Wing anti-icing air-entraining high-temperature early warning optimization method in navigation

Abstract

The invention relates to a wing anti-icing bleed air high-temperature early warning optimization method in navigation, and belongs to the technical field of aviation wing anti-icing systems, and the method comprises the steps: obtaining the heat exchange efficiency of an aircraft engine bleed air precooler and the historical flight data of an aircraft at different flight heights; creating an anti-icing early warning temperature expression of the aircraft wing; according to the anti-icing early-warning temperature expression and the obtained data, calculating an anti-icing air-entraining high-temperature early-warning limit of the wing; when wing anti-icing air-entraining high-temperature early warning occurs during navigation, whether the height-temperature for starting wing anti-icing at present is within the calculated wing anti-icing air-entraining high-temperature early warning limit range or not is judged through comparison display, and operation for anti-icing air-entraining high-temperature early warning is adopted according to the optimized judgment result. The method can assist a pilot in judgment, and abnormal events such as flight return and landing preparation are effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation wing anti-icing systems, and in particular relates to a method for optimizing high-temperature early warning of wing anti-icing bleed air during navigation. Background Art

[0002] The main function of aircraft engine bleed air is to provide high-temperature and high-pressure gas from the engine to downstream gas systems, including engine starting system, air conditioning and pressurization system, engine inlet fairing anti-icing system, wing anti-icing system, etc. The normal operation of these systems is crucial to ensure the safety and comfort of the aircraft.

[0003] Take the wing anti-icing system as an example. The aircraft engine bleed air system provides hot air for the wing anti-icing system. The hot air performs hot air anti-icing on the leading edge of the wing through the wing anti-icing valve. During the bleed air anti-icing process, if the engine bleed air temperature exceeds the warning temperature set by the aviation system, the aviation system will immediately generate an alarm such as L / R ENG BLEED FAULT, indicating an over-temperature warning. In this case, the pilot can only see the warning information and temperature anomalies. Due to the lack of specific data for further auxiliary judgment, in order to ensure the safety of the aircraft and personnel, the pilot will generally take the operation of returning or making an alternate landing and then troubleshooting, resulting in abnormal events such as flight return, delays and cancellations of subsequent flights, which not only bring inconvenience to passengers, but also have a wide-ranging impact on airlines, airports, related industries and even the entire society. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for optimizing high-temperature warning of wing anti-icing bleed air during navigation. By creating a wing anti-icing warning temperature expression, the high-temperature warning limit of the wing anti-icing bleed air is calculated. When an over-temperature alarm occurs in the aircraft engine bleed air, it is determined whether the current altitude-temperature of the wing anti-icing is within the calculated high-temperature warning limit of the wing anti-icing bleed air, so as to assist the pilot in taking the best operation mode and avoid abnormal events.

[0005] To achieve the above object, the present invention discloses a method for optimizing high temperature warning of wing anti-icing bleed air during flight, which comprises:

[0006] S1. Obtaining the heat exchange efficiency η of the aircraft engine bleed air precooler;

[0007] S2. Based on the obtained heat exchange efficiency η of the aircraft engine bleed air precooler, create an aircraft wing anti-icing warning temperature expression:

[0008] T=(W+ηT Hin -T Hin ) / η-T ISA

[0009] Where T is the anti-icing warning temperature at the aircraft altitude, W is the aircraft wing anti-icing bleed air temperature warning value, η is the heat exchange efficiency of the aircraft engine bleed air precooler, T Hin is the hot side inlet temperature of the aircraft engine bleed air precooler, T ISA The maximum icing temperature of the International Standard Atmosphere at the aircraft's altitude;

[0010] S3, obtaining historical flight data of the aircraft at different flight altitudes, and calculating the wing anti-icing bleed air high temperature warning limit at different flight altitudes based on the historical flight data and the created wing anti-icing warning temperature expression;

[0011] S4, when a high temperature warning of wing anti-icing bleed air occurs during navigation, determine whether the high temperature warning of single engine bleed air fails or the high temperature warning of dual engine bleed air fails. If the high temperature warning of single engine bleed air fails, execute step S5; if the high temperature warning of dual engine bleed air fails, execute step S7;

[0012] S5. Shut off the bleed air from the failed engine and use the bleed air from the other engine to supply wing de-icing to both sides.

[0013] S6. When the wing anti-icing bleed air high temperature warning appears again under the remaining single-engine bleed air working condition, execute step S7;

[0014] S7, by comparing the display, judging whether the current altitude-temperature of the wing anti-icing is within the established wing anti-icing bleed air high temperature warning limit range, if within the limit range, executing step S8, if not within the limit range, executing step S9;

[0015] S8: The aircraft leaves icing weather, shuts down the wing anti-icing system, resets the bleed air, and returns or makes an alternate landing;

[0016] S9. The aircraft leaves icing weather, turns off the wing anti-icing system, resets the bleed air, turns on the wing anti-icing again, and after confirming that there are no faults, continues to perform the flight mission.

[0017] Furthermore, the aircraft wing anti-icing bleed air temperature warning value W is 260 degrees.

[0018] Further, the step S3, obtaining historical flight data of the aircraft at different flight altitudes, and calculating the high temperature warning limit of the wing anti-icing bleed air at different flight altitudes according to the historical flight data and the created wing anti-icing warning temperature expression, specifically includes:

[0019] S31, obtaining a data sequence X of the maximum freezing temperature-altitude of the icing limit combination envelope;

[0020] X={(t1,h1),(t2,h2),……,(t i ,hi ),……,(t n ,h n )}

[0021] Where i is a positive integer from 1 to n, t i is the maximum atmospheric freezing temperature at point i on the icing limit combined envelope, h i is the height of point i.

[0022] S32, obtaining historical flight data of the aircraft at different flight altitudes, including multiple sets of flight altitudes, flight speeds, engine bleed air precooler hot side inlet temperatures T at the same timestamp and matching each other. Hin and outside temperature data;

[0023] S33, let i=1;

[0024] S34, obtaining the ith data in the temperature-altitude data sequence X, and searching for the highest atmospheric freezing temperature t that satisfies the external environment temperature = the ith data in the historical flight data at different flight altitudes. i , and the aircraft flight altitude = the height of the i-th data h i The data group is obtained by obtaining the aircraft flight speed data v in the data group. i And the engine bleed air precooler hot side inlet temperature data T Hin i ;

[0025] S35, based on the obtained aircraft flight speed v at the same time stamp i 、The flight altitude of the aircraft h i and the ambient temperature of the aircraft i , in the data correspondence relationship of η=f(h,v,t) provided by the manufacturer, the heat exchange efficiency η under the operating conditions of the engine bleed air precooler is obtained by matching and searching i ;

[0026] S36, substituting the obtained data into the created wing anti-icing warning temperature expression, and calculating the anti-icing warning limit temperature that matches the i-th point on the icing limit combination envelope;

[0027] T i =(W i +η i T Hin i -T Hin i ) / η i -T ISA i

[0028] Among them, T iis the anti-icing warning limit temperature at the aircraft altitude, that is, the anti-icing warning limit temperature matching the i-th point on the icing limit envelope; W i The aircraft anti-icing bleed air warning temperature value is 260 degrees; η i is the heat transfer efficiency of the aircraft engine bleed air precooler matching the i-th point on the icing limit combination envelope, T Hin i is the hot side inlet temperature of the aircraft engine bleed air precooler matching the i-th point on the icing limit combination envelope, T ISA i is the maximum icing temperature of the international standard atmosphere that matches the i-th point on the icing limit combination envelope. At this time, T ISA i =t i ;

[0029] S37, let i=i+1, determine whether i>n is true, if yes, execute step S39; otherwise, execute step S38;

[0030] S38. Repeat steps S34-S37 to obtain anti-icing warning limit temperatures that match the highest freezing temperature points of the standard atmosphere on the icing limit combination envelope.

[0031] Further, in step S34, if there are multiple data points that meet the conditions, the engine bleed air precooler hot side inlet temperature data T Hin The lowest data and its corresponding aircraft flight speed v.

[0032] Furthermore, in step S35, the heat exchange efficiency η can also take the maximum design value to participate in the calculation. Then, the larger the anti-icing warning threshold temperature T at the altitude of the aircraft is, the higher the limit is, and the higher the operational safety of the aircraft is.

[0033] Furthermore, the comparative display method in step S37 includes entering the ambient temperature-flight altitude within the warning limit into the flight control system and displaying the information when the warning is issued.

[0034] Furthermore, the comparative display method in step S37 includes adding warning content to the CAS information.

[0035] Furthermore, the comparative display method in step S37 also includes setting an indicator light for indication and reminder.

[0036] Furthermore, the method of the present invention also includes: when the flight enters an icing area and it is necessary to turn on wing anti-icing, by comparing the altitude-temperature at which the wing anti-icing is currently turned on to see whether it is within the anti-icing warning limit range; if it is not within the anti-icing warning limit range, the aircraft is lowered to a height where the wing anti-icing can be turned on and then the wing anti-icing is turned on.

[0037] Furthermore, the method of the present invention also includes: after a single-engine bleed air failure occurs on the ground, the aircraft is let go, and an engine bleed air overtemperature warning appears in the air. By comparing and displaying whether the altitude-temperature at which wing anti-icing is currently activated is within the anti-icing warning limit range, if it is not within the anti-icing warning limit range, the aircraft is lowered to an altitude where wing anti-icing can be activated, and measures such as resetting bleed air, restoring bleed air, restoring pressurization, and restarting anti-icing are taken to reduce the occurrence of abnormal events such as flight return and emergency landing.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The present invention creates an anti-icing warning temperature expression at the altitude of the aircraft based on the heat exchange efficiency of the aircraft engine bleed air precooler and the historical flight data of the aircraft at different flight altitudes, calculates the performance temperature margin of the aircraft engine bleed air precooler above the icing limit combination envelope, that is, the wing anti-icing bleed air high temperature warning limit, and provides specific data to assist the pilot in making judgments, thereby obtaining a more optimized judgment result.

[0040] 2. The present invention constructs a temperature-altitude relationship for engine bleed air high temperature warning according to the aircraft's icing limit envelope and actual design capabilities. According to the temperature-altitude relationship, it can be clearly determined whether the aircraft's anti-icing bleed air is within the limit range of the anti-icing bleed air high temperature warning when it is turned on, and a corresponding optimized judgment result can be obtained.

[0041] 3. The present invention searches for the maximum atmospheric freezing temperature t of the i-th data under different flight altitudes in the historical flight data. i , and the aircraft flight altitude = the height of the i-th data h i If there are multiple data points that meet the conditions, the engine bleed air precooler hot side inlet temperature data T is selected. Hin The lowest data is T Hin i and its corresponding aircraft flight speed v i ,, makes the obtained anti-icing warning limit temperature T of the aircraft's altitude larger. The higher the limit, the higher the aircraft's operating safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of a process flow of a method for optimizing high temperature early warning of wing anti-icing and bleed air during navigation according to the present invention;

[0043] Figure 2 A schematic diagram of aero-engine bleed air according to an embodiment of the present invention;

[0044] Figure 3 A continuous maximum icing limit envelope diagram according to an embodiment of the present invention;

[0045] Figure 4It is an intermittent maximum icing limit envelope diagram of an embodiment of the present invention;

[0046] Figure 5 The figure is a schematic diagram of an icing limitation combination envelope according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present invention more clear, further description is given below in conjunction with the accompanying drawings and embodiments.

[0048] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0049] Taking transport aircraft as an example, the aircraft is equipped with two independent ice detectors. When any ice detector detects ice, it will send out an ice signal. When the aircraft is flying under icing conditions, as the amount of ice on the ice detector probe increases, the vibration frequency of the probe decreases to the set frequency, and the ice detector will send out an ice signal to prompt the pilot to take anti-icing measures. The function of the wing anti-icing system is to prevent ice from forming on the leading edge of the wing. During flight, this system provides engine bleed air to the three slats on the left and right wings. When the ice detector sends out an ice signal, the pilot manually turns on the wing anti-icing switch according to the icing situation. The hot air from the air source system, which has been temperature and pressure regulated, passes through the wing anti-icing valves, anti-icing one-way valves and telescopic pipes on both sides, and is supplied to the leading edge slat flute pipe to meet the heat distribution requirements for anti-icing.

[0050] The present invention provides a method for optimizing high-temperature warning of wing anti-icing bleed air during navigation, which is used for providing a bleed air temperature-flight altitude information indication when an aircraft ice detector sends an ice signal during navigation, after which the pilot starts wing anti-icing and provides engine bleed air to three slats on the wing, when an over-temperature alarm occurs in the aircraft, so as to guide the pilot to optimize the judgment of the high-temperature warning of wing anti-icing bleed air and take the best operation.

[0051] like Figure 1-Figure 5 As shown, the method of the present invention comprises the following steps:

[0052] S1. Obtain the heat transfer efficiency η of the aircraft engine bleed air precooler.

[0053] The aircraft engine bleed air system is temperature-regulated by the engine bleed air precooler to ensure that the compressed air provided has an appropriate temperature, prevent the bleed air from overheating, and protect the normal operation of the aircraft systems. When the heat exchange capacity of the engine bleed air precooler is insufficient to meet the system temperature control requirements, the system will generate an overtemperature alarm. Therefore, the high temperature warning boundary line can be determined based on the design performance boundary of the engine bleed air precooler, and the bleed air temperature-flight altitude information indication can be performed to assist the pilot in optimizing the judgment of the warning cause, taking correct actions, and reducing unnecessary losses.

[0054] For fixed-model engine bleed air precoolers that have been matched in transport aircraft, manufacturers usually provide relevant data on heat transfer efficiency η, including maximum heat transfer efficiency and heat transfer efficiency under operating conditions. The heat transfer efficiency under operating conditions is the heat transfer efficiency of the engine bleed air precooler under actual working conditions. The manufacturer provides data corresponding to the relationship data:

[0055] η=f(h,v,t)

[0056] Among them, h is the flight altitude of the aircraft, v is the flight speed of the aircraft, and t is the external environment temperature of the aircraft.

[0057] S2. Based on the obtained heat exchange efficiency η of the aircraft engine bleed air precooler, create an anti-icing warning temperature expression at the aircraft altitude:

[0058] T=(W+ηT Hin -T Hin ) / η-T ISA

[0059] Where T is the anti-icing warning limit temperature at the aircraft altitude, W is the aircraft anti-icing bleed air warning temperature value, η is the heat exchange efficiency of the aircraft engine bleed air precooler, T Hin is the hot side inlet temperature of the aircraft engine bleed air precooler, T ISA It is the maximum icing temperature of the International Standard Atmosphere at the aircraft's altitude.

[0060] Regarding the aircraft anti-icing bleed air warning temperature value W in the expression:

[0061] The engine bleed air precooler cools the high-temperature compressed air drawn out of the engine by heat exchange, and adjusts it to a temperature that meets the wing anti-icing and air conditioning requirements. The hot side inlet temperature of the bleed air precooler from the engine is usually high. After being adjusted by the engine bleed air precooler, it is supplied to the wing from the hot side outlet of the engine bleed air precooler for anti-icing. Due to the temperature resistance of the material and other reasons, the typical engine bleed air temperature warning value is that the bleed air temperature does not exceed 260°C, that is, the aircraft anti-icing bleed air warning temperature value W is 260°C. Usually, the temperature resistance of the heat exchanger material of the air conditioning package is 260°C, so the typical engine bleed air temperature warning value is: the bleed air temperature does not exceed 260°C. If the material changes, this value will also change.

[0062] Regarding the hot side inlet temperature T of the aircraft engine bleed air precooler in the expression Hin :

[0063] Aircraft engine bleed air precooler hot side inlet temperature T Hin It can be obtained through the temperature sensors and related measurement systems on the aircraft. Temperature sensors are installed at the hot side inlet of the aircraft engine bleed air precooler. These sensors can measure the air temperature passing through the engine bleed air precooler in real time. Aircraft also usually have data acquisition and processing systems, such as flight data recorders FDR or quick access recorders QAR, which record various flight parameters including the engine bleed air precooler inlet temperature.

[0064] Regarding the international standard atmospheric icing temperature T at the aircraft altitude in the expression ISA :

[0065] According to Appendix C of the CCAR, the standard atmospheric icing conditions in the air, the standard atmospheric icing conditions in the air are divided into (a) continuous maximum icing and (b) intermittent maximum icing, as follows:

[0066] (a) Continuous Maximum Icing: The maximum continuous intensity of atmospheric icing (continuous maximum icing) is determined by three variables: the cloud liquid water content, the average effective diameter of cloud water droplets, and the ambient air temperature. The icing limit envelope expressed in terms of height and temperature is listed in the appendix. The present invention names this appendix as the Continuous Maximum Icing Limit Envelope Diagram, as shown in the appendix. Figure 3 shown.

[0067] (b) Intermittent maximum icing: The maximum intermittent intensity of atmospheric icing (intermittent maximum icing) is determined by three variables: the cloud liquid water content, the average effective diameter of cloud water droplets, and the ambient air temperature. The icing limit envelope represented by height and temperature is listed in the appendix. The present invention names this appendix as the intermittent maximum icing limit envelope diagram, as shown in the appendix. Figure 4 shown.

[0068] The icing limit envelope in the appendix is ​​based on the fact that the change of icing temperature with altitude is subject to the change rate of the International Standard Atmosphere (ISA), and the design of the aircraft engine must meet the requirements of the maximum atmospheric icing temperature in the icing limit envelope in Appendix C of the public transport aircraft airworthiness standard CCAR. According to the icing limit envelope, the maximum icing temperature T of the International Standard Atmosphere at the aircraft altitude can be obtained in real time. ISA ; When the aircraft ice detector sends an ice signal, the pilot activates the wing anti-icing and supplies the engine bleed air to the three slats on the wing. When the aircraft has an over-temperature alarm, the engine bleed air precooler adjusts the temperature. When the heat exchange capacity of the engine bleed air precooler is insufficient to meet the system temperature control requirements, the system will have an over-temperature alarm. Therefore, the design performance boundary of the engine bleed air precooler can be calculated based on the maximum icing temperature T of the international standard atmosphere. ISA Because the temperature downward is lower, the lower the outside temperature, the less likely it is that an over-temperature alarm will occur. The high temperature warning boundary line is determined, and the bleed air temperature-flight altitude information is indicated to assist pilots in optimizing their judgment, taking correct operations, and reducing unnecessary losses.

[0069] By integrating the continuous maximum icing limit envelope and the intermittent maximum icing limit envelope, we can obtain the icing limit combined envelope diagram in Appendix C of the airworthiness standard CCAR for transport aircraft, as shown in the attached figure. Figure 5 As shown, each point on the solid line and dashed line segment with Δ in the figure is a point of the maximum freezing temperature of the icing limit combination envelope used in the following of the present invention.

[0070] S3. Obtain historical flight data of the aircraft at different flight altitudes, and calculate the wing anti-icing bleed air high temperature warning limit at different flight altitudes based on the historical flight data of the aircraft and the created wing anti-icing warning temperature expression, specifically including:

[0071] S31. Obtain a data sequence X of the maximum freezing temperature-altitude of the icing limit combination envelope.

[0072] According to the corresponding relationship between the atmospheric maximum freezing temperature and the altitude data of each point on the icing limit combination envelope in the icing limit combination envelope diagram, the maximum freezing temperature-altitude data sequence X of each point on the icing limit envelope is obtained:

[0073] X={(t1,h1),(t2,h2),……,(t i ,h i ),……,(t n ,h n )}

[0074] Among them, t i is the maximum atmospheric freezing temperature at the i-th point on the icing limit envelope, h iis the height of point i; i is a positive integer from 1 to n, and the size of n depends on the density of the calculated data. Figure 5 As shown, the maximum pressure altitude is 30,000 ft. When a point is calculated in units of 10 ft on average, n is 3,000; when a point is calculated in units of 1 ft on average, n is 30,000; when a point is calculated in units of 0.5 ft on average, n is 60,000.

[0075] S32, obtaining historical flight data of the aircraft at different flight altitudes, including multiple sets of flight altitudes, flight speeds, engine bleed air precooler hot side inlet temperatures T at the same timestamp and matching each other. Hin and outside temperature data.

[0076] The aircraft's historical flight data recording system or black box records a large number of flight parameters, including but not limited to flight altitude, flight speed, various temperature readings, including the engine bleed air precooler hot side inlet temperature T Hin And the outside temperature. These data are usually time-stamped to record the specific time they occurred.

[0077] From a large amount of flight data at different flight altitudes, multiple sets of data are obtained. Each set of data represents a data point, which records the flight altitude, flight speed, engine bleed air precooler hot side inlet temperature T at the same timestamp. Hin And the outside temperature data. That is, the present invention obtains a set of data recorded and matched at the same time point, including at least 4 data: flight altitude, flight speed, engine bleed air precooler hot side inlet temperature T Hin The data of the ambient temperature and the ambient temperature are collected at the same timestamp because the data at the same time reflects the close relationship and performance presentation of all aspects of the aircraft and the external conditions. These data are collected by sensors on the aircraft and processed and recorded by the aircraft's avionics system.

[0078] S33. Let i=1.

[0079] S34, obtaining the ith data in the temperature-altitude data sequence X, and searching for data points in the historical flight data at different flight altitudes that simultaneously satisfy: external environment temperature = atmospheric maximum freezing temperature t of the ith data i , and the aircraft flight altitude = the height of the i-th data h i The data point is used to obtain the matching aircraft flight speed v at the same time stamp in the data point. i And the engine bleed air precooler hot side inlet temperature data T Hin i .

[0080] Furthermore, if there are multiple data points that meet the conditions such as equal height and temperature, the engine bleed air precooler hot side inlet temperature data T is selected. Hin The lowest data is T Hin i and its corresponding aircraft flight speed v i The purpose is to obtain the engine bleed air precooler hot side inlet temperature data T Hin The lower it is, the greater the anti-icing warning limit temperature T at the aircraft's altitude will be. The higher the limit, the higher the aircraft's operating safety will be.

[0081] S35, based on the obtained aircraft flight speed v at the same time stamp i 、The flight altitude of the aircraft h i and the ambient temperature of the aircraft i , in the data correspondence relationship provided by η=f(h,v,t), the heat transfer efficiency η under the operating conditions of the engine bleed air precooler is obtained by matching and searching i .

[0082] As another embodiment, the heat exchange efficiency η may also take the maximum design value. Then, the larger the anti-icing warning threshold temperature T at the aircraft altitude is, the higher the limit is, the higher the aircraft operation safety is, but the economic benefits will be significantly reduced.

[0083] S36. Substituting the obtained data into the created wing anti-icing warning temperature expression, calculate the anti-icing warning limit temperature that matches the i-th point on the icing limit envelope.

[0084] T i =(W i +η i T Hin i -T Hin i ) / η i -T ISA i

[0085] Among them, T i is the anti-icing warning limit temperature at the aircraft altitude, that is, the anti-icing warning limit temperature matching the i-th point on the icing limit envelope; W i The aircraft anti-icing bleed air warning temperature value is 260 degrees; η i is the heat transfer efficiency of the aircraft engine bleed air precooler matching the i-th point on the icing limit envelope, T Hin i is the hot side inlet temperature of the aircraft engine bleed air precooler matching the i-th point on the icing limit envelope, T ISA iis the maximum icing temperature of the international standard atmosphere that matches the i-th point on the icing limit envelope. At this time, T ISA i =t i .

[0086] S37, let i=i+1, determine whether i>n holds, if so, execute step S39; otherwise, execute step S38.

[0087] S38. Repeat steps S34-S37 to obtain anti-icing warning limit temperatures that match points on the icing limit envelope, such as the maximum atmospheric icing temperature.

[0088] Furthermore, further corrections can be made through technical means such as simulation analysis, design verification or determination of statistical experience from actual flight operations.

[0089] S4. When a high temperature warning for wing anti-icing bleed air occurs during navigation, determine whether the high temperature warning for single-engine bleed air fails or the high temperature warning for dual-engine bleed air fails. If the high temperature warning for single-engine bleed air fails, execute step S5; if the high temperature warning for dual-engine bleed air fails, execute step S7.

[0090] Aircraft engine bleed air system Figure 2 As shown, during the flight of the aircraft, air is mainly bleed through the engine. Normally, the left engine supplies air to the air conditioning system on the left, and the right engine supplies air to the air conditioning system on the right. When a high temperature warning of wing anti-icing bleed air occurs during navigation, it is determined whether the high temperature warning of single engine bleed air fails or the high temperature warning of dual engine bleed air fails. If the high temperature warning of single engine bleed air fails, step S5 is executed; if the high temperature warning of dual engine bleed air fails, step S7 is executed.

[0091] S5. Shut off the bleed air from the engine on the failed side and use the bleed air from the engine on the other side to supply wing de-icing to both sides.

[0092] In special cases, such as when the single-engine bleed air high temperature warning on one side of the aircraft fails, the bleed air of the engine on the failed side can be turned off, and the bleed air from the other engine can be supplied to the left and right sides for wing de-icing by opening the isolation valve, so that the two systems are connected. This design ensures that the aircraft can obtain the necessary compressed air under various flight conditions to meet the needs of its various systems.

[0093] S6. When the wing anti-icing bleed air high temperature warning appears again during the single-engine bleed air operation on the remaining side, execute step S7.

[0094] The present invention is also based on the most severe bleed air configuration, the twin-engine single bleed air configuration for analysis, that is, when the engines on both sides are working normally and the primary bleed air system fails, the bleed air of the engine on the other side needs to meet the working requirements of the air conditioning system and the wing anti-icing system, and the bleed air volume is the largest, and the corresponding engine bleed air precooler heat exchange demand is also the largest. Since the typical engine bleed air temperature warning value does not exceed 260°C, the design of the engine bleed air precooler must also meet the anti-icing limit envelope in Appendix C of CCAR, which is based on the temperature change with altitude and obeys the International Standard Atmosphere (ISA) change rate. The present invention calculates the maximum temperature of the cold side inlet of the engine bleed air precooler at different altitudes when the wing anti-icing high temperature warning temperature is triggered, and calculates the wing anti-icing high temperature warning limit, and compares the bleed air temperature-flight altitude information.

[0095] The engine bleed air on the failed side is turned off. When only the single engine bleed air on the remaining side is working, if the wing anti-icing bleed air high temperature warning appears again, step S7 is executed.

[0096] S7. By comparing the display, determine whether the height-temperature relationship of the wing anti-icing air bleed currently turned on is within the established wing anti-icing air bleed high temperature warning limit range. If it is within the anti-icing warning limit range, execute step S8; if not, execute step S9.

[0097] Comparison means that, based on the calculated high temperature warning values ​​of the wing anti-icing air bleed at different flight altitudes, a comparison is made to determine the relationship between the external environment temperature when the wing anti-icing air bleed is turned on at the current flight altitude and the high temperature warning value of the wing anti-icing air bleed at the same flight altitude.

[0098] Specifically, it is to determine whether the height-temperature at which the wing anti-icing air is currently turned on is within the constructed high temperature warning limit range of the wing anti-icing air, that is, whether the external environment temperature at which the wing anti-icing air is currently turned on is greater than the calculated high temperature warning limit of the wing anti-icing air at the same flight altitude. If it is not greater than, less than or equal to, it is within the anti-icing warning limit range, and step S8 is executed; if it is greater than, it is not within the anti-icing warning limit range, and step S9 is executed.

[0099] Furthermore, there may be a variety of display methods, such as entering the ambient temperature-flight altitude within the warning limit into the flight control system and displaying the information during the warning; adding the warning content to the CAS information; or displaying it on the environmental control diagram page; setting indicator lights to light up as a reminder when the limit is exceeded, etc.

[0100] S8: The aircraft leaves icing weather, shuts down the wing anti-icing system, resets the bleed air, and returns or makes an alternate landing;

[0101] By comparing the displayed values, it is determined whether the altitude-temperature relationship of the wing anti-icing bleed air currently being turned on is within the calculated high temperature warning limit of the wing anti-icing bleed air. If so, it indicates that there is a high probability that the engine bleed air precooler performance has not been exceeded and the problem lies in other systems or components. In this case, the aircraft should be separated from the icing weather, the wing anti-icing system should be turned off, the bleed air should be reset, and the aircraft should return home or make an emergency landing.

[0102] S9. After the aircraft leaves icing weather, turn off the wing anti-icing system, reset the bleed air, turn on the wing anti-icing again to confirm that there are no faults, and continue to perform the flight mission.

[0103] By comparing the display, it is determined whether the height-temperature relationship of the current wing anti-icing bleed air is within the constructed wing anti-icing bleed air high temperature warning limit. If it is not within the anti-icing warning limit, it means that there is a high probability that the high temperature alarm is caused only by exceeding the performance of the engine bleed air precooler. The aircraft can then leave the icing weather, shut down the wing anti-icing system, reset the bleed air, turn on the wing anti-icing again to confirm that there is no fault, and continue to perform the flight mission to reduce unnecessary abnormal events.

[0104] The aircraft engine bleed air system is temperature-regulated by the configured engine bleed air precooler to ensure that the compressed air provided has an appropriate temperature to prevent the bleed air from overheating and protect the normal operation of various aircraft systems. The present invention analyzes the internal and external conditions of the aircraft during the bleed air process according to the performance boundary of the engine bleed air precooler and the ambient temperature of the international standard atmosphere ISA (International Standard Atmosphere), and calculates and constructs the high temperature warning limit of the aircraft wing anti-icing bleed air. The standard in Appendix C of CCAR gives the conditions under which the aircraft will definitely freeze, and the given icing limit envelope is a minimum requirement, that is, within the icing limit envelope, it must have the deicing ability, which is the minimum requirement. The design of the present invention is to determine a real warning limit according to the actual operating conditions, that is, to calculate the limit performance of the engine bleed air precooler, and above the highest temperature of the icing envelope, float up to obtain the performance limit margin of the engine bleed air precooler. If it exceeds this limit margin, it can be determined that it is because the engine bleed air precooler performance cannot meet the cooling demand, and a high temperature alarm is generated, and the engine bleed air precooler performance is limited.

[0105] It should be noted that the design of the present invention is based on normal standard weather, but the application situation is applicable to all weather conditions.

[0106] The aircraft engine bleed air system provides hot air for the wing anti-icing system, and the hot air is used to perform hot air anti-icing on the leading edge of the wing through the wing anti-icing valve. The current design basis of the aircraft wing anti-icing system is CCAR-25-R4 Appendix C. Within this envelope, the system can meet the anti-icing requirements after design or flight test verification. When the anti-icing system is turned on above the limit, especially when the single engine bleed air high temperature warning fails, it is more likely that the heat exchange capacity of the engine bleed air precooler will be insufficient to meet the system temperature control requirements, and a system overtemperature alarm will occur.

[0107] The existing technical solution considers that the system will immediately alarm when the engine bleed air temperature exceeds the warning temperature, but does not consider whether the current temperature-altitude is outside the anti-icing warning limit. This is because the heat exchange capacity of the engine bleed air precooler is insufficient to meet the system temperature control requirements. In this case, the pilot usually applies for descent to escape the icing area, turns off anti-icing, resets bleed air, restores bleed air, restores pressurization, and takes the return operation, which will cause abnormal events such as flight return, delay / cancellation of subsequent flights, and make it difficult for normal operation.

[0108] For example, a certain aircraft had a L ENG BLEED DEGRADE alarm before flight, accompanied by a CMS message of BTS1 FAIL. Due to insufficient time, the flight crew reported that the aircraft entered the icing area at an altitude of 8,100 meters, and the CAS message "ICE DETECTED" appeared. The crew turned off PACK1 and turned on the wing anti-icing. A dozen seconds later, the CAS message "R ENG BLEED FAULT" appeared. After checking the environmental control diagram page, the aircraft was in a short-term non-pressurized state. The anti-icing diagram page showed that the right engine bleed air temperature was 263℃ amber. The crew decided to apply for descent to leave the icing area. After leaving, the wing anti-icing was turned off, the right engine bleed air was reset, the right engine bleed air was restored, and the pressurization was restored. The crew suspected that after the wing anti-icing was turned on again, the bleed air overheating phenomenon would occur again, and decided to return to Chengdu for troubleshooting. After landing, BTS1 and BTS2 were connected in series, and the fault was transferred. After the connection was restored, BTS1 was replaced, the test run was normal, and the subsequent flights were carried out normally.

[0109] Subsequent analysis showed that the cause of the left bleed air alarm was the system degradation caused by the failure of the bleed air temperature sensor. After the left bleed air was turned off, the single bleed air mode was used for air conditioning and wing anti-icing. According to the QAR data analysis, anti-icing was activated three times in total during the flight segment, with ambient temperatures of -3°C, -15°C, and -3°C, and the corresponding flight altitudes were 20,700ft, 26,600ft, and 20,000ft, respectively. The environmental conditions for activating anti-icing this time were all above the calculated anti-icing bleed air limits of -13°C, -22.5°C, and -13.4°C for the engine bleed air precooler at the same flight altitude, that is, under these conditions, the requirements were exceeded, and the heat exchange capacity of the engine bleed air precooler was insufficient to meet the system temperature control requirements, resulting in a system over-temperature alarm. This was an anti-icing bleed air high temperature warning that did not require return. The optimization judgment using the method of the present invention can effectively take risk control measures to avoid abnormal events.

[0110] Furthermore, the method of the present invention further comprises:

[0111] 1) When the aircraft enters an icing area and needs to turn on wing anti-icing, the altitude and temperature at which the wing anti-icing is currently turned on can be compared to see whether they are within the anti-icing warning limit. If not, the aircraft can be lowered to an altitude where the wing anti-icing can be turned on and then the wing anti-icing can be turned on to prevent a high temperature warning that exceeds the performance of the engine bleed air precooler.

[0112] 2) When the aircraft is let go after a single-engine bleed air failure on the ground, if an engine bleed air overtemperature warning appears in the air, the current altitude at which wing anti-icing is activated can be compared with the temperature to see if it is within the anti-icing warning limit. If not, the aircraft can be lowered to an altitude where wing anti-icing can be activated, and measures such as "resetting bleed air, restoring bleed air, restoring pressurization, and restarting anti-icing" can be taken to effectively reduce the occurrence of abnormal events such as flight returns and alternate landings.

[0113] 3) If an over-temperature warning appears in the air, the aircraft will return to the ground for inspection. By evaluating the ambient temperature and flight altitude when the problem occurs according to the content of the present invention, it is possible to quickly locate whether there is a mechanical problem, such as the engine bleed air precooler. If the warning occurs outside the warning limit, the mechanical problem can be ruled out, that is, the use is out of range. Otherwise, various inspections will be performed every time the flight returns, but the cause cannot be found, because the working conditions at that time cannot be reproduced on the ground. Therefore, the evaluation according to the content of the present invention can effectively reduce abnormal events such as flight delays and cancellations, and provide better support for normal operation.

[0114] In this embodiment, a person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a computer-readable storage medium, and the storage medium may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0115] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0116] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A method for optimizing high temperature warning of wing anti-icing bleed air during flight, characterized in that: It includes the steps of: S1. Obtaining the heat exchange efficiency η of the aircraft engine bleed air precooler; S2. Based on the obtained heat exchange efficiency η of the aircraft engine bleed air precooler, create an aircraft wing anti-icing warning temperature expression: T=(W+ηT Hin -T Hin ) / η-T ISA Where T is the anti-icing warning temperature at the aircraft altitude, W is the aircraft wing anti-icing bleed air temperature warning value, η is the heat exchange efficiency of the aircraft engine bleed air precooler, T Hin is the hot side inlet temperature of the aircraft engine bleed air precooler, T ISA The maximum icing temperature of the International Standard Atmosphere at the aircraft's altitude; S3, obtaining historical flight data of the aircraft at different flight altitudes, and calculating the wing anti-icing bleed air high temperature warning limit at different flight altitudes based on the historical flight data and the created wing anti-icing warning temperature expression; S4, when a high temperature warning of wing anti-icing bleed air occurs during navigation, determine whether the high temperature warning of single engine bleed air fails or the high temperature warning of dual engine bleed air fails. If the high temperature warning of single engine bleed air fails, execute step S5; If the dual-engine bleed air high temperature warning fails, execute step S7; S5. Shut down the bleed air from the engine on the failed side, and use the bleed air from the engine on the working side to supply wing de-icing to the left and right sides; S6, when the working side engine bleed air is in the single engine bleed air working condition, if the wing anti-icing bleed air high temperature warning appears again, execute step S7; S7, by comparing the display, judging whether the current altitude-temperature of the wing anti-icing is within the established wing anti-icing bleed air high temperature warning limit range, if within the limit range, executing step S8; if outside the limit range, executing step S9; S8: The aircraft leaves icing weather, shuts down the wing anti-icing system, resets the bleed air, and returns or makes an alternate landing; S9. The aircraft leaves the icing weather, turns off the wing anti-icing system, resets the bleed air, turns on the wing anti-icing again, and after confirming that there are no faults, continues the flight mission.

2. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 1, characterized in that: The aircraft wing anti-icing bleed air temperature warning value W is set to 260 degrees.

3. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 1, characterized in that: Step S3, obtaining historical flight data of the aircraft at different flight altitudes, and calculating the high temperature warning limit of the wing anti-icing bleed air at different flight altitudes according to the historical flight data and the created wing anti-icing warning temperature expression, specifically including: S31, obtaining a data sequence X of the maximum freezing temperature-altitude of the icing limit combination envelope; X={(t1,h1),(t2,h2),……,(t i ,h i ),……,(t n ,h n )} Where i is a positive integer from 1 to n, t i is the maximum atmospheric freezing temperature at point i on the icing limit combination envelope, h i is the height of point i; S32, obtaining historical flight data of the aircraft at different flight altitudes, including multiple sets of flight altitudes, flight speeds, engine bleed air precooler hot side inlet temperatures T at the same timestamp and matching each other. Hin and outside temperature data; S33, let i=1; S34, obtaining the ith data in the temperature-altitude data sequence X, and searching for the highest atmospheric freezing temperature t that satisfies the external environment temperature = the ith data in the historical flight data at different flight altitudes. i , and the aircraft flight altitude = the height of the i-th data h i The data group is obtained by obtaining the aircraft flight speed data v in the data group. i And the engine bleed air precooler hot side inlet temperature data T Hin i ; S35, based on the obtained aircraft flight speed v at the same time stamp i 、The flight altitude of the aircraft h i and the ambient temperature of the aircraft i , in the data correspondence relationship of the heat transfer efficiency η=f(h,v,t) of the aircraft engine bleed air precooler, the heat transfer efficiency ηi under the operating conditions of the engine bleed air precooler is obtained by matching and searching; S36, substituting the obtained data into the created wing anti-icing warning temperature expression, and calculating the anti-icing warning limit temperature that matches the i-th point on the icing limit combination envelope; Ti=(Wi+ηiTHini-THini) / ηi-TISAi Among them, Ti is the anti-icing warning limit temperature at the aircraft altitude, that is, the anti-icing warning limit temperature matching the i-th point on the icing limit envelope; Wi is the aircraft anti-icing bleed air warning temperature value of 260 degrees; ηi is the heat exchange efficiency of the aircraft engine bleed air precooler matching the i-th point on the icing limit combination envelope, THini is the hot side inlet temperature of the aircraft engine bleed air precooler matching the i-th point on the icing limit combination envelope, TISAi is the international standard atmosphere maximum icing temperature matching the i-th point on the icing limit combination envelope, at this time, TISAi=t i ; S37, let i=i+1, determine whether i>n is true, if yes, execute step S39; otherwise, execute step S38; S38. Repeat steps S34-S37 to obtain anti-icing warning limit temperatures that match the highest freezing temperature points of the standard atmosphere on the icing limit combination envelope.

4. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 3, characterized in that: In step S34, if there are multiple data points that meet the conditions, the engine bleed air precooler hot side inlet temperature data T is selected. Hin The lowest data and its corresponding aircraft flight speed v.

5. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 3, characterized in that: In step S35, the heat exchange efficiency η is selected to take the maximum design value for calculation. The greater the anti-icing warning threshold temperature T at the altitude of the aircraft, the higher the limit, and the higher the operational safety of the aircraft.

6. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 3, characterized in that: The comparative display method in step S37 includes entering the ambient temperature-flight altitude within the warning limit into the flight control system and displaying the information when the warning is issued.

7. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 3, characterized in that: The comparative display method in step S37 includes adding the warning information content to the CAS information.

8. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 7, characterized in that: The comparative display method in step S37 also includes setting an indicator light for indication and reminder.

9. The method for optimizing high temperature warning of wing anti-icing bleed air during flight according to claim 1, characterized in that: Also includes: When the aircraft enters an icing area and needs to turn on wing anti-ice, the altitude and temperature at which the wing anti-ice is currently turned on are compared to see if they are within the anti-ice warning limit. If they are not within the anti-ice warning limit, the aircraft is lowered to a height where the wing anti-ice can be turned on and then the wing anti-ice is turned on.

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