Heat storage device having a high volume capacity

Abstract

The invention is a heat storage device having a high volume capacity (defined as the ratio between the volume of the heat storage medium divided by the overall volume of the device) combined with a high heat transfer surface and a low envelope material volume (‘dead volume’). The heat storage device is composed of individual storage elements which encapsulate a heat storage medium. The storage elements are stacked in a way that creates channels for the passage of a heat transfer fluid. The (air) heat transfer fluid channels are surrounded by a large heat transfer surface and embossed in a way to improve the heat transfer.

What is claimed is: 
     
         1 . A heat storage element consisting of an embossed polymeric sheet encapsulating a heat storage medium. 
     
     
         2 . A heat storage element as described in  claim 1 , where the thickness of the embossed polymeric sheet is in the range from 0.1 to 1 mm. 
     
     
         3 . A heat storage device comprised of two or more of the heat storage elements of  claim 1  stacked in a way that creates fluid transfer channels. 
     
     
         4 . A heat storage device as described in  claim 3  and having a volume capacity ranges between 60% and 90%. 
     
     
         5 . A heat storage device as described in  claim 3  and having a heat transfer compactness of 212 m 2 /m 3 . 
     
     
         6 . A heat storage device as described in  claim 3  wherein the embossed polymeric sheet is made of a polymeric material selected from PVC, ABS, PP, HDPE, or PS. 
     
     
         7 . A heat storage device as described in  claim 3 , wherein the heat storage medium can be any material having a high sensible and latent heat, and having a melting temperature between −40 deg C and 150 deg C. 
     
     
         8 . A heat storage device as described in  claim 3  wherein the heat storage density is greater than 5 Wh/liter, on a 15° C. temperature difference. 
     
     
         9 . A heat storage device as described in  claim 3  wherein the thickness of a storage element is between 5 and 25 mm. 
     
     
         10 . A heat storage device as described in  claim 3  wherein the pressure drop through a module is less than 50 Pa, with a mean airflow velocity higher than 1 m/s. 
     
     
         11 . A heat storage device as described in  claim 3  where the overall heat coefficient of exchange is higher than 12 W/m 2 /K with an mean airflow velocity less than 2 m/s.