DE102022124381A1 - Method for raising groundwater levels in predetermined regions using seawater - Google Patents

Abstract

Disclosed is a method for raising the groundwater level in predetermined regions using seawater, comprising the steps of extracting the seawater, desalinating the extracted seawater, passing the desalinated seawater through at least one tunnel, and forwarding the desalinated seawater to freshwater consumption points.

Description

Field of invention

The present invention relates to a method for raising the groundwater level in predetermined regions using desalinated seawater.

State of the art

Dry years due to climate change are expected to become more common in the next few decades. There is no rain in many regions. The groundwater level will continue to fall. Dramatic consequences can be expected worldwide.

Artificial irrigation or water supply to large areas, where the water is taken from rivers or lakes, is technically not a problem and all the necessary components are technically sophisticated. However, the investment costs are huge and would only be justifiable if the drying out or desertification of these areas became so great that the follow-up costs would be even higher than the water supply costs.

Therefore, the object of the present invention is to provide a method with which the groundwater level can be raised in predetermined regions without taking water from rivers or lakes and thus ensure water supply.

Summary of the invention

According to a first aspect, the invention relates to a method for raising the groundwater level in predetermined regions using seawater, comprising the steps: extracting the seawater, desalinating the extracted seawater, passing the desalinated seawater through at least one tunnel and forwarding the desalinated seawater to fresh water -Consumption points.

The advantage of the method of raising the groundwater level in predetermined regions using seawater is that a further drop in the groundwater level is avoided. It is therefore not necessary to withdraw water from rivers or lakes.

It is preferred that the sea water has a salinity of 1-4%, preferably 0.7-2.5%, particularly preferably 0.3-1.5%.

The advantage of lower seawater salinity is that the costs of desalination, which preferably takes place on the coast, can be reduced.

It is preferred that the seawater is carried out using RO desalination.

It is preferred that the tunnel has a gradient of 1:50,000-1:150,000, preferably 1:75,000-1:125,000, particularly preferably 1:95,000-1:105,000.

The advantage of the tunnel gradient is that no pumps are needed to propel the desalinated seawater to reach target areas.

It is preferred that the tunnel has a temperature-resistant lining.

The advantage of a temperature-resistant cladding is that the water quality remains constant along the entire flow path to the consumer.

It is preferred that the tunnel has deformation-resistant formwork.

The advantage of the deformation-resistant formwork is that there is no stagnant water, which would impair the water quality.

It is preferred that the tunnel has at least one tunnel tube that is corrosion and/or frost resistant

The advantage of corrosion-resistant pipes is that they can be laid underground, thus minimizing evaporation losses.

It is preferred that the tunnel pipe has a diameter of 1.0-8.0 m, preferably 3.0-7.0 m, particularly preferably 5.5-6.5 m.

It is preferred that the tunnel has a minimum depth below the surface, which allows construction by tunnel boring machines (TBM) and ensures frost resistance.

The advantage of the minimal depth below the surface is that frost is avoided.

It is preferred that pumps are used to extract and transport the desalinated seawater from the tunnel pipes.

Groundwater motor pumps are preferred because they can overcome heights of up to 500 m and more and enable variable transfer.

It is preferred that the forwarding takes place using extraction pipes and/or forwarding pipes that are corrosion and/or frost resistant.

It is preferred that the transfer pipes have a minimum depth below the surface that ensures frost resistance.

It is preferred that the forwarded desalinated seawater is collected in at least one container at the points of consumption.

The advantage of the containers is that larger quantities of desalinated seawater can be stored.

It is preferred that the desalinated seawater flows out of the at least one container via at least one drainage pipe.

It is preferred that the at least one container is arranged on at least one surface elevation, preferably at its highest point.

The advantage of arranging the containers on at least one surface elevation is that a drainage area is larger than if the at least one container is arranged on the ground.

It is preferred that the surface elevation is 0-1000 m, preferably 15-750 m, particularly preferably 30-500 m.

It is preferred that the at least one surface elevation is artificially formed from excavation of the tunnel.

The advantage of forming at least one surface elevation from the excavation of the tunnel is that consumption points can be freely selected according to needs and are not dependent on existing surface elevations. In addition, there are no disposal costs for the excavation. Furthermore, containers and drainage pipes can be arranged during the filling, thereby avoiding further installation steps and costs.

It is preferred that the at least one drainage pipe has a length of 0.5-5.0 m, preferably 0.75-4.0 m, particularly preferably 1.0-2.0 m.

It is preferred that the method according to the invention be used to raise groundwater levels, feed the desalinated seawater into existing public or commercial networks, supply the desalinated seawater to consumers, fight forest fires and connect fire brigade hydrants.

The invention relates, according to a second aspect, to a system for raising the groundwater level in predetermined regions using seawater, comprising at least one seawater desalination unit for extracting and desalinating the seawater, at least one tunnel for conducting the desalinated water and at least one pump-pipe system. Device for transferring desalinated seawater to freshwater consumption points.

In the process according to the invention, so much additional water is added to the groundwater that the average level of the last 30 years can always be maintained. Extracting the water required for this from rivers or lakes is out of the question, as this would cause the groundwater level to drop further. Extracting and desalinating the water required for this from the sea would therefore be a solution. The product would be drinking water of good quality. The low salt content of the Baltic Sea, for example (1-1.5%) would significantly reduce the costs of RO desalination.

The desalinated water must then be passed on to consumers. This can be done through tunnel tubes. The respective consumers (municipalities, authorities or large customers such as steel mills, car factories, chemical industries) can then withdraw water from these tunnel tubes as needed and therefore forego the extraction of water from groundwater wells; the desalinated water can be fed into lakes and streams if they are significant Contribute to the enrichment of groundwater; it can be fed into existing public or commercial networks if their water is drawn from groundwater wells and these can then be partially decommissioned. Other possible uses for desalinated water include use to fight forest fires, connecting fire brigade hydrants at appropriate distances to the pipes from the tunnel to the consumer, to which the fire brigade can connect their hoses and thus get very quickly and very close to the sources of fire. As a result, the cost of extinguishing water would be significantly lower than transporting it from the nearest body of water with tank trucks or fire-fighting planes, although in certain cases these cannot of course be replaced, and extinguishing water would be available more quickly.

Since with surface irrigation a large part of the water would evaporate unused, including through interception, a direct feed would be necessary solution (seepage) into the groundwater area.

The seawater desalination plants would have to be built on the coast, as would the wind turbines required to generate electricity. A power cable along the tunnel is obvious and feasible.

Brief description of the drawings

• 1 eine schematische Darstellung einer Wasserentnahme aus einem Tunnel und eine Weiterleitung an einen Hügel aus Tunnelaushub und einen natürlichen Berg, und
• 2 eine mögliche von der Niederschlagshöhe abhängige Tunnelfiihrung in Deutschland

zeigt.Exemplary embodiments of the invention are described in more detail below with reference to the figures, where:

• 1 a schematic representation of water extraction from a tunnel and a transfer to a hill made of tunnel excavation and a natural mountain, and
• 2 a possible tunnel route in Germany that depends on the level of precipitation

shows.

Detailed description of the drawings

1 shows a tunnel 2 through which the desalinated water is passed. Sampling pipes 4, 6 are connected to this, with a pump 8 being arranged in the sampling pipe 6, which has a larger diameter than the sampling pipe 4. The pump 8 is connected to a drain device 10, which can be operated from the surface 12 in order to bring the pump 8 into a corresponding pumping position in the sampling tube 6. Extraction tube 4 is arranged horizontally and withdrawal tube 6 vertically, with withdrawal tube 4 protruding into the interior of the tunnel 2. On the sampling pipe 6, 12 forwarding pipes 14, 16 are arranged near the surface, the forwarding pipe 14 being arranged horizontally and the forwarding pipe 16 having a slope. Both transfer pipes 14, 16 are arranged underground, with a part of transfer pipe 16 being located below the surface 12. The other part of transfer pipe 16 is arranged above the surface 12, but is located within a surface elevation 18. Neither tunnel 2 nor sampling pipes 4, 6 nor transfer pipes 14, 16 are therefore visible to a user who is on the surface. At the highest point of surface elevation 18, here a plateau 20, a container 22 is arranged, into which the sampling tube 16 opens. Drainage pipes 24 lead from the container 22 down into the interior of the surface elevation 24. Furthermore, hydrants are connected to the forwarding pipe 14 and extend over the surface 12. Normal zero line 28 can also be seen. Tunnel 2, sampling pipe 4, part of sampling pipe 6 and pump 8 are located below normal zero line 28.

2 shows a possible routing of tunnels 2 in Germany depending on the level of precipitation.

Reference symbol list

2

tunnel

4, 6

Extraction tube

8th

pump

10

Drain device

12

surface

14, 16

Forwarding pipe

18

Surface elevation

20

plateau

22

container

24

Drainage pipe

26

hydrant

28

Normal zero

Claims (20)

Method for raising groundwater levels in predetermined regions using seawater, comprising the following steps: extraction of sea water; desalination of the extracted seawater; Conducting the desalinated seawater through at least one tunnel (2); and Forwarding desalinated seawater to freshwater consumption points. Procedure according to Claim 1 , wherein the seawater has a salt content of 1-4%, preferably 0.7-2.5%, particularly preferably 0.3-1.5%. Method according to one of the preceding claims, wherein the seawater is preferably carried out using RO desalination. Procedure according to Claim 1 , wherein the tunnel (2) has a gradient of 1:50,000-1:150,000, preferably 1:75,000-1:125,000, particularly preferably 1:95,000-1:105,000. Procedure according to Claim 4 , wherein the tunnel (2) has a temperature-resistant cladding. Procedure according to one of the Claims 4 - 5 , wherein the tunnel (2) has a deformation-resistant formwork. Procedure according to Claim 4 , wherein the tunnel (2) has at least one tunnel tube that is corrosion and / or frost resistant. Procedure according to Claim 7 , wherein the tunnel pipe has a diameter of 1.0-8.0 m, preferably 3.0-7.0 m, particularly preferably 5.5-6.5 m. Procedure according to Claim 1 , wherein the tunnel has a minimum depth below the surface (12), which allows construction by tunnel boring machines (TBM) and ensures frost resistance. Procedure according to Claim 1 , whereby pumps (8) are used to remove and forward the desalinated seawater from the tunnel pipes. Procedure according to Claim 10 , wherein the forwarding takes place by means of extraction pipes (4, 6) and/or forwarding pipes (14, 16) which are corrosion- and/or frost-resistant. Method according to one of the Claims 10 - 11 , wherein the transfer pipes (14, 16) have a minimum depth below the surface (12) which ensures frost resistance. Procedure according to Claim 1 , wherein the forwarded desalinated seawater is collected at the points of consumption in at least one container (20). Procedure according to Claim 13 , wherein the desalinated seawater flows out of the at least one container (20) via at least one drainage pipe 24. Procedure according to one of the Claims 13 - 14 , wherein the at least one container (20) is arranged on at least one surface elevation (18), preferably at its highest point. Procedure according to Claim 15 , wherein the at least one surface elevation (18) is 0-1000 m, preferably 15-750 m, particularly preferably 30-500 m. Procedure according to Claim 16 , wherein the at least one surface elevation (18) is artificially formed from excavation of the tunnel (2). Procedure according to Claim 14 , wherein the at least one drainage pipe has a length of 0.5-5.0 m, preferably 0.75-4.0 m, particularly preferably 1.0-2.0 m. Procedure according to Claim 1 for use when raising groundwater levels, feeding desalinated seawater into existing public or commercial networks, supplying desalinated seawater to consumers, fighting forest fires and connecting fire hydrants. System for raising groundwater levels in predetermined regions using seawater, comprising: at least one seawater desalination unit for extracting and desalinating the seawater; at least one tunnel (2) for conducting the desalinated water; and at least one pump-pipe device for forwarding the desalinated seawater to freshwater consumption points.

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