Gas turbine flameout monitoring and protecting method and system

Abstract

The invention discloses a gas turbine flameout monitoring and protecting method and system.The method comprises the steps that a preset sensor in a gas turbine is used for monitoring the operation working condition of a combustion chamber, and the preset sensor comprises an optical flame detector and / or a turbine exhaust temperature thermocouple; obtaining the turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple; and based on the flame signal detected by the optical flame detector and / or the turbine exhaust temperature thermocouple temperature, whether the gas turbine flames out or not is judged according to a preset gas turbine flameout criterion. According to the invention, the problems of missed detection and false detection caused by low sensitivity of long-term operation and insufficient arrangement of an optical flame detector can be solved, and the exhaust temperature of the turbine can accurately reflect combustion conditions such as flameout of a combustion chamber; the two methods are combined, so that the operation condition of the combustion chamber of the gas turbine can be monitored more effectively and reliably, the flameout fault can be judged more accurately, and flameout protection can be adopted more timely.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbines, and in particular to a method and system for monitoring and protecting a flameout of a gas turbine. Background Art

[0002] With the rapid advancement of carbon emission reduction and carbon neutrality in major countries around the world, gas turbines are beginning to face carbon emission pressure due to the long-term use of natural gas. Frequent global extreme climate, energy security, low-carbon emission reduction and other issues have made it imperative to develop new low-carbon green energy equipment. Gas turbines are clean thermal power generation technologies that are safe, reliable, peak-scalable and sustainable and stable. The development of new gas turbines that can use hydrogen or other renewable gas fuels is of great significance to the realization of a sustainable green economy. On the one hand, it can alleviate energy security issues, and on the other hand, it can lead the application direction of zero-carbon clean energy, and will play a key supporting role in "building a new power system with new energy as the main body". Major international gas turbine manufacturers have regarded hydrogen engines as an important development direction. At present, hydrogen gas turbines are mainly in the demonstration stage. The hydrogen blending ratio of mainstream international heavy-duty gas turbines can reach 30%, and the hydrogen blending ratio of small and medium-sized gas turbines can reach a level higher than 50%. The demonstration power stations of various manufacturers are mostly under construction or about to be built, and they plan to gradually transition to pure hydrogen gas turbine power stations. For hydrogen-blended or pure hydrogen engines, compared with traditional natural gas fuel, the addition of hydrogen will cause significant changes in the physical and chemical properties of the fuel. Hydrogen will broaden the flammable range of traditional hydrocarbon fuels, accelerate the flame propagation speed of the fuel, and increase the combustion speed in turbulent combustion of the fuel. It also has a lower minimum ignition energy, a wider explosion limit, and is more prone to spontaneous combustion. Therefore, hydrogen has a high risk of spontaneous combustion and explosion. In addition, the diffusion rate of hydrogen is faster than that of natural gas. When the combustion chamber of the gas turbine fails to ignite or flames out, a large amount of hydrogen will be discharged into the downstream turbine cylinder, exhaust diffuser, waste heat boiler and other chambers, which can easily cause serious safety accidents. The unit needs to be equipped with flameout protection to monitor the flameout of the combustion chamber and cut off the hydrogen supply in time to avoid accidents. Therefore, for the current mainstream dry low-emission premixed combustion organization mode of the gas turbine, in addition to using aerodynamic design in the nozzle design stage to prevent flameout to a certain extent and controlling the appropriate equivalence ratio in the operation stage to prevent flameout, flameout protection at the gas turbine operation control level is also a necessary measure when burning hydrogen-mixed / pure hydrogen fuel. The existing gas turbine flameout protection device mainly relies on optical flame detectors to determine whether the flame is established or extinguished by detecting the radiation intensity of specific infrared or ultraviolet frequency bands in the combustion flame. The problems existing in the existing technical solutions are as follows:

[0003] 1) Optical flame detectors may have reduced detection sensitivity due to oil, dust, etc. attached to the probe, resulting in the possibility of missed and false flame detections; and optical flame detectors are easily damaged in high temperature environments; 2) Optical flame detectors are relatively expensive, and for combustion chambers with a linked flame tube design, flame detectors are usually not installed in every combustion chamber, posing a risk of missed detections. 3) The method of using combustion chamber gas flow rate detection to determine whether the flame is established does not directly monitor the flame, and the flow rate fluctuation threshold is difficult to calculate accurately, posing a risk of missed and false detections. 4) The losses and consequences caused by the failure to ignite or flameout of a pure hydrogen gas turbine are serious, and a single optical flame detection and protection measure is difficult to guarantee sufficiently high reliability requirements.

[0004] The existing patent CN104676633A discloses a gas turbine flame detection method and system, which measures and calculates the gas flow rate of the combustion chamber of the gas turbine to be tested, monitors the fluctuation value of the gas flow rate of the combustion chamber in real time, and judges whether the flame is established according to the fluctuation value. If the fluctuation value of the combustion chamber flow rate decreases is less than the first preset threshold, the combustion chamber is in a flameout state, and if the fluctuation value of the combustion chamber flow rate increase is greater than the second preset threshold, the combustion chamber has established a flame. The flame detection method of this method is relatively simple, and does not solve the problem that the single optical flame detection and protection measures in the prior art are difficult to ensure sufficiently high reliability requirements.

[0005] The existing patent CN103195583A discloses a method for monitoring and protecting gas turbine combustion by exhaust temperature dispersion. The method is to install multiple temperature measuring thermocouples at the turbine exhaust end of the gas turbine, and use the multi-dimensional space cosine theorem to collect signals from the temperature measuring thermocouples to obtain the exhaust temperature dispersion, thereby indirectly predicting the stability of combustion in the combustion chamber; establish the alarm logic and alarm exit logic of gas turbine combustion monitoring and protection according to the exhaust temperature dispersion; and establish the dangerous tripping logic of gas turbine combustion monitoring and protection.

[0006] In summary, the above two existing patents do not solve the problem in the prior art that it is difficult to ensure sufficiently high reliability requirements when using optical flame detection and protection. Summary of the invention

[0007] Based on the above technical problems, the present invention proposes a method and system for monitoring and protecting a flameout of a combustion engine, which solves the problem in the prior art that it is difficult to ensure sufficiently high reliability requirements by using optical flame detection and protection.

[0008] A combustion engine flameout monitoring and protection method, comprising:

[0009] The operating condition of the combustion chamber is monitored by using preset sensors in the combustion engine, wherein the preset sensors include an optical flame detector and / or a turbine exhaust temperature thermocouple;

[0010] Obtaining the turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple;

[0011] Based on the flame signal detected by the optical flame detector and / or the temperature of the turbine exhaust temperature thermocouple, a preset engine flameout criterion is used to determine whether the engine has flameout.

[0012] Furthermore, the optical flame detector is arranged on the inner wall of the combustion chamber of the gas engine, and the turbine exhaust temperature thermocouple is arranged on the radial section of the turbine exhaust diffuser of the gas engine.

[0013] Furthermore, the optical flame detectors are arranged at equal intervals in the circumferential direction on the inner wall of the combustion chamber, and the turbine exhaust temperature thermocouples are arranged at equal intervals in the circumferential direction on the radial cross section of the turbine exhaust diffuser of the combustion engine.

[0014] Furthermore, the flame signal includes a flame signal, a no-fire signal, a normal signal and a fault signal. Based on the flame signal detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine flameout occurs, including:

[0015] Based on the number and duration of no-fire signals, normal signals and fault signals detected by the optical flame detector, the preset engine flameout criterion is used to determine whether the engine has flameout.

[0016] Furthermore, the preset engine flameout criterion includes one or more of a first criterion, a second criterion and a third criterion.

[0017] The first criterion is that at least two optical flame detectors in the same combustion chamber detect normal signals and no-fire signals, and the delay meets the first preset time length;

[0018] The second criterion is that at least one optical flame detector in the same combustion chamber detects a fault signal, and at least one optical flame detector detects a normal signal and a no-fire signal, and the delay meets the second preset time length;

[0019] The third criterion is that the optical flame detectors in the same combustion chamber all detect fault signals.

[0020] Furthermore, based on the flame signal detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine flameout occurs, including:

[0021] Determine whether the flame signal detected by the optical flame detector satisfies any one of the first criterion, the second criterion and the third criterion;

[0022] If any one of the first criterion, the second criterion and the third criterion is met, the combustion engine is turned off.

[0023] Further, based on the turbine exhaust temperature thermocouple temperature, a preset engine flameout criterion is used to determine whether the engine flameout occurs, including:

[0024] Based on the turbine exhaust temperature thermocouple temperature or the turbine exhaust temperature thermocouple temperature reduction rate, a preset engine flameout criterion is used to determine whether the engine flameout occurs.

[0025] Furthermore, the preset engine flameout criterion also includes one or more of a fourth criterion, a fifth criterion and a sixth criterion.

[0026] The fourth criterion is that the difference between the turbine exhaust temperature thermocouple temperature of at least a turbine exhaust temperature thermocouple and the average value of the turbine exhaust temperature thermocouple temperature of all turbine exhaust temperature thermocouples in the combustion engine is less than the first threshold value, and the delay meets the third preset time length;

[0027] The fifth criterion is that there are at least b turbine exhaust temperature thermocouples whose temperature reduction rate is greater than the second threshold value, and the delay meets the fourth preset time length;

[0028] The sixth criterion is that the difference between the turbine exhaust temperature thermocouple temperature of at least c turbine exhaust temperature thermocouples and the theoretical value of the turbine exhaust temperature thermocouple under the engine operating condition is less than the third threshold value, and the delay meets the fifth preset time length.

[0029] Furthermore, a, b, and c are determined by formula 1. Formula 1:

[0030] X=f 1 (T 0 ,P 0 ,RH,SPD,P k1, T K2 ,P k2 ,IGV,FR,PWR), where T 0 is the ambient temperature, P 0 is the ambient atmospheric pressure, RH is the ambient atmospheric humidity, SPD is the engine speed, P k1 is the gas turbine compressor inlet pressure, T K2 is the gas turbine compressor outlet temperature, P k2 is the outlet pressure of the gas turbine compressor, IGV is the opening of the adjustable inlet guide vane of the gas turbine, FR is the fuel quantity, and PWR is the active power of the gas turbine generator.

[0031] Further, based on the turbine exhaust temperature thermocouple temperature, a preset engine flameout criterion is used to determine whether the engine flameout occurs, including:

[0032] Determining whether the temperature of the turbine exhaust temperature thermocouple satisfies any one of the fourth criterion, the fifth criterion and the sixth criterion;

[0033] If any one of the fourth criterion, the fifth criterion and the sixth criterion is met, the engine is turned off.

[0034] Further, the determination of the average value of the turbine exhaust temperature thermocouple temperature includes:

[0035] According to the number of turbine exhaust temperature thermocouple monitoring signals, signal quality and the turbine exhaust temperature thermocouple temperature of each signal, the average value of the turbine exhaust temperature thermocouple temperature is determined through a signal conditioning optimization algorithm.

[0036] Further, according to the number of turbine exhaust temperature thermocouple monitoring signals, signal quality and turbine exhaust temperature thermocouple temperatures of each signal, the average value of the turbine exhaust temperature thermocouple temperatures is determined by a signal conditioning optimization algorithm, including:

[0037] The signal quality includes normal and abnormal. When the number of signals with normal signal quality is greater than a fourth threshold, the average value of the turbine exhaust temperature thermocouple temperature is a weighted average value of the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality and the corresponding weight of the turbine exhaust temperature thermocouple.

[0038] When the number of signals with normal signal quality is less than or equal to the fourth threshold value and greater than the fifth threshold value, the average value of the turbine exhaust temperature thermocouple temperature is determined according to the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality, the corresponding weight of the turbine exhaust temperature thermocouple and the confidence interval of the preset theoretical value of the turbine exhaust temperature thermocouple temperature;

[0039] When the number of signals with normal signal quality is less than or equal to the fifth threshold, the average value of the turbine exhaust temperature thermocouple temperature is the theoretical value of the turbine exhaust temperature thermocouple temperature.

[0040] Furthermore, the fourth threshold is 2 / 3 of the total number of all turbine exhaust temperature thermocouples in the gas engine turbine; and the fifth threshold is 1 / 3 of the total number of all turbine exhaust temperature thermocouples in the gas engine turbine.

[0041] Furthermore, the corresponding weight of the turbine exhaust temperature thermocouple is determined according to the arrangement of the turbine exhaust temperature thermocouple on the radial cross section of the turbine exhaust diffuser of the combustion engine, and the arrangement includes a single annular arrangement and a multi-annular arrangement.

[0042] Furthermore, the determination of the weight corresponding to the turbine exhaust temperature thermocouple includes:

[0043] When the turbine exhaust temperature thermocouple is arranged in a single ring on the radial cross section of the combustion engine turbine exhaust diffuser, the weight is 100%;

[0044] When the turbine exhaust temperature thermocouple is arranged in multiple rings on the radial cross section of the turbine exhaust diffuser of the combustion engine, the weight is determined by formula 2 according to the characteristics of each ring surface reflecting the uniformity of the turbine exhaust flow field. The formula 2 is, w=f(C 1 ,C 2 …C n ,n), where C 1 is the correlation between the characteristic of the first annular surface reflecting the uniformity of the turbine exhaust flow field and the uniformity of the turbine exhaust flow field; C n is the correlation between the characteristic of the nth annular surface reflecting the uniformity of the turbine exhaust flow field and the uniformity of the turbine exhaust flow field, and n is the number of annular surfaces where the turbine exhaust temperature thermocouples are arranged.

[0045] Further, the turbine exhaust temperature thermocouple temperature average value is determined according to the turbine exhaust temperature thermocouple temperature of the signal with normal signal quality, the corresponding weight of the turbine exhaust temperature thermocouple, and the confidence interval of the turbine exhaust temperature thermocouple temperature theoretical value, including:

[0046] Determining an initial turbine exhaust temperature thermocouple temperature average value according to the turbine exhaust temperature thermocouple temperature of the signal with normal signal quality and the corresponding weight of the turbine exhaust temperature thermocouple;

[0047] If the initial turbine exhaust temperature thermocouple temperature average value is within the preset confidence interval of the turbine exhaust temperature thermocouple temperature theoretical value, the initial turbine exhaust temperature thermocouple temperature average value is used as the turbine exhaust temperature thermocouple temperature average value;

[0048] If the initial turbine exhaust temperature thermocouple temperature average value is greater than the upper limit value of the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, the upper limit value is used as the turbine exhaust temperature thermocouple temperature average value;

[0049] If the initial turbine exhaust temperature thermocouple temperature average value is less than the lower limit value of the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, the lower limit value is used as the turbine exhaust temperature thermocouple temperature average value.

[0050] Furthermore, the theoretical value of the turbine exhaust temperature thermocouple temperature is determined by formula 3. Formula 3:

[0051] T x =f 2 (T 0 ,RH,SPD,P k1, T K1 ,P k2 ,T K2 ,IGV,FR,η F ,η T ,PWR), where T 0is the ambient temperature, RH is the ambient atmospheric humidity, SPD is the engine speed, P K1 is the gas turbine compressor inlet pressure, T K1 is the gas turbine compressor inlet temperature, P K2 is the gas turbine compressor outlet pressure, T K2 is the gas turbine compressor outlet temperature, IGV is the gas turbine adjustable inlet guide vane opening, FR is the fuel quantity, η F is the combustion efficiency of the gas turbine, η T is the turbine efficiency of the gas turbine, and PWR is the active power of the gas turbine generator.

[0052] Furthermore, based on the flame signal detected by the optical flame detector and the temperature of the turbine exhaust temperature thermocouple, a preset engine flameout criterion is used to determine whether the engine flameout occurs, including:

[0053] Based on the number of no-fire signals, the number of normal signals, the turbine exhaust temperature thermocouple temperature and the rate of decrease of the turbine exhaust temperature thermocouple temperature detected by the optical flame detector, the preset engine flameout criterion is used to determine whether the engine has flameout.

[0054] Furthermore, the preset engine flameout criterion also includes: one or both of the seventh criterion and the eighth criterion,

[0055] The seventh criterion is that at least h optical flame detectors among all optical flame detectors detect normal signals and no-fire signals, and at least i turbine exhaust temperature thermocouple temperatures among all turbine exhaust temperature thermocouple temperatures are less than the sixth threshold value, and the delay meets the sixth preset time length;

[0056] The eighth criterion is that at least j of all optical flame detectors detect normal signals and no-fire signals, and at least k of all turbine exhaust temperature thermocouples have a temperature reduction rate greater than the seventh threshold, and the delay satisfies the seventh preset time length.

[0057] Furthermore, the number of optical flame detectors h, i, j, k is determined by formula one.

[0058] A flameout monitoring and protection system for a combustion engine, the system is used to perform flameout monitoring and protection according to the above method, and the system comprises:

[0059] A monitoring module, used to monitor the operating conditions of the combustion chamber using preset sensors in the combustion engine, wherein the preset sensors include an optical flame detector and / or a turbine exhaust temperature thermocouple;

[0060] An acquisition module, used for acquiring a turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple;

[0061] The judgment module is used to judge whether the combustion engine has been flamed out based on the flame signal detected by the optical flame detector and / or the temperature of the turbine exhaust temperature thermocouple using a preset combustion engine flameout criterion.

[0062] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0063] 1. The present invention proposes to combine an optical flame detector and a turbine exhaust temperature thermocouple to monitor the state of the gas engine, which can make up for the problem of missed detection and false detection caused by the long-term reduction in sensitivity and insufficient arrangement of the single optical flame detector. The turbine exhaust temperature can accurately reflect the combustion conditions such as whether the combustion chamber is flameout. The combination of the two methods can more effectively and reliably monitor the operating conditions of the combustion chamber of the gas engine, more accurately judge the occurrence of flameout failure, and then take flameout protection more timely, reducing the risk and loss of serious safety accidents that may be caused by ignition failure or flameout of the combustion chamber.

[0064] 2. The present invention sets corresponding preset engine flameout criteria to judge whether the engine has flamed out according to three methods: based on the no-fire signal detected by the optical flame detector alone, based on the turbine exhaust temperature thermocouple temperature alone, or based on the no-fire signal detected by the optical flame detector and the turbine exhaust temperature thermocouple temperature. When one of the criteria is met, it is considered that the engine has flamed out. The method and system detect the engine status from multiple angles, which can reduce the risk of missed detection and improve the reliability of the detection method.

[0065] 3. The turbine exhaust temperature thermocouple used in the present invention is usually a long-term measuring point that has been installed in the gas turbine. There is no need to purchase and install it separately, which does not increase the cost. In general, multiple turbine exhaust temperature thermocouple measuring points are arranged, which can avoid the accuracy and reliability of flameout judgment being reduced due to the failure of individual turbine exhaust temperature thermocouple measuring points.

[0066] 4. The present invention proposes to arrange the turbine exhaust temperature thermocouples in a single ring or multiple rings in the radial cross-section of the turbine exhaust diffuser of the gas engine, and determine the average temperature of the turbine exhaust temperature thermocouples based on the weight corresponding to the ring surface where the turbine exhaust temperature thermocouples are located and the temperature of the turbine exhaust temperature thermocouples of a signal with normal signal quality, which can improve the accuracy of the average temperature of the turbine exhaust temperature thermocouples and thus more accurately judge the occurrence of flameout failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0068] Figure 1 A flow chart of a method for monitoring and protecting a combustion engine flameout according to an embodiment of the present invention;

[0069] Figure 2 This is a schematic diagram of the arrangement of the combustion chamber optical flame detector of this embodiment;

[0070] Figure 3 Schematic diagram of the arrangement of the turbine exhaust temperature thermocouple in this embodiment;

[0071] Figure 4 It is a schematic diagram of the arrangement of the turbine exhaust temperature thermocouple on the radial cross section of the turbine exhaust diffuser of the combustion engine in a specific embodiment of the present invention;

[0072] Figure 5 The present invention is a schematic diagram of a combustion engine flameout monitoring and protection system according to an embodiment of the present invention.

[0073] The above drawings include the following reference numerals:

[0074] 100, fuel nozzle; 200, combustion chamber; 300, transition section; 400, outlet; 500, optical flame detector; 600, gas turbine; 700, gas turbine exhaust diffuser; 701, gas turbine exhaust diffuser cylinder; 800, turbine exhaust temperature thermocouple; 801, turbine exhaust temperature thermocouple mounting bracket; 900, gas turbine axis. DETAILED DESCRIPTION

[0075] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0076] The present invention is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention.

[0077] Example

[0078] In order to solve the problem in the prior art that it is difficult to ensure sufficiently high reliability requirements when using optical flame detection and protection, the present invention proposes a combustion engine flameout monitoring and protection method and system.

[0079] like Figure 1 A flow chart of a method for monitoring and protecting a combustion engine flameout according to an embodiment of the present invention is shown in FIG. 1 , and the flow chart includes the following steps:

[0080] S1, using preset sensors in the combustion engine to monitor the operating conditions of the combustion chamber, the preset sensors include optical flame detectors and / or turbine exhaust temperature thermocouples.

[0081] The gas engine comprises a plurality of combustion chambers, and the combustion chamber of the gas engine comprises a fuel nozzle, a combustion chamber, a transition section and an outlet. When setting the sensor, an optical flame detector or a turbine exhaust temperature thermocouple, or a combination of the two sensors can be selected according to actual needs to monitor the operating conditions of the combustion chamber. Specifically, the optical flame detector can be set on the inner wall of the combustion chamber, and the turbine exhaust temperature thermocouple can be set on the radial section of the gas engine turbine exhaust diffuser.

[0082] In this embodiment, the sensors preset in each combustion chamber include an optical flame detector and a turbine exhaust temperature thermocouple, such as Figure 2 FIG. 5 is a schematic diagram of the arrangement of the combustion chamber optical flame detector of this embodiment. The combustion chamber includes a fuel nozzle 100, a combustion chamber 200, a transition section 300 and an outlet 400. Optical flame detectors 500 are arranged on the inner wall of the combustion chamber at equal intervals in the circumferential direction. Figure 3 FIG. 1 is a schematic diagram of the arrangement of the turbine exhaust temperature thermocouples in this embodiment. Figure 3 600 and a turbine exhaust diffuser 700 of a gas engine are shown in the figure. The turbine exhaust temperature thermocouples 800 are arranged at equal intervals in the circumferential direction on one or more annular surfaces of the radial cross section of the turbine exhaust diffuser 700 of the gas engine. The turbine exhaust temperature is closely related to the combustion condition of the combustion chamber. When the gas engine works at different ambient temperatures and atmospheric pressures, different speeds, different fuel amounts, and different powers, the corresponding turbine exhaust temperature will be in a certain reasonable range according to the performance characteristics of the gas engine, so it can accurately reflect the combustion condition such as whether the combustion chamber is flameout; and generally, multiple turbine exhaust temperature thermocouple measuring points are arranged to avoid the accuracy and reliability of using this method to judge flameout due to the failure of individual turbine exhaust temperature thermocouple measuring points.

[0083] Specifically, in this embodiment, multiple optical flame detectors are arranged in each combustion chamber, and multiple turbine exhaust temperature thermocouples are arranged in the radial cross section of the gas turbine turbine exhaust diffuser. It should be understood that the number of optical flame detectors and turbine exhaust temperature thermocouples can be set according to actual needs, and the arrangement positions of the optical flame detectors and turbine exhaust temperature thermocouples can be adjusted according to the actual monitoring effect.

[0084] S2, obtaining the turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple.

[0085] S3, based on the flame signal detected by the optical flame detector and / or the temperature of the turbine exhaust temperature thermocouple, using a preset engine flameout criterion to determine whether the engine has flameout.

[0086] The present invention sets corresponding preset engine flameout criteria to judge whether the engine is flameout according to three types: flame signal detected by optical flame detector alone, turbine exhaust temperature thermocouple temperature alone, or flame signal detected by optical flame detector and turbine exhaust temperature thermocouple temperature.

[0087] Furthermore, the flame signal includes a fire signal, a no-fire signal, a normal signal and a fault signal. Based on the flame signal detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine has flamed out, including: based on the number and duration of no-fire signals, normal signals and fault signals detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine has flamed out.

[0088] Furthermore, the preset engine flameout criterion includes one or more of the first criterion, the second criterion and the third criterion. The first criterion is that at least two optical flame detectors in the same combustion chamber detect normal signals and no-fire signals, and the delay meets the first preset time length. The second criterion is that at least one optical flame detector in the same combustion chamber detects a fault signal, and at least one optical flame detector detects a normal signal and no-fire signal, and the delay meets the second preset time length. The third criterion is that the optical flame detectors in the same combustion chamber all detect fault signals. It should be understood that the first to seventh thresholds and the first to seventh preset time lengths in the present invention can be set according to actual conditions.

[0089] Further, based on the flame signal detected by the optical flame detector, using the preset engine flameout criterion to determine whether the engine flameout occurs includes: determining whether the flame signal detected by the optical flame detector satisfies any one of the first criterion, the second criterion, and the third criterion. If any one of the first criterion, the second criterion, and the third criterion is satisfied, the engine flameout occurs.

[0090] In addition, based on the turbine exhaust temperature thermocouple temperature, a preset engine flameout criterion is used to determine whether the engine has flamed out, including: based on the turbine exhaust temperature thermocouple temperature or the turbine exhaust temperature thermocouple temperature reduction rate, a preset engine flameout criterion is used to determine whether the engine has flamed out.

[0091] Furthermore, the preset engine flameout criterion also includes one or more of the fourth criterion, the fifth criterion and the sixth criterion. The fourth criterion is that the difference between the temperature of the turbine exhaust temperature thermocouple of at least a turbine exhaust temperature thermocouple and the average temperature of the turbine exhaust temperature thermocouple of all turbine exhaust temperature thermocouples in the engine is less than the first threshold value, and the delay meets the third preset time length. The fifth criterion is that the temperature reduction rate of the turbine exhaust temperature thermocouple of at least b turbine exhaust temperature thermocouples is greater than the second threshold value, and the delay meets the fourth preset time length. The sixth criterion is that the difference between the temperature of the turbine exhaust temperature thermocouple of at least c turbine exhaust temperature thermocouples and the theoretical value of the turbine exhaust temperature thermocouple under the engine operating conditions is less than the third threshold value, and the delay meets the fifth preset time length.

[0092] The number of thermocouples required for the turbine exhaust temperature in the above criterion is a variable that is adaptively corrected based on the actual operating conditions of the engine. As the engine speed (SPD) and operating load increase, the engine operating conditions are closer to the engine design point conditions, the operating parameters are more stable, and the criteria for determining the flameout of the combustion chamber are more stringent. Further, a, b, and c are determined by formula 1. Formula 1: X = f 1 (T 0 ,P 0 ,RH,SPD,P k1, T K2 ,P k2 ,IGV,FR,PWR), where T 0 is the ambient temperature, P 0 is the ambient atmospheric pressure, RH is the ambient atmospheric humidity, SPD is the engine speed, P k1 is the gas turbine compressor inlet pressure, T K2 is the gas turbine compressor outlet temperature, P k2 is the outlet pressure of the gas turbine compressor, IGV is the opening of the adjustable inlet guide vane of the gas turbine, FR is the fuel quantity, and PWR is the active power of the gas turbine generator.

[0093] Further, based on the temperature of the turbine exhaust temperature thermocouple, using the preset engine flameout criterion to determine whether the engine flameout occurs includes: determining whether the temperature of the turbine exhaust temperature thermocouple satisfies any one of the fourth criterion, the fifth criterion, and the sixth criterion. If any one of the fourth criterion, the fifth criterion, and the sixth criterion is satisfied, the engine flameout occurs.

[0094] For the average value of the turbine exhaust temperature thermocouple temperature in the fourth criterion, this embodiment determines it through a signal conditioning optimization algorithm based on the number of turbine exhaust temperature thermocouple monitoring signals, signal quality and turbine exhaust temperature thermocouple temperature of each signal. Specifically, the process includes the following steps:

[0095] S301, signal quality includes normal and abnormal. When the number of signals with normal signal quality is greater than the fourth threshold, the average value of the turbine exhaust temperature thermocouple temperature is the weighted average value of the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality and the corresponding weight of the turbine exhaust temperature thermocouple.

[0096] Furthermore, the corresponding weight of the turbine exhaust temperature thermocouple is determined according to the arrangement of the turbine exhaust temperature thermocouple on the radial cross section of the turbine exhaust diffuser of the combustion engine, and the arrangement includes a single annular arrangement and a multi-annular arrangement. Figure 4 FIG. 1 shows a schematic diagram of the arrangement of the turbine exhaust temperature thermocouple on the radial cross section of the turbine exhaust diffuser of the combustion engine in a specific embodiment of the present invention. Figure 4 The figure shows the engine shaft 900, the turbine exhaust temperature thermocouple mounting bracket 801, the engine turbine exhaust diffuser cylinder 701 and the turbine exhaust temperature thermocouple 800 arranged in multiple annuli. The turbine exhaust temperature thermocouples are arranged in three annuli, wherein the turbine exhaust temperature thermocouples T4-1, T4-4, T4-7, and T4-10 are arranged on the first annulus 1, T4-2, T4-5, T4-8, and T4-11 are arranged on the second annulus 2, and T4-3, T4-6, T4-9, and T4-12 are arranged on the third annulus 3. The first annulus in this embodiment is the annulus close to the engine shaft center, and in other embodiments, it can be marked according to actual conditions.

[0097] Further, the determination of the corresponding weight of the turbine exhaust temperature thermocouple includes: when the turbine exhaust temperature thermocouple is arranged in a single ring on the radial cross section of the turbine exhaust diffuser of the gas engine, the weight is 100%; when the turbine exhaust temperature thermocouple is arranged in multiple rings on the radial cross section of the turbine exhaust diffuser of the gas engine, the weight is determined by formula 2 based on the characteristics of each ring surface reflecting the uniformity of the turbine exhaust flow field, and the formula 2 is, w=f(C 1 ,C 2 …C n ,n), where C 1 is the correlation between the characteristic of the first annular surface reflecting the uniformity of the turbine exhaust flow field and the uniformity of the turbine exhaust flow field; C n is the correlation between the characteristic of the nth annular surface reflecting the uniformity of the turbine exhaust flow field and the uniformity of the turbine exhaust flow field, and n is the number of annular surfaces where the turbine exhaust temperature thermocouples are arranged.

[0098] S302, when the number of signals with normal signal quality is less than or equal to the fourth threshold and greater than the fifth threshold, the average value of the turbine exhaust temperature thermocouple temperature is determined based on the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality, the corresponding weight of the turbine exhaust temperature thermocouple, and the confidence interval of the preset theoretical value of the turbine exhaust temperature thermocouple temperature.

[0099] Further, the turbine exhaust temperature thermocouple temperature average value is determined based on the turbine exhaust temperature thermocouple temperature of the signal with normal signal quality, the turbine exhaust temperature thermocouple corresponding weight, and the confidence interval of the turbine exhaust temperature thermocouple temperature theoretical value, including:

[0100] S3021, determining an initial turbine exhaust temperature thermocouple temperature average value based on the turbine exhaust temperature thermocouple temperature of a signal with normal signal quality and a weight corresponding to the turbine exhaust temperature thermocouple.

[0101] S3022: If the initial turbine exhaust temperature thermocouple temperature average value is within the preset confidence interval of the turbine exhaust temperature thermocouple temperature theoretical value, the initial turbine exhaust temperature thermocouple temperature average value is used as the turbine exhaust temperature thermocouple temperature average value.

[0102] Furthermore, the theoretical value of the turbine exhaust temperature thermocouple temperature is determined by formula 3. Formula 3:

[0103] T x =f 2 (T 0 ,RH,SPD,P k1, T K1 ,P k2 ,T K2 ,IGV,FR,η F ,η T ,PWR), where T 0 is the ambient temperature, RH is the ambient atmospheric humidity, SPD is the engine speed, P K1 is the gas turbine compressor inlet pressure, T K1 is the gas turbine compressor inlet temperature, P K2 is the gas turbine compressor outlet pressure, T K2 is the gas turbine compressor outlet temperature, IGV is the gas turbine adjustable inlet guide vane opening, FR is the fuel quantity, η F is the combustion efficiency of the gas turbine, η T is the turbine efficiency of the gas turbine, and PWR is the active power of the gas turbine generator.

[0104] The above formula 3 is the algorithm formula for the theoretical value of the thermocouple temperature of the turbine exhaust temperature in the full-operation operation of the gas engine under different ambient temperatures and atmospheric pressures, different speeds, different IGV openings, different fuel amounts, different powers, etc. It can be understood that the theoretical value of the thermocouple temperature of the turbine exhaust temperature is determined by the various parameters and function f in formula 1. 2 Comprehensive determination.

[0105] The confidence interval of the theoretical value of the preset turbine exhaust temperature thermocouple temperature can be described as, T x *A1 %~T x *B 1 %, specific A 1 %、B 1 % can be determined according to actual needs. For example, the confidence interval of a preset theoretical value of the turbine exhaust temperature thermocouple temperature is T x *95%~T x *106%.

[0106] S3023: If the initial turbine exhaust temperature thermocouple temperature average value is greater than the upper limit value of the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, the upper limit value is used as the turbine exhaust temperature thermocouple temperature average value.

[0107] S3024: If the initial turbine exhaust temperature thermocouple temperature average value is less than the lower limit of the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, the lower limit is used as the turbine exhaust temperature thermocouple temperature average value.

[0108] When the number of signals with normal signal quality is less than or equal to the fourth threshold and greater than the fifth threshold, the actually measured temperature value can be corrected and verified based on the confidence interval of the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality and the preset theoretical value of the turbine exhaust temperature thermocouple temperature, thereby improving the calculation accuracy of the average value of the turbine exhaust temperature thermocouple temperature.

[0109] It is understandable that the average value of the turbine exhaust temperature thermocouple temperature may also be determined by other methods other than the present embodiment.

[0110] S303: When the number of signals with normal signal quality is less than or equal to a fifth threshold, the average value of the turbine exhaust temperature thermocouple temperature is the theoretical value of the turbine exhaust temperature thermocouple temperature.

[0111] For example, the fourth threshold value may be set to 2 / 3 of the total number of all turbine exhaust temperature thermocouples in the gas turbine turbine; the fifth threshold value may be set to 1 / 3 of the total number of all turbine exhaust temperature thermocouples in the gas turbine turbine. When the number of signals with normal signal quality is less than or equal to the fifth threshold value, the average value of the turbine exhaust temperature thermocouple temperature is the theoretical value of the turbine exhaust temperature thermocouple temperature, and an alarm is issued that the number of abnormal turbine exhaust temperature thermocouple signals exceeds the standard.

[0112] In addition, based on the flame signal detected by the optical flame detector and the turbine exhaust temperature thermocouple temperature, a preset engine flameout criterion is used to determine whether the engine has flamed out, including: based on the number of no-fire signals, the number of normal signals, the turbine exhaust temperature thermocouple temperature and the turbine exhaust temperature thermocouple temperature reduction rate detected by the optical flame detector, using the preset engine flameout criterion to determine whether the engine has flamed out.

[0113] Further, the preset engine flameout criterion also includes: one or two of the seventh criterion and the eighth criterion, the seventh criterion is that at least h optical flame detectors among all optical flame detectors detect normal signals and no-fire signals, and at least i turbine exhaust temperature thermocouples among all turbine exhaust temperature thermocouples have temperatures less than the sixth threshold, and the delay meets the sixth preset time length. The eighth criterion is that at least j optical flame detectors among all optical flame detectors detect normal signals and no-fire signals, and at least k turbine exhaust temperature thermocouples among all turbine exhaust temperature thermocouples have a temperature reduction rate greater than the seventh threshold, and the delay meets the seventh preset time length. Further, the number of optical flame detectors h, i, j, k is determined by formula 1 based on the actual operating condition parameters of the engine.

[0114] This embodiment uses the above eight criteria to determine whether the engine is flameout. When any of the above criteria is met, it is considered that the engine is flameout. It should be understood that in actual applications, some of the criteria in the present invention can be selected according to the actual preset sensor type and the acquired data to determine whether the engine is flameout.

[0115] In order to achieve the same purpose as the above method, the present invention also proposes a combustion engine flameout monitoring and protection system, which is used to perform flameout monitoring and protection according to the above method.

[0116] like Figure 5 Schematic diagram of a combustion engine flameout monitoring and protection system according to an embodiment of the present invention is shown in FIG. 4 . The system includes: a monitoring module 41 , an acquisition module 42 and a judgment module 43 . The functions of each module will be introduced below.

[0117] The monitoring module 41 is used to monitor the operating conditions of the combustion chamber using preset sensors in the combustion engine. The preset sensors include optical flame detectors and / or turbine exhaust temperature thermocouples.

[0118] The acquisition module 42 is used to acquire the turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple.

[0119] The judgment module 43 is used to judge whether the combustion engine has been flamed out based on the flame signal detected by the optical flame detector and / or the temperature of the turbine exhaust temperature thermocouple and using a preset combustion engine flameout criterion.

[0120] It should be understood that a combustion engine flameout monitoring and protection system is consistent with the description of a corresponding combustion engine flameout monitoring and protection method embodiment, so it will not be repeated in this embodiment.

[0121] In summary, it can be seen from the above description that the above embodiments of the present invention achieve the following technical effects:

[0122] 1. The present invention proposes to combine an optical flame detector and a turbine exhaust temperature thermocouple to monitor the state of the gas engine, which can make up for the problems of missed detection and false detection caused by the reduced sensitivity of the optical flame detector used in the prior art due to long-term operation and insufficient arrangement. The turbine exhaust temperature can accurately reflect the combustion conditions such as whether the combustion chamber is flameout. The combination of the two methods can more effectively and reliably monitor the operating conditions of the combustion chamber of the gas engine, more accurately judge the occurrence of flameout failure, and then take flameout protection more promptly, reducing the risk and loss of serious safety accidents that may be caused by ignition failure or flameout of the combustion chamber.

[0123] 2. The present invention sets corresponding preset engine flameout criteria to judge whether the engine has flamed out according to three methods: based on the no-fire signal detected by the optical flame detector alone, based on the turbine exhaust temperature thermocouple temperature alone, or based on the no-fire signal detected by the optical flame detector and the turbine exhaust temperature thermocouple temperature. When one of the criteria is met, it is considered that the engine has flamed out. The method and system detect the engine status from multiple angles, which can reduce the risk of missed detection and improve the reliability of the detection method.

[0124] 3. The turbine exhaust temperature thermocouple used in the present invention is usually a long-term measuring point that has been installed in the gas turbine. There is no need to purchase and install it separately, which does not increase the cost. In general, multiple turbine exhaust temperature thermocouple measuring points are arranged, which can avoid the accuracy and reliability of flameout judgment being reduced due to the failure of individual turbine exhaust temperature thermocouple measuring points.

[0125] 4. The present invention proposes to arrange the turbine exhaust temperature thermocouples in a single annular surface or multiple annular surfaces in the radial cross-section of the turbine exhaust diffuser of the gas engine, and determine the average temperature of the turbine exhaust temperature thermocouples based on the weight corresponding to the annular surface where the turbine exhaust temperature thermocouples are located and the temperature of the turbine exhaust temperature thermocouples of a signal with normal signal quality, which can improve the accuracy of the average temperature of the turbine exhaust temperature thermocouples and thus more accurately judge the occurrence of flameout failure.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0127] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0128] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, which can be embodied in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a system including a processor or other system that can fetch instructions from an instruction execution system, apparatus or device and execute instructions), or used in combination with these instruction execution systems, apparatuses or devices.

[0129] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0130] It should be noted that, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. A method for monitoring and protecting a combustion engine flameout, characterized in that: include: The operating condition of the combustion chamber of the combustion engine is monitored by using a preset sensor in the combustion engine, wherein the preset sensor includes an optical flame detector and / or a turbine exhaust temperature thermocouple; Obtaining a turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple; Based on the flame signal detected by the optical flame detector and / or the temperature of the turbine exhaust temperature thermocouple, a preset engine flameout criterion is used to determine whether the engine has flameout.

2. The method according to claim 1, characterized in that The optical flame detector is arranged on the inner wall of the combustion chamber of the gas engine, and the turbine exhaust temperature thermocouple is arranged on the radial section of the turbine exhaust diffuser of the gas engine.

3. The method according to claim 2, characterized in that The optical flame detectors are arranged at equal intervals in the circumferential direction on the inner wall of the combustion chamber, and the turbine exhaust temperature thermocouples are arranged at equal intervals in the circumferential direction on the radial cross section of the turbine exhaust diffuser of the combustion engine.

4. The method according to claim 2, characterized in that: The flame signal includes a flame signal, a no-fire signal, a normal signal and a fault signal. Based on the flame signal detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine is flameout, including: Based on the number and duration of the no-fire signal, normal signal and fault signal detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine has flameout.

5. The method according to claim 4, characterized in that The preset engine flameout criterion includes one or more of a first criterion, a second criterion and a third criterion. The first criterion is that at least two optical flame detectors in the same combustion chamber detect normal signals and no-fire signals, and the delay meets the first preset time length; The second criterion is that at least one optical flame detector in the same combustion chamber detects a fault signal, and at least one optical flame detector detects a normal signal and a no-fire signal, and the delay meets a second preset time length; The third criterion is that the optical flame detectors of the same combustion chamber all detect fault signals.

6. The method according to claim 5, characterized in that Based on the flame signal detected by the optical flame detector, using a preset engine flameout criterion to determine whether the engine has flameout, the method includes: Determining whether the flame signal detected by the optical flame detector satisfies any one of the first criterion, the second criterion and the third criterion; If any one of the first criterion, the second criterion and the third criterion is satisfied, the combustion engine is turned off.

7. The method according to any one of claims 2 to 6, characterized in that: Based on the turbine exhaust temperature thermocouple temperature, using a preset engine flameout criterion to determine whether the engine flameout occurs, the method includes: Based on the turbine exhaust temperature thermocouple temperature or the turbine exhaust temperature thermocouple temperature reduction rate, a preset engine flameout criterion is used to determine whether the engine flameout occurs.

8. The method according to claim 7, characterized in that The preset engine flameout criterion also includes one or more of the fourth criterion, the fifth criterion and the sixth criterion. The fourth criterion is that the difference between the turbine exhaust temperature thermocouple temperature of at least a turbine exhaust temperature thermocouple and the average value of the turbine exhaust temperature thermocouple temperature of all turbine exhaust temperature thermocouples in the combustion engine is less than the first threshold value, and the delay meets the third preset time length; The fifth criterion is that there are at least b turbine exhaust temperature thermocouples whose temperature reduction rate is greater than the second threshold value, and the delay meets the fourth preset time length; The sixth criterion is that the difference between the turbine exhaust temperature thermocouple temperature of at least c turbine exhaust temperature thermocouples and the theoretical value of the turbine exhaust temperature thermocouple under the engine operating conditions is less than the third threshold value, and the delay meets the fifth preset time length.

9. The method according to claim 8, characterized in that a, b, c are determined by formula 1, wherein: X=f1(T0,P0,RH,SPD,P k1, T K2 ,P k2 ,IGV,FR,PWR), where T0 is Ambient temperature, P0 is ambient atmospheric pressure, RH is ambient atmospheric humidity, SPD is engine speed, P k1 is the gas turbine compressor inlet pressure, T K2 is the gas turbine compressor outlet temperature, P k2 is the outlet pressure of the gas turbine compressor, IGV is the opening of the adjustable inlet guide vane of the gas turbine, FR is the fuel quantity, PWR is the active power of the gas turbine generator.

10. The method according to claim 9, characterized in that Based on the turbine exhaust temperature thermocouple temperature, using a preset engine flameout criterion to determine whether the engine flameout occurs, the method includes: Determining whether the temperature of the turbine exhaust temperature thermocouple satisfies any one of the fourth criterion, the fifth criterion and the sixth criterion; If any one of the fourth criterion, the fifth criterion and the sixth criterion is satisfied, the combustion engine is turned off.

11. The method according to claim 9, characterized in that The determination of the average value of the turbine exhaust temperature thermocouple temperature includes: According to the number of the turbine exhaust temperature thermocouple monitoring signals, the signal quality and the turbine exhaust temperature thermocouple temperature of each signal, the average value of the turbine exhaust temperature thermocouple temperature is determined by a signal conditioning optimization algorithm.

12. The method according to claim 11, characterized in that According to the number of the turbine exhaust temperature thermocouple monitoring signals, the signal quality and the turbine exhaust temperature thermocouple temperature of each signal, the average value of the turbine exhaust temperature thermocouple temperature is determined by a signal conditioning optimization algorithm, including: The signal quality includes normal and abnormal. When the number of signals with normal signal quality is greater than a fourth threshold, the turbine exhaust temperature thermocouple temperature average value is a weighted average value of the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality and the corresponding weight of the turbine exhaust temperature thermocouple. When the number of signals with normal signal quality is less than or equal to a fourth threshold value and greater than a fifth threshold value, determining the average value of the turbine exhaust temperature thermocouple temperature according to the turbine exhaust temperature thermocouple temperature of the signals with normal signal quality, the corresponding weight of the turbine exhaust temperature thermocouple, and a confidence interval of a preset theoretical value of the turbine exhaust temperature thermocouple temperature; When the number of signals with normal signal quality is less than or equal to a fifth threshold, the turbine exhaust temperature thermocouple temperature average value is the turbine exhaust temperature thermocouple temperature theoretical value.

13. The method according to claim 12, characterized in that The fourth threshold is 2 / 3 of the total number of all turbine exhaust temperature thermocouples in the gas engine turbine; the fifth threshold is 1 / 3 of the total number of all turbine exhaust temperature thermocouples in the gas engine turbine.

14. The method according to claim 12, characterized in that The corresponding weight of the turbine exhaust temperature thermocouple is determined according to the arrangement of the turbine exhaust temperature thermocouple on the radial cross section of the turbine exhaust diffuser of the combustion engine, and the arrangement includes a single annular surface arrangement and a multi-annular surface arrangement.

15. The method according to claim 14, characterized in that The determination of the corresponding weight of the turbine exhaust temperature thermocouple includes: When the turbine exhaust temperature thermocouple is arranged in a single ring on the radial cross section of the combustion engine turbine exhaust diffuser, the weight is 100%; When the turbine exhaust temperature thermocouple is arranged in multiple rings on the radial cross section of the turbine exhaust diffuser of the combustion engine, the weight is determined by Formula 2 according to the characteristics of each ring surface reflecting the uniformity of the turbine exhaust flow field. The Formula 2 is, w=f(C1, C2…C n ,n), where C1 is the correlation between the characteristic of the first annular surface reflecting the uniformity of the turbine exhaust flow field and the uniformity of the turbine exhaust flow field; C n is the correlation between the characteristic of the nth annular surface reflecting the uniformity of the turbine exhaust flow field and the uniformity of the turbine exhaust flow field, and n is the number of annular surfaces where the turbine exhaust temperature thermocouples are arranged.

16. The method according to claim 12, characterized in that Determining the average value of the turbine exhaust temperature thermocouple temperature according to the turbine exhaust temperature thermocouple temperature of the signal with normal signal quality, the corresponding weight of the turbine exhaust temperature thermocouple, and the confidence interval of the theoretical value of the turbine exhaust temperature thermocouple temperature, including: Determining an initial turbine exhaust temperature thermocouple temperature average value according to the turbine exhaust temperature thermocouple temperature of the signal with normal signal quality and the corresponding weight of the turbine exhaust temperature thermocouple; If the initial turbine exhaust temperature thermocouple temperature average value is within the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, then the initial turbine exhaust temperature thermocouple temperature average value is used as the turbine exhaust temperature thermocouple temperature average value; If the initial turbine exhaust temperature thermocouple temperature average value is greater than the upper limit value of the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, the upper limit value is used as the turbine exhaust temperature thermocouple temperature average value; If the initial turbine exhaust temperature thermocouple temperature average value is less than the lower limit value of the confidence interval of the preset turbine exhaust temperature thermocouple temperature theoretical value, the lower limit value is used as the turbine exhaust temperature thermocouple temperature average value.

17. The method according to claim 12, characterized in that The theoretical value of the turbine exhaust temperature thermocouple temperature is determined by Formula 3, wherein: T x = f2(T0, RH, SPD, P k1, T K1 , P k2 , T K2 , IGV, FR, η F , η T , PWR), where middle, T0 is the ambient temperature, RH is the ambient atmospheric humidity, SPD is the engine speed, P K1 is the gas turbine compressor inlet pressure, T K1 is the gas turbine compressor inlet temperature, P K2 is the gas turbine compressor outlet pressure, T K2 is the gas turbine compressor outlet temperature, IGV is the gas turbine adjustable inlet guide vane opening, FR is the fuel quantity, η F is the combustion efficiency of the gas turbine, η T is the turbine efficiency of the gas turbine, and PWR is the active power of the gas turbine generator.

18. The method according to any one of claims 9 to 17, characterized in that Based on the flame signal detected by the optical flame detector and the temperature of the turbine exhaust temperature thermocouple, using a preset engine flameout criterion to determine whether the engine flameout occurs, the method includes: Based on the number of no-fire signals, the number of normal signals, the turbine exhaust temperature thermocouple temperature and the rate of decrease of the turbine exhaust temperature thermocouple temperature detected by the optical flame detector, a preset engine flameout criterion is used to determine whether the engine has flameout.

19. The method according to claim 18, characterized in that The preset engine flameout criterion also includes: one or both of the seventh criterion and the eighth criterion, The seventh criterion is that at least h optical flame detectors among all optical flame detectors detect normal signals and no-fire signals, and at least i turbine exhaust temperature thermocouple temperatures among all turbine exhaust temperature thermocouple temperatures are less than the sixth threshold value, and the delay meets the sixth preset time length; The eighth criterion is that at least j of all optical flame detectors detect normal signals and no-fire signals, and at least k of all turbine exhaust temperature thermocouples have a temperature reduction rate greater than the seventh threshold, and the delay meets the seventh preset time length.

20. The method according to claim 19, characterized in that The number h, i, j, k of optical flame detectors is determined by the above formula 1.

21. A combustion engine flameout monitoring and protection system, characterized in that: The system is used to perform flameout monitoring protection according to the method described in any one of claims 1 to 20 above, and the system comprises: A monitoring module, used for monitoring the operating condition of the combustion chamber using a preset sensor in the combustion engine, wherein the preset sensor includes an optical flame detector and / or a turbine exhaust temperature thermocouple; An acquisition module, used for acquiring the turbine exhaust temperature thermocouple temperature corresponding to the turbine exhaust temperature thermocouple; The judgment module is used to judge whether the combustion engine has been flamed out based on the flame signal detected by the optical flame detector and / or the temperature of the turbine exhaust temperature thermocouple and using a preset combustion engine flameout criterion.

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