An oil circuit adjustable low emission dual fuel nozzle

Abstract

The application discloses an oil path adjustable low-emission dual-fuel nozzle and relates to the technical field of gas turbines. The oil path adjustable low-emission dual-fuel nozzle comprises a gas fuel grading assembly, a first inner guide pipe, a second inner guide pipe and a mounting cover plate, the gas fuel grading assembly is inserted with a liquid fuel core body assembly, the gas fuel grading assembly is composed of a nozzle body, a flow divider, a third inner guide pipe, a sealing ring and a gas fuel mixing assembly, and the liquid fuel core body assembly further comprises a core body shell, and two fixed pin insertion blind holes for inserting and fixing fixed pins are arranged on the core body shell. Through the liquid fuel path core extraction type structure design technical means, the applicability of the dual-fuel nozzle can be improved, a plurality of design schemes can be matched under the condition of producing a small number of nozzles, a more convenient way is provided for the research and development design of a combustion chamber, the test piece investment cost is reduced while the test verification demand is ensured, and the design and development progress of the dual-fuel nozzle is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, specifically to a low-emission dual-fuel nozzle with adjustable oil circuit. Background Technology

[0002] Low-emission dual-fuel gas turbines possess advantages such as a wide range of fuel applicability, high power density, and high operating efficiency, making them a promising high-end equipment for the energy and power industry. Low-emission dual-fuel combustor design technology is one of the core technologies in the research and development of low-emission dual-fuel gas turbines, and the low-emission dual-fuel nozzle is a key component of the low-emission dual-fuel combustor; its successful design directly determines the success or failure of the low-emission dual-fuel combustor development.

[0003] In the design and development of low-emission dual-fuel nozzles, in order to ensure convenient application and maintenance of nozzle components, and to achieve rapid and efficient switching between the two fuels in the combustion chamber, low-emission dual-fuel nozzles usually adopt a highly integrated integrated structure, that is, the gas fuel working part and the liquid fuel working part are combined into a whole component structure. This greatly increases the difficulty of its processing, manufacturing and performance debugging. Specifically, it involves the manufacturing of gas fuel passages, liquid fuel passages and batch manufacturing of core atomizing elements and other components, performance debugging between different stages of gas fuel, performance debugging of liquid fuel, and performance debugging of multi-channel collaborative operation. When high-temperature resistant alloy materials are selected for manufacturing, the total cost of a single nozzle, including material costs and labor costs, is significantly increased compared with conventional single-fuel nozzles.

[0004] On the other hand, the dual-fuel combustion process involves many aspects, including the mixing of gaseous fuels, atomization, evaporation, and mixing of liquid fuels, air swirl, and heat, mass transfer, and turbulent flow of the mixed combustibles and products. The process is extremely complex, and numerical simulation often has limitations in analysis and finalization. In actual research and development, it is imperative to conduct experiments and adjustments using various schemes, such as different liquid fuel injection starting points, different liquid fuel atomization cone angles, different liquid fuel swirl intensities, and different auxiliary atomizing air configurations. In other words, the design and development of low-emission dual-fuel nozzles requires experimental simulation verification of specific performance under multiple design schemes, and performance comparison is necessary to confirm the effectiveness of the scheme. This causes research and development costs, especially manufacturing costs, to increase exponentially, and the development cycle to lengthen. Even with substantial investment, it is not guaranteed to obtain the most ideal design, and there is still a risk of development failure.

[0005] Therefore, there is an urgent need to improve this research and development dilemma, reduce research and development costs, and improve research and development efficiency. This invention can effectively solve this problem by utilizing a single dual-fuel nozzle to achieve multiple application schemes, meeting experimental requirements while reducing costs. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a low-emission dual-fuel nozzle with adjustable fuel lines, solving the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: a low-emission dual-fuel nozzle with adjustable oil circuit, comprising a gas fuel staged assembly, a first inner conduit, a second inner conduit, and a mounting cover plate, characterized in that: the gas fuel staged assembly is connected to a liquid fuel core assembly, and the gas fuel staged assembly is composed of a nozzle body, a distributor, a third inner conduit, a sealing ring, and a gas fuel mixing assembly;

[0008] The liquid fuel core assembly also includes a core shell and an inlet connector. The core shell is a shell structure with an outer positioning boss and an inner cavity. The core shell is provided with two blind holes for inserting fixing pins.

[0009] The liquid fuel core assembly passes through the nozzle body and the center hole of the distributor in sequence and abuts against the positioning boss inserted into the center of one side of the nozzle body. The liquid fuel core assembly is fixed to the nozzle body by a fixing pin.

[0010] A further improvement of the technical solution of the present invention is that: the nozzle body is a shell structure with an axial central hole, four medium inlets and four medium channels. The four medium inlets are connected to the four medium channels, and a threaded conical joint is provided at one end of the medium channel that penetrates the nozzle body, and is respectively connected to the first inner guide tube and the second inner guide tube. The two medium channels are respectively connected to the two inlet joints of the liquid fuel core assembly to form a high temperature and high pressure air cavity.

[0011] A further improvement of the technical solution of the present invention is that the diverter is a transition support structure with a central hole and a diverter ring wall;

[0012] The nozzle body is welded to the distributor after being inserted into the outer wall of the axial central hole to maintain coaxiality. The nozzle body is sealed by the outer ring after being connected to the sealing ring to form a first annular cavity and a second first annular cavity for media buffering and transition. The nozzle body and the distributor are respectively connected to the first channel and the second channel of the nozzle body.

[0013] A further improvement of the technical solution of the present invention is that: the gas fuel blending assembly is provided with two second annular cavities, and a second air cyclone is provided on one side of the two second annular cavities. The two second annular cavities are connected to the air inlet holes inside the cyclone blades of the second air cyclone. The third inner conduit is axially distributed between the outer side of the sealing ring and the gas fuel blending assembly. The two first annular cavities are connected to the two second annular cavities through the third inner conduit.

[0014] A further improvement to the technical solution of the present invention is that the splitter further includes the following specific configuration:

[0015] The distributor is provided with eight sets of connecting holes and eight radial air inlets, and the eight connecting holes are evenly distributed axially, while the eight connecting holes and the eight radial air inlets are staggered and alternately distributed.

[0016] A further improvement of the technical solution of the present invention is that the first inner conduit and the second inner conduit are disposed inside the high temperature and high pressure air cavity.

[0017] A further improvement to the technical solution of the present invention is that the third internal catheter further includes the following specific configuration:

[0018] The number of the third internal catheters is N, and 4≤N≤8, and the third internal catheters are evenly distributed along the axial direction.

[0019] A further improvement of the technical solution of the present invention is that the liquid fuel core assembly further includes a first inlet connector and a second inlet connector, the axes of the first inlet connector and the second inlet connector are arranged in an axially offset and axially symmetrical manner, and the included angle between the projections of the two axes in the plane perpendicular to the axis is 30-90°.

[0020] Beneficial effects

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. By using the liquid fuel circuit core-pulling structure design technology, the applicability of dual-fuel nozzles can be improved. Multiple design schemes can be matched with a small number of nozzles, providing a more convenient way for combustion chamber research and development. While ensuring the needs of test verification, the cost of test pieces is reduced, effectively improving the progress of dual-fuel nozzle design and development.

[0023] 2. This invention can also be applied to the matching of combustion chambers of gas turbines with different power levels and different operating parameters, providing the best low-emission dual-fuel combustion effect, and only the core component needs to be replaced during operation;

[0024] 3. The present invention addresses the fixation of liquid fuel core components by using two-sided fixing pins, which are characterized by high temperature resistance. Compared with threads, it can avoid the situation where threads will cause seizing failures and lead to disassembly difficulties due to long-term operation under high temperature conditions. It is especially suitable for a large number of commissioning tests during the combustion chamber commissioning stage. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the AA section in this invention;

[0027] Figure 3 This is a schematic diagram of the BB section in this invention;

[0028] Figure 4 This is an enlarged view of the K view in the BB view of this invention;

[0029] Figure 5 This is a schematic diagram of the CC section in this invention;

[0030] Figure 6 This is a schematic diagram of the liquid fuel core assembly in this invention.

[0031] In the picture:

[0032] 0. Gas fuel staged assembly; 1. Liquid fuel core assembly;

[0033] 2. Mounting cover; 3. Nozzle body; 4. Diverter; 5. Gas fuel mixing assembly; 6. First inner guide tube; 7. Second inner guide tube; 8. Third inner guide tube; 9. Sealing ring; 10. Fixing pin; 11. Fastener;

[0034] 1-1, First inlet connector; 1-2, Second inlet connector; 1-3, Core shell; 1-3a, Outer positioning boss; 1-3b, Collar ring; 1-3c, Center outlet; 1-3d, Outer ring outlet; 1-3e, End face of the boss inside the cavity; 1-4, Nozzle; 1-4a, Nozzle outlet; 1-5, Swirl generator; 1-6, Compression plug; 1-7, Sealing ring; 1-8, Compression nut; 1-A, First medium channel; 1-B, Second medium channel; 1-C, Cooling air annular cavity; 1-D, Positioning pin insertion blind hole; 1-E, First medium inlet; 1-F, Second medium inlet; 1-G, Third air inlet ring groove; 1-H, Fin groove;

[0035] 3-A, First channel of the body; 3-B, Second channel of the body; 3-C, Third channel of the body; 3-D, Fourth channel of the body; 3-E, Locating pin insertion hole; 3-F, Axial center hole; 3a, Center hole insertion positioning boss; 3b, Cover plate sleeve boss; 3c, Screw mounting hole;

[0036] 4. Flow divider; 4a. Flow divider ring wall; 4-C. Center hole; 4-A. Connecting hole; 4-B. Radial air inlet hole;

[0037] 5. Gas fuel blending assembly; 5-1. First air cyclone; 5-2. Second air cyclone; 5-3. Venturi tube; 5-4. Cup-shaped component; 5-5. Ring cap; 5-A. Air inlet cooling hole;

[0038] 9. Seal the ring;

[0039] M1, First annular cavity; M2, Second annular cavity; N1, First annular cavity; N2, Second annular cavity; P, High-temperature and high-pressure air cavity; Q, Combustion zone. Detailed Implementation

[0040] Various exemplary embodiments, features, and aspects of this application will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0041] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0042] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented without certain specific details. In some instances, methods, means, and elements well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.

[0043] Example 1: The present invention provides a low-emission dual-fuel nozzle with adjustable oil circuit, comprising a gas fuel staged assembly 0, a liquid fuel core assembly 1, a first inner guide tube 6, a second inner guide tube 7, a mounting cover plate 2, a fixing pin 10, and fasteners 11.

[0044] The gas fuel grading assembly 0 includes a nozzle body 3, a distributor 4, a third inner guide 8, a sealing ring 9, and a gas fuel blending assembly 5;

[0045] The nozzle body 3 is a shell structure with an axial central hole 3-F and four media channels;

[0046] The distributor 4 is a transition support structure with a central hole 4-C and a distributor ring wall 4a;

[0047] The nozzle body 3 and the distributor 4 are connected by welding after being inserted into the outer wall of the axial center hole 3-F to maintain coaxiality. They are then sealed by a sealing ring 9 after being connected to the outer ring, forming a first annular cavity M1 and a second annular cavity N1 for medium buffering and transition. These are respectively connected to the first gas fuel body channel 3-A and the second body channel 3-B of the nozzle body 3. The right side of the distributor 4 is connected to the inner center hole of the gas fuel mixing assembly 5 by insertion into the outer wall of the center hole 4-C and then welded axially to form a second annular cavity M2 for pressure stabilization. Its left end is connected to the first annular cavity M1 through the connecting hole 4-A of the distributor 4, and its right end is connected to the internal air inlet of the swirl blade of the first air swirler 5-1 of the gas fuel mixing assembly 5. The gas fuel mixing assembly 5 is provided with two second annular cavities N2, which are connected to the internal air inlet of the swirl blade of the second air swirler 5-2. Eight third inner guide tubes 8 are evenly distributed circumferentially. Figure 3 The liquid fuel core assembly 1 is located between the outer side of the sealing ring 9 and the gas fuel blending assembly 5, and is welded to its respective connecting holes, so that the two first annular cavities N1 and the two second annular cavities N2 are connected, ultimately forming an integrated gas fuel grading assembly 0; the liquid fuel core assembly 1 is connected to the gas fuel grading assembly 0 by plugging in, specifically, the liquid fuel core assembly 1 passes through the center holes of the nozzle body 3 and the distributor 4 in sequence and is inserted into the positioning boss 3a of the center hole on the left side of the nozzle body 3, and then is fixed by the fixing pin 10; the nozzle cover plate 2 is fixed by fastener 1. 1. Connected to the nozzle body 3, the nozzle body 3 has four medium inlets connected to four medium channels. Two of these channels pass through the nozzle body 3 and are connected to the first inner guide tube 6 and the second inner guide tube 7 via threaded tapered joints. These are then connected to the two inlet joints 1-1 and 1-2 of the liquid fuel core assembly 1, forming a detachable liquid fuel core assembly 1 dual-fuel low-emission nozzle structure for installation in gas turbines and related testing equipment. After installation, all structures except the mounting cover 2 are located within the high-temperature, high-pressure air chamber P. Example 2, as... Figure 1 and Figure 3As shown, the liquid fuel core assembly 1 is an independent structural component used for liquid fuel atomization. It comprises three media inlets (first media inlet 1-E, second media inlet 1-F, and third air intake ring groove 1-G, in sequence) and three media outlets (nozzle outlet 1-4a, center outlet 1-3c, and outer ring outlet 1-3d, in sequence). The specific structure includes a first inlet connector 1-1, a second inlet connector 1-2, a core shell 1-3, a nozzle 1-4, a cyclone separator 1-5, a clamping plug 1-6, a sealing ring 1-7, and a clamping nut 1-8. The core shell 1-3 is a shell structure with an external positioning boss 1-3a and an inner cavity. Two media inlets, the first media inlet 1-E and the second media inlet 1-F, are provided in the non-insertion portion, respectively welded to the first inlet connector 1-1 and the second inlet connector 1-2. Simultaneously, a third air intake ring groove 1-G and a finned channel 1-H are provided in the middle of the insertion portion of the core shell 1-3. Figure 1 , Figure 3 , Figure 4 To ensure head cooling and reliable operation; the nozzle 1-4 and cyclone separator 1-5 are sequentially inserted into the core shell 1-3 and then tightened sequentially using the clamping plug 1-6, sealing ring 1-7, and clamping nut 1-8, forming the first medium channel 1-A and the second medium channel 1-B. The first inlet connector 1-1, the first medium inlet 1-E, and the first medium channel 1-A are sequentially connected, and the medium is ejected from the outlet 1-4a of the nozzle 1-4, performing centrifugal cyclone atomization of the liquid fuel; the second inlet connector 1-2, the second medium inlet 1-F, and the second medium channel 1-B are sequentially connected, and the medium is ejected from the central outlet 1-3c of the core shell 1-3, which can perform centrifugal cyclone atomization of the liquid fuel, and can also assist in the centrifugal cyclone atomization of the liquid fuel by atomizing air; Figure 2 As shown, the core shell 1-3 is provided with positioning and insertion blind holes 1-D on both sides to cooperate with the fixing pins 10, for axial and circumferential fixation of the liquid fuel core assembly 1; 12 finned channels 1-H are evenly distributed circumferentially on the outer ring surface at the outlet end, and are positioned and welded together by the collar 1-3b to form a cooling air annular cavity 1-C, improving the uniformity of gas flow. The cooling air is ejected from the outer ring outlet 1-3d, effectively protecting the end of the liquid fuel core assembly 1; the entire assembly is effectively sealed by the compressed sealing ring 1-7, the nozzle 1-4 and the inner boss end face 1-3e of the core shell 1-3 cavity, preventing medium leakage and mutual flow between different channels. With the two fixing pins 10 removed, the liquid fuel core assembly 1 can move freely axially and rotate freely circumferentially within a certain range, ensuring smooth replacement of different core assemblies. After the liquid fuel core assembly 1 is installed, it will protrude from the end face of the distributor 4 by a length L. The present invention can use liquid fuel core assemblies 1 of different lengths L to match the entire set of dual-fuel low-emission nozzles to form the required solution.

[0048] Example 3, the first inlet connector 1-1 and the second inlet connector 1-2 can be configured according to... Figure 1 The arrangement shown is carried out so that the center axes of the two joints are in the same plane.

[0049] Preferably, the axes of the first inlet connector 1-1 and the second inlet connector 1-2 can be arranged according to... Figure 6 The arrangement shown features axial misalignment and circumferential symmetry. The angle α between the projections of the two axes in the plane perpendicular to the axis is (30-90°), ensuring a more compact overall structure and easier installation for the low-emission dual-fuel nozzle.

[0050] Example 4, as Figure 1 , Figure 2 and Figure 5 As shown, the nozzle body 3 is a shell structure with an axial central hole 3-F and a fuel channel, used to form a low-emission dual-fuel nozzle mounting support and to insert the liquid fuel core assembly 1. Specifically, it includes a first channel 3-A, a second channel 3-B, and a third channel 3-C. Figure 5 ) and the fourth channel 3-D of the main body ( Figure 5 The main body has a first channel 3-A for the first gaseous fuel flow and a second channel 3-B for the second gaseous fuel flow. These two channels work together to achieve low emissions from the gaseous fuel through fuel grading. The flow rate of the second gaseous fuel is greater than that of the first. The first gaseous fuel is used for startup and low-operation conditions, while the second gaseous fuel is used for high-operation conditions. The third channel 3-C is used for liquid fuel flow, and the fourth channel 3-D is used to assist in atomizing air or liquid fuel flow. Figure 2 As shown, a fixing pin 10 is provided on each side of the inlet end of the central hole, and is inserted into the through hole 3-E. The fixing pin 10 is installed with an interference fit to ensure a secure installation. Figure 1 As shown, the left end of the nozzle body 3 is provided with a cover plate 2 cover plate sleeve boss 3b and screw mounting hole 3c, which are used to fasten and seal with the cover plate 2 and thus to fix the overall nozzle structure to the combustion chamber casing or combustion test device.

[0051] like Figure 1 As shown, the flow divider 4 is a transitional support structure with a central hole 4-C and a flow divider ring wall 4a. It is mainly used to connect the nozzle body 3 and the gas fuel mixing assembly 5, forming staged independent gas fuel flow chambers, namely, one first annular chamber M1 and two first annular chambers N1; as shown... Figure 1 , Figure 3 and Figure 4As shown, M1 and M2 are connected by connecting holes 4-A. A preferred configuration of 4-A is that each pair of holes forms a group, for a total of 8 groups, evenly distributed circumferentially. This arrangement ensures that the airflow can pass smoothly while being distributed as evenly as possible, thus playing a role in rectifying and equalizing the flow. Furthermore, it avoids the increase in radial dimension caused by 8 groups of large individual holes, effectively reducing the radial space dimension and improving the overall compactness of the nozzle. Figure 3 and Figure 4 The distributor 4 is also provided with eight radial air inlets 4-B (the air inlet direction is shown by the centripetal arrow in the figure), which are evenly distributed circumferentially and staggered with the through holes 4-A. They are connected to the third air inlet ring groove 1-G of the liquid fuel core assembly, and in turn connect the high-temperature and high-pressure air chamber P of the combustion chamber with the cooling air ring chamber 1-C, so as to achieve effective cooling and purging of the head of the liquid fuel core assembly 1. Figure 1 (Center arrow direction) to reduce carbon buildup and adhesion, effectively protecting the medium outlet end of the liquid fuel core assembly 1.

[0052] like Figure 1 As shown, the gaseous fuel blending assembly 5 mainly includes a first air cyclone 5-1, a second air cyclone 5-2, a venturi tube 5-3, a cup-shaped component 5-4, and an annular cover 5-5. The overall arrangement is a two-stage radially graded structure. The cyclone blades of the first air cyclone 5-1 and the second air cyclone 5-2 are designed with a cavity structure, featuring air inlets and small gaseous fuel injection holes on the blade surface. This allows for effective and uniform mixing of the gaseous fuel with the swirling air in a transverse jet manner, facilitating low-emission combustion. Inlet annular channels M2 and N2 are provided in the inlet channels of the two-stage cyclone blades to ensure stable fuel flow and further enhance distribution uniformity. Sixteen circumferentially distributed cooling inlets 5-A are provided around the venturi tube 5-3, flowing out from the two-stage annular gaps to form a wall-adhering gas film for cooling protection. After two-stage radial premixing, the gaseous fuel and air flow out through the corresponding premixing channels and finally enter the combustion zone Q in the combustion chamber, forming a low-temperature flame to achieve the low-emission target. Figure 1 As shown, the sealing ring 9 is a thin-walled short tubular structure with eight through holes evenly distributed circumferentially on the tube wall for connecting the third inner guide tube 8; the mounting cover plate 2 is used for positioning and mounting the entire nozzle, and is provided with fastener 11 positioning and mounting holes. The first inner guide tube 6 and the second inner guide tube 7 are both bent tube structures with connecting nuts and sealing ball heads at both ends, which can achieve quick assembly and disassembly.

[0053] The liquid fuel core assembly 1 can use media including but not limited to liquid fuels such as diesel and kerosene, while the gaseous fuel blending assembly 5 can use media including but not limited to gaseous fuels such as natural gas and hydrogen. The first inner conduit 6 and the second inner conduit 7 can simultaneously supply liquid fuel, enabling phased supply of liquid fuel according to operating conditions; alternatively, the first inner conduit 6 can supply liquid fuel, while the second inner conduit can supply auxiliary atomizing air to assist in droplet breakage of the liquid fuel under various operating conditions, enhance atomization and rapid evaporation combustion, and improve combustion efficiency; the phased supply of gaseous or liquid fuel and other media can be matched according to the specific scheme of the liquid fuel core assembly.

[0054] In summary, when different scheme tests are required, the following operations can be performed: Remove the fasteners 11 between the low-emission dual-fuel nozzle mounting cover 2 and the mounting casing (or combustion chamber test device housing, etc.), so that the low-emission dual-fuel nozzle is detached from the mounting casing (or combustion chamber test device housing, etc.), at which point the dual-fuel nozzle is in an independent state. After fixing the low-emission dual-fuel nozzle with relevant clamps, loosen the fastening nuts at both ends of the first inner guide tube 6 and the second inner guide tube 7, so that the first inner guide tube 6 and the second inner guide tube 7 are disconnected from the threaded joints of the third channel 3-C and the fourth channel 3-D of the nozzle body 3, as well as the first inlet joint 1-1 and the second inlet joint 1-2 of the liquid fuel core assembly 1. At this point, the liquid fuel core assembly is in an independent state without any connecting pipe connected to it. Based on this, after removing the fixing pins 10 from both sides of the low-emission dual-fuel nozzle, the liquid fuel core assembly 1 can be removed, that is, the liquid fuel core assembly 1 is pulled out from the axial center hole of the nozzle body 3, realizing the "core removal" function. After the liquid fuel core assembly is removed, when different liquid fuel core assemblies 1 (with adjustable length, atomization cone angle, swirl intensity, and auxiliary atomizing air matching, etc.) need to be installed, the liquid fuel core assembly can be replaced by following the reverse process described above. This achieves different overall low-emission dual-fuel nozzle schemes, including the replacement of the liquid fuel core assembly 1. For example, as... Figure 1 As shown, when liquid fuel core components of different lengths L are replaced, the atomization effect of the liquid fuel can be adjusted, and the injection cross-sectional size H of the gaseous fuel can be adjusted to improve the mixing effect of gaseous fuel and air.

[0055] Preferably, the liquid fuel core assembly 1 in this invention can be used to supply gaseous fuel separately, so that the entire dual-fuel nozzle is supplied with gaseous fuel through multiple stages to match the different operating conditions of the combustion chamber and the gas turbine.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An oil circuit adjustable low emission dual fuel nozzle comprising a gas fuel staging assembly, a first inner conduit, a second inner conduit, and a mounting cover plate, characterized in that: The gas fuel staging assembly is plugged with a liquid fuel core assembly, and the gas fuel staging assembly is composed of a nozzle body, a flow divider, a third inner conduit, a sealing ring and a gas fuel mixing assembly; The liquid fuel core assembly further comprises a core shell and an inlet joint, the core shell is a shell structure with an outer positioning boss and an inner cavity, and two fixed pin plug-in blind holes for plugging and fixing pins are arranged on the core shell; The liquid fuel core assembly passes through the center hole of the nozzle body and the flow divider in sequence and abuts against the center plug-in positioning boss on one side of the nozzle body, and the liquid fuel core assembly is fixed with the nozzle body through the fixed pins. The nozzle body is a shell structure provided with an axial center hole, four medium inlets and four medium channels, four medium inlets are connected with four medium channels, and two of the medium channels are provided with threaded taper joints at one end of the nozzle body, and are connected with the first inner conduit and the second inner conduit respectively, and two of the medium channels are connected with two inlet joints of the liquid fuel core assembly respectively and form a high-temperature and high-pressure air cavity. The gas fuel mixing assembly is provided with a second ring cavity, and the second ring cavity is provided with a second air swirler on one side, the second ring cavity is communicated with the internal air inlet hole of the swirler blade of the second air swirler, the third inner conduit is axially distributed between the outer side of the sealing ring and the gas fuel mixing assembly, and the first ring cavity is communicated with the second ring cavity through the third inner conduit. The flow divider is a transition support structure provided with a center hole and a flow divider wall. The nozzle body is coaxially plugged through the outer wall of the axial center hole and then welded with the flow divider, and the nozzle body is connected with the outer ring through the sealing ring to form a first ring cavity and a second ring cavity for medium buffer transition, and the nozzle body and the flow divider are communicated with the first channel and the second channel of the nozzle body respectively. The right side of the flow divider is connected to the inner center hole of the gas fuel mixing assembly through the center hole outer wall plug-in mode and is axially close, and then is welded to form a second ring cavity for pressure stabilization, the left end is communicated with the first ring cavity through the communication hole of the flow divider, and the right end is communicated with the internal air inlet hole of the swirler blade of the first air swirler of the gas fuel mixing assembly. The gas fuel mixing assembly comprises a first air swirler, a second air swirler, a venturi, a cup-shaped part and a ring cover, and is arranged as a two-stage radial staging structure, wherein the swirler blades of the first air swirler and the second air swirler are designed as a hollow structure, are provided with an air inlet hole, and are provided with a gas fuel injection small hole on the surface of the blade.

2. An oil circuit adjustable low emission dual fuel nozzle as claimed in claim 1, wherein, The flow divider further comprises the following specific settings: The flow divider is provided with eight communication holes and eight radial air inlet holes, and the eight communication holes are axially distributed, and the eight communication holes and the eight radial air inlet holes are distributed in staggered positions.

3. An oil circuit adjustable low emission dual fuel nozzle as claimed in claim 1, wherein: The first inner conduit and the second inner conduit are arranged inside the high-temperature and high-pressure air cavity.

4. An oil circuit adjustable low emission dual fuel nozzle as claimed in claim 1, wherein, The third inner conduit further comprises the following specific settings: The number of the third inner conduit is N, and 4≤N≤8, and the third inner conduit is axially distributed.

5. An oil circuit adjustable low emission dual fuel nozzle as claimed in claim 1, wherein, The liquid fuel core assembly further comprises a first inlet joint and a second inlet joint, axes of the first and second inlet joints being arranged in axial misalignment and axial symmetry, the angle between the projections of the two axes in a plane perpendicular to the axes being 30-90°.

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