Development And Research Of Thermal Constant Analyzer Based On TPS Method

Thermal constant is an important heat transfer parameter of the material.Its research not only has extensive research object in the academic theory,and also has very important application in industrial practice.To obtain accurate and reliable thermal constant has very important academic value and practical significance.The measurement method of thermal constant mainly divided into two categories: the transient and steady state method.Transient plane source method is a kind of transient method which can simultaneously measure the thermal conductivity and thermal diffusivity of material.It has the many advantages,such as fast measurement,high accuracy and wide measurement range.It has no special requirements for the shape of samples to be tested.At present,there is mature instrument based TPS method aboard,while we don't have similar instrument in domestic.Based on the principle of TPS method,this paper analyzed and compensated the effects on the measurement results of the sensor heat capacity,the instability of heat power and time delay and simplified the theory model of the temperature rise and evaluated the rationality of parameter settings.Then this paper designed a thermal constant analyzer which can simultaneously measure the thermal constant of solid and liquid in order to fill the domestic blank in this field.The main content of this paper is:1?This part introduced the research content of heat transfer and the basis form of heat transfer and raised the research background and significance.Besides,this part introduced the basic concept of thermal constant.At last,this part summarized the main content of this paper after the contrast of the current domestic and foreign research about the thermal constant.2?This part introduced the basic theory of the TPS method,and based on the theory deduced theory model of the temperature rise.This part analyzed and compensated the influence factors of measurement error of the TPS method from the theoretical model.3?This part plotted the curve of D(?)in the theory model of TPS method.To deal with the complicated problem of the temperature rising model,this paper modified some parameters of the simplified model of square probe proposed in reference,to make it applicable to the calculation of the circular probe.At last,fitting error of the simplified model was analyzed.4?This part described the overall design scheme of this TPS thermal constant analyzer,and then introduced in detail the regulated power supply system consist of adjustable voltage regulator and digital potentiometer and software system based on Labview.5?In this part,the thermal resistance coefficient of the sensor,the resistance value of the standard resistance and the stability of the heating power were calibrated.Some constraints were introduced to make sure the reliability and accuracy of the measurement result.At last,the thermal constant of some materials were measured by the system designed in this paper and the results were analyzed.6?This part reviewed and summarized the whole research work.The shortage and improved method of the thermal constant analyzer were described and outlook of the next work was presented.