An aeroengine fuel dispenser based on differential pressure control

Abstract

The present invention discloses an aeroengine fuel dispenser based on differential pressure control, belonging to the technical field of aeroengine fuel accessories, and comprising: a distribution valve (1), a staging valve (2), a differential pressure valve (3), a boosting valve (4), an oil drain valve (5), an oil leakage valve (6), a first electro-hydraulic servo valve (7), a second electro-hydraulic servo valve (8), a first displacement sensor (9), a second displacement sensor (10), a first check valve (11), a second check valve (12), and a throttle nozzle (13). The present invention improves the fuel distribution accuracy at low flow rates and at the same time enhances the versatility, and is applicable to various large aircraft engines.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine fuel accessories and relates to a fuel dispenser based on differential pressure control. Background Art

[0002] The development of the modern aviation industry requires aero-engines to have low fuel consumption, low pollution, high reliability and maintainability. The technology of sectional and staged combustion has become the development direction of the aero-engine combustion chamber design. The fuel dispenser is the basis for sectional and staged combustion in the combustion chamber.

[0003] Existing electronically controlled fuel distribution devices are all single or double orifice fuel distribution devices. The distribution valve and the staging valve are driven by an electro-hydraulic servo valve, and the orifice opening is changed by the change of the valve position to achieve fuel distribution. This type of fuel dispenser controls the fuel distribution accuracy only by the change rate of the orifice area of the valve. On the one hand, it is difficult to improve the fuel distribution accuracy due to the influence of processing capacity in the case of small flow; on the other hand, the orifice design is affected by the characteristics of the downstream nozzle, and the versatility is poor. Summary of the Invention

[0004] The technical problem solved by the invention is to provide an aero-engine fuel dispenser based on differential pressure control, which improves the fuel distribution accuracy under small flow and improves the versatility at the same time.

[0005] The technical solution of the invention is as follows:

[0006] An aero-engine fuel dispenser based on differential pressure control includes:

[0007] a distribution valve 1, a staging valve 2, a differential pressure valve 3, a booster valve 4, an oil drain valve 5, an oil leakage valve 6, a first electro-hydraulic servo valve 7, a second electro-hydraulic servo valve 8, a first displacement sensor 9, a second displacement sensor 10, a first check valve 11, a second check valve 12, and a throttle nozzle 13;

[0008] Constant pressure servo oil supplies the first electro-hydraulic servo valve 7 and the second electro-hydraulic servo valve 8 for servo control, drives the distribution valve 1 and the staging valve 2 to move, and the servo return oil is discharged through the first check valve 11;

[0009] The distribution valve 1 is connected to the metered fuel, and the first electro-hydraulic servo valve 7 adjusts the opening of the distribution valve 1; the fuel flows through the distribution valve 1 and then flows to the differential pressure valve 3; the fuel flows through the differential pressure valve 3 and then flows to the first-stage oil circuit outlet; the metered fuel is connected to the fuel flowing through the distribution valve 1 through the throttle nozzle 13;

[0010] One end of the spool of the pressure boosting valve 4 is connected to the metered fuel, and the other end is connected to the fuel after flowing through the differential pressure valve 3, controlling the orifice opening of the pressure boosting valve 4. The metered fuel flows through the pressure boosting valve 4 and then flows to the outlet of the secondary oil circuit and the second check valve 12; the spring chamber of the second check valve 12 is connected to the metered fuel, and the other chamber is connected to the secondary oil circuit. The second check valve 12 remains closed under the action of the pressure difference and the spring force;

[0011] The staging valve 2 is connected to the secondary oil circuit, and the second electro-hydraulic servo valve 8 adjusts the opening of the staging valve 2; a part of the fuel flowing to the secondary oil circuit flows through the staging valve 2 and then flows to the outlet of the tertiary oil circuit;

[0012] The drain valve 5 is connected to the metered fuel. When the pressure of the metered fuel is less than a certain preset drain pressure value, the drain valve 5 is opened, and the metered fuel flows through the drain valve 5 and then flows to the leak valve 6. When the pressure of the metered fuel is higher than the leak pressure, the leak valve 6 opens to realize the leak function; when the pressure of the metered fuel is lower than the leak pressure, the leak valve 6 closes and the leak function stops; when the pressure value of the metered fuel is greater than the preset drain pressure value, the drain valve 5 closes, and the metered fuel cannot flow through the drain valve 5 and the leak valve 6, and the leak function stops.

[0013] The distribution valve 1 of the fuel distributor is controlled by the first electro-hydraulic servo valve 7 according to the EEC command to control the valve position. The first displacement sensor 9 feeds back the valve position signal to the EEC to form a closed-loop control, realizing continuously adjustable control of the fuel distribution ratio between the primary oil circuit and the secondary and tertiary oil circuits.

[0014] The tertiary oil circuit passes through the staging valve 2. The staging valve 2 is controlled by the second electro-hydraulic servo valve 8 according to the EEC command to control the valve position. The second displacement sensor 10 feeds back the valve position signal to the EEC to form a closed-loop control, which is used to adjust the continuously adjustable distribution ratio between the secondary and tertiary oil circuits.

[0015] When the engine stops, the metered fuel flows back to the fuel distributor from the outlets of the primary, secondary, and tertiary oil circuits under the action of the back pressure in the combustion chamber.

[0016] In the power-off state, the distribution valve 1 is in the closed state under the control of the first electro-hydraulic servo valve 7, the differential pressure valve 3 is in the fully open state under the action of the spring force. The metered fuel flowing from the outlet of the primary oil circuit to the fuel distributor flows through the orifice of the differential pressure valve 3 and then through the throttle nozzle 13 to the drain valve 5 and the leak valve 6 and finally flows to the leak port; the staging valve 2 is in the fully open state under the control of the second electro-hydraulic servo valve 8, the pressure boosting valve 4 is in the fully closed state under the action of the spring force. The metered fuel flowing from the outlet of the tertiary oil circuit to the fuel distributor flows through the staging valve 2 and then converges with the metered fuel flowing from the outlet of the secondary oil circuit to the fuel distributor, and together they flow through the second check valve 12 and then to the drain valve 5 and the leak valve 6 and finally flow to the leak port.

[0017] The differential pressure valve 3 is a throttling type, and the flow passage surface has a multi-segment line profile.

[0018] One end of the spool of the differential pressure valve 3 senses the metered fuel pressure, and the other end senses the fuel pressure after flowing through the distribution valve 1, controlling the orifice opening of the differential pressure valve 3.

[0019] The preset fuel drain pressure value is 0.3 MPa, and the oil leakage pressure value is 0.15 MPa.

[0020] The beneficial effects of the present invention: Compared with the existing electronically controlled fuel distributor, a differential pressure valve 3 is particularly introduced to control the differential pressure before and after the orifice of the distribution valve 1 under different working conditions, improving the fuel distribution accuracy and reducing the correlation between the distributor and the characteristics of the downstream nozzles. By introducing the differential pressure valve 1, it is ensured that the differential pressure at the inlet and outlet of the distribution valve is constant, so that the flow rate through the distribution valve is only related to the valve position, improving the fuel distribution accuracy under small flow rates, reducing the correlation between the distribution ratio and the characteristics of the downstream nozzles of the distributor, and improving the versatility of the product. At the same time, the distributor integrates the parking fuel drain function, avoiding carbon deposition caused by the fuel in the distributor flowing into the combustion chamber after parking. Description of the Drawings

[0021] Figure 1 is a schematic diagram of the principle of the present invention;

[0022] Figure 2 is a schematic cross-sectional view of the orifice of the differential pressure valve;

[0023] Figure 3 is a schematic structural diagram of the embodiment. Detailed Embodiments

[0024] An aeroengine fuel distributor based on differential pressure control, as Figure 1 、 Figure 3 shown, includes a distribution valve 1, a staging valve 2, a differential pressure valve 3, a boosting valve 4, a fuel drain valve 5, an oil leakage valve 6, a first electro-hydraulic servo valve 7, a second electro-hydraulic servo valve 8, a first displacement sensor 9, a second displacement sensor 10, a first check valve 11, a second check valve 12, and a throttle nozzle 13.

[0025] Constant-pressure servo oil is supplied to the electro-hydraulic servo valves 7 and 8 for servo control, driving the distribution valve 1 and the staging valve 2 to move, and the servo return oil is discharged through the check valve 11.

[0026] The metered fuel is connected to the distribution valve 1, the differential pressure valve 3, the boosting valve 4, the fuel drain valve 5, and the check valve 12 after entering the distributor.

[0027] The distribution valve 1 is connected to the metered fuel. The first electro-hydraulic servo valve 7 adjusts the opening of the distribution valve 1 according to the spool position of the distribution valve 1 and the theoretical opening of the distribution valve 1 collected by the first displacement sensor 9. After the fuel flows through the distribution valve 1, it flows to the differential pressure valve 3. One end of the spool of the differential pressure valve 3 senses the metered fuel pressure, and the other end of the spring chamber senses the fuel pressure after flowing through the distribution valve 1. It is in force balance under the action of the spring and the pressure difference to achieve position stability and control the orifice opening of the differential pressure valve 3. After the fuel flows through the differential pressure valve 3, it flows to the outlet of the first-stage oil circuit. The metered fuel is connected to the fuel after flowing through the distribution valve 1 through the throttle nozzle 13 to avoid forming a dead cavity under the condition that the distribution valve 1 is closed.

[0028] One end of the spool of the boost valve 4 is connected to the metered fuel, and the other end of the spring chamber is connected to the fuel after flowing through the differential pressure valve 3. The spool is in force balance under the action of the spring force and the pressure difference to achieve position stability and control the orifice opening of the boost valve 4. After the metered fuel flows through the boost valve 4, it flows to the outlet of the second-stage oil circuit and the second check valve 12. The spring chamber of the second check valve 12 is connected to the metered fuel, and the other chamber is connected to the second-stage oil circuit. Since the metered fuel pressure is greater than the second-stage oil circuit pressure, the second check valve 12 remains closed under the action of the pressure difference and the spring force.

[0029] The staging valve 2 is connected to the second-stage oil circuit. The second electro-hydraulic servo valve 8 adjusts the opening of the staging valve 2 according to the spool position of the staging valve 2 and the theoretical opening of the staging valve 2 collected by the second displacement sensor 10. A part of the fuel flowing to the second-stage oil circuit flows through the staging valve 2 and then flows to the outlet of the third-stage oil circuit.

[0030] The drain valve 5 is connected to the metered fuel. The spool adjusts its position by sensing the difference between the metered fuel pressure and the preset spring force to control the on-off of the drain valve 5. When the metered fuel pressure is less than a certain preset drain pressure value, the drain valve 5 is turned on, and the metered fuel flows through the drain valve 5 and then flows to the leak valve 6. The leak valve 6 presets the leak pressure value through the spring pre-tightening force. When the metered fuel pressure is higher than the leak pressure, the leak valve 6 opens to achieve the leak function; when the metered fuel pressure is lower than the leak pressure, the leak valve 6 closes and the leak function stops. When the metered fuel pressure value is greater than the preset drain pressure value, the drain valve 5 closes, and the metered fuel cannot flow through the drain valve 5 and the leak valve 6, and the leak function stops. The preset drain pressure value is 0.3 MPa, and the leak pressure value is 0.15 MPa.

[0031] In particular, the distribution valve 1 of the fuel distributor is controlled by the first electro-hydraulic servo valve 7 according to the EEC instruction, and the first displacement sensor 9 feeds back the valve position signal to the EEC to form a closed-loop control, realizing the continuous and adjustable control of the fuel distribution ratio of the primary oil circuit and the secondary and tertiary oil circuits; the secondary and tertiary oil circuits pass through the grading valve 2, and the grading valve 2 is controlled by the second electro-hydraulic servo valve 8 according to the EEC instruction. The valve position, the second displacement sensor 10 feeds back the valve position signal to the EEC to form a closed-loop control, which is used to adjust the distribution ratio between the secondary and tertiary oil circuits continuously and adjustable. The optimal fuel distribution ratio under any working condition of the engine is achieved through the operation of the distribution valve and the grading valve, which improves the combustion efficiency and reduces pollutants.

[0032] In particular, when the engine stops, the metered fuel flows back to the fuel distributor from the primary, secondary and tertiary oil circuit outlets under the action of the back pressure of the combustion chamber. In the power-off state, the distribution valve 1 is in a closed state under the control of the first electro-hydraulic servo valve 7, and the pressure difference valve 3 is in a fully open state under the action of the spring force. The metered fuel flowing from the primary oil circuit outlet to the fuel distributor flows through the pressure difference valve 3-shaped hole and then flows to the drain valve 5 and the oil leakage valve 6 through the throttle nozzle 13 and finally flows to the oil leakage port; the grading valve 2 is in a fully open state under the control of the second electro-hydraulic servo valve 8, and the boost valve 4 is in a fully closed state under the action of the spring force. The metered fuel flowing from the tertiary oil circuit outlet to the fuel distributor flows through the grading valve 2 and then merges with the metered fuel flowing from the secondary oil circuit outlet to the fuel distributor, and then flows through the second one-way valve 12 and then flows to the drain valve 5 and the oil leakage valve 6 and finally flows to the oil leakage port. The function of draining the fuel after the engine stops is realized to prevent the fuel in the distributor from flowing to the combustion chamber after stopping and causing carbon deposition.

[0033] In particular, if Figure 2 As shown, the pressure differential valve 3 of the fuel distributor is of throttling type, and the flow surface has a multi-segment line profile. The existence of the pressure differential valve 3 ensures that the pressure difference before and after the distribution valve 1 hole remains unchanged, and the fuel flowing through the distribution valve 1 to the primary oil circuit outlet is only related to the position of the distribution valve 1, which can significantly improve the defect of the existing electronically controlled distributor that the fuel flow is affected by the pressure difference change at a small flow rate, resulting in low distribution accuracy. At the same time, the fuel flowing through the distribution valve 1 to the primary oil circuit outlet is only related to the position of the distribution valve 1, and has nothing to do with the nozzle characteristics, thereby improving the versatility of the distributor.

Claims

1. An aircraft engine fuel dispenser based on differential pressure control, characterized in that Including: Distribution valve (1), staging valve (2), differential pressure valve (3), boost valve (4), drain valve (5), oil leakage valve (6), first electro-hydraulic servo valve (7), second electro-hydraulic servo valve (8), first displacement sensor (9), second displacement sensor (10), first check valve (11), second check valve (12), throttle orifice (13); Constant pressure servo oil supplies the first electro-hydraulic servo valve (7) and the second electro-hydraulic servo valve (8) for servo control, driving the distribution valve (1) and the staging valve (2) to move, and the servo return oil is discharged through the first check valve (11); The distribution valve (1) is connected to the metered fuel, and the first electro-hydraulic servo valve (7) adjusts the opening degree of the distribution valve (1); the fuel flows through the distribution valve (1) and then flows to the differential pressure valve (3); the fuel flows through the differential pressure valve (3) and then flows to the first-stage oil circuit outlet; the metered fuel is connected to the fuel flowing through the distribution valve (1) through the throttle orifice (13); One end of the spool of the boost valve (4) is connected to the metered fuel, and the other end is connected to the fuel flowing through the differential pressure valve (3). The opening degree of the orifice of the boost valve (4) is controlled. The metered fuel flows through the boost valve (4) and then flows to the second-stage oil circuit outlet and the second check valve (12); the spring chamber of the second check valve (12) is connected to the metered fuel, and the other chamber is connected to the second-stage oil circuit. The second check valve (12) remains closed under the action of the pressure difference and the spring force; The staging valve (2) is connected to the second-stage oil circuit, and the second electro-hydraulic servo valve (8) adjusts the opening degree of the staging valve (2); a part of the fuel flowing to the second-stage oil circuit flows through the staging valve (2) and then flows to the third-stage oil circuit outlet; The drain valve (5) is connected to the metered fuel. When the pressure of the metered fuel is less than a certain preset drain pressure value, the drain valve (5) is opened, and the metered fuel flows through the drain valve (5) and then flows to the oil leakage valve (6); when the pressure of the metered fuel is higher than the oil leakage pressure, the oil leakage valve (6) opens to realize the oil leakage function; when the pressure of the metered fuel is lower than the oil leakage pressure, the oil leakage valve (6) closes and the oil leakage function stops; When the pressure value of the metered fuel is greater than the preset drain pressure value, the drain valve (5) closes, and the metered fuel cannot flow through the drain valve (5) and the oil leakage valve (6), and the oil leakage function stops.

2. A fuel distributor for an aeroengine based on differential pressure control according to claim 1, characterized in that For the distribution valve (1) of the fuel distributor, the first electro-hydraulic servo valve (7) controls the valve position according to the EEC command, and the first displacement sensor (9) feeds back the valve position signal to the EEC to form a closed-loop control, realizing continuously adjustable control of the fuel distribution ratio between the first-stage oil circuit and the second- and third-stage oil circuits.

3. A fuel distributor for an aeroengine based on differential pressure control according to claim 1, characterized in that The third-stage oil circuit passes through the staging valve (2). The staging valve (2) is controlled by the second electro-hydraulic servo valve (8) according to the EEC command for the valve position, and the second displacement sensor (10) feeds back the valve position signal to the EEC to form a closed-loop control for continuously adjustable regulation of the distribution ratio between the second- and third-stage oil circuits.

4. A fuel dispenser for an aeroengine based on differential pressure control as claimed in claim 1, wherein when the engine stops, the metered fuel flows back to the fuel dispenser from the outlets of the first-stage, second-stage, and third-stage oil circuits under the action of the back pressure in the combustion chamber.

5. A fuel dispenser for an aeroengine based on differential pressure control as claimed in claim 1, wherein in the power-off state, the distribution valve (1) is in the closed state under the control of the first electro-hydraulic servo valve (7), the differential pressure valve (3) is in the fully open state under the action of the spring force, and the metered fuel flowing from the outlet of the first-stage oil circuit to the fuel dispenser flows through the orifice of the differential pressure valve (3) and then through the throttle nozzle (13) to the drain valve (5) and the oil leakage valve (6) and finally to the oil leakage port; the staging valve (2) is in the fully open state under the control of the second electro-hydraulic servo valve (8), the boosting valve (4) is in the fully closed state under the action of the spring force, and the metered fuel flowing from the outlet of the third-stage oil circuit to the fuel dispenser flows through the staging valve (2) and then converges with the metered fuel flowing from the outlet of the second-stage oil circuit to the fuel dispenser, and the combined fuel flows through the second check valve (12) and then to the drain valve (5) and the oil leakage valve (6) and finally to the oil leakage port.

6. A fuel dispenser for an aeroengine based on differential pressure control as claimed in claim 1, wherein the differential pressure valve (3) is of a throttling type, and the flow passage surface has a multi-segment line profile.

7. A fuel dispenser for an aeroengine based on differential pressure control as claimed in claim 6, wherein one end of the spool of the differential pressure valve (3) senses the pressure of the metered fuel, and the other end senses the pressure of the fuel flowing through the distribution valve (1), and controls the opening degree of the orifice of the differential pressure valve (3).

8. A fuel dispenser for an aeroengine based on differential pressure control as claimed in claim 1, wherein the preset drain pressure value is 0.3 MPa, and the oil leakage pressure value is 0.15 MPa.

Images