Experimental analysis of a commercial size bio-based latent thermal energy storage for air conditioning

Future smart and efficient energy management systems for space cooling and heating in building applications require novel solutions to store heat to decouple the energy demand and the availability of renewable energy sources. Latent thermal energy storages represent one of the most promising solutions; however, their cost-effective implementation in terms of energy and cost savings and payback time needs to be verified case by case. Thus, simplified, though accurate, performance correlations during both charging and discharging phases are strongly needed to be implemented into the different dynamic simulation tools. This work is intended to present the experimental behavior of a novel 18 kWh latent thermal energy storage that uses the roll-bond technology to efficiently store and release cold energy by exploiting the solid/liquid phase change process of 300 kg of a biobased phase change material having a melting temperature of 9 degrees C. The effects of the inlet water temperature and flow rate are studied to elucidate how the performance varies and to identify possible control strategies. On the basis of the experimental results, two correlations are proposed to accurately predict the performance of the latent thermal energy storage to be implemented in general dynamic simulation tools that can help in evaluating the system performance and the achievable energy and cost savings.