Thermal Simulation Analysis And Aging Test Of PTC Heater

PTC ceramic heater is a thermal sensitive material with Positive Temperature Coefficient.This material has no flame when heated,and it is dysoxidizable and stable,so it is widely used in automobile,communication industry,household appliances and so on.In the process of using PTC ceramic heaters,there are some problems,such as power attenuation,longer starting time and so on.In this paper,low voltage PTC ceramic heater is taken as the research object,and an aging test system is built.Through the combination of modeling,simulation and actual test,the research on low-pressure heater is carried out.The main contents are as follows:(1)Build an aging test system in order to test the temperature,voltage,current,resistance,power and other parameters of the heater.The system’s hardware includes computer,programmable power supply,temperature control meter,fixture and single chip system(integrated in the lower board of fixture).The upper computer software and the lower computer program are written with Qt5 and keil u Vision 5 respectively.(2)Modeling and thermodynamic simulation.3D Drawing Software Solid Works premium2016 is used to build the physical model of PTC ceramic heater.According to the position between the models,three different heating forms: single piece,double pieces and ring are completed.The simulation which is a module of Solid Works is used to complete the steadystate simulation of thermodynamics.The distribution of temperature field and the heating efficiency of a single heater are analyzed under different arrangements when heating the same object.(3)Aging test and temperature verification.ZWX-BC PTCR RT test system is used to obtain the resistance temperature characteristic curve of the heater,and the curve is used to fit the functional relationship between resistance and temperature,so as to verify the deviation between the temperature fed back by the fitting function and the actual measured temperature.The aging test system is used to test current / resistance / power / temperature voltage,resistance/ power / temperature time and aging characteristics.According to the test data,the aging law of PTC heater was summarized.