Dual-fuel liquefied gas carrier

Abstract

The invention relates to the technical field of ship design, in particular to a dual-fuel liquefied gas carrier which is characterized in that by designing a separation cabin, when goods in a goods cabin and goods in a fuel cabin are different, the separation cabin is kept empty, and the fuel cabin and the goods cabin can be separated, so that heat transfer between fuel and the goods is avoided; and therefore, simultaneous transportation and combustion of LPG and ammonia fuel are realized, and the functionality is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of ship design, and particularly to a dual-fuel liquefied gas carrier. Background Art

[0002] In terms of ship technology and operation, adjusting marine fuels and replacing traditional fuels with low-carbon or carbon-neutral fuels is an inevitable direction for the future development of ship shipping. Among many alternative fuels for ships, many large shipping companies have been taking ammonia as the most core fuel option. At present, ammonia fuel ship engines and technologies are still immature, and the design of ammonia fuel power systems for many large ships is still in the preparatory stage. Therefore, at this stage, LPG carriers are still the mainstay. The large ammonia carriers currently under construction are all designed to achieve ammonia loading functions based on the original LPG carriers as the parent type.

[0003] Since the liquefaction temperature of LPG is -52 degrees Celsius and that of ammonia is -33 degrees Celsius, the proximity of the two will cause the higher-temperature goods to reach the pour point state, affecting subsequent use. However, the existing ship designs have relatively single functions and cannot simultaneously meet the transportation and combustion of LPG and ammonia fuels. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a dual-fuel liquefied gas carrier, which is used to solve the problem that the existing ship designs have relatively single functions and cannot simultaneously meet the transportation and combustion of LPG and ammonia fuels.

[0005] To achieve the above purpose and other related purposes, the present invention provides a dual-fuel liquefied gas carrier, which includes a plurality of liquid cargo holds. A watertight dividing bulkhead is vertically arranged in one of the liquid cargo holds to divide the liquid cargo hold into an independent fuel tank, a dividing tank, and a cargo tank. Gas chambers are provided at the tops of the fuel tank, the dividing tank, and the cargo tank, and liquid collection wells are provided at the bottoms.

[0006] Optionally, the dividing tank and the cargo tank share the gas chamber and the liquid collection well, and both ends of the watertight dividing bulkhead between the fuel tank and the dividing tank and between the dividing tank and the cargo tank are respectively arranged in the shared gas chamber and the liquid collection well.

[0007] Optionally, the fuel tank is provided with a separate gas chamber and a separate liquid collection well. The dividing tank and the cargo tank share the gas chamber and the liquid collection well. Both ends of the watertight dividing bulkhead between the fuel tank and the dividing tank are arranged on the side wall of the liquid cargo hold. Both ends of the watertight dividing bulkhead between the dividing tank and the cargo tank are respectively arranged in the shared gas chamber and the liquid collection well. A communication air hole is opened at the top of the watertight dividing bulkhead between the dividing tank and the cargo tank, and a communication valve is provided at the bottom.

[0008] Optionally, the cargo hold separately provides the air chamber and the liquid collecting well. The partition hold and the fuel hold share the air chamber and the liquid collecting well. Both ends of the watertight partition bulkhead between the cargo hold and the partition hold are provided on the side wall of the liquid cargo hold. Both ends of the watertight partition bulkhead between the partition hold and the fuel hold are respectively provided in the shared air chamber and the liquid collecting well. A communication air hole is provided at the top of the watertight partition bulkhead between the partition hold and the fuel hold, and a communication valve is provided at the bottom.

[0009] Optionally, a cavity channel is reserved between the outer peripheral wall of the liquid cargo hold and the hull. A support seat is provided in the cavity channel to fix the liquid cargo hold on the hull, and the cavity channel can be used for crew members to enter.

[0010] Optionally, the liquid cargo hold includes an inner shell steel shield and an outer shell steel shield. A double hull tank is formed between the inner shell steel shield and the outer shell steel shield. The outer shell steel shield longitudinally provides uniformly vertical outer shell steel shield longitudinal stiffeners on the side close to the inner shell steel shield and extends towards the interior of the liquid cargo hold. The inner shell steel shield longitudinally provides uniformly vertical inner shell steel shield longitudinal stiffeners on the side close to the outer shell steel shield and extends towards the outside of the liquid cargo hold. Both the inner shell steel shield longitudinal stiffeners and the outer shell steel shield longitudinal stiffeners are located inside the double hull tank.

[0011] Optionally, the double hull tank is filled with polyurethane foam.

[0012] Optionally, the liquid cargo hold is integrally and fixedly connected to the hull.

[0013] Optionally, the liquid cargo hold includes an inner shell steel shield and an outer shell steel shield. The outer shell steel shield longitudinally provides uniformly vertical outer shell steel shield longitudinal stiffeners on the side close to the inner shell steel shield and extends towards the interior of the liquid cargo hold. The inner shell steel shield longitudinally provides uniformly vertical inner shell steel shield longitudinal stiffeners on the side far from the outer shell steel shield and extends towards the interior of the liquid cargo hold. A polyurethane insulation and heat preservation layer is laid on the outer wall of the inner shell steel shield.

[0014] Optionally, a feeding system equipment room is provided on the deck of the liquefied gas carrier. Feeding equipment is provided in the feeding system equipment room to transport fuel through the feeding equipment. The fuel tank is provided in one of the liquid cargo holds close to the feeding system equipment room.

[0015] In a dual-fuel liquefied gas carrier of the present invention, by designing a partition hold, when the goods in the cargo hold and the fuel hold are different, the partition hold can be kept empty to separate the fuel hold and the cargo hold, so that heat transfer between the fuel and the cargo will not occur, and thus the simultaneous transportation and combustion of LPG and ammonia fuel can be realized, with more powerful functionality. Brief Description of the Drawings

[0016] Figure 1 is a schematic diagram of the overall structure of a dual-fuel liquefied gas carrier according to an embodiment of the present invention;

[0017] Figure 2 is a schematic diagram of the positional structure of a fuel tank, a separation tank, and a cargo tank according to an embodiment of the present invention;

[0018] Figure 3 is a schematic diagram of the positional structure of a fuel tank, a separation tank, and a cargo tank according to another embodiment of the present invention;

[0019] Figure 4 is a schematic diagram of the positional structure of a fuel tank, a separation tank, and a cargo tank according to still another embodiment of the present invention;

[0020] Figure 5 is a schematic diagram of the structure of a liquid cargo tank according to an embodiment of the present invention;

[0021] Figure 6 is a schematic diagram of the connection structure of the inner and outer shell steel shielding transverse stiffeners according to an embodiment of the present invention;

[0022] Figure 7 is a schematic diagram of the connection structure of a watertight dividing bulkhead according to an embodiment of the present invention;

[0023] Figure 8 is a schematic diagram of the structure of a liquid cargo tank according to another embodiment of the present invention. Detailed Embodiments

[0024] The following refers to Figures 1 to 8 to describe a dual-fuel liquefied gas carrier of the present invention. In the description of this embodiment, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0025] As Figures 1 - 8As shown in the figure, an embodiment of the present invention provides a dual-fuel liquefied gas carrier, which generally includes a bow area 11, a cargo hold area 12, an engine room area 13, a stern area 14, a superstructure area 15, and a funnel area 16. The main engine 17 is arranged in the engine room area 13, and the engine room area 13 can be arranged at the stern of the ship to form a stern propulsion ship type. The superstructure area 15 can be arranged above the engine room area 13 or above the bow area 11 of the ship. Arranging the superstructure area 15 above the bow area 11 can improve the comfort of the crew's rooms. The cargo hold area 12 is provided with a plurality of liquid cargo holds 2 for carrying and transporting goods, and can adopt the form of IMO type A or type B liquid tanks. A transverse bulkhead 18 is arranged between two adjacent liquid cargo holds 2 for partitioning.

[0026] Further, a watertight dividing bulkhead 21 is vertically arranged in one of the liquid cargo holds 2 to divide the liquid cargo hold 2 into independent fuel tanks 22, separating tanks 23, and cargo holds 24. Gas chambers 25 are arranged at the tops of the fuel tanks 22, separating tanks 23, and cargo holds 24, and liquid collection wells 26 are arranged at the bottoms. The gas chambers 25 are used to provide a buffer space for installing equipment such as instruments and deep well pump motors in the gas chambers 25. The liquid collection wells 26 are used to collect and temporarily store liquids to facilitate the suction of the cargo pump and reduce the residual amount of liquid in the hold. By arranging gas chambers 25 at the tops and liquid collection wells 26 at the bottoms of the independent fuel tanks 22, separating tanks 23, and cargo holds 24, each of the three compartments has an independent cargo transfer system to independently transport the same or different goods into each compartment.

[0027] When the fuel and the goods are the same (i.e., transporting LPG and burning LPG or transporting ammonia fuel and burning ammonia fuel), the fuel tanks 22, separating tanks 23, and cargo holds 24 can be loaded with the same kind of goods at the same time. In the current context, it is possible to transport LPG and burn LPG. When ammonia is mass-produced on a large scale and the ammonia main engine technology is mature in the future, it will be possible to transport ammonia and burn ammonia.

[0028] When the fuel and the goods are different (i.e., transporting LPG and burning ammonia fuel or transporting ammonia fuel and burning LPG), the required fuel is loaded into the fuel tank 22, the required goods are loaded into the cargo hold 24, and the separating tank 23 remains completely empty. Specifically, when ammonia cannot be mass-produced but the ammonia main engine is mature, LPG can be loaded into the cargo hold 24 and ammonia fuel can be loaded into the fuel tank 22 to provide fuel for the main engine 17. When ammonia is mass-produced but the ammonia main engine is not mature, ammonia fuel can be loaded into the cargo hold 24 and LPG can be loaded into the fuel tank 22 to provide fuel for the main engine 17.

[0029] By designing the partition compartment 23, when the goods in the cargo hold 24 and the fuel tank 22 are different, keeping the partition compartment 23 empty can separate the fuel tank 22 and the cargo hold 24, so that heat transfer between the fuel and the goods is prevented, and thus the simultaneous transportation and combustion of LPG and ammonia fuel can be achieved, with more powerful functionality.

[0030] Furthermore, a fuel supply system equipment room 19 is provided on the deck of the liquefied gas carrier. A fuel supply device is arranged in the fuel supply system equipment room 19, and the fuel supply device can convey fuel to the main engine 17 through a double-wall conveying pipe. Using a double-wall conveying pipe can reduce the risk of fuel leakage. The fuel tank 22 is arranged in one of the liquid cargo holds 2 close to the fuel supply system equipment room 19 to facilitate the fuel supply device to pump fuel from the fuel tank 22.

[0031] In some embodiments of the present invention, referring to Figure 2 , the fuel tank 22, the partition compartment 23 and the cargo hold 24 share the gas chamber 25 and the sump 26. The two ends of the watertight partition bulkhead 21 between the fuel tank 22 and the partition compartment 23 and between the partition compartment 23 and the cargo hold 24 are respectively arranged in the shared gas chamber 25 and the sump 26. By sharing the gas chamber 25 and the sump 26, the structural design is made simpler.

[0032] In other embodiments of the present invention, referring to Figure 3 , the fuel tank 22 is provided with a separate gas chamber 25 and a sump 26. The partition compartment 23 and the cargo hold 24 share the gas chamber 25 and the sump 26. The two ends of the watertight partition bulkhead 21 between the fuel tank 22 and the partition compartment 23 are both arranged on the side wall of the liquid cargo hold 2. The two ends of the watertight partition bulkhead 21 between the partition compartment 23 and the cargo hold 24 are respectively arranged in the shared gas chamber 25 and the sump 26. A communication air hole 31 is opened at the top of the watertight partition bulkhead 21 between the partition compartment 23 and the cargo hold 24 and a communication valve 32 is arranged at the bottom. The fuel tank 22 is provided with a separate cargo transmission system to convey fuel into the fuel tank 22. The partition compartment 23 and the cargo hold 24 can share a cargo transmission system to convey goods into the partition compartment 23 and the cargo hold 24.

[0033] When the fuel and the goods are the same, keep the communication valve 32 open. At this time, the bottoms of the partition compartment 23 and the cargo hold 24 are kept in communication through the communication valve 32, and the gas phases at the tops are the same through the communication air hole 31. Using the cargo transmission system, convey goods to either the partition compartment 23 or the cargo hold 24. Through the communication valve 32 and the communication air hole 31, it is possible to convey goods into the partition compartment 23 and the cargo hold 24 respectively and keep the liquid levels inside the two the same. When the fuel and the goods are different, keep the communication valve 32 closed to separate the partition compartment 23 and the cargo hold 24, and only convey goods into the cargo hold 24 through the cargo transmission system.

[0034] By sharing the gas chamber 25 and the liquid collecting well 26 between the separation tank 23 and the cargo tank 24 and connecting the separation tank 23 and the cargo tank 24 through the connecting valve 32, the number of goods transfer systems can be reduced, thereby simplifying the structure of the system.

[0035] In some other embodiments of the present invention, referring to Figure 4 , the cargo tank 24 is provided with a gas chamber 25 and a liquid collecting well 26 separately. The separation tank 23 and the fuel tank 22 share the gas chamber 25 and the liquid collecting well 26. Both ends of the watertight partition wall 21 between the cargo tank 24 and the separation tank 23 are arranged on the side wall of the liquid cargo tank 2. Both ends of the watertight partition wall 21 between the separation tank 23 and the fuel tank 22 are respectively arranged in the shared gas chamber 25 and the liquid collecting well 26. A communication air hole 31 is opened at the top of the watertight partition wall 21 between the separation tank 23 and the fuel tank 22, and a connecting valve 32 is arranged at the bottom. The cargo tank 24 is provided with a goods transfer system separately to convey goods into the cargo tank 24. The separation tank 23 and the fuel tank 22 can share a goods transfer system to convey fuel into the separation tank 23 and the fuel tank 22.

[0036] When the fuel and the goods are the same, keep the connecting valve 32 open. At this time, the bottoms of the separation tank 23 and the fuel tank 22 are kept connected through the connecting valve 32, and the gas phases at the tops are the same through the communication air hole 31. Using the goods transfer system, convey goods to either the separation tank 23 or the fuel tank 22. Through the connecting valve 32 and the communication air hole 31, it is possible to convey fuel into the separation tank 23 and the fuel tank 22 respectively and keep the liquid levels inside the two the same. When the fuel and the goods are different, keep the connecting valve 32 closed to separate the separation tank 23 and the fuel tank 22, and only convey goods into the fuel tank 22 through the goods transfer system.

[0037] Similarly, by sharing the gas chamber 25 and the liquid collecting well 26 between the separation tank 23 and the fuel tank 22 and connecting the separation tank 23 and the fuel tank 22 through the connecting valve 32, the number of goods transfer systems can be reduced, thereby simplifying the structure of the system.

[0038] It should be noted that the above liquefied gas carrier is not only applicable to the simultaneous transportation and combustion of LPG and ammonia fuel, but also can be used for the simultaneous transportation and combustion of other fuel goods.

[0039] In some embodiments of the present invention, referring to Figure 5, a cavity channel 45 is reserved between the outer peripheral wall of the liquid cargo tank 2 and the hull 41. A support seat 44 is arranged in the cavity channel 45 to fix the liquid cargo tank 2 on the hull 41. With the above technical solution, after the construction of the liquid cargo tank 2 is completed separately, the installation and connection of the liquid cargo tank 2 can be carried out on the hull 41. In addition, the cavity channel 45 is set to be accessible to the crew, that is, the size of the cavity channel 45 can meet the entry and exit of the crew. When installing the support seat 44, it is more convenient for the crew to enter the cavity channel 45 for construction. At the same time, the cavity channel 45 can also be used as a maintenance channel, and maintenance personnel can enter the cavity channel 45 to conduct relevant inspections on the outer wall of the liquid cargo tank 2.

[0040] Further, referring to Figure 5 , the liquid cargo tank 2 includes an inner shell steel shield 43 and an outer shell steel shield 42, and a double-shell tank is formed between the inner shell steel shield 43 and the outer shell steel shield 42. On the side of the outer shell steel shield 42 close to the inner shell steel shield 43, outer shell steel shield longitudinal stiffeners 51 are uniformly and vertically arranged and extend towards the inside of the liquid cargo tank 2. On the side of the inner shell steel shield 43 close to the outer shell steel shield 42, inner shell steel shield longitudinal stiffeners 52 are uniformly and vertically arranged and extend towards the outside of the liquid cargo tank 2. The inner shell steel shield longitudinal stiffeners 52 and the outer shell steel shield longitudinal stiffeners 51 are both located inside the double-shell tank. The support seat 44 is connected to the outer shell steel shield 42. By arranging the inner shell steel shield longitudinal stiffeners 52 and the outer shell steel shield longitudinal stiffeners 51, the structural strength of the liquid cargo tank 2 can be enhanced. At the same time, by arranging the inner shell steel shield longitudinal stiffeners 52 and the outer shell steel shield longitudinal stiffeners 51 inside the double-shell tank, on the one hand, it can prevent the outer shell steel shield longitudinal stiffeners 51 from hindering the connection between the support seat 44 and the outer shell steel shield 42. On the other hand, it can prevent the outer shell steel shield longitudinal stiffeners 51 from hindering the inspection of the outer wall surface of the outer shell steel shield 42 and prevent the inner shell steel shield longitudinal stiffeners 52 from hindering the inspection of the inner wall surface of the inner shell steel shield 43.

[0041] Further, the liquid cargo tank 2 usually requires a low-temperature protection system. Therefore, polyurethane foam can be filled in the double-shell tank for heat preservation. Since the polyurethane foam can be directly filled into the double-shell tank, the operation is more convenient.

[0042] Further, referring to Figure 5 and Figure 6 , inner and outer shell steel shield longitudinal strong girders 53 and inner and outer shell steel shield transverse stiffening ribs 54 are also uniformly and spacedly arranged in the double-shell tank to further ensure the overall structural strength and stiffness requirements of the system. Reinforcing ribs and construction access holes 541 for the crew to pass through are arranged on the inner and outer shell steel shield transverse stiffening ribs 54.

[0043] Further, referring to Figure 7, when the liquid cargo tank 2 is divided by the watertight dividing bulkhead 21, the watertight dividing bulkhead 21 can be provided only within the inner shell steel shield 43, or can extend to both ends and be provided in the double hull tank.

[0044] In some other embodiments of the present invention, referring to Figure 8 , the liquid cargo tank 2 is integrally and fixedly connected to the hull 41, which is convenient for the integrated construction of the hull 41 and the liquid cargo tank 2. At the same time, the cavity passage 45 and the support base 44 are cancelled between the two, reducing the structural weight, and the saved space can also be used to increase the cabin volume of the liquid cargo tank 2.

[0045] Furthermore, referring to Figure 8 , the liquid cargo tank 2 includes an inner shell steel shield 43 and an outer shell steel shield 42. On the side of the outer shell steel shield 42 close to the inner shell steel shield 43, outer shell steel shield longitudinal stiffeners 51 are vertically arranged uniformly and extend towards the inside of the liquid cargo tank 2. On the side of the inner shell steel shield 43 far from the outer shell steel shield 42, inner shell steel shield longitudinal stiffeners 52 are vertically arranged uniformly and extend towards the inside of the liquid cargo tank 2. A polyurethane insulation layer 61 is laid on the outer wall of the inner shell steel shield 43. By arranging the inner shell steel shield longitudinal stiffeners 52 on the side of the inner shell steel shield 43 far from the outer shell steel shield 42 and extending towards the inside of the liquid cargo tank 2, it is convenient to lay the polyurethane insulation layer 61 on the outer wall of the inner shell steel shield 43. Using the polyurethane insulation layer 61 for heat preservation is more material-saving compared to directly filling the double hull tank with polyurethane foam.

[0046] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A dual-fuel liquefied gas carrier, characterized in that, The liquefied gas carrier includes a plurality of liquid cargo holds, and a watertight dividing bulkhead is vertically arranged in one of the liquid cargo holds to divide the liquid cargo hold into an independent fuel tank, a dividing tank and a cargo tank. Gas chambers are arranged at the tops of the fuel tank, the dividing tank and the cargo tank, and liquid collection wells are arranged at the bottoms of them.

2. The dual-fuel liquefied gas carrier according to claim 1, wherein The fuel tank, the dividing tank and the cargo tank share the gas chamber and the liquid collection well. Both ends of the watertight dividing bulkhead between the fuel tank and the dividing tank and between the dividing tank and the cargo tank are respectively arranged in the shared gas chamber and the liquid collection well.

3. The dual-fuel liquefied gas carrier according to claim 1, characterized in that, The fuel tank is provided with an independent gas chamber and an independent liquid collection well. The dividing tank and the cargo tank share the gas chamber and the liquid collection well. Both ends of the watertight dividing bulkhead between the fuel tank and the dividing tank are arranged on the side wall of the liquid cargo hold. Both ends of the watertight dividing bulkhead between the dividing tank and the cargo tank are respectively arranged in the shared gas chamber and the liquid collection well. A communication air hole is arranged at the top of the watertight dividing bulkhead between the dividing tank and the cargo tank, and a communication valve is arranged at the bottom.

4. The dual-fuel liquefied gas carrier according to claim 1, characterized in that, The cargo tank is provided with an independent gas chamber and an independent liquid collection well. The dividing tank and the fuel tank share the gas chamber and the liquid collection well. Both ends of the watertight dividing bulkhead between the cargo tank and the dividing tank are arranged on the side wall of the liquid cargo hold. Both ends of the watertight dividing bulkhead between the dividing tank and the fuel tank are respectively arranged in the shared gas chamber and the liquid collection well. A communication air hole is arranged at the top of the watertight dividing bulkhead between the dividing tank and the fuel tank, and a communication valve is arranged at the bottom.

5. The dual-fuel liquefied gas carrier according to claim 1, characterized in that, A cavity channel is reserved between the outer peripheral wall of the liquid cargo hold and the hull. A support seat is arranged in the cavity channel to fix the liquid cargo hold on the hull, and the cavity channel can be used for crew members to enter.

6. The dual-fuel liquefied gas carrier according to claim 5, wherein The liquid cargo hold includes an inner shell steel shield and an outer shell steel shield. A double hull tank is formed between the inner shell steel shield and the outer shell steel shield. Outer shell steel shield longitudinal stiffeners are uniformly and vertically arranged on the side of the outer shell steel shield close to the inner shell steel shield and extend towards the inside of the liquid cargo hold. Inner shell steel shield longitudinal stiffeners are uniformly and vertically arranged on the side of the inner shell steel shield close to the outer shell steel shield and extend towards the outside of the liquid cargo hold. Both the inner shell steel shield longitudinal stiffeners and the outer shell steel shield longitudinal stiffeners are located inside the double hull tank.

7. The dual-fuel liquefied gas carrier according to claim 6, characterized in that, The double hull tank is filled with polyurethane foam.

8. The dual-fuel liquefied gas carrier according to claim 1, characterized in that, The liquid cargo hold is integrally and fixedly connected to the hull.

9. The dual-fuel liquefied gas carrier according to claim 8, wherein, The liquid cargo hold includes an inner shell steel shield and an outer shell steel shield. Outer shell steel shield longitudinal stiffeners are uniformly and vertically arranged on the side of the outer shell steel shield close to the inner shell steel shield and extend towards the inside of the liquid cargo hold. Inner shell steel shield longitudinal stiffeners are uniformly and vertically arranged on the side of the inner shell steel shield away from the outer shell steel shield and extend towards the inside of the liquid cargo hold. A polyurethane insulating and heat-preserving layer is laid on the outer wall of the inner shell steel shield.

10. The dual-fuel liquefied gas carrier according to claim 1, characterized in that, A fuel supply system equipment room is provided on the deck of the liquefied gas carrier. A fuel supply device is provided in the fuel supply system equipment room to convey fuel through the fuel supply device. The fuel tank is arranged in one of the liquid cargo holds close to the fuel supply system equipment room.

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