Discharge chimney

Abstract

The invention relates to a discharge chimney (16) for discharging a cryogen (H2), which has a liquid phase (LH2) and a gaseous phase (GH2), into the surroundings (15) of the discharge chimney (16), comprising a tubular chimney section (21, 22A, 22B), which extends along the direction of the gravitational force (g), wherein the interior (36) of the discharge chimney (16) is heat-insulated from the surroundings (15); 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

[0001] Description

[0002] Exhaust chimney

[0003] The invention relates to a discharge chimney for discharging a cryogen having a liquid phase and a gaseous phase to an environment of the discharge chimney.

[0004] During operation of a hydrogen storage tank, it may be necessary to release hydrogen, particularly gaseous hydrogen, into the storage tank's surroundings. For this purpose, a discharge chimney may be provided according to internal company knowledge. Such a discharge chimney may be made, for example, from a single-walled, uninsulated steel pipe. When releasing hydrogen into the environment, the temperature on the outside of the discharge chimney may be below the condensation temperature of air components. This can lead to condensation or freezing of air components, particularly oxygen, on the outside of the discharge chimney.

[0005] Condensation of air components can lead to the formation of cryogenic liquid pools with high oxygen enrichment in the immediate vicinity of the exhaust stack. Dripping of the liquefied air components can, on the one hand, cause cold embrittlement and material failure of low-alloy steel in the immediate vicinity of the exhaust stack. On the other hand, a high oxygen concentration in the immediate vicinity of the exhaust stack can lead to an increased risk of fire and / or explosion. This must be improved.

[0006] Against this background, it is an object of the present invention to provide an improved discharge chimney.

[0007] Accordingly, a discharge stack for discharging a cryogen having a liquid phase and a gaseous phase to an environment of the discharge stack is proposed.The discharge chimney comprises a tubular chimney section which extends along a direction of gravity, wherein an inner wall of the tubular chimney section which surrounds an interior of the discharge chimney is thermally insulated from the environment, and wherein the tubular chimney section has a lower chimney section and an upper chimney section, wherein the upper chimney section has an outlet opening through which the upwardly rising, gaseous phase exits into the environment, a phase separator which is attached to the lower chimney section and is designed to separate the two-phase cryogen which can be supplied via a line into the liquid phase and the gaseous phase, and an evaporator unit for releasing heat to the interior for evaporating the separated liquid phase in the interior.

[0008] Because the interior of the exhaust chimney is thermally insulated from the surroundings, condensation or freezing of air particles on the outside of the exhaust chimney is reliably prevented. This particularly reduces the risk of condensed air particles dripping down the chimney.

[0009] The cryogen can be hydrogen. Therefore, the term "cryogen" can be replaced with the term "hydrogen" and vice versa. However, the cryogen can also be liquid helium or the like. The exhaust stack can also be referred to as a hydrogen exhaust stack. Preferably, the cryogen is fed to the exhaust stack as a two-phase mixture comprising the liquid phase and the gaseous 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 gaseous phase is preferably gaseous hydrogen. Accordingly, the term "gaseous phase" can be replaced with the term "gaseous hydrogen" and vice versa.

[0010] With the help of the discharge chimney, in particular, the gaseous phase can be released into the environment. To release the liquid phase to the environment, the liquid phase is first evaporated with the help of the evaporator unit and released into the environment as a gaseous phase. The chimney section can be designed rotationally symmetrically to a symmetry or central axis. The discharge chimney can have multiple chimney sections, which can be arranged one above the other when viewed along the direction of gravity. In particular, the interior of the discharge chimney is thermally insulated from the environment in such a way that it has low-temperature stable insulation, which is stable, for example, in a temperature range of -186 °C, which corresponds to the dew point of oxygen, and 3 K as the lowest temperature for helium as a cryogen. The thermal insulation can be designed uniformly over the entire length of the discharge chimney.However, this is not mandatory. The simplest and most cost-effective thermal insulation solution is a double-walled vacuum insulation made of steel, especially stainless steel.

[0011] With the help of the phase separator, the two-phase cryogen mixture is fed into the interior of the discharge stack. As the two-phase mixture enters the interior of the discharge stack, the gaseous phase separates from the liquid phase. The gaseous phase moves upwards, particularly against the direction of gravity, toward an outlet opening of the discharge stack. The liquid phase moves downwards, particularly along the direction of gravity, toward a sump of the discharge stack.

[0012] The phase separator can also be referred to as a separator, in particular as a phase separator. In particular, the phase separator is a gravity separator and can therefore also be referred to as such. The phase separator can also be referred to simply as a separator, in particular as a gravity separator. The phase separator can, for example, have the form of a flange or T-piece, with the aid of which a line through which the two-phase mixture is fed can be connected to the discharge chimney. The phase separator can be constructed rotationally symmetrically to a symmetry or central axis. The central axis of the phase separator is oriented, in particular, perpendicular to the central axis of the chimney section.

[0013] The phase separator is particularly designed to separate the two-phase mixture comprising the liquid phase and the gaseous phase, supplied via the aforementioned line, into the liquid phase and the gaseous phase by gravity. The separation occurs, in particular, due to gravity. The liquid phase has a greater density than the gaseous phase, so that the liquid phase moves downwards away from the outlet opening along the direction of gravity, while the gaseous phase moves upwards toward the outlet opening, counter to the direction of gravity.

[0014] The chimney section preferably has an evaporator unit receptacle for receiving the evaporator unit. This means, in particular, that the evaporator unit is attached to the chimney section, in particular to the lower chimney section. The evaporator unit can be a heat block. The evaporator unit is particularly suitable for dissipating heat to the interior and thus to the liquid phase in order to evaporate the liquid phase. The evaporator unit can be electrically heated. For this purpose, the evaporator unit can be heated, for example, inductively, with the aid of a heating coil and / or with the aid of a heating conductor.

[0015] According to one embodiment, the chimney section is double-walled for thermal insulation.

[0016] The double-walled design of the chimney section allows for cost-effective thermal insulation. For example, the chimney section is made of stainless steel.

[0017] According to a further embodiment, the chimney section has the inner wall facing the interior and an outer wall facing the environment, wherein a gap subjected to a vacuum is arranged between the inner wall and the outer wall.

[0018] The inner wall is therefore facing away from the environment, and the outer wall is facing away from the interior. A "vacuum" in this case is defined in particular as a pressure of less than 300 mbar, preferably less than 10 -3 mbar, more preferably less than 10 -7mbar. The discharge chimney is thus vacuum-insulated or vacuum-insulated. A multi-layer insulation element or a multi-layer thermal insulation element can also be arranged in the gap. In particular, so-called multilayer insulation (MLI) can be arranged in the gap. If high heat resistance is required, a heat-insulating glass foam, in particular a closed-cell glass foam, can also be placed in the gap for thermal insulation. According to a further embodiment, the phase separator and the evaporator unit are attached to the lower chimney section, wherein the phase separator is positioned above the evaporator unit as viewed along the direction of gravity.

[0019] Accordingly, the evaporator unit is positioned below the phase separator along the direction of gravity. Thus, the liquid phase flows from the phase separator by gravity to the evaporator unit, where the liquid phase is evaporated into the gaseous phase.

[0020] According to a further embodiment, the lower chimney section has a sump closing the chimney section at the front, wherein the evaporator unit is positioned between the sump and the phase separator, viewed along the direction of gravity.

[0021] The sump is therefore located below the evaporator unit, as viewed along the direction of gravity. Water, for example, can condense in the sump, which can then be drained from the sump. The sump can be pot-shaped or bowl-shaped. The sump is preferably also double-walled and thus thermally insulated.

[0022] According to a further embodiment, the discharge chimney has a condensate discharge line which is led from the sump through the evaporator unit into the environment.

[0023] The condensate drain line can be used to drain water from the sump into the environment, particularly into a drain. The condensate drain line can also be referred to as a drainage line. The condensate drain line leads to a water separator or condensate separator in the discharge stack.

[0024] According to a further embodiment, the discharge stack comprises a condensate separator for separating water from the liquid phase, with the condensate discharge line leading to the condensate separator. The condensate separator, in particular, prevents the release of the liquid phase and / or the gaseous phase to the environment. For example, the condensate separator may comprise a float switch that only floats on water. The condensate separator may be referred to as a water separator.

[0025] According to a further embodiment, the discharge chimney has a shut-off valve for shutting off and releasing the condensate discharge line.

[0026] In particular, the shut-off valve is located upstream of the condensate separator in or on the condensate discharge line. The shut-off valve can be used to close or open the condensate discharge line. The shut-off valve can be integrated into the evaporator unit.

[0027] According to a further embodiment, the discharge chimney has a low temperature switch integrated into the evaporator unit for controlling the shut-off valve.

[0028] The low-temperature switch can control the shut-off valve, for example, to close and open it. For this purpose, a operative connection can be provided between the low-temperature switch and the shut-off valve. The operative connection can be wireless or wired. The shut-off valve with the low-temperature switch can be used to prevent the liquid phase from entering the condensate separator.

[0029] According to a further embodiment, the evaporator unit has an outer side facing the environment and an inner side facing the interior.

[0030] Accordingly, the outside faces away from the interior. The inside thus faces away from the environment. In particular, the evaporator unit can be suitable for transporting heat from the environment to the interior. In particular, the evaporator unit is dimensioned such that, during operation of the exhaust chimney, the temperature on the outside does not fall below a temperature below which air components condense when the inside is in contact with the liquid phase. The evaporator unit is in particular insulated except for the outside.

[0031] According to a further embodiment, the evaporator unit is designed to transport heat from the outside to the inside.

[0032] This means, in particular, that the evaporator unit is designed to transport heat from the environment to the interior to evaporate the liquid phase. Thus, the environment can be used as a heat source for the evaporator unit.

[0033] The phase separator and the evaporator unit are preferably attached to the lower chimney section, which is also referred to below as the first chimney section. The upper chimney section, which is also referred to below as the second chimney section, can also be referred to as the chimney tip. The second chimney section is preferably firmly connected to the first chimney section. The phase separator opens in particular into the first chimney section, which in particular also has the sump and the evaporator unit receptacle. Both the first chimney section and the second chimney section are preferably double-walled. This means that both the first chimney section and the second chimney section can each have an inner wall and an outer wall enclosing the inner wall. A gap as mentioned above, which can be subjected to a vacuum, is provided between the inner wall and the outer wall.Thermal insulation can also be placed in the gap. The second chimney section is preferably fireproof. For this purpose, a fireproof insulation element, for example in the form of glass foam, in particular a closed-cell glass foam, can be accommodated in the gap of the second chimney section.

[0034] According to a further embodiment, the second chimney section is thermally separated from the first chimney section by means of a separator.

[0035] In particular, the first chimney section and the second chimney section are connected to each other by means of the separator. The connection between the first chimney section and the second chimney section can be detachable. According to a further embodiment, the second chimney section has a cross-sectional constriction provided at the outlet opening.

[0036] The cross-sectional constriction can be achieved, for example, by reducing the outer diameter and / or inner diameter of the second chimney section toward the outlet opening. As a result, the outlet opening has a diameter that is smaller than the outer diameter and / or the inner diameter of the second chimney section. The cross-sectional constriction can accelerate the gaseous phase as it exits the outlet opening. Any condensed air components are then entrained by the escaping gaseous phase. This prevents the condensed air components from accumulating and dripping down.

[0037] According to a further embodiment, the second chimney section has a flow-around body which is arranged downstream of the outlet opening.

[0038] "Downstream" is understood here to refer to the flow direction of the gaseous phase exiting the outlet opening. This means, in particular, that the flow-around body is positioned at a defined distance in front of the outlet opening. The flow-around body prevents, for example, water or snow from entering the outlet opening. The flow-around body can be constructed rotationally symmetrically to a symmetry or central axis. The central axis of the flow-around body can coincide with the central axis of the chimney section. The flow-around body preferably has a truncated cone-shaped or conical front side facing the outlet opening and a rear side facing away from the outlet opening. The rear side can, for example, be flat or curved.The flow-around body further has a diameter that is equal to or smaller than the outer diameter of the second chimney section and preferably larger than the diameter of the outlet opening. The flow-around body can be supported by several struts on the second chimney section, in particular on the cross-sectional constriction. The struts support the flow-around body. "One" in this case is not necessarily limited to exactly one element. Rather, multiple elements, such as two, three, or more, can also be provided. Any other counting term used here should also not be understood to imply a precise limitation to the exact number of elements. Rather, numerical deviations upwards and downwards are possible.

[0039] Further possible implementations of the exhaust chimney also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the exhaust chimney.

[0040] Further advantageous embodiments of the discharge chimney are the subject of the dependent claims and the exemplary embodiments of the discharge chimney described below. The discharge chimney is explained in more detail below using preferred embodiments with reference to the attached figures.

[0041] Fig. 1 shows a schematic sectional view of an embodiment of a storage container;

[0042] Fig. 2 shows a schematic sectional view of an embodiment of a discharge chimney for the storage tank according to Fig. 1; and

[0043] Fig. 3 shows a schematic sectional view of an embodiment of a chimney section for the discharge chimney according to Fig. 2.

[0044] In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise stated.

[0045] Fig. 1 shows a schematic sectional view of an embodiment of a storage container 1.

[0046] The storage container 1 can also be referred to as a storage tank.

[0047] Storage vessel 1 is preferably suitable for storing hydrogen H2 (boiling point: 1 bara: 20.268 K = -252.882 °C). Therefore, storage vessel 1 can also be referred to as a hydrogen storage vessel or hydrogen storage tank. However, storage vessel 1 can also be used for other cryogenic liquids. Examples of cryogenic fluids or liquids, or cryogens for short, in addition to the aforementioned hydrogen H2, are 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 can be a transport container. For example, the storage container 1 can be used to transport liquid hydrogen (LH2). The storage container 1 can be part of a vehicle, in particular a watercraft. In this case, the storage container 1 is suitable for mobile applications. However, the storage container 1 can also be used stationary, for example, in building services engineering.

[0049] The storage container 1 is constructed rotationally symmetrically to a symmetry or central axis 2. The central axis 2 is oriented perpendicular to a direction of gravity g. The storage container 1 comprises a first container or inner container 3, which is also constructed rotationally symmetrically to the central axis 2. The inner container 3 comprises a tubular or cylindrical base section 4, which is also constructed rotationally symmetrically to the central axis 2. The base section 4 can have a circular or approximately circular geometry in cross-section.

[0050] The base section 4 is closed at both ends by a cover section 5, 6. The cover sections 5, 6 are curved. A first cover section 5 and a second cover section 6 are curved in opposite directions, so that the cover sections 5, 6 are curved outward relative to the base section 4. The inner container 3 is fluid-tight, in particular gas-tight. The inner container 3 is made of steel.

[0051] The liquid hydrogen LH2 is contained in the inner container 3. As long as the hydrogen H2 is in the two-phase region, a gas zone 7 with gaseous hydrogen GH2 and a liquid zone 8 with liquid hydrogen LH2 can be provided in the inner container 3. After being filled into the inner container 3, the hydrogen H2 therefore has two phases with different states of aggregation, namely liquid and gaseous. This means that in 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 referred to as the gaseous phase. The liquid hydrogen LH2 can also be referred to as the liquid phase.

[0052] The inner container 3 is arranged entirely within a second container or outer container 10. The storage container 1 is thus double-walled. The outer container 10 is also constructed rotationally symmetrically to the central axis 2. The outer container 10, like the inner container 3, comprises a tubular or cylindrical base section 11, which is constructed rotationally symmetrically to the central axis 2. The base section 11 can have a circular or approximately circular geometry in cross-section.

[0053] The base section 11 is closed at each end by a lid section 12, 13. In particular, a first lid section 12 and a second lid section 13 are provided. The lid sections 12, 13 are curved in opposite directions, so that the lid sections 12, 13 are curved outward relative to the base section 11. The outer container 10 is fluid-tight, in particular gas-tight. 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 enclosing the inner container 3. A vacuum is applied to the gap 14. A "vacuum" in this case is understood to mean, in particular, a pressure of less than 300 mbar, preferably less than 10 -3 mbar, more preferably less than 10 -7 mbar. The storage container 1 is thus vacuum-insulated or vacuum-insulated. The fact that the gap 14 completely "encloses" or "envelops" the inner container 3 means, in this case, that the gap 14, on the one hand, completely surrounds the base section 4 and, on the other hand, is also provided between the two cover sections 5, 12 and between the two cover sections 6, 13.

[0055] A thermal insulation element (not shown) that completely encloses or surrounds the inner container 3 is provided in the gap 14. This means that the insulation element encloses both the base section 4 and the lid sections 5, 6 of the inner container 3. The insulation element serves for thermal insulation. The insulation element is multi-layered. This means that the insulation element comprises a plurality of layers. The insulation element can therefore also be referred to as a multi-layer insulation element or a multi-layer thermal insulation element. In particular, the insulation element is a so-called multilayer insulation (MLI).

[0056] During operation of the storage tank 1, for example, when it is being transported, it may be necessary to release hydrogen H2, in particular gaseous hydrogen GH2, but also liquid hydrogen LH2, into an environment 15 of the storage tank 1. For this purpose, a discharge chimney may be provided, which is connected to the storage tank 1 by means of a line. According to internal company knowledge, such a non-insulated discharge chimney for discharging gases with temperatures above the liquefaction temperature of air components is a common technical solution.

[0057] If the temperature of the hydrogen H2 released into the environment via the exhaust stack is below the condensation temperature of the air components, condensation or freezing of air components can occur at the exhaust stack. This can lead to the formation of cryogenic liquid pools with high oxygen enrichment in the immediate vicinity of the exhaust stack. Dripping of the liquefied air components can, on the one hand, result in cold embrittlement and material failure of low-alloy steel in the immediate vicinity of the exhaust stack. On the other hand, a high oxygen concentration in the immediate vicinity of the exhaust stack can lead to an increased risk of fire and / or explosion. This must be improved.

[0058] Fig. 2 shows a schematic sectional view of an embodiment of a discharge chimney 16 for the storage tank 1.

[0059] The discharge chimney 16 may be referred to as a gas discharge chimney. The discharge chimney 16 may be part of the storage vessel 1. However, this is not mandatory. The discharge chimney 16, together with the storage vessel 1, may form a storage vessel arrangement. The storage vessel arrangement comprises the storage vessel 1, a line 17 coming from a collector or a so-called header of the storage vessel 1, and the discharge chimney 16 itself. The header may be part of the storage vessel 1. The header may be or comprise a collection system for collecting hydrogen H2 escaping from the storage vessel 1. The header may also comprise, for example, safety and / or relief valves.

[0060] The line 17 can be double-walled and 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 can be provided between the inner wall 18 and the outer wall 19. A vacuum can be applied to the gap 20. This allows the line 17 to be thermally insulated or insulated using the gap 20. The gap 20 can also accommodate an MLI as mentioned above or another insulating material.

[0061] A two-phase mixture comprising liquid hydrogen LH2 and gaseous hydrogen GH2, which comes from the storage vessel 1, in particular from the header, can be fed to the discharge stack 16 via line 17. Line 17 can be oriented perpendicular to the direction of gravity g.

[0062] The discharge chimney 16 has a lower or first chimney section 21 and an upper or second chimney section 22A arranged above the first chimney section 21 along the direction of gravity g. An optional separator 23 can be provided between the first chimney section 21 and the second chimney section 22A. The discharge chimney 16 is thus in two parts. With the aid of the separator 23, the second chimney section 22A can be thermally separated from the first chimney section 21. The second chimney section 22A can also be referred to as the chimney tip.

[0063] The first chimney section 21 is double-walled and comprises 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 subjected to a vacuum. As a result, the first chimney section 21 can be thermally insulated or insulated with the help of the gap 26. An MLI as mentioned above or another insulating material can also be accommodated in the gap 26. The inner wall 24 and the outer wall 25 can be made of stainless steel. The second chimney section 22A is also double-walled and comprises 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 subjected to a vacuum. As a result, the second chimney section 22A can be thermally insulated or isolated by means of the gap 29.The gap 29 can also be filled at least in sections with glass foam, in particular with closed-pore glass foam.

[0064] The second chimney section 22A is tubular and includes an outlet opening 30 from which gaseous hydrogen GH2 exits during operation of the discharge chimney 16. The gaseous hydrogen GH2 can, for example, be combusted at the outlet opening 30. The second chimney section 22A extends along the direction of gravity g. The inner wall 27 and the outer wall 28 can be made of stainless steel.

[0065] In the orientation shown in Fig. 2, the outlet opening 30 is open at the top. There are no exposed surfaces for the formation of air condensate or snow deposition. The objective of the gaseous hydrogen GH2 flowing out of the outlet opening 30 is to prevent the formation of air ice. This can be achieved, in particular, by a high exit velocity of the gaseous hydrogen GH2 from the outlet opening 30.

[0066] The first chimney section 21 is also tubular and runs along the direction of gravity g. A separator, in particular 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 also be referred to as such. The phase separator 31 can also be referred to simply as a separator, in particular as a gravity separator. The phase separator 31 preferably has the shape of a flange or T-piece, with the aid of which the line 17 can be connected to the discharge chimney 16.

[0067] The phase separator 31 can be constructed rotationally symmetrically to a symmetry or central axis 32. The discharge chimney 16 itself, or the chimney sections 21, 22A, can also be constructed rotationally symmetrically to a symmetry or central axis 33. The central axis 32 is oriented perpendicular to the central axis 33.

[0068] The phase separator 31 is suitable for separating the two-phase mixture comprising liquid hydrogen LH2 and gaseous hydrogen GH2 supplied via line 17 into liquid hydrogen LH2 and gaseous hydrogen GH2. The separation occurs due to gravity. The liquid hydrogen LH2 has a greater density than the gaseous hydrogen GH2, so that the liquid hydrogen LH2 moves downward along the direction of gravity g, and the gaseous hydrogen GH2 moves upward against the direction of gravity g.

[0069] Line 17 is fluid-tightly connected to phase separator 31. Phase separator 31 is also double-walled. Viewed along the direction of gravity g, a sump 34 of the first chimney section 21 is provided below phase separator 31. Sump 34 can be pot-shaped or bowl-shaped. Sump 34 is also double-walled.

[0070] Adjacent to the sump 34 is an evaporator unit receptacle 35. The evaporator unit receptacle 35 is also double-walled. Viewed along the direction of gravity g, the evaporator unit receptacle 35 is positioned between the sump 34 and the phase separator 31. The first chimney section 21 and the second chimney section 22A together enclose an interior space 36 of the discharge chimney 16. The interior space 36 can be cylindrical, in particular circular-cylindrical.

[0071] An evaporator unit 37, particularly in the form of a heat block, is accommodated in the evaporator unit receptacle 35. The evaporator unit 37 is suitable for transferring heat Q to the interior space 36 in order to evaporate liquid hydrogen LH2. The evaporator unit 37 can be heated electrically. For this purpose, the evaporator unit 37 can be heated inductively, with the aid of a heating coil and / or with the aid of a heating conductor.

[0072] The evaporator unit 37 has an outer side 38 facing the environment 15 and an inner side 39 facing the interior 36. Accordingly, the outer side 38 faces away from the interior 36. The inner side 39 faces away from the environment 15. In particular, the evaporator unit 37 can also be suitable for transporting heat Q from the outer side 38 to the inner side 39 and thus also from the environment 15 to the interior 36.

[0073] The evaporator unit 37 is dimensioned such that, during operation of the discharge chimney 16, the temperature on the outside 38 does not fall below a temperature below which air components condense when the inside 39 is in contact with liquid hydrogen LH2. The evaporator unit 37 is insulated except for the outside 38.

[0074] A drainage line or condensate discharge line 40 runs through the evaporator unit 37. The condensate discharge line 40 leads from the interior space 36 to the environment 15. The condensate discharge line 40 leads to a water separator or condensate separator 41. The condensate separator 41 prevents the release of liquid hydrogen LH2 and / or gaseous hydrogen GH2. For example, the condensate separator 41 can have a float switch that only floats on water H2O.

[0075] Upstream of the condensate separator 41, a shut-off valve 42 can be provided in or on the condensate discharge line 40. The shut-off valve 42 can be used to close or open the condensate discharge line 40. The shut-off valve 42 can be integrated into the evaporator unit 37.

[0076] Optionally, a low-temperature switch 43 can be installed in the evaporator unit 37. The low-temperature switch 43 can control the shut-off valve 42, for example, to selectively close or open it. For this purpose, an operative connection 44 can be provided between the low-temperature switch 43 and the shut-off valve 42. The operative connection 44 can be wireless or wired. With the help of the condensate separator 41, water (H2O) can be separated and fed to a drain 45.

[0077] The operation of the discharge stack 16 is explained below. As previously mentioned, a cold two-phase mixture of liquid hydrogen LH2 and gaseous hydrogen GH2 is fed to the discharge stack 16 in a surge-like manner via line 17. The two-phase mixture comprising liquid hydrogen LH2 and gaseous hydrogen GH2 enters the interior space 36 via the phase separator 31. There, the phase separator 31 separates the two-phase mixture so that the gaseous hydrogen GH2 rises upward against the direction of gravity g and exits the outlet opening 30 into the environment 15. The gaseous hydrogen GH2 can be combusted at the outlet opening 30.

[0078] The liquid hydrogen LH2 flows from the phase separator 31 along the direction of gravity g downwards into the sump 34. With the help of the heat Q supplied via the evaporator unit 37, the liquid hydrogen LH2 is evaporated and rises as gaseous hydrogen GH2 against the direction of gravity g to exit from the outlet opening 30.

[0079] The gaseous hydrogen GH2 displaces the air located in the interior space 36. As soon as all of the liquid hydrogen LH2 has evaporated, the interior space 36 refills with air, which is then displaced from the interior space 36 when hydrogen H2 is again supplied to the exhaust chimney 16. The exhaust chimney 16 is specifically designed to withstand the ignition of oxyhydrogen, a mixture of oxygen and gaseous hydrogen GH2, in the interior space 36.

[0080] The double-walled design of the discharge chimney 16 prevents extremely cold temperatures on the outside of the discharge chimney 16, thus preventing condensation or freezing of air components on the outside of the discharge chimney 16. An additional barrier can be provided for this purpose. This additional barrier can be achieved by dividing the discharge chimney 16 at the separator 23 into the first chimney section 21 and the second chimney section 22A.

[0081] Furthermore, with the aid of the gaps 26, 29, vacuum insulation or vacuum insulation can be realized both on the first chimney section 21 and on the second chimney section 22A.

[0082] The exhaust chimney 16 can thus be provided with low-temperature-stable insulation that is stable in a temperature range from -186°C, the dew point of oxygen, to 3K, the lowest temperature for helium. The insulation can be designed uniformly over the entire length of the exhaust chimney 16. The most advantageous solution is double-walled vacuum insulation made of steel. The second chimney section 22A can be designed to be fireproof. Preferably, the second chimney section 22A has no non-metallic fittings and / or no non-metallic insulation in its gap 29, since non-metallic fittings may not be heat-resistant. As previously mentioned, however, the gap 29 can be filled, for example, with glass foam, perlite, or other low-temperature-resistant and simultaneously high-temperature-resistant fill materials.

[0083] The liquid hydrogen LH2, which reaches the discharge chimney 16, is advantageously evaporated at a low temperature at the evaporator unit 37. Due to the low evaporation temperature of liquid hydrogen LH2, the environment 15 is suitable as a heat source. The evaporator unit 37 can function as an external heat storage device. The evaporator unit 37 is preferably made of stainless steel. In particular, the evaporator unit 37 is designed such that, on the one hand, it serves as a heat storage device and, on the other hand, its design ensures that temperatures on the outside 38 of the evaporator unit 37 do not fall below temperatures at which air components condense. This enables a new design with inherent safety features to be realized.

[0084] An additional safety measure that can be taken is to protect the environment 15 from a possible leakage of liquid hydrogen LH2 at the sump 34, in particular at the condensate separator 41. To reliably prevent a leakage of liquid hydrogen LH2, several measures can be provided.

[0085] As one measure, the condensate separator 41 can be designed such that it remains closed in the presence of liquid hydrogen LH2. As previously mentioned, the condensate separator 41 can have a float switch that only floats on water H2O and not on liquid hydrogen LH2. This functionality is based on the fact that the density of liquid hydrogen LH2, at approximately 70 kg / m3, is significantly lower than the density of water at approximately 1000 kg / m3. As an additional measure, the shut-off valve 42 with the low-temperature switch 43 can be used to prevent liquid hydrogen LH2 from entering the condensate separator 41. The previously explained design of the discharge chimney 16 enables the installation of the discharge chimney 16 in the immediate vicinity of safety valves of the storage tank 1.This means that no long outlet lines are required from the safety valves to the discharge stack 16 to heat the hydrogen H2 by conduction from the environment 15 before it enters the discharge stack 16. Stationary heating is provided by the external evaporator unit 37. The evaporator unit 37 can be used as a circulation evaporator.

[0086] A double-walled design of the safety valve outlet lines is enabled, thus ensuring that in the event of a leak in one of the outlet lines, the hydrogen H2 is captured by a secondary barrier of the outlet lines and does not escape into the immediate environment. 15 This is important in the case of below-deck installation of hydrogen equipment or installation in enclosed spaces.

[0087] Fig. 3 shows a schematic sectional view of another embodiment of a second chimney section 22B as mentioned above.

[0088] All previous statements regarding the first chimney section 22A are correspondingly applicable to the second chimney section 22B, and vice versa. The second chimney section 22B according to Fig. 3 differs from the previously explained embodiment of the second chimney section 22A in that the second chimney section 22B is drawn in at the outlet opening 30 and has a cross-sectional constriction 46. The cross-sectional constriction 46 can be achieved, for example, by an outer diameter da and / or an inner diameter di of the second chimney section 22B decreasing toward the outlet opening 30.

[0089] Due to the cross-sectional constriction 46, the outlet opening 30 has a diameter d30 that is smaller than the inner diameter di of the second chimney section 22B. With the help of the cross-sectional constriction 46, an acceleration of the gaseous hydrogen GH2 can be achieved as it exits the outlet opening 30. Optionally, the second chimney section 22B can have a flow-around body 47 that is placed at a distance in front of the outlet opening 30. The flow-around body 47 prevents water H2O or snow from entering the outlet opening 30. The flow-around body 47 can be constructed rotationally symmetrically to a symmetry or central axis 48. The central axis 48 can coincide with the central axis 33.

[0090] The flow-circulating body 47 has a frustoconical or conical front side 49 facing the outlet opening 30 and a rear side 50 facing away from the outlet opening 30. The rear side 50 can be curved. The flow-circulating body 47 further has a diameter d47 that is equal to or smaller than the outer diameter da and larger than the diameter d30. The flow-circulating body 47 can be supported by a plurality of struts 51, 52 on the second chimney section 22B, in particular on the cross-sectional constriction 46. The struts 51, 52 support the flow-circulating body 47.

[0091] Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

[0092] Reference symbols used

[0093] 1 storage tank

[0094] 2 central axis

[0095] 3 inner containers

[0096] 4 Basic section

[0097] 5 Lid section

[0098] 6 Lid section

[0099] 7 Gas Zone

[0100] 8 Liquid zone

[0101] 9 Phase boundary

[0102] 10 outer containers

[0103] 11 Base section

[0104] 12 Lid section

[0105] 13 Lid section

[0106] 14 gap

[0107] 15 Surroundings

[0108] 16 Exhaust chimney

[0109] 17 Management

[0110] 18 inner wall

[0111] 19 Outer wall

[0112] 20 gap

[0113] 21 Chimney section

[0114] 22A chimney section

[0115] 22B Came in section

[0116] 23 Separator

[0117] 24 inner wall

[0118] 25 Outer wall

[0119] 26 gap

[0120] 27 inner wall

[0121] 28 Outer wall

[0122] 29 gap

[0123] 30 Exit opening

[0124] 31 Phase separator

[0125] 32 Central axis 33 Central axis

[0126] 34 Swamp

[0127] 35 Evaporator unit holder

[0128] 36 Interior

[0129] 37 Evaporator unit

[0130] 38 Outside

[0131] 39 Inside

[0132] 40 Condensate drain line

[0133] 41 condensate separator

[0134] 42 Shut-off valve

[0135] 43 Low temperature switch

[0136] 44 active compound

[0137] 45 Process

[0138] 46 Cross-sectional narrowing

[0139] 47 flow bodies

[0140] 48 Central axis

[0141] 49 Front

[0142] 50 Back

[0143] 51 Strut

[0144] 52 Strut da Outer diameter di Inner diameter d30 Diameter d47 Diameter g Direction of gravity

[0145] GH2 Cryogen / Hydrogen

[0146] H2 Cryogen / Hydrogen

[0147] H2O water

[0148] LH2 Cryogen / Hydrogen

[0149] Q Heat

Claims

Patent claims 1. Discharge chimney (16) for discharging a cryogen (H2) having a liquid phase (LH2) and a gaseous phase (GH2) to an environment (15) of the discharge chimney (16), comprising a tubular chimney section (21, 22A, 22B) extending along a direction of gravity (g), wherein an inner wall (24, 27) of the tubular chimney section (21, 22A, 22B), which surrounds an interior space (36) of the discharge chimney (16), is thermally insulated (25, 28, 26, 29) from the environment (15), and wherein the tubular chimney section (21, 22A, 22B) has a lower chimney section (21) and an upper chimney section (22A, 22B), wherein the upper chimney section (21, 22A, 22B) has an outlet opening (30) through which the upwardly rising gaseous phase (GH2) exits into the environment (15), - a phase separator (31) mounted on the lower chimney section (21) which is designed to separate the two-phase cryogen which can be supplied via a line (17) into the liquid phase (LH2) and the gaseous phase (GH2), and an evaporator unit (37) for releasing heat to the interior space (36) for evaporating the separated liquid phase (LH2) in the interior space (36).

2. Discharge chimney according to claim 1, wherein the chimney section (21, 22A, 22B) is double-walled for thermal insulation.

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

4. Discharge chimney according to one of claims 1 - 3, wherein the evaporator unit (37) is attached to the lower chimney section (21), and wherein the Phase separator (31) is positioned above the evaporator unit (37) as viewed along the direction of gravity (g).

5. Discharge chimney according to one of claims 1 - 4, wherein the lower chimney section (21) has a sump (34) closing the lower chimney section (21) at the end, and wherein the evaporator unit (37) is positioned between the sump (34) and the phase separator (31) as viewed along the direction of gravity (g).

6. Discharge chimney according to one of claims 1 - 5, further comprising a condensate discharge line (40) which is led from the sump (34) through the evaporator unit (37) into the environment (15).

7. Discharge chimney according to claim 6, further comprising a condensate separator (41) for separating water (H20) from the liquid phase (LH2), wherein the condensate discharge line (40) leads to the condensate separator (41).

8. Discharge chimney according to claim 7, further comprising a shut-off valve (42) for shutting off and releasing the condensate discharge line (40).

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

10. Discharge chimney according to one of claims 1 - 9, wherein the evaporator unit (37) has an outer side (38) facing the environment (15) and an inner side (39) facing the interior space (36). 1 1. Discharge chimney according to claim 10, wherein the evaporator unit (37) is arranged to transport heat (Q) from the outside (38) to the inside (39).

12. Discharge chimney according to one of claims 1 - 11, wherein the upper chimney section (22A, 22B) is thermally separated from the lower chimney section (21) by means of a separator (23).

13. Discharge chimney according to one of claims 1 - 12, wherein the upper chimney section (22B) has a cross-sectional constriction (46) provided at the outlet opening (30).

14. Discharge chimney according to one of claims 1-13, wherein the upper chimney section (22B) has a flow-circulating body (47) arranged downstream of the outlet opening (30).

15. Discharge chimney according to one of claims 1-14, wherein the upper chimney section (22B) is fireproof.

Images