Patent Application
20140060647
The present invention relates generally to a homogenizer with fixing structure, and particularly to a homogenizer in a concentrator-type photovoltaic receiver.
Concentrator-type photovoltaic power generation acquires photo energy via a contractor-type photovoltaic receiver and enhances power generating efficiency by concentrating a great deal of photo energy. When solar energy is focused by the Fresnel lens, it will enter a transparent light-guiding pillar with a shape close to an upside-down pyramid, namely, a homogenizer. The bottom side of the homogenizer is a smooth surface with a main function of evening the energy of the light spot focused by the Fresnel lens. If the energy of the light spot is not evened by the homogenizer but illuminated directly on the solar cell, due to excess concentration of energy, the optoelectronic conversion efficiency is not well. In addition, because the incident angle of sunlight is not fixed but varies instantly with time, a tracker system is required for a concentrator-type solar-cell module. The tracker system will adjust to the optimum angle instantly according to the sunlight angle. The function of the homogenizer here is to improve the tolerance in angle of the tracker system as well as in dimensions during assembling. Thereby, it is an extremely important and functional device.
Currently, the homogenizer is still assembled manually. Owing to its functional requirement, the homogenizer is an inverted-pyramid-shaped device with a wide top and a narrow bottom. With the top-heavy property, it's difficult to control the accuracy during bonding. In other words, the homogenizer is bonded on the solar cell by glue, which is a sticky fluid before drying off. Thereby, before hardening, the homogenizer located on the glue tends to tilt slightly by external force. Or it tilts during manual assembly and topples gradually before the glue is hardened. Even if the homogenizer is tilted but not toppled over, during subsequent practical operations, it is no guarantee that the tracker system will not collapse under rotation.
In addition to the tilt and collapse problem, how to maintain surface cleanness of a homogenizer is another major problem. Because a homogenizer makes the incident light to reach uniformly and completely the concentrator-type solar cell at the bottom by means of internal total reflection, the cleanness of its side surface is the key point. If dirt or moisture exists on the surrounding surface of a homogenizer, total reflection will be destroyed, leading to light leakage and loss.
Besides, the contact interface of a homogenizer and glue contact may be the critical place where light leakage occurs. During manual assembly of a homogenizer, if the homogenizer is pressed excessively on the glue to make the homogenizer deep into the glue, the glue will be squeezed and pushed to the bottom surface of sides of the homogenizer and hence resulting in glue spill. Glue spill will cause loss in light energy. Consequently, the light energy reaching the concentrator-type solar cell is reduced and thus lowering the efficiency.
Refer to
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Accordingly, because the instability of a homogenizer during gluing may introduce defects for a concentrator-type photovoltaic receiver, the present invention provides a concentrator-type photovoltaic receiver having homogenizer with fixed structure for solving the problem.
An objective of the present invention is to provide a concentrator-type photovoltaic receiver having homogenizer with fixed structure. The integrally-formed homogenizer has the function of isolating dirt, and hence extending the lifetime and quality of the concentrator-type photovoltaic receiver.
Another objective of the present invention is to provide a concentrator-type photovoltaic receiver having homogenizer with fixed structure. No extra frame to the homogenizer is required for assisting supporting the homogenizer. Thereby, the space occupied by a single photovoltaic receiver can be reduced.
Still another objective of the present invention is to provide a concentrator-type photovoltaic receiver having homogenizer with fixed structure. The homogenizer has an integrally-formed supporting structure, so that the originally unstable homogenizer can be fixed on the concentrator-type solar cell with certainty. Thereby, the stability of the concentrator-type photovoltaic receiver can be enhanced.
Still another objective of the present invention is to provide a concentrator-type photovoltaic receiver having homogenizer with fixed structure. The assembly is simple. In addition to more rapid assembly than the homogenizer according to the prior art, the assembly quality is also ensured.
For achieving the objectives described above, the present invention discloses a concentrator-type solar cell, glue, and a homogenizer. The glue is disposed on the concentrator-type solar cell; and the homogenizer is disposed on the glue. The homogenizer comprises a supporting part and a homogenizing part. The supporting part is a transparent hollow pillar, and further connects with an insulating substrate under the concentrator-type solar cell. The homogenizing part is a solid transparent body with its top wider than the bottom and disposed on the concentrator-type solar cell and at the center of the supporting part. A top-wide region of the homogenizing part connects with a top of the supporting part. Under such a structure, it is convenient to glue the homogenizer. In addition, tilt or collapse will not occur after gluing; the cleanness of the homogenizer can be maintained as well. Thereby, the bonding efficiency, the performance, and the lifetime of the homogenizer can be enhanced simultaneously.
In order to make the structure and characteristics as well as the effectiveness of the present invention to be further understood and recognized, the detailed description of the present invention is provided as follows along with embodiments and accompanying figures.
It is possible to produce defects during the bonding process of the homogenizer according to the prior art. Accordingly, for overcoming the technical defects, the present invention is provided for improving and solving the problems.
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The structure of the homogenizing part 32 is not limited to the inverted trapezoidal pillar; it could be a paraboloidal surface, similar to a bullet, or a semi-spherical body. Nonetheless, in general, the structure is a solid transparent body with its top wider than the bottom. Thereby, in order to be formed integrally with the supporting part 31, the homogenizing part 32 is located at the center of the supporting part 31. The top-wide region 321 is connected with the top 311 of the supporting part 31.
For the details of the structure, the metal conductive layer 12 cab be further divided into a first metal conductive layer 121 and a second metal conductive layer 122. The concentrator-type solar cell 11 is disposed on the first metal conductive layer 121. The electrodes at the bottom of the concentrator-type solar cell 11 are connected directly with the first metal conductive layer 121. In addition, the concentrator-type solar cell 11 is also connected electrically with the second metal conductive layer 122 via a plurality of metal wires 14 and hence forming a complete circuit. Moreover, the first and second metal conductive layers 121, 122 are connected with external circuitry and thus leading out electrical energy.
In addition to the bonding method described above,
Without the assistance of the supporting part 31, the homogenizing part 32, which is top-heavy because of its top-wide and bottom-narrow structure, is difficult to be stabilized and fixed on the glue 2. Besides, it is also hard to maintain its horizontal position. By forming integrally with the supporting part 31, the bonding effect is enhanced by the help of the supporting part 31 and the homogenizing part 32 can stand stably on the concentrator-type solar cell 11.
The shape of the supporting part 31 can be designed freely as a cylindrical pillar, a square pillar, or a polyhedral pillar depending on the shape of the homogenizing part 32, as long as the shape of the homogenizer 32 is a straight central pillar.
In the homogenizer 3, the heights of the supporting part 31 and the homogenizing part 32 are already fixed. Thereby, during assembling, the contact condition between the bottom of the homogenizing part 32 and the glue 2 can be stably controlled. Thereby, glue spill, caused by excessive reach of the homogenizing part 32 into the glue 2 and by pushes and squeezes of the glue 2 to the side surface of the homogenizing part 32, can be avoided. Consequently, the situation of light leakage caused by glue spill can be prevented accordingly.
Finally, in order to make the light pass through the homogenizer 3 and the glue 2 after being focused by Fresnel lens and reach the concentrator-type solar cell 11 smoothly, the material of the homogenizer 3 can be transparent high-polymer synthesized resin, glass, or quartz. The fabrication method is not limited. No matter die casting, grinding, molding, or ejection, once it's cost effective, the fabrication method can be adopted. Moreover, the glue 2 is insulating glue pervious to light. Thereby, conduction of the circuit of various conductive devices will not be affected by adherence of the glue 2.
The homogenizer in the concentrator-type photovoltaic receiver having homogenizer with fixing structure according to the present invention can have a better bonding result during assembling. The top-heavy homogenizer can be stable and not easy to collapse during the operation of a tracker system and thus extending the lifetime. In addition, the homogenizing part of the homogenizer can be protected from pollution of outdoor dirt. Moreover, because it is not required to fine-tune the locations of the homogenizer and the undried glue, manpower and time can be saved, leading to tremendous increase in assembling efficiency. Thereby, the present invention provides a concentrator-type photovoltaic receiver having substantial economic values.
Accordingly, the present invention conforms to the legal requirements owing to its novelty, nonobviousness, and utility. However, the foregoing description is only embodiments of the present invention, not used to limit the scope and range of the present invention. Those equivalent changes or modifications made according to the shape, structure, feature, or spirit described in the claims of the present invention are included in the appended claims of the present invention.
