Persistent test run low-pressure turbine outlet fuel gas temperature control method and device

Abstract

The invention belongs to the technical field of engine tests, and relates to a persistent test run low-pressure turbine outlet gas temperature control method and device, and the method comprises the steps: S1, determining a plurality of persistent test run gas inlet temperatures according to an engine flight mission profile given by a demand side; s2, determining the large-state working time of the engine corresponding to each persistent test run air inlet temperature; s3, for each persistent test run air inlet temperature, the time proportion of different low-pressure turbine outlet gas temperature ranges in the large-state working time of the engine is determined through simulation; s4, for the given large-state lasting test run time at different air inlet temperatures, performing duration distribution according to a time proportion; and S5, the working rotating speed and the nozzle area of the engine are controlled, so that the engine continuously operates for the distributed duration within the specified low-pressure turbine outlet gas temperature range. According to the method, the problem that the exam test is not matched with the actual use thermal load in the persistent test run process is solved.

Description

Technical Field

[0001] The present application belongs to the field of engine test 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] In the "General Specifications for Aviation Turbojet and Turbofan Engines", the development of aviation engines is divided into three stages, namely the initial pre-flight stage, the design finalization stage, and the production finalization stage. Each stage must complete the corresponding assessment test before entering the next development stage. Among the assessment tests at each stage, the endurance test is the most important and most difficult whole-machine assessment test. It is a comprehensive assessment of the engine's performance retention, structural integrity, strength and life, and is of great significance to the technical identification of the engine.

[0003] In the initial pre-flight and other endurance test requirements of the General Specifications for Aviation Turbojet and Turbofan Engines, it is stipulated that the inlet gas temperature of the first-stage turbine rotor under the specified inlet temperature and pressure conditions of the engine control system must be higher than the specified maximum allowable steady-state gas temperature. However, the inlet gas temperature of the first-stage turbine rotor cannot be measured because the temperature is too high, and is usually replaced or calculated by the low-pressure turbine outlet gas temperature. The provisions of this clause exceed the normal operating temperature range of the engine's high-temperature components, and the assessment is too strict. That is, the low-pressure turbine outlet gas temperature is usually increased or partially increased in accordance with the requirements of the General Specifications for Aviation Turbojet and Turbofan Engines, which ignores the heat load of the hot end components during actual use of the aircraft engine, resulting in a mismatch between the assessment test and the heat load of the high-temperature components during actual use. 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 test run.

[0005] The first aspect of 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 given by a demander;

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

[0008] Step S3, for each endurance test intake temperature, determine the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum state working time through simulation;

[0009] Step S4, for the given large-state endurance test time at different intake temperatures, allocating the large-state endurance test time according to the time proportion;

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

[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 static temperature of the atmosphere 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] The 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 air intake temperature of a sustained test, used to determine a plurality of corresponding air intake temperatures of a sustained test according to a plurality of altitudes and Mach numbers in the engine flight mission profile given by the demander;

[0018] The engine large-state working time determination module is used to determine the engine large-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 large-state working time for each endurance test intake temperature through simulation;

[0020] A duration allocation module is used for allocating the duration of the large-state endurance test time according to the time proportion for a given large-state endurance test time at different intake 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 run for the allocated time within the specified low-pressure turbine outlet gas temperature range.

[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 static temperature of the atmosphere 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 a 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 scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals 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 cannot 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 combination with the drawings.

[0030] The first aspect of the present application provides a method for controlling the temperature of 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 given by a demander;

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

[0033] Step S3, for each endurance test intake temperature, determine the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum state working time through simulation;

[0034] Step S4, for the given large-state endurance test time at different intake temperatures, allocating the large-state endurance test time according to the time proportion;

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

[0036] In this application, the intermediate state and the state above the intermediate state of the engine are collectively referred to as the large state. In step S2, this application uses the large state working time of the engine given by the engine flight mission profile, and then in step S3, based on the simulation test, the large state working time of the engine 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 outlet gas temperature of the low-pressure turbine 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 of too strict assessment.

[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, and N corresponding 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 static temperature of the atmosphere at the Nth altitude, Ma N is the Nth Mach number, k is the air gas constant, which is 1.4.

[0041] Then, in step S2, different endurance test intake air temperatures T1, T2, ..., T N The engine working time t1, t2...t N .

[0042] In step S3, a simulation test is performed for each sustained test air intake temperature. During the simulation process, the timing starts after the engine enters the large state after warming up, and the low-pressure turbine outlet gas temperature will continue to decrease. This process continuously monitors the low-pressure turbine outlet gas temperature. Every time a temperature gear (that is, the low-pressure turbine outlet gas temperature range) is dropped, the duration of the temperature gear is counted until the engine large state working time given in step S2 is used up, and the time proportion of each temperature gear is counted. It should be noted that according to the engine warm-up characteristics, the higher the working speed and the longer the time of the engine before entering the large state, the lower the low-pressure turbine outlet gas temperature will be when the engine is working in the large state. Accordingly, in order to obtain more time proportions of temperature gears during the engine large state working time, the working speed and time of the engine before entering the large 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. Further, 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 that the proportion of time when the low-pressure turbine outlet gas temperature reaches the limit value to 5°C lower than the limit value at the intake temperature T1 is x 11 , the time percentage of 5℃ lower than the limit value to 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 time percentage of 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°C lower than the low-pressure turbine outlet gas temperature limit value...; Similarly, assuming 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 of the low-pressure turbine outlet temperature.

[0046] Finally, in step S5, the operating speed and / or nozzle area of ​​the engine 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 endurance test.

[0047] The 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 air intake temperature of a sustained test, used to determine a plurality of corresponding air intake temperatures of a sustained test according to a plurality of altitudes and Mach numbers in the engine flight mission profile given by the demander;

[0049] The engine large-state working time determination module is used to determine the engine large-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 large-state working time for each endurance test intake temperature through simulation;

[0051] A duration allocation module is used for allocating the duration of the large-state endurance test time according to the time proportion for a given large-state endurance test time at different intake 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 run for the allocated time within the specified low-pressure turbine outlet gas temperature range.

[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 static temperature of the atmosphere 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 is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope 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 given by a demander; Step S2: determining the engine maximum state working time corresponding to each endurance test intake temperature according to the engine flight mission profile given by the demander; Step S3, for each endurance test intake temperature, determine the time proportion of different low-pressure turbine outlet gas temperature ranges during the engine's maximum state working time through simulation; Step S4, for the given large-state endurance test time at different intake temperatures, allocating the large-state endurance test time 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 a specified low-pressure turbine outlet gas temperature range.

2. The method for controlling the temperature of low-pressure turbine outlet gas during a long-term test run according to claim 1, characterized in that: 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 static temperature of the atmosphere at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

3. The method for controlling the temperature of low-pressure turbine outlet gas during a long-term test run 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.

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

5. A low-pressure turbine outlet gas temperature control device for long-term test, characterized in that: include: A module for determining the air intake temperature of a sustained test, used to determine a plurality of corresponding air intake temperatures of a sustained test according to a plurality of altitudes and Mach numbers in the engine flight mission profile given by the demander; The engine large-state working time determination module is used to determine the engine large-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 large-state working time for each endurance test intake temperature through simulation; A duration allocation module is used for allocating the duration of the large-state endurance test time according to the time proportion for a given large-state endurance test time at different intake temperatures; The endurance test control module is used to control the engine operating speed and nozzle area so that the engine can continue to run for the allocated time within the specified low-pressure turbine outlet gas temperature range.

6. The long-term test low-pressure turbine outlet gas temperature control device according to claim 5, 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 static temperature of the atmosphere at the Nth altitude, Ma N is the Nth Mach number, and k is the air gas constant.

7. The long-term test low-pressure turbine outlet gas temperature control device according to claim 5, 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.

8. The long-term test low-pressure turbine outlet gas temperature control device according to claim 7, 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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