DE2931349A1 - Solar heat energy installation - has turbo-heater using ascending air current with earth as heat storage medium - Google Patents

Abstract

The solar power arrangement has, e.g. a transparent collector, covering roof, a turbo-heater and a vertical wind tunnel. The earth under the covering roof is used as a heat absorber and thermal energy store. Its heat is released again to the working medium, e.g. at night. The earth region can be covered by a double transparent covering having a high transparency w.r.t. the incident solar spectrum but almost total opacity w.r.t. the heat spectrum irradiated from the earth. The second inner covering can be placed at a significant distance between the earth level and the outer covering. These coverings can be of normal glazing glass, of special glass with i.r. reflecting layers, e.g. of zinc or indium oxide, or wired glass or of plastics foil.

Description

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Solar thermal updraft power plant with thermal ground energy storage.

B. DESCRIPTION

Solar thermal and solar electric power plants initially generate useful energy according to the daily cycle of the sun a midday energy spike. Therefore these are the actual energy consumption with constant power until late at night or with specific needs Spread over the day, not adjusted. Need to adjust to actual energy consumption these- solar power plants with complex and expensive energy storage which cause costs similar to those of the power plant itself. Costs or energy costs therefore rise uneconomically with the additional energy storage system.

A wide variety of wind and solar power plants have already been proposed, which indirectly generate solar energy via the horizontal winch or via mirror concentration: and steam generation or gas turbine processes, or via convert photovoltaic direct conversion into electricity. Depending on the basic principle, electrical ones are used or thermal storage.

According to the invention, however, so-called Atmospheric thermal vertical wind power plants proposed under a large transparent canopy, such as at a greenhouse, generate warm air in one high chimney is converted into vertical air speed and into electrical energy via an air turbine. Even these solar vertical wind power plants have hitherto suffered from the same aforementioned energy storage problems.

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According to the invention, this energy storage problem should be solved in a cost-effective form in that the ground spanned by the transparent canopy is even used as an energy storage device without significant additional costs. This goal becomes thereby achieves that the initially undesirably flowing into the ground, and in normal cases by insulating measures the amount of heat hindered by it, with a corresponding time delay to heat the air again can be used.

E.g. at night when the sun has no air under the canopy can heat more, the ground warmed up by the day should 'by means of suitable heat capacities and thermal conductivities, the thermal energy stored in it again to the air flowing under the canopy »

So that during the time of energy storage too much energy is not lost unused through convection and radiation to the outside and to the atmosphere, a double transparent canopy surface is to be used according to the invention, which has a special transparency in the irradiating solar spectrum, but almost impermeability in reflected heat radiation, e.g. up to loo ⁰ C has *

According to the invention, this "second transparent canopy surface be arranged between an outer transparent cover and the ground to also in normal Daily operation by a reflection or absorption of the Heat radiation from the ground to increase the solar collector efficiency. According to the invention, the efficiency should be come to good use. " that the flow channel from this second transparent canopy surface into a hotter one lower and a less warm upper partial channel separated so that the convection losses to the

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Atmosphere can be reduced. In addition, the. Absorption of the heat emitted from the ground in the central transparent canopy surface usefully transferred convectively to the upper, less warm, air stream.

The transparent intermediate roof can, for example, be made of normal Window glass, made of specially coated IR reflection Glass such as zinc or indium. Oxide or even made of plastic sheeting that

_ have an IR absorption capacity which is shown in Fig. 1 by way of example. The transparent upper roof can also consist of windows or Wired glass is also made with an IR reflective layer. The insulating effect of the IR absorber layer on the transparent The upper roof, however, is less because the heat conduction upwards means that some of the energy is transferred directly to the Atmosphere is lost.

According to the invention, this upper roof can also consist of plastic films exist, which have a long lifespan of 15 - 20 years due to UV light stabilization and considerably shorter ones compared to glass Cause costs. To reduce the convective heat losses through, the upper roof can also e.g. consist of air cushion nub poles. .

TJm / to avoid blowing the warm air and ground heat energies under the canopy with horizontal winds, according to the invention, a radial segmentation of the canopy is carried out by 4-8 vertical partition walls, - '-. -

Fig. 2 shows schematically an atmospheric thermal vertical wind power plant with an inner double canopy. The solar radiation penetrates through the upper and middle transparent canopy layer down to the ground and heats it.

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The ground gives the heat to those above Layers of air, which thereby have the tendency to ascend through the tower. This creates new amounts of air sucked in from the outer edge of the canopy and flow continuously under the outer simple canopy. There the air on the ground is preheated and flows further inwards, into the lower canopy between the ground roof and into the upper canopy between the upper canopy intermediate roof .;

The air in the lower canopy heats up further on the ground up to the maximum temperature at the tower entrance. The air that flows through the upper duct is heated only through the convection losses from the lower channel and IE radiation losses from the ground. This gives this upper duct and air part a special insulation, efficiency and performance-increasing effect Effect too.

Without special measures, however, the soil only works as a passive energy store and causes a time-shifted Energy yield compared to solar radiation. Fig. 3 outlines this process with a shift of the percentage energy maximum From 12 p.m. to approx * 1pm - 2pm, during the drop in performance up well into the night, but steadily sloping.

According to the invention, a targeted performance profile is intended here be possible if the adjustable guide vanes and / or blades of the air turbine in the morning and / or be throttled over midday so that the ground heat energy storage it is additionally heated »by less or no cooling air flowing over it. Thus, according to FIG. 3, a constant value could be obtained from about ten o'clock Output of e.g. 3o - 5o% can be generated, while the excess energy at midday flows into the storage tank.

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If the solar irradiation falls below 5o or 3o% from 3pm to 5pm, the output is constant the air turbine blading again slowly and steadily de-throttled until late in the evening to an even lower, but if necessary, constant level of performance until the next morning.

According to the invention, any performance profile can also be Art can be driven with targeted peaks as required, as long as the sum of the daily output is not overwhelmed will.

According to the invention, a part of the performance in the the following day, etc., to e.g. a special weekly peak, for example around Monday to cover.

According to the invention, even a certain seasonal Energy shift takes place over the deeper layers of the earth.

/ While the time of day shifts only 1 to 2 m in penetrate the soil, seasonal soil temperature shifts occur up to about 20 m depth. : However, these effects are strongly dependent on the nature of the soil such as thermal conductivity and heat capacity dependent.

According to the invention, targeted measures are to be taken here, such as different degrees of moisture in the soil and, if necessary, in the case of high soil moisture, which increases the thermal conductivity and heat capacity, a cover should be used of the floor with black and / or transparent foil partially or completely in order to prevent further drying out to prevent.

According to the invention can also [mostly covered] water basins that allow rapid and intensive energy absorption and release

Cause convection within the water basin and a have greater heat storage capacity than the ground. "- _

Instead of water basins, thin-walled water hoses should also be used used, which are only filled at the respective end. These plastic tubes can according to the invention transparent or black, or even transparent at the top, black at the bottom. It can also be a colored, absorbent liquid can be filled into the fully transparent tubes. :

According to the invention, the black and / or transparent additional floor cover can be rolled up depending on the energy requirement or unrolled.

There are less short-term energy peaks during addressed one or two hours a day, but more from day into night or across days, or even the seasonal fluctuations from summer to winter, which would justify the large-scale cyclical changing of an additional floor membrane.

Another idea of the invention relates to the coating of the soil itself ^ with selective paints or varnishes, which has a high absorption in the solar spectrum, but only one Multiple reduced emissions in the infrared heat range having. Such varnishes and paints are already available today Can be applied for 1 - 2 DM / m2, but only stable on paved floors. The effect of these selective black lacquers in particular supports the storage effect or reduces heat losses during the night, but increases it also the collector efficiency during the day.

Another inventive idea with agricultural Use of the ground under the canopy rules out the aforementioned measure. An agricultural land use should according to the invention under the canopy under the aspect of increased ground and air temperatures

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as well as correspondingly faster growth. If necessary for the corresponding plant growth, the ground or air temperature almost constant thanks to the adjustable blades and / or guide vanes the air tower can be regulated.

Analogous to the agricultural land use mentioned, according to the invention, a hydrological use of the above-mentioned water basins are made by fish farming. When the water basin to avoid evaporative heat losses be covered with a transparent film, a corresponding oxygen enrichment should of the water with compressed air injection, which in turn has a heat-distributing effect within the Can take over the water basin.

The effect of the in Io. called adjustable turbine blades can, according to the invention, partly also from large end flaps of the radial partition walls mentioned under 6 be made, which partially or completely close the radial channels at the narrowest point in front of the turbine can.

As a result, segment-like parts of the canopy can optionally also be stored with the end flap closed. used, while at the same time other canopy segments with open end flaps and air flowing through Energy generation are used,

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The aforementioned properties of the soil together
To represent a large thermal energy store with a transparent roof is not limited according to the invention to vertical wind power plants,
but on all thermal power plant variants
applicable to those with such air collector systems and which can process the temperatures that can be generated with them. ·

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Claims (1)

C. PATENT REQUEST .. "- '. Solartiiermisch.es power plant e.g. with transparent collector canopy, Turbo chimney and vertical wind utilization characterized in that the under the canopy _; ground itself as an absorber and thermal Energy storage is used, which e.g. * at night gives its heat back to the working medium. 2. Solar thermal power plant e.g. with transparent collector canopy, turbo chimney and vertical wind utilization according to claim 1, characterized in that the ground covered by a double transparent cover - 'is thought to have a high level of transparency in the irradiated Solar spectrum, but an almost impermeability in the heat spectrum reflecting back from the ground. 3 Solar thermal power plant e.g. with a transparent collector canopy, Turbo chimney and vertical wind utilization according to at least one of claims 1 to 2 thereby characterized in that the second inner cover is at an appreciable distance between earth boa and outer cover is arranged. 4. Solar thermal power plant, for example with a transparent collector canopy, turbo chimney and vertical wind utilization according to at least one of claims 1 to 3-characterized in that the transparent covers, for example, made of normal window glass, special glass "- 'with infrared-reflecting layers, such as zinc or indium oxide, made of wire glass or plastic sheets' _ ■. - -f. · .- ■■■; -. ■ ---. "-CHT 2931343 5 Solar thermal power plant e.g. with a transparent collector canopy, Turbo chimney and vertical wind utilization according to at least one of claims 1 to 4 thereby characterized in that a radial segmentation of the collector canopy by 4-8 vertical partition walls is made, which can reach to the turbine, so that the segments are only separated from the turbine. 6. Solar thermal power plant e.g. with a transparent collector canopy, Turbo chimney and vertical wind utilization according to at least one of claims 1 to £ r thereby characterized in that a targeted performance profile with adjustable guide vanes and / or rotor blades the turbine is achieved with the inclusion of the thermal ground energy storage. 7 Solar thermal power plant e.g. with a transparent collector canopy, Turbo chimney and vertical wind utilization according to at least one of claims 1 to j? through this .- characterized that a targeted performance profile is supported by providing the soil with different levels of moisture and thermal conductivity and / or covered with transparent or black layers __, which can be rolled up or down, for example and / or be provided with selective lacquers and colors can. 8. Solar thermal power plant, for example with a transparent collector canopy, turbo chimney and vertical wind utilization according to at least one of claims 1 to Ji, characterized in that the ground is also associated with water basins with or without a transparent cover or thin-walled, long water hoses are used, which are transparent and above, for example can be black below and cover the ground. 13.0022 / 0014 ORIGINAL INSPECTH b NAOHQEREIOHT Solar thermal power plant e.g. with transparent KoI, lektor canopy, turbo chimney and vertical wind utilization according to at least one of claims 1 to ^ r characterized in that landwir τ - under the warmer canopy. Economic plant or animal breeding, including even fish breeding, can be operated, whereby these processes take place in separately separated sections or layers and a constant temperature profile can be made available by regulating the guide vanes. Solar thermal power plant e.g. with a transparent KoI-lector canopy, Turbo chimney and vertical wind utilization according to at least one of claims 1 to each characterized in that that for hydrological use the water basins are transparent to avoid evaporation to be covered and an oxygen supply through bubbling Air injection takes place. 11. Solar thermal power plant with a transparent collector canopy according to at least one of the preceding claims 1 to yL, characterized in that secondary thermodynamic circuits are coupled via heat exchangers as the energy conversion system. 13 OO 2 2/0 014