High efficiency conversion of solar radiation into thermal energy

Abstract

A high-efficiency solar radiation collection and conversion system is described. An array of evacuated collector tubes each includes two or more inner heat pipes that capture the solar energy and conduct it as heat through a condenser portion into a manifold that operates as part of a closed-loop circulation system. In another part of the loop, a heat exchanger transfers the heat into a hot-water holding tank or otherwise applies the heat energy in the circulating fluid.

1 . A solar energy collection system, comprising:
 an elongated, substantially cylindrical, transparent outer tube comprising an outer cylinder and an inner cylinder, wherein
 the outer and inner cylinders are transparent and substantially axially concentric, 
 the space between the outer and inner cylinders is evacuated, 
 the ends of the outer cylinder form an air-tight connection with the corresponding ends of the inner cylinder such that the evacuated space remains evacuated, and 
 one end of the outer tube is closed; 
   a first and a second heat pipe, each comprising a collection portion and a condenser portion, the collection portion being substantially contained within the outer tube;   a circulation path, comprising:
 a manifold in heat-conducting communication with an end of each of the first and second heat pipes; and 
 a load for using heat energy. 
   
     
     
         2 . The system of  claim 1 , wherein the first and second heat pipes each:
 comprise a collection portion and a condenser portion, the condenser portion being the end in communication with the manifold;   are evacuated; and   contain a first fluid.   
     
     
         3 . The system of  claim 1 , wherein a second fluid passes through the circulation path. 
     
     
         4 . The system of  claim 3 , wherein the circulation path is a closed-loop path through which the second fluid is driven by a pump. 
     
     
         5 . The system of  claim 3 , wherein the second fluid comprises water. 
     
     
         6 . The system of  claim 1 , wherein at least a portion of the first and second heat pipes are made of copper. 
     
     
         7 . The system of  claim 1 , wherein the first fluid comprises water. 
     
     
         8 . The system of  claim 1 , wherein the outer and inner cylinders are made of borosilicate glass. 
     
     
         9 . The system of  claim 8 , wherein the inner cylinder is coated with AIN/AI. 
     
     
         10 . The system of  claim 1 , further comprising a third heat pipe that is contained within the outer tube and is in heat-conducting communication with the manifold. 
     
     
         11 . A method of manufacturing a solar collector, comprising:
 placing two or more heat pipes, each having a collection portion and a condenser portion, and each being adapted to move heat from the collection portion to the condenser portion, in heat-transfer communication with a manifold; and   placing an evacuated tube around the collection portion of the two or more heat pipes, where the evacuated tube comprises an inner cylinder and an outer cylinder, the outer cylinder being substantially transparent, the inner cylinder defining an internal volume that contains the two or more heat pipes, and the ends of the inner cylinder a the outer cylinder being sealed to define an evacuated space;   such that the condenser portion of each heat pipe is elevated in relation to the collection portion.   
     
     
         12 . The method of  claim 11 , further comprising connecting the manifold to a load for using heat energy in a closed circulation path, wherein a second fluid passes through the circulation path. 
     
     
         13 . The method of  claim 12 , wherein the circulation path is a closed-loop path through which the second fluid is driven by a pump. 
     
     
         14 . The method of  claim 12 , wherein the second fluid comprises water. 
     
     
         15 . The method of  claim 11 , wherein at least a portion of the first and second heat pipes are made of copper. 
     
     
         16 . The method of  claim 11 , wherein the first fluid comprises water. 
     
     
         17 . The method of  claim 11 , wherein the outer and inner cylinders are made of borosilicate glass. 
     
     
         18 . The method of  claim 17 , wherein the inner cylinder is coated with AIN/AI. 
     
     
         19 . The method of  claim 11 , further comprising a third heat pipe that is contained within the outer tube and is in heat-conducting communication with the manifold.