Focal display panel for visual optimization of solar collection

Abstract

A focal display panel is situated in a parabolic solar energy collection array having reflective surfaces and a tube containing a working fluid to be heated. The panel comprises a target area to display patterns of light and shadow reflected from the array, and provides a visual means for determining the amount, if any, by which the focal point of the parabolic array misses the center of the tube containing the heated working fluid.

What is claimed is: 
     
         1 . In a solar energy collection array having reflective surfaces and a tube containing a working fluid, a focal display panel comprising:
 a target area, a spillage area, and mounting means for securing said focal display panel with respect to said array and said tube,   said focal display panel forming a cavity extending at least partially around said tube,   said focal display panel being situate to display patterns of light and shadow reflected from said array whereby a focal area formed by sunlight and shadow reflected from said array is visible on said display panel.   
     
     
         2 . The focal display panel of  claim 1  wherein said target area is predominantly flat, and said spillage area extends beyond said target area in a direction opposite said array. 
     
     
         3 . The focal display panel of  claim 2  wherein said spillage area is bent at an angle relative to the plane of said target area. 
     
     
         4 . The focal display panel of  claim 3  wherein the angle of the spillage area relative to the plane of the target area is an obtuse angle. 
     
     
         5 . The focal display panel of  claim 4  wherein the obtuse angle of the spillage area relative to the plane of the target area is at least 135 degrees. 
     
     
         6 . The focal display panel of  claim 4  wherein the obtuse angle of the spillage area relative to the plane of the target area is at most 135 degrees. 
     
     
         7 . The focal display panel of  claim 1  wherein said focal display panel is affixed to supports holding a said tube within said solar energy collection array. 
     
     
         8 . The focal display panel of  claim 7  wherein said focal display panel is wider than said support structure which holds said tube. 
     
     
         9 . The focal display panel of  claim 1  wherein, when light reflected from said array is focused upon said tube, said panel displays a shadow region that is symmetric on said target area and when light reflected from said array is not focused upon said tube, said panel displays a shadow region that is not symmetric on said target area. 
     
     
         10 . In a solar energy collection array, a method of focusing reflected solar energy in relation to a tube carrying working fluid comprising the steps of:
 (a) providing a movable linear array of reflective panels facing inwardly to form a substantially parabolic trough, said linear array being movable to align said substantially parabolic trough with parallel rays of direct sunlight during at least some daylight hours;   (b) suspending a tube carrying working fluid linearly along the focal axis of said substantially parabolically trough;   (c) affixing a focal display panel having a target area about said tube such that said focal display panel extends between said tube and said reflective panels and beyond said tube in a direction away from said reflective panels;   (d) directing said movable array toward incoming direct sunlight;   (e) observing on said focal display panel the position of the apex of a shadow caused by the reflection of sunlight around said tube; and   (f) positioning said movable array to cause said apex of said shadow to fall upon a predetermined position on said focal display panel.   
     
     
         11 . The method of  claim 10  wherein said predetermined position is based upon at least a determination of the angular velocity of the source of sunlight with respect to said focal axis of said substantially parabolic trough and the frequency and precision with which said movable linear array can be adjusted. 
     
     
         12 . The method of  claim 10  wherein said predetermined position is based upon at least a determination of the angular velocity of the source of sunlight with respect to said focal axis of said substantially parabolic trough and the length of time said substantially parabolic trough will be stationary between repositioning adjustments. 
     
     
         13 . The method of  claim 10  further comprising the step of repeating steps (d), (e) and (f) at regular intervals. 
     
     
         14 . The method of  claim 10  further comprising the step of repeating steps (d), (e) and (f) at predetermined times throughout a day. 
     
     
         15 . The method of  claim 10  further comprising the step of (e) repeating steps (d), (e) and (f) continuously. 
     
     
         16 . The method of  claim 10  wherein said focal display panel further comprises a target area and a spillage area. 
     
     
         17 . The method of  claim 16  wherein said target area of said focal display panel forms a plane, and said spillage area of said focal display panel is bent relative to said plane of said target area such that said spillage area forms an obtuse angle with said plane of said target area. 
     
     
         18 . The method of  claim 17  further comprising the steps of (g) generating data for computing an angle of difference between the instantaneous position of said substantially parabolic trough and a position that would cause said parabolic trough to focus incoming sunlight on said working fluid tube; (h) determining said angle of difference; and (i) causing said substantially parabolic trough to be moved to a predetermined position relative to said angle of difference. 
     
     
         19 . The method of  claim 18  further comprising the step of using a fuzzy logic algorithm to orient said substantially parabolic trough whenever said angle of difference exceeds a predetermined amount. 
     
     
         20 . A solar energy collector comprising:
 An array comprising at least one reflective surface and a working fluid;   a focal display panel comprising a target area and a spillage area, wherein:
 the panel indicates a focal area of said array; 
 the panel forms a cavity extending at least partially around said working fluid, 
 the panel is situated to display patterns of light and shadow reflected from said array whereby a focal area formed by light and shadow reflected from said array is visible on said panel.