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. A discharge circuit is used to recover the energy stored in the heat accumulator. The discharge circuit contains a pump, a discharge heat exchanger, a steam turbine, and a condenser, connected directly or indirectly to one another. The discharge heat exchanger is coupled to the heat accumulator in order to recover the thermal energy. To optimize the energy recovery, both the vaporizer and the condenser are coupled to the same cold reservoir.

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 and recovery.

[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] A discharge circuit is used to recover the energy stored in the heat accumulator. The discharge circuit contains a pump, a discharge heat exchanger, a steam turbine, and a condenser connected directly or indirectly to one another. The discharge heat exchanger is coupled to the heat accumulator to recover the thermal energy.

[0010] To optimize energy recovery, both the vaporizer and the condenser are coupled to the same cold reservoir.DESCRIPTION OF THE INVENTION

[0011] Storage systems of this type are used for storing thermal energy. These contain a charging circuit and a discharge circuit.

[0012] The charging circuit contains a vaporizer, a compressor, a charging heat exchanger, and an air regulator, connected to one another directly or indirectly. The charging heat exchanger is coupled to a heat accumulator to store thermal energy.

[0013] 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.

[0014] The discharge circuit is used to recover the energy stored in the heat accumulator. Discharge circuits of this type contain a pump, a discharge heat exchanger, a steam turbine, and a condenser, connected to one another directly or indirectly. The discharge heat exchanger is coupled to the heat accumulator to recover the thermal energy.

[0015] The discharge circuit in the storage system is operated when discharging energy. First, water is conveyed by a pump to the discharge heat exchanger. Thermal energy from the heat accumulator is then applied to the medium flowing through the discharge heat exchanger, thus vaporizing and heating the water. The heated steam is then supplied to the steam turbine. The steam turbine outlet returns the steam through a condenser to the pump.

[0016] Instead of simply discarding residual heat in the condenser during the discharge, the condenser is coupled to a cold reservoir according to the invention. Consequently, residual heat in the volumetric flow from the steam turbine is transferred to the cold reservoir.

[0017] The recovery of the energy in the cold reservoir is obtained by coupling the vaporizer with the cold reservoir.

[0018] It is also advantageous to be able to regulate the charging process with regard to heat discharge. There are a number of ways to regulate the heat discharge from the vaporizer in the charging circuit.

[0019] In a first embodiment, there is a vaporizer bypass parallel to the vaporizer, such that a portion of the main flow can bypass the vaporizer. For the regulation thereof, a bypass valve is necessary in the vaporizer bypass. A vaporizer valve can also be advantageously placed upstream of the vaporizer.

[0020] If more energy is supplied to the vaporizer than is needed for the charging process, and if excessive heating in the vaporizer would limit the time available for the charging process, the amount of energy supplied to the charging circuit can be reduced by the vaporizer bypass, thus increasing the time available for supplying energy, such that it is possible to charge the heat accumulator to a greater extent.

[0021] In a second embodiment, the vaporizer is coupled indirectly to the cold reservoir through a cold reservoir circuit. For this, there is a heat exchanger on the cold reservoir that takes thermal energy from the cold reservoir and sends it to the vaporizer through the cold reservoir circuit. By regulating the flow through the cold reservoir circuit, it is possible to control how much thermal energy is acquired from the vaporizer.

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

[0023] It is also advantageous if the removal of thermal energy from the heat accumulator can be controlled in the discharge process.

[0024] In a first variation, there can be a heat exchanger bypass that serves as a bypass to the discharge heat exchanger. Consequently, a portion of the main flow from the pump bypasses the discharge heat exchanger, thus reducing the amount of heat removed from the heat accumulator.

[0025] In an alternative embodiment, the discharge heat exchanger is coupled indirectly with the heat accumulator. There is a heat exchanger on the heat accumulator for this that takes thermal energy from the heat accumulator and supplies it to the dischargeheat exchanger through the heat exchanger circuit. By controlling the flow through the heat accumulator circuit, the thermal energy applied to the discharge circuit by the discharge heat exchanger can be controlled.

[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 embodiment of a storage system in which a charging circuit and a discharge circuit are connected to a heat accumulator and a cold reservoir.

[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 a heat exchanger bypass for increasing the flexibility in managing the process.

[0032] Fig. 5 shows a schematic illustration of a heat accumulator circuit for separating the discharge circuit from the heat accumulator.DESCRIPTION OF THE EMBODIMENTS

[0033] A storage device 01 that has a charging circuit 11 and a discharge circuit 21 is shown schematically in Figure 1. The essential element of the storage device is the heat accumulator 02. Arrows indicate the direction in which the media flows in both circuits 11 , 21.

[0034] The charging circuit 11 contains a charging heat exchanger 12 that is coupled to the heat accumulator 02. In this regard, it is not important whether the charging heat exchanger 12 is directly in or on the heat accumulator 02. It can also be separate therefrom, and the storage medium can flow from the heat accumulator 02 through the charging heat exchanger 12 and back into the heat accumulator 02.

[0035] When the charging circuit 11 is in operation, thermal energy from the charging heat exchanger 12 is used to heat the heat accumulator 02.

[0036] The embodiment according to the invention has a downstream air regulator 15 and a vaporizer 14 in the charging circuit 11 . The steam generated by the vaporizer 14 is subsequently compressed by the compressor 13 and sent to the charging heat exchanger 12.

[0037] There is also a discharge circuit 21 , which also has a discharge heat exchanger 22. Like the charging heat exchanger 12, this is also coupled to the heat accumulator 02.

[0038] When the discharge circuit 21 is in operation, heat is conveyed from the heat accumulator 02 to the discharge heat exchanger 22 such that the water is vaporized and the steam is heated.

[0039] A steam turbine 25 with which a generator can be powered is connected to the charging heat exchanger 12 in the discharge circuit 21 .

[0040] A condenser 24 cools and condenses the steam in the discharge circuit 21 , and the heat from the condenser 24 is preferably made use of.

[0041] A pump 23 is connected to the condenser 24, with which the water can be returned to the discharge heat exchanger 22.

[0042] Energy recovery is optimized in that the condenser 24 and the vaporizer are both coupled to a cold reservoir.

[0043] A vaporizer bypass 34 is shown by way of example in Figure 2. This makes it possible to divide the volumetric flow prior to reaching the vaporizer. In this example, there is a vaporizer valve 16 between the vaporizer bypass 34 and the vaporizer 14, and a bypass valve 36 in the vaporizer bypass 34.

[0044] An indirect coupling between the vaporizer 14’ and the cold reservoir 04 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.

[0045] 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).

[0046] A heat exchanger bypass 52 is shown by way of example in Figure 4. This makes it possible to divide the volumetric flow prior to reaching the discharge heat exchanger 22. There is a heat exchanger valve 26 between the discharge heat exchanger 22 and the heat exchanger bypass 52 and a bypass valve 56 in the heat exchanger bypass 52 in this example.

[0047] An indirect coupling between the discharge heat exchanger 22’ and the heat accumulator 02 is shown by way of example in Figure 5. A heat accumulator circuit 62 is used for this, which contains the discharge heat exchanger 22’ and the heat accumulator 02 itself, or a heat accumulator heat exchanger 64.

[0048] The amount of heat applied to the volumetric flow in the discharge heat exchanger 22’ by the heat accumulator 02 can be controlled with a heat accumulator valve 66 or a heat accumulator pump (not shown).

Claims

Claims1. A storage system (01 ) for storing thermal energy that has a charging circuit (11 , 31 , 41), which contains a vaporizer (14, 14’), a compressor (13), a charging heat exchanger (12) and an air regulator (15) connected directly or indirectly to one another, and has a discharge circuit (21 , 51 , 61), which contains a condenser (24), a pump (25), a discharge heat exchanger (22) and a steam turbine (23), connected directly or indirectly to one another, wherein the charging heat exchanger (12) and the discharge heat exchanger (22) are coupled to a heat accumulator (02), characterized in that the vaporizer (14, 14’) and condenser (24) are coupled to a cold reservoir (03).

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

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 comprises a cold reservoir heat exchanger (44) on or in the cold reservoir (03).

4. The storage system (01) according to claim 2, 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 discharge circuit (51) contains a heat exchanger bypass (52), which is parallel to the discharge heat exchanger (22) and contains a bypass valve (56).

6. The storage system (01) according to any of the claims 1 to 4, wherein the discharge heat exchanger (22’) is coupled to the heat accumulator (02) by a heataccumulator circuit (62), and contains a heat accumulator heat exchanger (64) on or in the heat accumulator (02).

7. The storage system (01) according to claim 6, wherein the heat accumulator circuit (62) contains a heat accumulator valve (66) and / or a heat accumulator pump.

8. A method for controlling a storage system according to any of the preceding claims, wherein water and / or steam are vaporized and / or heated by heat from the cold reservoir (03) in the vaporizer, and compressed and heated by the compressor (14) during the charging process, and thermal energy is conveyed from the steam into the heat accumulator (02) through the charging heat exchanger (12), and returned to the vaporizer (14) through the air regulator (15).

9. The method according to claim 8, wherein the thermal energy form the cold reservoir (03) is conveyed indirectly to the vaporizer (14’) through a cold reservoir circuit (42), wherein the amount of medium flowing in the cold reservoir circuit (42) is controlled as a means of controlling the performance of the system.

10. The method according to claim 8 or 9, wherein a vacuum is generated in the vaporizer (14) at least part of the time, in particular when the temperature in the cold reservoir (03) falls below a limit temperature.11 . The method according to any of the claims 8 to 10, wherein water is conveyed by the pump (25) to the discharge heat exchanger (22) during the discharging process, and vaporized and heated there by the heat from the heat accumulator (02), and sent to the steam turbine (23), and thermal energy is conveyed to the cold reservoir (03) in the condenser (24) and the water then flows back to the pump.

2. The method according to claim 11 , wherein the thermal energy from the heat accumulator (03) is conveyed indirectly to the discharge heat exchanger (22’) through a heat accumulator circuit (42), wherein the amount of medium flowing through the heat accumulator circuit (42) is controlled in order to control the performance of the system.

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