基于LCSR法的电阻温度计动态响应过程

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中图分类号：TK311 文献标志码：A

Dynamic response process of resistance temperature detector based on LCSR method

ZHANG Zhenwen1，SONG Yanyong12， LIANG Yi1，SU Mingxu’ （1.SchoolofEnergyandPowerEngineering，UniversityofShanghaiforScienceandTechnologyhanghai 2oo93，Chind; 2.Shanghai InspectionandTesting InstituteofInstrumentsandAutomation Systems Co.，Ltd.，Shanghai 2Oo33，China）

Abstract： The response time is a key factor afcting the dynamic measurement error of resistance temperature detector. The loop current step response （LSCR） method can realize the in-situ measurement of the response time of in-service resistance temperature detector. But the variable Joule heat， internal and external influencing factors on thermodynamic heat transfer processes， the conversion relationship and order are still to be studied. Based on COMSOL Multiphysics software， a multiphysical field coupling model was established to numerically study the coupling process of electric current excitation， temperature field， and external flow field in the LCSR， focusing on the mechanism of variable Joule heat generation of resistance wire involved. Consequently， the conversion relation between LSCR method and plunge test was established. The LCSR dynamic response curve was transformed by the third-order relation equation，and compared with the plunge test， the relative error of response time was only 1.51% . A study on the factors affecting LCSR response time was conducted， and the effects of external fluid flow rate， internal filing material and air layer on the response time were analyzed in depth. LCSR and plunge test validation experiments were simultaneously conducted. The comparison shows that the relative error between the simulation results and the experimental results of the response time of LCSR method is 2.46% . The LCSR experimental data were converted by the relation equation， and the results are compared with the experimental results of plunge test at three flow velocities， and the relative errors are all less than 5% ， verifying applicability of the established conversion relationship to the experiments.

Keywords： resistance temperature detector; in-situ measurement; LCSR; response time; influencing factors; numerical simulation

电阻温度计（resistance temperature detector，RTD）因其线性度、稳定性良好和抗干扰能力强等优势，广泛应用于工业领域。（剩余12051字）