Storage system with optimized heat supply

Abstract

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

Description

DescriptionTITLEStorage System With Optimized Heat SupplyTECHNICAL FIELD

[0001] The invention relates to a storage system for storing thermal energy, in which thermal energy is stored in a heat accumulator 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 charging circuit is used, which contains a storage vaporizer, a compressor, a charging heat exchanger coupled to a heat accumulator, and an air regulator, connected to one another directly or indirectly.

[0009] To optimize energy recovery, both the vaporizer and the condenser are coupled to the same cold reservoir.DESCRIPTION OF THE INVENTION

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

[0011] The charging circuit contains a vaporizer, a compressor, a charging heat exchanger, and an air regulator, connected to one another directly or indirectly. The heat exchanger is coupled to a heat accumulator to store thermal energy.

[0012] The charging circuit is operated when the storage system is charging. First, water in the circuit is vaporized by the vaporizer. This steam is then compressed and thus heated. A portion of the thermal energy in the steam is then discharged into the heat accumulator. The cooled steam is then conducted through the air regulator before returning to the vaporizer.

[0013] The vaporizer is coupled directly or indirectly to a cold reservoir for this in a first variation.

[0014] In a second variation, the vaporizer is supplied with thermal energy from an external heat source.

[0015] A third variation combines the first and second variations, thus resulting in two vaporizers that can be operated separately or together.

[0016] There are various means of controlling the heat supplied to the charging circuit from the vaporizer.

[0017] There is a vaporizer bypass in a first embodiment that is parallel to the vaporizer, such that a part of the main flow can bypass the vaporizer. A bypass valve is needed in the vaporizer bypass for this. Advantageously, there is also a vaporizer valve upstream of the vaporizer.

[0018] It does not matter whether the vaporizer is coupled to a cold reservoir in the first variation of the first embodiment, or external thermal energy is supplied in the second variation.

[0019] It is also advantageous if the supplying of heat can be controlled during the charging process. It is particularly advantageous if the supplying of thermal energy can be controlled in the vaporizer.

[0020] If more energy is supplied to the vaporizer than necessary for the charging process, and if excessive heating in the vaporizer limits the time available for the charging process, the amount of energy supplied in the charging circuit can be reduced by the vaporizer bypass, such that the energy is supplied over a longer time period, thus making it possible to charge the heat accumulator to a greater extent.

[0021] In a second embodiment, the vaporizer is coupled indirectly to the cold reservoir by a cold reservoir circuit in the first variation. There is a heat exchanger on the cold reservoir for this, which can take thermal energy from the cold reservoir and supply it to the vaporizer. It is possible to control the amount of thermal energy obtained from the vaporizer by controlling the flow of the medium through the cold reservoir circuit.

[0022] The cold reservoir circuit advantageously contains a cold reservoir pump and / or cold reservoir valve that can be controlled for this.

[0023] Furthermore, it is advantageously possible to accumulate heat and vaporize the water in the vaporizer when a vacuum is generated in the vaporizer. By this means, the pressure in the vaporizer can be advantageously reduced to less than 0.5 bar, at least temporarily. A maximum pressure of 0.2 bar, e.g. 0.1 bar, is particularly advantageous. The temperature in the charging circuit at the vaporizer is thus lower, resulting in a more efficient energy accumulation.

[0024] If the temperature is higher in the return from the heat exchanger than at the outlet of the vaporizer, it is particularly advantageous if there is a recuperator in the form of a heat exchanger between the heat exchanger and the air regulator. In this case, the recuperator must also be integrated in the connection between the vaporizer and the compressor.

[0025] This makes better use of the residual heat from the return path in the charging circuit, directly or indirectly downstream of the heat exchanger, making it possible to transfer this heat to the steam in the intake to the charging circuit downstream of the vaporizer.

[0026] It is also fundamentally possible to operate the charging circuit and / or discharge circuit with a medium other than water and steam. By way of example, CO2can be used with greater efficiency, although this is more difficult.

[0027] 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

[0028] Fig. 1 shows a schematic illustration of an exemplary storage device 01 that has a charging circuit 11 with two different vaporizers.

[0029] Fig. 2 shows a schematic illustration of a vaporizer bypass for increasing the flexibility in managing the process.

[0030] Fig. 3 shows a schematic illustration of a cold reservoir circuit for separating the charging circuit from the cold reservoir.

[0031] Fig. 4 shows a schematic illustration of an alternative storage device 01 that has a charging circuit 11 containing an additional recuperator.DESCRIPTION OF THE EMBODIMENTS

[0032] A storage device 01 that has a charging circuit 11 is schematically shown in Figure 1 . The essential element in the storage device is the heat accumulator 02. Arrows indicate the flow direction in the circuits 11 , 31 , 41 , 42, 51 .

[0033] The charging circuit 11 contains a heat exchanger 12 coupled to the heat accumulator 02. It does not matter whether the heat exchanger 12 is directly in or on the heat accumulator 02 for this. It can also be separate therefrom, and the storage medium can flow from the heat accumulator 02 through the heat exchanger 12, and back into the heat accumulator 02.

[0034] When the charging circuit 11 is in operation, thermal energy is released through the heat exchanger 12 to heat the heat accumulator 02.

[0035] The embodiment according to the invention contains a downstream air regulator 15 and a vaporizer 14 in the charging circuit 11. Regenerative thermal energy is advantageously supplied to the vaporizer 14.

[0036] The steam generated by the vaporizer 14 is subsequently compressed by the compressor 13 and sent to the heat exchanger 12.

[0037] There is also a branch to a second vaporizer 24 connected in parallel to the first vaporizer 14 on the cold reservoir. External thermal energy can be supplied to the second vaporizer 24.

[0038] If external thermal energy is being supplied to the second vaporizer 24 during the charging process, it is advantageous to operate this branch. If there is no further external thermal energy available, but sufficient heat in the cold reservoir 03, the first vaporizer 14 is used.

[0039] A vaporizer bypass 34 is shown in Figure 2. This makes it possible to divide the volumetric flow upstream of the vaporizer 14. There is a vaporizer valve between the vaporizer bypass 34 and the vaporizer 14, and a bypass valve 36 in the vaporizer bypass 34 in this example.

[0040] An indirect coupling between the vaporizer 14’ and the cold reservoir 03 is shown by way of example in Figure 3. A cold reservoir circuit 42 is used for this, which contains the vaporizer 14’ and the cold reservoir 03 itself, or a cold reservoir heat exchanger 44.

[0041] The heat exchange from the cold reservoir 03 to the volumetric flow in the vaporizer 14’ can be regulated with a cold reservoir valve 46 or a cold reservoir pump (not shown).

[0042] An expanded charging circuit 51 for a storage system 01 in the embodiment shown in Fig. 1 is shown in Figure 4. This contains a recuperator 17 in the return path in the charging circuit 51 between the heat accumulator 02 and the air regulator 15.This is also placed between the vaporizers 14, 24 and the compressor 13 in the intake to the charging circuit.

[0043] This results in an advantageous transfer of the residual heat from the heat exchanger to the volumetric flow from the vaporizer during the charging process.

Claims

Claims1. A storage system (01) for storing thermal energy, which has a charging circuit (11 , 31 , 41 , 51) that contains a vaporizer (14, 14’, 24), a compressor (13), a charging heat exchanger (12), and an air regulator (15), connected directly or indirectly to one another, wherein the heat exchanger (12) is coupled to a heat accumulator (02), and wherein the vaporizer (14, 14’) is coupled to a cold reservoir (03), and / or wherein the vaporizer (24) is coupled to an external heat source.

2. The storage system (01) according to claim 1 , wherein the charging circuit (31 ) contains a vaporizer bypass (34), which is parallel to the vaporizer (14) and contains a bypass valve (36), wherein there is a vaporizer valve (16) upstream of the vaporizer (14) in particular.

3. The storage system (01) according to claim 1 , wherein the vaporizer (14’) is coupled to the cold reservoir (03) by a cold reservoir circuit (42), and contains a cold reservoir heat exchanger (44) on or in the cold reservoir (03).

4. The storage system (01) according to claim 3, wherein the cold reservoir circuit (42) contains a cold reservoir valve (46) and / or a cold reservoir pump.

5. The storage system (01) according to any of the claims 1 to 4, wherein the charging circuit (51) contains a recuperator (17) between the heat exchanger (12) and the air regulator (15), directly or indirectly connected thereto, which is also between the vaporizer (14, 14’, 24) and the compressor (13), directly or indirectly connected thereto.

6. A method for controlling a storage system according to any of the preceding claims, wherein water and / or steam is vaporized and / or heated in the vaporizer (14) by heat from the cold reservoir (03), which is then compressed and heatedby the compressor (13), after which thermal energy from the steam is supplied to the heat accumulator (02) through the charging heat exchanger (12), and the water and / or steam is then returned to the vaporizer (14, 14’, 24) through the air regulator (15).

7. The method according to claim 7, wherein the thermal energy from cold reservoir (03) is supplied indirectly to the vaporizer (14’) through a cold reservoir circuit (42), wherein the volumetric flow through the cold reservoir circuit (42) is regulated in order to control the performance.

8. The method according to claim 7 or 8, wherein a vacuum is generated in the vaporizer (14), at least temporarily, in particular when the temperature in the cold reservoir (03) falls below a limit temperature.

9. The method according to claim 7 or 8, wherein steam form the heat exchanger (12) in the return path is conducted to the air regulator (15) through the recuperator (17), wherein steam from the vaporizer (14) in the forward path is conducted to the compressor (13) through the recuperator (17), wherein thermal energy from the steam in the return path is transferred in the recuperator (17) to the steam in the forward path.

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