Simulation and Testing of a Latent Heat Thermal Energy Storage Unit with Metallic Phase Change Material

Latent heat thermal energy storage in metallic phase change materials offers a thermal energy storage concept that can store energy at higher temperatures than with sensible thermal energy storage. This may enable the use of high efficiency thermodynamic cycles in CSP applications, which may lead to a reduction in levelised cost of electricity. Eutectic aluminum silicon alloy, AlSi12, is an attractive phase change material because of its moderate melting temperature, high thermal conductivity, and high heat of fusion. A prototype thermal energy storage test rig has been built and tested as to better understand the behavior of latent heat thermal energy storage. A mathematical model was developed to predict the behavior of such a heat storage unit. The model was compared with the behavior of the test rig during discharge. The model proved to simulate the latent heat thermal energy storage with reasonable accuracy. It is recommended that more accurate material property data be obtained and that the thermal energy storage test rig be modified as to improve readings.