Impact of thermal energy storage on the sizing and energy consumption of a district cooling system.

Thermal energy storage (TES) has been recognized to be a good way to ensure energy security, efficiency and environmental quality. Nevertheless many materials are available with variable thermodynamic properties. The aim of this work is to compare the energy consumption and sizing of a district cooling system with TES device in function of storage materials (water, CO2 hydrate slurry and TBPB hydrate slurry). A system modelling approach was developed by assembling component models: chiller, stirred tank reactor,
circulation loop and place of use (house equipped with heat exchanger). The evolution of room and storage temperature, chiller and pumping energy consumption for different materials and various operating conditions is analyzed. Results show that the use of PCM (hydrates) allows an under sizing of the system, limiting the volume of the storage device and improving the system efficiency compared to system with water.