Dual-fuel bulk carrier

Abstract

The dual fuel bulk carrier including the dual fuel bulk carrier's air intake system is configured such that the dual fuel bulk carrier's main deck (26) includes a cargo hold area (29) and an aft area (30) including an extension area (301), the extension area (301) is on both sides of the aft and extends along a direction away from the center of the ship, a superstructure (25) is installed on the side of the aft area (30) closer to the cargo hold area (29), and the dual fuel bulk carrier's air intake system is configured to be installed above the open aft area (30). The ship comprises LNG fuel tanks (1a, 1b) installed on the upper deck (20) and located on both the left and right sides of the upper building (25), a machinery room installed below the main deck (26), and a fuel gas processing room (3) installed above the open stern area (30) and located between the two LNG fuel tanks (1a, 1b), wherein fuel in the LNG fuel tanks (1a, 1b) is transported to the fuel gas processing room (3) for processing and also transported to gas-using equipment in the machinery room.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from Chinese patent application CN2020102308309, filed on March 27, 2020. This application incorporates reference to the above Chinese patent application in its entirety.

[0002] "Technology field" The present invention relates to a dual fuel bulk carrier. [Background technology]

[0003] Dual fuel bulk carriers are applicable to different routes, and the air supply system of a dual fuel bulk carrier generally has an LNG fuel tank, an engine room and a fuel gas treatment room. The LNG fuel tank is a pressure tank for storing LNG and provides gas fuel for the dual fuel gas using equipment on the ship. LNG is stored in the tank in a liquid state, and the temperature of LNG when it is liquid at normal pressure is about -163°C.

[0004] The location of LNG fuel tanks on a ship should first consider safety, and ensure that the location requirements for LNG fuel storage tanks of the IGF are met, and the distance of LNG fuel tanks from the ship's side and bottom shell meets the requirements, so as to minimize the probability of loss of LNG fuel tanks after a collision or grounding of the ship, and comprehensively consider the impact of LNG fuel tanks on the stability of the ship, the division of fire compartments and hazardous areas, and the convenience of LNG pipeline layout.

[0005] The volume of the LNG fuel tank is large, the LNG fuel supply system is complex and difficult to layout, and in the case of conventional bulk carriers, the LNG fuel tank cannot be arranged in the cargo hold area on the main deck because there is a cargo hold hatch cover in the cargo hold area on the main deck. Summary of the Invention [Problem to be solved by the invention]

[0006] The technical problem that the present invention aims to solve is to provide a dual-fuel bulk carrier to solve the disadvantages of the prior art, such as the large volume of the LNG fuel tank, the complex and difficult layout of the LNG fuel supply system, and the difficulty in rationally arranging the LNG fuel tank on the main deck. [Means for solving the problem]

[0007] The present invention solves the above technical problems through the following technical solutions.

[0008] A dual fuel bulk carrier including an air intake system for a dual fuel bulk carrier, wherein a main deck of the dual fuel bulk carrier includes a cargo hold area and an aft area including an extension area, the extension area being on both sides of the aft and extending along a direction away from the midship, and a superstructure is provided on a side of the aft area closer to the cargo hold area, and the air intake system of the dual fuel bulk carrier includes: LNG fuel tanks installed above the open aft area and located on both the left and right sides of the upper building; An engine room installed below the main deck; a fuel gas processing room installed above the open stern area and located between the two LNG fuel tanks, wherein fuel in the LNG fuel tanks is transported to the fuel gas processing room for processing and also transported to gas-using equipment in the engine room.

[0009] In this technical proposal, by installing an extension area on the main deck, the LNG fuel tank can be located on the main deck, and the LNG fuel tank has sufficient natural ventilation, thereby eliminating the need to install separate fire alarms, gas detectors and ventilation around the LNG fuel tank; the LNG fuel tank is located in the stern area and does not occupy space in the cargo hold area and engine room, so that the impact on the main scale of the ship and the integrity of the ship's main structure is small; the requirements for the operational visibility range of personnel in the driver's cab when the ship is sailing are met; and the IGF specification requirements can be met without installing a fuel tank connection space in the tank.

[0010] Preferably, the upper building narrows in width towards the amidships to accommodate the LNG fuel tanks.

[0011] In this technical proposal, the width of the upper building is reduced toward the center of the hull, allowing more positions to be reserved in advance on both sides of the upper building for placing LNG fuel tanks.

[0012] Preferably, the width of the stern region is constant along the length of the vessel, forming a full width tail deck.

[0013] In this technical proposal, the width of the stern region is set constant along the length of the ship, i.e., the stern region is set rectangular, thereby increasing the area of ​​the stern region, and the rectangular stern region has a simple structure and is easy to process.

[0014] Preferably, the design pressure of the LNG fuel tank is in the range of 4 barg to 7 barg.

[0015] Preferably, there is an air dome above the LNG fuel tank, and a maintenance work platform is disposed above the air dome.

[0016] In this technical solution, the maintenance work platform is used to position a crane for lifting an LNG transport pump installed in an LNG fuel tank.

[0017] Preferably, the air supply system of the dual fuel bulk carrier includes LNG filling stations located on both port and starboard sides of the cargo hold area.

[0018] In this technical proposal, the LNG filling station is installed on both the port and starboard sides of the cargo hold area, thereby increasing the flexibility of LNG filling of the bulk carrier and enabling the ship to fill and replenish fuel on either the port or starboard side depending on the operating conditions.

[0019] Preferably, the air supply system of the dual fuel bulk carrier further comprises a manual crane, the working range of the manual crane covering the LNG filling station.

[0020] In this technical solution, a manual crane is used to hoist an LNG filling hose in an LNG filling station.

[0021] Preferably, the LNG filling station is equipped with a fixed dry powder fire extinguishing system.

[0022] Preferably, a liquid collection tray is installed below the connector of the LNG filling station.

[0023] In this technical proposal, a liquid collection tray made of low temperature resistant stainless steel material should be installed below the connectors of the LNG filling stand and below any locations where leakage may occur to prevent the cryogenic liquid, cryogenic pipelines from contacting the ship's hull during filling, so that in the event of a fuel leak, the surrounding ship's hull or deck structure will not be subjected to unacceptable cooling.

[0024] Preferably, the LNG filling station, the LNG fuel tank and the fuel gas treatment room are connected via a low-temperature LNG pipe, and a steel protective cover is installed above the low-temperature LNG pipe located in the cargo hold area or the stern area.

[0025] In this technical proposal, the low-temperature LNG pipe is used to transport low-temperature liquid, and the installation of a steel protective cover can reduce the risk of damage to the low-temperature LNG pipe in the event of an unexpected collision with the ship.

[0026] Preferably, the dual fuel bulk carrier air supply system includes an LNG vent mast located on the port or starboard side of the main deck.

[0027] In this technical proposal, a vent mast is used to vent flammable gases from a pressurized system to the atmosphere in a safe manner, without harm to personnel and equipment.

[0028] Preferably, a dual-fuel generator group and a fuel gas valve group for the dual-fuel generator group are installed aft on the third deck of the engine room, and a dual-fuel steam boiler and a fuel gas valve group for the dual-fuel steam boiler are installed aft on the second deck of the engine room.

[0029] Preferably, an LNG transfer pump is provided in the LNG fuel tank, and fuel is transferred via the LNG transfer pump to the LNG vaporizer and passed through an LNG main engine buffer tank to the dual fuel main engine.

[0030] In this technical proposal, the LNG main engine buffer tank is used to stabilize the pressure of the gas after the LNG vaporizes.

[0031] Preferably, an LNG transport pump is installed in the LNG fuel tank, and the fuel is transported to an LNG vaporizer via the LNG transport pump, passes through an LNG main engine buffer tank, and is depressurized by a group of pressure reducing valves, and then branches into two flow paths, one of which is used to supply gas to a group of dual-fuel generators, and the other of which is used to supply gas to a dual-fuel steam boiler.

[0032] In this proposed technique, pressure reducing valves are used to reduce the LNG to an appropriate pressure to supply the dual fuel generators and dual fuel steam boilers.

[0033] Preferably, the air supply system of the dual fuel bulk carrier further includes a group of BOG compressors located within the fuel gas processing chamber.

[0034] In this technical solution, the BOG compressor group is used to compress and then discharge the BOG. ​​LNG vaporizes very easily at room temperature to form BOG, and the BOG is compressed and used as fuel, which not only solves the problems of the pressure retention time of the LNG fuel tank and BOG treatment, but also saves costs and eliminates the problems of pollutant emissions.

[0035] Preferably, the evaporative gas in the LNG fuel tank is passed through the BOG compressor group, then passed to an LNG main engine buffer tank, and is used to supply gas to the dual fuel generator group and the dual fuel steam boiler, respectively.

[0036] In this technical proposal, BOG is compressed and then supplied as fuel to a bank of dual-fuel generators and a dual-fuel steam boiler.

[0037] Preferably, the evaporative gas in the LNG fuel tank is passed through the BOG compressor group, then passed to the LNG main engine buffer tank, and is used to supply gas to the dual fuel main engine, the dual fuel generator group, and the dual fuel steam boiler, respectively.

[0038] In this technical proposal, BOG is compressed and then supplied as fuel to the dual-fuel main engine, the dual-fuel generator group and the dual-fuel steam boiler.

[0039] Preferably, the BOG compressor group includes two BOG compressors, one of which is used as a spare.

[0040] In this technical solution, when the pressure in the LNG fuel storage tank is too high, one can choose to start up and operate two BOG compressors simultaneously, so as to quickly and efficiently reduce the pressure in the tank.

[0041] Preferably, a dual fuel main engine is installed in the engine room, and a group of fuel gas valves for the dual fuel main engine is installed in the engine room or the fuel processing room.

[0042] Preferably, the air supply system of the dual-fuel bulk carrier includes a medium and low pressure LNG fuel air supply system, the fuel gas supply pressure of the medium and low pressure LNG fuel air supply system does not exceed 16 barg, the dual-fuel main engine adopts WinGD's dual-fuel main engine X-DF model, the LNG fuel tank includes an LNG transport pump, the fuel gas treatment chamber includes an LNG vaporizer, a low-pressure LNG vaporizer, a BOG compressor group, inlet and outlet heat exchangers of the BOG compressor group, a dual-fuel main engine fuel gas valve group, and a water-glycol unit.

[0043] Preferably, the air supply system of the dual-fuel bulk carrier includes a high and low pressure LNG fuel air supply system, the fuel gas supply pressure of the high and low pressure LNG fuel air supply system does not exceed 300 barg, the dual-fuel main engine adopts MAN's dual-fuel main engine ME-GI model, and the fuel gas treatment chamber includes a high-pressure pump, a high-pressure LNG vaporizer, a low-pressure LNG vaporizer, a BOG compressor group, inlet and outlet heat exchangers of the BOG compressor group, and a dual-fuel main engine fuel gas valve group.

[0044] Preferably, the dual fuel bulk carrier further includes safety systems and auxiliary systems, wherein the safety systems include one or more of a gas detection system, a fire alarm system, an emergency shut-off system, a fire extinguishing system, a ventilation system, and a vent exhaust system, and the auxiliary systems include one or more of a water-glycol system, a nitrogen system, and an instrument air system.

[0045] In this technical solution, the installation of the safety system can meet the needs of safety, evacuation and other issues, and the installation of the auxiliary system can make the process flow of the LNG supply air system more rational and smooth.

[0046] Preferably, the distance from the LNG fuel tank to the shipside and the distance from the LNG fuel tank to the bottom shell are calculated by a probability method in the IGF Code.

[0047] Preferably, the LNG fuel tank is a self-supporting prismatic IMO C type LNG fuel tank.

[0048] Each preferred embodiment of the present invention can be obtained by arbitrarily combining each of the above-mentioned preferred conditions as long as it is in accordance with the ordinary skill in the art. Effect of the Invention

[0049] The positive effects of the present invention are as follows: by installing the extension area on the main deck, the LNG fuel tank can be located on the main deck, and the LNG fuel tank has sufficient natural ventilation, thereby eliminating the need to install separate fire alarms, gas detectors and ventilation equipment around the LNG fuel tank; the LNG fuel tank is located in the stern area and does not occupy the space of the cargo hold area and the engine room, so that the impact on the main scale of the ship and the integrity of the ship's main structure is small; the requirements for the operational visibility range of personnel in the driver's cab when the ship is sailing are met; and the specification requirements of the IGF can be met without installing a fuel tank connection space for the tank. [Brief description of the drawings]

[0050] [Figure 1] 1 is a schematic diagram showing a front structure of a dual fuel bulk carrier according to a preferred embodiment of the present invention. [Diagram 2] 1 is a schematic diagram showing the left side structure of a dual fuel bulk carrier according to a preferred embodiment of the present invention. [Diagram 3]1 is a schematic diagram showing a planar structure of a dual-fuel bulk carrier according to a preferred embodiment of the present invention; [Figure 4] FIG. 2 is a structural schematic diagram of a fuel processing chamber according to a preferred embodiment of the present invention, in which the supply system of the dual-fuel bulk carrier adopts a low and medium pressure LNG fuel supply system. [Diagram 5] FIG. 2 is another structural schematic diagram of a fuel processing chamber according to a preferred embodiment of the present invention, in which the supply system of the dual-fuel bulk carrier adopts a high and low pressure LNG fuel supply system with an LNG high pressure pump. [Figure 6] FIG. 2 is another structural schematic diagram of a fuel processing chamber according to a preferred embodiment of the present invention, in which the supply system of the dual-fuel bulk carrier adopts a high and low pressure LNG fuel supply system with a pump vaporization unit. [Figure 7] 1 is a comparative schematic diagram of the aft area of ​​a preferred embodiment of the present invention and the aft area of ​​a main deck in the prior art; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

[0052] The symbols in FIGS. 1 to 7 are as follows: 1a, 1b...LNG fuel tank, 2a, 2b...Air dome, 3...Fuel processing room, 4...LNG vent mast, 5...Dual fuel main engine, 6...Dual fuel generator group, 7...Fuel gas valve group for dual fuel generator group, 8...Dual fuel steam boiler, 9...Fuel gas valve group for dual fuel steam boiler, 10a, 10b...Manual crane, 11a, 11b...LNG filling stand, 12...LNG fuel tank protective steel, 13a, 13b...High pressure pump, 14a, 14b...Evacuation exit, 15...Pump vaporization unit, 16...Low pressure vaporizer, 17...B OG preheater, 18a, 18b...BOG compressor group, 19...main engine buffer tank, 20...fuel gas valve group for dual fuel main engine, 21...water glycol unit, 22...high pressure vaporizer, 23...servo room, 24...pump vaporization unit hydraulic pump station, 25...upper building, 26...main deck, 27...second deck, 28...third deck, 29...cargo hold area, 30...stern area, 301...extension area, 31...support structure, 40...main deck contour, 41...normal main deck contour.

[0053] The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

[0054] As shown in Figures 1, 2, 3 and 7, this embodiment is a dual-fuel bulk carrier including an air supply system for the dual-fuel bulk carrier, the main deck 26 of the dual-fuel bulk carrier includes a cargo hold area 29 and an aft area 30 including an extension area 301, the extension area 301 is on both sides of the aft and extends along a direction away from the center of the ship, and a superstructure 25 is installed on the side of the aft area 30 approaching the cargo hold area 29, and the air supply system of the dual-fuel bulk carrier is: LNG fuel tanks 1a, 1b installed above the open stern area 30 and located on both the left and right sides of the upper building 25; An engine room located below the main deck 26; A dual fuel bulk carrier is provided, the dual fuel bulk carrier including a fuel gas processing room installed above an open stern region 30 and located between two LNG fuel tanks 1a, 1b, wherein fuel in the LNG fuel tanks 1a, 1b is transported to the fuel gas processing room for processing and also transported to gas-using equipment in the engine room.

[0055] The LNG fuel tank is a self-supporting rectangular LNG fuel tank, adopting IMO C type storage tank, and an aft area 30 is installed on the main deck 26. The LNG fuel tanks 1a, 1b are arranged on the open aft area 30 of the main deck. Taking into consideration the arrangement of the cargo oil loading and unloading station on the main deck, the associated cargo oil piping system and cable area, and in line with the requirements for the operational visibility range of the personnel in the driver's cab when the ship is sailing, the tank is provided with an airtight fuel tank connection space (Tank Connection The IGF specification requirements can be met without installing additional fire alarms, gas detectors and ventilation around the LNG fuel tanks 1a, 1b, the LNG fuel tanks 1a, 1b have sufficient natural ventilation in the stern area 30, which eliminates the need to install separate fire alarms, gas detectors and ventilation around the LNG fuel tanks 1a, 1b, the LNG fuel tanks 1a, 1b do not occupy space in the cargo hold area 29 and the engine room, so there is little impact on the ship's main scale and the integrity of the ship's main structure, and, assuming that cargo loading capacity is ensured, there is no impact on the layout of major equipment and cabins in the engine room, and the requirements for the operational visibility range of personnel in the driver's cab when the ship is sailing are met.

[0056] Furthermore, by installing a fuel tank connection space in the tank, the expansion of the danger area can be limited, the equipment can be protected from the effects of weather, the fuel tank and surrounding equipment can be protected, and the time required for gas detection can be shortened.

[0057] As shown in Fig. 3, the two LNG fuel tanks 1a, 1b are arranged symmetrically on both the left and right sides of the upper building 25 along the longitudinal direction of the ship. The width of the upper building 25 shrinks toward the center of the ship to form a thin and narrow upper building to accommodate the LNG fuel tanks 1a, 1b. Here, by shrinking the width of the upper building 25 toward the center of the ship, more positions can be reserved in advance on both sides of the upper building 25 for arranging the LNG fuel tanks 1a, 1b.

[0058] FIG. 7 shows the outline 41 of a normal main deck in the prior art and the outline 40 of a main deck in this embodiment, and as can be understood by referring to FIG. 3, the width of the stern region 30 is constant along the length of the ship, forming a full-width tail deck. Here, the width of the stern region 30 is set constant along the length of the ship, that is, the stern region 30 is set in a rectangular shape, so that the area of ​​the stern region 30 is enlarged, and the rectangular stern region 30 has a simple structure and is easy to process. Furthermore, by adjusting the height of the adjacent decks in the upper building 25 and adding one deck, the overall height of the upper building 25 is correspondingly increased, so that the upper building 25 has the same cargo carrying capacity and comfort as a conventional capesize bulk carrier.

[0059] As shown in FIG. 2, a support structure 31 is installed below the extension region 301 to support the extension region 301, and specifically, the support structure 31 may be a steel structure of the ship's main body.

[0060] Specifically, the design pressure range of an LNG fuel tank is 4 barg to 7 barg. LNG is stored in the tank in a liquid state, and the temperature of LNG when it is liquid at normal pressure is approximately -163°C. Taking into consideration the fuel gas supply pressure required for the gas-using equipment on the ship, the maintenance time of the LNG fuel tank pressure as stipulated in the IGF specifications, and the manufacturing costs of the fuel storage tank, the design pressure of the LNG fuel tank is generally set to 4 barg to 7 barg. The maximum allowable setting values ​​(MARVs) of the pressure relief valve of the LNG fuel storage tank coincide with the design pressure of the fuel tank.

[0061] As shown in Fig. 1, air domes 2a and 2b are provided above the LNG fuel tanks 1a and 1b, and a maintenance work platform is disposed above the air domes 2a and 2b. However, the maintenance work platform is used to place a crane for hoisting the LNG transport pumps installed in the LNG fuel tanks 1a and 1b.

[0062] As shown in Fig. 2, an LNG fuel tank protective steel 12 is installed above the LNG fuel tanks 1a, 1b. Here, the ship's monorail crane passes above the LNG fuel tanks 1a, 1b during operation, and the LNG fuel tank protective steel 12 can prevent damage to the LNG fuel tanks 1a, 1b due to the occurrence of an unexpected incident while the monorail crane is lifting parts.

[0063] As shown in FIG. 1 and FIG. 3, the air supply system of the dual-fuel bulk carrier includes LNG filling stands 11a, 11b arranged on both the port and starboard sides of the cargo hold area 29. Here, by installing the LNG filling stands 11a, 11b on both the port and starboard sides of the cargo hold area 29, the flexibility of LNG filling of the bulk carrier can be increased, and the ship can be filled and replenished with fuel on either the port or starboard side according to the operating situation. The air supply system of the dual-fuel bulk carrier further includes manual cranes 10a, 10b, and the working range of the manual cranes 10a, 10b covers the LNG filling stands 11a, 11b. Here, the manual cranes 10a, 10b are used to hoist the LNG filling hoses in the LNG filling stands 11a, 11b. Fixed dry powder fire extinguishing systems are arranged in the LNG filling stands 11a, 11b. Protective steel plates are installed on the top and both sides of the LNG filling stands 11a, 11b to reduce the risk of damage to the LNG filling stands 11a, 11b and filling piping due to unforeseen circumstances during loading and unloading of the ship. Liquid collection trays are installed below the connectors of the LNG filling stands 11a, 11b. Liquid collection trays made of low-temperature resistant stainless steel material should be installed below the LNG filling connectors and any places where leakage may occur to prevent the cryogenic liquid and cryogenic piping from contacting the ship's body during filling, so that in the event of a fuel leak, the surrounding ship's body or deck structure will not be subjected to unacceptable cooling. The LNG filling stands 11a, 11b, the LNG fuel tanks 1a, 1b and the fuel gas processing room are connected via low-temperature LNG piping, and steel protective covers are installed above the low-temperature LNG piping in the cargo hold area 29 or the stern area 30. Here, the cryogenic LNG pipe is used to transport cryogenic liquid, and the installation of a steel protective cover can reduce the risk of damage to the cryogenic LNG pipe in the event of an unexpected collision of the ship. In order to avoid cryogenic frostbite caused by leaking LNG fuel contacting the ship's body structure, the LNG filling stations 11a, 11b need to arrange a water spraying system to safely protect any overflow fuel.

[0064] As shown in FIG. 1, the dual-fuel bulk carrier's air supply system includes an LNG vent mast 4, which is arranged on the port or starboard side of the main deck 26. Here, the vent mast is used to release the flammable gas from the pressure system to the atmosphere in a safe manner and without harm to personnel and equipment. To be away from the living quarters and the fresh air outlet of the blower, the distance between the outlet of the LNG vent mast 4 and the opening of the upper building 25, the air inlet and outlet of the gas safety point, and the exhaust gas outlet of the machinery equipment is greater than 10m. Specifically, in order to avoid overpressure inside the LNG fuel storage tank and the LNG pipeline and ensure the safety of the fuel tank and related pipeline, the dual-fuel bulk carrier is installed with a vent system for pressure relief of the LNG fuel tanks 1a, 1b and emergency discharge of natural gas, and the vent system is connected to the LNG vent mast 4.

[0065] As shown in Fig. 1, a dual-fuel generator group 6 and a fuel gas valve group 7 for the dual-fuel generator group are installed at the aft of the third deck 28 of the engine room, and a dual-fuel steam boiler 8 and a fuel gas valve group 9 for the dual-fuel steam boiler are installed at the aft of the second deck 27 of the engine room. A dual-fuel main engine 5 is installed in the engine room, and a fuel gas valve group 20 for the dual-fuel main engine is installed in the engine room or the fuel processing room 3.

[0066] In this embodiment, an LNG transport pump is installed in the LNG fuel tanks 1a and 1b, and the fuel is transported to the LNG vaporizer via the LNG transport pump, passes through an LNG main engine buffer tank 19, and is passed to the dual-fuel main engine 5. Here, the LNG main engine buffer tank 19 is used to perform pressure stabilization for the gas after the LNG is vaporized. Specifically, the LNG transport pump is a submerged LNG transport pump.

[0067] In this embodiment, LNG transport pumps are installed in the LNG fuel tanks 1a and 1b, and the fuel is transported to the LNG vaporizer via the LNG transport pumps, passes through the LNG main engine buffer tank 19, and is depressurized by a group of pressure reducing valves before being branched into two flow paths, one of which is used to supply gas to the dual-fuel generator group 6 and the other is used to supply gas to the dual-fuel steam boiler 8. Here, the group of pressure reducing valves is used to reduce the pressure of the LNG to an appropriate level so that it can be supplied to the dual-fuel generator group 6 and the dual-fuel steam boiler 8.

[0068] In an alternative embodiment, an auxiliary engine buffer tank may be provided after the pressure reducing valves in the passages supplying the dual fuel generators 6 and the dual fuel steam boiler 8, and the fuel is pressure stabilized by the auxiliary engine buffer tank before being passed to the dual fuel generators 6 and the dual fuel steam boiler 8, respectively.

[0069] As shown in Fig. 4, the air supply system of the dual-fuel bulk carrier further includes a BOG compressor group 18a, 18b installed in the fuel gas treatment chamber. Here, the BOG compressor group 18a, 18b is used to compress and send out boil-off gas (BOG), and LNG is very easily vaporized at room temperature to form BOG, and the BOG is compressed and used as fuel, which not only solves the problems of the pressure retention time and BOG treatment of the LNG fuel tanks 1a, 1b, but also saves costs and solves the problem of pollutant emissions.

[0070] In this embodiment, the evaporation gas in the LNG fuel tanks 1a, 1b is passed through the BOG compressor group 18a, 18b, and then passed through the LNG main engine buffer tank 19, and is used to supply gas to the dual-fuel generator group 6 and the dual-fuel steam boiler 8, respectively, where the BOG compressor group 18a, 18b adopts a 16 barg level gas compressor. The BOG compressor group 18a, 18b includes two BOG compressors, one of which is used as a spare. When the pressure of the LNG fuel storage tank is too high, the two BOG compressors can be selected to be started and operated at the same time, so that the pressure in the tank can be quickly and efficiently reduced.

[0071] In another alternative embodiment, the evaporative gas in the LNG fuel tanks 1a, 1b is passed through the BOG compressor group 18a, 18b, and then passed to the LNG main engine buffer tank 19, and is used to supply gas to the dual-fuel main engine 5, the dual-fuel generator group 6, and the dual-fuel steam boiler 8, respectively, where the BOG compressor group 18a, 18b employs an 8 barg level gas compressor.

[0072] In addition, the dual-fuel bulk carrier air supply system can further include a BOG preheater 17, and the evaporated gas in the LNG fuel tanks 1a, 1b first passes through the BOG preheater 17 before entering the BOG compressor group 18a, 18b. The BOG in the LNG fuel storage tank is spontaneously discharged through the evaporated gas pipe at the top of the tank, and at this time, the temperature and pressure of the BOG are both low and cannot meet the gas usage conditions, so the BOG preheater 17 is used to heat the evaporated gas to an appropriate temperature before passing it through the normal temperature BOG compressor.

[0073] In this embodiment, the dual-fuel bulk carrier's air supply system adopts a medium-low pressure LNG fuel air supply system, the fuel gas supply pressure of the medium-low pressure LNG fuel air supply system does not exceed 16 barg, the dual-fuel main engine adopts the dual-fuel main engine X-DF model of WinGD, the LNG fuel tanks 1a and 1b include an LNG transport pump, the fuel gas processing room includes an LNG vaporizer, a low-pressure LNG vaporizer, a BOG preheater 17, a BOG compressor group 18a and 18b, an inlet and outlet heat exchanger of the BOG compressor group, a dual-fuel main engine fuel gas valve group 20, and a water-glycol unit 21. Two emergency exits 14a and 14b are installed in the fuel gas processing room, so there is no need to install an air shutter in the room.

[0074] In another alternative embodiment, the air supply system of the dual-fuel bulk carrier can adopt a high and low pressure LNG fuel air supply system, as shown in FIG. 5, the fuel gas supply pressure of the high and low pressure LNG fuel air supply system does not exceed 300 barg, the dual-fuel main engine adopts MAN dual-fuel main engine ME-GI model, the high and low pressure LNG fuel air supply system has high pressure pumps 13a, 13b, and the fuel gas processing chamber includes high pressure pumps 13a, 13b, a high pressure LNG vaporizer, a low pressure LNG vaporizer, a BOG preheater 17, a BOG compressor group 18a, 18b, an inlet and outlet heat exchanger of the BOG compressor group, and a dual-fuel main engine fuel gas valve group 20.

[0075] In another alternative embodiment, the high and low pressure LNG fuel supply system can adopt a pump vaporization unit 15 (PVU) instead of the high pressure pumps 13a, 13b, and as shown in FIG. 6, the fuel gas processing room includes the pump vaporization unit 15, the low pressure vaporizer 16, the BOG preheater 17, the BOG compressor group 18a, 18b, the main engine buffer tank 19, and the dual fuel main engine fuel gas valve group 20. The pump vaporization unit hydraulic pump station 24 is arranged in the servo room 23, which is close to the fuel gas processing room. The water glycol unit 21 is arranged at the bow of the second deck 27 of the engine room. Here, the volume of the pump vaporization unit 15 is small, which greatly reduces the equipment occupation area and system weight, and reduces the difficulty of arrangement. The pump vaporization unit 15 has a fast response speed and can better meet the requirements for flow rate and pressure of the high pressure dual fuel engine.

[0076] In this embodiment, the dual-fuel bulk carrier further includes a safety system and an auxiliary system, in which the safety system includes one or more of a gas detection system, a fire alarm system, an emergency shutdown system, a fire extinguishing system, a ventilation system, and a vent exhaust system, and the auxiliary system includes one or more of a water-glycol system, a nitrogen system, and an instrument air system, where the installation of the safety system can meet the needs of safety, evacuation, etc., and the installation of the auxiliary system can make the process flow of the LNG air supply system more rational and smooth.

[0077] To ensure that the distances from the LNG fuel tank to the ship's side and bottom shell meet the requirements and minimize the probability of loss of the LNG fuel storage tank after the ship has collided or run aground, the distances from the LNG fuel tank to the ship's side and bottom shell shall be calculated according to the probability method in the IGF Code, and shall comprehensively take into account the impact of the LNG fuel storage tank on the stability of the ship, the division of fire compartments and hazardous areas, and the convenience of the LNG pipeline layout.

[0078] In another alternative embodiment, the location of the LNG fuel may be obtained using physical protection isolation requirements (decision methods) to ensure that distance requirements from the LNG fuel tanks to the ship's side and bottom hull are met and to protect the vessel to minimize the probability of loss of the LNG fuel storage tanks after a collision or grounding event.

[0079] Specifically, the loading weight of the dual-fuel bulk carrier is 80,000 to 300,000 tons, and the material of the LNG fuel tank is 9 nickel steel or 304 stainless steel low-temperature resistant material, preferably 9 nickel steel to meet the requirement of storing LNG at low temperature. In addition, a layer of insulating material is installed on the surface of the LNG fuel tank, and the insulating material adopts polyurethane foam or polystyrene foam, preferably polyurethane foam, thereby preventing the continuous evaporation of the LNG liquid in the tank due to excessive external heat.

[0080] By applying this invention, a technical plan for a dual-fuel bulk carrier powered by LNG and fuel oil can be formed, which can directly meet the latest NOx Tier III and SOx 2020 environmental protection requirements, and achieve the requirements of the third stage of the 2025 EEDI, reaching the international advanced level in terms of energy saving, environmental protection and economy. The LNG fuel air supply system can select medium and low pressure air supply system or high and low pressure air supply system, and provide fuel gases of different pressures and temperatures for the dual-fuel engine and dual-fuel steam boiler according to the needs of the gas-using equipment. The bulk carrier mainly covers medium and long-distance bulk carriers from 80,000 tons to 300,000 tons.

[0081] Taking a 210,000-ton New Calus-type dual-fuel bulk carrier as an example, two IMO C-type LNG fuel storage tanks with the same capacity are installed on the ship based on the ship's operating distance, with the volume of each LNG fuel tank being approximately 3,000m3~3,500m3, which can meet the ship's need to use LNG as power fuel for the entire voyage, without the need to refuel with LNG along the way.

[0082] Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely examples, and the scope of protection of the present invention is limited by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and spirit of the present invention, and all of them are included in the scope of protection of the present invention.

Claims

1. A dual fuel bulk carrier including an air intake system for a dual fuel bulk carrier, wherein a main deck of the dual fuel bulk carrier includes a cargo hold area and an aft area, the aft area includes an extension area, the extension area is located on both sides of the aft and extends along a direction away from the midship, and an upper building is installed on the side of the aft area closer to the cargo hold area, and the air intake system of the dual fuel bulk carrier comprises: LNG fuel tanks installed above the open stern area and located on both the left and right sides of the upper building; An engine room installed below the main deck; a fuel gas processing room installed above the open stern area and located between the two LNG fuel tanks, in which fuel in the LNG fuel tanks is transported to the fuel gas processing room for processing and then transported to a gas-using facility in the engine room; The upper building has a width that narrows toward the center of the ship to accommodate the LNG fuel tank, A dual fuel bulk carrier, characterized in that the width of the stern region is constant along the length of the ship, forming a full-width tail deck.

2. A dual-fuel bulk carrier as described in claim 1, characterized in that the design pressure range of the LNG fuel tank is 4 barg to 7 barg.

3. A dual-fuel bulk carrier as described in claim 1 or 2, characterized in that an air dome is provided above the LNG fuel tank, and a maintenance work platform is positioned above the air dome.

4. A dual-fuel bulk carrier as described in at least one of claims 1 to 3, characterized in that the air supply system of the dual-fuel bulk carrier includes an LNG filling stand, the LNG filling stand being positioned on both the port and starboard sides of the cargo hold area.

5. A dual-fuel bulk carrier as described in claim 4, characterized in that the air supply system of the dual-fuel bulk carrier further includes a manual crane, the working range of which covers the LNG filling station.

6. A dual-fuel bulk carrier as described in claim 4 or 5, characterized in that a fixed dry powder fire extinguishing system is arranged at the LNG filling stand.

7. A dual-fuel bulk carrier as described in at least one of claims 4 to 6, characterized in that a liquid collection tray is installed below the connector of the LNG filling stand.

8. A dual-fuel bulk carrier as described in at least one of claims 4 to 7, characterized in that the LNG filling stand, the LNG fuel tank and the fuel gas treatment chamber are connected via low-temperature LNG pipes, and a steel protective cover is installed above the low-temperature LNG pipes located in the cargo hold area or the stern area.

9. A dual-fuel bulk carrier as described in at least one of claims 1 to 8, characterized in that the air supply system of the dual-fuel bulk carrier includes an LNG vent mast, the LNG vent mast being positioned on the port or starboard side of the main deck.

10. A dual-fuel bulk carrier as described in at least one of claims 1 to 9, characterized in that a group of dual-fuel generators and a group of fuel gas valves for the dual-fuel generators are installed at the stern of the third deck of the engine room, and a dual-fuel steam boiler and a group of fuel gas valves for the dual-fuel steam boiler are installed at the stern of the second deck of the engine room.

11. A dual-fuel bulk carrier as described in at least one of claims 1 to 10, characterized in that an LNG transport pump is installed in the LNG fuel tank, and fuel is transported to an LNG vaporizer via the LNG transport pump and passed through an LNG main engine buffer tank to the dual-fuel main engine.

12. A dual-fuel bulk carrier as described in at least one of claims 1 to 11, characterized in that an LNG transport pump is installed in the LNG fuel tank, and the fuel is transported to an LNG vaporizer via the LNG transport pump, passes through an LNG main engine buffer tank, is reduced in pressure by a group of pressure reducing valves, and then branches into two flow paths, one of which is used to supply air to a group of dual-fuel generators, and the other is used to supply air to a dual-fuel steam boiler.

13. The dual-fuel bulk carrier air supply system further includes a group of BOG compressors installed in the fuel gas treatment chamber, Preferably, the evaporative gas in the LNG fuel tank is passed through the BOG compressor group, then passed through an LNG main engine buffer tank, and used to supply air to the dual-fuel generator group and the dual-fuel steam boiler, respectively; A dual-fuel bulk carrier as described in at least one of claims 1 to 12, characterized in that the evaporated gas in the LNG fuel tank is passed through the BOG compressor group, then passed through an LNG main engine buffer tank, and used to supply steam to the dual-fuel main engine, the dual-fuel generator group and the dual-fuel steam boiler, respectively.

14. A dual-fuel bulk carrier as described in claim 13, characterized in that the BOG compressor group includes two BOG compressors, one of which is used as a spare.

15. A dual-fuel bulk carrier as described in any one of claims 1 to 14, characterized in that a dual-fuel main engine is installed in the engine room, and a group of fuel gas valves for the dual-fuel main engine is installed in the engine room or the fuel processing room.

16. A dual-fuel bulk carrier as described in claim 15, characterized in that the air supply system of the dual-fuel bulk carrier includes a medium-low pressure LNG fuel air supply system, the fuel gas supply pressure of the medium-low pressure LNG fuel air supply system does not exceed 16 barg, the dual-fuel main engine adopts a WinGD dual-fuel main engine X-DF model, the LNG fuel tank includes an LNG transport pump, the fuel gas processing chamber includes an LNG vaporizer, a low-pressure LNG vaporizer, a BOG compressor, inlet and outlet heat exchangers of the BOG compressor, a group of fuel gas valves for the dual-fuel main engine, and a water-glycol unit.

17. A dual-fuel bulk carrier as described in claim 15, characterized in that the air supply system of the dual-fuel bulk carrier includes a high and low pressure LNG fuel air supply system, the fuel gas supply pressure of the high and low pressure LNG fuel air supply system does not exceed 300 barg, the dual-fuel main engine adopts a MAN dual-fuel main engine ME-GI model, and the fuel gas processing chamber includes a high-pressure pump, a high-pressure LNG vaporizer, a low-pressure LNG vaporizer, a BOG compressor, inlet and outlet heat exchangers of the BOG compressor, and a group of fuel gas valves for the dual-fuel main engine.

18. The dual fuel bulk carrier further includes safety systems and auxiliary systems, wherein the safety systems include one or more of a gas detection system, a fire alarm system, an emergency shutoff system, a fire extinguishing system, a ventilation system, and an air exhaust system, and wherein the auxiliary systems include one or more of a water-glycol system, a nitrogen system, and an instrument air system; Preferably, the distance from the LNG fuel tank to the ship side and the distance from the LNG fuel tank to the bottom shell are calculated by a probability method in the IGF Code, A dual fuel bulk carrier according to at least one of the preceding claims, characterized in that the LNG fuel tank is a free-standing prismatic IMO C type LNG fuel tank.

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