A method for predicting the turbine inlet temperature under high-temperature conditions

Abstract

The present application provides a method for predicting the temperature before the turbine under high-temperature conditions, belonging to the field of engine data processing. The method includes: selecting several groups of high-pressure turbine guide vanes at different circumferential positions of the integral turbine guide vane, and arranging thermocouples at different radial height positions of the same high-pressure turbine guide vane, so as to form multiple measuring points for measuring the temperature before the turbine; assembling the turbine guide vane with thermocouples on the test engine, adjusting the state parameters of the test engine to make the test engine reach the predetermined test state, and collecting the parameter data under the test state; performing data cleaning and smoothing processing on the collected parameters; judging the measuring point data when the engine operating state is steady state, and extracting the measuring point data at steady state to obtain the temperature before the turbine under different test states; distinguishing the complete measuring points and the measuring points to be predicted in the steady-state measuring point data, constructing the relationship between the complete measuring points and the measuring points to be predicted, and obtaining the measuring point data to be predicted.

Description

Technical Field

[0001] This application belongs to the technical field of aeroengines, and particularly relates to a method for predicting the temperature before the turbine under high-temperature conditions. Background Technique

[0002] The temperature before the turbine (i.e., the temperature at the outlet of the combustion chamber) is a key parameter affecting the performance of the engine. It shows non-uniformity in the radial and circumferential directions, and this non-uniformity will also change under different engine conditions.

[0003] Currently, the methods for obtaining the temperature before the turbine include the following:

[0004] 1) Simulation calculation method. This method can obtain comprehensive circumferential and radial distribution data. However, due to the complexity of combustion, the accuracy of simulation calculation is relatively low.

[0005] 2) Combustion chamber component test method. Different measuring points are arranged at the outlet position under the condition of the combustion chamber components to directly measure the gas temperature. This method can obtain more data points. However, due to the differences between the component state and the whole-engine state, there may be differences in the distribution law and absolute value.

[0006] 3) Measuring the temperature before the turbine under the condition of the core engine or the whole engine. The data obtained by this method is the most accurate. However, due to limited measuring points and the measurement under high-temperature conditions, the measuring points are easily damaged, so the amount of data obtained is limited. Summary of the Invention

[0007] The purpose of this application is to provide a method for predicting the temperature before the turbine under high-temperature conditions to solve or alleviate at least one problem in the background technique.

[0008] The technical solution of this application is: A method for predicting the temperature before the turbine under high-temperature conditions, including:

[0009] Select several groups of high-pressure turbine guide vanes at different circumferential positions of the integral turbine guide vane ring to arrange thermocouples. Each group of thermocouples is arranged at different radial height positions of the same high-pressure turbine guide vane, thereby forming multiple measuring points for measuring the temperature before the turbine.

[0010] Assemble the turbine guide vane with thermocouples installed on the test engine. By adjusting the state parameters of the test engine, make the test engine reach the predetermined test state, and collect the engine state parameters and thermocouple temperature parameter data under the predetermined test state.

[0011] Perform data cleaning and smoothing processing on the collected engine state parameters and thermocouple temperature parameters.

[0012] Judge the measurement point data when the engine operating state is in a steady state, and extract the measurement point data when the engine operating state is in a steady state to obtain the turbine inlet temperature under different test states;

[0013] Distinguish the complete measurement points and the measurement points to be predicted in the steady-state measurement point data, construct the relationship between the complete measurement points and the measurement points to be predicted, and obtain the measurement point data to be predicted.

[0014] Preferably, the thermocouple is arranged at the leading edge position of the high-pressure turbine guide vane.

[0015] Preferably, the engine state parameters include the engine inlet temperature Tin, the inlet pressure Pin, and the high-pressure turbine speed N.

[0016] Preferably, the process of judging the measurement point data when the engine operating state is in a steady state and extracting the measurement point data when the engine operating state is in a steady state to obtain the turbine inlet temperature under different states is as follows:

[0017] Assume that the transient time for adjusting 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, and the transient time for the next adjustment of the engine state parameters is t2. The transient time corresponding to the engine operating state in a steady state extracted is t, which satisfies: t2 > t > t1 + tw, and within a unit time, △Tin < dTin, △Pin < dPin, △N < dN, where dTin, dPin, and dN are the allowable change values of the engine inlet temperature, inlet pressure, and high-pressure turbine speed when the engine operating state is stable, and △Tin, △Pin, and △N are the change values of the engine inlet temperature, inlet pressure, and high-pressure turbine speed within a unit time;

[0018] Obtain the temperature measurement points of each turbine inlet temperature T4 and the average values of the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N in the engine state parameters within the time period corresponding to the steady state time to obtain a data set, that is, obtain the measurement point data of the turbine inlet temperature T4 under different test states.

[0019] In an alternative embodiment of the present application, the process of constructing the relationship between the complete measurement points and the measurement points to be predicted and obtaining the measurement point data to be predicted is as follows:

[0020] Calculate the average value T4a of the turbine inlet temperature at the same measurement point of each group of high-pressure turbine guide vanes under different test states in the complete measurement points, and calculate the ratio ki of the average value T4a of the turbine inlet temperature at each measurement point, that is, ki = T4i / T4a, where T4i is the turbine inlet temperature in the i-th test state;

[0021] Sort the complete measurement points according to the average value T4a of the turbine inlet temperature;

[0022] The relational expression between the fitting ratio ki and the average turbine inlet temperature T4a, that is, ki = f(T4a);

[0023] The relational expression between the average turbine inlet temperature T4a and the engine state parameters is fitted, that is, T4a = f(N, Tin, Pin);

[0024] According to the relational expression T4a = f(N, Tin, Pin), calculate the average turbine inlet temperature T4a' of the measurement point to be predicted;

[0025] According to the relational expression ki = f(T4a) and the average turbine inlet temperature T4a' of the measurement point to be predicted, calculate the ratio ki' of the measurement point to be predicted;

[0026] According to the relational expression T4i' = T4a' • ki', predict the missing measurement point data and complete the data filling. T4i' is the turbine inlet temperature of the missing measurement point in the i-th test state predicted.

[0027] The method for predicting the turbine inlet temperature under high temperature conditions of this application can expand the turbine inlet temperature measurement data by cleaning, smoothing, extracting steady-state data, and predicting and filling the test data, and has the advantages of large amount of data and accurate data. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions provided by this application, the drawings will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application.

[0029] Figure 1 It is a schematic diagram of the method for predicting the turbine inlet temperature under high temperature conditions of this application.

[0030] Figure 2 It is a schematic diagram of the thermocouple arrangement of an embodiment of this application.

[0031] Figure 3 It is a schematic diagram of the measurement point data supplement of an embodiment of this application. Detailed Embodiments

[0032] 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 with reference to the drawings in the embodiments of this application.

[0033] This application proposes a method for predicting the turbine inlet temperature state data of non-measurement points or damaged measurement points based on the turbine inlet temperature measurement point data under the high temperature operating state of the core engine or the whole engine. By cleaning, smoothing, extracting steady-state data, and predicting and filling the test data, the turbine inlet temperature measurement point data can be expanded, and this method has the advantages of large amount of data and accurate data.

[0034] Such asFigure 1 As shown in the figure, the method for predicting the temperature in front of the turbine at high temperature provided by this application includes the following process:

[0035] Step S10: Measuring point arrangement.

[0036] Select n groups of high-pressure turbine guide vanes at different circumferential positions of the integral ring turbine guide vane and arrange m thermocouples 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 thermocouples lead wires from the inner cavity of the high-pressure turbine guide vane, and are arranged on the leading edge wall surface of the high-pressure turbine guide vane and led out from the opened lead holes for the lead wires to pass through to measure the temperature T4 in front of the turbine.

[0037] For example, in the embodiment shown in this application Figure 2 The high-pressure turbine guide vane for testing consists of 21 groups of high-pressure turbine guide vane assemblies. The high-pressure turbine guide vane assembly is formed by welding two single-piece high-pressure turbine blades. Select the 2nd, 7th, 13th, and 17th high-pressure turbine guide vane assemblies at the circumferential direction of the turbine guide vane for test modification. For each group of high-pressure turbine guide vane assemblies, 3 radial heights are respectively selected for the left and right blades in the radial direction, that is, 6 radial heights are selected for each group of high-pressure turbine guide vane assemblies (i.e., Figure 2 the positions of #1~#6), a total of 24 measuring points are arranged, and the diameter of each test lead hole is about 3mm.

[0038] Step S20: Measuring parameter data acquisition.

[0039] Assemble the turbine guide vane with thermocouple measuring points on the test engine, and adjust the engine state parameters such as the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N of the test engine to make it reach the predetermined test state, and collect the engine state parameters and thermocouple temperature parameters under this predetermined test state.

[0040] Step S30: Data cleaning and smoothing.

[0041] 1) Since the thermocouple is damaged or some measuring points do not work during the collected measurement time period, there are obvious uncollected data, which are presented in the form of continuous extreme values and need to be deleted; for example, in some embodiments of this application, the obvious uncollected data are presented as: 9999, -9999, and such data are deleted.

[0042] 2) Due to reasons such as thermocouple damage, the values of some measuring points will show large oscillations that are different from the general law of other measuring points, and such data are deleted.

[0043] 3) Due to reasons such as some thermocouples not being fully attached during the transient test, extreme values may appear at some measurement points. In this case, the extreme values should be deleted.

[0044] 4) Due to the damage or insecure installation of the measurement points in the early stage, although their data is stable and no longer shows the above-mentioned fluctuations, the data pattern of such measurement points is significantly deviated from that of the other similar measurement points at the same time. To ensure the accuracy of the data, they should also be deleted.

[0045] Affected by the engine operation and test accuracy, the normal measurement point data will also show small fluctuations up and down. In this application, the collected parameter data is smoothed. For example, in some embodiments of this application, the Lowess (Locally Weighted Scatterplot Smoothing) method can be used to smooth the collected parameters.

[0046] Step S40: Extract steady-state data.

[0047] Due to the influence of the adjustment of the engine state parameters, the measurement point data of the thermocouple temperature parameters also shows 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.

[0048] Assume that the transient time for 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 adjustment of the engine state parameters is tw, the transient time for the next adjustment of the engine state parameters is t2, and the transient time corresponding to the steady state of the extracted engine operation state is t. It should satisfy: t2 > t > t1 + tw, and within the unit time, △Tin < dTin, △Pin < dPin, △N < dN, where dTin, dPin, dN are the allowable change values of the engine inlet temperature, inlet pressure, and high-pressure turbine speed when the engine operation state is in a steady state, and △Tin, △Pin, △N are the change values of the engine inlet temperature, inlet pressure, and high-pressure turbine speed within the unit time. Obtain the temperature measurement points of the turbine front temperature T4 and the average values of the inlet temperature Tin, inlet pressure Pin, and high-pressure turbine speed N in the engine state parameters within the time period corresponding to the steady state time to obtain a data set, that is, obtain the measurement point data of the turbine front temperature T4 under different test states.

[0049] For example, in this embodiment of this application, the allowable change values of each engine state parameter per unit time during this test are shown in Table 1 below.

[0050] Table 1 Allowable change values of each engine state parameter

[0051]

[0052] Step S50: Data prediction and completion.

[0053] Due to reasons such as the damage of measurement points, there are cases where some turbine inlet temperature T4 measurement points are missing data under different test conditions in the obtained dataset. Therefore, data prediction and completion are required. The specific process is as follows:

[0054] 1) Distinguish the complete measurement points (i.e., all measurement point data are complete in a certain state) and the measurement points to be predicted (i.e., there are missing measurement point data in a certain state) in the steady-state data;

[0055] 2) Calculate the average value T4a of the turbine inlet temperature at the same measurement point of each group of high-pressure turbine guide vanes under different test conditions in the complete measurement points, and then calculate the ratio ki of each measurement point to the average value T4a of the turbine inlet temperature, that is, ki = T4i / T4a, where T4i is the turbine inlet temperature in the i-th test condition;

[0056] 3) Sort the complete measurement points according to the average value T4a of the turbine inlet temperature;

[0057] 4) Fit the relationship between the ratio ki and the average value T4a of the turbine inlet temperature, that is, ki = f(T4a);

[0058] 5) Fit the relationship between the average value T4a of the turbine inlet temperature and the engine state parameters (inlet temperature Tin, inlet pressure Pin, high-pressure turbine speed N), that is, T4a = f(N, Tin, Pin);

[0059] 6) According to the relationship T4a = f(N, Tin, Pin), calculate the average value T4a' of the turbine inlet temperature of the measurement points to be predicted;

[0060] 7) According to the relationship ki = f(T4a) and the average value T4a' of the turbine inlet temperature of the measurement points to be predicted, calculate the ratio ki' of the measurement points to be predicted;

[0061] 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 in the i-th test condition.

[0062] As Figure 3 shown are the measurement point curves in different test conditions in this embodiment of the present application, where the vertical coordinate is the blade height and the horizontal coordinate is the converted temperature. The measurement point data at the positions indicated by the circles in the figure are the predicted values.

[0063] The method for predicting the turbine inlet temperature under high-temperature conditions provided by the present application can expand the turbine inlet temperature measurement data by cleaning, smoothing, extracting steady-state data, predicting and completing the test data, and has the advantages of large amount of data and accurate data.

[0064] As described above, it is only the specific implementation manner of the present application. However, the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A method for predicting the temperature before the turbine 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, wherein the engine state parameters include the engine inlet temperature Tin, the inlet pressure Pin, and the high-pressure turbine speed N; 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 process includes: 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 in 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 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, the inlet pressure Pin, and the 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; Distinguish the complete measuring points and the measuring points to be predicted in the steady-state measuring point data, build the relationship between the complete measuring points and the measuring points to be predicted, and obtain the measuring point data to be predicted, including: Calculate the average value T4a of the turbine inlet temperature at 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 value T4a of the turbine inlet temperature, 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 pre-turbine temperature 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 pre-temperature of the measurement point to be predicted, the ratio ki' of the measurement point to be predicted is calculated; Predict the missing measurement point data and complete the data according to the relationship T4i’ = T4a’·ki’, where T4i’ is the turbine inlet temperature of the missing measurement point in the i-th test state predicted.

2. The method for predicting the turbine inlet temperature under high temperature conditions according to claim 1, wherein The thermocouple is arranged at the leading edge position of the high-pressure turbine guide vane.

Images