Flat Vacuum Solar Collector Having Chamber-Type Heads

Abstract

The invention relates to a flat solar collector comprising individual vacuum chambers. The invention is formed by two heads and a series of parallel tubes having high transmittance in the solar spectrum, which is disposed between said heads. The opposite side of the heads is provided with vacuum chambers which closure the connections of the conducting tubes. One of the vacuum chambers is characterized in that it is fitted with a vacuum valve at one end thereof. In addition, conducting tubes are disposed inside the aforementioned tubes having high transmittance in the solar spectrum and said conducting tubes are in turn connected to collector plates, all under vacuum conditions which minimize convection energy losses. When the conducting tubes are configured in series, the collector can raise the temperature of the working fluid to above 200° C. All of the above is performed in a novel, simple and economical manner.

1 . A flat solar collector with vacuum chambers characterized by comprising at least two high transmittance in solar spectrum tubes, arranged in parallel, with the same diameter and length; limited on each end side by a plate comprising in its whole length a number of aligned circular punctures, with a lower diameter than the high solar spectrum transmittance pipe diameter; the plate in one of its sides, having circular slots which diameter matches with the high transmittance tube diameter; and in the opposite side they have larger slots surrounding in pairs the circular punctures; a support of low thermal conduction is located inside each high transmittance tube with a conducting tube of lower diameter than the plate circular punctures being arranged longitudinally thereon; passing through them and protruding by the plate rear side; the protruding conducting tube end sides are located in the plate rear side and connected each other by means of elbows; at least a vacuum chamber over which means to generate and recover vacuum and means for measuring a pressure level are possible to be arranged, is located in the same plate rear side matching with the larger slot. 
     
     
         2 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that heads are preferably rectangular, having 2 or more circular punctures aligned along the head; a “circular slot” surrounding each circular puncture is located in the head front side, the number of “circular slots” is equivalent to the amount of high transmittance in solar spectrum tubes used for the solar collector. 
     
     
         3 . A flat solar collector with vacuum chambers according to  claim 2 , characterized in that the “circular slots” have the same diameter than the high transmittance in solar spectrum tubes and having a depth about the same than the high transmittance tube wall width. 
     
     
         4 . A flat solar collector with vacuum chambers according to  claim 3 , characterized in that the high transmittance in solar spectrum tubes are optionally joined with grease, silicone and structural glue. 
     
     
         5 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the rear side heads have slots in larger amounts equivalent to the high transmittance in solar spectrum tubes less  1 ; said slots are inserted and joined with grease, silicone or preferably structural glue, the vacuum chambers grouping in pairs the end sides protruding from the conducting tubes and leaving without grouping the conducting tubes wherein the working fluid is entering and leaving; said vacuum chambers are arranged in a position where a set of 2 consecutive conducting tubes may be covered. 
     
     
         6 . A flat solar collector with vacuum chambers according to  claim 4 , characterized in that the number of high transmittance tubes is odd in the rear side of both heads, one of the edge bores does not include a slot, while when the number of high transmittance tubes is even, the edge bores in one of the heads is always framed by a slot while in the other head, the edge bores are not framed by a slot. Slots shall be of a similar dimension to the vacuum chambers, and with a depth approximately the same than the chamber wall width. 
     
     
         7 . A flat solar collector with vacuum chambers according to  claim 4 , characterized in that each conducting tube is covering a collector plate length and the conducting tubes stand on low or null thermal transmission supports, preferably ceramics, and said supports in turn stand on the high transmittance in solar spectrum tubes. 
     
     
         8 . A flat solar collector device with vacuum chambers according to  claim 6 , characterized in that the collector plates are located in parallel to the head top portion and being covered by a selective surface in both sides, in addition the attachment means between collector plates and conducting tubes may be of a welded, pressed, glued base or any other attachment means which efficiently transmits energy therein. 
     
     
         9 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the high transmittance tubes have preferably an outer diameter of 50 mm. 
     
     
         10 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the vacuum chambers are preferably built with glass tubes and having a bottom larger than 5 mm, with a circular, elliptic, or polygonal cross-section, preferably elliptic. 
     
     
         11 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that when the number of high transmittance tubes is odd, the conducting tube inlet and outlet transporting the working fluid are located one on each head, while when the number of high transmittance tubes is even, the conducting tube inlet and outlet transporting the working fluid are located in the same head. 
     
     
         12 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the high transmittance in solar spectrum tubes form a geometric structure providing a body to the solar collector device. 
     
     
         13 . A flat solar collector device with vacuum chambers according to  claim 1 , characterized in that the conducting tubes y and the collector plates are coated with a high monochromatic absorptivity selective surface and a low monochromatic emittance in solar spectrum or they are painted with high temperature resistant reflection preventing black paint, which allows taking advantage of the solar energy. 
     
     
         14 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the conducting tubes are attached among them by means of elbows, and the elbows are coated with a high monochromatic absorptivity selective surface or they are painted with high temperature resistant reflection preventing black paint, which allows taking advantage of the solar energy. 
     
     
         15 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that within each high transmittance in solar spectrum tube is located a conducting tube. 
     
     
         16 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the high transmittance in solar spectrum tubes are preferably of borosilicate glass but they may be of any material which efficiently transmits solar energy. 
     
     
         17 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that there is sufficient space within the vacuum chamber for conducting tube thermal expansion. 
     
     
         18 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that the joint within the vacuum chamber between the conducting tubes is carried out by means of 90° or 180° elbows. 
     
     
         19 . A flat solar collector with vacuum chambers according to  claim 1 , characterized in that vacuum is generated by means of a vacuum generating pump and being able to recover and control as required. 
     
     
         20 . A flat solar collector with vacuum chambers according to  claims 1 , characterized in that the collector device may increase the working fluid temperature up to more than 200° C. 
     
     
         21 . A flat solar collector system with vacuum chambers, characterized in that at least two flat solar collectors with vacuum chambers are serially or parallel connected according to  claims 1 . 
     
     
         22 . A flat solar collector system with vacuum chambers, characterized in that connection of flat solar collectors with vacuum chambers is performed by attaching the inlet and outlet conducting tubes.