Thermal energy reservoir

Abstract

A heat or cool reservoir (4) intended for storing of thermal energy and later utilization of said energy, which reservoir (4) comprises material that accumulates heat or cool, the temperature of which can be raised to the value of 100 °C or close to it, and in case of cool reservoir to about -40 °C, and which thermal energy can be discharged from said thermal energy reservoir (4) at a later selected point of time. An accumulating mass (9) of the reservoir (4) partially and heat insulating constructions of said reservoir (4) additionally are formed of selected waste disposable in a landfill and that said reservoir (4) and its constructions are arranged and intended to be a permanent landfill remaining in its site.

Description

[0001] THERMAL ENERGY RESERVOIR

[0002] Background of the invention

[0003] The invention relates to a heat or cool reservoir intended for storing of thermal energy either heat or cool and later utilization of said energy, which reservoir comprises material that accumulates heat or cool, the temperature of which can be raised to the value of 100 °C or close to it, and in case of cool reservoir to about -40°C, and which thermal energy can be discharged from said reservoir at a later selected point of time.

[0004] Previously known storages of thermal energy are insulated water reservoirs, insulated sand reservoirs and hot water supplies located in a hole in the ground or a mining hole. Known accumulator reservoirs usually contain one liquid or solid accumulator material. Commonly known accumulator masses are water and sand which are easy to handle and can fill any shape of reservoirs without difficulty.

[0005] The known arrangements cannot utilize waste materials because their placement is only allowed in landfills of inert, non-hazardous or hazardous waste (The European Union Landfill Directive, more formally Council Directive 1999 / 31 / EC of 26 April 1999). Therefore, landfill waste cannot be used in construction, such as commonly as masses of thermal storages.

[0006] Brief description of the invention

[0007] The object of the invention is to provide a new arrangement for a landfill to be formed for storing heat or cool by selecting a waste filling suitable for this purpose in connection with establishing the landfill. In the invention, the selected waste being disposed in the landfill constitute either heat or cool insulating parts or heat or cool accumulating parts of the energy reservoir. When the accumulating mass is a combination of water and mineral material, the energy reservoir must be watertight as for the accumulating mass. The insulators are thus placed outside the watertight section. By means of the thermal energy reservoir according to the invention, a substantial improvement is accomplished to the current prior art when disposed waste can be put into practical use in the construction of the thermal energy reservoir . The thermal energy reservoir according to the invention is characterised by that the accumulating mass of said reservoir partially and the heat-insulating structures of said reservoir additionally are formed of selected waste disposable in a landfill and that said reservoir with its structures is arranged and intended to be a permanent landfill to remain in its site.

[0008] The other advantageous embodiments of the invention are characterised by what is presented in the dependent claims.

[0009] An advantage of the invention in relation to the known arrangements is that a landfill required for waste is in practical use when the waste material contained by it is in practical use. It is possible to construct the heat or cool reservoir mainly from waste material and said reservoir does not require a plant area or a hole in the ground. According to the invention, the thermal energy reservoir is formed of minerals and materials classified as waste, such as brick, concrete, slags, ashes, degraded soils, and water. The aim is to place useless waste material as either insulation or accumulating heat or cool.

[0010] When the operation of the thermal energy reservoir ends, the waste material stays in place because it is already situated in the landfill area where it was originally placed. The thermal energy reservoir according to the invention is a mixture of water and mineral material. It is advantageous to locate the thermal energy reservoir in connection with a heating plant, whereby it is easy to connect to a district heating network or a target to be heated or cooled.

[0011] Detailed description of some embodiments of invention

[0012] Next, the invention will be described in more detail with reference to the accompanying drawings in which

[0013] Fig. 1 shows a top view of a combination of a landfill and a heat or cool reservoir

[0014] Fig. 2 shows a sectional view of Fig. 1 cut along section C-C.

[0015] Fig. 3 shows the innermost heat or cool reservoir section of Fig. 2 supplemented with some parts.

[0016] Fig. 4 shows a horizontal layered view of some heat charge and discharge pipe systems in the heat or cool reservoir section.

[0017] Fig. 5 shows a top view of a charge and discharge pipe system of Fig. 4.

[0018] Fig. 6 shows a location of a landfill and a thermal energy reservoir.

[0019] Fig. 7 shows a combination of a landfill and a thermal energy reservoir constructed in a location of Fig. 6.

[0020] Fig. 1 shows a top view of a combination of a landfill and a thermal energy reservoir, whereby it includes in the middle a relatively flat and low-gradient mound section 1 and then a slightly steeper border section 2 which goes round the whole level middle part. In this example case, the area has a dimension A of e.g. 120 m and a dimension B of 100 m. The width of the border section 2 is 10 m. The example of Fig. 1 is solely in thermal energy reservoir use and no waste is transported there any longer. It now has e.g. a cover of grass.

[0021] In Fig. 2, section C-C shows the completed structure of the thermal energy reservoir 4. There are several metres of the structure below the ground, and the height of said reservoir 4 is e.g. about 30 m. In this example, a hole of required dimensions has been dug for said reservoir 4, and the hole is first being filled from the bottom with waste similar to a layer 7. From this layer 7, drainages are also taken as far as required away in the downward direction. The layer 7 contains e.g. slag, LECA gravel, sand etc. There is no need for this layer 7 to be heat insulation.

[0022] A next layer 6 can be separated from the previous layer 7 by a sheet or fabrics but no watertight separation is required. The layer 6 can already be heat insulation like material, such as ash or insulation waste. A layer 5 is the actual insulation layer and, on its inner surface, there is a watertight surface structure 3, which must also be of strong material in order to endure the accumulating mass 9 and water, that come on top of it, without damage. Fig. 2 does not yet show the accumulating mass in an accumulator space of the reservoir 4 which is limited by the watertight surface structure 3.

[0023] Fig. 3 shows an example of what the accumulator space of the reservoir 4 can contain. This example includes concrete blocks in addition to water as the accumulator mass 9. The size of the blocks is most suitably less than 1 m. In order for the surface structure 3 to be durable, it is advisable to install as the lowest layer on the bottom of the reservoir 4 some small-sized blocks or even round-shaped gravel, with the grain size of 50 mm.

[0024] Fig. 3 additionally shows concrete wells 8 located in the heat or cool reservoir 4, which include holes in their top part and bottom part. The wells are full of water. Accumulator mass should not enter them. When the reservoir 4 is heated by means of pipe systems 12 located in said reservoir 4, the number of pipe systems can be decreased by means of said wells 8 when the accumulator water heated in them can flow, due to its lightening, upwards in the wells 8 and improve the transfer of heat within the heat reservoir 4. These wells 8 can be positioned e.g. 15 metres apart from each other in the heat reservoir 4.

[0025] Fig. 4 shows an example of charging of the heat or cool reservoir 4 to be a storage of heat or cool by means of pipe systems 12a-12d located in four different layers. Fleating or cooling liquid is conveyed along a pipe 11 to distribution valves 14, of which, any one pipe system or more can be opened for the heater / cooler.

[0026] The charging can be started either from the lowest pipe system 12a or the upmost one 12d, depending on how powerfully the natural heat transfer upwards operates in the heat reservoir 4. Water in the heat reservoir 4 can be replaced at certain intervals due to its thickening. In order to make this replacement, there is an exit pipe 10 installed in the bottom part.

[0027] Fig. 5 shows a top view of the lowermost pipe system 12a located in the heat reservoir 4. Via the pipe system 12a, both heat or cool charge and discharge are performed. The charge and the discharge can be performed by conveying water or liquid always in the same direction which is shown in Fig. 5. The charging and the discharging can be monitored by means of a temperature gauge 13 which indicates the temperature of the liquid flow coming out of the pipe system 12a. If the temperature of water fed to the pipe system 12a differs a lot from the temperature of the water coming out, the charge or the discharge is still incomplete. When there is about 20% water of the volume in the heat reservoir 4, the mutual distances of the charging and discharging pipe systems 12a-12d can be kept quite long 10-15 m.

[0028] Fig. 6 shows a flat area authorized as a landfill, in which, there is an intention to construct a combination of a landfill and a heat reservoir 4 according to the invention. This method of construction is very advantageous compared with the method of construction in Fig. 2, wherein a large hole was dug, which means that a large amount of mass has to be transported from the site. In this embodiment, the reservoir 4 is constructed almost entirely of waste and masses brought to the site which, in accordance with Figs. 6 and 7 are piled up to a mound for the thermal energy reservoir area. Fig. 6 shows a flat construction site 16 intended for the thermal energy reservoir 4, wherein a groundwater level 15 is at a depth h which is at least 1 metre.

[0029] Fig. 7 shows an example on how the combination of the landfill and the thermal energy reservoir 4, which is shown in Fig. 2, is now formed in a flat area, with the size about 100 x 120 m, shown in Fig. 6, as a construction almost totally above ground. In this embodiment, the pipe systems conveyed inside said reservoir 4 are easy to install and use. Similarly, it is easier to construct drainage as well as arrange the removal of water or antifreeze liquid as Ethylene Glycol, inside the reservoir 4 and the pumping of new water or antifreeze liquid to replace the old.

Claims

AMENDED CLAIMS [received by the International Bureau on 11 December 2024 (11 .12.2024)]1 A heat or cool reservoir (4) intended for storing of thermal energy and later utilization of said energy, which reservoir (4) comprises material that accumulates heat or cool, a temperature of which material can be raised in case of heat reservoir to the value of 100 °C or close to it, and in case of cool reservoir to about -40°C, and which thermal energy can be discharged from said thermal energy reservoir (4) at a later selected point of time, characterized in that an accumulating mass (9) of the reservoir (4) partially and heat insulating constructions of said reservoir (4) additionally are formed of selected waste disposable in a landfill and that said reservoir (4) and its constructions are arranged and intended to be a permanent landfill remaining in its site and where the charging of the thermal energy reservoir and the discharging of thermal energy can be performed by layers by means of locating pipe systems (12a-12d) located in the layers to be separately controlled by means of e.g. stop valves (14).

2. A heat or cool reservoir (4) according to claim 1, characterized in that the accumulating mass (9) includes water or antifreeze liquid in addition to solid material.

3. A heat or cool reservoir (4) according to claim 1, characterized in that the accumulating mass (9) includes water or antifreeze liquid and mineral material, such as blocks or concrete blocks of specific size, such as less than 1 m.

4. A heat or cool reservoir (4) according to claim 1, characterized in that charging and discharging of thermal energy from the said reservoir (4) is performed by means of water in case of heat reservoir (4) and by means of antifreeze liquid pipe systems (12) conveyed inside the heat reservoir (4) in case of cool reservoir (4).

5. A heat or cool reservoir (4) according to claim 1, characterized in that the water operating as the accumulating mass (9) is arranged to convey heat within the heat reservoir (4) both by conveying heat and transmitting heat by means of its own vertical movement.

6. A heat or cool reservoir (4) according to claim 5, characterized in that vertical, empty wells (8) free of mineral materials are arranged in the heat reservoir (4), by means of which, the lifting of warm water upwards as lightened has been facilitated.

7. A heat or cool reservoir (4) according to claim 1, characterized in that the structure of said reservoir (4) is formed as self-supporting, which has been provided by filling the reservoir (4) by mineral materials, which also provides support of the top part of the heat reservoir (4).7AMENDED SHEET (ARTICLE 19)

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