A partially premixed fuel injector with adjustable fuel regulation range and its application

Abstract

This invention discloses a partially premixed combined nozzle with adjustable fuel adjustment range and its application. The nozzle includes a nozzle body with a dual-path, single-chamber, single-orifice design and an air-path swirl atomizing assembly. The air-path swirl atomizing assembly includes an air annular cavity and air swirl components disposed on the sidewall of the air annular cavity. The air swirl components rotate in the same direction as the main fuel path swirl components and the auxiliary fuel path swirl components. At low fuel supply pressure, the air-path swirl atomizing assembly is activated, and air and fuel rotate in the same direction within the air annular cavity, achieving partial premixing and atomization to form a stable spray cone angle. At high fuel supply pressure, the air path pressure is increased, and the fuel entering the air annular cavity achieves partial premixing under the action of air, increasing the spray cone angle. This invention can meet the requirements of good atomization performance, suitable atomization cone angle, and wide fuel adjustment range under different operating conditions and fuel supply pressures. It can also improve fuel-air premixing, reduce nozzle outlet temperature, and improve combustion efficiency.

Description

Technical Field

[0001] This invention relates to a liquid fuel nozzle structure, and more particularly to a partially premixed combined nozzle with adjustable fuel adjustment range and its application. Background Technology

[0002] With increasing environmental protection requirements, high efficiency and low emissions have become the goals pursued by gas turbines. Besides meeting these requirements, gas turbines also need to further improve thrust-to-weight ratio, reduce fuel consumption, and broaden stable operating boundaries. The three core components of a gas turbine are the compressor, combustion chamber, and turbine. As one of these three core components, the performance of the combustion chamber is crucial. During gas turbine operation, the nozzle is the smallest and most important working unit controlling fuel injection and atomization. They play a decisive role in fuel evaporation and mixing and directly affect the engine's ignition, combustion, and emission performance. To ensure complete contact between the atomized liquid droplets and air, improving combustion efficiency, the nozzle's atomization performance must be reliable and stable. Therefore, nozzle design is one of the key technologies in gas turbine performance design.

[0003] Centrifugal nozzles, as a type of pressure atomizing nozzle, possess advantages such as stable mechanical properties, simple structure, good atomization effect, and low energy consumption. Therefore, centrifugal nozzles are widely used in gas turbine combustion chambers. However, single-path centrifugal nozzles struggle to meet the dual requirements of good atomization performance and a wide fuel adjustment range under low fuel supply pressure, and are gradually being replaced by dual-path centrifugal nozzles. Dual-path single-chamber single-nozzle pressure atomizing nozzles offer simpler structure and a wider fuel adjustment range compared to dual-path dual-chamber single-nozzle and dual-path dual-chamber dual-nozzle structures. The fuel adjustment range of dual-path single-chamber single-nozzle pressure atomizing nozzles can reach 1:20-30, meeting the wide fuel adjustment range requirements of gas turbines. However, regardless of the type of centrifugal nozzle, they all exhibit poor atomization effect at low fuel supply pressure and a smaller spray cone angle and longer spray distance under high pressure. This affects the fuel distribution in the main combustion zone under different operating conditions, increases smoke and flame radiation, and deteriorates the quality of the combustion chamber outlet temperature field. Summary of the Invention

[0004] Purpose of the invention: The present invention aims to provide a partially premixed combined nozzle that can provide good atomization performance and a suitable atomization cone angle over an ultra-wide fuel adjustment range, as well as the application of the nozzle.

[0005] Technical Solution: The present invention discloses a partially premixed combined nozzle with adjustable fuel adjustment range, comprising a nozzle body with dual-path single-chamber single-nozzle and an air path swirl atomizing assembly. The air path swirl atomizing assembly is located below the fuel nozzle of the nozzle body and includes an air annular cavity and an air swirl component disposed on the side wall of the air annular cavity. The air swirl component rotates in the same direction as the main fuel path swirl component and the auxiliary fuel path swirl component of the nozzle body. At low fuel supply pressure, the air path swirl atomizing assembly is opened, and air and fuel rotate in the same direction in the air annular cavity, achieving partial premixing and atomization, forming a stable spray cone angle at the nozzle outlet of the nozzle body. At high fuel supply pressure, the air path pressure is increased, and the fuel entering the air annular cavity achieves partial premixing under the action of air, increasing the spray cone angle. Throughout the entire working range of the nozzle, due to the air annular cavity set at the fuel inlet of the nozzle, the air and fuel rotate coaxially in the air annular cavity, and the rotational momentum of the fuel and gas interacts. On the one hand, the aerodynamic force promotes fuel atomization, and on the other hand, it realizes the local premixing of air and fuel. The premixed fuel and gas enter the combustion chamber with the fuel spray, thereby improving the combustion efficiency of the combustion chamber.

[0006] Preferably, the main oil circuit swirl component and the auxiliary oil circuit swirl component are arranged concentrically and coaxially.

[0007] Preferably, the nozzle body further includes a main fuel flow channel, a secondary fuel flow channel, and a swirling chamber, wherein the swirling chamber is located below the main fuel flow channel and the secondary fuel flow channel.

[0008] Preferably, the main fuel flow channel and the auxiliary fuel flow channel are arranged concentrically and coaxially, with the auxiliary fuel flow channel located outside the main fuel flow channel. When the main and auxiliary fuel lines are open, the rotational momentum of the main fuel and the auxiliary fuel interacts, which can ensure good atomization performance at high flow rates.

[0009] Preferably, the main oil circuit swirling component is located at the top of the swirling chamber, and the auxiliary oil circuit swirling component is located around the upper side of the swirling chamber.

[0010] Preferably, the main oil passage swirl component is in the shape of a rectangular spiral groove, and the auxiliary oil passage swirl component is in the shape of a tangential hole.

[0011] Preferably, the swirling intensity of the auxiliary oil circuit swirling component is greater than that of the main oil circuit swirling component.

[0012] Preferably, the nozzle body of the dual-path single-chamber single-nozzle system and the air path swirl atomization component are designed as an integrated unit.

[0013] The combustion chamber of the present invention includes the aforementioned partially premixed combined nozzle with adjustable fuel adjustment range.

[0014] The present invention provides a gas turbine comprising the combustion chamber described above.

[0015] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: 1. Without requiring shutdown or nozzle switching, the ultra-wide fuel adjustment range from ignition to basic stable operation of the gas turbine can be met simply by adjusting the fuel supply pressure of the main and auxiliary oil circuits and the pressure of the auxiliary atomizing air; 2. Combined with the air-path swirl atomization component, partial premixing of fuel can be achieved, allowing for wide-range adjustment of flow rate and atomization angle while ensuring atomization quality; the design of the auxiliary air circuit and air annular cavity improves the atomization quality of the centrifugal nozzle, widens the lower and upper limits of the centrifugal nozzle's working range, and makes the fuel nozzle more efficient and less polluting during gas turbine operation; 3. While protecting the nozzle from high temperatures, it also effectively prevents the nozzle from being clogged by carbon deposits; 4. The dual-path single-chamber single-nozzle centrifugal nozzle and the air-path swirl atomization component are integrated into a single design, eliminating the need for assembly and resulting in a compact structure; it can be directly installed on the main combustion chamber of aero engines, afterburner combustion chambers, and combustion chambers of various types of gas turbines in other industrial devices, making it flexible for various scenarios. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 The diagram shows the main and auxiliary oil circuit swirling components of the present invention; (a) is the structure of the main oil circuit swirling component, (b) is the structure of the auxiliary oil circuit swirling component, and (c) is a top view of the main and auxiliary oil circuit swirling component structures.

[0018] Figure 3 This is a schematic diagram of the air swirl component structure of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0020] like Figure 1 As shown, the present invention provides a partially premixed combined nozzle with adjustable fuel adjustment range, which adopts a centrifugal nozzle body with dual-path single-chamber single-nozzle design and an air path swirl atomization component integrated design. The nozzle body includes a main oil path swirl atomization component, a secondary oil path swirl atomization component, a swirl chamber 7 and a fuel nozzle 8.

[0021] The main oil circuit swirl atomizing assembly includes a main oil circuit connector 1, a main fuel flow channel 3, and a main oil circuit swirl component 5. The main oil circuit connector 1 is connected to the main fuel flow channel 3. The main oil circuit swirl component 5 is a rectangular spiral groove located at the top of the swirl chamber 7. Figure 2As shown in (a). The auxiliary oil circuit swirl atomizing assembly includes an auxiliary oil circuit connector 2, an auxiliary fuel flow channel 4, and an auxiliary oil circuit swirl component 6. The auxiliary oil circuit connector 2 is connected to the auxiliary fuel flow channel 4. The swirl intensity of the auxiliary oil circuit swirl component 6 is greater than that of the main oil circuit swirl component 5. It is located around the upper side of the swirl chamber 7 and is in the form of tangential holes. Preferably, the auxiliary oil circuit swirl component has tangential openings on the upper side wall of the swirl chamber, such as... Figure 2 As shown in (b). The main fuel flow channel 3 and the auxiliary fuel flow channel 4 are concentrically and coaxially arranged, with the auxiliary fuel flow channel located outside the main fuel flow channel; the main fuel circuit swirl component 5 and the auxiliary fuel circuit swirl component 6 are concentrically and coaxially arranged, and their rotation directions are the same. When the main and auxiliary fuel circuits are open, the rotational momentum of the main fuel and the auxiliary fuel interacts, ensuring good atomization performance at high flow rates, such as... Figure 2 As shown. The swirl chamber 7 is located below the main fuel flow channel 3 and the auxiliary fuel flow channel 4, and the fuel nozzle 8 is located below the swirl chamber 7, and the fuel nozzle 8 is connected to the air annular cavity 12.

[0022] The air path swirl atomizing assembly includes an air connector 9, an air channel 10, an air annular cavity 12, and an air swirl component 11. The air swirl component 11 is disposed around the side wall of the air annular cavity 12. Preferably, the air swirl component 11 has tangential openings on the wall of the air annular cavity. The air connector 9 is connected to the air channel, and a nozzle outlet 13 is provided below the air annular cavity 12. Fuel from the main and auxiliary fuel channels is injected from the fuel nozzle 8 and partially premixed with the auxiliary atomizing air of the air annular cavity 12 before being injected from the nozzle outlet 13 below. The air swirl component 11 rotates in the same direction as the main fuel path swirl component 5 and the auxiliary fuel path swirl component 6. Figure 3 As shown.

[0023] The combustion chamber of the present invention includes the aforementioned partially premixed combined nozzle with adjustable fuel adjustment range.

[0024] The gas turbine described in this invention can be any power device that requires combustion and heat release, including the combustion chamber described above.

[0025] The working principle of this invention is as follows: Under low operating conditions, the auxiliary fuel circuit supplies fuel independently. The auxiliary fuel circuit swirl component 6 is a strong swirl component. At this time, due to the lower fuel flow rate and higher swirl intensity of the auxiliary fuel circuit, a larger spray cone angle can be formed, satisfying stable ignition conditions. Under high operating conditions, the main and auxiliary fuel circuits are opened simultaneously. The main fuel circuit swirl component 5 is a weak swirl component, which can increase the fuel flow rate while reducing the atomization cone angle, avoiding the risk of excessive penetration and excessively large fuel mist cone angle leading to a wet combustion chamber under high flow rates. The main and auxiliary fuel circuits rotate in the same direction in the same swirl chamber and are ejected from the same nozzle. Due to the higher fuel flow rate and lower swirl intensity of the main fuel circuit, and the lower fuel flow rate and higher swirl intensity of the auxiliary fuel circuit, the fuel in the main and auxiliary fuel circuits rotates in the same direction in the same swirl chamber. The rotational momentum of the two fuel circuits interacts, which can increase the nozzle outlet flow rate while reducing the spray cone angle while ensuring atomization quality, thus meeting the operating conditions of the gas turbine under high operating conditions.

[0026] When the fuel supply pressure of the nozzle is low, the fuel sprayed from the fuel nozzle 8 cannot form a stable atomization cone angle. At this time, the air path swirl atomization component is opened, and air enters the air annular cavity 12 through the air path connector 9 and the air flow channel 10, rotating in the same direction as the fuel. Under the action of the auxiliary atomizing air, the fuel achieves partial premixing and pneumatic atomization, which can make the fuel form a stable spray cone angle at the nozzle outlet, thereby improving the atomization quality of the nozzle, making combustion more complete, and reducing nitrogen oxides and other polluting gases produced during combustion. When the fuel supply pressure of the nozzle is high, the spray cone angle becomes smaller and the spray distance becomes longer, affecting the fuel distribution in the main combustion zone, increasing smoke and flame radiation, and also deteriorating the quality of the temperature field at the combustion chamber outlet. At this time, the air pressure is increased simultaneously, which can make the broken fuel partially premixed in the air annular cavity and increase the spray cone angle under the action of air, thereby improving the problem of low combustion chamber efficiency of centrifugal nozzles under high operating conditions. The air ring chamber design allows cold air to rotate in the same direction as the fuel in the air ring chamber, which has a certain cooling effect on the nozzle outlet area. The rotating low-temperature air can protect the fuel nozzle from high temperature and at the same time effectively prevent the nozzle from being blocked by carbon deposits.

Claims

1. A partially premixed combined nozzle with adjustable fuel adjustment range, characterized in that, The nozzle body includes a dual-path, single-chamber, single-nozzle nozzle and an air-path swirl atomizing assembly. The nozzle body further includes a main fuel flow channel (3), a secondary fuel flow channel (4), and a swirl chamber (7), with the swirl chamber (7) located below the main fuel flow channel (3) and the secondary fuel flow channel (4). The air-path swirl atomizing assembly is located below the fuel nozzle (8) of the nozzle body and includes an air flow channel (10), an air annular cavity (12), and an air swirl component (11) located on the side wall of the air annular cavity. The air swirl component (11) interacts with the main fuel flow channel of the nozzle body. The flow component (5) and the auxiliary oil circuit swirl component (6) rotate in the same direction; the nozzle body of the dual-path single-chamber single-nozzle and the air circuit swirl atomization component are designed as an integrated unit; when the fuel supply pressure is low, the air circuit swirl atomization component is opened, and the air and fuel rotate in the same direction in the air ring cavity (12) to achieve local premixing and atomization, forming a stable spray cone angle at the nozzle outlet (13) of the nozzle body; when the fuel supply pressure is high, the air circuit pressure is increased, and the fuel entering the air ring cavity (12) is partially premixed under the action of air and the spray cone angle is increased.

2. The locally premixed combined nozzle with adjustable fuel adjustment range according to claim 1, characterized in that, The main oil circuit swirl component (5) and the auxiliary oil circuit swirl component (6) are arranged concentrically and coaxially.

3. The locally premixed combined nozzle with adjustable fuel adjustment range according to claim 1, characterized in that, The main fuel flow channel (3) and the auxiliary fuel flow channel (4) are arranged concentrically and coaxially, with the auxiliary fuel flow channel located outside the main fuel flow channel.

4. The locally premixed combined nozzle with adjustable fuel adjustment range according to claim 1, characterized in that, The main oil circuit swirling component (5) is located at the top of the swirling chamber (7), and the auxiliary oil circuit swirling component (6) is located around the upper side of the swirling chamber (7).

5. The locally premixed combined nozzle with adjustable fuel adjustment range according to claim 4, characterized in that, The main oil circuit swirl component (5) is rectangular spiral groove, and the auxiliary oil circuit swirl component (6) is tangential hole.

6. The locally premixed combined nozzle with adjustable fuel adjustment range according to claim 5, characterized in that, The swirling intensity of the auxiliary oil circuit swirling component (6) is greater than that of the main oil circuit swirling component (5).

7. A combustion chamber, characterized in that, Includes the partially premixed combination nozzle with adjustable fuel adjustment range as described in any one of claims 1-6.

8. A gas turbine, characterized in that, Includes the combustion chamber as described in claim 7.

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