Prototype thermochemical heat storage with open reactor system

Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage system has been realized at ECN, applying an open sorption system concept. The packed bed contains 17 dm3 of sorption material and is capable of generating 150 W of thermal power. An effective energy storage density of approximately 0.5 GJ/m3 was obtained.

► A selection study on salt hydrates for thermochemical heat storage is carried out.
► A lab scale open sorption thermochemical heat storage system is built.
► The lab prototype thermochemical storage is tested with 17 l of MgCl2·6H2O.
► The lab prototype was able to provide 50 W heating power at 60 °C, with an instantaneous COP of 12.
► Improvement of heat recovery and pressure drop will increase the performance.