A fuel nozzle

Abstract

The present invention relates to the technical field of aircraft engines and discloses a fuel nozzle. By arranging a pressure differential valve in a secondary fuel channel of the fuel nozzle, the pressure differential valve can be fully opened according to the improvement of the working state of the aircraft engine, so that part of the fuel in the secondary fuel channel flows through the second secondary fuel pipeline and is ejected from the second oil outlet, thereby realizing secondary oil replenishment and ensuring that the oil supply pressures of the first secondary fuel pipeline and the second secondary fuel pipeline are equivalent, and the fuel nozzle can be well adapted to the same-ring rich-oil nozzle; in addition, when the fuel nozzle of the invention is used in combination with the rich-oil nozzle, it is only necessary to reasonably match the main-stage flow numbers of the two types of nozzles and ensure that the sum of the flow numbers of the first secondary fuel pipeline and the second secondary fuel pipeline of the fuel nozzle of the invention is equal to the flow number of the secondary fuel channel of the rich-oil nozzle, so as to meet the requirement that the secondary-stage flow characteristics of the fuel nozzle and the rich-oil nozzle are equivalent, effectively improve the uniformity of the main- and secondary-stage flow distribution of the entire ring, and improve the temperature distribution at the combustion chamber outlet.

Description

Technical Field

[0001] The invention relates to the technical field of aviation engines and discloses a fuel nozzle. Background Art

[0002] To improve ignition and flameout performance in traditional manifold combustors, fuel nozzles are typically configured in two ways: a single-stage, secondary-stage, fuel-rich nozzle and a dual-stage, secondary-stage, standard nozzle. The secondary-stage flow rate of a standard nozzle is lower than the single-stage flow rate of a rich nozzle. This improves fuel atomization quality under localized fuel enrichment and low-operating conditions, thereby widening the combustion chamber's ignition and flameout margins.

[0003] Because the number of individual secondary stages of a rich nozzle is greater than that of a standard nozzle, under low-power conditions, only the standard nozzle's secondary stage first circuit and the rich nozzle's secondary stage are active. This results in a higher fuel volume near the rich nozzle, improving ignition and flameout performance and facilitating localized fuel enrichment in the combustion chamber. However, under high-power conditions, to ensure proper temperature distribution and uniform flow throughout the entire annular manifold, the fuel flow in the standard nozzle's secondary stage first circuit remains lower than that of the rich nozzle's secondary stage. Furthermore, the deviation in the secondary stage fuel flow characteristics increases as engine performance improves. To ensure proper combustion chamber outlet temperature distribution, the standard nozzle's secondary stage second circuit is used to supplement fuel to the secondary stage, ensuring that the secondary stage equivalence ratio of the standard nozzle is comparable to that of the rich nozzle. Usually, without changing the structure of the combustion chamber main pipe, whether the secondary oil circuit is formed by directly drawing oil from the main stage or by setting a traditional valve structure in the main stage fuel channel or the secondary stage fuel channel, the fuel supply characteristics of the secondary oil circuit will be inconsistent with those of the secondary oil circuit. As a result, at most the secondary stage flow characteristics of the general nozzle and the oil-rich nozzle under a certain operating condition will be equivalent, while the secondary stages of the nozzles under other operating conditions will still have deviations, affecting the quality of the combustion chamber outlet temperature field. Summary of the Invention

[0004] The present invention aims to provide a fuel nozzle that can achieve secondary-stage fuel replenishment according to the improvement of the operating state of the aircraft engine, and can ensure that the fuel supply pressure (fuel supply pattern) of the first secondary-stage fuel pipeline and the second secondary-stage fuel pipeline are equivalent, and can be well adapted to the same-annular rich-fuel nozzle.

[0005] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0006] A fuel nozzle, comprising:

[0007] a nozzle housing, wherein a primary fuel passage and a secondary fuel passage are disposed within the nozzle housing; a primary fuel outlet and a secondary fuel nozzle are disposed at an outlet end of the nozzle housing; the secondary fuel nozzle includes a first oil outlet and a second oil outlet; the primary fuel outlet is connected to the primary fuel passage; and the first oil outlet is connected to the secondary fuel passage via a first secondary fuel pipeline;

[0008] A pressure differential valve is fixedly installed in the secondary fuel channel. The pressure differential valve includes a valve housing. A second secondary fuel pipeline is provided on the side wall of the valve housing. The outlet end of the second secondary fuel pipeline is connected to the second oil outlet hole. A pressure differential opening and closing valve body is also provided in the inner cavity of the valve housing. The pressure differential opening and closing valve body is used to open and close the inlet end of the second secondary fuel pipeline.

[0009] Furthermore, an oil passage is provided on the pressure differential opening and closing valve body, the inlet end of the oil passage is connected to the secondary fuel passage, and the outlet end of the oil passage is connected to the main fuel outlet through the third secondary fuel pipeline.

[0010] Furthermore, the valve housing is a cylindrical structure, and a sleeve is fixed to the inner cavity of the valve housing axially along the valve housing. The pressure differential opening and closing valve body is arranged in the sleeve and can move axially along the sleeve. A limiting component for limiting the pressure differential opening and closing valve body in the sleeve is also provided in the sleeve. A spring is provided between the pressure differential opening and closing valve body and the limiting component. The spring is used to adjust the relative position of the pressure differential opening and closing valve body and the inlet end of the second secondary fuel pipeline under the action of the pressure difference.

[0011] Furthermore, the pressure differential opening and closing valve body includes a first throttle plate, a second throttle plate and a third throttle plate fixedly connected in sequence along the axial direction of the sleeve, the first throttle plate is located near the inlet end of the secondary fuel channel, and a first oil hole is provided on the first throttle plate, a first annular groove communicating with the first oil hole is provided on the second throttle plate, and a second oil hole is provided on the second throttle plate at a position corresponding to the bottom of the first annular groove; a second annular groove is provided on the third throttle plate, and a third oil hole is provided on the third throttle plate at a position corresponding to the second annular groove; the first oil hole, the first annular groove, the second oil hole, the second annular groove and the third oil hole together form the oil channel.

[0012] Furthermore, the second oil hole and the first oil hole are staggered, and the second oil hole and the third oil hole are staggered.

[0013] Furthermore, the limit assembly includes a limit ring and a limit boss fixed in the sleeve, a plunger is coaxially fixed on the pressure differential opening and closing valve body, the plunger is movably arranged in the sleeve, and a limit block is provided at the end of the plunger away from the pressure differential opening and closing valve body, and the limit block is located between the limit ring and the limit boss.

[0014] Furthermore, the limiting ring, the limiting block and the limiting boss are all provided with channels for fuel flow, and the channels on the limiting block are a plurality of multi-slanted holes.

[0015] Furthermore, the limiting ring is arranged along the axial direction of the sleeve, and the outer wall of the plunger contacts the inner wall of the limiting ring, so as to enable the pressure differential opening and closing valve body to move along the axial direction of the sleeve.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention fully opens the pressure differential valve as the aircraft engine's operating state improves, allowing some fuel in the secondary fuel passage to flow through the second secondary fuel line and be ejected from the second oil outlet, achieving secondary fuel replenishment. It also ensures that the fuel supply pressure (fuel supply pattern) in the first and second secondary fuel lines remains the same, making it well-suited for use with the same-annular rich-fuel nozzle.

[0018] 2. When the fuel nozzle of the present invention is used in conjunction with a rich-fuel nozzle, the fuel nozzle and the rich-fuel nozzle can achieve equivalent secondary-stage flow characteristics simply by properly matching the primary-stage flow rates of the two nozzle types and ensuring that the sum of the primary- and secondary-stage fuel pipeline flow rates of the fuel nozzle of the present invention is equal to the secondary-stage fuel channel flow rate of the rich-fuel nozzle. This effectively improves the uniformity of the primary- and secondary-stage flow distribution throughout the entire ring and the combustion chamber outlet temperature distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the fuel nozzle structure in the embodiment;

[0020] Figure 2 Schematic diagram of the installation of the pressure differential valve in the secondary fuel channel in the embodiment;

[0021] Figure 3 Schematic diagram of the structure of the pressure differential opening and closing valve body in the embodiment;

[0022] Among them, 1. nozzle housing; 2. primary fuel channel; 3. secondary fuel channel; 4. primary fuel outlet; 5. first oil outlet; 6. second oil outlet; 7. first secondary fuel pipeline; 8. differential pressure valve; 801. valve housing; 802. second secondary fuel pipeline; 803. differential pressure opening and closing valve body; 8031. first throttle plate; 8032. second throttle plate; 8033. third throttle plate; 8034. first oil hole; 8035. first annular groove; 8036. second oil hole; 8037. second annular groove; 8038. third oil hole; 804. sleeve; 805. spring; 806. limit ring; 807. limit boss; 808. plunger; 809. limit block; 9. third secondary fuel pipeline; 10. multiple inclined holes. DETAILED DESCRIPTION

[0023] The present invention will be described in further detail below with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments, as all technologies implemented based on the present invention fall within the scope of the present invention.

[0024] Example

[0025] See also Figure 1-Figure 3 , a fuel nozzle, comprising:

[0026] A fuel nozzle, comprising:

[0027] A nozzle housing 1 is provided with a primary fuel passage 2 and a secondary fuel passage 3. A primary fuel outlet 4 and a secondary fuel nozzle are provided at the outlet end of the nozzle housing 1. The secondary fuel nozzle includes a first oil outlet 5 and a second oil outlet 6. The primary fuel outlet 4 communicates with the primary fuel passage 2. The first oil outlet 5 communicates with the secondary fuel passage 3 via a first secondary fuel line 7.

[0028] The pressure differential valve 8 is fixedly installed in the secondary fuel channel 3. The pressure differential valve 8 includes a valve housing 801. The side wall of the valve housing 801 is provided with a second secondary fuel pipeline 802, and the outlet end of the second secondary fuel pipeline 802 is connected to the second oil outlet hole 6; the inner cavity of the valve housing 801 is also provided with a pressure differential opening and closing valve body 803, and the pressure differential opening and closing valve body 803 is used to open and close the inlet end of the second secondary fuel pipeline 802.

[0029] In this embodiment, during low-power operation, only the secondary fuel channel 3 receives fuel. As the engine power increases, the primary fuel channel 2 begins supplying fuel, with both the primary and secondary fuel channels 2 and 3 supplying fuel simultaneously. Because a pressure differential valve 8 is provided within the secondary fuel channel 3 of the fuel nozzle, when the engine is operating at low power, the pressure differential across the secondary fuel channel 3 is minimal, and the second secondary fuel line 802 is closed. Fuel within the secondary fuel channel 3 flows through the gap between the pressure differential valve 8 and the nozzle housing 1, enters the first secondary fuel line 7, and is ejected from the first oil outlet 5. As the operating state of the aircraft engine improves, the main-stage fuel channel 2 and the secondary-stage fuel channel 3 are supplied with oil at the same time. The pressure differential opening and closing valve body 803 of the pressure differential valve 8 begins to move under the action of the fuel pressure differential, causing the pressure differential valve 8 to be fully opened. At this time, part of the fuel in the secondary-stage fuel channel 3 flows through the second secondary-stage fuel pipeline 802 and is ejected from the second oil outlet 6 to realize secondary-stage oil replenishment; and after the valve is fully opened, the oil supply pressure (oil supply pattern) of the first secondary-stage fuel pipeline 7 and the second secondary-stage fuel pipeline 802 are equivalent, which can be well adapted to the same-annular rich-oil nozzle.

[0030] When the fuel nozzle in this embodiment is used in combination with the rich oil nozzle, it is only necessary to reasonably match the main-stage flow rates of the two types of nozzles and ensure that the sum of the flow rates of the first-secondary fuel pipeline 7 and the second-secondary fuel pipeline 802 of the fuel nozzle in this embodiment is equal to the flow rate of the secondary-stage fuel channel of the rich oil nozzle. This can ensure that the secondary-stage flow characteristics of the fuel nozzle and the rich oil nozzle are equivalent, effectively improve the uniformity of the main-secondary flow distribution throughout the ring, improve the temperature distribution at the combustion chamber outlet, and lay the foundation for widening the combustion chamber point, flameout boundary, and improving engine performance and service life.

[0031] In this embodiment, to ensure the proper functioning of the differential pressure valve 8, an oil passage is provided in the differential pressure on-off valve body 803. The inlet of the oil passage communicates with the secondary fuel passage 3, and the outlet of the oil passage connects to the primary fuel outlet 4 via the third secondary fuel line 9. A portion of the fuel in the secondary fuel passage 3 passes through the oil passage and the third secondary fuel line 9 and is ejected from the primary fuel outlet 4, thereby enabling the differential pressure valve to divert fuel and replenish the primary fuel.

[0032] In this embodiment, the valve housing 801 is a cylindrical structure. A sleeve 804 is fixed axially along the inner cavity of the valve housing 801. The pressure differential opening and closing valve body 803 is disposed within the sleeve 804 and is movable axially along the sleeve 804. A limit assembly is also disposed within the sleeve 804 to confine the pressure differential opening and closing valve body 803 within the sleeve 804. A spring 805 is disposed between the pressure differential opening and closing valve body 803 and the limit assembly. The spring 805 is used to adjust the relative position of the pressure differential opening and closing valve body 803 and the inlet end of the second secondary fuel line 802 under the action of a pressure differential. It should be noted that this embodiment illustrates one structural form of the pressure differential valve 8. Other pressure differential valve 8 structures that can utilize a pressure differential to open the second fuel line are also applicable to the present invention.

[0033] In this embodiment, the pressure differential opening and closing valve body 803 includes a first throttle plate 8031, a second throttle plate 8032 and a third throttle plate 8033 which are fixedly connected in sequence along the axial direction of the sleeve 804. The first throttle plate 8031 ​​is located near the inlet end of the secondary fuel channel 3, and the first throttle plate 8031 ​​is provided with a first oil hole 8034, the second throttle plate 8032 is provided with a first annular groove 8035 which is connected to the first oil hole 8034, and the second throttle plate 8033 is provided with a first annular groove 8036 which is connected to the first oil hole 8036. 032 A second oil hole 8036 is provided at a position corresponding to the bottom of the first annular groove 8035; a second annular groove 8037 is provided on the third throttle plate 8033, and a third oil hole 8038 is provided on the third throttle plate 8033 at a position corresponding to the second annular groove 8037; the first oil hole 8034, the first annular groove 8035, the second oil hole 8036, the second annular groove 8037 and the third oil hole 8038 together form the oil passage. When the fuel nozzle is operating, a portion of the fuel in the secondary fuel channel 3 flows through the first oil hole 8034 of the first throttle plate 8031, sequentially through the first annular groove 8035, the second oil hole 8036, the second annular groove 8037, and the third oil hole 8038, before entering the valve. During this process, the fuel experiences cumulative energy losses along the way. At this point, the upper surface of the first throttle plate 8031 ​​is subjected to the secondary fuel supply pressure, while the lower surface of the third throttle plate 8033 is subjected to the secondary fuel pressure after the losses. This results in a valve pressure differential between the upper and lower surfaces of the first and third throttle plates 8031 ​​and 8033. As the secondary fuel supply pressure increases, the flow losses generated by the fuel flowing through the throttle plates increase, and the valve pressure differential increases. When the force generated by the valve pressure differential exceeds the preload of spring 805, the pressure differential on-off valve body 803 moves downward, and fuel begins to flow into the second secondary fuel line 802.

[0034] In this embodiment, the second oil hole 8036 is staggered with the first oil hole 8034, and the second oil hole 8036 is staggered with the third oil hole 8038. This further enhances the throttling effect between the first throttle plate 8031, the second throttle plate 8032, and the third throttle plate 8033, ensuring the proper formation of a pressure differential across the pressure differential valve 8. This reduces fuel flow losses across the pressure differential valve, increasing the fuel pressure differential between the upstream of the first throttle plate 8031 ​​and the downstream of the third throttle plate 8033, and ensuring that the pressure differential on-off valve body 803 can rapidly move downward at the designed secondary pressure. The arrangement, number, and diameter of the throttle holes, as well as the number of throttle plates in this embodiment, can be adjusted based on actual conditions. For example, if rapid downward movement of the plunger is desired under low operating conditions, given a given preload, the number of throttle plates can be increased, the diameter of the oil holes reduced, the number of holes reduced, and the plates staggered as much as possible. If slow downward movement of the plunger is desired under high operating conditions, the opposite approach is employed.

[0035] In this embodiment, the limiting assembly includes a limiting ring 806 and a limiting boss 807 fixed within the sleeve 804. A plunger 808 is coaxially fixed to the pressure differential on-off valve body 803. The plunger 808 is movably disposed within the sleeve 804. A limiting block 809 is provided at the end of the plunger 808 away from the pressure differential on-off valve body 803. The limiting block 809 is located between the limiting ring 806 and the limiting boss 807. The limiting ring 806 is disposed axially along the sleeve 804, and the outer wall of the plunger 808 contacts the inner wall of the limiting ring 806, thereby enabling the pressure differential on-off valve body 803 to move axially along the sleeve 804. In this embodiment, the relative position relationship between the limiting ring 806, the limiting boss 807 and the plunger 808 can play a dual role of limiting and guiding, which can not only prevent the spring 805 from being in a strong compression state for a long time and improve the service life of the spring 805, but also ensure the normal operation of the pressure differential opening and closing valve body 803, and limit the maximum movement of the pressure differential opening and closing valve body 803. For example, this embodiment can control the pressure differential valve 8 to be fully opened when the limiting block 809 moves to abut the limiting boss 807.

[0036] In this embodiment, the limiting ring 806, the limiting block 809, and the limiting boss 807 are all provided with channels for fuel flow, and the channels on the limiting block 809 are multiple multi-slanted holes 10. This ensures that the fuel in the third secondary fuel channel 3 can be properly collected at the primary fuel outlet 4. The multiple multi-slanted holes 10 also serve to straighten the fuel flow in the oil passage, avoiding flow turbulence, reducing unnecessary flow losses, and improving fuel supply stability.

[0037] It should be noted that the opening time of the pressure differential valve 8 in this embodiment can be achieved by adjusting the stiffness of the spring 805 and the opening of the throttle plate to adapt to the use requirements of different types of combustion chambers.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fuel nozzle, characterized in that: include: A nozzle housing (1) is provided with a primary fuel channel (2) and a secondary fuel channel (3) in the nozzle housing (1); a primary fuel outlet (4) and a secondary fuel nozzle are provided at the outlet end of the nozzle housing (1); the secondary fuel nozzle comprises a first oil outlet hole (5) and a second oil outlet hole (6); the primary fuel outlet hole (4) is connected to the primary fuel channel (2); the first oil outlet hole (5) is connected to the secondary fuel channel (3) via a first secondary fuel pipeline (7); A pressure differential valve (8) is fixedly installed in the secondary fuel channel (3). The pressure differential valve (8) includes a valve housing (801). A second secondary fuel pipeline (802) is provided on the side wall of the valve housing (801). The outlet end of the second secondary fuel pipeline (802) is connected to the second oil outlet hole (6). A pressure differential opening and closing valve body (803) is also provided in the inner cavity of the valve housing (801). The pressure differential opening and closing valve body (803) is used to open the inlet end of the second secondary fuel pipeline (802). and closing; an oil passage is provided on the pressure differential opening and closing valve body (803); the inlet end of the oil passage is communicated with the secondary fuel passage (3); the outlet end of the oil passage is communicated with the primary fuel outlet (4) via the third secondary fuel pipeline (9); the valve housing (801) is a cylindrical structure; a sleeve (804) is fixed to the inner cavity of the valve housing (801) along the axial direction of the valve housing (801); the pressure differential opening and closing valve body (803) is arranged in the sleeve (804) and can move axially along the sleeve (804); the pressure differential opening and closing valve body (803) is provided in the sleeve (804) and can move axially along the sleeve (804); The differential opening and closing valve body (803) comprises a first throttle plate (8031), a second throttle plate (8032) and a third throttle plate (8033) which are fixedly connected in sequence along the axial direction of the sleeve (804), wherein the first throttle plate (8031) is located near the inlet end of the secondary fuel channel (3), and the first throttle plate (8031) is provided with a first oil hole (8034), and the second throttle plate (8032) is provided with a first annular groove (8035) which is connected to the first oil hole (8034), and the second throttle plate (8032) is provided with a first annular groove (8035) which is connected to the first oil hole (8034). A second oil passage hole (8036) is provided at a position corresponding to the bottom of the first annular groove (8035); a second annular groove (8037) is provided on the third throttle plate (8033), and a third oil passage hole (8038) is provided on the third throttle plate (8033) at a position corresponding to the second annular groove (8037); the first oil passage hole (8034), the first annular groove (8035), the second oil passage hole (8036), the second annular groove (8037) and the third oil passage hole (8038) together form the oil passage channel.

2. The fuel nozzle according to claim 1, characterized in that A limit assembly for limiting the pressure differential opening and closing valve body (803) within the sleeve (804) is further provided in the sleeve (804). A spring (805) is provided between the pressure differential opening and closing valve body (803) and the limit assembly. The spring (805) is used to adjust the relative position of the pressure differential opening and closing valve body (803) and the inlet end of the second secondary fuel pipeline (802) under the action of the pressure difference.

3. The fuel nozzle according to claim 1, characterized in that The second oil passage hole (8036) and the first oil passage hole (8034) are staggered, and the second oil passage hole (8036) and the third oil passage hole (8038) are staggered.

4. The fuel nozzle according to claim 2, characterized in that The limiting assembly includes a limiting ring (806) and a limiting boss (807) fixed in the sleeve (804); a plunger (808) is coaxially fixed on the pressure differential opening and closing valve body (803); the plunger (808) is movably arranged in the sleeve (804); a limiting block (809) is provided at one end of the plunger (808) away from the pressure differential opening and closing valve body (803); the limiting block (809) is located between the limiting ring (806) and the limiting boss (807).

5. The fuel nozzle according to claim 4, characterized in that The limiting ring (806), the limiting block (809) and the limiting boss (807) are all provided with channels for fuel flow, and the channels on the limiting block (809) are a plurality of multi-slanted holes (10).

6. The fuel injection nozzle according to claim 5, characterized in that The limiting ring (806) is arranged axially along the sleeve (804), and the outer wall of the plunger (808) contacts the inner wall of the limiting ring (806), so as to enable the pressure differential opening and closing valve body (803) to move axially along the sleeve (804).

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