The fuel split distributes a total fuel flow to the combustor (106) between the first combustion zone (115) and the second combustion zone (117). The method (200) further comprises calculating a calculated fuel split (410) that causes the calculated operating temperature to approach the target operating temperature. The method (200) further comprises directing the first fuel flow to the first combustion zone (115) and directing the second fuel flow to the second combustion zone (117).

Description

Background Art

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

[0002] The energy extracted from the airflow of the turbine is used to power the mechanical load of at least some known rotary machines. Specifically, the rotary machine includes a compressor section, a combustor section, and a turbine section arranged in series. The compressor section compresses air to burn with fuel in the combustor section, and the turbine section extracts energy from the combustion gases produced in the combustor section. At least some known combustor sections include axial fuel staging (AFS) technology (including axial (sequential) combustion staging in at least two regions). More specifically, the combustor section may include a plurality of first-stage fuel nozzles located upstream of a plurality of second-stage fuel nozzles. The first fuel flow is directed into the combustor by the first-stage fuel nozzle, and the second fuel flow is directed into the combustor by the second-stage fuel nozzle. The temperature in the combustor of the combustion gases produced by the combustion of the first fuel flow is T 3.5 Temperature. Control the T 3.5 Temperature enables operators to control the emissions and dynamics profile of the combustor and allows for greater operational flexibility of the rotating machinery.

[0003] Due to the high temperatures in the burner, T is usually not measured directly. 3.5 Instead, the burner inlet temperature, the first fuel flow rate, the second fuel flow rate, and other known parameters are used to simulate or estimate T 3.5 temperature, and is used to control the T 3.5 More specifically, in at least some known rotating machines, a proportional-integral (PI) controller is used to control T 3.5 The PI controller uses the selected parameters to control the fuel split to the first and second stage nozzles, which then indirectly controls T 3.5 However, the rotating machine is adjusted so that the PI controller accurately controls T 3.5 Temperature can be time consuming and expensive. In addition, if the gains of the PI controller are not set correctly, the PI controller may not be able to properly control T 3.5 temperature, which may result in temperature oscillations and / or burner explosion. Summary of the invention

[0004] In one aspect, a method for controlling the operating temperature of a first combustion zone of a burner of a rotary machine is provided. The burner includes a first combustion zone and a second combustion zone. The method includes using a digital simulation of the rotary machine to determine the current operating temperature of the first combustion zone. The method also includes determining a target operating temperature of the first combustion zone. The method also includes using a digital simulation to determine the derivative of the current operating temperature of the first combustion zone relative to the current fuel split. The fuel split distributes the total fuel flow to the burner between the first combustion zone and the second combustion zone. The method also includes using the determined derivative to calculate a calculated fuel split, which causes the calculated operating temperature of the first combustion zone to approach the target operating temperature. The method also includes directing the first fuel flow to the first combustion zone and directing the second fuel flow to the second combustion zone. Determining the first fuel flow and the second fuel flow in response to the calculated fuel split. The method also includes iterating steps i to v until the calculated fuel split is equal to the target fuel split, wherein the target fuel split is 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 an inlet air flow, a burner and a computing device. The burner includes a first combustion zone, a second combustion zone, at least one first fuel nozzle and at least one second fuel nozzle. At least one first fuel nozzle is configured to guide a first fuel flow to the first combustion zone, and at least one second fuel nozzle is configured to guide a second fuel flow to the second combustion zone. The burner is configured to receive an inlet air flow. The fuel split is a fraction of the total fuel flow directed to the second combustion zone. The computing device includes a digital simulation of the rotary machine. The computing device is also configured to use the digital simulation to determine a current operating temperature of the first combustion zone. The computing device is also configured to determine a target operating temperature of the first combustion zone. The computing device is also configured to use the digital simulation to simultaneously determine the derivative of the current operating temperature of the first combustion zone relative to the current fuel split. The computing device is also configured to use a numerical method to calculate a calculated fuel split, which results in a calculated operating temperature of the first combustion zone. The computing device is also configured to guide the first fuel flow to the first combustion zone and guide the second fuel flow to the second combustion zone. The first fuel flow rate and the second fuel flow rate are determined from the calculated fuel split. The computing device is further configured to iterate until the calculated fuel split is equal to a target fuel split, wherein the target fuel split is a fuel split that results in a target operating temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] These and other features, aspects and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters refer to like parts throughout the several views, and in which:

[0007] Figure 1 is a schematic diagram of an exemplary rotating machine;

[0008] Figure 2A Yes Control Figure 1 A flow chart of an exemplary method for determining a temperature of a first combustion zone of a combustor of a rotary machine;

[0009] Figure 2B Yes Control Figure 2A a continuation of a flowchart of an exemplary method of determining a temperature of a first combustion zone of a combustor of a rotary machine;

[0010] Figure 3 is a control diagram showing a method of controlling the temperature of a first combustion zone of a combustor of a rotary machine shown in FIG. 2 ; and

[0011] Figure 4 It is T 3.5 A first graph of the relationship between temperature and fuel split and a first graph of a digital method for determining a target fuel split and a second graph of the corresponding transient response of the fuel split over time.

[0012] Unless otherwise indicated, the drawings provided herein are intended to illustrate features of the embodiments of the present disclosure. It is believed that these features are applicable to a variety of systems including one or more embodiments of the present disclosure. Therefore, the drawings are not intended to include all conventional features required for practicing the embodiments disclosed herein known to those of ordinary skill in the art. DETAILED DESCRIPTION

[0013] In the following specification and claims, reference will be made to a number of terms which shall be defined to have the following meanings.

[0014] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0015] Unless otherwise indicated, approximate language as used herein, such as "substantially", "substantially" and "about" indicate that as those of ordinary skill in the art will recognize, the terms so modified may only apply to approximate degrees, rather than absolute or perfect degrees. Therefore, the value modified by one or more terms (such as "about", "approximately" and "substantially") is not limited to the specified exact value. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range restrictions can be identified. Unless otherwise indicated by the context or language, these ranges can be combined and / or interchanged, and include all sub-ranges contained therein. In addition, unless otherwise indicated, the terms "first", "second", etc. are only used as marks in this article, and are not intended to impose order, position or hierarchical requirements on the items to which these terms are related. In addition, for example, the reference to the "second" item does not require or exclude the existence of, for example, "first" or lower numbered items or "third" or higher numbered items.

[0016] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the longitudinal axis of a rotating machine. In addition, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the longitudinal axis of a rotating machine. In addition, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations extending in an arc around the longitudinal axis of a rotating machine. Further, as used herein, the term "upstream" refers to the front end or inlet end of a rotating machine, and the term "downstream" refers to the rear end or outlet end of a rotating machine. When discussing the flow of fluid through a component, the starting direction of the fluid flow is described as "upstream", and the direction followed by the fluid flow is described as "downstream".

[0017] The method and system described herein relate to a method for controlling the temperature of a first combustion zone of a combustor of a gas turbine engine using 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. At least one first fuel nozzle directs a first fuel flow to the first combustion zone, and at least one second fuel nozzle directs a second fuel flow to the second combustion zone. The fuel split is a fraction of the total fuel flow directed to the second combustion zone. The digital simulation simultaneously determines the current operating temperature of the first combustion zone, the target operating temperature of the first combustion zone, and the derivative of the current operating temperature of the first combustion zone relative to the current fuel split. The computing device then uses a numerical method to calculate a calculated fuel split, which results in a calculated operating temperature of the first combustion zone. The first fuel flow and the second fuel flow are determined by the calculated fuel split, and the first fuel flow is directed to the first combustion zone, and the second fuel flow is directed to the second combustion zone. The method is iterated until the calculated fuel split is equal to the target fuel split that results in the target operating temperature. Thus, the systems and methods described herein control the temperature of the first combustion zone without using a traditional feedback controller, such as a PID controller, thereby reducing the time and cost of tuning the rotating machine.

[0018] Figure 1 1 is a schematic diagram of an exemplary rotary machine 100 (i.e., a turbine), and more specifically a turbine engine. In an exemplary embodiment, the rotary machine 100 is a gas turbine engine. Alternatively, the rotary machine can 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 an exemplary embodiment, the gas turbine engine 100 includes an intake portion 102, a compressor portion 104 coupled downstream of the intake portion 102, a combustor portion 106 coupled downstream of the compressor portion 104, a turbine portion 108 coupled downstream of the combustor portion 106, and an exhaust portion 110 coupled downstream of the turbine portion 108. The turbine portion 108 is coupled to the compressor portion 104 via a rotor shaft 112.

[0019] It should be noted that, as used herein, the term "coupled" is not limited to direct mechanical, thermal, electrical, and / or fluid communication connections between components, but may also include indirect mechanical, thermal, electrical, and / or fluid communication connections between multiple components. In an exemplary embodiment, the combustor section 106 includes a plurality of combustors 114. The combustor section 106 is coupled to the compressor section 104 so that each combustor 114 is in fluid communication with the compressor section 104. The rotor shaft 112 is also coupled to a load 116, such as, but not limited to, a generator and / or a mechanical drive application. In an exemplary embodiment, each of the compressor section 104 and the turbine section 108 includes at least one rotor assembly 118 coupled to the rotor shaft 112.

[0020] In this embodiment, the air intake section 102 includes at least one inlet guide vane 103, which is controlled by an inlet guide vane controller 105. The inlet guide vane 103 controls the inlet air flow 120, which is directed from the atmosphere to the compressor section 104 by the air intake section 102. Specifically, the inlet guide vane 103 may include a variable or fixed vane 107 that directs the inlet air 120 to the compressor section 104. The inlet guide vane 103 changes the angle of the inlet air flow 120 to improve the efficiency of the compressor section 104. In addition, the vane 107 of the inlet guide vane 103 may be variable, or the angle of the vane 107 relative to the compressor section 104 may be changed to change the angle of the inlet air flow 120 and improve the efficiency of the compressor section 104 under different operating conditions.

[0021] In an exemplary embodiment, the combustor 114 includes axial fuel staging (AFS) technology (including axial (sequential) combustion staging in at least two zones). Specifically, the combustor 114 is an axially staged combustor, 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. At least one first fuel nozzle 119 is located upstream of 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. At least one second fuel nozzle 121 is located downstream of 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 combustion zone 115 and the second combustion zone 117 stage the total fuel flow to the combustor to control the combustion dynamics within the combustor 114. In an exemplary embodiment, Figure 1 A single first fuel nozzle 119 and a single second fuel nozzle 121 are shown in FIG. However, the combustor 114 may include a plurality of first fuel nozzles 119 and / or a plurality of second fuel nozzles 121 .

[0022] The rotary machine 100 also includes a fuel supply system 130, which includes at least one valve 132, which controls the fuel diversion of the total fuel flow. The fuel diversion corresponds to the distribution of the total fuel flow to the burner between the first fuel flow and the second fuel flow. In an exemplary embodiment, the fuel diversion is expressed as a fraction of the total fuel flow directed to at least one second fuel nozzle 121 (i.e., the second fuel flow divided by the sum of the first fuel flow and the second fuel flow). Alternatively, the fuel diversion is expressed in any appropriate manner. Specifically, the fuel supply system 130 directs the total fuel flow to the burner 114. More specifically, the fuel supply system 130 directs the total fuel flow to the first fuel nozzle 119 and the second fuel nozzle 121, which in turn directs the total fuel flow to the first combustion zone 115 and the second combustion zone 117, respectively. The valve 132 diverts the total fuel flow into the first fuel flow and the second fuel flow according to the selected fuel diversion. As will be described in more detail below, controlling the fuel diversion control T 3.5 Temperature, the T 3.5 The temperature controls the combustion dynamics of the combustor 114 .

[0023] The rotary machine 100 also includes a computing device 134 that controls at least one operating parameter of the rotary machine 100. More specifically, in the exemplary embodiment, the computing device 134 controls a fuel split of a total fuel flow to the combustor 114 by controlling the valve 132. In addition, the computing device 134 may also control the inlet guide vane controller 105 and / or directly control the inlet guide vanes 103 to control the inlet air flow 120 directed to the combustor 114. Thus, the computing device 134 controls the stoichiometry of the combustion reaction within the combustor 114 by controlling the fuel split and the inlet air flow 120 to the combustor 114.

[0024] The computing device 134 is also programmed to perform a digital simulation of the rotary machine 100 that accurately determines at least one temperature within the combustor 114. More specifically, the digital simulation accurately determines T 3.5 Temperature and T 3.9 Temperature. 3.5 The temperature is the temperature within the first combustion zone 115 and within the combustor 114 axially upstream of the second fuel nozzle 121 and the second combustion zone 117. 3.9 The temperature is the temperature within the combustor 114 within the second combustion zone 117 and axially downstream of the second fuel nozzle 121. As will be discussed in more detail below, the computing device 134 controls the fuel split and the inlet air flow 120 flowing to the combustor 114 to control T using digital simulation.3.5 temperature.

[0025] During operation, the air intake section 102 directs inlet air 120 toward 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 inlet air flow 120. The compressor section 104 compresses the inlet air 120 to a higher pressure and then discharges the compressed air 122 toward the combustor section 106. The compressed air 122 is delivered to the combustor section 106 where it is mixed with fuel (not shown) and combusted to produce high temperature combustion gases 124. The computing device 134 controls the fuel split to the first fuel nozzle 119 and the second fuel nozzle 121 using digital simulation to control the T in the combustor 114. 3.5 Combustion gases 124 are directed downstream toward turbine section 108 and impinge on turbine blades (not shown), converting thermal energy into mechanical rotational energy that is used to drive rotor assembly 118 to rotate about longitudinal axis 126. In general, combustor section 106 and turbine section 108 are referred to as a hot gas section of turbine engine 100. If rotary machine 100 is a gas turbine as part of a combined cycle power plant, exhaust gases 128 are discharged through exhaust section 110 to the ambient atmosphere or a steam turbine (not shown).

[0026] FIG. 2 is a flow chart of an exemplary method 200 of controlling a temperature of a first combustion zone 115 of a combustor 114 of a rotary machine 100 ; Figure 3 is a control diagram 300 showing a 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 includes using a digital simulation of the rotary machine 100 to determine 202 a current operating temperature of the first combustion zone 115 3.5 Temperature. The digital simulation is a model of the rotating machine 100. Specifically, the digital simulation is a model that accurately determines the operating state of multiple operating parameters within the rotating machine 100 in real time during the operation of the rotating machine 100 based on control inputs from the computing device 134 and / or feedback from applicable sensors (not shown) located throughout the rotating machine 100. More specifically, the digital simulation is a thermodynamic and fluid dynamic model that accurately determines the operating state of multiple operating parameters within the rotating machine 100 in real time during the operation of the rotating machine 100. The multiple operating parameters determined by the digital simulation include T in the combustor 114. 3.5 and T 3.9 temperature and many other parameters. Thus, the digital simulation determines T in the combustor 114 in real time during operation of the rotary machine 100. 3.5 and T 3.9In the exemplary embodiment, the digital simulation is an existing simulation used to model rotary machine 100. In alternative embodiments, the digital simulation is a new digital simulation of rotary machine 100 or a new simulation of only combustor 114.

[0027] The method 200 also includes determining 204 a target work T 3.5 In an exemplary embodiment, a target operating temperature is determined 204. 3.5 The temperature includes determining 204 a target operating T using the outlet temperature of the compressor section 104 and the combustor mode. 3.5 Temperature. As discussed 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 of the plurality of first fuel nozzles 119 and / or the plurality of second fuel nozzles 121 are flowing fuel at a given time) at least partially determines the combustor mode. Thus, the target operating T 3.5 The temperature is determined at least in part by the outlet temperature of the compressor section 104 and the burner mode. At least some combustion modes are configured for low load conditions, while other combustion modes are configured for high load conditions. Each operating mode has a different ideal T 3.5 temperature to optimize the emissions and / or dynamic characteristics of the rotary machine 100. In some embodiments, the target operating T 3.5 The temperature is determined by at least one compressor outlet temperature and T 3.5 The temperature comparison table determines. In some embodiments, each burner mode has its own schedule.

[0028] In an exemplary embodiment, the target work T is determined 204. 3.5 The temperature includes determining 204 the target operating T using the outlet temperature of the compressor section 104 and the combustor mode using a digital simulation and / or computing device 134 3.5 The digital simulation and / or computing device 134 may iteratively determine the target operating temperature 3.5 temperature, and at the same time determining 202 the temperature of the first combustion region 115. For example, it is necessary to update the target operating temperature T 3.5 Temperature conditions may change so that the rotating machine 100 meets the load and emission requirements. For example, the requirements for the load 116 may increase or decrease, and therefore, the operating conditions of the rotating machine 100 may change to adapt to the changing requirements for the load 116. Specifically, in order to adapt to the changing requirements for the load 116, the target T 3.5 The operating temperature may vary. In an alternative embodiment, the target operating temperature 3.5 The temperature may be determined by an operator or some other method other than digital simulation and / or may not be repeatedly updated with each control cycle.

[0029] The method 200 also includes comparing 206 the current working T 3.5 Temperature and target operating T 3.5 Temperature. If the current working T 3.5 Temperature and target operating T 3.5 If the temperature is different, the computing device 134 controls the fuel split so that the current working temperature 3.5 Temperature changes to target operating T 3.5 Temperature, as described below.

[0030] The method 200 also includes determining 208 T using a digital simulation 3.5 The derivative of temperature with respect to the current fuel split. In an exemplary embodiment, the numerical simulation can determine T 3.5 The temperature of the first combustion zone 115 is determined 202 using a numerical simulation of the rotary machine 100 by taking the derivative of the temperature with respect to the current fuel split. In addition, small perturbations in the fuel split can be used to determine the temperature of the first combustion zone 115. 3.5 The temperature derivative is modeled. Therefore, no 3.5 An additional digital simulation module for the derivative of temperature with respect to the current fuel split. In addition, in the exemplary embodiment, the digital simulation determines T by simulating small changes in the current fuel split. 3.5 The derivative of temperature with respect to the current fuel split is evaluated via numerical simulation resulting in the simulated T 3.5 Alternatively, digital simulation determines T in any suitable manner. 3.5 The derivative of temperature with respect to the current fuel split.

[0031] The method 200 also includes calculating 210 a calculated fuel split using the determined derivative, the calculated fuel split resulting in a calculated operating T 3.5 Temperature 414 is close to the target operating T 3.5 Temperature, that is, the calculated working T 3.5 Temperature 414 is higher than the current working T 3.5 Temperature is closer to the target operating T 3.5 In the exemplary embodiment, computing device 134 uses a digital method on the output from the digital simulation to determine 210 a calculated fuel split. Figure 4 A first graph 400 is included, which includes T 3.5 A graphical representation 402 of the relationship between temperature and fuel split, with an additional dashed line illustrating a numerical method for determining a calculated fuel split. Figure 4 Also included is a second graph 401 that includes a corresponding graphical representation 418 of the transient response of the fuel split over time. For ease of illustration only, Figure 4 Medium T 3.5The graphical representation 402 of the relationship between temperature and fuel split is illustrated as a smooth curve. 3.5 The actual relationship between temperature and fuel split may be a more complex relationship.

[0032] Determine 210 the corresponding calculated working T 3.5 The calculated fuel split for the temperature includes using a numerical method to determine the calculated fuel split. For example, Figure 4 As shown and described above, this digital simulation determines the current working T 3.5 temperature 404, current fuel split 406, and T 3.5 The derivative 408 of the temperature with respect to the current fuel split 406. For example, as described above, the derivative 408 is determined by the corresponding change Δ that the simulated T due to a small change δ in the current fuel split 3.5 The computing device 134 receives the current working temperature. 3.5 temperature 404, current fuel split 406, and T 3.5 The derivative 408 of the temperature with respect to the current fuel split and the derived T 3.5 A second relationship 410 between temperature and fuel split. 3.5 The second relationship 410 between temperature and fuel split is Figure 4 The straight line extension from the current fuel split 406 shown as the derivative 408, i.e., having a value equal to T 3.5 The straight line having the slope of the derivative 408 of temperature with respect to the current fuel split and having an x-axis coordinate equal to the current fuel split 406 and a current operating T 3.5 The y-axis coordinate of temperature 404 intersects the point. The computing device 134 uses T 3.5 The second relationship 410 between temperature and fuel split is solved for a calculated fuel split 412 that results in a calculated operating T 3.5 Temperature 414 is close to the target operating T 3.5 Temperature 416. More specifically, in the exemplary embodiment, computing device 134 determines that second relationship 410 is related to target operating temperature 3.5 The calculated fuel split 412 is set as the x-axis coordinate of the intersection point. The point on the graphical representation 402 having the calculated fuel split 412 has a value that determines the calculated operating T 3.5 The y-axis coordinate of temperature 414. In the exemplary embodiment, due to the nature of derivative 208, the calculated working T 3.5 The temperature 414 is usually higher than the current working T 3.5 Temperature 404 is closer to the target operating T 3.5 temperature.

[0033] Therefore, determining 210 results in the current working T 3.5 The temperature changes to approach the target operating T 3.5 The calculated working temperature of 416 is T 3.5 The calculated fuel split of the temperature may include deriving 212T 3.5 A second relationship 410 between temperature and fuel split. Determining 210 results in approaching the target operating T 3.5 The calculated working temperature of 416 is T 3.5 The calculated fuel split for temperature may also include assuming 214T 3.5 The second relationship 410 between temperature and fuel split is a linear relationship. Determining 210 results in approaching the target operating T 3.5 The calculated working temperature of 416 is T 3.5 The calculated fuel split based on temperature may also include a 3.5 The temperature is determined 216T by the derivative 208 of the current fuel split 3.5 The slope of the second relationship 410 between temperature and fuel split. Determining 210 results in approaching the target operating T 3.5 The calculated working temperature of 416 is T 3.5 The calculated fuel split for temperature may also include a fuel split based on the current operating T 3.5 The temperature 404 and the current fuel split 406 determine 218T 3.5 At least one point of a second relationship 410 between temperature and fuel split 410. Determining 210 results in approaching the target operating T 3.5 The calculated working temperature of 416 is T 3.5 The calculated fuel split for the temperature may also include a calculation based on the second relationship 410 and the target operating temperature 3.5 The intersection calculation 220 of the temperature 416 results in a calculated operating T 3.5 Calculated fuel split 412 for temperature 414 .

[0034] After the computing device 134 has determined the calculated fuel split 412, the computing device 134 controls the valve 132 to adjust the total fuel flow rate into the first fuel flow rate and the second fuel flow rate in response to the calculated fuel split 412. After the valve 132 has adjusted the fuel split, the operating state of the combustor 114 and the rotary machine 100 changes, and the digital simulation iterates the method 200 as needed to achieve the target operating T 3.5 Temperature: 416.

[0035] More specifically, as shown in graph 400, because T 3.5 The second relationship 410 between temperature and fuel split 412 is only a linear approximation of the complex graphical representation 402, so the calculated fuel split 412 typically does not initially result in the target operating T 3.5Temperature 416. Conversely, changing the current fuel split 408 to the calculated fuel split 412 results in a calculated operating T 3.5 Temperature 414 is close to but different from the target operating T 3.5 Temperature 416. Thus, in the exemplary embodiment, computing device 134 is programmed to continuously iterate or repeat the above steps of method 200. In an alternative embodiment, computing device 134 is programmed to iterate or repeat the above steps of method 200 until the calculated working temperature is reached. 3.5 Temperature 414 is equal to the target operating T 3.5 Temperature 416, i.e., converges to the target operating T 3.5 The temperature is within the functional gap.

[0036] Shown below graph 400 is graph 401, which includes a corresponding graphical representation 418 of the transient response of the fuel split over time without a time lag, and a corresponding graphical representation 419 of the transient response of the fuel split over time with a time lag. Similar to graph 400, graph 401 has an x-axis representing fuel split, but has a y-axis representing time that extends away from graph 400 compared to graphical representation 402. Graph 401 is positioned relative to graph 400 such that the x-axis values ​​of the current fuel split 406 and the calculated fuel split 412 are aligned on both graph 400 and graph 401.

[0037] As shown in graphical representation 418, the calculated fuel split 412 initially exceeds the target fuel split 420, which represents the target fuel split that actually results in the target operating T 3.5The fuel split at the temperature 416 then approaches and substantially equals the target fuel split 420 as the method 200 iterates. However, in some embodiments, a sudden change in the fuel split may cause the operation of the combustor 114 and the rotary machine 100 to become unstable. Therefore, in some embodiments, a first-order lag time constant is set by the operator to delay the response of the fuel split to the method 200. Specifically, in order to prevent the fuel split from immediately jumping to the calculated fuel split 412 in a step-like 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 time constant 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 addition, because the valve 132 does not change the fuel split instantaneously, the method 200 may iterate multiple times during a given iteration before the fuel split applied by the valve 412 reaches the commanded calculated fuel split 412. The selection of the first order lag time constant explicitly defines the response time of the control, whereas a conventional PI regulator would leave the time response characteristics to be determined analytically, making adjustment of the time response more intuitive and easier. Thus, as the valve 132 changes the fuel split, the calculated fuel split 412 is continually refined and changed. 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 because 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, when the valve 132 successfully changes the fuel split from the current fuel split 406 to the commanded calculated fuel split 412 for the iteration, the calculated fuel split 412 is equal to the target fuel split 420. Therefore, the method 200 may also include setting 222 a first order hysteresis to delay the valve 132 from changing the fuel split from the current fuel split 406 to the calculated fuel split 412 .

[0038] In addition, the computing device 134 and the digital simulation may also control the inlet guide vanes 103 to control the flow of the inlet air 120 and the stoichiometry of the combustor 114. In addition, the computing device 134 and the digital simulation may further control the total fuel flow to the combustor 114 to further control the stoichiometry of the combustor 114. In this way, the computing device 134 and the digital simulation may control the stoichiometry of the combustor 114 by controlling the total fuel flow to the combustor 114 and / or by controlling the inlet guide vanes 103 to control the flow of the inlet air 120. Therefore, the method 200 may also include controlling 224 at least one fuel flow of the total fuel flow to the combustor 114 and / or controlling the inlet guide vanes 103 to control the flow of the incoming air 120 to the combustor 114 to control the stoichiometry of the combustor 114.

[0039] In addition, the computing device 134 is programmed to continuously iterate 226 or repeat the above steps of the method 200. In an alternative embodiment, the computing device 134 is programmed to iterate 226 or repeat the above steps of the method 200 until the calculated working T 3.5 Temperature 414 is equal to the target operating T 3.5 Temperature 416, i.e., converges to the target operating T 3.5 The temperature is within the functional gap.

[0040] The system described above relates to a method for controlling the temperature of a first combustion zone of a combustor of a gas turbine engine using 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. At least one first fuel nozzle directs a first fuel flow to the first combustion zone, and at least one second fuel nozzle directs a second fuel flow to the second combustion zone. The fuel split is a fraction of the total fuel flow directed to the second combustion zone. The digital simulation simultaneously determines the current operating temperature of the first combustion zone, the target operating temperature of the first combustion zone, and the derivative of the current operating temperature of the first combustion zone relative to the current fuel split. The computing device then uses a numerical method to calculate a calculated fuel split, which results in a calculated operating temperature of the first combustion zone. The first fuel flow and the second fuel flow are determined by the calculated fuel split, and the first fuel flow is directed to the first combustion zone, and the second fuel flow is directed to the second combustion zone. Iterate the method until the calculated fuel split is equal to the target fuel split that results in the target operating temperature. Thus, the systems and methods described herein control the temperature of the first combustion zone without using a traditional feedback controller, such as a PID controller, thereby reducing the time and cost of tuning the rotating machine.

[0041] In addition, an exemplary technical effect of the systems and methods described herein includes at least one of the following steps: (a) controlling the temperature of a first combustion zone of a burner; (B) directing a first fuel flow to the first combustion zone based on a calculated fuel split; (C) directing a second fuel flow to a second combustion zone based on a calculated fuel split; (D) controlling the combustion dynamics of the burner; and (e) controlling emissions from the burner.

[0042] Exemplary embodiments of systems and methods for controlling the temperature of the first combustion zone of a combustor of a gas turbine engine using digital simulation are described in detail above. The system and method are not limited to the specific embodiments described herein, but the components of the system and / or the steps of the method can be used independently and separately from other components and / or steps described herein. For example, the method can also be used in conjunction with other rotating machines and is not limited to practice performed only with a gas turbine engine as described herein. Instead, the exemplary embodiments can be implemented and used in conjunction with many other rotating machine applications.

[0043] Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in other drawings, this is for convenience only. According to the principles of the embodiments of the present disclosure, any feature of the drawings may be referenced and / or claimed in combination with any feature of any other drawings.

[0044] This written description uses examples to disclose embodiments of the present disclosure, including the best mode, and also enables 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 combined method. 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 are not substantially different from the literal language of the claims.

Claims

1. A method (200) for controlling an operating temperature of a first combustion zone (115) of a burner (106) of a rotary machine (100), the burner (106) comprising the first combustion zone (115) and a second combustion zone (117), the method (200) comprising: i) determining (202) a current operating temperature of the first combustion zone (115) using a digital simulation of the rotating machine (100); ii) determining (204) a target operating temperature of the first combustion zone (115); iii) using the numerical simulation to determine (208) a derivative (408) of the current operating temperature of the first combustion zone (115) with respect to a current fuel split, wherein the fuel split distributes a total fuel flow to the burner (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 (410) that results in a calculated operating temperature of the first combustion zone (115) approaching the target operating temperature; v) directing a first fuel flow rate to the first combustion zone (115) and directing a second fuel flow rate to the second combustion zone (117), wherein the first fuel flow rate and the second fuel flow rate are determined in response to the calculated fuel split (410); as well as vi) iterating (226) steps i through v until the calculated fuel split (410) is equal to a target fuel split (420), wherein the target fuel split (420) is the fuel split that results in the target operating temperature.

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

3. The method (200) of claim 1, wherein calculating (210) using a numerical method a calculated fuel split (410) that causes the calculated operating temperature of the first combustion zone (115) to approach the target operating temperature includes deriving (212) a second relationship between the operating temperature and the fuel split.

4. The method (200) of claim 3, wherein calculating (210) using a numerical method a calculated fuel split (410) that causes the calculated operating temperature of the first combustion zone (115) to approach the target operating temperature includes assuming (214) that the second relationship between the operating temperature and the fuel split is a linear relationship.

5. The method (200) of claim 4, wherein calculating (210) using a numerical method a calculated fuel split (410) that causes the calculated operating temperature of the first combustion zone (115) to approach the target operating temperature includes determining (216) a slope of the second relationship between the operating temperature and the fuel split based on the derivative (408) of the current operating temperature of the first combustion zone (115) with respect to the current fuel split.

6. The method (200) of claim 5, wherein calculating (210) using a numerical method a calculated fuel split (410) that causes the calculated operating temperature of the first combustion zone (115) to approach the target operating temperature includes determining (218) at least one point of the second relationship between the operating temperature and the fuel split based on the current operating temperature and the current fuel split.

7. The method (200) of claim 6, wherein calculating (210) using a numerical method a calculated fuel split (410) that causes the calculated operating temperature of the first combustion zone (115) to approach the target operating temperature includes calculating the calculated fuel split (410) that causes the calculated operating temperature to approach the target operating temperature based on the second relationship between the operating temperature and the fuel split.

8. The method (200) of claim 1, further comprising setting (222) a first order lag time constant to delay changing the fuel split from the current fuel split to the calculated fuel split (410).

9. The method (200) of claim 1, further comprising controlling (224) a total fuel flow to the burner (106) to control the stoichiometry of the burner (106).

10. The method (200) of claim 1, further comprising controlling (224) an inlet air flow to the burner (106) to control the stoichiometry of the burner (106).

11. The method (200) of claim 1, wherein determining (204) a target operating temperature of the first combustion zone (115) and using a digital simulation of the rotary machine (100) to determine a current operating temperature of the first combustion zone (115) by the digital simulation are performed simultaneously.

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

13. A rotating machine (100), comprising: a compressor (104) configured to compress an inlet air flow; A burner (106), the burner 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), wherein the at least one first fuel nozzle (119) is configured to direct a first fuel flow rate to the first combustion zone (115), and the at least one second fuel nozzle (121) is configured to direct a second fuel flow rate to the second combustion zone (117), and wherein the burner (106) is configured to receive the inlet air flow rate, and wherein the fuel split is a fraction of the total fuel flow rate directed to the second combustion zone (117); and A computing device (134) comprising a digital simulation of the rotating machine (100), wherein the computing device (134) is configured to: i) using the digital simulation to determine (202) a current operating temperature of the first combustion zone (115); ii) determining (204) a target operating temperature of the first combustion zone (115); iii) using the numerical simulation to simultaneously determine (208) a derivative (408) of the current operating temperature of the first combustion zone (115) with respect to a current fuel split; iv) using a numerical method to calculate (210) a calculated fuel split (410) that results in a calculated operating temperature of said first combustion zone (115); and v) directing the first fuel flow rate to the first combustion zone (115) and directing the second fuel flow rate to the second combustion zone (117), wherein the first fuel flow rate and the second fuel flow rate are determined by the calculated fuel split (410); as well as vi) iterating (226) steps i through v until the calculated fuel split (410) is equal to a target fuel split (420), wherein the target fuel split (420) is the fuel split that results in the target operating temperature.

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

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

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