Liquid hydrogen thermal envelope

Abstract

The application discloses a liquid hydrogen heat preservation and protection system, which comprises an independent liquid cargo tank, the independent liquid cargo tank is a double-shell structure with an inner shell and an outer shell, a vacuum heat insulation layer is arranged between the inner shell and the outer shell, an outer wall of the outer shell is coated with a heat preservation layer, an outer wall of the heat preservation layer is coated with a waterproof layer, a plurality of longitudinal strong frames and a plurality of transverse strong frames are fixedly connected to the outer wall of the outer shell, and support pads are arranged between the longitudinal strong frames and a ship body structure and between the transverse strong frames and the ship body structure. The liquid cargo tank has a larger tank capacity and good heat insulation performance, and can automatically form a water curtain to protect the ship body and prevent low-temperature damage after a main shield leaks.

Description

Technical Field

[0001] This invention relates to the field of marine technology, and in particular to a liquid hydrogen thermal insulation enclosure system. Background Technology

[0002] According to the regulations of the International Maritime Organization, the main types of cargo tanks for ships transporting liquefied gases in bulk are membrane cargo tanks and independent cargo tanks. Independent cargo tanks can be further divided into three types: Type A, Type B, and Type C. Type A requires a complete secondary bulkhead, Type B requires a partial secondary bulkhead, and Type C is a pressure vessel and does not require a secondary bulkhead.

[0003] The existing liquid hydrogen containment system is a C-type compartment structure. Due to material limitations, the compartment volume is relatively small, with each compartment being around 1250 cubic meters.

[0004] The liquid hydrogen containment system disclosed in patent CN 111801271 A employs a double-layered C-shaped compartment with a vacuum insulation layer between the two hulls. The inner layer is filled with liquid hydrogen (approximately -253°C), while the outer layer is in direct contact with air. When the vacuum level decreases, the outer layer cools down more rapidly, and nitrogen in the air liquefies into liquid nitrogen (approximately -196°C). At this point, seawater is allowed to enter the cargo hold, forming a seawater layer that protects the hull. The depth of the seawater layer ranges from tens to hundreds of millimeters.

[0005] Existing LNG (approximately -163°C) containment systems cannot be directly loaded with liquid hydrogen, primarily because the temperature of LNG is higher than that of liquefied nitrogen, and nitrogen in the air will not liquefy. When loading liquid hydrogen, it is necessary to address the problem of reduced insulation effectiveness, nitrogen in the air liquefying, and causing cryogenic damage to the ship's structure.

[0006] In the existing technology, the patent with publication number CN 111801271 A applies to Type C tanks. When directly applied to prismatic tanks, it is first necessary to set up complete or partial secondary shielding, and secondly, the effectiveness of the 30-degree heel secondary shielding required by the IGC rules must be considered. Considering a 30-degree heel, the seawater layer of a few hundred millimeters in the patented technology will not provide protection. The larger the tank, the more meters of seawater layer are needed. The more seawater layer required, the greater the impact on the ship's load capacity, which is detrimental to ship design. In addition, the excess seawater layer increases the ship's energy consumption, which is not conducive to the ship's low-carbon and environmentally friendly operation. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide a liquid hydrogen thermal insulation enclosure system.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution:

[0009] A liquid hydrogen thermal insulation enclosure system includes an independent liquid cargo tank, which is a double-shell structure with an inner shell and an outer shell; a vacuum insulation layer is located between the inner shell and the outer shell; the outer wall of the outer shell is covered with an insulation layer; the outer wall of the insulation layer is covered with a waterproof layer; a number of longitudinal reinforcing frames and a number of transverse reinforcing frames are fixed to the outer wall of the outer shell; support pads are provided between the longitudinal reinforcing frames and the hull structure, and between the transverse reinforcing frames and the hull structure.

[0010] The longitudinal strong frame has a T-shaped cross-section, and the panel and web of the longitudinal strong frame form a T-shape. The web of the longitudinal strong frame is distributed along the longitudinal direction of the shell, and the two sides of the web of the longitudinal strong frame along the length direction are fixed to the outer wall of the shell and the panel of the longitudinal strong frame, respectively.

[0011] The cross-section of the transverse strong frame is T-shaped, and the panel and web of the transverse strong frame form a T-shape. The web of the transverse strong frame is distributed transversely along the shell, and the two sides of the web of the transverse strong frame along the length direction are respectively fixed to the outer wall of the shell and the panel of the transverse strong frame.

[0012] The panels with vertical strong frames intersect with the panels with horizontal strong frames.

[0013] The top of the support pad abuts against the junction of the panels of the longitudinal and transverse strong frames.

[0014] The cross-section of an independent liquid cargo tank is polygonal; the independent liquid cargo tank is prismatic in shape.

[0015] The hull structure is equipped with a spray system distributed around the independent liquid cargo tanks.

[0016] The liquid hydrogen insulation enclosure system also includes an intelligent monitoring system that can control the spray system to spray water after the insulation of the independent liquid cargo tank fails.

[0017] A vacuum level monitor is installed inside the vacuum insulation layer and is connected to an intelligent monitoring system.

[0018] A temperature sensor is installed on the outside of the casing, and the temperature sensor is connected to the intelligent monitoring system.

[0019] The beneficial effects of this invention are as follows: By setting up a longitudinal strong frame, a transverse strong frame, and supporting pads, this invention not only ensures good fixation between the independent cargo tank and the hull structure, but also reduces the adverse effects of the low temperature of the independent cargo tank on the hull structure, thus protecting the hull structure. The independent cargo tank in this invention has a larger capacity than a C-type tank. In this invention, the supporting pads are located outside the vacuum insulation layer, and no supporting pads are placed inside the vacuum insulation layer, resulting in better insulation performance of the independent cargo tank. This invention employs an intelligent spray system; after a leak in the main shield, the intelligent spray system can automatically activate the spray pipe system to form a water curtain, protecting the hull structure and preventing low-temperature damage. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of a preferred embodiment of the present invention.

[0021] Figure 2 This is a longitudinal cross-sectional view of a preferred embodiment of the present invention. Detailed Implementation

[0022] The present invention will be described more clearly and completely below with reference to a preferred embodiment and the accompanying drawings.

[0023] like Figure 1 and Figure 2 As shown, a liquid hydrogen thermal insulation enclosure system includes an independent liquid cargo tank, which is a double-shell structure with an inner shell 11 and an outer shell 12; the cross-section of the independent liquid cargo tank is polygonal; the independent liquid cargo tank is prismatic in shape.

[0024] The inner shell 11 of the independent liquid cargo tank is a steel primary shield, which can be made of cryogenic materials such as aluminum alloy or stainless steel. The outer shell 12 of the independent liquid cargo tank is a steel secondary shield, which can be made of cryogenic materials such as aluminum alloy or stainless steel.

[0025] A vacuum insulation layer 13 is placed between the inner shell 11 and the outer shell 12. The inner shell 11 and the outer shell 12 do not contact each other and maintain a certain distance. The vacuum insulation layer 13 between them mainly serves the purpose of heat insulation.

[0026] The outer wall of the outer shell 12 is covered with an insulation layer 14. The insulation layer 14 is made of polyurethane material, so that it can still play a role in insulation even if the inner shell 11 leaks or the insulation effect of the vacuum insulation layer 13 is reduced, thus effectively improving the reliability of the entire insulation enclosure system.

[0027] The outer wall of the insulation layer 14 is covered with a waterproof layer 15. The waterproof layer 15 mainly serves to waterproof and prevent moisture from entering the insulation layer 14.

[0028] Several longitudinal reinforcing frames 60 and several transverse reinforcing frames 70 are fixedly connected to the outer wall of the outer shell 12.

[0029] The longitudinal reinforcing frame 60 has a T-shaped cross-section, with its panel and web forming the T-shape. The web 62 of the longitudinal reinforcing frame is distributed longitudinally along the outer shell, and its two sides along the length direction are fixed to the outer wall of the outer shell 12 and the panel 61 of the longitudinal reinforcing frame, respectively. The web of the longitudinal reinforcing frame and the outer shell are connected by welding.

[0030] The transverse reinforcing frame 70 has a T-shaped cross-section, with its panel and web forming the T-shape. The web 72 of the transverse reinforcing frame is distributed transversely along the outer shell, and its two sides along the length direction are fixed to the outer wall of the outer shell 12 and the panel 71 of the transverse reinforcing frame, respectively. The web of the transverse reinforcing frame and the outer shell are connected by welding.

[0031] The webs of the longitudinal strong frames are parallel to each other; the webs of the transverse strong frames are parallel to each other; the webs of the longitudinal strong frames are perpendicular to the webs of the transverse strong frames.

[0032] The outer shell 12 is welded with a longitudinal strong frame 60 and a transverse strong frame 70, which play a major supporting role and prevent the outer shell 12 from failing due to insufficient strength.

[0033] The panel 61 of the vertical strong frame and the panel 71 of the horizontal strong frame intersect.

[0034] Supporting pads 18 are provided between the longitudinal rigid frame 60 and the hull structure 10, and between the transverse rigid frame 70 and the hull structure 10.

[0035] In a preferred embodiment, the top of the support pad 18 abuts against the junction of the panel 61 of the longitudinal strong frame and the panel 71 of the transverse strong frame.

[0036] The support pads allow the load of the independent cargo tanks to be transferred smoothly to the hull structure. In addition, the support pads also serve as insulation, reducing the adverse effects of the low temperature of the independent cargo tanks on the hull structure and protecting it.

[0037] The hull structure 10 is equipped with a spray pipe system 19 distributed around the independent liquid cargo tanks.

[0038] The liquid hydrogen insulation enclosure system also includes an intelligent monitoring system (not shown in the figure) that can control the spray system to spray water after the insulation of the independent liquid cargo tank fails.

[0039] A vacuum level monitor (not shown in the figure) is installed inside the vacuum insulation layer; a temperature sensor (not shown in the figure) is installed on the outside of the outer casing 12.

[0040] Both the vacuum level monitor and the temperature sensor are connected to the intelligent monitoring system. In the event of insulation failure in the independent cargo tank, the intelligent monitoring system uses signals from the vacuum level monitor and temperature sensor to control the spray system, automatically opening it to form a water curtain and protect the ship's structure.

[0041] The spray piping system is arranged at regular intervals around the independent cargo tanks, and also in the middle and above the transverse bulkheads at the fore and aft of the hull. The seawater after spraying is collected in the hull's sludge wells, treated by the piping system, and then discharged or recycled.

[0042] This invention, through the structure of longitudinal strong frame, transverse strong frame and support pad, can not only ensure good fixation between the independent liquid cargo tank and the hull structure, but also reduce the adverse effects of the low temperature of the independent liquid cargo tank on the hull structure, thus protecting the hull structure.

[0043] The independent cargo tank in this invention has a larger capacity than the C-type tank. The tank structure is prismatic, and the maximum capacity of a single tank can reach about 50,000 cubic meters, thus solving the problems of small cargo capacity and low economic efficiency in liquid hydrogen shipping.

[0044] In this invention, the support pad is located outside the vacuum insulation layer, and no support pad is installed inside the vacuum insulation layer, which makes the insulation performance of the independent liquid cargo tank better.

[0045] This invention employs an intelligent spray system. After the main shield leaks, the intelligent spray system can automatically activate the spray piping to form a water curtain, protecting the hull structure and preventing low-temperature damage.

[0046] This invention employs an intelligent spraying system that recycles seawater, minimizing the impact on the ship's load capacity and maximizing the protection range for the ship; it solves the problem of limited seawater depth and small protection range for the ship in existing technologies.

[0047] In this invention, an external insulation layer is provided to further improve the insulation effect of the liquid cargo containment system and significantly reduce the amount of liquefied nitrogen generated in the cargo hold.

[0048] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A liquid hydrogen thermal insulation enclosure system, comprising an independent liquid cargo tank, wherein the independent liquid cargo tank is a double-shell structure with an inner shell and an outer shell; characterized in that, A vacuum insulation layer is placed between the inner and outer shells; the outer wall of the outer shell is covered with a thermal insulation layer; the outer wall of the thermal insulation layer is covered with a waterproof layer; several longitudinal and several transverse strong frames are fixed to the outer wall of the outer shell; support pads are provided between the longitudinal strong frames and the hull structure, and between the transverse strong frames and the hull structure; the cross-section of the independent liquid cargo tank is polygonal; the independent liquid cargo tank is prismatic; a spray pipe system is provided on the hull structure and distributed around the independent liquid cargo tank; the liquid hydrogen thermal insulation enclosure system also includes an intelligent monitoring system that can control the spray pipe system to spray water after the insulation of the independent liquid cargo tank fails.

2. The liquid hydrogen thermal insulation enclosure system as described in claim 1, characterized in that, The longitudinal strong frame has a T-shaped cross-section. The web of the longitudinal strong frame is distributed along the longitudinal direction of the shell. The two sides of the web of the longitudinal strong frame along the length direction are fixed to the outer wall of the shell and the panel of the longitudinal strong frame, respectively.

3. The liquid hydrogen thermal insulation enclosure system as described in claim 2, characterized in that, The cross-section of the transverse strong frame is T-shaped. The web of the transverse strong frame is distributed transversely along the shell. The two sides of the web of the transverse strong frame along the length direction are fixed to the outer wall of the shell and the panel of the transverse strong frame, respectively.

4. The liquid hydrogen thermal insulation enclosure system as described in claim 3, characterized in that, The panels with vertical strong frames intersect with the panels with horizontal strong frames.

5. The liquid hydrogen thermal insulation enclosure system as described in claim 4, characterized in that, The top of the support pad abuts against the junction of the panels of the longitudinal and transverse strong frames.

6. The liquid hydrogen thermal insulation enclosure system as described in claim 1, characterized in that, A vacuum level monitor is installed inside the vacuum insulation layer and is connected to an intelligent monitoring system.

7. The liquid hydrogen thermal insulation enclosure system as described in claim 1, characterized in that, A temperature sensor is installed on the outside of the casing, and the temperature sensor is connected to the intelligent monitoring system.

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