Civil aviation turboprop engine restarting capability test device and method

Abstract

The invention relates to the technical field of engine testing, in particular to a civil aviation turboprop engine restarting capability testing device and method. Comprising a turboprop vehicle platform body, and the turboprop vehicle platform body is provided with an engine, a fuel pump regulator suitable for regulating fuel supply of the engine and an electronic controller suitable for detecting the running state of the engine; the processor is electrically connected with the fuel pump regulator and the electronic controller respectively; and the fuel cut-off signal generating device is electrically connected with the processor and is suitable for generating a fuel cut-off signal under the operation of a user. In the application, a fuel cut-off signal can be sent to the processor through the fuel cut-off signal generation device, so that the controller controls the fuel pump regulator to cut off fuel supply to the engine, and the electronic controller sends a flameout signal to the processor when detecting that the engine is in a flameout state; and then the processor controls the fuel pump regulator to recover fuel supply of the engine.

Description

Technical Field

[0001] The present invention relates to the technical field of engine tests, and particularly to a test device and method for the restart ability of a civil aviation turboprop engine. Background Art

[0002] The purpose of the test for the restart ability of a civil aviation turboprop engine is to verify that when the engine encounters a bad weather condition or other reasons resulting in engine flameout during the specified working conditions such as climbing, it can automatically accelerate to the initial power setting value when the fuel supply is restored. Currently, there is a lack of verification tests for the restart ability of civil aviation turboprop engines in China. Summary of the Invention

[0003] In view of this, the present invention provides a test device and method for the restart ability of a civil aviation turboprop engine to solve the problem of the lack of verification tests for the restart ability of civil aviation turboprop engines in China.

[0004] In a first aspect, the present invention provides a test device for the restart ability of a civil aviation turboprop engine, including:

[0005] A turboprop vehicle platform body, on which an engine, a fuel pump regulator suitable for adjusting the fuel supply of the engine, and an electronic controller suitable for detecting the operating state of the engine are provided;

[0006] A processor, electrically connected to the fuel pump regulator and the electronic controller respectively;

[0007] A fuel cut-off signal generating device, electrically connected to the processor, suitable for generating a fuel cut-off signal under the operation of a user;

[0008] The processor is suitable for controlling the fuel pump regulator to cut off the fuel supply of the engine after receiving the fuel cut-off signal;

[0009] The electronic controller is suitable for sending a flameout signal to the processor when detecting that the engine is in a flameout state, and the processor is suitable for controlling the fuel pump regulator to restore the fuel supply of the engine after receiving the flameout signal.

[0010] In this application, a fuel cut-off signal can be sent to the processor through the fuel cut-off signal generating device, so that the controller controls the fuel pump regulator to cut off the fuel supply to the engine. When the electronic controller detects that the engine is in a flameout state, it sends a flameout signal to the processor, and the processor then controls the fuel pump regulator to restore the fuel supply of the engine. It can test the requirement clearly stated in the "25.903(e) Engine Restart Ability" clause of the airworthiness certification guidelines for civil transport aircraft to verify the ability to restart after a complete engine shutdown in flight and demonstrate the restart ability after an instantaneous shutdown.

[0011] In an alternative embodiment, it further includes a regulator control device, and the regulator control device includes:

[0012] A relay, electrically connected to the processor;

[0013] A power supply, electrically connected to the relay;

[0014] A parking solenoid valve, electrically connected to the relay, disposed on the fuel pump regulator. When the parking solenoid valve is energized, it is adapted to cut off the fuel supply to the engine. When the parking solenoid valve is de-energized, it is adapted to resume the fuel supply to the engine;

[0015] The processor is adapted to turn on the relay after receiving a fuel cut-off signal, so that the power supply supplies power to the parking solenoid valve, and is also adapted to turn off the relay after receiving a flameout signal, so that the parking solenoid valve is de-energized.

[0016] In this application, the processor can control the relay according to the fuel cut-off signal and the flameout signal, so that the power supply can supply power to or cut off the power supply of the parking solenoid valve, and also enables the parking solenoid valve to have two states of cutting off the fuel supply to the engine and resuming the fuel supply to the engine.

[0017] In an alternative embodiment, the fuel cut-off signal generating device is provided with a cut-off switch. When the cut-off switch is operated, the fuel cut-off signal generating device sends a fuel cut-off signal to the processor. During the test, the fuel cut-off signal generating device can send a fuel cut-off signal to the processor by disconnecting or closing the cut-off switch. The operation is relatively convenient and remote control can be performed.

[0018] In an alternative embodiment, the power supply is the 28V DC power supply of the turboprop vehicle platform body. The power supply of the turboprop vehicle platform body can be directly used to connect the relay and supply power to the parking solenoid valve.

[0019] In an alternative embodiment, it further includes:

[0020] An atmospheric condition simulation system, adapted to adjust the atmospheric conditions of the engine during the test;

[0021] A hydraulic dynamometer, adapted to adjust the rotational speed of the power turbine.

[0022] The atmospheric condition simulation system can simulate the atmospheric conditions of the engine, simulate the altitude, speed and temperature of the engine, so that the restart ability of the engine under various atmospheric conditions can be tested during the test.

[0023] In an alternative embodiment, the atmospheric condition simulation system includes an altitude simulation system, a speed simulation system and a temperature simulation system.

[0024] In an alternative embodiment, it further includes:

[0025] An oscilloscope, electrically connected to the relay, and adapted to display the output waveform of the relay. The oscilloscope can monitor the output waveform at the output end of the relay in real time to determine the actually output power signal.

[0026] Second, the present invention also provides a method for testing the restart ability of a civil aviation turboprop engine, which is applicable to the civil aviation turboprop engine restart ability test device as described above, and includes the following steps:

[0027] S1, accelerating the engine to the intermediate power state;

[0028] S2, adjusting the atmospheric conditions of the engine to the target atmospheric conditions;

[0029] S3, accelerating the engine to the maximum climb state;

[0030] S4, operating the cut-off switch, and checking the power state of the engine after a preset time;

[0031] S5, repeating step S4.

[0032] When receiving a fuel cut-off signal, the relay is turned on, and the power supply is supplied to the shutdown solenoid valve through the relay, and the fuel pump regulator cuts off the fuel supply of the engine; when receiving a flameout signal, the relay is turned off, that is, the 28VDC power supply of the shutdown solenoid valve is disconnected, and the fuel pump regulator restores the fuel supply of the engine. By checking whether the engine restarts successfully, checking the power state of the engine after a preset time, and checking whether it returns to the original power state, the test of the engine's restart ability can be completed.

[0033] In an alternative embodiment, the preset time is 2 - 3 minutes. This can make the engine in a stable state and reflect the true restart ability of the engine.

[0034] In an alternative embodiment, in step S4, it further includes:

[0035] Recording the flameout time of the engine. The reaction time of the processor from receiving the fuel cut-off signal to receiving the flameout signal can be recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 Schematic diagram of Structure of Embodiment 1 of the present invention;

[0038] Figure 2 Schematic diagram of principle of Embodiment 2 of the present invention.

[0039] Description of reference numerals in the drawings:

[0040] 1. Fuel pump regulator; 2. Processor; 3. Relay; 4. Parking solenoid valve; 5. Oscilloscope. Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] The purpose of the restart ability test of civil aviation turboprop engines is to verify that the engine can automatically accelerate to the initial power setting value when fuel supply is restored after the engine stalls due to reasons such as encountering adverse weather conditions during specified operating conditions such as climbing.

[0043] Currently, domestic turboprop engines mainly focus on the development of military aircraft, and no full-engine restart ability verification tests have been carried out for airworthiness regulations.

[0044] According to the service history of civil aviation aircraft, there are multiple incidents of loss of power or thrust of all engines during flight due to the following reasons: engine stalling caused by adverse weather conditions, ingestion of volcanic ash, carbon deposition on fuel nozzles, fuel contamination, and fuel management errors by flight crew members. These incidents all occurred during takeoff climb and high-altitude cruise.

[0045] The "25.903(e) Engine Restart Ability" clause in the airworthiness certification guidelines for civil transport aircraft clearly requires verifying the restart ability after all engines stop in the air, mainly for instantaneous stops at high power, and demonstrating the restart ability.

[0046] Since the flight scenarios of civil aircraft are different from those of military aircraft, the safety requirements are higher.

[0047] The following describes the embodiments of the present invention in conjunction with Figures 1 to 2 , the embodiments of the present invention.

[0048] Embodiment 1

[0049] As shown in the Figure 1 drawing, according to an embodiment of the present invention, a test device for the restart ability of a civil aviation turboprop engine is provided, including:

[0050] A turboprop vehicle platform body, on which an engine, a fuel pump regulator 1 suitable for adjusting the fuel supply of the engine, and an electronic controller suitable for detecting the operating state of the engine are provided; the electronic controller integrates a multi-channel sensor interface, collects engine speed, temperature, pressure and vibration signals in real time, and communicates with a processor 2 through a CAN bus.

[0051] A processor 2, which is electrically connected to the fuel pump regulator 1 and the electronic controller respectively; the processor 2 can adopt a high-performance programmable logic controller (PLC), whose input ports are respectively connected to a fuel cut-off signal generating device and an electronic controller, and the output port controls a stop solenoid valve 4 of the fuel pump regulator 1 through a relay 3. The PLC has a built-in logic program, can respond to fuel cut-off instructions (such as digital signals) and flame-out detection signals (such as low-speed trigger thresholds), and realizes millisecond-level on-off control of the relay 3.

[0052] The determination of the engine flame-out state by the electronic controller (ECU) can be based on a multi-parameter fusion judgment mechanism, and the specific logic is as follows:

[0053] 1. Core judgment parameters and threshold settings

[0054] Power turbine speed (Np)

[0055] Judgment condition: When the speed sensor detects that the power turbine speed is lower than 40% of the idle speed (for example, suddenly drops from 2500 RPM at normal intermediate power to ≤1000 RPM) and lasts for more than 200 ms, a flame-out warning is triggered.

[0056] Redundant design: Data is collected synchronously through a dual-channel speed sensor (magnetic-electric type + Hall type). If the difference between the two signals exceeds ±5%, the sensor self-check program is started to exclude the possibility of misjudgment.

[0057] Combustion chamber pressure (P3) and exhaust gas temperature (EGT)

[0058] Auxiliary criterion:

[0059] The combustion chamber pressure is lower than the lowest combustion maintenance threshold (such as <0.5 MPa);

[0060] The exhaust gas temperature drops by more than 300 °C within 30 seconds after fuel cut-off (such as drops from 600 °C to 300 °C).

[0061] Logic fusion: If the speed is lower than the threshold and P3 / EGT drops in the same step, it is directly determined that the flame-out occurs without waiting for the time window.

[0062] Fuel flow (Wf) and fuel supply instruction

[0063] Associated verification: When the fuel flow sensor detects that the actual fuel supply is zero and is consistent with the cut-off instruction (from the PLC) of the fuel pump regulator 1, it serves as an auxiliary verification condition.

[0064] 2. Decision-making process and timing control

[0065] Real-time monitoring stage:

[0066] The electronic controller continuously collects the above parameters with a sampling period of 10 ms and eliminates noise interference through the Kalman filtering algorithm.

[0067] Primary trigger condition:

[0068] When the rotational speed is lower than the preset threshold (such as 1000 RPM), start a 200-ms timing window and synchronously check the combustion chamber pressure and exhaust gas temperature.

[0069] Secondary verification stage:

[0070] If within the timing window:

[0071] The combustion chamber pressure continuously remains lower than 0.5 MPa;

[0072] The exhaust gas temperature decrease rate ≥ 10 °C / s;

[0073] The fuel flow is zero and there is no fuel supply instruction.

[0074] If any two of the above are satisfied, it is determined as the flameout state, and a digital output flameout signal (high level → low level) is sent to the processor 2.

[0075] 3. Anti-interference and fault tolerance mechanism

[0076] Dynamic threshold adjustment:

[0077] Automatically adjust the rotational speed decision threshold according to the current working state of the engine (such as ground idle, intermediate power, maximum climb). For example:

[0078] Ground idle state: The flameout threshold is set to 800 RPM;

[0079] Maximum climb state: The threshold is increased to 1500 RPM to avoid false triggering due to transient fluctuations under high load.

[0080] Time window adaptability:

[0081] If the engine is in a high-altitude simulation environment (such as 10,000 meters), since the rotational speed decrease rate is accelerated due to the thin air, shorten the timing window to 100 ms to ensure fast response.

[0082] Fault injection protection:

[0083] If the sensor data is abnormal (such as the speed signal jumping or the temperature sensor open circuit), the ECU switches to the backup control mode, makes a determination only relying on the fuel flow and the fuel supply command, and records the fault code for subsequent analysis.

[0084] 4. Specific applications in the test scenario

[0085] After fuel cut-off, the power turbine speed maintains for a short time due to inertia. The ECU completes the flameout determination within 1 - 2 seconds through the above logic.

[0086] After a successful determination, the ECU sends a 5V TTL level signal to the PLC to trigger the fuel recovery command, ensuring compliance with the requirement of "restart within 15 seconds" in the airworthiness clause.

[0087] The fuel cut-off signal generating device is electrically connected to the processor 2 and is adapted to generate a fuel cut-off signal under the operation of the user.

[0088] The processor 2 is adapted to control the fuel pump regulator 1 to cut off the fuel supply to the engine after receiving the fuel cut-off signal.

[0089] The electronic controller is adapted to send a flameout signal to the processor 2 when it detects that the engine is in the flameout state. The processor 2 is adapted to control the fuel pump regulator 1 to resume the fuel supply to the engine after receiving the flameout signal.

[0090] In this application, a fuel cut-off signal can be sent to the processor 2 through the fuel cut-off signal generating device, so that the controller controls the fuel pump regulator 1 to cut off the fuel supply to the engine. When the electronic controller detects that the engine is in the flameout state, it sends a flameout signal to the processor 2, and then the processor 2 controls the fuel pump regulator 1 to resume the fuel supply to the engine. Tests can be carried out on the requirement in the airworthiness certification guidelines for civil transport aircraft "25.903(e) Engine restart ability" which clearly requires verifying the restart ability after all engines stop in the air, and demonstrating the restart ability after an instantaneous stop.

[0091] In an alternative embodiment, it further includes a regulator control device, and the regulator control device includes:

[0092] Relay 3, electrically connected to the processor 2; the relay 3 can adopt a double-contact redundant electromagnetic relay 3 (such as Omron G7L series), its input end is connected to the digital output port of the processor 2 through an opto-isolation circuit, and the output end is connected to the parking solenoid valve 4 through two groups of independent contacts in parallel. The rated load current of the relay 3 is 10A / 28VDC, and the contact material uses a silver alloy coating to improve the arc resistance ability, ensuring that the contact resistance is stable (≤50mΩ) under frequent on-off operations. As an alternative solution, a solid-state relay 3 (SSR) can be used to achieve mechanical-contact-free power control, its response time can be shortened to ≤5ms, and it has a zero-crossing trigger characteristic to avoid inrush current impact.

[0093] Power supply, electrically connected to the relay 3; it can be directly taken from the 28V DC power bus of the turboprop vehicle platform body, and is connected to the input of the relay 3 through a reverse-polarity protection diode (such as 1N5822) and an overvoltage protector (TVS tube SMBJ28CA).

[0094] Parking solenoid valve 4, electrically connected to the relay 3, arranged on the fuel pump regulator 1, when the parking solenoid valve 4 is energized, it is suitable for cutting off the fuel supply of the engine, and when the parking solenoid valve 4 is de-energized, it is suitable for restoring the fuel supply of the engine;

[0095] The processor 2 is suitable for turning on the relay 3 after receiving the fuel cut-off signal, so that the power supply supplies power to the parking solenoid valve 4, and is also suitable for turning off the relay 3 after receiving the flameout signal, so that the parking solenoid valve 4 is de-energized. The processor 2 (PLC) can communicate with the upper computer through the RS485 bus, and upload the status of the relay 3, the solenoid valve current and the power supply voltage data in real time. A Hall current sensor (such as Allegro ACS712) is added to the output end of the relay 3, and its signal is input into the PLC analog input module after AD conversion, for monitoring the actual working current of the solenoid valve (accuracy ±1%). When abnormal current (such as open circuit, short circuit or overcurrent) is detected, the PLC immediately triggers a fault alarm and starts the standby control loop.

[0096] In this application, the processor 2 can control the relay 3 according to the fuel cut-off signal and the flameout signal, so that the power supply can supply power to or cut off the power of the parking solenoid valve 4, and also enables the parking solenoid valve 4 to have two states of cutting off the fuel supply of the engine and restoring the fuel supply of the engine.

[0097] In an optional implementation manner, the fuel cut-off signal generating device is provided with a cut-off switch. When the cut-off switch is operated, the fuel cut-off signal generating device sends a fuel cut-off signal to the processor 2. During the test, the fuel cut-off signal generating device can send a fuel cut-off signal to the processor 2 by disconnecting or closing the cut-off switch. The operation is relatively convenient and remote control can be performed.

[0098] The cut-off switch can be:

[0099] 1. Physical cut-off switch: Use a boat-shaped switch (such as the E-Switch TL3300 series), with an IP67 protection level and mechanical self-locking function, and connect to the digital input port of the processor 2 through hard wiring. When operating, the safety lock must be released first and then the switch is toggled to prevent accidental touch from causing unplanned fuel interruption.

[0100] 2. Touch screen control terminal: Integrate a 7-inch industrial-grade HMI display screen (such as Siemens KTP700Basic), with a dedicated fuel control interface built-in. The operator can send a cut-off instruction by clicking on the virtual button, and the instruction signal is transmitted to the processor 2 via the Ethernet protocol, with a response delay ≤ 10ms.

[0101] 3. Wireless remote control module: Configure a 2.4GHz RF remote control (such as the TI CC2652R7 solution), with an effective control distance of up to 300 meters. The remote control is built-in with dual-band frequency hopping technology to avoid interference from WiFi / Bluetooth signals in the airport environment, ensuring that the instruction transmission success rate > 99.9%.

[0102] The physical switch and the touch screen terminal adopt a dual-channel signal parallel input design, and a fuel cut-off signal is generated when any channel is triggered;

[0103] The wireless remote control module is built-in with the AES-128 encryption protocol to prevent illegal instruction injection. The receiving end is set with dual-antenna diversity reception, and automatically switches to the wired control mode when the signal strength is lower than -90dBm.

[0104] The fuel cut-off signal generating device can be a signal generating circuit. Operating the cut-off switch can send a high level or a low level to the processor 2, which is the fuel cut-off signal.

[0105] In an alternative embodiment, the power supply is the 28V DC power supply of the turboprop vehicle body. The power supply of the turboprop vehicle body can be directly used to connect the relay 3 and supply power to the parking solenoid valve 4.

[0106] In an alternative embodiment, it further includes:

[0107] An atmospheric condition simulation system, suitable for adjusting the atmospheric conditions of the engine during the test;

[0108] A hydraulic dynamometer, suitable for adjusting the speed of the power turbine. Among them, the power turbine is one of the core components of the engine.

[0109] The atmospheric condition simulation system can simulate the atmospheric conditions at the engine inlet, simulate the altitude, speed, and temperature of the engine, so that the restart ability of the engine under various atmospheric conditions can be tested during the test. The hydraulic dynamometer can adjust the power turbine to the actual speed under different atmospheric conditions. It should be noted that the atmospheric condition simulation system does not actually change the atmospheric conditions where the engine is located, but generates parameters related to the atmospheric conditions, such as altitude, speed, and temperature, and then the hydraulic dynamometer adjusts the speed of the power turbine. The atmospheric condition simulation system and the hydraulic dynamometer can be respectively connected to the processor 2.

[0110] In an alternative embodiment, the atmospheric condition simulation system includes an altitude simulation system, a speed simulation system, and a temperature simulation system.

[0111] The altitude simulation system, the speed simulation system, and the temperature simulation system can respectively output simulation parameters and are respectively connected to the hydraulic dynamometer. The hydraulic dynamometer adjusts the speed of the power turbine according to the simulation parameters related to the atmospheric conditions.

[0112] The atmospheric condition simulation system can also be an actual scenario simulation system, including:

[0113] The altitude simulation system is composed of a vacuum pressure chamber, a multi-stage centrifugal vacuum pump group (such as the Edwards STP-450 series), and a closed-loop feedback control unit, and specifically includes:

[0114] The vacuum pressure chamber can adopt a double-layer stainless steel structure, with an internal volume of ≥5m³, equipped with an electromagnetic seal valve and a bellows compensator, ensuring that the air pressure adjustment range in the chamber covers the pressure corresponding to 0 - 15,000 meters above sea level (101.3 kPa to 11.6 kPa), and the control accuracy is ±0.1 kPa;

[0115] The vacuum pump group can be configured with three frequency-converted drive vacuum pumps, and the pumping rate (0 - 500 L / s) is dynamically adjusted through the PID algorithm to achieve an adjustable air pressure change rate of 0 - 1,000 Pa / s, meeting the requirements of rapid pressure reduction (simulating emergency descent) and steady-state maintenance (simulating cruise altitude);

[0116] The pressure feedback network can be built-in with an absolute pressure sensor (such as the Honeywell 24PC series) and a differential pressure transmitter, and the chamber pressure data is real-time fed back to the PLC at a sampling period of 10 ms to generate an air pressure - time curve for test compliance verification.

[0117] Alternatively, a compressed air injection system can be used to replace the vacuum pump group. By cooperating the high-pressure gas storage tank (20MPa) with a proportional regulating valve, low-altitude simulation (0 - 5,000 meters) can be achieved, reducing the power consumption of the equipment. An interface of the meteorological database can be integrated to automatically generate a dynamic pressure curve according to real-time flight data (such as the ICAO standard atmosphere model), improving the simulation authenticity.

[0118] The speed simulation system consists of a variable-frequency driven axial-flow wind tunnel, a rectifying grid, and a flow velocity sensing unit, specifically including:

[0119] The axial-flow wind tunnel can adopt a carbon fiber duct with a diameter of 1.2 meters, equipped with a dual-rotor variable-frequency motor (such as ABB ACS880 series), with an output wind speed range of 0 - 500 km / h and a turbulence intensity ≤ 1%;

[0120] The rectifying grid can install a honeycomb aluminum rectifier and a damping net at the wind tunnel outlet to eliminate eddy currents and ensure the uniformity of the air flow (the standard deviation of the speed distribution ≤ ±2%);

[0121] The flow velocity closed-loop control can be based on the composite measurement data of a hot-wire anemometer (such as Dantec Dynamics 54N60) and a Pitot tube array, and adjust the motor speed through a fuzzy PID algorithm to achieve a target wind speed tracking error ≤ ±0.5 km / h.

[0122] Alternatively, a hydraulic-driven turbine can be used to replace the variable-frequency motor, and stepless speed regulation can be achieved by adjusting the hydraulic oil flow, which is suitable for high-power (>1,000 kW) test scenarios. Adjustable guide vanes can be added to simulate the composite conditions of crosswind (±30° yaw angle) and gust (instantaneous wind speed fluctuation ±20%) to verify the restart ability under extreme airflows.

[0123] The temperature simulation system consists of a liquid nitrogen injection module, an electric heating array, and a distributed temperature control unit, specifically including:

[0124] The low-temperature generation module can be configured with a liquid nitrogen storage tank (-196°C) and an atomizing nozzle, and adjust the injection volume through a proportional-integral valve to achieve linear control of the engine inlet temperature from -50°C to +25°C, with a cooling rate ≥ 10°C / s;

[0125] The high-temperature generation module can adopt silicon carbide rod electric heaters (rated power 200 kW), cooperate with an alumina ceramic insulation layer, and raise the temperature to +60°C, with a heating rate ≥ 5°C / s;

[0126] The temperature equalization design can arrange multi-stage guide plates and static mixers in the air flow channel, and combine an infrared thermal imager (such as FLIR A655sc) to monitor the temperature field uniformity in real time (temperature difference ≤ ±3°C).

[0127] Alternatively, a phase change material (such as paraffin / metal hydride) energy storage module can be adopted. During the temperature maintenance stage, the external energy supply is cut off, and stable temperature control is achieved through the latent heat of phase change of the material, with the energy-saving efficiency increased by 40%. The integrated volcanic ash simulation unit can be linked with the temperature system through a quantitative dust injection device (particle size 5 - 50 μm) to simulate the working condition of inhaling high-temperature volcanic ash.

[0128] The above-mentioned subsystems can be connected to the main control PLC through an industrial Ethernet (Profinet protocol) to achieve synchronous adjustment of multi-dimensional parameters. Standard test conditions (such as "high-altitude low-temperature cruise" and "tropical high-temperature climb") can be pre-stored in the PLC, and the coordinated changes of altitude, speed, and temperature can be triggered with one key. According to the real-time power output of the engine, the set values of wind speed and temperature can be automatically corrected to eliminate the deviation of environmental parameters caused by load changes. When any subsystem exceeds the limit (such as pressure cabin leakage, heater over-temperature), the PLC immediately activates the safety protocol, suspends the test, and restores the benchmark environmental conditions.

[0129] Alternatively, the altitude, speed, and temperature simulation systems can be designed as independent detachable modules and connected to the test bench through quick interfaces (such as DIN standard flanges), which is convenient for flexible configuration according to specific test requirements. A virtual model of the atmospheric condition simulation system (based on ANSYS Fluent) can be established to pre-run the parameter adjustment process in the digital space. After optimizing the control logic, physical tests are carried out to reduce the cost of trial and error. A humidity simulation expansion module (such as a steam injection system) can be developed to achieve multi-physical field coupling tests of temperature-humidity-pressure, covering the restart verification of tropical high-humidity environments.

[0130] In an alternative embodiment, it further includes:

[0131] An oscilloscope 5, electrically connected to the relay 3, is adapted to display the output waveform of the relay 3. The oscilloscope 5 can monitor the output waveform of the output terminal of the relay 3 in real time to determine the actually output power signal.

[0132] Embodiment 2

[0133] As shown in the attached Figure 1 figure, the present invention also provides a method for testing the restart ability of a civil aviation turboprop engine, which is applicable to the civil aviation turboprop engine restart ability test device as described above, and includes the following steps:

[0134] S1, accelerate the engine to the intermediate power state and maintain it stably for five minutes. It should be noted that before step S1, the engine can be started to ground idle speed first, maintained stably for 5 minutes, and then slowly accelerated to air idle speed and maintained stably for 5 minutes.

[0135] S2. Adjust the atmospheric conditions of the engine to the target atmospheric conditions, which include the target altitude, target speed, and target temperature, and can be stabilized for five minutes.

[0136] S3. Accelerate the engine to the maximum climb state, and it can be stabilized for five minutes while keeping the atmospheric conditions unchanged.

[0137] S4. Operate the cut-off switch, and check the power state of the engine after a preset time. The preset time can be two minutes, which can make the state of the engine tend to be stable.

[0138] S5. Repeat step S4. Specifically, step S4 can be repeated twice, and then the engine can be slowly decelerated to the in-air idle speed and stabilized for 2 minutes, and then slowly decelerated to the ground idle speed and stabilized for 2 minutes. Finally, the engine is shut down.

[0139] It should be noted that before the test, the engine needs to undergo a complete configuration check and obtain an airworthiness label. The engine needs to complete the acceptance test before the test. During the test, the manual control mode is adopted, and the power turbine speed is kept constant by the hydraulic dynamometer.

[0140] When the fuel cut-off signal is received, relay 3 is turned on, and the power supply is supplied to the shutdown solenoid valve 4 through relay 3, and the fuel pump regulator 1 cuts off the fuel supply of the engine. When the flameout signal is received, relay 3 is turned off, that is, the 28VDC power supply of the shutdown solenoid valve 4 is disconnected, and the fuel pump regulator 1 restores the fuel supply of the engine. By checking whether the engine restarts successfully, checking the power state of the engine after a preset time, and checking whether it returns to the original power state, the restart ability test of the engine can be completed.

[0141] In an alternative embodiment, the preset time is 2 - 3 minutes, which can make the engine in a stable state and reflect the true restart ability of the engine.

[0142] In an alternative embodiment, in step S4, it further includes:

[0143] Record the flameout time of the engine, which can record the reaction time of the processor 2 from receiving the fuel cut-off signal to receiving the flameout signal.

[0144] In this application, after the engine flameout and short-term shutdown, it can restart automatically and accelerate to the initial power setting value within at most 15 seconds, that is, the flameout time is at most 15 seconds, indicating that the test passes the standard.

[0145] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An experimental device for the restart ability of a turboprop engine for civil aviation, characterized in that, Comprising: A turboprop test stand body, on which an engine, a fuel pump regulator (1) suitable for adjusting the fuel supply of the engine, and an electronic controller suitable for detecting the operating state of the engine are provided; A processor (2), electrically connected to the fuel pump regulator (1) and the electronic controller respectively; A fuel cut-off signal generating device, electrically connected to the processor (2), suitable for generating a fuel cut-off signal under the operation of a user; The processor (2) is suitable for controlling the fuel pump regulator (1) to cut off the fuel supply of the engine after receiving the fuel cut-off signal; The electronic controller is suitable for sending a flameout signal to the processor (2) when detecting that the engine is in a flameout state, and the processor (2) is suitable for controlling the fuel pump regulator (1) to resume the fuel supply of the engine after receiving the flameout signal.

2. The civil aviation turboprop engine restart ability test device according to claim 1, wherein, It further includes a regulator control device, and the regulator control device includes: A relay (3), electrically connected to the processor (2); A power supply, electrically connected to the relay (3); A stop solenoid valve (4), electrically connected to the relay (3), arranged on the fuel pump regulator (1), when the stop solenoid valve (4) is energized, it is suitable for cutting off the fuel supply of the engine, and when the stop solenoid valve (4) is de-energized, it is suitable for resuming the fuel supply of the engine; The processor (2) is suitable for turning on the relay (3) after receiving the fuel cut-off signal, so that the power supply supplies power to the stop solenoid valve (4), and is also suitable for turning off the relay (3) after receiving the flameout signal, so that the stop solenoid valve (4) is de-energized.

3. The civil aviation turboprop engine restart ability test device according to claim 1, characterized in that The fuel cut-off signal generating device is provided with a cut-off switch, and when the cut-off switch is operated, the fuel cut-off signal generating device sends a fuel cut-off signal to the processor (2).

4. The civil aviation turboprop engine restart ability test device according to claim 2, characterized in that The power supply is the 28V DC power supply of the turboprop test stand body.

5. The civil aviation turboprop engine restart ability test device according to claim 1, characterized in that, It further includes: An atmospheric condition simulation system, suitable for adjusting the atmospheric conditions of the engine during the test; A hydraulic dynamometer, suitable for adjusting the rotational speed of the power turbine.

6. The civil aviation turboprop engine restart ability test device according to claim 5, characterized in that, The atmospheric condition simulation system includes a height simulation system, a speed simulation system, and a temperature simulation system.

7. The civil aviation turboprop engine restart ability test device according to claim 2, characterized in that, It further includes: An oscilloscope (5), electrically connected to the relay (3), suitable for displaying the output waveform of the relay (3).

8. A test method for the restart ability of a civil aviation turboprop engine, applicable to the test device for the restart ability of a civil aviation turboprop engine as described in any one of claims 1 - 7, characterized in that, Including the following steps: S1, accelerating the engine to an intermediate power state; S2, adjusting the atmospheric conditions of the engine to the target atmospheric conditions; S3, accelerating the engine to the maximum climb state; S4, operating the cut-off switch, and checking the power state of the engine after a preset time; S5, repeating step S4.

9. The test method for the restart ability of a civil aviation turboprop engine according to claim 8, wherein The preset time is 2 - 3 minutes.

10. The test method for the restart ability of a civil aviation turboprop engine according to claim 8, characterized in that, In step S4, it further includes: Recording the flameout time of the engine.

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