FIELD OF THE INVENTION

The present invention relates to a watertight bulkhead compartment of a ship supporting a hydrogen fuel tank inside the bulkhead compartment, wherein at least one end surface of the bulkhead on a port side or starboard side of the ship hull loosens if an explosive ignition of hydrogen happens inside the bulkhead compartment.

BACKGROUND OF THE INVENTION

Hydrogen is a beneficial fuel for motors and fuel cells in different applications areas as known in prior art. Especially, the property that the rest product from the hydrogen fuel is pure water makes it an attractive replacement for oil-driven machines and processes.

One aspect of hydrogen gas is that it is much lighter than air, has no odour but is highly explosive in contact with for example open flames. Therefore, there are security issues related to hydrogen driven energy production and use.

Hydrogen burns 6-7 times faster than methane. Hydrogen requires 15 times less energy to ignite than liquid natural gas. Flames from burning hydrogen can travel with a speed of up to 1000 m/s.

Despite the security issues related to hydrogen there are some examples of use of hydrogen as a fuel in ships and trucks for example. The ferry MF Hydra is under construction at Westcon Yard and the company Scania is building trucks with hydrogen driven fuel cells.

A further aspect of hydrogen is that it is present in many materials , also inside steel plates for example. Carbon is also present and can react with hydrogen. This weakens the steel. Therefore, it is normal to use steel qualities with less carbon in hydrogen applications. From a security standpoint it is common to have detectors that can identify an unexpected increase of pressure and/or detection of flames etc. Due to the characteristics of hydrogen detailed above it is probably impossible to make a detection soon enough before a disaster actually happens.

WO 2012/007900 disclose a ship utilizing gas as a fuel. The ship includes a tank space (580) holding at least one gas storage tank (590). The tank space is open on one side (582) and the open end extends from the tank space to the open air outside the ship allowing venting of gas in the event of a leakage from the gas storage tank. A gas consumer (500) in a gas consumer room (505) and the tank space provides collectively only one potentially hazardous ventilation point outside the ship per tank space.

KR 102147544 Bl disclose a a fuel storage system for a hydrogen-propelled container carrier comprising: a hydrogen storage module including a hydrogen storage container in which liquefied hydrogen is stored, an outer container having a size and shape corresponding to a container conveyed by the container carrier and holding the hydrogen storage container, and a fuel supply unit installed in a space between the hydrogen storage container and the outer container to gasify and decompress the liquefied hydrogen discharged from the hydrogen storage container; a cell guide unit including a plurality of cell guides perpendicularly up and down installed in a space of a ship to movably up and down support both corner portions of the front end portion and the rear end portion of the hydrogen storage module; a cell stack installation unit in which a fuel cell stack is installed wherein the fuel cell stack is disposed outside the cell guide unit to receive hydrogen gas supplied from a fuel supply unit of the hydrogen storage module to generate electricity for propulsion of the container carrier; and a hydrogen supply unit penetrating through a partition body of the cell guide unit to supply hydrogen from the hydrogen storage module to the fuel cell stack.

WO 2015/151850 Al disclose a technique with which it is possible to further improve the stiffness of a hullin a fuel cell boat that runs with a fuel cell as a power source. A fuel cell (5) is supplied with hydrogen form a hydrogen fuel tank (6). The fuel tank (6) is configured to be supported by beams (20) of the hull (2). Preferably, the fuel tanks (6) are arranged from a left end portion to a right end portion of horizontal beams (21) of the hull (2), or the fuel tanks (6) are arranged from the bow-side end portion to the stern-side end portion of vertical beams (22) of the hull (2).

The present invention is related to a hydrogen fuel tank onboard ships providing hydrogen fuel for a ship-motor. It is possible to have storage tanks for liquid hydrogen (LH2) or hydrogen gas that can be used as fuel for adapted ship motors. In liquid form the hydrogen takes up much less storage volume as known in prior art.

Leakage of hydrogen at open sea is not a same security issue as if a hydrogen tank starts leaking in a populated area on shore. If the hydrogen storage tank is located in free air on a ship deck for example, any limited leakage will probably just blow away in the wind. However, an ignition of leaked hydrogen will probably destroy the whole ship. Therefore, there are examples of different measures related to preventing flames to reach a hydrogen storage tank as known in prior art related for example to gas tank ships in general. For example, having extra nitrogen compartments surrounding explosive gas containing compartments is a commonly known security measure. However, such a system may fail, and an explosion may occur.

The present invention is based on an assumption that it may be extremely difficult to stop a development of a hydrogen leakage becoming an explosive incident. The present invention is therefore related to a hydrogen fuel storage tank system for a ship wherein an explosive ignition of hydrogen is dealt with by diverting the energy from an explosion away from the ship itself.

OBJECT OF THE INVENTION

It is a further object of the present invention to provide an alternative to the prior art.

In particular, it may be seen as an object of the present invention to provide a strong bulkhead compartment onboard a ship supporting a hydrogen storage tank with at least one surface plate facing outwards from a ship hull of the ship loosening when an explosive ignition of hydrogen happens inside the bulkhead compartment. SUMMARY OF THE INVENTION

Thus, the above described object and several other objects are intended to be obtained in a first aspect of the invention by providing a bulkhead compartment in a ship hull supporting a hydrogen fuel storage tank, wherein at least one surface of the bulkhead compartment facing outward from the ship hull loosens if an explosive ignition of hydrogen happens.

The invention is particularly, but not exclusively, advantageous for obtaining a a bulkhead compartment of a ship arranged inside a ship hull of the ship, wherein the bulkhead compartment is configured with a hydrogen fuel tank inside the bulkhead compartment, wherein the bulkhead compartment has a first end surface plate on a port side of the ship hull, and a second end surface plate on a starboard side of the ship hull, wherein at least one of the first and second end surface plates is configured to loosen if an explosive ignition of hydrogen happens inside the bulkhead compartment.

Respective aspects of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described herein.

DESCRIPTION OF THE FIGURES

The cryogenic storage tank according to the present invention will now be described in more detail with reference to the accompanying figures. The attached figures illustrates an example of embodiment of the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

Figure 1 illustrates an example of embodiment of the present invention.

DETAILED DESCRIPTION OF AN EXAMPLE OF EMBODIMENT

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Further, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.

Figure 1 illustrates an example of embodiment of the present invention, wherein a ship 10 comprises a bulkhead compartment 11 stretching from for example a port to a starboard side of the ship. Details of the bulkhead compartment 11 is provided in a blown-up section 10a in Figure 1.

A hydrogen storage tank may for example be adapted and located inside the space defined by the respective side walls 16 of the bulkhead compartment 11. The bulkhead compartment is an enforced steel construction that can withstand impact from waves, and which is also watertight. In this respect a bulkhead compartment may also be gas tight. An end surface 15 on the port side of the ship hull 14 and an end surface 17 on the starboard side of the ship hull 14 closes the bulkhead compartment 11.

An aspect of the present invention is that if an explosive ignition of hydrogen happens inside the bulkhead compartment 11, respective end surface plates 15 and 17 will loosen due to the pressure build up from an explosion and the energy from the explosion is guided outside the ship hull 14 through respective openings in the ship hull 14 left when att least one end surface plates 15, 17 loosens. The respective arrows 13 and 18 indicates this situation. It is also within the scope of the present invention that only one of the end surfaces plates 15 or 17 is configured to loosen when an explosive ignition of hydrogen happens.

The mechanical strength of the steel construction constituting the bulkhead compartment 11 is made to be stronger than the mechanical strength of the fastening of the end surface plates 15, 17. This relative difference of mechanical strength makes sure that the end surface plates 15, 17 actually loosens before any damage to any side walls 16 of the bulkhead compartment 11 happens. Since the bulkhead compartment 11 is watertight and intact after an explosion, water entering the bulkhead compartment 11 will just be drained out again through the openings provided by the explosion. It is also within the scope of the present invention that the bulkhead compartment (11) may stretch from the port side to an end inside the ship hull (14) in a defined distance from the starboard side.

It is also within the scope of the present invention that the bulkhead compartment (11) may stretch from the starboard side to an end inside the ship hull (14) in a defined distance from the port side.

The end surface plate 15, 17 may for example be fastened to the bulkhead via a frame 12 comprising for example a false the end surface plate 15, 17 can be attached inside. The backside of the end surface plate 15, 17 is enforced with for example steel beams. This ensures that if the end surface plate 15, 17 is hit by a wave when the ship is passing through rough weather, they will not be damaged by the weather. The fastening of the end surface 15, 17 inside for example the frame 12 is done for example by welding. As long as this welding provides a mechanical fastening of the end surface 15 to the ship hull (14), via for example the frame (12), that is less in strength than the mechanical strength of the internal walls 16 of the bulkhead 11, the energy from the explosive ignition of hydrogen will blow out the end surface 15 as indicated by the arow 13. The same arrangement can be made for the end surface 17 on the starboard side if two end surfaces 15, 17 are arranged.

The respective end surface plates 15, 17 can be arranged flush with the outer surface of the ship hull 14 when attached.

The explosive ignition of hydrogen happens almost instantly, which leaves the ship unharmed as long as at least one end surface plates 15, 17 loosens due to the explosive ignition of hydrogen.

It is also within the scope of the present invention to arrange a bulkhead compartment 11 in an aft section of a ship 10. Then only one end surface 15, 17 is arranged giving away when an explosive ignition of hydrogen happens.

According to an example of embodiment of the present invention, a wate tight bulkhead compartment 11 of a ship 10 is arranged inside a ship hull 14 of the ship 10, wherein the bulkhead compartment 11 is configured with a hydrogen fuel tank inside the bulkhead compartment 11, wherein the bulkhead compartment 11 has a first end surface plate 15 on a port side of the ship hull 14, and a second end surface plate 17 on a starboard side of the ship hull 14, wherein at least one of the first and second end surface plates 15, 17 is configured to loosen from the ship hull 14 if an explosive ignition of hydrogen happens inside the bulkhead compartment 11.

According to the example of embodiment of the present invention disclosed above, the respective first and second end surface plate 15,17 may be attached to a frame 12 of the bulkhead compartment 11 being integral with the ship hull 14.

According to the example of embodiment of the present invention disclosed above, a backside of the first end surface plate 15 and a backside of the second end surface plate 17 may be arranged with strengthening steel beams.

According to the example of embodiment of the present invention disclosed above, the fastening of the frame 12 of the respective first and second end plates 15, 17 may be done with a mechanical strength being less than the mechanical strength of respective side walls 16 of the bulkhead compartment 11.

According to the example of embodiment of the present invention disclosed above, the bulkhead compartment 11 may be arranged in an aft section of the ship 10 with a defined length stretching inwards into the hull 14.

According to the example of embodiment of the present invention disclosed above, the bulkhead compartment 11 may be arranged with a single end surface plate 15, 17 facing rearward from the ship hull 14 when the bulkhead is arranged in the aft section of the ship 10)

According to the example of embodiment of the present invention disclosed above, the attachment of the first and second end surface plates 15, 17) to the frame 12 may be done by welding.

According to the example of embodiment of the present invention disclosed above, the frame 12 may comprise a false running around a periphery of the frame 12.

According to the example of embodiment of the present invention disclosed above, the bulkhead compartment 11 may stretche from the port side to an end location inside the ship hull 14, wherein the end location is in a defined distance from the starboard side. According to the example of embodiment of the present invention disclosed above, the bulkhead compartment ll)may stretche from the starboard side to an end location inside the ship hull 14, wherein the end location is in a defined distance from the port side.