Electrolysis device with heating device

Abstract

The present invention relates to an electrolysis device (10) for producing a fuel (B) in electrolysis cells of at least one electrolysis stack (100), having an air supply portion (122) for supplying feed air (ZL) to an air side (120) of the electrolysis stack (100) and an air discharge portion (124) for discharging exhaust air (AL) from the air side (120) of the electrolysis stack (100), further having a water supply portion (132) for supplying water (W) to a fuel side (130) of the electrolysis stack (100) and a fuel discharge portion (134) for discharging fuel (B) from the fuel side (130) of the electrolysis stack (100), wherein at least one heating device (20) is arranged in the water supply portion (132) in order to heat a heating gas (AG) conducted therein during a heating process, and furthermore, a heating supply portion (140) is fluidically connected to the water supply portion (132) upstream of the heating device (20) in order to supply the heating gas (AG) to the electrolysis stack (100) via the water supply portion (132).

Description

[0001] ELECTROLYSIS DEVICE WITH HEATING DEVICE

[0002] The present invention relates to an electrolysis device for producing a fuel, a control method for carrying out a heating process in an electrolysis device and a computer program product for carrying out such a control method.

[0003] It is known that electrolysis devices are used to produce fuel in gaseous form. Electrolysis devices are usually equipped with a large number of electrolysis cells arranged in electrolysis stacks. Depending on the size and capacity of the electrolysis device, two or more such electrolysis stacks are also provided. In each electrolysis cell, the input reactants are converted into products using electrical current. This conversion primarily involves the production of fuel, in most cases hydrogen. To produce hydrogen, water is required as one of the reactants, which is usually provided in vapor form. In addition, supply air is drawn in from the ambient air to carry out the desired chemical reactions within the respective electrolysis cell.Such electrolysis devices are also referred to as power-to-gas plants, for example when producing so-called green hydrogen.

[0004] A major disadvantage of known electrolysis devices is that they require relatively complex operation during start-up. The start-up process includes a heating phase, which is necessary to bring the individual components of the electrolysis device to the desired operating temperature. Two limit temperatures are particularly relevant here. The first required temperature is the condensation temperature of water. Since water is usually introduced into the electrolysis cells in vapor form, it is necessary to ensure that the vaporous water does not undesirably condense again in the electrolysis device. The vaporous water should therefore only be introduced when the overall temperature of the individual components of the electrolysis device exceeds the condensation temperature of water accordingly.Because the chemical reactions carried out in the electrolysis stacks are endothermic, an elevated temperature is also necessary to compensate for the heat loss due to the endothermic nature of the reaction. Thus, the actual operating temperature of such electrolysis devices, especially SOEC devices, is significantly above the condensation temperature of water. Therefore, known heating processes use a heating gas, which usually also serves as a protective gas. Commercial solutions for such heating gases include so-called ARCAL. This heating gas is preheated externally and can thus be introduced into the electrolysis device as a chemically passive heat transfer medium. This leads to the disadvantage that an external source of this heating gas with an external heating device must be provided.This leads to increased energy consumption, increased complexity of the overall system and, in particular, to an undesirably expensive heating process, since the heating gas used for heating is neither available for operation of the electrolysis device nor for a further heating process.

[0005] The object of the present invention is to at least partially remedy the disadvantages described above. In particular, the object of the present invention is to improve the heating process of an electrolysis device in a cost-effective and simple manner.

[0006] The above object is achieved by an electrolysis device having the features of claim 1, a control method having the features of claim 14, and a computer program product having the features of claim 15. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the electrolysis device according to the invention naturally also apply in connection with the control method according to the invention and the computer program product according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0007] According to the invention, an electrolysis device serves to generate a fuel in electrolysis cells of at least one electrolysis stack. This electrolysis stack has an air side and a fuel side, wherein the electrolysis device is designed with an air supply section for supplying supply air to the air side of the electrolysis stack. Furthermore, an air discharge section is provided for discharging exhaust air from the air side of the electrolysis stack. With the aid of a water supply section, the supply of water to a fuel side of the electrolysis stack is possible. Fuel is discharged from the fuel side of the electrolysis stack via a fuel discharge section. An electrolysis device according to the invention is characterized in that at least one heating device is arranged in the water supply section for heating a heating gas conducted therein during a heating process.Furthermore, a heating supply section upstream of this heating device is fluidly connected to the water supply section for supplying the heating gas via the water supply section to the electrolysis stack.

[0008] The core concept of the invention is that the heating of the heating gas takes place within the electrolysis device. The heating device can, in particular, be a heating device specific to this heating process. However, other heating devices are also conceivable in principle, which fulfill an additional purpose in the regular operation of the electrolysis device. Furthermore, in a first step, it is irrelevant which heating gas is used. As will be explained later, external protective gases, such as the aforementioned ARCAL, can also be used as the heating gas. At certain heating times, however, the vaporous water and / or even the fuel itself can also be used, at least in part, as the heating gas. It is also irrelevant whether this heating gas is supplied completely, partially, or not at all from an external source.

[0009] The advantages according to the invention are achieved in particular in that a heating process can now be carried out with or without external heating gases. A decisive advantage, particularly when using an external heating gas, is that a heating function is now integrated into the electrolysis device. This means that there is no longer any need for external control options or external heating of the heating gas. The complexity of the peripherals of the electrolysis device is thus significantly reduced. If an external heating gas is used, a cold source of heating gas is sufficient. Furthermore, an electrolysis device according to the invention can even be operated without external sources and thus purely internal heating gas, as explained later, which in turn is only possible thanks to the heating device integrated into the electrolysis device.In summary, this approach allows for greater flexibility in the design of the electrolysis device with regard to the heating phase. Last but not least, regardless of the actual design and supply of the heating gas, the integration of the heating device into the electrolysis device significantly reduces the complexity of the design and also the complexity of operation during the heating phase.

[0010] It can be advantageous if, in an electrolysis device according to the invention, the heating supply section has a heating gas inlet for connection to a heating gas source. This is a solution with externally supplied heating gas. This can be, for example, a protective gas, in particular the aforementioned ARCAL or a similar product. The heating gas is therefore supplied in particular from a cold heating gas source and can be introduced into the heating supply section via the heating gas inlet. The heating gas supplied cold here is then introduced into the water supply section via the heating supply section, integrated in the electrolysis device, and is brought there to the desired heating temperature by means of the heating device.The heating gas serves as a heat transfer medium, absorbing heat in the heating device and then releasing this heat back to the individual components of the electrolysis device located downstream of this heating device. Depending on the temperature difference and the performance of the heating device, the integral heating capability allows the relevant components of the electrolysis device to be heated quickly and with high efficiency. It should also be noted that, in addition to using a protective gas, a fuel, such as hydrogen, can also be used as the heating gas source. Mixing multiple heating gas sources, such as an ARCAL source and a hydrogen source, is also conceivable in principle within the scope of this embodiment of the present invention.

[0011] Furthermore, it can be advantageous if, in an electrolysis device according to the invention, the heating supply section is fluidly connected to the fuel discharge section via a recirculation section for introducing fuel, at least as a component of the heating gas. As already explained, depending on the situation and heating phase during heating operation, the fuel itself can also be used as the heating gas. The heating gas can consist of 100% fuel, but in particular can only form a portion of the heating gas. By using the fuel, which in particular has been produced by the electrolysis device itself, the need for and the amount of external heating gas required can be further reduced.Rather, it is possible to use stored fuel during the heating operation, for example, from a previous operating phase, to reduce the required amount of externally supplied heating gas, such as ARCAL. In particular, this is based on the use of an integrated buffer storage, which can be integrated into the electrolysis device, in particular the fuel discharge section.

[0012] Further advantages can be achieved if, in an electrolysis device according to the invention, the fuel discharge section has a fuel compressor for compressing the fuel, with the recirculation section branching off from the fuel discharge section downstream of the fuel compressor. Using a fuel compressor results in a fuel in compressed and thus highly pressurized form being present at the outlet of the fuel discharge section of the electrolysis device. For example, a fuel pressure of over 8 bar can be provided, so that the electrolysis device can be connected directly to corresponding external fuel networks. This allows downstream large storage devices, as well as fuel networks, to be connected, which are supplied directly or indirectly with the produced fuel by the electrolysis device.The fuel compressor thus represents the pressure interface to such external connections. Because the fluid-communicating connection to the recirculation section is now arranged downstream of such a fuel compressor, this increased pressure can also be used to convey this recirculated fuel into the recirculation section. In other words, it becomes possible to dispense with separate conveying devices, in particular the blower device explained later, and thus also enable recirculation conveyance for the fuel compressor as a secondary function, so to speak. This eliminates the need for another component of the recirculation blower and improves the compactness and cost of the electrolysis device. In principle, it can also be advantageous if the fuel compressor is arranged outside the electrolysis device itself.Further advantages can be achieved if, in an electrolysis device according to the invention, the fuel discharge section is fluidly connected to the recirculation section via a blower section, in particular upstream of a fuel compressor. In other words, such a blower section is present in addition to or alternatively to the embodiment according to the preceding paragraph. In particular, if very high pressures are to be generated by the fuel compressor, for example, to meet corresponding requirements of a connected fuel network, recirculating the fuel at high pressure can entail further technical complexity. In such a case, it may be simpler to branch off a separate blower section on the low-pressure side of the fuel compressor, which is intended to supply the recirculating fuel to the recirculating section.This makes it possible to combine it with a fuel compressor even when high compression pressures are required for the fuel.

[0013] It is also advantageous if, in an electrolysis device according to the invention, the fuel discharge section is fluidly connected to a heating outlet via a heating discharge section for discharging at least a portion of the heating gas. Discharging this non-reactive gas is particularly advantageous when externally supplied heating gas is used, and preferably especially when it is a protective gas, for example the aforementioned ARCAL. To prevent the produced fuel from being contaminated with the external heating gas for part of the operation after the heating phase, the introduced external heating gas can be removed from the system of the electrolysis device again through such a heating discharge section.This can also be referred to as purging to ensure that, after the heating phase has ended, steady-state operation with the desired fuel quality can be achieved as quickly as possible.

[0014] Preferably, this is a common branch in the blower section, as explained above. Such a heat-up discharge section is also provided, for example, upstream of the fuel compressor, in order to separate and thus discharge the heat-up gas on the low-pressure side at the end of the heating process.

[0015] It is also advantageous if, in an electrolysis device according to the invention, the heating device has an electric heating device. An electric heating device is particularly useful because, on the one hand, the electrolysis device is equipped with the appropriate electrical power supply for producing the fuel, so that this electrical power and the corresponding connections for the heating device are already available. Furthermore, the electric heating device is independent of the composition of the heating gas, since, in particular, no combustion process is necessary to generate a heating temperature. Last but not least, the use of an electric heating device is very simple and cost-effective to implement, can be controlled very precisely, and can be used for a wide variety of heating gas mixtures, in particular a mixture of the components ARCAL, hydrogen, and / or steam.

[0016] Further advantages can also be achieved if, in an electrolysis device according to the invention, the heating device has a burner device which is connected to the water supply section in a heat-transfer manner via a burner heat exchanger, wherein the burner device is fluidly connected to a fuel inlet and / or the fuel discharge section via a burner supply section. In addition to or as an alternative to the electrical heating option, a burner heating option can also be provided here. Such a burner device can combust the fuel produced in the electrolysis device itself. This fuel, in particular hydrogen, can be provided both from an external source via the fuel inlet, but also in the form of the self-produced fuel from the fuel discharge section.In particular, this correlates with a buffer tank integrated into the electrolysis device, allowing existing and stored fuel from a previous production operation to be made available for the burner. This combusted fuel is now not introduced directly into the electrolysis stack as a heat medium, but rather is used via a heat-transfer contact as a heat source for the heat transport medium in the form of the heating gas. Of course, in this embodiment, in addition to water vapor and the protective gas, unburned hydrogen can also form a component of the heating gas separately from the burner device.

[0017] It is also advantageous if, in an electrolysis device according to the invention, the fuel discharge section, particularly downstream of a fuel compressor, has a fuel buffer storage unit. As has already been explained several times, such a fuel buffer storage unit can be used, for example, to utilize the fuel stored therein for subsequent heating processes. However, such a fuel buffer storage unit can also offer advantages for connection to an external fuel network in order to be able to provide the most constant fuel output possible during operating fluctuations, particularly during power fluctuations for operating the electrolysis device.

[0018] It can also be advantageous if, in an electrolysis device according to the invention, the fuel discharge section has a water separator for separating water from the fuel. Depending on the actual intended use of the fuel, certain quality requirements regarding the purity of the fuel are necessary. In the electrolysis stack, the fuel is generated as a gas mixture, which in particular has a significant residual proportion of water vapor. Depending on the stoichiometric ratios in the supply and the current electrical operating situation of the individual electrolysis cells, the proportion of remaining residual water in the form of water vapor can fluctuate. Such a water separator serves to separate this residual water and accordingly provide a high concentration of pure hydrogen as fuel in the residual gas.For example, the water separator, particularly with the help of a cooling device acting as a condenser, may separate the remaining water in the form of water vapor through condensation. Liquid residual water or liquefied condensate, after such cooling, can also be separated from the fuel by a suitable water separator acting as a liquid separator.

[0019] It is also advantageous if, in an electrolysis device according to the invention, the fuel discharge section is directly connected to the water supply section in a fluid-communicating manner via an ejector section with an ejector arranged therein. Such direct recirculation is particularly advantageous for later regular operation, for example, if direct recirculation of generated fuel is partially desired. Last but not least, direct heat recovery can also be provided here, so that the intake of hot fuel as part of the heating gas, but also of a more complex heating gas, is possible directly via the ejector section without moving parts.For example, the ejector section, like all other sections in particular, is equipped with appropriate control valves in order to be able to flexibly and specifically control the heating process depending on the actual operating condition and in particular depending on the actual temperatures of the individual components and the individual gas flows.

[0020] A further advantage can be achieved if, in an electrolysis device according to the invention, a first air heat exchanger and a second air heat exchanger are arranged in series in the air supply section with their cold sides connected, in particular, to the air discharge section in a fluid-communicating manner. In other words, this makes it possible to achieve advantages both during the heating process and during regular operation. During the heating process, residual heat will be present in the exhaust air on the air side of the electrolysis device. This residual heat can be used to preheat the supply air also supplied for the heating process, thus ensuring an increase in temperature efficiency and thus an acceleration of the heating phase. During regular production operation of the electrolysis device, a constant heat flow will occur due to the endothermic nature of the reaction in the electrolysis stack.By recirculating the residual heat from the exhaust air, the additional heat required to compensate for the endothermic energy loss can be reduced accordingly, thus increasing temperature efficiency for production operations. In particular, the serial arrangement of the first and second air heat exchangers reduces the residual temperature of the exhaust air to below 60 degrees Celsius.

[0021] Furthermore, it can be advantageous if, in an electrolysis device according to the invention, an external heat exchanger is arranged in the water supply section with its cold side, the hot side of which is equipped with an external heat inlet and an external heat outlet in fluid communication. Such an external heat connection can be useful, for example, if waste heat is available for use in a system adjacent to the electrolysis device. Connecting such an external heat exchanger can supply external heat to the electrolysis device system and thus further improve temperature efficiency both during the heating process and during regular production operation to compensate for the endothermic heat losses of the reaction in the electrolysis stacks.The present invention also relates to a control method for carrying out a heating process of an electrolysis device according to the invention, comprising the following steps:.

[0022] - Introducing a heating gas via the heating supply section into the water supply section,

[0023] - Heating the heating gas by means of the heating device,

[0024] - guiding the heated heating gas in the electrolysis stack,

[0025] - discharging the heating gas from the electrolysis stack at least in sections via the fuel discharge section,

[0026] - Detection of an exceedance of the condensation temperature of water in the water supply section,

[0027] - Introduction and evaporation of water in the water supply section,

[0028] - Mixing the evaporated water with the heating gas,

[0029] - Feeding the mixture of evaporated water and heating gas in an electrolysis stack,

[0030] - removing the evaporated water and the heating gas from the electrolysis stack at least in sections via the fuel removal section,

[0031] - Detection of an exceedance of the operating temperature of the electrolysis stack.

[0032] A control method according to the invention offers the same advantages as those explained in detail with reference to an electrolysis device according to the invention. The control method is characterized in particular by its two-stage structure. In a first stage, essentially only the heating gas is used, for example as an external heating gas or as a mixture with a fuel, to carry out a first heating step. This first heating step is terminated when a condensation temperature, in particular in the water supply section, has been exceeded. At this point, it is ensured that vaporous water in the water supply section can no longer condense undesirably due to the temperature being above the condensation temperature of water.In other words, it is now possible to supply water via the water supply section for even further accelerated heating and to use it in vaporized form as an additional heat carrier and thus as superheated steam after the heating device for faster heating of the components of the electrolysis device.

[0033] A further subject of the present invention is a computer program product comprising instructions which, when executed by a computer, cause the computer to perform the steps of a control method according to the invention. Thus, a computer program product according to the invention also provides the same advantages as those explained in detail with reference to an electrolysis device according to the invention.

[0034] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. They show schematically:

[0035] Fig. 1 shows an embodiment of an electrolysis device according to the invention,

[0036] Fig. 2 shows a further embodiment of an electrolysis device according to the invention,

[0037] Fig. 3 shows a further embodiment of an electrolysis device according to the invention,

[0038] Fig. 4 shows a further embodiment of an electrolysis device according to the invention,

[0039] Fig. 5 shows a further embodiment of an electrolysis device according to the invention,

[0040] Fig. 6 shows a further embodiment of an electrolysis device according to the invention,

[0041] Fig. 7 shows a further embodiment of an electrolysis device according to the invention, Fig. 8 shows a further embodiment of an electrolysis device according to the invention,

[0042] Fig. 9 shows a further embodiment of an electrolysis device according to the invention and

[0043] Fig. 10 shows a further embodiment of an electrolysis device according to the invention.

[0044] Using Figures 1 to 10, different design variants of the electrolysis device 10 will now be explained with respect to different subcomponents. Of course, the individual design variants can also be freely combined with one another with respect to the different subcomponents.

[0045] Figure 1 shows a particularly simple embodiment of an electrolysis device 10 according to the invention. A single electrolysis stack 100 is shown schematically here, which is divided into an air side 120 and a fuel side 130. Of course, several such electrolysis stacks 100 can also be provided side by side as part of the electrolysis device 10.

[0046] For regular production operation, supply air ZL can now be supplied externally via an air supply section 122 via a corresponding connection to the air side 120. Water W can also be supplied to the fuel side 130 from an external source via the water supply section 132. During regular production operation, electrical power is now available to generate exhaust air AL and fuel B from these two reactants, water W and supply air ZL, via the reaction taking place in the electrolysis cells in the electrolysis stack 100, wherein the fuel B contains a high proportion of hydrogen. The exhaust air AL is separated again via the air discharge section 124 and can either be released directly into the environment or fed to a post-treatment facility.The fuel B is discharged from the fuel side 130 via the fuel discharge section 134 and can be made available here directly or, as explained later, indirectly to another fuel network.

[0047] The core concept of the present electrolysis device according to the invention is provided here by an external connection for heating gas AG as heating gas inlet 142. From outside, for example, fuel B as well as heating gas AG and / or a protective gas, for example ARCAL, can be introduced. The heating gas AG is introduced into the water supply section 132 downstream of an evaporator 90 and then heated downstream of this supply point via a heating device 20. Thus, the heating gas AG can be introduced as a heat transfer medium in its heated form via the water supply section 132 into the fuel side 130 of the electrolysis stack 100. There, it can transfer the absorbed heat from the heating device to the individual components of the electrolysis device 10 and in particular of the electrolysis stack 100 via convection and heat transfer, thus serving the desired heating.

[0048] Figure 2 shows an alternative solution in which the heating gas AG is at least partially recirculated internally. This internal recirculation takes place via the fuel discharge section 134. In this fuel discharge section 134 of this embodiment, a fuel compressor 30 is provided, which enables increased pressure for the fuel B. This fuel compressor 30 can, in principle, also be arranged outside the electrolysis device 10. A fuel buffer storage 40 is also provided to provide intermediate storage and buffering for different production situations. The fuel B as well as the heating gas AG can now be recirculated here and fed to the heating feed section 140 via the recirculation section 150.This can of course be combined with an external design and external supply of heating gas AG, which is then also available for recirculation and thus for multiple use in addition to or as an alternative to fuel B.

[0049] Figure 3 also shows a corresponding development, in which, however, a separate supply of fuel B and / or heating gas AG from the fuel discharge section 134 is provided. For example, a blower section 160 is provided here, which is located in particular upstream of the fuel compressor 30, but also upstream of a water separator 50, and has a blower 32. This decouples the recirculation from the high-pressure side of the fuel compressor 30 and can thus provide this recirculation cost-effectively and efficiently even when high pressure requirements are present on the high-pressure side of the fuel compressor 30. Figure 4 shows a variant showing the blower section 160 as an alternative to the recirculation section 150.Figure 5 shows a variant in which externally supplied heating gas AG according to Figure 1 can now be discharged from the system of the electrolysis device 10 during or at the end of the heating process. For this purpose, a heating discharge section 170 is provided in the fuel discharge section 134, here upstream of the fuel compressor 30, which discharge section opens into a heating gas outlet 172. This can also be provided in addition to or as an alternative to the internal recirculation according to Figures 2, 3, and 4.

[0050] Figure 6 shows a possibility in which externally supplied fuel B can also be provided for heating via a fuel inlet 132. The heating device 20 is designed in two stages here, with a burner heat exchanger 26 being provided as the first stage. The externally supplied fuel B is fed to a burner device 24 via a fuel supply section 180 and burned exothermically there. This can take place by open combustion or catalytically. The heated exhaust gas downstream of the burner device 24 is then used via the burner heat exchanger 26 as a heat source for the heating gas AG in the heating device 20. In addition here, but fundamentally also possible as an alternative, the heating device 20 is equipped with an electric heating device 22, which is integrated into the water supply section 132 downstream of the burner heat exchanger 26 in a heat-transfer manner.

[0051] Figure 7 shows an alternative internal use of fuel B. The fuel B can in particular originate from a previous production process and can be used, for example, from the fuel buffer storage 40.

[0052] Figure 8 shows a variant in which the fuel B from the buffer storage according to Figure 7 is used and at the same time an external use of heating gas AG via the heating gas inlet 142 is possible.

[0053] Figure 9 shows another variant of improved residual heat utilization in the heating process, as well as during this production operation. Here, a pair of two air heat exchangers 74 and 72 are provided in series, allowing dual heat transfer from the exhaust air AL to the supply air ZL in the air supply section 122.

[0054] Figure 10 illustrates another use when external heat is available. A medium with external heat can then make it available to the water W via an external heat exchanger 80 via an external heat inlet 32. Here, the water W can be heated in parallel with the evaporator 90 via the external heat exchanger 80.

[0055] The above explanation of the embodiments describes the present invention exclusively by way of examples.

[0056] List of reference symbols

[0057] 10 Electrolysis device

[0058] 20 Heating device

[0059] 22 electric heater

[0060] 24 burner device

[0061] 26 burner heat exchangers

[0062] 30 fuel compressor

[0063] 32 blowers

[0064] 40 fuel buffer storage

[0065] 50 water separators

[0066] 60 Ejector

[0067] 72 first air heat exchanger

[0068] 74 second air heat exchanger

[0069] 80 external heat exchangers

[0070] 82 External heat input

[0071] 84 External heat output

[0072] 90 evaporators

[0073] 100 electrolysis stacks

[0074] 120 airside

[0075] 122 Air supply section

[0076] 124 Air discharge section

[0077] 130 Fuel side

[0078] 132 Water supply section

[0079] 134 Fuel discharge section

[0080] 140 Heating feed section

[0081] 142 Heating gas inlet

[0082] 150 recirculation section

[0083] 160 blower section

[0084] 170 Heating discharge section

[0085] 172 Heating gas outlet

[0086] 180 burner feed section

[0087] 182 Fuel inlet

[0088] 190 Ejector section B fuel

[0089] W Water

[0090] ZL supply air

[0091] AL exhaust air

[0092] AG heating gas

Claims

Patent claims 1. An electrolysis device (10) for producing a fuel (B) in electrolysis cells of at least one electrolysis stack (100), comprising an air supply section (122) for supplying supply air (ZL) to an air side (120) of the electrolysis stack (100) and an air discharge section (124) for discharging exhaust air (AL) from the air side (120) of the electrolysis stack (100), further comprising a water supply section (132) for supplying water (W) to a fuel side (130) of the electrolysis stack (100) and a fuel discharge section (134) for discharging fuel (B) from the fuel side (130) of the electrolysis stack (100), characterized in that at least one heating device (20) is arranged in the water supply section (132) for heating a heating gas (AG) guided therein during a heating process,wherein a heating supply section (140) upstream of the heating device (20) is fluidly connected to the water supply section (132) for supplying the heating gas (AG) via the water supply section (132) to the electrolysis stack (100).

2. Electrolysis device (10) according to claim 1, characterized in that the heating supply section (140) has a heating gas inlet (142) for connection to a heating gas source.

3. Electrolysis device (10) according to one of the preceding claims, characterized in that the heating supply section (140) is connected to the fuel discharge section (134) in a fluid-communicating manner via a recirculation section (150) for introducing fuel (B) at least as a component of the heating gas (AG).

4. Electrolysis device (10) according to claim 3, characterized in that the fuel discharge section (134) has a fuel compressor (30) for compressing the fuel (B), wherein the recirculation section (150) branches off from the fuel discharge section (134) downstream of the fuel compressor (30).

5. Electrolysis device (10) according to one of claims 3 or 4, characterized in that the fuel discharge section (134) is connected to a fan section (160) is fluidly connected to the recirculation section (150), in particular upstream of a fuel compressor (30).

6. Electrolysis device (10) according to one of the preceding claims, characterized in that the fuel discharge section (134) is fluidly connected to a heating gas outlet (172) via a heating discharge section (170) for discharging at least a portion of the heating gas (AG).

7. Electrolysis device (10) according to one of the preceding claims, characterized in that the heating device (20) has an electric heating device (22).

8. Electrolysis device (10) according to one of the preceding claims, characterized in that the heating device (20) has a burner device (24) which is connected to the water supply section (132) in a heat-transferring manner via a burner heat exchanger (26), wherein the burner device (26) is fluidly connected to a fuel inlet (182) and / or the fuel discharge section (134) via a burner supply section (180).

9. Electrolysis device (10) according to one of the preceding claims, characterized in that the fuel discharge section (134), in particular downstream of a fuel compressor (30), has a fuel buffer storage (40).

10. Electrolysis device (10) according to one of the preceding claims, characterized in that the fuel discharge section (134) has a water separator (50) for separating water from the fuel (B).

11. Electrolysis device (10) according to one of the preceding claims, characterized in that the fuel discharge section (134) is directly connected to the water supply section (132) in a fluid-communicating manner via an ejector section (190) with an ejector (60) arranged therein.

12. Electrolysis device (10) according to one of the preceding claims, characterized in that in the air supply section (122) a first air Heat exchanger (72) and a second air heat exchanger (74) are arranged serially one after the other with their cold side, which are connected on their hot side in particular in a fluid-communicating manner to the air discharge section (124).

13. Electrolysis device (10) according to one of the preceding claims, characterized in that an external heat exchanger (80) is arranged in the water supply section (132) with its cold side, the hot side of which is fluidly connected to an external heat inlet (82) and an external heat outlet (84).

14. Control method for carrying out a heating process in an electrolysis device (10) having the features of one of claims 1 to 13, comprising the following steps: - introducing a heating gas (AG) via the heating supply section (140) into the water supply section (132), - heating the heating gas (AG) by means of the heating device (20), - feeding the heated heating gas (AG) into the electrolysis stack (100), - discharging the heating gas (AG) from the electrolysis stack (100) at least in sections via the fuel discharge section (134), - detecting an exceeding of the condensation temperature of water (W) in the water supply section (132), - introducing and evaporating water (W) in the water supply section (132), - Mixing the evaporated water (W) with the heating gas (AG). - Feeding the mixture of evaporated water (W) and heating gas (AG) into the electrolysis stack (100), - discharging the evaporated water (W) and the heating gas (AG) from the electrolysis stack (100) at least in sections via the fuel discharge section (134), - detecting an exceeding of an operating temperature of the electrolysis stack (100).

15. A computer program product comprising instructions which, when executed by a computer, cause the computer to carry out the steps of a control method having the features of claim 14.

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