Liquefied air protector

Abstract

To protect a peripheral device from liquefied air generated on a surface of piping through which a cryogenic fluid flows.SOLUTION: A liquefied air protector (1) comprises: an upside tray (2) that is arranged below piping (101) through which a cryogenic fluid (H) flows and that receives liquefied air (LA) generated on a surface of the piping (101) and flowing down; and a downside tray (3) that is arranged below the upside tray (2) and that receives the liquefied air (LA) generated on an undersurface of the upside tray (2) and flowing down.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a liquefied air protection device applied to a pipe through which a cryogenic fluid flows. [Background technology]

[0002] A known technology related to piping through which a cryogenic fluid flows is a cryogenic fluid piping structure described in Patent Document 1 below. The piping structure in Patent Document 1 includes a cryogenic pipe arranged above a structural material of a ship that stores liquefied hydrogen, and a storage area partition member provided on the structural material to receive liquefied air formed on the surface of the cryogenic pipe due to the influence of the liquefied hydrogen flowing through the cryogenic pipe. An evaporation-promoting liquid is stored inside the storage area partition member, which receives and evaporates the liquefied air that flows down from the cryogenic pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-103902 Summary of the Invention [Problem to be solved by the invention]

[0004] When liquefied air is caught by a liquid stored in a compartment on a structural material as in Patent Document 1, some of the liquefied air may not be caught and may reach the structural material depending on conditions such as the long distance from the low-temperature piping to the structural material. Also, if there is any equipment between the low-temperature piping and the structural material, the liquefied air may come into contact with that equipment.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a liquefied air protection device that can effectively protect peripheral equipment from liquefied air generated on the surface of a pipe through which a cryogenic fluid flows. [Means for solving the problem]

[0006] In order to solve the above problem, a liquefied air protection device according to one aspect of the present disclosure comprises an upper tray that is positioned below a pipe through which a cryogenic fluid flows and that catches liquefied air that is generated on the surface of the pipe and flows down, and a lower tray that is positioned below the upper tray and that catches liquefied air that is generated on the underside of the upper tray and flows down. [Effects of the Invention]

[0007] According to the liquefied air protection device of the present disclosure, peripheral equipment can be effectively protected from liquefied air generated on the surface of a pipe through which a cryogenic fluid flows. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view illustrating a piping system including a liquefied air protection device according to one embodiment of the present disclosure. FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a perspective view showing the three-dimensional shapes of an upper tray and a lower tray. [Figure 5] FIG. 2 is a perspective view showing the three-dimensional shape of the auxiliary tray. [Figure 6] 4 is an enlarged cross-sectional view showing the joints between the upper and lower supports and the heat insulating plate. FIG. [Figure 7] FIG. 3 is a view corresponding to FIG. 2 for explaining the operation of the embodiment. [Figure 8] FIG. 4 is an enlarged side view for explaining the operation of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the liquefied air protection device of the present disclosure will be described in detail with reference to the drawings. The liquefied air protection device of the present disclosure is a device for protecting peripheral equipment from liquefied air that may be generated on the surface of a pipe through which a cryogenic fluid flows. The cryogenic fluid may be of any type as long as it has the potential to lower the temperature of the surface of the pipe to a temperature at which air liquefies. Examples of the cryogenic fluid include liquefied hydrogen, liquid helium, and boil-off gas (boil-off gas) formed by evaporation of these liquefied gases.

[0010] [Overall configuration] FIG. 1 is a side view showing a piping system 100 including a liquefied air protection device 1 according to an embodiment of the present disclosure. As shown in this figure, the piping system 100 includes a hydrogen pipe 101, a pipe support 102 that supports the hydrogen pipe 101 on a foundation surface BS, and the liquefied air protection device 1 for protecting peripheral equipment from liquefied air LA (FIG. 7) that may be generated on the surface of the hydrogen pipe 101. The hydrogen pipe 101 is a pipe through which cryogenic hydrogen H (FIG. 2) flows and corresponds to the "piping" in the present disclosure. That is, this embodiment illustrates a case where the cryogenic fluid flowing through the pipe is hydrogen H. The hydrogen H may be liquefied hydrogen or may be boil-off gas, i.e., liquefied hydrogen that has evaporated from the liquefied hydrogen. Liquefied hydrogen is liquid-phase hydrogen H that reaches approximately −253°C at atmospheric pressure, and the boil-off gas is gas-phase hydrogen H that reaches a temperature slightly higher than −253°C at atmospheric pressure. The foundation surface BS may be the top surface of the ground such as a concrete foundation, or the top surface of a member such as a grating installed above the ground.

[0011] FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. As shown in FIGS. 2 and 3, the hydrogen pipe 101 is a single pipe made of low-temperature steel such as stainless steel. The direction in which the hydrogen pipe 101 extends is not particularly important, but the hydrogen pipe 101 of this embodiment includes a portion that extends horizontally as shown in FIG. 1. The direction X in FIGS. 1 to 3 is a direction parallel to the axis of the hydrogen pipe 101, i.e., the longitudinal direction. The hydrogen pipe 101 is arranged so that the longitudinal direction X of at least a portion thereof coincides with the horizontal direction, and the portion that extends horizontally is shown in FIG. 1. The direction Y is a left-right direction that is perpendicular to the longitudinal direction X and the up-down direction.

[0012] The hydrogen pipe 101 is, for example, a branch pipe branching off from a thermally insulated pipe (not shown) that transports liquefied hydrogen while keeping it cool, and is provided mainly for transporting boil-off gas. In such hydrogen pipe 101, boil-off gas (hydrogen gas) at a temperature slightly higher than −253°C may flow as hydrogen H, or in some cases, liquefied hydrogen may flow. In such cases, the surface temperature of the hydrogen pipe 101 may drop to the temperature at which air liquefies, that is, approximately −190°C or lower at normal pressure.

[0013] 1 and 3, the piping support 102 includes a column 103 erected on the foundation surface BS, a support plate 104 fixed to the hydrogen piping 101, and a heat insulating material 105 interposed between the column 103 and the support plate 104. An appropriate number of piping supports 102 are provided along the longitudinal direction X of the hydrogen piping 101, but only one of them is shown in FIG.

[0014] The support plate 104 is a plate member that extends in the vertical direction with its thickness direction coinciding with the left-right direction Y. The upper end of the support plate 104 is fixed to the bottom (lowest end) of the hydrogen pipe 101 by welding or the like. The lower end of the support plate 104 is installed on the upper end of the column 103 via a heat insulating material 105.

[0015] [Detailed structure of liquefied air protection device] As shown in Figures 1 to 3, the liquefied air protection device 1 comprises a plurality of upper trays 2 arranged below the hydrogen piping 101, a plurality of lower trays 3 arranged below each of the upper trays 2, an auxiliary tray 4 arranged between the upper trays 2 and the lower trays 3 in the vertical direction, a tray support 5 supporting the upper trays 2 and the lower trays 3, and a cover member 6 arranged above the hydrogen piping 101.

[0016] The upper trays 2 are arranged in the same row along the longitudinal direction X of the hydrogen pipe 101. Each upper tray 2 has an open top and a downwardly convex semicircular cross section. The upper trays 2 only need to be roughly semicircular in cross section, and do not necessarily have to be semicircular in the strict sense. The same applies to the lower trays 3.

[0017] The multiple lower trays 3 are arranged in the same row along the longitudinal direction X at a height below the upper tray 2. Like the upper tray 2, each lower tray 3 has a semicircular cross-sectional shape that is open on the top and convex downward.

[0018] Here, the upper tray 2 located below the hydrogen pipe 101 only needs to cover at least a portion of the hydrogen pipe 101 from below, but in this embodiment, an example is shown in which the entire hydrogen pipe 101 is covered from below by the upper tray 2, as shown in Figures 2 and 3. More specifically, in this embodiment, the width of the upper tray 2 in the left-right direction Y is set larger than that of the hydrogen pipe 101, and the upper tray 2 covers an area from below that is wider than the width of the hydrogen pipe 101. Furthermore, the lower tray 3 located below the upper tray 2 only needs to cover at least a portion of the upper tray 2 from below, but in this embodiment, an example is shown in which the entire upper tray 2 is covered from below by the lower tray 3. Furthermore, the upper tray 2 and the lower tray 3 may have the same shape or different shapes, but in this embodiment, an example is shown in which the upper tray 2 and the lower tray 3 have the same shape.

[0019] 2 and 3, the lowest portion of the hydrogen pipe 101 is referred to as the bottom 101a. Furthermore, the lowest portion of the curved bottom wall 21 (described later) of the upper tray 2 is referred to as the bottom 21a. Based on the layout described above, in this embodiment, the upper tray 2 is arranged so as to overlap with the region including the bottom 101a of the hydrogen pipe 101 when viewed in the vertical direction. Furthermore, the lower tray 3 is arranged so as to overlap with the region including the bottom 21a of the upper tray 2 when viewed in the vertical direction.

[0020] 4 is a perspective view showing the three-dimensional shapes of the upper tray 2 and the lower tray 3. As shown in FIGS. 1 to 4, the upper tray 2 has a curved bottom wall 21 that is curved in a downwardly convex semicircular shape in a cross-sectional view, and a pair of front and rear end walls 22 formed on both ends of the curved bottom wall 21 in the longitudinal direction X. Inside the upper tray 2, a semi-cylindrical space R1 with an open top is formed, surrounded by the curved bottom wall 21 and the pair of end walls 22. This space R1 functions as a storage space for storing liquefied air LA (FIG. 7), which will be described later, that is generated on the surface of the hydrogen pipe 101 and flows down.

[0021] Similarly, the lower tray 3 has a curved bottom wall 31 that is curved in a downwardly convex semicircular shape in a cross-sectional view, and a pair of front and rear end walls 32 formed on both ends of the curved bottom wall 31 in the longitudinal direction X. Inside the lower tray 3, a semicylindrical space R2 with an open top is formed, surrounded by the curved bottom wall 31 and the pair of end walls 32. This space R2 functions as a storage space for storing liquefied air LA (FIG. 7), which will be described later, that is generated on the underside of the upper tray 2 and flows down.

[0022] The vaporization promoter 8 shown in Fig. 2 is disposed inside the lower tray 3. The vaporization promoter 8 includes a large number of granular materials that are uniformly dispersed on the upper surface of the curved bottom wall 31 of the lower tray 3. In a preferred example, the vaporization promoter 8 includes a large number of granular materials having relatively small particle sizes so as to have a surface area larger than the area of ​​the upper surface of the curved bottom wall 31. An example of such granular materials is gravel.

[0023] As shown in FIG. 1 , the piping support 102 is located between two upper trays 2 adjacent to each other in the longitudinal direction X, and between two lower trays 3 adjacent to each other in the longitudinal direction X. Hereinafter, one of the two upper trays 2 adjacent to each other in the longitudinal direction X with the piping support 102 sandwiched therebetween will be referred to as the first upper tray 2A, and the other will be referred to as the second upper tray 2B. Similarly, one of the two lower trays 3 adjacent to each other in the longitudinal direction X with the piping support 102 sandwiched therebetween will be referred to as the first lower tray 3A, and the other will be referred to as the second lower tray 3B. The first lower tray 3A is located below the first upper tray 2A, and the second lower tray 3B is located below the second upper tray 2B.

[0024] An upper gap G1 is formed between the first upper tray 2A and the second upper tray 2B to allow the upper part of the piping support 102 to pass through. The upper gap G1 is a strip-shaped gap in a vertical view between an end A1 of the first upper tray 2A closer to the piping support 102 and an end B1 of the second upper tray 2B closer to the piping support 102. The upper gap G1 corresponds to the "gap" in the present disclosure.

[0025] Similarly, a lower gap G2 is formed between the first lower tray 3A and the second lower tray 3B to allow the lower part of the piping support 102 to pass through. The lower gap G2 is a strip-shaped gap in a vertical view, located between an end A2 of the first lower tray 3A closer to the piping support 102 and an end B2 of the second lower tray 3B closer to the piping support 102. The lower gap G2 is located below the upper gap G1.

[0026] The piping support 102 extends vertically through the gaps G1 and G2. That is, the piping support 102 extends vertically through the upper gap G1 between the opposing ends A1 and B1 of the first upper tray 2A and the second upper tray 2B, and the lower gap G2 between the opposing ends A2 and B2 of the first lower tray 3A and the second lower tray 3B. The piping support 102 disposed in the corresponding position of each gap G1 and G2 can support the hydrogen piping 101 while avoiding interference with the trays 2A, 2B, 3A, and 3B.

[0027] In the following description, when referring to any of the multiple upper trays 2 including the first upper tray 2A and the second upper tray 2B without any particular distinction, it will simply be referred to as the upper tray 2. Similarly, when referring to any of the multiple lower trays 3 including the first lower tray 3A and the second lower tray 3B without any particular distinction, it will simply be referred to as the lower tray 3.

[0028] The auxiliary tray 4 is disposed between the upper tray 2 and the lower tray 3 in the vertical direction and at a position corresponding to the piping support 102 in the longitudinal direction X. The auxiliary tray 4 has an open top and a rectangular dish-like cross section. As shown in FIG. 3 , the width of the auxiliary tray 4 in the left-right direction Y is smaller than those of the upper tray 2 and the lower tray 3.

[0029] Fig. 5 is a perspective view showing the three-dimensional shape of the auxiliary tray 4. As shown in Figs. 1, 3, and 5, the auxiliary tray 4 has a flat bottom wall 41 extending in the longitudinal direction X, and a pair of left and right side walls 42 rising from both ends of the bottom wall 41 in the left-right direction Y. Unlike the upper tray 2 and the lower tray 3, the auxiliary tray 4 has an open end in the longitudinal direction X. This is because, when liquefied air LA accumulates in the auxiliary tray 4, the outlet for the liquefied air LA is limited to the end of the auxiliary tray 4 in the longitudinal direction X (see dashed arrow Q in Fig. 8).

[0030] The auxiliary tray 4 is fixed to a support plate 104 of the piping support 102. Specifically, the auxiliary tray 4 has a hole 41a (FIG. 3) in its bottom wall 41 that receives the support plate 104. The support plate 104 is inserted into the hole 41a, and the bottom wall 41 is fixed to the support plate 104 by welding or the like, whereby the auxiliary tray 4 is supported by the piping support 102.

[0031] As shown in FIG. 1, the auxiliary tray 4 is disposed near the lower sides of the first upper tray 2A and the second upper tray 2B so as to cover from below the upper gap G1 between the two trays 2A and 2B. The dimension of the auxiliary tray 4 in the longitudinal direction X is greater than the dimension of the upper gap G1 in the longitudinal direction X. That is, the auxiliary tray 4 is disposed so that both ends of the auxiliary tray 4 in the longitudinal direction X overlap with the opposing ends A1 and B1 of the first upper tray 2A and the second upper tray 2B in a vertical view. The both ends of the auxiliary tray 4 in the longitudinal direction X also overlap with the opposing ends A2 and B2 of the first lower tray 3A and the second lower tray 3B in a vertical view.

[0032] 1 to 3, the tray support 5 includes a plurality of support pillars 51 arranged on both sides of the upper tray 2 and the lower tray 3 in the left-right direction Y. That is, the tray support 5 has pairs of left and right support pillars 51 that support the upper tray 2 and the lower tray 3 at multiple locations spaced apart in the longitudinal direction X. Pairs of support pillars 51 are arranged at appropriate intervals along the longitudinal direction X so that at least one pair of support pillars 51 is provided for each upper and lower set of upper tray 2 and lower tray 3.

[0033] Each support column 51 has a lower support column 53 erected on the foundation surface BS, an upper support column 52 arranged above the lower support column 53, and an insulating plate 54 arranged between the lower support column 53 and the upper support column 52. The insulating plate 54 corresponds to the "insulating material" in this disclosure.

[0034] The upper support columns 52 support the upper tray 2, and the lower support columns 53 support the lower tray 3. In other words, the tray support 5 has a pair of upper support columns 52 that support the upper tray 2 and a pair of lower support columns 53 that support the lower tray 3.

[0035] 2 and 3, the upper tray 2 is supported by the pair of upper support columns 52 by fixing both side edges in the left-right direction Y to the pair of upper support columns 52 by welding or the like. The lower tray 3 is supported by the pair of lower support columns 53 by fixing both side edges in the left-right direction Y to the pair of lower support columns 53 by welding or the like. In other words, the upper tray 2 and the lower tray 3 are fixed separately to the upper support column 52 and the lower support column 53, and are supported between the pair of support columns 51 in this order from above.

[0036] The heat insulating plate 54 is made of a heat insulating material having a lower thermal conductivity than the upper support column 52 and the lower support column 53. The heat insulating plate 54 is formed in the shape of a disk having a predetermined thickness, for example.

[0037] 6 is an enlarged cross-sectional view showing the joint between the upper and lower columns 52, 53 and the heat insulating plate 54. As shown in this figure, the upper column 52 is fixed to the heat insulating plate 54 by fastening a cylindrical bracket 55 attached to its lower end to the upper surface of the heat insulating plate 54 with bolts 56. Similarly, the lower column 53 is fixed to the heat insulating plate 54 by fastening a cylindrical bracket 55 attached to its upper end to the lower surface of the heat insulating plate 54 with bolts 56. In this way, the upper column 52 and the lower column 53 are coaxially connected with the heat insulating plate 54 in between.

[0038] 1 to 3, the cover member 6 includes a flat ceiling wall 61 extending in the longitudinal direction X above the hydrogen pipe 101, and a pair of side walls 62 extending downward from both ends of the ceiling wall 61 in the left-right direction Y. The cover member 6 is made of a water-impermeable material, such as resin or metal.

[0039] The width of the cover member 6 in the left-right direction Y is greater than the width of any of the hydrogen piping 101, upper tray 2, and lower tray 3. In other words, the cover member 6 covers the hydrogen piping 101, upper tray 2, and lower tray 3 from above in a manner that overlaps the entirety of these elements when viewed in the vertical direction.

[0040] The cover member 6 is attached to the upper end of the upper support column 52 (support column 51). That is, the upper end of the upper support column 52 is connected to the ceiling wall 61 of the cover member 6 via a bracket 55, thereby attaching the cover member 6 to the upper end of the upper support column 52.

[0041] A ventilation pipe 7 is attached to the cover member 6. The ventilation pipe 7 is attached to the cover member 6 in a state where it penetrates the ceiling wall 61 of the cover member 6 so as to connect the space below the cover member 6 with the space above it. The ventilation pipe 7 has a bent shape in the middle. This is to prevent rainwater and the like from leaking from the top to the bottom of the cover member 6 through the ventilation pipe 7.

[0042] [Action and effect] As described above, the liquefied air protection device 1 of this embodiment comprises the upper tray 2 arranged below the hydrogen pipe 101 through which cryogenic hydrogen H flows, and the lower tray 3 arranged below the upper tray 2. This configuration has the advantage of being able to effectively protect peripheral equipment from the liquefied air LA generated on the surface of the hydrogen pipe 101.

[0043] The surface temperature of the hydrogen pipe 101 through which cryogenic hydrogen H flows may drop to a temperature at which air liquefies. If the surface temperature drops to such a temperature, liquefied air LA will be formed on the surface of the hydrogen pipe 101, as shown in Fig. 7. If this liquefied air LA flows down from the hydrogen pipe 101, for example, if there is any equipment below the hydrogen pipe 101, the liquefied air LA may come into contact with that equipment, i.e., peripheral equipment, and may adversely affect that peripheral equipment.

[0044] To address this problem, in this embodiment, an upper tray 2 is placed below the hydrogen pipe 101, so that the liquefied air LA that is generated on the surface of the hydrogen pipe 101 and flows down can be received by the upper tray 2, as shown in Figure 7. This makes it possible to prevent the liquefied air LA from coming into contact with peripheral equipment and the like located below the hydrogen pipe 101, and to appropriately protect the peripheral equipment from the liquefied air LA.

[0045] However, depending on the amount of liquefied air LA that has flowed down onto the upper tray 2, the temperature of the upper tray 2 may drop significantly, which may result in liquefied air LA also being formed on the underside of the upper tray 2. Even in such a case, in this embodiment, the lower tray 3 is further disposed below the upper tray 2, so that the liquefied air LA that has flowed down from the underside of the upper tray 2 can be received by the lower tray 3. This further reduces the possibility that the liquefied air LA will come into contact with the peripheral devices and the like.

[0046] In this embodiment, a vaporization promoter 8 containing a large number of granular materials is placed on the lower tray 3. According to this configuration, the vaporization promoter 8 can promote the vaporization of the liquefied air LA that has flowed down from the upper tray 2 to the lower tray 3.

[0047] Furthermore, in this embodiment, the upper tray 2 has a downwardly convex semicircular cross-sectional shape, and the lower tray 3 is arranged so as to overlap an area including the bottom 21a of the upper tray 2 when viewed in the vertical direction. With this configuration, the liquefied air LA (FIG. 7) flowing down from the hydrogen pipe 101 can be stably held within the downwardly convex upper tray 2. Furthermore, when liquefied air LA is formed on the underside of the upper tray 2, the liquefied air LA tends to collect at the bottom 21a of the upper tray 2. Therefore, the proportion of liquefied air LA flowing down from the bottom 21a of the upper tray 2 can be increased, and the probability that the flowing down liquefied air LA will enter the lower tray 3 can be increased.

[0048] In this embodiment, the first upper tray 2A and the second upper tray 2B are disposed adjacent to each other in the longitudinal direction X with the piping support 102 sandwiched therebetween, and the first lower tray 3A and the second lower tray 3B are disposed below the upper trays 2A and 2B (FIG. 1). An auxiliary tray 4 is disposed near the underside of the first upper tray 2A and the second upper tray 2B, covering the upper gap G1 between the two trays 2A and 2B from below. Furthermore, both ends of the auxiliary tray 4 in the longitudinal direction X overlap with the opposing ends A1 and B1 of the first upper tray 2A and the second upper tray 2B when viewed in the vertical direction, and also overlap with the opposing ends A2 and B2 of the first lower tray 3A and the second lower tray 3B when viewed in the vertical direction. With this configuration, even if the upper tray 2 and the lower tray 3 are separated in the longitudinal direction X to allow the piping support 102 to pass through, that is, even if gaps (G1, G2) are formed between the first upper tray 2A and the second upper tray 2B and between the first lower tray 3A and the second lower tray 3B, respectively, the liquefied air LA can be accurately received.

[0049] That is, the upper gap G1 between the first upper tray 2A and the second upper tray 2B, which are spaced apart in the longitudinal direction X, is covered from below by the auxiliary tray 4, so that the liquefied air LA that flows down into the upper gap G1 can be received by the auxiliary tray 4, as shown in Fig. 8. Furthermore, the opposing ends A1, B1 of the first upper tray 2A and the second upper tray 2B overlap with both ends of the auxiliary tray 4 in a vertical view, so that the liquefied air LA that has passed through the upper gap G1 can be sufficiently prevented from flowing down without being received by the auxiliary tray 4. Furthermore, the opposing ends A2, B2 of the first lower tray 3A and the second lower tray 3B overlap with both ends of the auxiliary tray 4 in a vertical view, so that the liquefied air (indicated by dashed arrows Q) that flows down from both ends of the auxiliary tray 4 can be received by the lower trays 3A, 3B.

[0050] Furthermore, in this embodiment, a heat insulating plate 54 is disposed between the lower support column 53 supporting the lower tray 3 and the upper support column 52 supporting the upper tray 2. With this configuration, the heat insulating plate 54 prevents cold heat from being transferred from the upper support column 52 to the lower support column 53, thereby preventing a decrease in the temperature of the lower tray 3 supported by the lower support column 53 and promoting evaporation of the liquefied air LA that has entered the lower tray 3.

[0051] In this embodiment, the hydrogen pipe 101 is covered from above with a water-impermeable cover member 6. This configuration makes it possible to prevent rainwater from entering the interior of the upper tray 2 and the lower tray 3.

[0052] Furthermore, the cover member 6 is fitted with a ventilation pipe 7 that connects the spaces above and below the cover member 6. With this configuration, it is possible to prevent oxygen-rich gas from accumulating below the cover member 6.

[0053] That is, comparing nitrogen and oxygen, which are the main components of air, the boiling point of nitrogen is approximately −196°C, while the boiling point of oxygen is approximately −183°C, making nitrogen a lower boiling point than oxygen. Therefore, when liquefied air LA evaporates, nitrogen begins to evaporate before oxygen. Because nitrogen and oxygen evaporate at different times, oxygen-rich gas with a higher oxygen concentration than normal is likely to be formed in an environment such as this embodiment, where air is repeatedly liquefied and evaporated. If this oxygen-rich gas moves upward in the hydrogen pipe 101, a region Z where the oxygen-rich gas accumulates may be formed, as shown in FIG. 7 . However, in this embodiment, the vent pipe 7 is attached to the cover member 6, so the oxygen-rich gas in this region Z can escape above the cover member 6 through the vent pipe 7. This prevents oxygen-rich gas from accumulating below the cover member 6.

[0054] [Variations] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0055] For example, in the above embodiment, the upper tray 2 and the lower tray 3 have a semicircular cross-sectional shape that is convex downward, but the shape of each tray 2, 3 is not limited to this. For example, the cross-sectional shape of each tray 2, 3 may be a trapezoidal or triangular shape that is convex downward. Alternatively, the cross-sectional shape of each tray 2, 3 may be a square plate shape similar to that of the auxiliary tray 4.

[0056] In the above embodiment, the upper tray 2 and lower tray 3 are provided with the same shape, but the shapes of the trays 2, 3 may be different. For example, the widths of the upper tray 2 and lower tray 3 in the left-right direction Y may be different. In this case, however, it is preferable that the width of the lower tray 3 is greater than that of the upper tray 2. In other words, when the vertical projection area of ​​the upper tray 2 is AR1 and the vertical projection area of ​​the lower tray 3 is AR2, it is preferable that the relationship AR2 ≥ AR1 holds.

[0057] In the above embodiment, an example was shown in which the entire hydrogen piping 101 was covered from below by the upper tray 2, but the upper tray 2 need only be located in a position where it can receive the liquefied air LA flowing down from the hydrogen piping 101, and does not necessarily have to cover the entire hydrogen piping 101 from below. In other words, the upper tray 2 only needs to be located below the hydrogen piping 101 in a manner that overlaps at least a portion of the hydrogen piping 101 when viewed in the vertical direction.

[0058] Similarly, in the above embodiment, an example was shown in which the entire upper tray 2 was covered from below by the lower tray 3, but the lower tray 3 need only be located in a position where it can receive the liquefied air LA flowing down from the upper tray 2, and does not necessarily have to cover the entire upper tray 2 from below. In other words, the lower tray 3 only needs to be located below the upper tray 2 in a manner that overlaps at least a portion of the upper tray 2 when viewed in the up-down direction.

[0059] [summary] The above-described embodiment and its modifications include the following disclosures.

[0060] The liquefied air protection device of the first aspect of the present disclosure comprises an upper tray that is positioned below a pipe through which a cryogenic fluid flows and that catches liquefied air that is generated on the surface of the pipe and flows down, and a lower tray that is positioned below the upper tray and that catches liquefied air that is generated on the underside of the upper tray and flows down.

[0061] According to this first aspect, the liquefied air that is generated on the surface of the piping and flows down is received by the upper tray, thereby preventing the liquefied air from coming into contact with peripheral equipment and the like located below the piping. Furthermore, even if the temperature of the upper tray that receives the liquefied air drops significantly and liquefied air is generated on the underside of the upper tray, the liquefied air can be received by the lower tray below the upper tray. This further reduces the possibility of the liquefied air coming into contact with the peripheral equipment and the like.

[0062] The liquefied air protection device according to a second aspect is the same as the first aspect, and further comprises an evaporation promoter disposed on the lower tray and including a number of particulates.

[0063] According to the second aspect, the evaporation of the liquefied air that has flowed down from the upper tray to the lower tray can be promoted by the evaporation promoter.

[0064] The liquefied air protection device of the third aspect is the first or second aspect, wherein the upper tray has a downwardly convex cross-sectional shape, and the lower tray is arranged so as to overlap with an area including the bottom of the upper tray when viewed in the vertical direction.

[0065] According to the third aspect, the liquefied air flowing down from the piping can be stably held in the downwardly convex upper tray. Furthermore, if liquefied air is generated on the underside of the upper tray, the liquefied air is likely to collect at the bottom of the upper tray. This increases the proportion of liquefied air flowing down from the bottom of the upper tray, thereby increasing the probability that the liquefied air that flows down will enter the lower tray.

[0066] The liquefied air protection device of the fourth aspect, in any of the first to third aspects, further comprises a pair of pillars supporting the upper tray and the lower tray, each of the pillars including a lower pillar erected on a foundation surface and supporting the lower tray, an upper pillar positioned above the lower pillar and supporting the upper tray, and insulation material positioned between the lower pillar and the upper pillar.

[0067] According to the fourth aspect, the heat insulating material can prevent cold from being transferred from the upper support to the lower support, thereby preventing a temperature drop in the lower tray supported by the lower support and promoting evaporation of the liquefied air that has entered the lower tray.

[0068] The liquefied air protection device according to a fifth aspect is the liquefied air protection device according to any one of the first to fourth aspects, further comprising a water-impermeable cover member that covers an upper portion of the piping.

[0069] According to the fifth aspect, it is possible to prevent rainwater from entering the interior of the upper tray and the lower tray.

[0070] The liquefied air protection device according to a sixth aspect is the fifth aspect, further comprising a ventilation pipe that connects the space below the cover member with the space above the cover member.

[0071] According to the sixth aspect, even if oxygen-rich gas generated through liquefaction and evaporation of air moves upward in the piping, the oxygen-rich gas can be released above the cover member through the ventilation pipe, thereby preventing the oxygen-rich gas from accumulating below the cover member.

[0072] The liquefied air protection device of the seventh aspect is any of the first to sixth aspects, wherein the piping is supported by a piping support erected on a foundation surface, the upper tray includes a first upper tray and a second upper tray adjacent to the first upper tray in the longitudinal direction of the piping, with the piping support sandwiched between them, and the lower tray includes a first lower tray located below the first upper tray and a second lower tray adjacent to the first lower tray in the longitudinal direction, with the piping support sandwiched between them, and located below the second upper tray, and further includes an auxiliary tray arranged between the upper tray and lower tray in the vertical direction and covering the longitudinal gap between the first upper tray and the second upper tray from below, and both longitudinal ends of the auxiliary tray overlap with the opposing ends of the first upper tray and the second upper tray when viewed in the vertical direction, and also overlap with the opposing ends of the first lower tray and the second lower tray when viewed in the vertical direction.

[0073] According to the seventh aspect, liquefied air can be accurately received even when the upper tray and the lower tray are separated in the longitudinal direction to allow the piping support to pass through. Specifically, the gap between the first upper tray and the second upper tray, which are separated in the longitudinal direction, is covered from below by the auxiliary tray, so that liquefied air flowing down into the gap can be received by the auxiliary tray. Furthermore, the opposing ends of the first upper tray and the second upper tray overlap with both ends of the auxiliary tray in a vertical view, so that liquefied air that has passed through the gap can be sufficiently prevented from flowing down without being received by the auxiliary tray. Furthermore, the opposing ends of the first lower tray and the second lower tray, which are located below the first upper tray and the second upper tray, overlap with both ends of the auxiliary tray in a vertical view, so that liquefied air flowing down from both ends of the auxiliary tray can be received by each lower tray. [Explanation of symbols]

[0074] 1. Liquefied Air Protection Device 2 Upper tray 2A First upper tray 2B Second upper tray 3 Lower tray 3A First Lower Tray 3B Second lower tray 4 Auxiliary tray 6 Cover member 7 Ventilation pipe 8 Vaporization promoter 21a Bottom (of upper tray) 51 Post 52 Upper support 53 Lower pillar 54 Insulation plate (insulation material) 101 Hydrogen piping (piping) 102 Piping Support A1 Opposite end (of first upper tray) B1 Opposite end (of second upper tray) A2 Opposite end (of first lower tray) B2 (second lower tray) opposite end BS basic surface G1 Upper gap (gap) LA Liquefied Air

Claims

1. an upper tray that is disposed below the pipe through which the cryogenic fluid flows and that receives liquefied air that is generated on the surface of the pipe and flows down; A liquefied air protection device comprising: a lower tray arranged below the upper tray for receiving liquefied air generated on the underside of the upper tray and flowing downward.

2. 2. The liquefied air protection device according to claim 1, The liquefied air protection device further comprises an evaporation promoter disposed on the lower tray and including a number of particulates.

3. 2. The liquefied air protection device according to claim 1, the upper tray has a downwardly convex cross-sectional shape, A liquefied air protection device in which the lower tray is positioned so as to overlap an area including the bottom of the upper tray when viewed in the vertical direction.

4. 2. The liquefied air protection device according to claim 1, a pair of support columns supporting the upper tray and the lower tray; A liquefied air protection device in which each of the supports includes a lower support that is erected on the foundation surface and supports the lower tray, an upper support that is positioned above the lower support and supports the upper tray, and insulation material that is positioned between the lower support and the upper support.

5. 2. The liquefied air protection device according to claim 1, The liquefied air protection device further comprises a water-impermeable cover member covering the upper part of the piping.

6. 6. The liquefied air protection device according to claim 5, The liquefied air protection device further comprises a ventilation pipe communicating the space below the cover member with the space above the cover member.

7. The liquefied air protection device according to any one of claims 1 to 6, The piping is supported by a piping support erected on the foundation surface, the upper tray includes a first upper tray and a second upper tray adjacent to the first upper tray in the longitudinal direction of the pipe with the pipe support interposed therebetween, the lower trays include a first lower tray located below the first upper tray, and a second lower tray adjacent to the first lower tray in the longitudinal direction with the piping support interposed therebetween and located below the second upper tray, an auxiliary tray disposed between the upper tray and the lower tray in the vertical direction and covering the gap in the longitudinal direction between the first upper tray and the second upper tray from below; A liquefied air protection device in which both longitudinal ends of the auxiliary tray overlap with the opposing ends of the first upper tray and the second upper tray when viewed in the vertical direction, and also overlap with the opposing ends of the first lower tray and the second lower tray when viewed in the vertical direction.

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