Storage system with optimized energy recovery

Abstract

The invention relates to a storage system for storing thermal energy that has a charging circuit comprising a vaporizer, a compressor, a charging heat exchanger coupled to a heat accumulator, and an air regulator, connected to one another directly or indirectly. The vaporizer is coupled to a cold reservoir or an external heat source from which it absorbs heat.

Description

DescriptionTITLEStorage System with Optimized Energy RecoveryTECHNICAL FIELD

[0001] The invention relates to a storage system for storing thermal energy in which heat is stored in a heat accumulators via a charging circuit.BACKGROUND

[0002] Unneeded energy is available at times that has been obtained in particular in a regenerative manner. At other times, there may not be enough of this energy available. Various storage technologies are used to balance out the acquisition of energy and the need thereof.

[0003] One means of doing so is to store excess heat and electricity in the form of thermal energy in heat accumulators. This thermal energy can then be recovered at a later point in time.

[0004] In one embodiment, a charging circuit contains a vaporizer, a compressor, the heat accumulator and an air regulator. In this case, waste heat from other processors and energy obtained regeneratively is supplied to the vaporizer. Advantageously, the compressor is also powered by energy acquired regeneratively.

[0005] If more energy is needed at another time, the energy in the heat accumulator can be recovered by using it to vaporize and superheat water, such that the steam can be used in a steam turbine to drive a generator.SUMMARY OF THE INVENTION

[0006] The object of the present invention is to optimize energy storage.

[0007] This object is achieved with an inventive embodiment in accordance with the teachings of claim 1 . Advantageous embodiments are the subject matter of the dependent claims.

[0008] First, a storage system for storing thermal energy that has a primary charging circuit is used, which contains a storage vaporizer coupled to a cold reservoir, a compressor, a charging heat exchanger coupled to a heat accumulator, and an air regulator, connected to one another directly or indirectly.

[0009] A waste heat vaporizer is coupled to an external heat source to make use of external thermal energy, and integrated in the storage system.DESCRIPTION OF THE INVENTION

[0010] Storage systems of this type are used for storing thermal energy. These contain a primary charging circuit and a discharge circuit.

[0011] The primary charging circuit comprises a storage vaporizer, a compressor, a heat exchanger, and an air regulator, connected to one another directly or indirectly. The storage vaporizer is coupled to a cold reservoir, which absorbs thermal energy. The heat exchanger is coupled to a heat accumulator in order to store thermal energy.

[0012] The primary charging circuit is used when the storage system is in the primary charging state. For this, water is first vaporized in the storage vaporizer. The steam is then compressed and consequently heated. When passing through the heat exchanger, the thermal energy in the steam is accumulated in the heat accumulator. After it has been cooled, the steam is then conducted through the air regulator beforebeing returned to the vaporizer. The vaporizer is coupled directly or indirectly to a cold reservoir for this.

[0013] According to the invention, thermal energy from an external source can be stored for later use. The storage system contains a waste heat vaporizer for this, to which the external thermal energy can be supplied. This waste heat vaporizer can be used in a variety of ways in the storage system.

[0014] In a first variation, the waste heat vaporizer is integrated in the primary charging circuit in parallel to the storage vaporizer. With the appropriate circuits, the waste heat vaporizer and the storage vaporizer can be operated simultaneously or in an alternating sequence.

[0015] The use of thermal energy from an external source is particularly advantageous if there is a secondary charging circuit. This contains the waste heat vaporizer, the compressor, the storage vaporizer, and an air regulator, connected to one another directly or indirectly.

[0016] The secondary charging circuit is operated in a secondary charging state. For this, the mass flow of water is vaporized, and / or the steam is heated for this in the waste heat vaporizer by the external thermal energy. The heated steam is sent to the storage vaporizer, in which heat exchange then takes place in the other direction. This means that thermal energy from hot steam is returned to the cold reservoir. The cooled steam is returned through the air regulator to the waste heat heat exchanger.

[0017] With this particularly advantageous approach, a large amount of thermal energy can be stored in the storage system in both the heat accumulator and the cold reservoir, when there is enough external thermal energy, which is normally waste heat from other processors that cannot be otherwise used effectively.

[0018] External thermal energy can also be advantageously made use of if it is possible to store the heated steam directly. This involves a storage path containing a water source, the waste heat vaporizer, the compressor, and the cold reservoir, connected to one another directly or indirectly.

[0019] The water from the water source is vaporized and heated for this in the waste heat vaporizer. The steam is then compressed in the compressor and heated further. The heated steam is conducted directly to the cold reservoir in order to store the thermal energy therein.

[0020] Conducting the heated steam directly to the cold reservoir is the best means of storing the thermal energy obtained from the external heat source.

[0021] The cold reservoir is advantageously a type of Ruths accumulator. The structure and functioning of a Ruths accumulator is familiar to a person skilled in the art, and thus require no further explanation.

[0022] The primary charging circuit and / or secondary charging circuit can also be operated with a medium other than water and steam. By way of example, CO2can be used with greater efficiency, although this is more difficult.

[0023] Other media that have a phase shift from liquid to gas within a technologically reasonable range can also be used. Accordingly, the use of media other than water and steam in the primary charging circuit and / or in the secondary charging circuit, and / or in the storage path, is expressly included in the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Fig. 1 shows a schematic illustration of an exemplary storage device 01 that has a primary charging circuit 11 , comprising a storage vaporizer 14 and a waste heat vaporizer 24.

[0025] Fig. 2 shows a schematic illustration of an alternative storage device 06 that has a primary charging circuit 11 with a storage vaporizer 14 and a secondary charging circuit 21 that has a waste heat vaporizer 24.

[0026] Fig. 3 shows a schematic illustration of a third exemplary storage device 07 that has a primary charging circuit 11 with a storage vaporizer 14 and a storage path 31 that has a waste heat vaporizer 24.DESCRIPTION OF THE EMBODIMENTS

[0027] A storage device 01 that has a primary charging circuit 11 is shown schematically in Figure 1. The essential part of the storage device 01 is the heat accumulator 02. Arrows indicate the direction in which the medium flows in the circuits 11 , 21 , 31.

[0028] The primary charging circuit 11 comprises a heat exchanger 12, that is coupled to the heat accumulator 02. It this regard, it is unimportant whether the heat exchanger 12 is located directly on or in the heat accumulator 02. It can also be separate therefrom, and a storage medium can flow from the heat accumulator 02 through the heat exchanger 12 and back to the heat accumulator 02.

[0029] When the primary charging circuit 11 is in operation, thermal energy is released by the heat exchanger 12 to heat the heat accumulator 02.

[0030] This embodiment according to the invention contains an air regulator 15 and a storage vaporizer 14 in the primary charging circuit 11. The steam generated by the storage vaporizer 14 is subsequently compressed in the compressor 13 and sent to the heat exchanger 12.

[0031] There is also a branch to a waste heat vaporizer 24 connected to the cold reservoir 03 in parallel to the storage vaporizer 14. It is also possible to supply external thermal energy to the waste heat vaporizer 24.

[0032] If heat is supplied to the waste heat vaporizer 24 during the charging process, operation of this branch is advantageous. If instead, no additional external thermal energy is available, but the cold reservoir 03 has enough heat, the storage vaporizer 14 is used.

[0033] If external thermal energy is still available after completely heating the heat accumulator 02, and regeneratively generated electricity in particular is available for operating the compressor, then thermal energy can be stored with the exemplary embodiment of a storage system 06 in addition to the storage of heat. Figure 2 shows a solution that contains the primary charging circuit 11 that is used in preceding embodiment shown in Fig. 1.

[0034] In this case, the storage device 06 has an additional, secondary charging circuit 21 . It is possible to switch back and forth between the primary charging circuit 11 and the secondary charging circuit 21 .

[0035] The secondary charging circuit 21 comprises a waste heat vaporizer 24, the compressor 13, the storage vaporizer 14, and an air regulator, connected to one another directly or indirectly. The compressor 13 in this case does not conduct the steam generated in the waste heat vaporizer 24 to the heat exchanger 12, but instead back to the storage vaporizer 14. This storage vaporizer 14 functions as a cold reservoir heat exchanger and transfers the thermal energy form the steam directly or indirectly to the cold reservoir 03. As a result, more thermal energy is available for a discharge process and / or for a new charging process.

[0036] An alternative embodiment of a storage system 07 for energy recovery after completely charging the heat accumulator is shown in Figure 3. The charging circuit 11 corresponds otherwise to the preceding embodiments.

[0037] In this case, a storage path 31 leads from a water source 32 to the cold reservoir 03. Water from the water source 32 is then vaporized in the waste heat vaporizer 24 and compressed by the compressor 13 and further heated. The heated steam is then conducted directly into the cold reservoir 03. This cold reservoir 03 can be a type of Ruths accumulator.

Claims

Claims1. A storage system (01 , 06, 07) for storing thermal energy that has a primary charging circuit (11), which contains a storage vaporizer (14), a compressor (13), a charging heat exchanger (12) and an air regulator (15), connected to one another directly or indirectly, wherein the heat exchanger (12) is coupled to a heat accumulator (02) and the storage vaporizer (14) is coupled to a cold reservoir (03), characterized by a waste heat vaporizer (24), which is coupled to an external heat source.

2. The storage system (01) according to claim 1 , wherein the waste heat vaporizer (24) can be interconnected in the primary charging circuit (11), in parallel to or alternatively to the storage vaporizer (14).

3. The storage system (06) according to claim 1 or 2, characterized by a secondary charging circuit (21) that can be switched on or off, which comprises the waste heat vaporizer (24), the compressor (13), the storage vaporizer (14), and an air regulator (25), connected to one another directly or indirectly.

4. The storage system (07) according to claim 1 or 2, characterized by a storage path (31) that can be switched on or off, which comprises a water source (32), the waste heat vaporizer (24), the compressor (13) and the cold reservoir (03).

5. The storage system (01) according to claim 4, wherein the cold reservoir (03) is a Ruths accumulator.

6. A method for controlling a storage system according to any of the preceding claims, wherein water and / or steam is vaporized in a storage vaporizer (14) by heat from the cold reservoir (03) and compressed and heated by a compressor (13), and thermal energy is transferred from the steam to the heat accumulator(02) via the charging heat exchanger (02), and the steam is returned through the air regulator (15) to the storage vaporizer (14).

7. The method according to claim 7, wherein at least part of the volumetric flow from the air regulator (15) is conducted through the waste heat vaporizer (24) in parallel to, or instead of to, the storage vaporizer (14).

8. The method according to claim 7 or 8, wherein water and / or steam are vaporized and / or heated in the waste heat vaporizer (14) in a secondary charging state by means of external heat and compressed and heated by the compressor (13), and thermal energy from the steam is sent to the cold reservoir (02) via the storage vaporizer (14), and the steam is returned through the air regulator (25) to the storage vaporizer (14).

9. The method according to claim 7 or 8, wherein water is vaporized and / or heated in a secondary charging state in the waste heat vaporizer (14) by external heat, and compressed and heated by the compressor (13), and conducted to the cold reservoir (02).

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