The present invention consists of a technology to harvest solar energy to be used as an alternative energy source.
There are solar concentrators of various types [I]. The most commonly used are channel, tower-type, and parabolic concentrators. Channel concentrators do not provide a high concentration coefficient. The tower-type concentrators use a complex control system and are also expensive. Conventional parabolic concentrators are expensive because the parabolic surface comprises two components: a rigid and a flexible mirror (
Flexible mirrors are made of a special high-cost glass.
It is proposed to approximate the parabolic surface with a large number of spherical mirrors [2]. The cost of spherical mirrors is cheaper than that of parabolic mirrors though still high.
There is a concentrator that uses a large number of small flat mirrors, which approximate a parabolic surface [2] [3] [4] [5] [6]. This type of concentrator was developed by the Australian National University [5] and was used in the solar power plant “White Cliffs” in Australia. This concentrator device had a dish-shaped holder made of fiberglass. More than 2,300 flat mirrors of 100×100 mm are glued to the concave surface of the dish (
This solar concentrator had the peak concentration coefficient of 970 suns [5]. Its disadvantages are on one hand the high cost of the fiberglass support and on the other, the glue used to stick the flat mirrors reduces the accuracy of the solar concentrator.
Literature describes the solar concentrator of flat mirrors with support rods and nodes [3] [4]. The cell support is presented below.
The support device cell of the solar concentrator (
The first terminal of the first upper bar is connected to the first upper bushing, and the second terminal of this bar is connected to the second upper bushing. The first terminal of the second upper bar is connected to the second upper bushing, and the second terminal of this bar is connected to the third upper bushing. The first terminal of the third upper bar is connected to the third upper bushing, and the second terminal of this bar is connected to the first upper bushing. The first terminal of the first lower bar is connected to the first lower bushing, and the second terminal of this bar is connected to the second lower bushing. The first terminal of the second lower bar is connected to the second lower bushing, and the second terminal of this bar is connected to the third lower bushing. The first terminal of the third lower bar is connected to the third lower bushing, and the second terminal of this bar is connected to the first lower bushing. The first terminal of the first vertical bar is connected to the second lower bushing, and the second terminal of this bar is connected to the second upper bushing. The first terminal of the second vertical bar is connected to the third lower bushing and the second terminal of this bar is connected to the third upper bushing. The first terminal of the third vertical bar is connected to the first lower bushing and the second terminal of this bar is connected to the first upper bushing. The first terminal of the first diagonal bar is connected to the first lower bushing and the second terminal of this bar is connected to the second upper bushing. The first terminal of the second diagonal bar is connected to the second lower bushing and the second terminal of this bar is connected to the third upper bushing. The first terminal of the third diagonal bar is connected to the third lower bushing and the second terminal of this bar is connected to the first upper bushing. The first vertex of the mirror is connected to the first upper bushing, the second vertex of the mirror is connected to the second upper bushing, the third vertex of the mirror is connected to the third upper bushing.
The disadvantage of this prototype is that the cell supports only one flat mirror. The object of the invention is to increase the number of flat mirrors in a support cell, preserving the possibility to approximate the parabolic surface.
The present invention consist of approximate the parabolic surface with a large amount of flat mirrors [3] [4].
The cost of flat mirrors is less than that of parabolic or spherical mirrors. There is a concentrator that uses a large number of small flat mirrors that approximate a parabolic surface [3] [4]. This type of concentrator was developed at UNAM, Mexico, in 2007. This concentrator comprises a bar and nodes support device. Each support cell of this concentrator supports a triangular flat mirror of 50 mm width (
To increase the number of flat mirrors and the solar concentration factor and decrease the cost of the solar concentrator support we propose a new design of solar concentrator cell that supports four flat mirrors instead of one flat mirror in the known array. We have two options with this new array:
Each of the four mirrors has the same size as a mirror known array. Here, we obtain a larger concentration surface and relatively increase the concentration power while preserving the consumption of metallic materials (bars and nodes) to the same level as that of the known array.
The cell size does not change; we obtain four smaller mirrors than in the known array and achieve a better adjustment of the parabolic surface and a better solar concentration coefficient.
The main difference of the new array is that each upper bar of the cell contains in its center an additional upper bushing to support additional flat mirrors. This array is novel and allows the placement of four flat mirrors instead of one of the known array. This array maintains the same number of bars and nodes and can increase the number of flat mirrors four times. This feature of the new array allows an improvement of the solar concentration factor maintaining or lowering the cost preserving however, the concentration factor.
The cell proposed for the device to support the solar concentrator (
The first terminal of the first upper bar is connected to the first upper bushing, and the second terminal of this bar is connected to the second upper bushing. The first terminal of the second upper bar is connected to the third upper bushing, and the second terminal of this bar is connected to the second upper bushing. The first terminal of the third upper bar is connected to the third upper bushing, and the second terminal of this bar is connected to the first upper bushing. The first terminal of the first lower bar is connected to the first lower bushing, and the second terminal of this bar is connected to the second lower bushing. The first terminal of the second lower bar is connected to the second lower bushing, and the second terminal of this bar is connected to the third lower bushing. The first terminal of the third lower bar is connected to the third lower bushing, and the second terminal of this bar is connected to the first lower bushing. The first terminal of the first vertical bar is connected to the second lower bushing, and the second terminal of this bar is connected to the second upper bushing. The first terminal of the second vertical bar is connected to the third lower bushing, and the second terminal of this bar is connected to the third upper bushing. The first terminal of the third vertical bar is connected to the first lower bushing, and the second terminal of this bar is connected to the first upper bushing. The first terminal of the first diagonal bar is connected to the second lower bushing, and the second terminal of this bar is connected to the first upper bushing. The first terminal of the second diagonal bar is connected to the third lower bushing, and the second terminal of this bar is connected to the second upper bushing. The first terminal of the third diagonal bar is connected to the first lower bushing, and the second terminal of this bar is connected to the third upper bushing. The fourth upper bushing is connected to the center of the first upper bar. The fifth upper bushing is connected to the center of the second upper bar. The sixth upper bushing is connected to the center of the third upper bar. The first vertex of the first mirror is connected to the first upper bushing; the second vertex of the first mirror is connected to the fourth upper bushing; the third vertex of the first mirror is connected to the sixth upper bushing. The first vertex of the second mirror is connected to the fourth upper bushing; the second vertex of the second mirror is connected to the second upper bushing; the third vertex of the second mirror is connected to the fifth upper bushing. The first vertex of the third mirror is connected to the sixth upper bushing; the second vertex of the third mirror is connected to the fourth upper bushing; the third vertex of the third mirror is connected to the fifth upper bushing. The first vertex of the fourth mirror is connected to the sixth upper bushing, the second vertex of the fourth mirror is connected to the fifth upper bushing; the third vertex of the fourth mirror is connected to the third upper bushing.
To adjust the mirror positions, the solar concentrator with four flat mirrors contains bushings; each bushing contains a bolt and nut (
Is possible to increase the number of mirrors in a cell to 16 instead of four. For this purpose, we add three additional bars (
Using these additional bars we add nine additional bushings at the positions marked with circles (as examples, number 10 in
With additional bars (
Continuing this method it is possible to divide each triangular mirror in four smaller mirrors using the following equation:
F(n)=4n
where F(n) is the number of mirrors in a support cell, n is the integral number and n=0, 1, 2, 3 . . . etc., each n corresponding to a new array, n=0 is the known array, n=1 corresponding to the proposed array, for the purposes of this patent application (
The cell proposed for the device to support the solar concentrator (
Number | Date | Country | Kind |
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MX/A/2008/005063 | Apr 2008 | MX | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/MX2009/000035 | 4/15/2009 | WO | 00 | 11/1/2010 |