Adiabatic compressed air energy storage system (A-CAES) and process

Abstract

The present invention relates to an A-CAES system comprising: a first compressor unit for compressing supplied air to a first pressure and a first temperature; a first air / heat storage heat exchanger system connected to the first compressor unit, with a first heat storage unit for cooling the air by heating the first heat storage unit to a first heat storage temperature and a first heat storage pressure using the heat of compression of the air; a first hot-temperature storage unit for storing the first heat storage unit heated in the first air / heat storage heat exchanger system; a second compressor unit, which is connected to the first compressor unit and the first air / heat storage heat exchanger system in the direction of flow for compressing the cooled air to a second, lower pressure and a second, lower temperature than the first compressor unit;a second air / heat storage heat exchanger system connected to the second compressor unit, comprising a second heat storage unit for cooling the air by heating the second heat storage unit to a second, lower heat storage temperature and pressure than the first heat storage unit using the heat of compression of the air; a second hot-temperature storage unit for storing the second heat storage unit heated in the second air / heat storage heat exchanger system.

Description

[0001] The present invention relates to an adiabatic compressed air energy storage system (A-CAES) and a method.

[0002] It is generally known that significant fluctuations can occur in the generation of renewable energy, for example, from wind turbines or photovoltaic systems. Various options exist for storing the generated electricity. These include, for example, pumped-storage hydroelectric plants. However, these have the disadvantage of requiring a difference in altitude, which is not present in flat regions. Furthermore, compressed air energy storage systems, also known as CAES (Compressed Air Energy Storage) systems, are also available. These include adiabatic compressed air energy storage systems, or A-CAES (Adiabatic Compressed Air Energy Storage) systems.

[0003] Compressed air energy storage power plants or systems, i.e. CAES power plants or systems, are based on the principle of compressing air to absorb power, storing the compressed air, and expanding it to deliver power.

[0004] From DE 10 2011 112 280 A1, a system for storing energy using compressed air is known. In this system, a storage volume holds air under increased pressure. Ambient air is compressed for energy storage and introduced into the storage volume. To release the energy, compressed air is drawn from the storage volume and released into the environment, releasing energy in the process.

[0005] Compressing air heats it up. This heat of compression is used and stored by adiabatic compressed air energy storage systems, also known as A-CAES (Adiabatic Compressed Air Energy Storage). Currently, this requires expensive storage tanks.

[0006] Against this background, the present invention aims to provide an improved A-CAES system.

[0007] According to the invention, this problem is solved by an A-CAES system with the features of claim 1 and / or by a method with the features of claim 13.

[0008] Accordingly, the following is planned: Featuring an adiabatic compressed air energy storage system (A-CAES): - a first compressor unit for compressing supplied air to a first pressure d K1 and a first temperature T K1 in at least one compression stage, - a first air / heat storage heat exchanger system connected to the first compressor unit, with a first heat storage unit for cooling the air after at least one compression stage by heating the first heat storage unit to a first heat storage temperature T using the heat of compression of the air Heiss1and an initial heat storage pressure d Heiss1 , - a first hot-temperature storage unit for storing the first heat storage unit heated in the first air / heat storage heat exchanger system, for providing the heated first heat storage unit to a first expander unit connected to the first compressor unit for heating the air to be expanded in the first expander unit before an expansion stage, - a second compressor unit, which is connected to the first compressor unit and the first air / heat storage heat exchanger system in the direction of flow for compressing the cooled air in several compression stages to a second, lower pressure d K6 and a second, lower temperature T K6 as the first compressor unit, - a second air / heat storage heat exchanger system connected to the second compressor unit, with a second heat storage unit for cooling the air after each compression stage by heating the second heat storage unit to a second, lower heat storage temperature T using the heat of compression of the air Warm2 and a second, low heat storage pressure d Warm2 as the first heat storage device, - a second hot-temperature storage tank for storing the heat heated in the second air / heat storage heat exchanger system, a second heat storage tank for providing the heated second heat storage tank to a second expander unit connected to the second compressor unit for heating the air to be expanded in the second expander unit before each expansion stage, and - a compressed air storage system for storing the air compressed in the first and second compression units, and - an air piping system which connects the first compressor unit and its first air / heat storage heat exchanger system to the second compressor unit and its second air / heat storage heat exchanger system and to the compressed air storage device in the direction of flow.

[0009] The underlying idea of ​​the present invention is to provide heat storage at two temperature levels in an A-CAES system. First, the heat is stored at a high temperature and pressure in a pressurized high-temperature storage tank, and second, it is stored at a lower temperature, e.g., at most 100°C, and a lower pressure, preferably unpressurized or atmospherically, in a warm-temperature storage tank. This has the advantage that the entire heat storage capacity does not need to be stored in a high-temperature storage tank, which would require a pressurized storage tank with a correspondingly large heat storage volume. Conversely, the entire heat storage capacity does not need to be cooled to a lower temperature and pressure level by means of numerous intermediate cooling stages in order to be stored in a warm-temperature storage tank at the lowest possible pressure or unpressurized or atmospherically.The heat storage unit with the two temperature levels can then be provided to a corresponding expander unit to heat or warm the air as needed before expansion.

[0010] Furthermore, a method for adiabatic compressed air energy storage is provided, wherein the method comprises the following steps: - Compressing air, in particular ambient air, in a first compressor unit in at least one compression stage to a first temperature and a first pressure, wherein the air is cooled in the at least one compression stage by a first air / heat storage heat exchanger system with a first heat storage unit, - Supplying air to a second compressor unit and compressing the air in the second compressor unit in several compression stages, wherein the air in each of the compression stages is cooled by a second air / heat storage heat exchanger system with a second heat storage unit, and - Supplying air to a compressed air storage device and storing the air therein.

[0011] Advantageous designs and further developments result from the further sub-claims as well as from the description with reference to the figures in the drawing.

[0012] In one embodiment of the invention, the A-CAES system comprises a first expander unit for expanding the air in the at least one expansion stage, and a further first air / heat storage heat exchanger system connected to the first heat storage unit for heating the air upstream of the at least one expansion stage by cooling the first heat storage unit. The A-CAES system further comprises a first heat storage piping system that connects the first air / heat storage heat exchanger system to the first high-temperature storage unit for supplying and storing the heated first heat storage unit.The first heat storage piping system connects the first hot temperature storage with the further first air / heat storage heat exchanger system for supplying the heated, first heat storage and heating the air before at least one expansion stage through the first heat storage, whereby the first heat storage is cooled down again.

[0013] In a further embodiment of the invention, the A-CAES system comprises a second expander unit for expanding the air in the multiple expansion stages. Furthermore, the A-CAES system comprises a second air / heat storage heat exchanger system connected to the second heat storage unit, which heats the air before each expansion stage by cooling the second heat storage unit. The A-CAES system also comprises a second heat storage piping system that connects the second air / heat storage heat exchanger system to the second heat storage unit for supplying and storing the heated second heat storage unit.The second heat storage piping system connects the second hot temperature storage tank to the further, second air / heat storage heat exchanger system for supplying the heated, second heat storage tank and heating the air before at least one expansion stage through the second heat storage tank, whereby the second heat storage tank is cooled down again.

[0014] According to one embodiment of the invention, the A-CAES system comprises a first cold-temperature storage tank in which the first heat storage tank is stored at a first heat storage outlet temperature and a first heat storage outlet pressure. The first cold-temperature storage tank is connected to the first air / heat storage heat exchanger system via the first heat storage piping system for supplying the first heat storage tank. Additionally or alternatively, the A-CAES system comprises a second cold-temperature storage tank in which the second heat storage tank is stored at a second heat storage outlet temperature and a second heat storage outlet pressure. The second cold-temperature storage tank is connected to the second air / heat storage heat exchanger system via the second heat storage piping system for supplying the second heat storage tank.

[0015] In one embodiment of the invention, the A-CAES system comprises a first hot-temperature storage tank and, for example, a first heat storage trim cooler. The first heat storage piping system connects the further, first air / heat storage heat exchanger system in the flow direction to the first hot-temperature storage tank, and the first hot-temperature storage tank preferably to the first heat storage trim cooler, and the first heat storage trim cooler to the first cold-temperature storage tank. This allows the first heat storage tank to circulate within the A-CAES system.

[0016] In another embodiment of the invention, the A-CAES system includes a second heat storage trim cooler. The second heat storage piping system connects the second air / heat storage heat exchanger system in the direction of flow to the second heat storage trim cooler, and the second heat storage trim cooler to the second cold temperature storage unit. This allows the second heat storage unit to circulate within the A-CAES system.

[0017] In a further embodiment of the invention, the A-CAES system includes an air trim cooler. The air piping system connects the second compressor unit and its second air / heat storage heat exchanger system to the air trim cooler and the air trim cooler to the compressed air storage device.

[0018] According to one embodiment of the invention, the first compression unit comprises at least one compressor or, for example, at most two, three, or four compressors connected sequentially in the direction of flow through the air piping system. The first air-to-heat storage heat exchanger system comprises, for example, a first air-to-heat storage heat exchanger after each compressor for intermediate cooling of the air by the first heat storage unit in the respective compression stage. Additionally or alternatively, the second compression unit comprises at least two, three, four, five, or six compressors connected sequentially in the direction of flow through the air piping system. The second air-to-heat storage heat exchanger system comprises, for example, a second air-to-heat storage heat exchanger after each compressor for intermediate cooling of the air in the respective compression stage by the second heat storage unit.

[0019] In one embodiment of the invention, the first expander unit comprises at least one first expander or at most two, three, or four expanders connected sequentially in the direction of flow through the air piping system. The further, first air / heat storage heat exchanger system comprises, for example, a first air / heat storage heat exchanger upstream of each expander for intermediate heating of the air by the first heat storage element in the respective expansion stage. Additionally or alternatively, the second expander unit comprises at least two, three, four, five, or six expanders connected sequentially in the direction of flow through the air piping system. The further, second air / heat storage heat exchanger system comprises, for example, a second air / heat storage heat exchanger downstream of each expander for intermediate heating of the air in the respective expansion stage by the second heat storage element.

[0020] In a further embodiment of the invention, at least the first hot-temperature storage unit, the first warm-temperature storage unit, the second warm-temperature storage unit, the first cold-temperature storage unit, and / or the second cold-temperature storage unit comprise at least one storage tank, in particular an above-ground storage tank or an underground storage tank, and / or at least one cavity for storing the first or second heat storage unit. The first heat storage unit and / or the second heat storage unit can be, for example, water, thermal oil, a liquid salt, or a latent heat storage unit, in particular a phase-change material (PCM) heat storage unit.

[0021] In one embodiment of the invention, the compressed air storage device has at least one storage tank, in particular an above-ground storage tank or an underground storage tank, and / or at least one cavity, e.g. a salt dome, for storing the air.

[0022] According to one embodiment of the invention, the first heat storage medium, in particular water or thermal oil, is stored in the first high-temperature storage tank connected to the first compressor unit at a first heat storage temperature of greater than 100°C, in particular approximately 200°C, and a first heat storage pressure of 6 to 7 bar. In another embodiment of the invention, the second heat storage medium, in particular water or thermal oil, is stored in the second high-temperature storage tank connected to the second compressor unit at a second heat storage temperature of less than or equal to 100°C and a second heat storage pressure. The second heat storage pressure preferably corresponds to atmospheric pressure or substantially to atmospheric pressure.

[0023] In one embodiment of the invention, the air in the compressed air storage device is stored with an inlet pressure and an inlet temperature of the compressed air storage device.

[0024] In a further embodiment of the invention, the method comprises the steps of supplying air from the compressed air storage device to an expander unit and intermediate heating of the air to be expanded by the second heat exchanger. The air is then supplied to the next expander unit and intermediate heating of the air by the first heat exchanger. Finally, the air is expanded in the next expander unit to an output temperature and pressure, for example, an ambient temperature and pressure, for release into the environment.

[0025] The above embodiments and further developments can be combined with one another as appropriate. Further possible embodiments, further developments, and implementations of the invention also include combinations of features of the invention described previously or subsequently with regard to the exemplary embodiments, even if not explicitly mentioned. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

[0026] The present invention is explained in more detail below with reference to the embodiment shown in the schematic figure of the drawing. It shows: Fig. 1 A schematic block diagram of an adiabatic compressed air energy storage system, abbreviated A-CAES system 1, according to an embodiment according to the invention.

[0027] The accompanying drawing is intended to provide a further understanding of the embodiments of the invention. It illustrates one embodiment and, in conjunction with the description, serves to explain the principles and concepts of the invention. Other embodiments and many of the advantages mentioned will become apparent with reference to the drawing. The elements of the drawing are not necessarily shown to scale.

[0028] In the figure of the drawing, identical, functionally equivalent and equally effective elements, features and components - unless otherwise stated - are each provided with the same reference symbols.

[0029] In Fig. Figure 1 shows an embodiment of a compressed air energy storage system 1 according to the invention, i.e., a so-called CAES (Compressed Air Energy Storage) system 1, here an adiabatic compressed air energy storage system, i.e., abbreviated A-CAES system 1, for storing air in a compressed air storage device 2. In the following, the adiabatic compressed air energy storage system will be consistently abbreviated as A-CAES system 1.

[0030] In the A-CAES system 1, the heat of compression generated during the charging process is extracted from the compressed air by a heat storage device in a corresponding heat exchanger. Such a heat storage device, i.e., a thermal energy storage device, is, for example, water.

[0031] During expansion, the stored compression heat or thermal energy is then supplied to the expansion air. This increases the efficiency of the A-CAES system 1 and avoids the need to supply thermal energy from external sources, potentially fossil fuels such as gas. Compression / expansion can be performed in one or more stages. The pressure levels depend significantly on the operating temperature range of the heat storage system, i.e., the thermal energy storage system. The term "heat storage system" is used throughout this text. However, the term "thermal energy storage system" can also be used.

[0032] Water, as a heat storage medium, has a boiling point of approximately 100°C. Therefore, water at temperatures above 100°C must be stored under pressure in a storage tank or a pressure storage tank to prevent evaporation.

[0033] Key restrictions / boundary conditions for determining the storage temperature and storage pressure are: - maximum permissible temperature of the compressed air storage device - technically and economically feasible operating temperature and pressure range of the heat storage units as transfer and storage media - High storage temperature = high RTE (Round Trip Efficiency)

[0034] If the maximum operating temperature of the heat storage unit is, for example, 200°C, this means that compression can only occur up to a pressure level of approximately 7 bara, depending on the efficiency of the compressor. Compression to higher pressures therefore takes place in multiple stages with various intermediate cooling cycles of the compressed air, transferring the thermal energy or heat of compression to the heat storage unit.

[0035] In the exemplary embodiment in Fig. In the A-CAES system 1 shown, a combination of two heat storage devices, i.e. thermal energy storage devices, at different temperature levels is therefore used for the A-CAES system 1.

[0036] On the one hand, an atmospheric warm temperature storage tank 23 is used, here for the medium and high pressures, in order to take advantage of the inexpensive storage, since the volume flows are manageable.

[0037] On the other hand, a hot-temperature storage tank 7 is provided. Here, a second, higher temperature level is used for the lower pressure stages in order to raise the air-side pressure level of the corresponding intermediate superheating or cooling processes, as well as to reduce the number of intermediate superheating or cooling processes in the low-pressure range and thus, for example, to be able to significantly reduce the required flow cross-sections.

[0038] For example, the following has an effect: 1. The increase in pressure level from, for example, approximately 3.5 bar in the warm-temperature storage tank with a temperature of at most 100°C to a pressure level of, for example, approximately 7 bar in the hot-temperature storage tank with a temperature of, for example, at least 200°C and 2. the reduction of the number of intermediate superheating and intermediate cooling cycles, as illustrated below using the exemplary embodiment in Fig. As explained in point 1, the outcome is positive.

[0039] The following section describes the individual components of the A-CAES system 1.

[0040] The A-CAES system 1 comprises a first compressor unit 1 and a first expander unit 8, and a second compressor unit 9 and a second expander unit 10, which are connected to each other in the direction of flow via an air piping system 11. The first and second compressor units 3, 9 are connected in series in the direction of flow to a pressure storage device 2 for storing the compressed air in the compressed air storage device 2. The compressed air storage device has an air inlet 30 and an air outlet 44. Furthermore, the pressure storage device 2 is connected in series in the direction of flow to the second and first expander units 10, 8 for supplying the air to be expanded.

[0041] The first compressor unit 3 has an air inlet 12 through which air enters at an inlet pressure d. E and an inlet temperature T E, in particular ambient air at ambient pressure, is supplied to the first compressor unit 3. The air is then compressed in the first compressor unit 3, for example in a single compression stage or in 1 to 2 or 1 to 3 compression stages, to a first or high pressure d. K1 and a first or high temperature T K1 .

[0042] The second compressor unit 9 is connected to the first compressor unit 3 in the direction of flow via the air piping system 11 and compresses the air supplied to it from the first compressor unit 3 through the air piping system 11 in several compression stages to a second or lower pressure d. K6 and a second or lower temperature T K6 .

[0043] In the first compressor unit 3, the air is initially compressed strongly, for example to the first pressure d. K1of, for example, 7 bar and a first temperature T K1 for example 230°C.

[0044] This results in the air compressed in the first compressor unit 3 being heated to a correspondingly high temperature above 100°C, for example to the first temperature T. K1 of, for example, 230°C. Therefore, the heat energy or heat of compression from the air is absorbed by a first heat storage device and stored in a subsequently described first high-temperature storage device 7, e.g., at least a storage tank, in order to be supplied back to the air for expansion and thus in the discharge process when required.

[0045] The A-CAES system 1 comprises a first air / heat storage heat exchanger system 5 for cooling the air heated in the compression stage of the first compressor unit 3 and conveying the air via the air piping system 11 to the second compressor unit 9. The air piping system 11 connects the air outlet 16 of the first air / heat storage heat exchanger system 5 to the air inlet of the second compressor unit 9. The first air / heat storage heat exchanger system 5 has, corresponding to the number of compression stages, one air / heat storage heat exchanger 6 with a first heat storage unit for cooling the air after preferably each compression stage. In the exemplary embodiment in Fig. 1 the first air / heat storage heat exchanger system 5 accordingly e.g. a first air / heat storage heat exchanger 6 with a first heat storage.

[0046] Furthermore, the A-CAES system 1 has at least one further first air / heat storage heat exchanger system 13 for warming or heating the air before the air expands in the expansion stage in the first expander unit 8. The further first air / heat storage heat exchanger system 13 has, corresponding to the number of expansion stages, a further first air / heat storage heat exchanger 14 with the first heat storage unit for heating the air before preferably each expansion stage. In the exemplary embodiment in Fig. 1 shows the further first air / heat storage heat exchanger system 13 accordingly e.g. a further first air / heat storage heat exchanger 14 with the first heat storage.

[0047] The first heat storage medium is, for example, water. The respective air / heat storage heat exchanger 6, 14, as well as the subsequent air / heat storage heat exchanger 28 or 33, has an air inlet 15 and an air outlet 16, as well as a heat storage inlet 17 and a heat storage outlet 18. This applies to all those described herein and in Fig. The air / heat storage heat exchangers 6, 14, 28 and 33 shown in Figure 1 are used in the A-CAES system 1 according to the invention, where water is used as the first and / or second heat storage medium. Alternatively, other air / heat storage heat exchangers can be used instead of the air / water heat exchanger 6, 14, 28 and 33. Instead of water as the first and / or second heat storage medium, thermal oil, liquid salt (i.e., a molten salt), or any other latent heat storage medium, e.g., phase change material (PCM) heat storage medium, etc., can also be used. Accordingly, in addition to the air / water heat exchanger, an air / thermal oil heat exchanger, an air / liquid salt heat exchanger, and / or an air / latent heat storage heat exchanger, e.g., an air / phase change heat storage heat exchanger, can be used.

[0048] The A-CAES system 1 further includes a first cold temperature storage tank 19 for storing the first heat storage tank at an initial temperature T. Kalt1and an initial pressure d Kalt1 The initial temperature T Kalt1 is preferably chosen such that the first heat storage unit can absorb as much heat energy or compression heat from the air as possible and later release it to expand the air, and preferably also allows storage in a pressureless or atmospheric cold temperature storage unit.

[0049] The first cold-temperature storage tank 19 has at least one or more storage tanks. Furthermore, the first cold-temperature storage tank 19, as well as all other storage tanks 7, 23, 31, 36, has a heat storage inlet 20 and a heat storage outlet 21. The heat storage outlet 21 of the first cold-temperature storage tank 19 is connected via a first heat storage piping system 20 to a heat storage inlet 17 of the first air / heat storage heat exchanger system 5 for supplying the first heat storage tank with heat for cooling the air compressed in the first compressor unit 3.

[0050] Furthermore, the A-CAES system 1 includes a first hot-temperature storage tank 7 for storing the first heat storage medium heated by the first compressor unit 3 in at least one compressor stage. The first hot-temperature storage tank 7 also includes at least one storage tank for storing the heated first heat storage medium. The first heat storage medium can be heated in the first compressor unit 3 by the compressed air, for example, up to its maximum operating temperature and then stored in the first hot-temperature storage tank 7. If water is used as the first heat storage medium, it can be stored in the hot-temperature storage tank 7 at a maximum operating temperature of, for example, 200°C or higher. Since the boiling point of water is approximately 100°C, the water must be stored under pressure in the hot-temperature storage tank 7, for example, in at least one pressurized storage tank.In the case of liquid salt as the primary heat storage medium, it can be stored at higher temperatures than water without pressure in the high-temperature storage tank 7. However, the temperature of the liquid salt, i.e., the molten salt, as the primary and / or secondary heat storage medium in the A-CAES system 1 must at least correspond to the melting point of the liquid salt, or preferably be above the melting point of the liquid salt, i.e., the molten salt, at a predetermined buffer temperature, so that the liquid salt does not crystallize. Below this melting point, the liquid salt, i.e., the molten salt, begins to crystallize. The buffer temperature is selected to be sufficiently above the melting point of the liquid salt to prevent unwanted crystallization and, on the other hand, to absorb and store as much thermal energy or heat of compression as possible during operation.

[0051] The A-CAES system 1 also has a first hot temperature storage 23, e.g. at least one storage tank, for storing the first heat exchanger after it has been cooled again to heat the air in the first expander unit 8, at a temperature T Warm1 and a pressure d Warm1 The first heat storage unit can preferably be stored without pressure or at a lower pressure than in the first hot-temperature storage unit 7. The at least one further first air / heat storage heat exchanger system 13 is therefore connected to the hot-temperature storage unit 7 to supply the heated first heat exchanger, in order to transfer as much thermal energy as possible to the air to be expanded in the first expander unit 8. This cools the first heat exchanger again, and the heat is then transferred by the further first air / heat storage heat exchanger system 5 to the hot-temperature storage unit 23 to store the first heat storage unit at temperature T. Warm1and the pressure of Warm1 .

[0052] Optionally, the A-CEAS system 1 can also include a first heat storage trim cooler 24, in this case a first water trim cooler. The first heat storage trim cooler 24 serves to equalize a temperature difference between the first heat storage element of the first cold-temperature storage tank 19 and the first heat storage element in the first hot-temperature storage tank 23. The first heat storage trim cooler 24 is therefore connected to the hot-temperature storage tank 23 and the first cold-temperature storage tank 19.

[0053] Thus, the first heat storage piping system 20 connects, in the direction of flow, the heat storage outlet 22 of the first cold temperature storage 19 with the heat storage inlet 15 of the first air / heat storage heat exchanger system 5, and the heat storage outlet 18 of the first air / heat storage heat exchanger system 5 with the heat storage inlet 21 of the first hot temperature storage 7, and the heat storage outlet 22 of the first hot temperature storage 21 with the heat storage inlet 17 of the further first air / heat storage heat exchanger system 13.

[0054] Furthermore, the first heat storage piping system 20 connects the heat storage outlet of the further first air / heat storage heat exchanger system 13 with the heat storage inlet 21 of the hot temperature storage 23 and the heat storage outlet 22 of the hot temperature storage 23 with the heat storage inlet 25 of the first heat storage trim cooler 24 and the heat storage outlet 26 of the first heat storage trim cooler 24 in turn with the heat storage inlet 21 of the first cold temperature storage 19.

[0055] This means that the first cold-temperature storage tank 19, which is located at a temperature T, is heated by the first cold-temperature storage tank. Kalt1 and the pressure of Kalt1 stored cold, first heat storage, e.g. water, in Fig. The air is directed to the first air / heat storage heat exchanger 6 to absorb the thermal energy or heat of compression from the air compressed in the first compressor unit 3. The cooled compressed air is then passed to the second compressor unit 9 via the air piping system 11. The air in the first air / heat storage heat exchanger 6 is cooled to temperature T. Heiss1 with the pressure d Heiss1 The heated first heat storage unit is stored in the first high-temperature storage unit 7, e.g., water with a temperature of e.g., T. Heiss1 = 200°C and a pressure d Heiss1 for example 6-7 bar.

[0056] The heat storage medium, here the water, with temperature T Heiss1 and the pressure of Heiss1 is transferred from the first hot temperature storage tank 6 to the next first air / heat storage heat exchanger 14 and supplied there to heat the air before the expansion stage of the first expander unit 8, here the last expansion stage.

[0057] Since the air cools during expansion, heat energy is supplied to the air in the first expander unit 8 before expansion via the first air / heat storage heat exchanger 14 by means of its heated first heat storage unit. The first heat storage unit is thereby cooled back down to temperature T. Warm1 with the pressure d Warm1 and fed into the first hot temperature storage tank 23.

[0058] To compensate for a temperature difference between the currently warm first heat storage unit in the hot-temperature storage unit 23 and the cold first heat storage unit in the cold-temperature storage unit 19, the following is done in the example in Fig. 1 e.g. the first heat storage trim cooler 24 between the hot temperature storage 23 and the cold temperature storage 19 is intended to cool the first heat storage back down to temperature T Kalt1 . Each of the trim coolers 24, 37 has the heat storage inlet 17 and the heat storage outlet 18.

[0059] As previously stated, the A-CAES system 1 has the second compressor unit 2 and the second expander unit 10.

[0060] In the second compressor unit 2, the air is compressed to a temperature T in several stages. K6 and a pressure d K6 compressed. This preferably occurs after each compression stage, as in Fig. As shown by example in 1, an intermediate cooling takes place before the air subsequently enters the compressed air storage device 2 with the inlet temperature T. DS and the entry pressure d DS The A-CAES system 1 accordingly has a second air / heat storage heat exchanger system 27, preferably with a second air / heat storage heat exchanger 28 for each compression stage. In this way, after each compressor 29 of the second compressor unit 9, the air can be intermediate-cooled by the respective second air / heat storage heat exchanger 28.

[0061] The compressed air storage device 2 has at least one storage tank, such as an above-ground storage tank or an underground storage tank, including, for example, a cavern, in particular a salt dome. The air can be stored in the storage tank at, for example, a temperature T. DS in the range of, for example, 40°C to 60°C and a pressure of d DS The pressure and temperature in the storage tank can be stored at pressures ranging from, for example, 70 bar to 200 bar. The values ​​given for pressure and temperature in the storage tank are merely examples and may be higher or lower than the specified values, depending on the storage tank, such as a salt dome cavern, etc. The inlet temperature T DS and inlet pressure d DS Therefore, a value from this range is preferably chosen. For example, the inlet temperature T DSThe air to be stored in the compressed air storage device 2 is preferably selected such that it corresponds to the temperature in the storage tank, e.g. the underground storage tank or the salt dome as a cavern, etc., or is as close as possible to the temperature of this storage tank, and storage at an inlet pressure d suitable for the storage tank. DS This is done. In an above-ground storage tank, the air is preferably stored without pressure or at atmospheric pressure. The air inlet 30 of the compressed air storage unit 2 is connected to the air outlet of the last of the second air / heat storage heat exchanger 28. Optionally, an air trim cooler (not shown in Fig.1) between the last of the second air / heat storage heat exchangers 28 and the compressed air storage device 2. In this case, the air inlet of the air trim cooler is connected to the air outlet 16 of the last of the second air / heat storage heat exchangers 28 and its air outlet to the air inlet 30 of the compressed air storage device 2.

[0062] The A-CAES system 1 includes a second heat storage unit 31 with at least one heat storage tank for storing the heat of compression from the air compressed in the second compressor unit 9. The second heat storage unit is heated less by the air compressed in the second compressor unit 9 than the first heat storage unit in the first compressor unit 3. Accordingly, the second heat storage unit, e.g., water, is heated more quickly due to its lower temperature T. Warm2The heat is stored in a warm-temperature storage tank, not in a high-temperature storage tank like the first heat storage tank. This has the advantage that the second warm-temperature storage tank 31 can heat the second heat storage tank at a lower temperature T. Warm2 and a lower pressure dW arm2 as the temperature T Heiss1 and the pressure of Heiss1 The first heat storage unit can store heat in the first hot-temperature storage unit 7. This makes the hot-temperature storage unit 31 more advantageous, since, for example, in the case of water as the second heat storage unit, it can store the water at a temperature T. Warm2 For example, it can store temperatures of less than or equal to 100°C without pressure. The first heat storage unit with a temperature of T Heiss1For temperatures of e.g. 200°C and higher, it is necessary to store the water under pressure in the first hot temperature storage tank 7 to prevent evaporation; in return, the air to be expanded can be heated more strongly by the hot, first heat storage tank, thus increasing the efficiency of the A-CAES system 1.

[0063] The A-CAES system 1 has a further second air / heat storage heat exchanger system 32, preferably with one further second air / heat storage heat exchanger 33 for each expansion stage of the second expander unit 10. In this way, the air can be preheated by the respective second air / heat storage heat exchanger 33 upstream of each expander 34 of the second expander unit 10. To heat the air to be expanded, the second heat storage from the second hot-temperature storage 31 is supplied to the respective further second air / heat storage heat exchanger system via a second heat storage piping system 35. The second heat storage piping system 35 connects the heat exchanger outlet of the second hot-temperature storage 31 to the heat exchanger inlets 21 of the further second air / heat storage heat exchangers 33.

[0064] The A-CAES system 1 has a second cold temperature storage tank 36 for storing the second heat storage tank at an initial temperature T. Kalt2 and an initial pressure d Kalt2 The initial temperature T Kalt2 The second heat storage unit is preferably selected such that it can absorb as much thermal energy or heat of compression from the air as possible and later release it to expand the air, and preferably allows storage in a pressureless or atmospheric cold-temperature storage system. The initial temperature T Kalt2 and the initial pressure d Kalt2 The temperature of the second heat storage unit in the second cold temperature storage unit can be equal to or less than the initial temperature T. Kalt1 and the output pressure d Kalt1 of the first heat storage unit in the first cold temperature storage unit.

[0065] The second cold-temperature storage tank 36 supplies the cold second heat storage tank to the second air / heat storage heat exchanger system 27 for cooling the air in the second compressor unit 9. The second air / heat storage heat exchanger system 27 then supplies the heated second heat storage tank to the second hot-temperature storage tank 31 for storage. The second hot-temperature storage tank 31 supplies the warm second heat storage tank to the second air / heat storage heat exchanger system 32, as needed, for heating the air in the second expander unit 10. The air is then conveyed to the first expander unit 8 through the air piping system 11 to be pressurized to the outlet pressure d. A and the initial temperature T Aexpands and is released, for example, into the environment. Between the second hot-temperature storage tank 31 and the second cold-temperature storage tank 36, for example, a second heat storage trim cooler 37 is provided to compensate for a temperature difference between the second heat storage tank of the second hot-temperature storage tank 31 and the second heat storage tank of the second cold-temperature storage tank 36.

[0066] The second heat storage piping system 35 accordingly connects the heat storage outlet 22 of the second cold temperature storage unit 36 ​​with the heat storage inlet 17 of the further second air / heat storage heat exchanger system 32, the heat storage outlet 18 of the further second air / heat storage heat exchanger system 32 with the heat storage inlet 21 of the second hot temperature storage unit 31, the heat storage outlet 22 of the second hot temperature storage unit 31 with the heat storage inlet 25 of the second heat storage trim cooler 37, and the heat storage outlet 26 of the second heat storage trim cooler 37 with the heat storage inlet 21 of the second cold temperature storage unit 36.

[0067] The first compressor unit 3 has at least one, two, or three compressors 4, which are driven by a first drive unit 38. The second compressor unit 9, for example, has a second drive unit 39 for driving the multiple compressors 29 of the second compressor unit 9. The expanders 34 of the first and second expander units 8, 10 can be driven by a common drive unit, here a generator 40, or by a first or second separate drive unit 38, 39, depending on their function and purpose.

[0068] Although the present invention has been fully described above with reference to preferred embodiments, it is not limited thereto, but can be modified in many ways. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2011 112 280 A1

[0004]

Claims

[1] Having an adiabatic compressed air energy storage system (A-CAES) (1): - a first compressor unit (3) for compressing supplied air to a first pressure (d K1 ) and a first temperature (T K1 ) in at least one compression stage, - a first air / heat storage heat exchanger system (5) connected to the first compressor unit (3) with a first heat storage unit for cooling the air after at least one compression stage by heating the first heat storage unit to a first heat storage temperature (T) using the heat of compression of the air Heiss1 ) and an initial heat storage pressure (d Heiss1 ), - a first hot-temperature storage unit (7) for storing the first heat storage unit heated in the first air / heat storage heat exchanger system, for providing the heated first heat storage unit to a first expander unit (8) connected to the first compressor unit (3) for heating the air to be expanded in the first expander unit (8), - a second compressor unit (9) which is connected in the direction of flow to the first compressor unit (3) and the first air / heat storage heat exchanger system (5) for compressing the cooled air in several compression stages to a second, lower pressure (d K6 ) and a second, lower temperature (T K6 ) as the first compressor unit (3), - a second air / heat storage heat exchanger system (27) connected to the second compressor unit (9) with a second heat storage unit for cooling the air after each compression stage by heating the second heat storage unit to a second, lower heat storage temperature (T) using the heat of compression of the air Warm2 ) and a second, low heat storage pressure (d Warm2 ) as the first heat storage device, - a second hot-temperature storage tank (23) for storing the heated second heat storage tank in the second air / heat storage heat exchanger system (27) for supplying the heated second heat storage tank to a second expander unit (10) connected to the second compressor unit (9) for heating the air to be expanded in the second expander unit (10), and - a compressed air storage device (2) for storing the air compressed in the first and second compression units (3, 9), and - an air piping system (11) which connects in the direction of flow the first compressor unit (3) and its first air / heat storage heat exchanger system (5) with the second compressor unit (9) and its second air / heat storage heat exchanger system (27) and with the compressed air storage device (2). [2] Adiabatic compressed air energy storage system according to claim 1, comprising: - the first expander unit (8) for expanding the air in at least one expansion stage, - a further first air / heat storage heat exchanger system (13) connected to the first expander unit (8) with the first heat storage unit for heating the air before the at least one expansion stage by cooling the first heat storage unit, - a first heat storage piping system (20) which connects the first air / heat storage heat exchanger system (13) with the first hot temperature storage (7) for supplying and storing the heated, first heat storage and wherein the first heat storage piping system (20) connects the first hot temperature storage (7) with the further first air / heat storage heat exchanger system (13) for supplying the heated, first heat storage and heating the air before the at least one expansion stage through the first heat storage, wherein the first heat storage is thereby cooled down again. [3] Adiabatic compressed air energy storage system according to claim 1 or 2, comprising: - the second expander unit (10) for expanding the air in the several expansion stages, - a further second air / heat storage heat exchanger system (32) connected to the second expander unit (10) with the second heat storage unit for heating the air before the respective expansion stage by cooling the second heat storage unit, - a second heat storage piping system (35) which connects the second air / heat storage heat exchanger system (27) with the second hot temperature storage (31) for supplying and storing the heated, second heat storage and wherein the second heat storage piping system (35) connects the second hot temperature storage (31) with the further second air / heat storage heat exchanger system (32) for supplying the heated, second heat storage and heating the air before the at least one expansion stage through the second heat storage, wherein the second heat storage is cooled down again. [4] Adiabatic compressed air energy storage system according to claim 2, comprising: - a first cold temperature storage (19) in which the first heat storage at a first heat storage outlet temperature (T Kalt1 ) and an initial heat storage outlet pressure (d Kalt1 ) is stored, wherein the first cold temperature storage (19) is connected to the first air / heat storage heat exchanger system (5) via the first heat storage piping system (20) for supplying the first heat storage, and / or - a second cold temperature storage unit (36) in which the second heat storage unit operates at a second heat storage outlet temperature (T Kalt2 ) and a second heat storage outlet pressure (d Kalt2 ) is stored, wherein the second cold temperature storage (36) is connected to the second air / heat storage heat exchanger system (27) via the second heat storage piping system (35) to supply the second heat storage. [5] Adiabatic compressed air energy storage system according to any one of claims 1 to 4, comprising: - a first hot temperature storage tank (23), and - preferably a first heat storage trim cooler (24), wherein the first heat storage piping system (20) connects the further, first air / heat storage heat exchanger system (13) in the flow direction with the first hot temperature storage (23) and the first hot temperature storage (23) preferably with the first heat storage trim cooler (24) and preferably the first heat storage trim cooler (24) with the first cold temperature storage (19). [6] Adiabatic compressed air energy storage system comprising one of the preceding claims: - a second heat storage trim cooler (37), wherein the second heat storage piping system (35) connects the further, second air / heat storage heat exchanger system (32) in the direction of flow to the second heat storage trim cooler (37) and the second heat storage trim cooler (37) to the second cold temperature storage (36). [7] Adiabatic compressed air energy storage system according to any one of the preceding claims, comprising: - an air trim cooler, wherein the air piping system (11) connects the second compressor unit (9) and its second air / heat storage heat exchanger system (32) to the air trim cooler and the air trim cooler to the compressed air storage device (2). [8] Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the first compression unit (3) comprises at least one first compressor (4) or at least two compressors connected one after the other in the direction of flow through the air piping system (11), wherein the first air-heat storage heat exchanger system (5) comprises a first air / heat storage heat exchanger (6) after each compressor (4) for intermediate cooling of the air by the first heat storage in the respective compression stage, and / or wherein the second compression unit (9) comprises at least two, three, four, five or six compressors (29) connected one after the other in the direction of flow through the air piping system (11),wherein the second air / heat storage heat exchanger system (27) has a second air / heat storage heat exchanger (28) after each compressor (29) for intermediate cooling of the air in the respective compression stage by the second heat storage. [9] Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the first expander unit (8) comprises at least one first expander (34) or at least two expanders connected one after the other in the direction of flow through the air piping system (11), wherein the further, first air / heat storage heat exchanger system (13) comprises a first air / heat storage heat exchanger (14) upstream of each expander (34) for intermediate heating of the air by the first heat storage in the respective expansion stage, and / or wherein the second expander unit (10) comprises at least two, three, four, five or six expanders (34) connected one after the other in the direction of flow through the air piping system (11), wherein the further, second air / heat storage heat exchanger system (32) comprises a further,A second air / heat storage heat exchanger (33) after each expander (34) has a secondary heat storage element for intermediate heating of the air in the respective expansion stage by the second heat storage element. [10] Adiabatic compressed air energy storage system according to one of the preceding claims, wherein at least the first hot temperature storage (7), the first warm temperature storage (23), the second warm temperature storage (31), the first cold temperature storage (19) and / or the second cold temperature storage (36) has at least one storage tank, in particular an above-ground storage tank or an underground storage tank, and / or at least one cavity for storing the first or second heat storage, wherein the first heat storage and / or the second heat storage is or are in particular water, thermal oil, a liquid salt or a latent heat storage, in particular a phase change (PCM) heat storage. [11] Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the compressed air storage device (2) has at least one storage tank, in particular an above-ground storage tank or an underground storage tank, and / or at least one cavity for storing the air, preferably atmospherically or without pressure or at a pressure that corresponds to or is as close as possible to the pressure in the cavity as a compressed air storage device. [12] Adiabatic compressed air energy storage system according to one of the preceding claims, wherein in the first hot temperature storage unit (7) connected to the first compressor unit (3) the first heat storage unit, in particular water or thermal oil, at a first heat storage temperature (T Heiss1 ) of greater than 100°C, in particular approximately 200°C, and an initial heat storage pressure (d Heiss1) is stored at a temperature of 6 bar to 7 bar, and / or wherein in the second hot temperature storage unit (31), which is connected to the second compressor unit (9), the second heat storage unit, in particular water or thermal oil, is stored at a second heat storage temperature (T Warm2 ) of less than or equal to 100°C, and a second heat storage pressure (d Warm2 ), where the second heat storage pressure (d Warm2 ) corresponds to atmospheric pressure or essentially corresponds to atmospheric pressure. [13] Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the air in the compressed air storage device (2) is pressurized at an inlet pressure (d DS ) and an inlet temperature (T DS ) the compressed air storage device (2) is stored. [14] Method for adiabatic compressed air energy storage, in particular by means of an adiabatic compressed air energy storage system according to one of the preceding claims, wherein the method comprises the steps: - Compressing air, in particular ambient air, in a first compressor unit (3) in at least one compression stage to a first temperature (T K1 ) and a first print (d K1 ), wherein the air is cooled in at least one compression stage by a first air / heat storage heat exchanger system (5) with a first heat storage unit, - Supplying air to a second compressor unit (9) and compressing the air in the second compressor unit (9) in several compression stages, wherein the air in each of the compression stages is cooled by a second air / heat storage heat exchanger system (27) with a second heat storage, and - Supplying air to a compressed air storage device (2). [15] The method of claim 14, wherein the method comprises the steps: - Supplying air from the compressed air storage device to an expander unit (10) and intermediate heating of the air to be expanded by the second heat exchanger, - Supplying air to the next expander unit (8) and intermediate heating of the air by the first heat exchanger, - Expansion of the air in the further expander unit (8) to an initial temperature (T A ) and an output pressure (d A ).

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