GB2064756A - Solar collector - Google Patents

Abstract

Solar collector cells 4 through which a heat exchange medium flows are supported in an oblique position on means comprising vertical tubes 8, 9 (which may be adjustable in length), horizontal tubes 1, 2 freely supported on the upper ends of tubes 8, 9 to permit unhindered expansion of tubes 1, 2, and bearing rails 5 to which the cells 4 are mounted and which are hookable at their ends over the tubes 1, 2, flexible connections 3 for the heat exchange medium being provided between the cells 4 and the tubes 1, 2. All the support means may be combined into a frame movable on wheels or rollers and rotatable (e.g. by a time-controlled drive) about a horizontal or vertical axis to follow the sun. <IMAGE>

Description

SPECIFICATION Solar collector DESCRIPTION The invention relates to a solar collector having pipes through which a heat exchange medium flows and also comprising a means for bearing it in an oblique position.

Such a solar collector is known from United States Patent Specification No. 4,083,359.

The known device is a portable structure which can be erected as required and e.g.

connected to an industrial water circuit. The known solar collector is a closed, compact device and is correspondingly easy and simple to handle. The known device, however, is very expensive to construct, since the tubes through which the heat exchange medium ' flows and the tank connected thereto are incorporated in a common housing and the tank and tubes are mainly embedded in insulating material. The means for bearing the device in an oblique position comprise a curved member pivoted to one side of the housing receiving the tank and tubes.

Another problem of the known device is that no steps are taken to allow the tubes to expand lengthwise without hindrance when the heat exchange medium flows through them. There is thus a risk of cracking through tension at the places where the pipes are connected to the tank.

The present invention seeks to overcome the above difficulties by providing a solar collector having pipes through which a heat exchange medium flows and also comprising a means for bearing it in an oblique position, characterized in that it comprises a substantially horizontal top tube at a distance from a likewise substantially horizontal bottom tube, the tubes resing in receiving means at the free top ends of substantially vertical supports of varying lengths, the receiving means being such that they allow the tubes, through which heat-exchange medium flows, to expand lengthwise without hindrance, and bearing rails for solar collector cells are disposed at an angle over the two tubes and hooked to the tubes, a flexible heat-exchange medium connection being provided between each solar collector cell and the bottom and top tube.

The collector of the invention has very simple components which can be put together at the place of assembly, even by a layman and may be constructed to an increased size without special difficulty.

More particularly, the solar collector of the invention is substantially completely free from tension between the individual components, i.e. the supports, the tubes, the bearing rails and the solar collector cells.

The supports can be driven into or inserted or buried in the ground, depending on its nature.

Preferably the vertical supports are adjustable in length. Telescopic supports are particularly suitable. In this manner the inclination and/or oblique position of the solar collector cells can be adjusted in simple manner to the position of the sun. In the case of relatively large solar collectors, the adjustment in length and consequent adjustment of the oblique position of the cells are made by a pneumatic or hydraulic or mechanically operated lifting device.

In order to obtain even greater freedom from tension at the contact places between the tubes and the tube-receiving means at the top free ends of the supports, the tube-bearing surfaces of the receiving means are coated with a resiliently expansible and heat-insulating material which either itself has a very low frictional resistance or is coated with a lubricant. The heat-insulating material also prevents any undesirable heat losses via the upright supports.

A particularly advantageous construction is characterized in that the bearing rails for hooking to the top and bottom tube have a recess at the end facing the top tube and corresponding to the outer diameter of the top tube and an elongated slot at the bottom end and having a width substantially equal to the outer diameter of the bottom tube. As a result of this construction, the bearing rails are firmly held on the tubes. It also ensures that the solar collector cells disposed on the rails are at a sufficient distance from the two tubes.

Hose connections are preferably used as the flexible connection for heat exchange medium between the individual solar collector cells and the tubes. The flow cross-sections are made such as to avoid pressure losses.

In order to increase the mobility of the solar collector of the invention, the supports, tubes and bearing rails can be combined into a fixed frame structure which can be moved on rollers, wheels or the like.

Preferably the pipes, bearing rails and solar collector cells are pivotable around a common horizontal axis, in which case there is no need for variable-length supports.

A particularly advantageous embodiment is characterised in that the tubes, rails and cells are mounted so that they can rotate around a common vertical axis, the rotation being produced by a time-controlled rive means. This ensures that the solar collector follows the sun and thus always receives a maximum amount of radiation.

Since such solar collectors are exposed to a wide variety of weather conditions, the tubes and/or bearing rails and/or supports are preferably made of non-rusting chrome steel, more particularly type ELi-T chromium steel.

This steel has a relatively low thermal expansion coefficient, which also helps to reduce the tension of the total structure.

A preferred embodiment of the invention will now be described by way of example with reference to the figures of the accompanying drawing, in which: Figure 1 is a front view of a solar collector, and Figure 2 is a side view.

Referring now to Figs. 1 and 2 the solar collector is seen to comprise upright supports 8, 9 having fork-like receiving means on their top free ends in which substantially horizontal tubes 2 and 2 are mounted. The tube-receiving means are constructed so as not to prevent the tubes from expanding lengthwise.

Supports 8, 9 are secured in the ground so that the supports bearing the top tube project somewhat further from the ground than the supports for the bottom tube.

Spaced-apart bearing rails 5 are disposed at an angle above the tubes and hooked thereto.

For this purpose, the rails are formed with a recess 6 at their end facing the top tube and corresponding to the diameter thereof, whereas at their bottom end the rails have an elongated slot 7 having a width approximately equal to the outer diameter of the bottom tube. In this manner, the rails are firmly secured to the tubes. Tubes 1, 2 and rails 5 are essential parts of the bearing structure for solar collector cells 4. Each rail 5 preferably serves as a bearing for two adjacent solar collectors 4.

The connection for heat exchange medium between tubes 1, 2 and cells 4 is preferably via flexible hoses, which can be connected to nipples 3 of tubes 1 and 2.

A solar collector having the described structure, as diagrammatically shown in Figs. 1 and 2, is of course very simple and can easily be assembled on site by any layman. It is only necessary first to drive the vertical supports 8, 9 into the ground, taking care only that the supports bearing the top tube project somewhat further from the ground than the supports bearing the bottom tube, assuming that the ground is horizontal. Next, tubes 1 and 2 are laid in the corresponding receiving means at the top free ends of supports 8 and 9.

Next, rails 5 are suspended from the tubes.

Rails 5 of course have means for holding the cells 4, which are laid on the rails. Next, the tubes are provided with connecting nipples 3 which are connected to corresponding inlet and outlet nipples of cells 4 via hoses, so as to convey fluid. Instead of hoses, flexible tubes can be used as connections for the fluid and/or heat exchange medium.

Claims (11)

1. A solar collector having pipes through which a heat exchange medium flows and also comprising a means for bearing it in an oblique position, characterised in that it comprises a substantially horizontal top tube at a distance from a likewise substantially horizontal bottom tube, the tubes resting in receiving means at the free top ends of substantially vertical supports of varying lengths, the receiving means being such that they allow the tubes through which heat-exchange medium flows, to expand lengthwise without hindrance, and bearing rails for solar collector cells are disposed at an angle over the two tubes and hooked to the tubes, a flexible heatexchange medium connection being provided between each solar collector cell and the bottom and top tube.

2. The solar collector according to claim 1, wherein the substantially vertical supports are adjustable in length.

3. The solar collector according to claim 1 wherein the substantially vertical supports are telescopic.

4. The solar collector according to any preceding claim, wherein the tube bearing surfaces of the receiving means are coated with a resiliently expansible and heat-insulating material which either itself has a very low frictional resistance or is coated with a lubricant.

5. The solar collector according to any preceding claim, wherein the bearing rails for hooking to the top and bottom tube have a recess at the end facing the top tube and corresponding to the outer diameter of the top tube and an elongated slot at the bottom end and having a width substantially equal to the outer diameter of the bottom tube.

6. The solar collector according to any preceding claim wherein each flexible connection for heat exchange medium between the individual solar collector cells and the tubes is a flexible hose connection which is given a flow cross-section which avoids pressure losses.

7. The solar collector according to any preceding claim wherein the supports and rails are combined to form a fixed frame structure which can be moved on rollers or the like.

8. The solar collector according to claim 7, wherein the tubes, rails and cells are pivotably mounted around a common horizontal axis.

9. The solar collector according to any preceding claim, wherein the tubes, rails and cells are mounted so that they can rotate around a common vertical axis, the rotation being produced by a time-controlled drive means.

10. The solar collector according to any preceding claim, wherein the tube and/or rails and/or supports are made of a nonrusting chrome steel.

11. The solar collector according to claim 10 wherein the steel is ELiT chrome steel.

1 2. A solar collector constructed and arranged substantially as herein described and as shown in the figures of the drawing.