Fuel supply system, engine and fuel quantity adjusting method

Abstract

The invention provides a fuel supply system, an engine and a fuel quantity adjusting method of the fuel supply system. The fuel supply system comprises a fuel pump, an adjusting oil way and a main fuel filter. One end of the adjusting oil way is communicated with the upstream inlet end of the fuel pump, and the other end of the adjusting oil way is communicated with the downstream outlet end of the fuel pump; an adjusting pump is arranged on the adjusting oil way, and the adjusting pump is used for jointly inputting fuel oil on the upstream of the fuel oil pump and fuel oil output by the fuel oil pump into the main fuel oil filter in an open state. According to the fuel oil supply system, more fuel oil is supplied to the main fuel oil filter from the fuel oil pump, so that in the low-rotating-speed state of the engine, extra fuel oil supply is achieved, the fuel oil flow requirement of the engine is met, the displacement requirement of the fuel oil pump can be reduced through the adjusting pump, and the size and weight of the fuel oil pump are reduced; the fuel pump power extraction requirement is lowered, and engine power loss is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and particularly relates to a fuel supply system, an engine, and a fuel quantity adjustment method. Background Art

[0002] The fuel system of an aeroengine mainly consists of a fuel pump, a fuel filter, a fuel metering device, a fuel distribution device, and a fuel nozzle. A common fuel pump generally combines a low-pressure centrifugal pump and a high-pressure gear pump. The centrifugal pump and the gear pump are coaxial and are driven by a transmission mechanism in an engine accessory gearbox.

[0003] For a high-low pressure two-stage combined fuel pump, the displacement of the gear pump meets the fuel supply requirements of the system. However, for a fixed-displacement gear pump, the fuel supply of the fuel pump is low at low engine speeds, especially during the starting process, and cannot meet the fuel requirements for system servo operation and metering fuel supply. At high engine speeds, the fuel supply of the fuel pump is too large, and the metered fuel for combustion only accounts for one-third or less of the total fuel supply of the fuel pump. A large amount of fuel that has done work in the fuel pump needs to return to the low-pressure flow path, resulting in a large amount of energy loss and reducing the engine efficiency. At the same time, a large amount of returned fuel will cause a relatively high fuel temperature rise in the fuel system. The high-temperature fuel will reduce the reliability of the fuel system accessories and further reduce the engine reliability.

[0004] Based on this, the inventors of the present application propose a fuel supply system, an engine, and a fuel quantity adjustment method to solve the above technical problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that a large amount of energy loss occurs in fuel quantity supply in the prior art and reduce the engine efficiency, and to provide a fuel supply system, an engine, and a fuel quantity adjustment method.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] In a first aspect, the present invention provides a fuel supply system, which is characterized by including:

[0008] A fuel pump, a regulating oil circuit, and a main fuel filter;

[0009] One end of the regulating oil circuit is communicated with the upstream inlet end of the fuel pump, and the other end is communicated with the downstream outlet end of the fuel pump and they jointly flow into the main fuel filter; wherein,

[0010] A regulating pump is provided on the regulating oil circuit, and the regulating pump is used to jointly input the fuel upstream of the fuel pump and the fuel output by the fuel pump into the main fuel filter in an open state.

[0011] According to an embodiment of the present invention, the regulating pump is an electric centrifugal pump, and the electric centrifugal pump is connected to a driving motor;

[0012] The regulating oil circuit is further provided with a check valve downstream of the electric centrifugal pump.

[0013] According to an embodiment of the present invention, it further includes a metering device and an electronic controller;

[0014] The fuel pump and the main fuel filter are both communicated with the metering device, and the driving motor and the metering device are both connected to the electronic controller.

[0015] According to an embodiment of the present invention, it further includes a fuel actuating mechanism. One path of fuel from the main fuel filter is communicated with the fuel metering device, and the other path flows to the fuel actuating mechanism.

[0016] According to an embodiment of the present invention, a fuel distribution device is further provided downstream of the metering device, and the fuel distribution device is connected to the electronic controller.

[0017] According to an embodiment of the present invention, fuel nozzles are further provided downstream of the fuel distribution device, and three paths of fuel enter the fuel nozzles downstream of the fuel distribution device.

[0018] According to an embodiment of the present invention, the fuel pump includes a low-pressure stage centrifugal pump and a high-pressure stage gear pump, and the low-pressure stage centrifugal pump is located upstream of the high-pressure stage gear pump;

[0019] The output end of the low-pressure stage centrifugal pump converges the bypass return oil in the metering device and is communicated with the inlet of the high-pressure stage gear pump.

[0020] In a second aspect, the present invention further provides an engine, which is characterized in that it includes the fuel supply system as described above and a combustion chamber, and the fuel nozzles of the fuel supply system supply fuel to the combustion chamber for combustion.

[0021] In a second aspect, the present invention further provides a method for regulating the fuel quantity of a fuel supply system, which is implemented by using the fuel supply system as described above, and includes:

[0022] Determine the engine speed;

[0023] When the engine speed exceeds the first threshold, turn on the regulating pump to provide additional oil input to the main fuel filter.

[0024] According to an embodiment of the present invention, it further includes turning off the regulating pump when the engine speed exceeds the second threshold.

[0025] The positive and progressive effects of the present invention are as follows:

[0026] The fuel supply system of the present invention utilizes a regulating pump to achieve an additional fuel supply from the fuel pump to the main fuel filter. Thus, when the engine is running at a low speed and the fuel supply of the fuel pump is insufficient, an additional fuel supply can be realized to meet the fuel flow demand of the engine. By using the regulating pump, the displacement requirement of the fuel pump can be reduced, the size and weight of the fuel pump can be decreased, and further, during the operation of the engine, the power extraction requirement of the fuel pump can be reduced, and the power loss of the engine can be decreased. Description of the Drawings

[0027] The above and other features, properties, and advantages of the present invention will become more apparent from the following description in conjunction with the drawings and embodiments, where:

[0028] Figure 1 is a schematic structural diagram of the fuel supply system of the present invention;

[0029] Figure 2 is a fuel supply timing diagram of the fuel supply system of the present invention;

[0030] Figure 3 is a comparison diagram of optimized fuel supply amounts of the fuel supply system of the present invention;

[0031] Figure 4 is Figure 3 a partial enlarged view of;

[0032] Figure 5 is a flowchart of the fuel amount regulation method of the fuel supply system of the present invention.

[0033] 1. Fuel pump; 11. Low-pressure stage centrifugal pump; 12. High-pressure stage gear pump;

[0034] 2. Regulation oil circuit; 21. Regulating pump; 22. Check valve; 23. Driving motor;

[0035] 3. Main fuel filter;

[0036] 4. Metering device;

[0037] 5. Electronic controller;

[0038] 7. Fuel distribution device;

[0039] 8. Fuel nozzle. Detailed Embodiments

[0040] The present invention will be further described below in conjunction with specific embodiments and the drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from this description. Those skilled in the art can make similar extensions and deductions according to the actual application situation without departing from the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0042] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of this application. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods and devices should be regarded as part of the authorized specification. In all examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0043] Referring to Figure 1 , the present invention provides a fuel supply system, comprising: a fuel pump 1, a regulating oil circuit 2, and a main fuel filter 3. One end of the regulating oil circuit 2 is communicated with the upstream inlet end of the fuel pump 1, and the other end is communicated with the downstream outlet end of the fuel pump 1 and jointly flows into the main fuel filter 3. Wherein, a regulating pump 21 is provided on the regulating oil circuit 2, and the regulating pump 21 is used for inputting the fuel upstream of the fuel pump 1 and the fuel output by the fuel pump 1 into the main fuel filter 3 together in the open state.

[0044] The fuel supply system further comprises a metering device 4, an electronic controller 5, a fuel distribution device 7, and a fuel nozzle 8. The regulating pump 21 is an electric centrifugal pump, the electric centrifugal pump is connected to a drive motor 23, and a check valve 22 is further provided downstream of the electric centrifugal pump on the regulating oil circuit 2.

[0045] The fuel pump 1 is driven by an engine drive system, and the fuel filtered by the main fuel filter 3 flows into the engine fuel nozzle 8 through the metering device 4 and the fuel distribution device 7.

[0046] It should be noted that the fuel pump 1 comprises a low-pressure stage centrifugal pump 11 and a high-pressure stage gear pump 12. The low-pressure stage centrifugal pump 11 is located upstream of the high-pressure stage gear pump 12, and the output end of the low-pressure stage centrifugal pump 11 converges with the bypass return oil in the metering device 4 and is communicated with the inlet of the high-pressure stage gear pump 12.

[0047] That is, the fuel supplied to the aircraft is fed to the low-pressure stage centrifugal pump 11 for preliminary pressurization, and is combined with the bypass return oil in the metering device 4, then enters the inlet of the high-pressure stage gear pump 12, and after being further pressurized by the high-pressure stage gear pump 12, it enters the main fuel filter 3 for filtration.

[0048] Refer to Figure 1 In the solid-line fuel circuit shown in , the fuel is divided into two paths from the main fuel filter 3. One path of fuel is used as metered fuel, which is metered by the fuel metering device 4 and then enters the fuel distribution device 7, and is divided into three paths of fuel and then supplied to the fuel nozzle 8 and then to the combustion chamber for combustion.

[0049] The other path of fuel is used as servo fuel. Specifically, refer to Figure 1 the dotted-line fuel circuit shown in , which is used to drive various fuel actuating mechanisms.

[0050] Specifically, one path of the servo fuel in the main fuel filter 3 flows to the metering device 4 and is combined with the bypass return oil in the metering device 4, and then they flow together to the inlet of the high-pressure stage gear pump 12. Another path of the servo fuel in the main fuel filter 3 flows to the fuel distribution device 7, and after driving the actuating mechanism in the fuel distribution device 7, it returns to the metering device 4, and then is combined with the bypass return oil in the metering device 4 and flows together to the inlet of the high-pressure stage gear pump 12, and this process circulates.

[0051] Specifically, the fuel supplied to the aircraft is fed to the electric centrifugal pump through the regulating oil circuit 2 before reaching the main fuel pump. After being pressurized by the electric centrifugal pump, it is supplied to the outlet of the high-pressure stage gear pump 12 through the check valve 22. The electric centrifugal pump is driven by the drive motor 23, and the drive motor 23 is supplied with a control current by the electronic controller 5 to achieve motor drive.

[0052] Refer to Figure 2 , when the engine enters the starting state, the electronic controller 5 controls the ignition device to start ignition when the engine N2 speed reaches speed 1.

[0053] When the engine N2 speed reaches speed 2, the electronic controller 5 controls the motor to drive the electric centrifugal pump to start working. At this time, part of the fuel flows through the electric centrifugal pump and the check valve 22 to the outlet of the high-pressure stage gear pump 12. The electric centrifugal pump increases the fuel supply at low engine speeds, and thus can reduce the size of the high-pressure stage gear pump 12, so as to reduce the displacement of the high-pressure stage gear pump 12 at high speeds, and further reduce the fuel flow rate of the engine at high speeds.

[0054] Furthermore, when the engine N2 speed reaches speed 3, the electronic controller 5 controls the fuel metering valve in the metering device 4 to open, and starts to supply the fuel for engine combustion.

[0055] When the engine N2 speed reaches speed 4, the electronic controller 5 controls the ignition device to turn off the ignition.

[0056] When the N2 speed of the engine reaches speed 5, the electronic controller 5 controls the drive motor 23 to stop the operation of the electric centrifugal pump.

[0057] When the N2 speed of the engine reaches speed 6, the engine starts and reaches the idle state.

[0058] By adopting the fuel supply system of the present invention, only a fuel supply capacity of about 500 kg / h @ 3 MPa needs to be provided, the input power requirement for the drive motor 23 is low, the weight requirement for the electric centrifugal pump is low, the volume requirement is small, and the working environment and conditions are relatively suitable, which is beneficial to improving the reliability of the electric centrifugal pump.

[0059] Refer to Figure 3 , for the fuel supply system of the present invention, the use of the electric centrifugal pump can increase the fuel supply amount at low engine speeds, which is beneficial to reducing the size of the high-pressure stage gear pump 12, and then reducing the fuel supply amount of the high-pressure stage gear pump 12. Thus, at high speeds, the required fuel flow rate of the fuel supply system is greatly reduced. Furthermore, while meeting the required fuel flow rate of the engine, the displacement requirement of the fixed displacement gear pump is greatly reduced, and it is expected to reduce the displacement index by more than half compared with the traditional solution.

[0060] Refer to Figure 4 , by adopting the fuel supply system of the present invention, the fuel flow rate that can be provided in the low engine speed state is higher than that of the traditional solution. While enabling the engine to supply fuel at a lower speed, the overall power consumption of the fuel pump 1 is reduced.

[0061] That is to say, when the additional fuel supply is carried out at low speeds by using the regulating oil circuit 2, the high fuel volume requirement of the engine at low speeds is met. At the same time, at high speeds, by reducing the size of the high-pressure stage gear pump 12 and thus reducing the flow rate of the high-pressure stage gear pump 12, the amount of returned oil is further reduced, avoiding the problem of high fuel temperature rise in the fuel system, and improving the reliability of the fuel supply system and the reliability of the engine.

[0062] The present invention also provides an engine, including the above fuel supply system and a combustion chamber. The fuel nozzle 8 of the fuel supply system supplies fuel to the combustion chamber for combustion.

[0063] In summary, the fuel supply system of the present invention uses the regulating pump 21 to realize an additional supply of fuel from the fuel pump 1 to the main fuel filter 3. Thus, in the low engine speed state where the fuel supply amount of the fuel pump 1 is insufficient, additional fuel supply can be realized to meet the fuel flow rate requirement of the engine. By using the regulating pump 21, the displacement requirement of the fuel pump 1 can be reduced, the size and weight of the fuel pump 1 can be reduced, and further, during the operation of the engine, the power extraction requirement of the fuel pump 1 can be reduced, and the engine power loss can be reduced.

[0064] Refer to Figure 5, the present invention also provides a method for regulating the fuel quantity of a fuel supply system, which is implemented by using the above fuel supply system, and includes:

[0065] S1. Determine the engine speed.

[0066] S2. When the engine speed exceeds the first threshold, turn on the regulating pump to provide an additional fuel quantity input to the main fuel filter.

[0067] It should be noted that it also includes turning off the regulating pump when the engine speed exceeds the second threshold.

[0068] That is, please refer to Figure 2 , when the engine enters the starting state, when the engine N2 speed reaches speed 1, the electronic controller controls the ignition device to start ignition, and at this time, it corresponds to speed 1.

[0069] When the engine N2 speed reaches speed 2, the electronic controller controls the motor to drive the electric centrifugal pump to start working. At this time, part of the fuel flows to the outlet of the high-pressure stage gear pump through the electric centrifugal pump and the check valve. At this time, it corresponds to speed 2, and speed 2 is the first threshold. When the speed exceeds the first threshold, the drive motor drives the electric centrifugal pump to start working. The electric centrifugal pump improves the fuel supply quantity at low engine speeds, and thus can reduce the size of the high-pressure stage gear pump to reduce the displacement of the high-pressure stage gear pump at high speeds, and further reduce the fuel flow rate of the engine at high speeds.

[0070] When the engine N2 speed reaches speed 3, the electronic controller controls the fuel metering valve in the metering device to open, and starts to supply fuel for engine combustion.

[0071] When the engine N2 speed reaches speed 4, the electronic controller controls the ignition device to turn off the ignition.

[0072] When the engine N2 speed reaches speed 5, the electronic controller controls the drive motor to stop the electric centrifugal pump. That is, speed 5 corresponds to the second threshold. When the engine speed exceeds speed 5, turn off the regulating pump (electric centrifugal pump).

[0073] When the engine N2 speed reaches speed 6, the engine is pneumatically actuated to reach the idle state.

[0074] By using the fuel supply system of the present invention, only a fuel supply capacity of about 500 kg / h @ 3 MPa needs to be provided, the input power requirement for the drive motor is low, the weight requirement for the electric centrifugal pump is low, the volume requirement is small, and the working environment and conditions are relatively suitable, which is beneficial to improving the reliability of the electric centrifugal pump.

[0075] By adopting the fuel supply amount adjustment method of the present invention, it is possible to achieve additional fuel supply under the condition that the main fuel pump has insufficient fuel supply amount at the low engine speed state, so as to meet the fuel flow demand of the engine. Moreover, by using the electric centrifugal pump for oil supply, the displacement demand of the fuel pump can be reduced, the size and weight of the fuel pump can be decreased, and further, during the whole engine operation process, the power extraction demand of the fuel pump can be reduced, and the engine power loss can be decreased.

[0076] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may also be a mechanical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0077] The present application uses specific terms to describe the embodiments of the present application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "an embodiment" or "one embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification is not necessarily the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0078] In addition, it should be noted that using terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without otherwise stating, the above terms have no special meanings, so they cannot be understood as limiting the protection scope of the present application. In addition, although the terms used in the present application are selected from well-known and commonly used terms, some terms mentioned in the specification of the present application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand the present application not only through the actual terms used, but also through the meanings implied by each term.

[0079] Although the present invention is disclosed above in preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention all fall within the protection scope defined by the claims of the present invention.

Claims

1. A fuel supply system, characterized in that, comprising: a fuel pump, a regulating oil passage, and a main fuel filter; one end of the regulating oil passage is communicated with the upstream inlet end of the fuel pump, and the other end is communicated with the downstream outlet end of the fuel pump and jointly flows into the main fuel filter; wherein, a regulating pump is provided on the regulating oil passage, and the regulating pump is used for jointly inputting the fuel upstream of the fuel pump and the fuel output by the fuel pump into the main fuel filter in an open state.

2. The fuel supply system according to claim 1, characterized in that, the regulating pump is an electric centrifugal pump, and the electric centrifugal pump is connected to a driving motor; a check valve is further provided downstream of the electric centrifugal pump on the regulating oil passage.

3. The fuel supply system according to claim 2, characterized in that, further comprising a metering device and an electronic controller; both the fuel pump and the main fuel filter are communicated with the metering device, and the driving motor and the metering device are both connected to the electronic controller.

4. The fuel supply system according to claim 3, characterized in that, further comprising a fuel actuating mechanism, one path of fuel of the main fuel filter is communicated with the fuel metering device, and the other path flows to the fuel actuating mechanism.

5. The fuel supply system according to claim 3, characterized in that, a fuel distribution device is further provided downstream of the metering device, and the fuel distribution device is connected to the electronic controller.

6. The fuel supply system according to claim 3, characterized in that, a fuel nozzle is further provided downstream of the fuel distribution device, and three paths of fuel enter the fuel nozzle downstream of the fuel distribution device.

7. The fuel supply system according to claim 3, characterized in that, the fuel pump comprises a low-pressure stage centrifugal pump and a high-pressure stage gear pump, and the low-pressure stage centrifugal pump is located upstream of the high-pressure stage gear pump; the output end of the low-pressure stage centrifugal pump converges the bypass return oil in the metering device and is communicated with the inlet of the high-pressure stage gear pump.

8. An engine, characterized in that, comprising the fuel supply system according to any one of claims 1-7 and a combustion chamber, and the fuel nozzle of the fuel supply system supplies fuel to the combustion chamber for combustion.

9. A method for regulating the fuel quantity of a fuel supply system, implemented by using the fuel supply system according to any one of claims 1-7, characterized in that, comprising: determining the rotational speed of the engine; when the rotational speed of the engine exceeds a first threshold, turning on the regulating pump to provide additional fuel quantity input to the main fuel filter.

10. The method for regulating the fuel quantity of a fuel supply system according to claim 9, characterized in that, further comprising turning off the regulating pump when the rotational speed of the engine exceeds a second threshold.

Images