Fuel oil control system nozzle back pressure rapid dynamic following test method and system

Abstract

The embodiment of the invention provides a fuel control system nozzle back pressure rapid dynamic following test method and system, and relates to the field of aero-engine nozzle back pressure simulation. The invention aims to solve the problems of large back pressure simulation error and insufficient real-time accuracy of the fuel control system under the transient working condition. The method comprises the steps that the calibration relation between the valve opening degree of a back pressure simulation valve and the valve front-back pressure difference under different fuel oil flows is obtained, and the back pressure simulation valve opening degree is obtained according to the real-time valve back pressure, nozzle back pressure and the real-time fuel oil flow in combination with the calibration relation; and controlling the back pressure simulation valve according to the opening degree of the back pressure simulation valve. The fuel control system nozzle back pressure rapid dynamic following test system is used for implementing the method. Pressure closed-loop control is changed into valve opening degree open-loop control through a control algorithm, disturbance of flow and pressure to a pressure closed loop is avoided, and the precision of back pressure simulation and the response speed of back pressure following are improved.

Description

Technical Field

[0001] This invention relates to the field of back pressure simulation after the nozzle of an aero-engine, and more specifically, to a rapid dynamic following test method and system for back pressure after the nozzle of a fuel control system. Background Technology

[0002] Currently, when conducting semi-physical simulation tests or fuel icing tests on the control system of aero-engines, it is not only necessary to simulate the back pressure behind the nozzle of the fuel control system under steady-state conditions, but also the back pressure simulation during the transient operation of the fuel control system is very important. If the simulated back pressure value is too large or too small during the transient process, the dynamic response of the servo actuation system may not meet the requirements of the control system. At the same time, the power extraction and transient heat generation of the fuel system will also be too large or too small, affecting the fuel temperature, making it impossible to assess the thermal management of the fuel system, and even affecting the fuel icing test results.

[0003] For steady-state back pressure simulation after the nozzle, high-precision valve throttling / flow resistance characteristics are generally used to simulate the back pressure in the combustion chamber after the nozzle. This involves continuously adjusting the valve opening through a pressure closed loop to achieve the required back pressure under constant back pressure and flow rate. However, in transient conditions, both flow rate and pressure change (flow rate variation is a disturbance term in the valve-front pressure closed-loop control). These flow rate and pressure changes are two disturbance terms in the closed-loop circuit. Using a simple pressure closed loop to simulate back pressure leads to excessive simulation errors, making it impossible to accurately follow the given back pressure in real time. Furthermore, pressure closed-loop control itself requires a long response time. If the pressure and flow rate changes drastically in transient conditions, it may cause excessively high fuel line pressure, damaging components of the fuel conditioning system. Summary of the Invention

[0004] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0005] The present invention aims to provide, for example, a rapid dynamic following test method for back pressure after the nozzle of a fuel control system, which can improve the problem of large back pressure simulation error and insufficient real-time accuracy under transient operating conditions of the fuel control system.

[0006] The present invention also aims to provide a rapid dynamic following test system for back pressure after the nozzle of a fuel control system, which can improve the problem of large back pressure simulation error and insufficient real-time accuracy under transient conditions of the fuel control system.

[0007] The embodiments of the present invention can be implemented as follows:

[0008] An embodiment of the present invention provides a rapid dynamic following test method for back pressure after the nozzle in a fuel control system, comprising the following steps: obtaining the calibration relationship between the valve opening and the pressure difference across the valve of the back pressure simulation valve under different fuel flow rates; obtaining the real-time back pressure after the valve of the back pressure simulation valve; obtaining the real-time fuel flow rate; obtaining the back pressure after the nozzle calculated and output by the engine model based on the real-time fuel flow rate; obtaining the back pressure simulation valve opening based on the real-time back pressure, the back pressure after the nozzle, and the real-time fuel flow rate, combined with the calibration relationship; and controlling the back pressure simulation valve according to the back pressure simulation valve opening.

[0009] In addition, the fuel control system nozzle back pressure rapid dynamic following test method provided in the embodiments of the present invention may also have the following additional technical features:

[0010] Optionally, the step of obtaining the calibration relationship between the valve opening and the pressure difference across the valve of the back pressure simulation valve under different fuel flow rates includes: under the condition that the fuel flow rate is a set value, obtaining the corresponding pressure difference across the valve according to different valve openings of the back pressure simulation valve, thereby obtaining the flow-pressure difference-opening curve; under the condition that the set value is different, repeating the step of obtaining the corresponding pressure difference across the valve according to different valve openings of the back pressure simulation valve, thereby obtaining the flow-pressure difference-opening curve, to obtain multiple flow-pressure difference-opening curves.

[0011] Optionally, the step of obtaining the real-time downstream pressure of the back pressure simulation valve includes: obtaining the real-time downstream pressure of the back pressure simulation valve as measured by a pressure sensor.

[0012] Optionally, the step of obtaining real-time fuel flow includes: obtaining real-time fuel flow measured by a flow meter; wherein the flow meter is connected to the FMV and the engine model, the flow meter is used to measure the fuel flow output by the FMV, and outputs the measured real-time fuel flow value to the engine model and the controller.

[0013] Optionally, the step of obtaining the back pressure simulated valve opening based on the real-time valve downstream pressure, the nozzle downstream back pressure, and the real-time fuel flow rate, combined with the calibration relationship, includes: obtaining the valve pressure difference based on the difference between the real-time valve downstream pressure and the nozzle downstream back pressure; and obtaining the back pressure simulated valve opening based on the valve pressure difference value, combined with the real-time fuel flow rate and the calibration relationship.

[0014] Optionally, the step of obtaining the back pressure simulation valve opening by taking the valve pressure difference as the value before and after the valve, combining the real-time fuel flow rate and the calibration relationship, includes: taking the corresponding value on the calibration relationship based on the valve pressure difference and the real-time fuel flow rate to obtain the back pressure simulation valve opening; or, selecting multiple points closest to the valve pressure difference and the real-time fuel flow rate within the calibration relationship, and calculating the back pressure simulation valve opening by fitting and interpolation.

[0015] Optionally, the step of selecting multiple points closest to the valve pressure difference and the real-time fuel flow rate within the calibration relationship, and then fitting and interpolating to calculate the back pressure simulation valve opening includes: selecting the points (P) closest to the valve pressure difference and the real-time fuel flow rate within the calibration relationship. x Q x The four most recent differential pressure and flow rate points (P) n Q n ), (P n+1 Q n ), (P n Q n+1 ), (P n+1 Q n+1 These four points correspond to openings of K respectively. n,n K n+1,n K n,n+1 K n+1,n+1 ;

[0016] According to P n+1 P x P n K n,n+1 and K n+1,n+1 Linear interpolation yields K x,n+1 ;

[0017] According to P n+1 P x P n K n,n and K n+1,n Linear interpolation yields K x,n ;

[0018] According to K x,n K x,n+1 Q n+1 Q x and Q n The opening degree K of the back pressure simulation valve is obtained by linear interpolation. x,x .

[0019] Optionally, the statement based on P n+1 P x P n Kn,n+1 and K n+1,n+1 Linear interpolation yields K x,n+1 The calculation formula includes, According to P n+1 P x P n K n,n and K n+1,n Linear interpolation yields K x,n The calculation formula includes, According to K x,n K x,n+1 Q n+1 Q x and Q n The opening degree K of the back pressure simulation valve is obtained by linear interpolation. x,x The calculation formula includes, Among them, K n,n Point (P) n Q n The corresponding valve opening, K n+1,n Point (P) n+1 Q n The corresponding valve opening, K n,n+1 Point (P) n Q n+1 The valve opening degree, K n+1,n+1 Point (P) n+1 Q n+1 The corresponding valve opening, K x,x Point (P) x Q x The valve opening degree, K x,n+1 and K x,n This is for interpolation.

[0020] Embodiments of the present invention also provide a rapid dynamic following test system for fuel control system nozzle back pressure, used to implement a rapid dynamic following test method for fuel control system nozzle back pressure. The rapid dynamic following test system for fuel control system nozzle back pressure includes an engine control unit (EEC), an engine model, a flow meter, a pressure sensor, and a back pressure simulation valve. The pressure sensor is used to detect the real-time downstream pressure of the back pressure simulation valve. The flow meter is connected to the engine model and the EEC, and is used to measure the real-time fuel flow rate. The engine model is connected to the EEC, and is used to calculate and output the nozzle back pressure based on the real-time fuel flow rate.

[0021] Optionally, the fuel control system nozzle back pressure rapid dynamic follow test system further includes a fuel pump, an FMV, and a nozzle, wherein the fuel pump, the FMV, the flow meter, the nozzle, and the back pressure simulation valve are connected in sequence.

[0022] The beneficial effects of the fuel control system nozzle back pressure rapid dynamic following test method and system of the present invention include, for example:

[0023] A rapid dynamic tracking test method for back pressure after the fuel control system nozzle includes the following steps: obtaining the calibration relationship between the valve opening and the pressure difference across the back pressure simulation valve under different fuel flow rates; obtaining the real-time back pressure after the back pressure simulation valve; obtaining the real-time fuel flow rate; obtaining the back pressure after the nozzle calculated by the engine model based on the real-time fuel flow rate; obtaining the back pressure simulation valve opening based on the real-time back pressure, back pressure after the nozzle, and real-time fuel flow rate, combined with the calibration relationship; and controlling the back pressure simulation valve based on the back pressure simulation valve opening.

[0024] First, the flow rate of the back pressure simulation valve is calibrated to obtain the relationship between the valve opening and the pressure difference across the valve under different flow rates. Then, the fuel flow rate is measured in real time by the flow meter, and the back pressure after the nozzle is calculated by the engine model. Combined with the pressure after the back pressure valve, the required pressure difference across the back pressure valve is calculated. Then, the required valve opening is obtained from the calibration relationship based on the flow rate and pressure difference. The valve opening command is sent to the controller to enable the valve to perform closed-loop control, so as to achieve rapid follow-up response of the back pressure after the nozzle, improve the accuracy of back pressure simulation and the response speed of back pressure follow-up.

[0025] The fuel control system nozzle back pressure rapid dynamic follow test system is used to implement the above-mentioned fuel control system nozzle back pressure rapid dynamic follow test method, which can improve the problem of large back pressure simulation error and insufficient real-time accuracy under transient conditions of fuel control system. Attached Figure Description

[0026] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0027] Figure 1 This invention provides a flowchart illustrating the steps of a rapid dynamic following test method for fuel control system nozzle back pressure according to an embodiment of the present invention.

[0028] Figure 2 A flowchart of the rapid dynamic following test method for fuel control system nozzle back pressure provided in an embodiment of the present invention is shown;

[0029] Figure 3This diagram illustrates the calculation points for the back pressure simulation valve opening in the rapid dynamic following test method for back pressure after the nozzle in the fuel control system provided by an embodiment of the present invention. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0031] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0032] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] The following is combined Figures 1 to 3 The rapid dynamic following test method for back pressure after the fuel control system nozzle provided in this embodiment is described in detail.

[0035] Please refer to Figure 1 and Figure 2 The present invention provides a method for rapid dynamic following test of back pressure after the nozzle in a fuel control system, comprising the following steps:

[0036] Step S1: Obtain the calibration relationship between the valve opening and the pressure difference across the valve for the back pressure simulation valve under different fuel flow rates. Perform constant flow calibration on the back pressure simulation valve to obtain the relationship between the valve opening and the pressure difference across the valve at a certain flow rate. Given different flow rates, obtain the calibration relationship between the valve opening and the pressure difference across the valve at different flow rates.

[0037] Step S2: Obtain the real-time downstream pressure of the back pressure simulation valve. The real-time upstream pressure of the back pressure simulation valve is used to simulate the back pressure after the engine nozzle. The pressure difference across the back pressure simulation valve can be obtained through the real-time downstream pressure.

[0038] Step S3: Obtain real-time fuel flow rate. This real-time fuel flow rate is the fuel flow rate measured in real time, which is the fuel flow rate entering the engine combustion chamber.

[0039] Step S4: Obtain the nozzle back pressure calculated by the engine model based on the real-time fuel flow rate. The engine model is a mathematical model that describes the engine's working process and performance characteristics through mathematical equations. The real-time fuel flow rate is input into the engine model, and the engine model calculates engine state parameters, including the nozzle back pressure, based on the currently measured fuel flow rate and the current engine state.

[0040] Step S5: Based on the real-time downstream valve pressure, downstream nozzle back pressure, and real-time fuel flow rate, and in conjunction with the calibration relationship, obtain the back pressure simulation valve opening. The calibration relationship includes the relationship between flow rate, pressure difference, and opening. By substituting the measured and calculated parameters into the calibration relationship, the corresponding back pressure simulation valve opening can be obtained.

[0041] Step S6: Control the back pressure simulation valve according to the opening degree of the back pressure simulation valve.

[0042] The process involves first calibrating the back pressure simulation valve at a constant flow rate to obtain the relationship between the valve opening and the pressure difference across the valve under different fuel flow rates. Then, the back pressure after the nozzle is calculated using the engine model, combined with the real-time valve pressure, to calculate the required pressure difference across the valve, and the real-time fuel flow rate measured by the flow meter. Based on the calibrated relationship between flow rate and pressure difference, the required back pressure simulation valve opening is obtained. The command for the back pressure simulation valve opening is sent to the valve to control the back pressure simulation valve, achieving rapid response to the back pressure after the nozzle. This method is suitable for semi-physical simulation tests of fuel control systems, fuel icing tests, and other fuel system tests requiring back pressure simulation. It can more accurately verify the dynamic response of servo actuation systems in transient processes and verify the thermal management design of fuel oil systems. It has wide applicability and strong practicality in the field of engine fuel system testing. Based on the real-time fuel flow rate and pressure after the nozzle obtained during the test, the required valve opening is obtained through fitting and interpolation methods, enabling rapid and accurate tracking of the back pressure after the nozzle of the fuel distribution system, improving test efficiency and the validity of test results, and reducing test risks.

[0043] Reference Figure 1 and Figure 2 In this embodiment, step S1, obtaining the calibration relationship between the valve opening and the pressure difference across the back pressure simulation valve under different fuel flow rates, includes:

[0044] Step S11: Under the condition that the fuel flow rate is a set value, the pressure difference across the valve is obtained according to the different valve openings of the back pressure simulation valve, thereby obtaining the flow rate-pressure difference-opening curve.

[0045] Step S12: Under the condition that the set value is different, repeat step S21. Under the condition that the fuel flow rate is the set value, according to the different valve openings of the back pressure simulation valve, obtain the corresponding pressure difference before and after the valve, thereby obtaining the flow rate-pressure difference-opening curve, and obtaining multiple flow rate-pressure difference-opening curves.

[0046] Through experiments, while maintaining a constant fuel flow rate, the opening of the back pressure simulation valve was adjusted, and the corresponding pressure difference across the valve was recorded. This allows for the generation of a curve showing the relationship between valve opening and pressure difference for each given flow rate. This establishes the correlation between valve opening and pressure difference under different flow rates. This is to achieve precise control of the back pressure simulation valve, ensuring accurate simulation of the back pressure after the nozzle under various operating conditions.

[0047] Reference Figure 1 and Figure 2 In this embodiment, step S2, obtaining the real-time downstream pressure of the back pressure simulation valve includes: step S21, obtaining the real-time downstream pressure of the back pressure simulation valve measured by a pressure sensor.

[0048] The pressure sensor measures the pressure after the valve of the back pressure simulation valve. Based on the back pressure after the nozzle output by the engine model, the pressure difference before and after the valve of the back pressure simulation valve is obtained. Substituting this into the calibration relationship, the corresponding valve opening can be obtained.

[0049] Reference Figure 1 and Figure 2 In this embodiment, step S3, obtaining the real-time fuel flow rate, includes: step S31, obtaining the real-time fuel flow rate measured by the flow meter; wherein, the flow meter is connected to the FMV (Fuel Metering Valve) and the engine model, the flow meter is used to measure the fuel flow rate output by the FMV, and outputs the measured real-time fuel flow rate value to the engine model and the controller. After receiving the real-time measured fuel flow rate, the engine model outputs back pressure after the nozzle, and at the same time, based on the real-time fuel force and valve pressure difference, the valve opening can be obtained by substituting it into the calibration relationship.

[0050] Reference Figure 1 and Figure 2 In this embodiment, step S5, which involves obtaining the back pressure simulation valve opening based on the real-time valve downstream pressure, nozzle downstream back pressure, and real-time fuel flow rate, combined with the calibration relationship, includes:

[0051] Step S51: Obtain the valve differential pressure based on the difference between the real-time downstream valve pressure and the downstream nozzle back pressure;

[0052] Step S52: Based on the valve pressure difference value, the back pressure simulation valve opening is obtained by combining the real-time fuel flow rate and calibration relationship.

[0053] The calibration relationship stores a database of correspondences between flow rate, differential pressure, and opening degree. The difference between the real-time downstream pressure and the back pressure after the nozzle is the valve differential pressure. In the calibration relationship, the differential pressure across the valve is taken as the valve differential pressure. Combined with the real-time fuel flow rate, the corresponding back pressure simulates the valve opening degree.

[0054] Reference Figure 1 and Figure 2 In this embodiment, step S52, which involves obtaining the back pressure simulation valve opening based on the valve pressure difference across the valve and combining it with the real-time fuel flow rate and calibration relationship, includes:

[0055] Step S521: Based on the valve pressure difference and real-time fuel flow rate, the back pressure simulation valve opening is obtained by taking the corresponding values ​​from the calibration relationship. This step is for cases where the values ​​of valve pressure difference and real-time fuel flow rate can be directly read from the calibration relationship. If they cannot be directly read, they need to be calculated in step S522.

[0056] Alternatively, in step S522, select multiple points closest to the valve pressure differential and real-time fuel flow rate within the calibration relationship, and calculate the back pressure simulated valve opening using fitting interpolation. Select the closest points, and then calculate the back pressure simulated valve opening corresponding to the valve pressure differential and real-time fuel flow rate.

[0057] Reference Figure 2 and Figure 3 In this embodiment, step S522, which involves selecting multiple points closest to the valve pressure difference and real-time fuel flow rate within the calibration relationship and then using fitting interpolation to calculate the back pressure simulation valve opening, includes:

[0058] Select the point (P) where the valve pressure difference and real-time fuel flow rate are located in the calibration relationship. x Q x The four most recent differential pressure and flow rate points (P) n Q n ), (P n+1 Q n ), (P n Q n+1 ), (P n+1 Q n+1 These four points correspond to openings of K respectively. n,n K n+1,n K n,n+1 Kn+1,n+1 ;

[0059] According to P n+1 P x P n K n,n+1 and K n+1,n+1 Linear interpolation yields K x,n+1 ;

[0060] According to P n+1 P x P n K n,n and K n+1,n Linear interpolation yields K x,n ;

[0061] According to K x,n K x,n+1 Q n+1 Q x and Q n Linear interpolation yields the back pressure simulation valve opening K. x,x .

[0062] A certain pressure difference P a The following corresponds to a certain flow Q b The required valve opening is represented by K. a,b This means that if the pressure difference P at the uncalibrated point is to be obtained... x Traffic Q x The required valve opening K x,x The distance (P) needs to be found in the calibration table. x Q x The four points most recently calibrated for differential pressure and flow rate: (P) n Q n ), (P n+1 Q n ), (P n Q n+1 ), (P n+1 Q n+1 The flow rate, differential pressure, and valve opening K at these four points are used to determine the values. n,n K n+1,n K n,n+1 K n+1,n+1 K can be obtained by linear interpolation. x,n+1 and K x,n : Then interpolation will yield the point (P) x Q x Valve opening degree K x,x .

[0063] Specifically, according to P n+1 P x P n Kn,n+1 and K n+1,n+1 Linear interpolation yields K x,n+1 The calculation formula includes,

[0064] According to P n+1 P x P n K n,n and K n+1,n Linear interpolation yields K x,n The calculation formula includes,

[0065] According to K x,n K x,n+1 Q n+1 Q x and Q n Linear interpolation yields the back pressure simulation valve opening K. x,x The calculation formula includes,

[0066] Among them, K n,n Point (P) n Q n The corresponding valve opening, K n+1,n Point (P) n+1 Q n The corresponding valve opening, K n,n+1 Point (P) n Q n+1 The valve opening degree, K n+1,n+1 Point (P) n+1 Q n+1 The corresponding valve opening, K x,x Point (P) x Q x The valve opening degree, K x,n+1 and K x,n This is for interpolation.

[0067] Reference Figure 2 The present invention also provides a rapid dynamic following test system for fuel control system nozzle back pressure, used to implement a rapid dynamic following test method for fuel control system nozzle back pressure. The rapid dynamic following test system for fuel control system nozzle back pressure includes an engine control unit (EEC), an engine model, a flow meter, a pressure sensor, and a back pressure simulation valve. The pressure sensor is used to detect the real-time downstream pressure of the back pressure simulation valve. The flow meter is connected to the engine model and the EEC, and is used to measure the real-time fuel flow rate. The engine model is connected to the EEC, and is used to calculate and output the nozzle back pressure based on the real-time fuel flow rate.

[0068] EEC (Electronic Engine Control) is a core component of aircraft engine control systems, playing a crucial role, especially in Full Authority Digital Engine Control (FADEC) systems.

[0069] Reference Figure 2 In this embodiment, the fuel control system nozzle back pressure rapid dynamic following test system also includes a fuel pump, an FMV and a nozzle, with the fuel pump, FMV, flow meter, nozzle and back pressure simulation valve connected in sequence.

[0070] The fuel pump is responsible for drawing fuel from the fuel tank, pressurizing it, and delivering it to the engine. The main function of the fuel injection fan (FMV) is to regulate the flow of fuel into the engine's combustion chamber. By changing the opening of the FMV, the amount of fuel injected can be precisely controlled to meet the engine's needs under different operating conditions. The opening of the FMV is adjusted by the engine control engine (EEC) via a control signal to achieve precise control of the fuel flow.

[0071] According to the embodiment provided, a rapid dynamic following test method for nozzle back pressure of a fuel control system is provided. The working principle of the rapid dynamic following test method for nozzle back pressure of a fuel control system includes: applicable to nozzle back pressure simulation. During the operation of an aero-engine, the combustion chamber has high pressure, which causes a certain back pressure on the nozzle and fuel conditioning system. When conducting fuel conditioning system tests, the combustion chamber pressure is simulated using hydraulic components, which is called nozzle back pressure simulation. Transient condition refers to the state during engine operation where the flow and pressure of various parts of the fuel system are constantly changing. A semi-physical test bench is used to support the implementation of semi-physical tests on the engine control system, using the engine fuel control system as the test object, to perform system integration verification; to verify the matching of the fuel control system's hardware and software, and its compliance with the technical requirements of the fuel control system. A fuel icing test bench is used to support the implementation of fuel icing tests on the engine control system, using the engine fuel control system as the test object; to verify the reliable operation capability of the fuel control system under different ambient temperatures, different medium temperatures, and different ice contents.

[0072] First, the back pressure simulation valve is calibrated at a constant flow rate to obtain the relationship between the valve opening and the pressure difference across the valve at a certain flow rate. Different flow rates are then used to obtain the relationship between the valve opening and the pressure difference across the valve at different flow rates. During semi-physical tests of the control system and fuel icing tests, the Electronic Control Unit (EEC) receives the start signal and outputs the engine mathematical model start signal. The engine mathematical model calculates engine state parameters (including back pressure after the nozzle) based on the currently measured fuel flow rate and the current engine state. The EEC collects the output of the engine mathematical model and calculates the control values ​​of various valves and actuators in the fuel control system according to the control law. Simultaneously, it controls the corresponding hydraulic servo actuators and fuel metering valves to ensure that each control quantity meets the requirements of the EEC. The required back pressure simulation valve differential pressure is calculated from the nozzle back pressure and back pressure simulation valve pressure output by the engine mathematical model. The fuel flow rate is measured in real time by the flow meter. The required back pressure simulation valve opening is obtained by fitting and interpolating the flow rate and pressure difference in the calibration relationship. Then, the valve opening is controlled in an open loop. The open loop control of the valve opening replaces the closed loop pressure following under flow and pressure disturbances, so as to realize the rapid following of the nozzle back pressure simulation and improve the accuracy of the nozzle back pressure simulation.

[0073] The rapid dynamic following test method for fuel control system nozzle back pressure provided in this embodiment has at least the following advantages:

[0074] First, the flow rate of the back pressure simulation valve is calibrated to obtain the relationship between valve opening and pressure difference across the valve under different flow rates. Then, the fuel flow rate is measured in real time by a flow meter, and the back pressure after the nozzle is calculated by the engine model. Combined with the pressure after the back pressure valve, the required pressure difference across the back pressure valve is calculated. Then, based on the flow rate and pressure difference, the required valve opening is obtained from the calibration relationship. The valve opening command is sent to the controller to enable closed-loop control of the valve, thereby achieving rapid response to the back pressure after the nozzle. This eliminates the dependence on the actual combustion chamber back pressure in semi-physical tests of aero-engines, and simulates the back pressure after the nozzle in a hydraulic circuit, thereby improving the test efficiency, test quality, and reducing test costs. By changing the pressure closed-loop control to valve opening open-loop control through the control algorithm, the disturbance of flow rate and pressure to the pressure closed loop is avoided, improving the accuracy of back pressure simulation and the response speed of back pressure following.

[0075] Based on the real-time fuel flow and nozzle back pressure obtained during the test, the required valve opening is obtained through fitting and interpolation. This method can quickly and accurately follow the back pressure after the fuel distribution system nozzle, improving test efficiency and the validity of test results, and reducing test risks.

[0076] This device is used for semi-physical simulation testing of fuel control systems, fuel icing tests, and other fuel system tests requiring back pressure simulation. It can more accurately verify the dynamic response of servo actuation systems during transient processes and validate the thermal management design of lubricating oil systems. It has wide applicability and strong practicality in the field of engine fuel system testing. It simulates the dynamic changes of back pressure in a real combustion chamber, providing assurance for performance testing of fuel control systems and fuel thermal management testing. The nozzle back pressure simulation test device, which balances economy, flexibility, high efficiency, and simulation accuracy, is used to conduct performance and reliability assessments of semi-physical simulation of aero-engine fuel control systems and fuel icing tests under transient conditions.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid dynamic following test of back pressure after the nozzle in a fuel control system, characterized in that, Includes the following steps: Obtain the calibration relationship between the valve opening and the pressure difference across the valve for the back pressure simulation valve under different fuel flow rates; Obtain the real-time downstream pressure of the back pressure simulation valve; Obtain real-time fuel flow; Obtain the nozzle back pressure calculated by the engine model based on the real-time fuel flow rate; Based on the real-time valve downstream pressure, the nozzle downstream back pressure, and the real-time fuel flow rate, combined with the calibration relationship, the back pressure simulates the valve opening. The back pressure simulation valve is controlled according to its opening degree.

2. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 1, characterized in that, The steps for obtaining the calibration relationship between the valve opening and the pressure difference across the back pressure simulation valve under different fuel flow rates include: With the fuel flow rate set, the pressure difference across the valve is obtained according to the different valve openings of the back pressure simulation valve, thus obtaining the flow rate-pressure difference-opening curve. Under different set values, the process of obtaining the corresponding pressure difference across the valve based on different valve openings of the back pressure simulation valve under the condition of a set fuel flow rate is repeated, thereby obtaining the flow-pressure difference-opening curve, and thus obtaining multiple flow-pressure difference-opening curves.

3. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 1, characterized in that, The step of obtaining the real-time downstream pressure of the back pressure simulation valve includes: The real-time downstream pressure of the back pressure simulation valve is obtained by measuring the pressure sensor.

4. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 1, characterized in that, The steps for obtaining real-time fuel flow include: The flow meter is used to measure the real-time fuel flow rate. The flow meter is connected to the FMV and the engine model. The flow meter is used to measure the fuel flow rate output by the FMV and output the measured real-time fuel flow rate value to the engine model and the controller.

5. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 1, characterized in that, The step of obtaining the back pressure simulated valve opening based on the real-time valve post-pressure, the nozzle post-back pressure, and the real-time fuel flow rate, combined with the calibration relationship, includes: The valve differential pressure is obtained based on the difference between the real-time downstream valve pressure and the downstream nozzle back pressure. The valve opening degree is obtained by taking the valve pressure difference value as the valve pressure difference value, combining the real-time fuel flow rate and the calibration relationship.

6. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 5, characterized in that, The step of obtaining the back pressure simulation valve opening based on the valve pressure difference value and combining it with the real-time fuel flow rate and the calibration relationship includes: The opening degree of the back pressure simulation valve is obtained by taking the corresponding value on the calibration relationship based on the valve pressure difference and the real-time fuel flow rate. Alternatively, based on the calibration relationship, select multiple points that are closest to the valve pressure difference and the real-time fuel flow, and use fitting interpolation to calculate the back pressure simulation valve opening.

7. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 6, characterized in that, The step of selecting multiple points closest to the valve pressure difference and the real-time fuel flow rate within the calibration relationship, and then using fitting interpolation to calculate the back pressure simulation valve opening includes: Select the point (P) in the calibration relationship that is far from the valve pressure difference and the real-time fuel flow rate. x Q x The four most recent differential pressure and flow rate points (P) n Q n ), (P n+1 Q n ), (P n Q n+1 ), (P n+1 Q n+1 These four points correspond to openings of K respectively. n,n K n+1,n K n,n+1 K n+1,n+1 ; According to P n+1 P x P n K n,n+1 and K n+1,n+1 Linear interpolation yields K x,n+1 ; According to P n+1 P x P n K n,n and K n+1,n Linear interpolation yields K x,n ; According to K x,n K x,n+1 Q n+1 Q x and Q n The opening degree K of the back pressure simulation valve is obtained by linear interpolation. x,x .

8. The rapid dynamic following test method for back pressure after the fuel control system nozzle according to claim 7, characterized in that, According to P n+1 P x P n K n,n+1 and K n+1,n+1 Linear interpolation yields K x,n+1 The calculation formula includes, According to P n+1 P x P n K n,n and K n+1,n Linear interpolation yields K x,n The calculation formula includes, According to K x,n K x,n+1 Q n+1 Q x and Q n The opening degree K of the back pressure simulation valve is obtained by linear interpolation. x,x The calculation formula includes, Among them, K n,n Point (P) n Q n The corresponding valve opening, K n+1,n Point (P) n+1 Q n The corresponding valve opening, K n,n+1 Point (P) n Q n+1 The valve opening degree, K n+1,n+1 Point (P) n+1 Q n+1 The corresponding valve opening, K x,x Point (P) x Q x The valve opening degree, K x,n+1 and K x,n This is for interpolation.

9. A rapid dynamic following test system for back pressure after the nozzle of a fuel control system, used to implement the rapid dynamic following test method for back pressure after the nozzle of a fuel control system according to any one of claims 1-8, characterized in that, The fuel control system nozzle back pressure rapid dynamic following test system includes an engine control unit (EEC), an engine model, a flow meter, a pressure sensor, and a back pressure simulation valve. The pressure sensor is used to detect the real-time back pressure of the back pressure simulation valve. The flow meter is connected to the engine model and the EEC, and is used to measure the real-time fuel flow rate. The engine model is connected to the EEC, and is used to calculate and output the nozzle back pressure based on the real-time fuel flow rate.

10. The rapid dynamic following test system for back pressure after the fuel control system nozzle according to claim 9, characterized in that, The fuel control system nozzle back pressure rapid dynamic follow test system also includes a fuel pump, an FMV, and a nozzle, wherein the fuel pump, the FMV, the flow meter, the nozzle, and the back pressure simulation valve are connected in sequence.

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