Small-flow fuel nozzle capable of changing direction of auxiliary atomized air

Abstract

The invention provides a small-flow fuel nozzle with a variable auxiliary atomized air direction, and belongs to the technical field of gas turbines. The adjustable air cap is internally provided with the tapered flow channel, so that the relative position of the adjustable air cap and the nozzle shell can be changed by rotating the adjustable air cap, the spraying direction of the auxiliary atomizing air is changed, the auxiliary atomizing air is matched with atomizing characteristic parameters such as a spraying cone angle, and the auxiliary atomizing air acts on the spray at a vertical angle all the time. The nozzle comprises a nozzle base and a nozzle shell, a fuel inlet is formed in the top of the nozzle base, a fuel nozzle is formed in the bottom of the nozzle shell, a fuel rectifier and a flow guide column are coaxially installed in the nozzle shell, an air channel inlet is formed in the outer side wall of the nozzle shell, and the air channel inlet communicates with an air channel groove; the air channel groove is communicated to the air collection cavity through an air channel outlet; a fuel oil cavity inlet is formed in the outer side wall of the fuel oil rectifier, and a fuel oil cavity is formed between the outer wall of the fuel oil rectifier and the inner wall of the nozzle shell.

Description

Technical Field

[0001] This invention relates to a low-flow fuel nozzle with variable auxiliary atomizing air direction, specifically belonging to the field of gas turbine technology. Background Technology

[0002] The combustion chamber is one of the three core components of power equipment such as gas turbines. Fuel nozzles are often used as the core component of combustion organization within the combustion chamber. When the nozzle is working, fuel is atomized and injected into the combustion chamber through the nozzle under high pressure, mixes with air, and then ignites to achieve combustion. Centrifugal nozzles are widely used in power equipment such as gas turbines due to their advantages such as stable mechanical properties, simple structure, good atomization effect, and low energy consumption. However, for centrifugal nozzles operating under high viscosity fuel or low oil pressure, their atomization performance drops sharply. Air atomizing nozzles, on the other hand, use auxiliary atomizing air to impact the liquid film at a certain angle, thereby accelerating the fluctuation and breakup of the liquid film, which can effectively improve the atomization quality and produce a wider spray coverage. Publication number "CN103967671A" discloses a dual-valve variable orifice area fuel nozzle, comprising a push rod, a sleeve valve spring, an adapter seat, a needle valve spring, a sleeve valve, a nozzle body, and a needle valve. The nozzle body houses the sleeve valve and needle valve for controlling orifice opening; the sleeve valve is housed within the nozzle body, and the needle valve is housed within the sleeve valve. The nozzle body has a secondary orifice and a primary orifice. The sleeve valve controls the opening and closing of the secondary orifice, and the needle valve controls the opening and closing of the primary orifice. This dual-valve variable orifice area fuel nozzle can be applied to fuel supply systems composed of inline injection pumps or unit pumps. By controlling the orifice area through the pump's fuel supply pressure, it ultimately achieves a slow-to-fast or stepped injection pattern and improves fuel atomization at low injection pressures. The variable orifice area can also be achieved through changes in fuel pressure. However, some gas turbines have a wide range of operating conditions, often requiring adjustments to the fuel supply pressure of the nozzle to meet the varying fuel supply requirements under different operating conditions. This leads to changes in atomization characteristic parameters such as the spray cone angle. At the same time, the injection angle of the auxiliary atomizing air has a significant impact on the velocity and pressure distribution of the gas and liquid phases in the internal and external flow fields, thus greatly affecting the atomization characteristics of the spray. If the injection angle of the auxiliary atomizing air remains constant and does not match the atomization characteristic parameters such as the spray cone angle, the most ideal atomization effect cannot be achieved. Therefore, it is essential to develop a fuel nozzle with variable auxiliary atomizing air direction. Summary of the Invention

[0003] The purpose of this invention is to provide a low-flow fuel nozzle with variable auxiliary atomizing air direction, so as to optimize the atomization characteristics of the centrifugal nozzle through auxiliary atomizing air, realize the real-time adjustment of the auxiliary atomizing air injection direction, and improve the adaptability of the air atomizing nozzle.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: The invention includes a nozzle base and a nozzle housing, the nozzle base and the nozzle housing are connected together, the top of the nozzle base is provided with a fuel inlet and the bottom of the nozzle housing is provided with a fuel nozzle, a fuel rectifier and a guide column are coaxially installed inside the nozzle housing, and the top of the fuel rectifier is connected to the bottom of the nozzle base, and the bottom of the fuel rectifier is connected to the top of the guide column. An air channel inlet is provided on the outer wall of the nozzle housing. The air channel inlet is connected to an air channel groove, and the air channel groove is connected to the air collection chamber through an air channel outlet. A fuel inlet is provided on the outer wall of the fuel rectifier. A fuel chamber is formed between the outer wall of the fuel rectifier and the inner wall of the nozzle housing. One end of the fuel inlet is connected to the inside of the fuel rectifier, and the other end of the fuel inlet is connected to the fuel chamber. A swirl groove is provided at the bottom of the guide column. The swirl groove is connected to the fuel swirl chamber, and a fuel annular slit channel is formed between the outer wall of the guide column and the inner wall of the nozzle housing.

[0005] Furthermore, by integrating the adjustable air cap mechanism and the convex spherical guide column, dynamic matching of atomization parameters is achieved within a single nozzle, resolving the long-standing technical contradiction in the field of small flow rate variable operating conditions.

[0006] A gasket and a sealing ring are provided at the connection between the nozzle base and the nozzle housing; Furthermore, this design ensures a sealed connection between the nozzle base and the nozzle housing, reducing the air leakage rate. An adjustable air cap is coaxially arranged on the outside of the nozzle housing, and an air collecting chamber is formed between the inner wall of the adjustable air cap and the outer wall of the nozzle housing; an auxiliary atomizing air outlet is formed between the outer wall of the fuel injection port and the inner wall of the adjustable air cap. Furthermore, the axial displacement of the adjustable air cap is adjusted by means of a threaded connection, thereby changing the injection angle of the auxiliary atomizing air outlet and matching the spray cone angle under varying operating conditions.

[0007] There are 20 air passage inlets evenly arranged at equal angles on the outer wall of the nozzle housing, and 3 fuel inlets evenly arranged at equal angles on the outer wall of the fuel rectifier. Furthermore, by arranging the airflow at equal angles, the non-uniformity of the circumferential airflow is reduced.

[0008] The air passage inlet, air passage groove, air passage outlet, air collection chamber and auxiliary air outlet inside the nozzle housing are connected in sequence; the fuel inlet, fuel chamber, fuel annular groove, swirl groove and fuel swirl chamber inside the fuel rectifier are connected in sequence. Furthermore, this enables multi-channel air confluence.

[0009] The beneficial effects of this invention are: 1. By using a tapered flow channel inside the adjustable air cap, rotating the adjustable air cap can change the relative position between the adjustable air cap and the nozzle housing, thereby changing the injection direction of the auxiliary atomizing air. This matches the atomization characteristic parameters such as the spray cone angle, ensuring that the auxiliary atomizing air always acts on the spray at a vertical angle, increasing the Weber number, and achieving the optimal atomization effect.

[0010] 2. By designing the guide column head as a convex spherical structure, the convex spherical structure and the conical structure of the nozzle shell are matched, which is more conducive to determining the center position, improving processing accuracy, and reducing processing difficulty. Except for the swirl groove, there is no gap between the guide column head and the nozzle shell, which helps atomization. Grooving the convex spherical head of the guide column simplifies processing and makes it easier to improve the uniformity of circumferential spray.

[0011] 3. The convex spherical structure of the guide column head, matched with the fuel swirl chamber, results in a smaller fuel swirl chamber volume, higher fuel flow velocity, and shorter residence time, which helps reduce coking. Attached Figure Description

[0012] Figure 1 This is a three-dimensional structural diagram of the fuel nozzle of the present invention; Figure 2 This is a schematic cross-sectional view of the fuel nozzle structure of the present invention; Figure 3 This is a three-dimensional structural diagram of the nozzle housing of the present invention; Figure 4 This is a schematic cross-sectional view of the nozzle housing structure of the present invention; Figure 5 This is a three-dimensional structural schematic diagram of the fuel rectifier of the present invention; Figure 6 This is a schematic diagram of the three-dimensional structure of the guide column of the present invention.

[0013] 1. Nozzle base; 1-1. Fuel inlet; 2. Gasket; 3. Sealing ring; 4. Nozzle housing; 4-1. Air passage inlet; 4-2. Air passage groove; 4-3. Air passage outlet; 4-4. Fuel swirl chamber; 4-5. Fuel nozzle; 5. Fuel rectifier; 5-1. Fuel inlet; 6. Fuel chamber; 7. Guide column; 7-1. Swirl groove; 8. Fuel annular seam channel; 9. Adjustable air cap; 10. Air collection chamber; 11. Auxiliary atomizing air outlet. Detailed Implementation

[0014] The following will be combined with the appendix Figure 1-6 The technical solutions in the embodiments are described clearly and completely.

[0015] Specific implementation method one: as follows Figure 1-2As shown, the nozzle assembly consists of a nozzle base 1 and a nozzle housing 4. The nozzle base 1 and the nozzle housing 4 are connected together, and a gasket 2 and a sealing ring 3 are provided at the connection between the nozzle base 1 and the nozzle housing 4 to ensure a sealed connection. The top of the nozzle base 1 has a fuel inlet 1-1. A fuel rectifier 5 and a guide column 7 are coaxially mounted inside the nozzle housing 4. The top end of the fuel rectifier 5 is connected to the bottom end of the nozzle base 1, and the bottom end of the fuel rectifier 5 is connected to the top end of the guide column 7. The head of the guide column 7 has a convex spherical structure, and the bottom of the inner side of the nozzle housing 4 has a conical structure. The convex spherical structure of the guide column 7 and the conical structure of the nozzle housing 4 are matched and configured to match each other. The outer wall of the fuel rectifier 5 has a fuel inlet 5-1, such as Figure 5 As shown, three fuel inlets 5-1 are evenly arranged at equal angles on the outer wall of the fuel rectifier 5. A fuel chamber 6 is formed between the outer wall of the fuel rectifier 5 and the inner wall of the nozzle housing 4. One end of the fuel inlet 5-1 communicates with the interior of the fuel rectifier 5, and the other end of the fuel inlet 5-1 communicates with the fuel chamber 6. A swirl groove 7-1 is provided at the bottom of the guide column 7, such as... Figure 6 As shown, the swirl channel 7-1 is connected to the fuel swirl chamber 4-4, and a fuel annular channel 8 is formed between the outer wall of the guide column 7 and the inner wall of the nozzle housing 4. A fuel nozzle 4-5 is provided at the bottom of the nozzle housing 4. The fuel inlet 5-1, fuel chamber 6, fuel annular channel 8, swirl channel 7-1, fuel swirl chamber 4-4 and fuel nozzle 4-5 in the fuel rectifier 5 are sequentially connected. Fuel enters the fuel rectifier 5 from the fuel inlet 1-1 of the nozzle base 1; it enters the fuel chamber 6 through three circumferentially distributed fuel inlets 5-1, forms a liquid film through the fuel annular seam channel 8, enters the fuel swirl chamber 4-4 tangentially through the swirl groove 7-1, and is finally sprayed out from the fuel nozzle 4-5, thus forming a fuel passage. Specific implementation method two: such as Figure 3-4 As shown, an air channel inlet 4-1 is provided on the outer wall of the nozzle housing 4. There are 20 air channel inlets 4-1 evenly arranged at equal angles on the outer wall of the nozzle housing 4. The air channel inlets 4-1 are connected to the air channel slots 4-2. The air channel slots 4-2 are connected to the air collection chamber 10 through the air channel outlets 4-3. The air channel inlets 4-1, air channel slots 4-2, air channel outlets 4-3, air collection chamber 10 and auxiliary air outlet 11 in the nozzle housing 4 are connected in sequence. High-pressure air enters the gradually narrowing air channel slot 4-2 from 20 air channel inlets 4-1, enters the air collection chamber 10 through the air channel outlet 4-3, and is ejected at high speed from the annular auxiliary air outlet 11. An adjustable air cap 9 is coaxially provided on the outside of the nozzle housing 4, and the adjustable air cap 9 is connected to the nozzle housing 4 by a thread. An air collecting chamber 10 is formed between the inner wall of the adjustable air cap 9 and the outer wall of the nozzle housing 4. An auxiliary atomizing air outlet 11 is formed between the outer wall of the fuel injection port 4-5 and the inner wall of the adjustable air cap 9. The adjustable air cap 9 is threadedly connected to the nozzle housing 4. Rotating the air cap 9 can change the relative position of its converging flow channel and the housing 4, thereby adjusting the air injection direction. After the auxiliary air is accelerated through the converging channel, it impacts the liquid film vertically from the annular outlet 11 at an adjustable angle. When the air cap 9 is rotated under low operating conditions, the air injection angle is increased to match the small cone angle spray, thereby achieving dynamic matching of atomization characteristic parameters, overcoming the industry bottleneck of unstable fuel atomization under varying operating conditions, and breaking through the fixed angle limitation of traditional air-assisted nozzles. Working process: Fuel enters the device through the fuel inlet 1-1 at the top of the nozzle base 1. The fuel flows through the three fuel inlets 5-1 of the fuel rectifier 5 to achieve uniform circumferential distribution of the fuel. The fuel can achieve pressure equalization in the fuel chamber 6. The fuel forms a liquid film through the fuel annular channel 8, so that the fuel is injected tangentially into the swirl chamber 4-4 through the swirl groove 7-1. The fuel rotates in the swirl chamber 4-4 and is sprayed out as atomized particles from the nozzle 4-5. High-pressure air enters the tapered air channel slot 4-2 from 20 air channel inlets 4-1, causing the airflow to accelerate and vertically impact the liquid film. The airflow flows from the air channel outlet 4-3 into the air collection chamber 10 for temporary pressure equalization. The adjustable air cap 9 is rotated to change its relative position with the nozzle housing 4, and the spray angle of the auxiliary atomizing air outlet 11 can be adjusted in real time to ensure that the liquid film can be vertically impacted.

[0016] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A low-flow fuel nozzle with variable auxiliary atomizing air direction, characterized in that, It includes a nozzle base (1) and a nozzle housing (4). The nozzle base (1) and the nozzle housing (4) are connected together. The top of the nozzle base (1) is provided with a fuel inlet (1-1), and the bottom of the nozzle housing (4) is provided with a fuel nozzle (4-5). A fuel rectifier (5) and a guide column (7) are coaxially installed inside the nozzle housing (4). The top of the fuel rectifier (5) is connected to the bottom of the nozzle base (1), and the bottom of the fuel rectifier (5) is connected to the top of the guide column (7). An air passage inlet (4-1) is provided on the outer wall of the nozzle housing (4). The air passage inlet (4-1) is connected to an air passage groove (4-2). The air passage groove (4-2) is connected to the air collection chamber (10) through an air passage outlet (4-3). A fuel inlet (5-1) is provided on the outer wall of the fuel rectifier (5). A fuel chamber (6) is formed between the outer wall of the fuel rectifier (5) and the inner wall of the nozzle housing (4). One end of the fuel inlet (5-1) is connected to the inside of the fuel rectifier (5), and the other end of the fuel inlet (5-1) is connected to the fuel chamber (6). A swirl groove (7-1) is provided at the bottom of the guide column (7). The swirl groove (7-1) is connected to the fuel swirl chamber (4-4), and a fuel annular groove channel (8) is formed between the outer wall of the guide column (7) and the inner wall of the nozzle housing (4).

2. A low-flow fuel nozzle with variable auxiliary atomizing air direction according to claim 1, characterized in that, A gasket (2) and a sealing ring (3) are provided at the connection between the nozzle base (1) and the nozzle housing (4) to make the nozzle base (1) and the nozzle housing (4) sealed together.

3. A low-flow fuel nozzle with variable auxiliary atomizing air direction according to claim 1, characterized in that, An adjustable air cap (9) is coaxially provided on the outside of the nozzle housing (4), and the adjustable air cap (9) and (4) are connected together by threads. An air collecting chamber (10) is formed between the inner wall of the adjustable air cap (9) and the outer wall of the nozzle housing (4).

4. A low-flow fuel nozzle with variable auxiliary atomizing air direction according to claim 1, characterized in that, An auxiliary atomizing air outlet (11) is formed between the outer wall of the fuel injector (4-5) and the inner wall of the adjustable air cap (9).

5. A low-flow fuel nozzle with variable auxiliary atomizing air direction according to claim 1, characterized in that, There are 20 air passage inlets (4-1) evenly arranged at equal angles on the outer wall of the nozzle housing (4), and 3 fuel inlets (5-1) evenly arranged at equal angles on the outer wall of the fuel rectifier (5).

6. A low-flow fuel nozzle with variable auxiliary atomizing air direction according to claim 1, characterized in that, The air passage inlet (4-1), air passage groove (4-2), air passage outlet (4-3), air collection chamber (10) and auxiliary air outlet (11) in the nozzle housing (4) are connected in sequence to form a gradually narrowing flow channel. The fuel inlet (5-1), fuel chamber (6), fuel annular seam channel (8), swirl groove (7-1), fuel swirl chamber (4-4) and fuel nozzle (4-5) in the fuel rectifier (5) are connected in sequence.

7. A low-flow fuel nozzle with variable auxiliary atomizing air direction according to claim 1, characterized in that, The head of the guide column (7) is spherical, and the bottom of the inner side of the nozzle housing (4) is conical. The spherical structure of the guide column (7) and the conical structure of the nozzle housing (4) are matched.

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