Fuel delivery assembly

Abstract

A fuel delivery assembly for providing fuel to an auxiliary power plant of an aircraft, comprising: a fuel module for providing fuel to other components of the fuel delivery assembly; a plurality of fuel nozzles that inject fuel from the fuel module; and a fuel line connecting the fuel module and the plurality of fuel nozzles, including a main fuel line and an auxiliary fuel line disposed in parallel with each other. Wherein the fuel delivery assembly further includes a one-way valve in the secondary fuel line positioned such that a length along the secondary fuel line from the fuel module is greater than a length along the secondary fuel line from the fuel nozzle. The fuel conveying assembly ensures that a certain amount of fuel exists in the auxiliary fuel pipeline all the time, and the situation that starting of the auxiliary power device fails due to the fact that fuel pressure and flow in the main fuel pipeline are reduced at the moment when the auxiliary fuel pipeline is started is avoided.

Description

Technical Field

[0001] The utility model relates to the field of fuel flow control, in particular to a fuel delivery assembly which is used to supply fuel to an auxiliary power unit of a civil aircraft. Background Art

[0002] For civil aircraft, an auxiliary power unit (APU) is often installed at the tail of the aircraft. The APU is generally a small gas turbine engine, which is used to provide the aircraft with compressed air, electricity and other resources before takeoff to reduce the aircraft's dependence on airport equipment; provide emergency energy for the aircraft during flight to prevent the aircraft from being disabled when the main engine or its power generation device fails; and provide auxiliary energy for the aircraft when landing.

[0003] A fuel delivery assembly including a main fuel line and an auxiliary fuel line is used to supply fuel to the APU, specifically to the fuel nozzle of the APU, which then atomizes and sprays the fuel so that it is mixed with air and then burned. Specifically, a fuel distribution valve is provided at a position in the auxiliary fuel line connected to the fuel supply portion. In the initial stage of the APU startup, the fuel distribution valve is closed, and only the main fuel line supplies fuel. When the fuel supply pressure reaches the opening pressure of the fuel distribution valve, the fuel distribution valve opens, so that the main fuel line and the auxiliary fuel line supply fuel at the same time. However, since there is no fuel in the auxiliary fuel line, when the fuel distribution valve is opened to supply fuel to the auxiliary fuel line, it takes a certain amount of time for the fuel to fill the auxiliary fuel line, thereby establishing fuel pressure. In this way, the fuel pressure in the main fuel line will drop instantly because the fuel is distributed more to the auxiliary fuel line at the moment when the fuel distribution valve is opened, resulting in a decrease in the flow rate in the main fuel line. This will reduce the atomization effect of the fuel nozzle on the fuel, which may cause the APU to stall and fail to start.

[0004] Therefore, there is a need to provide an improved fuel delivery assembly that can solve the above-mentioned problems and defects in the prior art. Utility Model Content

[0005] The utility model aims to provide a fuel delivery assembly, which can control the auxiliary fuel main control of the auxiliary fuel line in the fuel pipeline to always keep fuel. In this way, the liquid pressure of the main fuel line fluctuates less when the auxiliary fuel line is activated, which can improve the starting reliability of the auxiliary power unit.

[0006] According to the utility model, a fuel delivery assembly is proposed, which is used to provide fuel for the auxiliary power unit of an aircraft, and includes: a fuel module, which is used to provide fuel for other components of the fuel delivery assembly; a plurality of fuel nozzles, which spray fuel from the fuel module; a fuel pipeline, which connects the fuel module and the plurality of fuel nozzles, including a main fuel pipeline and an auxiliary fuel pipeline arranged in parallel with each other. Among them, the fuel delivery assembly also includes a one-way valve, which is located in the auxiliary fuel pipeline and is positioned so that the length along the auxiliary fuel pipeline from the fuel module is greater than the length along the auxiliary fuel pipeline from the fuel nozzle. In this way, before the auxiliary fuel pipeline is enabled to deliver fuel to the fuel nozzle, a certain amount of fuel must exist in the portion between the one-way valve and the fuel module in the auxiliary fuel pipeline. Since the length of the section between the one-way valve and the fuel module of the auxiliary fuel pipeline is greater than the length between the one-way valve and the fuel nozzle, in other words, there is a certain amount of fuel in most sections of the auxiliary fuel pipeline. Therefore, only a small amount of fuel is needed to normally activate the auxiliary fuel pipeline without significantly affecting the fuel pressure and flow in the main fuel pipeline and thus affecting the APU start-up.

[0007] According to one aspect of the present disclosure, the fuel delivery assembly further includes a fuel distribution valve in the auxiliary fuel line positioned proximate to the fuel module.

[0008] According to one aspect of the present disclosure, the auxiliary fuel line includes an auxiliary fuel manifold and a plurality of auxiliary fuel manifolds coupled to the auxiliary fuel manifold, one end of the auxiliary fuel manifold is connected to the fuel module, the other end of the auxiliary fuel manifold is connected to the plurality of auxiliary fuel manifolds, each of the plurality of auxiliary fuel manifolds is connected to a corresponding one of the plurality of fuel nozzles.

[0009] According to one aspect of the present disclosure, a one-way valve is disposed in the auxiliary fuel manifold near a position where the auxiliary fuel manifold is combined with a plurality of auxiliary fuel branch pipes; and a fuel distribution valve is disposed on the one end of the auxiliary fuel manifold near the fuel module.

[0010] According to one aspect of the present disclosure, the one-way valve is a spring mechanical valve or a solenoid valve; and the fuel distribution valve is a spring mechanical valve or a solenoid valve.

[0011] In a preferred embodiment of the present disclosure, both the one-way valve and the fuel dispensing valve are spring mechanical valves, wherein the activation pressure of the one-way valve is higher than that of the fuel dispensing valve. In another alternative embodiment, both the one-way valve and the fuel dispensing valve are solenoid valves, wherein the one-way valve is controlled to be activated or shut down simultaneously with the fuel dispensing valve; or the one-way valve is controlled to be shut down before the fuel dispensing valve is shut down, and not to be activated before the fuel dispensing valve is activated.

[0012] According to one aspect of the present disclosure, the one-way valve and the fuel distribution valve are controlled to be activated after the fuel reaches the fuel nozzle via the main fuel line.

[0013] According to one aspect of the present disclosure, the main fuel pipeline includes a main fuel main pipe and multiple main fuel manifolds coupled to the main fuel main pipe, one end of the main fuel main pipe is connected to the fuel module, and the other end of the main fuel main pipe is connected to the multiple main fuel manifolds, each of the multiple main fuel manifolds is connected to a corresponding one of the multiple fuel nozzles.

[0014] According to one aspect of the present disclosure, a plurality of fuel nozzles are arranged in an annular array to atomize and inject fuel. However, it is also conceivable in alternative embodiments to arrange a plurality of fuel nozzles in a circular or other array to facilitate atomization and injection of fuel.

[0015] The utility model sets a one-way valve at a position close to the auxiliary fuel manifold in the auxiliary fuel main pipe. And when there is a fuel distribution valve located close to the fuel module in the auxiliary fuel main pipe, the one-way valve is set to be closed no later than the fuel distribution valve and started no earlier than the fuel distribution valve. When the APU stops, the one-way valve is closed so that the fuel in the auxiliary fuel manifold flows out of the fuel pipeline through the fuel nozzle, but the fuel between the one-way valve and the fuel distribution valve in the auxiliary fuel main pipe is intercepted by the one-way valve and cannot flow out of the fuel pipeline through the fuel nozzle; at the same time, since the pressure in the fuel module is always higher than the pressure in the fuel pipeline, these fuels will not flow back to the fuel module in a short time. In this way, when the fuel distribution valve is closed, a certain amount of fuel will remain in the section between the one-way valve and the fuel distribution valve in the auxiliary fuel main pipe. When the APU is started again and the auxiliary fuel line is enabled, the fuel distribution valve is started. Since a certain amount of fuel remains in the auxiliary fuel line, a large amount of fuel will not flow into the auxiliary fuel line instantly, thereby preventing the pressure and flow in the main fuel line from dropping significantly and causing APU start-up failure, thereby improving the APU start-up reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a more complete understanding of the present disclosure, reference may be made to the following description of exemplary embodiments considered in conjunction with the accompanying drawings. The accompanying drawings are not intended to limit the present disclosure to the specific embodiments depicted therein and are not necessarily to scale. In the drawings:

[0017] Figure 1 It is a schematic diagram of a fuel delivery assembly according to a preferred embodiment of the utility model.

[0018] Reference numerals list

[0019] 100 Fuel delivery assembly

[0020] 1 Fuel module

[0021] 2 Fuel lines

[0022] 21 Main fuel line

[0023] 211 Main fuel manifold

[0024] 212 Main fuel manifold

[0025] 22 Auxiliary fuel line

[0026] 221 Auxiliary fuel main

[0027] 222 Auxiliary fuel manifold

[0028] 3 Fuel Nozzles

[0029] 4 Check valve

[0030] 5 Fuel distribution valve

[0031] 6 Gas collecting chamber

[0032] 7 Combustion Chamber

[0033] 8 Exhaust case

[0034] X Binding Position

[0035] A. The central axis of the auxiliary power unit

[0036] l1 Distance from one-way valve to fuel module

[0037] l2 Distance from check valve to fuel nozzle DETAILED DESCRIPTION

[0038] The following description of the present invention for specific embodiments refers to the accompanying drawings, which show specific embodiments in which the present invention can be practiced. The embodiments are intended to fully describe the various aspects of the present invention in detail so that those skilled in the art can implement the present invention. Other embodiments may be utilized and may be changed without departing from the scope of the present invention. Therefore, the following description of specific embodiments should not be considered restrictive. The scope of the present invention is limited only by the appended claims and the full range of equivalents covered by the claims. The same reference numerals are used in all drawings and specific embodiments to refer to the same or similar parts.

[0039] As used herein, "upstream" and "downstream" are directional terms relative to the direction of fuel flow. For example, when component A is upstream of component B, it means that the fuel flows through component A before flowing through component B.

[0040] Figure 1 The fuel delivery assembly 100 of the preferred embodiment of the utility model is shown. The fuel delivery assembly 100 is from upstream to downstream (in Figure 11 and 2) sequentially include a fuel module 1, a fuel pipeline 2 connected to the fuel module 1, and a plurality of fuel nozzles 3 connected to the fuel pipeline 2. The fuel module 1, the fuel pipeline 2, and the fuel nozzles 3 are fluidly connected to each other.

[0041] Figure 1 The components of the auxiliary power unit (APU) are also schematically shown. In general, the APU is a rotary device with a central axis A, which includes a gas collection chamber 6, a combustion chamber 7 and an exhaust casing 8 from upstream to downstream. The fuel module 1 is arranged outside the APU, upstream of the gas collection chamber 6, and is used to pressurize the fuel and supply it to other components of the fuel delivery assembly 100. The fuel pipeline 2 is connected to the fuel module 1 at one end, then passes through the gas collection chamber 6 to the combustion chamber 7, and is connected to a plurality of fuel nozzles 3 at the other end. The plurality of fuel nozzles 3 are installed in the combustion chamber 7, preferably arranged in an annular array (not shown in the drawings), and can also be arranged in a circular or other array shape that is conducive to atomization and injection of fuel. In this way, when the APU is working, the fuel starts from the fuel module 1, travels along the fuel pipeline 2 to the plurality of fuel nozzles 3, and then is atomized and injected into the combustion chamber 7 through the fuel nozzles 3, mixed with the high-temperature air and burned to provide power, and then the exhaust gas after combustion is discharged to the outside of the aircraft through the exhaust casing 8.

[0042] As shown in the figure, the fuel pipeline 2 includes a main fuel pipeline 21 and an auxiliary fuel pipeline 22 arranged in parallel with each other. Among them, the main fuel pipeline 21 includes a main fuel main pipe 211 and a plurality of main fuel manifolds 212. The main fuel main pipe 211 is connected to the fuel module 1 at one end and connected to the plurality of main fuel manifolds 212 at the other end. Each of the plurality of main fuel manifolds 212 is connected to a corresponding one of the plurality of fuel nozzles 3, so the plurality of main fuel manifolds 212 are also correspondingly arranged into an array shape formed by the fuel nozzles 3 such as a ring array.

[0043] The auxiliary fuel line 22 is connected in parallel with the main fuel line 21, and its arrangement is similar to the main fuel line 21, and also includes an auxiliary fuel main pipe 221 and a plurality of auxiliary fuel manifolds 222. One end of the auxiliary fuel main pipe 221 is connected to the fuel module 1, and the other end is coupled to the plurality of auxiliary fuel manifolds 222 at the coupling position X. Each of the plurality of auxiliary fuel manifolds 222 is also connected to a corresponding one of the plurality of fuel nozzles 3, and thus is also arranged in the same array shape as the fuel nozzles 3.

[0044] For each fuel nozzle 3, Figure 1 As shown, the primary fuel manifold 212 and the secondary fuel manifold 222 are simultaneously connected thereto to deliver fuel.

[0045] The fuel delivery module is also provided with a one-way valve 4 in the auxiliary fuel pipeline 22. When activated, the one-way valve 4 allows the fuel to flow from the fuel module 1 to the fuel nozzle 3, but does not allow the fuel to flow back; when shut down, the one-way valve 4 does not allow the fuel to flow through. The one-way valve 4 is positioned so that the length l1 along the auxiliary fuel pipeline 22 from the fuel module 1 is greater than the length l2 along the auxiliary fuel pipeline 22 from the fuel nozzle 3. Specifically, the one-way valve 4 is provided in the auxiliary fuel main pipe 221, near the combination position X where the auxiliary fuel main pipe 221 is combined with a plurality of auxiliary fuel manifolds 222.

[0046] With this arrangement, if the fuel distribution valve 5 is not provided in the fuel delivery assembly 100, when the APU is started but the check valve 4 is closed, that is, when only the main fuel line 21 is used to supply fuel, the fuel module 1 supplies fuel and fills the main fuel line 21 and the section between the end of the auxiliary fuel main pipe 221 of the auxiliary fuel line 22 connected to the fuel module 1 and the check valve 4 (that is, Figure 1 Since the one-way valve 4 is close to the fuel nozzle 3, the fuel fills most of the section of the auxiliary fuel main pipe 221. When the one-way valve 4 is activated to enable the auxiliary fuel line 22, at this moment, the amount of fuel that needs to be injected into the auxiliary fuel line 22 for the fuel nozzle 3 to spray is small, so the fuel pressure and flow rate in the main fuel line 21 do not fluctuate much, and will not affect the atomization and spraying functions of the fuel nozzle 3.

[0047] A fuel distribution valve 5 may also be provided in the auxiliary fuel pipeline 22 near the fuel module 1. When the fuel distribution valve 5 is activated, fuel is allowed to flow, preferably allowing fuel to flow from the fuel module 1 to the fuel nozzle 3, but fuel backflow is not allowed; when the fuel distribution valve 5 is closed, fuel is not allowed to flow. Specifically, Figure 1 As shown, the fuel distribution valve 5 is arranged at one end of the auxiliary fuel main pipe 221 close to the fuel module 1.

[0048] The one-way valve 4 is a spring mechanical valve or a solenoid valve, and the fuel distribution valve 5 is a spring mechanical valve or a solenoid valve. In general, during the start-up of the APU, the one-way valve 4 and the fuel distribution valve 5 need to be activated to allow the fuel to reach the fuel nozzle 3 via the auxiliary fuel line 22 after the fuel reaches the fuel nozzle 3 via the main fuel line 21. This is to achieve the effect that the fuel is first supplied to the fuel nozzle 3 via the main fuel line 21 for injection and combustion, and then further supplied to the fuel nozzle 3 via the auxiliary fuel line 22 to increase the fuel supply to further assist combustion or adjust the air-fuel ratio (AFR).

[0049] In this preferred embodiment, both the one-way valve 4 and the fuel distribution valve 5 are spring mechanical valves. Here, the starting pressure of the one-way valve 4 is set to be higher than that of the fuel distribution valve 5. In this way, when the APU stops and the fuel module 1 stops supplying fuel to the fuel line 2, the fuel pressure in the fuel line 2 decreases, and the one-way valve 4 is closed before the fuel distribution valve 5. A portion of the fuel in the auxiliary fuel line 22 between the fuel nozzle 3 and the one-way valve 4 flows out of the auxiliary fuel line 22 through the fuel nozzle 3, while a portion between the one-way valve 4 and the fuel module 1 cannot quickly flow back to the fuel module 1 because the fuel pressure of the fuel module 1 is greater than the fuel pressure in the auxiliary fuel line 22, or because the fuel distribution valve 5 prohibits the fuel from flowing back. When the fuel pressure in the auxiliary fuel line 22 drops to below the starting pressure of the fuel distribution valve 5, the fuel distribution valve 5 is closed, preventing the remaining fuel from continuing to flow out of the auxiliary fuel line 22, so that a certain amount of fuel remains in the auxiliary fuel line 22. When the APU starts, the fuel module 1 supplies fuel to the fuel pipeline 2, and when the fuel pressure reaches the starting pressure of the fuel distribution valve 5, the fuel distribution valve 5 starts, and only a small amount of fuel is needed to fill the section between the one-way valve 4 of the auxiliary fuel main pipe 221 and the fuel distribution valve 5; when the fuel pressure in the auxiliary fuel main pipe 221 reaches the starting pressure of the one-way valve 4, the one-way valve 4 starts, allowing the fuel to be supplied to multiple fuel nozzles 3 through the auxiliary fuel pipeline 22.

[0050] However, the present invention is not limited thereto, and it is also conceivable that both the one-way valve 4 and the fuel distribution valve 5 are electromagnetic valves in an alternative embodiment. In this alternative embodiment, the one-way valve 4 is controlled to be started or shut down simultaneously with the fuel distribution valve 5, or to be shut down before the fuel distribution valve 5 is shut down, and not to be started before the fuel distribution valve 5 is started. Similar to the case where both the one-way valve 4 and the fuel distribution valve 5 are set as spring mechanical valves, this sequential setting of starting and shutting down allows a certain amount of fuel to be retained in the section between the one-way valve 4 and the fuel distribution valve 5 of the auxiliary fuel main pipe 221 when the APU is stopped, so that when the APU is started, only a small amount of fuel is needed to supply fuel to multiple fuel nozzles 3 via the auxiliary fuel pipeline 22.

[0051] Of course, in other alternative embodiments, it is also possible to imagine that the one-way valve 4 is a spring mechanical valve and the fuel distribution valve 5 is a solenoid valve, or the one-way valve 4 is a solenoid valve and the fuel distribution valve 5 is a spring mechanical valve. As long as the one-way valve 4 is set to be closed no later than the fuel control valve and no earlier than the fuel control valve is started, the effect is achieved.

[0052] As described above, the one-way valve 4 and the spring mechanical valve are arranged in such a way that a certain amount of fuel can be retained in the auxiliary fuel main pipe 221 during the APU shutdown period, so that when the APU is started, only a small amount of fuel is needed to enable the auxiliary fuel line 22 to supply fuel to multiple fuel nozzles 3. In this way, when the auxiliary fuel line 22 is enabled, the fuel pressure and flow rate in the main fuel line 21 will not drop significantly and instantaneously, and thus the atomization and injection effect of the fuel nozzle 3 will not be affected, thereby reducing the risk of APU start failure.

[0053] The fuel delivery assembly of the utility model is provided with a one-way valve in the auxiliary fuel main pipe near the position where it is combined with each auxiliary fuel manifold. In the case where there is a fuel distribution valve in the auxiliary fuel main pipe near the fuel module, the one-way valve is closed no later than the fuel distribution valve and is activated no earlier than the fuel distribution valve. In this way, fuel is always retained in the auxiliary fuel main pipe. In this way, it is possible to avoid the APU starting failure caused by the instantaneous reduction of pressure and flow in the main fuel pipeline due to the activation of the auxiliary fuel pipeline when the APU is started, thereby solving the problem of low reliability of APU starting in the prior art.

[0054] As used herein, the terms "comprises," "comprising," "having," or any further variations thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that includes a list of elements is not necessarily limited to only those elements and may include other elements not expressly listed or inherent to such method, article, or apparatus.

[0055] The present invention is not limited to the above-mentioned embodiments, which are merely illustrative and non-restrictive. Under the guidance of the present invention, those skilled in the art can make any possible changes and modifications without departing from the purpose of the present invention and the scope of protection of the claims. Therefore, any modification, equivalent changes and modifications made to the above-mentioned embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A fuel delivery assembly, the fuel delivery assembly being used to provide fuel to an auxiliary power unit of an aircraft, comprising: A fuel module for providing fuel to other components of the fuel delivery assembly; a plurality of fuel nozzles that inject fuel from the fuel module; a fuel pipeline, the fuel pipeline connecting the fuel module and the plurality of fuel nozzles, comprising a main fuel pipeline and an auxiliary fuel pipeline arranged in parallel with each other, It is characterized in that The fuel delivery assembly further includes a one-way valve in the auxiliary fuel line positioned such that a length along the auxiliary fuel line from the fuel module is greater than a length along the auxiliary fuel line from the fuel nozzle.

2. The fuel delivery assembly according to claim 1, characterized in that The fuel delivery assembly also includes a fuel distribution valve in the auxiliary fuel line positioned proximate to the fuel module.

3. The fuel delivery assembly according to claim 2, characterized in that The auxiliary fuel line includes an auxiliary fuel main pipe and a plurality of auxiliary fuel manifolds coupled to the auxiliary fuel main pipe, one end of the auxiliary fuel main pipe is connected to the fuel module, the other end of the auxiliary fuel main pipe is connected to the plurality of auxiliary fuel manifolds, and each of the plurality of auxiliary fuel manifolds is connected to a corresponding one of the plurality of fuel nozzles.

4. The fuel delivery assembly according to claim 3, characterized in that The one-way valve is disposed in the auxiliary fuel main pipe near a position where the auxiliary fuel main pipe is combined with the plurality of auxiliary fuel manifolds; and The fuel distribution valve is arranged on the end of the auxiliary fuel main pipe close to the fuel module.

5. The fuel delivery assembly according to claim 2, characterized in that The one-way valve is a spring mechanical valve or a solenoid valve; And the fuel distribution valve is a spring mechanical valve or a solenoid valve.

6. The fuel delivery assembly according to claim 2, characterized in that The one-way valve and the fuel distribution valve are both spring mechanical valves, wherein the starting pressure of the one-way valve is higher than that of the fuel distribution valve.

7. The fuel delivery assembly according to claim 2, characterized in that The one-way valve and the fuel distribution valve are both solenoid valves, wherein: The one-way valve is controlled to be activated or shut down simultaneously with the fuel distribution valve; or The one-way valve is controlled to be closed before the fuel dispensing valve is closed and not to be activated before the fuel dispensing valve is activated.

8. The fuel delivery assembly according to claim 7, characterized in that The one-way valve and the fuel distribution valve are controlled to be activated after the fuel reaches the fuel nozzle via the main fuel line.

9. The fuel delivery assembly according to claim 1 or 2, characterized in that: The main fuel pipeline includes a main fuel main pipe and a plurality of main fuel manifolds coupled to the main fuel main pipe, one end of the main fuel main pipe is connected to the fuel module, the other end of the main fuel main pipe is connected to the plurality of main fuel manifolds, and each of the plurality of main fuel manifolds is connected to a corresponding one of the plurality of fuel nozzles.

10. The fuel delivery assembly according to claim 1 or 2, characterized in that: The plurality of fuel nozzles are arranged in an annular array, wherein the plurality of fuel nozzles are configured to atomize injection fuel.

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