Real-Time Estimation of Some Thermodynamics Properties During a Microwave Heating Process

Edgar Garcia,Ivan Amaya,Rodrigo Correa

doi:10.11144/javeriana.iyu21-2.rest

Abstract

This work considers the prediction in real time of physicochemical parameters of a sample heated in a uniform electromagnetic field. The thermal conductivity (K)and the combination of density and heat capacity terms (pc) were estimated as a demonstrative example.The sample (with known geometry) was subjected to electromagnetic radiation, generating a uniform and time constant volumetric heat flow within it. Real temperature profile was simulated adding white Gaussian noise to the original data, obtained from the theoretical model. For solving the objective function, simulated annealing and genetic algorithms, along with the traditional Levenberg-Marquardt method were used for comparative purposes. Results show similar findings of all algorithms for three simulation scenarios, as long as the signal to noise ratio sits at least at 30 dB. It means for practical purposes, that the estimation procedure presented here requires both, a good experimental design and an electronic instrumentation correctly specified.If both requirements are satisfied simultaneously, it is possible to estimate these type of parameters on-line, without need for an additional experimental setup.This work considers the prediction in real time of physicochemical parameters of a sample heated in a uniform electromagnetic field. The thermal conductivity and the combination of density and heat capacity terms ( were estimated as a demonstrative example.The sample (with known geometry) was subjected to electromagnetic radiation, generating a uniform and time constant volumetric heat flow within it. Real temperature profile was simulated adding white Gaussian noise to the original data, obtained from the theoretical model. For solving the objective function, simulated annealing and genetic algorithms, along with the traditional Levenberg-Marquardt method were used for comparative purposes. Results show similar findings of all algorithms for three simulation scenarios, as long as the signal to noise ratio sits at least at 30 dB. It means for practical purposes, that the estimation procedure presented here requires both, a good experimental design and an electronic instrumentation correctly specified.If both requirements are satisfied simultaneously, it is possible to estimate these type of parameters on-line, without need for an additional experimental setup.

Highlights

This work considered real-time prediction of physicochemical parameters for a sample heated in a uniform electromagnetic field
For all of the results shown in these tables dealing with SNR values lower than 20, the RMSE reached considerably higher values, indicating a substantial disagreement between the predicted temperatures and the estimated ones
In this article, we analyzed an alternative technique for estimating, in real-time, the thermal conductivity and the volumetric heat capacity of a material heated by microwaves

Summary

Introduction

This work considered real-time prediction of physicochemical parameters for a sample heated in a uniform electromagnetic field. Conclusion: for practical purposes, the estimation procedure presented here requires both, a good experimental design and a correctly specified electronic instrumentation. If both requirements are satisfied simultaneously, it is possible to estimate these type of parameters on-line, without need for an additional experimental setup. Most materials heated by microwaves suffer from a high degree of non-uniform heating This problem is accentuated because of their short heating times and because of the pronounced temperature dependence of their thermodynamic properties. The current work considers an inverse problem approach for estimating thermal properties. Other applications include phase equilibrium, dehydrator performance, and gas analysis in materials such as natural gas, ionic fluids, hydrates, and oil field brine [3]–[7]

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Results

Conclusion