Refrigeration, or thermal, energy storage system by phase change materials

The present invention relates to a refrigeration, or thermal, energy storage system (1) for storing refrigeration, or thermal, energy to be released when required by users, comprising a body (2), closed and insulated, said body (2) being configured to contain two fluids within its volume, respectively a Phase Change Material (PCM) type fluid and a secondary fluid, said two fluids being immiscible each other and having different density, so as to be stratified within the volume of said body (2); withdrawal means (3) configured to draw said secondary fluid from said body (2), and to convey the same inside a heat exchanger (6), said heat exchanger (6) being configured to exchange frigories, or calories, with said secondary fluid; and distribution means (4) configured to draw said secondary fluid from said heat exchanger (6), and to distribute, within said body (2), said secondary fluid into said PCM type fluid, so as that said secondary fluid exchanges with said PCM type fluid frigories, or calories, absorbed in said heat exchanger (6), said secondary fluid having a solidification temperature substantially lower than that of said PCM type fluid, said heat exchanger (6) being housed inside said body (2), and being exchange frigories, or calories, between said secondary fluid and a primary fluid, said heat exchanger (6) comprising a first pipe, connected at its ends respectively to said withdrawal means (3) and to said distribution means (4), for the circulation of said secondary fluid, and a second pipe, concentric with respect to said first pipe, configured to be connected to a circuit (9) external to said body (2), for the circulation of said primary fluid.