Nozzle structure

Abstract

The present invention provides a nozzle structure, comprising: a fuel nozzle and a Helmholtz resonator, wherein the outlet of the fuel nozzle is located at the bottom thereof, and the fuel nozzle has a front end away from the bottom thereof and a terminal end near the bottom thereof; the Helmholtz resonator comprises: a resonator body having a resonance cavity therein, at least one neck air inlet, and at least one neck air outlet, the resonator body being sleeved around the periphery of the fuel nozzle and located at the terminal end of the fuel nozzle, the neck air inlet being located at the top of the resonator body or at a sidewall away from the fuel nozzle and communicating with the resonance cavity and being located outside the combustion chamber, and the neck air outlet being located at the bottom of the resonator body and communicating with the resonance cavity and being located inside the combustion chamber. The fuel nozzle with a Helmholtz resonator provided by the present invention solves the problem of thermoacoustic oscillation existing in existing combustion systems.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine combustion, in particular to a nozzle structure. Background Art

[0002] A gas turbine is a heat engine that converts the thermal energy of fuel into mechanical energy using flowing gas as a working fluid. Its core components include the compressor, combustion chamber, and turbine. The nozzle is a core component of the combustion chamber, injecting fuel into the combustion chamber to release heat. However, thermal and acoustic disturbances in the nozzle, and the resulting thermoacoustic oscillations caused by the superposition of these two, can lead to flame instability, reduced combustion efficiency, and damage to the gas turbine's mechanical load capacity.

[0003] Therefore, how to solve the thermoacoustic oscillation existing in the nozzle is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a nozzle structure for solving the acoustic and thermal oscillation problems existing in the existing combustion system.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a nozzle structure, which includes: a fuel nozzle and a Helmholtz resonator, wherein:

[0006] The outlet of the fuel nozzle is provided at the bottom thereof, and the fuel nozzle has a front end away from the bottom thereof and a tail end close to the bottom thereof;

[0007] The Helmholtz resonator includes: a resonator body with a resonance cavity inside, at least one neck air inlet and at least one neck air outlet, the resonator body is sleeved on the periphery of the fuel nozzle and is arranged at the end of the fuel nozzle, the neck air inlet is arranged at the top of the resonator body or the side wall away from the fuel nozzle and is connected to the resonance cavity and is placed outside the combustion chamber, and the neck air outlet is arranged at the bottom of the resonator body and is connected to the resonance cavity and is placed in the combustion chamber.

[0008] Optionally, the resonant frequency of the Helmholtz resonator is related to the volume of the resonance cavity, the cross-section of the neck air inlet and the cross-sectional area of ​​the neck air outlet, wherein the volume of the resonance cavity is negatively correlated with the resonant frequency of the Helmholtz resonator, the cross-sectional area of ​​the neck air inlet is positively correlated with the resonant frequency of the Helmholtz resonator, and the cross-sectional area of ​​the neck air outlet is positively correlated with the resonant frequency of the Helmholtz resonator.

[0009] Optionally, the volume of the resonance cavity, the total cross-sectional area of ​​the neck air inlet and the total cross-sectional area of ​​the neck air outlet are adjusted based on the system vibration frequency, wherein the volume of the resonance cavity is negatively correlated with the system vibration frequency, and the total cross-sectional area of ​​the neck air inlet and the total cross-sectional area of ​​the neck air outlet are both positively correlated with the system vibration frequency.

[0010] Optionally, the total cross-sectional area of ​​the neck air inlet is adjusted based on the number of the neck air inlets and the cross-sectional area of ​​each neck air inlet, and the total cross-sectional area of ​​the neck air outlet is adjusted based on the number of the neck air outlets and the cross-sectional area of ​​each neck air inlet.

[0011] Optionally, the shape of the longitudinal section of the resonance cavity is adjusted based on the size of the combustion chamber inlet, thereby adjusting the volume of the resonance cavity; wherein the shape of the longitudinal section of the resonance cavity is rectangular or inverted trapezoidal.

[0012] Optionally, there are multiple neck air inlets, which are arranged at intervals on the top of the resonator body; wherein the axis of the neck air inlet is parallel to the axis of the fuel nozzle, or intersects with the axis of the fuel nozzle at the outlet of the fuel nozzle.

[0013] Optionally, there are multiple neck air inlets, which are spaced apart on the side wall of the resonator body away from the fuel nozzle, wherein the axis of the neck air inlet intersects with the axis of the fuel nozzle at the outlet of the fuel nozzle.

[0014] Optionally, there are multiple neck air outlets, which are arranged at intervals at the bottom of the resonator body; wherein the axis of the neck air outlet is parallel to the axis of the fuel nozzle, or intersects with the axis of the fuel nozzle at the outlet of the fuel nozzle.

[0015] Optionally, the fuel nozzle is a single-fuel nozzle or a multi-fuel nozzle.

[0016] As described above, a nozzle structure of the present invention has the following beneficial effects: the present invention suppresses the thermoacoustic oscillation phenomenon of the entire combustion system by integrating a Helmholtz resonator at the end of the fuel nozzle. Placing the Helmholtz resonator at the end of the fuel nozzle can improve the flexibility of the combustion chamber design and minimize the modification of the existing combustion system. It can also significantly reduce the amplitude of the thermoacoustic oscillation and improve the combustion quality of the combustion nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a cross-sectional view of a nozzle structure with a first Helmholtz resonator according to the present invention.

[0018] Figure 2 Schematic diagram showing the gas flow in the Helmholtz resonator of the present invention

[0019] Figure 3 Shown is a cross-sectional view of a second Helmholtz resonator nozzle structure according to the present invention.

[0020] Figure 4 Shown is a cross-sectional view of a third Helmholtz resonator nozzle structure according to the present invention.

[0021] Figure 5 Shown is a top view of the Helmholtz resonator of the present invention.

[0022] Figure 6 Shown is a cross-sectional view of a single fuel nozzle with a Helmholtz resonator according to the present invention.

[0023] Figure 7 Shown is a cross-sectional view of a dual-fuel nozzle with a Helmholtz resonator according to the present invention.

[0024] Component number description

[0025] 1 fuel nozzle

[0026] 11 Nozzle housing

[0027] 111 First Cavity

[0028] 112 Second cavity

[0029] 113 Internal Passage

[0030] 114 First Fuel Inlet

[0031] 115 Second fuel inlet

[0032] 116 Hollow thread

[0033] 117 positioning slot

[0034] 118 fixed steps

[0035] 118a First fixed step

[0036] 118b Second fixed step

[0037] 12 Nozzle body

[0038] 121 cavity

[0039] 121a Upper cavity

[0040] 121b lower cavity

[0041] 122 fixed structure

[0042] 123 boss structure

[0043] 123a Vent

[0044] 123b Air tank

[0045] 123c slot cover

[0046] 123d connecting pipe

[0047] 13 Duty Supervisor

[0048] 131 Fuel Clearance

[0049] 132 Duty Entrance

[0050] 133 Hollow Nut

[0051] 134 Duty Nozzle

[0052] 14. First isolation component

[0053] 141 First Fuel Pipeline

[0054] 141a First fuel injection hole

[0055] 15 Second isolation component

[0056] 151 Second fuel pipeline

[0057] 151a Second fuel injection hole

[0058] 152 Air Duct

[0059] 152a Radial injection hole

[0060] 152b Axial injection hole

[0061] 16 Main airway

[0062] 161 Main gas inlet

[0063] 17 Cyclone

[0064] 171 cyclone blades

[0065] 171a Internal Pipeline

[0066] 171b Gas injection hole

[0067] 172 fixed connector

[0068] 172a First fixing portion

[0069] 172b Second fixing portion

[0070] 2 Helmholtz resonator

[0071] 21 Resonant Cavity

[0072] 22 Resonator body

[0073] 23 Neck air intake

[0074] 24 Neck air outlet

[0075] 3 Combustion chamber DETAILED DESCRIPTION

[0076] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0077] See also Figures 1 to 7 It should be noted that the illustrations provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation, the form, quantity, and proportion of each component in actual implementation may be arbitrarily changed, and the component layout may also be more complex.

[0078] like Figure 1 As shown, this embodiment provides a nozzle structure, which includes: a fuel nozzle 1 and a Helmholtz resonator 2, wherein:

[0079] The outlet of the fuel nozzle 1 is provided at the bottom thereof, and the fuel nozzle 1 has a front end away from the bottom thereof and a tail end close to the bottom thereof;

[0080] The Helmholtz resonator 2 includes: a resonator body 22 with a resonance cavity 21 inside, at least one neck air inlet 23 and at least one neck air outlet 24. The resonator body 22 is sleeved on the periphery of the fuel nozzle 1 and is located at the end of the fuel nozzle 1. The neck air inlet 23 is located at the top of the resonator body 22 or the side wall away from the fuel nozzle 1 and is connected to the resonance cavity 21 and is placed outside the combustion chamber 3. The neck air outlet 24 is located at the bottom of the resonator body 22 and is connected to the resonance cavity 21 and is placed inside the combustion chamber 3.

[0081] In this embodiment, the resonator body 22 is fixed to the periphery of the fuel nozzle 1 by welding, and its side wall is adapted to the inner wall of the combustion chamber entrance. As the fuel burns in the combustion chamber, there is a certain pressure difference between the inside and outside of the combustion chamber. Therefore, the air outside the combustion chamber will flow into the combustion chamber and enter the neck air inlet 23. Figure 2 As shown, a portion of the air a entering the resonance cavity 21 through the neck air inlet 23 will continue to move toward the location of the neck air outlet 24 and enter the combustion chamber through the neck air outlet 24, while another portion of the air b will diffuse in the resonance cavity 21, causing the air in the resonance cavity 21 to move, thereby being converted into other forms of energy (such as mechanical energy) and consumed. As a result, the Helmholtz resonance cavity 21 resonates to eliminate vibrations in the combustion system, especially in the combustion chamber.

[0082] Specifically, the resonant frequency of the Helmholtz resonator 2 is related to the volume of the resonant cavity 21, the cross-sectional area of ​​the neck air inlet 23, and the cross-sectional area of ​​the neck air outlet 24, wherein the volume of the resonant cavity 21 is negatively correlated with the resonant frequency of the Helmholtz resonator 2 (the volume of the resonant cavity 21 and the resonant frequency of the Helmholtz resonator 2 have opposite changing trends, that is, as the volume of the resonant cavity 21 increases, the resonant frequency of the Helmholtz resonator 2 decreases, and as the volume of the resonant cavity 21 decreases, the resonant frequency of the Helmholtz resonator 2 increases), and the cross-sectional area of ​​the neck air inlet 23 is positively correlated with the resonant frequency of the Helmholtz resonator 2 (the cross-sectional area of ​​the neck air inlet 23 is positively correlated with the resonant frequency of the Helmholtz resonator 2). The cross-sectional area of ​​the neck air inlet 23 and the resonant frequency of the Helmholtz resonator 2 show the same changing trend, that is, the cross-sectional area of ​​the neck air inlet 23 increases, the resonant frequency of the Helmholtz resonator 2 increases, the cross-sectional area of ​​the neck air inlet 23 decreases, and the resonant frequency of the Helmholtz resonator 2 decreases), and the cross-sectional area of ​​the neck air outlet 24 is positively correlated with the resonant frequency of the Helmholtz resonator 2 (the cross-sectional area of ​​the neck air outlet 24 and the resonant frequency of the Helmholtz resonator 2 show the same changing trend, that is, the cross-sectional area of ​​the neck air outlet 24 increases, the resonant frequency of the Helmholtz resonator 2 increases, the cross-sectional area of ​​the neck air outlet 24 decreases, and the resonant frequency of the Helmholtz resonator 2 decreases). Among them, the cross-sectional areas of the neck air inlet 23 and the neck air outlet 24 refer to the cross-sectional areas along the horizontal direction ( Figure 1 The area of ​​the cross section of the neck air inlet 23 and the neck air outlet 24 when the direction (indicated by the letter X) is cut to the neck air inlet 23 and the neck air outlet 24.

[0083] As an example, the volume of the resonance cavity 21, the total cross-sectional area of ​​the neck air inlet 23, and the total cross-sectional area of ​​the neck air outlet 24 are adjusted based on the system vibration frequency, wherein the volume of the resonance cavity 21 is negatively correlated with the system vibration frequency (the system vibration frequency and the volume of the resonance cavity 21 have an opposite trend of change, that is, as the system vibration frequency increases, the volume of the resonance cavity 21 decreases, and as the system vibration frequency decreases, the volume of the resonance cavity 21 increases), and the total cross-sectional area of ​​the neck air inlet 23 and the total cross-sectional area of ​​the neck air outlet 24 are both It is positively correlated with the system vibration frequency (the system vibration frequency and the total cross-sectional area of ​​the neck air inlet 23 show the same changing trend, that is, as the system vibration frequency increases, the total cross-sectional area of ​​the neck air inlet 23 increases, and as the system vibration frequency decreases, the total cross-sectional area of ​​the neck air inlet 23 decreases; the system vibration frequency and the total cross-sectional area of ​​the neck air outlet 24 show the same changing trend, that is, as the system vibration frequency increases, the total cross-sectional area of ​​the neck air outlet 24 increases, and as the system vibration frequency decreases, the total cross-sectional area of ​​the neck air outlet 24 decreases).

[0084] As an example, the shape of the longitudinal section of the resonance cavity 21 is adjusted based on the size of the combustion chamber inlet, thereby adjusting the volume of the resonance cavity 21; wherein the shape of the longitudinal section of the resonance cavity 21 is rectangular or inverted trapezoidal.

[0085] In this embodiment, the shape of the combustion chamber inlet is determined, and the space in which it is located is limited. If the combustion chamber inlet is large, the Helmholtz resonator 2 can select a resonance cavity 21 with a rectangular longitudinal section so that the volume of the corresponding resonance cavity 21 meets the system requirements, such as Figure 1 If the combustion chamber inlet size is small, the Helmholtz resonator 2 may select a resonant cavity 21 having an inverted trapezoidal longitudinal section to increase the volume of the resonant cavity so that it meets the system requirements, such as Figure 3 As shown. Wherein, the longitudinal section of the resonant cavity 21 is along the vertical direction (such as Figure 1 The cross section of the diagram is shown by cutting the resonance cavity 21 in the direction indicated by the letter Y in FIG.

[0086] Furthermore, the total cross-sectional area of ​​the neck air inlets 23 is adjusted based on the number of the neck air inlets 23 and the cross-sectional area of ​​each of the neck air inlets 23, and the total cross-sectional area of ​​the neck air outlets 24 is adjusted based on the number of the neck air outlets 24 and the cross-sectional area of ​​each of the neck air outlets 24. In practical applications, the total cross-sectional area of ​​the neck air inlets 23 can be adjusted by adjusting the cross-sectional area of ​​each of the neck air inlets 23, or by adjusting the number of the neck air inlets 23, or by adjusting the total cross-sectional area of ​​the neck air inlets 23 simultaneously. For the neck air outlet 24, the total cross-sectional area of ​​the neck air outlet 24 can be adjusted by adjusting the cross-sectional area of ​​a single neck air outlet 24, or by adjusting the number of the neck air outlets 24 to adjust the total cross-sectional area of ​​the neck air outlet 24, or by simultaneously adjusting the number of the neck air outlets 24 and the cross-sectional area of ​​a single neck air outlet 24 to adjust the total cross-sectional area of ​​the neck air outlet 24.

[0087] As an example, there are multiple neck air inlets 23, which are arranged at intervals on the top of the resonator body 22; wherein the axis of the neck air inlet 23 is parallel to the axis of the fuel nozzle 2, or intersects with the axis of the fuel nozzle 1 at the outlet of the fuel nozzle 1.

[0088] As an example, there are multiple neck air inlets 23, which are arranged at intervals on the side wall of the resonator body 22 away from the fuel nozzle 1, wherein the axis of the neck air inlet 23 intersects with the axis of the fuel nozzle 1 at the outlet of the fuel nozzle 1.

[0089] In this embodiment, Figures 1 to 4 As shown, by changing the number of the neck air inlets 23, the Helmholtz resonator 2 can produce different resonant frequencies, and the number of the neck air inlets 23 can be adjusted as needed. When designing the neck air inlet 23, it is also necessary to adjust the inclination angle α between the axis of the neck air inlet 23 and the axis of the fuel nozzle 1 according to the air injection volume of the fuel nozzle 1, so that the Helmholtz resonator 2 produces different vibration reduction effects. When specifically designing and manufacturing the neck air inlet 23, the number of the neck air inlet 23 and the inclination angle α of the neck air inlet 23 can be determined based on actual simulation results, so that the Helmholtz resonator 2 achieves a good vibration reduction effect.

[0090] As an example, there are multiple neck air outlets 24, which are arranged at intervals at the bottom of the resonator body 22; wherein the axis of the neck air outlet 24 is parallel to the axis of the fuel nozzle 1, or intersects with the axis of the fuel nozzle 1 at the outlet of the fuel nozzle 1.

[0091] In this embodiment, Figures 1 to 4 As shown, by varying the number of neck air outlets 24, the Helmholtz resonator 2 can produce different resonant frequencies, and the number of neck air outlets 24 can be adjusted as needed. When designing the neck air outlets 24, the tilt angle α between the axis of the neck air outlet 24 and the axis of the fuel nozzle 1 can be adjusted based on the air injection rate of the fuel nozzle 1, thereby achieving different vibration damping effects in the Helmholtz resonator 2. If the air injection rate of the fuel nozzle 1 is insufficient, the tilt angle α between the axis of the neck air outlet 24 and the axis of the fuel nozzle 1 can be designed to be larger, allowing the air in the resonance cavity 21 to be ejected through the neck air outlet 24 toward the outlet of the fuel nozzle 1, providing more oxygen there. If the air injection rate of the fuel nozzle 1 is sufficient, the tilt angle α between the axis of the neck air outlet 24 and the axis of the fuel nozzle 1 can be designed to be smaller, or to be parallel to the axis of the fuel nozzle 1. When the neck air outlets 24 are specifically manufactured, the number of the neck air outlets 24 and the inclination angle α of the neck air outlets 24 can be determined according to actual simulation results, so that the Helmholtz resonator 2 can achieve a good resonance effect.

[0092] Specifically, the fuel nozzle 1 is a single-fuel nozzle or a dual-fuel nozzle.

[0093] As an example, Figure 6 In this embodiment, the fuel nozzle 1 includes a nozzle housing 11 , a nozzle body 12 , a service pipe 13 , a first isolation assembly 14 and a second isolation assembly 15 .

[0094] The nozzle housing 11 is provided with a first cavity 111 and a second cavity 112, which extend through the upper and lower surfaces of the nozzle housing 11. The second cavity 112 is located on one side of the first cavity 111 and communicates with the first cavity 111 via an internal passage 113 within the nozzle housing 11. A first fuel inlet 114 and a second fuel inlet 115 are provided on the sidewall of the nozzle housing 11. The first fuel inlet 114 is located on one side of the first cavity 111 and communicates with the first cavity 111, while the second fuel inlet 115 is located away from the first cavity 111 and communicates with the second cavity 112. Hollow threads 116 are provided at the first and second fuel inlets 114, 115 for connecting to an external fuel supply device. A positioning groove 117 is provided on the lower end surface of the nozzle housing 11. The positioning groove 117 has an annular cross-section and communicates with the second cavity 112. A fixing step 118 is provided on the side wall of the nozzle housing 11 near the lower end surface. The fixing step 118 includes a first fixing step 118a and a second fixing step 118b. The first fixing step 118a is arranged away from the second cavity 111, and the second fixing step 118b is arranged between the first fixing step 118a and the positioning groove 117, and is located below the first fixing step 118a.

[0095] The nozzle body 12 includes a cavity 121, a fixing structure 122, and a boss structure 123. The nozzle body 12 is fixedly connected to the first fixing step 118a by welding via the fixing structure 122, thereby securing the nozzle body 12 to the bottom end of the nozzle housing 11. The cavity 121 includes an upper cavity 121a and a lower cavity 121b communicating with the upper cavity 121a. The diameter of the upper cavity 121a is larger than that of the lower cavity 121b. The boss structure 123 is connected to the fixing structure 122 and has a plurality of spaced-apart vents 123a on its sidewall.

[0096] The service pipe 13 passes through the first cavity 111 and extends into the nozzle body 12, and there is a gap between the service pipe 13 and the inner wall of the first cavity 111, and the gap is a fuel gap 131. The top of the service pipe 13 serves as a service entrance 132. The top of the service pipe 13 passes through a hollow nut 133, and the service pipe 13 is fixed in the first cavity 111 of the nozzle housing 11 by using a hollow thread 116 that is compatible with the hollow nut 133. The bottom end of the service pipe 13 is fixed with a service nozzle 134 by welding, wherein the service pipe 13 and the service nozzle 134 form a service path.

[0097] The first isolation assembly 14 and the second isolation assembly 15 are cylindrical structures with upper and lower openings, and are arranged in the cavity of the nozzle body 12. The first isolation assembly 14 is fixed to the bottom end of the nozzle housing 11 through the positioning groove 117 near the side wall of the first cavity 111, and is sleeved around the periphery of the service pipe 13 with a gap between it and the service pipe 13 to form a first fuel pipeline 141, wherein the first fuel pipeline 141 and the fuel gap 131 form a first main oil circuit. In addition, the side of the first isolation assembly 14 away from the bottom end of the nozzle housing 11 is sleeved around the periphery of the upper part of the service nozzle 134, and there is a gap between it and the service nozzle 134. The gap is a first fuel injection hole 141a, which is used to connect the first fuel pipeline 14 1 is sprayed out; the second isolation component 15 is fixed to the bottom end of the nozzle housing 11 through the vertical side wall of the second fixing step 118b, and is sleeved on the periphery of the first isolation component 14 with a gap, and the gap between it and the first isolation component 14 forms a second fuel pipeline 151, wherein the second fuel pipeline 151 and the second cavity 112 form a second main oil path; at the same time, there is a gap between the second isolation component 15 and the body wall of the nozzle body 12, and the gap is an air pipeline 152, and the air pipeline 152 is connected to the vent 123a and forms an air path with the vent 123a.

[0098] A plurality of second fuel injection holes 151 a are provided on one side of the second fuel pipeline 151 close to the service nozzle 134 for spraying the fuel in the second fuel pipeline 151 , wherein the second fuel injection holes 151 a are provided in the wall of a cylindrical injection structure, and the cylindrical injection structure is sleeved on the periphery of the service nozzle 134 and fixed between the first isolation component 14 and the second isolation component 15 .

[0099] The bottom end of the air duct 152 is provided with a plurality of injection hole groups, and the plurality of injection hole groups are arranged in a ring around the periphery of the second fuel injection hole 151a, wherein the injection hole group includes a radial injection hole 152a and an axial injection hole 152b, the radial injection hole 152a faces the second fuel injection hole 151a and is arranged below the second fuel injection hole 151a, and the axial injection hole 152b is arranged below the radial injection hole 152a.

[0100] In this embodiment, the resonator body 22 of the Helmholtz resonator 2 is mounted on the periphery of the nozzle body 12 and is fixed to the end of the nozzle body 12 (i.e., the end close to the service nozzle 134) by welding, so as to generate resonance to eliminate vibrations in the combustion chamber.

[0101] As another example, Figure 7 As shown, the fuel nozzle 2 is a dual-fuel nozzle. In this embodiment, the dual-fuel nozzle includes a nozzle housing 11 , a nozzle body 12 , a service pipe 13 , a first isolation assembly 14 , a second isolation assembly 15 , a main air pipe 16 and a swirler 17 .

[0102] The nozzle housing 11 is provided with a first cavity 111 and a second cavity 112, which extend through the upper and lower surfaces of the nozzle housing 11. The second cavity 112 is located on one side of the first cavity 111 and communicates with the first cavity 111 via an internal passage 113 within the nozzle housing 11. A first fuel inlet 114 and a second fuel inlet 115 are provided on the sidewall of the nozzle housing 11. The first fuel inlet 114 is located on one side of the first cavity 111 and communicates with the first cavity 111, while the second fuel inlet 115 is located on a side away from the first cavity 111 and communicates with the second cavity 112. Threads 116 are provided on the first and second fuel inlets 114, 115 for connecting to an external fuel supply device. A positioning groove 117 is provided on the lower end surface of the nozzle housing 11. The positioning groove has an annular cross-section and communicates with the second cavity 112. A fixing step 118 is provided on the side wall of the nozzle housing 11 near the lower end surface. The fixing step 118 includes a first fixing step 118a and a second fixing step 118b. The first fixing step 118a is arranged away from the second cavity 112, and the second fixing step 118b is arranged between the first fixing step 118a and the positioning groove 117, and is located below the first fixing step 118a.

[0103] The nozzle body 12 includes a cavity 121, a fixing structure 122, and a boss structure 123. The nozzle body 12 is fixedly connected to the first fixing step 118a by welding via the fixing structure 122, thereby fixing the nozzle body 12 to the bottom end of the nozzle housing 11. The cavity 121 includes an upper cavity 121a and a lower cavity 121b communicating with the upper cavity 121a. The diameter of the upper cavity 121a is larger than the diameter of the lower cavity 121b. The boss structure 123 is connected to the fixed structure 122, and an air storage tank 123b is provided above the boss structure 123. The air storage tank 123b is arranged around the periphery of the nozzle housing 11, and a tank cover 123c with a reserved opening is welded thereto. The sidewall of the boss structure 123 is provided with a plurality of spaced-apart vents 123a, which are located below the air storage tank 123b and communicate with the cavity 121. The boss structure 123 is provided with a plurality of spaced-apart communicating pipes 123d, wherein the communicating pipes 123d are in communication with the air storage tank 123b and are located below the air storage tank 123b, extending to the bottom end of the boss structure 123. The communicating pipes 123d are staggered with the air inlet 123a.

[0104] The main gas pipe 16 is arranged on the outside of the nozzle housing 11, and its top end serves as the main gas inlet 161. A hollow thread 116 is fixed at the main gas inlet 161 by welding for connecting to an external device that provides fuel. Its bottom end is connected to the gas storage tank 123b through a reserved opening on the tank cover 123c.

[0105] The swirler 17 includes a plurality of swirler blades 171 and a fixing member 172. The swirler blades 171 are located on a side of the boss structure 123 away from the gas storage tank 123b. An internal pipe 171a is provided within the swirler blades 171, which communicates with the connecting pipe 123d. The internal pipe 171a, the connecting pipe 123d, the gas storage tank 123b, and the main gas pipe 16 form a main gas path. A plurality of gas path injection holes 171b are provided on a side of the swirler blades 171 near the nozzle body 12 for ejecting the gas in the main gas pipe 16. The fixed connection member 172 includes a first fixed portion 172a and a second fixed portion 172b. The first fixed portion 172a is fixed to the bottom end of the swirler blade 171 by bolts, and the second fixed portion 172b is connected to the side of the first fixed portion 172a close to the nozzle body 12 and extends downward. During specific production, the first fixed portion 172a and the second fixed portion 172b can be integrally formed.

[0106] The service pipe 13 passes through the first cavity 111 and extends into the nozzle body 12, and there is a gap between the service pipe 13 and the inner wall of the first cavity 111, and the gap is a fuel gap 131. The top of the service pipe 13 serves as a service entrance 132. The top of the service pipe 13 passes through a hollow nut 133, and the service pipe 13 is fixed in the first cavity 111 of the nozzle housing 11 by using a hollow thread 116 that is compatible with the hollow nut 133. The bottom end of the service pipe 13 is fixed with a service nozzle 134 by welding, wherein the service pipe 13 and the service nozzle 134 form a service path.

[0107] The first isolation assembly 14 and the second isolation assembly 15 are cylindrical structures with upper and lower openings, and are arranged in the cavity of the nozzle body 12. The first isolation assembly 14 is fixed to the bottom end of the nozzle housing 11 through the positioning groove 117 near the side wall of the first cavity 111, and is sleeved around the periphery of the service pipe 13 with a gap between it and the service pipe 13 to form a first fuel pipeline 141, wherein the first fuel pipeline 141 and the fuel gap 131 form a first main oil circuit. In addition, the side of the first isolation assembly 24 away from the bottom end of the nozzle housing 21 is sleeved around the periphery of the upper part of the service nozzle 134, and there is a gap between it and the service nozzle 134. The gap is a first fuel injection hole 141a, which is used to connect the first fuel pipeline 14 1 is sprayed out; the second isolation component 15 is fixed to the bottom end of the nozzle housing 11 through the vertical side wall of the second fixing step 118b, and is sleeved on the periphery of the first isolation component 14 with a gap, and the gap between it and the first isolation component 14 forms a second fuel pipeline 151, wherein the second fuel pipeline 151 and the second cavity 112 form a second main oil path; at the same time, there is a gap between the second isolation component 15 and the body wall of the nozzle body 12, and the gap is an air pipeline 152, and the air pipeline 152 is connected to the vent 123a and forms an air path with the vent 123a.

[0108] A plurality of second fuel injection holes 151 a are provided on one side of the second fuel pipeline 151 close to the service nozzle 134 for spraying the fuel in the second fuel pipeline 151 , wherein the second fuel injection holes 151 a are provided in the wall of a cylindrical injection structure, and the cylindrical injection structure is sleeved on the periphery of the service nozzle 134 and fixed between the first isolation component 14 and the second isolation component 15.

[0109] The bottom end of the air duct 152 is provided with a plurality of injection hole groups, and the plurality of injection hole groups are arranged in a ring around the periphery of the second fuel injection hole 151a, wherein the injection hole group includes a radial injection hole 152a and an axial injection hole 152b, the radial injection hole 152a faces the second fuel injection hole 151a and is arranged below the second fuel injection hole 151a, and the axial injection hole 152b is arranged below the radial injection hole 152a.

[0110] In this embodiment, the resonant body 22 of the Helmholtz resonator 2 is mounted on the periphery of the second fixed portion 172b and is fixed to the end of the second fixed portion 172b (i.e., the end close to the service nozzle) by welding, so as to generate resonance to eliminate vibrations in the combustion chamber.

[0111] See below Figure 6 and Figure 7 , the working process of the nozzle structure of this embodiment is explained.

[0112] The fuel nozzle of the nozzle structure includes a main combustion path and a duty path, and its working mode is different according to different fuels (oil / gas).

[0113] The single-fuel nozzle uses fuel oil, while the dual-fuel nozzle can use both fuel oil and gas. Regardless of whether it's a single-fuel or dual-fuel nozzle, when using fuel oil, the service circuit introduces fuel and sprays it into the combustion chamber at the service nozzle, where it undergoes diffusion combustion, ensuring stable combustion. The main combustion circuits consist of the first and second main oil circuits. Fuel is introduced into the first and second main oil circuits, while high-pressure air is introduced into the vents. Fuel is ejected through the first and second main oil injection holes, while high-pressure air is ejected through the air injection hole. After mixing, a lean fuel-air mixture is quickly formed, which enters the combustion chamber for combustion.

[0114] When the fuel nozzle is a dual-fuel nozzle, the fuel can be natural gas. In this case, the service path introduces fuel and sprays it into the combustion chamber at the service nozzle, where the fuel can undergo diffusion combustion to ensure stable combustion. The main combustion path is the main gas path. Natural gas is introduced into the main gas pipe, and then the gas flows into the gas storage tank and fills the gas storage tank. Then, it flows into the internal pipe inside the cyclone blade through the connecting pipe and is sprayed into the cyclone through the gas path injection hole. It is mixed with high-pressure air to form oil-lean gas. Then, under the action of the pressure inside and outside the combustion chamber, the oil-lean gas enters the combustion chamber.

[0115] During the combustion process, the temperature rises sharply and the airflow moves repeatedly, generating combustion vibrations. The Helmholtz resonator is mounted on the bottom end of the fuel nozzle and resonates, thereby eliminating vibrations in the main system, especially in the combustion chamber.

[0116] In summary, the nozzle structure of the present invention suppresses the thermoacoustic oscillations of the entire combustion system by integrating a Helmholtz resonator at the end of the fuel nozzle. Placing the Helmholtz resonator at the end of the nozzle enhances the flexibility of combustion chamber design and minimizes modifications to existing combustion systems. It also significantly reduces the amplitude of thermoacoustic oscillations, improving the combustion quality of the nozzle. Therefore, the present invention effectively overcomes the shortcomings of existing technologies and possesses high industrial value.

[0117] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A nozzle structure, characterized in that: The nozzle structure includes: a fuel nozzle and a Helmholtz resonator, wherein: The outlet of the fuel nozzle is provided at the bottom thereof, and the fuel nozzle has a front end away from the bottom thereof and a tail end close to the bottom thereof; The Helmholtz resonator includes: a resonator body having a resonant cavity therein, at least one neck air inlet, and at least one neck air outlet. The resonator body is sleeved around the periphery of the fuel nozzle and is located at the end of the fuel nozzle. The neck air inlet is located at the top of the resonator body or a sidewall away from the fuel nozzle and is in communication with the resonant cavity and is located outside the combustion chamber. The neck air outlet is located at the bottom of the resonator body and is in communication with the resonant cavity and is located inside the combustion chamber. The resonant frequency of the Helmholtz resonator is related to the volume of the resonant cavity, the cross-sectional area of ​​the neck air inlet, and the cross-sectional area of ​​the neck air outlet, wherein the volume of the resonant cavity is negatively correlated with the resonant frequency of the Helmholtz resonator, the cross-sectional area of ​​the neck air inlet is positively correlated with the resonant frequency of the Helmholtz resonator, and the cross-sectional area of ​​the neck air outlet is positively correlated with the resonant frequency of the Helmholtz resonator; adjusting the volume of the resonance cavity, the total cross-sectional area of ​​the neck air inlet, and the total cross-sectional area of ​​the neck air outlet based on the system vibration frequency, wherein the volume of the resonance cavity is negatively correlated with the system vibration frequency, and the total cross-sectional area of ​​the neck air inlet and the total cross-sectional area of ​​the neck air outlet are both positively correlated with the system vibration frequency; The shape of the longitudinal section of the resonance cavity is adjusted based on the size of the combustion chamber inlet, thereby adjusting the volume of the resonance cavity; wherein the shape of the longitudinal section of the resonance cavity is rectangular or inverted trapezoidal.

2. The nozzle structure according to claim 1, characterized in that: The total cross-sectional area of ​​the neck air inlets is adjusted based on the number of the neck air inlets and the cross-sectional area of ​​each neck air inlet, and the total cross-sectional area of ​​the neck air outlets is adjusted based on the number of the neck air outlets and the cross-sectional area of ​​each neck air outlet.

3. The nozzle structure according to claim 1 or 2, characterized in that: There are multiple neck air inlets, which are spaced apart at the top of the resonator body; wherein the axis of the neck air inlet is parallel to the axis of the fuel nozzle, or intersects with the axis of the fuel nozzle at the outlet of the fuel nozzle.

4. The nozzle structure according to claim 1 or 2, characterized in that: There are multiple neck air inlets, which are spaced apart on the side wall of the resonator body away from the fuel nozzle, wherein the axis of the neck air inlet intersects with the axis of the fuel nozzle at the outlet of the fuel nozzle.

5. The nozzle structure according to claim 1 or 2, characterized in that: There are multiple neck air outlets, which are spaced apart at the bottom of the resonator body; wherein the axis of the neck air outlet is parallel to the axis of the fuel nozzle, or intersects with the axis of the fuel nozzle at the outlet of the fuel nozzle.

6. The nozzle structure according to claim 1, characterized in that: The fuel nozzle is a single-fuel nozzle or a dual-fuel nozzle.

Images