CN117307329A - Gas turbine and combustion chamber backfire monitoring method thereof - Google Patents

Gas turbine and combustion chamber backfire monitoring method thereof Download PDF

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Publication number
CN117307329A
CN117307329A CN202311475517.1A CN202311475517A CN117307329A CN 117307329 A CN117307329 A CN 117307329A CN 202311475517 A CN202311475517 A CN 202311475517A CN 117307329 A CN117307329 A CN 117307329A
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China
Prior art keywords
temperature
passage
premixing
gas turbine
fuel
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Pending
Application number
CN202311475517.1A
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Chinese (zh)
Inventor
申春艳
刘超逸
栾旭
尹峰
孙昌宏
李鑫国
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China Hangfa Gas Turbine Co ltd
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China Hangfa Gas Turbine Co ltd
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Priority to CN202311475517.1A priority Critical patent/CN117307329A/en
Publication of CN117307329A publication Critical patent/CN117307329A/en
Pending legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
    • F02C3/14—Gas-turbine plants characterised by the use of combustion products as the working fluid characterised by the arrangement of the combustion chamber in the plant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
    • F23M11/00—Safety arrangements
    • F23M11/04—Means for supervising combustion, e.g. windows
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D21/00—Measuring or testing not otherwise provided for
    • G01D21/02—Measuring two or more variables by means not covered by a single other subclass
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K13/00—Thermometers specially adapted for specific purposes
    • G01K13/02—Thermometers specially adapted for specific purposes for measuring temperature of moving fluids or granular materials capable of flow
    • G01K13/024—Thermometers specially adapted for specific purposes for measuring temperature of moving fluids or granular materials capable of flow of moving gases
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)

Abstract

The application discloses a gas turbine and a combustion chamber tempering monitoring method thereof, and relates to the technical field of gas turbines. The gas turbine includes a combustor, a compressor, and a sensor assembly. The combustion chamber is internally provided with a premixing channel, and the premixing channel is used for mixing air and fuel to form premixed gas. The sensor assembly is used for acquiring at least the temperature of the outlet gas of the compressor and the temperature of the premixed gas in the premixing passage. According to the combustion chamber backfire monitoring method, the sensor component capable of acquiring the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing channel is arranged, and in the subsequent combustion chamber backfire judgment, the combustion chamber backfire under the unstable state of the gas turbine can be effectively monitored. The combustion chamber tempering monitoring method provided by the application can be suitable for application scenes of improving the automation degree of the gas turbine.

Description

Gas turbine and combustion chamber backfire monitoring method thereof
Technical Field
The application relates to the technical field of gas turbines, in particular to a gas turbine and a combustion chamber tempering monitoring method thereof.
Background
With the improvement of environmental awareness and requirements, low emission of the gas turbine is imperative. The combustion chamber, which is one of the three main core components of a gas turbine, plays an important role in reducing emissions, since it not only can efficiently release the chemical energy of the fuel and convert it into high temperature gas, providing conditions for its work in the turbine, but also dominates the emissions of pollutants, in particular NOx.
The low NOx emission of the gas turbine can be realized by the lean fuel premixed combustion technology, so the technology is a key technology for solving the low NOx emission problem of the gas turbine, but the combustion stability of the lean fuel premixed combustion is poor, and the main reason is that flashback is easy to occur under the low working condition and the high working condition of the gas turbine, namely, flame is transferred into a premixing zone from a combustion chamber. The flashback problem is more pronounced when medium and low heating value fuels are burned. If flashback problems occur in the combustion chamber, the downstream flame can flow up into the premixing zone, which can not only severely damage the components of the combustion chamber such as injectors, swirlers, and nozzles, but also increase pollutant emissions. Based on this, it is desirable to establish a flashback monitoring system to determine whether flashback of the combustion chamber has occurred.
Methods of monitoring combustion chamber flashback in the prior art are various, such as: temperature, pressure or optical sensors, etc. are arranged. Specifically, in the prior art, the arrangement of the temperature sensor means that the temperature of the connection part of the premixed pipeline and the combustion chamber of the gas turbine is monitored through the temperature sensor, and if the temperature data is greater than a certain temperature threshold value, the combustion chamber is judged to be in a backfire state. However, the prior art method can only be applied to combustion chamber flashback monitoring in a stable state of the gas turbine, and if the gas turbine is in an unstable state (for example, the working condition of the gas turbine is changed or the fuel-air ratio of the gas turbine is changed), it is difficult to determine whether flashback occurs in the combustion chamber. With the improvement of the automation degree of the gas turbine, when the gas turbine is in the combustion chamber tempering, the state of the gas turbine needs to be adjusted to protect the gas turbine. If a certain monitoring method cannot monitor whether backfire occurs in the unstable state of the gas turbine, the monitoring method is not suitable for the application scene of the improvement of the degree of automation. That is, the combustion chamber backfire monitoring method based on the temperature sensor in the prior art is not suitable for the application scene of improving the automation degree of the gas turbine.
Disclosure of Invention
The purpose of the application is to provide a gas turbine and a combustion chamber backfire monitoring method thereof, so as to solve the technical problem that whether the backfire of the gas turbine occurs cannot be accurately judged based on a temperature sensor in the prior art.
In order to achieve the above purpose, the present application provides the following technical solutions:
in a first aspect, the present application presents a gas turbine that includes a combustion chamber, a compressor, and a sensor assembly. The combustion chamber is internally provided with a premixing channel, and the premixing channel is used for mixing air and fuel to form premixed gas. The sensor assembly is used for acquiring at least the temperature of the outlet gas of the compressor and the temperature of the premixed gas in the premixing passage.
As a specific aspect of the technical solutions of the present application, the combustion chamber includes: an outer housing; the inner shell is sleeved in the outer shell, and an air flow passage is arranged between the inner shell and the outer shell; an end cap for plugging an end of the outer housing; the central spray rod penetrates through the end cover, the head end of the central spray rod is positioned outside the combustion chamber, the tail end of the central spray rod extends to the inside of the inner shell, the premixing channel comprises a first premixing channel arranged between the central spray rod and the inner shell, and the first premixing channel is communicated with the air flow channel; the first fuel conveying structure is arranged on the end cover and used for conveying fuel to the first premixing passage.
As a specific solution in the technical solution of the present application, the central spray rod includes: a diffusion spray bar; the premixing spray rod is sleeved outside the diffusion spray rod, and the first premixing channel is arranged between the premixing spray rod and the inner shell; the premixing passage further comprises a second premixing passage arranged between the premixing spray rod and the diffusion spray rod, and the second premixing passage is communicated with the air flow passage.
As a specific aspect of the technical solution of the present application, the fuel injection device further includes a second fuel delivery structure, disposed on the end cover, for delivering fuel to the second premixing channel; the second premix passage includes a first fuel passage disposed in the end cover with an end opening of the first fuel passage facing the second premix passage.
As a specific scheme in the technical scheme of the application, a first cyclone is arranged in the first premixing channel; and a second cyclone is arranged in the second premixing passage.
As a specific scheme in the technical scheme, the inside of diffusion spray lance is provided with the second fuel passageway, the end of diffusion spray lance is provided with a plurality of diffusion orifices, every diffusion orifice all with the second fuel passageway is linked together.
As a specific scheme in the technical scheme, a plurality of through holes are formed in the side wall of the inner shell, and the through holes are used for communicating the inside of the inner shell with the air flow channel.
As a specific aspect of the technical solutions of the present application, the first fuel delivery structure includes: a third fuel passage open to the end cap; at least one fuel spray lance, each fuel spray lance all set up in the end cover, and the head end of every fuel spray lance all with third fuel channel is linked together, and the end of every fuel spray lance all extends to the inside of first premix passageway.
As a specific aspect of the technical solutions of the present application, the sensor assembly includes:
the temperature sensing probes of the first temperature sensors extend to the first premixing channel; at least one second temperature sensor for measuring the temperature of the compressor inlet; at least one first pressure sensor for measuring the pressure at the compressor inlet; at least one second pressure sensor for measuring the pressure at the compressor outlet.
In a second aspect, the present application provides a method of monitoring flashback in a combustion chamber of a gas turbine, the method comprising: acquiring a first temperature, wherein the first temperature is the temperature of the premixed gas in the premixing channel; acquiring a second temperature, wherein the second temperature is the gas temperature of an outlet of the gas compressor; based on the first temperature and the second temperature, it is determined whether a combustion chamber of the gas turbine is tempered.
As a specific aspect of the technical solution of the present application, the obtaining the first temperature includes: acquiring a first temperature average value, wherein the first temperature average value is the temperature average value of each first temperature sensor, and acquiring the first temperature based on the first temperature average value; the obtaining the second temperature includes: the method comprises the steps of obtaining a third temperature average value, wherein the third temperature average value is a temperature average value of each second temperature sensor, obtaining a first pressure average value, wherein the first pressure average value is a pressure average value of each first pressure sensor, obtaining a second pressure average value, wherein the second pressure average value is a pressure average value of each second pressure sensor, and obtaining the second temperature based on the first pressure average value, the second pressure average value and the third temperature average value.
As a specific aspect of the present application, the determining whether the combustion chamber of the gas turbine is tempered based on the first temperature and the second temperature includes: acquiring a third temperature, wherein the third temperature is equal to the sum of the second temperature and a threshold temperature, and the threshold temperature is preset; if the first temperature is greater than or equal to a third temperature, determining that backfire occurs in the combustion chamber of the gas turbine; otherwise, judging that tempering does not occur.
Compared with the prior art, the beneficial effects of this application are:
by arranging the sensor assembly capable of acquiring the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing passage, the combustion chamber flashback monitoring method provided by the application is combined, and in the subsequent combustion chamber flashback judgment, the combustion chamber flashback in the unstable state of the gas turbine can be effectively monitored. The combustion chamber tempering monitoring method provided by the application can be suitable for application scenes of improving the automation degree of the gas turbine.
Drawings
FIG. 1 is a schematic view of a gas turbine combustor according to an embodiment of the present disclosure;
FIG. 2 is a schematic illustration of an end cap and center spray bar according to an embodiment of the present application;
FIG. 3 is a schematic flow diagram of compressed air in the combustor of FIG. 1 according to an embodiment of the present application;
FIG. 4 is a schematic flow diagram of fuel in the combustion chamber of FIG. 1 according to an embodiment of the present application;
FIG. 5 is a flow chart of a method for monitoring flashback in a combustion chamber of a gas turbine according to an embodiment of the present application.
In the figure: 1. an outer housing; 2. an inner housing; 21. a through hole; 3. an end cap; 31. a third fuel passage; 32. a first fuel passage; 33. a fuel boom; 4. a diffusion spray bar; 41. diffusing the spray holes; 5. premixing a spray rod; 61. an air flow passage; 62. a first premix passage; 63. a second premix passage; 64. a second fuel passage; 7. a first cyclone; 8. a second cyclone; 9. a first temperature sensor.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
It should be noted that, in the description of the present application, the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate an orientation or a positional relationship based on that shown in the drawings, which are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.
Furthermore, it should be understood that the dimensions of the various elements shown in the figures are not drawn to actual scale, e.g., the thickness or width of some layers may be exaggerated relative to other layers for ease of description.
It should be noted that like reference numerals and letters refer to like items in the following figures, and thus once an item is defined or illustrated in one figure, no further detailed discussion or description thereof will be necessary in the following description of the figures.
Before understanding the embodiments presented herein, it should be apparent that temperature sensors have been used in the prior art to monitor the temperature at the junction of a gas turbine premix tube and a combustor to determine whether flashback has occurred in the combustor of the gas turbine. For example: if the temperature at the connection of the premixing pipeline and the combustion chamber is higher than a certain temperature T s For example, setting to 420 ℃, the combustion chamber is considered to be tempered. It will be readily appreciated that during steady operation of the gas turbine, the temperature in the premix circuit or combustor (generally at T s -50 ℃, e.g. around 370 ℃) is also stable, whereas the temperature inside the combustion chamber is typically above 1000 ℃. That is, during steady operation of the gas turbine, if a flashback of the combustion chamber occurs, the temperature at the junction of the premix conduit and the combustion chamber must be greatly increased, in other words, if the junction of the premix conduit and the combustion chamber is suddenly greatly increased (i.e.Lifting from 370 ℃ to 420 ℃) then the combustion chamber can be considered to be tempered. It should be appreciated that during the non-steady state of the gas turbine, the temperature at the junction of the premix conduit and the combustion chamber is also non-steady, i.e., in the non-steady state application scenario of the gas turbine, even if the combustion chamber is not tempered, the temperature at the junction of the premix conduit and the combustion chamber may still exceed 420 ℃, i.e., it is considered that tempering has occurred. In order to avoid the situation that the combustion chamber is tempered when the gas turbine is in an unstable state, the temperature threshold value can only be adjusted to be higher, for example, the temperature threshold value is adjusted to be higher than 470 ℃ from 420 ℃, that is, the temperature of the connection part of the premixing pipeline and the combustion chamber exceeds 470 ℃ when the gas turbine is in an unstable state, and the combustion chamber is considered to be tempered. However, as is evident from the foregoing, since the temperature at the junction of the premix pipe and the combustion chamber is unstable during the unstable state of the gas turbine, the temperature at the junction of the premix pipe and the combustion chamber cannot exceed 470 ℃ in some cases even if the combustion chamber is tempered. That is, if the temperature threshold is set too high (e.g., 470 ℃), the gas turbine cannot accurately detect even if flashback occurs in the combustion chamber.
It is to be understood that the service life of a gas turbine is typically tens of thousands to hundreds of thousands of hours. In the long-term use process of the gas turbine, the working time length (generally several minutes to tens of minutes) of the gas turbine in an unstable state is almost negligible relative to the working time length (generally several tens to thousands of hours) of the gas turbine in a stable state. That is, since the gas turbine is in an unstable state for a short period of time, even if tempering occurs, it is difficult to adjust the state of the gas turbine by taking measures in time, and since the time is short, damage to the gas turbine caused by short-time tempering is limited. Therefore, the combustion chamber backfire monitoring methods in the prior art are focused on monitoring backfire when the gas turbine is in a stable state, and if the backfire of the combustion chamber is monitored, the state of the gas turbine is immediately adjusted or stopped for maintenance.
It is readily appreciated that although the gas turbine is in an unstable state (either with a change in gas turbine operating conditions or with a change in gas turbine fuel), the resulting combustor flashback has limited damage to the gas turbine. However, during long-term use of the gas turbine, if the gas turbine is in an unstable state more times, the accumulated damage to the gas turbine is still considerable. With the improvement of the degree of automation, if it is determined that the gas turbine is tempered, the state of the gas turbine can be adjusted based on an automation program so as to avoid the occurrence of tempering. However, as can be seen from the foregoing, the flashback monitoring method in the prior art is not capable of accurately monitoring whether the gas turbine is in an unstable state or not.
To solve this technical problem, as shown in fig. 1 to 4, the present application provides an embodiment of a gas turbine. Specifically, the gas turbine includes a combustor, a compressor (prior art and therefore not shown in the figures), and a sensor assembly. Wherein, be provided with the premix passageway in the combustion chamber, the premix passageway is used for air and fuel to mix and forms the premix gas. The sensor assembly is used for acquiring at least the outlet temperature of the compressor and the temperature of the premix gas in the premix passage.
It should be clear from the background art that lean premixed combustion refers to a technique in which air and fuel are mixed in a premixing passage (i.e., a premixing zone) in advance to form a premixed gas, and the premixed gas is then fed into a combustion chamber to be combusted. Because the technology is a mature prior art, redundant description is omitted. It will be readily appreciated that all gas turbines based on lean premixed combustion technology have premixing passages, except that the configuration of premixing passages for different types of gas turbines may vary and will not be described in detail herein.
From the above, it is clear that if flashback occurs in the combustion chamber, combustion occurs in the premix passage, that is, the temperature of the premix gas in the premix passage must rise. However, the temperature rise of the premix gas in the premix passage does not represent a certain flashback of the combustion chamber (e.g., a gas turbine operating condition rise). It is emphasized that the premix gas is a gas formed by mixing air and fuel, whereas premix gas based on lean premixed combustion technology has a high air content and a low fuel content. In gas turbines, air is typically derived from the compressor, that is, the temperature of the premixed gas based on lean premixed combustion technology is closely related to the temperature of the air from the compressor.
It should be clear that in gas turbines, the compressor is mainly used to boost the pressure of the air entering the combustion chamber, i.e. to compress the air, in order to increase the efficiency of the thermodynamic cycle of the combustion chamber. It is easy to understand that if the working condition of the gas turbine is high, the pressure of the compressed air generated by the compressor is high; if the working condition of the gas turbine is low, the pressure of the compressed air generated by the gas compressor is small. It is also clear that during air compression the air temperature is positively correlated with the air pressure, i.e. the higher the operating conditions of the gas turbine, the higher the temperature of the compressed air, i.e. the temperature of the premix gas.
It is readily appreciated that the sensor of the gas turbine of the embodiments of the present application is capable of acquiring not only the temperature of the premix gas in the premix passage, but also the temperature of the compressor outlet. That is, in embodiments of the present application, it may be determined whether flashback of the combustion chamber has occurred based on the temperature of the premix gas and the compressed air temperature at the compressor outlet (see below for specific methods). Compared with the prior art, whether the combustion chamber is tempered can only be determined based on the temperature of the connection part of the premixing pipeline and the combustion chamber, and whether the combustion chamber of the gas turbine is tempered can be determined more accurately by the gas turbine provided by the embodiment of the application in cooperation with the method provided by the embodiment of the application.
As can be seen from the foregoing, the gas turbine provided in the embodiments of the present application does not limit the structure of the combustion chamber, but only needs to have a premixing passage. That is, in embodiments of the present application, the combustion chamber of the gas turbine may be any of the combustion chambers commonly available on the market based on lean premixed combustion technology. That is, in the embodiments of the present application, the premixing passage may be any configuration of premixing passage, and is not limited in any way.
In one embodiment of the present application, as shown in fig. 1-4, a combustion chamber of a gas turbine includes an outer casing 1, an inner casing 2, an end cover 3, a center lance, and a first fuel delivery structure. Wherein, the inner shell 2 is sleeved in the outer shell 1, and an air flow passage 61 is arranged between the inner shell and the outer shell 1. The end cap 3 is used to close off the end of the outer housing 1. The center spray boom penetrates through the end cover 3, the head end of the center spray boom is located outside the combustion chamber, and the tail end of the center spray boom extends to the inside of the inner shell 2. The premixing passage includes a first premixing passage 62 provided between the center boom and the inner housing 2, the first premixing passage 62 being in communication with the air flow passage 61. A first fuel delivery structure is provided to the end cover 3 for delivering fuel to the first premix passage 62.
It should be clear that in the embodiments of the present application, we define the end of a fluid (e.g., air, fuel, or premix gas, etc.) that enters a component or structure (e.g., outer housing 1, first fuel passage 32, or center boom, etc.) as the head end of the component or structure; one end of a fluid flowing out of a component or structure is defined as the end of the component or structure.
Specifically, in the embodiment of the present application, the flow path of the compressed air from the compressor in the air flow path 61 is shown as path a in fig. 3. Since the first premix passage 62 communicates with the air flow passage 61, compressed air located in the air flow passage 61 may also enter the first premix passage 62 along the path C in fig. 3. The air entering the first premix passage 62 may be mixed with the fuel in the first premix passage 62 to form a premix gas. After the premix gas is discharged from the end of the first premix passage 62, a combustion reaction occurs in the inner casing 2. It is to be appreciated that in embodiments of the present application, the temperature of the premix gas in the first premix passage 62 may be measured to represent the temperature of the premix gas in the premix passage of the gas turbine.
It should be clear that during operation of the gas turbine combustion takes place inside the inner housing 2. It is readily understood that the higher the operating conditions of the gas turbine, the higher the temperature of the inner casing 2. As can be seen from the foregoing, the air flow channel 61 for supplying compressed air is provided between the outer casing 1 and the inner casing 2, that is, if the operating condition of the gas turbine is higher, the higher the temperature of the compressed air, that is, the higher the temperature of the premixed gas to be subsequently generated, is based on the warming-up effect of the inner casing 2 on the compressed air. From the foregoing, it can be seen that the embodiment of the present application mainly determines whether the combustion chamber is tempered based on the temperature of the premixed gas and the temperature of the compressed air at the outlet of the compressor, so as to avoid the influence of the temperature of the inner casing 2 itself on the temperature of the premixed gas during the lifting operation of the gas turbine, and influence the determination result. In a specific embodiment of the present application, as shown in fig. 1, the sidewall of the inner housing 2 is provided with a plurality of through holes 21, and the through holes 21 are used to communicate the inside of the inner housing 2 with the air flow path 61. Based on the through-hole 21, during operation of the gas turbine, part of the compressed air from the compressor can enter the interior of the inner casing 2 along a path B as shown in fig. 3. Because the temperature of compressed air is lower, consequently compressed air can cool down the lateral wall of inner shell 2, reduces gas turbine and is in under the circumstances of different operating modes, and inner shell 2 is to the promotion difference of compressed air temperature, also can be further promote the accuracy of whether tempering judgement takes place for follow-up combustion chamber.
It should be apparent that in one particular embodiment of the present application, the combustion chamber of the gas turbine set forth in the embodiments of the present application is provided with staged combustion functionality. As shown in fig. 1 and 2, the center boom includes a diffusion boom 4 and a premix boom 5. Wherein, the premixing spray rod 5 is sleeved outside the diffusion spray rod 4, and the first premixing channel 62 is arranged between the premixing spray rod 5 and the inner shell 2; the premix passage further includes a second premix passage 63 provided between the premix boom 5 and the diffusion boom 4, the second premix passage 63 being in communication with the air flow passage 61.
Specifically, since the second premixing passage 63 is in communication with the air flow passage 61, part of the compressed air in the air flow passage 61 can enter the second premixing passage 63 as shown by a path D in fig. 3 to mix with the fuel in the second premixing passage 63 to form a premixed gas, and then enter the interior of the inner casing 2 through the second premixing passage 63 to form combustion. It will be readily appreciated that in embodiments of the present application, the second premix passage 63 may be designed as a primary premix passage and the first premix passage 62 as a secondary premix passage. It should be clear that, in the embodiments of the present application, the main premixing channel refers to a premixing channel for generating premixed gas when the gas turbine is in a high working condition, so as to increase the amount of premixed gas generated, so as to ensure the combustion stability when the gas turbine is lifted from a low working condition to a high working condition. The secondary premix passage refers to a premix passage for generating premix gas at low operating conditions of the gas turbine. That is, the secondary premix passage produces less premix gas and the primary premix passage produces more premix gas.
It should be clear that in embodiments of the present application, the temperature of the premix gas in the primary premix passage may be measured, as well as the temperature of the premix gas in the secondary premix passage. It will be readily appreciated that the temperature of the premix gas in the main premix passage is less disturbed by the outside (e.g. the warming effect of the inner housing 2 on the air or fuel) due to the large amount of premix gas generated by the main premix passage, i.e. the large amount of air in the main premix passage. To ensure accuracy of monitoring, the premix gas temperature in the main premix passage may preferably be measured to represent the premix gas temperature of the premix passage in the combustion chamber.
In the embodiment of the present application, if the second premixing passage 63 is a main premixing passage, as shown in fig. 1, in order to measure the temperature of the premixed gas in the second premixing passage 63, a temperature sensor is required to pass through the inner housing 2 and the premixing boom 5 in sequence. It will be readily appreciated that during operation of the gas turbine, large vibrations are generated, which can easily cause damage to the temperature sensor if it passes through the inner casing 2 and the premix boom 5 at the same time. To increase the service life of the temperature sensor, in another embodiment of the present application, the first premix passage 62 is designed as a main premix passage; while the second premix passage 63 is designed as a secondary premix passage. As shown in fig. 1, in the embodiment of the present application, if the temperature of the premixed gas in the main premixing passage needs to be measured, only the temperature sensor needs to pass through the inner casing 2, which is beneficial to prolonging the service life of the temperature sensor.
It is clear that in order to ensure combustion stability at start-up or at low operating conditions of the gas turbine. As shown in fig. 1 and 2, the diffusion boom 4 is internally provided with a second fuel passage 64, and the end of the diffusion boom 4 is provided with a plurality of diffusion nozzle holes 41, each of the diffusion nozzle holes 41 being in communication with the second fuel passage 64. It is easily understood that the second fuel passage 64 is used to deliver fuel directly to the inside of the inner case 2 through the diffusion nozzle holes 41 for combustion. That is, the fuel ejected from the second fuel passage 64 forms diffusion combustion inside the inner housing 2. Compared with premixed combustion, the diffusion combustion is more stable, and is beneficial to maintaining the combustion stability of the gas turbine at the time of starting or under low working conditions. Specifically, in the embodiment of the present application, the path of the fuel in the second fuel passage 64 into the interior of the inner housing 2 is shown as a route G in fig. 4.
It should be apparent that in the embodiments of the present application, the first fuel delivery structure is primarily used to deliver fuel to the first fuel passage 32. Thus, in embodiments of the present application, the first fuel delivery structure may be any structure capable of delivering fuel. For example: the first fuel delivery structure may be similar to the diffusion boom 4 in a tubular configuration (not shown) with the tube extending through the end cap 3, the tube having a head end located outside the combustion chamber and a tail end extending to the first premix passage 62; alternatively, as shown in fig. 1 and 2, the first fuel delivery structure includes a third fuel passage 31 open to the end cover 3, at least one fuel rail 33. Specifically, each fuel boom 33 is disposed on the end cover 3, and a head end of each fuel boom 33 is in communication with the third fuel passage 31, and a tail end of each fuel boom 33 extends into the first premixing passage 62. Specifically, in the embodiment of the present application, the path of the fuel entering the first premix passage 62 is shown as path E in FIG. 4.
It should be appreciated that in one embodiment of the present application, the first fuel delivery structure may be just a third fuel passage 31 provided in the end cover 3, with the third fuel passage 31 opening out toward the first premix passage 62 (not shown, similar to the first fuel passage 32 hereinafter). It should be clear that in the embodiments of the present application, if the gas turbine also has a second premix passage 63, it is also possible to open a part of the end of the third fuel passage 31 towards the first premix passage 62 and another part towards the second premix passage 63. That is, the fuel is simultaneously supplied to the first and second premix passages 62 and 63 through only the third fuel passage 31.
In one embodiment of the present application, the combustion chamber of the gas turbine further comprises a second fuel delivery structure provided to the end cover 3 for delivering fuel to the second premix passage 63. It will be readily appreciated that in embodiments of the present application, the second fuel delivery structure is similar to the first fuel delivery structure described above, and need not be limited in any way, for example: the second fuel delivery structure may be similar to the diffusion boom 4; or the second fuel delivery structure is similar to the first fuel delivery structure.
In a particular embodiment of the present application, as shown in FIGS. 1 and 2, the second premix passage 63 includes a first fuel passage 32 disposed in the end cover 3, with the end of the first fuel passage 32 opening toward the second premix passage 63. Specifically, in the embodiment of the present application, the path of the fuel in the first fuel passage 32 into the second premix passage 63 is shown as path F in FIG. 4.
It should be clear that in the embodiments of the present application, a premixed gas with better uniformity is obtained in order that the fuel and air can be mixed more uniformly. As shown in fig. 1, a first swirler 7 is provided in the first premix passage 62. The first swirler 7 enables a more uniform mixing of the air and fuel in the first premix passage 62.
It will be readily appreciated that in order to enable a more uniform mixing of the fuel and air in the second premix passage 63 as well. In another embodiment of the present application, as shown in fig. 1 and 2, a second swirler 8 is provided in the second premix passage 63.
From the foregoing, it is appreciated that in embodiments of the present application, the sensor assembly is configured to obtain at least an outlet temperature of the compressor and a temperature of the premix gas in the premix passage. That is, the sensor assembly may be any combination of a plurality of sensors capable of acquiring the outlet temperature of the compressor and the temperature of the premix gas in the premix passage.
Specifically, in embodiments of the present application, the outlet temperature of the compressor and the temperature of the premix gas in the premix passage may be obtained based on a plurality of temperature sensors. For example: in one embodiment of the present application, the sensor assembly comprises at least one first temperature sensor 9 and at least one third temperature sensor (not shown in the figures).
In the embodiment of the present application, the first temperature sensor 9 is used to measure the temperature of the premix gas in the first premix passage 62; and a third temperature sensor is used to measure the temperature of the compressed air at the compressor outlet. It is easy to understand that the temperature uniformity of the fluid is generally poor, and in order to accurately measure the temperature of the premixed gas and the compressed air, in the embodiment of the present application, a plurality of first temperature sensors 9 and a plurality of third temperature sensors may be provided. The temperature values of the premix gas and the compressed air are determined using the measured average values of the plurality of temperature sensors.
In order to avoid that too many temperature sensors are arranged at the outlet of the compressor, the temperature of the compressed air can be accurately measured. In one embodiment of the present application, the sensor assembly comprises at least two first temperature sensors 9, at least one second temperature sensor, at least one first pressure sensor and at least one second pressure sensor. The second temperature sensor is used for measuring the temperature of the inlet of the compressor. The first pressure sensor is used for measuring the pressure of the inlet of the compressor; and a second pressure sensor is used to measure the pressure at the compressor outlet. As shown in fig. 1, the first temperature sensors 9 are uniformly distributed around the axis of the first premixing passage 62, and the temperature sensing probe of each first temperature sensor 9 extends to the first premixing passage 62, that is, the first temperature sensor 9 is used to measure the temperature of the premixed gas in the first premixing passage 62.
It will be readily appreciated that the air entering the compressor inlet comes from the surroundings of the compressor, that is to say the second temperature sensor only needs to measure the temperature of the air surrounding the compressor. It should be noted that when air is compressed from one volume to another, the change in air temperature is positively correlated with the change in air pressure, that is, the temperature of the compressed air can be obtained based on the change in air front-back pressure before and after the compressor compresses the air. In other words, in the embodiment of the present application, there is no need to provide a plurality of temperature sensors to measure the temperature of the compressed air, and only a small number of pressure sensors (i.e., one first pressure sensor and one second pressure sensor) are required to obtain the temperature of the compressed air.
It should be clear that in embodiments of the present application, there may be no limitation on the temperature sensor and the pressure sensor. It can be any commonly used temperature sensor and pressure sensor in the market. It should be noted that, due to the higher temperature of the gas turbine during operation, in order to provide a better service life of the temperature sensor, in embodiments of the present application, the temperature sensor may employ a type K thermocouple having a heat resistant temperature greater than 1000 ℃.
It should be apparent that the gas turbine provided in the embodiments of the present application is provided with a sensor assembly capable of acquiring the temperature of the compressed air at the compressor outlet and the temperature of the premix gas in the premix passage. In the subsequent combustion chamber flashback determination, the combustion chamber flashback of the gas turbine in an unstable state can be accurately monitored based on the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing passage. That is, the gas turbine engine provided by the application can be suitable for the application scene that the degree of automation of the gas turbine is promoted.
After all embodiments of the gas turbine set forth herein are described, all embodiments of the method for monitoring combustion chamber flashback of a gas turbine set forth herein are described below.
As shown in fig. 5, an embodiment of the present application proposes a combustion chamber flashback monitoring method of a gas turbine, which is characterized in that the method specifically includes:
step S100: a first temperature is obtained.
Specifically, in embodiments of the present application, the first temperature is the temperature of the premix gas in the premix passage (e.g., first premix passage 62 and/or second premix passage 63). As can be seen from the foregoing, the temperature of the premixed gas may be a temperature value at a certain point in the premixed gas, or may be an average value of temperature values at a plurality of points in the premixed gas. That is, the first temperature may be a temperature value at a certain point, or may be an average value of temperature values at a plurality of points, which is not described in detail herein.
In a specific embodiment of the present application, the temperature of the premix gas is precisely obtained. Step S100: the obtaining of the first temperature may include,
step S110: a first temperature average is obtained.
Specifically, the first temperature average value is the temperature average value of each first temperature sensor 9. In the embodiment of the present application, the number of the first temperature sensors 9 is at least two.
Step S120: based on the first temperature average value, a first temperature is obtained.
Specifically, in the embodiment of the present application, the first temperature average value is the first temperature.
Step S200: a second temperature is obtained.
Specifically, in the embodiment of the present application, the step S100 and the step S200 are only used to distinguish between two steps, and do not represent the execution sequence of the two steps. For example, in the embodiment of the present application, step S100 may be performed first, and then step S200 may be performed. Step S200 may be performed first, and step S100 may be performed; step S100 and step S200 may also be performed simultaneously.
In an embodiment of the present application, the second temperature is a gas temperature of the compressor outlet. It is readily understood that in embodiments of the present application, the second temperature may be similar to the first temperature, and may be the temperature of a certain point in the gas at the compressor outlet, or may be an average of the temperatures of a plurality of points in the gas at the compressor outlet.
From the foregoing, it can be seen that in order to avoid providing too many temperature sensors in the compressor. In one embodiment of the present application, step S200: the obtaining of the second temperature may include,
step S210: a third temperature average value is obtained.
Specifically, the third temperature average value is a temperature average value of each second temperature sensor. In an embodiment of the present application, the second temperature sensor is used to measure the air temperature at the compressor inlet. The air temperature at the inlet of the compressor is generally balanced, that is, only one second temperature sensor may be provided to obtain the third temperature average value in the embodiment of the present application. In other words, the third temperature average value may be a measurement value of one second temperature sensor, or may be an average value of measurement values of a plurality of second temperature sensors.
Step S220: a first pressure average is obtained.
Specifically, the first pressure average value is a pressure average value of each first pressure sensor. In an embodiment of the present application, the first pressure sensor measures the pressure at the compressor inlet. It is easily understood that in the embodiment of the present application, the first pressure average value may be a measurement value of one first pressure sensor, or may be an average value of measurement values of a plurality of first pressure sensors.
Step S230: a second pressure average is obtained.
Specifically, the second pressure average value is a pressure average value of each second pressure sensor. In an embodiment of the present application the second pressure sensor is used to measure the pressure at the compressor outlet. It is easily understood that in the embodiment of the present application, the first pressure average value may be a measurement value of one second pressure sensor, or may be an average value of measurement values of a plurality of second pressure sensors.
Step S240: the second temperature is obtained based on the first pressure average, the second pressure average, and the third temperature average.
Specifically, in the embodiment of the present application, the second temperature may be obtained empirically based directly on the first pressure average value, the second pressure average value, and the third temperature average value. For example, in one embodiment of the present application, the second temperature may be obtained based on the following calculation formula:
wherein T is 1 Representing a third temperature average; t (T) 2 Representing a second temperature; p (P) 1 Representing a first pressure average; p (P) 2 Representing a second pressure average; k is a constant and is typically 1.4.
Of course, in other embodiments of the present application, the above T may also be applied 2 The value is corrected to obtain a second temperature. For example, as described above, the compressed air is warmed by the inner casing 2 during the flow along the air flow path 61, and the empirical value T of the warming can be based on 3 And T 2 A second temperature is obtained. For example, in another embodiment of the present application, the second temperature may be obtained based on the following calculation formula:
wherein T is 1 Representing a third temperature average; t (T) 2 Representing a second temperature; t (T) 3 An empirical value representing the temperature rise of the compressed air; p (P) 1 Representing a first pressure average; p (P) 2 Representing a second pressure average; k is a constant and is typically 1.4.
Step S300: based on the first temperature and the second temperature, it is determined whether the combustion chamber of the gas turbine is tempered.
It should be clear that in the embodiments of the present application, the first temperature refers to the temperature of the premix gas in the premix channel; the second temperature refers to the temperature of the compressed air ejected from the compressor outlet. The first temperature is theoretically close to the second temperature, regardless of other factors. For example, in one embodiment of the present application, a flashback is considered to occur in a combustion chamber of a gas turbine if the first temperature is greater than the second temperature. However, considering that the temperature of the compressed air is raised during the flow process, and the compressed air is mixed with the fuel to form a premixed gas, the fuel reduces the temperature of the compressed air. In one embodiment of the present application, step S300: based on the first temperature and the second temperature, determining whether the combustion chamber of the gas turbine is tempered includes,
Step S310: a third temperature is obtained.
Specifically, in the embodiment of the present application, the third temperature is equal to the sum of the second temperature and the threshold temperature, and the threshold temperature is preset. The threshold temperature is mainly used for making up the influence of the external environment on the temperature of the compressed air after the compressed air flows out of the outlet of the air compressor, and can be an empirical value obtained through multiple experiments. It is readily understood that the threshold temperature may be different for different gas turbines.
In one embodiment of the present application, the threshold temperature may range from 10 ℃ or more to 90 ℃ or less. Specifically, in the embodiment of the present application, the threshold temperature may be any one temperature of 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃ and 90 ℃, or any temperature between any two adjacent temperatures.
Step S320: if the first temperature is greater than or equal to the third temperature, determining that flashback occurs in the combustion chamber of the gas turbine; otherwise, judging that tempering does not occur.
It should be clear that the combustion chamber flashback monitoring method of the gas turbine provided by the embodiment of the application can comprehensively judge whether the combustion chamber is tempered or not through the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing passage. The combustion chamber tempering monitoring device can effectively monitor the combustion chamber tempering of the gas turbine in an unstable state. The combustion chamber tempering monitoring method provided by the application can be suitable for application scenes of improving the automation degree of the gas turbine.
In the foregoing embodiments presented in the present application, the descriptions of the embodiments are emphasized, and for a part of the detailed description of one embodiment, reference may be made to related descriptions of other embodiments.
Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A gas turbine, comprising:
the combustion chamber is internally provided with a premixing passage, and the premixing passage is used for mixing air and fuel to form premixing gas;
a compressor;
and the sensor assembly is at least used for acquiring the temperature of the outlet gas of the compressor and the temperature of the premixed gas in the premixing passage.
2. The gas turbine of claim 1, wherein the combustion chamber comprises:
an outer case (1);
an inner shell (2) sleeved in the outer shell (1), and an air flow passage (61) is arranged between the inner shell and the outer shell (1);
an end cap (3) for plugging the end of the outer housing (1);
The central spray rod penetrates through the end cover (3), the head end of the central spray rod is positioned outside the combustion chamber, the tail end of the central spray rod extends to the inside of the inner shell (2), the premixing passage comprises a first premixing passage (62) arranged between the central spray rod and the inner shell (2), and the first premixing passage (62) is communicated with the air flow passage (61);
a first fuel delivery structure is disposed at the end cap (3) for delivering fuel to the first premix passage (62).
3. The gas turbine of claim 2, wherein the center spray bar comprises:
a diffusion spray bar (4);
the premixing spray rod (5) is sleeved outside the diffusion spray rod (4), and the first premixing channel (62) is arranged between the premixing spray rod (5) and the inner shell (2); the premixing passage further comprises a second premixing passage (63) arranged between the premixing spray rod (5) and the diffusion spray rod (4), and the second premixing passage (63) is communicated with the air flow passage (61).
4. A gas turbine according to claim 3, further comprising a second fuel delivery structure provided to the end cover (3) for delivering fuel to the second premix passage (63); the second premixing passage (63) includes a first fuel passage (32) provided to the end cover (3), and a distal opening of the first fuel passage (32) is directed toward the second premixing passage (63).
5. The gas turbine according to claim 4, characterized in that a first swirler (7) is provided in the first premixing passage (62); a second swirler (8) is arranged in the second premixing passage (63).
6. A gas turbine according to claim 3, characterized in that the diffusion boom (4) is internally provided with a second fuel passage (64), the diffusion boom (4) being provided at its end with a plurality of diffusion nozzles (41), each diffusion nozzle (41) being in communication with the second fuel passage (64).
7. Gas turbine according to any one of claims 2 to 6, wherein a plurality of through holes (21) are provided in a side wall of the inner casing (2), the through holes (21) being for communicating the interior of the inner casing (2) with the air flow passage (61).
8. The gas turbine of any one of claims 2 to 6, wherein the first fuel delivery structure comprises:
a third fuel passage (31) provided in the end cover (3);
at least one fuel spray rod (33), each fuel spray rod (33) is arranged on the end cover (3), the head end of each fuel spray rod (33) is communicated with the third fuel channel (31), and the tail end of each fuel spray rod (33) extends to the inside of the first premixing channel (62).
9. The gas turbine of claim 8, wherein the sensor assembly comprises:
at least two first temperature sensors (9), wherein each first temperature sensor (9) is uniformly distributed around the axis of the first premixing passage (62), and the temperature sensing probe of each first temperature sensor (9) extends to the first premixing passage (62);
at least one second temperature sensor for measuring the temperature of the compressor inlet;
at least one first pressure sensor for measuring the pressure at the compressor inlet;
at least one second pressure sensor for measuring the pressure at the compressor outlet.
10. A method of monitoring flashback in a combustion chamber of a gas turbine, the method comprising:
acquiring a first temperature, wherein the first temperature is the temperature of the premixed gas in the premixing channel;
acquiring a second temperature, wherein the second temperature is the gas temperature of an outlet of the gas compressor;
based on the first temperature and the second temperature, it is determined whether a combustion chamber of the gas turbine is tempered.
CN202311475517.1A 2023-11-07 2023-11-07 Gas turbine and combustion chamber backfire monitoring method thereof Pending CN117307329A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311475517.1A CN117307329A (en) 2023-11-07 2023-11-07 Gas turbine and combustion chamber backfire monitoring method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311475517.1A CN117307329A (en) 2023-11-07 2023-11-07 Gas turbine and combustion chamber backfire monitoring method thereof

Publications (1)

Publication Number Publication Date
CN117307329A true CN117307329A (en) 2023-12-29

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Country Link
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