Evaluation of the temperature measurement in a finned latent heat thermal energy storage

Abstract

Accurate temperature measurement is crucial for the characterization of Latent Heat Thermal Energy Storage (LHTES) systems. This study optimizes and evaluates an existing concept for determining temperatures in a finned tube design LHTES element, for its implementation in a planned larger-scale test facility. An analytical heat transfer model was developed to estimate the temperature distribution inside the LHTES element and determine the optimal position for the thermocouple to measure the tube wall temperature with minimal influence on the system. The feasibility of the optimized test rig concept was evaluated through experiments to assess the quality of temperature measurements during the melting and solidification process. Results obtained from the analytical model showed that a parallel arrangement of the thermocouple for wall temperature measurement had less influence on the wall temperature than a radial arrangement. Additionally, a welded joint ensured optimal contact between the sensor and the measured object. The test stand was successfully constructed, and suggestions for further improvements were developed for the final test stand's construction. Initial experimental results demonstrate that the existing concept is feasible and suitable to realize a narrow temperature measurement network in an LHTES element.