System for heating liquid by solar radiation

Abstract

A system for heating liquid using solar radiation, includes a plurality of solar panels ( 1, 2, 3, 4, 5 ), at least one reservoir for heated liquid and pipes for circulating liquid between the respective solar panel and the at least one liquid reservoir, the liquid circulating by gravity circulation. The present system is characterised in that a non-return valve ( 17 ) for controlling the flow of heated liquid from the respective solar panel is placed in a portion of the circulation pipe between the upper end of the solar panel and the at least one liquid reservoir, the non-return valve ( 17 ) being adapted to open and close at a predetermined pressure in the liquid flow from the solar panel.

1 . A system for heating liquid by solar radiation, comprising a plurality of solar panels ( 1 ,  2 ,  3 ,  4 ,  5 ), at least one reservoir ( 6 ) for heated liquid and pipes ( 7 ,  8 ;  9 ,  10 ,  11 ) for circulating liquid between the respective solar panel and the at least one liquid reservoir, the liquid circulating by gravity circulation, characterised in that a non-return valve ( 17 ) for controlling the flow of heated liquid from the respective solar panel is located in a portion of the circulation pipe between the upper end of the solar panel and the at least one liquid reservoir, the non-return valve ( 17 ) being adapted to open and close at a predetermined pressure in the liquid flow from the solar panel.  
     
     
         2 . A system according to  claim 1 , characterised in that the non-return valve ( 17 ) comprises a valve seat ( 18 ;  37 ) with a central fluid opening, a movable float body ( 19 ;  33 ,  34 ) for opening and closing the fluid opening and a spindle ( 20 ;  35 ) for controlling the movement of the float body.  
     
     
         3 . A system according to  claim 2 , characterised in that the float body is in the form of a thin disc ( 33 ) that has an outer element ( 34 ) of greater thickness, the thickness of the element being variable.  
     
     
         4 . A system according to  claim 1 , characterised in that the at least one liquid reservoir ( 6 ) has a large height relative to its dimensions in cross-section.  
     
     
         5 . A system according to  claim 1 , characterised in that the circulation pipes for the liquid form part of a flow circuit that is open to the respective liquid reservoir, and which consists of flow channels ( 21 ) in the respective solar panel and pipes ( 7 ,  8 ) which respectively convey the liquid from the upper end of the solar panel to the upper end of the liquid reservoir and back from the lower end of the liquid reservoir to the lower end of the solar panel.  
     
     
         6 . A system according to  claim 1 , characterised in that the circulation pipes for the liquid form part of a flow circuit that is closed to the respective liquid reservoir, and which consists of flow channels ( 21 ) in the respective solar panel and pipe sections ( 9 ,  10 ,  11 ) which respectively convey the liquid from the upper end of the solar panel, through the respective liquid reservoir and back to the lower end of the solar panel.  
     
     
         7 . A system according to  claim 1 , characterised in that at least two solar panels ( 1 ,  2 ) are joined together along their adjacent lateral edges ( 12 ,  14 ) and their outer, free lateral edges ( 13 ,  15 ) are positioned in such relationship to each other that a space can be formed between the solar panels for accommodating the at least one liquid reservoir and the circulation pipes.  
     
     
         8 . A system according to  claim 7 , characterised in that the upper end of the solar panels ( 1 ,  2 ) that form the side walls of the formed space slant downwards in the direction of the joined lateral edges ( 12 ,  14 ) and are covered by a solar panel ( 3 ) placed on top of the joined solar panels.  
     
     
         9 . A system according to  claim 1 , characterised in that a solar panel ( 4 ,  5 ) extends out from and is joined to the free lateral edge ( 13 ,  15 ) of the respective joined solar panels ( 1 ,  2 ).  
     
     
         10 . A system according to  claim 1 , characterised in that at least one sunlight reflector ( 16 ) is placed directly on and/or at a distance from the solar panel or panels in question.