A method for supertorque test of turboprop engine

Abstract

This application discloses a method for supertorque testing of a complete turboprop engine, comprising the following steps: S1. Determining the supertorque test target requirements for the turboprop engine, including the target engine oil temperature, the target turbine inlet gas steady-state temperature, the target engine torque, the target engine output shaft speed, and the test time requirement; S2. Performing a pre-test performance calibration test on the turboprop engine to obtain performance calibration data for the turboprop engine; S3. Performing a supertorque test on the turboprop engine based on the supertorque test target requirements and the performance calibration data obtained from the performance calibration test; and S4. Disassembling and inspecting the turboprop engine after the supertorque test. This application utilizes a combination of various methods, such as the engine's thermal power margin and speed reduction, to conduct supertorque testing, resolving the difficulty of performing supertorque testing on some turboprop engines. The method is highly adaptable, easy to implement, saves manpower and financial resources, and is time-efficient and successful on the first try, thereby reducing testing costs.

Description

Technical Field

[0001] The present application relates to the field of engine testing technology, and in particular, to a method for super-torque testing of a turboprop engine as a whole. Background Art

[0002] The engine overtorque test is a crucial test subject required during initial flight and type approval testing as specified in the National Military Standard GJB242A-2018 (4.4.1.4.4.3). The engine overtorque test involves operating the engine with the power turbine for 15 minutes at a maximum allowable steady-state torque limit (mechanical) of no less than 120% of the torque value to verify the requirements of 3.2.4.10 (the maximum allowable steady-state torque limit (mechanical) shall be at least 20% higher than the specified value; the specific value shall be provided in the model specification). The test may be conducted in stages, each lasting at least 2.5 minutes. The power turbine speed must be equal to the highest possible engine speed at which maximum torque is generated during operation, but not exceeding the takeoff limit speed or the limit speed for single-engine operation lasting no more than 2 minutes. The turbine inlet gas temperature must be equal to the maximum allowable steady-state temperature. For engines with an internal gear reducer, the internal gear reducer oil temperature must be equal to the maximum temperature at which maximum torque is generated during operation.

[0003] Currently, the main methods for achieving engine over-torque testing include increasing the intake temperature, bleed air, adjusting the guide vane angle (guide vane area), retracting and extending the nozzle, etc. Generally, a combination of the above methods is required to complete the engine over-torque test.

[0004] While methods such as increasing intake air temperature, bleed air, adjusting guide vane angle (guide vane area), and retracting the nozzle can achieve and meet the overtorque test requirements for certain engine models, some implementations are complex, difficult to control, and time-consuming. Some engines may not even meet the overtorque test requirements using these methods. For example, adjusting the guide vane angle can only be performed during the assembly phase for some engines, and the turbine guide vane area adjustment must be calculated based on the impact of the engine's turbine guide vane flow function on engine performance. If the adjustment is not in place, reassembly is required, requiring multiple iterations of calculation and assembly, which is time-consuming and labor-intensive. Furthermore, retracting the nozzle requires redesigning and machining the corresponding nozzle based on calculations, which takes a long time and may not guarantee success on the first try. Multiple iterations of calculation and machining may also be required, wasting manpower and financial resources. Summary of the Invention

[0005] This application provides a turboprop engine whole machine overtorque test method to solve the existing engine overtorque The experiment has technical problems such as being cumbersome to implement, difficult to control, time-consuming, costly and having limited adaptability.

[0006] This application is implemented through the following scheme:

[0007] A method for supertorque testing of a turboprop engine comprises the following steps:

[0008] S1. Determine the target requirements for the turboprop engine overtorque test, including the target engine oil temperature, the target turbine inlet gas steady-state temperature, the target engine torque, the target engine output shaft speed, and the test time requirements.

[0009] S2. performing a performance calibration test on the turboprop engine before testing to obtain performance calibration data of the turboprop engine;

[0010] S3. performing a super-torque test on the turboprop engine according to the super-torque test target requirements of the turboprop engine and the performance calibration data obtained from the performance calibration test;

[0011] S4. Disassemble and inspect the turboprop engine that has completed the super-torque test.

[0012] Furthermore, in step S1, the engine lubricating oil temperature target is specifically: for an engine with an internal speed reducer, the lubricating oil temperature of the internal speed reducer is equal to the highest temperature when the maximum torque occurs during engine use.

[0013] Furthermore, in step S1, the turbine inlet gas steady-state temperature target is specifically: the turbine inlet gas steady-state temperature is equal to the maximum allowable steady-state temperature.

[0014] Furthermore, in step S1, the engine torque target is specifically: if the maximum allowable steady-state torque limit of the turboprop engine is 106%, the over-torque is 120% of the limit, that is, the engine torque target is 127.2% torque.

[0015] Furthermore, in step S1, the engine output shaft speed target is specifically: the maximum output shaft speed n1 when the engine has maximum steady-state torque, wherein the maximum steady-state torque is the torque when the engine torque reaches 106% of the maximum value.

[0016] Furthermore, in step S1, the test time requirement is specifically as follows: 15 minutes are required to reach the lubricating oil temperature, turbine inlet gas steady-state temperature, output shaft speed, and torque targets. The test is run in stages, with each stage lasting at least 2.5 minutes.

[0017] Furthermore, in step S1, when determining the turbine inlet gas temperature target, the power turbine is used to Outlet temperature Monitors the turbine inlet gas temperature instead.

[0018] Furthermore, in step S1, when determining the test time, the test is run in three stages, with each stage lasting 5 minutes.

[0019] Furthermore, in step S1, according to the corresponding relationship between the engine output shaft speed and the power turbine speed, the engine output shaft speed is reduced during over-torque, that is, the power turbine speed is reduced.

[0020] Furthermore, step S3 specifically includes the steps of:

[0021] S31. Based on the engine performance calibration data, estimate the engine power and air flow required to achieve the super torque test target as a test reference;

[0022] S32. Modify relevant parameters in the propeller electronic control simulator according to the relationship between the propeller electronic control simulator and the output shaft speed to obtain the output shaft speed required for super torque;

[0023] S33. Calculate the power rod angle required for the over-torque test based on the relationship between the power rod angle and power, and between power and torque;

[0024] S34. Calculate or estimate the torque and speed based on the over-torque target torque, and set corresponding alarm values ​​and protection values ​​for the torque, speed, and temperature before the over-torque test;

[0025] S35. Start the engine and bring it to ground slow speed, and operate for 2 to 3 minutes;

[0026] S36: Push the engine up to the idle position in the air and operate for 3 to 5 minutes;

[0027] S37. Raise the engine power to 60% to 70% of the maximum rated power and operate for 4 to 6 minutes to stabilize the lubricating oil temperature within the test requirements. The intake air heating device heats the air to the required inlet temperature.

[0028] S38. Continue to push the engine upward to the intermediate position and operate for 2 to 3 minutes.

[0029] S39. Slowly push up the engine power lever to reach the target torque value for the over-torque test. If the turbine outlet temperature has not reached the target temperature, open the bleed air to the target temperature. Once all indicators reach the over-torque target, start the 5-minute timer and closely monitor the engine condition.

[0030] S310: Lower the engine to the intermediate position, turn off the bleed air, and wait for 2 to 3 minutes until the lubricating oil temperature stabilizes to the limit value;

[0031] S311, repeat steps S39 and S310 once;

[0032] S312, repeat step S39 once;

[0033] S313. Slowly lower the engine to the air idle state, turn off the bleed air and intake air heating, and operate for 3 to 5 minutes;

[0034] S314: Pull down the engine to ground idle and operate for 2 to 3 minutes.

[0035] S315: Engine stops.

[0036] Compared with the existing technology, this application has the following beneficial effects:

[0037] The present application provides a method for super-torque testing of a whole turboprop engine. The method for super-torque testing of a whole turboprop engine proposes for the first time to conduct super-torque testing by combining the engine's thermal power margin with multiple methods such as reducing the speed, thereby solving the problem that super-torque testing of some turboprop engines cannot be achieved, and has strong adaptability. The present application provides an additional method for achieving super-torque testing, providing new ideas for other engines and greatly improving the technical level of super-torque testing of this type of engine. The present application is easy to implement, greatly saves manpower and financial resources, takes a short time and can succeed in one go, thereby greatly shortening the time and cost of completing the test.

[0038] In addition to the above-described purposes, features and advantages, the present application also has other purposes, features and advantages. The present application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings that constitute a part of this application are used to provide further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute improper limitations on this application.

[0040] Figure 1 It is a flow chart of the super-torque test method for a turboprop engine according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0041] The embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application can be implemented in a variety of different ways defined and covered below.

[0042] like Figure 1 As shown, the preferred embodiment of the present application provides 1. A method for super-torque testing of a turboprop engine, characterized in that it includes the following steps:

[0043] S1. Determine the target requirements for the turboprop engine overtorque test, including the target engine oil temperature, the target turbine inlet gas steady-state temperature, the target engine torque, the target engine output shaft speed, and the test time requirements.

[0044] S2. performing a performance calibration test on the turboprop engine before testing to obtain performance calibration data of the turboprop engine;

[0045] S3. performing a super-torque test on the turboprop engine according to the super-torque test target requirements of the turboprop engine and the performance calibration data obtained from the performance calibration test;

[0046] S4. Disassemble and inspect the turboprop engine that has completed the super-torque test.

[0047] This embodiment provides a method for super torque testing of a turboprop engine. The super-torque test method proposes for the first time to conduct super-torque tests by combining the engine's thermal power margin with multiple methods such as reducing the speed, which solves the problem that super-torque tests on some turboprop engines cannot be achieved and has strong adaptability. This embodiment provides an additional method for achieving super-torque tests, provides new ideas for other engines, and greatly improves the technical level of super-torque tests for this type of engine. This embodiment is easy to implement, greatly saves manpower and financial resources, takes a short time and can succeed in one go, greatly shortening the time and cost of completing the test.

[0048] Preferably, in step S1, the engine lubricating oil temperature target is specifically: for an engine with an internal speed reducer, the lubricating oil temperature of the internal speed reducer is equal to the highest temperature when the maximum torque occurs during engine use.

[0049] Preferably, in step S1, the turbine inlet gas steady-state temperature target is specifically: the turbine inlet gas steady-state temperature is equal to the maximum allowable steady-state temperature. Because high turbine inlet gas temperature is difficult to test, complex structures make modification difficult, and modification can lead to a series of problems such as air leakage and uneven temperature fields, based on the corresponding relationship between the turbine inlet gas temperature and the power turbine outlet temperature, the power turbine outlet temperature is used instead of the turbine inlet gas temperature for monitoring.

[0050] Preferably, in step S1, the engine torque target is specifically: if the maximum allowable steady-state torque limit of the turboprop engine is 106%, the over-torque is 120% of the limit, that is, the engine torque target is 127.2% torque.

[0051] Preferably, in step S1, the engine output shaft speed target is specifically: the maximum output shaft speed n1 when the engine has the maximum steady-state torque, wherein the maximum steady-state torque is the torque when the engine torque reaches 106% of the maximum value. The national military standard requires that the power turbine speed during the over-torque test is equal to the maximum possible speed when the maximum over-torque occurs during engine use. If the propeller pitch adjustment mechanism has an abnormality, the propeller output shaft speed may drop to n1, at which time the engine torque reaches the maximum value of 106% torque. Therefore, the maximum output shaft speed when the maximum steady-state torque (106%) occurs is n1. There is a corresponding relationship between the engine output shaft speed and the power turbine speed. Reducing the engine output shaft speed during over-torque means reducing the power turbine speed.

[0052] Preferably, in step S1, the test time requirement is specifically: 15 minutes to reach the target of lubricating oil temperature, turbine inlet gas steady-state temperature, output shaft speed, and torque, and the test is run in stages, each stage is at least 2.5 minutes. Preferably, in step S1, when a certain model of turboprop engine determines the test time, the test is divided into 3 stages. The system runs in stages, with each stage lasting 5 minutes.

[0053] The over torque of a certain type of turboprop engine is 127.2%. According to the torque formula (Where P is power and n is the output shaft speed.) During overtorque, the engine output shaft speed n is reduced by 6%, which can increase the torque value. Certain turboprop engines have a thermal power margin. Moving the power lever above the rated power position will cause the required power to reach 100% to 120% of the maximum rated power. In this way, when the power reaches 120% of the maximum rated power, an overtorque torque of 127.2% can be achieved.

[0054] In summary, the turboprop engine of the above embodiment mainly achieves super-torque by reducing the output shaft speed and utilizing the thermal power margin, thereby solving the problem that super-torque tests cannot be performed on some types of turboprop engines.

[0055] In a preferred embodiment of the present application, step S3 specifically includes the following steps:

[0056] S31. Based on the engine performance calibration data, estimate the engine power and air flow required to achieve the super torque test target as a test reference;

[0057] S32. Modify relevant parameters in the propeller electronic control simulator according to the relationship between the propeller electronic control simulator and the output shaft speed to obtain the output shaft speed required for super torque;

[0058] S33. Calculate the power rod angle required for the over-torque test based on the relationship between the power rod angle and power, and between power and torque;

[0059] S34. Calculate or estimate the torque and speed based on the over-torque target torque, and set corresponding alarm values ​​and protection values ​​for the torque, speed, and temperature before the over-torque test;

[0060] S35. Start the engine and bring it to ground slow speed, and operate for 2 to 3 minutes;

[0061] S36: Push the engine up to the idle position in the air and operate for 3 to 5 minutes;

[0062] S37. Raise the engine power to 60% to 70% of its maximum rated power and operate for 4 to 6 minutes to stabilize the lubricating oil temperature within the test requirements. Heat the air intake to the required inlet temperature to ensure optimal operation of the engine rotor.

[0063] S38, continue to push the engine up to the intermediate state and work for 2 to 3 minutes. The intermediate state is a transition state;

[0064] S39. Slowly push up the engine power lever until the over-torque test torque target is reached. At this point, the engine output shaft n is reduced by 6%. This ensures that the maximum rated power is within 120% and the torque reaches 127.2% (over-torque requirement). If the power turbine outlet temperature does not reach the target temperature, open the bleed air to the target temperature. Once all indicators reach the over-torque target, start a 5-minute timer and closely monitor the engine condition.

[0065] S310: Lower the engine to the intermediate position, turn off the bleed air, and wait for 2 to 3 minutes until the lubricating oil temperature stabilizes to the limit value;

[0066] S311, repeat steps S39 and S310 once;

[0067] S312, repeat step S39 once;

[0068] S313. Slowly lower the engine to the air idle state, turn off the bleed air and intake air heating, and operate for 3 to 5 minutes;

[0069] S314: Pull down the engine to ground idle and operate for 2 to 3 minutes.

[0070] S315: Engine stops.

[0071] In summary, the above embodiments of the present application propose for the first time to conduct super-torque tests by combining the engine's thermal power margin with multiple methods such as reducing the output shaft speed, which solves the problem that the super-torque test of a certain turboprop engine cannot be achieved. It is relatively easy to implement, greatly saves manpower and financial resources, and is successful at one time, greatly shortening the time to complete the test.

[0072] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0073] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for supertorque testing of a turboprop engine, characterized in that: Including steps: S1. Determine the target requirements for the turboprop engine overtorque test, including the target engine oil temperature, the target turbine inlet gas steady-state temperature, the target engine torque, the target engine output shaft speed, and the test time requirements. S2. performing a performance calibration test on the turboprop engine before testing to obtain performance calibration data of the turboprop engine; S3. performing a super-torque test on the turboprop engine according to the super-torque test target requirements of the turboprop engine and the performance calibration data obtained from the performance calibration test; S4. Disassemble and inspect the turboprop engine that has completed the super-torque test; Step S3 specifically includes the following steps: S31. Based on the engine performance calibration data, estimate the engine power and air flow required to achieve the super torque test target as a test reference; S32. Modify relevant parameters in the propeller electronic control simulator according to the relationship between the propeller electronic control simulator and the output shaft speed to obtain the output shaft speed required for super torque; S33. Calculate the power rod angle required for the over-torque test based on the relationship between the power rod angle and power, and between power and torque; S34. Calculate or estimate the torque and speed based on the over-torque target torque, and set corresponding alarm values ​​and protection values ​​for the torque, speed, and temperature before the over-torque test; S35. Start the engine and bring it to ground slow speed, and operate for 2 to 3 minutes; S36: Push the engine up to the idle state in the air and operate for 3 to 5 minutes; S37. Raise the engine power to 60% to 70% of the maximum rated power and operate for 4 to 6 minutes to stabilize the lubricating oil temperature within the test requirements. The intake air heating device heats the air to the required inlet temperature. S38. Continue to push the engine upward to the intermediate position and operate for 2 to 3 minutes. S39. Slowly push up the engine power lever to reach the target torque value for the over-torque test. If the turbine outlet temperature has not reached the target temperature, open the bleed air to the target temperature. Once all indicators reach the over-torque target, start the 5-minute timer and closely monitor the engine condition. S310: Lower the engine to the intermediate position, turn off the bleed air, and wait for 2 to 3 minutes until the lubricating oil temperature stabilizes to the limit value; S311, repeat steps S39 and S310 once; S312, repeat step S39 once; S313. Slowly lower the engine to the air idle state, turn off the bleed air and intake air heating, and operate for 3 to 5 minutes; S314: Pull down the engine to ground idle and operate for 2-3 minutes. S315: Engine stops.

2. The turboprop engine whole machine super torque test method according to claim 1, characterized in that: In step S1, the engine lubricating oil temperature target is specifically: for an engine with an internal speed reducer, the lubricating oil temperature of the internal speed reducer is equal to the highest temperature when the maximum torque occurs during engine use.

3. The turboprop engine whole machine super torque test method according to claim 2, characterized in that: In step S1, the turbine inlet gas steady-state temperature target is specifically: the turbine inlet gas steady-state temperature is equal to the maximum allowable steady-state temperature.

4. The turboprop engine whole machine super torque test method according to claim 3, characterized in that: In step S1, the engine torque target is specifically: if the maximum allowable steady-state torque limit of the turboprop engine is 106%, the over-torque is 120% of the limit, that is, the engine torque target is 127.2% torque.

5. The turboprop engine whole machine super torque test method according to claim 4, characterized in that: In step S1 , the engine output shaft speed target is specifically: the maximum output shaft speed n1 when the engine has the maximum steady-state torque, wherein the maximum steady-state torque is the torque when the engine torque reaches 106% of the maximum value.

6. The turboprop engine whole machine super torque test method according to claim 5, characterized in that: In step S1, the test time requirement is specifically: 15 minutes to reach the lubricating oil temperature, turbine inlet gas steady-state temperature, output shaft speed, and torque target. The test is run in stages, each stage is at least 2.5 minutes.

7. The turboprop engine whole machine super torque test method according to claim 3, characterized in that: In step S1, when determining the turbine inlet gas temperature target, the power turbine outlet temperature is used to monitor the turbine inlet gas temperature instead of the turbine inlet gas temperature.

8. The turboprop engine whole machine super torque test method according to claim 6, characterized in that: In step S1, when determining the test time, the test is run in three stages, with each stage lasting 5 minutes.

9. The turboprop engine whole machine super torque test method according to claim 5, characterized in that: In step S1, according to the corresponding relationship between the engine output shaft speed and the power turbine speed, the engine output shaft speed is reduced during over-torque, that is, the power turbine speed is reduced.

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