DE102006022426A1 - Solar panel has rows of wedge-shaped, translucent conveyance for air, where air conducted in panel during operation is led-through transparent thermal insulation and subsequently discharged from air-permeable and light-absorbing mat - Google Patents

Abstract

The solar panel has rows of wedge-shaped, translucent conveyance for air (3), which are provided below a cover disc (1). The conveyance comprises multiple small openings, through which air or another gas into the panel interior is conducted. The openings are provided at the side panels of the conveyance or between the edges of the conveyance and the cover disc. The air conducted in the panel during the operation is led-through a transparent thermal insulation (4) and subsequently discharged from a air-permeable and light-absorbing mat (5) from a cavity behind the light-absorbing mat. Independent claims are also included for the following: (1) a device, in which compressed and heated air is relaxed in a compressed air motor (2) a method.

Description

Generally

As Air is flowing in known air-operated flat collectors from a room under the cover disc through a black colored absorber mat, takes heat there up and out of the room behind this mat for the use of the recorded Heat carried away.

In The present invention is in addition to the reduction of heat loss by radiation and convection a transparent thermal insulation between Cover disc and absorber mat inserted.

The to be heated in the collector Air is through rows of wedge-shaped, translucent passageways, which are mounted under the cover plate, in the collector interior introduced.

The entire heat generated in the collector is Recorded in this way and it occurs even at high temperatures no big ones heat loss on.

There the heat generated in the collector has a high energy potential, it will be beneficial not directly used for heating purposes, but serves to drive a Engine, which in turn drive an electric generator can.

The heated in the collector Air is under low pressure and is therefore for direct operation of a Hot-air engine not well suited.

Out For this reason, a special combination of a compressed air motor with a compressor, a heat exchanger and a collecting vessel proposed.

The flowing from the collector heated air first releases its heat in a heat exchanger, afterwards in a chilled Compressor to be compressed. (Instead of a cooled compressor can also come another construction)

The compressed air flows in a collection vessel and takes when overflowing into the Air motor heat from the aforementioned heat exchanger on.

in the Compressed air motor will apply the heated and compressed air to the Collector prevailing pressure relaxes.

The Temperature can drop to below ambient temperatures, so heat out the environment can be recorded.

In detail

construction

To 1 are under the cover plate ( 1 ) Rows of wedge-shaped, translucent ducts for air ( 3 ), which are provided with a plurality of small openings. The openings may be attached to the side surfaces of the wedge-shaped passages or in the form of narrow slots between the cover plate and the edges of the passages.

The individual leads for Air is at some distance from each other.

Below the air ducts is a transparent thermal insulation ( 4 ).

Because of the relatively high In the collector achieved temperatures, the use is recommended of glass capillaries.

Instead of glass can also be used in the form of tubes or honeycombs. Airgel has a much lower heat transfer coefficient than Glass. A honeycomb construction of this material may e.g. by Nesting of correspondingly slotted Airgel discs are manufactured.

Below the transparent thermal insulation, an absorber mat ( 5 ), which may for example consist of a metal wool with selective coating. Behind the absorber mat is a cavity.

The collector becomes the back ( 7 ) through a conventional thermal insulation ( 6 ) isolated.

In order to absorb the heat flowing in spite of thermal insulation to the back of the collector, an air flow through the heat insulation ( 6 ) absorb this heat.

function

The incident solar radiation penetrates the cover disk ( 1 ) and the wedge-shaped, light-transmitting passages for air ( 3 ) as well as the transparent thermal insulation ( 4 ) from the selective absorber mat ( 5 ) to be absorbed.

The Reflection losses at the passages for air are due to the wedge-shaped shape quite low.

The Reflection on the cover disc and on the wedge-shaped passages can be reduced by a special coating.

absorbed Solar radiation in the ducts for air and in the transparent Thermal insulation will in heat transformed and from the flowing through Taken in air.

The Amount of air flowing through absorbed heat is therefore greater than it corresponds to the total energy transmission, which is only the strength of the passing through the thermal insulation Radiation taken into account.

The Transits for Air is at the side of the collector through a manifold fed.

The density of the light-absorbing mat ( 5 ) and their flow resistance are selected so that during operation of the collector the air flows in a smooth and even flow through the mat in the cavity below and is discharged therefrom.

The flow the air can be regulated to absorb just enough heat as from the absorber mat to the transparent heat insulation and in the direction of the cover disk is delivered. The collector then collects the entire in the collector generated heat up to the height in flat-plate collectors without heat absorption counter-current attainable standstill temperature.

Because of the comparatively high operating temperatures is only a fraction the usual with air collectors Amount of air for heat absorption necessary.

usage of warmth

The heat generated in the collector can, as usual, directly for heating serve of service water or for other purposes of heating.

There the collector but also at higher Temperatures little heat outward it often reaches temperatures above the useful temperature.

The generated heat often has a relatively high energy potential. That's why it, the heat, the collector at a higher temperature as the useful temperature provides, to operate an engine to use.

2 shows in a schematic drawing a possible construction. Heated air from the collector first enters a heat exchanger ( 15 ) their heat. The heat exchanger is expediently designed so that it can store a certain amount of heat and thus absorb and release heat continuously. After passing through the heat exchanger, the largely cooled air in a compressor ( 12 ) with the inlet and outlet valves ( 13 ) and ( 14 ) compacted. The heat of compression is released during the compression process via the cylinder wall and / or the piston, so that a possible isothermal compression takes place.

to better heat transfer can piston wall and cylinder wall by appropriate shaping or suitable inserts in their Surface to be enlarged.

The released heat can be used as useful heat serve or - if the plant exclusively to serve for the production of mechanical and electrical energy - to the Environment dissipated become.

The heat In the case of isothermal compression, of course, not quite the ideal correspond. Exclusive Operation of the plant as a heat engine here a certain loss must be accepted.

at simultaneous or exclusive Use for heating purposes and as heat pump play these losses not matter.

The compacted and cooled Air is poured into a collection vessel ().

Instead of a cooled compressor can also be a construction after 3 be used.

The compressor ( 17 ) pumps compressed air into a collecting vessel ( 16 ), which also serves as a heat exchanger and in which the air heat is removed. The temperature of the heat exchanger can range from the ambient temperature (when operating as an engine) to the respective operating temperatures (hot water or space heating).

When the piston in the compressor drops, it is controlled by the controllable valve ( 19 ) a portion of the compressed and cooled air from the reservoir returned to the cylinder of the compressor. After that closes the controllable valve (). The cooled and compressed air is released and cools down considerably. When the pressure in the collector is reached, air flows out of the collector through the automatically opening inlet valve ( 18 ) in the cylinder. The temperature of the resulting air mixture is below the temperature of the incoming air from the collector.

In the subsequent compression is therefore achieved a lower temperature than in exclusive compression of the strö from the collector air.

Of the Advantage of this design is a simpler compressor with a simpler heat dissipation in a heat exchanger.

The compressed after the first or second construction and cooled air is after 2 from the collecting vessel ( 11 ) over the heat exchanger ( 15 ) an air motor ( 10 ). The displacement is only filled to a certain extent. Then the inflow valve closes ( 8th ) and the trapped air is released to the pressure prevailing in the interior of the collector. The air cools down, either to the temperature of the environment or to lower values. Via the discharge valve ( 9 ), the air flows back into the collector interior.

If the temperature of the air flowing back into the collector below the ambient temperature lies, can heat from the environment, e.g. above the cover plate of the collector are absorbed.

compressor and engine can on the same shaft or connected by a gear be.

The displacements Compressor and air motor must be matched be.

A regulation of the compression and / or cooling power as well as the amount of the delivered mechanical power can be controlled via the inlet valve ( 8th ) on the air motor.

At the Air motor can be connected to an electric generator.

Of the Generator can also serve as a motor or it can be a separate engine be mounted on the same shaft.

With An electric motor can be used to start the operation of the plant the necessary Compression pressure produced in the collection vessel become.

With An electric motor can also be the heat pump function of the system be enlarged.

In Times of low solar radiation or increased heating demand The plant can supply its capacity as a heat pump by supplying electrical energy increase.

The described plant consisting of heat exchanger, compressor, collecting vessel and compressed air motor can also for purposes other than those described in combination with a solar system be used.

Claims (5)

Flat solar collector, characterized in that rows of wedge-shaped, translucent air ducts are mounted below the cover plate, that these passages contain a plurality of small openings through which air or other gas is passed into the collector interior, that these openings at the Side walls of the passages are mounted or between the edges of the passages and the cover plate, that during operation, the air conducted into the collector flows through a transparent thermal insulation and then an air-permeable and light-absorbing mat to be discharged from a cavity behind the light-absorbing mat, that the air heated in the collector releases its heat in an external heat exchanger and is recirculated again. Apparatus and method according to claim 1, characterized in that the air heated in the collector in one heat exchangers their heat outputs, that the cooled Compressed air in a compressor with simultaneous heat release, that the condensed and cooled Air flows into a collection vessel and out this the heat exchanger flows through in which the air that flowed from the collector into the compressor, before released their heat Has, that the compressed and heated air in a compressed air motor relaxed, that the temperature of the relaxed air below Ambient temperature can be so that heat is absorbed from the environment can be, that the generated mechanical energy to drive a can serve electrical generator. Apparatus and method according to claim 1.-2., Characterized in that instead of a cooled compressor a simple Compressor is used that the condensed and in one Heat exchanger cooled air, is returned to the part again in the compressor, that after a relaxation of the returned air, further air from the collector flows into the cylinder, that the compressed mixture of the air in a heat exchanger at the same time as a collecting vessel, pumped becomes. Apparatus and method according to claim 1.-3., Characterized in that the system mechanical energy, for example via a motor, is supplied to increase the heat pumping process. Apparatus and method according to claims 1 to 4, characterized characterized in that the combination of heat exchanger, compressor, collecting vessel and compressed air motor also for other purposes than in connection with a solar system is used.