A low emission premix nozzle assembly for a gas turbine and a gas turbine

Abstract

The application provides a low emission premixing nozzle assembly for a gas turbine and the gas turbine, the nozzle assembly comprising a nozzle shell and an elastic sealing ring. The gas turbine comprises a flame tube, the nozzle shell is cylindrically and coaxially arranged in the flame tube, there is an assembly gap between the outer side of the nozzle shell and the inner side of the head of the flame tube, the outer side of the nozzle shell is provided with an annular groove, the elastic sealing ring is sleeved in the annular groove, the radial thickness of the elastic sealing ring is greater than the depth of the annular groove, the elastic sealing ring is located between the assembly gap, and the radial two sides of the elastic sealing ring are in close contact with the annular groove and the head of the flame tube respectively. The elastic sealing ring sleeved in the annular groove is used to press the nozzle shell and the head of the flame tube, the sealing effect of the assembly gap is enhanced, the floating connection between the nozzle shell and the head of the flame tube is realized, the assembly problem caused by the difficulty in ensuring the machining precision is prevented, the assemblability of the nozzle shell and the head of the flame tube is improved, and the machining cost and difficulty of the nozzle shell are reduced.

Description

Technical Field

[0001] This invention relates to the field of jet propulsion technology, and more specifically to a low-emission premixed nozzle assembly for a gas turbine and a gas turbine. Background Technology

[0002] In existing jet propulsion devices, such as gas turbines, air is pressurized in a compressor and then mixed with fuel in a combustion chamber for combustion to produce high-temperature combustion gases. In a toroidal gas turbine, the combustion section consists of a ring array of combustion chambers, each supplying high-temperature combustion gases to the turbine section of the engine. In the turbine section, the high-temperature combustion gases expand and extract energy to provide output power, which is then used to generate electricity.

[0003] In jet propulsion systems, low-emission combustors primarily employ lean premixed combustion technology. The core principle is that before combustion, fuel (such as natural gas) and air are fully mixed in a specially designed premixer to form a uniform premixed gas, thereby achieving more uniform and efficient combustion. This reduces the formation of high-temperature local areas and incomplete combustion products, thus lowering NOx and CO emissions and meeting the emission requirements of gas turbines.

[0004] The core components of the combustion chamber in a gas turbine are the flame tube and the fuel nozzle. Currently, in low-emission combustion chambers, the central fuel nozzle and flame tube are typically coaxially mounted. However, the fuel nozzle and flame tube head are currently connected by a floating connection. Excessive gap between the nozzle and flame tube head not only leads to excessive gas leakage and increased pollutant emissions but also increases the risk of backfire at the gap. Conversely, insufficient gap increases the machining precision and difficulty of the fuel nozzle, and also causes assembly difficulties or high assembly stress, reducing the reliability of the combustion chamber structure. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of difficulty in sealing the nozzle and flame tube head in the combustion chamber of existing gas turbines, poor assemblability, and high processing costs.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides a low-emission premixed nozzle assembly for a gas turbine, the gas turbine including a flame tube, the nozzle assembly including: a nozzle housing, which is cylindrical and coaxially disposed within the flame tube, with an assembly gap between the outer side of the nozzle housing and the inner side of the flame tube head, and an annular groove provided on the outer side of the nozzle housing; and an elastic sealing ring, which is fitted into the annular groove, the radial thickness of the elastic sealing ring being greater than the depth of the annular groove; the elastic sealing ring is located between the assembly gap, and its radial sides are in close contact with the annular groove and the flame tube head, respectively.

[0008] Preferably, the elastic sealing ring includes an annular elastic core and an elastic shell wrapped around the elastic core, wherein the elastic shell has circumferentially distributed arc-shaped convex surfaces on both radial sides.

[0009] Preferably, the elastic shell has an axial opening facing upstream of the nozzle housing.

[0010] Preferably, the annular groove is provided with a step, the step axially supports the elastic sealing ring, and the opening is away from the step.

[0011] Preferably, the nozzle housing includes a first fuel flow channel located on the central axis, a first air flow channel arranged coaxially in an annular shape, a first fuel injection hole, a first cleaning hole, and a second cleaning hole; the first fuel injection hole and the first cleaning hole are both located on the downstream end face of the nozzle housing, the first fuel injection hole communicates with the first fuel flow channel, and the first cleaning hole and the second cleaning hole communicate with the first air flow channel; the second cleaning hole is disposed on the axial sidewall of the nozzle housing and is located downstream of the step.

[0012] Preferably, a converging end is provided on one side of the annular groove, and the converging end is located downstream of the second blowing hole.

[0013] Preferably, the second cleaning hole is inclined in the direction of downstream of the nozzle housing, and the angle between the axial direction of the second cleaning hole and the axial direction of the nozzle housing is 30º-60º.

[0014] Preferably, the elastic core is made of copper alloy material.

[0015] Preferably, it further includes a flow divider located upstream of the nozzle housing and coaxially mounted; the flow divider includes a second fuel flow channel located on the central axis, a second air flow channel located beside the second fuel flow channel, and an air inlet; the second fuel flow channel communicates with the first fuel flow channel, and the second air flow channel communicates with the first air flow channel; the air inlet is disposed on the axial sidewall of the flow divider and communicates with the second air flow channel.

[0016] Preferably, the distributor is further provided with a plurality of fuel nozzles, which are radially distributed along the radial direction; each fuel nozzle has a second fuel injection hole on its sidewall, which is positioned downstream of the flame tube, and the fuel nozzle is located downstream of the air inlet.

[0017] Preferably, the axial direction of the second fuel injection orifice is perpendicular to the axial direction of the fuel injection pipe, and the angle between the axial direction of the second fuel injection orifice and the axial direction of the splitter is 45º.

[0018] Preferably, the thickness of the step is 1 / 5 to 2 / 5 of the depth of the annular groove.

[0019] Preferably, the depth of the annular groove is 2.5mm-3.5mm.

[0020] Preferably, the diameter of the first fuel injection orifice is 2.5mm-3.5mm, and / or the diameter of the second fuel injection orifice is 1.5mm-2.5mm.

[0021] Based on the same inventive concept, the present invention also provides a gas turbine, including the aforementioned low-emission premixed nozzle assembly and flame tube for the gas turbine, wherein the nozzle assembly is installed inside the flame tube.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention provides a low-emission premixed nozzle assembly for a gas turbine. The nozzle assembly includes a nozzle housing and an elastic sealing ring. The gas turbine includes a flame tube. The nozzle housing is cylindrical and coaxially disposed within the flame tube. An assembly gap exists between the outer side of the nozzle housing and the inner side of the flame tube head. An annular groove is provided on the outer side of the nozzle housing, and the elastic sealing ring is fitted into this groove. The radial thickness of the elastic sealing ring is greater than the depth of the annular groove. The elastic sealing ring is located within the assembly gap, and its radial sides are in close contact with the annular groove and the flame tube head, respectively. The nozzle housing and the flame tube head are pressed together by the elastic sealing ring fitted into the annular groove, preventing abrasion and enhancing the sealing effect of the assembly gap. This achieves a floating connection between the nozzle housing and the flame tube head, preventing assembly problems caused by difficulties in ensuring machining accuracy. This improves the assemblability of the nozzle housing and the flame tube head while reducing the machining cost and difficulty of the nozzle housing. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the axial assembly of the nozzle assembly and the flame tube of the present invention;

[0025] Figure 2 A partially enlarged schematic diagram of the side wall of the nozzle housing of the nozzle assembly of the invention;

[0026] Figure 3 This is a partially enlarged schematic diagram of the assembly of the nozzle assembly with the flame tube head.

[0027] Reference numerals: 1-Nozzle assembly; 11-Splitter; 111-Air inlet; 112-Second air passage; 113-Second fuel passage; 12-Nozzle housing; 120-Downstream end face; 121-First air passage; 122-First fuel passage; 123-First purge orifice; 124-First fuel injection orifice; 125-Second purge orifice; 126-Annular groove; 127-Step; 128-Converging end; 13-Fuel injection pipe; 131-Second fuel injection orifice; 2-Flame tube housing; 21-Flame tail combustion chamber; 3-Axial vortex generator; 4-Elastic sealing ring; 41-Elastic core; 42-Elastic shell; 421-Opening; 422-Fixed end. Detailed Implementation

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the invention and are not intended to limit the scope of protection of the invention. Those skilled in the art can make adjustments as needed to adapt to specific applications.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] It should be noted that in the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Example 1

[0032] like Figures 1 to 3As shown, the low-emission premixed nozzle assembly for a gas turbine provided in this embodiment includes a nozzle housing 12 and an elastic sealing ring 4. The gas turbine includes a flame tube. The nozzle housing 12 is cylindrical and coaxially disposed within the flame tube. An assembly gap of 0.25 mm exists between the outer side of the nozzle housing 12 and the inner side of the flame tube head. An annular groove 126 is provided on the outer side of the nozzle housing 12. The elastic sealing ring 4 is fitted into the annular groove 126. The radial thickness of the elastic sealing ring 4 is greater than the depth of the annular groove 126. The elastic sealing ring 4 is located within the assembly gap, and its radial sides are in close contact with the annular groove 126 and the flame tube head, respectively. The depth of the annular groove 126 is 2.5 mm to 3.5 mm. Preferably, the depth of the annular groove 126 is 3 mm.

[0033] Specifically, such as Figure 1 As shown, the flame tube includes a flame tube shell 2 and an axial swirler 3. The flame tube shell 2 increases in diameter from the head to the tail, i.e., from left to right, forming a flame tail combustion chamber 21 at its tail. The axial swirler 3 is installed inside the head of the flame tube shell 2. The nozzle shell 12 is cylindrical and coaxially disposed inside the axial swirler 3, with its annular groove 126 opposite to the inner hub of the axial swirler 3. The width of the annular groove 126 is 1 / 2 to 3 / 4 of the width of the inner hub of the swirler 3.

[0034] When the elastic sealing ring 4 is assembled in the assembly gap, the radial outer surface of the elastic sealing ring 4 is in close radial contact with the inner side of the axial vortex 3, and the radial inner surface of the elastic sealing ring 4 is in close radial contact with the annular groove 126.

[0035] With this configuration, the elastic sealing ring 4 can prevent fuel from flowing downstream through the assembly gap between the nozzle assembly 1 and the flame tube head, thereby avoiding the risk of backfire.

[0036] like Figure 3As shown, the elastic sealing ring 4 includes an annular elastic core 41 and an elastic shell 42 enclosing the elastic core 41. Both radially distributed arc-shaped convex surfaces of the annular elastic shell 42 are present. The inner arc-shaped convex surface of the elastic shell 42 is in elastic compression and tight contact with the annular groove 126, and the outer arc-shaped convex surface of the elastic shell 42 is in elastic compression and tight contact with the inner side of the axial cyclone separator 3. The elastic shell 42 has openings 421 on both axial sides and fixed ends 422 opposite to the openings 421, with the openings 421 facing upstream of the nozzle housing 12. On the one hand, the openings 421 facilitate the assembly of the elastic sealing ring 4 into the annular groove 126, increasing the assembly convenience of the spray assembly; on the other hand, the openings 421 can alleviate the stress concentration phenomenon generated during the elastic deformation of the elastic sealing ring 4, extending the service life of the spray assembly. The elastic core 41 is made of a copper alloy material, such as C19005 high-elasticity copper alloy, and the elastic shell 42 is made of a high-temperature resistant elastic metal material, such as nickel-based high-temperature alloy GH4169. Opening 421 is a ring-shaped distribution.

[0037] like Figure 2 and Figure 3 As shown, in this embodiment, the annular groove 126 of the nozzle housing 12 has a step 127 inside. The elastic sealing ring 4 is located in the annular groove 126 on the left side of the step 127. The step 127 axially supports the elastic sealing ring 4. The opening 421 of the elastic shell 42 is away from the step 127, and the fixed end 422 of the elastic shell 42 is axially limited and matched with the step 127. The step 127 is annular.

[0038] The groove depth on the right side of step 127 is 3 / 5 to 4 / 5 of the groove depth on the left side of step 127, or the thickness of step 127 is 1 / 5 to 2 / 5 of the depth of annular groove 126.

[0039] More specifically, such as Figure 1 As shown, the nozzle housing 12 of this embodiment includes a first fuel flow channel 122 located on the central axis, a first air flow channel 121 arranged coaxially in an annular shape, a first fuel injection hole 124, a first cleaning hole 123, and a second cleaning hole 125; the first fuel injection hole 124 and the first cleaning hole 123 are both located on the downstream end face 120 of the nozzle housing 12, the first fuel injection hole 124 communicates with the first fuel flow channel 122, and the first cleaning hole 123 and the second cleaning hole 125 communicate with the first air flow channel 121; the second cleaning hole 125 is disposed on the axial sidewall of the nozzle housing 12 and is located downstream of the step 127, and the second cleaning hole 125 is inclined in the direction of the downstream of the nozzle housing 12.

[0040] The number of first cleaning holes 123 is 6 to 10, and the diameter of the holes is 0.8 mm to 1.5 mm. The first cleaning holes 123 are evenly distributed around the first fuel injection hole 124.

[0041] The second cleaning holes 125 are arranged in 1 to 2 rows along the axial direction of the nozzle housing 12, with 6 to 10 holes in each row, and are evenly distributed circumferentially along the axial sidewall of the nozzle housing 12.

[0042] The diameters of both the second blow-through orifice 125 and the first fuel injection orifice 124 are 2.5mm-3.5mm. The angle between the axial direction of the second blow-through orifice 125 and the axial direction of the nozzle housing 12 is 30º-60º. Preferably, the diameters of both the second blow-through orifice 125 and the first fuel injection orifice 124 are 3mm, and the angle between the axial direction of the second blow-through orifice 125 and the axial direction of the nozzle housing 12 is 45º.

[0043] With this configuration, the second purging hole 125 can purge the outer wall of the nozzle housing 12, reducing the risk of boundary layer backfire and enhancing the operational reliability of the flame tube combustion chamber.

[0044] Furthermore, a converging end 128 is provided on the right side of the annular groove 126, and the converging end 128 is located downstream of the second clearing hole 125. The converging end 128 is an annular arc-shaped surface. The converging end 128 is located downstream of the step 127, and the step 127 and the converging end 128 in the annular groove 126 form a converging structure with the whole and the inner hub of the cyclone separator 3.

[0045] When the air ejected from the second blow-out hole 125 flows downstream at high speed, the high-speed air flows through the converging end 128 and forms a skirt-shaped isolation gas film on the outer wall of the nozzle housing 12, thereby protecting the outer wall of the nozzle housing 12 and further reducing the risk of boundary layer flashback.

[0046] like Figure 1 As shown, the nozzle assembly 1 in this embodiment also includes a flow divider 11 located on the upstream end face of the nozzle housing 12 and coaxially mounted. The flow divider 11 is located upstream of the nozzle housing 12 and welded to it. The flow divider 11 is cylindrical with the same diameter as the nozzle housing 12, and has channels inside for splitting air and fuel. The flow divider 11 includes a second fuel flow channel 113 located on the central axis, a second air flow channel 112 located beside the second fuel flow channel 113, and an air inlet 111. The second fuel flow channel 113 communicates with the first fuel flow channel 122, and the second air flow channel 112 communicates with the first air flow channel 121. The air inlet 111 is disposed on the axial sidewall of the flow divider 11 and communicates with the second air flow channel 112. The number of air inlets 111 is 4 to 6, and they are evenly distributed circumferentially along the sidewall of the flow divider 11.

[0047] The distributor 11 is also provided with multiple fuel nozzles 13, which are radially distributed along the radial direction of the distributor 11. The number of fuel nozzles 13 is the same as that of the air inlet 111. Each fuel nozzle 13 has at least two pairs of second fuel nozzles 131 on its sidewall. The second fuel nozzles 131 are arranged facing downstream of the flame tube. The orientation of the second fuel nozzles 131 is perpendicular to the axial direction of the fuel nozzle 13 and makes an angle of 45 degrees with the axial direction of the distributor 11. The two second fuel nozzles 131 in each pair are arranged in opposite directions. The multiple fuel nozzles 13 are connected at one end by a uniform second fuel flow channel 113.

[0048] The angle between the axial direction of the second fuel injection orifice 131 and the axial direction of the distributor 11 is 45°, and the diameter of the second fuel injection orifice 131 is 1.5mm-2.5mm. Preferably, the diameter of the second fuel injection orifice 131 is 2mm. The fuel injection pipe 13 is located downstream of the air inlet 111 to prevent fuel from entering the air inlet 111 and causing erosion of the downstream end face 120 of the nozzle housing 12.

[0049] When fuel passes through the distributor 11, a portion of the fuel is diverted through the second fuel channel 113 to multiple fuel nozzles 13. The fuel is then ejected through the second fuel nozzle 131 on each fuel nozzle 13 and thoroughly mixed with the axially supplied air for lean premixed combustion, which reduces NOx emissions. The remaining fuel enters directly into the first fuel channel 122 through the second fuel channel 113. After being ejected through the first fuel nozzle 124, the fuel undergoes diffusion combustion to maintain flame stability and enhance the reliability of the combustion chamber.

[0050] Meanwhile, the axially supplied air passes through the air inlet 111 on the splitter 11, then sequentially through the second air channel 112 and the first air channel 121, and finally exits at high speed through the first cleaning hole 123 and the second cleaning hole 125. The air ejected from the first cleaning hole 123 can prevent carbon deposits and coking from forming on the downstream end face 120 of the nozzle housing 12, thereby increasing the overall service life of the nozzle assembly 1.

[0051] Example 2

[0052] Based on the same inventive concept, the present invention also provides a gas turbine, including a low-emission premixed nozzle assembly 1 for a gas turbine and a flame tube as described in Embodiment 1, wherein the nozzle assembly 1 is installed inside the flame tube.

[0053] The specific implementation process of the nozzle assembly 1 is detailed in Example 1, and will not be repeated here.

[0054] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A low-emission premixed nozzle assembly for a gas turbine, characterized in that, The gas turbine includes a flame tube, and the nozzle assembly includes: A nozzle housing (12) is cylindrical and coaxially disposed inside the flame tube. An assembly gap exists between the outer side of the nozzle housing (12) and the inner side of the flame tube head. An annular groove (126) is provided on the outer side of the nozzle housing (12). An elastic sealing ring (4) is fitted into the annular groove (126), and the radial thickness of the elastic sealing ring (4) is greater than the depth of the annular groove (126). The elastic sealing ring (4) is located between the assembly gaps, and the radial sides of the elastic sealing ring (4) are in close contact with the annular groove (126) and the flame tube head, respectively. The elastic sealing ring (4) includes an annular elastic core (41) and an elastic shell (42) that wraps the elastic core (41). The elastic shell (42) has circumferentially distributed arc-shaped convex surfaces on both radial sides. The elastic shell (42) has an axial opening (421) facing upstream of the nozzle housing (12).

2. The low-emission premixed nozzle assembly for a gas turbine according to claim 1, characterized in that, The annular groove (126) is provided with a step (127), the step (127) axially supports the elastic sealing ring (4), and the opening (421) is away from the step (127).

3. The low-emission premixed nozzle assembly for a gas turbine according to claim 2, characterized in that, The nozzle housing (12) includes a first fuel flow channel (122) located on the central axis, a first air flow channel (121) arranged in a coaxial annular shape, a first fuel injection hole (124), a first cleaning hole (123) and a second cleaning hole (125). The first fuel injection hole (124) and the first air blowing hole (123) are both located on the downstream end face (120) of the nozzle housing (12). The first fuel injection hole (124) is connected to the first fuel flow channel (122), and the first air blowing hole (123) and the second air blowing hole (125) are both connected to the first air flow channel (121). The second cleaning hole (125) is disposed on the axial sidewall of the nozzle housing (12) and is located downstream of the step (127).

4. The low-emission premixed nozzle assembly for a gas turbine according to claim 3, characterized in that, The annular groove (126) has a converging end (128) on one side, and the converging end (128) is located downstream of the second blowing hole (125).

5. The low-emission premixed nozzle assembly for a gas turbine according to claim 3, characterized in that, The second cleaning hole (125) is inclined in the direction of the downstream of the nozzle housing (12), and the angle between the axial direction of the second cleaning hole (125) and the axial direction of the nozzle housing (12) is 30º-60º.

6. The low-emission premixed nozzle assembly for a gas turbine according to claim 1, characterized in that, The elastic core (41) is made of copper alloy material.

7. The low-emission premixed nozzle assembly for a gas turbine according to claim 3, characterized in that, It also includes a splitter (11) located upstream of the nozzle housing (12) and coaxially mounted. The splitter (11) includes a second fuel flow channel (113) located on the central axis, a second air flow channel (112) located beside the second fuel flow channel (113), and an air inlet (111). The second fuel flow channel (113) is connected to the first fuel flow channel (122), and the second air flow channel (112) is connected to the first air flow channel (121); The air inlet (111) is located on the axial sidewall of the splitter (11) and communicates with the second air passage (112).

8. The low-emission premixed nozzle assembly for a gas turbine according to claim 7, characterized in that, The distributor (11) is also provided with a plurality of fuel nozzles (13), which are radially distributed along the radial direction; Each of the fuel nozzles (13) has a second fuel nozzle (131) on its sidewall, the second fuel nozzle (131) being disposed downstream of the flame tube, and the fuel nozzle (13) being located downstream of the air inlet (111).

9. The low-emission premixed nozzle assembly for a gas turbine according to claim 8, characterized in that, The axial direction of the second fuel injection orifice (131) is perpendicular to the axial direction of the fuel injection pipe (13), and the angle between the axial direction of the second fuel injection orifice (131) and the axial direction of the splitter (11) is 45º.

10. The low-emission premixed nozzle assembly for a gas turbine according to claim 2, characterized in that, The thickness of the step (127) is 1 / 5 to 2 / 5 of the depth of the annular groove (126).

11. The low-emission premixed nozzle assembly for a gas turbine according to claim 1, characterized in that, The depth of the annular groove (126) is 2.5mm-3.5mm.

12. The low-emission premixed nozzle assembly for a gas turbine according to claim 8, characterized in that, The diameter of the first fuel injection orifice (124) is 2.5mm-3.5mm, and / or the diameter of the second fuel injection orifice (131) is 1.5mm-2.5mm.

13. A gas turbine, characterized in that, Includes a low-emission premixed nozzle assembly (1) for a gas turbine and a flame tube as described in any one of claims 1-12, wherein the nozzle assembly (1) is installed inside the flame tube.

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