JP2019189172A - Offshore floating body structure - Google Patents

Abstract

To more safely arrange equipment regarding safety of a hull in a simple composition in an offshore floating body structure including a vessel including a class 0 hazardous spot.SOLUTION: In an offshore floating body structure provided with an oil tank 18 which is a class 0 hazardous spot, a cofferdam 25 and a fore peak tank 24 are arranged in between the oil tank 18 and a sea water supply pump chamber for fire pump 26 where a bow unit fire pump 30P are arranged, and a cargo pump chamber 34 and the cofferdam 38 are arranged in between the oil tank 18 and an engine room 36 where a stern unit fire pump 36P is arranged. Thus, a zone where equipment concerning safety of a hull is prevented from being adjacent to the class 0 hazardous spot.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an offshore floating structure in which a zero-type dangerous place is provided in the hull.

  For example, in an offshore floating structure such as a floating production storage / loading facility (FPSO) or a floating storage loading / unloading facility (FSO), an oil storage tank is disposed at the center of the hull where the shore side is substantially parallel. A fore peak tank is formed in front of the oil storage tank with a partition wall therebetween (Patent Document 1), and an engine room is disposed on the rear stern part with a pump chamber or the like interposed therebetween, for example. In FPSO and FSO, it is necessary to provide equipment related to the safety of the hull such as a fire pump and a seawater supply pump for the fire pump. These facilities are arranged at the bow and stern, respectively, on the bow side in the fore peak tank and on the upper deck of the bow, and in the engine room at the stern.

JP-A-2015-116974

  However, the oil storage tank provided in the central part of the hull is a zero-type hazardous place, and the fore peak tank and the pump chamber, which are enclosed compartments adjacent thereto, are one-type dangerous places. For this reason, the fire pump room, the seawater supply pump room for the fire pump, the engine room, etc. are in contact with hazardous areas.

  An object of the present invention is to more safely arrange equipment related to the safety of a hull with a simple configuration in an offshore floating structure including a ship having a zero-type hazardous area.

  The offshore floating structure of the present invention also has the same type of overlap in cofferdams, fuel tanks, pump rooms, ballast tanks, and fresh water tanks between Class 0 hazardous locations and sections where equipment related to ship safety is placed. In addition to being separated through at least two compartments, the fresh water tank is characterized by not being adjacent to the zero-type hazardous area.

  The zero-type hazardous area is, for example, an oil storage tank. When a cofferdam is placed adjacent to a zero-hazardous location between the zero-hazardous location and the compartment where the hull safety equipment is located, the cophadam has an inert gas sealing device, a gas detector, a flood warning At least one of a device and a drainage device is arranged. In addition, when the ballast tank is disposed adjacent to the zero-class hazardous area between the zero-class hazardous area and the section where the equipment relating to the safety of the hull is disposed, the ballast tank includes an inert gas sealing device, a gas detection device. At least one of the vessels is arranged.

  The length in the longitudinal direction of the hull of the cofferdam, the ballast tank, or the fuel tank arranged adjacent to the dangerous place is 1.2 m or more. The type 1 or type 2 hazardous area and the compartment where the equipment relating to the safety of the hull are arranged are separated via at least one of a cofferdam, a fuel tank, a pump room, a ballast tank, and a fresh water tank.

  In the present specification, claims, etc., “Zero hazardous area” means “a compartment or area where an explosive mixture is present continuously or for a long period of time”. The “1 type dangerous place” means “a section or a zone where an explosive mixture is generated in a normal state”. In addition, “two kinds of dangerous places” means “a section or a zone where an explosive mixture may be generated in an abnormal state”.

  According to the present invention, in an offshore floating structure including a ship having a zero-type dangerous place, it is possible to more safely arrange equipment related to the safety of the hull with a simple configuration.

It is a side view which shows arrangement | positioning of the offshore floating structure which is 1st Embodiment of this invention. It is an enlarged plan view of the bow part of the offshore floating structure of FIG. It is an enlarged side view of the bow part of the offshore floating structure of 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a schematic side view of an offshore floating structure according to a first embodiment of the present invention, and FIG. 2 is an enlarged plan view of a bow portion of FIG.

  The offshore floating structure 10 is, for example, a floating production storage and loading facility (FPSO) having a hull shape, and the hull is composed of a hull center portion 14 and a stern portion 16 that are substantially parallel to the bow portion 12 and the shore side. The In the hull center portion 14, for example, a tank (oil storage tank) 18 that is partitioned into a large number and stores cargo oil or the like is disposed. For example, ballast tanks 20 are disposed on both sides of the tank 18, and the bow portion 12 and the hull center portion 14 are separated by, for example, a partition wall 22 (see FIG. 2). A forepeak tank 24 is formed in the bow portion 12 separated from the hull center portion 14 by the partition wall 22. A first separation section, for example a cofferdam 25, is provided for separation from the first separation section. The cofferdam 25 is provided with at least one of an inert gas sealing device, a gas detector, a flooding alarm device, and a drainage device.

  In the forepeak tank 24, a seawater supply pump chamber 26 for a fire pump is disposed so that the entire periphery thereof is surrounded by the forepeak tank 24 and is not adjacent to the cofferdam 25 as the first separation section. That is, the forepeak tank 24 is provided so that a section in which equipment relating to the safety of the hull such as the seawater supply pump chamber 26 for the fire pump is installed is not adjacent to the first separation section (hazardous area) which is a one-type dangerous place. It functions as a second separation section.

  The seawater supply pump chamber 26 for the firefighting pump passes vertically from the ship bottom to the upper deck 28 of the bow 12, and the bow firefighting pump chamber 30 is provided on the upper deck 28 to which the seawater supply pump chamber 26 for the firefighting pump communicates. . A pump 26P for pumping up seawater is disposed near the bottom of the seawater supply pump chamber 26 for the fire pump, and seawater can be supplied to the bow fire pump 30P installed in the bow fire pump chamber 30 through the pipe 26A.

  On the stern side of the hull center portion 14, a cargo pump chamber 34 is disposed behind the tank 18 with a partition wall 32 therebetween. For example, a cofferdam 38 is provided behind the cargo pump chamber 34 (stern side) so that the cargo pump chamber 34 and the engine chamber 36 provided in the stern portion 16 are not adjacent to each other. A stern fire extinguishing pump 36P is provided in the engine room 36, and seawater pumped up by a pump 40P disposed near the bottom of the ship can be supplied through a pipe 36A.

  That is, the cargo pump chamber 34 functions as a first separation section that separates the cofferdam 38 from the tank 18 that is a zero-type dangerous place, and the cofadam 38 is an engine room 36 that is a section in which equipment related to the safety of the hull is installed. Functions as a second separation section provided so as not to be adjacent to the cargo pump chamber 34 which is the first separation section. Thereby, the section where the equipment related to the safety of the hull such as the pump 40P for supplying seawater to the stern fire pump 36P and the stern fire pump 36P is installed is separated so as not to be adjacent to the dangerous place. That is, in FIG. 1, the section A including the tank 18, the cofferdam 25, and the cargo pump chamber 34 is a dangerous place.

  By configuring as described above, in the offshore floating structure according to the first embodiment, a section in which equipment related to the safety of the hull such as a fire pump and a seawater supply pump for a fire pump is installed is not adjacent to a dangerous place. Devices that are separated and have a simple configuration can be arranged more safely with respect to the safety of the hull.

Under MODU code (mobile offshore drilling vessel structure Equipment Regulations), compartment equipment related to the safety of the hull is arranged adjacent to the hazardous area, technical evaluation on the predicted heat flux during fire 100kw / m ² If it exceeds, it is necessary to perform class H fire prevention treatment. Class H fire prevention treatment is costly, has a strict construction procedure, and takes a long time for construction, so it greatly affects the cost and construction period of the entire ship. However, according to the present embodiment, in the initial design stage, regardless of the magnitude of the heat flux predicted in the event of a fire, a section in which equipment related to zero-type hazardous locations (for example, cargo tanks) and hull safety is arranged in advance. By arranging the two sections between the fire extinguishing pump chambers (for example, a fire extinguishing pump chamber), it is possible to save the technical evaluation effort and the material / construction cost of the H-class fire prevention treatment even under the MODU code.

  Next, the offshore floating structure of the second embodiment will be described with reference to FIG. In the second embodiment, the bow fire extinguishing pump chamber 30 provided on the upper deck 28 of the bow portion 12 in the first embodiment is provided in the bow tower 42, and cargo oil is supplied to the shuttle tanker etc. on the bow tower deck 44. An off-loading hose reel 46 around which a hose for discharging the cargo is wound, and a cargo oil pipe 48 for feeding cargo oil to the reel are arranged. In addition, about the structure similar to 1st Embodiment, the same referential mark is used and the description is abbreviate | omitted.

  Since the periphery of the connection flange 48F of the offloading hose reel 46 and the cargo oil pipe 48 is one or two kinds of dangerous places, a part on the bow tower deck 44 becomes a dangerous place. Therefore, in the present embodiment, the section where the equipment related to the safety of the hull such as the bow fire extinguishing pump chamber 30 is not located adjacent to the hazardous area is located above the bow fire extinguishing pump chamber 30, that is, below the bow tower deck 44. Sections such as Cofferdam 50 are provided. Since the section that is in contact with the 1st or 2nd type hazardous area does not become a hazardous area, the cofferdam 50 separates the bow fire extinguishing pump chamber 30 so as not to be adjacent to the hazardous area (1st or 2nd type hazardous area). Functions as a separation compartment. In the present embodiment, the type 2 dangerous place corresponds to an open section adjacent to the type 0 dangerous place.

  As described above, in the second embodiment, in addition to the effects of the first embodiment, the bow fire extinguishing pump chamber is dangerous even if an offloading hose reel and cargo oil piping joints are arranged on the bow deck. It can be separated without being adjacent to the location, and equipment related to the safety of the hull can be arranged more safely with a simple structure, and the labor of technical evaluation and the materials / construction costs of class H fire prevention treatment can be saved. .

  As described above, in the present embodiment, the first separation section that becomes one or two kinds of dangerous places is not a dangerous place between the zero-type dangerous place and the section in which equipment related to the safety of the hull is arranged. By sequentially arranging the second separation section, and by arranging the second separation section that does not become a dangerous place between the one or two kinds of dangerous place and the section where the equipment related to the safety of the hull is arranged, The section where the equipment related to the safety of the hull is placed should not be adjacent to the hazardous area. In addition, the same kind of tank and space (chamber) can also be applied to the first and second separation sections.

  In the present embodiment, the cofferdam and the cargo pump chamber have been described as examples of the first separation section. However, a section such as a cofadam, a fuel tank, a pump chamber, and a ballast tank can be employed as the first separation section. In the present embodiment, the fore peak tank and the cofferdam are described as examples of the second separation section. However, a section such as a cofadam, a fuel tank, a pump chamber, a ballast tank, and a fresh water tank is employed as the second separation section. be able to.

  In addition, when a cofferdam is employed in the first separation section as in the present embodiment, at least one of an inert gas sealing device, a gas detector, a flooding alarm device, and a drainage device is disposed in the first separation section. Is done. When a ballast tank is adopted as the first separation section, at least one of the inert gas sealing device and the gas detector is arranged in the first separation section.

  When a cofferdam, a ballast tank, or a fuel tank is employed as the first separation section or the second separation section, the length in the longitudinal direction of the first separation section or the second separation section is set to 1.2 m or more. Also, for example, the length of the cofferdam, ballast tank, or fuel tank arranged adjacent to the hazardous area in the longitudinal direction of the hull is 1.2 m or more.

  In the present embodiment, the fire pump room is cited as a section for installing equipment related to the safety of the hull, but a section for installing equipment related to safety of the hull, such as an emergency generator room for installing an emergency generator, is provided. There are other fire extinguishing pump rooms. In this embodiment, FPSO has been described as an example. However, in this embodiment, other offshore areas that have zero-type hazardous areas and need to be provided with low-cost sections for installing equipment related to ship safety. It can also be applied to floating structures (including ships).

DESCRIPTION OF SYMBOLS 10 Offshore floating structure 12 Bow part 14 Hull center part 16 Stern part 18 Oil storage tank 20 Ballast tank 24 Fore peak tank (2nd separation section)
25 Cofferdam (first separation zone)
26 Seawater supply pump room for fire pumps 26P, 40P Pump 28 Upper deck 30 Bow fire extinguishing pump room 30P Bow fire extinguishing pump 34 Cargo pump room (first separation section)
36 Engine room 36P Stern fire pump 38 Cofferdam (second separation section)
46 Offloading hose reel 48 Cargo oil piping 48F Connection flange A Hazardous area

Claims (6)

  Between at least two compartments, including co-dams, fuel tanks, pump rooms, ballast tanks, and fresh water tanks, between the zero-hazardous location and the compartment where the hull safety equipment is located An offshore floating structure characterized in that, while being separated, the fresh water tank is not adjacent to the zero-type hazardous area.   The offshore floating structure according to claim 1, wherein the zero-type hazardous area is an oil storage tank.   When the cofferdam is disposed adjacent to the zero-type hazardous area between the zero-class hazardous area and a section where equipment relating to safety of the hull is disposed, the cofferdam includes an inert gas sealing device, a gas The offshore floating structure according to claim 1 or 2, wherein at least one of a detector, an inundation alarm device, and a drainage device is disposed.   When the ballast tank is arranged adjacent to the zero-type hazardous location between the zero-type hazardous location and the section where the equipment relating to the safety of the hull is arranged, it is adjacent to the zero-type hazardous location. The offshore floating structure according to any one of claims 1 to 3, wherein at least one of an inert gas sealing device and a gas detector is disposed in the disposed ballast tank.   The length of the hull longitudinal direction of the cofferdam, the ballast tank, or the fuel tank arranged adjacent to a hazardous area is 1.2 m or more, 5. The offshore floating structure described in 1.   Separating one or two hazardous locations from the compartment where the equipment related to the safety of the hull is located via at least one of the cofferdam, fuel tank, pump room, ballast tank, and fresh water tank The offshore floating structure according to any one of claims 1 to 5.

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