Thermal Energy Storage by Means of an Absorption Cycle

摘要

A model for the absorption cycle was used to investigate 18 working pairs. Results show that the volumetric energy density of an absorption cycle with NH3/H2O as a working pair is more than twice that of heat storage in water, despite the separate storage of both components. A cycle with a compressor is more favorable than one with a heat pump. The calculated energetic efficiency of a cycle with components separated by supply of heat is 68 percent, that of a cycle with the compressor is 94 percent, based on primary energy. The model was verified for cycles with the first and third storage alternatives, for a mixture (NH3/H2O) as well as for a solution (NH3/NaSCN). An experimental installation was built with a net heat output of 5 kW and a storage capacity of 40 kWh. Experimental results agree within 9 percent with the model.