Solar heat powered system comprising a circuit for a heat transfer medium

Abstract

A solar heat powered system has a circuit for a heat transfer medium and at least one spur line that branches off from the circuit for the heat transfer medium. There is at least one expansion container connected to the at least one spur line. The spur line has a cooling element that has an enlarged surface at least in sections.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of German Application No. 20 2008 007 256.5 filed May 29, 2008.

BACKGROUND OF THE INVENTION

The invention relates to a solar heat powered system comprising a circuit for a heat transfer medium.

Solar heat powered systems are used to heat fluids, in particular water. They encompass a heat transfer medium, which is subjected to heating by means of solar radiation. For this purpose, solar heat powered systems often have so-called collectors, which are subjected to the sun, e.g. on inclined roof areas and by means of which the heat transfer medium is guided.

Furthermore, solar heat powered systems often encompass an accumulator for the industrial water, which is to be heated. These accumulators are connected to a fluid installation, in which the heated fluid is fed to consumers. Periodically, the accumulator is arranged in a basement; accumulator and collector are connected to pipelines in a heat transfer medium-conductive manner.

The aforementioned circuit is embodied via these pipelines. A feed line leads from the collector in the direction of the accumulator. A return line leads from the accumulator back in the direction of the collector again. Valves, fittings, display instruments and similar equipment are inserted into the pipelines in the course of this circuit. These fittings can be subjected to high temperatures by the heat transfer medium, in particular in the feed line. In response to intense solar radiation, said heat transfer medium reaches high temperatures of above 100° C. These high temperatures represent danger to the fittings. Seals, in particular, are stressed by means of the hot medium so that damages to these components can appear due to the high temperatures.

A possibility for cooling the heat transfer medium has been proposed in DE 10 2006 009 112 A1 for a solar heat powered system of the aforementioned species in that a coolant, namely water, is advanced to the circuit. However, the advancement of a coolant requires technical effort, due to the fact that the coolant must be conveyed and discharged. A control system is furthermore necessary for doing so.

SUMMARY OF THE INVENTION

The invention is based on the object of specifying a solar heat powered system, by means of which the heat transfer medium can be sufficiently cooled with small technical effort.

This object is solved according to the invention in that at least one spur line branches off from the circuit for the heat transfer medium to at least one expansion container, and this spur line is embodied as a cooling element comprising an enlarged surface at least in sections.

The systems according to the invention do not use a coolant, so that no technical effort is necessary for piping and conveying a coolant. Instead, the cooling element is embodied by means of a pipe that encompasses an enlarged surface at least in sections.

In one embodiment the cooling element is not inserted directly into the feed line or the return line of the circuit, but into a spur line leading to an expansion container. This embodiment thus includes an expansion container, into which hot heat transfer medium can expand and into which it can flow. The hot heat transfer medium thereby passes the cooling element and is cooled down. The heat transfer medium can be guided out of a vapor phase and can reach the expansion container as a fluid. The temperature of the heat transfer medium is thus reduced and fittings and equipment, which are located in the circuit, are protected against the hot heat transfer medium.

According to a first embodiment of the invention, the cooling element is embodied by a section of the spur line, which is designed in coils. Due to the coils, the spur line runs in the shape of a meander; it encompasses a greater length and thus a larger surface. The cooling of the cooling element, which is heated by means of a hot heat transfer medium, takes place by means of ambient air; a fluid medium for accommodating the heat is not required. The cooling element can be dimensioned accordingly so as to be able to reduce temperature peaks, which are to be expected. When installing the solar heat powered system, it is thus no longer necessary for the determination of the size of a cooling possibility to take place on location; provision for the correct size of the cooling element can already be made in the factory.

Such a cooling element can also be embodied by means of a section of the spur line, which is embodied as a ribbed tube. An enlargement of the surface of the spur line also takes place herein by dividing the spur line into a plurality of partial ribs.

According to a next development, the spur line can be directly connected to the circuit. This immediacy is characterized in that flaps or valves are not arranged between spur line and circuit. An escape of a hot, in particular vaporous heat transfer medium into the spur line is not hindered by a valve.

Preferably, the spur line is connected directly to the feed line of the circuit. The feed line is guided from the collector; it thus includes the heat transfer medium, which was just heated. Here, the temperatures are at their highest level and it is most likely for a fitting in the circuit to be damaged here. It is also possible to branch off the spur line in the return line of the circuit.

For a particularly constructive embodiment, the spur line is connected to the circuit in the spatial area of a solar station, wherein the solar station encompasses components for conveying the medium and/or for controlling the system.

A solar station is routinely part of a solar heat powered system. Oftentimes, such a station is a compact component assembly for the feed line and the return line; it includes pumps and fittings, such as a shut-off valve, thermometer, gravity brake, volume gauge, airscoop, gully trap, manometer as well as safety valve. Partly, these are components that are endangered by a hot heat transfer medium so that it is sensible to connect the spur line to the circuit here for draining hot heat transfer medium. The cooling element can be assigned to the solar station in this manner, and it is even possible to arrange and to fasten the solar station to the section of the spur line, which is embodied as cooling element. The cooling element is thus also used as an accommodating element for the solar station, because it encompasses a mechanical stability, due to its design, which is present in coils, e.g.

The cooling element and the solar station can encompass the same housing. In so doing, a covering of the cooling element is preferably attained by means of the solar station and the housing thereof. The cooling element is thus protected from being touched by persons; preferably, these persons are thus protected from being burned by touching the cooling element.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment, which results in further inventive features, is illustrated in the drawing.

FIG. 1 shows a diagrammatic view of a solar heat powered system,

FIG. 2 shows a perspective view of a component of the solar heat powered system according to FIG. 1, and

FIG. 3 shows a further perspective view of the component according to FIG. 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The solar heat powered system in FIG. 1 encompasses a collector 1 as well as an accumulator 2. The heat transfer medium heated in the collector 1 by means of solar radiation is guided to the accumulator 2 via a circuit, which consists of a feed line 3 and a return line 4 and is guided away from the accumulator 2, respectively. Within the accumulator 2, the feed line 3 transfers into the return line 4 in a heat exchanger 5.

Several fittings, valves, airscoops, gully traps, manometers or similar components 6 are used in the feed line 3 as well as in the return line 4.

Provision is furthermore made for a spur line 7, which branches off from the feed line 3 and which leads into an expansion container 8. The branching of the spur line 7 from the feed line 3 takes place in flow direction of the heat transfer medium upstream of the components 6. The spur line 7 is connected directly to the feed line 3; a flow indicator 9 and a thermometer 9, respectively, are arranged in the spur line 7. Flaps and valves are not provided.

A cooling element 10 is furthermore arranged in the spur line 7. This cooling element 10 is embodied by means of a section of the spur line 7 itself, and is in the form of a ribbed tube in FIG. 1.

FIG. 2 shows the spur line 7 in vertical orientation to the expansion container 8. In an upper section, the spur line 7 is guided in coils 10a. Feed line 3 and return line 4 are not illustrated in FIG. 2, only connections 11 within a solar station 12, which accommodates the fittings 6. The solar station 12 accommodates the components 6 and further connections 11a in a compact form. The solar station 12 is thereby arranged on the coils 10a, the coils 10a thereby form the cooling element 10. Using an angle 13, the entire structural unit of expansion container 8, spur line 7, cooling element 10 and solar station 12 can be fastened to a wall, which is not illustrated in detail. The cooling element 10 is thereby affixed to an assembly location, for example a wall; the solar station 2 is subsequently fastened to the cooling element 10. The weight of the expansion container 8 is absorbed via the angle 13.

The cooling element 10 thus has an assembly device for accommodating the solar station 2. It can be designed in a mechanical manner such that it is fastened to the original assembly location of the solar station 12 and then serves itself as assembly location for the solar station 12.

FIG. 3 shows that the solar station 12 and the cooling element 10 can be covered by means of a common housing 14. The housing 14 encompasses recesses, by means of which the components 6 are visible and by means of which they can be actuated.

Claims

1. A solar heat powered system comprising:

a circuit for a heat transfer medium;

at least one spur line that branches off from the circuit for the heat transfer medium; and

at least one expansion container connected to the at least one spur line,

wherein said at least one spur line has a cooling element comprising an enlarged surface at least in sections.

2. The solar heat powered system according to claim 1, wherein a section of the spur line is designed in coils and forms the cooling element.

3. The solar heat powered system according to claim 1, wherein a section of the spur line is designed as a ribbed tube and forms the cooling element.

4. The solar heat powered system according to claim 1, wherein the spur line is connected directly to the circuit.

5. The solar heat powered system according to claim 1, wherein the spur line is connected to a feed line of the circuit.

6. The solar heat powered system according to claim 1, wherein the spur line is connected to the circuit in a spatial area of a solar station, and wherein the solar station encompasses components for conveying the medium or for controlling the system.

7. The solar heat powered system according to claim 6, wherein the cooling element is assigned to the solar station.

8. The solar heat powered system according to claim 6, wherein the solar station is arranged on the section of the spur line forming the cooling element.

9. The solar heat powered system according to claim 7, wherein the cooling element and the solar station are located in one housing.