Adiabatic compressed-air energy storage system (a-CAES) and method

Abstract

The present invention relates to an A-CAES system comprising: a compressed-air storage device for storing air; a low-pressure compressor unit for compressing supplied air to a first air pressure and a first air temperature; a high-temperature heat exchanger system containing a high-temperature heat storage medium for cooling the air compressed in the low-pressure compressor unit, this cooling being brought about by the heat storage medium taking up heat of compression of the air, wherein the high-temperature heat storage medium is heated to a first heat-store temperature with a first heat-store pressure by the taking-up of the heat of compression; a medium- or high-pressure compressor unit for compressing the air downstream of the high-temperature heat exchanger system in further compression stages to a store-air pressure; a low-temperature heat exchanger system containing a low-temperature heat storage medium for cooling the air from the medium- or high-pressure compressor unit to a store-air temperature by taking up heat of compression of the air compressed in the medium- or high-pressure compressor unit, wherein the low-temperature heat storage medium is heated to a second heat-store temperature with a second heat-store pressure by the taking-up of the heat of compression of the air; and an air pipeline system, which connects the following in the flow direction: the low-pressure compressor unit to the high-temperature heat exchanger system, the high-temperature heat exchanger system to the medium- or high-pressure compressor unit, the medium- or high-pressure compressor unit to the low-temperature heat exchanger system and the low-temperature heat exchanger system to the compressed-air storage device, in order to supply and store the air in the compressed-air storage device with the store-air pressure and the store-air temperature.

Description

[0001]2024PF00225 1 Description Adiabatic Compressed Air Energy Storage System (A-CAES) and Method The present invention relates to an adiabatic compressed air energy storage system (A-CAES) and a method. It is generally known that significant fluctuations can occur in electricity production from renewable energies, e.g., from wind turbines or photovoltaic systems, etc. Various options exist for storing generated electricity. These include, for example, pumped-storage hydroelectric plants. However, these have the disadvantage that they require a difference in altitude, which is not the case in flat regions. Furthermore, so-called compressed air energy storage systems, which are also referred to as CAES (Compressed Air Energy Storage) systems, are known. Among these are so-called adiabatic compressed air energy storage systems or A-CAES (Adiabatic Compressed Air Energy Storage) systems. Compressed air energy storage power plants or systems, i.e., CAES power plants or systems, are described in this invention.These systems are based on the principle of compressing air to absorb power, storing the compressed air, and expanding it to release power. DE 102011112 280 A1 discloses a system for storing energy using compressed air. In this system, a storage volume holds air at increased pressure. Ambient air is compressed for energy storage and introduced into the storage volume. For release, compressed air is extracted from the storage volume and released into the environment, performing work. The compression of the air heats it up. This heat of compression is stored by adiabatic compressed air energy storage systems (A-CAES) and released again during expansion. Against this background, the present invention aims to provide an improved A-CAES system.2024PF00225 2 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 14. Accordingly, the following is provided: An adiabatic compressed air energy storage system (A-CAES) comprising: - a compressed air storage device for storing air, - a low-pressure compressor unit for compressing supplied air to a first air pressure d. K1 and an initial air temperature T K1 , - a high-temperature heat exchanger system with a high-temperature heat storage medium for cooling the air compressed in the low-pressure compressor unit by absorbing the heat of compression from the air, wherein the high-temperature heat storage medium is heated to a first heat storage temperature T by absorbing the heat of compression HT with a first heat storage pressure d HT, - a medium- or high-pressure compressor unit for compressing the air after the high-temperature heat exchanger system in further compression stages to a storage air pressure d DS , - a low-temperature heat exchanger system with a low-temperature heat storage medium for cooling the air of the medium- or high-pressure compressor unit to a storage air temperature T DS , by absorbing the heat of compression from the air compressed in the medium- or high-pressure compressor unit, whereby the low-temperature heat storage medium is heated to a second heat storage temperature T by absorbing the heat of compression from the air NT with a second heat storage pressure d NT, and - an air piping system which, in the direction of flow, connects the low-pressure compressor unit with the high-temperature heat exchanger system, the high-temperature heat exchanger system with the medium- or high-pressure compressor unit, the medium- or high-pressure compressor unit with the low-temperature heat exchanger system, and the low-temperature heat exchanger system with the compressed air storage device for supplying and storing the air in the compressed air storage device at the storage air pressure d DS and the storage air temperature T DS2024PF00225 3 The idea underlying the present invention is to store a thermal energy storage medium at two temperature levels. By using a first, lower temperature level (in the case of the low-temperature heat storage medium) for the medium and high pressures, the advantage of cost-effective storage can be utilized, since the volume flows are manageable. Furthermore, by using a second, higher temperature level (in the case of the high-temperature heat storage medium) for the lower pressure stages, the air-side pressure level of the corresponding intermediate superheating / cooling processes can be increased, thereby significantly reducing the required flow cross-sections.Furthermore, a method for adiabatic compressed air energy storage is provided, wherein the method comprises the steps: - Compressing air, in particular ambient air, in a low-pressure compressor unit in at least one compression stage to a first air temperature T. K1 and an initial air pressure d K1 , wherein the air is cooled after at least one compression stage by a high-temperature heat exchanger system with a high-temperature heat storage medium, and the high-temperature heat storage medium is thereby cooled to a first heat storage temperature T HT with an initial heat storage pressure d HT is heated, - the air is directed to a medium- or high-pressure compressor unit and compressed in the medium- or high-pressure compressor unit in one or more compression stages to a storage air pressure d DS, wherein the air in the compression stages is heated to a storage air temperature T by a low-temperature heat exchanger system with a low-temperature heat storage medium DS cooled and the low-temperature heat storage medium thereby cooled to a second heat storage temperature T NT with a second heat storage pressure d NT is heated, and - conveying the air of a compressed air storage device and storing the air in the compressed air storage device at the storage air pressure d DS and the storage air temperature T DS. 2024PF00225 4 Advantageous embodiments and further developments are described in the dependent claims and in the description with reference to the figures of the drawing. In one embodiment of the invention, the A-CAES system has a low-temperature storage tank for storing the low-temperature heat storage medium of the low-temperature heat exchanger system with the second heat storage temperature T. NT and the second heat storage pressure d NT; a medium- or high-pressure expander unit connected to the compressed air storage device for expanding the air in the compressed air storage device in several expansion stages; a further low-temperature heat exchanger system connected to the medium- or high-pressure expander unit with the low-temperature heat storage medium for intermediate heating of the air to be expanded before an expansion stage by transferring the thermal energy of the low-temperature heat storage medium to the air to be expanded. The low-temperature heat storage medium is thereby heated to a heat storage outlet temperature T KaltNT with a heat storage output pressure d KaltNT cooled. Furthermore, the A-CAES system features a cold medium storage unit for storing the low-temperature heat storage medium with the heat storage outlet temperature T. KaltNT and the heat storage outlet pressure d KaltNT, and a low-temperature piping system which, in the direction of flow, connects the low-temperature heat exchanger system with the low-temperature storage tank, the low-temperature storage tank with the further low-temperature heat exchanger system, the further low-temperature heat exchanger system with the cold medium storage tank, and the cold medium storage tank with the low-temperature heat exchanger system (26). In a further embodiment of the invention, the A-CAES system includes a high-temperature storage tank for storing the high-temperature heat storage medium of the high-temperature heat exchanger system at the first heat storage temperature T. HT and the first heat storage pressure d HT ; a low-pressure expander unit, which is connected to the medium- or high-pressure expander unit via the further high-temperature heat exchanger system, for expanding the air from the medium- or high-pressure expander unit to an outlet air pressure d Awith an outlet air temperature T A in at least one expansion stage- 2024PF00225 5 fe; a further high-temperature heat exchanger system connected to the low-pressure expander unit with the high-temperature heat storage medium for transferring the thermal energy of the high-temperature heat storage medium to the air to be expanded for intermediate heating of the air before an expansion stage of the low-pressure expander unit, wherein the high-temperature heat storage medium is thereby heated to a heat storage outlet temperature T KaltHT at a heat storage tank output pressure d KaltHT is cooled; a cold medium storage tank for storing the high-temperature heat storage medium with the heat storage outlet temperature T KaltHT and the heat storage outlet pressure d KaltHT, and a high-temperature piping system which, in the direction of flow, connects the high-temperature heat exchanger system with the high-temperature storage tank, the high-temperature storage tank with the further high-temperature heat exchanger system, the further high-temperature heat exchanger system with the cold medium storage tank, and the cold medium storage tank with the high-temperature heat exchanger system. In another embodiment of the invention, the second heat storage temperature T NT and the second heat storage pressure d NT of the low-temperature heat storage medium lower than the first heat storage temperature T HT and the first heat storage pressure d HT of the high-temperature heat storage medium, wherein the second heat storage pressure d NTThe low-temperature heat storage medium preferably corresponds to atmospheric pressure or is as close to atmospheric pressure as possible. According to one embodiment of the invention, the pressure at which the first air pressure d K1 associated first air temperature T K1 selected depending on the maximum operating temperature of the high-temperature heat storage medium, where the first air temperature T K1 preferably sufficiently high to heat the high-temperature heat storage medium of the high-temperature heat exchanger system to the first heat storage temperature T HT , where the first heat storage temperature T HT preferably selected depending on the maximum operating temperature of the high-temperature heat storage medium, wherein the first heat storage temperature T HTParticularly preferably, the temperature is equal to or as close as possible to the maximum operating temperature of the high-temperature heat storage medium. In one embodiment of the invention, the storage air pressure d DS and the storage air temperature T DS depending on the operating air pressure and operating air temperature of the compressed air storage device and the storage air pressure d DS the operating air pressure of the compressed air storage device corresponds to or comes as close as possible to it and the storage air temperature T DSThe operating air temperature of the compressed air storage device corresponds to or comes as close as possible to it, wherein the compressed air storage device preferably has at least one storage tank, in particular an above-ground storage tank, an underground storage tank, or a cavern for storing the air.In one embodiment of the invention, the A-CAES system comprises a high-temperature trim cooler, which is provided in the flow direction in the high-temperature piping system upstream of the cold medium storage and preferably downstream of the high-temperature heat exchanger system, and / or a low-temperature trim cooler, which is provided in the flow direction in the low-temperature piping system upstream of the cold medium storage and preferably downstream of the low-temperature heat exchanger system, and / or an air trim cooler, which is provided in the flow direction in the air piping system upstream of the compressed air storage device and preferably downstream of the low-temperature heat exchanger system.In a further embodiment of the invention, the low-pressure compressor unit comprises at least one low-pressure compressor and the high-temperature heat exchanger system comprises at least one high-temperature heat exchanger for intermediate cooling of the air by the high-temperature heat storage medium after a compression stage. In another embodiment of the invention, the medium- or high-pressure compressor unit comprises at least two, three, four, five, or six medium- or high-pressure compressors connected one after the other in the direction of flow through the air piping system, and the low-temperature heat exchanger system comprises one low-temperature heat exchanger each, preferably after each medium- or high-pressure compressor, for intermediate cooling of the air by the low-temperature heat storage medium after a compression stage.In a further embodiment of the invention, the low-pressure expander unit comprises at least one low-pressure expander, and the further high-temperature heat exchanger system comprises at least one high-temperature heat exchanger for intermediate heating of the air by the high-temperature heat storage medium upstream of an expansion stage. According to one embodiment of the invention, the medium- or high-pressure expander unit comprises at least two, three, four, five, or six medium- or high-pressure expanders connected one after the other in the direction of flow by the air piping system, and the further low-temperature heat exchanger system comprises one further low-temperature heat exchanger, preferably upstream of each medium- or high-pressure expander, for intermediate heating of the air by the low-temperature heat storage medium upstream of an expansion stage.In one embodiment of the invention, at least the high-temperature storage unit, the low-temperature storage unit, the cold medium storage unit connected to the high-temperature storage unit, or the cold medium storage unit connected to the low-temperature storage unit comprises at least one storage tank, in particular an above-ground storage tank, an underground storage tank, or a cavern, for storing the associated low-temperature heat storage medium or high-temperature heat storage medium, wherein the at least one storage tank is in particular a single-storage tank, preferably a stratified storage tank, or a multi-storage tank, and wherein the low-temperature heat storage medium and / or the high-temperature heat storage medium is / are preferably water, thermal oil, a liquid salt, or a latent heat storage medium, in particular a phase-change (PCM) heat storage medium.According to one embodiment of the invention, the method comprises the following steps: Directing the air from the compressed air storage device to a medium- or high-pressure expander unit for expanding the air in several expansion stages, wherein the air is preheated before each expansion stage by a further low-temperature heat exchanger system with the low-temperature heat storage medium, thereby bringing the low-temperature heat storage medium to a heat storage output temperature T. KaltNT with a heat storage output pressure d KaltNT The air is cooled, and then directed to a low-pressure expander unit and expanded in the low-pressure expander unit to an output pressure d. A and an initial temperature T A, wherein the air is preheated by a further high-temperature heat exchanger system with the high-temperature heat storage medium before the respective expansion stage, and the high-temperature heat storage medium is thereby heated to a heat storage output temperature T KaltHT with a heat storage outlet pressure d KaltHTis cooled. 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. The present invention is explained in more detail below with reference to the exemplary embodiment shown in the schematic figure of the drawing. Figure 1 shows a schematic block diagram of an adiabatic compressed air energy storage system, abbreviated A-CAES system 1, according to an embodiment of the invention. The accompanying drawing is intended to provide a further understanding of the embodiments of the invention.It illustrates one embodiment and serves, in connection with the description, to explain the principles and concepts of the invention. Other embodiments and many of the advantages mentioned become apparent with reference to the drawing. The elements of the drawing are not necessarily shown to scale with respect to one another. In the figure of the drawing, identical, functionally equivalent, and similarly acting elements, features, and components are each provided with the same reference numerals, unless otherwise stated. Fig. 1 shows an embodiment of a compressed air energy storage system according to the invention, i.e., a so-called CAES (Compressed Air Energy Storage) system, here an adiabatic compressed air energy storage system, i.e., for short, an A-CAES system, to store air in a compressed air storage device with a storage air temperature T. DS and a storage air pressure d DSto store. In the following, the adiabatic compressed air energy storage system will be abbreviated as A-CAES system. In the A-CAES system, the heat of compression generated during the charging process is extracted from the compressed air by a heat storage medium. Water, for example, can be used as the heat storage medium, i.e., thermal energy storage, for absorbing and transferring thermal energy. During expansion, the stored thermal energy of the respective heat storage medium is fed back into the expanding air. This avoids the need to supply thermal energy from external sources, such as fossil fuels like gas. Compression / expansion can be performed in one or more stages. The pressure levels depend significantly on the operating temperature range of the respective heat storage medium.Water has a boiling point of approximately 100°C at atmospheric pressure. To store water in liquid form at temperatures above 100°C, it must be stored under pressure. Key restrictions / boundary conditions for determining the storage air temperature T. DS and the storage air pressure d DSThe following are important for storing air in a compressed air storage device, as well as for the heat storage temperature and pressure for storing the heat storage medium in an associated storage tank: - maximum permissible operating temperature of the compressed air storage device - maximum permissible operating pressure of the compressed air storage device - technically and economically feasible operating temperature and pressure range of the heat storage medium and the storage tank (e.g., steel pressure tank) - high storage temperature = high RTE (Round Trip Efficiency). If the maximum operating temperature of the heat storage medium is, for example, 200°C, this means that compression, depending on the efficiency of the compressor and the temperature of the heat storage medium, can take place up to a pressure level of approximately 6-7 bar.Compression to higher pressures therefore occurs in multiple stages with various intermediate cooling of the compressed air, transferring the thermal energy or heat of compression to the heat storage medium. In the A-CAES system 1 shown in the exemplary embodiment in Fig. 1, a combination of two heat storage media is used, which are stored at different temperature levels. On the one hand, a preferably atmospheric low-temperature storage medium is used, here for the medium and high air pressures, in order to utilize the advantage of an economical / atmospheric storage medium, since the air volume flows are manageable on a large scale at medium to high air pressures. On the other hand, a high-temperature storage medium is provided. Here, a second, higher temperature level is used for the lower pressure stages to maintain the air-side pressure level of the corresponding intermediate superheating stages.to increase the number of intermediate cooling cycles and to reduce the number of intermediate superheating or cooling cycles in the low-pressure range, thus enabling, for example, a significant reduction in the required flow cross-sections. This is achieved, for example, by: 1. Increasing the atmospheric pressure level from, for example, approximately 2.1 bar in conjunction with the preferably atmospheric low-temperature storage tank 30 with a water temperature of at most 100°C to an atmospheric pressure level of, for example, approximately 6-7 bar in conjunction with the pressurized high-temperature storage tank 30 (e.g., 15.5 bar) with a water temperature of, for example, 200°C, and 2. reducing the number of intermediate superheating and cooling cycles, as explained below with reference to the embodiment in Fig. 1. The individual components of the A-CAES system 1 and their connections via piping systems are described below with reference to Fig. 1.2024PF00225 11 The A-CAES system 1 comprises a high-temperature storage system 42 with a high-temperature storage tank 7 and a cold medium storage tank 19 for storing a high-temperature heat storage medium, which are connected to each other via a high-temperature piping system 20 for transporting the high-temperature heat storage medium. The term high-temperature piping system 20 generally refers to the piping system of the high-temperature storage system 42. The components of the high-temperature storage system 42 are connected to each other via the piping system 20 of the high-temperature storage system 42, e.g., the high-temperature storage tank 7, the cold medium storage tank 19, etc.Between the high-temperature storage tank 7 and the cold medium storage tank 19, a high-temperature heat exchanger system 5 is provided in the high-temperature piping system 20 for absorbing thermal energy from compressed air via the high-temperature heat storage medium, and another high-temperature heat exchanger system 13 for transferring thermal energy via the high-temperature heat storage medium to expanding air. The high-temperature heat exchanger system 5 absorbs thermal energy from air compressed in a low-pressure compressor unit 3 via the high-temperature heat storage medium. The heated high-temperature heat storage medium is then conveyed via the high-temperature piping system 20 to the high-temperature storage tank 7 and temporarily stored.The further high-temperature heat exchanger system 13 transfers thermal energy from the high-temperature heat storage medium in the high-temperature storage tank 7 to the air to be expanded in a low-pressure expander unit 8. The high-temperature heat storage medium, cooled in this way, is then directed to the cold medium storage tank 19 and temporarily stored there before being fed back to the high-temperature heat exchanger system 5. The A-CAES system 1 also has a low-temperature storage system 43 with a low-temperature storage tank 30 and a cold medium storage tank 36 for storing a low-temperature heat storage medium, which are connected to each other via a low-temperature piping system 35 for transporting the low-temperature heat storage medium.Between the low-temperature storage tank 30 and the cold medium storage tank 36, a low-temperature heat exchanger system 26 is provided in the low-temperature piping system 35 for absorbing thermal energy from compressed air through the low-temperature heat storage medium. Furthermore, another low-temperature heat exchanger system 31 is provided for transferring thermal energy to expanding air through the low-temperature heat storage medium. The low-temperature heat exchanger system 26 absorbs thermal energy from air compressed in a medium- or high-pressure compressor unit 9 through the low-temperature heat storage medium, and the heated low-temperature heat storage medium is then conveyed through the low-temperature piping system 35 to the low-temperature storage tank 30 and temporarily stored.The further low-temperature heat exchanger system 31 transfers thermal energy from the low-temperature heat storage medium in the low-temperature storage tank 30 to the air to be expanded in a medium- or high-pressure expander unit 10. The cooled low-temperature heat storage medium is then conveyed to the cold medium storage tank 36 and temporarily stored there before being returned to the low-temperature heat exchanger system 26. Accordingly, the A-CAES system 1 comprises the low-pressure compressor unit 3, the medium- or high-pressure compressor unit 9, a compressed air storage unit 2, the medium- or high-pressure expander unit 10, and the low-pressure expander unit 8, which are connected to each other in the direction of flow via an air piping system 11.The low-pressure compressor unit 3 and the medium- or high-pressure compressor unit 9 are connected in series in the direction of flow to the compressed air storage unit 2 for storing the compressed air via the air piping system 11. The compressed air storage unit 2 has an air inlet 29 and an air outlet 41. Furthermore, the compressed air storage unit 2 is connected in series in the direction of flow to the medium- or high-pressure expander unit 10 and the low-pressure expander unit 8. As indicated in Fig. 1, the compressed air storage unit 2, shown with a solid line, with its air inlet 29 2024PF00225 13 as one connection and its air outlet 41 as another connection, can also be replaced in an alternative embodiment by a single connection for the air inlet and the air outlet, as indicated by a dashed line. In Fig.Figure 1 shows an additional embodiment in which the compressed air storage device 2 has only one connection in the form of an air inlet and outlet 44, indicated by a dashed line. In this case, the air inlet and the air outlet are designed as a single connection, i.e., as an air inlet and outlet 44. This variant, shown with a dashed line in Figure 1, can replace the embodiment of the compressed air storage device 2 with the air inlet 29 and the air outlet 41 shown with a solid line. The high-temperature heat exchanger system 5 of the high-temperature storage system 42 is provided between the low-pressure compressor unit 3 and the medium- or high-pressure compressor unit 9.For this purpose, an air outlet of the low-pressure compressor unit 3 is connected to an air inlet 15 of the high-temperature heat exchanger system 5, and the air outlet 16 of the high-temperature heat exchanger system 5 is connected to the air inlet 12 of the medium- or high-pressure compressor unit 9. A heat storage medium inlet 17 of the high-temperature heat exchanger system 5 is connected to a storage outlet 22 of the cold medium storage tank 19, and a heat storage medium outlet 18 of the high-temperature heat exchanger system 5 is connected to the storage inlet 21 of the high-temperature storage tank 7. The high-temperature heat exchanger system 13 of the high-temperature storage system 42 is provided between the low-pressure expander unit 8 and the medium- or high-pressure expander unit 10.For this purpose, an air inlet of the low-pressure expander unit 8 is connected to an air outlet 16 of the high-temperature heat exchanger system 13, and the air inlet 15 of the high-temperature heat exchanger system 13 is connected to the air outlet of the medium- or high-pressure expander unit 10. A heat storage medium inlet 17 of the high-temperature heat exchanger system 13 is connected to a storage outlet 22 of the high-temperature storage tank 7, and a heat storage medium outlet 18 of the high-temperature heat exchanger system 13 is connected to the storage inlet 21 of the cold medium storage tank 19. The low-temperature heat exchanger system 26 of the low-temperature storage system 43 is provided between the medium- or high-pressure compressor unit 9 and the compressed air storage device 2.For this purpose, an air outlet of the medium- or high-pressure compressor unit 9 is connected to an air inlet 15 of the low-temperature heat exchanger system 26, and the air outlet 16 of the low-temperature heat exchanger system 26 is connected to the air inlet 29 of the compressed air storage unit 2. A heat storage medium inlet 17 of the low-temperature heat exchanger system 26 is connected to a storage outlet 22 of the cold medium storage unit 36, and a heat storage medium outlet 18 of the low-temperature heat exchanger system 26 is connected to the storage inlet 21 of the low-temperature storage unit 30. The low-temperature heat exchanger system 31 of the low-temperature storage system 43 is provided between the medium- or high-pressure expander unit 10 and the compressed air storage unit 2.For this purpose, an air inlet of the medium- or high-pressure expander unit 10 is connected to an air outlet 16 of the low-temperature heat exchanger system 31, and the air inlet 15 of the low-temperature heat exchanger system 31 is connected to the air outlet 41 of the compressed air storage unit 2. A heat storage medium inlet 17 of the low-temperature heat exchanger system 31 is connected to a storage outlet 22 of the low-temperature storage unit 30, and a heat storage medium outlet 18 of the low-temperature heat exchanger system 31 is connected to the storage inlet 21 of the cold medium storage unit 36. During operation, particularly during charging, air, preferably ambient air, is drawn in at an inlet pressure d. E (ambient pressure) and an inlet temperature T E (Ambient temperature), supplied to the low-pressure compressor unit 3 via its air inlet 12. The air is first pressurized to a first air pressure d in the low-pressure compressor unit 3. K1with a first air temperature T K1 The compressed air is then cooled or intermediate-cooled by the high-temperature heat storage medium of the high-temperature heat exchanger system 5. For this purpose, thermal energy from the compressed air is transferred to the high-temperature heat storage medium of the high-temperature heat exchanger system 5, thereby raising the high-temperature heat storage medium to a first heat storage temperature T. HT with an initial heat storage pressure d HT heated, or heated, to then be temporarily stored in the high-temperature storage tank 7. The pressure increase to the first heat storage pressure d HTThis can be achieved, for example, by a pump. The heated high-temperature heat storage medium, temporarily stored in the high-temperature storage tank 7, is later used to preheat the air before expansion in the low-pressure expander unit 8. In Fig. 1, the low-pressure compressor unit 3 has, for example, a low-pressure compressor 4, the low-pressure expander unit 8 has, for example, a low-pressure expander 33, the medium- or high-pressure compressor unit 9 has several medium- or high-pressure compressors 28, and the medium- or high-pressure expander unit 10 has several medium- or high-pressure expanders 34. After ambient air, for example, has been supplied to the low-pressure compressor unit 3, the air is subsequently expanded to the first atmospheric pressure d in the low-pressure compressor unit 3. K1 and the first air temperature T K1 compressed, for example an initial air pressure d K1 of, for example, 6-7 bar and an initial air temperature T K1of, for example, 235°C. This can occur in a single compression stage or in 1 to 2, 1 to 3, or more compression stages. In the case of multiple compression stages, the low-pressure compressor unit 3 has a corresponding low-pressure compressor 4 for each compression stage. The same applies to the number of expansion stages of the low-pressure expander unit 8 and its low-pressure expander 33. In the subsequent high-temperature heat exchanger system 5 with its high-temperature heat storage medium, the heat of compression of the air previously compressed in the low-pressure compressor unit 3 is transferred to the high-temperature heat storage medium, thus heating the high-temperature heat storage medium while the air is cooled or intermediately cooled. The heated high-temperature heat storage medium is then fed to the high-temperature storage tank 7 via the high-temperature piping system 20 and heated there to the first heat storage temperature T HT2024PF00225 16 and the first heat storage pressure d HT The high-temperature storage unit 7, in the embodiment shown in Fig. 1, consists of a storage tank. However, several separate storage tanks or a multi-storage tank, etc., can also be provided, depending on the function and intended use. The air, cooled by the high-temperature heat transfer system 5, is then conveyed to the medium- or high-pressure compressor unit 9 via the air piping system 11. The medium- or high-pressure compressor unit 9 compresses the air to the storage air pressure d using its medium- or high-pressure compressors 28 in several compression stages. DSfor storage in the compressed air storage device 2. In Fig. 1, preferably after each compression stage, the air is intermediately cooled by the respective low-temperature heat exchanger 27 of the low-temperature heat exchanger system 26. In the last low-temperature heat exchanger 27 before the compressed air storage device 2, the air is cooled by the low-temperature storage medium down to the storage air temperature T. DS cooled for subsequent storage of the air in the compressed air storage unit 2 with the storage air temperature T DS and the storage air pressure d DSOptionally, an additional air trim cooler (not shown) can be provided between the last low-temperature heat exchanger 27 and the compressed air storage unit 2 to dissipate excess thermal energy from the air before it enters the compressed air storage unit 2. In this case, the air inlet of the air trim cooler is connected to the air outlet 16 of the last low-temperature heat exchanger 27, and its air outlet is connected to the air inlet 29 of the compressed air storage unit 2. The storage air temperature T DS and the storage air pressure d DS The values ​​are selected depending on the compressed air storage device 2 and its operating temperature and operating pressure. In the case of a cavern, such as a salt dome, as the compressed air storage device 2, the storage air temperature T is DSThe temperature is chosen so that it preferably corresponds as closely as possible to the temperature inside the salt dome, i.e., the operating temperature of the salt dome, and does not exceed it. A similar principle applies to the storage air pressure d. DS The air is compressed to a pressure compatible with the salt dome and does not exceed this pressure. For example, at a higher storage air temperature T DSa At operating temperature 2024PF00225 17, the compressed air storage device would need to be additionally insulated. 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, for example, at a storage air temperature T. DS from, for example, up to 80°C and a storage air pressure d DSThe heat can be stored at pressures ranging from, for example, 70 bar to 200 bar. The pressure and temperature values ​​in the storage tank are merely examples and can be higher or lower than the specified values, depending on the storage tank, such as the salt dome cavern, etc. The previously described intermediate cooling of the air by the low-temperature heat exchanger medium of the low-temperature heat exchanger system 26, in turn, causes the low-temperature heat exchanger medium to warm up, absorbing the heat of compression from the air. The low-temperature heat exchanger medium of the low-temperature heat exchanger system 26 is thus heated to a second heat storage temperature T. NT with a second heat storage pressure d NTThe air is heated and temporarily stored in the downstream low-temperature storage unit 30 for later intermediate heating before expansion in the low-pressure expander unit 8. As previously described, the air outlet 41 of the compressed air storage unit 2 is connected to the medium- or high-pressure expander unit 10 via the air piping system 11. Preferably, a corresponding number of medium- or high-pressure expanders 34 are provided, corresponding to the number of expansion stages of the medium- or high-pressure expander unit 10. In the example shown in Fig. 1, for instance, a low-temperature heat exchanger 32 of the low-temperature heat exchanger system 31 is provided upstream of each expansion stage. The respective low-temperature heat exchanger 32 serves to intermediately heat the air to be expanded in the downstream medium- or high-pressure expander 34.For this purpose, the respective low-temperature heat exchanger 32 is supplied with the heat stored in the low-temperature storage tank 30 at the second heat storage temperature T. NT and the second heat storage pressure d NT The intermediately stored low-temperature heat storage medium (2024PF00225 18) is supplied through the low-temperature piping system 35. Thermal energy from the low-temperature heat storage medium is then transferred to the air before expansion in the medium- or high-pressure expander 34, in order to preheat or intermediately heat the air before the respective subsequent expansion stage. This, in turn, raises the low-temperature heat storage medium to a heat storage outlet temperature T. KaltNT at a heat storage outlet pressure d KaltNT It cools down by transferring its thermal energy to the air. This affects the heat storage initial temperature T. KaltNTThe cooled low-temperature heat storage medium is then conveyed via the low-temperature piping system 35 to the associated cold medium storage tank 36 and there at d KaltNTThe cold medium storage tank 36 is in turn connected to the low-temperature heat exchanger system 26 via the low-temperature piping system 35 in order to transfer the temporarily stored low-temperature heat storage medium to this system and its low-temperature heat exchangers 27. Optionally, an additional low-temperature trim cooler 37 can be provided between the low-temperature heat exchanger system 31 and the cold medium storage tank 36 in the low-temperature piping system 35 to remove excess thermal energy from the low-temperature heat storage medium before it enters the cold medium storage tank 36. In this case, the trim cooler inlet 24 of the low-temperature trim cooler 37 is connected to the respective heat storage outlet 18 of the low-temperature heat exchangers 32 of the low-temperature heat exchanger system 31, and the trim cooler outlet 25 is connected to the heat storage inlet 21 of the cold medium storage tank 36.The medium- or high-pressure expander unit 10 is connected to the low-pressure expander unit 8 via the air piping system 11, with the high-temperature heat exchanger system 13 interposed to further heat the air before expansion by means of the high-temperature heat storage medium from the high-temperature storage tank 7. For this purpose, the high-temperature heat storage medium, which is at the first heat storage temperature T. HT and the first heat storage pressure d HTThe air is temporarily stored in the high-temperature storage unit 7 and is then conveyed to the further high-temperature heat exchanger system 13 via the high-temperature piping system 20. This reheats the air after the medium- or high-pressure expander unit 10 and before its subsequent expansion in the low-pressure expander unit 8. Thermal energy is transferred from the high-temperature heat storage medium of the high-temperature heat exchanger system 13 to the air before the air is finally expanded to an outlet pressure d in the low-pressure expander unit 8. A , in particular ambient pressure, and an initial temperature T A, especially ambient temperature, expands again and, in the example shown in Fig. 1, releases the heat into the environment. By transferring thermal energy from the high-temperature heat storage medium to the air before expansion, the high-temperature heat storage medium itself is brought back up to a heat storage initial temperature T. KaltHT The cooled high-temperature heat storage medium is conveyed through the high-temperature piping system 20 to the associated cold medium storage tank 19 and there cooled to the heat storage outlet temperature T. KaltHT and the heat storage outlet pressure d KaltHTThe cold medium storage tank 19 is connected via the high-temperature piping system 20 to the high-temperature heat exchanger system 5 for conveying the high-temperature heat exchanger medium to intermediately cool the air, as previously described, after the low-pressure compressor unit 3. Optionally, an additional high-temperature trim cooler 23 can be provided in the high-temperature piping system 20 between the high-temperature heat exchanger system 13 and the cold medium storage tank 19 to dissipate excess thermal energy from the high-temperature heat storage medium before it enters the cold medium storage tank 19. In this case, the trim cooler inlet 24 of the high-temperature trim cooler 23 is connected to the heat storage outlet 18 of the high-temperature heat exchanger system 13, and the trim cooler outlet 25 is connected to the heat storage inlet 21 of the cold medium storage tank 19. Both storage tanks of the low-temperature storage system 43 in Fig.1. Here, the low-temperature storage tank 30 and the cold medium storage tank 36 can be designed as atmospheric or unpressurized storage tanks in the low-temperature range, which has a positive effect on the cost of the system. Furthermore, a displacement storage system is possible, in which a common storage tank is used for both cold and hot media. 2024PF00225 20 The high-temperature storage system 42 comprises the high-temperature storage tank 7 and the associated cold medium storage tank 19. In the high-temperature storage tank 7, the heat storage medium, such as water, is stored at a higher pressure. HT stored to achieve a higher storage temperature T HTto enable the storage medium (in this example, water). With water as the heat storage medium, a storage temperature of, for example, 200°C can be achieved by storing it in a pressurized water tank at approximately 15.5 bar, without evaporation. In the associated cold media storage tank 19, the cold heat storage medium is at an initial temperature T. KaltHT and at an initial pressure d KaltHTThe high-temperature storage system 42, as previously described, absorbs the heat of compression generated by the low-pressure compressor unit 3, stores it temporarily, and feeds it back to the low-pressure expander unit 8 during the expansion process. In the embodiment shown in Fig. 1, water is used as the heat storage medium for storing and transferring heat, i.e., thermal energy, in both the low-temperature and high-temperature storage systems 43 and 42. In the A-CAES system 1 according to the invention, other heat storage media can also be used for storing and transferring thermal energy in the respective heat exchangers 6, 14, 27, and 32, in addition to water as the heat storage medium. Instead of water, thermal oil, molten salt, etc., can also be used.A molten salt or other heat storage media can be used as a high-temperature and / or low-temperature heat storage medium. In the case of molten salt as a heat storage medium, e.g., a high-temperature heat storage medium, it can be stored at temperatures higher than water without pressure in the high-temperature storage tank 7. However, the temperature of the molten salt must be above its melting point at a predetermined buffer temperature to prevent crystallization. Below this melting point, the molten salt begins to crystallize. The buffer temperature is chosen to be sufficiently above the melting point of the molten salt to prevent unwanted crystallization and, at the same time, to absorb and store as much thermal energy as possible during operation, in this case, the heat of compression from the air.2024PF00225 21 The previously described high-temperature heat exchangers 6, 14, and low-temperature heat exchangers 27, 32 for compression and expansion can be implemented in the same heat exchanger. In other words, the high-temperature heat exchanger 6 for compression can be the same as the high-temperature heat exchanger 14 for expansion, and the low-temperature heat exchanger 27 for compression can be the same as the low-temperature heat exchanger 32 for expansion (6=14 and 27=32, respectively). In the example in Fig. 1, the low-pressure compressor unit 3 has at least one, two, or three low-pressure compressors 4, which can be driven by one or more drive units 38. The medium or high-pressure compressor unit 9 also has one or more drive units 39 for driving the medium or high-pressure compressors 28 of the medium or high-pressure compressor unit 9.Expanders 33 and 34 of expander units 8 and 10 can be connected to one or more common generators 40. The thermal component of an A-CAES system can be divided into energy-related and power-related cost components. The energy-related component consists primarily of the heat exchanger, including its heat storage medium, while the power-related component comprises the compressors, expanders, and main air heat exchangers, as well as the connecting air ducts of the air piping system. The total costs are then significantly influenced by the heat storage medium as the thermal energy storage medium. To reduce storage costs, a low-pressure storage system (e.g., atmospheric) could be used, at the expense of efficiency and increasing the costs of the power-related component (i.e., more reheating / cooling cycles).One possible embodiment would be the storage of thermal energy using water as a heat storage medium in an atmospheric earth basin storage tank near its boiling point. A low temperature level would necessitate a low compression / expansion ratio, which in turn would require a high number of intermediate heating (expansion) / intercooling (compression) cycles. Particularly in the low-pressure air-side area, this would lead to very large volume flows. These would require very large nominal diameters for piping, expanders, compressor housings, quick-closing valves, and control valves, resulting in disproportionately high costs and limiting feasibility. This would lead to higher investment costs for the rotating machinery and the more complex BOP (piping). Against this background, the A-CAES system described above with reference to Fig. 1 provides an improved system.This is achieved by combining a low-temperature heat storage medium and a high-temperature heat storage medium as thermal energy storage devices, which are stored at different temperature levels in the A-CAES system according to Fig. 1. The same heat storage medium, e.g., water, can be used for both the low- and high-temperature heat storage media, and each can be stored at a different temperature level, as in the example in Fig. 1. However, two different heat storage media can also be used for the low- and high-temperature heat storage media to store energy at two different temperature levels, for example, molten salt as the high-temperature heat storage medium and water as the low-temperature heat storage medium, etc.By using a first, lower temperature level (with the low-temperature heat storage medium) for the medium and high pressures, the advantage of cost-effective storage can be utilized, as the volume flows are manageable. Furthermore, by using a second, higher temperature level (with the high-temperature heat storage medium) for the lower pressure stages to increase the air-side pressure level of the corresponding intermediate superheating / cooling cycles, the number of intermediate superheating / cooling cycles in the low-pressure range can be reduced (2024PF00225 23), and thus the required flow cross-sections can be significantly reduced. The provision of two temperature levels (for the low- and high-temperature heat storage medium), as previously described with reference to Fig.The A-CAES system described in Section 1 enables the use of the advantages of these two system approaches as follows: The low-temperature storage system 43 for medium and higher air pressures has the advantage of low storage costs due to preferably atmospheric storage in an associated low-temperature storage tank 30 and / or cold medium storage tank 36. However, this requires more intermediate heating / cooling cycles and a higher BOP (Balance of Performance) cost. The high-temperature storage system 42 for low air pressures has the advantage of fewer intermediate heating / cooling cycles and thus a lower BOP cost. Storage primarily takes place in pressure storage tanks. The combination of the low- and high-temperature storage systems 43, 42 of the A-CAES system 1 can be individually adapted depending on the weighting of technical feasibility or complexity, costs, and the efficiency of the system.Although the present invention has been fully described above with reference to preferred embodiments, it is not limited to such embodiments but can be modified in many different ways.

Claims

2024PF00225 24 Claims 1. An adiabatic compressed air energy storage system (A-CAES) (1) comprising: - a compressed air storage device (2) for storing air, - a low-pressure compressor unit (3) for compressing supplied air to a first air pressure (d K1 ) and an initial air temperature (T K1 ), - a high-temperature heat exchanger system (5) with a high-temperature heat storage medium for cooling the air compressed in the low-pressure compressor unit (3) by absorbing compression heat from the air, wherein the high-temperature heat storage medium is heated to a first heat storage temperature (T) by absorbing the compression heat HT ) with a first heat storage pressure (d HT ), - a medium or high pressure compressor unit (9) for compressing the air after the high temperature heat exchanger system (5) in further compression stages to a storage air pressure (d DS), - a low-temperature heat exchanger system (26) with a low-temperature heat storage medium for cooling the air of the medium- or high-pressure compressor unit (9) to a storage air temperature (T DS ), by absorbing heat of compression from the air compressed in the medium or high pressure compressor unit (9), wherein the low-temperature heat storage medium is heated to a second heat storage temperature (T) by absorbing the heat of compression from the air NT ) with a second heat storage pressure (d NT), and - an air piping system (11) which, in the direction of flow, connects the low-pressure compressor unit (3) with the high-temperature heat exchanger system (5), the high-temperature heat exchanger system (5) with the medium- or high-pressure compressor unit (9), the medium- or high-pressure compressor unit (9) with the low-temperature heat exchanger system (26) and the low-temperature heat exchanger system (26) with the compressed air storage device (2) for supplying and storing the air in the compressed air storage device (2) at the storage air pressure (d DS ) and the storage air temperature (T DS ). 2024PF00225 25 2. Adiabatic compressed air energy storage system according to claim 1, comprising: - a low-temperature storage unit (30) for storing the low-temperature heat storage medium of the low-temperature heat exchanger system (26) with the second heat storage temperature (T NT ) and the second heat storage pressure (d NT), - a medium- or high-pressure expander unit (10) connected to the compressed air storage device (2) for expanding the air of the compressed air storage device (2) in several expansion stages, - a further low-temperature heat exchanger system (31) connected to the medium- or high-pressure expander unit (10) with the low-temperature heat storage medium for intermediate heating of the air to be expanded before an expansion stage by transferring the thermal energy of the low-temperature heat storage medium to the air to be expanded, wherein the low-temperature heat storage medium is thereby heated to a heat storage output temperature (T KaltNT ) with a heat storage outlet pressure (d KaltNT ) is cooled, - a cold medium storage unit (36) for storing the low-temperature heat storage medium with the heat storage outlet temperature (T KaltNT ) and the heat storage outlet pressure (d KaltNT), and - a low-temperature piping system (35) which, in the direction of flow, connects the low-temperature heat exchanger system (26) with the low-temperature storage tank (30), the low-temperature storage tank (30) with the further low-temperature heat exchanger system (31), the further low-temperature heat exchanger system (31) with the cold medium storage tank (36), and the cold medium storage tank (36) with the low-temperature heat exchanger system (26).

3. Adiabatic compressed air energy storage system according to claim 1 or 2, comprising: - a high-temperature storage tank (7) for storing the high-temperature heat storage medium of the high-temperature heat exchanger system (5) at the first heat storage temperature (T HT ) and the first heat storage pressure (d HT ), - a low-pressure expander unit (8) which is connected to the medium- or high-pressure expander unit (10) via the further high-temperature heat exchanger system (13) for expanding the air 2024PF00225 26 from the medium or high pressure expander unit (10) to an outlet air pressure (d A ) with an outlet air temperature (T A ) in at least one expansion stage, - a further high-temperature heat exchanger system (13) connected to the low-pressure expander unit (8) with the high-temperature heat storage medium for transferring the thermal energy of the high-temperature heat storage medium to the air to be expanded for intermediate heating of the air before an expansion stage in the low-pressure expander unit (8), wherein the high-temperature heat storage medium is thereby heated to a heat storage output temperature (T KaltHT ) at a heat storage outlet pressure (d KaltHT ) is cooled, - a cold medium storage unit (19) for storing the high-temperature heat storage medium with the heat storage outlet temperature (T KaltHT ) and the heat storage outlet pressure (d KaltHT), and - a high-temperature piping system (20) which, in the direction of flow, connects the high-temperature heat exchanger system (5) to the high-temperature storage tank (7), the high-temperature storage tank (7) to the further high-temperature heat exchanger system (13), the further high-temperature heat exchanger system (13) to the cold medium storage tank (19), and the cold medium storage tank (19) to the high-temperature heat exchanger system (5).

4. Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the second heat storage temperature (T NT ) and the second heat storage pressure (d NT ) of the low-temperature heat storage medium are lower than the first heat storage temperature (T HT ) and the first heat storage pressure (d HT ) of the high-temperature heat storage medium, wherein the second heat storage pressure (d NT) of the low-temperature heat storage medium preferably corresponds to atmospheric pressure or is as close as possible to atmospheric pressure.

5. Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the pressure corresponding to the first atmospheric pressure (d K1 ) associated first air temperature (T K1 ) is selected depending on the maximum operating temperature of the high-temperature heat storage medium, where the first air temperature (T K1 ) preferably is sufficiently high to heat the high-temperature heat storage medium of the 2024PF00225 27 High-temperature heat exchanger system (5) to the first heat storage temperature (T HT ), where the first heat storage temperature (T HT ) is preferably selected depending on the maximum operating temperature of the high-temperature heat storage medium, wherein the first heat storage temperature (T HT) is particularly preferably equal to or as close as possible to the maximum operating temperature of the high-temperature heat storage medium.

6. Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the storage air pressure (d DS ) and the storage air temperature (T DS ) are dependent on an operating air pressure and an operating air temperature of the compressed air storage device (2) and the storage air pressure (d DS ) corresponds to or comes as close as possible to the operating air pressure of the compressed air storage device (2) and the storage air temperature (T DS) corresponds to or comes as close as possible to the operating air temperature of the compressed air storage device (2), wherein the compressed air storage device (2) preferably has at least one storage tank, in particular an above-ground storage tank or an underground storage tank, and / or at least one cavern for storing the air. 7.An adiabatic compressed air energy storage system according to one of the preceding claims, comprising: - a high-temperature trim cooler (23) which is provided in the flow direction in the high-temperature piping system (20) upstream of the cold medium storage unit (19) and preferably downstream of the high-temperature heat exchanger system (13), and / or - a low-temperature trim cooler (37) which is provided in the flow direction in the low-temperature piping system (35) upstream of the cold medium storage unit (36) and preferably downstream of the low-temperature heat exchanger system (31), and / or - an air trim cooler which is provided in the flow direction in the air piping system (11) upstream of the compressed air storage unit (2) and preferably downstream of the low-temperature heat exchanger system (26). 8.Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the low-pressure compressor unit (3) comprises at least one low-pressure compressor (4) and the high-temperature. 2024PF00225 28 Heat exchanger system (5) comprising at least one high-temperature heat exchanger (6) for intermediate cooling of the air by the high-temperature heat storage medium after a compression stage.

9. Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the medium- or high-pressure compressor unit (9) comprises at least two, three, four, five, or six medium- or high-pressure compressors (28) connected to one another in the direction of flow by the air piping system (11), and the low-temperature heat exchanger system (26) comprises one low-temperature heat exchanger (27), preferably after each medium- or high-pressure compressor (28), for intermediate cooling of the air by the low-temperature heat storage medium after a compression stage. 10.Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the low-pressure expander unit (8) comprises at least one low-pressure expander (33) and the further high-temperature heat exchanger system (13) comprises at least one high-temperature heat exchanger (14) for intermediate heating of the air by the high-temperature heat storage medium before an expansion stage. 11.An adiabatic compressed air energy storage system according to one of the preceding claims, wherein the medium- or high-pressure expander unit (10) comprises at least two, three, four, five, or six medium- or high-pressure expanders (34) connected one after the other in the direction of flow through the air piping system (11), and the further low-temperature heat exchanger system (31) comprises a further low-temperature heat exchanger (32), preferably upstream of each medium- or high-pressure expander (34), for intermediate heating of the air by the low-temperature heat storage medium upstream of an expansion stage. 12.Adiabatic compressed air energy storage system according to one of the preceding claims, wherein at least the high-temperature storage (7), the low-temperature storage (30), the cold medium storage (19) connected to the high-temperature storage or the cold medium storage (36) connected to the low-temperature storage (30) comprises at least one storage tank, in particular an above-ground storage tank. 2024PF00225 29 an underground storage tank, or a cavern, for storing the associated low-temperature heat storage medium or high-temperature heat storage medium, wherein the at least one storage tank is in particular a single-storage tank, preferably a stratified storage tank, or a multi-storage tank, and wherein the low-temperature heat storage medium and / or the high-temperature heat storage medium is / are preferably water, thermal oil, a liquid salt or a latent heat storage medium, in particular a phase-change (PCM) heat storage medium.

13. Adiabatic compressed air energy storage system according to one of the preceding claims, wherein the high-temperature heat storage medium is water, wherein the high-temperature storage medium (7) is preferably a pressurized water storage medium, wherein the first heat storage temperature (T) is preferably HT ) in a range of 100°C to 230°C and the first heat storage pressure (d HT) in a range of 28 bar, wherein the cold medium storage (19) connected to the high-temperature storage (7) by the high-temperature piping system (20) is preferably a pressureless or as pressureless as possible water storage, and / or wherein the low-temperature heat storage medium is water, wherein the low-temperature storage (30) is preferably an atmospheric storage, wherein the second heat storage temperature (T) is preferably NT) in a range below 100°C, wherein the cold medium storage (36) connected to the low-temperature storage (30) by the low-temperature piping system (35) is preferably also an atmospheric storage.

14. Method for adiabatic compressed air energy storage, in particular by means of an adiabatic compressed air energy storage system (1) according to one of the preceding claims, wherein the method comprises the steps of: - Compressing air, in particular ambient air, in a low-pressure compressor unit (3) in at least one compression stage to a first air temperature (T K1 ) and an initial air pressure (d K1 ), wherein the air is cooled after at least one compression stage by a high-temperature heat exchanger system (5) with a high-temperature heat storage medium and the high- 2024PF00225 30 temperature-heat storage medium thereby to a first heat storage temperature (T HT) with a first heat storage pressure (d HT ) is heated, - directing the air to a medium- or high-pressure compressor unit (9) and compressing the air in the medium- or high-pressure compressor unit (9) in several compression stages to a storage air pressure (d DS ), wherein the air in the compression stages is heated to a storage air temperature (T) by a low-temperature heat exchanger system (26) with a low-temperature heat storage medium (T DS ) cooled and the low-temperature heat storage medium thereby cooled to a second heat storage temperature (T NT ) with a second heat storage pressure (d NT ) is heated, and - conveying the air to a compressed air storage device (2) and storing the air in the compressed air storage device (2) at the storage air pressure (d DS ) and the storage air temperature (T DS).

15. Method according to claim 14, wherein the method comprises the steps of: - directing the air from the compressed air storage device (2) to a medium- or high-pressure expander unit (10) for expanding the air in several expansion stages, wherein the air is preheated before each expansion stage by a further low-temperature heat exchanger system (31) with the low-temperature heat storage medium and the low-temperature heat storage medium is thereby heated to a heat storage output temperature (T KaltNT ) with a heat storage outlet pressure (d KaltNT ) is cooled, - Directing the air of a low-pressure expander unit (8) and expanding the air in the low-pressure expander unit (8) to an output pressure (d A ) and an initial temperature (T A), wherein the air is preheated by a further high-temperature heat exchanger system (13) with the high-temperature heat storage medium before the respective expansion stage, and the high-temperature heat storage medium is thereby heated to a heat storage output temperature (T KaltHT ) with a heat storage outlet pressure (d KaltHT ) is cooled.

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