Research On Temperature Measurement System Of Turbine Blade Based On Analog-to-Digital Converter

Increasing temperature,which is an important factor affecting gas turbine performance,can effectively improve the operation efficiency and power of gas turbine that is developed toward high temperature and high rotational speed at present.The main component that restricts temperature increase of gas turbine is turbine blade,which easily corrodes and oxidizes under the long-time air erosion of high temperature.Once the turbine temperature exceeds the design limit of the blade material,its service life will be affected seriously.Therefore,it is of great importance important to monitor the blade surface temperature when the gas turbine is running.Generally,the colorimetric method is used for projects to measure turbine blade.According to the method,by comparing the spectral intensity data in the two optical paths,the emissivity can be considered approximately equal if the two optical channel wave bands are relatively close to each other.At this time,the color temperature of the measured object can be calculated.The method has a simple structure and higher accuracy than the traditional temperature measurement methods such as radiance thermometry.However,there is usually a gap between the emissivity of the two channels in reality,and the approximately equal processing will cause a certain error.At the same time,if the optical channel has a strong absorption capacity for spectral radiation with a certain wavelength,it may seriously affect the temperature measurement result.As for the radiation thermometry of turbine blades,the following work is done in this paper:(1)The data acquisition card with stronger application performance replaces the original data acquisition module.Multi-channel acquisition and TCP / IP protocol transmission of spectral radiation data are realized through programming.Without a data acquisition card driver,the host computer can control the acquisition module via LAN to complete the remote data acquisition and transmission.At the same time,after the applied data acquisition card of the acquisition module is finished,the hardware resources of the host computer are saved,so that more resources can be used for subsequent data processing.(2)This paper analyzes the factors affecting the error and accuracy of traditional radiation thermometry,and compares the data processing result worked out by multi-spectral radiation thermometry with traditional genetic algorithms,traditional Non-dominated Sorting Genetic Algorithms-II(NSGA-II),and the improved NSGA-II algorithm.The calculation results show that the improved NSGA-II algorithm’s multispectral thermometry has the highest calculation accuracy,but the calculation speed is slow because of the introduction of genetic algorithm,making it impossible to guarantee the real-time performance of temperature measurement system.The radiance thermometry,featured by fast calculation speed and strong anti-interference ability,can accurately measure the blade surface lightness temperature under an appropriate wavelength,and reflect the distribution and change trend of blade temperature.Program design is finished using LabVIEW so the temperature can be quickly converted after inputting the measurement data.(3)The radiation temperature measurement system software is designed in the LabVIEW environment,and modules such as TCP/IP network data receiving,voltage temperature conversion,blade segmentation,record storing and reading,circular graph and trend graph display and channel parameter setting are added to realize high-precision segmentation of turbine blade temperature waveform.The circular graph and temperature trend display control shows the current turbine blade temperature and working temperature trend online.