Plasma ignition generator with cooling holes

Abstract

The invention discloses a plasma ignition generator with cooling holes, relates to the technical field of gas turbines, solves the problem that an existing generator is not suitable for ignition of a heavy gas turbine due to insufficient length, and comprises a fixed flange, an anode shell, a cathode and insulating ceramic which are coaxially arranged; the anode shell is detachably mounted at the rear end of the fixed flange, and the insulating ceramic penetrates into the fixed flange from front to back; the cathode penetrates into the insulating ceramic from front to back; in the cathode, the multiple cathode rods are modularly assembled, and the cathode can be suitable for ignition of head combustion chambers with different length requirements by adjusting the number of the cathode rods and replacing the anode shells with different lengths, and is particularly suitable for ignition of heavy gas turbines.

Description

Technical Field

[0001] This invention relates to the technical field of gas turbines, and more particularly to a plasma ignition generator with cooling holes. Background Technology

[0002] With the continuous growth of energy demand and increasingly stringent environmental requirements, improving the thermal efficiency of gas turbines has become one of the core driving forces for the development of modern power technology. The key to the efficiency of gas turbine cycles lies in increasing the temperature of the combustion chamber outlet gas—higher temperatures mean greater energy contained in the working fluid and stronger work-capacity. Therefore, continuously pushing the upper limit of combustion chamber operating temperature is an inevitable technological path to pursue ultimate thermal efficiency. However, the increase in combustion chamber temperature brings severe technical challenges to the service life and structural stability of igniters. The main strategy of traditional igniters to cope with this challenge is to rely on more advanced high-temperature alloy materials and complex thermal barrier coating technologies. Although these materials can improve the temperature resistance limit to a certain extent, their research, development, manufacturing, and maintenance costs are extremely high. Simply relying on material upgrades to resist high temperatures is not only costly, but its sustainability is also questionable.

[0003] Meanwhile, in existing generators, the cathode is an integrated structure with a non-adjustable length, and it is mostly used for conventional single-head combustion chamber ignition. However, the ignition nozzle of heavy-duty gas turbines is generally located in the middle of the combustion chamber head, and the generator must be inserted into the combustion chamber near the ignition head. Existing generators are not suitable for heavy-duty gas turbine ignition due to insufficient length, and the high temperature in this area after ignition shortens the generator's service life. Summary of the Invention

[0004] To address the problem that existing plasma ignition generators are unsuitable for heavy-duty gas turbine ignition due to insufficient length, the present invention aims to provide a plasma ignition generator with cooling holes. By designing multiple cathode rods for modular assembly and adjusting the overall length of the cathodes, it is suitable for both heavy-duty gas turbine ignition and conventional single-head combustion chamber ignition. Furthermore, by replacing the anode shell with one of different lengths, the operating temperature of the plasma ignition generator itself can be reduced.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A plasma ignition generator with cooling holes includes: a fixed flange 1, an anode housing 2, a cathode 3, and an insulating ceramic 4, wherein the fixed flange 1, the anode housing 2, the cathode 3, and the insulating ceramic 4 are coaxially arranged; the anode housing 2 is detachably installed at the rear end of the fixed flange 1, and the insulating ceramic 4 is inserted into the fixed flange 1 from front to back; the cathode 3 is inserted into the insulating ceramic 4 from front to back.

[0007] The anode shell 2 is a hollow cylindrical structure. The rear end of the anode shell 2 is provided with a first diameter reduction structure with a reduced inner diameter. The anode shell 2 is provided with a plurality of side cooling holes 33, which are arranged in an array along the surface of the anode shell 2. The front end of the anode shell 2 is provided with a plurality of circumferentially oriented vent holes 32, which are located in front of the plurality of side cooling holes 33. The first diameter reduction structure is provided with a plurality of end face cooling holes 34.

[0008] The cathode 3 includes a cathode rod assembly and a cathode head 53. One end of the cathode rod assembly is located inside the insulating ceramic 4, and the cathode head 53 is installed at the other end of the cathode rod assembly. The rear end face of the cathode head 53 and the rear end face of the first diameter reduction structure are located on the same plane, and a gap is provided between the outer periphery of the cathode head 53 and the inner periphery of the first diameter reduction structure.

[0009] The cathode rod assembly includes at least two cathode rods, multiple cathode rods arranged coaxially, any two adjacent cathode rods being detachably connected by a fixed sleeve, the foremost cathode rod being located inside the insulating ceramic 4, and the cathode head 53 being detachably mounted on the rear end of the last cathode rod.

[0010] The aforementioned plasma ignition generator with cooling holes, wherein the cathode rod assembly consists of three cathode rods, the cathode rod assembly including: a first cathode rod 41, a first fixing sleeve 43, a second cathode rod 44, a second fixing sleeve 51, and a third cathode rod 52, the first cathode rod 41 being installed inside the insulating ceramic 4, the front end of the second cathode rod 44 being detachably connected to the rear end of the first cathode rod 41 through the first fixing sleeve 43, and the rear end of the second cathode rod 44 being detachably connected to the front end of the third cathode rod 52 through the second fixing sleeve 51.

[0011] In the aforementioned plasma ignition generator with cooling holes, the first cathode rod 41 has a three-section structure, with its outer diameter decreasing in a stepped manner from front to back, and the outer wall of the first cathode rod 41 matches the inner wall of the insulating ceramic 4.

[0012] In the aforementioned plasma ignition generator with cooling holes, the front and rear ends of the first fixed sleeve 43 are provided with internal threads, the rear end of the first cathode rod 41 is provided with external threads, the first cathode rod 41 and the first fixed sleeve 43 are connected by threads, the front end of the second cathode rod 44 is provided with external threads, and the second cathode rod 44 and the first fixed sleeve 43 are connected by threads.

[0013] In the aforementioned plasma ignition generator with cooling holes, the front and rear ends of the second fixed sleeve 51 are provided with internal threads, the rear end of the second cathode rod 44 is provided with external threads, the second cathode rod 44 and the second fixed sleeve 51 are connected by threads, the front end of the third cathode rod 52 is provided with external threads, and the third cathode rod 52 and the second fixed sleeve 51 are connected by threads.

[0014] In the aforementioned plasma ignition generator with cooling holes, the rear end of the third cathode rod 52 is provided with an external thread, and the inner circumference of the cathode head 53 is provided with an internal thread. The cathode head 53 and the third cathode rod 52 are connected by threads.

[0015] In the aforementioned plasma ignition generator with cooling holes, the outer diameters of the second cathode rod 44 and the third cathode rod 52 are the same and are both the same as the rear end outer diameter of the first cathode rod 41.

[0016] In the aforementioned plasma ignition generator with cooling holes, the fixed flange 1 is a cylindrical structure that runs through the front and rear; the front end of the fixed flange 1 is provided with a first external thread 21, the rear end of the fixed flange 1 is provided with a first internal thread 23, and the interior of the fixed flange 1 is provided with a limiting structure 24 whose inner diameter decreases from front to back; the outer wall of the insulating ceramic 4 matches the inner wall of the fixed flange 1; the outer periphery of the fixed flange 1 is provided with an external hexagonal structure 22 for assembly.

[0017] In the aforementioned plasma ignition generator with cooling holes, the front end of the anode housing 2 is provided with a second external thread 31, and the front end of the anode housing 2 and the rear end of the fixed flange 1 are connected by threads.

[0018] The axis of each side cooling hole (33) forms a 30° angle with the axis of the plasma ignition generator;

[0019] The axis of each end face cooling hole (34) forms a 60° angle with the rear end face of the cathode head (53).

[0020] In the aforementioned plasma ignition generator with cooling holes, the foremost cathode rod has a three-section structure, with its outer diameter decreasing in a stepped manner from front to back. The outer diameters of the cathode rods other than the foremost cathode rod are the same and are all the same as the outer diameter of the rear end of the foremost cathode rod.

[0021] The present invention, by employing the above-mentioned technology, has the following positive effects compared with the prior art:

[0022] (1) In this invention, the cathode is modularly assembled with multiple cathode rods. By adjusting the number of cathode rods and replacing the anode shells of different lengths, it can be adapted to the head combustion chamber ignition of different length requirements, especially suitable for heavy-duty gas turbine ignition.

[0023] (2) In this invention, low-temperature high-pressure gas can enter the generator through the vent hole on the anode shell and be discharged through the side cooling hole, end cooling hole and the gap between the cathode head and the end of the anode shell, forming a gas film that isolates high temperature on the surface of the anode shell, thereby reducing the working temperature of the plasma ignition generator itself in a low-cost way. At the same time, the high-pressure gas can lengthen the electric arc generated at the end of the cathode head and the anode shell, which is more conducive to ignition. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a plasma ignition generator with cooling holes according to the present invention.

[0025] Figure 2 This is a longitudinal cross-sectional view of a plasma ignition generator with cooling holes according to the present invention.

[0026] Figure 3 This is a schematic diagram of the fixed flange structure of a plasma ignition generator with cooling holes according to the present invention.

[0027] Figure 4 This is a schematic diagram of the anode housing structure of a plasma ignition generator with cooling holes according to the present invention.

[0028] Figure 5 This is a schematic diagram of the insulating ceramic and part of the cathode structure of a plasma ignition generator with cooling holes according to the present invention.

[0029] Figure 6 This is a schematic diagram of a partial cathode structure of a plasma ignition generator with cooling holes according to the present invention.

[0030] Figure 7 This is a schematic diagram of the fixed sleeve structure of a plasma ignition generator with cooling holes according to the present invention.

[0031] Figure 8 This is a schematic diagram of the cathode head structure of a plasma ignition generator with cooling holes according to the present invention.

[0032] In the attached diagram: 1. Fixed flange; 2. Anode housing; 3. Cathode; 4. Insulating ceramic; 21. First external thread; 22. External hexagonal structure; 23. First internal thread; 24. Limiting structure; 31. Second external thread; 32. Vent hole; 33. Side cooling hole; 34. End face cooling hole; 41. First cathode rod; 43. First fixing sleeve; 44. Second cathode rod; 51. Second fixing sleeve; 52. Third cathode rod; 53. Cathode head. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0034] Please refer to Figures 1 to 8 As shown, a plasma ignition generator with cooling holes is illustrated, comprising: an anode housing 2, an insulating ceramic 4, a cathode 3, and a fixing flange 1 arranged coaxially. The plasma ignition generator is connected to a cable via a first external thread 21 on the head of the fixing flange. The fixing flange 1 is threadedly connected to the anode housing 2. The anode housing 2 is provided with a vent hole 32 and a side cooling hole 33. The plasma ignition generator includes the insulating ceramic 4 and the cathode 3. The cathode 3 includes multiple cathode rods, multiple fixing sleeves, and a cathode head 53.

[0035] Furthermore, in a preferred embodiment, the fixed flange 1 has an external hexagonal structure 22, which facilitates the installation and disassembly of the cable connector and the anode housing 2.

[0036] Furthermore, in a preferred embodiment, two fixing sleeves are provided on the cathode rod to fix the cathode rod. The fixing sleeves are connected to the cathode rod by threads, which facilitates the disassembly and installation of the cathode rod.

[0037] Furthermore, in a preferred embodiment, the cathode rod and the cathode head 53 are connected by threads, and the cathode head 53 is flush with the end of the anode housing 2.

[0038] Furthermore, in a preferred embodiment, three vent holes 32 are evenly distributed around the anode housing 2 to introduce high-pressure gas, which is discharged through the side cooling holes 33 and the gap between the cathode head 53 and the end of the anode housing 2. The resulting air film can achieve the effect of cooling.

[0039] Furthermore, in a preferred embodiment, 17 rows and 16 columns of circular side cooling holes 33 are evenly distributed on the side of the anode housing 2. The first 4 rows of side cooling holes 33 near the flange are slightly spaced larger, and the diameter of the cooling holes is 0.6 mm, forming a 30° angle with the axis of the plasma ignition generator.

[0040] Furthermore, in a preferred embodiment, a row of 16 end-face cooling holes 34 with a diameter of 0.6 mm are uniformly arranged circumferentially at the end of the anode housing 2, forming a 60° angle with the front end face of the plasma ignition generator.

[0041] Furthermore, in a preferred embodiment, the cathode rod and the insulating ceramic 4 are fixed inside the fixed flange 1 by means of their own limiting structure and insulating adhesive.

[0042] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention.

[0043] In addition to the above, the present invention also has the following embodiments:

[0044] In a further embodiment of the present invention, the plasma ignition generator comprises four parts: a fixed flange 1, an anode housing 2, a cathode 3, and an insulating ceramic 4. The fixed flange 1 is connected to a cable at one end via a first external thread 21, and at the other end via a first internal thread 23 to a second external thread 31 on the anode housing. The upper part of the flange disc has an external hexagonal structure 22, facilitating the assembly and disassembly of the fixed flange 1 and the structure. A limiting structure 24 is provided inside the fixed flange 1 to facilitate the fixing of the cathode 3 and the insulating ceramic 4. The anode housing 2 has three vent holes 32 axially arranged, allowing the introduction of low-temperature, high-pressure gas. The gas exits from the side cooling holes 33, the end face cooling holes 34, and the gap between the end face and the cathode head, forming a gas film to isolate external high-temperature gas and lengthening the arc for easier ignition. The cathode 3 is fixed by the limiting structure of the insulating ceramic 4 and insulating adhesive. The cathode 3 includes a first cathode rod 41 and a second cathode rod 44. The third cathode rod 52, the first fixing sleeve 43, the second fixing sleeve 51, and the cathode head 53 are connected by external threads to the internal threads of the first fixing sleeve 43 and the second fixing sleeve 51. The fixing sleeves serve to fix and extend the cathode rods and facilitate disassembly. The rear end of the third cathode rod 52 is fixed by external threads to the internal threads of the cathode head 53. The end face of the cathode head 53 is flush with the end face of the anode shell 2. The insulating ceramic 4 is fixed by the limiting structure 24 and insulating glue in the fixing flange 1 and then connected to the cathode 3. It plays an insulating role between the cathode 3 and the anode shell 2 of the plasma ignition generator, so that the plasma ignition generator can only discharge and generate an arc at the end position of the anode shell 2.

[0045] In a further embodiment of the present invention, when the present invention is applied, the device is first assembled, then the device is fixed by the fixing flange 1, connected to the gas source, and then the plasma igniter generator cable is connected by the first external thread 21 on the head of the fixing flange 1. The temperature, pressure and flow rate of the air supplied are selected according to the requirements to control the temperature of the plasma igniter generator and the length of the outlet jet. Finally, the head of the device is aligned with the gas fuel outlet to complete the ignition.

[0046] In a further embodiment of the present invention, the present invention relates to a plasma ignition generator with cooling holes, which is convenient and quick to install. During operation, low-temperature high-pressure gas can enter the generator through the vent 32 on the anode shell 2 and be discharged through the side cooling holes 32, the end cooling holes 34 and the gap between the cathode head 53 and the end of the anode shell 2, forming a high-temperature insulating gas film on the surface of the anode shell 2. This achieves the purpose of reducing the working temperature of the plasma ignition generator itself in a low-cost manner. At the same time, the high-pressure gas can lengthen the electric arc generated between the cathode head 53 and the end of the anode shell 2, which is more conducive to ignition.

[0047] In a further embodiment of the present invention, the present invention solves the problem that existing plasma ignition generators suffer from shortened service life and reduced structural reliability due to prolonged exposure to the high-temperature environment of the combustion chamber. The plasma ignition generator of this application includes a coaxially arranged anode housing 2, insulating ceramic 4, cathode 3, and fixing flange 1. The plasma ignition generator is connected to a cable via the external thread of the fixing flange 1 head, and the end of the fixing flange 1 is fixed to the anode housing 2 via an internal thread. The upper part of the disc of the fixing flange 1 has an external hexagonal structure 22. The anode housing 2 is provided with vent holes 32 and cooling holes. The cathode 3 includes a cathode rod, a fixing sleeve, and a cathode head 53. The fixing sleeve is provided on the cathode rod, and the cathode head 53 is connected to the cathode rod via threads. The insulating ceramic 4 is fixed between the cathode rod and the anode housing 2 by adhesive. When the plasma ignition generator is working, the high-pressure airflow can enter the plasma ignition generator through the vent 32 on the anode shell 2 and exit from the cooling hole and the gap at the rear end of the plasma ignition generator. Under the action of high pressure, the airflow can carry away some of the high-temperature gas in the plasma ignition generator, and at the same time form an air film that isolates the high temperature at the anode shell 2, thereby reducing the temperature of the generator, extending the service life of the plasma ignition generator and enhancing the structural reliability.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A plasma ignition generator with cooling holes, characterized in that, include: The fixed flange (1), anode housing (2), cathode (3) and insulating ceramic (4) are coaxially arranged; the anode housing (2) is detachably installed at the rear end of the fixed flange (1); the insulating ceramic (4) is inserted into the fixed flange (1) from front to back; the cathode (3) is inserted into the insulating ceramic (4) from front to back. The anode shell (2) is a hollow cylindrical structure. The rear end of the anode shell (2) is provided with a first diameter reduction structure with a reduced inner diameter. Multiple side cooling holes (33) are provided on the anode shell (2), and the multiple side cooling holes (33) are arranged in an array along the surface of the anode shell (2). Multiple vent holes (32) are provided at equal angles around the front end of the anode shell (2), and the multiple vent holes (32) are located in front of the multiple side cooling holes (33). Multiple end face cooling holes (34) are provided around the first diameter reduction structure. The cathode (3) includes a cathode rod assembly and a cathode head (53). One end of the cathode rod assembly is located inside the insulating ceramic (4), and the cathode head (53) is installed at the other end of the cathode rod assembly. The rear end face of the cathode head (53) and the rear end face of the first diameter reduction structure are located on the same plane. A gap is provided between the outer periphery of the cathode head (53) and the inner periphery of the first diameter reduction structure. The cathode rod assembly includes: at least two cathode rods, multiple cathode rods coaxially arranged, any two adjacent cathode rods being detachably connected by a fixed sleeve, the cathode rod at the foremost end being located inside the insulating ceramic (4), and the cathode head (53) being detachably installed at the rear end of the cathode rod at the last end.

2. The plasma ignition generator with cooling holes according to claim 1, characterized in that, When the cathode rod group consists of three cathode rods, the cathode rod group includes: a first cathode rod (41), a first fixing sleeve (43), a second cathode rod (44), a second fixing sleeve (51), and a third cathode rod (52). The first cathode rod (41) is installed inside the insulating ceramic (4). The front end of the second cathode rod (44) and the rear end of the first cathode rod (41) are detachably connected through the first fixing sleeve (43). The rear end of the second cathode rod (44) and the front end of the third cathode rod (52) are detachably connected through the second fixing sleeve (51).

3. The plasma ignition generator with cooling holes according to claim 2, characterized in that, The first cathode rod (41) has a three-section structure, and its outer diameter decreases in a stepped manner from front to back. The outer wall of the first cathode rod (41) matches the inner wall of the insulating ceramic (4).

4. The plasma ignition generator with cooling holes according to claim 3, characterized in that, The first fixed sleeve (43) has internal threads at both the front and rear ends, and the first cathode rod (41) has external threads at the rear end. The first cathode rod (41) and the first fixed sleeve (43) are connected by threads. The second cathode rod (44) has external threads at the front end, and the second cathode rod (44) and the first fixed sleeve (43) are connected by threads.

5. The plasma ignition generator with cooling holes according to claim 4, characterized in that, The second fixed sleeve (51) has internal threads at both the front and rear ends, and the second cathode rod (44) has external threads at the rear end. The second cathode rod (44) and the second fixed sleeve (51) are connected by threads. The third cathode rod (52) has external threads at the front end, and the third cathode rod (52) and the second fixed sleeve (51) are connected by threads.

6. The plasma ignition generator with cooling holes according to claim 5, characterized in that, The rear end of the third cathode rod (52) is provided with an external thread, and the inner circumference of the cathode head (53) is provided with an internal thread. The cathode head (53) and the third cathode rod (52) are connected by threads.

7. The plasma ignition generator with cooling holes according to claim 6, characterized in that, The outer diameters of the second cathode rod (44) and the third cathode rod (52) are the same, and both are the same as the outer diameter of the rear end of the first cathode rod (41).

8. The plasma ignition generator with cooling holes according to claim 1, characterized in that, The fixed flange (1) is a cylindrical structure that runs through the front and rear. The front end of the fixed flange (1) is provided with a first external thread (21), the rear end of the fixed flange (1) is provided with a first internal thread (23), and the interior of the fixed flange (1) is provided with a limiting structure (24) whose inner diameter decreases from front to back. The outer wall of the insulating ceramic (4) matches the inner wall of the fixed flange (1). The outer periphery of the fixed flange (1) is provided with an external hexagonal structure (22) for assembly.

9. The plasma ignition generator with cooling holes according to claim 1, characterized in that, The front end of the anode housing (2) is provided with a second external thread (31), and the front end of the anode housing (2) and the rear end of the fixed flange (1) are connected by threads; The axis of each side cooling hole (33) forms a 30° angle with the axis of the plasma ignition generator; The axis of each end face cooling hole (34) forms a 60° angle with the rear end face of the cathode head (53).

10. The plasma ignition generator with cooling holes according to claim 1, characterized in that, The foremost cathode rod has a three-section structure, with its outer diameter decreasing in a stepped manner from front to back. The outer diameters of the cathode rods other than the foremost cathode rod are the same and are all the same as the outer diameter of the rear end of the foremost cathode rod.

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