A flight recorder heat flux meter, working method and flight recorder

Abstract

The application relates to the field of aircraft technology and provides a flight recorder heat flux metering instrument, a working method and a flight recorder. The method comprises the following steps: one end of a flow metering pipe is used for inputting medium, the other end of the flow metering pipe is connected with one end of a first temperature metering pipe through an adjustable spacing pipe fixing device, the other end of the first temperature metering pipe is connected with one port of a flight recorder heat flux test piece, the other port of the flight recorder heat flux test piece is connected with one end of a second temperature metering pipe, the other end of the second temperature metering pipe is connected with one end of a medium discharge pipe through the adjustable spacing pipe fixing device, and the other end of the medium discharge pipe is used for discharging medium; temperature sensors are arranged in the first temperature metering pipe and the second temperature metering pipe and used for detecting the temperature of the medium flowing into the flight recorder heat flux test piece and the temperature of the medium flowing out of the flight recorder heat flux test piece; and a turbine flowmeter is arranged in the flow metering pipe and used for detecting the flow of the medium.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and in particular to a flight recorder heat flux meter, its working method, and a flight recorder. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the development of the aviation industry and the liberalization of the low-altitude economy, the number of light sport aircraft, light aircraft, and eVTOL aircraft will experience rapid growth, putting significant pressure on flight safety supervision. The size and weight of traditional flight recorders are insufficient to meet the usage requirements of these aircraft; therefore, it is necessary to design miniature or small flight recorders adapted to these aircraft.

[0004] As a device for recording and protecting flight data, flight recorders need to meet the corresponding minimum operating performance specifications (MOPS). There are strict and clear test requirements for their ability to withstand high-temperature fire. The traditional method of measuring the heat flux of flight recorders in fire tests is limited by factors such as pipeline insulation conditions, temperature sensor installation location, and fire test conditions. It cannot accurately measure the heat flux of flight recorders, and it cannot even be used for fire tests of small-sized flight recorders. Summary of the Invention

[0005] To address the technical problems mentioned above, this invention provides a flight recorder heat flux meter, a working method, and a flight recorder. This invention provides a flight recorder heat flux meter that is applicable to the heat flux measurement of micro and small flight recorders and can accurately measure heat flux, which is of great significance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a flight recorder heat flux meter.

[0008] A flight recorder heat flux meter includes: a first temperature measuring tube, a second temperature measuring tube, a flow measuring tube, an adjustable spacing pipe holder, a flight recorder heat flux test piece, and a medium discharge pipe.

[0009] One end of the flow metering tube is used to input the medium, and the other end of the flow metering tube is connected to one end of the first temperature metering tube through an adjustable spacing pipe fixer. The other end of the first temperature metering tube is connected to one port of the flight recorder heat flux test piece. The other port of the flight recorder heat flux test piece is connected to one end of the second temperature metering tube. The other end of the second temperature metering tube is connected to one end of the medium discharge pipe through an adjustable spacing pipe fixer. The other end of the medium discharge pipe is used to discharge the medium.

[0010] Both the first and second temperature measuring tubes are equipped with temperature sensors to detect the temperature of the heat flux test piece flowing into and out of the flight recorder.

[0011] A turbine flow meter is installed inside the flow metering tube to detect the flow rate of the medium.

[0012] Furthermore, the first temperature measuring tube and the second temperature measuring tube have the same structure.

[0013] Furthermore, the first temperature measuring tube also includes: two sections of the first tube body, an inner protective tube, a support frame, a first quick-connect pipe connector, a tee, a sensor wiring harness, an outlet pipe connector, and a first quick-connect pipe connector seat;

[0014] The inner protective tube is fixed to the central axis of the first tube body by a support frame. The end of the inner protective tube near the flight recorder heat flux test piece is used to fix the temperature sensor. The temperature sensor is connected to the sensor harness, and the sensor harness is placed inside the inner protective tube. The end of the inner protective tube near the adjustable spacing pipe fixer is provided with a boss for cooperating with the support frame for limiting movement. One end of the first quick-connect pipe is connected to the first tube body, and the other end of the first quick-connect pipe is connected to the flight recorder heat flux test piece. The two ends of the tee are used to connect the two sections of the first tube body, and the third end is connected to the outlet pipe connector. The sensor harness passes through the inner protective tube and the outlet pipe connector. The first quick-connect pipe seat is used to connect the first tube body and the flow metering tube.

[0015] Furthermore, a hole is made on the boss to embed the inner protective tube section of the outlet pipe connector, forming a right-angle bend and limiting its position.

[0016] Furthermore, the flow metering tube also includes: a second tube body, a second quick-connect fitting, a first reducing fitting, and a third tube body; the second tube body is used to fix the turbine flow meter, the first reducing fitting is used to connect the second tube body and the third tube body, and the second quick-connect fitting is used to connect the third tube body and the temperature metering tube.

[0017] Furthermore, the diameter of the second tube is larger than the diameter of the third tube.

[0018] Furthermore, the adjustable spacing pipe fixing device includes a first fixing clip, a second fixing clip, and a sliding groove. The first fixing clip and the second fixing clip have the same structure, and both the first fixing clip and the second fixing clip slide on the sliding groove. By adjusting the distance between the first fixing clip and the second fixing clip, it can adapt to flight recorder heat flux test pieces of different shapes and sizes.

[0019] Furthermore, the first tube passes through the first fixing clip, which is used to limit and fix the temperature measuring tube.

[0020] Furthermore, the flight recorder heat flux test piece includes: a flight recorder equivalent shell, a dielectric baffle, a fixing tube, and a second quick-connect fitting seat;

[0021] The flight recorder housing is equipped with a media baffle to divide the space inside the flight recorder housing into two parts, so as to isolate the inlet for media to flow into the flight recorder housing and the outlet for media to flow out of the flight recorder housing.

[0022] The fixed tube is connected to the second quick-connect fitting, through which the flight recorder's equivalent outer shell is fixed to the fixed tube; the second quick-connect fitting is used to connect the fixed tube and the temperature measuring tube.

[0023] Furthermore, a heat-insulating protective layer is provided on the outer circumferential surface of the fixing tube for heat insulation of the fixing tube.

[0024] Furthermore, the medium discharge pipe includes: a third quick-connect pipe joint, a fourth pipe body, a second reducing pipe joint, and a 90° elbow. One end of the third quick-connect pipe joint is connected to the second temperature metering pipe, and the other end is connected to one end of the fourth pipe body. The other end of the fourth pipe body is connected to the second reducing pipe joint, and the second reducing pipe joint is connected to the 90° elbow for discharging the medium.

[0025] A second aspect of the present invention provides a method for operating a flight recorder heat flux meter.

[0026] A method for operating a flight recorder heat flux meter, applied to the flight recorder heat flux meter described in the first aspect, comprising:

[0027] The turbine flow meter in the flow metering tube measures the flow rate of the medium and uploads it to the processor;

[0028] The temperature sensor in the first temperature metering tube collects the inlet temperature value of the heat flux test piece flowing into the flight recorder and uploads it to the processor;

[0029] The temperature sensor in the second temperature metering tube collects the outlet temperature value of the heat flux test piece flowing out of the flight recorder and uploads it to the industrial control computer.

[0030] The industrial control computer calculates the temperature difference based on the difference between the outlet and inlet temperatures; and calculates the heat flux of the flight recorder based on the flow rate, temperature difference, specific heat of the medium, and the surface area of ​​the flight recorder's casing.

[0031] A third aspect of the present invention provides a flight recorder.

[0032] A flight recorder includes a memory and a flight recorder heat flux meter as described in the first aspect, connected to the memory.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] This invention provides a heat flux meter for flight recorders, used to measure the heat flux of flight recorders during high-temperature fire tests. It features low requirements on the size of the tested structural components, high measurement accuracy, and good versatility.

[0035] This invention enables direct measurement of the outlet and inlet temperatures of the flight recorder's casing using a temperature measuring tube, avoiding measurement input errors caused by flame heating of the pipe. At the same time, the protection of the medium prevents damage to the sensor wiring harness and seals.

[0036] This invention improves accuracy by designing a fixed tube length so that the surface area of ​​the tube section not covered by the heat insulation layer is equal to the surface area of ​​the flight recorder's proportional outer shell that is covered by the fixed tube. The heat flux meter of the flight recorder can be approximately equivalent to the heat flux surface area of ​​the test flight recorder, thereby improving accuracy.

[0037] This invention reduces the size of the first tube, the fixed tube, and the heat insulation layer through system design, making it suitable for smaller flight recorders and reducing measurement errors introduced by the above-mentioned components.

[0038] This invention enables more accurate and efficient measurement of heat flux in flight recorders and is applicable to flight recorders with a minimum diameter or side length of 50mm, playing an important role in the design and verification of micro and small flight recorders. Attached Figure Description

[0039] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0040] Figure 1 This is a schematic diagram of the structure of the flight recorder heat flux meter shown in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of a fire test system shown in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of the temperature measuring tube shown in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the flow metering tube shown in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the adjustable spacing pipe fixation device shown in an embodiment of the present invention;

[0045] Figure 6This is a schematic diagram of the structure of the flight recorder heat flux test piece shown in an embodiment of the present invention;

[0046] Figure 7 This is a top cross-sectional view of the flight recorder heat flux meter shown in an embodiment of the present invention;

[0047] Figure 8 This is a side cross-sectional view of the medium inlet pipe section shown in an embodiment of the present invention;

[0048] in,

[0049] 1. Temperature metering tube; 1-1. First tube body; 1-2. Inner protective tube; 1-3. Temperature sensor; 1-4. Support frame; 1-5. First quick connector; 1-6. T-junction; 1-7. Sensor wiring harness; 1-8. Outlet connector; 1-9. First quick connector seat.

[0050] 2. Flow metering tube; 2-1. Second tube body; 2-2. Turbine flow meter; 2-3. Second quick connector; 2-4. First reducer connector; 2-5. Third tube body;

[0051] 3. Adjustable spacing pipe fastener, 3-1, First fastener clip, 3-2, Second fastener clip.

[0052] 4. Flight recorder heat flux test piece; 4-1. Flight recorder equivalent shell; 4-2. Medium baffle; 4-3. Fixing tube; 4-4. Heat insulation layer; 4-5. Second quick-connect fitting.

[0053] 5. Medium discharge pipe; 5-1. Fourth pipe body; 5-2. Third quick-connect fitting; 5-3. Second reducing fitting; 5-4. 90° elbow.

[0054] 6. Flight recorder heat flux meter; 7. Firewall; 8. First burner; 9. Second burner; 10. Third burner; 11. Burner; 12. Thermocouple. Detailed Implementation

[0055] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0056] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0057] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0058] Example 1

[0059] like Figure 1 As shown, a flight recorder heat flux meter includes: a temperature measuring tube 1, a flow measuring tube 2, an adjustable spacing pipe fixing device 3, a flight recorder heat flux test piece 4, and a medium discharge pipe 5.

[0060] The purpose of the fire test is to verify whether the flight recorder meets the designed fire resistance standards, which must satisfy the minimum operating performance specifications (MOPS) for flame coverage, heat flux, and flame temperature. Typical requirements are full flame coverage, a heat flux of 158 kW / m², and a flame temperature of 1100°C. A flight recorder heat flux meter is used to measure the heat flux during the fire test. It simulates the fire process using a casing identical in shape to the flight recorder under test. The collected temperature and flow information is used to calculate the heat flux of the flight recorder under the current flame conditions, serving as the basis for adjusting the burner gas flow, airflow, and position distance, among other test environmental parameters. Throughout the test environment adjustment process, the flight recorder heat flux meter continuously monitors the heat flux. Once the test environment meets the requirements of the corresponding MOPS, the flight recorder under test will directly replace the heat flux meter in situ for the fire test to ensure consistency of test conditions.

[0061] like Figure 2 As shown, the fire test system includes: a flight recorder heat flux meter 6, a firewall 7, a first burner 8, a second burner 9, a third burner 10, burners 11, and three thermocouples 12.

[0062] The firewall 7 primarily isolates the flame and heat during the fire test, preventing heat absorption by the pipeline of the flight recorder heat flux meter 6 and protecting sensors such as the flow meter. It also fixes the flight recorder heat flux meter 6 at a designated height above the ground and includes a mechanism for fixing and switching the tested flight recorder to its original position for in-situ replacement of the heat flux meter 6. The burner mixes and burns the fuel gas to form a high-temperature flame that is directed at the tested flight recorder, providing a stable combustion time of 1.5 hours. The thermocouple 12 ensures continuous temperature measurement throughout the entire test. Firewall 7 and burner are placed directly on the ground. Firewall 7 is usually fixed and burner is mobile. The flame temperature and heat flux can be adjusted by moving the burner as a whole and setting the height and angle of the burner 11. Flight recorder heat flux meter 6 is fixed to firewall 7 by adjustable spacing fixture 3. Two temperature measuring tubes 1 pass through firewall 7 along with adjustable spacing fixture 3. Thermocouple 12 is fixed with a fixed bracket, and the temperature monitoring point should be located 25 mm away from the center of the flight recorder surface.

[0063] In some embodiments, such as Figure 3 As shown, the temperature measuring tube 1 includes: a first tube body 1-1, an inner protective tube 1-2, a temperature sensor 1-3, a support frame 1-4, a first quick-connect pipe connector 1-5, a tee 1-6, a sensor wiring harness 1-7, an outlet pipe connector 1-8, and a first quick-connect pipe connector seat 1-9.

[0064] Specifically, the first tube 1-1 serves as the structural support for the flight recorder's heat flux meter and as a medium flow pipeline; the inner protective tube 1-2 is a long tube structure fixed to the central axis of the first tube 1-1 through an inner ring opening of the support frame 1-4; the tip blind tube is used to fix the temperature sensor 1-3; the middle long tube section serves as a protective container for the sensor wiring harness 1-7; the thickened tail section with a boss is used to cooperate with the support frame 1-4 for positioning; the opening on the boss can be inserted to connect with the inner protective tube section of the wire connector 1-8 to form a right-angle bend and for positioning; the temperature sensor 1-3 is fixed at the tip of the blind tube of the inner protective tube 1-2, used to collect the inlet or outlet medium temperature of the flight recorder heat flux test piece, and outputs the temperature signal to the data acquisition module through the sensor harness 1-7; the support frame 1-4 has a hollow structure with inner and outer rings, and the inner and outer rings are coaxial and fixed with four ribs. The hollow part serves as a medium flow pipeline. The outer ring is fixed to the opening of the first tube 1-1 through interference fit or other connection methods. The inner ring has an opening for supporting the inner protective tube 1-2 and isolating it from the first tube 1-1 for medium flow, which is used for temperature sensor 1-3 and... The sensor wiring harness 1-7 is protected from fire. The first quick-connect fitting 1-5 is connected to the first pipe body 1-1 via an internal thread and is used to quickly connect the temperature measuring tube 1 to the flight recorder heat flux test piece 4. Sealing is achieved through labyrinth seals and other methods to reduce test preparation time and ensure the versatility of the test equipment. The tee 1-6 connects the two sections of the first pipe body 1-1 via an internal thread and fixes the outlet fitting 1-8 via an internal thread. The sensor wiring harness 1-7 is used for signal transmission from the temperature sensor 1-3, passing through the inner protective tube 1-2 and the outlet fitting. The cavity of head 1-8 enables the external output of temperature signals; the outlet pipe connector 1-8 is fixed to the tee 1-6 by threads, and the inner protective tube section is inserted into the tail opening of the inner protective tube 1-2 to form a right-angle bend for use by the sensor wire harness 1-7 and to limit the inner protective tube 1-2. After the limit is completed, glue is injected to fix it; the first quick pipe connector seat 1-9 is connected to the first pipe body 1-1 by threads and is used to realize the quick pipe connector connection between the temperature measuring tube 1 and other components. The sealing is achieved by means of labyrinth seal, etc., to reduce the test preparation time and ensure the versatility of the test equipment.

[0065] In some embodiments, such as Figure 4 As shown, the flow metering tube 2 includes: a second tube body 2-1, a turbine flow meter 2-2, a second quick-connect pipe joint 2-3, a first reducing pipe joint 2-4, and a third tube body 2-5.

[0066] Specifically, the second pipe body 2-1 is used to fix the turbine flow meter 2-2 and serves as a medium flow pipeline to provide a metering straight pipe section for the turbine flow meter 2-2; the turbine flow meter 2-2 is connected to the second pipe body 2-1 by threads and is used to measure the flow rate of the medium in the flight recorder heat flux meter; the second quick-connect pipe joint 2-3 is connected to the third pipe body 2-5 by internal threads to realize the quick connection between the flow metering pipe 2 and the temperature metering pipe 1, and the sealing is achieved by means of labyrinth seals, etc., which facilitates the maintenance and calibration of the flow meter and reduces the test preparation time; the first reducing pipe joint 2-4 is connected to the second pipe body 2-1 and the third pipe body 2-5 by threads to realize the connection of two pipe bodies of different sizes; the third pipe body 2-5 is fixed to the first reducing pipe joint 2-4 by threads for structural support and serves as a medium flow pipeline.

[0067] In this embodiment, the turbine flow meter 2-2 can be an intelligent turbine flow meter with signal transmission capability.

[0068] In some embodiments, such as Figure 5 As shown, the adjustable spacing pipe fixing device 3 includes: a first fixing clip 3-1 and a second fixing clip 3-2.

[0069] Specifically, the first fixing clip 3-1 and the second fixing clip 3-2 pass through the first tube body 1-1 through two circular fixing holes and use the first quick pipe connector 1-5 and the first quick pipe connector seat 1-9 to limit and fix the temperature measuring tube 1. The gap between the two is quickly adjusted by the sliding groove between them, which can be used for flight recorder heat flux test pieces 4 of different shapes and sizes. A scale is set at the position of the sliding groove to quickly confirm the axial gap between the two temperature measuring tubes 1 for the installation of flight recorder heat flux test pieces 4.

[0070] In some embodiments, such as Figure 6 As shown, the flight recorder heat flux test piece 4 includes: a flight recorder equivalent shell 4-1, a medium baffle 4-2, a fixing tube 4-3, a heat insulation protective layer 4-4, and a second quick-connect pipe seat 4-5.

[0071] Specifically, the flight recorder's equivalent outer shell 4-1 is fixed to the fixed pipe 4-3 to receive flames simulating the flight recorder's state when exposed to high-temperature fire, and to serve as a carrier for independent heat exchange between the medium and the flame as much as possible; the medium baffle 4-2 is located on the symmetrical plane of the flight recorder's equivalent outer shell 4-1, isolating the medium inside the flight recorder's equivalent outer shell 4-1 according to the inlet and outlet, allowing the medium to flow fully and absorb heat evenly within it; the fixed pipe 4-3 is connected to the second quick-connect fitting 4-5 by threads, used to fix the flight recorder's equivalent outer shell 4-1, and serves as a medium flow pipeline; the heat insulation layer 4-4 is fixed to the fixed pipe 4-3 after being coated or pressed, used to insulate the fixed pipe 4-3, reducing the heat exchange between the medium and the flame through the fixed pipe 4-3; the second quick-connect fitting 4-5 is connected to the fixed pipe 4-3 by internal threads, and is used to achieve quick connection with the temperature measuring pipe 1, reducing test preparation time and ensuring the versatility of the test equipment.

[0072] In some embodiments, such as Figure 7 , Figure 8 As shown, except for the temperature measuring tube 1, which requires installation with the adjustable spacing pipe fixing device 3 during assembly, all other components of the flight recorder heat flux meter can be assembled independently. When assembling the temperature measuring tube 1, do not first install the assembly of the first tube body 1-1 and the first quick-connect fitting seat 1-9, nor the quick-connect fitting 1-5. Pass the first tube body 1-1 on the temperature measuring tube assembly through one of the two concentric holes of the fixing clip and install the first quick-connect fitting 1-5. Then, pass the assembly of the first tube body 1-1 and the first quick-connect fitting seat 1-9 through the other of the two concentric holes in the fixing clip. Finally, complete the assembly of the temperature measuring tube 1 through a threaded connection. Repeat this step to connect both sets of temperature measuring tubes 1 to the adjustable spacing pipe fixing device 3; via the second quick-connect fitting... Quick-connect fitting 2-3 connects to the first quick-connect fitting seat 1-9 to connect the flow metering tube 2 and the temperature metering tube 1; the third quick-connect fitting 5-2 connects to the first quick-connect fitting seat 1-9 to connect the medium discharge tube 5 and the temperature metering tube 1; the two exposed inner protective tubes 1-2 are inserted into the fixed tube 4-3, and the two second quick-connect fitting seats 4-5 are connected to the two first quick-connect fittings 1-5. The inner protective tubes 1-2 are then inserted into the interface between the fixed tube 4-3 and the flight recorder's proportional outer shell 4-1, completing the connection between the flight recorder's heat flux test piece 4 and the two sets of temperature metering tubes 1. Once all components are connected, the flight recorder's heat flux meter assembly is complete.

[0073] Working principle of flight recorder heat flux meter: Before use, the flight recorder heat flux meter needs to be filled with medium and provided with stable pressure to keep the medium flowing inside. Then, the burner is ignited and the flame formed covers the flight recorder's outer shell by 4-1 as required, and then it enters the working state.

[0074] During the measurement of the flight recorder's heat flux meter, the medium flows into the flow metering tube 2 through the second tube 2-1. The flow rate is measured when the medium passes through the turbine flow meter 2-2. The medium then flows into the temperature metering tube 1 after passing through the third tube 2-5 and the second quick connector 2-3. After passing through the tee 1-6, the medium begins to receive thermal protection from the inner protective tube 1-2. The medium then flows into the flight recorder's heat flux testing piece 4 after passing through the support frame 1-4 and the first quick connector 1-5. The medium begins to absorb heat and heat up when it enters the flame-affected area. When passing through the fixed tube 4-3, it is minimally heated by the thermal insulation layer 4-4. The medium then enters the fixed tube 4-3 (not covered by the thermal insulation layer 4-4) and connects to the flight recorder's outer casing 4-1 at the inlet position, where it contacts the temperature sensor 1-3 to measure the inlet temperature. Simultaneously, it begins to rapidly absorb heat. The medium enters the flight recorder's equivalent outer shell 4-1, absorbing a large amount of heat. At the same time, it is blocked by the medium baffle 4-2 and flows into the gap between the medium baffle 4-2 and the flight recorder's equivalent outer shell 4-1, and begins to flow towards the outlet position. At the outlet position, it comes into contact with another temperature sensor 1-3 to measure the temperature and obtain the "outlet temperature" value. At the same time, it begins to provide thermal protection for the inner protective tube 1-2. Then, when the medium passes through the fixed tube 4-3, it is protected by the thermal insulation layer 4-4, and the temperature rise of the medium is very small. It then flows into the temperature measuring tube 1 through the second quick pipe connector seat 4-5. After passing through the first tube body 1-1 and the first quick pipe connector seat 1-9 in sequence, the medium flows into the medium discharge tube 5. After passing through the fourth tube body 5-1, the second reducing pipe connector 5-3, and the 90° elbow 5-4 in sequence, the medium is discharged through the 90° elbow 5-4.

[0075] The temperature sensor outputs a 4-20mA analog signal, and the turbine flow meter outputs the flow rate value. These data are transmitted to the industrial control computer of the fire test system through the 485 interface of the data acquisition module.

[0076] The industrial control computer (processor) calculates the heat flux using data on the "flow rate of the medium," "inlet temperature," and "outlet temperature." The formula for calculating the heat flux of the flight recorder is as follows:

[0077]

[0078] Where: dT represents the temperature rise of the medium, F represents the flow rate of the medium, SH represents the specific heat of the medium, A represents the surface area of ​​the flight recorder's equivalent outer shell, and C represents the absorption constant.

[0079] After the heat flux stabilizes and reaches the test conditions, the flight recorder heat flux meter inside the flame is replaced in place with the flight recorder to ensure that the heat flux of the fire test is the same. The fire test is then started, and the flight recorder heat flux meter has completed its working process.

[0080] The calculation formula for flight recorder heat flux shows that improving heat flux accuracy requires accurate measurement of the temperature rise and flow rate of the medium within the flight recorder's equivalent outer casing 4-1. Since the fire test requires the flight recorder's equivalent outer casing 4-1 to be completely surrounded by flame, the fixed tube 4-3 will inevitably be heated by the flame. This will further cause a temperature rise in the medium within the fixed tube 4-3, thus affecting the accuracy of heat flux measurement. If the fixed tube 4-3 is completely thermally shielded using a heat-insulating protective layer 4-4, the heat-insulating protective layer 4-4 will be too thick and excessive, leading to a decrease in the fire-affected surface area at the connection between the flight recorder's equivalent outer casing 4-1 and the fixed tube 4-3, thus affecting the accuracy of heat flux measurement.

[0081] The aforementioned pain points are particularly prominent when flight recorders are small in size and traditional measurement methods are used: In traditional measurement methods, temperature measurement uses thermocouples or resistance temperature detectors (RTDs) mounted on the outside of pipes. The pipe diameter is relatively large. In addition, to avoid direct contact between the thermocouples or RTDs and the flame, which could damage the wiring harness and seals, a long pipe is usually used to install them behind a firewall. The long and thick pipe in front of the firewall will greatly increase the actual fire-affected surface area. Therefore, when the surface area of ​​the flight recorder's equivalent casing is small, the large actual temperature rise of the medium will lead to a significant error. If a heat insulation layer is added to prevent the error introduced by the increased fire-affected surface area caused by the pipe, it is still limited by the pipe diameter and the size of the flight recorder. A considerable area of ​​the flight recorder's equivalent casing will be blocked by the heat insulation material, affecting the accuracy of heat flux measurement.

[0082] This invention achieves direct measurement of the outlet and inlet temperatures of the flight recorder's equivalent outer casing 4-1 via a temperature measuring tube 1, avoiding measurement input errors caused by flame heating of the pipe. Simultaneously, the protection of the medium prevents damage to the sensor wiring harness 1-7 and the seals. By designing the length of the fixed tube 4-3, the surface area of ​​the section not covered by the heat insulation layer 4-4 is equal to the surface area of ​​the flight recorder's equivalent outer casing 4-1 obscured by the fixed tube 4-3. This ensures that the surface area of ​​the flight recorder's heat flux meter is approximately equivalent to the surface area of ​​the tested flight recorder, thereby improving accuracy. Furthermore, the system design reduces the dimensions of the first tube 1-1, the fixed tube 4-3, and the heat insulation layer 4-4 to accommodate smaller flight recorders, reducing measurement errors introduced by the aforementioned steps. Through these designs, this invention enables more accurate and efficient measurement of flight recorder heat flux and is applicable to flight recorders with a minimum diameter or side length of 50mm, playing a crucial role in the design and verification of micro and small flight recorders.

[0083] Example 2

[0084] This embodiment provides a method for operating a flight recorder heat flux meter, applied to the flight recorder heat flux meter described in Embodiment 1, including:

[0085] The turbine flow meter in the flow metering tube measures the flow rate of the medium and uploads it to the processor;

[0086] The temperature sensor in the first temperature metering tube collects the inlet temperature value of the heat flux test piece flowing into the flight recorder and uploads it to the processor;

[0087] The temperature sensor in the second temperature metering tube collects the outlet temperature value of the heat flux test piece flowing out of the flight recorder and uploads it to the industrial control computer.

[0088] The industrial control computer calculates the temperature difference based on the difference between the outlet and inlet temperatures; and calculates the heat flux of the flight recorder based on the flow rate, temperature difference, specific heat of the medium, and the surface area of ​​the flight recorder's casing.

[0089] The formula for calculating the heat flux of a flight recorder is as follows:

[0090]

[0091] Where: dT represents the temperature rise of the medium, F represents the flow rate of the medium, SH represents the specific heat of the medium, A represents the surface area of ​​the flight recorder's equivalent outer shell, and C represents the absorption constant.

[0092] Example 3

[0093] This embodiment provides a flight recorder, including a memory and a flight recorder heat flux meter as described in Embodiment 1, which is connected to the memory.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flight recorder heat flux meter, characterized in that, include: First temperature measuring tube, second temperature measuring tube, flow measuring tube, adjustable spacing pipe fixing device, flight recorder heat flux test piece, and medium discharge pipe. One end of the flow metering tube is used to input the medium, and the other end of the flow metering tube is connected to one end of the first temperature metering tube through an adjustable spacing pipe fixer. The other end of the first temperature metering tube is connected to one port of the flight recorder heat flux test piece. The other port of the flight recorder heat flux test piece is connected to one end of the second temperature metering tube. The other end of the second temperature metering tube is connected to one end of the medium discharge pipe through an adjustable spacing pipe fixer. The other end of the medium discharge pipe is used to discharge the medium. The first and second temperature measuring tubes have the same structure. Both the first and second temperature measuring tubes are equipped with temperature sensors to detect the temperature of the heat flux test piece flowing into and out of the flight recorder. The first temperature measuring tube further includes: two sections of first tube body, inner protective tube, support frame, first quick pipe connector, tee, sensor wiring harness, outlet pipe connector and first quick pipe connector seat; The inner protective tube is fixed to the central axis of the first tube body by a support frame. The end of the inner protective tube near the flight recorder heat flux test piece is used to fix the temperature sensor. The temperature sensor is connected to the sensor harness, and the sensor harness is placed inside the inner protective tube. The end of the inner protective tube near the adjustable spacing pipe fixer has a boss for cooperating with the support frame for limiting movement. One end of the first quick-connect pipe is connected to the first tube body, and the other end of the first quick-connect pipe is connected to the flight recorder heat flux test piece. The two ends of the tee are used to connect the two sections of the first tube body, and the third end is connected to the outlet pipe connector. The sensor harness passes through the inner protective tube and the outlet pipe connector. The first quick-connect pipe seat is used to connect the first tube body and the flow metering tube. A turbine flow meter is installed inside the flow metering tube to detect the flow rate of the medium.

2. The flight recorder heat flux meter according to claim 1, characterized in that, The protrusion has a hole for embedding the inner protective tube section of the outlet pipe connector, forming a right-angle bend and limiting its position.

3. The flight recorder heat flux meter according to claim 1, characterized in that, The flow metering tube further includes: a second tube body, a second quick-connect fitting, a first reducing fitting, and a third tube body; the second tube body is used to fix the turbine flow meter, the first reducing fitting is used to connect the second tube body and the third tube body, and the second quick-connect fitting is used to connect the third tube body and the temperature metering tube.

4. The flight recorder heat flux meter according to claim 3, characterized in that, The diameter of the second tube is larger than the diameter of the third tube.

5. The flight recorder heat flux meter according to claim 1, characterized in that, The adjustable spacing pipe fixing device includes a first fixing clip, a second fixing clip, and a sliding groove. The first fixing clip and the second fixing clip have the same structure, and both the first fixing clip and the second fixing clip slide on the sliding groove. By adjusting the distance between the first fixing clip and the second fixing clip, it can adapt to flight recorder heat flux test pieces of different shapes and sizes.

6. The flight recorder heat flux meter according to claim 5, characterized in that, The first tube passes through the first fixing clip, which is used to limit and fix the temperature measuring tube.

7. The flight recorder heat flux meter according to claim 1, characterized in that, The flight recorder heat flux test piece includes: a flight recorder equivalent shell, a dielectric baffle, a fixing tube, and a second quick-connect pipe connector seat; The flight recorder housing is equipped with a media baffle to divide the space inside the flight recorder housing into two parts, so as to isolate the inlet for media to flow into the flight recorder housing and the outlet for media to flow out of the flight recorder housing. The fixed tube is connected to the second quick-connect fitting, through which the flight recorder's equivalent outer shell is fixed to the fixed tube; the second quick-connect fitting is used to connect the fixed tube and the temperature measuring tube.

8. The flight recorder heat flux meter according to claim 7, characterized in that, The outer circumferential surface of the fixed tube is provided with a heat insulation protective layer for heat insulation of the fixed tube.

9. The flight recorder heat flux meter according to claim 1, characterized in that, The medium discharge pipe includes: a third quick-connect pipe joint, a fourth pipe body, a second reducing pipe joint, and a 90° elbow. One end of the third quick-connect pipe joint is connected to the second temperature metering pipe, and the other end is connected to one end of the fourth pipe body. The other end of the fourth pipe body is connected to the second reducing pipe joint, and the second reducing pipe joint is connected to the 90° elbow for discharging the medium.

10. A method for operating a flight recorder heat flux meter, characterized in that, The flight recorder heat flux meter according to any one of claims 1-9 comprises: The turbine flow meter in the flow metering tube measures the flow rate of the medium and uploads it to the processor; The temperature sensor in the first temperature metering tube collects the inlet temperature value of the heat flux test piece flowing into the flight recorder and uploads it to the processor; The temperature sensor in the second temperature metering tube collects the outlet temperature value of the heat flux test piece flowing out of the flight recorder and uploads it to the industrial control computer. The industrial control computer calculates the temperature difference based on the difference between the outlet and inlet temperatures; and calculates the heat flux of the flight recorder based on the flow rate, temperature difference, specific heat of the medium, and the surface area of ​​the flight recorder's casing.

11. A flight recorder, characterized in that, Includes a memory, and a flight recorder heat flux meter according to any one of claims 1-9 connected to the memory.

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