Method for manufacturing a controller and combustion system

Abstract

The invention relates to a method for manufacturing a controller and a combustion system. In particular, a method for manufacturing a controller (17) comprises providing a combustion system test bench (1), operating the combustion system test bench (1) using different sets of operating parameters, measuring local temperatures of a hot gas stream using at least two temperature sensors (13), obtaining local temperature operating parameter set data, for each set of operating parameters, calculating a theoretical mixer exit temperature (MET) based on the supplied oxidizer and fuel mass flow, providing a correlation between the local temperatures and the theoretical mixer exit temperature (MET), programming the controller (17) using the correlation.

Description

[0001] Cross-references to related applications

[0002] This patent application claims priority to European Patent Application No. 20187862.6, filed on 27 July 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to a method for manufacturing a controller and to a combustion system.

[0004] The controller is used to calculate the temperature of the hot gas flow delivered through the combustion system, which is in turn part of the gas turbine. The temperature calculated by the controller can then be advantageously used to drive the gas turbine. Background Technology

[0005] Gas turbines are known, comprising a compressor in which air is compressed and supplied to a first combustor, where fuel is supplied and burned to produce a hot gas stream. The hot gas stream is supplied to a high-pressure turbine, where it partially expands and is then directed to a second combustor, where additional fuel is supplied and burned together with an oxidizer still present in the hot gas stream. The hot gas stream exiting the second combustor then expands in a low-pressure turbine and is then released into the atmosphere.

[0006] These gas turbines may have combustors with annular combustion chambers, such that the hot gas flow is agitated as it passes through the entire annular combustion chamber and through the high-pressure turbine. For this purpose, the hot gas flow has a temperature that can be reliably calculated (e.g., via simulation software); in other words, there are no regions that are significantly colder or hotter than the average temperature of the hot gas flow (higher or lower).

[0007] Gas turbines are driven based on the temperature of the hot gas flow passing through the combustor; for this purpose, the temperature of the hot gas flow is measured by a temperature sensor downstream of the high-pressure turbine, and the temperature measured in this way is used to drive the gas turbine because these temperature measurements (or measurements) can directly provide an accurate representation of the average temperature of the hot gas flow.

[0008] Different gas turbines have a configuration with a first burner and a second burner, with a diluter mixer between them through which air is introduced into the hot gas. These burners may have a canister-like configuration, such that the first burner, the diluter mixer, and the second burner are all housed within a tubular casing.

[0009] In order to drive the gas turbine, the temperature of the hot gas flow also needs to be measured in these embodiments. However, due to the canister-like structure, the interaction of hot gas flows from different canisters is prevented, and the lack of a high-pressure turbine to agitate the hot gas flow means that the temperature distribution on the burner can vary depending on the operating conditions.

[0010] In this situation, temperature measurements can provide results that do not represent the actual average temperature of the hot gas flow; for example, a temperature measurement may provide the correct average temperature of the hot gas flow under one operating condition, but under different operating conditions with different temperature distributions, the measured temperature may no longer represent the average temperature of the hot gas flow. Therefore, it is not feasible to drive a gas turbine based on these temperature measurements.

[0011] Another type of gas turbine may have a combustion chamber but no second combustion chamber fed by the hot gas flow generated in the first combustion chamber. Difficulties in measuring the temperature of the hot gas flow generated in the combustion chamber can arise regardless, for example, because the way fuel is supplied to the combustion chamber typically varies depending on operating conditions. For example, the temperature distribution on the hot gas flow may depend on the supply of pilot fuel (i.e., the fuel-rich fuel used to maintain the flame), or tiered (i.e., the supply of fuel from different injection points driven differently), or grouped (i.e., not all nozzles or burners are driven in the same way, but one group of nozzles or burners is driven according to one procedure to supply fuel, while another group is driven according to a different procedure, or may not receive fuel at all).

[0012] Providing a large number of temperature sensors to obtain a complete picture of the temperature distribution of the hot airflow independently of operating conditions is technically difficult and expensive, and should be avoided. Summary of the Invention

[0013] One aspect of the invention includes providing a method for manufacturing a controller and a combustion system in which the average temperature of the hot gas flow can be reliably detected independently of specific operating conditions.

[0014] Furthermore, the number of temperature sensors used for localized measurement of hot airflow temperature can be limited and kept to a minimum.

[0015] Advantageously, even if a complete picture of the temperature distribution over the hot airflow is not achieved, the desired average temperature can be reliably obtained, and specific areas can be monitored, which can be appropriately selected according to requirements such as controlling hot or cold spots.

[0016] These and other aspects are obtained by providing methods and combustion systems according to the appended claims. Attached Figure Description

[0017] Further features and advantages will become more apparent from the description of preferred, but not exclusive, embodiments of the method and combustion system, which are illustrated in the accompanying drawings by way of non-limiting example, wherein:

[0018] Figure 1 The combustion system test rig used to implement this method is shown.

[0019] Figure 2 A gas turbine having the combustion system of the present invention is shown;

[0020] Figure 3 and Figure 4 The cross-sections of the burner connected to the first combustion chamber and the combustion system test bench are shown respectively. Detailed Implementation

[0021] Referring to the accompanying drawings, these figures illustrate a combustion system test bench 1. The combustion system test bench reproduces (i.e., is equivalent to) a combustion system 15, which is part of or to be assembled onto a gas turbine 16. In the specific references below to combustion systems and combustion system test benches with sequential combustion, it is clear, in any case, that the same concept applies to different types of combustion systems, such as those without sequential combustion and those with premixed or diffusion combustion, for the purpose of combustion chambers in which premixed combustion occurs.

[0022] The combustion system test bench 1 has a first burner 2, a dilution mixer 3, and a second burner 4.

[0023] The first burner 2 is of the premixed type (i.e., it is arranged to produce a premixed flame) and has a combustion chamber 6 with at least two burners 7 for supplying a mixture of fuel and oxidizer therein. In the example shown, the first burner 2 has four burners 7, which are operably divided into a first group 8 of three burners 7 operating under the same conditions and a second group 9 of burners 7; the burners 7 of the first group 8 and the second group 9 may operate under the same conditions or not under the same conditions, but the burners 7 of each group operate under the same conditions.

[0024] The dilution mixer 3 is fluidly (or fluidically) connected downstream of the first burner 2 and arranged to supply dilution air into the hot gas stream.

[0025] The second burner 4 is fluidly connected downstream of the dilution mixer 3 and is arranged to supply additional fuel to the hot gas stream and burn it together with the oxidant still present in the hot gas stream.

[0026] The second burner 4 has a mixing section 10 and a second combustion chamber 11, and it is also of the premixed type (that is, it is arranged for premixed combustion of fuel) and the ignition of the fuel and oxidizer mixture occurs by automatic ignition.

[0027] The first burner 2, the dilution mixer 3, and the second burner 4 have a canister-like structure and are housed in a tubular shell 12.

[0028] During operation, fuel and oxidizer (typically air) are supplied to and mixed in the burner 7. The resulting mixture is then fed into the combustion chamber 6 and burned there, producing a hot gas stream, which is then directed to the dilution mixer 3.

[0029] As the air passes through the dilution mixer 3, the dilution air is supplied to the hot air stream.

[0030] The hot gas flow is then passed through the second burner 4, where additional fuel is injected, for example, via a long lance 25 provided across the mixing section 10; the fuel is mixed with the hot gas flow in the mixing section 10 and then burned in the combustion chamber 11.

[0031] To measure the temperature of the hot gas flow, a temperature sensor 13, such as a thermocouple, is provided. Specifically, at least two temperature sensors 13 are provided for detecting the local temperature of the hot gas flow. These at least two temperature sensors 13 are located in region 14 between the first burner 2 or preferably the dilution mixer 3 and the second combustion chamber 11.

[0032] Advantageously, the axial distance between the temperature sensors is short, and preferably, the temperature sensors are located in the same axial position, wherein the axial position is determined with reference to the longitudinal axis of the combustion system (i.e., the axis parallel to the direction of the hot gas flow). In other words, the temperature sensors are substantially located in a plane perpendicular to the longitudinal axis of the combustion system.

[0033] The relevant temperature that must be measured is the mixer outlet temperature (MET), which is theoretically the temperature reached by the fuel supplied to the test burner through combustion and the oxidizer supplied to the test burner in region 14 downstream of the first burner 2 (in the current case, downstream of the mixer 3) and upstream of the combustion chamber 11. This is the average temperature of the hot gas flow that cannot be directly measured because the temperature distribution on the burner varies with the burner operating parameters.

[0034] Therefore, according to this method, the combustion system test bench 1 operates with different sets of operating parameters, and the local temperature of the hot gas flow is measured using at least two temperature sensors 13 that obtain the local temperature operating parameter set.

[0035] Then, for each set of operating parameters, the theoretical mixer outlet temperature MET (i.e., the heat balance) is calculated based on the supplied oxidant and fuel mass flow rate.

[0036] Therefore, a correlation between the local temperature and the theoretical mixer outlet temperature (MET) is provided, and the controller is programmed to use this correlation so that, based on the local temperature measurement, the controller can calculate the theoretical mixer outlet temperature (MET).

[0037] There are different possibilities for defining the operating parameters, but preferably, the different operating parameters include at least different fuel distributions between the burner groups 8 and 9 of the first burner 2 and / or different fuel distributions between the first burner 2 and the second burner 4 and / or different oxidizer mass flow rate supplies and / or pilot fuel supplies.

[0038] Correlation is advantageously expressed as a polynomial, for example

[0039] MET = a1·T1 + a2·T2 + a3·T3 + …… + an·Tn + b

[0040] in:

[0041] T1, T2, ... Tn: These are the local temperatures measured by temperature sensors.

[0042] a1, a2, a3, ..., an, b: are coefficients that match the measured values ​​with the mixer outlet temperature (MET).

[0043] In a preferred embodiment, the polynomial expression is:

[0044] MET = a1·T1 + a2·T2 + b

[0045] It provides only two temperature sensors; this makes the hardware of the combustion system test bench 1 and the combustion system of the gas turbine simpler and cheaper, and similarly, data collection and processing are easier and cheaper.

[0046] The controller manufactured according to the described method can be used with the sequential combustion system 15 to reliably calculate the mixer outlet temperature MET.

[0047] The combustion system 15 is constructed in a tank shape and includes a first burner 2, a dilution mixer 3, and a second burner 4. The combustion system is equivalent to the combustion system test bench 1, and therefore will not be described in detail below; in the accompanying drawings, the same reference numerals are used for the combustion system test bench.

[0048] Specifically, the combustion system 15 includes a controller 17 manufactured according to the described method and two or more (but preferably two) temperature sensors 13, such as thermocouples, for locally measuring the temperature of the hot gas flow in a region 14 between the dilution mixer 3 and the second combustion chamber 11 (in this case, the dilution mixer is referenced, but typically the reference could be the first combustion chamber 6, for example, if a dilution mixer is not provided). When the method for manufacturing the controller is implemented, the temperature sensors 13 are positioned at the same locations where the temperature sensors on the combustion system test bench 1 are located.

[0049] Controller 17 is connected to temperature sensor 13, such that during operation, temperature sensor 13 detects the local temperature of the hot gas flow and transmits it to controller 17. Controller 17 calculates the mixer outlet temperature MET based on these measured local temperatures and by means of correlations, such as polynomial expressions. The gas turbine control unit drives the gas turbine based on the mixer outlet temperature MET.

[0050] In different embodiments, controller 17 may be a dedicated circuit, a separate computer, or may be implemented via circuitry of the gas turbine control unit.

[0051] An embodiment of the method is described below, according to which not only the correlation is determined, but also the location for the temperature sensor 13 is determined.

[0052] In this embodiment, at least three local temperatures are measured, and then a subset of the local temperatures is selected, and multiple correlations between the local temperature in each of the selected subset and the theoretical mixer outlet temperature (MET) are provided.

[0053] Therefore, a subset of local temperatures is selected; this selection can be based on the accuracy of the correlation, i.e., a correlation that is more representative of the mixer outlet temperature can be selected; this optimal representation can be made within a defined temperature range or over all available data. Furthermore, this selection can be based on the need to provide a temperature sensor at a given location so that the temperature at that location can be measured, for example, to control local temperatures that may cause hot spots during gas turbine operation.

[0054] For example, see the cross-section of the combustion system test bench shown. Figure 4 Six local temperatures are measured, and then a subset of temperatures from two temperature sensors is obtained. The temperature sensor couple that provides the most accurate mixer outlet temperature for different operating conditions is selected, such as temperature sensors A and C.

[0055] Therefore, the controller is programmed using correlations based on a selected subset of local temperatures from the selected temperature sensor.

[0056] It is clear that, Figure 4This is just one possible example of a cross-section for a combustion system test bench; other cross-sections are also possible, such as circular, square, or others.

[0057] The number of temperature sensors 13 provided on the combustion system test grid 1 can vary depending on the size and shape of the burner. For example, in the case of a burner system test bench 1 with three, four, or even six (for larger burners) temperature sensors, a subset of two temperatures can be selected.

[0058] Once a subset of local temperatures has been selected, the temperature sensors 13 that detect these local temperatures and their locations on the combustion system test bench 1 are defined. The burner system 15 then preferably provides temperature sensors 13 only at the locations on the combustion system test bench 1 where the local temperatures of the selected subset are measured, because the correlation is based solely on the local temperature measurements performed there and the mixer outlet temperature can be reliably calculated based on the local temperatures measured there. Therefore, see... Figure 4 The combustion system is only equipped with temperature sensors A and B.

[0059] When the combustion system 15 is assembled in the gas turbine 16 and is in operation, it is fed with fuel and compressed air from the compressor 20. The combustion of the fuel in the compressed air produces a hot gas flow, which is then fed to the turbine 21.

[0060] Temperature sensor 13 measures the local temperature of the hot gas flow and sends this information to controller 17, which calculates the mixer outlet temperature (MET) of the hot gas flow. The mixer outlet temperature (MET) of the hot gas flow is then sent to the control unit of the gas turbine for driving the gas turbine.

[0061] Naturally, the described features can be provided independently of each other.

[0062] In practice, the materials and dimensions used can be freely selected according to requirements and technical level.

Claims

1. A method for manufacturing a controller (17) for calculating the mixer outlet temperature (MET) of a hot gas stream generated in a combustion system (15), the method comprising: Provide a combustion system test machine (1); At least two temperature sensors (13) are provided for local detection of the temperature of the hot gas flow generated in the combustion system test bench (1); The method includes: The combustion system test bench (1) is operated using different sets of operating parameters; The local temperature of the hot airflow is measured using the at least two temperature sensors (13) to obtain a set of local temperature operating parameters; For each set of operating parameters, the theoretical mixer outlet temperature (MET) is calculated based on the supplied oxidant and fuel mass flow rates. The theoretical mixer outlet temperature is the temperature theoretically achieved by burning the fuel supplied to the test burner and the oxidant supplied to the test burner. Provide the correlation between the local temperature and the theoretical mixer outlet temperature (MET); The controller (17) is programmed using the correlation so that it can calculate the mixer outlet temperature (MET) based on local temperature measurements.

2. The method according to claim 1, characterized in that, The combustion system test bench (1) has: A first burner (2) having at least two burners (7) connected to a first combustion chamber (6) arranged to supply a mixture of fuel and oxidant in the first combustion chamber (6), the first combustion chamber (6) being arranged to burn the mixture to generate the hot gas flow. A dilution mixer (3) is fluidly connected downstream of the first burner (2) and is used to supply dilution air in the hot gas stream; A second burner (4) is fluidly connected downstream of the dilution mixer (3), the second burner (4) having a mixing zone (10) and a second combustion chamber (11) and being arranged to supply fuel to the hot gas stream and to burn the fuel together with an oxidant present in the hot gas stream; The different operating parameters include at least different fuel distributions between the burners (7) of the first burner (2) and / or different fuel distributions between the first burner (2) and the second burner (4) and / or different oxidizer mass flow rates and / or pilot fuel supplies.

3. The method according to claim 1, characterized in that, The correlation is a polynomial expression.

4. The method according to claim 3, characterized in that, The polynomial expression is MET = a1·T1 + a2·T2 + a3·T3 + ... + an·Tn + b in: T1, T2, ... Tn: local temperatures measured by the temperature sensor (13); a1, a2, a3, ..., an, b: are coefficients that match the measured values ​​with the mixer outlet temperature (MET).

5. The method according to claim 4, characterized in that, The polynomial expression is MET = a1·T1 + a2·T2 + b.

6. The method according to claim 4, characterized in that, Measure at least three local temperatures, then Select a subset of local temperatures, thereby Select a subset of local temperatures that provide the most accurate correlation for mixer outlet temperature (MET), then The controller (17) is programmed using correlations based on a selected subset of local temperatures.

7. The method according to claim 6, characterized in that, The coefficients of the polynomial expression are calculated based only on a selected subset of local temperatures.

8. The method according to claim 1, characterized in that, The combustion system test bench (1) has: A first burner (2) having at least two burners (7) connected to a first combustion chamber (6) arranged to supply a mixture of fuel and oxidant in the first combustion chamber (6), the first combustion chamber (6) being arranged to burn the mixture to generate the hot gas flow. A dilution mixer (3) is fluidly connected downstream of the first burner (2) and is used to supply dilution air in the hot gas stream; The second burner (4) is fluidly connected downstream of the dilution mixer (3). The second burner (4) has a mixing zone (10) and a second combustion chamber (11) and is arranged to supply fuel to the hot gas stream and to burn the fuel together with an oxidant present in the hot gas stream. The at least two temperature sensors (13) are located in the region (14) between the dilution mixer (3) and the second combustion chamber (11).

9. The method according to claim 8, characterized in that, The first burner (2), the dilution mixer (3) and the second burner (4) have a canister-like structure.

10. The method according to any one of claims 1 to 9, characterized in that, The temperature sensors are located substantially at the same axial position, wherein the axial position is determined with reference to the longitudinal axis of the combustion system, that is, the axis parallel to the flow direction of the hot gas flow.

11. A combustion system (15), comprising: The first burner (2) is used to generate hot airflow; A controller (17) manufactured according to the method defined in any one of claims 1-10; Wherein, the combustion system is equivalent to the combustion system test bench (1); At least two temperature sensors (17) for the hot airflow; The at least two temperature sensors are positioned at the following locations on the combustion system, where the temperature sensors are positioned on the combustion system test bench (1); The controller (17) is connected to the at least two temperature sensors (13).

12. The combustion system according to claim 11, characterized in that, The combustion system includes: A first burner (2) having at least two burners (7) connected to a first combustion chamber (6) arranged to supply a mixture of fuel and oxidant in the first combustion chamber (6), the first combustion chamber (6) being arranged to burn the mixture to generate the hot gas flow. A dilution mixer (3) is fluidly connected downstream of the first burner (2) and is used to supply dilution air in the hot gas stream; A second burner (4) is fluidly connected downstream of the dilution mixer (3). The second burner (4) has a mixing zone (10) and a second combustion chamber (11) and is arranged to supply fuel to the hot gas stream and to burn the fuel together with an oxidant present in the hot gas stream.

13. The combustion system according to claim 12, characterized in that, The first burner (2), the dilution mixer (3) and the second burner (4) have a canister-like structure.

14. The combustion system according to any one of claims 11 to 13, characterized in that, The temperature sensors are located substantially at the same axial position, wherein the axial position is determined with reference to the longitudinal axis of the combustion system, that is, the axis parallel to the flow direction of the hot gas.

Images