System identification calorimetry

TL;DR

This paper introduces a model-based calorimetry method that uses multiple sensors and system identification to accurately quantify heat flow and storage in complex thermal systems, surpassing traditional limitations.

Contribution

It presents a novel approach combining non-linear lumped element models and system identification, enabling calorimetry under diverse and complex conditions.

Findings

Achieved 0.02% accuracy in total energy measurement

Measured instantaneous power with 10% RMS error

Applicable to systems with non-linear heat transfer and multiple thermal masses

Abstract

We report a model-based method for quantifying heat flow and storage in thermal systems using data from multiple thermal sensors. This approach avoids stringent requirements on the system geometry and sensor positions and enables calorimetry to be performed under a broader range of circumstances than is accessible with existing calorimeters, such as when non-linear heat transfer occurs, when spatially separated heat sources are active, or when multiple thermal masses participate. Using experimental data from a model thermal system, this paper provides a tutorial on the construction of non-linear lumped element heat transfer models and the use of system identification to estimate the parameters of these models from calibration data. The calibrated models are then used to estimate unknown energy inputs to the thermal system from sensor data. Our best model enabled the measurement of the total input energy with 0.02% accuracy; the instantaneous input power could be measured with a root-mean-square error of 10% of the average input power.