A novel 3-D model of an industrial-scale tube-fin latent heat storage using salt hydrates with supercooling: A model validation

Abstract

Latent heat storage using salt hydrates based on tube-fin heat exchanger is a promising heat storage approach for distributed building heating. In spite of abundant experimental investigations, there is quite a lack of numerical works focusing on the industrial-oriented design and optimization on this technology. The present work develops a reasonably accurate 3-D model for the evaluation of the thermal behavior of a pilot-scale tube-fin latent heat storage device using salt hydrates, considering the balance between computing effort and simulation accuracy. The availability and accuracy of the proposed model are validated through comparisons with experimental results in which numerical discrepancies and model applicability are comprehensively discussed. The results show that the model is able to portray a clear heat transfer process of a 100 kWh-level pilot-scale latent heat storage device during a continuous 24-h charge-discharge operation, with considering detailed thermal behaviors of PCMs including non-isothermal melting and solidification with supercooling effect. The calculation errors on the transient temperature variation of the heat transfer fluid and storage medium, as well as the overall thermal performances of the storage device are less than 7%. The CPU time consumed for the calculation is around half of the actual operation time.