Energy store and device for providing thermal energy

Abstract

The invention presented relates to an energy store for storing thermal energy. The energy store comprises a storage volume and a system of hydraulic lines, wherein the storage volume is an earth bank, wherein the system of hydraulic lines comprises a multiplicity of lines for conducting a fluid through the storage volume, wherein the multiplicity of lines extend through the storage volume in the longitudinal direction, and wherein the multiplicity of lines are arranged in a multiplicity of layers extending one above the other.

Description

[0001] Energy storage and device for providing thermal energy

[0002] The presented invention relates to an energy storage device, a device for providing thermal energy and a manufacturing method according to the appended claims.

[0003] Large amounts of energy, such as those required for air conditioning, i.e. for heating or cooling buildings, are generally based on the combustion of fossil fuels.

[0004] Furthermore, renewable energy sources, such as geothermal energy, are known for providing thermal energy.

[0005] Two approaches have been established for tapping geothermal energy. First, a ground-mounted collector can be used to tap near-surface geothermal energy. Second, a borehole probe can be inserted into deep layers of the earth to tap into geothermal energy from the Earth's interior, known as "deep geothermal energy." Borehole probes have the disadvantage that they are technically complex to manufacture, and the drilling depth is limited in many locations. Furthermore, the energy yield is highly dependent on the soil conditions.

[0006] Surface collectors have the disadvantage that they require a very large amount of space.

[0007] Thermal energy can also be used from rivers or lakes.

[0008] The limits of use are also very limited here for environmental and nature conservation reasons.

[0009] In contrast to fluid-based storage media and energy sources, an earth wall can also perform functions such as noise and visual protection.

[0010] Furthermore, it is well known that, for example, excavating a foundation pit for a building generates significant amounts of earth, which must be removed and disposed of at great expense. Many neighborhoods, buildings, and infrastructure facilities are enclosed by earth embankments for visual or noise protection reasons.

[0011] Against this background, it is an object of the invention presented to provide thermal energy, in particular for air conditioning a building, without burning fossil fuels.

[0012] An energy storage system for storing thermal energy is thus presented.

[0013] The proposed energy storage device comprises a storage volume and a hydraulic conduit system. The storage volume is an earth embankment, the hydraulic conduit system comprises a plurality of conduits for conducting a fluid, such as treated water, through the storage volume. The plurality of conduits extend longitudinally through the storage volume, and the plurality of conduits are arranged in a plurality of superimposed layers. In the context of the proposed invention, an earth embankment is understood to mean an elevation consisting essentially of earth and extending in the direction of gravity beyond a reference point, such as an area in the vicinity of the earth embankment. In particular, an earth embankment can comprise compacted soil.

[0014] The earth wall provided according to the invention has at least four effects. First, it provides the storage volume provided for thermal energy, so that the earth wall acts as an energy storage device.

[0015] Secondly, the earth wall extracts thermal energy from its surroundings, so that the earth wall acts as an energy accumulator or source of thermal energy.

[0016] Both of the above-mentioned effects are achieved via a thermo-hydraulic system.

[0017] Thirdly, the earth wall acts as a protective element, for example against wind, views into a property, noise and moving objects.

[0018] Fourthly, it supports the fundamental goals of sustainable management of excavated soil and its optimal utilization. The reduction in CO2 emissions through the elimination of truck transport and the installation at the site of extraction is another advantage.

[0019] The presented invention is based on the principle that a large amount of thermal energy is stored in a storage volume provided by an earth embankment. Accordingly, a thermal consumer, such as a heating system, can be supplied for a very long time, particularly continuously, with thermal energy stored in the energy storage device.

[0020] The high amount of energy that can be tapped into by the proposed energy storage system results in particular from its geometry and a pipeline system running through the earth wall, whose pipelines run in several layers, i.e., at different positions or heights, through the storage volume or the earth wall. Accordingly, thermal energy can be tapped as needed in different layers, particularly in the interior or middle layer of the earth wall.

[0021] Furthermore, the proposed energy storage system is in thermal contact with open or unsealed soil on its base, allowing thermal energy to flow from deeper layers into the energy storage system. In addition, the wall surface reacts with the environment.

[0022] In particular, the energy storage device can store a quantity of thermal energy that is greater than the amount of energy required by a consumer in a given period of time, such as a heating period. Accordingly, the energy storage device can regenerate itself outside of the heating period. In other words, the energy storage device can store thermal energy so densely, i.e. in such a compact space, that a building can be heated throughout the entire winter using only the energy stored in the energy storage device. Of course, the energy storage device can also store a quantity of energy that is smaller than the amount of energy required by a consumer in a given period of time, such as a heating period, so that the amount of energy supplied to the consumer is provided by an amount of energy stored in the energy storage device and an amount of energy regenerated by the energy storage device.

[0023] Furthermore, the energy storage unit can of course also be used as an energy source for cooling a consumer, such as a building. For this purpose, the energy storage unit can be thermally emptied or cooled during a heating period, so that the cold generated or stored in the energy storage unit can be supplied to the consumer during a cooling period, thus regenerating the energy storage unit for the next heating period.

[0024] Furthermore, the energy storage system presented here allows the use of excavated material from a construction pit by piling it up into an earth bank to provide the storage volume. This saves resources and money and protects both the climate and the environment.

[0025] The fluid provided according to the invention can be, for example, a coolant, in particular a mixture of ammonia and / or glycol with water, so that the fluid can flow through the pipe system even when the earth wall is frozen or in a state of freezing.

[0026] It can be provided that the earth wall can be supplied with ambient air from several sides.

[0027] Due to its spatial configuration, an earth wall can be exposed to ambient air from several sides, so that a storage volume provided by the earth wall, at least in areas close to the surface, can absorb thermal energy from the ambient air or from solar radiation from the surrounding area and thus regenerate itself. Accordingly, the earth wall can store ambient energy and make it available to external systems, allowing the earth wall to serve as an energy storage device and, optionally, as an energy source for external systems.

[0028] Furthermore, an earth embankment is usually connected to a subsoil through which geothermal energy flows into the earth embankment and regenerates it.

[0029] It may also be provided that the storage volume comprises compacted soil at least in some areas.

[0030] Compacted soil enables, in particular, mechanical support of the earth wall and / or the pipeline system.

[0031] Furthermore, compacted soil can minimize an insulating layer of air between the soil and the piping system, thereby maximizing the exchange of thermal energy between the storage volume and the piping system. It can further be provided that each layer comprises a plurality of adjacent piping.

[0032] Depending on the geometry of the earth wall of the proposed energy storage system, the pipeline system can be designed in such a way that the extraction capacity and energy quantity are matched to the demand.

[0033] A large number of lines running next to one another in respective layers enables a register operation in which respective layers are activated independently of one another or one after the other, ie fluid is flowed through, or deactivated, ie fluid is excluded from flow through.

[0034] It can further be provided that respective lines of the plurality of lines extend in loops through the storage volume.

[0035] Pipes running in loops allow, on the one hand, a cold inlet and warm outlet or vice versa, and, on the other hand, the development of several layers, for example by using a vertical loop.

[0036] Accordingly, it can also be provided that a respective line extends through several layers.

[0037] It can further be provided that a first line extending in a first layer and a second line extending in a second layer are hydraulically separated from each other.

[0038] By hydraulically separating lines in different layers, the different layers can be accessed independently of each other, so that, for example, an upper layer, far from the ground, can be deactivated while a lower layer, near the ground, remains activated. Alternatively, a first line extending in an inner region of the storage volume and a second line extending in an outer volume of the storage volume can be hydraulically separated from each other.

[0039] By means of hydraulically separated pipes in different layers or depths of the storage volume, the different depths can be accessed independently of each other, so that, for example, an outer layer can be deactivated while an inner layer remains activated.

[0040] It can further be provided that the energy storage device comprises an interface for thermally coupling the line system with a pumping system.

[0041] An interface for thermal coupling with a pumping system, such as a heat exchanger or a fluid distributor, enables the transfer of thermal energy stored in the energy storage device to the pumping system and, as a result, the supply of thermal energy to a consumer, such as a building.

[0042] It may also be provided that the earth wall is trapezoidal in shape.

[0043] A trapezoidal design of the earth wall requires, on the one hand, a mechanically stable shape, thus protecting it against mechanical stress. On the other hand, a trapezoidal design of the earth wall requires a large surface area that is permeable to ambient air and can be aligned at a predetermined angle to the ground and / or the sun's path, thus enabling an energy-efficient arrangement of solar collectors.

[0044] Accordingly, solar collectors can be installed at least in certain areas of the energy storage system. Furthermore, the earth embankment can be covered with vegetation using special seeding to protect against erosion.

[0045] Solar collectors, such as solar thermal modules or solar absorbers in various designs, or photovoltaic modules, can be installed on the earth wall and, as a result, positioned particularly favorably toward the sun's path. The electricity generated by photovoltaic modules can be fed, for example, into a pumping system coupled to the energy storage system, thus achieving a high degree of self-sufficiency.

[0046] Solar thermal modules or solar absorbers arranged on the earth wall collect solar energy in a fluid, so that the solar thermal modules can be used to heat the fluid circulating in the earth wall, i.e., to store thermal energy in the energy storage unit or to regenerate the storage volume. However, the solar thermal modules can also generate thermal energy directly from solar radiation and feed it directly to the final energy consumer.

[0047] It may further be provided that the earth wall is compacted at least on its surfaces in contact with the ambient air.

[0048] Since the earth embankment is subject to particular mechanical stress from wind energy on its surfaces in contact with the ambient air, compaction of the earth embankment on its surfaces can protect the earth embankment from damage caused, for example, by soil erosion.

[0049] It can further be provided that a controllable shut-off valve is arranged on at least one end of each line of the plurality of lines of the line system.

[0050] By means of shut-off valves arranged on the respective lines, the respective lines can be selectively allowed to flow with fluid or prevented from flowing with fluid. Accordingly, for example, fluid pumped by a pump can selectively flow through a line located in a region of the storage volume where the temperature is particularly high, e.g., above a predetermined threshold. Alternatively, fluid heated by a solar collector can flow through a line located in a region of the storage volume where the temperature is particularly low, e.g., below a predetermined threshold.

[0051] Of course, the respective lines of the presented energy storage device can also be flowed through with fluid that has been heated by an external energy source, such as a power plant, in order to conduct thermal energy into the storage volume and, thereby, to store it in the energy storage device.

[0052] It can further be provided that the energy storage device comprises a number of temperature sensors and heat meters for detecting a temperature or an exchanged heat quantity of the storage volume.

[0053] Temperature sensors, which are arranged, for example, at predetermined locations within the storage volume, enable the detection and assessment of the energy storage device's status, i.e., information about how much thermal energy is stored in the energy storage device and where thermal energy is stored. Accordingly, thermal energy can be extracted from the energy storage device depending on the temperatures or temperature values ​​determined by the respective temperature sensors. Accordingly, particularly warm or particularly cold areas can be flowed through with a particularly large amount of fluid.

[0054] The cables of the presented energy storage device can be made of plastic and / or metal as well as an alloy.

[0055] The lines of the proposed energy storage system can be secured in the earth wall by means of point fixing elements, such as ground anchors, and / or surface fixing elements, such as nets or tiles. According to a second aspect, the proposed invention relates to a device for providing thermal energy.

[0056] The presented device comprises a possible embodiment of the presented energy storage device and a pumping system, wherein the pumping system comprises a counter interface for thermal coupling with the line system of the energy storage device.

[0057] It may be provided that the pumping system is configured to pump a fluid through the conduit system.

[0058] A fluid such as brine is suitable for transporting thermal energy between the energy storage unit and the pump or through the energy storage unit.

[0059] The pumping system may, for example, comprise a geothermal heat pump, in particular a reversible brine heat pump.

[0060] It can be provided that the device comprises a computing unit which is configured to control shut-off valves for shutting off respective lines of the line system in order to adjust a volume flow flowing through a respective line in a line-specific manner.

[0061] In the context of the invention presented, a computing unit is understood to mean a computer, a processor, a control unit or any other programmable circuit.

[0062] The processing unit can control the shut-off valves electrically, for example, via an electrical cable or wirelessly, via a wireless network. Alternatively, the processing unit can control a hydraulic unit that transmits hydraulic control pulses to the shut-off valves.

[0063] It can further be provided that the computing unit is configured to determine a temperature profile and / or a profile of an amount of energy stored in the energy storage device in the storage volume of the energy storage device by means of temperature sensors arranged in the storage volume and to adjust the shut-off valves depending on the determined temperature profile.

[0064] Temperature-dependent adjustment of the shut-off valves of the proposed device enables dynamic, i.e., variable, fluid flow through the storage volume, allowing thermal energy to be extracted from or added to the energy storage system selectively for selected areas of the storage volume. This can prevent, for example, icing of individual areas of the energy storage system by excluding these areas from fluid flow or closing the shut-off valves of the pipes running through these areas.

[0065] By preventing the earth wall from freezing, a base load or a supply of a specified minimum amount of thermal energy can be continuously provided.

[0066] Alternatively, by adjusting the shut-off valves of the device presented in a temperature-dependent manner, icing of individual areas of the energy storage device can be forced or stopped by increasing the flow of fluid through these areas or by opening the shut-off valves of lines running in these areas.

[0067] For example, by deliberately freezing the earth wall, peak thermal energy output can be provided.

[0068] Accordingly, the computing unit can be configured to shut off a shut-off valve of a respective line if a temperature sensor assigned to the line detects a temperature that is less than or equal to a predefined shut-off threshold. Alternatively or additionally, the computing unit can be configured to open a shut-off valve of a respective line if a temperature sensor assigned to the line detects a temperature that is greater than a predefined shut-off threshold.

[0069] It can further be provided that the pumping system is thermally coupled to a device for releasing thermal energy.

[0070] A device for dissipating thermal energy, such as a heater, in particular a surface heater, enables efficient extraction of thermal energy from the energy storage device. The device for dissipating thermal energy can be connected to the pumping system, for example, via an intermediate storage device, in order to adjust the temperature of the device for dissipating thermal energy independently of the thermal energy delivered by the pumping system's pump, for example, using a mixer for mixing with cold water or hot water.

[0071] It may further be provided that the pumping system is thermally coupled to a thermal energy source.

[0072] A thermal energy source, such as a combined heat and power plant, can provide thermal energy, which is then pumped into the energy storage system and stored there. Accordingly, the thermal energy source can, for example, store excess capacity in the energy storage system.

[0073] It can further be provided that the device is a heating system and / or a cooling system connected via a reversible heat pump.

[0074] Depending on the configuration, the proposed device can be operated as a heating system, so that positive thermal energy is extracted from the energy storage device, or as a cooling system, so that negative thermal energy is extracted from the energy storage device or positive thermal energy is stored in the energy storage device. Furthermore, the pumping system and / or the heat pump can be electrically coupled to photovoltaic elements arranged on the energy storage device.

[0075] The electrical power generated by photovoltaic elements arranged on the energy storage system ensures a high degree of self-sufficiency of the proposed device, allowing it to operate without the need for energy supplied by fossil fuels. Depending on their dimensions, solar modules mounted on the surface of the earth wall of the proposed energy storage system can generate more electricity than is required for the pumping system and feed it into the public grid.

[0076] According to a third aspect, the presented invention relates to a method for producing an energy storage device.

[0077] The presented method comprises the backfilling of soil to form a first layer, the introduction of pipes for conducting a fluid into the first layer, the backfilling of further soil to form a further layer and the introduction of further pipes for conducting a fluid into the further layer.

[0078] A layer-by-layer backfill of soil allows for the installation of cables in layers, so that a corresponding energy storage facility can be developed layer by layer.

[0079] It may further be provided that the method comprises the filling of a covering layer on a top layer so that the filled soil forms an earth embankment.

[0080] A covering layer can, for example, form a flat surface and consist, in particular, of compacted soil. The soil may be compacted using light compaction devices.

[0081] Lightweight compaction vehicles, such as vibratory plates or trench rollers, preferably weighing less than 5 tons, and particularly preferably less than 2 tons, have proven particularly suitable for compacting the soil of the energy storage facility in layers, allowing the earth embankment to be compacted quickly without damaging the energy storage facility's pipes. Repeated layer-by-layer compaction eliminates the need for heavy compaction machines, such as wheel loaders, which could cause mechanical damage to the energy storage facility's pipe system.

[0082] It may be provided that the soil is taken from an excavation pit of a building to be supplied with thermal energy by the energy storage system.

[0083] By using soil extracted from an excavation pit as the storage volume of the energy storage system, a cost-effective and energy-efficient, particularly self-sufficient, temperature control system can be provided for a corresponding building, while at the same time avoiding the climate-damaging and expensive disposal of the soil with the corresponding logistical effort.

[0084] Further features, details, and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. They show:

[0085] Fig. 1 a possible design of the presented energy storage device in a cross-section, 5

[0086] Fig. 2 shows a hydraulic diagram of a possible embodiment of the device presented, Fig. 3 shows a possible embodiment of the method presented.

[0087] Figure 1 shows an energy storage device 100. The energy storage device 100 comprises an earth wall 101, which serves as a storage volume for storing thermal energy and, consequently, for the utilization or development of geothermal energy.

[0088] To utilize thermal energy stored in the storage volume, the energy storage device 100 comprises a pipe system 103 or a collector.

[0089] The line system 103 comprises a plurality of lines 105 which extend longitudinally through the storage volume and are arranged in several layers 107, 109, 111, 113, 115.

[0090] In the present case, the earth wall 101 is designed, for example, trapezoidally with a cuboid-shaped substructure. An angle a, at which the respective sides of the trapezoidal part are inclined to a base surface of the earth wall 101, can be selected such that optional solar collectors 117 arranged on the earth wall are illuminated with solar rays in an energy-efficient manner. In the present case, the angle a is, for example, 45°.

[0091] Figure 2 shows a device 200 for providing thermal energy. The device 200 comprises a pump system 201 connected to the line system 103 extending through the storage volume of the energy storage device shown in Figure 1.

[0092] The respective lines 105 of the line system 103 can be adjusted by shut-off valves 203, which can be configured, for example, as proportional valves. This means that the volume flow through the lines 105 can be adjusted by means of the shut-off valves 201.

[0093] To control or regulate the shut-off valves 203 or a flow through the lines 105, the device 200 comprises a computing unit 205, which is further communicatively connected to optional temperature sensors 207, heat meters 209, a controller 211, a measuring transducer 213 and / or a mixer 215.

[0094] The pumping system 201 includes a fluid pump 217 that regulates the flow of fluid through the piping system 103, and a heat pump 219 that accumulates heat or thermal energy in a temperature control system 221, such as a heating or cooling system. The temperature control system 221 can also be used as an interface for thermal coupling with a heating and / or cooling system.

[0095] The heat pump 219 is connected via a heat exchanger 223 to a distributor 225 on a hot side of the piping system 103 and to a distributor 227 on a cold side of the piping system 103.

[0096] The distributors 225 and 227 can, for example, be connected to a surface heating system and / or additional ground collectors.

[0097] The shut-off valves 203 on the hot side of the piping system 103 are each connected to a distributor 229.

[0098] The shut-off valves 203 on the cold side of the piping system 103 are each connected to a distributor 231.

[0099] The cold side is separated from the hot side by expansion elements.

[0100] Figure 3 shows a method 300 for producing an energy storage device.

[0101] The method 300 comprises a first backfilling step 301 in which soil is backfilled to form a first layer and a first introduction step 303 in which lines for conducting a fluid are introduced into the first layer.

[0102] Furthermore, the method 300 comprises a second backfilling step 305 in which further soil is arranged to form a further layer arranged above the first layer, and a second introduction step 307 in which further lines for conducting a fluid are introduced into the further layer.

[0103] The invention is not limited to one of the embodiments described above, but can be modified in many ways.

[0104] All features and advantages arising from the claims, the description and the drawings, including design details, spatial arrangements and method steps, can be essential to the invention both individually and in a wide variety of combinations.

Claims

Patent claims 1 . Energy storage device for storing thermal energy, the energy storage device comprising: - a storage volume, - a hydraulic conduit system, wherein the storage volume is an earth embankment, wherein the hydraulic conduit system comprises a plurality of conduits for conducting a fluid through the storage volume, wherein the plurality of conduits extend longitudinally through the storage volume, and wherein the plurality of conduits are arranged in a plurality of superimposed layers.

2. Energy storage device according to claim 1, characterized in that the earth wall can be supplied with ambient air from several sides.

3. Energy storage device according to claim 1 or 2, characterized in that the storage volume comprises at least partially compacted soil.

4. Energy storage device according to one of the preceding claims, characterized in that each layer comprises a plurality of lines running alongside one another.

5. Energy storage device according to one of the preceding claims, characterized in that respective lines of the plurality of lines extend in loops through the storage volume.

6. Energy storage device according to one of the preceding claims, characterized in that a respective line extends through several layers.

7. Energy storage device according to one of the preceding claims, characterized in that a first line extending in a first layer and a second line extending in a second layer are hydraulically separated from one another.

8. Energy storage device according to one of the preceding claims, characterized in that the energy storage device comprises an interface for thermally coupling the line system with a pumping system.

9. Energy storage device according to one of the preceding claims, characterized in that the earth wall is trapezoidal in shape.

10. Energy storage device according to one of the preceding claims, characterized in that solar collectors are arranged on the energy storage device at least in some areas. 11 . Energy storage device according to one of the preceding claims, characterized in that the earth wall is compacted at least on its surfaces in contact with ambient air.

12. Energy storage device according to one of the preceding claims, characterized in that a shut-off valve is arranged on at least one end of each line of the plurality of lines of the line system.

13. Energy storage device according to one of the preceding claims, characterized in that the energy storage device comprises a number of temperature sensors for detecting a temperature in the storage volume.

14. A device for providing thermal energy, the device comprising: - an energy storage device according to one of claims 1 to 13, - a pumping system, wherein the pumping system comprises a counter interface for thermal coupling with the piping system of the energy storage device.

15. The device according to claim 14, characterized in that the pumping system is configured to pump a fluid through the conduit system.

16. Device according to claim 14 or 15, characterized in that the device comprises a computing unit which is configured to control shut-off valves for shutting off respective lines of the line system in order to adjust a volume flow flowing through a respective line in a line-specific manner.

17. Device according to claim 16, characterized in that the computing unit is configured to determine a temperature profile in the storage volume of the energy storage device by means of temperature sensors arranged in the storage volume and to adjust the shut-off valves depending on the determined temperature profile.

18. Device according to claim 17, characterized in that the computing unit is configured to shut off a shut-off valve of a respective line when a temperature sensor assigned to the line detects a temperature that is less than or equal to a predetermined shut-off threshold value.

19. Device according to claim 17, characterized in that the computing unit is configured to open a shut-off valve of a respective line when a temperature sensor associated with the line detects a temperature that is greater than a predetermined shut-off threshold value.

20. Device according to one of claims 14 to 19, characterized in that the pumping system is thermally coupled to a device for releasing thermal energy.

21. Device according to one of claims 14 to 20, characterized in that the pumping system is thermally coupled to a thermal energy source.

22. Device according to one of claims 14 to 21, characterized in that the device is a heating system and / or a cooling system.

23. Device according to one of claims 14 to 21, characterized in that the pumping system is electrically coupled to photovoltaic elements arranged on the energy storage device.

24. Method for producing an energy storage device, the method comprising: - Piling up soil to form a first layer, - Inserting pipes to conduct a fluid into the first layer, - Piling up more soil to form another layer, - Inserting additional pipes to conduct a fluid into the next layer.

25. The method according to claim 23 or 24, characterized in that the method further comprises: - Piling a covering layer on top of a top layer so that the piled up soil forms an earth embankment.

26. A method according to any one of claims 23 to 25, characterized in that the method further comprises: - compaction of the excavated soil at least in some areas.

27. Method according to claim 26, characterized in that the respective heaped earth is compacted after the installation of the respective pipes.

28. Method according to claim 27, characterized in that the soil is compacted by a light compaction device.

29. Method according to one of claims 23 to 28, characterized in that the soil is taken from an excavation pit of a building to be supplied with thermal energy by the energy storage device.

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