Gas turbine combustor backfire thermocouple mounting structure, combustor and gas turbine

Abstract

The application provides a gas turbine combustion chamber backfire thermocouple mounting structure, a combustion chamber and a gas turbine. The mounting structure comprises an elastic extrusion assembly and a thermocouple guide tube. The lead wire of the backfire thermocouple penetrates into the thermocouple guide tube and extends out of an outlet. The outlet is fixedly connected to the outer wall of a nozzle cover cylinder. The elastic extrusion assembly is arranged at the outlet of the thermocouple guide tube. The elastic extrusion assembly can press the measuring end of the backfire thermocouple when the backfire thermocouple is inserted, and automatically release the pressing when the backfire thermocouple is pulled out. The application realizes the function of replacing the backfire thermocouple without disassembling the combustion chamber on the whole machine, realizes the repeated disassembly and replacement of the backfire thermocouple, reduces the risk of monitoring failure caused by damage of the backfire thermocouple, and guarantees the reliability of the backfire monitoring function. Moreover, the lead wire of the backfire thermocouple is protected in the whole path, and the lead wire of the backfire thermocouple is not exposed to the high-speed airflow in the combustion chamber.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and more particularly to a gas turbine combustion chamber backfire thermocouple mounting structure, combustion chamber and gas turbine. Background Technology

[0002] Heavy-duty gas turbines employ lean premixed combustion, which is prone to backfire and damage to the nozzle assembly. Therefore, during whole-unit testing or commercial operation, a backfire thermocouple is typically installed at the combustion chamber head to monitor for backfire. This backfire thermocouple is connected to the control system, with alarm and trip thresholds set. Once an alarm is triggered, corresponding protective actions are immediately executed, such as rapid load reduction and shutdown or tripping.

[0003] like Figure 13 , Figure 14 As shown, the combustion chamber of a heavy-duty gas turbine mainly comprises the following components: a combustion chamber head assembly 13 (including a central nozzle assembly 1301, a peripheral nozzle assembly 1302, a combustion chamber end cover 7, a fairing assembly 1303, a casing 11, and a cap assembly 1304), a flow guide bushing assembly 14, a flame tube assembly 15, a transition section assembly 16, and related sealing components. The existing backfire detection scheme involves arranging thermocouple measuring points on the casing walls of the central and peripheral nozzles. The thermocouple leads are led out through holes drilled in the outer ring of the cap and the casing, and the thermocouple leads are fixed along their path with thin metal clamps. This thermocouple installation method is a one-time installation, meaning it is not removable. After the thermocouple end is fixed to the measuring point, the thermocouple measuring point is permanently sealed inside the cap after the welding and installation process of the cap components is completed.

[0004] The main disadvantages of the existing backfire detection scheme are: (1) The combustion chamber contains one central nozzle and six peripheral nozzles. A backfire thermocouple is installed on the outer wall of the cover of each nozzle to detect backfire. Thus, there are a total of seven backfire thermocouples in one combustion chamber. If the whole machine contains N combustion chambers, then the whole machine has 7N backfire thermocouples. Too many measuring points will bring additional complexity to manufacturing, installation and monitoring. (2) The backfire thermocouple measuring points are fixed along the process by metal clamps. It is a one-time installation. After installation, it is sealed in the combustion chamber cover and cannot be disassembled or replaced. If the backfire thermocouple is damaged during the operation of the whole machine, it will lose part of the backfire monitoring function, which will bring great risks to the safe operation of the gas turbine and lose the control and protection functions. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a gas turbine combustion chamber tempering thermocouple mounting structure, a combustion chamber and a gas turbine, making the tempering thermocouple easy to install and remove, and ensuring the reliability of the tempering monitoring function.

[0006] One embodiment of the present invention provides a gas turbine combustor tempering thermocouple installation structure, comprising: a thermocouple guide tube and an elastic compression assembly. The thermocouple guide tube has an insertion port and an extension port. The lead wire of the tempering thermocouple is adapted to pass through the insertion port into the thermocouple guide tube and extend out of the extension port. The extension port is fixedly connected to the outer wall of the nozzle shroud, so that the measuring end of the lead wire extending out of the extension port is in contact with the outer wall of the nozzle shroud. The elastic compression assembly is disposed at the extension port of the thermocouple guide tube. The elastic compression assembly can press the measuring end of the tempering thermocouple when the tempering thermocouple is inserted, and automatically release the pressing when the tempering thermocouple is pulled out.

[0007] In some embodiments, one end of the thermocouple conduit with an insertion port is inserted into the thermocouple inlet of the combustion chamber end cap, and the other end of the thermocouple conduit with an extension port is a bend, a portion of which is fitted to the outer wall of the nozzle shroud, and the extension port is located on the side of the bend.

[0008] In some embodiments, the elastic extrusion assembly includes a spring sheet, which has an Ω-shaped structure and is made of metal. The two ends of the spring sheet are a fixed end and a free end, respectively. The fixed end of the spring sheet is fixedly connected to the inner wall of the bent pipe section. The middle of the spring sheet protrudes towards the nozzle cover to form an extrusion part. When the extrusion part extrudes the measuring end of the lead wire, the spring sheet deforms and the free end of the spring sheet extends along the length of the spring sheet.

[0009] In some embodiments, the bend section includes a bend section body and a mounting member. The mounting member is fixedly connected to the top end of the bend section body and is used to install a spring clip. A groove is formed on the side wall of the mounting member. The groove communicates with the interior of the bend section body. The opening of the groove is the protrusion of the thermocouple conduit. The fixed end of the spring clip is fixedly connected to the bottom of the groove.

[0010] In some embodiments, the thermocouple conduit includes a connected bend, a first section, an adapter, and a second section. The second section has an inlet end and a connecting end. The inlet end of the second section is inserted into the thermocouple inlet of the combustion chamber end cap. The adapter is fixedly connected to the side wall of the outer cylinder of the cap and passes through the inner and outer walls of the outer cylinder. The connecting end of the second section is connected to the outer wall of the outer cylinder of the cap through the adapter. The first section has a first end and a second end. The first end of the first section is connected to the inner wall of the outer cylinder of the cap through the adapter. The second end of the first section is connected to the bend.

[0011] In some embodiments, the adapter is a hollow pipe fitting, with a first socket and a second socket at each end. The first socket is connected to the first end of the first pipe segment, and the second socket is connected to the connecting end of the second pipe segment.

[0012] In some embodiments, the gas turbine combustion chamber tempering thermocouple mounting structure further includes a support member, one end of which is fixedly connected to the outer wall of the outer cylinder of the cover, and the other end of which is fixedly connected to the outer wall of the second pipe section to support and fix the second pipe section.

[0013] A second aspect of the present invention provides a combustion chamber including multiple nozzles and the aforementioned gas turbine combustion chamber backfire thermocouple mounting structure. The nozzles include a central nozzle, a primary peripheral nozzle, and a secondary peripheral nozzle. The primary peripheral nozzle and the secondary peripheral nozzle are distributed around the outer periphery of the central nozzle. The operating equivalence ratio of the primary peripheral nozzle is greater than that of the secondary peripheral nozzle. The nozzle shroud includes a central nozzle shroud, a primary peripheral nozzle shroud, and a secondary peripheral nozzle shroud. Several thermocouple conduits are provided and respectively installed on the outer wall of the central nozzle shroud and the outer wall of the primary peripheral nozzle shroud.

[0014] In some embodiments, the tempering thermocouple is a dual-armored thermocouple, and each dual-armored thermocouple acquires two thermocouple data.

[0015] A third aspect of the present invention provides a gas turbine including the combustion chamber described above. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings. in: Figure 1 This is a schematic diagram of the gas turbine combustion chamber tempering thermocouple installation structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the assembly of the thermocouple conduit and the outer sleeve of the cap; Figure 3 for Figure 1 Sectional view of plane AA in the middle; Figure 4 for Figure 3 An enlarged schematic diagram of the bend in the pipe section; Figures 5-10 This is a flowchart of the processing of the pipe bend. in: Figure 5 This is a structural schematic diagram of the base plate; Figure 6 This is a schematic diagram of the assembly of the base plate and the spring clip; Figure 7 This is a structural diagram of the U-shaped component; Figure 8 This is a schematic diagram of the assembly of the mounting parts and the spring clip; Figure 9 This is a schematic diagram of the structure of the bend section. Figure 10This is an assembly diagram of the bend section body, mounting components, and spring clips; Figure 11 for Figure 3 A schematic diagram of the internal structure of the adapter in the middle; Figure 12 for Figure 1 BB section view in the middle; Figure 13 This is a schematic diagram of the combustion chamber according to an embodiment of the present invention; Figure 14 for Figure 13 A schematic diagram of the combustion chamber head assembly in the middle; Figure label: 1. Support component; 2. Thermocouple conduit; 201. First pipe section; 202. Second pipe section; 203. Adapter; 2031. First socket; 2032. Second socket; 204. Bend section; 2041. Bend section body; 2042. Mounting component; 20421. Base plate; 20422. U-shaped component; 3. Primary peripheral nozzle cover; 4. Central nozzle cover; 5. Secondary peripheral nozzle cover; 6. Diverging panel; 7. Combustion chamber end 8. Cover; 9. Outer cylinder of the cover; 10. Thermocouple inlet; 11. NPT threaded interface; 12. Casing; 13. Spring; 14. Fixed end; 15. Extrusion section; 16. Free end; 17. Combustion chamber head assembly; 18. Center nozzle assembly; 19. Peripheral nozzle assembly; 10. Fairing assembly; 11. Cover assembly; 12. Casing assembly; 13. Guide bushing assembly; 14. Flame tube assembly; 15. Transition section assembly. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0018] The following description, with reference to the accompanying drawings, describes the gas turbine combustion chamber tempering thermocouple mounting structure, combustion chamber, and gas turbine according to an embodiment of the present invention.

[0019] like Figures 1-12 As shown, one embodiment of the present invention proposes a gas turbine combustion chamber tempering thermocouple installation structure, including: a thermocouple conduit 2 and an elastic compression assembly. The thermocouple conduit 2 has an insertion port and an extension port. The lead wire of the tempering thermocouple is adapted to pass through the insertion port into the thermocouple conduit 2 and extend out of the extension port. The extension port is fixedly connected to the outer wall of the nozzle shroud, so that the measuring end of the lead wire extending out of the extension port is in contact with the outer wall of the nozzle shroud. The elastic compression assembly is provided at the extension port of the thermocouple conduit 2. The elastic compression assembly can press the measuring end of the inserted lead wire and automatically release the pressing when the tempering thermocouple is pulled outward.

[0020] This invention, through the provision of thermocouple conduit 2, enables the replacement of the tempering thermocouple without disassembling the combustion chamber, allowing for repeated disassembly and replacement of the tempering thermocouple. This reduces the risk of monitoring failure due to tempering thermocouple damage and ensures the reliability of the tempering monitoring function. Furthermore, it provides full-path protection for the tempering thermocouple leads, preventing them from being exposed to the high-speed airflow in the combustion chamber.

[0021] It should be noted that the tempering thermocouple in this embodiment monitors the temperature of the outer wall of the nozzle shroud, and the leads of the tempering thermocouple do not penetrate the wall of the nozzle shroud. This is because if the leads of the tempering thermocouple penetrated the wall of the nozzle shroud, it would introduce an interference source into the nozzle premixing channel, forming a boundary layer, which is equivalent to adding an additional source of tempering risk.

[0022] Furthermore, the nozzle cover includes a central nozzle cover 4 and a primary peripheral nozzle cover 3.

[0023] Furthermore, the wall thickness of the thermocouple conduit 2 is 0.8~1.5mm. The outer and inner diameters of the thermocouple conduit 2 are not limited and can be determined according to the design. In this embodiment, the outer diameter of the thermocouple conduit 2 is 10.2mm.

[0024] In some embodiments, such as Figure 3 As shown, the end of the thermocouple conduit 2 with the insertion port is inserted into the thermocouple inlet 9 of the combustion chamber end cover 7. The end of the thermocouple conduit 2 with the protrusion port is a bent section 204. A portion of the bent section 204 is welded to the outer wall of the nozzle cover, and the protrusion port is located on the side of the bent section 204. This ensures that the measuring end of the tempered thermocouple is in close contact with the outer wall of the nozzle cover, providing sufficient heat conduction and ensuring the accuracy of the measurement results.

[0025] When installing a tempered thermocouple, the lead wire of the tempered thermocouple is slowly inserted into the protrusion of the bend section 204 along the channel of the thermocouple conduit 2, and the measuring end of the lead wire is pressed against the outer wall of the nozzle cover by the elastic compression component.

[0026] Furthermore, the bending radius of the bend section 204 is not less than five times the diameter of the lead wire of the tempering thermocouple. The specific dimensions can be designed according to actual needs, with the principle of not affecting the aerodynamic cooling performance and structural integrity of the combustion chamber, not interfering with other components, and not affecting the installation of other parts such as instruments. In this embodiment, the bending radius of the bend section 204 at the central nozzle shroud 4 is 40mm, the inner diameter of the bend section 204 is 4mm, and the wall thickness is 2mm.

[0027] In some embodiments, such as Figure 4 , Figure 6As shown, the elastic extrusion assembly includes a spring sheet 12, which has an Ω-shaped structure and is made of metal. The two ends of the spring sheet 12 are a fixed end 1201 and a free end 1203, respectively. The fixed end 1201 of the spring sheet 12 is fixedly connected to the inner wall of the bent pipe section 204. The middle of the spring sheet 12 protrudes towards the nozzle cover to form an extrusion part 1202. When the extrusion part 1202 extrudes the measuring end of the lead wire, the spring sheet 12 deforms. The free end 1203 of the spring sheet 12 extends along the length of the spring sheet 12 and slides along the inner wall surface of the bent pipe section 204.

[0028] Before the lead wire of the tempering thermocouple is installed, a gap is left between the extrusion part 1202 and the nozzle cover, which is smaller than the outer diameter of the measuring end of the thermocouple.

[0029] When the measuring end of the lead wire is inserted into the space between the extrusion section 1202 and the nozzle cover, the spring 12 is compressed and undergoes elastic deformation, causing the measuring end of the lead wire to press against the outer wall of the nozzle cover. This avoids gaps between the measuring end of the lead wire and the outer wall of the nozzle cover, ensuring the accuracy of temperature measurement and shortening the temperature measurement response time.

[0030] Furthermore, before the lead wire of the tempering thermocouple is inserted, a 1mm gap is maintained between the extrusion section 1202 and the nozzle shroud, and the diameter of the lead wire of the tempering thermocouple is 2mm.

[0031] Furthermore, the material for spring 12 can be GH4145 (corresponding to ASTM Inconel X-750). GH4145 alloy is an age-hardening nickel-based superalloy reinforced with tantalum, titanium, and niobium. This alloy has good high-temperature resistance, stress relaxation resistance, and stress corrosion resistance, making it suitable for manufacturing components such as high-temperature fasteners for steam turbines and spring 12. Alternatively, other high-temperature elastically stable materials can be selected.

[0032] In some embodiments, such as Figure 4 , Figure 10 As shown, the bend section 204 includes a bend section body 2041 and a mounting component 2042. The mounting component 2042 is fixedly connected to the top of the bend section body 2041. The mounting component 2042 is used to install the spring piece 12. A groove is opened on the side wall of the mounting component 2042. The groove communicates with the interior of the bend section body 2041. The opening of the groove is the protrusion of the thermocouple conduit 2. The fixed end 1201 of the spring piece 12 is fixedly connected to the bottom of the groove.

[0033] Furthermore, such as Figures 5-10 As shown, the manufacturing method of the bend section 204 includes the following steps: Step 1, as follows Figure 5 As shown, prepare a base plate 20421, and open a groove on one side of the upper end of the base plate 20421. Step 2, as follows Figure 6As shown, the fixed end 1201 of the spring piece 12 is welded and fixed to the groove of the base plate 20421; Step 3, as follows Figure 7 As shown, prepare a U-shaped part 20422. The length of the U-shaped part 20422 is equal to the length of the base plate 20421, and the width of the U-shaped part 20422 is equal to the width of the base plate 20421. Step 4, as follows Figure 8 As shown, the U-shaped part 20422 is welded to the upper end of the base plate 20421, forming a groove structure after welding. The spring piece 12 is located in the groove. Both the upper end and the front end of the groove have openings. The mounting part 2042 is completed. The front opening of the groove is the outlet of the thermocouple conduit 2. Step 5, as follows Figure 9 As shown, the bent pipe section body 2041 can be manufactured by machining or 3D printing; Step 6, as follows Figure 10 As shown, the upper opening of the mounting component 2042 is connected to the lower port of the bent pipe section body 2041 and welded to fix it, thus completing the preparation of the bent pipe section 204.

[0034] Furthermore, a small hole is formed on the side wall of the bent pipe section body 2041 near the lower end. The small hole is connected to and welded to the front opening of the mounting part 2042 to form the protrusion of the thermocouple conduit 2. The small hole and the front opening of the mounting part 2042 are welded together to the outer wall of the nozzle cover.

[0035] In some embodiments, gaps are left between the two sides of the spring piece 12 in the width direction and the two side walls of the groove, respectively, to prevent the spring piece 12 from contacting the two side walls of the groove and getting stuck when it slides.

[0036] Furthermore, a gap of 0.3~0.5mm is left between the two sides of the spring piece 12 in the width direction and the two side walls of the groove.

[0037] In some embodiments, such as Figure 3 As shown, the thermocouple conduit 2 includes a connected bend section 204, a first section 201, an adapter 203, and a second section 202. The second section 202 has an inlet end and a connecting end. The inlet end of the second section 202 is inserted into the thermocouple inlet 9 of the combustion chamber end cap 7. The adapter 203 is fixedly connected to the side wall of the outer cylinder 8 of the cap and penetrates both the inner and outer walls of the outer cylinder 8. The connecting end of the second section 202 is connected to the outer wall of the outer cylinder 8 of the cap through the adapter 203. The first section 201 has a first end and a second end. The first end of the first section 201 is connected to the inner wall of the outer cylinder 8 of the cap through the adapter 203, and the second end of the first section 201 is connected to the bend section 204. The insertion port of the thermocouple conduit 2 is located at the inlet end of the second section 202, and the outlet of the thermocouple conduit 2 is located at the bend section 204.

[0038] In this embodiment of the invention, the adapter 203 serves as a support and bridge, connecting the first pipe section 201 and the second pipe section 202.

[0039] Furthermore, the outer diameter of the first pipe section 201 and the outer diameter of the second pipe section 202 may be equal or unequal. In this embodiment, the outer diameter of the first pipe section 201 and the outer diameter of the second pipe section 202 are equal. The first pipe section 201 is a straight pipe and is inclined, while the second pipe section 202 is a bent pipe with a bend, because the second pipe section 202 needs to be connected to the thermocouple inlet 9 of the combustion chamber end cover 7.

[0040] Furthermore, the bending radius of the bend in the second pipe section 202 is designed according to actual needs, with the principle that the second pipe section 202 can be smoothly connected with the thermocouple inlet 9 of the combustion chamber end cover 7 and the adapter 203. In this embodiment, the bending radius of the bend in the second pipe section 202 at the center nozzle cover 4 is 60mm.

[0041] Furthermore, the thermocouple inlet 9 has a stepped hole at one end facing the nozzle cover. The inner diameter of the stepped hole is slightly larger than the inner diameter of the thermocouple inlet 9. The second tube section 202 is inserted into the stepped hole by 3-5 mm. A 2 mm gap is maintained between the inlet end of the second tube section 202 and the bottom surface of the stepped hole. A 0.5-1 mm gap is maintained between the outer wall of the second tube section 202 and the inner wall of the stepped hole to reserve space for thermal expansion. This ensures that the lead of the tempering thermocouple is protected by the thermocouple conduit 2 throughout the entire process, preventing it from being exposed to high-temperature air and reducing the life of the tempering thermocouple.

[0042] Furthermore, the end of the thermocouple inlet 9 located outside the combustion chamber end cover 7 is an NPT threaded interface 10, used for the detachable installation of the thermocouple sealing lead connector. The lead of the tempered thermocouple is sequentially inserted into the combustion chamber end cover 7 and the thermocouple guide tube 2 from the thermocouple sealing lead connector. The thermocouple sealing lead connector is threaded into the combustion chamber end cover 7, and the lead of the tempered thermocouple is sealed to the thermocouple sealing lead connector to ensure a tight seal. If the tempered thermocouple is damaged, the lead can be pulled out from the thermocouple sealing lead connector for replacement.

[0043] Furthermore, the thermocouple sealed lead connector can be replaced with other sealing structures.

[0044] Furthermore, the angle between the first pipe section 201 and the divergence panel 6 is designed according to actual needs, with the principle of not affecting the aerodynamic cooling performance and structural integrity of the combustion chamber, not interfering with other components, and not affecting the installation of other parts such as instruments. In this embodiment, the angle δ between the first pipe section 201 at the center nozzle shroud 4 and the divergence panel 6 is 30°.

[0045] In some embodiments, such as Figure 11As shown, the adapter 203 is a hollow pipe fitting. The two ends of the adapter 203 have a first socket 2031 and a second socket 2032, respectively. The first socket 2031 is connected to the first end of the first pipe section 201, and the second socket 2032 is connected to the connecting end of the second pipe section 202.

[0046] Furthermore, the inner diameter of the first socket 2031 is slightly larger than the outer diameter of the first pipe section 201, and the inner diameter of the second socket 2032 is slightly larger than the outer diameter of the second pipe section 202, to ensure that the first pipe section 201, the second pipe section 202 and the adapter 203 can be smoothly connected. For example, if the outer diameter of the first pipe section 201 is 10.2 mm, then the inner diameter of the first socket 2031 is 10.6 mm.

[0047] Furthermore, the inner diameter of the first socket 2031 and the inner diameter of the second socket 2032 can be equal or unequal. When the outer diameter of the first pipe segment 201 is equal to the outer diameter of the second pipe segment 202, the inner diameter of the first socket 2031 is equal to the inner diameter of the second socket 2032; when the outer diameter of the first pipe segment 201 is unequal to the outer diameter of the second pipe segment 202, the inner diameter of the first socket 2031 is unequal to the inner diameter of the second socket 2032. In this embodiment, the inner diameter of the first socket 2031 and the inner diameter of the second socket 2032 are equal.

[0048] In some embodiments, such as Figures 1-3 As shown, the gas turbine combustor backfire thermocouple mounting structure also includes a support member 1. One end of the support member 1 is welded to the outer wall of the outer cylinder 8 of the cover, and the other end of the support member 1 is fixedly connected to the outer wall of the second pipe section 202 to support and fix the second pipe section 202. This can prevent damage caused by structural stress and vibration during the operation of the combustor.

[0049] Furthermore, the installation method of the thermocouple conduit 2 includes the following steps: Step 1: Fix the first pipe section 201 to the bent pipe section 204, and then put it into the inside of the outer cylinder 8 of the nozzle cap. Weld the protruding end of the bent pipe section 204 to the outer wall of the nozzle cap. Step 2: Make a hole in the side wall of the outer cylinder 8 of the cap and insert the adapter 203 so that the two ends of the adapter 203 extend out of the inner wall and the outer wall of the outer cylinder 8 of the cap respectively. Insert the first end of the first pipe section 201 into the first socket 2031 of the adapter 203 and weld it in place. Fix the adapter 203 to the outer cylinder 8 of the cap by spot welding. Step 3: Assemble the diverging panel 6, the outer sleeve of the cap 8, and the nozzle sleeve to form the cap; Step 4: Insert the connecting end of the second pipe section 202 into the second socket 2032 of the adapter 203 and weld it in place; Step 5: Weld one end of the support member 1 to the outer wall of the cap outer cylinder 8, and weld the other end of the support member 1 to the outer wall of the second pipe section 202 to fix and support the second pipe section 202. Step 6: Make a through hole along the thickness direction of the combustion chamber end cap 7 to form a thermocouple inlet 9. Insert the inlet end of the second pipe section 202 into the thermocouple inlet 9 for a certain distance. Connect the thermocouple sealing lead connector to the outward end of the thermocouple inlet 9. Step 7: Assemble the casing 11, combustion chamber end cover 7, and hood assembly 1304; Step 8: Insert the lead of the tempering thermocouple into the thermocouple inlet 9 of the combustion chamber end cover 7. The lead is inserted into the combustion chamber end cover 7 and the thermocouple guide tube 2 in sequence. The spring clip 12 presses the measuring end of the lead against the outer wall of the nozzle shroud.

[0050] This layout ensures that the removal and installation of the tempering thermocouple will not affect the aerodynamic cooling performance and structural integrity of the combustion chamber, will not interfere with other components, and will not affect the installation of other parts such as instruments.

[0051] like Figure 1 As shown, a second aspect of the present invention provides a combustion chamber including multiple nozzles and the aforementioned gas turbine combustion chamber backfire thermocouple mounting structure. The nozzles include a central nozzle, primary peripheral nozzles, and secondary peripheral nozzles, distributed around the outer periphery of the central nozzle. The operating equivalence ratio of the primary peripheral nozzles is greater than that of the secondary peripheral nozzles. The nozzle housing includes a central nozzle housing 4, a primary peripheral nozzle housing 3, and a secondary peripheral nozzle housing 5. Several thermocouple conduits 2 are provided and respectively installed on the outer walls of the central nozzle housing 4 and the primary peripheral nozzle housing 3. The thermocouple conduits 2 are installed in the same manner on the central nozzle housing 4 and the primary peripheral nozzle housing 3.

[0052] The embodiments of the present invention can reduce the number of tempering thermocouples required, simplify the manufacturing and installation process, reduce the complexity of monitoring, and reduce procurement costs.

[0053] For example, in existing solutions, tempering thermocouples are arranged on both the central nozzle and the six peripheral nozzles. However, in this embodiment of the invention, the peripheral nozzles are classified into two primary peripheral nozzles and four secondary peripheral nozzles. Since the operating equivalence ratio of the primary peripheral nozzles is greater than that of the secondary peripheral nozzles, tempering thermocouples are only arranged on the central nozzle shroud 4 and the primary peripheral nozzle shroud 3. In other words, only three tempering thermocouples are needed. Compared with the existing solutions, four tempering thermocouples are reduced on each combustion chamber. If the entire machine contains N combustion chambers, then 4N thermocouples will be reduced.

[0054] It should be noted that, based on the nozzle operating mode and the range of the operating equivalence ratio (i.e., fuel-air mixture equivalence ratio) in the combustion chamber, the operating equivalence ratio of the first-stage peripheral nozzle is consistently higher than that of the second-stage peripheral nozzle throughout the entire operating range of the gas turbine, from startup loading to load ramp-up to base load. Therefore, the risk of backfire is higher for the first-stage peripheral nozzle than for the second-stage peripheral nozzle. For simplicity and reliability in design, manufacturing, and monitoring, it is sufficient to install backfire thermocouples on the central nozzle and the first-stage peripheral nozzles to monitor the metal wall temperature of the casing, thus meeting the backfire monitoring requirements. When the backfire thermocouple detects that the metal wall temperature has risen to a preset value, the gas turbine TCS control and protection system activates an alarm, executing a rapid load reduction or turbine shutdown.

[0055] Furthermore, the combustion chamber outer perimeter nozzle grading scheme is "2+4", meaning the nozzle includes one central nozzle, two primary peripheral nozzles, and four secondary peripheral nozzles. Three thermocouple conduits 2 are provided, respectively installed on the outer wall of one central nozzle shroud 4 and the outer walls of two primary peripheral nozzle shrouds 3.

[0056] Furthermore, such as Figure 1 As shown, the azimuth angles of the three thermocouple conduits 2 during installation can be determined according to design requirements. The principle is: the design should be simple and reliable, and should not affect the functional integrity (such as aerodynamics and cooling performance) and reliability (such as instrument interfaces) of the existing combustion chamber structure. In this embodiment, the azimuth angle β of the thermocouple conduit 2 of the central nozzle is 30°, and the azimuth angles α and γ of the thermocouple conduits 2 of the two peripheral nozzles are both 10°.

[0057] In some embodiments, the tempering thermocouples are dual-armored thermocouples, meaning each tempering thermocouple includes two leads, and each dual-armored thermocouple acquires data from two thermocouples. This provides redundant measurement points, improving the reliability of the measurement points and the control and protection system.

[0058] In this embodiment, each combustion chamber is equipped with 3 dual-armored thermocouples, and a total of 6 thermocouple data are obtained. The whole machine contains N combustion chambers, so there are a total of 6N tempering thermocouple temperature data.

[0059] The backfire monitoring method includes the following steps: Select the maximum temperature value from the thermocouple data of all combustion chambers in the gas turbine. The difference between the maximum temperature value and the temperature at the compressor outlet is dT. During the operation of the gas turbine, if dT>80℃, an alarm signal is issued, and the operating status of the combustion chamber nozzles needs to be closely monitored; if dT>100℃, protective actions are taken, such as a 2-second delay to trip the turbine.

[0060] A third aspect of the present invention provides a gas turbine including the combustion chamber described above.

[0061] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0065] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0066] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A gas turbine combustion chamber tempering thermocouple mounting structure, characterized in that, include: Thermocouple conduit has an insertion port and an extension port. The lead wire of the tempered thermocouple is adapted to pass through the insertion port into the thermocouple conduit and extend out from the extension port. The extension port is fixedly connected to the outer wall of the nozzle shroud, so that the measuring end of the lead wire extending out from the extension port is in contact with the outer wall of the nozzle shroud. An elastic compression assembly is provided at the protrusion of the thermocouple conduit. The elastic compression assembly can press the measuring end of the inserted lead and automatically release the compression when the tempered thermocouple is pulled outward.

2. The gas turbine combustion chamber tempering thermocouple mounting structure according to claim 1, characterized in that, The thermocouple conduit has an insertion port at one end, which is inserted into the thermocouple inlet of the combustion chamber end cap. The thermocouple conduit has an extension port at the other end, which is a bent section. A portion of the bent section is attached to the outer wall of the nozzle shroud, and the extension port is located on the side of the bent section.

3. The gas turbine combustion chamber tempering thermocouple mounting structure according to claim 2, characterized in that, The elastic extrusion assembly includes a spring sheet, which has an Ω-shaped structure and is made of metal. The two ends of the spring sheet are a fixed end and a free end, respectively. The fixed end of the spring sheet is fixedly connected to the inner wall of the bent pipe section. The middle of the spring sheet protrudes towards the nozzle cover to form an extrusion part. When the extrusion part extrudes the measuring end of the lead wire, the spring sheet deforms, and the free end of the spring sheet extends along the length of the spring sheet.

4. The gas turbine combustion chamber tempering thermocouple mounting structure according to claim 3, characterized in that, The bend section includes a bend section body and an mounting component. The mounting component is fixedly connected to the top of the bend section body and is used to install the spring piece. A groove is formed on the side wall of the mounting component. The groove communicates with the interior of the bend section body. The opening of the groove is the protrusion of the thermocouple conduit. The fixed end of the spring piece is fixedly connected to the bottom of the groove.

5. The gas turbine combustion chamber tempering thermocouple mounting structure according to claim 2, characterized in that, The thermocouple conduit includes a connected bend, a first section, an adapter, and a second section. The second section has an inlet end and a connecting end. The inlet end of the second section is inserted into the thermocouple inlet of the combustion chamber end cap. The adapter is fixedly connected to the side wall of the outer cylinder of the cap and penetrates the inner and outer walls of the outer cylinder. The connecting end of the second section is connected to the outer wall of the outer cylinder of the cap through the adapter. The first section has a first end and a second end. The first end of the first section is connected to the inner wall of the outer cylinder of the cap through the adapter. The second end of the first section is connected to the bend.

6. The gas turbine combustion chamber tempering thermocouple mounting structure according to claim 5, characterized in that, The adapter is a hollow tube, and its two ends have a first socket and a second socket, respectively. The first socket is connected to the first end of the first pipe segment, and the second socket is connected to the connecting end of the second pipe segment.

7. The gas turbine combustion chamber tempering thermocouple mounting structure according to claim 5, characterized in that, It also includes a support member, one end of which is fixedly connected to the outer wall of the outer cylinder of the cap, and the other end of which is fixedly connected to the outer wall of the second pipe section to support and fix the second pipe section.

8. A combustion chamber comprising a plurality of nozzles, characterized in that, The gas turbine combustion chamber backfire thermocouple mounting structure includes any one of claims 1-7, wherein the nozzle includes a central nozzle, a primary peripheral nozzle, and a secondary peripheral nozzle, the primary peripheral nozzle and the secondary peripheral nozzle are distributed around the outer periphery of the central nozzle, the operating equivalent ratio of the primary peripheral nozzle is greater than the operating equivalent ratio of the secondary peripheral nozzle, the nozzle cover includes a central nozzle cover, a primary peripheral nozzle cover, and a secondary peripheral nozzle cover, and the thermocouple conduit is provided with a plurality of conduits and is respectively installed on the outer wall of the central nozzle cover and the outer wall of the primary peripheral nozzle cover.

9. The combustion chamber according to claim 8, characterized in that, The tempering thermocouples are dual-armored thermocouples, and each dual-armored thermocouple acquires data from two thermocouples.

10. A gas turbine, characterized in that, Includes the combustion chamber as described in claim 8 or 9.

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