DEVICE AND METHOD FOR PREVENTING FLOODS

Abstract

The invention relates to a device and a method for preventing floods in the event of a river carrying floodwater. At least one mainline is provided which leads from the region of the floodplain to a collection basin and has one or more pumps in order to pump part of the floodwater through said mainline to the aforementioned collection basin in the event of floodwater, the base of said collection basin lying at a higher level than the riverbed such that electric energy is converted into potential energy of the water during the operation of the at least one pump. According to the method, the electric energy for operating the at least one pump is drawn from a local energy store or is converted in situ from a third energy form which differs from electric energy and hydropower. This is achieved using a device for drawing the electric energy for operating the at least one pump from a local energy store or converting the electric energy in situ from a third energy form which differs from electric energy and hydropower.

Claims

1. A method for preventing floods in the event of a river (1) carrying floodwater, wherein at least one mainline (5) is provided which leads from the region of the floodplain to a collection basin (6) and has one or more pumps (4) in order to pump part of the floodwater to said collection basin (6) in the event of floodwater (6), the base of said collection basin lying at a higher level than the bed of the river (1) so that electric energy is converted into potential energy of the water during the operation of the at least one pump (4), characterized in that the electric energy for operating the at least one pump (4) is drawn from a local energy store or is converted in situ, preferably in the region of the collection basin (6) or the pump(s) (4) from a third energy form which differs from electric energy and hydropower.

2. The method according to claim 1, characterized in that the electric energy for operating the at least one pump (4) is stored as direct current by means of accumulators.

3. The method according to claim 1, characterized in that the electric energy for operating the at least one pump (4) is stored in the form of a gas, for example in the form of hydrogen gas.

4. The method according to claim 3, characterized in that the gas, for example the hydrogen gas, is produced through electrolysis from water by means of electricity.

5. The method according to claim 3, characterized in that electric energy can be produced from the stored gas, preferably hydrogen gas, if needed, by means of at least one fuel cell.

6. The method according to claim 1, characterized in that the electric energy for operating the at least one pump (4) or for charging the accumulators or for producing a gas by means of electrolysis in situ is produced from wind energy or solar energy or from geothermal energy.

7. The method according to claim 6, characterized in that an apparatus for converting wind energy into electric energy is constructed as a wind power plant, consisting of a tower and a wind turbine arranged movably thereon.

8. The method according to claim 1, wherein several pumps (4) are provided at various locations, in particular at various heights, in a mainline between the floodplain and the collection basin (6), characterized in that the pumps (4) are put into operation one after the other in the case of an emptied mainline (5), beginning with the pump (4) nearest to the floodplain.

9. A device for preventing floods in the event of a river (1) carrying floodwater, with at least one mainline (5), which leads from the region of the floodplain to a collection basin (6) and has one or more pumps (4) in order to pump part of the floodwater to said collection basin (6) in the event of floodwater, the base of said collection basin lying at a higher level than the bed of the river (1) so that electric energy is converted into potential energy of the water during the operation of the at least one pump (4), characterized in that to supply the at least one pump (4) with electric energy in situ, preferably in the region of the collection basin (6) or of the pump(s) (4), a local energy store is provided and/or an apparatus for converting a third energy form, which differs from electric energy and hydropower, to electric energy.

10. The device according to claim 9, characterized by accumulators for storing the electric energy in the form of direct current to supply the at least one pump (4) with electric energy.

11. The device according to claim 9, characterized by at least one storage reservoir, preferably at least one pressure storage reservoir, for storing a gas, preferably hydrogen gas, to supply the at least one pump (4) with electric energy.

12. The device according to claim 11, characterized by an apparatus to produce gas, preferably hydrogen gas, through electrolysis from water by means of electricity, in particular from pure, filtered or distilled water.

13. The device according to claim 9, characterized by at least one apparatus installed in situ, preferably in the region of the collection basin (6) or the pump(s) (4), for generating electric energy to operate the at least one pump (4) or to charge the accumulators or to produce a gas by means of electrolysis, from wind energy or solar energy or from geothermal energy.

14. The device according to claim 13, characterized in that the at least one apparatus for converting wind energy or solar energy or geothermal energy into electric energy is located in the region of a collection basin (6), preferably in the collection basin (6) itself, if necessary, protected from moisture by a pedestal or other supports or by bulkheads.

15. The device according to claim 9, characterized in that an apparatus for converting wind energy into electric energy is constructed as a wind power plant, consisting of a tower and a wind turbine arranged movably thereon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Additional features, details, advantages and effects based on the invention are yielded from the following description of a preferred embodiment of the invention as well as based on the drawing, which shows:

[0044] FIG. 1 A first arrangement for protecting the areas adjacent to a river optionally carrying floodwater from the negative effects of floodwater; and

[0045] FIG. 2 Another arrangement to preserve areas in a region of the river carrying floodwater from damage in the event of floodwater.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] The drawing depicts a river 1, which can potentially produce floodwater in special situations, for example in the case of melting snow. The reference number 2 identifies its normal direction of flow.

[0047] In a region that is endangered by floodwater, it is preferred that several lines 3 branch off from the river 1, each of which is always equipped with at least one pump 4. These pumps 4 are used to suction off excess water from the river 1 in the event of a floodwater and transport it in the direction of a higher-lying mainline 5, which in this case runs parallel to the river 1.

[0048] The mainline 5 is likewise equipped with one or more pumps 4, which transport the water in the mainline in the direction of a collection basin 6, in which it can be stored.

[0049] The water remains in the collection basin 6 until the floodwater situation has improved substantially, and then can be redirected back to the riverbed 1 gradually, in particular if electricity is currently needed. In the process, the motors of the pumps 4 can be used as generators and the pumps 4 themselves as turbines, in order to generate electricity from the potential energy of the water and to supply said electricity to the power supply network, for storage or to be used otherwise.

[0050] Then, the sludge carried along by the water collects on the bottom of the collection basin 6 in question and in the subsequent growing season is used as a natural fertilizer in order to increase the yield of the relevant agricultural areas.

[0051] With the previously described system, it is possible to avert the risk of floodwater even in narrow valleys without the possibility of a polder, by pumping the excess water temporarily to a higher-lying level.

[0052] However, energy in particular three-phase current is required to operate the pumps 4. This energy is normally drawn from the public power supply network. However, especially in the region of larger rivers, energy for supplying the public power supply network is often derived from waterpower plants, which, however, in the case of floodwater, only provide a severely diminished level of power. If the power supply network is overloaded and collapses because of the concurrence of these events in the case of floodwater —lower electricity generation from hydropower, on the one hand, and increased demand for electricity to pump out the floodwater wave, on the other hand—then the system that was actually designed to protect against floodwater will fail at the crucial moment, because the pumps 4 are not supplied with electricity.

[0053] In order to be forearmed against this worst case, the invention provides for the pumps 4 according to the invention to be supplied primarily by neither the public power supply network nor by hydropower. Because precisely these forms of energy are relatively uncertain in the event of floodwater and therefore endanger the reliability of the system according to the invention.

[0054] Instead a first embodiment provides that an energy store be provided to supply the pumps 4, for example in the form of at least one system 7 having accumulators for the chemical storage of electricity. This type of system 7 can be situated in the direct proximity of the pumps 4. The charging capacity of such a system 7 should be designed so that a multi-hour operation of pumps 4 is ensured, for example for at least 12 hours, preferably for at least 24 hours, in particular for at least 36 hours. Furthermore, it must be ensured that the stored amount of energy always corresponds to at least half or at least two thirds of the maximum charging capacity or to preferably at least three quarters of the maximum charging capacity.

[0055] The electricity flowing out of this type of electricity storage system 7 is normally direct current to begin with, which must be converted into an alternating current or three-phase current to supply the powerful pumps 4. Inverters can be used for this. On the other hand, it would also be possible to drive a three-phase current generator with a powerful direct current motor, which then supplies the pumps 4; finally the pumps 4 could also be designed as direct current pumps.

[0056] So that charging such an electricity storage system 7 does not burden the public power supply network, the invention furthermore provides that the accumulators of an electricity storage system 7 according to the invention are not charged by the power supply network, but by means of renewable energies. The form of energy that is primarily recommended in this case would be wind energy, because it is available to a an increasing degree especially at higher elevations where most of the time a system according to the invention is installed. One could therefore set up one or preferably more wind turbines 8 in the proximity of a system according to the invention and supply the energy therefrom to the electricity storage system 7, and, once it is fully charged, supply the electricity that can no longer be accommodated to the public power supply network.

[0057] Even though this is not mandatory, the necessary wind power plants 8 could be set up in the process in the region of a collection basin 6 or even directly in such a collection basin 6. In standby mode, there is indeed no water in a collection basin 6 so that the wind power plants 8 located there are accessible via dry ground and can be serviced regularly. If the collection basin 6 in question is then flooded in the event of floodwater then the pedestals of the towers 9 of the wind power plants 8 might be standing in several meters of water, which is not a big problem though.

[0058] However, for this case, the access door to a wind power plant 8 could be positioned at a correspondingly high level, i.e., several meters above the level of the landscape with a dry collection basin 6, in particular above the maximum water level in the relevant collection basin 6 in the event of floodwater. Then special sealing measures are not required, which otherwise would have to be observed so that no water can penetrate into the tower.

[0059] In addition, if the power supply lines leading away from such a wind power plant 8 are likewise guided at a level above the maximum water level in the relevant collection basin 6 up to the rim thereof, for example in the form of a power supply line suspended on a pole, there is no danger of a short circuit from water, and in such a case the pedestal of a wind power plant could even be designed in such a way that, when the relevant collection basin 6 is flooded, it runs full of water, which is able to drain off again when the collection basin 6 empties. One advantage in this case would be that the empty tower pedestal is not subject to any buoyancy force and therefore the anchoring of the wind power plant 8 is ensured even when the collection basin 6 is flooded.

[0060] When the collection basin 6 is flooded, the maintenance personnel would come by a boat to the pedestal of a power plant 8, if a higher-lying bridge does not lead to the wind power plant 8 from the rim or banks of the collection basin 6.

[0061] A wind power plant 8 can also continue to generate electricity when the collection basin 6 is flooded and, as a result, refill the electricity storage system 7 again so that, in an ideal case, the service life of the pumps 4 is longer than would be anticipated in accordance with the charging capacity of the electricity storage system 7.

[0062] Solar energy also would also be considered for supplying the electricity storage system 7, wherein, however, photovoltaic modules should be arranged inside the collection basin 6, only if short circuits of all kinds are ruled out when the collection basin 6 is flooded.

[0063] Therefore, in general in the case of a flooded basin 6, an operation of the solar installation and therefore a refilling of the electricity storage system 7 are not possible in the event of floodwater.

[0064] The same applies for a replenishment of the electricity storage system 7 using hydropower, because in the event of floodwater most of the time this is available only to a limited extent or not at all.

[0065] If, in the event of floodwater, the electricity storage 7 gradually dwindles and also can no longer be recharged adequately by wind energy, it is also possible to fall back on the public power supply network if need be. Often the maximum level of the floodwater has already been exceeded by then and all pumps 4 do not need to run simultaneously anymore so that the public power supply network is spared nevertheless.

[0066] If calculations for a project according to the invention show that realizing the electricity storage system 7 by means of accumulators entails undesired high costs because of a high required charging capacity, there is the possibility of realizing a system such as the one depicted in FIG. 2.

[0067] In this case, the supply pipes 3 having pumps 4, the mainline pipe 5, the collection basin 6 and the wind power plant 8 can be realized like the system in FIG. 1; only the electricity storage system 7 is replaced or supplemented by a special design, which can be seen in FIG. 2.

[0068] In contrast to the circuit diagram according to FIG. 1, the positive and negative poles of a direct current system are depicted separately from each other in FIG. 2.

[0069] FIG. 2 shows that the electricity generated from wind energy in the wind turbine 8 is made available as direct current. It is supplied to an electrolysis plant 10, where an electrolyte 11, in particular distilled water H.sub.2O, is converted by means of direct current into hydrogen H.sub.2 and oxygen O.sub.2. In the process, the hydrogen H.sub.2 bubbles upward at the cathode 12, and the oxygen O.sub.2 at the anode 13. In a region above the cathode 12 and anode 13 separated spatially from each other in the horizontal direction, the space 14 of the electrolysis plant 10 which accommodates the aqueous electrolytes 11 is divided by a separating wall 15 into a first collection space 16 for the hydrogen H.sub.2 and a second collection space 17 for the oxygen O.sub.2.

[0070] Because these collections spaces 16, 17 can be built to be any size, large quantities of hydrogen H.sub.2 and oxygen O.sub.2 can be stored. In order to rapidly recover the energy stored therein if required, at least one fuel cell 18 is provided which has two chambers 20, 21 separated from each other by a membrane 19, and said chambers can be filled with hydrogen H.sub.2, on the one hand, and with oxygen O.sub.2, on the other, from the collection spaces 16, 17.

[0071] The membrane is configured such that it allows only ions to pass through, for example only protons H.sup.+. So that the protons H.sup.+ can nevertheless combine with the oxygen O.sub.2 to form water H.sub.2O, every proton H.sup.+ still needs an electron. However, the electrons are forced flow through a pipeline network attached to electrodes 22, 23 inside the chambers 20, 21, whereby they are able to perform work.

[0072] In particular, the electrodes 22, 23 can be used together with supply lines to supply the pumps 4. The water accumulating in the fuel cell 18 can be fed back to the electrolysis plant 10 via a pipe 24.

[0073] The generation of electricity within the fuel cell 18 can be controlled by valves 25, 26, which influence, in particular allow or block, the inflow of O.sub.2 and H.sub.2 from the collection spaces 16, 17 into the chambers 20, 21 of the fuel cell 18.

[0074] In the case of the depicted embodiment, instead of large chemical accumulators, only an unlimited number of large pressure vessels 16, 17 must be set up to collect hydrogen H.sub.2 and oxygen O.sub.2. If the fuel cell 18 is in a position to use the oxygen from the air, even the storage of oxygen O.sub.2 can be dispensed with, and only vessels for hydrogen H.sub.2 must be provided.

[0075] In order to obtain a sufficient amount of direct voltage if required, it can be necessary to use a plurality of fuel cells instead of a single fuel cell 18 and to connect those in series so that their voltages add up.

[0076] When using three-phase current pumps 4 naturally the direct current generated in the fuel cell 18 must first be converted to three-phase current, for example by means of one or more inverters.

[0077] An alternating voltage can then be stepped up with little effort in order to reach the voltage amplitude required for the three-phase current pumps 4.

[0078] To further support the gas storage system 27, the output voltage of the wind power plant 8 can be attached directly to the output voltage of the fuel cell system 18.

LIST OF REFERENCE NUMBERS

[0079] 1 River

[0080] 2 Direction of flow

[0081] 3 Supply pipes

[0082] 4 Pump

[0083] 5 Mainline pipe

[0084] 6 Collection basin

[0085] 7 Electricity storage system

[0086] 8 Wind power plant

[0087] 9 Tower

[0088] 10 Electrolysis plant

[0089] 11 Electrolyte

[0090] 12 Cathode

[0091] 13 Anode

[0092] 14 Space

[0093] 15 Separating wall

[0094] 16 Collection space

[0095] 17 Collection space

[0096] 18 Fuel cell

[0097] 19 Membrane

[0098] 20 Chamber

[0099] 21 Chamber

[0100] 22 Electrode

[0101] 23 Electrode

[0102] 24 Pipe

[0103] 25 Valve

[0104] 26 Valve

[0105] 27 Gas storage system