GB1585597A - Solar collector having an integrated outside-air heat exchanger - Google Patents

Description

(54) SOLAR COLLECTOR HAVING AN INTEGRATED OUTSIDE-AIR HEAT EXCHANGER (71) We, ROBERT BOSCH GMBH, a German company of Postfach 50, 7 Stuttgart 1, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a solar collector which is combined with an outsideair heat exchanger as a heat pump. The collector is used to extract heat from solar radiation and outside air, and may be used as a means of providing a heat loss when necessary.

From German Offenlegungsschrift 26 17 324, for example, solar colleotors are already known which use incident solar radiation to collect heat. It is also known from "Energiewirtschaftliche Tagesfragen" ("Energy Questions of the Day") vol. 3, 1975 to use for heat extraction, heat pumps which extract heat, for example, from the outside air. It has also been suggested to combine solar collectors, air heat-exchangers and heat pumps in a common heating system. In this case, solar collectors, air heat-exchangers and heat pumps are set up at separate locations and are interconnected by a complicated piping system and valves. Apart from the space taken up by the heat exchangers and the solar- colleotors, this piping in particular makes a combined heating system very expensive to produce and maintain.

There is provided by the present invention apparatus for collecting heat, wherein a collector for collecting heat from solar radiation and having an absorber plate and a channel mounted thereon for a heat carrier, is formed on one or both sides thereof with an additional channel through which a fluid or gaseous medium may be passed; means preferably being provided for interrupting the passage of the medium through the or each additional channel.

The apparatus acocrding to the invention has by comparison with the known arrangements the advantage that a collector is used to extract heat from solar radiation and from outside air. Another advantage is that the gaseous or fluid medium passing through the collector, for example, outside air or water, may possibly also be used to eliminate excess heat in a heating system.

It is particularly advantageous to site the air channel required for extracting heat from the outside air on the side of the collector remote from the sun. It is also advantageous to obtain by means of additional ribs in the air channel, a surface of maximum size permitting an advantageous heat transfer co- efficient. It is also advantageous to provide the rear and the side walls of the collector with thermally insulating material.

An embodiment of the invention is illustrated diagrammatically in the accompanying drawing the sole Figure of which is a sectional side elevation of the apparatus of the embodiment.

The embodiment of the sole Figure comprises a solar collector shown having a glass plate 2 to receive the solar radiation indicated at 1. The radiation passes through the glass plate 2 to an absorber plate 3 below which is a channel 4 to conduct the heat carrier. As a heat carrier, a water-glycol compound may, for example, be used. Below the heat channel 4, a chamber 5 with a through passage is provided through which air may be passed.

In order to make it possible to stop the air passage, the inlet and outlet openings 6 of the chamber are closable. Advantageously, the chamber is enclosed with insulation 7 which is made, for example, from polyurethane foam.

To obtain an upper surface of chamber 5 of maximllm size it is advantageous to form ribs (not shown) thereon yin:~ in order to reduce the heat transfer coefficient between the outside air and the heat carrier. It is particularly advantageous to dispose these ribs parallel to the air flow through the chamber, to encourage free convection. The inlet and outlet openings 6 are then best mounted on the upper and lower side of the collector as shown in the sole Figure. The air flow itself may be effected by a fan (not shown) and/or by convection. To obtain a further enlargement of the surface along which air flow takes place it is advantageous to pass the outside air also through a front chamber 8.

Usually, the collector is used to extract heat from solar radiation. The mode of operation of such a collector is described, for example, in German Offlengungsschrift: 24 02 999. If the heat in the heat carrier channel 4 increases to an inadmissible level, it is possible by opening the inlet and outlet 6 to eliminate the excess heat by means of the outside air flow through the chamber 5.

If solar radiation is insufficient as a heat source, it is possible to use both solar energy and the outside air or the latter alone in which case the apparatus serves as an air heat exchanger. Instead of air it is, of course, possible to use another gaseous or fluid medium, for example, water. The collector used as a heat exchanger is then connected to a heat pump. The mode of operation of a heat pump with heat exchangers is described, for example, in the article "Rational use of energy by means of a heat pump in self-contained houses" in the periodical "Energy Questions of the Day" vol. 3, 1975.

WHAT WE CLAIM IS: 1. Apparatus for collecting heat, wherein a collector for collecting heat from solar radiation and having an absorber plate and a channel mounted thereon for a heat carrier, is formed on one or both sides thereof with an additional channel through which a fluid or gaseous medium may be passed.

2. Apparatus as claimed in claim 1, in which the additional channel is disposed on the side of the collector remote from the solar incident side.

3. Apparatus as claimed in claim 1, in which an additional channel is provided on both sides of the collector.

4. Apparatus as claimed in any of claims 1 to 3, in which means are provided to interrupt the passage of the medium through the additional channel or channels.

5. Apparatus as claimed in any of claims 1 to 4, in which, to obtain a large surface between the or each additional channel and the heat carrier channel, ribs are formed on the heat carrier channel exterior.

6. Apparatus as claimed in claim 5, in which the ribs are disposed parallel to the direction of flow of the medium through the or each additional channel.

7. Apparatus as claimed in any of claims 1 to 6, in which the side of the collector remote from the solar incident side, and the side walls of the collector are provided with thermally insulating material.

8. Apparatus as claimed in any of claims 1 to 7, in which the or each additional channel is formed with closable apertures to admit ambient air to thereto to serve as the gaseous medium.

9. Apparatus for collecting heat substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. shown) and/or by convection. To obtain a further enlargement of the surface along which air flow takes place it is advantageous to pass the outside air also through a front chamber 8. Usually, the collector is used to extract heat from solar radiation. The mode of operation of such a collector is described, for example, in German Offlengungsschrift: 24 02 999. If the heat in the heat carrier channel 4 increases to an inadmissible level, it is possible by opening the inlet and outlet 6 to eliminate the excess heat by means of the outside air flow through the chamber 5. If solar radiation is insufficient as a heat source, it is possible to use both solar energy and the outside air or the latter alone in which case the apparatus serves as an air heat exchanger. Instead of air it is, of course, possible to use another gaseous or fluid medium, for example, water. The collector used as a heat exchanger is then connected to a heat pump. The mode of operation of a heat pump with heat exchangers is described, for example, in the article "Rational use of energy by means of a heat pump in self-contained houses" in the periodical "Energy Questions of the Day" vol. 3, 1975. WHAT WE CLAIM IS:

1. Apparatus for collecting heat, wherein a collector for collecting heat from solar radiation and having an absorber plate and a channel mounted thereon for a heat carrier, is formed on one or both sides thereof with an additional channel through which a fluid or gaseous medium may be passed.

2. Apparatus as claimed in claim 1, in which the additional channel is disposed on the side of the collector remote from the solar incident side.

3. Apparatus as claimed in claim 1, in which an additional channel is provided on both sides of the collector.

4. Apparatus as claimed in any of claims 1 to 3, in which means are provided to interrupt the passage of the medium through the additional channel or channels.

5. Apparatus as claimed in any of claims 1 to 4, in which, to obtain a large surface between the or each additional channel and the heat carrier channel, ribs are formed on the heat carrier channel exterior.

6. Apparatus as claimed in claim 5, in which the ribs are disposed parallel to the direction of flow of the medium through the or each additional channel.

7. Apparatus as claimed in any of claims 1 to 6, in which the side of the collector remote from the solar incident side, and the side walls of the collector are provided with thermally insulating material.

8. Apparatus as claimed in any of claims 1 to 7, in which the or each additional channel is formed with closable apertures to admit ambient air to thereto to serve as the gaseous medium.

9. Apparatus for collecting heat substantially as hereinbefore described with reference to the accompanying drawing.