Turbine front temperature prediction method in high-temperature state

Abstract

The invention provides a turbine front temperature prediction method in a high-temperature state, and belongs to the field of engine data processing, and the method comprises the steps: selecting a plurality of groups of high-pressure turbine guide blades at different circumferential positions of a whole-ring turbine guide device, arranging thermocouples at different radial height positions of the same high-pressure turbine guide blade, therefore, a plurality of measuring points for measuring the front temperature of the turbine are formed; assembling the turbine guider provided with the thermocouple on a test engine, adjusting state parameters of the test engine to enable the test engine to reach a preset test state, and collecting parameter data in the test state; performing data cleaning and fairing processing on the acquired parameters; judging measuring point data when the running state of the engine is a steady state, and extracting the measuring point data in the steady state to obtain turbine front temperatures in different testing states; and distinguishing a complete measuring point and a to-be-predicted measuring point in the steady-state measuring point data, and constructing a relationship between the complete measuring point and the to-be-predicted measuring point to obtain to-be-predicted measuring point data.

Description

Technical Field

[0001] The present application belongs to the field of aero-engine technology, and in particular relates to a method for predicting the pre-turbine temperature under high temperature conditions. Background Art

[0002] The pre-turbine temperature (i.e., the combustion chamber outlet temperature) is a key parameter that affects engine performance. It manifests itself as radial and circumferential non-uniformity, and this non-uniformity will also change under different engine conditions.

[0003] The current methods for obtaining the turbine pre-temperature include the following methods: 1) Simulation calculation method: This method can obtain comprehensive circumferential and radial distribution data, but due to the complexity of combustion, the accuracy of simulation calculation is low; 2) Combustion chamber component test method: different measuring points are arranged at the outlet of the combustion chamber component to directly measure the gas temperature. This method can obtain more data points, but due to the difference between the component state and the whole machine state, the distribution law and absolute value may be different; 3) The temperature before the turbine is measured in the core engine or complete machine state. This method can obtain the most accurate data. However, due to the limited number of measuring points and the measurement under high temperature, the measuring points are easily damaged, so the amount of data obtained is limited. Summary of the invention

[0004] The purpose of the present application is to provide a method for predicting the temperature before a turbine under high temperature conditions, so as to solve or alleviate at least one problem in the background technology.

[0005] The technical solution of the present application is: a method for predicting the temperature before the turbine under high temperature conditions, comprising: Selecting a plurality of groups of high-pressure turbine guide blades at different circumferential positions of the turbine guide vane of the entire ring to arrange thermocouples, each group of thermocouples is arranged at different radial height positions of the same high-pressure turbine guide blade, thereby forming multiple measuring points for measuring the temperature before the turbine; Assembling a turbine guide arranged with a thermocouple on a test engine, adjusting the state parameters of the test engine to make the test engine reach a predetermined test state, and collecting engine state parameters and thermocouple temperature parameter data under the predetermined test state; Perform data cleaning and smoothing on the collected engine status parameters and thermocouple temperature parameters; Determine the measurement point data when the engine is in a steady state, and extract the measurement point data when the engine is in a steady state to obtain the turbine front temperature under different test conditions; The complete measuring points and the measuring points to be predicted in the steady-state measuring point data are distinguished, the relationship between the complete measuring points and the measuring points to be predicted is established, and the measuring point data to be predicted is obtained.

[0006] Preferably, the thermocouple is arranged at the leading edge of the high-pressure turbine guide vane.

[0007] Preferably, the engine state parameters include engine inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N.

[0008] Preferably, the process of determining the measurement point data when the engine is in a steady state and extracting the measurement point data when the engine is in a steady state to obtain the turbine front temperature under different states is as follows: Assume that the transient time of the adjustment of the engine state parameters during operation is t1, the estimated time required for the engine state to reach a steady state after the engine state parameters are adjusted is tw, the transient time of the next engine state parameter adjustment is t2, and the corresponding transient time when the extracted engine operation state is a steady state is t, which satisfies: t2>t>t1+tw, and △Tin<dTin, △Pin<dPin, △N<dN per unit time, wherein dTin, dPin, dN are the allowed changes of the engine inlet temperature, inlet pressure and high-pressure turbine speed when the engine operation state is stable, and △Tin, △Pin, △N are the changes of the engine inlet temperature, inlet pressure and high-pressure turbine speed per unit time; The temperature measurement points of each turbine inlet temperature T4 in the corresponding time period of the steady-state time and the average values ​​of the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N in the engine state parameters are obtained to obtain a data set, that is, the measurement point data of the turbine inlet temperature T4 under different test conditions are obtained.

[0009] In an optional implementation manner of the present application, the process of constructing the relationship between the complete measurement point and the measurement point to be predicted and obtaining the data of the measurement point to be predicted is: Calculate the average turbine inlet temperature T4a of the same measuring point of each group of high-pressure turbine guide blades under different test conditions in the complete measuring points, and calculate the ratio ki of each measuring point to the average turbine inlet temperature T4a, that is, ki=T4i / T4a, T4i is the turbine inlet temperature under the i-th test state; Sort the complete measurement points according to the average value of the temperature before the turbine T4a; The relationship between the fitting ratio ki and the average temperature before the turbine T4a is ki = f(T4a); Fit the relationship between the average temperature before the turbine T4a and the engine state parameters, that is, T4a=f(N,Tin,Pin); According to the relationship T4a=f(N,Tin,Pin), calculate the average value T4a' of the turbine front temperature of the predicted measuring point; According to the relationship ki=f(T4a) and the average value T4a' of the turbine inlet temperature of the measurement point to be predicted, the proportion ki' of the measurement point to be predicted is calculated; According to the relationship T4i' = T4a'•ki', the missing measurement point data are predicted and the data is completed. T4i' is the predicted turbine inlet temperature of the missing measurement point under the i-th test state.

[0010] The method for predicting the pre-turbine temperature under high temperature conditions of the present application can expand the pre-turbine temperature measurement data by cleaning, smoothing, extracting steady-state data, and completing predictions of the test data, and has the advantages of large data volume and accurate data. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0012] Figure 1 This is a schematic diagram of the turbine pre-temperature prediction method under high temperature conditions of the present application.

[0013] Figure 2 FIG. 1 is a schematic diagram of thermocouple arrangement according to an embodiment of the present application.

[0014] Figure 3 This is a schematic diagram for supplementing measurement point data according to an embodiment of the present application. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0016] The present application proposes a method for predicting the turbine pre-temperature status data of non-measuring points or damaged measuring points based on the turbine pre-temperature measuring point data under the high-temperature operation state of the core machine or the whole machine. The turbine pre-temperature measuring point data can be expanded by cleaning, smoothing, extracting steady-state data, and predicting and completing the test data. This method has the advantages of large data volume and accurate data.

[0017] like Figure 1 As shown, the method for predicting the turbine front temperature under high temperature state provided by the present application includes the following process: Step S10: arranging measuring points.

[0018] At different circumferential positions of the full ring turbine guide vane, n groups of high-pressure turbine guide vanes are selected to arrange thermocouples, and at the same time, m thermocouples are arranged at different radial height positions of the same high-pressure turbine guide vane, so that a total of n×m measuring points are arranged in the circumferential and radial directions of the high-pressure turbine guide vane. The thermocouple is led from the inner cavity of the high-pressure turbine guide vane, and is arranged on the leading edge wall of the high-pressure turbine guide vane and led out from the lead hole opened, so that the lead can pass through to measure the turbine front temperature T4.

[0019] For example, in this application Figure 2 In the embodiment shown, the high-pressure turbine guide vane assembly for testing is composed of 21 sets of high-pressure turbine guide vane assemblies, which are welded from two single-piece high-pressure turbine blades. The 2nd, 7th, 13th and 17th high-pressure turbine guide vane assemblies are selected in the circumferential direction of the turbine guide vane for testing and modification. Three radial heights are selected in the radial direction of the left and right blades in each set of high-pressure turbine guide vane assemblies, that is, six radial heights are selected in each set of high-pressure turbine guide vane assemblies (i.e. Figure 2 There are 24 test points in total (#1~#6 positions), and the diameter of each test lead hole is about 3mm.

[0020] Step S20: collecting measurement parameter data.

[0021] The turbine guide arranged with thermocouple measuring points is assembled on the test engine. By adjusting the engine state parameters such as the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N of the test engine, the predetermined test state is achieved, and the engine state parameters and thermocouple temperature parameters under the predetermined test state are collected.

[0022] Step S30: data cleaning and smoothing.

[0023] 1) Due to the damage of the thermocouple or the fact that some measuring points were not working during the measurement period, there is data that is obviously not collected. This data is expressed in the form of continuous extreme values ​​and needs to be deleted. For example, in some embodiments of the present application, the data that is obviously not collected is expressed as: 9999, -9999, and such data is deleted.

[0024] 2) Due to reasons such as thermocouple damage, the values ​​of some measuring points may be different from the general rules of other measuring points and will fluctuate greatly. Such data will be deleted.

[0025] 3) Due to the fact that some thermocouples are not completely fitted during transient testing, extreme values ​​may appear at some measuring points. In this case, the extreme values ​​should be deleted.

[0026] 4) Since the measuring point was damaged in the early stage or was not installed firmly, although its data is stable and no longer has the above-mentioned fluctuations, such measuring point has obvious deviations from the data rules of other similar measuring points in the same period of time. In order to ensure the accuracy of the data, it should also be deleted.

[0027] Affected by the engine operation and test accuracy, normal measurement point data will also show up and down jumps within a small range. In this application, the collected parameter data is smoothed. For example, in some embodiments of this application, the Lowess (local weighted regression algorithm) method can be used to smooth the collected parameters.

[0028] Step S40: extracting steady-state data.

[0029] Due to the influence of the adjustment of the engine state parameters, the measurement point data of the thermocouple temperature parameters also show a change from transient to steady state as the engine state parameters are adjusted. Therefore, it is necessary to judge and extract the steady-state data.

[0030] Assuming that the transient time of the engine state parameter adjustment during operation is t1, the estimated time required for the engine state to reach a steady state after the engine state parameter adjustment is tw, the transient time of the next engine state parameter adjustment is t2, and the corresponding transient time when the engine operation state is steady is t, which should satisfy: t2>t>t1+tw, and △Tin<dTin, △Pin<dPin, △N<dN per unit time, where dTin, dPin, dN are the allowed changes in the engine inlet temperature, inlet pressure and high-pressure turbine speed when the engine operation state is steady, and △Tin, △Pin, △N are the changes in the engine inlet temperature, inlet pressure and high-pressure turbine speed per unit time. The temperature measurement points of each turbine inlet temperature T4 in the time period corresponding to the steady-state time and the average values ​​of the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N in the engine state parameters are obtained to obtain a data set, that is, the measurement point data of the turbine inlet temperature T4 under different test conditions are obtained.

[0031] For example, in this embodiment of the present application, the allowable variation values ​​per unit time of each engine state parameter in steady state during this test process are shown in Table 1 below.

[0032] Table 1 Allowable changes in the values ​​of various engine status parameters

[0033] Step S50: data prediction and completion.

[0034] Due to the damage of the measuring point and other reasons, some of the turbine pre-temperature T4 measuring points in the obtained data set are missing data under different test conditions. Therefore, data prediction and completion are required. The specific process is as follows: 1) Distinguish between complete measurement points in steady-state data (i.e., all measurement point data in a certain state are complete) and measurement points to be predicted (i.e., there are measurement points with missing data in a certain state); 2) Calculate the average temperature T4a before the turbine of the same measuring point of each group of high-pressure turbine guide blades under different test conditions in the complete measuring points, and then calculate the ratio ki of each measuring point to the average temperature T4a before the turbine, that is, ki=T4i / T4a, T4i is the temperature before the turbine under the i-th test state; 3) Sort the complete measurement points according to the average value of the temperature before the turbine T4a; 4) Fitting the relationship between the ratio ki and the average temperature before the turbine T4a, that is, ki=f(T4a); 5) Fit the relationship between the average pre-turbine temperature T4a and the engine state parameters (inlet temperature Tin, inlet pressure Pin, high-pressure turbine speed N), that is, T4a=f(N,Tin,Pin); 6) According to the relationship T4a=f(N,Tin,Pin), calculate the average temperature T4a' before the turbine of the predicted measuring point; 7) Calculate the proportion ki' of the measurement point to be predicted based on the relationship ki=f(T4a) and the average value of the turbine inlet temperature T4a' of the measurement point to be predicted; 8) According to the relationship T4i' = T4a'•ki', predict the missing measurement point data and complete the data. T4i' is the predicted turbine inlet temperature of the missing measurement point under the i-th test state.

[0035] like Figure 3 Shown is the measurement point curve of different test states in this embodiment of the present application, wherein the ordinate is the leaf height, the abscissa is the converted temperature, and the measurement point data at the position indicated by the circle in the figure is the predicted value.

[0036] The method for predicting the pre-turbine temperature under high temperature conditions provided in the present application can expand the pre-turbine temperature measurement data by cleaning, smoothing, extracting steady-state data, and completing predictions of the test data, and has the advantages of large data volume and accurate data.

[0037] 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 predicting the turbine inlet temperature under high temperature conditions, characterized in that: include: Selecting a plurality of groups of high-pressure turbine guide blades at different circumferential positions of the turbine guide vane of the entire ring to arrange thermocouples, each group of thermocouples is arranged at different radial height positions of the same high-pressure turbine guide blade, thereby forming multiple measuring points for measuring the temperature before the turbine; Assembling a turbine guide arranged with a thermocouple on a test engine, adjusting the state parameters of the test engine to make the test engine reach a predetermined test state, and collecting the measurement point data of the engine state parameters and the thermocouple temperature parameters under the predetermined test state; Perform data cleaning and smoothing on the collected engine status parameters and thermocouple temperature parameters; Determine the measurement point data when the engine is in a steady state, extract the measurement point data when the engine is in a steady state to obtain the turbine front temperature under different test conditions; The complete measuring points and the measuring points to be predicted in the steady-state measuring point data are distinguished, the relationship between the complete measuring points and the measuring points to be predicted is established, and the measuring point data to be predicted is obtained.

2. The method for predicting the temperature before the turbine under high temperature conditions according to claim 1, characterized in that: The thermocouple is arranged at the leading edge of the high-pressure turbine guide vane.

3. The method for predicting the temperature before the turbine under high temperature conditions according to claim 2, characterized in that: The engine state parameters include engine inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N.

4. The method for predicting the temperature before the turbine under high temperature conditions according to claim 3, characterized in that: The process of judging the measuring point data when the engine is in a steady state and extracting the measuring point data when the engine is in a steady state to obtain the turbine front temperature under different test conditions is as follows: Assume that the transient time of the engine state parameter adjustment during operation is t1, the estimated time required for the engine state to reach a steady state after the engine state parameter adjustment is tw, the transient time of the next engine state parameter adjustment is t2, and the corresponding transient time when the extracted engine operation state is a steady state is t, which satisfies: t2>t>t1+tw, and △Tin<dTin, △Pin<dPin, △N<dN per unit time, wherein dTin, dPin, dN are the allowed changes of the engine inlet temperature, inlet pressure and high-pressure turbine speed when the engine operation state is a steady state, and △Tin, △Pin, △N are the changes of the engine inlet temperature, inlet pressure and high-pressure turbine speed per unit time; The temperature measurement points of each turbine inlet temperature T4 in the corresponding time period of the steady-state time and the average values ​​of the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N in the engine state parameters are obtained to obtain a data set, that is, the measurement point data of the turbine inlet temperature T4 under different test conditions are obtained.

5. The method for predicting the temperature before the turbine under high temperature conditions according to claim 4, characterized in that: The process of building the relationship between the complete measuring point and the measuring point to be predicted and obtaining the data of the measuring point to be predicted is as follows: Calculate the average turbine inlet temperature T4a of the same measuring point of each group of high-pressure turbine guide blades under different test conditions in the complete measuring points, and then calculate the ratio ki of each measuring point to the average turbine inlet temperature T4a, that is, ki=T4i / T4a, T4i is the turbine inlet temperature under the i-th test state; Sort the complete measurement points according to the average value of the temperature before the turbine T4a; The relationship between the fitting ratio ki and the average temperature before the turbine T4a is ki = f(T4a); Fit the relationship between the average temperature before the turbine T4a and the engine state parameters, that is, T4a=f(N,Tin,Pin); According to the relationship T4a=f(N,Tin,Pin), calculate the average value T4a' of the turbine front temperature of the predicted measuring point; According to the relationship ki=f(T4a) and the average value T4a' of the turbine inlet temperature of the measurement point to be predicted, the proportion ki' of the measurement point to be predicted is calculated; According to the relationship T4i' = T4a'•ki', the missing measurement point data are predicted and the data is completed. T4i' is the predicted turbine inlet temperature of the missing measurement point under the i-th test state.

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