Research On Temperature Measurement Device For Strip In Induction Heating Based On LabVIEW

Transverse flux induction heating device can be appropriately applied to heat treatment for continuously moving strip,but the temperature distribution of strip at the heater exit is uneven.Temperature is the most important technological parameter in strip heat treatment.Only by choosing and controlling heating temperature properly can the strip have the required mechanical,physical and chemical properties.Therefore,it is highly necessary to monitor and record the temperature of strip during heat treatment.In this paper,a temperature measurement device for strip in induction heating based on LabVIEW is designed,and the main contents of the research Include as follows.(1)The temperature distribution on the surface of strip in transverse flux induction heating is analyzed.After introducing the composition and working principle of the transverse flux induction heating system,the eddy current field and temperature field of transverse flux induction heating are numerically analyzed by finite element method,and the magnetic-thermal coupling field is simulated by Mag Net and Therm Net software.According to the simulation results,the temperature distribution on the surface of strip is analyzed.(2)The design scheme of temperature measuring device for strip is determined.Firstly,the functions to be achieved of temperature measuring device for strip is put forward.Then,after comparing the characteristics of different temperature measurement methods,noncontact temperature measurement is adopted according to the requirement of temperature measurement environment.Finally,two different design schemes are put forward in this paper.Considering their advantages and disadvantages,the design scheme of the temperature measurement device for strip based on LabVIEW is determined.(3)The design of hardware and software system of temperature measurement device for strip is completed.According to the design scheme,infrared temperature sensors,data acquisition card,NI CompactDAQ controller and display are reasonably selected,and the performance parameters of the selected hardware are introduced.Temperature measurement program for strip is written by using LabVIEW software,including data acquisition,data processing,temperature display and data storage,etc.(4)The emissivity of strip is analyzed and processed.The law of blackbody radiation is introduced.The curves of three different kinds of carbon steel radiation rate varying with temperature are drawn,and the effect of temperature on strip emissivity is analyzed.The emissivity date at different temperatures is piecewise fitted to the analytical function with the least square method,which is written to the LabVIEW program by formula node.(5)After debugging temperature measurement device for strip,the experiment is carried out.The experimental results show that the device the device can real-time monitor and display the distribution and change trend of strip temperature in induction heating and record the temperature of sampling points for follow-up analysis and statistics,which achieves the predetermined objectives.