Steam generating system comprising a heat exchanger

Abstract

The invention relates to a steam generation system (100) for generating gaseous working medium (403) from a liquid working medium (400, 401, 402) comprising a heat exchanger (200) and a separation chamber (280), wherein the heat exchanger (200) has an outer shell with an inlet (500) and outlet (501) for a heat transfer medium and the outer shell defines an interior space of the heat exchanger (200), wherein transfer tubes (210) are arranged in the interior space of the heat exchanger for guiding the working medium (401) from an inlet area (205) to an outlet area (215), wherein the heat exchanger (200) is configured to transfer heat from the heat transfer medium to the working medium, and wherein the separation chamber (280) is configured to separate gaseous (403) and liquid (402) working medium from each other and discharge them separately.wherein the interior of the heat exchanger (200) is separated from the outlet region (215) and from the inlet region (205) by a tube plate (220, 230) connected to the outer shell, the transfer tubes (210) arranged within the outer shell of the heat exchanger (200) are essentially straight and are oriented at an angle of 0 to 45° to the vertical, and the separation chamber (280) is arranged above the heat exchanger (200), and the heat exchanger (200) is configured to guide the working medium in the transfer tubes (210) from bottom to top towards the separation chamber (280). The invention further relates to a method for generating a gaseous working medium using the steam generation system according to the invention.

Description

[0001] The present invention relates to a steam generation system for producing gaseous working fluid from a liquid working fluid, comprising a heat exchanger and a separation chamber, wherein the heat exchanger has an outer shell with an inlet and outlet for a heat transfer medium and the outer shell defines an interior space of the heat exchanger, wherein transfer tubes are arranged in the interior space of the heat exchanger for guiding the working fluid from an inlet area to an outlet area, wherein the heat exchanger is configured to transfer heat from the heat transfer medium to the working fluid, and wherein the separation chamber is configured to separate the gaseous and liquid working fluids from each other and discharge them separately.

[0002] Industrial heat requirements often take the form of saturated or slightly superheated steam at pressures between 10 and 40 bar. Currently, steam is typically produced using fossil fuel-fired steam generators. In the future, renewable electricity will increasingly become the primary energy source. To decouple electricity generation and heat demand, a thermal storage system can be used. This allows heat to be generated from electricity and stored. The stored heat can then be used to produce steam as needed. State of the art

[0003] Document EP 2 910 781 A1 describes a solar thermal power plant with a solar receiver and a thermal energy storage arrangement with a thermal energy storage fluid that circulates through the solar receiver to store thermal energy. The system includes a multi-stage steam turbine operated with variable-pressure steam generated by a steam generation system utilizing the thermal energy storage fluid. The steam generation system comprises an economizer section, an evaporator section, and a superheater section, configured to utilize the heat from the hot thermal energy storage fluid to generate the variable-pressure steam and supply it to the turbine.

[0004] Molten salts are frequently used as a heat storage medium. During steam generation, it is essential to prevent the molten salt from solidifying within the steam generation system. Simultaneously, the aim is to cool the molten salt as much as possible within the steam generation system to achieve the largest possible temperature difference between the two storage tanks, thereby reducing the required storage mass and thus lowering investment costs.

[0005] Document EP 2 910 781 A1 describes this problem and possible technical solutions for use in solar thermal power plants. Among other things, it proposes feeding boiling water from the steam drum into the feedwater at the economizer inlet to achieve a desired mixing temperature at the economizer inlet. A pump is proposed for pumping the boiling water, positioned between the steam drum and the mixing point. The document does not provide specific details regarding the design of the economizer and the steam generator, although the figures suggest a horizontal orientation.

[0006] Document US5123480 A relates to an integrated, compact, vertical tube heat exchanger for use with a variety of heat exchange media, including recirculating fluidized solid particles and heated gases such as hot combustion products.

[0007] Various concepts for steam generation are known. Horizontally arranged devices are generally used. In a steam generator, the boiling water is located in the jacket and the molten salt on the tube side (WO2010 / 149387 A1). In an economizer, the molten salt is located on the jacket side and the water on the tube side. Known heat exchangers are designed, among other things, as U-tube bundles or header types (WO2020 / 069704 A1).

[0008] The design types and configurations described in the prior art have several disadvantages: In U-tube bundle heat exchangers, the tube plate is exposed to at least two different temperatures on the shell side, which leads to thermal stresses. Thermal stresses can lead to component failure, especially with frequent and rapid load changes. However, many thermal storage systems will be required to meet precisely this requirement in order to be able to adequately replace fossil fuel combustion or direct electric steam generation.

[0009] With a horizontal arrangement of the evaporator tubes, a sufficiently high flow velocity is required to prevent gravity-induced phase separation within the tube. This necessitates sufficiently small tube cross-sections and thus a relatively large number of evaporator tubes, which complicates or practically eliminates possible connection methods between the tube and tube sheet, such as through bore welding. Furthermore, the requirement for sufficient flow limits the part-load capability of the heat exchanger component.

[0010] The horizontal arrangement and orientation of the heat exchanger also has the disadvantage of requiring a relatively large amount of space.

[0011] If the economizer and evaporator are designed as separate devices, there is a risk that partial evaporation may occur unintentionally in the economizer, which can lead to increased pressure losses and damage the component in the long run.

[0012] In the known solutions, a pump is provided for the recirculation of the boiling water.

[0013] Furthermore, a largely horizontal arrangement of the transfer pipes, deflections in the transfer pipes and high flow velocities lead to relatively high pressure losses and thus to a relatively high power requirement for the pump.

[0014] To preheat the devices before filling them with heat exchanger medium, it is known to heat water in a separate external electric heater and to supply the heated water or steam to the devices to be heated, possibly using pumps. Several additional components are therefore required for preheating. Technical problem of the invention

[0015] The technical objective of the present invention was therefore to reduce or eliminate thermal stresses in the tube plates of shell-and-tube heat exchangers. Furthermore, it was an objective to prevent damage caused by partial evaporation in the transfer tubes, to reduce pressure losses in the transfer tubes of the heat exchanger, and to increase the part-load capability of the heat exchanger. Finally, it was an objective to reduce the space required for a heat exchanger, particularly for retrofitting, and to save on components and thus costs. Solution to the problem / Description of the invention

[0016] The technical problem is solved by a steam generation system for producing gaseous or vaporous working medium from a liquid working medium, comprising a heat exchanger and a separation chamber, wherein the heat exchanger has an outer shell with an inlet and outlet for a heat transfer medium and the outer shell defines an interior of the heat exchanger, wherein transfer tubes are arranged in the interior of the heat exchanger for guiding the working medium from an inlet area to an outlet area, wherein the heat exchanger is configured to transfer heat from the heat transfer medium to the working medium, and wherein the separation chamber is configured to separate the gaseous and liquid working medium from each other and discharge them separately.

[0017] According to the present invention The interior of the heat exchanger is separated from the outlet area and the inlet area by a tube plate connected to the outer shell, the transfer tubes arranged inside the outer shell of the heat exchanger are essentially straight and aligned at an angle of 0 to 45° to the vertical, and the separation chamber is arranged above the heat exchanger and the heat exchanger is designed to guide the working medium in the transfer tubes from bottom to top towards the separation chamber.

[0018] The steam generation system according to the invention can be part of a thermal storage system. With the steam generation system according to the invention, saturated steam, having a pressure of 10 to 40 bar (corresponding to a temperature of approximately 180 to 250 °C), can be generated from feedwater, which preferably has a temperature of 50 to 150 °C. A heat transfer medium, preferably a molten salt, is used for heating.

[0019] The steam generation system of the present invention comprises a device (heat exchanger) for preheating and evaporating the working medium, e.g., feedwater. The working medium is supplied to the lower section and rises through substantially vertical transfer tubes, which serve as preheating and evaporator tubes, partially evaporating in the process. A separation chamber or steam drum is located in the upper part of the steam generation system, in which the gaseous phase (e.g., steam) is separated from the liquid phase (e.g., water). The lower part of the heat exchange surfaces serves as an economizer, and the upper part as an evaporator. The transition is gradual and variable, depending on the operating point. The transfer tubes are connected at their ends to upper and lower tube plates, which spatially separate the heat transfer medium and the working medium (e.g., water / steam).

[0020] Furthermore, due to the vertical orientation of the transfer tubes, evaporation in them is no longer a problem, and pressure losses and damage in the transfer tubes of the heat exchanger are reduced or avoided.

[0021] Due to the vertical arrangement of the heat exchanger tubes according to the invention, unwanted gravity-induced phase separation in the tube cross-section does not occur. Therefore, low flow velocities and thus a small number of tubes are permissible. Furthermore, the part-load range is larger than with a horizontally oriented variant. The vertical arrangement results in a significant buoyancy force, which considerably reduces the power required to return the boiling water or working fluid to the inlet area and preferably eliminates the need for a pump.

[0022] The use of predominantly straight transfer tubes also minimizes pressure losses on the working medium side of the heat exchanger. This significantly reduces the power required to return the boiling water or working medium to the inlet area, or may even eliminate the need for a pump.

[0023] With the steam generation system according to the invention, in which an upper and a lower tube plate are used, there is therefore no longer a tube plate that would be exposed to two different temperatures and thus to temperature difference-induced stresses. Thus, thermal stresses such as those found in the tube plates of U-tube bundle heat exchangers are avoided.

[0024] The vertical orientation of the heat exchanger requires less space, which is particularly advantageous when retrofitting a steam generation system with a limited amount of space.

[0025] The steam generation system is preferably part of a thermal storage system. Since the temperature difference in the heat transfer medium should be as large as possible in order to require as little storage mass / volume as possible and to keep the heat transfer medium mass flow rate as low as possible, it is advantageous to cool the heat transfer medium to a temperature below its boiling point, which can be achieved with the steam generation system according to the invention.

[0026] In In a preferred embodiment of the steam generation system, the separation chamber (280) connects directly to the heat exchanger. The interior of the separation chamber is separated from the interior of the heat exchanger, through which the heat transfer medium flows, only by the tube plate.

[0027] InIn an alternative embodiment of the steam generation system, the separation chamber is designed as a separate container, wherein the steam generation system is configured to supply the separate container with working medium via a supply line from the outlet area of ​​the heat exchanger.

[0028] In another preferred embodiment of the steam generation system, a tube bundle for a heat transfer medium is arranged within the separation chamber to superheat the gaseous working medium.

[0029] In a further advantageous preferred embodiment of the steam generation system, the heat exchanger is configured to guide the heat transfer medium in counterflow or cross-counterflow to the flow direction of the working medium flowing in the transfer tubes. The heat transfer bundle can be equipped with baffles designed such that the heat transfer medium flows around the transfer tubes in crossflow (cross-counterflow) sections. Alternatively, the heat transfer bundle can be alternately equipped with annular and disc-shaped baffles designed such that the heat transfer medium flows around the transfer tubes in crossflow (cross-counterflow) sections.

[0030] In another preferred embodiment of the steam generation system, a circulation system is arranged to direct liquid working medium from the separation chamber, mix it with fresh working medium at a mixing point, and direct it back into the separation chamber via the inlet area and the transfer tubes of the heat exchanger.

[0031] To regulate the feedwater inlet temperature, boiling water is taken from the drum and mixed with the feedwater before it enters the heat exchanger.

[0032] The amount of boiling water is regulated to maintain the feedwater temperature within the desired range. This is achieved by measuring the water temperature before it enters the heat exchanger and adjusting the circulation rate to reach the desired temperature. By controlling the inlet temperature of both the feedwater and the circulating water, a defined water / steam flow rate is established in the steam generator, depending on the temperature conditions. This procedure can also be used with an organic working fluid.

[0033] In a further preferred embodiment of the steam generation system, a flow control device is arranged on the circulation loop to regulate the flow of liquid working fluid from the separation chamber. It is particularly preferred that the flow control device includes a control valve. The vertical arrangement of the heat exchanger tubes makes it possible for the control valve to be sufficient to regulate the circulation rate, eliminating the need for a pump. Due to the vertical arrangement of the heat exchanger tubes, the difference in density between the working fluid in the circulation loop and the working fluid in the heat exchanger tubes is sufficient to generate a flow (natural circulation). Therefore, in a preferred embodiment, a control valve is arranged on the circulation loop as the flow control device, but no pump is required.

[0034] In an alternative embodiment, the flow control device of the circulation system has at least one pump, which is preferably speed-controlled.

[0035] The flow rate control unit can be located upstream or downstream of the mixing point.

[0036] In a further particularly preferred embodiment, the steam generation system is configured such that a first section of the transfer tubes serves as an economizer (preheating section) for the working medium, and a downstream section thereof serves as an evaporator for the working medium. Advantageously, the steam generation system is configured such that the working medium evaporates within the length of the heat exchanger's transfer tubes. As explained above, the working medium is supplied at the bottom and rises through vertical transfer tubes (preheating and evaporator tubes). The working medium partially evaporates within the length of the transfer tubes. In the separation chamber, the gaseous phase (e.g., steam) is separated from the liquid phase (e.g., water). The lower part of the transfer tubes serves as heat exchange surfaces and thus as an economizer, while the upper part serves as an evaporator.The transition is fluid and variable, depending on the operating point.

[0037] In a further preferred embodiment, a device for heating the working medium, preferably an electric heater or electric heating elements, is provided in the inlet area. This heating device can be used to preheat the working medium (e.g., water) in the steam generation system. An external heater with a separate jacket, connecting pipes, pumps, etc., are no longer required.

[0038] Furthermore, in a preferred embodiment, the steam generation system is configured for heat transfer media with a melting point above 60°C. It is further preferred that the steam generation system is configured for a heat transfer medium selected from the group consisting of molten salts, molten metals, and molten sulfur, preferably a molten salt. Molten salts can be used as liquid heat transfer media in the temperature range of 180 to 550°C. Heat transfer media with a melting point of approximately 130 to 240°C are preferred, preferably mixtures of alkali nitrite and / or nitrate. The use of molten salts is advantageous because they have excellent heat transfer properties, the systems operate without pressure, and the heat transfer medium is non-flammable compared to thermal oils.

[0039] In a further preferred embodiment, the steam generation system is configured such that the working medium is water or an organic medium including the respective gaseous phase. Particularly preferred is the use of water, including its gaseous phase, as the working medium.

[0040] In In another preferred embodiment of the steam generation system, the transfer tubes arranged inside the outer shell of the heat exchanger are aligned at an angle of 0 to 20° to the vertical, preferably at an angle of 0 to 10° to the vertical and particularly preferably substantially vertically.

[0041] In In another preferred embodiment, the mixing point is arranged outside the inlet area of ​​the heat exchanger. This makes it possible to monitor the temperature of the working medium before it enters the steam generation system.

[0042] InIn an alternative embodiment of the steam generation system, the mixing point is arranged within the inlet area of ​​the heat exchanger.

[0043] In In another preferred embodiment of the steam generation system, a temperature measurement is arranged which detects the temperature of the working medium downstream of the mixing point.

[0044] In further preferred embodiments, this is designed for a transmitted power of 1 and 30 MW th, preferably 0.1 and 100 MW th.

[0045] The steam generation system according to the invention can be operated such that the minimum operating temperature of the working medium at the inlet to the heat exchanger is above the melting point of the heat transfer medium (e.g., 135°C for molten salts). Therefore, a minimum inlet temperature of the working medium is maintained. Thus, the steam generation system is preferably configured such that the temperature of the working medium entering the inlet region of the heat exchanger is kept above the melting point of the heat transfer medium. The heat transfer medium leaves the heat exchanger at the lowest possible level to ensure safe operation above its freezing / melting point. For this purpose, the steam generation system preferably includes a recirculation loop. The recirculation loop is arranged around the heat exchanger to return heated working medium to the inlet region of the heat exchanger.

[0046] The inlet temperature to the heat exchanger is maintained at the desired level to avoid the risk of the heat transfer medium freezing by adjusting the amount of circulated working medium accordingly.

[0047] The steam generation system according to the invention can be part of a system in which the heat transfer medium is electrically heated. Alternatively, the heat transfer medium can be heated partially or completely with heat from waste heat recovery. Preferably, the steam generation system is part of a heat storage system. Alternatively, the heat transfer medium can be heated directly, e.g., partially or completely with heat from waste heat recovery. In a preferred application, the steam generation system according to the invention is used for industrial applications with heat demand. Alternatively, it is used for steam generation for power generation or combined heat and power generation.

[0048] Furthermore, the invention provides a method for generating a gaseous working medium using the steam generation system according to the invention. Description of the characters

[0049] Figure 1 shows an exemplary embodiment of a steam generation system 100 according to the present invention. Figure 2 shows schematically how the steam generation system according to the invention 100 It can be integrated into larger systems.

[0050] The Figure 1 shows an example of a steam generation system 100 according to the present invention. It serves to generate a gaseous working medium. 403 from a liquid working medium 400, 401, 402 and features a heat exchanger 200 and a separation chamber 280 up. The heat exchanger 200 It has an outer shell with an inlet. 500 and an outlet 501 for a heat transfer medium. The outer shell of the heat exchanger.200 defines the interior of the heat exchanger 200. Inside the heat exchanger 200 are transfer pipes 210 arranged to serve the working medium 401 from an entrance area 205 to an exit area 215 of the working medium towards the separation chamber 280 to lead.

[0051] The heat exchanger 200 The separation chamber serves to transfer heat from the heat transfer medium to the working medium. 280 serves to gaseous 403 and liquid 402 to separate the working medium from each other and discharge it separately. The gaseous working medium 403 can be directed into a turbine for power generation, while the liquid working medium 402 via a cycle 404 to the entrance area 205 is returned to the heat exchanger.

[0052] The interior of the heat exchanger 200is from the entrance area 205 and from the exit area 215 for the working medium, each with a pipe plate connected to the outer casing 230, 220 separated.

[0053] Furthermore, those within the outer shell of the heat exchanger 200 arranged transfer pipes 210 Essentially straight and, in the example shown, vertically aligned.

[0054] The separation chamber 280 is above the heat exchanger 200 arranged and the working medium flows in the transfer tubes 210 of the heat exchanger 200 from bottom to top towards the separation chamber 280. In the example shown, the interior of the separation chamber 280 only through the pipe plate 220 from the interior of the heat exchanger 200 separated.

[0055] Inside the separation chamber 280Can a tube bundle for a heat transfer medium be used to superheat the gaseous working medium? 403 arranged (not shown).

[0056] In the illustrated embodiment, the heat transfer medium flows in a cross-counterflow to the flow direction of the water in the transfer tubes. 210 The flowing working medium is guided through this process. The transfer tubes are designed for this purpose. 210 equipped with guide plates (shown schematically here).

[0057] As explained above, a cycle 404 arranged, the liquid working medium from the separation chamber 280 to the entrance area 205 of the heat exchanger 200 This is further reduced by the amount from the separation chamber. 280 returned working medium at the mixing point 130 with fresh working medium 400 mixed. On the circuit 404 is a flow control device 120arranged to regulate the flow of liquid working medium from the separation chamber 280 It serves this purpose. Preferably, the flow rate control device includes 120 A control valve. The vertical arrangement of the transfer pipes. 210 The heat exchanger typically allows the circulation rate of the working medium to be controlled by a regulating valve. 120 to regulate the flow rate so that a pump is usually not necessary. The flow rate control unit 120 In the example shown, it is in the direction of flow in front of the mixing point. 130 and outside the entrance area 205 of the heat exchanger 200 arranged.

[0058] Furthermore, the circulation 404 a temperature measurement 140 arranged to control the temperature of the working medium downstream of the mixing point 130 The measured values ​​are recorded. Using these measurements, the mixing ratio of the freshly added working medium can be determined. 400lower temperature compared to that from the separation chamber 280 The temperature of the working medium entering the heat exchanger is adjusted using the returned liquid working medium of a higher temperature. 200 enters.

[0059] The steam generation system 100 It is advantageously operated in such a way that a first section of the transfer pipes 210 The system serves as a preheating section for the working fluid, and a downstream section of it acts as an evaporator for the working fluid. Thus, a portion of the working fluid evaporates within the path of the transfer tubes. 210. In the separation chamber 280 The gaseous phase (e.g., water vapor) is separated from the liquid phase (e.g., water). Thus, the lower part of the transfer tubes serves this purpose. 210 as economizer and the upper part of the transfer tubes 210 as an evaporator. Depending on the operating point, the transition is gradual and variable.

[0060] Figure 2 The possible integration of the steam generation system according to the invention is shown using an example. 100 into larger systems. Thus, the steam generation system according to the invention can be used in larger systems. 100 be part of a system in which a heat transfer medium is of a lower temperature 2' with electrical energy, heat from waste heat recovery or with solar thermal energy 5 in a heating system 6 is heated to transfer a heat transfer medium of higher temperature 2 to obtain. The heat transfer medium at a higher temperature 2 is used in the steam generation system according to the invention 100 for example saturated steam 4 , which has a pressure of 10 to 40 bar (corresponding to a temperature of approximately 180 to 250 °C), from feedwater 3, to generate a heat transfer medium of a higher temperature, preferably between 50 and 150 °C. 2 in the steam generation system 100absorbs some of the heat and is used as a heat transfer medium at a lower temperature 2 'recirculated. The steam generation system according to the invention 100 can be part of a thermal storage system that stores storage 1, 1' for the heat transfer medium at a higher temperature or for the heat transfer medium at a lower temperature. Reference symbol list

[0061] 1 Storage tank for higher temperature heat transfer medium 1' Storage tank for lower temperature heat transfer medium 2 Higher temperature heat transfer medium 2' Lower temperature heat transfer medium 3 Liquid working medium / feed water 4 Gaseous working medium / steam 5 Heat source 6 Heating device for heating the heat transfer medium 100 Steam generation system 120 Flow control unit 130 Mixing point 140 Temperature measurement 200 Heat exchanger 205 Inlet area (for working medium) 210 Transfer tubes (of the heat exchanger) 215 Outlet area (for working medium) 220 (Upper) tube plate 230 (Lower) tube plate 280 Separation chamber 400 Fresh working medium 401 Liquid working medium (in the inlet area before the heat exchanger) 402 Liquid working medium (in the separation chamber) 403 Gaseous working medium 404 Circulation 500 Inlet (for heat transfer medium) 501 Outlet (for heat transfer medium) 502 Interior of the heat exchanger (filled with heat transfer medium)

Claims

1. A steam generating system (100) for generating a gaseous or vaporous working medium (403) from a liquid working medium (400, 401, 402) comprising a heat exchanger (200) and a separation chamber (280), wherein the heat exchanger (200) has an outer shell with an inlet (500) and an outlet (501) for a heat carrier medium, and wherein the outer shell defines an inside space of said heat exchanger (200), wherein, inside the heat exchanger, transfer tubes (210) are arranged for conducting the working medium (401) from an entry area (205) to an exit area (215), wherein the heat exchanger (200) is configured to transfer heat from the heat carrier medium to the working medium, wherein the separation chamber (280) is configured to separate gaseous (403) and liquid (402) working medium from each other and to discharge them separately, wherein the inside space of the heat exchanger (200) is separated from the exit area (215) and the entry area (205), respectively, by a tube plate (220, 230) connected to the outer shell, the transfer tubes (210), arranged inside the outer shell of the heat exchanger (200), are essentially straight and oriented at an angle from 0° to 45° to the vertical, and the separation chamber (280) is arranged above the heat exchanger (200), and the heat exchanger (200) is configured to conduct the working medium in the transfer tubes (210) upwards from the bottom toward the separation chamber (280).

2. The steam generating system (100) according to claim 1, characterized in that the separation chamber (280) is designed as a separate container, wherein the steam generating system (100) is configured to supply said separate container with working medium via a feeding line from the exit area (215) of the heat exchanger (200).

3. The steam generating system (100) according to claim 1 or 2, characterized in that inside the separation chamber (280) a tube bundle for a heat carrier medium for overheating the gaseous working medium (403) is arranged.

4. The steam generating system (100) according to any one of claims 1 to 3, characterized in that the heat exchanger (200) is configured to conduct the heat carrier medium in counterflow or cross-counterflow to the direction of flow of the working medium flowing in the transfer tubes (210).

5. The steam generating system (100) according to any one of claims 1 to 4, characterized in that a circulation line (404) is arranged, configured to conduct liquid working medium out of the separation chamber (280), to mix it with fresh working medium (400) at a mixing point (130) and to conduct it back into the separation chamber (280) via the entry area (205) and the transfer tubes (210) of the heat exchanger.

6. The steam generating system (100) according to claim 5, characterized in that, on the circulation line (404), a flow rate control device (120) is arranged to regulate the flow rate of liquid working medium flowing out of the separation chamber (280).

7. The steam generating system (100) according to claim 6, characterized in that the flow rate control device (120) contains a control valve.

8. The steam generating system (100) according to any one of claims 1 to 7, characterized in that said steam generating system (100) is configured in such a way that a first section of the transfer tubes (210) serves as an economizer or as a preheating line, respectively, for the working medium, and a downstream section thereof as a vaporizer for the working medium.

9. The steam generating system (100) according to any one of claims 1 to 8, characterized in that said steam generating system (100) is configured in such a way that evaporation of the working medium occurs along the course of the transfer tubes (210) of the heat exchanger.

10. The steam generating system (100) according to any one of claims 1 to 9, characterized in that inside the entry area (205) a device for heating the working medium is provided, preferably electric heating rods.

11. The steam generating system (100) according to any one of claims 1 to 10, characterized in that it is configured for molten salt or molten metal, preferably for molten salt.

12. The steam generating system (100) according to any one of claims 1 to 11, characterized in that the working medium is water or an organic medium, including the respective gaseous phase, preferably water, including the gaseous phase of water.

13. The steam generating system (100) according to any one of claims 1 to 12, characterized in that the transfer tubes (210) arranged within the outer shell of the heat exchanger (200) are oriented at an angle from 0 to 20° to the vertical, particularly at an angle from 0 to 10° to the vertical, and preferably essentially vertically.

14. The steam generating system (100) according to claim 5 and any one of claims 6 to 13, if dependent on claim 5, characterized in that the mixing point (130) is arranged inside the entry area (205) of the heat exchanger (200).

15. The steam generating system (100) according to claim 5 and any one of claims 6 to 13, if dependent on claim 5, characterized in that the mixing point (130) is arranged outside the entry area (205) of the heat exchanger (200).

16. The steam generating system (100) according to claim 5 and any one of claims 6 to 15, if dependent on claim 5, characterized in that a temperature measurement (140) is provided that measures the temperature of the working medium downstream from the mixing point (130).

17. A method for generating a gaseous working medium by using the steam generating system according to any one of claims 1 to 16.

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