DE102010004874A1 - PV / T systems in water treatment systems - Google Patents

Abstract

The present invention relates to a desalination system comprising a photovoltaic system, the system being configured to heat the water to be desalinated by the waste heat of the photovoltaic system. The invention also relates to a process for desalination in which the water to be desalinated is heated with the waste heat of a photovoltaic system.

Description

The The invention relates to a system for desalination of water comprising a Photovoltaic system, where the system is the water to be desalinated heated by the waste heat of the photovoltaic system. In particular, this heating of the water in water treatment systems through a PV / T system (plant, with the photovoltaic and thermal energy can be obtained) can be realized. Such systems can z. B. are used for seawater desalination, v. a. also together with membrane processes in which it is beneficial that too desalting water has a certain elevated temperature before the actual preparation.

• • Enorme Steigerung der Trinkwasserproduktion
• • Alternative zu Druckrückgewinnungssystemen
• • Umsatzpotential von ca. 300 Mio. EUR pro Jahr

The invention relates to the use of PV / T systems for the energy supply of water treatment plants with membrane technology and is aimed primarily at small, energy self-sufficient systems in the decentralized area. In the following, plants for the desalination of seawater and brackish water and for the treatment of contaminated surface and well water are referred to as water treatment plants. The combination of PV / T systems and water treatment plants is completely new and has great technical and economic potential:

• • Enormous increase in drinking water production
• • Alternative to pressure recovery systems
• • Sales potential of approx. EUR 300 million per year

at certain plant configurations, eg. B. in combination of reverse osmosis (RO) with PV / T is one compared to purely PV-powered systems Increase of drinking water production from approx. 35 to 40% realistic. That is, about 25 to 30% of the PV module area can be saved if one assumes that the considered PV / T-powered and PV-powered plants the same Produce quantities of drinking water. The investment costs for PV / T systems are about 10% higher than PV systems. This means that the use of PV / T systems instead of PV systems for Energy supply from RO plants seems economically sensible.

Of the In addition, use of PV / T systems in water treatment can as a serious alternative to previous pressure recovery systems whose purpose is the reduction of energy consumption a desalination plant. If one calculates the surplus of drinking water through the use of PV / T systems in a comparable energy saving around, can be a surplus of 35% as an energy recovery of 25%. PV / T systems do not achieve this the dimensions of pressure recovery systems (with energy savings of 65 to 75%), but these are unprofitable for small plants, so the use of PV / T systems just makes sense in this field power.

The Drinking water problems are increasingly becoming one of the most acute problems in the world. The United Nations predict that by 2025 two-thirds of the world's population of drinking water shortages Suffer. Although the earth is almost two-thirds covered in water is, according to UNESCO, only about 0.02% of the people as fresh water accessible. Not least because of this is the water treatment and especially seawater desalination a very promising Technology to solve this problem. A big part The underserved people live in developing countries in rural areas, cut off from any infrastructure. The also means that a reliable access to the electrical Power supply via a power grid is not available. Therefore, self-sufficient desalination plants have to be developed become. As in countries such as Africa or India, in especially drinking water due to drought periods is scarce, the solar supply is very high, it is obvious, water treatment plants to supply with solar energy.

It is known that water treatment plants, especially reverse osmosis systems can be operated with electricity generated by solar cells, which z. B. off ES000002299396A1 . CN000101337749A or WO2006067240 evident. The electric current drives all necessary for the desalting machine, z. As pumps or systems for water pre- and water after-treatment on. The problem that solar energy does not allow a constant power supply to the system is achieved here by means of storage systems for electrical energy, especially batteries or accumulators. A disadvantage of the power supply with solar energy are the high investment costs for the photovoltaic. These systems use solar energy exclusively electrically.

It is also known that the performance of the reverse osmosis membranes, which filter the salt from the seawater, is temperature dependent. The higher the salt water temperature, the more permeate can be produced. The "Recovery Ratio", ie the ratio of permeate flow to raw water flow (in this case raw water is called the seawater to be desalinated), becomes larger. This means that more permeate can be recovered from a given raw water flow. The drinking water production can therefore be increased by raising the raw water temperature. The temperature increase is limited by the material properties of the membranes to temperatures of 40 ° C to 45 ° C. There are different ways of getting the raw water to this temperature preheat.

In US020050236309A1 Seawater, which has been heated to temperatures above 40 ° C, for example, as cooling water in a power plant, is mixed with cooler seawater to maintain the temperature limit of 40 ° C. This seawater is then desalted in a reverse osmosis system. Out CN000101318724A It is known that thermal solar collectors are also suitable for preheating the salt water to temperatures of 40 ° C to 45 ° C. The solar energy is used exclusively thermally.

such Systems have the disadvantage that they are not used energy self-sufficient can be. Power plants, the seawater as cooling water use, and are electricity from the conventional power grid not available in all drinking water poor regions. In addition, fossil ones Energy sources for power generation not only expensive, but also only limited available.

The Preheating of salt water makes in principle also in the Seawater desalination based on membrane distillation sense. The Temperature levels are then not as in reverse osmosis limited to 40 ° C, instead are temperatures of 80 up to 85 ° C required. This is with limitations for the electrical efficiency of photovoltaic modules connected. Existing PV / T systems can also the required thermal power is not complete provide. Nevertheless, a combination of PV / T collectors with desalination plants based on membrane distillation quite possible. Publications on this topic are currently unknown.

Similar Results as for the example of reverse osmosis are for the combination of PV / T systems with nanofiltration, ultrafiltration or Microfiltration plants for the treatment of contaminated Surface or well water to be expected. The on the Raw water side pressures are much lower than in reverse osmosis, which increases the raw water mass flow and Thus, the thermal efficiency of PV / T systems a little less favorable than will turn out in reverse osmosis.

task the invention is to find a way of treating water treatment plants, especially those with membrane technology, energy self-sufficient with the help of solar energy at comparatively low cost. Another or additional task is the existing procedures and to improve systems and the disadvantages of the prior art avert.

These The object is solved by the features of claim 1.

The Invention provides a system for water treatment with a photovoltaic system ready, with the waste heat of the photovoltaic system in operation preheating the raw water for later processing.

Under A PV / T system or a PV / T system, for example, is the combination a photovoltaic system (PV) with a thermal solar collector (T) in a structural unit. This affects everyone Systems and / or installations that are both electrical and thermal Generate energy from solar energy. A property of conventional PV modules is that with increasing solar Irradiation increases the module temperature and the electrical efficiency with about 0.5% per K falls. In so-called hybrid PV / T systems you can use this temperature increase for heating a fluid (mostly water or air) use. A thermal efficiency from 45-65% is possible. At the same time that will Photovoltaic module, z. B. by the water to be desalinated, cooled, which has a positive effect on the electrical efficiency of the photovoltaic module effect. The solar energy is thus used by the photovoltaic modules of Plant not only electrically, but also used thermally, so that a PV / T system with photovoltaic and simultaneous thermal Application exists. Overall, this also results in a higher overall efficiency of the water treatment system. The use of PV / T systems in the field of water treatment is novel and can be an amount to solve the global drinking water problem contribute.

The The present invention relates to a system for desalination of water, the system comprising a photovoltaic system. The system is configured so the water to be desalinated by the waste heat to heat the photovoltaic system.

The System is preferably in addition to use in the desalination of Also generally used for water treatment in the sea Generally beneficial.

Of the Term "water desalination" is the name here for the production of drinking water or industrial water Seawater by reducing the salt content.

A "desalination" can refer to several processes, the salts and minerals from the water remove, especially to win drinking water.

The system for desalination or water treatment includes a photovoltaic system ge and may comprise in one embodiment, a pump system and / or supply lines for the water to be desalted or treated (ie the raw water). The supply lines may in this case be suitable, in particular, to lead salt water and z. B. made of a salt water resistant material such as a plastic (for example, polypropylene, polyethylene, polytetrafluoroethylene (PTFE), synthetic resin, etc .. Also plastics with fillers such as metals or ceramics to increase the thermal conductivity of the plastic are conceivable). The pump system may be suitable to bring the raw water to the photovoltaic system and / or from the photovoltaic system to a membrane unit described in more detail below. At the photovoltaic system, the raw water is heated by the waste heat of the photovoltaic system, whereby the raw water on the other hand can cool the photovoltaic system. The thus heated raw water can then be processed in the membrane unit.

The Photovoltaic system can z. B. one or more solar cells (photovoltaic cells) include. If several solar cells are provided, these can be over an electrical interconnection of the solar cells in a module (solar cell module, Photovoltaic module) may be arranged. This module can then be designed in this way be that several solar cells are connected in series and on this way a solar cell array inside the solar cell module form so that their output voltages add up. Also can within the solar cell module several of these rows of solar cells be switched in parallel. The photovoltaic system can z. B. a Array of solar cell modules include, where in well-defined Way certain solar cell modules are added or turned off can. In one embodiment, the array comprises Solar cell modules of different efficiency. For example, a few solar cell modules may be off Solar cells can be constructed, even at higher heat-exhaust temperatures as the solar cells of other solar cell modules reach the same efficiency, so that the raw water when connecting these solar cell modules stronger can be heated. Under "waste heat" is here in particular by the solar cell through the heat conduction and / or radiation emitted heat understood. The more energy the solar cell has absorbed by the sun, the more more waste heat can be available.

This Concept of adding or disabling certain solar cell modules with higher waste heat can z. B. for the later explained membrane distillation, can use the higher preheated raw water, be beneficial. Should instead of membrane distillation the system for Water treatment can be carried out according to the reverse osmosis process, could be the existing solar cell modules, the stronger Have waste heat, be turned off. Thus, it is possible the system in a simple way the respective water treatment process adapt. Also, with such a system depending on the needed electrical energy (eg for the pump system) the full electrical power of the array or just a specific one Part of it will be retrieved.

According to the According to the present invention, the system is configured to Desalinating water due to the waste heat of the photovoltaic system to warm up. In this case, the photovoltaic system generates not only electrical, but also thermal (eg inherent) Energy. The heating of the water can be characterized in particular happen that the system has means to be desalted (or general: the water to be treated close to the photovoltaic system bring to. For example, this can be done through hoses, on at least one of the side surfaces of the photovoltaic system or the solar cell module, in particular at the rear side (The side facing away from sunlight) are arranged. In one embodiment, these hoses be arranged in loops / loops or in any other pattern, z. B. to a heat radiating surface of the photovoltaic system or the solar cell module as effectively as possible. In this way, that can be passed through the hoses Raw water also cool the photovoltaic system or the solar cell module, z. B. to control the efficiency accordingly. The tubes can z. B. made of a salt water resistant material be, z. B. of a plastic.

In an embodiment may conventional PV / T systems used to treat the water to be treated, preferably Salt water, to warm. In this case, preferably a heat exchanger provided, which the reprocessed Water heated by another fluid, from which the reprocessed Water in the heat exchanger absorbs energy. In this way can the water to be treated indirectly, so z. B. over another fluid, to be heated.

• (a) einem Material der Solarzellen (Solarzellen aus monokristallinem, polykristallinem Silizium, Dünnschichtzellen, Farbstoff-(Gräzel)-Solarzellen, organische Solarzellen, usw.),
• (b) einem Material des Absorbers und Wärmeübertragers der thermischen Einheit (Metalle wie z. B. Kupfer, Kunststoffe, Keramiken, usw.),
• (c) einer Geometrie des PV/T-Systems (Flachkollektoren, konzentrierende Systeme, usw.),
• (d) einer Geometrie der sich hinter den Solarzeilen befindenden thermischen Einheit (Kanal- oder röhrenförmiger Wärmeübertrager, usw.),
• (e) einer Anzahl der eventuellen Abdeckungen, die über den Solarzellen angebracht sind (keine, eine, mehrere),
• (f) einem Material der Abdeckungen (Glas, Teflon, Kunststoff, usw.),
• (g) einem eventuellen Arbeitsfluid, das in dem PV/T-System strömt (Wasser, Luft, usw.),
• (h) einer Art und einem Material der verwendeten Isolierungen,
• (i) einem Einsatz von Spiegeln zur Konzentration von Sonnenstrahlen.

The PV / T systems described here, which are used in conjunction with water treatment plants with membrane technology, thus generate both electrical and thermal energy (and heat a fluid for example with the aid of this thermal unit) with the aid of solar cells and use the latter to heat the water to be treated. It does not matter how this system, referred to as a PV / T system, is constructed. All systems are recorded, independent of

• (a) a material of the solar cells (monocrystalline, polycrystalline silicon solar cells, Thin-film cells, dye (Gräzel) solar cells, organic solar cells, etc.),
• (b) a material of the absorber and heat exchanger of the thermal unit (metals such as copper, plastics, ceramics, etc.),
• (c) a geometry of the PV / T system (flat plate collectors, concentrating systems, etc.),
• (d) a geometry of the thermal unit located behind the solar cells (duct or tubular heat exchanger, etc.),
• (e) a number of any covers that are placed over the solar cells (none, one, more),
• (f) a material of the covers (glass, teflon, plastic, etc.),
• (g) any working fluid that is flowing in the PV / T system (water, air, etc.),
• (h) a type and a material of the insulation used,
• (i) use of mirrors to concentrate sunbeams.

Much more The above alternatives provide preferred embodiments represents.

When a disadvantage of PV / T systems outside the technical Area of water treatment was previously considered that in a comparatively good electrical efficiency that flowing in the PV / T collector Fluid can only be heated to low temperature levels. Good electrical efficiency can be achieved at PV module temperatures guaranteed up to 40 ° C. That in turn means that a cooling fluid circulating behind the solar cells maximum temperatures of 30 ° C to 40 ° C can. This temperature level can, however, for a Conventional PV / T application in the field of process water, process heat or heating without additional heating support (eg by means of a separate solar collector) to be too low.

One Field of application that has not yet been developed is now the invention described use of PV / T systems for the energy supply of water treatment plants. The one of the Solar cells generated electricity, for example, the pumps for drive the necessary raw water flow, as above described. Due to the simultaneous thermal application of the photovoltaic system the raw water is preheated, causing it to temperatures be heated to a maximum of 40 ° C to 45 ° C. can. This temperature level, as already explained above was at the same time the upper limit for the water temperatures in Membrane systems, since the majority of the membranes at higher Temperatures are destroyed.

Consequently provides the present invention a simpler and thus more cost-effective, with only one photovoltaic system (PV / T system) operated water treatment system to disposal.

In order to estimate the technical potential of systems according to the invention with PV / T-operated reverse osmosis plants for brackish water and seawater desalination, a simulation for 16 different cases has been implemented and carried out (see Spinnler, M., Kroiß, A., "Potential Analysis for Integrated Brine Preheating in Solar-Powered Water Treatment Systems" , Internal Feasibility Study). With weather data from Almeria and Puerto Rico locations of two different latitudes were simulated. Almeria stands for a Mediterranean and Puerto Rico for a tropical climate. The analyzes were each done for two different salt water sources: open sea water on the one hand and deep well water on the other. In order to make a statement about the added value of each of these PV / T-powered plants, the systems under consideration were compared with a corresponding PV-operated plant without thermal utilization according to the invention.

For a PV / T RO system according to the invention was obtained The following: Due to the preheating of the raw water and the Cooling the solar cells can increase the permeate production of about 35 to 40% can be achieved. This could be approximately Save 25 to 30% of PV module area, assuming that the plants considered produce equal amounts of permeate should.

The Investment costs for PV / T systems with photovoltaic and thermal application are about 10% higher than the pure PV systems in which only electrical energy can be used should be made. This means that the inventive Use of PV / T systems instead of PV systems for power supply of reverse osmosis systems makes economic sense, after all 25 to 30% savings in PV module area. This realization can also be applied to pure filtration processes for processing transmitted from contaminated surfaces or well water. The potentials are similar here, being opposite RO systems a slightly lower thermal efficiency of the PV / T systems could be expected.

Of the Use of a photovoltaic system using its waste heat is thus in the present technical field of water treatment, in particular desalination, a great advantage.

Known photovoltaic systems have been used for water treatment purposes only for powering up the plant supply system. By heating the solar cells by solar radiation, however, the efficiency of the solar cell can be significantly reduced, so that cooling of the solar cells, usually by air or water, may be necessary.

This The present invention makes use of the fact that the (For example, water to be desalinated) heated by the waste heat of the solar cells and thus better to the needs of the following treatment steps can be adjusted. Thus, advantageously, an optimum Operation of both the solar cells and a subsequent treatment plant be achieved.

existing Systems for water treatment systems use the photovoltaic system only for the production of electricity, without the resulting thermal To use energy.

The previous teachings regarding thermal energy development When sun exposure on a solar cell go into a completely other direction: The heat radiation of the solar cell became common by appropriate cooling as much as possible equalized while the present invention is this makes use of thermal energy.

In In one embodiment, the photovoltaic system is such configured, necessary for operating the system electrical energy to deliver.

On this way the system can, preferably independent of other energy sources, water treatment, especially the Desalination water. Thus, the system is just for use in developing countries and of electricity or other energy networks far away places particularly suitable.

In In one embodiment, the system comprises a membrane unit, which is configured to the salinity of the heated To reduce water.

A Membrane unit here is any device that includes a membrane and configured to treat raw water. Possible Methods using such a membrane unit are for. B. reverse osmosis, membrane distillation, nanofiltration, ultrafiltration and microfiltration. Depending on the used Processing, in particular desalting, is the Membrane of the membrane unit a semipermeable membrane and has a pore size of 0.1 to 5 nm (eg for Reverse osmosis) and / or 0.05 to 0.5 mm (membrane distillation). In one embodiment, the membrane may be hydrophobic, z. B. in use as a membrane for membrane distillation.

• (a) einem bestimmten Membrantyp (Spiral-Wickelmembranen, Hohlfasermembranen, Platten-Membranen, usw.) und Membranmaterial,
• (b) einem Wirkprinzip (Umkehrosmose, Membrandestillation, Nanofiltration, Ultrafiltration, Mikrofiltration usw.),
• (c) einer Anzahl an Membranen,
• (d) einer Anordnung der Membranen (parallel oder in Serie,)
• (e) einer Zusammensetzung des Fluids, das durch die Membran strömt.

For example, water treatment plants, in particular water desalination systems, based on membrane processes operated with PV / T systems, require semipermeable membranes for the filtration of the raw water. Various membranes can be used in a membrane unit of the system according to the invention. All conceivable membrane units which are suitable for carrying out a water treatment, in particular a water desalination, are possible in the system. The membrane unit of the system can thus be independent of

• (a) a certain type of membrane (spiral wound membranes, hollow fiber membranes, plate membranes, etc.) and membrane material,
• (b) a mode of action (reverse osmosis, membrane distillation, nanofiltration, ultrafiltration, microfiltration, etc.),
• (c) a number of membranes,
• (d) an arrangement of the membranes (parallel or in series)
• (e) a composition of the fluid flowing through the membrane.

Much more The above alternatives provide preferred embodiments represents.

In In one embodiment, the membrane unit comprises a Reverse osmosis system.

A Variant of water treatment plants with membrane technology are so-called reverse osmosis plants. In a desalination is the salt in this case by membrane filtration under high pressure from the water separated. The remaining, pure water, the so-called Permeate, can then be treated to drinking water.

in the Detail becomes in the reverse osmosis (RO) ("reverse osmosis") the solution to be treated (eg the seawater) under high pressure, in order to overcome the osmotic pressure, pressed by a semipermeable membrane. This membrane acts like a filter and leaves only certain atoms and / or molecules and / or ions. Thus one obtains a separation of original solution. Through the membrane filter can be z. As salt, bacteria, viruses, lime and certain Poisons, such as As heavy metals, withhold.

In In one embodiment, the membrane unit comprises a Membrane distillation plant.

Membrane distillation is based on a process where treated water is obtained by condensation after membrane filtration. For example, in a desalting process a microporous and / or hydrophobic membrane may be used which only allows water vapor to pass but retains liquid water. On one side of the membrane is warm salt water (eg heated by the waste heat of the photovoltaic system) and on the other side a colder surface. If there is a temperature difference along the entire length of the membrane, a water vapor partial pressure gradient results, which causes water molecules to pass from the hot to the cold side of the membrane and condense there.

at The desalination based on membrane distillation can be achieved by the Use of PV / T systems the required thermal power though may not be fully available be put, but the preheating by such photovoltaic systems is nevertheless profitable and increases in an advantageous manner Way the efficiency of the overall system.

In In one embodiment, the system may be thermal solar collectors include.

To the Example, the raw water on the waste heat of the Photovoltaic system will be heated (preheated), then from the thermal solar collectors to an even higher Temperature to be brought. In this way are particularly high To reach temperatures for the raw water, in particular Temperatures at which the photovoltaic system too low Efficiency would still be effective to power produce.

Especially could such a system in the water treatment be used with a membrane distillation process, at the higher raw water temperatures of about 80 ° C were beneficial.

In In one embodiment, the system does not include any additional Means for heating the water to be desalinated, in particular no solar panels.

In Thus, in one embodiment, the system comprises for heating of the raw water (i e of the product to be desalinated and / or treated Water) only the photovoltaic system. For example, no thermal Solar collectors provided to (further) heat the raw water, to reach higher temperatures for the raw water, before it is processed in the membrane unit (eg by its salt content is reduced). "No additional Means for heating the water to be desalinated "means in particular, that no thermal energy generating Means is provided that non-thermal energy targeted in converts thermal energy, then the water to be desalinated to warm up.

On This way, a particularly simple and therefore cost-effective Be provided system in which the necessary for the power supply Photovoltaic system also as a thermal component of the system is used to heat the raw water.

Especially could such a system in the water treatment be used with a reverse osmosis process, in which raw water temperatures from 40 ° C to 45 ° C would be beneficial and already by the waste heat of the photovoltaic system can be achieved.

As described, the present invention uses the waste heat of solar cells or a photovoltaic system to the reprocessed To heat water directly or indirectly and thus one optimized operation of the treatment or desalination plant enable. While retaining this advantage allows the invention further, the photovoltaic system by desalzendes or to be treated water to cool and thus simultaneously to optimize the operation of the photovoltaic system. In a preferred Embodiment is allowed to be desalted or the water to be treated or cleaned, the photovoltaic system cools.

By the cooling of the photovoltaic system with the colder Raw water can ensure their effectiveness and their efficiency is kept constant.

In In one embodiment, the system comprises an energy buffer, which is coupled to the photovoltaic system and configured in such a way is to compensate for temperature fluctuations of the waste heat.

The energy buffer can be in the form of a heat accumulator, wherein the heat accumulator optionally stores excess heat energy from the photovoltaic system. Excess heat energy can z. B. be present if not all the waste heat for the heating of a certain amount to be reprocessed (eg., To be desalinated) water is needed. Heat storage can z. B. long-term and / or temporary storage. Long-term storage can z. B. hot water heat storage (insulated container with water). Also thermochemical (eg on the basis of silica gel and / or zeolite) and latent heat storage (salts or paraffins melt when supplied with heat and give exactly this received heat energy on solidification again) can be used as long-term storage. Short term storage stores heat only for a few hours or days. For this purpose, for. As self-standing water storage tank or thermochemical heat storage as described above be set.

Consequently if necessary, the heat accumulator can be the photovoltaic system when heating particularly cool raw water support and temperature fluctuations in a simple way compensate.

In In one embodiment, the system comprises a cache for the heated water. For example, heated Water is led out of the buffer to the membrane unit, in particular if water to be desalinated or water to be treated not fast enough and / or in insufficient amount from the photovoltaic system can be heated.

On This way can cause fluctuations in the water supply the membrane unit can be reduced.

In In one embodiment, the system comprises a battery (Accumulator) for storing or caching electrical Energy. For example, part of the photovoltaic system received / generated electrical energy stored in the battery become. Especially with insufficient solar radiation on the photovoltaic system may need to operate the system electrical energy can be taken from the battery.

On This way, in particular, fluctuations in the power supply of the system. In a particular embodiment Thus, a substantially constant operating pressure can be achieved become.

In In one embodiment, the system comprises a heat exchanger. For example, the heat exchanger may be suitable, the Preheat raw water before entering the photovoltaic system, and / or heated water, especially before and / or after treatment / desalination z. B. to use for cooling the photovoltaic system.

On this way, the efficiency of the system can be further increased. Also, this way can be cooled with fresh water be realized when cooling or already desalinated water led to the photovoltaic system becomes. The water to be desalinated is then preferably in a Heat exchanger through the heated cooling water heated. In particular, water can pass through the PV / T facility was heated, the raw water, preferably over Heat the heat exchanger.

In In one embodiment, components of the system are in particular made of a salt water resistant material such as a plastic (e.g. Polypropylene, polyethylene, polytetrafluoroethylene (PTFE), synthetic resin, and much more .; also plastics with fillers such. For example metals or ceramics for increasing the thermal conductivity the plastic are conceivable) and / or at least partially with this coated and / or treated accordingly. These components can For example, be components of the system that use salt water in Contact, in particular hoses, supply lines, etc.

The The present invention also relates to a process for desalination of water. The method comprises the following step: (a) heating of the water to be desalinated with the waste heat of a photovoltaic system.

In particular embodiments of the method are the above descriptions and explanations of the characteristics of inventive system and in the above context explained concept of the invention as well for the Inventive here and hereinafter described Method.

In In one embodiment, the photovoltaic system provides for Desalination of water necessary electrical energy, ie z. B. the for operation of the water treatment system (eg the desalination system) necessary electrical energy.

The from the photovoltaic system generated electrical energy can For example, to be used to demineralized water z. B. via lines by means of pumps to the photovoltaic system to bring where the water is preheated. Next can the electricity generated by the photovoltaic system should serve others System components, such as B. the membrane unit to supply, to the actual water treatment / desalination of the preheated To carry out water.

In In one embodiment, the method comprises the following Step: (b) Reduce the salt content of the heated water in a membrane unit.

In In one embodiment, in step (b), the heated Water under high pressure through a semipermeable membrane filtered.

To the Example, the heated water in a reverse osmosis process be prepared or desalted.

In In one embodiment, in step (b) steam of the heated water through a semi-permeable hydrophobic membrane separated from saline water.

To the Example may be the heated water in a membrane distillation process be prepared or desalted.

In In one embodiment, the temperature of the heated Water using an energy buffer on the photovoltaic system controlled and / or adjusted.

To the For example, the energy buffer can be coupled with the photovoltaic system be. Further, the energy buffer may be configured to vary temperature to compensate for the waste heat, thereby reducing the temperature of the heated water and / or (on a certain value).

The The present invention also relates to a computer program product. the at least one computer-readable medium executable on a computer Instructions for carrying out the method steps discussed above includes.

To the For example, the computer program product may include a computer program, which is suitable to control the flow of water treatment and / or to control. In one embodiment, the computer program the functioning of the system with photovoltaic system and, if necessary also with membrane unit control and / or control. For example came at the end of the computer program, the photovoltaic system so be controlled that solar cell modules at certain times be turned on or off, that the generated electricity for additional means in the system (eg for a pump system) is used and that the heated water is the membrane unit reached and there prepared accordingly and if necessary afterwards is treated further. In one embodiment, the Computer program product may be suitable for use in the system to control located sensors to z. B. Data about the Temperature and / or the salt content of the heated water and / or the raw water and depending on from this one particular process of the water treatment process set.

The The present invention further relates to the use of PV / T systems both to the electrical power supply for a Plant for water treatment based on the membrane technology necessary Machines that require electrical power to operate is, as well as for preheating the raw water, to an optimum operating temperature and thus the greatest possible performance to guarantee the membranes.

1 schematically shows a water treatment system with a photovoltaic system.

To illustrate how, for example, a PV / T operated reverse osmosis system can be constructed serve. shows a possible plant configuration, exemplified here as a combination of PV / T systems (a PV / T system) with a reverse osmosis system / unit for solar desalination in a water treatment system, in particular in a desalination system.

For the reverse osmosis process, the membranes are the basic building block 8th , The high pressure pump 7 increases the pressure of salt water 0 Depending on the salt content, before the entry of the membrane, approx. 60 bar. The pump 7 is supplied with the electrical energy in the PV / T systems 3 is produced. To cushion too high fluctuations in the energy supply, an accumulator 6 used as a buffer for the electric current. The temperature dependence of the performance of the membrane is intended by preheating the raw water 0 in the PV / T collectors or in the photovoltaic system 3 be exploited. Between high-pressure pump 7 and the collectors 3 there is a hot water tank 5 , This serves as a buffer for the heated raw water. In this way, large fluctuations in the water supply of the individual reverse osmosis units 8th be avoided. The temperature at which the membranes work optimally is about 40 ° C. In order to keep the temperature level almost constant, in addition to the PV / T systems, optional pure solar collectors could be used 4 or means for heating the water to be treated / desalted be attached.

One way of recovering energy is here with the heat exchanger 1 indicated. The temperature of the feed water (raw water) 0 It will be so even before entering the individual collectors 3 . 4 raised. Overall, an additional increase in drinking water production can be achieved. Whether the water pre-treatment 2 before or after the heat exchanger 1 and the collectors 3 . 4 is to be decided in the design of the plant. The permeate 9 For example, by adding minerals, pH correction, etc. 11 finally to drinking water 12 edited.

In large plants, a second form of energy recovery is often used: The pressure recovery - it is due to high investment costs only in large plants economically viable. With such systems, energy savings of 65 to 75% are possible. If the excess yield of permeate stream is converted into comparable energy savings through the use of PV / T systems, an additional yield of 35% can be interpreted as energy recovery of 25%. PV / T Syste Although this does not reach the dimensions of pressure recovery systems, the result is nevertheless very promising. The idea now suggests that PV / T systems can be used exactly where pressure recovery systems become unprofitable - especially in energy-self-sufficient small plants.

LIST OF REFERENCE NUMBERS

0

Meerwasser/aufzubereitendes Wasser/Brackwasser (bspw. aus einem Tiefbrunnen, einem Reservoir oder direkt aus dem offenen Meer)

1

Wärmetauscher

2

Wasservorbehandlung (Filtration, Säurezugabe, und/oder Anti-Scalants, usw.)

3

PV/T-Systeme

4

Thermische Solarkollektoren

5

Warmwasserbehälter

6

Batterie(n)/Akkumulator(en)

7

Pumpe (z. B. 60 bar)

8

Umkehrosmoseeinheiten (Membranen)

9

Permeat

10

Konzentrat

11

Wassernachbehandlung (Zugabe von Mineralien, PH-Wertkorrektur, usw.)

12

Trinkwasser

Designation list Fig. 1:

0

Sea water / water / brackish water (eg from a deep well, a reservoir or directly from the open sea)

1

heat exchangers

2

Water pre-treatment (filtration, acid addition, and / or anti-scalants, etc.)

3

PV / T systems

4

Thermal solar collectors

5

Hot water tank

6

Battery (n) / accumulator (s)

7

Pump (eg 60 bar)

8th

Reverse osmosis units (membranes)

9

permeate

10

concentrate

11

Water after-treatment (addition of minerals, pH correction, etc.)

12

Drinking water

2 shows schematically another example of a water treatment system with a photovoltaic system.

Also in 2 are the membrane units 26 the basic building block for the reverse osmosis process. The high pressure pump 25 can reduce the pressure of salt water 20 depending on the salt content on the z. B. increase about 60 bar. The pump 25 For example, it is supplied with electrical energy in the photovoltaic system 22 , preferably a PV / T system. An accumulator 24 can be used as a buffer for electric power, in particular to cushion too high fluctuations in the power supply. Similar to the example described above, the temperature dependency of the performance of the membrane units also becomes 26 preferably by preheating the raw water 20 in the photovoltaic system 22 exploited. Between the pump 25 and the photovoltaic system 22 is preferably a hot water tank 23 provided to serve as a buffer for the heated raw water. In this way, preferably large fluctuations in the water supply of the individual reverse osmosis units can be avoided.

As in 1 already described, preferably a water pretreatment 21 provided, z. B. to pre-filter the water to be treated accordingly, adjust the acidity or admit Antiscalants. After the reverse osmosis process then the permeate 27 for example, by adding minerals, and / or by a pH correction, etc. 28 finally to drinking water 29 be prepared. That in the membrane units 26 from the permeate 27 separate concentrate 30 For example, it may ultimately be returned to seawater or a raw water reservoir 20 be supplied.

LIST OF REFERENCE NUMBERS

20

Meerwasser/aufzubereitendes Wasser/Brackwasser (bspw. aus einem Tiefbrunnen, einem Reservoir oder direkt aus dem offenen Meer)

21

Wasservorbehandlung (Filtration, Säurezugabe, und/oder Anti-Scalants, usw.)

22

Photovoltaik-Anlage, vorzugsweise PV/T-System

23

Warmwasserbehälter

24

Batterie(n)/Akkumulator(en)

25

Pumpe (z. B. 60 bar)

26

Umkehrosmoseeinheiten (Membranen)

27

Permeat

28

Wassernachbehandlung (Zugabe von Mineralien, PH-Wertkorrektur, usw.)

29

Trinkwasser

30

Konzentrat

Designation list Fig. 2:

20

Sea water / water / brackish water (eg from a deep well, a reservoir or directly from the open sea)

21

Water pre-treatment (filtration, acid addition, and / or anti-scalants, etc.)

22

Photovoltaic system, preferably PV / T system

23

Hot water tank

24

Battery (n) / accumulator (s)

25

Pump (eg 60 bar)

26

Reverse osmosis units (membranes)

27

permeate

28

Water after-treatment (addition of minerals, pH correction, etc.)

29

Drinking water

30

concentrate

The Detailed description of the present invention and v. a. the Embodiments are essentially illustrative and are exemplary and not restrictive to understand. Features that in connection with a particular embodiment or a Under claim are described, can also be beneficial when they are considered features for other described embodiments or not described alternatives and / or equivalents or other subclaims, even if they are in their Context were not explicitly described. amendments and modifications of the described embodiments and The claimed subjects are covered by the invention as well as a person skilled in the art while reading the description and studying the figures and the claims this would have recognized. The verb "to include" means in the description and the claims that further Elements and / or process steps may be present and the indefinite article "a" closes the plural is not enough.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - ES 000002299396 A1 [0006]
• - CN 000101337749 A [0006]
• - WO 2006067240 [0006]
• US 200200236309 A1 [0008]
• - CN 000101318724 A [0008]

Cited non-patent literature

• - Spinnler, M., Kroiß, A., "Potential analysis of integrated brine preheating in solar-powered water treatment plants" [0030]

Claims (14)

Desalination system comprising a photovoltaic system ( 3 ), the system being configured to deliver the water to be desalinated ( 0 ) by the waste heat of the photovoltaic system to heat. System according to claim 1, wherein the photovoltaic system ( 3 ) is configured to supply necessary electrical power to operate the system A system according to claim 1 or 2, wherein the system comprises a membrane unit ( 8th ) configured to reduce the salinity of the heated water. A system according to claim 3, wherein the membrane unit ( 8th ) comprises a reverse osmosis system. A system according to any one of claim 3, wherein the membrane unit ( 8th ) comprises a membrane distillation plant. System according to one of the preceding claims, wherein the water to be desalted ( 0 ) the photovoltaic system ( 3 ) cools. The system of any one of claims 2-6, wherein the system comprises an energy buffer coupled to the photovoltaic system and configured to compensate for temperature variations in the waste heat, and wherein the photovoltaic system ( 3 ) is a PV / T system. A process for the desalination of water, comprising the following step: (a) heating the water to be desalted ( 0 ) with the waste heat of a photovoltaic system ( 3 ). Method according to claim 8, wherein the photovoltaic system ( 3 ) provides for water desalination necessary electrical energy. A method according to claim 8 or 9, comprising the following step: (b) reducing the salinity of the heated water in a membrane unit ( 8th ). The method of claim 10, wherein in step (b) the heated water under a high pressure by a semipermeable membrane is filtered. The method of claim 10, wherein in step (b) Water vapor of the heated water through a semipermeable hydrophobic membrane is separated from saline water. Method according to one of the preceding claims, wherein the temperature of the heated water by means of an energy buffer ( 5 ) at the photovoltaic system ( 3 ) is controlled and / or adjusted. Computer program product comprising at least one computer readable medium. with instructions that can be run on a computer for carrying out the method steps according to one of the claims 8 to 13.

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