Patent Description:
During operation of a turbine system of an engine (e.g., a gas turbine engine), one or more burners of a combustor of the turbine system may fail. For example, flames of the one or more burners may unexpectedly extinguish. In some cases, a burner fault detection may be temperature-based and may be accomplished by using temperature sensors (e.g., thermocouples).

Current temperature-based burner fault detection method and systems may not be immune to a single sensor failure and therefore cause inadvertent alarms. This may also lead to unnecessary shutdowns. Further, temperature sensors, such as thermocouples, may not be the most reliable of sensors and automated hazard protection (e.g., reduction of thrust) based on temperature readings alone should be avoided. The temperature readings of the temperature sensors may further vary with swirl of the hot gases in turbines of the turbine system. The swirl may vary with the speed and acceleration of the engine.

In some cases, such methods and systems may further detect positions of burner failure. However, detecting positions of the burner failure may not be required for hazard protection. Such methods and systems may be complex and therefore may take more time to execute. This may be undesirable in a hazardous situation and may delay the hazard protection. Further, information related to the positions of the burner failure may be required for maintenance benefit only and would need a swirl calculation.

United States patent <CIT> discloses a method of monitoring for combustion anomalies in a gas turbomachine. The method includes sensing an exhaust gas temperature at each of a plurality of temperature sensors arranged in an exhaust system of the gas turbomachine, comparing the exhaust gas temperature at each of the plurality of temperature sensors with a mean exhaust gas temperature, determining whether the exhaust gas temperature at one or more of the plurality of temperature sensors deviates from the mean exhaust temperature by a predetermined threshold value, and identifying an instantaneous combustion anomaly at one or more of the temperature sensors sensing a temperature deviating from the mean exhaust temperature by more than the predetermined threshold value.

European patent <CIT> discloses a gas turbine engine that has an annular first combustor assembly and a second combustor assembly. At least three flame detectors are arranged to monitor flame presence in the first combustor assembly and supply respective flame monitoring signals indicating flame presence. A temperature monitoring assembly detects a control temperature of hot gas flowing from the first combustor assembly to the second combustor assembly downstream of the first combustor assembly. A processing unit determines dangerous flame failure based, at least in a control range of operating conditions, on the flame monitoring signals and a control function of the control temperature and based on M-out-of-N activation redundancy with Hardware Failure Tolerance of at least <NUM>, wherein M is at least <NUM> and N is at least <NUM>.

United States patent <CIT> discloses a method of detecting a temperature sensor failure in a turbine system. The method includes obtaining individual measurement values from each temperature sensor in a group of temperature sensors, calculating a characteristic value for each temperature sensor in the group based on the measurement values for the corresponding temperature sensor, selecting a first characteristic value among the calculated characteristic values, determining a first maximum value as the maximum of the characteristic values except for the first characteristic value, and determining that the temperature sensor corresponding to the first characteristic value is defective if the first characteristic value is larger than the first maximum value multiplied by a predetermined factor.

There remains a need for a simple method of burner fault detection that is robust to multiple sensor failures and the effects of swirl of hot gases around the turbines, which may cause variability in temperature readings.

According to a first aspect of the invention there is provided method for detecting a burner failure in a gas turbine engine as set out in claim <NUM>.

The method of the present disclosure may eliminate invalid signals. The method is not solely based upon comparison of the plurality of individual temperature signals with a mean. Further, the method may be simple and may not require determining a temperature spread and/or step(s) for detecting position(s) of the burner failure. The detection of the position(s) of the burner failure may not be necessary for hazard protection. Thus, the method of the present disclosure may be robust, simple to implement, and quicker to execute.

Further, the method of the present disclosure may prevent tripping any alarm or shutdown criterion on the basis of a single temperature signal. The method may help to determine an anomaly, for example, whether a condition would become potentially-hazardous within a current flight, further performing at least one hazard protection action at least when the condition would become potentially-hazardous.

In some embodiments, steps B), C), D), and E) are cyclically repeated in time. In some embodiments, the method proceeds to at least one of steps E) and F) when the temperature focus is outside the tolerance range for a predefined number of consecutive cycles.

Therefore, if the temperature focus is outside the tolerance range for the predefined number of consecutive cycles, the method may detect an anomaly and may either improve the temperature focus or perform the at least one hazard protection action.

In some embodiments, the tolerance range for a predefined number of consecutive cycles is a standard fault integrator with a threshold from <NUM> to <NUM>, an up-count from <NUM> to <NUM> per cycle of exceedance, and/or a down-count from <NUM> to <NUM> per cycle of compliance with the temperature focus threshold. For example, a set of values may be <NUM>, <NUM>, and <NUM> respectively.

In some embodiments, step C) includes the sub-steps of: C1) eliminating one or more temperature signals from the plurality of temperature signals to determine the plurality of validated temperature signals, such that the plurality of validated temperature signals are within respective temperature ranges of the respective temperature sensors; C2) determining a location of each of the plurality of respective sensors generating the plurality of validated temperature signals; and C3) selecting one validated temperature signal from each location from which two or more of the plurality of validated temperature signals are received, wherein the selection is based on at least one of a channel based selection, a temperature value based selection, a mean based selection, and a model based selection.

Therefore, the method may screen out outliers among the temperature values which may be due to a fault or a defect in the respective temperature sensors. This may help to reduce occurrence of an inadvertent trip which, in turn, may trigger an alarm, or any other hazard protection action due to the fault or the defect in the temperature sensors.

In some embodiments, the method proceeds to at least one of steps E) and F) when a number of the plurality of validated temperature signals is less than a predetermined number.

In some embodiments, the total number of temperature sensors around the turbine is from <NUM> to <NUM>, for example from <NUM> to <NUM>. In some embodiments for a small engine, the total number of temperature sensors around the turbine may be from <NUM> to <NUM>. In some embodiments for a large engine, the total number of temperature sensors around the turbine may be from <NUM> to <NUM>. In some embodiments, at least half the total number of temperature sensors provide a validated temperature signal (optionally with redundancy at each location) else reporting as "Faulty".

In some embodiments, the method proceeds to at least one of steps E) and F) when the plurality of validated temperature signals is absent in a predetermined angular range. For example, from <NUM> to <NUM> degrees.

The useful range may depend on the number of temperature sensors. In some embodiments, two adjacently placed temperature sensors failing to provide a validated temperature signal is sufficient to provide a report of "Faulty".

In some embodiments, step D) includes the sub-steps of: D1) determining a whole mean of the plurality of validated temperature signals; D2) determining a subset of the plurality of validated temperature signals by eliminating one or more of the plurality of validated temperature signals having corresponding temperature values less than a low threshold from the whole mean; D3) determining a focused mean of the subset; and D4) determining the temperature focus as a difference between the focused mean and the whole mean.

In some embodiments, the low threshold is from <NUM> to <NUM> below, for example from <NUM> to <NUM> below the whole mean. In some embodiments, the low threshold is approximately <NUM> below the whole mean.

Therefore, the method may screen out low outliers among the temperature values. Further, if a burner is blocked then the corresponding temperature value will be a low outlier and will be eliminated. Thus, the focused mean will be higher than the whole mean. The method may therefore be designed to work with a variable number of validated temperature signals, with one or more being eliminated and restored as the validated temperature signals may vary. The method may also work with some temperature sensors having failed on a permanent basis.

In some embodiments, step D2) further includes the sub-step of: D2a) eliminating one or more of the plurality of validated temperature signals having corresponding temperature values greater than a high threshold from the whole mean from the subset.

Therefore, the method may further screen out high outliers among the temperature values. This may help to reduce occurrence of an inadvertent trip which, in turn, may trigger an alarm, or any other hazard protection action. Further, the method recognizes that high temperatures owing to multiple blocked burners may cause turbine degradation, leading to high energy debris release and may be considered as potentially-hazardous.

In some embodiments, the high threshold is from <NUM> to <NUM>, for example from <NUM> to <NUM> above the whole mean. In some embodiments, the high threshold is approximately <NUM> above the whole mean.

In some embodiments, step D) includes the sub-steps of: D1) determining a whole mean of the plurality of validated temperature signals; D2) comparing each of the plurality of validated temperature signals to a standard distribution; D3) determining a subset of the plurality of validated temperature signals by eliminating one or more of the plurality of validated temperature signals having corresponding temperature values below a standard deviation threshold from the whole mean; D4) eliminating one or more of the plurality of validated temperature signals having corresponding temperature values above the standard deviation threshold from the whole mean from the subset; D5) determining a focused mean of the subset; and D6) determining the temperature focus as a difference between the focused mean and the whole mean.

The standard deviation threshold typically depends on the distribution and on real data from tests to show the grouping of signal values. In some embodiments, the standard deviation threshold is from <NUM> to <NUM>, for example approximately <NUM> with a Normal distribution.

In some embodiments, the standard distribution is selected from at least one of Exponential distribution, Normal distribution, Lognormal distribution, Poisson distribution, and Weibull distribution.

Therefore, the method may also screen out the low and high outliers according to a shape of the standard distribution. The shape of the standard distribution may be determined and chosen based on historical data/tests.

In some embodiments, the method proceeds at least one of steps E) and F) when a number of the plurality of validated temperature signals remaining in the subset after eliminating the one or more of the plurality of validated temperature signals having the corresponding temperature values less than the low threshold is less than a predetermined number.

In some embodiments, the predetermined number is from four to eight, of which two, three, four or five should be above the low threshold to remain valid, for example the predetermined number is six, of which four should be above the low threshold to remain valid.

Such a predetermined number typically depends on how many temperature signals are valid. In some embodiments, for example, when only six temperature signals are valid the predetermined number is two, leaving four to compose the focused mean. Large engines may lose up to eight of twelve temperature signals and still have four temperature signals to compose the focused mean, whereas small engines with seven temperature signals may only lose one temperature signal before reporting as "Faulty".

In some embodiments, the method proceeds to at least one of steps E) and F) when a number of the plurality of validated temperature signals remaining in the subset after eliminating the one or more of the plurality of validated temperature signals having the corresponding temperature values greater than the high threshold is less than a predetermined number.

In some embodiments, the method proceeds to at least one of steps E) and F) when a number of the plurality of validated temperature signals remaining in the subset is less than a predetermined number.

Therefore, when the number of the plurality of validated temperature signals is insufficient or the number of the plurality of validated temperature signals that are not outliers is insufficient, the method proceeds to at least one of steps E) and F). In some cases, there may be a potential for an engine control system to prevent the dispatch of an aircraft or prohibit restarting the gas turbine engine in a land-based or marine application. In some cases, upon detecting the anomaly, further operation may be determined by evaluating risk to the gas turbine engine from the detected anomaly. Further, this may also allow dispatchability with a number of faults sufficient to provide planned maintenance, such as when the aircraft visits a main base or when a power plant or oil & gas platform is shut down for long-term maintenance.

A moderate temperature focus (i.e., a difference between the focused mean and the whole mean) may indicate that cleaning the gas turbine engine may suffice to ensure that any blocked burners are unblocked, and this may alleviate the difference between the focused mean and the whole mean. In other words, the temperature focus may be improved such that the temperature focus is within the tolerance range.

In some embodiments, step E) includes transmitting a command to a fuel staging control system to increase a fuel flow to at least one burner from the plurality of burners.

A high temperature focus may indicate that the gas turbine engine may have a limited life if it were to continue running at the same conditions. A higher temperature focus may indicate that the predicted engine life may be no more than the current mission, in which case the gas turbine engine should not be run again. However, in order to continue the current mission, there may be further accommodation, such as applying a thrust limit to the gas turbine engine. This would apply differently to the aircraft than to other applications because the total thrust provision must remain sufficient. Therefore, the thrust limit (e.g., by modifying the fuel flow) may accommodate anomalies of moderate severity.

In some embodiments, step F) includes transmitting a warning to a cockpit of an aircraft powered by the gas turbine engine.

In some embodiments, step F) further includes transmitting a command to reduce the fuel flow to a lower point within the operating range.

In some embodiments, step F) further includes transmitting a command to shut down the gas turbine engine.

Therefore, when the temperature focus is greater than the predetermined threshold, it may indicate that the predicted engine life may be less than the length of the current mission, in which case the function may warn the pilot, driver, or operator to reduce engine power straight away or to shut down the gas turbine engine straight away.

In some embodiments the predetermined threshold is from <NUM> to <NUM>, for example from <NUM> to <NUM>, more particularly a value of approximately <NUM>.

In some embodiments, the gas turbine engine further includes a final stage turbine disposed downstream of the turbine. In some embodiments, step A) includes providing the plurality of temperature sensors upstream of the final stage turbine.

As noted elsewhere herein, the present disclosure relates to a gas turbine engine, which is not subject-matter of the claims. Such a gas turbine engine may include an engine core comprising a turbine, a combustor, a compressor, and a core shaft connecting the turbine to the compressor.

The gearbox may be a reduction gearbox (in that the output to the fan is a lower rotational rate than the input from the core shaft). Any type of gearbox may be used.

The gas turbine engine as described herein may have any suitable general architecture. The engine core may further include a second turbine, a second compressor, and a second core shaft connecting the second turbine to the second compressor.

In any gas turbine engine as described herein, a combustor may be provided axially downstream of the fan and compressor(s).

Gas turbine engines in accordance with the present disclosure may have any desired bypass ratio, where the bypass ratio is defined as the ratio of the mass flow rate of the flow through the bypass duct to the mass flow rate of the flow through the core at cruise conditions. The bypass duct may be substantially annular. The bypass duct may be radially outside the engine core. The radially outer surface of the bypass duct may be defined by a nacelle and/or a fan case.

Specific thrust of an engine may be defined as the net thrust of the gas turbine engine divided by the total mass flow through the gas turbine engine. At cruise conditions, the specific thrust of an engine described herein may be less than (or on the order of) any of the following: <NUM> Nkg-<NUM>s, <NUM> Nkg-<NUM>s, <NUM> Nkg-<NUM>s, <NUM> Nkg-<NUM>s, <NUM> Nkg-<NUM>s, <NUM> Nkg-<NUM>s or <NUM> Nkg-<NUM>s. The specific thrust may be in an inclusive range bounded by any two of the values in the previous sentence (i.e., the values may form upper or lower bounds), for example in the range of from <NUM> Nkg-<NUM>s to <NUM> Nkg-<NUM>s, or <NUM> Nkg-<NUM>s to <NUM> Nkg-<NUM>s. Such engines may be particularly efficient in comparison with conventional gas turbine engines.

A fan blade and/or aerofoil portion of a fan blade described herein may be manufactured from any suitable material or combination of materials. For example, at least a part of the fan blade and/or aerofoil may be manufactured at least in part from a composite, for example a metal matrix composite and/or an organic matrix composite, such as carbon fibre.

The fan of a gas turbine as described herein may have any desired number of fan blades, for example <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> fan blades.

The gas turbine engine <NUM> includes an air intake <NUM> and a propulsive fan <NUM> that generates two airflows: a core airflow A and a bypass airflow B. The gas turbine engine <NUM> includes an engine core <NUM> that receives the core airflow A. The engine core <NUM> includes, in axial flow series, a low-pressure compressor <NUM>, a high-pressure compressor <NUM>, a combustor <NUM>, a high-pressure turbine <NUM>, a low-pressure turbine <NUM>, and a core exhaust nozzle <NUM>. The fan <NUM> is attached to and driven by the low-pressure turbine <NUM> via a shaft <NUM> and an epicyclic gearbox <NUM>.

In use, the core airflow A is accelerated and compressed by the low-pressure compressor <NUM> and directed into the high-pressure compressor <NUM> where further compression takes place. The compressed air exhausted from the high-pressure compressor <NUM> is directed into the combustor <NUM> where it is mixed with fuel and the mixture is combusted. The resultant hot combustion products then expand through, and thereby drive, the high-pressure and low-pressure turbines <NUM>, <NUM> before being exhausted through the core exhaust nozzle <NUM> to provide some propulsive thrust.

Note that the terms "low-pressure turbine" and "low-pressure compressor" as used herein may be taken to mean the lowest pressure turbine stages and lowest pressure compressor stages (i.e., not including the fan <NUM>) respectively and/or the turbine and compressor stages that are connected together by the interconnecting shaft <NUM> with the lowest rotational speed in the gas turbine engine (i.e., not including the gearbox output shaft that drives the fan <NUM>). In some literature, the "low-pressure turbine" and "low-pressure compressor" referred to herein may alternatively be known as the "intermediate-pressure turbine" and "intermediate-pressure compressor".

Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. For example, such engines may have an alternative number of compressors and/or turbines and/or an alternative number of interconnecting shafts. By way of further example, the gas turbine engine <NUM> shown in <FIG> has a split flow nozzle <NUM>, <NUM> meaning that the flow through the bypass duct <NUM> has its own nozzle <NUM> that is separate to and radially outside the core exhaust nozzle <NUM>. However, this is not limiting, and any aspect of the present disclosure may also apply to engines in which the flow through the bypass duct <NUM> and the flow through the core <NUM> are mixed, or combined, before (or upstream of) a single nozzle, which may be referred to as a mixed flow nozzle. One or both nozzles (whether mixed or split flow) may have a fixed or variable area. Whilst the described example relates to a turbofan engine, the disclosure may apply, for example, to any type of gas turbine engine, such as an open rotor (in which the fan stage is not surrounded by a nacelle) or turboprop engine, for example. In some arrangements, the gas turbine engine <NUM> may not include a gearbox <NUM>.

The geometry of the gas turbine engine <NUM>, and components thereof, is defined by a conventional axis system, including an axial direction (which is aligned with the rotational axis <NUM>), a radial direction (in the bottom-to-top direction in <FIG>), and a circumferential direction (perpendicular to the page in the <FIG> view). The axial, radial, and circumferential directions are mutually perpendicular.

<FIG> illustrates a detailed schematic exploded side view of a portion of the gas turbine engine <NUM> in accordance with an embodiment of the present disclosure.

As discussed above, the gas turbine engine <NUM> incudes the combustor <NUM>. The combustor <NUM> includes a plurality of burners <NUM>. Specifically, the combustor <NUM> has the plurality of burners <NUM> arranged annularly. As illustrated in <FIG>, the gas turbine engine <NUM> further incudes a turbine <NUM> disposed downstream of the combustor <NUM>.

In some cases, the turbine <NUM> may be the high-pressure turbine <NUM> (shown in <FIG>). In some cases, the turbine <NUM> may be the low-pressure turbine <NUM> (shown in <FIG>).

The gas turbine engine <NUM> further includes a plurality of temperature sensors <NUM>. Specifically, the gas turbine engine <NUM> further includes the plurality of temperature sensors <NUM> arranged annularly at an outlet <NUM> of the turbine <NUM>.

In some embodiments, the gas turbine engine <NUM> further includes a final stage turbine <NUM> disposed downstream of the turbine <NUM>. In some embodiments, the plurality of temperature sensors <NUM> is disposed upstream of the final stage turbine <NUM>. The temperature sensors <NUM> are therefore disposed between the turbine <NUM> and the final stage turbine <NUM>. In some cases, the turbine <NUM> may be the high-pressure turbine <NUM> (shown in <FIG>) and the final stage turbine <NUM> may be the low-pressure turbine <NUM> (shown in <FIG>).

The plurality of temperature sensors <NUM> is configured to generate a plurality of temperature signals <NUM>. In some embodiments, each of the plurality of temperature sensors <NUM> is configured to generate one or more temperature signals <NUM>. In the illustrated example of <FIG>, each of the plurality of temperature sensors <NUM> generates one temperature signal <NUM>. In some other examples, each of the plurality of temperature sensors <NUM> is configured to generate two temperature signals <NUM>. The number of temperature signals <NUM> generated by a temperature sensor <NUM> may be based on the type of the temperature sensor <NUM>.

The gas turbine engine <NUM> further incudes a controller <NUM>. The controller <NUM> may be configured for detecting a burner failure in the gas turbine engine <NUM> (shown in <FIG>). The controller <NUM> may include one or more processors and one or more memories. It should be noted that the one or more processors may embody a single microprocessor or multiple microprocessors for receiving various input signals. Numerous commercially available microprocessors may be configured to perform the functions of the one or more processors. Each processor may further include a general processor, a central processing unit, an application specific integrated circuit (ASIC), a digital signal processor, a field programmable gate array (FPGA), a digital circuit, an analog circuit, a controller, a microcontroller, any other type of processor, or any combination thereof. Each processor may include one or more components that may be operable to execute computer executable instructions or computer code that may be stored and retrieved from the one or more memories.

In some embodiments, the controller <NUM> is communicably coupled to each of the plurality of temperature sensors <NUM>. The controller <NUM> obtains the plurality of temperature signals <NUM> from the plurality of temperature sensors <NUM>.

In some embodiments, the gas turbine engine <NUM> further includes a fuel staging control system <NUM>. The fuel staging control system <NUM> may control a fuel flow to the at least one burner <NUM> from the plurality of burners <NUM>. Specifically, the fuel staging control system <NUM> may control the fuel flow to the at least one burner <NUM> from the plurality of burners <NUM> via a fuel staging valve (not shown). In some embodiments, the controller <NUM> may be configured to determine a staging state of the gas turbine engine <NUM> based on a state of the fuel staging valve. In some embodiments, a fuel flow sensing valve may be used to determine the staging state of the engine <NUM>. The staging state of the gas turbine engine <NUM> may be determined so that the burner failure is not confused with a normal operation condition of the turbine system during which one or more burners <NUM> may be purposely inactive.

<FIG> illustrates a schematic front view of the combustor <NUM> of the gas turbine engine <NUM> shown in <FIG> in accordance with an embodiment of the present disclosure.

As illustrated in <FIG>, the plurality of temperature sensors <NUM> is arranged annularly at respective locations <NUM>. In the illustrated embodiment of <FIG>, the plurality of temperature sensors <NUM> includes <NUM> temperature sensors. In some embodiments, the plurality of temperature sensors <NUM> may include <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> temperature sensors. The plurality of temperature sensors <NUM> may include any number of temperature sensors <NUM>, as per desired application attributes.

Further, in the illustrated embodiment of <FIG>, the plurality of temperature sensors <NUM> arranged annularly at respective locations <NUM> is substantially equally angularly spaced apart from each other. However, in some other embodiments, the plurality of temperature sensors <NUM> arranged annularly at respective locations <NUM> may not be equally angularly spaced apart from each other.

<FIG> illustrates a graph depicting the plurality of temperature signals <NUM> in accordance with an embodiment of the present disclosure. Specifically, the graph depicts a plot of temperature signals versus time.

Referring to <FIG>, the plurality of temperature sensors <NUM> has respective temperature ranges <NUM>. In some embodiments, the plurality of temperature sensors <NUM> may have similar respective temperature ranges <NUM>. However, in some other embodiments, the plurality of temperature sensors <NUM> may have different respective temperature ranges <NUM>. The temperature ranges <NUM> of the temperature sensors <NUM> may be based on the type of the temperature sensors <NUM>.

The controller <NUM> may be configured to determine a plurality of validated temperature signals <NUM> from the plurality of temperature signals <NUM>. The plurality of validated temperature signals <NUM> is within the respective temperature ranges <NUM> of the respective temperature sensors <NUM>.

In some embodiments, the controller <NUM> may eliminate one or more temperature signals <NUM> from the plurality of temperature signals <NUM> to determine the plurality of validated temperature signals <NUM>, such that the plurality of validated temperature signals <NUM> is within respective temperature ranges <NUM> of the respective temperature sensors <NUM>.

Therefore, the controller <NUM> may screen out outliers among the temperature values which may be due to a fault or a defect in the respective temperature sensors <NUM>. This may help to reduce occurrence of an inadvertent trip which, in turn, may trigger an alarm, or any other hazard protection action due to the fault or the defect in the temperature sensors <NUM>.

In some embodiments, the controller <NUM> may further determine the location <NUM> (shown in <FIG>) of each of the plurality of respective sensors <NUM> generating the plurality of validated temperature signals <NUM>.

In some embodiments, the controller <NUM> may further select one validated temperature signal <NUM> from each location <NUM> from which two or more of the plurality of validated temperature signals <NUM> are received. In some embodiments, the selection is based on at least one of a channel based selection, a temperature value based selection, a mean based selection, and a model based selection.

In some embodiments, the controller <NUM> may be a dual channel controller. In some cases, each of the plurality of temperature sensors <NUM> may be connected to both channels of the controller <NUM>. In some cases, one channel from the dual channels may have a higher priority. The one validated temperature signal <NUM> from that channel may then be selected by the controller <NUM>. In some embodiments, the controller <NUM> may be configured to select the one validated temperature signal <NUM> having a higher temperature value. In some other embodiments, the controller <NUM> may be configured to select the one validated temperature signal <NUM> having a lower temperature value. In some embodiments, the controller <NUM> may be configured to select a mean of the two or more of the plurality of validated temperature signals <NUM> that are received. In some embodiments, the controller <NUM> may be configured to select the one validated temperature signal <NUM> closer to a model value or a model distribution. In some embodiments, the model may be a standard distribution.

<FIG> illustrates a graph depicting a temperature focus <NUM> in accordance with an embodiment of the present disclosure. Specifically, the graph depicts a plot of temperature focus versus time.

Referring to <FIG>, the controller <NUM> may be configured to determine the temperature focus <NUM> at least based on the plurality of validated temperature signals <NUM>.

Further, the controller <NUM> may be configured to improve the temperature focus <NUM> such that the temperature focus <NUM> is within a tolerance range <NUM>. This can involve, for example, eliminating outliers and/or smoothing the validated temperature signals. A moderate temperature focus <NUM> may indicate that cleaning the gas turbine engine may suffice to ensure that any blocked burners <NUM> are unblocked, and this may alleviate the difference between the focused mean and the whole mean. In other words, the temperature focus <NUM> may be improved such that the temperature focus <NUM> is within the tolerance range <NUM>.

In some embodiments, the controller <NUM> may be configured to transmit a command <NUM>. In some embodiments, the controller <NUM> may be configured to transmit the command <NUM> to the fuel staging control system <NUM> to increase the fuel flow to at least one burner <NUM> from the plurality of burners <NUM> to improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM>.

A high temperature focus <NUM> may indicate that the gas turbine engine <NUM> may have a limited life if it were to continue running at the same conditions. A higher temperature focus <NUM> may indicate that the predicted engine life may be no more than the current mission, in which case the gas turbine engine <NUM> should not be run again. However, in order to continue the current mission, there may be further accommodation, such as applying a thrust limit to the gas turbine engine <NUM>. This would apply differently to the aircraft than to other applications because the total thrust provision must remain sufficient. Therefore, the thrust limit (e.g., by modifying the fuel flow) may accommodate anomalies of moderate severity.

Furthermore, the controller <NUM> may be configured to perform at least one hazard protection action <NUM> at least when the temperature focus <NUM> crosses a predetermined threshold <NUM>. In some embodiments, the at least one hazard protection action <NUM> may include transmitting a warning <NUM> to a cockpit of an aircraft powered by the gas turbine engine <NUM>. In some embodiments, the at least one hazard protection action <NUM> may include transmitting the command <NUM> to reduce the fuel flow to a lower point within the operating range. In some embodiments, the at least one hazard protection action <NUM> may include transmitting the command <NUM> to shut down the gas turbine engine <NUM>.

Therefore, when the temperature focus <NUM> is greater than the predetermined threshold <NUM>, it may indicate that the predicted engine life may be less than the length of the current mission, in which case the function may warn the pilot, driver, or operator to reduce engine power straight away or to shut down the gas turbine engine <NUM> straight away.

In some embodiments, when a number of the plurality of validated temperature signals <NUM> is less than a predetermined number, the controller <NUM> may improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM>. In some embodiments, when the number of the plurality of validated temperature signals <NUM> is less than the predetermined number, the controller <NUM> may perform the at least one hazard protection action <NUM>. In some embodiments, the predetermined number may be <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be a minimum number of validated temperature signals <NUM> required by the controller <NUM> to detect the burner failure in the gas turbine engine <NUM>. In some embodiments, the predetermined number may be any number based on desired application attributes.

In some embodiments, when the plurality of validated temperature signals <NUM> is absent in a predetermined angular range <NUM> (shown in <FIG>), the controller <NUM> may improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM>. In some embodiments, when the plurality of validated temperature signals <NUM> is absent in the predetermined angular range <NUM>, the controller <NUM> may perform the at least one hazard protection action <NUM>.

In some embodiments, the predetermined angular range <NUM> may be about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, about <NUM> degrees, or about <NUM> degrees. In some embodiments, the predetermined angular range <NUM> may be based on the arrangement of the plurality of temperature sensors <NUM>. In some embodiments, the predetermined angular range <NUM> may be based on the total number of the plurality of temperature sensors <NUM>. In some embodiments, the predetermined angular range <NUM> may be any angular range based on desired application attributes.

In some embodiments, the controller <NUM> may determine a whole mean of the plurality of validated temperature signals <NUM>. Specifically, the whole mean is an arithmetic mean of the plurality of validated temperature signals <NUM>.

In some embodiments, the controller <NUM> may determine a subset of the plurality of validated temperature signals <NUM>.

In some embodiments, the controller <NUM> may determine the subset of the plurality of validated temperature signals <NUM> by eliminating one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values less than a low threshold from the whole mean. In some embodiments, the low threshold may be from about <NUM> Kelvin (K) to about <NUM> from the whole mean. In some embodiments, the low threshold may from about <NUM> to about <NUM> from the whole mean. In some embodiments, the low threshold may be any threshold temperature based on desired application attributes.

Therefore, the controller <NUM> may screen out low outliers among the temperature values. Further, if a burner <NUM> is blocked then the corresponding temperature value will be a low outlier and will be eliminated. Thus, the focused mean will be higher than the whole mean. The controller <NUM> may therefore work with a variable number of validated temperature signals <NUM>, with one or more being eliminated and restored as the validated temperature signals <NUM> may vary. The controller <NUM> may also work with some temperature sensors <NUM> having failed on a permanent basis.

In some embodiments, when a number of the plurality of validated temperature signals <NUM> remaining in the subset after eliminating the one or more of the plurality of validated temperature signals <NUM> having the corresponding temperature values less than the low threshold is less than a predetermined number, the controller <NUM> may improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM> or perform the at least one hazard protection action <NUM>. In some embodiments, the predetermined number may be <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be a minimum number of validated temperature signals <NUM> required by the controller <NUM> to detect the burner failure in the gas turbine engine <NUM>. In some embodiments, the predetermined number may be any number based on desired application attributes.

In some embodiments, the controller <NUM> may further eliminate one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values greater than a high threshold from the whole mean from the subset. In some embodiments, the high threshold may be from about <NUM> to about <NUM> from the whole mean. In some embodiments, the high threshold may from about <NUM> to about <NUM> from the whole mean. In some embodiments, the high threshold may be any threshold temperature from the whole mean based on desired application attributes.

Therefore, the controller <NUM> may further screen out high outliers among the temperature values. This may help to reduce occurrence of an inadvertent trip which, in turn, may trigger an alarm, or any other hazard protection action <NUM>. Further, high temperatures owing to multiple blocked burners may cause turbine degradation, leading to High Energy Debris release and may be considered as potentially-hazardous.

In some embodiments, when a number of the plurality of validated temperature signals <NUM> remaining in the subset after eliminating the one or more of the plurality of validated temperature signals <NUM> having the corresponding temperature values greater than the high threshold is less than a predetermined number, the controller <NUM> may improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM> or perform the at least one hazard protection action <NUM>. In some embodiments, the predetermined number may be <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be a minimum number of validated temperature signals <NUM> required by the controller <NUM> to detect the burner failure in the gas turbine engine <NUM>. In some embodiments, the predetermined number may be any number based on desired application attributes.

In some other embodiments, the controller <NUM> may compare each of the plurality of validated temperature signals <NUM> to a standard distribution. In some embodiments, the standard distribution is selected from at least one of Exponential distribution, Normal distribution, Lognormal distribution, Poisson distribution, and Weibull distribution.

In some embodiments, the controller <NUM> may determine the subset of the plurality of validated temperature signals <NUM> by eliminating one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values below a standard deviation threshold from the whole mean. Further, the controller <NUM> may eliminate one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values above the standard deviation threshold from the whole mean from the subset.

In some embodiments, the standard deviation threshold may be about <NUM> from the whole mean. In some embodiments, the standard deviation threshold may be about <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> from the whole mean. In some embodiments, the standard deviation threshold may be based on desired application attributes.

Therefore, the controller <NUM> may also screen out the low and high outliers according to a shape of the standard distribution. The shape of the standard distribution may be determined and chosen based on historical data/tests.

In some other embodiments, when a number of the plurality of validated temperature signals <NUM> remaining in the subset is less than a predetermined number, the controller <NUM> may improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM> or perform the at least one hazard protection action <NUM>. In some embodiments, the predetermined number may be <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of the total number of the plurality of temperature signals <NUM>. In some embodiments, the predetermined number may be a minimum number of validated temperature signals <NUM> required by the controller <NUM> to detect the burner failure in the gas turbine engine <NUM>. In some embodiments, the predetermined number may be any number based on desired application attributes.

Therefore, when the number of the plurality of validated temperature signals <NUM> is insufficient or the number of the plurality of validated temperature signals <NUM> that are not outliers is insufficient, the controller may improve the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM> or perform the at least one hazard protection action <NUM>. In some cases, there may be a potential for the controller <NUM> to prevent the dispatch of the aircraft or prohibit restarting the gas turbine engine <NUM> in a land-based or marine application. In some cases, upon detecting the anomaly, further operation may be determined by evaluating risk to the gas turbine engine <NUM> from the detected anomaly. Further, this may also allow dispatchability with a number of faults sufficient to provide planned maintenance, such as when the aircraft visits a main base or when a power plant or oil & gas platform is shut down for long-term maintenance.

In some embodiments, the controller <NUM> may further determine a focused mean of the subset. Specifically, the focused mean is an arithmetic mean of the plurality of validated temperature signals <NUM> remaining in the subset.

In some embodiments, the controller <NUM> may determine the temperature focus <NUM> as a difference between the focused mean and the whole mean.

<FIG> illustrates a flow chart for a method <NUM> for detecting the burner failure in the gas turbine engine <NUM> (shown in <FIG>) in accordance with an embodiment of the present disclosure. The method <NUM> will be described with reference to <FIG>.

At step <NUM>, the method <NUM> includes providing the plurality of temperature sensors <NUM> arranged annularly at the outlet <NUM> of the turbine <NUM>. As discussed above, the plurality of temperature sensors <NUM> has respective temperature ranges <NUM>. Further, as discussed above, in some embodiments, the gas turbine engine <NUM> further includes the final stage turbine <NUM> disposed downstream of the turbine <NUM>.

In some embodiments, step <NUM> includes providing the plurality of temperature sensors <NUM> upstream of the final stage turbine <NUM>. In other words, providing the plurality of temperature sensors <NUM> arranged annularly at the outlet <NUM> of the turbine <NUM> includes providing the plurality of temperature sensors <NUM> upstream of the final stage turbine <NUM>.

At step <NUM>, the method <NUM> includes obtaining the plurality of temperature signals <NUM> from the plurality of temperature sensors <NUM>.

At step <NUM>, the method <NUM> includes determining the plurality of validated temperature signals <NUM> from the plurality of temperature signals <NUM>. The plurality of validated temperature signals <NUM> is within the respective temperature ranges <NUM> of the respective temperature sensors <NUM>.

In some embodiments, the method <NUM> may include determining the staging state of the gas turbine engine <NUM>. The staging state of the gas turbine engine <NUM> may be determined so that the burner failure condition is not confused with the normal operation condition of the turbine system during which the one or more burners <NUM> may be purposely inactive.

At step <NUM>, the method <NUM> includes determining the temperature focus <NUM> at least based on the plurality of validated temperature signals <NUM>.

At step <NUM>, the method <NUM> includes improving the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM>.

In some embodiments, step <NUM> includes transmitting the command <NUM> to the fuel staging control system <NUM> to increase the fuel flow to at least one burner <NUM> from the plurality of burners <NUM>. In other words, in some embodiments, improving the temperature focus <NUM> such that the temperature focus <NUM> is within the tolerance range <NUM> includes transmitting the command <NUM> to the fuel staging control system <NUM> to increase the fuel flow to at least one burner <NUM> from the plurality of burners <NUM>.

At step <NUM>, the method <NUM> includes performing the at least one hazard protection action <NUM> at least when the temperature focus <NUM> crosses the predetermined threshold <NUM>. In some embodiments, step <NUM> includes transmitting the warning <NUM> to the cockpit of the aircraft powered by the gas turbine engine <NUM>. In other words, in some embodiments, performing the at least one hazard protection action <NUM> at least when the temperature focus <NUM> crosses the predetermined threshold <NUM> includes transmitting the warning <NUM> to the cockpit of the aircraft powered by the gas turbine engine <NUM>.

In some embodiments, step <NUM> includes transmitting the command <NUM> to reduce the fuel flow to the lower point within the operating range. In other words, in some embodiments, performing the at least one hazard protection action <NUM> at least when the temperature focus <NUM> crosses the predetermined threshold <NUM> includes transmitting the command <NUM> to reduce the fuel flow to the lower point within the operating range.

In some embodiments, step <NUM> includes transmitting the command <NUM> to shut down the gas turbine engine <NUM>. In other words, in some embodiments, performing the at least one hazard protection action <NUM> at least when the temperature focus <NUM> crosses the predetermined threshold <NUM> includes transmitting the command <NUM> to shut down the gas turbine engine <NUM>.

In some embodiments, steps <NUM>, <NUM>, <NUM>, and <NUM> are cyclically repeated in time. In some embodiments, the method <NUM> proceeds to at least one of steps <NUM> and <NUM> when the temperature focus <NUM> is outside the tolerance range <NUM> for a predefined number of consecutive cycles.

Therefore, if the temperature focus <NUM> is outside the tolerance range <NUM> for the predefined number of consecutive cycles, the method <NUM> may detect an anomaly and may either improve the temperature focus <NUM> or perform the at least one hazard protection action <NUM>.

The method <NUM> of the present disclosure may eliminate invalid signals. Further, the method <NUM> is not solely based upon comparison of the plurality of individual temperature signals <NUM> with a mean. Further, the method <NUM> may be simple and may not require determining a temperature spread and/or step(s) for detecting location(s) <NUM> of the burner failure. The detection of the location(s) <NUM> of the burner failure may not be necessary for hazard protection. Thus, the method <NUM> may be robust, simple to implement, and quicker to execute.

<FIG> illustrates a flow chart for a method <NUM> for determining the plurality of validated temperature signals <NUM> from the plurality of temperature signals <NUM> in accordance with an embodiment of the present disclosure. In other words, <FIG> illustrates the flow chart for the method <NUM> including sub-steps for step <NUM> of the method <NUM>, according to an embodiment of the present disclosure.

Referring to <FIG> and <FIG>, at sub-step <NUM>, the method <NUM> includes eliminating the one or more temperature signals <NUM> from the plurality of temperature signals <NUM> to determine the plurality of validated temperature signals <NUM>, such that the plurality of validated temperature signals <NUM> are within the respective temperature ranges <NUM> of the respective temperature sensors <NUM>.

At sub-step <NUM>, the method <NUM> includes determining the location <NUM> of each of the plurality of respective sensors <NUM> generating the plurality of validated temperature signals <NUM>.

At sub-step <NUM>, the method <NUM> includes selecting the one validated temperature signal <NUM> from each location <NUM> from which two or more of the plurality of validated temperature signals <NUM> are received. In some embodiments, the selection is based on at least one of the channel based selection, the temperature value based selection, the mean based selection, and the model based selection.

At sub-step <NUM>, the method <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the number of the plurality of validated temperature signals <NUM> is less than the predetermined number.

At sub-step <NUM>, the method <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the plurality of validated temperature signals <NUM> is absent in the predetermined angular range <NUM>.

<FIG> illustrates a flow chart for a method <NUM> for determining the temperature focus <NUM> at least based on the plurality of validated temperature signals <NUM> in accordance with an embodiment of the present disclosure. In other words, <FIG> illustrates the flow chart for the method <NUM> including sub-steps for step <NUM> of the method <NUM>, according to an embodiment of the present disclosure.

Referring to <FIG> and <FIG>, at sub-step <NUM>, the method <NUM> includes determining the whole mean of the plurality of validated temperature signals <NUM>.

At sub-step <NUM>, the method <NUM> includes determining the subset of the plurality of validated temperature signals <NUM> by eliminating the one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values less than the low threshold from the whole mean.

At sub-step <NUM>, the method <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the number of the plurality of validated temperature signals <NUM> remaining in the subset is less than the predetermined number. Specifically, in some embodiments, the sub-step <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the number of the plurality of validated temperature signals <NUM> remaining in the subset after eliminating the one or more of the plurality of validated temperature signals <NUM> having the corresponding temperature values less than the low threshold is less than the predetermined number.

At sub-step <NUM>, the method <NUM> includes determining the focused mean of the subset.

At sub-step <NUM>, the method <NUM> includes determining the temperature focus <NUM> as the difference between the focused mean and the whole mean.

<FIG> illustrates a flow chart for a method <NUM> for determining the temperature focus <NUM> at least based on the plurality of validated temperature signals <NUM> in accordance with another embodiment of the present disclosure.

The method <NUM> is substantially similar to the method <NUM> shown in <FIG>. However, the method <NUM> includes an additional sub-step <NUM> of eliminating the one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values greater than the high threshold from the whole mean from the subset. Further, the method <NUM> includes sub-step <NUM> instead of sub-step <NUM>.

At sub-step <NUM>, the method <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the number of the plurality of validated temperature signals <NUM> remaining in the subset is less than the predetermined number. Specifically, in some embodiments, the sub-step <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the number of the plurality of validated temperature signals <NUM> remaining in the subset after eliminating the one or more of the plurality of validated temperature signals <NUM> having the corresponding temperature values greater than the high threshold is less than the predetermined number.

At sub-step <NUM>, the method <NUM> includes determining the whole mean of the plurality of validated temperature signals <NUM>.

At sub-step <NUM>, the method <NUM> includes comparing each of the plurality of validated temperature signals <NUM> to the standard distribution. As discussed above, in some embodiments, the standard distribution is selected from at least one of Exponential distribution, Normal distribution, Lognormal distribution, Poisson distribution, and Weibull distribution.

At sub-step <NUM>, the method <NUM> includes determining the subset of the plurality of validated temperature signals <NUM> by eliminating the one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values below the standard deviation threshold from the whole mean.

At sub-step <NUM>, the method <NUM> includes eliminating the one or more of the plurality of validated temperature signals <NUM> having corresponding temperature values above the standard deviation threshold from the whole mean from the subset.

At sub-step <NUM>, the method <NUM> includes proceeding to at least one of steps <NUM> and <NUM> when the number of the plurality of validated temperature signals <NUM> remaining in the subset is less than the predetermined number.

Claim 1:
A method (<NUM>) for detecting a burner failure in a gas turbine engine (<NUM>) having a combustor (<NUM>) and a turbine (<NUM>) disposed downstream of the combustor (<NUM>), the combustor (<NUM>) having a plurality of burners (<NUM>) arranged annularly, the method comprising the steps of:
A) providing a plurality of temperature sensors (<NUM>) arranged annularly at an outlet (<NUM>) of the turbine (<NUM>), the plurality of temperature sensors (<NUM>) having respective temperature ranges (<NUM>);
B) obtaining a plurality of temperature signals (<NUM>) from the plurality of temperature sensors (<NUM>);
C) determining a plurality of validated temperature signals (<NUM>) from the plurality of temperature signals (<NUM>), wherein the plurality of validated temperature signals (<NUM>) is within the respective temperature ranges (<NUM>) of the respective temperature sensors (<NUM>);
D) determining a temperature focus (<NUM>) at least based on the plurality of validated temperature signals (<NUM>);
E) improving the temperature focus (<NUM>) such that the temperature focus (<NUM>) is within a tolerance range (<NUM>); and
F) performing at least one hazard protection action (<NUM>) at least when the temperature focus (<NUM>) crosses a predetermined threshold (<NUM>).