A method and device for controlling the temperature of low-pressure turbine outlet gas during a long-term test run

Abstract

The present application belongs to the field of engine test technology, and relates to a method and device for controlling the temperature of the low-pressure turbine outlet gas during a sustained test. The method comprises: step S1, determining a plurality of sustained test intake temperatures according to the engine flight mission profile given by the demander; step S2, determining the engine large-state operating time corresponding to each sustained test intake temperature; step S3, for each sustained test intake temperature, determining by simulation the time proportion of different low-pressure turbine outlet gas temperature ranges within the engine large-state operating time; step S4, allocating the duration of the large-state sustained test time at given different intake temperatures according to the time proportion; step S5, controlling the engine operating speed and nozzle area so that the engine continues to operate for the allocated time within the specified low-pressure turbine outlet gas temperature range. The present application solves the problem of mismatch between the assessment test and the actual thermal load during the sustained test.

Description

Technical Field

[0001] The present application belongs to the field of engine testing technology, and in particular relates to a method and device for controlling the temperature of low-pressure turbine outlet gas during a long-term test. Background Art

[0002] The "General Specifications for Aviation Turbojet and Turbofan Engines" divides aircraft engine development into three phases: initial pre-flight, design finalization, and production finalization. Each phase requires the completion of corresponding assessment tests before moving on to the next development phase. Among these phases, the endurance test is the most important and challenging full-machine assessment test. It comprehensively evaluates the engine's performance, structural integrity, and strength and lifespan, and is crucial for the engine's technical evaluation.

[0003] The "General Specification for Aviation Turbojet and Turbofan Engines," in its initial pre-flight and other endurance test requirements, stipulates that the engine control system's first-stage turbine rotor inlet gas temperature must be higher than the specified maximum allowable steady-state gas temperature under specified inlet temperature and pressure conditions. However, since the first-stage turbine rotor inlet gas temperature is too high to measure, it is typically substituted or calculated using the low-pressure turbine outlet gas temperature. This provision exceeds the normal operating temperature range of the engine's high-temperature components and constitutes an overly stringent assessment. Specifically, the low-pressure turbine outlet gas temperature is typically increased or partially increased in accordance with the "General Specification for Aviation Turbojet and Turbofan Engines," ignoring the thermal loads on the hot-end components during actual aircraft engine operation. This results in a mismatch between the assessment test and the actual thermal loads on the high-temperature components during actual operation. Summary of the Invention

[0004] In order to solve the above problems, the present application provides a method and device for controlling the temperature of low-pressure turbine outlet gas during a long-term trial run.

[0005] In a first aspect, the present application provides a method for controlling the temperature of low-pressure turbine outlet gas during a long-term test run, mainly comprising:

[0006] Step S1: determining a plurality of corresponding endurance test intake temperatures according to a plurality of altitudes and Mach numbers in an engine flight mission profile provided by a demander;

[0007] Step S2: Determine the engine maximum operating time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander;

[0008] Step S3: for each sustained test air intake temperature, determine by simulation the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum operating time;

[0009] Step S4: for the given extended-state endurance test time at different intake air temperatures, allocating the extended-state endurance test time according to the time proportions;

[0010] Step S5: Control the engine operating speed and nozzle area so that the engine continues to operate within the specified low-pressure turbine outlet gas temperature range for the allocated time.

[0011] Preferably, in step S1, the sustained test intake air temperature T is calculated by the following formula: N :

[0012] T N =(T 0N +273.15)*(1+(k-1) / 2*Ma N *Ma N )-273.15;

[0013] Among them, T N is the inlet temperature of the endurance test at the Nth altitude and Mach number, T 0N is the atmospheric static temperature at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

[0014] Preferably, in step S3, a plurality of low-pressure turbine outlet gas temperature ranges are constructed with a step size of 3-10°C.

[0015] Preferably, in step S3, a plurality of low-pressure turbine outlet gas temperature ranges are constructed with a step size of 5°C.

[0016] A second aspect of the present application provides a low-pressure turbine outlet gas temperature control device for a long-term test run, mainly comprising:

[0017] A module for determining the inlet air temperature of a sustained test, used to determine the corresponding multiple inlet air temperatures of the sustained test according to multiple altitudes and Mach numbers in the engine flight mission profile given by the demander;

[0018] The engine maximum state working time determination module is used to determine the engine maximum state working time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander;

[0019] The time proportion calculation module is used to determine the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum operating time for each sustained test intake temperature through simulation;

[0020] A duration allocation module is configured to allocate the duration of the large-state endurance test time according to the time proportions for a given large-state endurance test time at different intake air temperatures;

[0021] The endurance test control module is used to control the engine operating speed and nozzle area so that the engine can continue to operate within the specified low-pressure turbine outlet gas temperature range for the allocated time.

[0022] Preferably, in the sustained test intake air temperature determination module, the sustained test intake air temperature T is calculated by the following formula: N :

[0023] T N =(T 0N +273.15)*(1+(k-1) / 2*Ma N *Ma N )-273.15;

[0024] Among them, T N is the inlet temperature of the endurance test at the Nth altitude and Mach number, T 0N is the atmospheric static temperature at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

[0025] Preferably, in the time proportion calculation module, a plurality of low-pressure turbine outlet gas temperature ranges are constructed with a step size of 3-10°C.

[0026] Preferably, in the time proportion calculation module, a plurality of low-pressure turbine outlet gas temperature ranges are constructed with a step size of 5°C.

[0027] This application solves the problem of mismatch between assessment tests and actual thermal loads during endurance test runs, effectively supports the use of engines in field flights, and avoids situations where assessments are too strict. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of a preferred embodiment of the method for controlling the low-pressure turbine outlet gas temperature during a long-term test run of the present application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the implementation of this application will be described in more detail below in conjunction with the drawings in the implementation of this application. In the drawings, the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and should not be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in conjunction with the drawings.

[0030] The first aspect of the present application provides a method for controlling the temperature of the low-pressure turbine outlet gas during a long-term test run, such as Figure 1 As shown, it mainly includes:

[0031] Step S1: determining a plurality of corresponding endurance test intake temperatures according to a plurality of altitudes and Mach numbers in an engine flight mission profile provided by a demander;

[0032] Step S2: Determine the engine maximum operating time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander;

[0033] Step S3: for each sustained test air intake temperature, determine by simulation the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum operating time;

[0034] Step S4: for the given extended-state endurance test time at different intake air temperatures, allocating the extended-state endurance test time according to the time proportions;

[0035] Step S5: Control the engine operating speed and nozzle area so that the engine continues to operate within the specified low-pressure turbine outlet gas temperature range for the allocated time.

[0036] In this application, the intermediate state and states above the intermediate state of the engine are collectively referred to as the large state. In step S2, this application uses the engine large state working time given by the engine flight mission profile. Then, in step S3, based on the simulation test, the engine large state working time is allocated to obtain the allocation ratio. Finally, in step S4, the actual large state sustained test time is allocated according to the ratio, thereby completing the sustained test. It can be seen that this application controls the low-pressure turbine outlet gas temperature of the sustained test based on the thermal load of the hot end components when the engine is actually used, so that the assessment test is consistent with the actual use of the thermal load, avoiding the situation where the assessment is too strict.

[0037] In step S1, the altitude and Mach number in the engine flight mission profile are matched, and N altitudes and Mach numbers are discretized by specifying a step size, corresponding to which N endurance test intake temperatures can be calculated.

[0038] In some optional embodiments, in step S1, the sustained test intake air temperature T is calculated by the following formula: N :

[0039] T N =(T 0N +273.15)*(1+(k-1) / 2*Ma N *Ma N)-273.15;

[0040] Among them, T N is the inlet temperature of the endurance test at the Nth altitude and Mach number, T 0N is the atmospheric static temperature at the Nth altitude, Ma N is the Nth Mach number, k is the air gas constant, and its value is 1.4.

[0041] Then, in step S2, different endurance test intake air temperatures T1, T2, ..., T N The engine's maximum operating time t1, t2...t N .

[0042] In step S3, a simulation test is performed for each sustained run inlet temperature. During the simulation, the timing starts after the engine enters the high-pressure state after warming up. The low-pressure turbine outlet gas temperature will continue to decrease. This process continuously monitors the low-pressure turbine outlet gas temperature. Each time a temperature level (i.e., the low-pressure turbine outlet gas temperature range) is dropped, the duration of the temperature level is counted until the engine high-pressure state operating time given in step S2 is used up, and the time proportion of each temperature level is counted. It should be noted that, based on the engine warm-up characteristics, the higher the engine operating speed and the longer the time before entering the high-pressure state, the lower the low-pressure turbine outlet gas temperature will be when the engine is operating in the high-pressure state. Therefore, in order to obtain a larger time proportion of each temperature level within the engine high-pressure state operating time, the engine operating speed and time before entering the high-pressure state can be controlled accordingly.

[0043] The above-mentioned low-pressure turbine outlet gas temperature range can be set according to actual needs. For example, in some optional embodiments, in step S3, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 3-10°C. Furthermore, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 5°C.

[0044] For example, with a step size of 5°C, determine the time percentage of the low-pressure turbine outlet gas temperature from reaching the limit value to 5°C lower than the limit value at the intake air temperature T1 as x 11 The proportion of time between 5℃ lower than the limit value and 10℃ lower than the limit value is x 12 ...; Similarly, we can get the time proportion x at intake air temperature T2 21 、x 22 ...; At the intake air temperature T N The proportion of time under x N1 、x N2 …….

[0045] Then, in step S4, the above time proportion is applied to the given duration of the endurance test. For example, the large state test time under the condition of intake air temperature T1 is td1 , t d1 *x 11 As the test time when the low-pressure turbine outlet gas temperature reaches the limit value under the condition of inlet temperature T1, t d1 *x 12 As the test time when the intake air temperature T1 is 5℃ lower than the low-pressure turbine outlet gas temperature limit value... Similarly, assume that the intake air temperature T N The large state test time under the condition is t dN , t dN *x N1 As the intake air temperature T N The test time when the low-pressure turbine outlet gas temperature reaches the limit value under the condition of t dN *x N2 As the intake air temperature T N The test time is when the temperature of the gas at the outlet of the low-pressure turbine is 5°C lower than the limit value under the conditions.

[0046] Finally, in step S5, the engine's operating speed and / or nozzle area are controlled so that the low-pressure turbine outlet gas temperature meets the set value, and then the set value is maintained for the time calculated in step S4 to complete the temperature and time control of the long-term test.

[0047] A second aspect of the present application provides a low-pressure turbine outlet gas temperature control device for a long-term test corresponding to the above method, mainly comprising:

[0048] A module for determining the inlet air temperature of a sustained test, used to determine the corresponding multiple inlet air temperatures of the sustained test according to multiple altitudes and Mach numbers in the engine flight mission profile given by the demander;

[0049] The engine maximum state working time determination module is used to determine the engine maximum state working time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander;

[0050] The time proportion calculation module is used to determine the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum operating time for each sustained test intake temperature through simulation;

[0051] A duration allocation module is configured to allocate the duration of the large-state endurance test time according to the time proportions for a given large-state endurance test time at different intake air temperatures;

[0052] The endurance test control module is used to control the engine operating speed and nozzle area so that the engine can continue to operate within the specified low-pressure turbine outlet gas temperature range for the allocated time.

[0053] In some optional embodiments, in the sustained test intake air temperature determination module, the sustained test intake air temperature T is calculated by the following formula: N :

[0054] T N =(T 0N +273.15)*(1+(k-1) / 2*Ma N *Ma N )-273.15;

[0055] Among them, T N is the inlet temperature of the endurance test at the Nth altitude and Mach number, T 0N is the atmospheric static temperature at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

[0056] In some optional embodiments, in the time proportion calculation module, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 3-10°C.

[0057] In some optional embodiments, in the time proportion calculation module, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 5°C.

[0058] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for controlling the temperature of low-pressure turbine outlet gas during a long-term test run, characterized in that: include: Step S1: determining a plurality of corresponding endurance test intake temperatures according to a plurality of altitudes and Mach numbers in an engine flight mission profile provided by a demander; Step S2: Determine the engine maximum operating time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander; Step S3: for each sustained test air intake temperature, determine by simulation the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum operating time; Step S4: for the given extended-state endurance test time at different intake air temperatures, allocating the extended-state endurance test time according to the time proportions; Step S5: controlling the engine operating speed and nozzle area so that the engine continues to operate within a specified low-pressure turbine outlet gas temperature range for the allocated time; In step S1, the sustained test intake air temperature T is calculated by the following formula: N : T N =(T 0N +273.15)* (1+(k-1) / 2*Ma N *Ma N )-273.15; Among them, T N is the inlet temperature of the endurance test at the Nth altitude and Mach number, T 0N is the atmospheric static temperature at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

2. The method for controlling the temperature of the low-pressure turbine outlet gas during a long-term test according to claim 1, characterized in that: In step S3, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 3-10°C.

3. The method for controlling the temperature of the low-pressure turbine outlet gas during a long-term test according to claim 2, characterized in that: In step S3, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 5°C.

4. A long-term test low-pressure turbine outlet gas temperature control device, characterized in that: The device for implementing the method for controlling the temperature of the low-pressure turbine outlet gas during a long-term test according to claim 1 comprises: A module for determining the inlet air temperature of a sustained test, used to determine the corresponding multiple inlet air temperatures of the sustained test according to multiple altitudes and Mach numbers in the engine flight mission profile given by the demander; The engine maximum state working time determination module is used to determine the engine maximum state working time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander; The time proportion calculation module is used to determine the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum operating time for each sustained test intake temperature through simulation; A duration allocation module is configured to allocate the duration of the large-state endurance test time according to the time proportions for a given large-state endurance test time at different intake air temperatures; The endurance test control module is used to control the engine operating speed and nozzle area so that the engine can continue to operate within the specified low-pressure turbine outlet gas temperature range for the allocated time.

5. The long-term test low-pressure turbine outlet gas temperature control device according to claim 4, characterized in that: In the sustained test intake air temperature determination module, the sustained test intake air temperature T is calculated by the following formula: N : T N =(T 0N +273.15)* (1+(k-1) / 2*Ma N *Ma N )-273.15; Among them, T N is the inlet temperature of the endurance test at the Nth altitude and Mach number, T 0N is the atmospheric static temperature at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

6. The long-term test low-pressure turbine outlet gas temperature control device according to claim 4, characterized in that: In the time proportion calculation module, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 3-10°C.

7. The long-term test low-pressure turbine outlet gas temperature control device according to claim 6, characterized in that: In the time proportion calculation module, multiple low-pressure turbine outlet gas temperature ranges are constructed with a step size of 5°C.

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