Solar thermal collector

Abstract

The invention relates to a solar thermal collector for heating a fluid to be heated ( 600 ), comprising:—a thermally insulating body ( 1 );—a light transparent barrier ( 2 );—a heat accumulator ( 3 ) comprising a thermal accumulating material ( 30 ), and—a heat exchanger ( 5 ) designed for transmit thermal energy from the thermal accumulating material to the fluid to be heated ( 600 ), wherein heat exchanger ( 5 ) is formed by a pileup of die-forged metal sheets and wherein the thermal accumulating material consists of a phase transfer material comprising a salt solutions based hydrogel and gelling agents.

1 . A solar thermal collector for heating a fluid to be heated ( 600 ), comprising
 a thermally insulating body ( 1 ),   a light transparent barrier ( 2 ),   a heat accumulator ( 3 ) comprising a thermal accumulating material ( 30 ), and   a heat exchanger ( 5 ) designed for transmit thermal energy from the phase transfer material to the fluid to be heated ( 600 ),   wherein heat exchanger ( 5 ) is formed by a pileup of die-forged metal sheets and wherein the thermal accumulating material comprises a salt solutions based hydrogel and gelling agents.   
     
     
         2 . A solar thermal collector according to  claim 1 , wherein at least one surface of the heat accumulator ( 3 ) is coated with a selectively light-absorbing material ( 4 ). 
     
     
         3 . A solar energy collector according to  claim 1  or  2 , wherein the thermal accumulating material comprises a sodium acetate solution in distilled water (acetate trihydrate) with a gelling agent. 
     
     
         4 . A solar energy collector according to any of  claims 1  to  3  wherein the gelling agent comprises a solution of carboxymethyl cellulose (CMC) and/or a solution of polyvinylpyrollidon (PVP) and/or a solution of sodium laureth sulphate and/or carrageenan. 
     
     
         5 . A solar energy collector according to any of  claims 1  to  4  wherein the thermal accumulating material comprises a coating of high coefficient thermal dilatation material. 
     
     
         6 . A solar energy collector according to  claim 5 , wherein the high coefficient thermal dilatation material comprises paraffin. 
     
     
         7 . A solar energy collector according to any of  claims 1  to  6  wherein it further comprises metal bars ( 70 ) thermally linked to thermally insulating body ( 1 ). 
     
     
         8 . A solar energy collector according to  claim 7  wherein it further comprises metal ribs ( 72 ) thermally linked to the metal bars ( 70 ). 
     
     
         9 . Window comprising at least a solar energy collector according to  claim 8  wherein the metal ribs ( 72 ) are in the form of louvers.