Exhaust chimney

Abstract

An exhaust chimney (16) for discharging a cryogen (H2) having a liquid phase (LH2) and a gaseous phase (GH2) to the surrounding area (15) of the exhaust chimney (16), comprising a tubular chimney section (21, 22A, 22B) extending along the direction of gravity (g), the interior (36) of the exhaust chimney (16) being insulated from the surrounding area (15), and comprising a phase separator (31) for separating the liquid phase (LH2) from the gaseous phase (GH2), and an evaporator unit (37) for evaporating the separated liquid phase (LH2).

Description

Technical Field

[0001] The present invention relates to an exhaust chimney for discharging a cryogenic agent having a liquid phase and a gas phase around the exhaust chimney.

[0002] In the operation of a hydrogen storage container, it may be necessary to release hydrogen, particularly gaseous hydrogen, around the storage container. For this reason, according to the knowledge within the enterprise, an exhaust chimney may be provided. This type of exhaust chimney can be manufactured, for example, from a single-layer non-insulated steel pipe. When releasing hydrogen to the surroundings, the temperature outside the exhaust chimney may become lower than the condensation temperature of the air components. As a result, there is a risk that the air components, particularly oxygen, may condense or freeze outside the exhaust chimney.

[0003] The condensation of air components may form a pool of cryogenic liquid with a high oxygen enrichment directly around the exhaust chimney. When the liquefied air components drip, on the one hand, cold embrittlement and material damage of low-alloy steel may occur in the immediate vicinity of the exhaust chimney. On the other hand, the high oxygen concentration in the immediate vicinity of the exhaust chimney may increase the risk of fire and / or explosion. This needs to be improved.

[0004] Based on such a background, an object of the present invention is to provide an improved exhaust chimney.

[0005] Accordingly, an exhaust chimney for discharging a cryogenic agent having a liquid phase and a gas phase around the exhaust chimney is proposed. The exhaust chimney includes a tubular chimney portion extending along the gravitational direction, and the inner wall of the tubular chimney portion surrounding the inside of the exhaust chimney is insulated from the surroundings. The tubular chimney portion has a lower chimney portion and an upper chimney portion. The upper chimney portion has an outlet opening through which the rising gas phase flows out to the surroundings. The exhaust chimney also includes a phase separator attached to the lower chimney portion for separating the two-phase cryogenic agent that can be supplied through a pipe into a liquid phase and a gas phase, and an evaporator unit that releases heat to the inside to evaporate the separated internal liquid phase.

[0006] The interior of the exhaust chimney is insulated from its surroundings, which reliably prevents the condensation or freezing of air components outside the chimney. This reduces the risk of condensed air components dripping from the exhaust chimney.

[0007] The cryogenic agent may be hydrogen. Therefore, the concept of "cryogenic agent" can be replaced with the term "hydrogen" in this case, and vice versa. However, the cryogenic agent may also be liquid helium or the like. The exhaust chimney can also be called a hydrogen exhaust chimney. Preferably, the cryogenic agent is sent to the exhaust chimney as a two-phase mixture containing a liquid phase and a gas phase. The liquid phase is preferably liquid hydrogen. Accordingly, the term "liquid phase" can be replaced with the term "liquid hydrogen," and vice versa. The gas phase is preferably gaseous hydrogen. Accordingly, the term "gas phase" can be replaced with the term "gaseous hydrogen," and vice versa.

[0008] In particular, the gas phase can be released into the surroundings using an exhaust chimney. To release the liquid phase into the surroundings, the liquid phase is first evaporated using an evaporator unit and then released into the surroundings as a gas. The exhaust chimney can be configured to be rotationally symmetric with respect to the axis of symmetry or the central axis. The exhaust chimney can have multiple chimney sections that can be arranged vertically when viewed in the direction of gravity.

[0009] In particular, the interior of the exhaust chimney is insulated from its surroundings by having a low-temperature stable insulation or insulating material that is stable in a temperature range from, for example, -186°C, which corresponds to the dew point of oxygen, to 3K, the lowest temperature of helium, which is a refrigerant. The thermal insulation or insulating material can be formed uniformly along the entire length of the exhaust chimney. However, this is not essential. The simplest and cheapest solution for insulation is a double-walled vacuum insulation made of steel, especially stainless steel.

[0010] The two-phase mixture of the cryogenic agent is guided into the exhaust chimney using a phase separator. At this point, the gas phase separates from the liquid phase as the two-phase mixture enters the exhaust chimney. The gas phase moves upward, particularly along the direction of gravity, towards the exhaust chimney's outlet opening. The gas phase also moves downward, particularly along the direction of gravity, towards the exhaust chimney's sump.

[0011] A phase separator can be called a separator, or more specifically, a phase separator. In particular, a phase separator is a gravity separator and can therefore be called that as well. A phase separator can also be simply called a separator, or more specifically, a gravity separator. A phase separator can have the shape of, for example, a flange or a T-shaped component, which can be used to connect piping into which a two-phase mixture is introduced to a discharge chimney. A phase separator can be configured to be rotationally symmetric with respect to an axis of symmetry or a central axis. In this case, the central axis of the phase separator is oriented perpendicular to the central axis of the chimney section in particular.

[0012] The phase separator is specifically designed to separate a two-phase mixture, including a liquid phase and a gas phase, delivered using the aforementioned piping, into a liquid phase and a gas phase by gravity. In this case, the separation is carried out primarily by gravity. Since the liquid phase has a higher density than the gas phase, the liquid phase moves downward along the direction of gravity away from the outlet opening, while the gas phase moves upward along the direction of gravity towards the outlet opening.

[0013] The chimney section preferably has an evaporator unit housing for accommodating an evaporator unit. That is, the evaporator unit is attached to the chimney section, particularly the lower chimney section. The evaporator unit may be a heating block. The evaporator unit is particularly suitable for evaporating the liquid phase by releasing heat into the interior and, consequently, into the liquid phase. The evaporator unit can be heated electrically. For this purpose, the evaporator unit can be heated, for example, by induction, using a heating coil and / or heating conductor.

[0014] According to one embodiment, the chimney section has a double-walled structure for insulation.

[0015] The double-walled structure of the chimney section allows for low-cost insulation or thermal isolation. For example, the chimney section is made of stainless steel.

[0016] In a further embodiment, the chimney section has an inner wall facing the interior and an outer wall facing the periphery, with a vacuum gap between the inner wall and the outer wall.

[0017] Therefore, the inner wall is separated from the surroundings, and the outer wall is separated from the interior. In this case, "vacuum" specifically refers to a pressure lower than 300 mbar, preferably 10 -3 Lower than mbar, more preferably 10 -7 It is understood that the pressure is lower than mbar. Thus, the exhaust chimney is vacuum-insulated or vacuum-insulated. Multilayer insulating elements or multilayer thermal insulating elements may also be placed in this gap. In particular, so-called multilayer insulation (MLI) may be placed in the gap. If high heat resistance is required, for insulation purposes, for example, thermal insulating glass foam, especially closed-cell glass foam, may also be placed in the gap.

[0018] In a further embodiment, the phase separator and evaporator unit are mounted on the lower chimney section, and the phase separator is positioned above the evaporator unit when viewed along the direction of gravity.

[0019] Therefore, the evaporator unit is positioned below the phase separator when viewed along the direction of gravity. This causes the liquid phase to flow from the phase separator towards the evaporator unit by gravity, where it evaporates into the gas phase.

[0020] In a further embodiment, the lower chimney section has a sump that closes the end face of the chimney section, and the evaporator unit is positioned between the sump and the phase separator when viewed along the direction of gravity.

[0021] Therefore, this sample is arranged below the evaporator unit when viewed in the direction of gravity. In the sample, for example, water condenses and the water can be discharged from the sample. This sample may be in the form of a pot or a bowl. Preferably, this sample is also a double-walled structure and is thus insulated.

[0022] According to a further embodiment, the exhaust chimney has a condensate drain pipe that leads from the sample through the evaporator unit to the surroundings.

[0023] Using the condensate drain pipe, for example, water can be discharged from the sample to the surroundings, particularly to the outlet. The condensate drain pipe can also be referred to as a drain pipe. The condensate drain pipe leads to a water separator or a condensate separator in the exhaust chimney.

[0024] According to a further embodiment, the exhaust chimney has a condensate separator for separating water from the liquid phase, and the condensate drain pipe leads to the condensate separator.

[0025] The condensate separator particularly prevents the liquid phase and / or the gas phase from being released to the surroundings. For example, the condensate separator can have a float switch that floats only on the water. The condensate separator can also be referred to as a water separator.

[0026] According to a further embodiment, the exhaust chimney has a shut-off valve for closing and opening the condensate drain pipe.

[0027] In particular, the shut-off valve is provided upstream of the condensate separator, in the condensate drain pipe or on the condensate discharge pipe. The shut-off valve can be used to close or open the condensate drain pipe. This shut-off valve can be incorporated into the evaporator unit.

[0028] According to a further embodiment, the exhaust chimney has a low-temperature switch incorporated into the evaporator unit for controlling the shut-off valve.

[0029] The cryogenic switch can control the shut-off valve, for example, to open and close this shut-off valve. For this purpose, an operable connection may be provided between the cryogenic switch and the shut-off valve. The operable connection can be connected wirelessly or wired. The shut-off valve with a cryogenic switch can be used to prevent the liquid phase from reaching the condensate separator.

[0030] According to a further embodiment, the evaporator unit has an outer surface facing the surroundings and an inner surface facing the inside.

[0031] Thereby, the outer surface is away from the inside. Therefore, the inner surface is away from the surroundings. In particular, the evaporator unit may be suitable for transferring heat from the surroundings to the inside. In particular, the evaporator unit is dimensioned such that during operation of the exhaust chimney, when the inner surface is in contact with the liquid phase, the temperature of the outer surface does not drop below the condensation temperature of the air components. The evaporator unit is particularly insulated up to the outer surface.

[0032] According to a further embodiment, the evaporator unit is set to transfer heat from the outer surface to the inner surface.

[0033] This particularly means that it is set to transfer heat from the surroundings to the inside in order to evaporate the liquid phase. Therefore, the surroundings can be used as a heat source for the evaporator unit.

[0034] Preferably, the phase separator and evaporator unit are attached to the lower chimney section, also referred to hereafter as the first chimney section. The upper chimney section, also referred to hereafter as the second chimney section, may also be called the chimney tip. Preferably, the second chimney section is fixed to the first chimney section. The phase separator leads to the first chimney section, which also has a sump and an evaporator unit housing. Preferably, both the first and second chimney sections have a double-wall structure. That is, both the first and second chimney sections may each have one inner wall and an outer wall surrounding this inner wall. There is one gap between the inner and outer walls, which can be a vacuum. Insulation material may be placed in the gap. Preferably, the second chimney section is fire-resistant. For this purpose, a fire-resistant insulating element can be housed in the gap of the second chimney section, for example, in the form of glass foam, particularly in the form of closed-cell glass foam.

[0035] In a further embodiment, the second chimney section is thermally separated from the first chimney section using a separator.

[0036] In particular, the first chimney section and the second chimney section are connected to each other using a separator. The connection between the first chimney section and the second chimney section may be detachable.

[0037] In a further embodiment, the second chimney section has a section of narrowing provided at the outlet opening.

[0038] The cross-sectional narrowing can be achieved, for example, by reducing the outer and / or inner diameter of the second chimney section toward the outlet opening. This results in the outlet opening having a smaller diameter than the outer and / or inner diameter of the second chimney section. The cross-sectional narrowing allows for acceleration of the gas phase velocity as it flows out of the outlet opening. Therefore, even if condensation of air components occurs, it is carried away by the outflowing gas phase. Accumulation and dripping of condensed air components are prevented.

[0039] In a further embodiment, the second chimney section has a flow deflector (Umstromungskorper) located downstream of the outlet opening.

[0040] Here, "downstream" must be understood to refer to the flow direction of the gas phase flowing out of the outlet opening. In other words, the flow deflector is positioned at a defined distance in front of the outlet opening. The flow deflector prevents, for example, water or snow from entering the outlet opening. The flow deflector can be configured to be rotationally symmetric with respect to an axis of symmetry or a central axis. The central axis of the flow deflector can coincide with the central axis of the chimney section. Preferably, the flow deflector has a frustoconical or conical front facing the outlet opening and a rear side away from the outlet opening. The rear side may be, for example, flat or curved. Furthermore, the flow deflector has a diameter that is the same as or smaller than the outer diameter of the second chimney section, and preferably larger than the diameter of the outlet opening. The flow deflector can be supported by a plurality of supports in the second chimney section, particularly in the section with a narrow cross-section. The supports support the flow deflector.

[0041] Here, "one" does not necessarily mean limited to exactly one element. Rather, there may be, for example, two, three, or more elements. The other numbers used here do not necessarily mean that they are precisely limited to the number of elements mentioned. Rather, numerical differences above or below are possible.

[0042] Other possible implementations of the exhaust chimney include combinations of the constituent elements or embodiments described above or below with respect to the examples, which are not explicitly stated. Those skilled in the art may also add individual embodiments as improvements or supplements to each basic form of the exhaust chimney. [Brief explanation of the drawing]

[0043] Other advantageous embodiments of the exhaust chimney are subject to the dependent claims and the embodiments of the exhaust chimney described below. Next, preferred embodiments of the exhaust chimney will be described in detail with reference to the attached figures.

[0044] [Figure 1] This is a schematic cross-sectional view showing an embodiment of a storage container. [Figure 2] Figure 1 is a schematic cross-sectional view showing an embodiment of the exhaust chimney for the storage container. [Figure 3] Figure 2 is a schematic cross-sectional view showing an embodiment of the chimney section for the exhaust chimney.

[0045] Unless otherwise specified, identical elements or elements with the same function are given the same symbol in the diagrams.

[0046] Figure 1 shows a schematic cross-sectional view of an embodiment of storage container 1.

[0047] Storage container 1 can also be called a storage tank. Storage container 1 is preferably suitable for storing hydrogen H2 (boiling point: 1 bara: 20.268 K = -252.882 °C). Therefore, storage container 1 can also be called a hydrogen storage container or a hydrogen storage tank. However, storage container 1 can also be used for other cryogenic liquids. Examples of cryogenic fluids or liquids, or simply cryogenic liquids, include, in addition to the hydrogen H2 mentioned above, liquid helium He (boiling point: 1 bara: 4.222 K = -268.928 °C), liquid nitrogen N2 (boiling point: 1 bara: 77.35 K = -195.80 °C), or liquid oxygen O2 (boiling point: 1 bara: 90.18 K = -182.97 °C).

[0048] The storage container 1 may be a transport container. For example, liquid hydrogen LH2 can be transported using the storage container 1. The storage container 1 may be part of a vehicle, particularly a water vehicle. In this case, the storage container 1 is suitable for mobile applications. However, the storage container 1 can also be used in a stationary manner, for example, from a construction technical standpoint.

[0049] The storage container 1 is configured to be rotationally symmetric with respect to an axis of symmetry or central axis 2. The central axis 2 is oriented perpendicular to the direction of gravity g. The storage container 1 includes a first container or inner container 3, which is also configured to be rotationally symmetric with respect to the central axis 2. The inner container 3 includes a tubular or cylindrical base area 4, which is also configured to be rotationally symmetric with respect to the central axis 2. The base area 4 may have a circular or approximately circular geometry when viewed in cross-section.

[0050] The base section 4 is closed on both sides at the end face by cover sections 5 and 6, respectively. Cover sections 5 and 6 are curved. The first cover section 5 and the second cover section 6 are curved in opposite directions, so that cover sections 5 and 6 curve outward with respect to the base section 4. The inner container 3 is fluid-tight and, in particular, airtight. The inner container 3 is made of steel.

[0051] Liquid hydrogen LH2 is contained within the inner container 3. Within the inner container 3, a gaseous zone 7 containing gaseous hydrogen GH2 and a liquid zone 8 containing liquid hydrogen LH2 may be provided, as long as the hydrogen H2 is in a two-phase region. In other words, after being injected into the inner container 3, hydrogen H2 has two phases with different condensation states, namely liquid and gas. That is, within the inner container 3, there is a phase boundary 9 between the liquid hydrogen LH2 and the gaseous hydrogen GH2. The gaseous hydrogen GH2 can also be called the gas phase. The liquid hydrogen LH2 can also be called the liquid phase.

[0052] The inner container 3 is entirely located inside the second container or the outer container 10. Thus, the storage container 1 has a double wall. The outer container 10 is also configured rotationally symmetric with respect to the central axis 2. Like the inner container 3, the outer container 10 includes a tubular or cylindrical base area 11 that is configured rotationally symmetric with respect to the central axis 2. The base area 11 may have a circular or approximately circular geometry when viewed in cross-section.

[0053] The base area 11 is closed off at its end faces by cover areas 12 and 13, respectively. In particular, a first cover area 12 and a second cover area 13 are provided. The cover areas 12 and 13 are curved in opposite directions, so that they curve outward with respect to the base area 11. The outer container 10 is fluid-tight and especially airtight. The outer container 10 is also made of stainless steel.

[0054] A gap 14 is provided between the inner container 3 and the outer container 10, completely surrounding or encompassing the inner container 3. The gap 14 is under vacuum. In this case, "vacuum" specifically refers to a vacuum lower than 300 mbar, preferably 10 -3 Lower than mbar, more preferably 10 -7 It is understood that the pressure is lower than mbar. Thus, the storage container 1 is vacuum insulated or vacuum-heated. The fact that the gap 14 completely "surrounds" or "encloses" the inner container 3 means, in this case, that the gap 14 extends completely around the outer perimeter of the base area 4 on the one hand, and is also provided between both cover areas 5 and 12, and between both cover areas 6 and 13, on the other hand.

[0055] Within the gap 14, there is an insulating or thermal insulation element (not shown) that completely encloses or surrounds the inner container 3. That is, the insulating element surrounds not only the base area 4 of the inner container 3 but also the cover areas 5 and 6. The insulating element serves as thermal insulation. The insulating element has a multilayer structure; that is, it contains multiple layers or strata. Therefore, this insulating element can also be called a multilayer insulating element or a multilayer thermal insulation element. In particular, the insulating element is a so-called multilayer thermal insulation material (MLI).

[0056] During the operation of storage container 1, for example when transporting it, it may be necessary to release hydrogen H2, particularly gaseous hydrogen GH2, and liquid hydrogen LH2 into the surrounding area 15. For this purpose, an exhaust chimney connected to storage container 1 by piping can be provided. According to company knowledge, this type of uninsulated exhaust chimney for discharging gases at temperatures above the liquefaction temperature of air components is a common technical solution.

[0057] If the temperature of hydrogen (H2) released from the exhaust chimney into the surrounding area falls below the condensation temperature of air components, condensation or freezing of air components may occur in the exhaust chimney. This could lead to the formation of puddles of highly oxygen-enriched cryogenic liquid in the immediate vicinity of the exhaust chimney. When liquefied air components drip, on the one hand, cold embrittlement and material failure of low-alloy steel may occur in the immediate vicinity of the exhaust chimney. On the other hand, the increased oxygen concentration in the immediate vicinity of the exhaust chimney could increase the risk of fire and / or explosion. This needs to be rectified.

[0058] Figure 2 shows a schematic cross-sectional view of an embodiment of the exhaust chimney 16 for the storage container 1.

[0059] The exhaust chimney 16 can also be called a gas exhaust chimney. This exhaust chimney 16 may be part of the storage container 1, but this is not mandatory. The exhaust chimney 16 can form a storage container system together with the storage container 1. The storage container system comprises the storage container 1, piping 17 coming from the collector or so-called header of the storage container 1, and the exhaust chimney 16 itself. The header may be part of the storage container 1. The header is or may have a collection system for collecting hydrogen H2 flowing out of the storage container 1. The header may also have, for example, a safety valve and / or a pressure reducing valve.

[0060] The piping 17 may have a double-wall structure and may have an inner wall 18 and an outer wall 19 surrounding the inner wall 18. The inner wall 18 and the outer wall 19 are each tubular. A gap 20 may be provided between the inner wall 18 and the outer wall 19. The gap 20 can be evacuated. This allows the piping 17 to be insulated or sealed by the gap 20. The gap 20 may also contain the MLI or other insulating material already mentioned.

[0061] Through this piping 17, a two-phase mixture containing liquid hydrogen LH2 and gaseous hydrogen GH2, particularly coming from the storage container 1 and especially from the header, can be supplied to the exhaust chimney 16. The piping 17 can be oriented perpendicular to the direction of gravity g.

[0062] The exhaust chimney 16 has a lower or first chimney section 21 and an upper or second chimney section 22A located above the first chimney section 21 along the direction of gravity g. An optional separator 23 may be provided between the first chimney section 21 and the second chimney section 22A. Thus, the exhaust chimney 16 is composed of two parts. The separator 23 can be used to thermally separate the second chimney section 22A from the first chimney section 21. The second chimney section 22A can also be called the chimney tip.

[0063] The first chimney section 21 has a double-wall structure and includes an inner wall 24 and an outer wall 25 surrounding the inner wall 24. A gap 26 is provided between the inner wall 24 and the outer wall 25. The gap 26 can be made into a vacuum. This allows the first chimney section 21 to be insulated or sealed by the gap 26. The gap 26 can also accommodate the MLI or other insulating material already mentioned. The inner wall 24 and the outer wall 25 can be made of stainless steel.

[0064] The second chimney section 22A is similarly a double-walled structure, including an inner wall 27 and an outer wall 28 surrounding the inner wall 27. A gap 29 is provided between the inner wall 27 and the outer wall 28. The gap 29 can be made into a vacuum. This allows the second chimney section 22A to be insulated or sealed by the gap 29. The gap 29 can also be filled at least partially with glass foam, particularly closed-cell glass foam.

[0065] The second chimney section 22A is tubular and includes an outlet opening 30 through which gaseous hydrogen GH2 flows out during operation of the exhaust chimney 16. The gaseous hydrogen GH2 may burn, for example, at the outlet opening 30. The second chimney section 22A extends along the direction of gravity g. The inner wall 27 and outer wall 28 can be made of stainless steel.

[0066] In the orientation shown in Figure 2, the outlet opening 30 is open upwards. There is no free surface where air condensation and snow accumulation can occur. The goal when gaseous hydrogen GH2 flows out of the outlet opening 30 is to prevent air freezing. This can be achieved, in particular, by allowing gaseous hydrogen GH2 to flow out of the outlet opening 30 at high speed.

[0067] The first chimney section 21 is similarly tubular and extends along the direction of gravity g. A separator, more specifically a phase separator, or phase separator 31 is attached to the first chimney section 21. The phase separator 31 is a gravity separator and can therefore be called as such. The phase separator 31 can also be simply called a separator or more specifically a gravity separator. Preferably, the phase separator 31 may have the shape of a flange or a T-shaped component, which can be used to connect the piping 17 to the exhaust chimney 16.

[0068] The phase separator 31 can be configured to be rotationally symmetric with respect to the axis of symmetry or the central axis 32. The exhaust chimney 16 itself or the chimney sections 21, 22A can also be configured to be rotationally symmetric with respect to the axis of symmetry or the central axis 33. The central axis 32 is oriented perpendicular to the central axis 33.

[0069] The phase separator 31 is suitable for separating a two-phase mixture containing liquid hydrogen LH2 and gaseous hydrogen GH2, which is transported through the piping 17, into liquid hydrogen LH2 and gaseous hydrogen GH2. In this case, the separation is carried out by gravity. Since liquid hydrogen LH2 has a higher density than gaseous hydrogen GH2, the liquid hydrogen LH2 moves downward along the direction of gravity g, and the gaseous hydrogen GH2 moves upward in the opposite direction of gravity g.

[0070] The piping 17 is fluid-tightly connected to the phase separator 31. Similarly, the phase separator 31 has a double-walled structure. Viewed along the direction of gravity g, the sump 34 of the first chimney section 21 is located below the phase separator 31. This sump 34 may be pot-shaped or bowl-shaped. Similarly, the sump 34 has a double-walled structure.

[0071] The evaporator unit housing 35 is connected to the sump 34. The evaporator unit housing 35 also has a double-wall structure. Viewed along the direction of gravity g, the evaporator unit housing 35 is positioned between the sump 34 and the phase separator 31. The first chimney section 21 and the second chimney section 22A jointly surround the interior 36 of the exhaust chimney 16. The interior 36 can be cylindrical, particularly cylindrical.

[0072] The evaporator unit housing 35 houses the evaporator unit 37, particularly in the form of a heating block. The evaporator unit 37 is suitable for evaporating liquid hydrogen LH2 by releasing heat Q into the interior 36. The evaporator unit 37 can be heated electrically. The evaporator unit 37 can be heated by induction using a heating coil and / or heating conductor.

[0073] The evaporator unit 37 has an outer surface 38 facing the surrounding area 15 and an inner surface 39 facing the interior 36. As a result, the outer surface 38 is separated from the interior 36, and the inner surface 39 is separated from the surrounding area 15. In particular, the evaporator unit 37 is also suitable for transferring heat Q from the outer surface 38 to the inner surface 39, and therefore from the surrounding area 15 to the interior 36.

[0074] The evaporator unit 37 is sized so that when its inner surface 39 is in contact with liquid hydrogen LH2 during operation of the exhaust chimney 16, the temperature of its outer surface 38 does not drop below the condensation temperature of the air components. The evaporator unit 37 is insulated up to its outer surface 38.

[0075] A drain pipe or condensate discharge pipe 40 passes through the evaporator unit 37. The condensate discharge pipe 40 extends from the interior 36 to the periphery 15. The condensate discharge pipe 40 leads to a water separator or condensate separator 41 in the exhaust chimney. The condensate separator 41 prevents liquid hydrogen LH2 and / or gaseous hydrogen GH2 from being released. For example, the condensate separator 41 may have a float switch that floats only on water H2O.

[0076] Upstream of the condensate separator 41, a shut-off valve 42 may be provided inside or on the condensate discharge pipe 40. The condensate discharge pipe 40 can be opened or closed using the shut-off valve 42. This shut-off valve 42 may be incorporated into the evaporator unit 37.

[0077] Optionally, a low-temperature switch 43 can be installed on the evaporator unit 37. The low-temperature switch 43 controls the shut-off valve 42, allowing it to selectively close or open, for example, the shut-off valve 42. For this purpose, an operable connection 44 may be provided between the low-temperature switch 43 and the shut-off valve 42. The operable connection 44 can be connected wirelessly or wired. A condensate separator 41 can be used to separate water (H2O) and send it to the outlet 45.

[0078] The function of the exhaust chimney 16 is described below. As already mentioned, a low-temperature two-phase mixture consisting of liquid hydrogen LH2 and gaseous hydrogen GH2 is sent to the exhaust chimney 16 in one go via piping 17. The two-phase mixture containing liquid hydrogen LH2 and gaseous hydrogen GH2 flows into the interior 36 via the phase separator 31. There, the phase separator 31 separates the two-phase mixture, so the gaseous hydrogen GH2 rises in the opposite direction to gravity g and flows out into the surrounding area 15 from the outlet opening 30. The gaseous hydrogen GH2 may burn at the outlet opening 30.

[0079] Liquid hydrogen LH2 flows downward into the sump 34 from the phase separator 31 along the direction of gravity g. Using the heat Q supplied from the evaporator unit 37, the liquid hydrogen LH2 evaporates and rises as gaseous hydrogen GH2 in the opposite direction of gravity g, flowing out from the outlet opening 30.

[0080] The gaseous hydrogen GH2 displaces the air present in the interior 36. Once all the liquid hydrogen LH2 has evaporated, the interior 36 is filled with air again, which is then pushed out of the interior 36 again when new hydrogen H2 is introduced into the exhaust chimney 16. The exhaust chimney 16 is specifically designed to withstand the ignition of a loud gas, which is a mixture of oxygen and gaseous hydrogen GH2 in the interior 36.

[0081] The double-wall structure of the exhaust chimney 16 prevents cryogenic temperatures outside the exhaust chimney 16, thereby preventing condensation and freezing of air components outside the exhaust chimney 16. For this purpose, an additional barrier can be provided. This additional barrier can be realized by dividing the exhaust chimney 16 into a first chimney section 21 and a second chimney section 22A by a separator 23. Furthermore, the gaps 26 and 29 enable vacuum insulation or vacuum thermal insulation in both the first chimney section 21 and the second chimney section 22A.

[0082] Therefore, the exhaust chimney 16 can provide low-temperature stable insulation or thermal insulation in the temperature range from -186°C, which corresponds to the dew point of oxygen, to 3K, the lowest temperature of helium. This insulation can be formed uniformly along the entire length of the exhaust chimney 16. Steel double-wall vacuum insulation is the most inexpensive solution.

[0083] The second chimney section 22A can be formed to be fire-resistant. Preferably, the second chimney section 22A does not have non-metallic mounting parts and / or non-metallic insulation in the gap 29, because non-metallic mounting parts may not be heat-resistant. However, as already mentioned, the gap 29 may be filled with, for example, glass foam, perlite, or other filler that is both cold-resistant and hot-resistant.

[0084] The liquid hydrogen LH2 that reaches the exhaust chimney 16 is advantageously evaporated in the evaporator unit 37 at low temperatures. Due to the low evaporation temperature of liquid hydrogen LH2, the surrounding area 15 is used as a heat source. The evaporator unit 37 can function as an external heat storage device. Preferably, the evaporator unit 37 is manufactured from stainless steel. In particular, the evaporator unit 37 is designed to be used as a heat storage device on the one hand, and on the other hand, according to its specifications, so that the outer surface 38 of the evaporator unit 37 does not fall below the condensation temperature of air components. This enables a safety-technically essential and novel design.

[0085] The applicable additional safety measure is to protect the surrounding area 15 from the possibility of liquid hydrogen LH2 leaking from the sump 34, particularly from the condensate separator 41. Multiple measures may also be put in place to ensure that liquid hydrogen LH2 leaks are prevented.

[0086] As one measure, the condenser separator 41 can be configured to remain closed in the presence of liquid hydrogen LH2. As already mentioned, the condenser separator 41 may have a float switch that floats only on water H2O and not on liquid hydrogen LH2. This feature is based on the fact that the density of liquid hydrogen LH2 is approximately 70 kg / m3, which is significantly lower than that of water, which has a density of approximately 1000 kg / m3. As an additional measure, a shut-off valve 42 with a cryogenic switch 43 can be used to prevent liquid hydrogen LH2 from reaching the condenser separator 41.

[0087] The design of the exhaust chimney 16, as already described, allows it to be installed in close proximity to the safety valve of the storage container 1. This means that a long exhaust pipe from the safety valve to the exhaust chimney 16 is unnecessary, and the water H2 is heated by heat conduction from the surroundings 15 before reaching the exhaust chimney 16. Stationary heating is performed by the external evaporator unit 37. The evaporator unit 37 can be used as a circulating evaporator.

[0088] The double-walled design of the safety valve's discharge pipe ensures that even if a leak occurs in either part of the discharge pipe, hydrogen (H2) will be collected by the secondary barrier of the discharge pipe and will not reach the surrounding environment directly. This is important when hydrogen equipment is installed indoors or in a confined space.

[0089] Figure 3 shows a schematic cross-sectional view of a further embodiment of the second chimney section 22B mentioned earlier.

[0090] All the specifications described above relating to the first chimney section 22A are also applicable to the second chimney section 22B, and vice versa. The second chimney section 22B shown in Figure 3 differs from the embodiment of the second chimney section 22A already described in that the outlet opening 30 of the second chimney section 22B is recessed inward and has a cross-sectional narrowing section 46. The cross-sectional narrowing section 46 can be achieved, for example, by reducing the outer diameter da and / or inner diameter di of the second chimney section 22B toward the outlet opening 30.

[0091] Due to the cross-sectional narrowing section 46, the outlet opening 30 has a diameter d30 that is smaller than the inner diameter di of the second chimney section 22B. The cross-sectional narrowing section 46 allows the velocity of gaseous hydrogen GH2 to be accelerated as it flows out of the outlet opening 30.

[0092] Optionally, the second chimney section 22B has a flow deflector 47 positioned at a distance in front of the outlet opening 30. The flow deflector 47 prevents water H2O or snow from entering the outlet opening 30. The flow deflector 47 can be configured to be rotationally symmetric with respect to an axis of symmetry or a central axis 48. The central axis 48 can coincide with the central axis 33.

[0093] The flow diverter 47 has a frustoconical or conical front surface 49 facing the outlet opening 30 and a back surface 50 away from the outlet opening 30. The back surface 50 may be curved. Furthermore, the flow diverter 47 has a diameter d47 that is the same as or smaller than the outer diameter da and larger than the diameter d30. The flow diverter 47 can be supported by a plurality of support columns 51, 52 in the second chimney section 22B, particularly in the section narrowed 46. The support columns 51, 52 support the flow diverter 47.

[0094] Although the present invention has been described using examples, it is possible to modify the present invention in various ways. [Explanation of symbols]

[0095] 1. Storage container 2 center axis 3 Inner container 4 Base Area 5. Coverage Area 6. Coverage Area 7. Gas Zone 8 Liquid Zones 9 phase boundary 10 Outer container 11 Base Area 12 Coverage Areas 13 Coverage Area 14 Gap 15 Surroundings 16. Exhaust chimney 17 Piping 18 Inner wall 19 Exterior Wall 20 gap 21 Chimney section 22A Chimney section 22B Chimney section 23 Separator 24 Inner wall 25 Exterior Wall 26 Gap 27 Inner wall 28 Exterior Wall 29 Gap 30 outlet opening 31-phase separator 32 Center axis 33 Central axis 34 Samp 35 Evaporator unit housing 36 Internal 37 Evaporator Unit 38 Exterior 39. Inner self 40 Condensate discharge pipe 41 Condensate separator 42 Shut-off valve 43 Low Temperature Switch 44 Operable connections 45 Outlet 46 Cross-sectional narrowing 47 Flow derivatives 48 Center axis 49 Front 50 back 51 Post 52 Pillar da outer diameter inner diameter d30 diameter d47 diameter g direction of gravity GH2 Cryogenic Agent / Hydrogen H2 Cryogenic Agent / Hydrogen H2O (Water) LH2 Cryogenic Agent / Hydrogen Q Heat

Claims

1. The discharge chimney (16) is for discharging a cryogen (H2) having a liquid phase (LH2) and a gaseous phase (GH2) to the area surrounding the discharge chimney (16), - The structure comprises tubular chimney sections (21, 22A, 22B) extending along the direction of gravity (g), and the inner walls (24, 27) of the tubular chimney sections (21, 22A, 22B) surrounding the interior (36) of the exhaust chimney (16) are insulated from the surroundings (15) (25, 28, 26, 29), and the tubular chimney sections (21, 22A, 22B) have a lower chimney section (21) and an upper chimney section (22A, 22B), and the upper chimney sections (21, 22A, 22B) have an outlet opening (30) through which the rising gas phase (GH2) flows out to the surroundings (15). - The system includes a phase separator (31) attached to the lower chimney section (21) that separates the two-phase cryogenic agent, which can be supplied via piping (17), into the liquid phase (LH2) and the gas phase (GH2), - The system includes an evaporator unit (37) that releases heat into the interior (36) to evaporate the separated liquid phase (LH2) inside the interior (36). Exhaust chimney (16).

2. The exhaust chimney according to claim 1, wherein the chimney sections (21, 22A, 22B) have a double-wall structure for heat insulation.

3. The exhaust chimney according to claim 1 or 2, wherein the chimney section (21, 22A, 22B) has an inner wall (24, 27) facing the interior (36) and an outer wall (25, 28) facing the surrounding area (15), and a vacuum gap (26, 29) is provided between the inner wall (24, 27) and the outer wall (25, 28).

4. The exhaust chimney according to any one of claims 1 to 3, wherein the evaporator unit (37) is attached to the lower chimney section (21), and the phase separator (31) is positioned above the evaporator unit (37) when viewed along the direction of gravity (g).

5. The exhaust chimney according to any one of claims 1 to 4, wherein the lower chimney section (21) has a sump (34) that closes the end face of the lower chimney section (21), and the evaporator unit (37) is positioned between the sump (34) and the phase separator (31) when viewed along the direction of gravity (g).

6. Furthermore, the exhaust chimney according to any one of claims 1 to 5, further comprising a condensate discharge pipe (40) that extends from the sump (34) through the evaporator unit (37) to the surrounding area (15).

7. Furthermore, the exhaust chimney according to claim 6, further comprising a condensate separator (41) for separating water (H2O) from the liquid phase (LH2), wherein the condensate discharge pipe (40) is connected to the condensate separator (41).

8. Furthermore, the exhaust chimney according to claim 7 has a shut-off valve (42) for closing and opening the condensate discharge pipe (40).

9. The exhaust chimney according to claim 8, further comprising a low-temperature switch (43) incorporated within the evaporator unit (37) for controlling the shut-off valve (42).

10. The exhaust chimney according to any one of claims 1 to 9, wherein the evaporator unit (37) has an outer surface (38) facing the surrounding area (15) and an inner surface (39) facing the interior (36).

11. The exhaust chimney according to claim 10, wherein the evaporator unit (37) is configured to transfer heat (Q) from the outer surface (38) to the inner surface (39).

12. The exhaust chimney according to any one of claims 1 to 11, wherein the upper chimney sections (22A, 22B) are thermally separated from the lower chimney section (21) using a separator (23).

13. The exhaust chimney according to any one of claims 1 to 12, wherein the upper chimney section (22B) has a cross-sectionally narrowed section (46) provided at the outlet opening (30).

14. The exhaust chimney according to any one of claims 1 to 13, wherein the upper chimney section (22B) has a flow diverter (47) located downstream of the outlet opening (30).

15. The exhaust chimney according to any one of claims 1 to 14, wherein the upper chimney section (22B) is fire-resistant.

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