Apparatus for heating service water

Abstract

An apparatus is described for heating service water with a solar collector, comprising a service water tank (7) with a partly cylindrical jacket (8) as an absorber and an enclosure (1) which covers the service water tank (7) and forms a translucent cylindrical jacket (3), the axis of which extends parallel to the axis of the jacket (8) of the service water tank (7). In order to provide advantageous heating conditions, it is proposed that the service water tank (7) is connected in a thermally conductive manner with an absorber plate (4) forming a bottom part of the enclosure (1) and that the absorber plate (4) and the jacket (8) of the service water tank (7) are covered with a wide-meshed, thermally insulating fabric (11).

Description

FIELD OF THE INVENTION[0001]The invention relates to an apparatus for heating service water with a solar collector, comprising a service water tank with a partly cylindrical jacket as an absorber and an enclosure which covers the service water tank and forms a translucent cylindrical jacket, the axis of which extends parallel to the axis of the jacket of the service water tank.DESCRIPTION OF THE PRIOR ART[0002]If service water is to be heated with the help of solar power, solar collectors are usually used which comprise a trough-like frame with a base plate acting as an absorber, on which parallel tubular flow channels are provided for water as a heat carrier for example. The trough with the absorber plate and the flow channels which are connected to a distribution and a collecting line is provided with a translucent cover, so that especially the thermal radiation is absorbed by the absorber plate and the flow channels arranged thereon, and the absorbed heat is transferred to the he...

AI Technical Summary

Benefits of technology

[0004]The invention is therefore based on the object of improving the efficiency in solar collectors in which the jacket of the service water tank is used as an absorber.

[0006]The provision of an additional absorber plate which forms the bottom part of the enclosure and which is connected with the service water tank in a thermally conductive manner provides a better utilization of the thermal radiation entering the enclosure because the absorber plate heated by this thermal radiation will pass on the absorbed heat to the service water tank. Covering this absorber plate and the jacket of the service water tank with a wide-meshed, thermally insulating fabric prevents direct contact of air flows formed as a result of convection within the enclosure with the absorber plate and the service water tank, leading to a higher temperature of the absorber plate and a lower cooling of the service water tank and therefore to improved heating conditions for the service water. The wide meshes of the fabric ensure direct passage of thermal radiation to the absorber plate and to the service water tank through the fabric, wherein especially favorable heating conditions are obtained when the fabric is permissible to thermal radiation itself, as is the case in a glass-fiber fabric.

[0008]This construction is especially useful for service water tanks with a circular-cylindrical jacket. The invention is not limited to such circular-cylindrical service water tanks. Especially simple constructional conditions are obtained when the service water tank is composed of a jacket approximately forming a semi-cylinder and a cylindrical wall connected to the inside of said jacket, the axis of which extends perpendicularly to the jacket axis. Since as a result of this measure the service water tank can be produced from two sheet metal cuttings which are each cylindrically bent and then welded together with each other, comparatively simple production conditions can be maintained. The semi-cylindrical jacket of the service water tank which closes off the cylindrical wall of the service water tank to the outside forms protruding edge sections at least in the connection area of the cylindrical wall, which edge sections represent an additional absorber surface area which has an advantageous effect on the heat transmission, since the semi-cylindrical jacket of the service water tank can be arranged approximately co-axially with the jacket of the enclosure which also forms a semi-cylinder, so that the thermal radiation is aligned substantially radially with respect to the jacket of enclosure and the jacket of the service water tank, which therefore occurs substantially independent of any change in the position of the sun during the day.

Problems solved by technology

The disadvantageous aspect in such solar collectors is that a respective orientation is required with respect to solar radiation and that a hot water storage tank is required for heating the service water, which hot water storage tank is connected via a heat exchanger to the solar collector.

However, despite these measures efficiency remains limited.

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