Solar Collector

Abstract

A solar collector is provided that concentrates solar energy for heating a medium such as air. The solar collector includes a housing with a first end wall, a second end wall and a cavity therebetween. A receiver tube is extended through the first end wall on a first end and extending longitudinally within the cavity. A receiver core member made from a metal foam material is disposed within the receiver tube. At least one mirror is arranged within the cavity opposite the receiver tube, the at least one mirror being arranged to reflect light onto the receiver tube. In one embodiment, an automated cleaning system is arranged to clean the collector cover. In another embodiment, the mirror is made from a dielectric mirror.

1 . A solar collector comprising:
 a housing having a first end wall, a second end wall and a cavity therebetween;   a receiver tube extending through said first end wall on a first end and extending longitudinally within said cavity;   a receiver core member disposed within said receiver tube, said receiver core member being made from a porous material; and,   at least one mirror arranged within said cavity opposite said receiver tube, said at least one mirror being arranged to reflect light onto said receiver tube.   
     
     
         2 . The solar collector of  claim 1  wherein said first end wall includes at least one opening. 
     
     
         3 . The solar collector of  claim 2  wherein said receiver tube has a second end opposite said first end, said second end being arranged a predetermined distance from said second end wall to define a gap. 
     
     
         4 . The solar collector of  claim 3  wherein said receiver tube is made from borosilicate glass. 
     
     
         5 . The solar collector of  claim 4  wherein said receiver core member is made from a steel foam material. 
     
     
         6 . The solar collector of  claim 5  further comprising a cover coupled to one side of said housing adjacent said receiver tube. 
     
     
         7 . A solar collector comprising:
 a parallelepiped housing having a first end wall with at least one first opening, a second end wall and a pair of sides therebetween, said first end wall, said second end wall and said pair of sides defining a cavity;   at least one first mirror arranged on one side of said cavity;   a cover arranged on a side of said cavity opposite said at least one first mirror; and,   a receiver coupled to said first end wall and extending longitudinally within said housing, said receiver having a second opening within said cavity adjacent said second end wall.   
     
     
         8 . The solar collector of  claim 7  further comprising a porous metal core member disposed within said receiver between said second opening and said first end wall. 
     
     
         9 . The solar collector of  claim 8  wherein:
 said porous metal core member is a metal foam material having a black oxide coating; and, 
 said receiver is a tube made from borosilicate glass. 
 
     
     
         10 . The solar collector of  claim 9  wherein said metal foam core member is made from a steel foam material. 
     
     
         11 . The solar collector of  claim 7  further comprising a second mirror extending longitudinally within said cavity opposite said at least one first mirror, wherein said receiver is arranged between said at least one first mirror and said second mirror. 
     
     
         12 . A method of operating a solar collector comprising:
 reflecting light off a mirror towards a focal point;   providing a receiver tube at said focal point;   providing a core made from a porous metal within said receiver tube;   heating said core with said reflected light; and,   flowing a heat transfer medium through said core.   
     
     
         13 . The method of  claim 12  further comprising providing a housing, said mirror being arranged on one side of said housing and said focal point being arranged on a second side of said housing, said housing having a first end wall and a second end wall, said receiver tube extending through said first end wall, wherein said receiver tube includes a first opening adjacent said second end wall. 
     
     
         14 . The method of  claim 13  wherein said heat transfer medium is air. 
     
     
         15 . The method of  claim 14  further comprising flowing air through at least one second opening in said first end wall. 
     
     
         16 . The method of  claim 15  further comprising heating said air with radiated heat from said receiver tube. 
     
     
         17 . A solar collector comprising:
 a housing having a first end wall, a second end wall and a cavity therebetween;   a receiver tube extending through said first end wall on a first end and extending longitudinally within said cavity; and,
 at least one mirror arranged within said cavity opposite said receiver tube, said at least one mirror being arranged to reflect light onto said receiver tube, wherein said at least one mirror is a dielectric mirror. 
   
     
     
         18 . The solar collector of  claim 17  wherein said at least one mirror includes at least one layer of silica and at least one layer silicon. 
     
     
         19 . The solar collector of  claim 18  wherein said at least one mirror has a reflectivity efficiency of greater than 99.99%. 
     
     
         20 . The solar collector of  claim 19  further comprising a receiver core member disposed within said receiver tube, said receiver core member being made from a metal foam.