WO2009025002A1

WO2009025002A1 - Heat exchanger for solar energy generators

Info

Publication number: WO2009025002A1
Application number: PCT/IT2007/000591
Authority: WO
Inventors: Reginald Ian Williams
Original assignee: Reginald Ian Williams
Priority date: 2007-08-21
Filing date: 2007-08-21
Publication date: 2009-02-26

Abstract

A heat exchanger comprising one or more ducts (1) suitable for being exposed to a source of solar rays (2) and for containing a fluid to be heated with the energy transmitted by these rays (2), as well as a plurality of fins (4) arranged transversely with respect to the ducts (1) and provided with holes to be crossed by the latter, further includes a plurality of inserts (5) arranged to the inside with respect to the ducts (1) and connecting pairs of adjacent fins (4). The arrangement and shape of the inserts (5) allow to absorb in an optimal manner not only the energy directly transmitted by the solar rays hitting the fins (4), but also the energy, even if very low, reflected by these fins (4), and the protected position of the inserts (5) inside the exchanger case prevents or at least minimizes the dissipation of heat by convection caused by possible air streams touching the surface of the exchanger.

Description

HEAT EXCHANGER FOR SOLAR ENERGY GENERATORS

The present invention relates to a heat exchanger for solar energy generators, and in particular to a heat exchanger which can be employed in the collectors receiving the solar rays from the reflectors of these generators.

The known heat exchangers for solar energy generators generally comprise one or more ducts which are arranged with the longitudinal axis substantially perpendicular with respect to the solar rays and which are crossed by a fluid to be heated with the energy transmitted by these rays. The efficiency of the heat exchange between the outer surface of the ducts and the fluid flowing therein depends on many factors, among which the shape, the material and the size of the same ducts.

It is therefore an object of the present invention to improve the efficiency of the known heat exchangers. Said object is achieved with a heat exchanger, the main features of which are disclosed in the first claim and other features are disclosed in the subsequent claims.

Thanks to the particular inserts which internally connect the fins with which it is provided, the heat exchanger according to the present invention has a high efficiency in absorbing the solar energy. As a matter of fact, the arrangement and the "funnel" shape of said inserts allows to absorb in an optimal manner not only the energy directly transmitted by the solar rays hitting the fins, but also the energy, even if very low, reflected by these fins.

Furthermore, the protected position of the inserts inside the exchanger case prevents or at least minimizes the dissipation of heat by convection caused by possible air streams touching the surface of the exchanger. Further advantages and features of the heat exchanger according to the present invention will become clear to those skilled in the art from the following detailed and non-limiting description of an embodiment thereof with reference to the attached drawings, wherein:

- figure 1 shows a partial internal perspective view of the heat exchanger; - figure 2 shows a partial longitudinal and enlarged sectional view of the heat exchanger of figure 1; and - figure 3 shows a front enlarged view of one of the inserts connecting the fins of the heat exchanger of figure 1.

Referring to said figures, there is seen that the heat exchanger according to the present invention comprises in a known way one or more ducts 1 suitable for being exposed to a source of solar rays 2, for example the reflector of a solar energy generator, and for containing a fluid to be heated with the energy transmitted by these rays. Ducts

1 are preferably arranged parallel on a plane and are mutually connected by connections

3 fixed to their ends, so as to form one or more serpentines. A plurality of fins 4, for example rectangular, are arranged transversely with respect to ducts 1, and in particular are provided with holes for being crossed by the latter.

According to the novel aspect of the present invention, each pair of adjacent fins 4 is internally connected by a substantially V-shaped insert 5. Said insert 5 preferably extends from the internal edge of fins 4 up to the holes for the passage of ducts 1, and to this purpose it is also provided with top recesses 5 a for the passage of the latter. Fins 4, inserts 5 and/or ducts 1 are coated with dark and opaque paints for improving the solar energy absorption.

It should be noted that fins 4 are enclosed by an inner case (not shown) open only from the side turned toward the solar rays 2, the inserts 5 being arranged on the other side and thus being protected from dissipation. Thanks to such an arrangement, the solar rays 2 reaching the exchanger surface are fully captured and in particular in the innermost region of the exchanger limiting the dissipation and thus increasing the efficiency in absorbing the solar energy.

It is clear that the above-described and illustrated embodiment of the exchanger according to the invention is just an example susceptible of various modifications. In particular, the exact shape and size of inserts 5 may somewhat change as long as they are arranged to the inside with respect to ducts 1 and they connect pairs of adjacent fins

4.

Claims

1. Heat exchanger comprising one or more ducts (1) suitable for being exposed to a source of solar rays (2) and for containing a fluid to be heated with the energy transmitted by these rays (2), as well as a plurality of fins (4) arranged transversely with respect to the ducts (1) and provided with holes to be crossed by the latter, characterized in that it further includes a plurality of inserts (5) arranged to the inside with respect to the ducts (1) and connecting pairs of adjacent fins (4).

2. Heat exchanger according to claim 1, characterized in that the inserts (5) are substantially V-shaped.

3. Heat exchanger according to one of the previous claims, characterized in that the inserts (5) extend from the internal edge of the fins (4).

4. Heat exchanger according to one of the previous claims, characterized in that the inserts (5) extend up to the holes formed in the fins (4) for the passage of the ducts (1) and they are provided with top recesses (5a) for the passage of the latter.

5. Heat exchanger according to one of the previous claims, characterized in that the fins (4), the inserts (5) and/or the ducts (1) are coated with dark and opaque paints.

6. Heat exchanger according to one of the previous claims, characterized in that the ducts (1) are arranged parallel on a plane and are mutually connected by connections (3) fixed to their ends, so as to form one or more serpentines.