PARABOLIC CONCENTRATING SOLAR COLLECTOR

Abstract

The element on which solar radiation is concentrated, specifically, a vacuum tube, remain static at all times with respect to the movements that a parabolic reflective surface may make according to the direction of solar radiation, such that inlet and outlet pipes of the vacuum tube do not need to be articulated, which facilitates the installation and insulation thereof and reduces production costs. The parabolic reflective surface can pivot 360° with respect to the vacuum tube without interfering with the pipes, allowing an active safety system for protecting against strong winds and preventing overheating to be produced, in addition to allowing the surfaces to be cleaned by means of nozzles spray pressurized water. The collector also includes passive safety means against strong winds.

Claims

1. A parabolic concentrating solar collector, which being of the type that includes a parabolic reflective surface associated with programmed and/or calculated solar tracking means in real time, as well as an element on which solar radiation is concentrated, wherein the element on which solar radiation is concentrated is made of a vacuum tube, with its corresponding duly insulated inlet and outlet of fluid to be heated, with the particularity that the vacuum tube is statically arranged on a frame, having envisaged that the parabolic reflective surface includes complete and controlled pivoting means with respect to the imaginary central longitudinal axis of the vacuum tube, in which bushings or bearings through which the pipes associated with the inlet and outlet of the vacuum tube pass participate, not being affected by the angular movements of the parabolic reflective surface, with the particularity that the chamber through which the fluid to be heated circulates in the vacuum tube is subdivided into two concentric chambers, an internal chamber, through which the cold fluid is fed, open at one of its ends through which it communicates with an external chamber, concentric to it, on which solar radiation is concentrated inside the vacuum tube, having envisaged that the inlet section to the internal chamber is the same as the outlet section of the external chamber and wherein the parabolic reflection surface includes passive safety means against strong winds, made up of sectors, of a reflective nature, as folding gates with respect to axes against the tension of a spring.

2. The parabolic concentrating solar collector, according to claim 1, wherein a helical deflector is arranged between the internal chamber and the external chamber of the vacuum tube.

3. The parabolic concentrating solar collector, according to claim 1, wherein the parabolic reflective surface is linked to the structure of the vacuum tube through its lateral ends by means of arms that converge in a bearing or bushing axial to the imaginary central longitudinal axis of the vacuum tube, having envisaged that in correspondence with the inlet and outlet of the vacuum tube, the arms are integral with a ring, which is in turn integral with a toothed wheel with which a pinion associated with a small electric motor engages, integral with the structure associated with the vacuum tube.

4. The parabolic concentrating solar collector, according to claim 1, wherein the frame incorporates nozzles that spray pressurized water against the parabolic reflective surface.

5. The parabolic concentrating solar collector, according to claim 1, wherein a Fresnel-type concentrator lens is arranged on the area of the vacuum tube that is not affected by the parabolic reflective surface, lens which is integral with the bearing structure of said parabolic reflective surface.

6. The parabolic concentrating solar collector, according to claim 1, wherein the vacuum tube and consequently the parabolic reflective surface adopt a horizontal arrangement with respect to their longitudinal axis.

7. The parabolic concentrating solar collector, according to claim 1, wherein the vacuum tube and consequently the parabolic reflective surface adopt a vertical arrangement with respect to their longitudinal axis.

8. The parabolic concentrating solar collector, according to claim 1, wherein it participates in installations together with other collectors of the same type, all of them controlled through a single control electronics, so that it includes means for enabling and disabling some and other collectors in order to adapt to the changing requirements that said installation may have.

9. The parabolic concentrating solar collector, according to claim 1, wherein it includes at least one photovoltaic panel for electrically powering the control electronics of the collector.

10. The parabolic concentrating solar collector, according to claim 1, wherein one of the end support frames of the device has a scissor-type structure, adjustable by means of a transverse worm screw, which threads into respective nuts associated with the intermediate joints of the scissor structure, and which is controlled by an electric motor linked to the control electronics of the device.

11. (canceled)

Description

DESCRIPTION OF THE DRAWINGS

[0031] As a complement to the description that will be provided herein, and for the purpose of helping to make the features of the invention more readily understandable, according to a preferred practical exemplary embodiment thereof, said description is accompanied by a set of drawings constituting an integral part thereof in which, by way of illustration and not limitation, the following is represented:

[0032] FIG. 1 shows a plan view of a parabolic concentrating solar collector made according to the object of the present invention.

[0033] FIG. 2 shows a profile view of the device of the previous figure.

[0034] FIG. 3 shows a view similar to that of the previous figure, but in which the parabolic reflective surface has changed its inclination to its safety/inoperative position that coincides with the washing position, being able to observe how the vacuum tube is not affected by such movement.

[0035] FIG. 4 shows a profile view of the device, in which it appears with its passive safety means in a working situation.

[0036] FIG. 5 shows a sectional detail of the new internal structure envisaged for the vacuum tube that participates in the device of the invention.

[0037] FIG. 6 shows a detail of one of the end support frames of the device.

PREFERRED EMBODIMENT OF THE INVENTION

[0038] In view of the figures described, it can be seen how the parabolic concentrating solar collector of the invention is comprised of a parabolic reflective surface (1) and an element on which solar radiation is concentrated, in this case a tube vacuum tube (2), with its corresponding inlet (3) for water or fluid to be heated and outlet (4) for hot fluid, with the particularity that the vacuum tube (2) is statically arranged on a frame (5), in other words, integral with said frame, being linked to it at both ends.

[0039] For its part, and contrary to what occurs with the usual parabolic concentrating collectors, it has been envisaged that the parabolic reflective surface (1) pivots with respect to the imaginary central longitudinal axis (6) of the vacuum tube (2).

[0040] More specifically, said parabolic reflective surface (1) is linked through its lateral ends with arms (7) that converge in a bearing or bushing whose axis, as mentioned, is axial to the imaginary central longitudinal axis of the vacuum tube, so that in correspondence with the inlet and outlet (3-4) of the vacuum tube, it has been envisaged that said arms are integral with a ring (8), which is linked to the structure of the vacuum tube (2) through a bushing or bearing, a ring with which a toothed wheel (9) is integral, wheel with which a pinion (10) associated with a small electric motor (11) engages, integral with the structure associated with the vacuum tube (2) itself.

[0041] This structure allows the parabolic reflective surface (1) to rotate 360° with respect to the vacuum tube without interfering with the pipes associated with the inlet (3) and the outlet (4), which allows said parabolic reflective surface (1) to rotate to the position shown in FIG. 3, or any other active safety position depending on the direction of the wind, which will be controlled by a microprocessor and the corresponding conventional control/sensor means, and can also be used to generate shade on the vacuum tube itself, when the temperatures reached therein may be excessive.

[0042] In order to maximise performance in heat transmission in the vacuum tube (2), it has been envisaged that it has a completely new structure, as shown in FIG. 5, so that the chamber through which the heat transfer fluid to be heated circulates is subdivided into two concentric cylindrical chambers, an internal chamber (19), through which the cold fluid is intended to flow, open at one of its ends through which it communicates with an external chamber (20), concentric to it, on which solar radiation is concentrated inside the vacuum tube, with the particularity that for a better distribution of the heat transfer fluid inside said chamber, it has been envisaged that there is a helical deflector (21) therein which forces the heat transfer fluid to rotate on the heat concentrating surface in its movement towards the outlet of said vacuum tube.

[0043] In this sense, and as mentioned previously, the section of the inlet to the internal chamber (19) must be the same as the outlet section of the external chamber (20) so that no pressure differences are created.

[0044] Returning again to FIG. 3, it has been envisaged that the frame (5) incorporates nozzles (12) that spray pressurised water, which allow the parabolic reflective surface (1) to be automatically washed, either periodically or in a programmed manner, or when it is calculated that its performance is not what it would correspond to based on the parameters obtained by the sensor means associated with the collector.

[0045] As mentioned previously, the collector will be able to auto-orient itself using any known auto-orientation system, based on the calculation of the angle of incidence of the sun, being assisted by one or more photovoltaic panels that ensure its complete autonomy.

[0046] Furthermore, the collector can also be inclined on one of its ends to control the azimuth. To do this, and as shown in FIG. 6, one of the end support frames of the device has a scissor-type structure (5′-5″), adjustable by means of a transverse worm screw (16), which threads into respective nuts (17) associated with the intermediate joints of the scissor structure, and which will be controlled by an electric motor (18) associated with the control electronics of the device.

[0047] According to FIG. 4, it has been envisaged that the parabolic reflective surface (1) includes a series of sectors (13) in its central area which, also being reflective in nature, act as folding gates with respect to the axes (14) against the tension of a spring, thus determining passive safety means against strong gusts of wind (15).

[0048] Although it is not shown in the figures, a Fresnel-type concentrator lens can be arranged on the area of the vacuum tube (2) that is not affected by the parabolic reflective surface (1), lens which would be integral with the bearing structure of the parabolic reflective surface (1) in order to never interfere with it.