A gas turbine and a method of monitoring the backfire of a combustion chamber thereof

Abstract

The application discloses a gas turbine and a combustion chamber backfire monitoring method thereof, and relates to the technical field of gas turbines. The gas turbine comprises a combustion chamber, a compressor and a sensor assembly. The combustion chamber is provided with a premixing channel, which is used for mixing air and fuel to form premixed gas. The sensor assembly is used for acquiring at least the temperature of outlet gas of the compressor and the temperature of the premixed gas in the premixing channel. The application sets the sensor assembly which can acquire the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing channel, and combines the combustion chamber backfire monitoring method proposed in the application. In the subsequent combustion chamber backfire determination, the combustion chamber backfire of the gas turbine in the unstable state can be effectively monitored. The combustion chamber backfire monitoring method proposed in the application can be applied to the application scene of the improvement of the automatic degree of the gas turbine.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbines, in particular to a gas turbine and a combustion chamber backfire monitoring method thereof. BACKGROUND

[0002] With the improvement of people's environmental awareness and requirements, low emission of gas turbines is imperative. As one of the three core components of gas turbines, the combustion chamber plays an important role in reducing emissions, because the combustion chamber not only can effectively release the chemical energy of fuel and convert it into high-temperature gas to provide conditions for doing work in the turbine, but also dominates the emission of pollutants, especially the emission of NOx.

[0003] Since the lean fuel premixed combustion technology can achieve low NOx emission of gas turbines, it is the key technology to solve the problem of low emission of gas turbines. However, the combustion stability of lean fuel premixed combustion is poor, mainly because backfire occurs in the premixed zone from the combustion chamber under low and high operating conditions of the gas turbine. When using medium and low calorific value fuel, the backfire problem is more prominent. If the combustion chamber has backfire problem, the downstream flame will flow upstream into the premixed zone, which will not only seriously damage the combustion chamber components such as injectors, swirlers and nozzles, but also increase the emission of pollutants. Therefore, it is necessary to establish a backfire monitoring system to determine whether the combustion chamber has backfire phenomenon.

[0004] There are various methods for monitoring the backfire of the combustion chamber in the prior art, such as arranging temperature, pressure or optical sensors. Specifically, the prior art of arranging temperature sensors means monitoring the temperature at the connection between the premixed pipe of the gas turbine and the combustion chamber by the temperature sensor. If the temperature data is greater than a certain temperature threshold, it is determined that the combustion chamber is in backfire state. However, the method of the prior art can only be applied to the backfire monitoring of the combustion chamber under the stable state of the gas turbine. If the gas turbine is in a non-stable state (for example, the operating condition of the gas turbine changes or the fuel to air ratio of the gas turbine changes), it is difficult to determine whether the combustion chamber has backfire. With the improvement of the automation level of the gas turbine, it is necessary to adjust the state of the gas turbine when the combustion chamber backfire occurs to protect the gas turbine. If a certain monitoring method cannot monitor whether the gas turbine has backfire under the non-stable state, it means that the monitoring method cannot be applied to the above application scenario with improved automation level. That is to say, the combustion chamber backfire monitoring method based on temperature sensors in the prior art is not suitable for the application scenario with improved automation level of the gas turbine. SUMMARY

[0005] The present application aims to provide a gas turbine and a combustion chamber backfire monitoring method thereof, to solve the technical problem that the prior art based on temperature sensors cannot accurately determine whether the gas turbine has backfire.

[0006] To achieve the above object, the present application provides the following technical solutions:

[0007] In a first aspect, the present application provides a gas turbine, which comprises a combustion chamber, a compressor and a sensor assembly. The combustion chamber is provided with a premixing channel for mixing air and fuel to form a premixed gas. The sensor assembly is used to acquire at least the temperature of the outlet gas of the compressor and the temperature of the premixed gas in the premixing channel.

[0008] As a specific solution of the present application, the combustion chamber comprises an outer shell, an inner shell sleeved in the inner part of the outer shell and provided with an air flow channel between the outer shell and the inner shell, an end cover for blocking the end of the outer shell, a center nozzle rod penetrating through the end cover and having a first end outside the combustion chamber and a second end extending into the inner part of the inner shell, the premixing channel comprising a first premixing channel provided between the center nozzle rod and the inner shell, and the first premixing channel being in communication with the air flow channel; and a first fuel delivery structure provided on the end cover and used to deliver fuel to the first premixing channel.

[0009] As a specific solution of the present application, the center nozzle rod comprises a diffusion nozzle rod and a premixing nozzle rod sleeved outside the diffusion nozzle rod, the first premixing channel being provided between the premixing nozzle rod and the inner shell, and the premixing channel further comprising a second premixing channel provided between the premixing nozzle rod and the diffusion nozzle rod, and the second premixing channel being in communication with the air flow channel.

[0010] As a specific solution of the present application, it further comprises a second fuel delivery structure provided on the end cover and used to deliver fuel to the second premixing channel, and the second premixing channel comprises a first fuel channel provided on the end cover, and the end opening of the first fuel channel facing the second premixing channel.

[0011] As a specific solution of the present application, the first premixing channel is provided with a first cyclone, and the second premixing channel is provided with a second cyclone.

[0012] As a specific solution of the present application, the inner part of the diffusion nozzle rod is provided with a second fuel channel, and the second end of the diffusion nozzle rod is provided with a plurality of diffusion nozzles, each of which being in communication with the second fuel channel.

[0013] As a specific solution of the present application, the side wall of the inner shell is provided with a plurality of through holes for connecting the inner part of the inner shell and the air flow channel.

[0014] As a specific scheme of the technical scheme in the application, the first fuel delivery structure comprises: a third fuel passage formed in the end cover; and at least one fuel injection rod, each fuel injection rod being arranged in the end cover and having a first end in communication with the third fuel passage and a second end extending into the first premixing passage.

[0015] As a specific scheme of the technical scheme in the application, the sensor assembly comprises:

[0016] at least two first temperature sensors, each first temperature sensor being uniformly distributed around an axial line of the first premixing passage and having a temperature sensing probe extending into the first premixing passage;

[0017] at least one second temperature sensor for measuring a temperature of an inlet of the compressor; at least one first pressure sensor for measuring a pressure of the inlet of the compressor; and at least one second pressure sensor for measuring a pressure of an outlet of the compressor.

[0018] In a second aspect, the application provides a method for monitoring backfire of a combustion chamber of a gas turbine, the method comprising: obtaining a first temperature, the first temperature being a temperature of premixed gas in a premixing passage; obtaining a second temperature, the second temperature being a temperature of gas at an outlet of the compressor; and determining whether the combustion chamber of the gas turbine backfires based on the first temperature and the second temperature.

[0019] As a specific scheme of the technical scheme in the application, the obtaining of the first temperature comprises: obtaining a first temperature average value, the first temperature average value being an average value of temperatures of the first temperature sensors, and obtaining the first temperature based on the first temperature average value; and the obtaining of the second temperature comprises: obtaining a third temperature average value, the third temperature average value being an average value of temperatures of the second temperature sensors, obtaining a first pressure average value, the first pressure average value being an average value of pressures of the first pressure sensors, obtaining a second pressure average value, the second pressure average value being an average value of pressures of the second pressure sensors, and obtaining the second temperature based on the first pressure average value, the second pressure average value and the third temperature average value.

[0020] As a specific scheme of the technical scheme in the application, the determining whether the combustion chamber of the gas turbine backfires based on the first temperature and the second temperature comprises: obtaining a third temperature, the third temperature being equal to a sum of the second temperature and a threshold temperature, the threshold temperature being preset; determining that the combustion chamber of the gas turbine backfires if the first temperature is greater than or equal to the third temperature; and determining that no backfire occurs otherwise.

[0021] Compared with the prior art, the application has the following beneficial effects:

[0022] By setting a sensor assembly capable of acquiring the temperature of the compressor outlet compressed air and the temperature of the premixed gas in the premixing channel, combined with the combustion chamber backfire monitoring method proposed in the present application, the combustion chamber backfire of the gas turbine in unstable state can be effectively monitored in the subsequent combustion chamber backfire determination. The combustion chamber backfire monitoring method proposed in the present application can be applied to the application scenario of the improvement of the automation degree of the gas turbine. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A structural schematic diagram of a combustion chamber of a gas turbine proposed in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of an end cover and a center injection rod proposed in an embodiment of the present application;

[0025] Figure 3 A flow schematic diagram of the compressed air in the combustion chamber proposed in an embodiment of the present application; Figure 1

[0026] Figure 4 A flow schematic diagram of the fuel in the combustion chamber proposed in an embodiment of the present application; Figure 1

[0027] Figure 5 A flowchart of a combustion chamber backfire monitoring method of a gas turbine proposed in an embodiment of the present application.

[0028] In the figure: 1, outer shell; 2, inner shell; 21, through hole; 3, end cover; 31, third fuel channel; 32, first fuel channel; 33, fuel injection rod; 4, diffusion injection rod; 41, diffusion injection hole; 5, premixing injection rod; 61, air flow channel; 62, first premixing channel; 63, second premixing channel; 64, second fuel channel; 7, first swirler; 8, second swirler; 9, first temperature sensor. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0030] ​​It should be noted that, in the description of the present application, the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0031] In addition, it should be understood that, for the convenience of description, the sizes of various components shown in the drawings are not drawn in accordance with the actual proportional relationship, for example, the thickness or width of certain layers can be exaggerated relative to other layers.

[0032] It should be noted that similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined or described in one drawing, it will not need to be further specifically discussed and described in the description of subsequent drawings.

[0033] Before understanding the embodiments proposed in the present application, it needs to be clear that in the prior art, the temperature sensor is used to monitor the temperature at the connection between the premixing pipeline and the combustion chamber of the gas turbine, to determine whether the combustion chamber of the gas turbine is backfiring. For example, if the temperature at the connection between the premixing pipeline and the combustion chamber is higher than a certain temperature T s , for example, set to 420℃, it is considered that the combustion chamber is backfiring. It is easy to understand that in the stable operation process of the gas turbine, the temperature in the premixing pipeline or the combustion chamber is generally T sThe temperature of the combustion chamber is generally over 1000°C. That is, during the stable operation of the gas turbine, if the combustion chamber is backfired, the temperature at the connection between the premixing pipeline and the combustion chamber will inevitably increase substantially. In other words, if the temperature at the connection between the premixing pipeline and the combustion chamber suddenly increases substantially (i.e., increases from 370°C to 420°C), it can be considered that the combustion chamber is backfired. It should be understood that during the process that the gas turbine is in a non-stable state, the temperature at the connection between the premixing pipeline and the combustion chamber is also unstable. That is, in the application scenario that the gas turbine is in a non-stable state, even if the combustion chamber is not backfired, the temperature at the connection between the premixing pipeline and the combustion chamber can still exceed 420°C, that is, it is considered that the combustion chamber is backfired. In order to avoid misjudgment of the backfiring of the combustion chamber when the gas turbine is in a non-stable state, the temperature threshold can only be increased, for example, the temperature threshold is increased from 420°C to 470°C. That is, when the gas turbine is in a non-stable state, the temperature at the connection between the premixing pipeline and the combustion chamber exceeds 470°C, and it is considered that the combustion chamber is backfired. However, as known from the foregoing, during the process that the gas turbine is in a non-stable state, the temperature at the connection between the premixing pipeline and the combustion chamber is also unstable. Therefore, in some cases, even if the combustion chamber is backfired, the temperature at the connection between the premixing pipeline and the combustion chamber cannot exceed 470°C. That is, if the temperature threshold is set too high (for example: 470°C), even if the combustion chamber is backfired, the gas turbine cannot accurately monitor it.

[0034] It should be understood that the service life of the gas turbine is generally tens of thousands to hundreds of thousands of hours. During the long-term use of the gas turbine, the working time of the gas turbine in a non-stable state (generally a few minutes to tens of minutes) is almost negligible compared with the working time of the gas turbine in a stable state (generally tens to thousands of hours). That is, because the working time of the gas turbine in a non-stable state is short, even if backfiring occurs, it is difficult to adjust the state of the gas turbine in time by taking measures, and because the time is short, the damage caused by the short backfiring to the gas turbine is also limited. Therefore, the backfiring monitoring method of the combustion chamber in the prior art focuses on monitoring the backfiring of the combustion chamber when the gas turbine is in a stable state. If it is monitored that the combustion chamber is backfired, the state of the gas turbine is immediately adjusted or shut down for maintenance.

[0035] It is easy to understand that although the gas turbine is in the non-steady state for a single time (the working condition of the gas turbine changes or the fuel of the gas turbine is switched), the damage caused by the backfire of the combustion chamber to the gas turbine is limited. However, in the long-term use of the gas turbine, if the number of times that the gas turbine is in the non-steady state is relatively large, the cumulative damage caused by the backfire to the gas turbine is still considerable. With the improvement of the degree of automation, if it is determined that the gas turbine backfires, the state of the gas turbine can be adjusted based on the automatic program to avoid the occurrence of backfire. However, as known from the foregoing, the backfire monitoring method of the prior art cannot accurately monitor whether the gas turbine is in the non-steady state and whether backfire occurs.

[0036] To solve this technical problem, as shown in the background art, Figures 1 to 4 An embodiment of a gas turbine is provided. Specifically, the gas turbine includes a combustion chamber, a compressor (prior art, therefore not shown in the figure) and a sensor assembly. The combustion chamber is provided with a premixing channel, which is used for mixing air and fuel to form a premixed gas. The sensor assembly is used to acquire at least the outlet temperature of the compressor and the temperature of the premixed gas in the premixing channel.

[0037] It should be noted that, as known from the background art, the lean fuel premixing combustion technology refers to a technology of mixing air and fuel in a premixing channel (i.e., a premixing zone) in advance to form a premixed gas, and then inputting the premixed gas into the combustion chamber for combustion. Since this technology is a relatively mature prior art, it will not be described in detail. It is easy to understand that all gas turbines based on the lean fuel premixing combustion technology have a premixing channel, and only the structure of the premixing channel of different types of gas turbines may be different, which will not be described in detail here.

[0038] As known from the foregoing, if the combustion chamber backfires, it means that combustion occurs in the premixing channel, that is, the temperature of the premixed gas in the premixing channel rises. However, the temperature rise of the premixed gas in the premixing channel does not mean that the combustion chamber backfires (for example, the working condition of the gas turbine is improved). It should be emphasized that the premixed gas is a gas mixed by air and fuel, and the premixed gas based on the lean fuel premixing combustion technology contains more air and less fuel. In the gas turbine, air generally comes from the compressor, that is, the temperature of the premixed gas based on the lean fuel premixing combustion technology is closely related to the temperature of the air from the compressor.

[0039] It should be noted that in the gas turbine, the compressor is mainly used to increase the pressure of the air entering the combustion chamber, that is, to compress the air, so as to improve the efficiency of the thermal cycle of the combustion chamber. It is easy to understand that if the working condition of the gas turbine is high, the compressed air pressure generated by the compressor is large; if the working condition of the gas turbine is low, the compressed air pressure generated by the compressor is small. It should also be noted that in the process of compressing air, the temperature of the air is positively correlated with the pressure of the air, that is, the higher the working condition of the gas turbine, the higher the temperature of the compressed air, that is, the higher the temperature of the premixed gas.

[0040] It is easy to understand that the sensor of the gas turbine in the embodiment of the present application can not only obtain the temperature of the premixed gas in the premixing channel, but also obtain the temperature of the outlet of the compressor. That is, in the embodiment of the present application, whether the combustion chamber backfires can be determined based on the temperature of the premixed gas and the temperature of the compressed air at the outlet of the compressor (the specific method is described below). Compared with the prior art, which can only determine whether the combustion chamber backfires based on the temperature at the connection between the premixing pipeline and the combustion chamber, the gas turbine proposed in the embodiment of the present application in combination with the method proposed in the embodiment of the present application can more accurately determine whether the combustion chamber of the gas turbine backfires.

[0041] As can be seen from the foregoing, the gas turbine proposed in the embodiment of the present application does not make any limitation on the structure of the combustion chamber, and only needs to have a premixing channel. That is, in the embodiment of the present application, the combustion chamber of the gas turbine can be any common combustion chamber based on lean fuel premixed combustion technology on the market. That is, in the embodiment of the present application, the premixing channel can be any structure of premixing channel, and no limitation is made on it.

[0042] In one embodiment of the present application, as shown in Figures 1 to 4 the combustion chamber of the gas turbine includes an outer shell 1, an inner shell 2, an end cover 3, a center jet rod, and a first fuel delivery structure. The inner shell 2 is sleeved inside the outer shell 1, and an air flow channel 61 is provided between the inner shell 2 and the outer shell 1. The end cover 3 is used to block the end of the outer shell 1. The center jet rod penetrates the end cover 3, and the first end of the center jet rod is located outside the combustion chamber, and the second end of the center jet rod extends into the inner shell 2. The premixing channel includes a first premixing channel 62 provided between the center jet rod and the inner shell 2, and the first premixing channel 62 is in communication with the air flow channel 61. The first fuel delivery structure is provided on the end cover 3 and is used to deliver fuel to the first premixing channel 62.

[0043] It should be noted that in the embodiment of the present application, the end of a component or structure (for example, the outer shell 1, the first fuel channel 32, or the center jet rod) through which a fluid (for example, air, fuel, or premixed gas) enters is defined as the first end of the component or structure, and the end of a component or structure through which a fluid flows out is defined as the end of the component or structure.

[0044] Specifically, in the embodiment of the present application, the flow path of the compressed air from the compressor in the air flow channel 61 is as shown in path A of Figure 3 Since the first premixing channel 62 is in communication with the air flow channel 61, the compressed air in the air flow channel 61 can also enter the first premixing channel 62 along path C of Figure 3 The air entering the first premixing channel 62 can mix with the fuel in the first premixing channel 62 to form a premixed gas. The premixed gas is ejected from the end of the first premixing channel 62 and combusts in the interior of the inner casing 2. It should be noted that in the embodiment of the present application, the temperature of the premixed gas in the first premixing channel 62 can be measured to represent the temperature of the premixed gas in the premixing channel of the gas turbine.

[0045] It should be noted that during the operation of the gas turbine, combustion occurs in the interior of the inner casing 2. It is easy to understand that the higher the operating condition of the gas turbine, the higher the temperature of the inner casing 2. As known from the foregoing, the air flow channel 61 for conveying the compressed air is arranged between the outer casing 1 and the inner casing 2, that is, the higher the operating condition of the gas turbine, the higher the temperature of the compressed air based on the warming effect of the inner casing 2 on the compressed air, that is, the higher the temperature of the subsequently generated premixed gas. As known from the foregoing, the embodiment of the present application mainly determines whether the combustion chamber is backfiring based on the temperature of the premixed gas and the temperature of the compressed air at the outlet of the compressor, in order to avoid the temperature of the inner casing 2 itself affecting the temperature of the premixed gas during the process of the gas turbine operating condition rising and falling, and affecting the determination result. In a specific embodiment of the present application, as shown in Figure 1 , the side wall of the inner casing 2 is provided with a plurality of through holes 21 for communicating the interior of the inner casing 2 and the air flow channel 61. Based on the through holes 21, during the operation of the gas turbine, part of the compressed air from the compressor can enter the interior of the inner casing 2 along path B as shown in Figure 3 Since the temperature of the compressed air is low, the compressed air can cool the side wall of the inner casing 2, reduce the difference in the temperature of the compressed air raised by the inner casing 2 under different operating conditions of the gas turbine, that is, further improve the accuracy of the determination of whether the subsequent combustion chamber is backfiring.

[0046] It should be noted that in a specific embodiment of the present application, in order to make the combustion chamber of the gas turbine proposed in the embodiment of the present application have a staged combustion function. As shown in Figure 1 and Figure 2As shown, the center spray rod includes a diffusion spray rod 4 and a premix spray rod 5. The premix spray rod 5 is sleeved outside the diffusion spray rod 4, and a first premix passage 62 is arranged between the premix spray rod 5 and the inner casing 2. The premix passage further includes a second premix passage 63 arranged between the premix spray rod 5 and the diffusion spray rod 4, and the second premix passage 63 is in communication with the air flow channel 61.

[0047] Specifically, since the second premix passage 63 is in communication with the air flow channel 61, part of the compressed air in the air flow channel 61 can enter the second premix passage 63 along the path D in FIG. 6 to mix with the fuel in the second premix passage 63 to form premix gas, and then the premix gas enters the inner casing 2 from the second premix passage 63 to form combustion. Figure 3 It is easy to understand that in the embodiment of the present application, the second premix passage 63 can be designed as a main premix passage, and the first premix passage 62 can be designed as a secondary premix passage. It should be noted that in the embodiment of the present application, the main premix passage refers to a premix passage used to generate premix gas when the gas turbine is in a high working condition, so as to increase the amount of premix gas generated 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 used to generate premix gas when the gas turbine is in a low working condition. That is, the amount of premix gas generated by the secondary premix passage is less, and the amount of premix gas generated by the main premix passage is more.

[0048] It should be noted that in the embodiment of the present application, the temperature of the premix gas in the main premix passage can be measured, and the temperature of the premix gas in the secondary premix passage can also be measured. It is easy to understand that since the amount of premix gas generated by the main premix passage is large, that is, the air in the main premix passage is more, the temperature of the premix gas in the main premix passage is less affected by external interference (for example, the heating effect of the inner casing 2 on the air or the fuel). In order to ensure the accuracy of monitoring, it is preferred to measure the temperature of the premix gas in the main premix passage to represent the temperature of the premix gas in the premix passage in the combustion chamber.

[0049] In the embodiment of the present application, if the second premix passage 63 is the main premix passage, as shown in FIG. 6, in order to measure the temperature of the premix gas in the second premix passage 63, the temperature sensor needs to pass through the inner casing 2 and the premix spray rod 5 in sequence. Figure 1 It is easy to understand that during the working process of the gas turbine, a large vibration will be generated, and if the temperature sensor passes through the inner casing 2 and the premix spray rod 5 at the same time, the temperature sensor is easy to be damaged. In order to improve the service life of the temperature sensor, in another embodiment of the present application, the first premix passage 62 is designed as the main premix passage, and the second premix passage 63 is designed as the secondary premix passage. As shown in FIG. 7, in order to measure the temperature of the premix gas in the second premix passage 63, the temperature sensor needs to pass through the inner casing 2 and the diffusion spray rod 4 in sequence. Figure 1As shown, in the embodiment of the present application, if it is necessary to measure the temperature of the premixed gas in the main premixing channel, only the temperature sensor needs to pass through the inner casing 2, which is beneficial to prolong the service life of the temperature sensor.

[0050] It should be noted that, in order to ensure the combustion stability of the gas turbine during startup or low load operation, the fuel is directly injected into the inner casing 2 to form diffusion combustion. Figure 1 and Figure 2 As shown, the inside of the diffusion lance 4 is provided with a second fuel channel 64, and the end of the diffusion lance 4 is provided with a plurality of diffusion injection holes 41, each of which is in communication with the second fuel channel 64. It is easy to understand that the second fuel channel 64 is used to directly deliver fuel to the inside of the inner casing 2 through the diffusion injection holes 41 for combustion. That is, the fuel injected from the second fuel channel 64 forms diffusion combustion inside the inner casing 2. Compared with premixed combustion, diffusion combustion is more stable, which is beneficial to maintain the combustion stability of the gas turbine during startup or low load operation. Specifically, in the embodiment of the present application, the path of the fuel in the second fuel channel 64 into the inside of the inner casing 2 is shown as route G in Figure 4 .

[0051] It should be noted that, in the embodiment of the present application, the first fuel delivery structure is mainly used to deliver fuel to the first fuel channel 32. Therefore, in the embodiment of the present application, the first fuel delivery structure can be any structure capable of delivering fuel. For example: the first fuel delivery structure can be similar to the diffusion lance 4, in the form of a tubular structure (not shown in the figure), the tube penetrates the end cover 3, the first end of the tube is located outside the combustion chamber, and the end of the tube extends into the first premixing channel 62; or, as shown in Figure 1 and Figure 2 Specifically, each fuel lance 33 is arranged on the end cover 3, and the first end of each fuel lance 33 is in communication with the third fuel channel 31, and the end of each fuel lance 33 extends into the inside of the first premixing channel 62. Specifically, in the embodiment of the present application, the path of the fuel into the first premixing channel 62 is shown as path E in Figure 4 .

[0052] It is to be understood that, in one embodiment of the present application, the first fuel delivery structure can be only the third fuel passage 31 formed in the end cover 3, and the third fuel passage 31 has an end opening facing the first premix passage 62 (not shown in the figure, which is similar to the first fuel passage 32 described below). It is to be understood that, in one embodiment of the present application, if the gas turbine further has a second premix passage 63, the third fuel passage 31 can have an end opening facing both the first premix passage 62 and the second premix passage 63. That is, the third fuel passage 31 is used to deliver fuel to both the first premix passage 62 and the second premix passage 63.

[0053] In one embodiment of the present application, the combustion chamber of the gas turbine further comprises a second fuel delivery structure arranged in the end cover 3, and the second fuel delivery structure is used to deliver fuel to the second premix passage 63. It is to be understood that, in one embodiment of the present application, the second fuel delivery structure is similar to the first fuel delivery structure described above, and is not limited in any way, for example: the second fuel delivery structure can be similar to the diffusion lance 4; or the second fuel delivery structure is similar to the first fuel delivery structure.

[0054] In one specific embodiment of the present application, as shown in Figure 1 and Figure 2 , the second premix passage 63 comprises a first fuel passage 32 arranged in the end cover 3, and the first fuel passage 32 has an end opening facing the second premix passage 63. Specifically, in one embodiment of the present application, the path of the fuel in the first fuel passage 32 into the second premix passage 63 is shown by route F in Figure 4 .

[0055] It is to be understood that, in one embodiment of the present application, in order to make the fuel and air in the second premix passage 63 mix more uniformly to obtain premix gas with better uniformity, as shown in Figure 1 , a first swirler 7 is arranged in the first premix passage 62. The first swirler 7 can make the air and fuel in the first premix passage 62 mix more uniformly.

[0056] It is to be understood that, in order to make the fuel and air in the second premix passage 63 also mix more uniformly. In another embodiment of the present application, as shown in Figure 1 and Figure 2 , a second swirler 8 is arranged in the second premix passage 63.

[0057] As described above, in one embodiment of the present application, the sensor assembly is used to obtain at least the outlet temperature of the compressor and the temperature of the premix gas in the premix passage. That is, the sensor assembly can be a combination of any number of sensors capable of obtaining the outlet temperature of the compressor and the temperature of the premix gas in the premix passage.

[0058] Specifically, in the embodiments of the present application, the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing passage can 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 figure).

[0059] In the embodiments of the present application, the first temperature sensor 9 is used to measure the temperature of the premixed gas in the first premixing passage 62, and the third temperature sensor is used to measure the temperature of the compressed air at the outlet of the compressor. It is easy to understand that the temperature uniformity of general fluid is poor, and in order to accurately measure the temperature of the premixed gas and the compressed air, in the embodiments of the present application, a plurality of first temperature sensors 9 and a plurality of third temperature sensors can be provided. The average value measured by the plurality of temperature sensors is used to determine the temperature value of the premixed gas and the compressed air.

[0060] In order to avoid installing too many temperature sensors at the outlet of the compressor to accurately measure the temperature of the compressed air, 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 to measure the temperature at the inlet of the compressor. The first pressure sensor is used to measure the pressure at the inlet of the compressor, and the second pressure sensor is used to measure the pressure at the outlet of the compressor. As shown in the figure, 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 into 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. Figure 1

[0061] It is easy to understand that the air entering the inlet of the compressor comes from the surroundings of the compressor, that is, the second temperature sensor only needs to measure the temperature of the air around the compressor. It should be noted that when air is compressed from one volume to another volume, the change of the temperature of the air is positively correlated with the change of the pressure of the air, that is, based on the change of the pressure of the air before and after the compression by the compressor, the temperature of the compressed air can be obtained. In other words, in the embodiments of the present application, a plurality of temperature sensors are not needed to measure the temperature of the compressed air, and only a small number of pressure sensors (that is, one first pressure sensor and one second pressure sensor) are needed to obtain the temperature of the compressed air.

[0062] ​It needs to be clear that in the embodiments of the present application, the temperature sensor and the pressure sensor can not be limited. It can be any commonly used temperature sensor and pressure sensor on the market. It needs to be noted that since the gas turbine works at a high temperature, in order to make the temperature sensor have a good service life, in the embodiments of the present application, the temperature sensor can adopt a K-type thermocouple with a heat-resistant temperature greater than 1000°C.

[0063] It needs to be clear that the gas turbine proposed in the embodiments of the present application can obtain the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing channel through the sensor assembly. In the subsequent combustion chamber backfire determination, the combustion chamber backfire of the gas turbine in the 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 channel. That is, the gas turbine proposed in the present application can be applied to the application scenario of improving the automation degree of the gas turbine.

[0064] After introducing all the embodiments of the gas turbine proposed in the present application, the following introduces all the embodiments of the combustion chamber backfire monitoring method of the gas turbine proposed in the present application.

[0065] As shown in Figure 5 The embodiments of the present application propose a combustion chamber backfire monitoring method of a gas turbine, and specifically the method comprises:

[0066] Step S100: obtaining a first temperature.

[0067] Specifically, in the embodiments of the present application, the first temperature is the temperature of the premixed gas in the premixing channel (for example: the first premixing channel 62 and / or the second premixing channel 63). As known from the foregoing, the temperature of the premixed gas can be the temperature value of a certain point in the premixed gas, or the average value of the temperature values of multiple points in the premixed gas. That is, the first temperature can be a temperature value of a certain point, or an average value of multiple temperature values, which will not be described in detail here.

[0068] In a specific embodiment of the present application, in order to obtain the accurate temperature of the premixed gas, step S100: obtaining a first temperature comprises,

[0069] Step S110: obtaining a first temperature average value.

[0070] Specifically, the first temperature average value is the average value of the temperatures of each first temperature sensor 9. In the embodiments of the present application, the number of first temperature sensors 9 is at least two.

[0071] Step S120: obtaining a first temperature based on the first temperature average value.

[0072] Specifically, in the embodiments of the present application, the first temperature average is the first temperature.

[0073] Step S200: obtaining a second temperature.

[0074] Specifically, in the embodiments of the present application, steps S100 and S200 are only used to distinguish two steps, which do not represent the execution order of the two steps. For example, in the embodiments of the present application, step S100 can be executed first, and then step S200 can be executed; or step S200 can be executed first, and then step S100 can be executed; or steps S100 and S200 can be executed simultaneously.

[0075] In the embodiments of the present application, the second temperature is the gas temperature at the outlet of the compressor. It is easy to understand that in the embodiments of the present application, the second temperature can be similar to the first temperature, which can be the temperature of a point in the gas at the outlet of the compressor, or can be the average value of the temperatures of multiple points in the gas at the outlet of the compressor.

[0076] From the foregoing, in order to avoid setting too many temperature sensors in the compressor, in an embodiment of the present application, step S200: obtaining a second temperature comprises:

[0077] Step S210: obtaining a third temperature average.

[0078] Specifically, the third temperature average is the temperature average of each second temperature sensor. In the embodiments of the present application, the second temperature sensor is used to measure the air temperature at the inlet of the compressor. Generally, the air temperature at the inlet of the compressor is balanced, that is, in the embodiments of the present application, only one second temperature sensor can be set to obtain the third temperature average. In other words, the third temperature average can be the measurement value of one second temperature sensor, or can be the average value of the measurement values of multiple second temperature sensors.

[0079] Step S220: obtaining a first pressure average.

[0080] Specifically, the first pressure average is the pressure average of each first pressure sensor. In the embodiments of the present application, the first pressure sensor is used to measure the pressure at the inlet of the compressor. It is easy to understand that in the embodiments of the present application, the first pressure average can be the measurement value of one first pressure sensor, or can be the average value of the measurement values of multiple first pressure sensors.

[0081] Step S230: obtaining a second pressure average.

[0082] Specifically, the second pressure average is an average of pressures measured by the second pressure sensors. In the embodiment of the present application, the second pressure sensors are used to measure the pressure at the outlet of the compressor. It is easily understood that in the embodiment of the present application, the first pressure average can be a measured value of one second pressure sensor or an average of measured values of multiple second pressure sensors.

[0083] Step S240: obtaining the second temperature based on the first pressure average, the second pressure average and the third temperature average.

[0084] Specifically, in the embodiment of the present application, the second temperature can be obtained directly based on the first pressure average, the second pressure average and the third temperature average according to experience. For example, in one embodiment of the present application, the second temperature can be obtained based on the following calculation formula:

[0085]

[0086] wherein, represents the third temperature average; represents the second temperature; represents the first pressure average; represents the second pressure average; is a constant, generally 1.4.

[0087] Of course, in other embodiments of the present application, the above-mentioned values can be corrected to obtain the second temperature. For example, as described above, the compressed air is heated by the inner casing 2 during flowing along the air flow channel 61, and the second temperature can be obtained based on the experience value and of the heating of the compressed air. For example, in another embodiment of the present application, the second temperature can be obtained based on the following calculation formula:

[0088]

[0089] wherein, represents the third temperature average; represents the second temperature; represents the experience value of the heating of the compressed air; represents the first pressure average; represents the second pressure average; is a constant, generally 1.4.

[0090] Step S300: determining whether the combustion chamber of the gas turbine is backfired based on the first temperature and the second temperature.

[0091] It should be noted that in the embodiments of the present application, the first temperature refers to the temperature of the premixed gas in the premixing channel, and the second temperature refers to the temperature of the compressed air sprayed from the outlet of the compressor. Without considering other factors, theoretically, the first temperature is close to the second temperature. For example, in an embodiment of the present application, if the first temperature is greater than the second temperature, it is considered that the combustion chamber of the gas turbine is backfired. However, it is considered that the temperature of the compressed air is increased during the flow process, and the fuel mixed with the compressed air to form the premixed gas can reduce the temperature of the compressed air. In an embodiment of the present application, step S300: determining whether the combustion chamber of the gas turbine is backfired based on the first temperature and the second temperature comprises,

[0092] Step S310: obtaining a third temperature.

[0093] Specifically, in the embodiments of the present application, the third temperature is equal to the sum of the second temperature and a threshold temperature, and the threshold temperature is pre-set. The threshold temperature is mainly used to compensate for the influence of the outside environment on the temperature of the compressed air after the compressed air flows out of the outlet of the compressor, and it can be an empirical value obtained through multiple experiments. It is easy to understand that the threshold temperature can be different for different gas turbines.

[0094] In an embodiment of the present application, the threshold temperature can be greater than or equal to 10℃ and less than or equal to 90℃. Specifically, in the embodiments of the present application, the threshold temperature can be any one 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.

[0095] Step S320: if the first temperature is greater than or equal to the third temperature, it is determined that the combustion chamber of the gas turbine is backfired; otherwise, it is determined that the backfiring does not occur.

[0096] It should be noted that the combustion chamber backfiring monitoring method of the gas turbine proposed in the embodiments of the present application can determine whether the combustion chamber is backfired by comprehensively considering the temperature of the compressed air at the outlet of the compressor and the temperature of the premixed gas in the premixing channel. The combustion chamber backfiring of the gas turbine in a non-steady state can be effectively monitored. Therefore, the combustion chamber backfiring monitoring method proposed in the present application can be applied to the application scenario of improving the automation degree of the gas turbine.

[0097] In the above embodiments proposed in the present application, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0098] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary and that changes can be made in detail without departing from the principles and spirit of the application. The scope of the application is therefore defined by the appended claims and their equivalents.

Claims

1. A gas turbine engine characterized by, The application relates to a gas turbine, which comprises: a combustion chamber, wherein a premixing channel is arranged in the combustion chamber, and the premixing channel is used for mixing air and fuel to form premixed gas; a compressor; a sensor assembly, which is used for acquiring at least the temperature of outlet gas of the compressor and the temperature of the premixed gas in the premixing channel; the temperature of the outlet gas of the compressor and the temperature of the premixed gas in the premixing channel are used for judging whether the combustion chamber of the gas turbine is backfired, which comprises: acquiring a third temperature, wherein the third temperature is equal to the sum of a second temperature and a threshold temperature, and the threshold temperature is preset; if the first temperature is greater than or equal to the third temperature, it is judged that the combustion chamber of the gas turbine is backfired; otherwise, it is judged that the combustion chamber is not backfired; the first temperature is the temperature of the premixed gas in the premixing channel, and the second temperature is the temperature of the outlet gas of the compressor.

2. The gas turbine engine of claim 1, wherein, The combustion chamber comprises: an outer shell (1); an inner shell (2), which is arranged in the inner part of the outer shell (1) and is arranged with an air flow channel (61) between the outer shell (1); an end cover (3), which is used for blocking the end of the outer shell (1); a central injection rod, which penetrates through the end cover (3), the first end of the central injection rod is located outside the combustion chamber, and the second end of the central injection rod extends into the inner part of the inner shell (2), the premixing channel comprises a first premixing channel (62) arranged between the central injection rod and the inner shell (2), and the first premixing channel (62) is connected with the air flow channel (61); a first fuel conveying structure, which is arranged on the end cover (3) and is used for conveying fuel to the first premixing channel (62).

3. The gas turbine engine of claim 2, wherein, The central injection rod comprises: a diffusion injection rod (4); a premixing injection rod (5), which is arranged outside the diffusion injection rod (4), the first premixing channel (62) is arranged between the premixing injection rod (5) and the inner shell (2), and the premixing channel further comprises a second premixing channel (63) arranged between the premixing injection rod (5) and the diffusion injection rod (4), and the second premixing channel (63) is connected with the air flow channel (61).

4. The gas turbine engine of claim 3, wherein, The application further comprises a second fuel conveying structure, which is arranged on the end cover (3) and is used for conveying fuel to the second premixing channel (63), the second premixing channel (63) comprises a first fuel channel (32) arranged on the end cover (3), and the end of the first fuel channel (32) is opened towards the second premixing channel (63).

5. The gas turbine engine of claim 4, wherein, The first premixing channel (62) is arranged with a first swirler (7), and the second premixing channel (63) is arranged with a second swirler (8).

6. The gas turbine engine of claim 3, wherein, The inner part of the diffusion injection rod (4) is arranged with a second fuel channel (64), and the end of the diffusion injection rod (4) is arranged with a plurality of diffusion injection holes (41), each of the diffusion injection holes (41) is connected with the second fuel channel (64).

7. The gas turbine according to any one of claims 2 to 6, characterized in that A plurality of through holes (21) are arranged on the side wall of the inner shell (2), and the through holes (21) are used for connecting the inner part of the inner shell (2) with the air flow channel (61).

8. The gas turbine according to any one of claims 2 to 6, characterized in that The first fuel conveying structure comprises: a third fuel channel (31) arranged on the end cover (3). At least one fuel injection rod (33), each fuel injection rod (33) is arranged on the end cover (3), and the first end of each fuel injection rod (33) is communicated with the third fuel channel (31), and the second end of each fuel injection rod (33) extends into the first premixing channel (62).

9. The gas turbine engine of claim 8, wherein, The sensor assembly comprises: At least two first temperature sensors (9), each first temperature sensor (9) is uniformly distributed around the axis of the first premixing channel (62), and the temperature sensing probe of each first temperature sensor (9) extends into the first premixing channel (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 of the compressor inlet; At least one second pressure sensor for measuring the pressure of the compressor outlet.

10. A method of monitoring the tempering of a combustion chamber of a gas turbine according to any one of claims 1 to 9, characterized in that The method comprises: Obtaining a first temperature, the first temperature being the temperature of the premixed gas in the premixing channel; Obtaining a second temperature, the second temperature being the temperature of the gas at the outlet of the compressor; Based on the first temperature and the second temperature, determining whether the combustion chamber of the gas turbine is backfired; The determination of whether the combustion chamber of the gas turbine is backfired based on the first temperature and the second temperature comprises: Obtaining a third temperature, the third temperature being equal to the sum of the second temperature and a threshold temperature, the threshold temperature being preset; If the first temperature is greater than or equal to the third temperature, it is determined that the combustion chamber of the gas turbine is backfired; otherwise, it is determined that no backfiring occurs.

11. The method of claim 10, wherein the method further comprises: The obtaining of the first temperature comprises: Obtaining a first temperature average, the first temperature average being the average of the temperatures of each first temperature sensor (9), each first temperature sensor (9) being uniformly distributed around the axis of the first premixing channel (62), and the temperature sensing probe of each first temperature sensor (9) extending into the first premixing channel (62); Based on the first temperature average, obtaining the first temperature; The obtaining of the second temperature comprises: Obtaining a third temperature average, the third temperature average being the average of the temperatures of each second temperature sensor, each second temperature sensor being used for measuring the temperature of the compressor inlet; Obtaining a first pressure average, the first pressure average being the average of the pressures of each first pressure sensor, each first pressure sensor being used for measuring the pressure of the compressor inlet; Obtaining a second pressure average, the second pressure average being the average of the pressures of each second pressure sensor, each second pressure sensor being used for measuring the pressure of the compressor outlet; Based on the first pressure average, the second pressure average and the third temperature average, obtaining the second temperature.

Images