Steam accumulator power plant and method for operating same

Abstract

The invention relates to a steam accumulator power plant (01) having a water-steam circuit. The latter has, in a direct or indirect sequence, a water tank (02), an evaporator (04), a steam pump (05) which (05) allows a pressure of between 15 bar and 50 bar at the outlet, a desuperheater (06), a steam accumulator (07), a steam heater (08), a steam turbine (09), and a condenser (10). For heat storage, heat transfer from the steam to a heat storage medium takes place in the desuperheater and heat transfer from the heat storage medium to the steam takes place in the steam heater.

Description

Description TITLE Steam storage power plant and method for operating such a plant TECHNICAL FIELD

[0001] The invention relates to a steam storage power plant in which a steam storage unit and an additional heat storage medium are used as energy storage units to enable a time-delayed provision of steam for a steam turbine. BACKGROUND D

[0002] A steam storage power plant is typically used when the supply of steam needs to be decoupled from the demand for steam. This can be the case when there is excess energy but no demand for steam. It can also be necessary when the supply of steam cannot be reliably guaranteed at all times. In this case, a steam storage facility is typically used in the steam storage power plant.

[0003] EP 3025031 B1, for example, is known from the prior art, in which steam is fed into a Ruths storage tank following a steam generator. If there is a demand for steam but the steam generator cannot provide the required amount, the steam is extracted from the Ruths storage tank and fed to a steam turbine.

[0004] In a so-called Ruths storage tank, a storage vessel is mostly filled with boiling water. The remaining space above the water is filled with steam at the same temperature. The Ruths storage tank is charged by introducing steam, whereby the pressure must be higher than the extraction pressure at the beginning of the steam extraction. The steam condenses to boiling water. When steam is extracted, re-evaporation begins. The required heat comes from the boiling water. Pressure and temperature drop. The operating range of the steam accumulator is defined by the initial and final parameters (pressure and temperature) as well as the initial fill level with boiling water.

[0005] The well-known designs of steam storage power plants with Ruths storage enable flexibility in terms of steam generation and steam consumption.

[0006] Regarding the specification of pressures in the water-steam cycle in the following description, the absolute pressure is generally specified, even if only pressure (without the attribute “absolute”) is mentioned.

[0007] The disadvantage is that only limited steam temperatures can be achieved with the Ruths storage and thus the use of the Ruths storage is restricted to applications in which correspondingly lower temperatures are sufficient. SUMMARY OF THE INVENTION

[0008] The object of the present invention is to create a heat storage system that can store steam at very high temperatures and subsequently recover steam at very high temperatures from the heat storage system. The aim is to improve the efficiency of the system.

[0009] The object is achieved by an embodiment of the invention according to the teaching of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0010] The typical steam storage power plant has a water-steam cycle. This cycle includes at least a water storage tank and an evaporator with a downstream steam heater, as well as a steam turbine and a condenser.

[0011] The evaporator enables the evaporation of the supplied water by supplying thermal energy. In the steam heater, the steam is superheated to a temperature that allows it to be used in the steam turbine. This also requires the supply of thermal energy.

[0012] In the steam turbine, the steam expands, resulting in a temperature drop. The steam turbine is preferably used to drive a generator. In the condenser, the steam is cooled so that it can be transferred to the water storage tank in the form of water.

[0013] According to the invention, the steam storage power plant is now expanded to include the following components.

[0014] First, a steam pump is installed in the water-steam circuit downstream of the evaporator. This can preferably be powered by renewable energy. The steam pump must be designed so that a pressure of at least 15 bar is achieved at the steam pump outlet. A pressure of 50 bar is sufficient.

[0015] Compressing steam to a higher pressure directly increases the steam temperature. The goal is to achieve a steam temperature at the steam pump outlet that would be suitable for driving the steam turbine.

[0016] To store the thermal energy from the steam for later use, a steam cooler is installed downstream of the steam pump. The steam cooler is designed to transfer the thermal energy from the steam to a heat storage medium.

[0017] Preferably, the system is designed and the process is conducted in such a way that the pressure and temperature of the steam downstream of the steam cooler approximately correspond to the state of saturated steam.

[0018] Following the steam cooler, the steam is fed to a Ruths storage tank. The design and operation of a Ruths storage tank are well known and therefore require no further explanation. At the very least, the Ruths storage tank allows for a time shift between the supply and removal of steam. The outlet of the Ruths storage tank is then connected to the steam heater. The steam heater is designed to heat the steam to a higher temperature, preferably close to the temperature reached at the outlet of the steam pump. At the same time, the heat energy dissipated by the steam cooler is to be recovered. For this to happen, the steam heater must enable heat transfer from the heat storage medium into the steam.

[0020] The high temperature now achieved and the resulting increased pressure make it possible to use the steam in the subsequent steam turbine.

[0021] By dividing the energy storage in the water-steam cycle according to the invention on the one hand into the Ruths storage and on the other hand into the heat storage medium, a high degree of efficiency can be achieved and, in addition, the temperature required for the operation of the steam turbine can be reached when recovering the stored energy.

[0022] To ensure a reliable flow in the water-steam circuit, a first water pump is advantageously arranged between the water reservoir and the evaporator. This advantageously ensures the discharge of water from the water reservoir into the water-steam circuit.

[0023] Furthermore, alternatively or preferably additionally, a second water pump can be provided between the condenser and the water tank. This advantageously ensures the return of water from the condenser to the water tank.

[0024] For energy storage in the heat storage medium according to the invention, a storage device is arranged in a particularly advantageous manner between the steam cooler and the steam heater, in which at least a larger portion of the heat storage medium is accommodated.

[0025] The storage device preferably comprises a warm storage unit and a hot storage unit. The thermal energy extracted from the steam in the steam cooler and fed to the heat storage medium is stored in the hot storage unit. In contrast, the residual heat is stored in the heat storage medium following heat transfer in the steam heater to the steam in the warm storage unit. Using molten salt as the heat storage medium has proven particularly suitable. This allows the heat storage medium to be transferred from the steam cooler to the hot storage tank and returned from the steam heater to the hot storage tank.

[0027] A storage circuit through which the heat storage medium flows is preferred. The storage circuit includes the steam cooler, the hot storage tank, the steam heater, and the hot storage tank. It can be provided that the storage circuit is switchable for the state of storing heat energy and the state of discharging heat energy. Thus, it can be provided that, in order to supply heat energy, the heat storage medium flows in a first storage circuit from the steam cooler through the hot storage tank and subsequently the warm storage tank, thereby passing the steam heater in a bypass. In contrast, in order to recover the stored heat energy, in a second In the storage circuit, the heat storage medium is led from the hot storage tank through the steam heater and then to the warm storage tank, whereby the steam cooler is bypassed by a bypass in the circuit to the hot storage tank.

[0029] Furthermore, it may be advantageous to provide pumps or other devices in the storage circuit. This particularly advantageous design, combining a Ruths storage tank with the use of molten salt as a heat storage medium with separate warm storage and hot storage, achieves a high level of efficiency in energy storage in a water-steam cycle.

[0031] There are various options available for the evaporator design and the type of energy supply. On the one hand, waste heat from external processes can be used directly.

[0032] It is advantageous to use heat from natural sources directly for heating the evaporator. Renewable heat energy is particularly advantageous. This could, for example, be thermal energy from solar collectors. It is also possible (especially depending on the location) to use solar energy directly for heating the evaporator.

[0033] Another possibility is to use an electric heater in the evaporator, especially if excess renewable electricity is available.

[0034] The use of a heat pump is preferred, as this allows for particularly high efficiency in the evaporation process, for example, when renewable electricity is available and a certain amount of usable heat is available. The operation of a heat pump is well known and requires no further explanation.

[0035] The need for recooling the steam following the steam turbine in the condenser can be used in a particularly advantageous manner to Energy recovery can be utilized in the heat pump. For this purpose, a cooling water circuit is provided, which includes the condenser and the heat pump. It should be noted that different switching states (flow direction, bypass, etc.) can also be provided in the cooling water circuit, depending on whether thermal energy is being stored or recovered. At a minimum, a cooling water storage tank is required in the cooling water circuit in conjunction with the condenser. A cooling water pump ensures circulation in the cooling water circuit, while a water cooler is also required, which also forms part of the heat pump. Alternatively or in addition, the above-mentioned options for supplying heat to the heat pump can also be used, especially if external heat is not sufficient to directly heat the evaporator.

[0038] It is also possible to supply the evaporator with heat energy from the storage tank. This is particularly advantageous when no or insufficient external heat source is available for heating the evaporator, but sufficient energy can be provided to operate the steam pump.

[0039] Depending on the process control with the temperature and pressure of the steam supplied to the Ruths storage tank, and in particular at a temperature above saturated steam, it is particularly advantageous if water from the water storage tank can be supplied to the Ruths storage tank to balance the mass balance between injection and discharge.

[0040] To control and ensure a parallel water supply from the water reservoir to the Ruths reservoir, a third water pump is advantageously arranged in the connection.

[0041] In the event that other plants can also provide steam or consume steam, it may be advantageous to connect an external plant to the steam storage power plant. For example, it may be possible for steam to be supplied to the Ruths storage facility from the external plant, or for steam from the Ruths storage facility to be made available to an external plant.

[0042] Furthermore, it is possible to introduce steam from external sources at other points in the water-steam cycle or to discharge it to an external system.

[0043] The individual components in the water-steam cycle of the steam storage power plant are advantageously coupled as follows:

[0044] An advantageous first line connects the water reservoir with the first water pump. An advantageous second line connects the first water pump to the evaporator.

[0046] An advantageous third line connects the evaporator to the vapor pump.

[0047] An advantageous fourth line connects the steam pump to the steam cooler.

[0048] An advantageous fifth line connects the steam cooler with the Ruths storage tank.

[0049] An advantageous branch of the first line leads to the third water pump or another line connects the water tank with the third water pump. An advantageous sixth line connects the Ruths storage tank with the steam heater.

[0051] An advantageous seventh line connects the steam heater to the steam turbine.

[0052] An advantageous eighth line connects the steam turbine to the condenser.

[0053] A beneficial ninth line connects the condenser to the second water pump.

[0054] A beneficial tenth line connects the second water pump to the water tank. An advantageous eleventh line connects the third water pump with the Ruths reservoir. The novel steam storage power plant according to the invention enables a new method according to the invention for operating the steam storage power plant, wherein different process configurations are possible in detail, particularly with regard to the temperatures and pressures to be set. [0CCT] The outlet for the water-steam cycle is the water tank, where the water stored therein usually has a temperature between 10°C and 70°C.

[0058] The water pumped to the evaporator is heated and evaporated.

[0059] The steam is then compressed and heated by the steam pump. The pressure downstream of the steam pump should be at least 15 bar. A pressure above 50 bar, however, results in disproportionately high installation costs without a corresponding increase in efficiency. The temperature at the steam pump outlet should be at least 400°C. However, a temperature above 800°C should be avoided.

[0060] It is particularly advantageous if the steam pump output is superheated steam. This means that the steam temperature, taking into account the achieved pressure, is significantly above the boiling point.

[0061] The steam is then cooled in the steam cooler to a temperature between 150°C and 300°C. This temperature can be approximately equal to the boiling point.

[0062] At least the steam coming from the steam cooler is led into the Ruths storage tank and stored there as boiling water.

[0063] Steam is extracted from the Ruths reservoir at different times. In this case, it is usually saturated steam. (0064j The steam is led from the Ruths storage tank to the steam heater, where the steam is heated to a temperature between 350°C and 700°C. For this purpose, a heat transfer from the heat storage medium to the steam flowing through the steam heater is necessary. The aim is to Heat storage medium to reach approximately the temperature that existed at the outlet of the steam pump when the heat energy was stored in the heat storage medium. As the amount of stored boiling water in the Ruths reservoir decreases from the beginning of the withdrawal, the steam pressure will obviously decrease continuously.

[0066] The reheated steam can now be fed to the steam turbine. The purpose of the steam turbine is initially irrelevant. The steam turbine is most preferably used to drive a generator. [00675 |At the end of the cycle, the expanded and cooled steam is led from the steam turbine to the condenser, where it is further cooled and condensed into water.

[0068] The water can then be led back from the condenser to the water tank.

[0069] During operation, the pressure in the water-steam circuit from the steam turbine to the steam pump should be as low as possible, or approximately at normal pressure. Keeping the pressure in the aforementioned lines as low as possible is particularly beneficial for the efficiency of the steam storage power plant. However, this increases the installation effort accordingly.

[0070] Accordingly, it is advantageous if the pressure in the connection from the second water pump at the end of the water-steam circuit upstream of the water reservoir to the steam pump is at least 0.2 bar. This applies to the first line, the second line, the third line, and the tenth line. A pressure of at least 0.4 bar is preferred. In contrast, the pressure should not exceed 1.4 bar. The pressure in the lines is preferably at most 1.2 bar.

[0071] The pressure in the fourth and fifth lines connecting the steam pump to the Ruths storage tank is preferably at least 20 bar. It is also advantageous to limit the pressure to a maximum of 40 bar.

[0072] During operation of the steam pump, pressure fluctuations may occur in the connection between the steam pump and the Ruths storage tank. The difference between the highest and lowest pressures encountered during the process should not exceed 5 bar.

[0073] The pressure in the connection from the Ruths reservoir to the steam turbine will normally (due to its function) drop from a higher pressure at the beginning of steam extraction until the end of steam extraction from the Ruths reservoir. Care should be taken to ensure that the pressure in the sixth and seventh lines is at least 5 bar. A minimum pressure of 10 bar is preferred during steam turbine operation.

[0074] In the connection from the steam turbine to the second water pump after the condenser, the pressure should be less than 1.2 bar. A maximum pressure of 0.6 bar is preferred. It is particularly advantageous if a maximum pressure of 0.3 bar is achieved.

[0075] High efficiency in the storage process is achieved when the steam at the steam pump outlet exhibits the greatest possible superheat. The absolute steam temperature in the connection from the steam pump to the steam cooler should be at least 1.5 times the absolute boiling temperature. A process in which the absolute steam temperature in this connection is at least twice the absolute boiling temperature is particularly preferred.

[0076] Regarding the steam flow from the steam cooler to the Ruths storage tank, i.e., in the fifth line, various conditions can be provided. It is possible for wet steam to be present downstream of the steam cooler. In this case, the steam proportion in the mass flow should be at least 90%. However, it is preferable to ensure that the steam proportion in the mass flow is at least 95%.

[0077] However, it is more advantageous if saturated steam is fed from the steam cooler to the Ruths storage tank instead of wet steam.

[0078] Particularly preferred is slightly superheated steam from the steam cooler to the Ruths storage tank. This largely eliminates the need for liquid water.

[0079] In an alternative process, superheated steam is fed to the Ruths reservoir. At the same time, it must be ensured that water from the water reservoir and / or an external source is added as needed to balance the temperature in the Ruths reservoir.

[0080] It can also be provided that the state of the steam, ie Wet steam, saturated steam or superheated steam, in the connection from the steam cooler to the Ruths storage tank changes during the process.

[0081] To recover the stored energy, steam is fed from the Ruths storage tank to the steam heater, i.e., in the sixth line. This can be wet steam, with the steam component of the mass flow being at least 90%.

[0082] As a rule, the steam released from the Ruths storage tank is saturated steam, which is led to the steam heater in the sixth pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The following figures outline two exemplary embodiments of a steam storage power plant according to the invention.

[0084] FIG 1 shows schematically a first embodiment of a steam storage power plant 01 according to the invention with a water-steam circuit and a cooling circuit, wherein it is provided that saturated steam is introduced into the Ruths storage 07.

[0085] FIG 2 shows schematically a second embodiment of a steam storage power plant 11 according to the invention with a water-steam circuit and a cooling circuit, wherein it is provided that superheated steam is introduced into the Ruths storage 07. DESCRIPTION OF THE EMBODIMENT

[0086] Figure 1 schematically outlines the structure of an exemplary steam storage power plant 01 according to the invention. It shows the water-steam circuit, starting from the water reservoir 02 via a first water pump 03 to the second water pump 12 and back to the water reservoir 02.

[0087] In the water tank 02, water is stored at a temperature between 10 °C and 70 °C. In the simplest case, the pressure in the water tank 02 corresponds to the ambient pressure and is therefore approximately 1 bar. Higher efficiency can be achieved if a pressure reduction is possible, i.e., if the pressure in the water tank 02 is approximately 0.5 bar. A first line 21 leads from the water tank 02 to the first water pump 03. The pressure and temperature in the first line 21 approximately correspond to those in the water tank 02.

[0089] In the middle of the first water pump 03, the flow from the water reservoir 02 into the water-steam circuit is ensured.

[0090] A second line 22 leads from the first water pump 03 to the evaporator 04. The temperature in the second line 22 essentially corresponds to that in the water reservoir 02. Due to the arrangement downstream of the first water pump 03, there is a slightly higher pressure than in the first line 21.

[0091] The water is heated and evaporated into steam in the evaporator 04. For this purpose, the evaporator 04 is part of a heat pump 12.

[0092] With almost unchanged pressure, but increased temperature above the boiling point, the steam is passed from the evaporator 04 through a third line 23 to a steam pump 05.

[0093] The steam pump 05 can be designed in various ways, whereby it must be ensured that the steam pump 05 enables compression of the steam to a pressure of at least 15 bar. At the same time, it is intended that the steam pump also causes a temperature increase to a temperature above 300 °C, resulting in significantly superheated steam.

[0094] The superheated steam is then led from the steam pump 05 through a fourth line 24 to a steam cooler 06.

[0095] In the steam cooler 06, heat is transferred from the steam to a heat storage medium. In this embodiment, the temperature is reduced to the boiling point. Saturated steam therefore leaves the steam cooler 06 through a fifth line 25. The fifth line 25 leads to the Ruths reservoir 07, where the saturated steam condenses into boiling water and can thus be stored. The pressure in the fifth line 25 is slightly lower than in the fourth line 24 upstream of the steam cooler 06.

[0097] It can also be provided that the temperature of the steam in the steam cooler 06 is reduced to a temperature just above the boiling point and thus slightly superheated steam leaves the steam cooler 06 on its way to the Ruths storage tank 07. Both with the nominal supply of saturated steam and slightly superheated steam into the Ruthsspeicher 07, it may be necessary to add small amounts of liquid water to balance the mass. In the event of an energy demand, steam can now be extracted from the Ruths reservoir 07 and fed through a sixth line 26 to a steam heater 08. The process of extracting steam from the Ruths reservoir 07 results in a continuous pressure drop in the sixth line 26. At the beginning of the extraction of steam from the Ruths reservoir 07, the pressure in the sixth line approximately corresponds to the pressure in the fifth line when it is stored in the Ruths reservoir 07. The extraction of steam must be stopped at the latest when the pressure has dropped to 5 bar.

[0100] In the subsequent steam heater 08, the heat energy from the heat storage medium is transferred back to the flowing steam. Heating takes place, the aim being to achieve approximately the temperature of the steam before the steam cooler 06.

[0101] The thus reheated steam can now be fed to the steam turbine 09 through a seventh line 27, so that the steam turbine 09 can, for example, drive a generator (not shown) by performing mechanical work. As the steam flows through the steam turbine 09, a pressure drop and a simultaneous temperature reduction occur.

[0102] The cold, expanded steam is then led through an eighth line 28 to a condenser 10, in which condensation of the steam is effected.

[0103] The water-steam cycle is completed by the return of the condensed water from the condenser 10 through a ninth line 29 by means of a second water pump 12 and a tenth line 30 back into the water tank 02.

[0104] During the thermal energy storage process, the heat storage medium is fed from a warm storage tank 13 through the steam cooler 06 to a hot storage tank 14. Accordingly, the hot storage tank 14 heats up during storage. It is possible for the cooler heat storage medium to be fed directly from the hot storage tank 14 or via the steam heater 08 into the warm storage tank 13 without heat loss to create a closed circuit.

[0105] During the process of extracting thermal energy, the heat storage medium is fed from the hot storage tank 14 via the steam heater 08 to the warm storage tank 13. It is also possible for the hotter heat storage medium to be fed from the warm storage tank 13 directly or via the steam cooler 06 without heat absorption into the hot storage tank 14 to create a closed circuit.

[0106] Furthermore, in this embodiment, there is a cooling circuit which starts from a cooling water reservoir 32 and leads via a cooling water pump 33 to the condenser 10.

[0107] The cooling water is heated in the condenser and then fed to the heat pump 12 and a water cooler 34. The water cooler 34 is thus also a component of the heat pump 12 for transferring heat energy from the cooling water by means of the heat pump 12 to the steam flowing through the evaporator 04.

[0108] The cooled cooling water is then led from the water cooler 34 back to the cooling water reservoir 32.

[0109] Figure 2 schematically outlines a second embodiment of a steam storage power plant 11 according to the invention. The second embodiment essentially corresponds to the design of the first embodiment of a steam storage power plant 01. Therefore, only the differences will be discussed below.

[0110] In the second embodiment of the steam storage power plant 11, it is provided that superheated steam is led from the steam cooler 06 through the fifth line 25 to the Ruths storage 07.

[0111] The introduction of superheated steam into the Ruths reservoir 07 leads to a mass imbalance between the inlet and outlet water levels, requiring additional water to be added to the Ruths reservoir. Therefore, this embodiment provides for an additional connection from the water reservoir 02 to the Ruths reservoir 07.

[0112] For this purpose, in this embodiment, a branch leads from the first line 21 to a third water pump 13. An eleventh line 35 leads from the third water pump 13 to the Ruths reservoir 07. Thus, the necessary mass balance in the Ruths reservoir 07 can be ensured.

[0113] In the first embodiment, the following process parameters have proven to be advantageous in a first variant:

[0114] The following pressure distribution is possible in the water-steam cycle: - approx. 1 bar in the water tank 02, in the first line 21, in the second line 22, in the evaporator 04, in the third line 23 and in the tenth line 30; - approx. 30 bar in the fourth line 24, in the steam cooler 06 and in the fifth line 25; - approx. 27 bar to approx. 10 bar (decreasing during withdrawal) in the sixth line 26, in the steam heater 08 and in the seventh line 27; - approx. 0.2 bar in the eighth line 28, in the condenser 10 and in the ninth line 29.

[0115] In the first variant, the following temperature distribution can be provided: - approx. 50°C in the water tank, in the first line 21, in the second line 22, in the ninth line 29 and in the tenth line 30; - approx. 100°C in the third line 23; - approx. 600°C in the fourth line 24; - approx. 230°C in the fifth line 25; - approx. 230°C to approx. 180°C in the sixth line 26; - approx. 580°C to approx. 500°C in the seventh line 27.

[0116] In the first embodiment, it is also possible to run the process in a second variant with higher pressures:

[0117] The following pressure distribution is possible in the water-steam cycle: - approx. 1 bar in the water tank 02, in the first line 21 and in the tenth line 30; - approx. 1.5 bar in the second line 22, in the evaporator 04 and in the third line 23; - approx. 40 bar in the fourth line 24, in the steam cooler 06 and in the fifth line 25; - approx. 40 bar to approx. 10 bar (decreasing during withdrawal) in the sixth line 26, in the steam heater 08 and in the seventh line 27; - approx. 0.2 bar in the eighth line 28, in the condenser 10 and in the ninth line 29.

[0118] In the second variant, the following temperature distribution can be provided: - approx. 50°C in the water tank, in the first line 21, in the second line 22, in the ninth line 29 and in the tenth line 30; - approx. 110°C in the third line 23; - approx. 600°C in the fourth line 24; - approx. 240°C in the fifth line 25; - approx. 240°C to approx. 180°C in the sixth line 26; - approx. 580°C to approx. 500°C in the seventh line 27.

[0119] In the first embodiment, it is also possible to run the process with lower pressures in a third variant:

[0120] The following pressure distribution is possible in the water-steam cycle: - approx. 0.5 bar in the water tank 02, in the first line 21, in the second line 22, in the evaporator 04, in the third line 23 and in the tenth line 30; - approx. 20 bar in the fourth line 24, in the steam cooler 06 and in the fifth line 25; - approx. 20 bar to approx. 10 bar (decreasing during withdrawal) in the sixth line 26, in the steam heater 08 and in the seventh line 27; - approx. 0.1 bar in the eighth line 28, in the condenser 10 and in the ninth line 29.

[0121] In the second variant, the following temperature distribution can be provided: - approx. 40°C in the water tank, in the first line 21, in the second line 22, in the ninth line 29 and in the tenth line 30; - approx. 80°C in the third line 23; - approx. 600°C in the fourth line 24; - approx. 210°C in the fifth line 25; - approx. 210°C to approx. 180°C in the sixth line 26; - approx. 600°C to approx. 500°C in the seventh line 27.

[0122] In the second embodiment, the following process parameters have proven advantageous in a fourth variant:

[0123] The following pressure distribution is possible in the water-steam cycle: - approx. 1 bar in the water tank 02, in the first line 21, in the second line 22, in the evaporator 04, in the third line 23 and in the tenth line 30; - approx. 30 bar in the fourth line 24, in the steam cooler 06 and in the fifth line 25; - approx. 27 bar to approx. 10 bar (decreasing during withdrawal) in the sixth line 26, in the steam heater 08 and in the seventh line 27; - approx. 0.2 bar in the eighth line 28, in the condenser 10 and in the ninth line 29.

[0124] In the fourth variant, the following temperature distribution can be provided: - approx. 50°C in the water tank 02, in the first line 21, in the second line 22, in the ninth line 29, in the tenth line 30 and in the eleventh line 35; - approx. 100°C in the third line 23; - approx. 600°C in the fourth line 24; - approx. 250°C in the fifth line 25; - approx. 230°C to approx. 180°C in the sixth line 26; - approx. 580°C to approx. 500°C in the seventh line 27.

Claims

Claims What is claimed: 1 . Steam storage power plant (01 , 11 ) with a water-steam cycle comprising in direct or indirect sequence - a water reservoir (02); and - an evaporator (04) which enables heating and evaporation; and - a steam pump (05) which allows a pressure of between 15 bar and 50 bar at the outlet; and - a steam cooler (06) which (06) enables heat transfer directly or indirectly from the steam to a heat storage medium; and - a Ruthsspeicher (07); and - a steam heater (08), which (08) enables direct or indirect heat transfer from the heat storage medium to the steam; and - a steam turbine (09); and - a condenser (10) which enables condensation of the steam leaving the steam turbine.

2. Steam storage power plant (01, 11) according to claim 1, wherein a first water pump (03) is arranged between the water reservoir (02) and the evaporator (04); and / or wherein a second water pump (12) is arranged between the condenser (10) and the water reservoir (02).

3. Steam storage power plant (01, 11) according to claim 1 or 2, wherein at least one storage device is arranged between the steam cooler (06) and the steam heater (08).

4. Steam storage power plant (01, 11) according to claim 3, wherein the storage device comprises a warm storage (16) and a hot storage (18).

5. Steam storage power plant (01, 11) according to claim 4, wherein the heat storage medium is a molten salt.

6. Steam storage power plant (01, 11) according to claim 3 or 4, comprising a storage circuit through which the heat storage medium can flow, in which the steam cooler (06) and the hot storage (18) and the steam heater (06) and the warm storage (16) are arranged.

7. Steam storage power plant (01, 11) according to one of claims 1 to 6, wherein the evaporator (04) is heatable with waste heat from external processes; and / or wherein the evaporator (04) is heatable with heat from natural sources, in particular with solar energy; and / or wherein the evaporator (04) is heatable with electrical energy, in particular electricity generated from renewable sources.

8. Steam storage power plant (01, 11) according to one of claims 1 to 6, wherein the evaporator (04) is integrated in a heat pump (14).

9. Steam storage power plant (01, 11) according to claim 8, comprising a cooling water circuit in which a water cooler (34) integrated into the heat pump (14), the condenser (10), a cooling water reservoir (32), and a cooling water pump (33) are arranged; and / or wherein waste heat from external processes or natural sources can be supplied to the heat pump (14).

10. Steam storage power plant according to one of claims 1 to 6, wherein the evaporator (04) is coupled to the heat storage.

11. Steam storage power plant (01, 11) according to one of claims 1 to 10, wherein the water reservoir (02) is connected to the Ruth reservoir (07); and / or wherein the water reservoir (02) is connected to a third water pump (13) and the third water pump (13) is connected to the Ruth reservoir (07).

12. Steam storage power plant (01, 11) according to one of claims 1 to 11, wherein a first line (21) connects the water reservoir (02) to the first water pump (03); and / or wherein a second line (22) connects the first water pump (03) to the evaporator (04); and / or wherein a third line (23) connects the evaporator (04) to the steam pump (05); and / or wherein a fourth line (24) connects the steam pump (05) to the steam cooler (06); and / or wherein a fifth line (25) connects the steam cooler (06) to the Ruths reservoir (07); and / or wherein a sixth line (26) connects the Ruths reservoir (07) to the steam heater (08); and / or wherein a seventh line (27) connects the steam heater (08) to the steam turbine (09); and / or wherein an eighth line (28) connects the steam turbine (09) to the condenser (10); and / or wherein a ninth line (29) connects the condenser (10) to the second water pump (11);and / or wherein a tenth line (30) connects the second water pump (11) to the water reservoir (02); and / or wherein an eleventh line (35) connects the third water pump (13) to the water reservoir (07); 13. A method for operating a steam storage power plant (01, 11) according to one of the preceding claims, wherein in the circuit - water is stored in the water tank (02) at a temperature between 10°C and 70°C; - the water is heated and evaporated in the evaporator (04); - the steam is compressed by the steam pump (05) to an absolute pressure between 15 bar and 50 bar and heated to a temperature between 400°C and 800°C; - the steam is cooled in the steam cooler (06) to a temperature between 150°C and 300°C; - the steam is fed to the Ruths storage (07); - steam is withdrawn from the Ruths storage tank (07) at a later time; - the steam is heated in the steam heater (08) to a temperature between 350°C and 700°C; - the steam is fed to the steam turbine (09); - the steam is cooled and condensed in the condenser (10); - the water is fed to the water reservoir (02).

14. The method according to claim 13, wherein the absolute pressure in the first line (21) and the second line (22) and in the third line (23) and in the tenth line (30) is at least 0.2 bar, in particular at least 0.4 bar, and at most 1.4 bar, in particular at most 1.2 bar; and / or wherein the absolute pressure in the fourth line (24) and in the fifth line (25) is at least 20 bar and / or at most 40 bar; and / or wherein the absolute pressure in the fourth line (24) and in the fifth line (25) fluctuates by at most 5 bar during operation of the steam pump (05); and / or wherein the absolute pressure in the sixth line (26) and in the seventh line (27) is at least 5 bar, in particular at least 10 bar; and / or wherein the absolute pressure in the eighth line (28) and in the ninth line (29) is at most 1.2 bar, in particular at most 0.6 bar, in particular at most 0.3 bar.

15. The method according to claim 13 or 14, wherein the absolute steam temperature from the steam pump (05) to the steam cooler (06) is at least 1.5 times, in particular at least 2 times, the absolute boiling temperature.

16. The method according to any one of claims 12 to 14, wherein saturated steam is conducted in the fifth line (25).

17. Method according to one of claims 12 to 15, wherein superheated steam is conducted in the fifth line (25) and water is supplied to the Ruths storage tank (07) from the water storage tank (02) or an external source as required.

18. The method according to any one of claims 12 to 16, wherein saturated steam is conducted in the sixth line (26).

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