Offshore electrolysis system and method for operating offshore electrolysis system

Abstract

The invention relates to an offshore electrolysis system (100) comprising a wind power generation device (1) having a platform (3) and an electrolysis device (5) arranged on the platform (3), the electrolysis device being coupled to the wind power generation device (1) for supplying an electrolysis current, and a heat supply device (7) coupled to the electrolysis device (5), the heat supply device being designed to supply the electrolysis current to the wind power generation device (1) during shutdown operation. And heat can be transferred to the electrolysis equipment through the heat supply device (7), so that the temperature is kept above the lowest temperature. The invention also relates to a method for operating an offshore electrolysis system. In this case, during shutdown operation, heat is transferred to the electrolysis device (5) by means of the heat supply device (7), so that the temperature is maintained above the minimum temperature, and freezing of the water delivery components of the electrolysis device (5) is prevented.

Description

Technical Field

[0001] This invention relates to an offshore electrolysis system and a method for operating the offshore electrolysis system. Background Technology

[0002] An electrolysis device is a device that uses electric current to achieve the transformation (electrolysis) of substances. Various types of electrolysis devices exist depending on the different electrochemical electrolysis processes, such as those used for water electrolysis. To supply direct current for electrolysis, the electrolysis device is connected to a production capacity device, thus forming an electrolysis system in this combination. Typically, an electrolysis device has multiple electrolytic cells, thereby enabling large-scale electrolysis power for the transformation of electrochemical substances under appropriate design.

[0003] Currently, hydrogen is produced from water, for example, through proton exchange membrane (PEM) electrolysis or alkaline electrolysis. Electrolysis equipment uses electrical energy to produce hydrogen and oxygen from supplied water. This process takes place in an electrolytic reactor consisting of multiple electrolytic cells. Water is introduced as a reactant into the electrolytic reactor under DC voltage, and after flowing through the electrolytic cells, two fluid streams emerge, consisting of water and gas bubbles (O2 or H2).

[0004] Current research focuses on utilizing surplus energy from renewable energy sources to produce useful substances during periods of abundant sunshine and wind—when solar or wind power generation is above average. One such useful substance could be hydrogen produced through water electrolysis. Hydrogen can then be used to prepare so-called EE gases (renewable energy gases). EE gases are combustible gases obtained from renewable energy sources using electricity.

[0005] Hydrogen is a particularly environmentally friendly and sustainable energy carrier. It has the unique potential to achieve carbon dioxide-free energy systems, transportation, and most chemical industries. To achieve this, hydrogen must not be derived from fossil fuels but must be produced using renewable energy sources.

[0006] Wind power is a source of renewable energy. Especially with offshore wind power systems, large electrical outputs can be achieved. However, a challenge lies in overcoming the long distances between the wind turbines and the load. Therefore, energy should be delivered to the load with as little loss as possible. Hydrogen is very suitable as a transmission medium. For example, hydrogen can be transported in gaseous form through pipelines. An added advantage is that the pipelines guiding the hydrogen can also function as energy storage devices, as the internal pressure can vary within a certain range. Based on this idea, it is significant to directly produce hydrogen on-site at the energy acquisition site, i.e., to place offshore electrolysis equipment directly on or adjacent to offshore wind power systems. Therefore, current research focuses on offshore electrolysis systems, where the electrolysis equipment is directly mounted on the platform of the offshore wind power system. Here, the wind power system can be connected to the electrolysis equipment, forming a basically self-sufficient, nearly grid-independent electrolysis system, specifically designed for operation on isolated offshore islands.

[0007] Ideally, electrolysis systems, including combinations of wind power generation units and electrolysis equipment, can be constructed entirely without auxiliary connections to the power grid and are specifically designed for island operation. This is particularly suitable for electrolysis systems built in offshore areas to avoid long-distance connection paths to the public power grid in coastal regions. Here, electrolysis equipment equipped with multiple electrolyzers is ideally placed directly near renewable energy sources, namely wind power generation units, thereby reducing or avoiding transformer losses and line losses. Therefore, there is currently significant research and development on offshore electrolysis systems equipped with electrolysis equipment, which are directly installed on platforms with offshore wind power generation units. For this type of coupling, whether "onshore" or "offshore," the equipment can operate without grid connection. However, during periods of no wind, weak winds, or, for example, scheduled maintenance of wind turbines, power cannot be supplied by generators or the grid without grid coupling.

[0008] In offshore electrolysis systems, it is crucial to prevent corrosion of the electrolysis equipment, as the presence of seawater leads to a significantly higher corrosion rate, jeopardizing the long-term uninterrupted operation of the equipment. In principle, offshore electrolysis equipment can be equipped with electrolytic cells housed in enclosed hulls, i.e., containers. This provides a degree of protection against external environmental influences. However, for operational needs, the electrolytic cells must be cooled during normal operation to continuously release the waste heat generated during electrolysis into the surrounding environment. Overall, thermal management of offshore electrolysis equipment presents significant challenges compared to onshore systems, specifically in terms of both the required cooling during normal operation and maintaining minimum temperatures during long-term shutdowns. In the latter case, especially during winter months when there is no wind or sunlight and wind power generation is shut down, it is essential to ensure adequate freeze protection for the water-containing electrolytic cells. Therefore, considering the cooling requirements of offshore electrolysis equipment during normal operation, at least one enclosed container structure is necessary—that is, a sealed structure to protect the electrolyzer. This requires preventing both overheating and failure of the electrolyzer, as well as avoiding harmful corrosion caused by exposure to marine salt. Consequently, in offshore electrolysis equipment, the interface and exchange between the electrolyzer and the environment are ultimately unavoidable, in order to properly dissipate the heat generated during normal operation and ensure safe equipment operation.

[0009] Therefore, to protect the electrolyzer from environmental impacts, as mentioned above, it requires an enclosed structure, such as a container. PEM (proton exchange membrane) water electrolyzers must also operate using deionized water, especially high-purity water. Simultaneously, the internal temperature of the container must generally not fall below approximately 5°C. Otherwise, the water-containing supply components may freeze, causing the entire system to shut down. This would contradict the initial intention of offshore electrolysis systems with wind power generation to operate with minimal maintenance and self-sufficiency without grid coupling.

[0010] When the external temperature outside the encapsulation structure is below 5°C, heat will be transferred from the inside of the container to the outside through thermal conduction, convection, and radiation. At a minimum design temperature of -20°C in the external area, approximately 1 to 2 kW of heat energy is lost per hour from the corresponding container of the electrolysis equipment. However, heat loss also depends on the container's own insulation. Heat must be replenished to the container to maintain a relatively constant temperature of 5°C and reliably prevent freezing damage. During normal operation of the electrolysis equipment, i.e., when the electrolysis current is supplied by the wind power generation unit, the temperature inside the container can be maintained even in extremely low ambient temperatures because the electrolysis process provides sufficient waste heat.

[0011] Conversely, if no renewable electricity is available in extremely cold weather, for example due to lack of wind, or if wind power generation equipment needs to be shut down for possible unexpected maintenance, then other means must reliably provide the thermal energy required to maintain the temperature of the electrolysis equipment. Otherwise, the electrolyzers will face irreversible damage due to freezing, and the electrolytic cells installed in the equipment may even be completely rendered unusable. The water supply pipes between the containers and encapsulation structures must also be kept above the minimum temperature to prevent freezing. This also requires energy, which must be provided by other energy sources when there is no wind.

[0012] Existing solutions include using and configuring appropriately designed battery energy storage devices within the electrolysis system. These devices provide electrical power to maintain electric heating and temperature control. However, this approach has significant drawbacks. Firstly, the battery pack capacity is limited; secondly, installation space on offshore platforms is significantly limited. In practice, for current applications on offshore wind power platforms, a relatively high battery capacity of at least 100 to 150 kWh is required to ensure temperature maintenance during extended shutdowns. This appears uneconomical given current battery technology. Especially at cold ambient temperatures, cold conditions weaken battery performance. Low temperatures increase electrolyte viscosity and make it more difficult to penetrate, resulting in fewer ions reaching the positive electrode and a sharp drop in battery power. Low temperatures also significantly slow down processes within the battery, causing faster wear than normal. So-called battery energy storage systems (BESS) also suffer from high cost, large size, and heavy weight. Therefore, there is an urgent need for other, superior solutions for temperature maintenance during shutdowns of offshore electrolysis systems.

[0013] Another technically simpler solution is to integrate a diesel generator on the offshore platform for emergency power supply and heating. However, this solution has the drawback that the diesel fuel needs to be replenished regularly, thus failing to achieve the fundamental concept and goal of developing a reliable, CO2-free offshore electrolysis system. Summary of the Invention

[0014] Therefore, the object of this invention is to provide a marine electrolysis system that enables safe and environmentally friendly operation, while also being designed to be as self-sufficient and low-maintenance as possible. Another object is to provide a method for operating the marine electrolysis system.

[0015] According to the present invention, the objectives proposed regarding the offshore electrolysis system are achieved by an offshore electrolysis system comprising a wind power generation device having a platform and electrolysis equipment arranged on the platform, the wind power generation device being connected to the electrolysis equipment to supply electrolysis current, and the offshore electrolysis system further comprising a heating device coupled to the electrolysis equipment, the heating device being designed to transfer heat to the electrolysis equipment during shutdown operation, thereby maintaining the temperature above a minimum temperature.

[0016] According to the present invention, the objective proposed regarding the operation method of the marine electrolysis system is achieved by the following operation method of the marine electrolysis system, wherein during shutdown operation, heat is transferred to the electrolysis equipment by a heating device, thereby maintaining the temperature above the minimum temperature and preventing the water supply components of the electrolysis equipment from freezing.

[0017] The following advantages and preferred embodiments of the marine electrolysis system can be meaningfully applied to the operation method of the electrolysis system.

[0018] This invention is based on the understanding that the increasing number of installed, higher-power, grid-independent offshore wind turbines and their ever-increasing power generation require correspondingly higher-power electrolysis equipment. Therefore, it is anticipated that the power levels and number of offshore electrolysis systems will increase significantly in the future.

[0019] The increasing demands for safe and environmentally friendly operation in marine environments must be considered. As efforts to scale up offshore electrolysis systems to larger scales in the open ocean focus, the issue of achieving as much self-sufficiency as possible—that is, independent of the power grid and utilizing 100% renewable wind energy for hydrogen production in isolated island environments—has become a key focus, in addition to the environmental compatibility of such systems. Here, from an environmental perspective, operation with the lowest possible impact must be ensured. Therefore, providing a self-sufficient solution for reliably maintaining the temperature of the water delivery components, especially the particularly sensitive submerged electrolysis cells of PEM electrolysis equipment, is crucial, particularly in cases of shutdown operation due to wind power failure and interruption of electrolysis current. With the solution of this invention, heating and temperature maintenance are reliably guaranteed, even during winter months when there is no wind or sunlight and low ambient temperatures pose a risk of freezing, without concern about the failure or damage of water delivery components. This invention employs a heat preservation scheme in the offshore electrolysis system, which possesses high reliability and inherent fail-safe characteristics under harsh weather conditions and operating conditions. This provides a virtually maintenance-free offshore electrolysis system that reliably mitigates the risk of freezing damage to the water supply components of the electrolysis equipment, particularly the electrolyzers and electrolytic cells. This results in a long service life and ensures immediate availability and operational readiness for resuming normal operation after downtime.

[0020] The marine electrolysis system of this invention advantageously identifies and overcomes, for the first time, the shortcomings of conventional heating schemes in grid-independent electrolysis systems. As previously mentioned, conventional heating schemes use large-capacity battery packs or even diesel generators mounted on the platform to heat the electrolysis equipment, as needed. These schemes are not only extremely environmentally unfavorable but also expensive and cumbersome to maintain. In contrast, the heating system can ensure temperature maintenance for several days even in windless and sunless conditions, where heat transfer can be regulated to maintain the required minimum temperature. Therefore, this heating system can be tailored to the needs of the electrolysis equipment, matching the minimum heat emission and the minimum heat consumption for maintaining the temperature.

[0021] In a particularly preferred design of an offshore electrolysis system, the electrolysis equipment includes an electrolytic cell arranged in a container and a heat exchanger designed to remove process heat from the electrolysis process from the container during normal operation.

[0022] This advantageously allows waste heat generated by the electrolysis process during normal operation to be used as needed for temperature maintenance during shutdown, rather than simply being released into the environment. Typically, during electrolysis operation, process heat is released into the environment from containers surrounding the electrolyzer and protecting it from weather influences and salt intrusion. Currently, heat exchangers are advantageously designed to selectively transfer process heat from electrolysis to the heating system as needed, particularly for storing heat and maintaining it for subsequent temperature maintenance. Therefore, process heat is not released, or at most partially released, into the surrounding environment.

[0023] Simultaneously, during normal operation, heat exchangers are used to assist in cooling the container and the electrolytic cell containing numerous electrolytic cells. For this purpose, the heat exchanger can, for example, be connected to and thermally coupled to the coolant circuit driven by the coolant pump of the electrolytic cell on the primary side, thereby enabling targeted heat absorption, release, and subsequent utilization in the heating system on the secondary side of the heat exchanger. This advantageously enables the safe and environmentally friendly operation of a marine electrolysis system employing a closed container structure, which has an electrolytic cell (e.g., a PEM electrolytic cell for hydrogen production) arranged within the container and a coolant pump arranged within the container or tightly flanged to the container. In the latter case, a shell unit is formed between the container and the flanged-connected coolant pump, thus the coolant pump is also understood to be arranged within the container. Through a closed cooling circuit, heat can be absorbed from the process heat generated by electrolysis at the equipment via the heat exchanger within the container. Multiple heat exchangers can also be provided, with each specially configured heat exchanger being part of the heating system.

[0024] In another preferred embodiment of the marine electrolysis system, the heating device has a heat pump coupled to a heat storage device.

[0025] This allows heat stored in a heat storage device to be extracted by a heat pump and then selectively transferred to the frost-prone components of the electrolysis equipment via a heat exchanger. This is particularly useful during shutdown operations where there is a significant risk of freezing, where heat is provided from the heat storage device to maintain the temperature above the required minimum.

[0026] In a particularly preferred embodiment of the marine electrolysis system, the heating device has a heat pump with a deep probe designed to extract heat from seawater.

[0027] This provides a particularly advantageous possibility for reliably protecting offshore electrolysis systems not coupled to the power grid from freezing damage when the external temperature above the water surface is below 5°C. Heat can be supplied to the electrolysis equipment, especially the freezing-prone electrolyzers, via a heat pump equipped with a deep-sea probe that uses deep seawater as a heat storage device.

[0028] For this purpose, a small battery storage device with a limited electrical capacity is preferred, used solely to drive the heat pump. A capacity far below 50 kWh is sufficient; typically, a capacity in the range of 20-30 kWh is enough to heat multiple electrolyzers, each housed in a corresponding number of containers on an offshore platform. A significant advantage is that the required capacity is far less than the heat needed to maintain the temperature, as the water temperature in the deep sea remains above 0°C even in winter. According to the working principle of heat pumps, the smaller the temperature difference between the energy source and the required usable heat, the lower the required driving power. This results in energy savings and cost advantages compared to pure electric heating with large battery packs or heating via diesel generators. For example, a water-water-heat pump (WWWP) can be used to extract heat from deep seawater as a heat storage device. Alternatively, based on the working principle of heat pumps, a refrigerant can be used instead of water as the working medium in the pipeline of the deep probe, circulating in a closed loop. With a typical coefficient of performance (COP) of at least 4 to 5, at least four to five times the input power is provided as available thermal power, with this gain derived from ambient heat extracted from the thermal storage unit. The COP is highly dependent on both low and high temperature levels, which are very close in offshore applications during shutdown operation of the offshore electrolysis system.

[0029] In a particularly preferred embodiment of the offshore electrolysis system, the heating device is arranged on the tower of the wind power generation unit, wherein the deep probe is immersed in seawater.

[0030] Mounting and securing a heating unit with a deep-sea probe to the exterior of the wind turbine tower offers the additional advantage of eliminating the need for additional structural space on the platform. Furthermore, securing and oriented the unit on the tower is structurally straightforward and presents no static challenges. Operational advantages are particularly pronounced as the deep-sea probe can be vertically and unobstructedly immersed and positioned at the seawater depth set for the operating temperature. Here, the heating unit extends at least partially above sea level, allowing for thermal coupling and heat transfer to the electrolysis equipment, approximately at the height of the equipment positioned on the platform, via a heat exchanger.

[0031] In another advantageously designed offshore electrolysis system, the heating device has a heat storage tank that is designed to be heated by the waste heat generated during the electrolysis process during normal operation, and to transfer the heat stored in the heat storage tank to the electrolysis equipment during shutdown.

[0032] This provides another feasible solution to reliably protect off-grid coupled offshore electrolysis systems from freezing damage when the external temperature above the water surface is below 5°C. The working principle involves supplying heat energy to the electrolysis equipment via a heat pump, which uses a dedicated thermal storage unit as a heat reserve. This implementation can be used as an alternative to or supplement to heating systems with deep-sea probes that utilize seawater as an unlimited heat reserve. In this implementation, the thermal storage unit is advantageously mounted as a component of the offshore electrolysis system, for example, on a platform or in a container.

[0033] In particularly advantageous improvements and designs for offshore electrolysis systems, the heating unit has a heat storage device, which is constructed within the tower of the wind power generation unit.

[0034] In this way, the thermal storage device, for example, can be constructed or fabricated from a cavity within the tower of the wind turbine itself, serving as a corresponding thermal storage unit. Thus, the thermal storage device is preferably embedded deep within the tower, below the water surface, to fully utilize the relatively constant ambient temperature underwater. The structure enclosed within the tower also advantageously provides insulation for the thermal storage unit. Simultaneously, installing the thermal storage unit in a cavity deep within the tower has virtually no impact on the tower structure or the mechanical stability of the nacelle containing the wind turbine. Furthermore, it provides or fully utilizes previously unused structural space for the thermal storage unit. The thermal storage unit does not require any area or structural space on the platform itself. The platform can be used for electrolysis equipment and its components, without being limited by the heating system.

[0035] In an advantageous embodiment, the heat storage device in the offshore electrolysis system has a container into which the heat storage medium is introduced.

[0036] A heat storage device with a container including a heat storage medium can, for example, be constructed or installed in the base area below the electrolysis equipment or within the base of the tower in a geodesic context. The heat storage device can be implemented, for example, as an isolated water tank as a container or as a cavity-type container with salt as the heat storage medium. The corresponding heat storage medium is introduced into the container and at least partially or completely fills the container.

[0037] Advantageously, during normal operation of the electrolysis equipment, waste heat generated by the electrolytic cell is used to load heat onto the heat storage medium. When the entire equipment is shut down, the heat energy stored in the heat storage device can be transferred back to the electrolysis equipment through pipelines as needed, thus preventing freezing damage. A certain amount of stored electrical energy is also provided for the operation of the heat pump to circulate and maintain heat exchange. Based on the expected high coefficient of performance at the temperature level, only a much smaller amount of electrical energy needs to be stored than is required to maintain the temperature. This again achieves energy savings, and brings cost advantages because the size of the backup battery used for shutdown operation can be designed to be significantly smaller.

[0038] In a particularly preferred embodiment of the marine electrolysis system, water and / or materials with low melting points between approximately 30°C and 70°C that store latent heat are used as the heat storage medium, especially salt, salt mixtures, or paraffin.

[0039] Water is already present in offshore electrolysis systems, and it is generally considered an excellent heat storage medium due to its high specific heat capacity. Water is also easy to handle and particularly environmentally friendly. Therefore, water-based heat storage devices are advantageously applicable and very easy to operate. However, materials that store latent heat also offer significant advantages as heat storage media, especially in terms of energy density and the temperature levels achievable during heat release. Furthermore, latent heat can be stored for extended periods. Therefore, designing heat storage devices as latent heat storage devices is particularly advantageous for applications in offshore electrolysis systems.

[0040] Latent heat storage, also known as phase change or PCM storage, is a special type of thermal energy storage that stores most of the heat energy supplied to it as conversion enthalpy (formerly known as latent heat), for example, in solid-liquid phase changes. The stored energy is latent because the temperature of the substance will not rise further even if heat is supplied until the phase change is complete. Therefore, latent heat storage can store large amounts of heat within a small temperature range near the phase change point, surpassing energy storage devices that utilize the heat energy of only one substance, such as hot water storage devices. Since a wide range of substances with different melting points are suitable for use as phase change materials (PCMs), this technology can, in principle, cover a wide range of energy storage applications from low-temperature to high-temperature thermal energy storage.

[0041] In advantageous implementation structures and designs of marine electrolysis systems, sodium acetate trihydrate, disodium hydrogen phosphate, or a supersaturated mixture of the above substances is introduced into the container as a material for storing latent heat.

[0042] Material for storing latent heat is introduced into the container, thus providing a heat storage device with a high latent heat capacity. Advantageously, this latent heat storage device can be charged in a particularly simple manner during normal operation using waste heat generated from the electrolysis process. However, instead of or in addition to loading waste heat from electrolysis, electrically operable heating elements, such as resistance heating elements, can be used, with the latent heat storage device arranged within and surrounded by the latent heat storage material. Thus, electric heating can be achieved as needed, and phase change can be realized with extremely high thermal power, where the required heating energy is temporarily drawn, for example, directly from the generator side of a wind power plant. This allows for rapid charging of the heat storage device, which is particularly advantageous in situations where there may be a recurrence of no light or wind. Temperatures higher than those from the waste heat from electrolysis can also be achieved using this heating element, thus allowing for the application of materials with higher conversion temperatures within the container as needed. Heating energy can also be drawn from rechargeable backup batteries or from renewable energy sources, such as photovoltaic devices.

[0043] Advantageously, an activation device is provided in the heat storage device designed as a latent heat energy storage device, which can induce crystallization and release the stored latent heat.

[0044] The activation device is designed to selectively introduce pressure pulses or pressure waves as triggers for crystallization in supersaturated solutions into materials that have been heated and store latent heat. This can be achieved, for example, by using a small piezoelectric actuator with a piezoelectric element or a flip-up metal plate to locally trigger pressure waves within the material storing latent heat, thereby releasing and exothermic the latent heat. The principle is that the pressure pulse releases microscopic crystal nuclei, which initiate crystallization and simultaneously release heat.

[0045] Another aspect of the invention relates to a method for operating a corresponding marine electrolysis system. Here, during shutdown operation, heat is transferred to the electrolysis equipment via a heating device to maintain the temperature above a minimum and prevent freezing of the water supply components of the electrolysis equipment.

[0046] This method can be advantageously implemented autonomously, meaning that no grid connection to the electrolysis system is required. More precisely, the electrolysis system is advantageously designed for islanded operation, thereby ensuring temperature maintenance and preventing freezing even during periods of no light and no wind.

[0047] In this method, temperature maintenance is preferably initiated when the external temperature is below 5°C, wherein stored heat is extracted from the heat storage device and transferred to the water supply component of the electrolysis equipment, thereby achieving antifreeze protection.

[0048] Heat exchangers are used to couple or transfer the heat stored in the heat storage unit to the freeze-prone water supply components of the electrolysis equipment. These heat exchangers can also use the waste heat generated by electrolysis to heat the heat storage unit during normal operation, meaning they can operate in both directions. They can also be used to cool the electrolysis equipment by selectively extracting process heat.

[0049] Therefore, in a preferred embodiment of the method, during normal operation, the wind power generation device supplies electrolytic current to the electrolysis equipment, wherein the process heat generated by the electrolytic cell is exported through a heat exchanger and transferred to a heat storage device.

[0050] In another preferred embodiment of the method, process heat is extracted from the electrolytic cell and transferred to the heat storage medium, thereby loading the heat storage device.

[0051] In a particularly preferred embodiment of the method, the heat storage device is heated by transferring heat to a material storing latent heat, particularly salt, wherein the material is at least partially liquefied. Attached Figure Description

[0052] The implementation methods, features, and / or advantages of the marine electrolysis systems described herein are similarly applicable to the operating methods, and vice versa. Embodiments of the invention are described in detail below with reference to the accompanying drawings. The drawings are shown in a schematic and highly simplified form:

[0053] Figure 1 An offshore electrolysis system with electrolysis equipment and wind power generation device is shown;

[0054] Figure 2 A schematic side view of an offshore electrolysis system including a heating unit with a heat pump is shown.

[0055] Figure 3 A schematic side view of the marine electrolysis system of the thermal storage tank is shown. Detailed Implementation

[0056] The same reference numerals in the accompanying drawings have the same meaning.

[0057] Figure 1 The image shows an offshore electrolysis system 100. The offshore electrolysis system 100 includes an electrolysis unit 5 and a wind power generation device 1, the wind power generation device having a tower 19, such as... Figure 1 As shown in the upper right section. In the lower region of tower 19, a platform 3 is fixed on the tower above sea level 25 (see...). Figure 2 The platform was specifically designed and constructed to house the various equipment components required for the intended operation of the offshore electrolysis system 100. These equipment components are located in... Figure 1 The lower part is shown as an example with an enlarged illustration:

[0058] An electrolysis unit 5 is installed on platform 3 and is systematically connected to the wind power generation unit 1 to form an offshore electrolysis system 100. For this purpose, containers 9 are specifically arranged on platform 3, housing electrolysis elements (not shown in detail), such as individual electrolytic cells, thereby protecting the particularly sensitive functional components of the electrolysis unit 5 from weather effects. Each container 9 on platform 3 includes and protectively houses control devices 27 or so-called "auxiliary equipment" components. Containers 9 are selected here and are typically dedicated to individually housing and operating these control devices 27 and any other possible auxiliary systems for the electrolysis unit 5. The electrolytic cells for electrochemical conversion are arranged in containers 9 specifically designed for this purpose. Other components or equipment components housed in containers 9 may also be storage containers for reactant water in the electrolytic cells or similar items.

[0059] In this embodiment, the wind power generation device 1 preferably does not have a grid connection or grid coupling, but instead directly supplies power to the electrolysis equipment 5 using the absorbed wind energy within an autonomously operating offshore electrolysis system 100. The electrolysis equipment is configured to produce, preferably, green hydrogen, from water electrolysis. Therefore, the offshore electrolysis system 100 is configured for isolated island operation independent of the power grid and is suitable for autonomous operation far from the coast. The wind power generation device 1 is therefore an offshore wind turbine. Figure 1 and Figure 3 Unlike the illustrations, the facilities proposed according to the present invention for improving the heating of the offshore electrolysis system 100 can also be applied to "onshore" equipment without any problems.

[0060] The strategy of supplying the electrolysis equipment 5 using multiple containers 9, preferably ISO containers, advantageously ensures a simple maintenance and repair process, while protecting equipment components from the effects of climate and weather, as well as corrosion and harmful mechanical effects during operation. The electrolysis system 100 faces particular risk in situations where the wind power generation unit cannot generate electricity for electrolysis under freezing conditions, thus posing an emergency risk of freezing of the water supply system of the electrolysis equipment 5, especially during prolonged periods of darkness and windlessness during shutdown operations, accompanied by the risk of freezing.

[0061] The present invention addresses the aforementioned problems by means of a heating device 7 advantageously integrated into the electrolysis system 100. The heating device 7 is coupled to the electrolysis equipment 5 and is designed to transfer heat to the electrolysis equipment 5 during shutdown operation, thereby maintaining the temperature of the water supply system above a minimum temperature. Figure 2The diagram illustrates a schematic side view of an offshore electrolysis system 100 equipped with a corresponding heating device 7. The heating device 7 is fixed to the tower 19 of the wind turbine 1, approximately at the height of the platform 3, and extends deep down along the tower 19 into the underwater region 31 below sea level 25. The tower 19 is securely anchored to the seabed 35 via a base 33. The heating device 7 includes a heat pump 13 with a deep-sea probe 17, thereby using seawater as a heat storage device 15. Thus, during shutdown operation, heat can be extracted from the seawater serving as the heat storage device 15 in the deep sea area via the deep-sea probe and transferred via the heat pump 13 to the electrolysis unit 5 through the heat exchanger 11. The deep-sea probe 17 is positioned at a depth at a favorable temperature level for the seawater, with a maximum temperature above approximately 5°C. Because heat pump 13 has an advantageous coefficient of performance in operating environments with only a few degrees Celsius (e.g., 1-5°C) of temperature difference, only a small-capacity rechargeable battery pack, typically 25-30 kWh, is needed in container 9 to electrically drive the heat pump. Thus, even during long periods of winter with no light or wind for several days, the temperature of the electrolysis unit 5 can be maintained. This provides a particularly advantageous solution for reliably protecting the offshore electrolysis system 100, which is not coupled to the power grid, from freezing damage when the ambient temperature above the water surface is below 5°C. Heat pump 13, equipped with a deep-sea probe 17 and using deep seawater as a heat storage device 15, can very efficiently supply heat to the electrolysis unit 5, especially to the freeze-prone electrolytic cells in container 9. Electrolysis unit 5 has electrolytic cells arranged in container 9, whose waste heat generated during normal operation serves as process heat and can also be removed from container 9 via heat exchanger 11 or a specially designed cooling circuit when needed. Therefore, heating device 7 can also be used to cool electrolysis unit 5 during normal operation when needed. The upper part of the heating device 7 can be structurally integrated with the heat exchanger 11 in the container 9.

[0062] The following is combined Figure 3 Another embodiment of the present invention will be described below. Figure 3A schematic side view shows an advantageous configuration of an offshore electrolysis system 100 with an integrated heating unit 7. Here, the heating unit 7 includes a heat storage device 21 serving as a heat storage device 15. The heat storage device 21 is constructed as a container or cavity within the tower 19 of a wind power generation unit, in this embodiment extending below sea level into a base 33, and has a corresponding heat storage volume. The container of the heat storage device 21 is filled with a heat storage medium 23. The heat storage medium 23 can be, for example, water or a material having a low melting point between about 25°C and 80°C, particularly between 30°C and 70°C, storing latent heat. Salt, supersaturated salt solutions, or paraffin can be used as the heat storage medium 23 for storing latent heat. Practice has shown that salt solutions based on sodium acetate trihydrate, disodium hydrogen phosphate, or mixtures thereof, in the form of supersaturated solutions in the container, are advantageous because they enable the latent heat stored in the heat storage device to have a high energy density when releasing heat on demand at high temperatures. To release heat from the material storing latent heat, a [further details are needed]. Figure 3 An activation device, not shown in detail, can induce crystallization and release the stored latent heat. The activation device may include, for example, a pressure pulse generator capable of piezoelectric or mechanical activation, thereby forming and activating crystal nuclei. An upper heat exchanger 11 and a lower heat exchanger 11 are connected to heat exchange line 37, allowing the heat exchange medium (e.g., water) to circulate in the loop via heat pump 13. Here, the lower heat exchanger 11 is immersed in the heat storage tank 21 and surrounded by the heat storage medium 23. The upper heat exchanger 11 is coupled to the electrolysis device 5. During normal operation of the electrolysis system 100, the heat storage tank 21 can be heated, for example, by transferring process heat from the electrolysis device 5 to the heat exchange medium via the upper heat exchanger 11. The heat exchange medium releases heat to the heat storage medium 23 in the container. In addition to extracting process heat from the electrolysis device 5, resistance heating elements can be provided to achieve higher storage temperatures and thus higher stored energy when needed, or to load materials storing latent heat at higher transition temperatures for short periods. Therefore, for example, the resistance heating element can be placed directly into or immersed in the heat storage medium 23. During normal operation, the resistance heating element is powered by the wind power generation device 1 to charge the heat storage device 21.

[0063] During the shutdown operation of the electrolysis system 100, if there is a risk of freezing and the wind power generation unit malfunctions, the heat or latent heat stored in the thermal storage tank 21 can be used for long-term temperature maintenance, thereby reliably preventing the freezing of the sensitive water supply components of the electrolysis equipment 5. This specifically involves the protection of components, such as the electrolytic cells with numerous electrolytic cells, as well as the piping of the water-filled gas separator, auxiliary systems, and the hydraulic topology of the electrolysis equipment 5. Therefore, in the operation method of the offshore electrolysis system 100, during shutdown operation, the stored heat is transferred to the electrolysis equipment 5 via the heating device 7, thereby maintaining the temperature above the minimum temperature and preventing the freezing of the water supply components of the electrolysis equipment. When the external temperature is below 5°C, temperature maintenance is activated, in which heat is extracted from the thermal storage device 15 and transferred to the water supply components of the electrolysis equipment 5, thereby achieving antifreeze protection.

[0064] During normal operation, the wind power generation unit 1 supplies electrolytic current to the electrolysis equipment 5. Here, the process heat generated by the electrolytic cell is discharged through the upper heat exchanger 11 and transferred to the heat storage device 15. This process heat is then transferred to the heat storage medium 23, thereby charging the heat storage device 21. According to... Figure 3 In a particular and advantageous embodiment of the heat storage tank 21, the heat storage tank 21 is loaded by transferring heat to a material storing latent heat, particularly salt, wherein the material is at least partially liquefied. The heat of crystallization can be stored for a long time and released as needed. The released latent heat can be used particularly efficiently for temperature maintenance of the electrolysis equipment 5 in the heating unit 7 via a heat exchange process through heat exchange lines 37, upper heat exchanger, and lower heat exchanger 11.

Claims

1. An offshore electrolysis system (100) comprising a wind power generation device (1) having a platform (3) and an electrolysis device (5) arranged on the platform (3), the wind power generation device (1) being connected to the electrolysis device to supply electrolysis current, the offshore electrolysis system further comprising a heating device (7) coupled to the electrolysis device (5), the heating device being designed to transfer heat to the electrolysis device during shutdown operation, thereby maintaining the temperature above a minimum temperature.

2. The marine electrolysis system (100) according to claim 1, characterized in that, The electrolysis equipment (5) includes an electrolytic cell arranged in a container (9) and a heat exchanger (11) designed to remove process heat from the electrolysis from the container (9) during normal operation.

3. The marine electrolysis system (100) according to claim 1 or 2, characterized in that, The heating device (7) has a heat pump (13) coupled to a heat storage device (15).

4. The marine electrolysis system (100) according to any one of the preceding claims, characterized in that, The heating device (7) has a heat pump (13) with a deep probe (17) designed to extract heat from seawater.

5. The marine electrolysis system (100) according to claim 4, characterized in that, The heating device (7) is arranged on the tower (19) of the wind power generation device (1), wherein the deep probe (17) is immersed in seawater.

6. The marine electrolysis system (100) according to any one of the preceding claims, characterized in that, The heating device (7) has a heat storage device (21) designed to utilize waste heat from the electrolysis process to load the heat storage device (21) during normal operation and to transfer the heat stored in the heat storage device (21) to the electrolysis equipment (5) during shutdown operation.

7. The marine electrolysis system (100) according to any one of the preceding claims, characterized in that, The heating device (7) has a heat storage device (15) which is constructed inside the tower (19) of the wind power generation device (5).

8. The marine electrolysis system (100) according to claim 7, characterized in that, The heat storage device (15) has a container into which the heat storage medium (23) is introduced.

9. The marine electrolysis system (100) according to claim 8, characterized in that, The heat storage medium (23) is water and / or a material with a low melting point between approximately 30°C and 70°C that stores latent heat, especially salt, salt mixtures or paraffin.

10. The marine electrolysis system (100) according to claim 9, characterized in that, As a material for storing latent heat, a supersaturated solution of sodium acetate trihydrate, disodium hydrogen phosphate, or a mixture thereof is introduced into the container.

11. The marine electrolysis system (100) according to claim 10, characterized in that, An activation device is provided, which can induce crystallization and release the stored latent heat.

12. A method of operating the offshore electrolysis system (100) according to any one of the preceding claims, wherein, During shutdown operation, heat is transferred to the electrolysis equipment (5) through the heating device (7) to maintain the temperature above the minimum temperature and prevent the water supply components of the electrolysis equipment (5) from freezing.

13. The method according to claim 12, characterized in that, Temperature maintenance is activated when the external temperature is below 5°C, wherein heat is extracted from the heat storage device (15) and transferred to the water supply component of the electrolysis device (5) to achieve antifreeze protection.

14. The method according to claim 12 or 13, characterized in that, During normal operation, the wind power generation device (1) supplies electrolysis current to the electrolysis equipment (5), wherein the process heat generated by the electrolysis cell is exported through the heat exchanger (11) and transferred to the heat storage device (15).

15. The method according to claim 14, characterized in that, Process heat is extracted from the electrolytic cell and transferred to the heat storage medium (23), wherein the heat storage tank (21) is loaded.

16. The method according to claim 15, characterized in that, A heat storage device (21) is loaded by transferring heat to a material that stores latent heat, particularly salt, wherein the material is at least partially liquefied.

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