A method for increasing the temperature of the inlet fuel of a system and of the accessories

Abstract

The application belongs to the field of engine fuel thermal management, and particularly relates to a test method for improving system and accessory fuel inlet temperature, based on flight data, obtaining existing load spectrum under different flight states, formulating test operation spectrum; based on the test operation spectrum, statistically analyzing actual flight data, determining working time and temperature distribution of the engine under different states; selecting the highest temperature under the corresponding state as the test state, and performing fuel system test under different temperatures; obtaining temperature rise of different elements of the fuel system under the corresponding working state, determining the temperature load spectrum of the control system and accessories; statistically analyzing the temperature rise of the control system and accessories under different states, and determining the inlet fuel temperature rise. According to 14 kinds of mission profiles of the aircraft, combining test flight data statistics and working principles of the fuel system, precise distribution prediction of the inlet fuel temperature rise to the highest 93 DEG C is realized, and a scientific basis is provided for test load design.

Description

Technical Field

[0001] This application belongs to the field of engine fuel thermal management, and specifically relates to a test method for improving the fuel inlet temperature of systems and accessories. Background Technology

[0002] Modern aircraft are constantly demanding higher requirements in terms of supersonic cruise capability, stealth, and maneuverability. As the power of aircraft avionics increases, the contradiction between the high temperature of the equipment cooling medium and the extended mission usage time becomes more prominent. Reducing the equipment cooling medium through fuel heat exchange has become the main method, and the resulting increase in engine inlet fuel temperature urgently needs to be addressed.

[0003] Modern aircraft employ integrated management technology, rationally connecting their disparate electromechanical systems to significantly improve performance. A key technological aspect of this is energy / thermal management. Aircraft use fuel as the final heat sink, cooling the environmental control system, hydraulic system, lubrication system, and engine's thermal load before entering the engine for combustion. Excess fuel can return to the aircraft's fuel tanks, forming a circulation system. Compared to ram air, fuel offers advantages such as temperature stability under all flight conditions, no impact on stealth performance, and minimal compensatory losses, making it a viable new heat sink. Currently, due to the separate design of aircraft components and engines, domestic and international research primarily focuses on aircraft fuel thermal management systems, with less research on engine fuel thermal management systems.

[0004] The aircraft engine is the "heart" of an aircraft. High-temperature fuel entering the fuel injection system and its accessories can pose a safety hazard. Currently, the inability to raise the temperature of imported fuel not only reduces the control accuracy and reliability of the engine's fuel control system and shortens the service life of fuel accessories, but also significantly reduces the cooling efficiency of the fuel for the lubricating oil. High-temperature fuel can harm engine performance and safety. Changes in fuel temperature alter its physical properties, reducing the accuracy of fuel metering devices and causing inaccurate fuel measurements; fuel leakage may increase; pump cavitation may occur; the thermal stability of the fuel may be compromised, leading to coking and blockage of pipelines; and electrical components within the engine's fuel system cannot operate at high temperatures.

[0005] Therefore, how to effectively manage engine fuel thermal power is a problem that needs to be solved. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a test method for increasing the fuel inlet temperature of a system and its accessories, thereby resolving the problem of limited research on engine fuel thermal management systems in the prior art.

[0007] The technical solution of this application is: a test method for improving the fuel inlet temperature of a system and its accessories, comprising:

[0008] Based on the aircraft's mission profile, flight data under various states are collected; based on the flight data, the existing load spectrum under different flight states is obtained, and the test operation spectrum is formulated.

[0009] Based on the test operation map, the actual flight data were statistically analyzed to determine the engine's operating time and temperature distribution under different conditions;

[0010] The highest temperature under the corresponding condition is selected as the test condition, and fuel system tests are conducted at different temperatures; the temperature rise of different components of the fuel system under the corresponding working conditions is obtained, and the temperature load spectrum of the control system and accessories is determined.

[0011] Statistical analysis of temperature rise was performed on the temperature load spectrum of the control system and its components under different conditions to determine the temperature rise of the imported fuel.

[0012] Preferably, the flight data for each state is statistically analyzed, specifically as follows:

[0013] Statistical analysis of booster pump outlet fuel temperature Tt and physical speed under various conditions of the task profile;

[0014] Collect experimental data, establish a temperature-time distribution map (Tt), divide the experimental temperature into four regions: low temperature, medium temperature, high temperature, and extreme temperature, and determine the main experimental temperature.

[0015] Then, based on the test temperatures of the four regions and the main test region, the inlet temperature of each test piece was determined, and a test operation chart was developed.

[0016] Preferably, the operating time and temperature distribution of the engine under different conditions are determined, specifically as follows:

[0017] Obtain operational data for four regions in the test operation map, including: the maximum statistical value of Tt, the Tt temperature after Tfin is increased, the test temperature of the main fuel pump regulator, the test temperature of the starting device, the test temperature of the nozzle fuel source pump, the test temperature of the nozzle afterburner regulator, and the test temperature of the afterburner fuel distributor; Tfin is the aircraft fuel inlet temperature;

[0018] The usage time of the four zones and the Tt temperature after the aircraft provides fuel temperature rise are determined based on the operational data.

[0019] Preferably, the temperature load spectrum of the control system and its components is determined as follows:

[0020] Obtain the number of cycles and cycle time of a fuel system test at different temperatures for a certain component, and statistically analyze the speed distribution data under the corresponding temperature conditions for each cycle, including speed range, duration, test speed, and speed range time.

[0021] After processing the rotational speed distribution data, a corresponding temperature load spectrum is established. After establishing the temperature load spectrum of all components, the temperature load spectrum of the control system and its accessories is obtained.

[0022] Preferably, after obtaining the speed distribution data, the time of the speed interval is rounded up, and the minimum speed interval is the difference between the working time of 5 hours and other speed intervals; for the same speed conditions in the speed distribution data, a constant temperature is used.

[0023] Preferably, temperature rise statistical analysis is performed on the temperature load spectrum of the control system and its components under different states. Specifically, based on the temperature load spectrum of the four intervals, the cyclic spectrum under the extreme temperature, the cyclic spectrum under the high temperature condition, the cyclic spectrum under the medium temperature condition, the cyclic spectrum under the low temperature condition, and the semi-physical load spectrum are established for each component. The temperature rise of the imported fuel is determined, and the impact of the temperature rise of the imported fuel on the control quality is verified by recording dynamic performance before and after the semi-physical long-term test.

[0024] The test method for increasing the fuel inlet temperature of the system and accessories in this application has the following advantages:

[0025] Based on 14 mission profiles of the aircraft, combined with flight test data statistics and the working principle of the fuel system, the accurate distribution prediction of the imported fuel temperature after it rises to a maximum of 93°C is achieved, providing a scientific basis for the design of test loads.

[0026] The proposed load requirements for the accessory tests and semi-physical tests have a load spectrum that comprehensively covers the engine's full envelope, full mission profile, and fuel temperature operating range throughout its entire lifespan, and is highly similar to actual operating conditions.

[0027] A complete test system was established, consisting of "temperature range division - speed statistical matching - multi-parameter load spectrum design of core accessories - semi-physical verification", which enabled the standardized and systematic implementation of high-temperature fuel inlet tests for the system and accessories. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the fuel system and related flow paths in this application;

[0029] Figure 2 This is a schematic diagram of the time segmentation of the Tt temperature data in this application (226 state points sorted by Tt);

[0030] Figure 3 This is a schematic diagram of the rotational speed distribution data (sorted by N2) under low-temperature conditions according to this application;

[0031] Figure 4 This is a schematic diagram of the rotational speed distribution data (sorted by N2) under the temperature conditions in this application;

[0032] Figure 5This is a schematic diagram of the rotational speed distribution data (sorted by N2) under high temperature conditions in this application;

[0033] Figure 6 This is a schematic diagram of the rotational speed distribution data (sorted by N2) under extreme temperature conditions of this application;

[0034] Figure 7 This is a schematic diagram of the load spectrum of the main fuel pump regulator under the extreme temperature (123℃) condition of this application;

[0035] Figure 8 This is a schematic diagram of the load spectrum of the main fuel pump regulator under high temperature (113℃) conditions in this application;

[0036] Figure 9 This is a schematic diagram of the load spectrum of the main fuel pump regulator under medium temperature (98°C) conditions in this application;

[0037] Figure 10 This is a schematic diagram of the load spectrum of the main fuel pump regulator under medium temperature (83℃) conditions in this application;

[0038] Figure 11 This is a schematic diagram of flight profile data at different state points (sorted by T1) in this application;

[0039] Figure 12 This is a schematic diagram of the semi-physical test pattern (fuel system inlet temperature 93℃) of this application. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0041] Based on the fuel system piping diagram of a certain type of engine, the main fuel line and the main return fuel line were identified, forming the schematic diagram of the main fuel flow path of the fuel thermal management system (see...). Figure 1 The main components related to the flow characteristics of the fuel working fluid in the fuel thermal management system include the fuel booster pump, main fuel pump regulator, afterburner fuel pump, fuel injection pump, main fuel radiator, starting device, fuel injectors, etc.

[0042] The first aspect of this application provides a test method for increasing the fuel inlet temperature of a system and its accessories, comprising the following steps:

[0043] Step S100: Based on the aircraft's mission profile, collect flight data under various states; based on the flight data, obtain the existing load spectrum under different flight states and formulate the test operation map.

[0044] Preferably, the flight data for each state is statistically analyzed, specifically as follows:

[0045] Statistical analysis of booster pump outlet fuel temperature Tt and physical speed under various conditions of the task profile;

[0046] Collect experimental data, establish a temperature-time distribution map (Tt), divide the experimental temperature into four regions: low temperature, medium temperature, high temperature, and extreme temperature, and determine the main experimental temperature.

[0047] Then, based on the test temperatures of the four regions and the main test region, the inlet temperature of each test piece was determined, and a test operation chart was developed.

[0048] The four regions of low temperature, medium temperature, high temperature and extreme temperature are respectively: [min, 70], (70, 85], (85, 100], (100, max] four temperature ranges; taking an increase of about 13℃ and a temperature rise of 10℃ on the existing Tfin as an example, the main test temperatures are determined to be 83+10℃, 98+10℃, 113+10℃ and 123+10℃.

[0049] Since the most severe conditions are taken when calculating the Tt temperature, the safety factor is no longer added to the Tt temperature.

[0050] Step S200: Based on the test operation map, statistical analysis of actual flight data is performed to determine the operating time and temperature distribution of the engine under different conditions.

[0051] Preferably, the operating time and temperature distribution of the engine under different conditions are determined, specifically as follows:

[0052] Obtain operational data for four regions in the test operation map, including: the maximum statistical value of Tt, the Tt temperature after Tfin is increased, the test temperature of the main fuel pump regulator, the test temperature of the starting device, the test temperature of the nozzle fuel source pump, the test temperature of the nozzle afterburner regulator, and the test temperature of the afterburner fuel distributor; Tfin is the aircraft fuel inlet temperature;

[0053] The usage time of the four zones and the Tt temperature after the aircraft provides fuel temperature rise are determined based on the operational data.

[0054] The inlet temperatures of each test piece are shown in Table 1, and the time distribution of each temperature is summarized in Table 2. Each test procedure is tentatively set at 5 hours, and the number of test cycles at different temperatures is shown in Table 3.

[0055] Table 1 Inlet temperature of each test piece

[0056]

[0057] in:

[0058] Tt statistical range: four intervals after dividing the Tt temperature;

[0059] Tt statistical maximum value: the maximum value for each temperature range;

[0060] Tt temperature after Tfin increase: The Tt temperature after the aircraft provides a 13°C increase in fuel temperature (considered as the same as an increase of 13°C).

[0061] Test temperature for each test piece: inlet fuel temperature for each test piece;

[0062] △T: 10℃ (forced state) or 15℃ (unforced state).

[0063] Table 2 Summary of Temperature Distribution Time

[0064]

[0065] in:

[0066] Temperature range: The four intervals after dividing the temperature Tt;

[0067] Usage time: The cumulative working time within each Tt temperature range after dividing the Tt temperature range;

[0068] Test temperature: Tt temperature after the aircraft fuel temperature is increased by 13°C (considered as the same as an increase of 13°C).

[0069] Table 3 Summary of test cycles at each temperature

[0070]

[0071] in:

[0072] Test temperature: Tt temperature after the aircraft fuel temperature is increased by 13°C (considered as the same as an increase of 13°C);

[0073] Usage time: The cumulative working time within each Tt temperature range after dividing the Tt temperature range;

[0074] Number of cycles: Calculated based on 5 hours per cycle spectrum, the number of cycles required for each test temperature;

[0075] Cycle time: The test time calculated by multiplying the number of cycles by 5 hours is used to compare the time required to complete the test.

[0076] Step S300: Select the highest temperature under the corresponding state as the test state, and conduct fuel system tests at different temperatures; obtain the temperature rise of different components of the fuel system under the corresponding working state, and determine the temperature load spectrum of the control system and accessories.

[0077] Preferably, the temperature load spectrum of the control system and its components is determined as follows:

[0078] Obtain the number of cycles and cycle time of a fuel system test at different temperatures for a certain component, and statistically analyze the speed distribution data under the corresponding temperature conditions for each cycle, including speed range, duration, test speed, and speed range time.

[0079] After processing the rotational speed distribution data, a corresponding temperature load spectrum is established. After establishing the temperature load spectrum of all components, the temperature load spectrum of the control system and its accessories is obtained.

[0080] After obtaining the speed distribution data, the time of the speed interval is rounded up, and the minimum speed interval is the difference between the working time of other speed intervals and 5 hours, thus completing the processing of the speed distribution data. For the same speed conditions in the speed distribution data, the fluctuation within the temperature interval is ignored, and a constant temperature is used.

[0081] Based on the existing load spectrum, a test operation chart was developed. To fully simulate engine usage, an idle / fuel temperature Tt=123℃ condition was set before each takeoff.

[0082] The rotational speed distribution under low temperature conditions is shown in the figure. Figure 3 See Table 4. The rotational speed distribution under intermediate temperature conditions is shown in Table 4. Figure 4 See Table 5. The rotational speed distribution under high-temperature conditions is shown in Table 5. Figure 5 See Table 6. The rotational speed distribution under extreme temperature conditions is shown in Table 6. Figure 6 See Table 7.

[0083] Table 4 Rotational speed distribution data under low temperature conditions

[0084]

[0085] Table 5 Rotational speed distribution data under intermediate temperature conditions

[0086]

[0087] Table 6 Rotation speed distribution under high temperature conditions

[0088]

[0089] Table 7 Rotational speed distribution under extreme temperature conditions

[0090]

[0091] in:

[0092] Speed ​​range: Divide the speed range into intervals;

[0093] Duration: The cumulative operating time of N2 within each speed range, in seconds;

[0094] Test speed: The upper limit of each test speed range is taken as the test speed;

[0095] Rotational speed range time: The cumulative working time of N2 within each rotational speed range, in minutes;

[0096] Test rounding: The time in the speed range is rounded up, and the minimum speed range time is the difference between 5 hours and the working time in other speed ranges.

[0097] Step S400: Perform temperature rise statistical analysis on the temperature load spectrum of the control system and accessories under different states to determine the temperature rise of the imported fuel.

[0098] Preferably, temperature rise statistical analysis is performed on the temperature load spectrum of the control system and its components under different states. Specifically, based on the temperature load spectrum of the four intervals, the cyclic spectrum under the extreme temperature, the cyclic spectrum under the high temperature condition, the cyclic spectrum under the medium temperature condition, the cyclic spectrum under the low temperature condition, and the semi-physical load spectrum are established for each component. The temperature rise of the imported fuel is determined, and the impact of the temperature rise of the imported fuel on the control quality is verified by recording dynamic performance before and after the semi-physical long-term test.

[0099] In one specific implementation, taking the main fuel pump as an example, the load spectrum of the main fuel pump regulator and the starting device is as follows: Figure 7 And Table 8:

[0100] Table 8. Limiting Temperature Load Spectrum for High-Temperature Test of Main Fuel Pump Regulator Medium

[0101]

[0102] Cyclic spectra under high temperature conditions, such as Figure 8 As shown in Table 9:

[0103] Table 9 High-Temperature Load Spectrum of Main Fuel Pump Regulator Medium High-Temperature Test

[0104]

[0105] Cyclic spectra under mesothermal conditions, as follows Figure 9 As shown in Table 10:

[0106] Table 10 Temperature Load Spectrum of Main Fuel Pump Regulator Medium in High Temperature Test

[0107]

[0108] Cyclic spectra under low temperature conditions, such as Figure 10 As shown in Table 11:

[0109] Table 11. Limiting Temperature Load Spectrum of Main Fuel Pump Regulator Medium High Temperature Test

[0110]

[0111] Combination Figures 11-12 The specific method for establishing the semi-physical load spectrum is as follows:

[0112] Based on flight profile state points, flight test data was compiled to obtain conditions such as the engine inlet temperature T1 temperature variation range and the fuel system inlet medium temperature. A semi-physical load spectrum was then developed to verify the impact of increased medium temperature on control quality (through dynamic performance comparison analysis before and after the semi-physical long-term test). Figures 11-12 N2 and n2 represent engine speeds.

[0113] In summary, this application has the following advantages:

[0114] Based on 14 mission profiles of the aircraft, combined with flight test data statistics and the working principle of the fuel system, the accurate distribution prediction of the imported fuel temperature after it rises to a maximum of 93°C is achieved, providing a scientific basis for the design of test loads.

[0115] The proposed load requirements for the accessory tests and semi-physical tests have a load spectrum that comprehensively covers the engine's full envelope, full mission profile, and fuel temperature operating range throughout its entire lifespan, and is highly similar to actual operating conditions.

[0116] A complete test system was established, consisting of "temperature range division - speed statistical matching - multi-parameter load spectrum design of core accessories - semi-physical verification", which enabled the standardized and systematic implementation of high-temperature fuel inlet tests for the system and accessories.

[0117] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A test method for increasing the fuel inlet temperature of a system and its accessories, characterized in that, include: Based on the aircraft's mission profile, flight data under various states are collected; based on the flight data, the existing load spectrum under different flight states is obtained, and the test operation spectrum is formulated. Based on the test operation map, the actual flight data were statistically analyzed to determine the engine's operating time and temperature distribution under different conditions; The highest temperature under the corresponding condition is selected as the test condition, and fuel system tests are conducted at different temperatures; the temperature rise of different components of the fuel system under the corresponding working conditions is obtained, and the temperature load spectrum of the control system and accessories is determined. Statistical analysis of temperature rise was performed on the temperature load spectrum of the control system and its components under different conditions to determine the temperature rise of the imported fuel.

2. The test method for increasing the fuel inlet temperature of the system and its accessories as described in claim 1, characterized in that, The flight data for each state is statistically analyzed, specifically as follows: Statistical analysis of booster pump outlet fuel temperature Tt and physical speed under various conditions of the task profile; Collect experimental data, establish a temperature-time distribution map (Tt), divide the experimental temperature into four regions: low temperature, medium temperature, high temperature, and extreme temperature, and determine the main experimental temperature. Then, based on the test temperatures of the four regions and the main test region, the inlet temperature of each test piece was determined, and a test operation chart was developed.

3. The test method for increasing the fuel inlet temperature of the system and its accessories as described in claim 2, characterized in that, Determine the operating time and temperature distribution of the engine under different conditions, specifically: Obtain operational data for four regions in the test operation map, including: the maximum statistical value of Tt, the Tt temperature after Tfin is increased, the test temperature of the main fuel pump regulator, the test temperature of the starting device, the test temperature of the nozzle fuel source pump, the test temperature of the nozzle afterburner regulator, and the test temperature of the afterburner fuel distributor; Tfin is the aircraft fuel inlet temperature; The usage time of the four zones and the Tt temperature after the aircraft provides fuel temperature rise are determined based on the operational data.

4. The test method for increasing the fuel inlet temperature of the system and its accessories as described in claim 1, characterized in that, The temperature load spectrum of the control system and its components is determined as follows: Obtain the number of cycles and cycle time of a fuel system test at different temperatures for a certain component, and statistically analyze the speed distribution data under the corresponding temperature conditions for each cycle, including speed range, duration, test speed, and speed range time. After processing the rotational speed distribution data, a corresponding temperature load spectrum is established. After establishing the temperature load spectrum of all components, the temperature load spectrum of the control system and its accessories is obtained.

5. The test method for increasing the fuel inlet temperature of the system and its accessories as described in claim 4, characterized in that, After obtaining the speed distribution data, the time of the speed interval is rounded up, and the minimum speed interval is the difference between the working time of 5 hours and other speed intervals; for the same speed conditions in the speed distribution data, a constant temperature is used.

6. The test method for increasing the fuel inlet temperature of the system and its accessories as described in claim 1, characterized in that, Temperature rise statistical analysis was performed on the temperature load spectrum of the control system and its components under different states. Specifically, based on the temperature load spectrum of the four intervals, the cyclic spectrum under the extreme temperature, the cyclic spectrum under the high temperature condition, the cyclic spectrum under the medium temperature condition, the cyclic spectrum under the low temperature condition, and the semi-physical load spectrum were established for each component. The temperature rise of the inlet fuel was determined, and the impact of the temperature rise of the inlet fuel on the control quality was verified by recording dynamic performance before and after the semi-physical long-term test.

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