Optimization method for high temperature warning of wing anti-icing bleed air during flight

Abstract

The present invention relates to a method for optimizing a high-temperature warning for wing anti-icing bleed air during flight, belonging to the technical field of aviation wing anti-icing systems. The method comprises the following steps: obtaining the heat exchange efficiency of the aircraft engine bleed air precooler and historical aircraft flight data at different flight altitudes; creating an aircraft wing anti-icing warning temperature expression; calculating the wing anti-icing bleed air high-temperature warning limit based on the anti-icing warning temperature expression and the obtained data; when a high-temperature warning for wing anti-icing bleed air occurs during flight, determining by comparison whether the altitude-temperature at which the wing anti-icing is currently activated is within the calculated high-temperature warning limit for the wing anti-icing bleed air, and taking actions to address the high-temperature warning for the wing anti-icing bleed air based on the optimized judgment result. The present invention can assist pilots in making judgments and effectively reduce the occurrence of abnormal events such as flight return and diversion.

Description

Technical Field

[0001] The present 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 primary function of aircraft engine bleed air is to supply high-temperature, high-pressure air from the engine to downstream air-consuming systems, including the engine starting system, air conditioning and pressurization systems, engine inlet cowling anti-icing system, and wing anti-icing system. The proper operation of these systems is crucial to ensuring aircraft safety and comfort.

[0003] Taking the wing anti-icing system as an example, the engine bleed air system provides hot air for the wing anti-icing system. This hot air passes through the wing anti-icing valves to protect the leading edge of the wing from ice. 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 message and the temperature anomaly. Lacking specific data to assist in further judgment, to ensure the safety of the aircraft and personnel, the pilot will generally make a return or diversion and then troubleshoot the problem. This can lead to abnormal events such as flight return, subsequent flight delays, and cancellations. This not only causes inconvenience to passengers, but also has a wide-ranging impact on airlines, airports, related industries, and even society as a whole. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a method for optimizing the high-temperature warning of wing anti-icing bleed air during flight. 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 at which the wing anti-icing is activated 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 operating method and avoid abnormal events.

[0005] To achieve the above objectives, 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 the 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. Obtain historical flight data of the aircraft at different flight altitudes, and calculate the wing anti-icing bleed air high temperature warning limits 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 for wing anti-icing bleed air occurs during flight, determine whether the high temperature warning for single engine bleed air or dual engine bleed air has failed. If the high temperature warning for single engine bleed air has failed, execute step S5; if the high temperature warning for dual engine bleed air has failed, 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 single-engine bleed air working condition on the remaining side, execute step S7;

[0014] S7. Determine, by comparing the displayed values, whether the current altitude-temperature at which wing anti-icing is enabled is within the established wing anti-icing bleed air high temperature warning limit range. If so, proceed to step S8; otherwise, proceed to step S9.

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

[0016] 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.

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

[0018] Furthermore, step S3, obtaining historical flight data of the aircraft at different flight altitudes, and calculating the wing anti-icing bleed air high temperature warning limits at different flight altitudes based on 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 envelope, h i is the height of point i.

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

[0023] S33, let i=1;

[0024] S34. Obtain the i-th data in the temperature-altitude data sequence X, and find the highest atmospheric freezing temperature t that satisfies the external environment temperature = the i-th 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 to obtain 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 aircraft flight speed v obtained at the same time stamp i 、The aircraft's flight altitude h i and the aircraft's ambient temperature t 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, calculate 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 that matches 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 that matches 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 line. At this time, T ISA i =t i ;

[0029] S37, let i=i+1, determine whether i>n is true, if yes, go to step S39; otherwise, go to 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] Furthermore, if there are multiple data points that meet the conditions in step S34, 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 be calculated using the maximum design value. The greater the anti-icing warning threshold temperature T at the aircraft altitude, the higher the limit, and the higher the operational safety of the aircraft.

[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 further includes: when the aircraft enters an icing area and wing anti-icing needs to be activated, comparing the altitude and temperature at which the wing anti-icing is currently activated to determine whether they are within an anti-icing warning limit range; if not, lowering the aircraft to an altitude at which the wing anti-icing can be activated before activating the wing anti-icing.

[0037] Furthermore, the method of the present invention also includes: after a single-engine bleed air failure occurs on the ground, the aircraft is launched, and an engine bleed air overtemperature warning appears in the air. By comparing the altitude and temperature at which the wing anti-icing is currently activated, it is displayed 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 an altitude where the wing anti-icing can be activated, and measures such as resetting the bleed air, restoring the bleed air, restoring the pressurization, and restarting the 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 for the aircraft's altitude based on the acquired heat exchange efficiency of the aircraft's engine bleed air precooler and historical aircraft flight data at different altitudes. This expression then calculates the engine bleed air precooler's performance temperature margin above the combined icing limit envelope, i.e., the wing anti-icing bleed air high-temperature warning limit. This provides pilots with specific data to aid in their decision-making, resulting in more optimized results.

[0040] 2. The present invention establishes a temperature-altitude relationship for engine bleed air high-temperature warning based on the aircraft's icing limit envelope and actual design capabilities. Based on this temperature-altitude relationship, it can be clearly determined whether the aircraft's anti-icing bleed air is within the anti-icing bleed air high-temperature warning limit when it is turned on, resulting in a corresponding optimized judgment result.

[0041] 3. The present invention searches for the maximum atmospheric freezing temperature t of the i-th data at 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 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 at 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 flow chart of a method for optimizing high-temperature early warning of wing anti-icing bleed air during flight according to the present invention;

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

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

[0045] Figure 4This is a diagram of the intermittent maximum icing limit envelope according to an embodiment of the present invention;

[0046] Figure 5 FIG. 1 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 with reference to the accompanying drawings and embodiments.

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

[0049] Taking transport aircraft as an example, the aircraft is equipped with two independent ice detectors. If either ice detector detects ice, it will issue an ice signal. When the aircraft is flying in icing conditions, as the amount of ice on the ice detector increases and the probe's vibration frequency decreases to a set frequency, the ice detector will issue an ice signal, prompting the pilot to take anti-icing measures. The wing anti-icing system prevents ice from forming on the leading edge of the wing. During flight, this system supplies engine bleed air to the three slats on the left and right wings. When the ice detector issues an ice signal, the pilot manually activates the wing anti-icing switch based on the icing conditions. Hot air from the air supply system, which has been temperature and pressure regulated, passes through the wing anti-icing valves, anti-icing check valves, and telescopic pipes on both sides, and is supplied to the leading edge slat flute pipes 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 flight. The method is used to provide a bleed air temperature-flight altitude information indication when an aircraft over-temperature alarm occurs after an aircraft ice detector sends an ice signal during flight and the pilot activates wing anti-icing and supplies engine bleed air to three slats on the wing. The method guides the pilot to optimize the judgment of the high-temperature warning of the wing anti-icing bleed air and take the best action.

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

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

[0053] Aircraft engine bleed air systems use bleed air precoolers to regulate temperature, ensuring the proper compressed air temperature, preventing overheating and protecting the normal operation of aircraft systems. When the bleed air precooler's heat exchange capacity is insufficient to meet system temperature control requirements, an overtemperature warning alert will be issued. Therefore, a high-temperature warning boundary can be determined based on the design performance of the bleed air precooler. This provides a bleed air temperature-altitude indicator to help pilots optimize their assessment of the warning cause, take corrective action, and minimize unnecessary losses.

[0054] For fixed-model engine bleed air precoolers used in transport aircraft, manufacturers typically provide 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 refers to the heat transfer efficiency of the engine bleed air precooler under actual operating conditions. The manufacturer provides the corresponding 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 for 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 from the engine through heat exchange, adjusting it to a temperature that meets the requirements of wing anti-icing and air conditioning. The bleed air precooler's hot-side inlet temperature is typically higher. After being regulated by the engine bleed air precooler, it is supplied to the wing from the hot-side outlet for anti-icing. Due to the material's heat resistance and other factors, the typical engine bleed air temperature warning value is no more than 260°C. That is, the aircraft anti-icing bleed air warning temperature W is 260°C. The heat exchanger material of the air conditioning package typically has a temperature resistance of 260°C, so the typical engine bleed air temperature warning value is: no more than 260°C. This value will also change if the material changes.

[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 Aircraft temperature data can be obtained through temperature sensors and related measurement systems. Temperature sensors are installed at the hot-side inlet of the engine bleed air precooler. These sensors can measure the temperature of the air passing through the engine bleed air precooler in real time. Aircraft also typically have data acquisition and processing systems, such as flight data recorders (FDRs) or quick access recorders (QARs), 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 (Category 2 Airworthiness Standards for Transport Airplanes), 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 altitude and temperature, is listed in the appendix. This appendix is ​​named the Continuous Maximum Icing Limit Envelope Diagram by the present invention, 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, expressed in terms of altitude and temperature, is listed in the appendix. This appendix is ​​named the Intermittent Maximum Icing Limit Envelope, 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). The design of the aircraft engine must meet the maximum atmospheric icing temperature requirements in the icing limit envelope in Appendix C of the public transport aircraft airworthiness standard CCAR. Based on the icing limit envelope, the maximum icing temperature T of the ISA 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 issue an over-temperature alarm. Therefore, the design performance boundary of the engine bleed air precooler can be calculated based on the maximum icing temperature of the international standard atmosphere, T ISA Because the temperature is lower downwards, 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 judgments, taking correct actions, and reducing unnecessary losses.

[0069] By combining 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 CCAR airworthiness standard for transport aircraft, as shown in the attached figure. Figure 5 As shown in the figure, each point on the solid line and dashed line segment with Δ is the point of the maximum freezing temperature of the freezing limit combination envelope used in the following of the present invention.

[0070] S3. Obtain historical flight data of the aircraft at different flight altitudes. Calculate the wing anti-icing bleed air high temperature warning limits at different flight altitudes based on the historical flight data and the created wing anti-icing warning temperature expression. Specifically, the calculation includes:

[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 altitude data at 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 point i 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, obtain the historical flight data of the aircraft at different flight altitudes, including multiple sets of flight altitudes, flight speeds, and engine bleed air precooler hot side inlet temperatures T at the same time stamp that match 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 These data are usually time-stamped to record the specific time when 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, and engine bleed air precooler hot side inlet temperature T at the same time stamp. Hin And the outside temperature data. That is, the present invention obtains a set of data that is recorded and matched at the same time at a point in time, including at least 4 data: flight altitude, flight speed, engine bleed air precooler hot side inlet temperature T Hin The data for the ambient temperature and the ambient temperature are collected at the same timestamp because the data at the same moment reflects the close relationship between the aircraft and the external conditions and its performance. This data is collected by sensors on the aircraft and processed and recorded by the aircraft's avionics system.

[0078] S33. Let i=1.

[0079] S34. Obtain the i-th data in the temperature-altitude data sequence X, and search for data points in the historical flight data at different flight altitudes that simultaneously satisfy the following conditions: ambient temperature = atmospheric maximum freezing temperature t of the i-th data. i , and the aircraft flight altitude = the height of the i-th data h i The data point is obtained 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 the same 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 is. The higher the limit, the higher the aircraft's operational safety.

[0081] S35, based on the aircraft flight speed v obtained at the same time stamp i 、The aircraft's flight altitude h i and the aircraft's ambient temperature t 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, the higher the limit, the higher the aircraft operation safety, but the economic benefits will be significantly reduced.

[0083] S36: Substitute the obtained data into the created wing anti-icing warning temperature expression to 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 that matches 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 freezing 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, and 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 statistical experience determination of actual flight operations.

[0089] S4. When a high temperature warning for wing anti-icing bleed air occurs during flight, determine whether the high temperature warning for single engine bleed air or 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 flight, an aircraft primarily bleeds air through the engines. Normally, the left engine supplies air to the left air conditioning system, and the right engine supplies air to the right air conditioning system. When a high-temperature warning for wing anti-icing bleed air occurs during flight, a determination is made as to whether the warning has failed for a single engine or for both engines. If the warning has failed for a single engine, step S5 is executed; if the warning has failed for both engines, 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 other engine to supply wing de-icing to both sides.

[0092] In special circumstances, such as when a single engine bleed air high-temperature warning fails on one side of the aircraft, the bleed air from the failed engine can be shut off. By opening an isolation valve, bleed air from the other engine can be supplied to both left and right wing de-icing systems, connecting the two systems. This design ensures that the aircraft receives the necessary compressed air under all 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 also analyzes the most severe bleed air configuration, a twin-engine, single-bleed air configuration. That is, when both engines are operating normally and one bleed air system fails, the bleed air from the other engine needs to meet the operating requirements of the air conditioning system and the wing anti-icing system, with the bleed air volume being the largest. Accordingly, the heat exchange demand for the engine bleed air precooler 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 the CCAR. This envelope is based on the temperature change rate of the International Standard Atmosphere (ISA) with altitude. The present invention calculates the maximum external temperature at 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, performing a bleed air temperature-flight altitude information comparison.

[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 displayed values, determine whether the current altitude-temperature relationship for enabling wing anti-icing bleed air is within the established high-temperature warning limit for wing anti-icing bleed air. If so, proceed to step S8; otherwise, proceed to step S9.

[0097] Comparison refers to comparing and judging the relationship between the external ambient 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 based on the calculated high temperature warning values ​​of the wing anti-icing air bleed at different flight altitudes.

[0098] Specifically, it is to determine whether the altitude-temperature at which the wing anti-icing air is currently turned on is within the established high-temperature warning limit range of the wing anti-icing air. That is, whether the external ambient 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, then it is within the anti-icing warning limit range, and step S8 is executed; if it is greater than, then it is not within the anti-icing warning limit range, and step S9 is executed.

[0099] Furthermore, there are many ways to display, 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 an indicator light to light up as a reminder when the limit is exceeded, etc.

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

[0101] By comparing the display, determine whether the altitude-temperature relationship of the current wing anti-icing bleed air is within the calculated wing anti-icing bleed air high temperature warning limit. If it is within the anti-icing warning limit, it means 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 will be taken out of the icing weather, the wing anti-icing system will be turned off, the bleed air will be reset, and the aircraft will return or make an emergency landing.

[0102] S9. After the aircraft leaves the 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 the flight mission.

[0103] By comparing the display, it is determined whether the current altitude-temperature relationship of the wing anti-icing bleed air is within the established 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. In this case, the aircraft can leave the icing weather, turn off 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] Aircraft engine bleed air systems are temperature-regulated by an engine bleed air precooler (EAP) configured to ensure that the compressed air provided has an appropriate temperature to prevent bleed air 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 based on the performance limits of the EAP and the ISA (International Standard Atmosphere) ambient temperature, and calculates and constructs an aircraft wing anti-icing bleed air high-temperature warning limit. The standards in Appendix C of the CCAR specify the conditions under which an aircraft will inevitably ice. The icing limit envelope provided is a minimum requirement, meaning that within the icing limit envelope, deicing capability must be maintained, which is the minimum requirement. The design of the present invention is to determine a true warning limit based on actual operating conditions, that is, to calculate the ultimate performance of the EAP. Above the maximum temperature of the icing envelope, the performance limit margin of the EAP is obtained. If this limit margin is exceeded, it can be determined that the EAP performance cannot meet the cooling requirement, generating a high-temperature warning, and that the EAP 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 to the wing anti-icing system, which then flows through the wing anti-icing valves to protect the wing leading edge from hot air ice. Current aircraft wing anti-icing system designs are based on Appendix C of CCAR-25-R4. Within this envelope, systems have been designed or flight-tested to meet anti-icing requirements. If the anti-icing system activates above this limit, especially when the single-engine bleed air high-temperature warning fails, there's a greater risk that the engine bleed air precooler's heat exchange capacity will be insufficient to meet system temperature control requirements, triggering a system overtemperature alarm.

[0107] Existing technical solutions consider triggering an immediate alarm when the engine bleed air temperature exceeds the warning temperature, but fail to consider whether the current temperature-altitude ratio is outside the anti-icing warning threshold. This is due to the engine bleed air precooler's insufficient heat exchange capacity to meet the system's temperature control requirements. In such situations, pilots typically request a descent to escape the icing zone, disabling anti-icing, resetting bleed air, restoring bleed air, and recovering pressurization before returning to base. This can result in abnormal events such as flight return and subsequent flight delays / cancellations, compromising normal operations.

[0108] For example, a preflight aircraft displayed an L ENG BLEED DEGRADE alarm, accompanied by a CMS message indicating BTS1 FAIL. Due to insufficient time, the flight crew reported entering an icing area at 8,100 meters. The CAS message "ICE DETECTED" appeared, and the crew shut down PACK1 and reactivated wing anti-ice. A dozen seconds later, the CAS message "R ENG BLEED FAULT" appeared. A check of the environmental control diagram revealed a brief depressurization period. A check of the anti-ice diagram revealed an amber temperature of 263°C for the right engine bleed air. The crew decided to request a descent to exit the icing area. After exiting, they shut down wing anti-ice, reset the right engine bleed air, and restored pressurization. Suspecting that reactivating wing anti-ice would result in a further overtemperature, the crew decided to return to Chengdu for troubleshooting. After landing, they connected BTS1 and BTS2, transferring the fault. After the connection was restored, BTS1 was replaced. The test run was normal, and the subsequent flight was carried out normally.

[0109] Subsequent analysis showed that the cause of the left bleed air alarm was system degradation caused by the failure of the bleed air temperature sensor. After the left bleed air was turned off, a 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, corresponding to flight altitudes of 20,700ft, 26,600ft, and 20,000ft, respectively. The environmental conditions for activating anti-icing 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, these conditions exceeded the requirements, and the heat exchange capacity of the engine bleed air precooler was insufficient to meet the system temperature control requirements, resulting in a system overtemperature alarm. This was an anti-icing bleed air high temperature warning that did not require return. By using the method of the present invention for optimization and judgment, risk control measures can be effectively taken 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 activate wing anti-ice, the altitude and temperature at which wing anti-ice is currently activated can be compared to see if they are within the anti-ice warning limit. If not, the aircraft can be lowered to an altitude where wing anti-ice can be activated before activating it to prevent a high temperature warning exceeding the engine bleed air precooler performance.

[0112] 2) If a single-engine bleed air failure occurs on the ground and the aircraft is launched, and an engine bleed air overtemperature warning is issued in the air, a comparison can be made between the altitude at which wing anti-ice is currently activated and the temperature to determine whether it is within the anti-ice warning limit. If not, the aircraft can be lowered to an altitude where wing anti-ice can be activated, and measures such as "resetting bleed air, restoring bleed air, restoring pressurization, and restarting anti-ice" can be taken to effectively reduce the occurrence of abnormal events such as flight returns and diversions.

[0113] 3) If an overtemperature warning occurs in mid-flight, the flight returns to the ground for inspection. By evaluating the ambient temperature and altitude at the time of the problem using the present invention, we can quickly identify any mechanical issues, such as those with the engine bleed air precooler. If the warning occurs outside the warning limits, mechanical issues can be ruled out, indicating an out-of-range situation. Otherwise, every return flight would require numerous inspections without identifying the cause, as the operating conditions at the time cannot be replicated on the ground. Therefore, the present invention's evaluation can effectively reduce abnormal flight delays, cancellations, and other incidents, providing better support for normal operations.

[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 a program to instruct the hardware related to the terminal device, and the program can be stored in a computer-readable storage medium, which can include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0115] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0116] The present invention and its embodiments are described above. This 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 a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection 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 the 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. Obtain historical flight data of the aircraft at different flight altitudes, and calculate the wing anti-icing bleed air high temperature warning limits 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 for wing anti-icing bleed air occurs during flight, determine whether the high temperature warning for single engine bleed air or dual engine bleed air fails. If the high temperature warning for single engine bleed air fails, execute step S5. If the dual-engine bleed air high temperature warning fails, execute step S7; S5. Shut off the bleed air from the inoperative engine and use the bleed air from the active engine to supply wing de-icing to both sides. S6. When the working side engine bleed air is in single engine bleed air working condition and the wing anti-icing bleed air high temperature warning appears again, execute step S7; S7. Determine, by comparing the displayed values, whether the current altitude-temperature for enabling wing anti-icing is within the established wing anti-icing bleed air high temperature warning limit range. If so, proceed to step S8; if not, proceed to step S9. S8: The aircraft leaves icing conditions, shuts down the wing anti-icing system, resets the bleed air, and returns or makes an emergency 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 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, specifically including: S31. Obtaining a data sequence X of the maximum freezing temperature-altitude of the icing limit combined 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 envelope, h i is the height of point i; S32, obtain the historical flight data of the aircraft at different flight altitudes, including multiple sets of flight altitudes, flight speeds, and engine bleed air precooler hot side inlet temperatures T at the same time stamp that match each other. Hin and outside temperature data; S33, let i=1; S34. Obtain the i-th data in the temperature-altitude data sequence X, and find the highest atmospheric freezing temperature t that satisfies the external environment temperature = the i-th 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 to obtain 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 aircraft flight speed v obtained at the same time stamp i 、The aircraft's flight altitude h i and the aircraft's ambient temperature t i , in the data correspondence relationship of the heat exchange efficiency η=f(h,v,t) of the aircraft engine bleed air precooler, the heat exchange 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, calculate the anti-icing warning limit temperature that matches the i-th point on the icing limit combination envelope; Ti=(Wi+ηiTHini-THini) / ηi-TISAi Where Ti is the anti-icing warning limit temperature at the aircraft altitude, that is, the anti-icing warning limit temperature that matches 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 aircraft engine bleed air precooler heat exchange efficiency that matches the i-th point on the icing limit combination envelope; THini is the aircraft engine bleed air precooler hot side inlet temperature that matches the i-th point on the icing limit combination envelope; TISAi is the international standard atmosphere maximum icing temperature that matches 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, go to step S39; otherwise, go to 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 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 calculated to have the maximum design value. The greater the anti-icing warning threshold temperature T at the aircraft altitude, 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 into 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 activate wing anti-ice, the altitude and temperature at which wing anti-ice is currently activated 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 an altitude where wing anti-ice can be activated before activating it.

Images