WO2001090660A1

WO2001090660A1 - Method of use of solar energy and appliance for implementation of this method

Info

Publication number: WO2001090660A1
Application number: PCT/CZ2001/000032
Authority: WO
Inventors: Antonín ŠMÍD
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-05-26
Filing date: 2001-05-25
Publication date: 2001-11-29
Anticipated expiration: 2002-11-26
Also published as: CZ20001973A3; AU2001258180A1

Abstract

The invention relates method of use of solar energy falling down to Earth, especially in transformation of energy to heat using a heat-carrying substance, where a loose material is used as the heat-carrying substance. The loose material is fine dry sand. The invention also relates appliance for realization of this method. It consists of collectors (1) for the heat-carrying substance, one end of the collectors being furnished with a feed opening for the heat-carrying substance, and the other end being furnished with an exit port with a shut-off valve (5), after which a heat exchanger (10) and a container (11) for the heat-carrying substance are located.

Description

Method of use of solar energy and appliance for implementation of this method.

Technical field

The invention relates to a method of use of solar energy falling down to the Earth, especially in transformation of energy to heat using a heat-carrying substance, and it also relates to an appliance for implementation of this method.

Background of the invention

The sun currently supplies our planet with a huge amount of energy/ Approximately 1,100 kWh of solar energy per year falls to 1 m² of ground in geographical latitudes in the area around Prague. This is very much, and our whole planet is charged with an immense quantity of heat energy as well. It is necessary to start on this point of view in looking for a strategic global conception of utilization of solar energy.

For several decades, the whole world of technology has been pursuing utilization of direct transformation of solar beams to electricity using photo- silicon cells, which seems to be the easiest way, but it is also the most expensive method of obtaining electricity at present. At the same time, it is necessary to solve in some way the accumulation of this energy and its release in the time, where the sun does not shine, both for short and long periods. As for necessary short-term accumulation, it is necessary to point out that this is a problem of the whole power industry, where it is necessary to solve, at the cost of multi-milliard investments, the transfer of energy peak hours e.g. over several geographical time zones using long-distance high-voltage networks. This problem can be also solved by construction of pumped-storage hydroelectric power plants and other financially demanding constructions.

Various warm-water solar systems are known as well, but these usually do not produce electricity, but only solve heating of warm water for consumption and heating. Various scientific experiments, which are many, are not described in detail, because their realizations is impossible at present, due to high prices and low effects in mass production.

With the current prices of energy, there is no suitable solar system available at present, which would have a chance of mass spread and could compete with current classical power industry, especially thermal and nuclear, regarding its prices.

Summary of the invention

The above-mentioned drawbacks are eliminated to a certain extant by the method of utilization of solar energy falling down to the ground, especially in transformation of energy to heat using a heat-carrying substance according to this invention. Its substance is the fact that a loose material is used as the heat-carrying-' substance.

The loose material is ideally fine dry sand, which can contain blackwash, especially carbon black.

For implementation of the mentioned method, it is possible to use an appliance, which consists of collectors for the heat-carrying substance, one end of the collectors being furnished with a feed opening for the heat-carrying' substance, and the other end being furnished with an exit port with shut-off valve, after which a heat exchanger and a container for the heat-carrying substance are located.

The collector ideally consist of two glasses, between which there is a through space, while the glasses are at a distance of 2.5 - 7 mm from each other. The collector can also consist of glass tubes, which are located in other tubes with vacuum, while the internal surface of the other tube is furnished with a reflex layer.

The heat exchanger ideally consists of a wire heat exchanger sand-water.

The heat exchanger can be connected to a steam line connected to a turbine with an electric generator, and the shut-off valve can consist of a throttle valve, which ideally consists of a compressible spacer made of high-temperature silicon rubber.

The shut-off valve can also consist of pressure combs.

Distribution of the heat-carrying substance consists of a glass piping, in which a transport mechanism in the form of belt conveyor and/or worm conveyor-' is located. *

Loose material as the heat-carrying substance has more convenient characteristics for the given purpose than the existing liquids. With regard to the fact that it can be fine dry sand, its availability is easy both regarding its price, and transport, maintenance and so on. Blackwash, especially carbon black, increases heat absorption of the substance.

Construction of the appliance can use a large number of elements from the known solar collectors. Costs of the construction are not higher than in case of the known solar collectors, while no increased demands are laid on the whole construction. Together with the heat exchanger and the container for heat-carrying substance, the whole appliance forms a closed unit.

If the collector consists of two glasses, between which a through space is created, it is a very easy construction, regarding both production and price, providing high functionality. Distance of 2.5 - 7 mm from one glass to the other provides a satisfying movement of the heat-carrying substance, while allowing the required accumulation of heat.

In case the collector consists of glass tubes, it is utilization of a large existing solution.

The heat exchanger in form of a wire heat exchanger sand-water has high efficiency, long service life, and its acquisition costs are not high.

If a steam line connected with a turbine with electric generator is connected to the heat exchanger, a compact appliance is created.

The shut-off valve in the form of a throttle valve has affordable price and provides all required functions. To facilitate control and decrease production costs, the throttle valve can consist of a compressible spacer made of' high- temperature silicon rubber. *

If the shut-off valve consists of pressure combs, it is possible to produce an appliance of any length with easy control of the flow volume of the heat-carrying substance.

The glass piping, in which the transport mechanism is placed, provides a sufficient transport of the heat-carrying substance, and prevents it^'s leak and change of its characteristics, especially with regard to admission of humidity.

The above-mentioned facts imply that even with the existing prices of energy, it is possible to find a suitable solar source, which has a chance of mass spread, and the price of which can compete with the existing classical thermal or nuclear energy.

The mentioned solution produces relatively cheap, competitive solar energy systems with high efficiency in comparable economic parameters. It is an effective system with relatively low operational and acquisition costs, which allows accumulation of energy in both short and long term.

Another advantage is the fact that it is possible to use generally available construction materials. The mentioned appliances do not burden the environment, but to the contrary, they can better use the areas, which are already built up and serve to other purposes, e.g. walls or roofs of buildings.

Brief description of the drawings

An appliance for use of solar energy according to this invention will be described on the example of particular realization using the enclosed drawings. Fig. 1 shows the connection diagram. Fig. 2 is a schematic representation of the collector tube in front view. Fig. 3 shows a schematic representation of the wire heat exchanger in front view under cut. Fig. 3B shows this^' exchanger in side' view. Fig. 4 shows a schematic representation of location of the wire exchanger. Fig. 5 shows the shut-off valve of the collector in front view. Fig. 6 is a schematic representation and another version of appliance according to the invention with pressure combs. Fig. 7 shows one version of the transport mechanism in front view.

Detailed description of the preferred embodiments

A sample appliance pursuant to this invention consists of collectors 1 for the heat-carrying substance, one end of the collectors being furnished with a feed opening for the heat-carrying substance, and the other end being furnished with an exit port with a shut-off valve 5, after which a heat exchanger 10 and a container 11 for the heat-carrying substance are located. The collector 1 consists of glass tubes V, which are located in other tubes 4| with vacuum, while the internal surface of the other tube 4| is furnished with a reflex layer. The heat exchanger 10 consists of a wire heat exchanger sand-water. A steam line 7 connected to a turbine with an electric generator 9 is connected to the heat exchanger 10. The shut-off valve 5 consists of a throttle valve, which consists of a compressible spacer made of high-temperature silicon rubber.

In another version, the collector 1 consist of two glasses, between which there is a through space, while the glasses are at a distance of 4 mm from each other. In this case, the shut-off valve 5 consists of pressure combs.

In both cases, distribution 2 of the heat-carrying substance consists of a glass piping, in which a transport mechanism 3 in the form of a worm conveyor is located.

In the first case, it is possible to create simple concentration collectors 1, based either on Frenel's lenses, or parabolic vacuum specularly longitudinal reflectors collimating the beams to glass tubes, in which the loose material, which can contain blackwash, is heated in vertical or horizontal position at a controlled-' flow rate. *

Another version is made in such way that the walls of buildings, especially on southern insolated areas, are covered with two glasses in distance of 4 mm form each other, through which fine sand with addition of graphite slowly flows at a controlled rate. It is not necessary to emphasize that these are probably some of the cheapest collector systems in the world. At the same time, walls modified in this way substantially warm the building up in winter, because the energy from its walls is connected using the flowing sand, and is also processed. Sloping roofs and other suitable places can be used in a similar way as well, for example for roofing of motorways, railway lines, large parking lots and so on.

Heated-up loose material is then concentrated using a glass piping to one pipe, through which it slowly passes at a controlled rate by a special wire heat exchanger JO, ideally made of copper. Here it transmits all accumulated heat to water, either for direct consumption, or steam for propulsion of a small turbine is produced of the water. Or it is possible to replace the small turbine with a special swinging electric generator 9, which has higher efficiency for low energetic outputs and large energetic fluctuations, and reacts more easily to theses energetic fluctuations.

In case of surplus of energy, the surplus loose material can fall to a side tube, which ends in a container JJ. with a volume of more cubic meters for accumulation of the energy. With regard to the fact that dry sand basically acts as heat insulator, it is possible to store it in the middle of this container JJ. at relatively high temperatures of 350 to 400 C, which can be easily achieved by the concentration collectors 1. Lower temperatures of up to 200°C from the walls can be then stored in the peripheral parts of the container JJ,. The whole container JJ, ^' is then insulted and a warm- water receptacle is located around the whole container JJ_.. So the remains of escaping heat are caught in service water, as well as the heat from condenser turbine returns together with the water to this container JJ.. If it is necessary to acquire heat from the stored loose material, a discharge valve of^' special construction is opened, and the loose material runs through a funnel- shaped opening, at a controlled rate, through another wire heat exchanger J4. It is necessary to perform the whole operation, if an increased quantity of service water is required, then the water runs faster, so that steam is not produced, and the water is discharged to the peripheral container, from which it is drawn. The energy in form of sand can be stored for a relatively long period; it only depends on size of the container JJ, and the temperature stored in the sand. For long-term storage in large systems, it is convenient to produce hydrogen from surplus for the winter period, and then keep the whole system going in winter months.

The whole system is supplemented with a glass piping with a transport mechanism 3, which transports the used loose material back to the collectors 1. The material goes down by gravity feeding.

240 kWh can be stored in 1 m² of sand and the temperature of 400°C, which is three times more than in 1 m² of water, due to the fact that much higher temperature can be stored. Leak of heat from the middle of container 11 is incomparably slower than from water, approximately ten times.

Major part of the construction consists of glass, which is commonly available, and of sand, which can be found on the earth in large quantity as well. Of course, the whole system is controlled by computers through regulation elements and using sensors.

As obvious from the description, the whole system has been designed in such way that especially the economic costs of its acquisition and operation were as low as possible. It can be assumed that compared to classic common solar ' systems, this one could be economically coordinated with the prices of energy produced in classical ways. The system can be also supplemented by special thermal pumps, which further make this system more effective.

The system appears to be cogenerational, where the heat from production electricity, which is otherwise lost, is used in full. It is also necessary be aware of the fact that the outlined system has many constructional modifications and variants.

A wide range of collecting collector systems can be created, e.g. sloping, or vertically placed flat arrangement, of in the form of vertical pillar systems with a possibility of easy turning to the sun, etc. The appliances can be furnished with concentrators, either lenticular or parabolic reflectors collimating the beams to the central tube. They can be also produced of many constructional materials.

Collection of electricity is performed using fine sand with graphite or other blackwash, which is fed using cableway bucket feeder from the top through a traverse tube, which is connected with all vertical collectors I, which are thus continuously replenished from the top. The surplus of unused sand passes through the whole traverse tube down to the end, where an overflow pipe is located. Here, the unused sand returns back to the central container JJ, located at a suitable place in the lower part of the whole system, A larger quantity of sand serving an accumulator of heat energy is also located here. The container JJ_. is heat-insulated from the surrounding environment. The sand, which has been filled to collectors 1, is in case of sunshine heated to higher temperatures of approximately 300 to 400°C, and is gradually slowly discharged from the bottom of collectors 1, using a controlled, temperature-dependant throttling of the shut-off valve 5. The sand, which has accumulated heat energy in this way, is discharged to a collecting, vertically located tube in the lower part of collectors I. The collecting tube is properly heat-insulated up to the upright vertical ending, where the heated sand is poured into this collecting vertically located tube, in which a wire heat exchanger is located, which transforms heat from the sand to water. The sand slowly flows ^■ around this wire heat exchanger and transforms heat to the water. Here, steam for operation of a small turbine for production of electricity is generated. Surplus of sand is filled into the container JJ, using another overflow pipe, where the unprocessed heat energy is concentrated into large volume. In this container JJ, -' there is also another wire collector, which is connected by the control compute e.g. at night, when the sun supplied no energy.

The quantity of energy accumulated in this way freely depends on the size and quantity of the mentioned container JJ, and the quantity and performance of solar units.

Another possibility of a simpler version suggests itself in very simple collectors J suitable for both slope roofs of southern walls of facades, in which way the facades are heat-insulated at the same time. Sand, which is replenished from the top and discharged at the bottom in a similar way, can be located between two glasses close to each other in this case. This system will work with lower temperatures, but it will be very cheap. It is possible to combine both systems as well. Using a low-temperature steam-generator or Strisling's engine, it is possible to acquire from this system a substantial amount of both heat energy suitable for operation of the building, and electric energy generated in al the above-mentioned methods, because temperature of sand can achieve much higher temperatures than 150°C even in this system. In case of combined systems, it can be more than 300°C. These are in fact liquid elements of the facade, which not only heat-insulate the building, but also help its air conditioning in summer months, while producing electricity.

Buildings designed in this way can be combined very easily with air- conditioning, and it is also possible to solve inner heating of halls or other rooms in the building in a similar way as in case of facades, using two flat glasses close to each other, systematically filled in winter periods with hot sand directly from branches of outer overflow tubes. Inner and outer systems can be appropriately combined.

Regulation of heat would be controlled by a computer using heat probes and throttle valves. These would be probably the cheapest heating systems. They would be suitable especially for larger buildings. In newly assembled buildings of' apartment type, it would be then possible to place these down-take tubes in suέh way, that it would be possible to fill with them the inner heating branches as well. The solution can be also supplemented by acquisition of energy using modernized thermal pumps.

Industrial applications

The method of use of solar energy, and appliance for implementation of this method can be used in heating of residential houses and industrial objects, and in production of energy.

Claims

PATENT CLAIMS

1. Method of use of solar energy falling down to Earth, especially in transformation of energy to heat using a heat-carrying substance, characterized by the fact that a loose material is used as the heat-carrying substance.

2. Method pursuant to claim 1, characterized by the fact that the loose material is fine dry sand.

3. Method pursuant to claim 1 or 2, characterized by the fact that the loose material contains blackwash, especially carbon black.

4. Appliance for realization of the method pursuant to any of the above-' mentioned claims, characterized by the fact that it consists of collectors (U) for the heat-carrying substance, one end of the collectors being furnished with a feed opening for the heat-carrying substance, and the other end being furnished with an exit port with a shut-off valve (5), after which a heat exchanger (10) and a container (11) for the heat-carrying substance are located.

5. Appliance pursuant to claim 4, characterized by the fact that the collector (1) consist of two glasses, between which there is a through space, while the glasses are at a distance of 2.5 - 7 mm from each other.

6. Appliance pursuant to claim 4, characterized by the fact that the collector (1) consist of glass tubes (V), which are located in other tubes (4') with vacuum, while the internal surface of the other tube (4') is furnished with a reflex layer (5').

7. Appliance pursuant to claim 4, 5 or 6, characterized by the fact that the heat exchanger (10) consist of a wire heat exchanger sand- water.

8. Appliance pursuant to claim 4, 5, 6 or 7, characterized by the fact that a steam line (7) connected with a turbine with electric generator (9) is connected to the heat exchanger (10).

9. Appliance pursuant to claim 4, 6, 7 or 8, characterized by the fact that the shut-off valve (5) consists of a throttle valve.

10. Appliance pursuant to claim 9, characterized by the fact that the throttle ^• valve consists of a compressible spacer made of high-temperature silicon rubber.

1 1. Appliance pursuant to claim 4, 5, 6, 7 or 8, characterized by the fact that the shut-off valve (5) consists of pressure combs.

12. Appliance pursuant to any of the above-mentioned claims, characterized by the fact that the distribution (2) of the heat-carrying substance consists of a glass piping, in which a transport mechanism (3) in the form of a belt or worm conveyor is located.