Anti-backfire gas turbine combustion chamber

Abstract

The application discloses a backfire-proof gas turbine combustor and relates to the field of gas turbines.The backfire-proof gas turbine combustor comprises main fuel nozzles, at least three of which are uniformly distributed in a ring shape and are in communication with a flame tube; and duty nozzles, the number of which corresponds to the number of the main fuel nozzles one by one, are uniformly distributed in a ring shape, are tangent to the main fuel nozzles, and are in communication with the flame tube; the main fuel nozzles comprise at least one high-speed fuel channel and at least two main fuel sub-nozzles, and the main fuel sub-nozzles are composed of main fuel nozzle air channels and main fuel nozzle premixing channels; the duty nozzles comprise at least one duty nozzle diffusion fuel channel and at least two duty sub-nozzles, and the duty sub-nozzles are composed of duty nozzle air channels and duty nozzle premixing channels.The application can flexibly switch the combustion method of the duty nozzles in different working stages of the combustor, optimizes combustion stability and pollutant emission, can guarantee that the backfire phenomenon does not occur, and improves the safety and stability of the gas turbine during operation.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and in particular to a backfire-proof gas turbine combustion chamber. Background Technology

[0002] In recent years, with the increasing severity of environmental pollution, countries around the world have formulated emission standards for power plants, imposing higher requirements on combustion. Heavy-duty gas turbines play a crucial supporting role in power generation. Currently, most gas turbines employ dry-type lean-burn premixed combustion technology to reduce pollutant emissions. Fuel and oxidizer are thoroughly mixed before entering the flame tube, and the flame temperature is reduced by controlling the fuel-oxidizer mixing ratio, thus achieving the goal of reducing pollutant emissions. While lean-burn premixed combustion technology has these advantages, it also introduces the risk of backfire. Backfire refers to an unstable combustion phenomenon where the flame propagates upstream, along the flame tube, and into the nozzle. In severe cases, it can burn combustion chamber components, affecting the normal operation of the gas turbine.

[0003] To further reduce carbon emissions, major gas turbine suppliers have successively developed natural gas-blended combustion technology and simultaneously researched and developed gas turbine combustors capable of using pure hydrogen as fuel, aiming to completely replace non-renewable energy sources such as natural gas in the future and protect the environment to the greatest extent. During hydrogen premixed combustion, the flame propagation speed is fast, approximately 275 cm / s, resulting in a higher risk of backfire. Lean premixed combustors can no longer safely and stably burn hydrogen. If diffusion combustion is used, the flame surface temperature will be too high and uncontrollable, significantly increasing the emission of thermal nitrogen oxides. Therefore, the hydrogen backfire problem places more stringent requirements on future hydrogen-fueled gas turbine combustors.

[0004] To address the aforementioned issues, this invention, based on the airflow organization and fuel distribution within the gas turbine combustion chamber, combined with a rational combustion control method, can effectively prevent backfire regardless of the type of gaseous fuel being burned, while ensuring that pollutant emissions meet standards, thus eliminating the aforementioned defects and enabling the gas turbine to operate safely and stably. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is how to effectively prevent backfire in the combustion chamber of a gas turbine while reducing pollutant emissions.

[0007] To address the aforementioned technical problems, this invention provides a backfire-preventing gas turbine combustor, comprising: at least three main combustion nozzles arranged in a ring-shaped, uniform distribution and communicating with the flame tube; and standby nozzles, the number of which corresponds one-to-one with the number of the main combustion nozzles, arranged in a ring-shaped, uniform distribution and tangent to the main combustion nozzles, and communicating with the flame tube; each main combustion nozzle comprising at least one high-speed fuel channel and at least two main combustion sub-nozzles, each main combustion sub-nozzle consisting of a main combustion nozzle air channel and a main combustion nozzle premixing channel; and each standby nozzle comprising at least one standby nozzle diffusion fuel channel and at least two standby sub-nozzles, each standby sub-nozzle consisting of a standby nozzle air channel and a standby nozzle premixing channel.

[0008] As a preferred embodiment of the backfire-proof gas turbine combustion chamber of the present invention, the main combustion nozzle further includes at least one main combustion nozzle partition, which is used to separate different main combustion sub-nozzles. The main combustion nozzle partition is provided with a high-speed fuel injection hole, which is used to connect the high-speed fuel passage and the flame tube.

[0009] As a preferred embodiment of the backfire prevention gas turbine combustion chamber of the present invention, a main combustion nozzle swirler is provided in each of the main combustion nozzle air passages, and the main combustion nozzle swirler causes the gas passing through the main combustion nozzle air passage to swirl.

[0010] As a preferred embodiment of the backfire prevention gas turbine combustion chamber of the present invention, the main combustion sub-nozzle further includes a main combustion sub-nozzle premixing injection hole, which is used to connect the main combustion nozzle premixing channel and the main combustion nozzle air channel.

[0011] As a preferred embodiment of the anti-backfire gas turbine combustion chamber of the present invention, wherein: the duty nozzle includes at least one duty nozzle partition, the duty nozzle partition being used to separate different duty sub-nozzles;

[0012] The duty nozzle also includes a duty nozzle premixed fuel injection orifice, which is used to connect the duty nozzle premixing channel and the duty nozzle air channel.

[0013] As a preferred embodiment of the backfire-proof gas turbine combustion chamber of the present invention, the duty nozzle further includes a duty nozzle diffusion fuel mixing hole and a duty nozzle diffusion fuel direct injection hole. Both the duty nozzle diffusion fuel mixing hole and the duty nozzle diffusion fuel direct injection hole are used to connect the duty nozzle diffusion fuel channel and the flame tube. The duty nozzle diffusion fuel mixing hole has an angle with the axis of the duty nozzle diffusion fuel channel.

[0014] As a preferred embodiment of the backfire prevention gas turbine combustion chamber of the present invention, wherein: a duty nozzle vortex is provided in each of the duty nozzle air passages, and the duty nozzle vortex causes the gas passing through the duty nozzle air passage to swirl.

[0015] As a preferred embodiment of the backfire prevention gas turbine combustion chamber of the present invention, wherein: a flame tube gas film cooling hole and a mixing hole are provided on the outer wall of the flame tube, and an end cap is also provided inside the flame tube, the end cap being used to position and fix the main combustion nozzle and the duty nozzle.

[0016] As a preferred embodiment of the backfire-proof gas turbine combustor of the present invention, wherein: the air-fuel ratio of the premixed gas introduced into the two adjacent main combustion nozzles is different, with the air-fuel ratio of one premixed gas being lower than the lower limit of the ignition concentration limit and the air-fuel ratio of the other premixed gas being higher than the upper limit of the ignition concentration limit; the air-fuel ratio of the premixed gas introduced into the two adjacent shift nozzles is different, with the air-fuel ratio of one premixed gas being lower than the lower limit of the ignition concentration limit and the air-fuel ratio of the other premixed gas being higher than the upper limit of the ignition concentration limit.

[0017] As a preferred embodiment of the backfire prevention gas turbine combustion chamber of the present invention, fuel is introduced into the diffusion fuel channel of the duty nozzle during the initial acceleration phase of the gas turbine; when the speed or load of the gas turbine reaches a set value, the fuel flow rate entering the diffusion fuel channel of the duty nozzle is gradually reduced while fuel is introduced into the duty sub-nozzle until the fuel supply to the diffusion fuel channel of the duty nozzle is stopped.

[0018] The beneficial effects of this invention are as follows: This invention can flexibly switch the combustion method of the duty nozzle at different working stages of the combustion chamber, optimize combustion stability and pollutant emissions, and at the same time ensure that backfire will not occur during premixed combustion, protect the gas turbine components, and improve the safety and stability of the gas turbine during operation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the overall structure of the gas turbine combustion chamber to prevent backfire.

[0021] Figure 2 Rear view of the gas turbine combustion chamber to prevent backfire.

[0022] Figure 3 This is a schematic diagram of the main combustion nozzle structure.

[0023] Figure 4 Front view of the main combustion nozzle.

[0024] Figure 5 This is a schematic diagram of the nozzle structure for duty operation.

[0025] Figure 6 This is a front view of the nozzle in operation.

[0026] Figure 7 This is a cross-sectional view of the nozzle on duty.

[0027] Figure 8 This is a partial sectional view of the nozzle on duty.

[0028] Figure 9 This is a schematic diagram showing the coordination between each transition section and the main combustion nozzle.

[0029] Figure 10 This is a schematic diagram showing the coordination between each transition section and the duty nozzle.

[0030] Figure 11 Front view of the combustion chamber of a gas turbine designed to prevent backfire.

[0031] Figure 12 This is a grouping diagram when the number of main combustion nozzles is an odd number divisible by 3.

[0032] Figure 13 This is a grouping diagram when the number of main combustion nozzles is an even number divisible by 3.

[0033] Figure 14 This is a grouping diagram when the number of main combustion nozzles is an even number that is not divisible by 3.

[0034] Figure 15 This is a schematic diagram showing the arrangement of the duty nozzles inside the main combustion nozzles. Detailed Implementation

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive, either alone or selectively, with other embodiments.

[0038] Example 1

[0039] Reference Figures 1 to 11 This is the first embodiment of the present invention, which provides a backfire-proof gas turbine combustor, which includes a main combustion nozzle 100 and a duty nozzle 200.

[0040] Specifically, the number of main combustion nozzles 100 is greater than or equal to 3; in this embodiment, the number is 3, evenly arranged in a ring around the circumference of the flame tube 300, such as... Figure 1 As shown.

[0041] The number of duty nozzles 200 is the same as the number of main combustion nozzles 100 and corresponds one-to-one. In this embodiment, there are three duty nozzles 200, arranged circumferentially with the main combustion nozzles 100 along the circumference of the flame tube 300. Each main combustion nozzle 100 is tangent to its adjacent duty nozzle 200. Figure 1 As shown.

[0042] In addition, the outer wall of the flame tube 300 is provided with flame tube film cooling holes 301 and mixing holes 302, which are used to cool the wall surface of the flame tube 300 and adjust the outlet temperature distribution of the combustion chamber, respectively. Inside the flame tube 300, an end cap 303 is also provided for positioning and fixing the main combustion nozzle 100 and the standby nozzle 200. The end cap 303 is also provided with end cap film cooling holes 303a for cooling the end cap 303. Figure 2 As shown.

[0043] Preferably, the main combustion nozzle 100 includes at least one high-speed fuel passage 101 and at least two main combustion sub-nozzles 102. In this embodiment, each main combustion nozzle 100 includes two high-speed fuel passages 101 and two main combustion sub-nozzles 102, wherein each main combustion sub-nozzle 102 is composed of a main combustion nozzle air passage 102a and a main combustion nozzle premixing passage 102b, as shown below. Figure 3 .

[0044] Two main combustion nozzles 102 are separated by a main combustion nozzle partition 103. Two high-speed fuel channels 101 are provided on the main combustion nozzle partition 103. The cross-section of each high-speed fuel channel 101 is rhomboid. A high-speed fuel injection hole 103a is formed at the end of each high-speed fuel channel 101 and connects to the flame tube 300. The main combustion nozzle partition 103 prevents the premixed gas in adjacent main combustion nozzles 102 from mixing before it exits the nozzle outlet. Furthermore, the high-speed fuel injection hole 103a, located on the main combustion nozzle partition 103, compensates for the poor airflow organization downstream of the partition, improving the uniformity of temperature distribution within the flame tube 300. Figure 4 .

[0045] Furthermore, such as Figure 3 The premixed channel 102b of the main combustion nozzle has a semi-circular cross-sectional shape. It is closed at its end and has a premixed injection hole 102c for the main combustion nozzle sub-nozzle on its side wall, connecting the premixed channel 102b to the air passage 102a. A main combustion nozzle swirler 104 is installed in each air passage 102a. Fuel in the premixed channel 102b enters the air passage 102a through the premixed injection hole 102c and mixes with air. After passing through the swirler 104, a stable swirling flow is generated, forming a recirculation zone. All the swirlers 104 rotate in the same direction.

[0046] Preferably, the standby nozzle 200 includes at least one standby nozzle diffusion fuel channel 201 and at least two standby sub-nozzles 202. In this embodiment, each standby nozzle 200 includes one standby nozzle diffusion fuel channel 201 and two standby sub-nozzles 202. Each standby sub-nozzle 202 is further composed of a standby nozzle air channel 202a and a standby nozzle premixing channel 202b, as shown below. Figure 5 .

[0047] The two standby nozzles 202 are separated by a standby nozzle partition (the standby nozzle partition is not shown in the attached drawings to make the diffusion combustion mode of the standby nozzles 200 easier to understand, but it needs to be used in actual production). The cross-section of the standby nozzle diffusion fuel channel 201 is circular, and at its end are standby nozzle diffusion fuel mixing holes 201a and standby nozzle diffusion fuel direct injection holes 201b, both of which are connected to the flame tube 300. Figure 6 .

[0048] Both the shift nozzle fuel mixing orifice 201a and the shift nozzle fuel direct injection orifice 201b are arranged in a ring shape, with the shift nozzle fuel direct injection orifice 201b located inside the shift nozzle fuel mixing orifice 201a. The shift nozzle fuel mixing orifice 201a forms an angle of 30° to 60° with the axis of the shift nozzle fuel channel 201 to improve mixing efficiency. The shift nozzle fuel direct injection orifice 201b is parallel to the axis of the shift nozzle fuel channel 201, maintaining the fuel's direction of travel and directly injecting fuel into the flame tube 300. Based on Bernoulli's principle, this causes the surrounding gas to converge towards the center, further enhancing the uniformity of fuel-oxidant mixing. Figure 7 .

[0049] Symmetrically arranged on both sides of the premixed fuel channel 201 of the duty nozzle are premixed fuel channels 202b for the duty nozzle. The premixed fuel channel 202b has an arc-shaped cross-section and is closed at its end. A premixed fuel injection hole 202c for the duty nozzle is provided on the side wall of the premixed fuel channel 202b and is connected to the air channel 202a of the duty nozzle. Figure 8 .

[0050] Each duty nozzle air passage 202a is equipped with a duty nozzle swirler 203. Fuel in the duty nozzle premixing passage 202b enters the duty nozzle air passage 202a through the duty nozzle premixed fuel injection hole 202c, mixes with air, and then, after passing through the duty nozzle swirler 203, generates a stable swirling flow and forms a recirculation zone. All duty nozzle swirlers 203 rotate in the same direction, such as... Figure 8 .

[0051] It should be noted that the rotation directions of the main combustion nozzle swirler 104 and the standby nozzle swirler 203 can be the same or different. When the uniformity of the combustion chamber outlet temperature distribution is the primary consideration, the rotation directions of the main combustion nozzle swirler 104 and the standby nozzle swirler 203 should be the same to ensure a uniform combustion chamber outlet temperature distribution. When it is necessary to fully utilize the ignition source function of the standby flame and enhance its ability to ignite the main combustion mixture, the rotation directions of the main combustion nozzle swirler 104 and the standby nozzle swirler 203 should be opposite. In this case, the position, number, and flow rate of the mixing holes 302 should be reasonably arranged to adjust the uniformity of the combustion chamber outlet temperature distribution.

[0052] Furthermore, to ensure better fuel flow into the various channels of each nozzle, a high-speed fuel channel transition section 105 and a main combustion nozzle premixing channel transition section 106 are installed at the inlets of the high-speed fuel channel 101 and the main combustion nozzle premixing channel 102b of the main combustion nozzle 100, respectively. The high-speed fuel channel transition section 105 has a rhomboid cross-sectional shape and mates with the high-speed fuel channel 101. The main combustion nozzle premixing channel transition section 106 has a rectangular cross-section at its inlet and a semi-circular cross-section at its end, mates with the main combustion nozzle premixing channel 102b. Figure 9 .

[0053] Similarly, transition sections 204 and 205 for the diffusion fuel channel and premixing channel, respectively, are installed at the inlets of the operating nozzle diffusion fuel channel 201 and the operating nozzle premixing channel 202b, respectively. The inlet cross-section of the transition section 204 is rectangular, and the end cross-section is circular and mates with the operating nozzle diffusion fuel channel 201. The inlet cross-section of the transition section 205 is rectangular, and the end cross-section is semi-circular and mates with the operating nozzle premixing channel 202b. Figure 10 .

[0054] Furthermore, to better control combustion in the combustion chamber, the nozzles can be categorized and graded. In this embodiment, looking from the head to the tail of the combustion chamber, the main combustion nozzle 100 located at the 12 o'clock position is the primary main combustion nozzle 107, and clockwise, they are the secondary main combustion nozzle 108 and the tertiary main combustion nozzle 109. Similarly, clockwise, they correspond to the primary duty nozzle 206, the secondary duty nozzle 207, and the tertiary duty nozzle 208, as follows. Figure 11 .

[0055] It should also be noted that the fuel supply pressure of the high-speed fuel channel 101 and the duty nozzle diffusion fuel channel 201 is higher than the fuel supply pressure of the other fuel channels.

[0056] The fuel supply flow rates between the two main combustion sub-nozzles 102 in a main combustion nozzle 100 are different, which results in different air-fuel ratios of the premixed gas between the two main combustion sub-nozzles 102. The proportion of premixed gas in one main combustion sub-nozzle 102 is lower than the lower limit of the ignition concentration limit, while the proportion of premixed gas in the other main combustion nozzle 102 is higher than the upper limit of the ignition concentration limit.

[0057] The fuel supply flow rates between the two sub-nozzles 202 in a single operating nozzle 200 are different, resulting in different air-fuel ratios of the premixed gas between the two sub-nozzles 202. The proportion of premixed gas in one operating nozzle 202 is lower than the lower limit of the ignition concentration limit, while the proportion of premixed gas in the other operating nozzle 202 is higher than the upper limit of the ignition concentration limit.

[0058] To better illustrate the working principle of this invention, the working process of this combustion chamber is now described:

[0059] During normal operation, the combustion chamber first allows air to exit from the compressor outlet and then enter the duty nozzle air passage 202a and the main combustion nozzle air passage 102a.

[0060] During the initial acceleration phase of the gas turbine, fuel is first supplied to the transition section 204 of the three shift nozzle diffusion fuel channels. The fuel then enters the flame tube 300 through the shift nozzle diffusion fuel channel 201, the shift nozzle diffusion fuel mixing hole 201a, and the shift nozzle diffusion fuel direct injection hole 201b.

[0061] Simultaneously, air enters the air passage 202a of the duty nozzle, and after passing through the swirler 203 of the duty nozzle, it generates a stable swirling flow and forms a recirculation zone. In the flame tube 300, it rapidly mixes with the fuel transmitted from the diffusion fuel mixing hole 201a and the diffusion fuel direct injection hole 201b of the duty nozzle and is ignited by the igniter to form a stable ignition source and enter the diffusion combustion mode.

[0062] After the combustion of the three main combustion nozzles 200 stabilizes, fuel is supplied to the premixing channel transition sections 106 of the six main combustion nozzles and all high-speed fuel channel transition sections 105. The fuel enters the main combustion nozzle premixing channel 102b from the main combustion nozzle premixing channel transition section 106, and then exits through the main combustion sub-nozzle premixing injection hole 102c to the main combustion nozzle air channel 102a, where it is premixed with air and generates a stable swirling flow under the action of the swirler, before exiting from the nozzle outlet. The fuel supply flow rates between the two main combustion sub-nozzles 102 of the main combustion nozzle 100 are different, resulting in different air-fuel ratios in the premixed air between the two main combustion sub-nozzles 120. The premixed air ratio in one main combustion sub-nozzle 102 is lower than the lower limit of the ignition concentration limit, while the premixed air ratio in the other main combustion nozzle 102 is higher than the upper limit of the ignition concentration limit.

[0063] After the premixed gas in the two main combustion nozzles 102 exits from the nozzle outlet, it is rapidly and uniformly mixed within the flame tube 300 by the swirling effect, so that different proportions of premixed gas are mixed together and the air-fuel ratio reaches the design value for the current operating condition of the gas turbine. Then it is ignited and burned by the duty flame. Since the proportion of premixed gas in each main combustion nozzle 102 is not within the normal ignition concentration range of the fuel, backfire can be prevented, ensuring the safe and stable operation of the gas turbine.

[0064] At the same time, the high-speed fuel passage transition section 105 transfers fuel to the high-speed fuel passage 101, and then the fuel is injected into the flame tube 300 through the high-speed fuel injection hole 103a. Based on Bernoulli's principle, the premixed gas ejected from different main combustion nozzles 102 around the periphery moves towards the center, which is conducive to the uniform mixing of different proportions of premixed gas and quickly reaches the design value of air-fuel ratio under the current gas turbine operating conditions.

[0065] In addition, the high-speed fuel injection hole 103a is provided on the main combustion nozzle partition 103, which can make up for the defect of poor airflow organization downstream of the main combustion nozzle partition 103 and improve the uniformity of temperature distribution in the flame tube 300.

[0066] When the gas turbine speed or load reaches a certain set value and the main combustion nozzle and the shift nozzle are burning stably, the shift nozzle 200 can be switched to premixed combustion mode.

[0067] First, while reducing the fuel flow rate entering the shift section 204 of the shift nozzle diffusion fuel channel in the first-level shift nozzle 206, fuel is supplied to the shift nozzle premixing channel transition section 205 of the first-level shift nozzle 206 according to a set ratio. The fuel enters the shift nozzle air channel 202a through the shift nozzle premixing channel 202b and the shift sub-nozzle premixed fuel injection hole 202c, and is premixed with air before being discharged from the nozzle outlet.

[0068] During this process, the amount of fuel in the premixed channel 202b of the duty nozzle is gradually increased, and the amount of fuel in the diffusion fuel channel 201 of the duty nozzle is reduced, until the fuel entering the diffusion fuel channel transition section 204 in the first-stage duty nozzle 206 is completely cut off, so that the first-stage duty nozzle 206 switches to the premixed combustion mode.

[0069] During fuel flow variations, it is crucial to maintain combustion chamber pressure fluctuations and temperatures within normal ranges. The primary control nozzle 206 first switches from diffusion combustion mode to premixed combustion mode. Once combustion stabilizes, the secondary control nozzle 207 and tertiary control nozzle 208 then switch sequentially, avoiding potential combustion instability that might occur when all control nozzles 200 switch simultaneously. The control nozzle 200 employs premixed combustion mode, significantly reducing pollutant emissions; its backfire prevention principle is the same as that of the main combustion nozzle 100.

[0070] It is worth noting that when there are three main combustion nozzles 100 and three shift nozzles 200, the increase in gas turbine speed and load is mainly achieved by increasing the flow rate of the three main combustion nozzles 100.

[0071] The fuel flow supplied to each main combustion nozzle premixing channel transition section 106, high-speed fuel channel transition section 105, shift nozzle premixing channel transition section 205, and shift nozzle diffusion fuel channel transition section 204 can be independently adjusted.

[0072] Based on the combustion control method in this invention, during the initial speed increase stage of the gas turbine, the duty nozzle 200 is in diffusion combustion mode, which is more stable than premixed combustion and acts as a stable ignition source to continuously ignite the fresh mixed gas from the main combustion nozzle.

[0073] When the main combustion nozzle 100 can burn stably, the duty nozzle 200 switches to premixed combustion mode, thereby reducing pollutant emissions.

[0074] During the switching process, one of the three duty nozzles 200 first switches from diffusion combustion to premixed combustion. After the combustion stabilizes, the other two then switch to premixed combustion in sequence to avoid combustion instability that may occur when all duty nozzles 200 switch at the same time.

[0075] In summary, this invention can flexibly switch the combustion method of the duty nozzle at different working stages of the combustion chamber, optimize combustion stability and pollutant emissions, and at the same time ensure that backfire does not occur during premixed combustion, protect the gas turbine components, and improve the safety and stability of the gas turbine during operation.

[0076] Example 2

[0077] Reference Figures 12-15 This is the second embodiment of the present invention. This embodiment is based on the previous embodiment, and also provides a backfire-preventing gas turbine combustor, but differs from the previous embodiment in that:

[0078] When the number of main combustion sub-nozzles 102 in a main combustion nozzle 100 or the number of duty sub-nozzles 202 in a duty nozzle 200 is an even number greater than 2, the premixed gas ratio in each sub-nozzle can be different, which facilitates fuel distribution and combustion adjustment and improves the flexibility of combustion control in the combustion chamber. However, it is still necessary to ensure that the premixed gas ratio of one of the adjacent sub-nozzles is lower than the lower limit of the fuel ignition concentration limit, and the premixed gas ratio of the other sub-nozzle is higher than the upper limit of the fuel ignition concentration limit to prevent backfire.

[0079] To facilitate combustion adjustment in this combustion chamber and optimize combustion organization and flow field distribution, the main combustion nozzles 100 need to be grouped in the following way, which is beneficial for individual adjustment (the number of duty nozzles 200 and main combustion nozzles 100 is the same, and the grouping method is also the same; here we only take the main combustion nozzles 100 as an example).

[0080] (1) When the number of main combustion nozzles 100 is an odd number that is greater than 3 and divisible by 3.

[0081] Let the result after division be n. Then, divide the main combustion nozzle 100 into n groups, denoted as group 1, group 2, ..., group n. Each group contains 3 main combustion nozzles 100, so the total number of main combustion nozzles 100 is 3n.

[0082] In this configuration, viewed from the head to the tail of the combustion chamber, the first main combustion nozzle 100 at the 12 o'clock position belongs to group 1. The second, third, ..., nth main combustion nozzles 100, arranged clockwise, belong to groups 2, 3, ..., n respectively. Then, the (n+1), (n+2), (n+3), ... main combustion nozzles 100 are further categorized using the same method, meaning the (n+1), (n+2), and (n+3)th main combustion nozzles 100 belong to groups 1, 2, and 3 respectively, until all 3n main combustion nozzles 100 are evenly distributed. Figure 12 As shown.

[0083] (2) When the number of main combustion nozzles 100 is an even number that is greater than 3 and divisible by 3.

[0084] The grouping method for the main combustion nozzle 100 is the same as that in (1), such as... Figure 13 As shown.

[0085] (3) When the number of main combustion nozzles is an even number greater than 3 and not divisible by 3.

[0086] Divide the total number of main combustion nozzles 100 by 2 and denote the result as m. Then, divide the main combustion nozzles 100 into m groups, denoted as the 1st, 2nd...mth group. Each group contains 2 main combustion nozzles 100, and the total number of main combustion nozzles 100 is 2m.

[0087] Looking from the head to the tail of the combustion chamber, the main combustion nozzle 100 at the 12 o'clock position is the first one, belonging to group 1. The second, third...mth main combustion nozzles 100, arranged clockwise, belong to groups 2, 3,...m respectively. Then the (m+1), (m+2), (m+3)th... main combustion nozzles continue to be categorized in the same way, meaning the (m+1), (m+2), and (m+3)th main combustion nozzles belong to groups 1, 2, and 3 respectively, until all 2m main combustion nozzles are evenly distributed. Figure 14 As shown.

[0088] In this embodiment, the center of the main combustion nozzle 100 is located on the same circle, and the duty nozzle 200 is tangent to the main combustion nozzle 100 outside this circle.

[0089] Optionally, the duty nozzle 200 may also be tangent to the main combustion nozzle 100 within this circle, such as... Figure 15 As shown, this design is particularly suitable for situations with a large number of main combustion nozzles (up to 100), which can improve space utilization and make the combustion chamber more compact.

[0090] The combustion control methods for the main combustion nozzle 100 can be categorized as follows:

[0091] (1) When the number of main combustion nozzles 100 is greater than 3 and divisible by 3, the duty nozzle 200 can still switch combustion modes as needed, and the combustion control methods of the main combustion nozzles 100 can have more options:

[0092] ① During the initial acceleration phase of the gas turbine, fuel can be supplied to all main combustion nozzles 100 simultaneously, and the acceleration of the gas turbine and the driving of the load are both achieved by increasing the amount of fuel.

[0093] ② During the initial acceleration phase of the gas turbine, the main combustion nozzles 100 can be grouped for combustion, with fuel supplied to only 40% to 60% of the main combustion nozzles 100. Before reaching a specific point, the output can be increased by increasing the amount of fuel in the main combustion nozzles 100.

[0094] The selection of the main combustion nozzle 100 should ensure uniform temperature distribution and reasonable flow field organization within the combustion chamber, and should be as symmetrical as possible. For example, in Figure 12 In the middle, you can choose group 1 and group 3 or group 2 and group 3. Figure 13 Groups 1 and 3, or groups 2 and 4, or groups 3 and 5, or even groups 2, 3, and 4, can be selected. The specific group allocation method can be appropriately selected according to the design operating conditions of the gas turbine. When the gas turbine speed or load reaches a certain set value, fuel can be introduced into the remaining main combustion nozzles 100, and the fuel quantity can be gradually increased until the gas turbine reaches full load operation. By grouping the main combustion nozzles 100 for combustion, the flexibility of gas turbine combustion can be improved, and it is also beneficial to extend the service life of the hot-end components of the combustion chamber. When a main combustion nozzle 100 is burning normally, the two duty nozzles 200 tangential to it must burn simultaneously to ensure ignition efficiency.

[0095] ③ During the initial acceleration phase of the gas turbine, the main combustion nozzles 100 can be grouped for combustion, supplying fuel only to 40% to 60% of the main combustion nozzles. Before reaching a specific point, the output can be increased by increasing the amount of fuel in the main combustion nozzles 100.

[0096] When the gas turbine speed or load reaches a certain set value, all remaining main combustion nozzles 100 are no longer activated simultaneously; instead, the remaining main combustion nozzles 100 are grouped together. For example... Figure 12 If the first and third groups of main combustion nozzles 100 are selected during the initial acceleration phase of the gas turbine, the remaining second and fourth groups of main combustion nozzles 100 can be gradually activated based on different load stages. For example, the second group of main combustion nozzles 100 can be activated first, and its fuel flow rate can be increased. When the load enters the next stage, the fourth group of main combustion nozzles 100 can be activated, and the fuel quantity can be gradually increased to improve the output.

[0097] When a main combustion nozzle 100 is burning normally, the two duty nozzles 100 tangential to it must burn simultaneously to ensure ignition efficiency. This combustion control method regroups the remaining main combustion nozzles 100 for combustion, which can further improve the combustion flexibility of the gas turbine and extend the service life of the hot-end components of the combustion chamber.

[0098] (2) When the number of main combustion nozzles is an even number greater than 3 and not divisible by 3.

[0099] ① During the initial acceleration phase of the gas turbine, fuel can be supplied to all main combustion nozzles 100 simultaneously, and the acceleration of the gas turbine and the driving of the load are both achieved by increasing the amount of fuel.

[0100] ② During the initial acceleration phase of the gas turbine, the main combustion nozzles 100 can be grouped for combustion, with fuel supplied to only 40% to 60% of the main combustion nozzles 100. Before reaching a specific point, the output can be increased by increasing the amount of fuel in the main combustion nozzles 100.

[0101] The selection of the main combustion nozzle 100 should ensure uniform temperature distribution and reasonable flow field organization within the combustion chamber, and should be selected as symmetrically as possible. For example, in... Figure 14 In this configuration, groups 1, 3, and 5, or groups 2, 3, and 4, or groups 2 and 4, can be selected. The specific group allocation method can be appropriately selected according to the design operating conditions of the gas turbine. When the gas turbine speed or load reaches a certain set value, fuel can be introduced into the remaining main combustion nozzles 100, and the fuel quantity can be gradually increased until the gas turbine reaches full load operation. When a main combustion nozzle 100 is burning normally, the two duty nozzles 200 tangential to it must burn simultaneously to ensure ignition efficiency.

[0102] ③ During the initial acceleration phase of the gas turbine, the main combustion nozzles 100 can be grouped for combustion, and fuel can be supplied to only 40% to 60% of the main combustion nozzles 100. Before reaching a specific point, the output can be increased by increasing the amount of fuel in the main combustion nozzles 100.

[0103] When the gas turbine speed or load reaches a certain set value, all remaining main combustion nozzles 100 are no longer activated simultaneously. Instead, the remaining main combustion nozzles 100 are further grouped, for example... Figure 14 If the second and fourth groups of main combustion nozzles 100 are selected during the initial acceleration phase of the gas turbine, the remaining first, third, and fifth groups of main combustion nozzles 100 can be gradually activated based on different load stages. In order to make the temperature distribution in the combustion chamber uniform, the third group of main combustion nozzles 100 should be activated first and its fuel flow rate should be increased. When the load enters the subsequent stage, the first and fifth groups of main combustion nozzles 100 should be activated and the fuel quantity should be gradually increased to improve the output.

[0104] The load in subsequent stages can be further divided according to actual needs, meaning that the first and fifth groups of nozzles can be activated sequentially to further improve the combustion flexibility of the gas turbine. When a main combustion nozzle 100 is burning normally, the two duty nozzles 200 tangent to it must burn simultaneously to ensure ignition efficiency.

[0105] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A backfire-proof gas turbine combustion chamber, characterized in that: include, The main combustion nozzle (100) is provided in at least three and is evenly distributed in a ring, and is connected to the flame tube (300); The number of duty nozzles (200) corresponds one-to-one with the number of main combustion nozzles (100), they are evenly distributed in a ring and tangent to the main combustion nozzles (100), and are connected to the flame tube (300); The main combustion nozzle (100) includes at least one high-speed fuel passage (101) and at least two main combustion sub-nozzles (102), wherein the main combustion sub-nozzle (102) is composed of a main combustion nozzle air passage (102a) and a main combustion nozzle premixing passage (102b); The duty nozzle (200) includes at least one duty nozzle diffusion fuel channel (201) and at least two duty sub-nozzles (202), the duty sub-nozzles (202) being composed of a duty nozzle air channel (202a) and a duty nozzle premixing channel (202b); The premixed air-fuel ratios introduced into the two adjacent main combustion nozzles (102) are different, with one premixed air-fuel ratio being lower than the lower limit of the ignition concentration limit and the other premixed air-fuel ratio being higher than the upper limit of the ignition concentration limit. The air-fuel ratios of the premixed gas introduced into the two adjacent duty nozzles (202) are different, with the air-fuel ratio of one premixed gas being lower than the lower limit of the ignition concentration limit and the air-fuel ratio of the other premixed gas being higher than the upper limit of the ignition concentration limit.

2. The backfire-proof gas turbine combustion chamber as described in claim 1, characterized in that: The main combustion nozzle (100) further includes at least one main combustion nozzle partition (103), which is used to separate different main combustion sub-nozzles (102). The main combustion nozzle partition (103) is provided with a high-speed fuel injection hole (103a), which is used to connect the high-speed fuel channel (101) and the flame tube (300).

3. The backfire-proof gas turbine combustion chamber as described in claim 1 or 2, characterized in that: Each of the main combustion nozzle air passages (102a) is provided with a main combustion nozzle swirler (104), which causes the gas passing through the main combustion nozzle air passage (102a) to swirl.

4. The backfire-proof gas turbine combustion chamber as described in claim 1, characterized in that: The main combustion sub-nozzle (102) further includes a main combustion sub-nozzle premix injection hole (102c), which is used to connect the main combustion sub-nozzle premix channel (102b) and the main combustion sub-nozzle air channel (102a).

5. The backfire-resistant gas turbine combustion chamber as described in any one of claims 1, 2, or 4, characterized in that: The duty nozzle (200) includes at least one duty nozzle partition for separating different duty sub-nozzles (202). The duty sub-nozzle (202) also includes a duty sub-nozzle premixed fuel injection hole (202c), which is used to connect the duty nozzle premixed channel (202b) and the duty nozzle air channel (202a).

6. The backfire-proof gas turbine combustion chamber as described in claim 1, characterized in that: The duty nozzle (200) further includes a duty nozzle diffusion fuel mixing hole (201a) and a duty nozzle diffusion fuel direct injection hole (201b). Both the duty nozzle diffusion fuel mixing hole (201a) and the duty nozzle diffusion fuel direct injection hole (201b) are used to connect the duty nozzle diffusion fuel channel (201) and the flame tube (300). The duty nozzle diffusion fuel mixing hole (201a) has an angle with the axis of the duty nozzle diffusion fuel channel (201).

7. The anti-backfire gas turbine combustion chamber as described in any one of claims 1, 2, 4 or 6, characterized in that: Each of the duty nozzle air passages (202a) is provided with a duty nozzle vortex (203), which causes the gas passing through the duty nozzle air passages (202a) to swirl.

8. The backfire-proof gas turbine combustion chamber as described in claim 1, characterized in that: Flame tube (300) is provided with a flame tube gas film cooling hole (301) and a mixing hole (302) on the outer wall. An end cap (303) is also provided inside the flame tube (300). The end cap (303) is used to position and fix the main combustion nozzle (100) and the duty nozzle (200).

9. The backfire-proof gas turbine combustion chamber as described in claim 1, characterized in that: During the initial acceleration phase of the gas turbine, fuel is introduced into the fuel diffusion channel (201) of the duty nozzle; When the gas turbine speed or load reaches the set value, the fuel flow rate entering the duty nozzle diffusion fuel channel (201) is gradually reduced while fuel is introduced into the duty sub-nozzle (202) until fuel is stopped from being introduced into the duty nozzle diffusion fuel channel (201).

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