Temperature Measurement Inside Fuel Cell Based On Magnetic Nanoparticles

The Solid Oxide Fuel Cell(SOFC)has a high energy conversion efficiency,the fuel resource is abundant,and the product is clean and pollution-free,which all wins SOFC a wide application prospect.While SOFC is working,the uneven temperature distribution will affect the working performance and efficiency.Accurately obtaining the internal temperature inside the SOFC is very important for the battery performance study.However,the high working temperature and the sealing structure of SOFC lead many of the temperature measurement methods to be high-cost but low-precision,non-contact temperature measurement method can overcome these drawbacks.Based on the temperature-sensitive property of magnetic nanoparticles,the thesis mainly introduce a non-contact temperature measurement method to obtain the temperature inside SOFC.Then the thesis building up a one-dimensional temperature measurement model by combining field-free point scanning principle used in magnetic nanoparticle imaging,and designing the temperature measurement system.Finally,by carrying out series of experiments to verify the feasibility of the measurement model.In this thesis,according to the different cases of the internal temperature distribution inside SOFC,two kinds of one-dimension temperature measurement models are built up.Model 1 requires that the temperature of each point within measurement range in the SOFC is consistent,while Model 2 allows a temperature difference between the temperatures of each point.In addition,the temperature of the point can be instantly obtained when the field-free point scans each measured point by Model 1,but the temperature information of each point can only be obtained after field-free point scans all the measured points within the temperature measurement area,thus,the temperature change during the scanning process has a greater influence on Model two.The choice of temperature measurement model must be considered with the practical condition.After the model is established,a temperature measurement system needs to be designed to achieve one-dimensional temperature measurement.When designing the excitation generating device,the uniform distribution of the excitation magnetic field and the selection of the AC excitation current are analyzed.When the weak magnetic detection device is designed,the position of the differential detection coil is graphically illustrated,and the appropriate coil size selected by deducing the formula.A digital phase-sensitive detection algorithm for obtaining harmonic signals and eliminating remanence is briefly introduced and implemented,as well as the Levenberg-Marquardt algorithm for inversion of temperature.One-dimensional temperature measurement system was used to design the experimental scheme and analyze the experimental results for the two one-dimensional temperature measurement models.The experiment simulates the different temperature distribution inside SOFC.Using these two temperature measurement models to obtain the temperature measurement error in each case through multiple sets of experiments,observe and analyze the experimental results.The error obtained by using the two models does not exceed ?2K,verifying The feasibility of temperature measurement models.