Storage system with multiple circulations

Abstract

The invention relates to a storage system for storing thermal energy, which has a charging circuit that 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. In order to increase the efficiency of the system, the compression and heat exchange take place in multiple stages. This means that there are numerous assemblies comprising compressors and charging heat exchangers, with downstream connecting lines. According to the invention, the charging circuit has a connection between each separator and the associated connecting lines in order to further increase the efficiency in multiple stages, wherein each separator is located between an air regulator in the subsequent stage and an air regulator belonging to the stage in which it is contained.

Description

DescriptionTITLEStorage System With Multiple CirculationsTECHNICAL 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. High efficiency is obtained through multiple circulations.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] To increase efficiency, the compression and heat exchange takes place in multiple stages. This means that there are numerous assemblies comprising compressors and charging heat exchangers, with downstream connecting lines.

[0010] According to the invention, the charging circuit has a connection between each separator and its associated connecting line in order to increase the efficiency in multiple stages, in which the separator is located between an air regulator in the next stage and the air regulator belonging to the stage in which it is contained.DESCRIPTION OF THE INVENTION

[0011] A storage system of this type is used to store thermal energy. It comprises a multistage charging circuit and, advantageously, a multistage discharge circuit.

[0012] The charging circuit comprises a vaporizer, compressor, charging heat exchanger, and air regulator, connected directly or indirectly to one another. The heat exchanger is coupled in this case to a heat accumulator for storing thermal energy.

[0013] To increase efficiency, the compression and heat exchange takes place in multiple stages. For this, there is a first compressor, a first charging heat exchanger, a first connecting line, a second compressor, a second charging heat exchanger, a second connecting line, a last compressor, and a last charging heat exchanger downstream of the vaporizer. The last air regulator is connected directly or indirectly to the last charging heat exchanger.

[0014] All of the charging heat exchangers are coupled directly or indirectly to the heat accumulator, such that heat can be transferred from the heated steam to the storage medium.

[0015] According to the invention, the charging circuit is supplemented with a second separator, a second air regulator, a first separator, and a first air regulator between the last air regulator and the vaporizer, connected directly or indirectly to one another, in order to further increase the efficiency. The first separator is connected to the first connecting line, and the second separator is connected to the second connecting line.

[0016] The charging circuit is operated when the storage system is charging. For this, water is first vaporized in the vaporizer, and the steam is subsequently compressed by the first compressor. A portion of the thermal energy in the steam is conveyed to the heat accumulator through the first charging heat exchanger. At this point, steam coming from the first separator is added thereto.

[0017] This process is repeated in the next stages, in which the steam is compressed by the second compressor and a portion of the thermal energy in the steam is conveyed to the heat accumulator (02) by the second charging heat exchanger. Steam coming from the second separator is again added thereto.

[0018] The steam is again compressed by the last compressor in the final stage, and a portion of the thermal energy in the steam is conveyed to the heat accumulator by the last charging heat exchanger. The cooled steam coming from the last charging heat exchanger then passes through the air regulator.

[0019] To make better use of the heat in the steam, a portion of the steam is separated out by the second separator, and conducted to the second connecting line. The remaining water, and potentially a remaining portion of the steam, are conducted through the second air regulator.

[0020] This process is repeated in the final stage, in which a portion of the steam is again separated out in the first separator, and then conducted to the first connecting line. The remaining portion of the steam then passes through the air regulator.

[0021] The thermal energy in the circuit can be optimally used to transfer heat to the heat accumulator through the multistage heat exchange and the multistage return of portions of steam. This results in a particularly high efficiency.

[0022] It is possible to further increase the efficiency with regard to the thermal energy that can be stored if the embodiment is further supplemented with one or more additional stages. The greater installation complexity must be taken into account for this.

[0023] In this regard, it is at least advantageous if the charging circuit is also supplemented with a third compressor, third charging heat exchanger, and a third connecting line between the second connecting line and the last compressor, connected directly or indirectly to one another. The third charging heat exchanger should also be coupled to the heat accumulator.

[0024] If there is a third stage, it is also advantageous to place a third separator and third air regulator between the last air regulator and the second separator in the charging circuit, connected directly or indirectly to one another, in which case the third separator is connected to the third connecting line.

[0025] To obtain greater flexibility in managing the process, and in particular to be able to more effectively take different pressures and temperatures into account at the start of the charging circuit, it is advantageous if there is a connection between the second separator and the first connecting line.

[0026] In this regard, it does not matter whether the connections run separately from the second separator to the first connecting line and second connecting line, or whether the same line is first separated into branches to obtain a first connecting line segment and second connecting line segment. It also does not matter whether the connections from the first separator and second separator are connected individually to the first connecting line, or the connections from the first separator and second separator are joined and then connected to the first connecting line.

[0027] If there is a third separator, it is advantageously connected to the second connecting line in the same manner as described above.

[0028] It is particularly advantageous if the respective separators are designed to portion out the steam such that only steam is contained in these portions. Furthermore, the separator is able to separate out the steam such that there is only water in the other portion.

[0029] It is particularly preferred that there are control valves in the connections between the separators and the corresponding connecting lines.

[0030] It is particularly advantageous when the storage system is enhanced by a multistage discharge circuit.

[0031] The discharge circuit comprises 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 thermal energy.

[0032] In order to increase efficiency, the heat exchange and recovery take place in multiple stages. For this, there are a last discharge heat exchanger, a last steam turbine, a second connection, a second discharge heat exchanger, a second steam turbine, a first connection, a first discharge heat exchanger, and a first steam turbine connected indirectly thereto by the pump. The condenser is connected directly or indirectly to the first steam turbine.

[0033] All of the discharge heat exchangers are coupled directly or indirectly to the heat accumulator, such that heat can be transferred from the heated heat accumulator to the steam.

[0034] A first separator and a second separator are preferably incorporated in the first connection and second connection in the discharge circuit, in order to further increase the efficiency. Furthermore, a first preliminary heat exchanger and second preliminary heat exchanger are placed between the pump and the last discharge heat exchanger, connected directly or indirectly thereto.

[0035] The first separator is connected to the first preliminary heat exchanger and the second separator is connected to the second preliminary heat exchanger. The volumetric flow from the steam turbine is separated in the respective separators, such that one portion is conducted to the associated preliminary heat exchanger, and the other portion is conducted to the downstream discharge heat exchanger.

[0036] The discharge circuit is operated when the storage system is discharging energy. In this case, water is first conveyed by the pump to the first preliminary heat exchanger, which is then heated by the thermal energy in the steam coming from thefirst separator. This is repeated in the second preliminary heat exchanger. The water is heated and / or vaporized at this point.

[0037] The mixture of water and steam is vaporized in the last discharge heat exchanger after passing through the preliminary heat exchanger (if it has not been fully vaporized in the preliminary heat exchanger), and heated by the thermal energy from the heat accumulator. The heated steam is then used to power the last steam turbine.

[0038] To increase the efficiency, the second separator, with which the volumetric flow is divided, is connected directly or indirectly to the second connection. One portion is separated out and sent to the second preliminary heat exchanger.

[0039] The other portion is sent to the second discharge heat exchanger and heated by the heat accumulator. The heated steam then powers the second steam turbine.

[0040] The process is repeated in the next stage. First, the volumetric flow is divided in the first separator, and one portion is sent to the first preliminary heat exchanger, while the other portion is sent to the first discharge heat exchanger. The steam is then heated again, such that first steam turbine can be powered therewith.

[0041] The steam is then cooled in the condenser, and the water obtained therebx is conveyed back to the discharge circuit by the pump.

[0042] Optimal use of the thermal energy stored in the heat accumulator can be obtained through the multistage heat exchange and the multistage conversion of the thermal energy into rotational energy by the steam turbines. This results in a particularly high efficiency.

[0043] The efficiency can be further increased with regard to the thermal energy conversion if the embodiment is supplemented with one or more additional stages. The greater installation complexity must be taken into account for this.

[0044] It is at least advantageous when the discharge circuit contains a third connection, a third discharge heat exchanger, and a third steam turbine, connected directly or indirectly between the last steam turbine and the second connection. In this case, the third discharge heat exchanger is to be coupled to the heat accumulator.

[0045] If there is a third stage, it is also advantageous to place a third separator in the third connection, and a third preliminary heat exchanger downstream of the second heat heat exchanger in the charging circuit, in which case the third separator is connected to the third preliminary heat exchanger.

[0046] 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.

[0047] 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

[0048] Fig. 1 shows a schematic illustration of an exemplary storage device with a charging circuit.

[0049] Fig. 2 shows a schematic illustration of an exemplary storage device with a discharge circuit.DESCRIPTION OF THE EMBODIMENTS

[0050] A storage device 01 is shown schematically with a charging circuit 11 in Figure 1 . The essential element of the storage device 01 is the heat accumulator 02. Arrows indicate the flow directions in the circuits 11 .

[0051] The charging circuit 11 comprises a first compressor 13.1, with which the steam in the circuit 11 is compressed and therefore heated.

[0052] A first heat exchanger 12.1 is connected to the first compressor 13.1 , which is coupled to the heat accumulator 02. It does not matter whether the first heat exchanger 12.1 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 first heat exchanger 12.1 and back to the heat accumulator 02.

[0053] When the charging circuit 11 is operating, thermal energy is released by the first heat exchanger 12.1 to heat the heat accumulator 02.

[0054] The first heat exchanger 12.1 is connected by a first connection to a second compressor 13.2, which is connected to a second heat exchanger 12.2. This is the same as with the first compressor 13.2 and the first heat exchanger 12.1.

[0055] There is also a third compressor 13.3 and a third heat exchanger 12.3 connected to the second connection 16.2 in this exemplary embodiment.

[0056] The third connection comes after a last compressor 13.n and a last heat exchanger 12.n in this exemplary embodiment, which also conveys thermal energy to the heat accumulator 02.

[0057] The embodiment has a last air regulator 15. n and a vaporizer 14 in the charging circuit 11. Regenerative thermal energy is advantageously supplied to the vaporizer 14.

[0058] Other connections are used to increase the efficiency. There is a third separator 17.3, a third air regulator 15.3, a second separator 17.2, a second air regulator 15.2, a first separator 17.1 , and a first air regulator 15.1 between the last air regulator 15.n and the vaporizer 14 in this case.

[0059] At least a portion of the steam is removed from the volumetric flow in the respective separators 17.1 , 17.2, and 17.3. Preferably, the medium is separated into steam, which is removed, and water, which is conveyed further.

[0060] Each separator 17.1 , 17.2, 17.3 is connected to an associated connection 16.1 , 16.2, 16.3 for this.

[0061] A storage device 01 is shown schematically with a discharge circuit 21 in Figure 2.

[0062] The discharge circuit 21 contains a pump 25 with which water is conveyed to a first preliminary heat exchanger 28.1 , a second preliminary heat exchanger 28.2, and a third preliminary heat exchanger 28.3. The water then flows through the last discharge heat exchanger 22. n, in which the water is fully vaporized and heated.

[0063] The heated steam is conducted through a last steam turbine 23. n, and then through a third connection 26.3 to a third discharge heat exchanger 22.3. There is a third separator 27.3 in the third connection 26.3, which separates out a portion of the main flow. This portion is conducted to the third preliminary heat exchanger 28.3.

[0064] The process is repeated with the third discharge heat exchanger 22.3 and the downstream third steam turbine 23.3. There is a second separator 27.2 the subsequent second connection 26.2, which also separates out a portion of the main flow that can then be conducted to the second preliminary heat exchanger 28.2.

[0065] The second discharge heat exchanger 22.2 and second steam turbine 23.2, as well as the first connection 26.1 with the first separator 27.1 are downstream thereof.

[0066] The circuit is completed after the first discharge heat exchanger 22.1 and the first steam turbine 23.1 , and returns to the pump 25 through a condenser 24.

Claims

Claims1. A storage system (01 ) for storing thermal energy that has a charging circuit (11), which contains a vaporizer (14), a first compressor (13.1), a first charging heat exchanger (12.1), a first connecting line (16.1), a second compressor (13.2), a second charging heat exchanger (12.2), a second connecting line (16.2), a last compressor (13.n), a last charging heat exchanger (12. n), and a last air regulator (15.n), connected directly or indirectly to one another, wherein the charging heat exchangers (12.1 , 12.2, 12.3, 12.4) are coupled to a heat accumulator (02), characterized in that the charging circuit (11) contains a second separator (17.2), a second air regulator (15.2), a first separator (17.1), and a first air regulator (15.1) between the last air regulator (15.n) and the vaporizer (14), connected directly or indirectly to one another, wherein the first separator (17.1) is connected to the first connecting line (16.1) and the second separator (17.2) is connected to the second connecting line (16.2).

2. The storage system (01) according to claim 1 , wherein the charging circuit (11) contains a third compressor (13.3), a third charging heat exchanger (12.3), and a third connecting line (16.3) between the second connecting line (16.2) and the last compressor (13.n), connected directly or indirectly to one another, wherein the last charging heat exchanger (12.3) is coupled to the heat accumulator (03).

3. The storage system according to claim 2, wherein the charging circuit (11) also contains a third separator (17.3) and a third air regulator (15.3) between the last air regulator (15.n) and the second separator (17.2), connected directly or indirectly to one another, wherein the third separator (17.2) is connected to the third connecting line (16.3).

4. The storage system (01) according to any of the claims 1 to 3, wherein the second separator (17.2) is connected to the first connecting line (16.1), and / orwherein the third separator (17.3) is connected to the second connecting line(16.2).

5. The storage system (01) according to any of the claims 1 to 4, wherein the respective separators are designed to conduct a portion of the steam to the corresponding connecting lines.

6. The storage system (01) according to any of the claims 1 to 5, which has a discharge circuit (21), containing a pump (25), a last charging heat exchanger (22. n), a last steam turbine (23. n), a second connection (26.2), a second discharge heat exchanger (22.2), a second steam turbine (23.2), a first connection (26.1), a first discharge heat exchanger (22.1) a first steam turbine(23.1) and a condenser (24), connected directly or indirectly to one another, wherein the discharge heat exchangers (22.1 , 22.2, 22.3, 22.4) are connected to the heat accumulator (02), wherein the discharge circuit (21) contains a first preliminary heat exchanger (28.1), and a second preliminary heat exchanger(28.2) between the pump (25) and the last discharge heat exchanger (22. n), a second separator (27.2) connected to the second preliminary heat exchanger(28.2) in the second connection (26.2), and a first separator (27.1) connected to the first preliminary heat exchanger (28.2) in the first connection (26.1), connected directly or indirectly to one another.

7. The storage system (01) according to claim 6, wherein the discharge circuit (21 ) contains a third connection (26.3), a third discharge heat exchanger (22.3), and a third steam turbine (23.3) between the last steam turbine (23. n) and the second connection (26.2), connected directly or indirectly to one another, wherein the third discharge heat exchanger (22.3) is coupled to the heat accumulator (02).

8. The storage system according to claim 7, wherein the discharge circuit (21) contains a third preliminary heat exchanger (28.3) between the second preliminary heat exchanger (28.2) and the last discharge heat exchanger (22. n),and a third separator (27.3) in the third connection (26.3), which is connected to the third preliminary heat exchanger (28.3).

9. A method for operating a storage system (01) according to any of the preceding claims, wherein- water is vaporized in the vaporizer (14),- the steam is compressed by the first compressor (13.1 ),- a portion of the thermal energy contained in the steam is transferred to the heat accumulator (02) by the first charging heat exchanger (12.1),- steam coming from the first separator (17.1) is added thereto,- the steam is compressed by the second compressor (13.2),- a portion of the thermal energy contained in the steam is transferred to the heat accumulator (02) by the second charging heat exchanger (12.2),- steam coming from the second separator (17.2) is added thereto,- the steam is compressed by the last compressor (13.n),- a portion of the thermal energy contained in the steam is transferred to the heat accumulator (02) by the last charging heat exchanger (12.n),- the cooled steam is conducted through the last air regulator (15.n),- a portion of the steam is separated out in the second separator (17.2),- the steam that has been separated out is conveyed to the second connecting line (16.2),- the remaining portion of the steam is conducted through the second air regulator (15.2),- a portion of the steam is separated out in the first separator (17.1),- the steam that has been separated out is conveyed to the first connecting line(16.1), and- the remaining portion of the steam is conducted through the first air regulator(15.1).

10. A method for operating a storage system (01) according to any of the preceding claims, wherein- water is conveyed by the pump (25),- the water is heated and potentially vaporized in the first preliminary heat exchanger (28.1),- the water and / or steam is heated and potentially vaporized in the second preliminary heat exchanger (28.1),- vaporization and / or heating takes place in the last heat exchanger (22. n), with a transfer of thermal energy from the heat accumulator (02),- the steam is conducted through a last steam turbine (23. n),- at least a portion of the steam is separated out by the second separator (27.2),- the remaining portion of the steam is heated in the second discharge heat exchanger (22.2),- the steam is conducted through the second steam turbine (23.2),- at least a port of the steam is separated out by the first separator (27.1 ),- the remaining portion of the steam is heated in the first discharge heat exchanger (22.1),- the steam is conducted through the first steam turbine (23.1), and- cooling takes place in the condenser (24).

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