Combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC

Abstract

A methanol dual fuel VLCC combined anti-alcohol foam fire extinguishing system, fuel tank is arranged on the open deck, the ship is formed with main deck area, engine room inner bottom area, fuel preparation room area, the foam tank of the system is provided with 1% concentration of concentrated anti-alcohol foam liquid, the foam pump unit is connected with proportional mixer P1 through F1 injection pipe, is connected with proportional mixer P2 through F2 injection pipe, is connected with proportional mixer P3 through F3 injection pipe, proportional mixer P1 is connected with main deck area through S1 distribution pipeline, proportional mixer P2 is connected with engine room inner bottom area through S2 distribution pipeline, proportional mixer P3 is connected with fuel preparation room area through S3 distribution pipeline.The concentration of the traditional 3% is changed to 1%, the volume of the foam tank is reduced from the original 6m3 to 2m3, the arrangement of the system equipment is convenient.Two independent systems are combined into a whole system, a set of foam tank and pump unit are saved, and the fireproofing requirements of different areas can be met.

Description

Technical Field

[0001] This invention belongs to the field of marine vessel design and construction, and specifically relates to a combined methanol-resistant foam fire extinguishing system for methanol dual-fuel VLCCs. Background Technology

[0002] For fire suppression systems on open decks of methanol dual-fuel VLCCs, the following two requirements must be met: 1) When fuel tanks are located on open decks, the vessel shall be equipped with a fixed foam fire suppression system using an alcohol-resistant extinguishing agent. The foam fire suppression system shall be able to cover the maximum deck area affected by a fuel tank leak. 2) Approved alcohol-resistant foam systems shall be installed for Category A machinery spaces / critical machinery spaces and fuel preparation rooms containing methanol / ethanol. These foam systems shall cover the inner bottom plate and the bilge area below the bottom plate.

[0003] Methanol dual-fuel VLCCs are equipped with methanol fuel tanks and methanol day storage tanks. The methanol fuel tanks are located in the cargo hold area, forward of the fourth cargo hold, while the methanol day storage tanks are located in an open area at the stern of the main deck cargo hold. Currently, the market only offers deck foam fire suppression systems that cover the entire cargo deck area, and localized methanol-resistant foam fire suppression systems that cover the engine room floor and fuel preparation area containing the methanol main engine. However, there is no combined methanol-resistant foam fire suppression system that can meet all the above requirements. Summary of the Invention

[0004] To address the above problems, this invention provides a combined methanol-resistant foam fire extinguishing system for methanol dual-fuel VLCCs, the technical solution of which is as follows:

[0005] A combined methanol-resistant foam fire suppression system for a methanol dual-fuel VLCC is disclosed. The fuel tank is located on an open deck, creating three protected areas on the ship: the main deck area, the engine room bottom area, and the fuel preparation area. The system includes a foam tank and a foam pump unit. The foam tank contains a 1% concentration of concentrated methanol-resistant foam solution. The foam pump unit is connected to proportioner P1 via injection pipe F1, proportioner P2 via injection pipe F2, and proportioner P3 via injection pipe F3. Proportioner P1 is connected to the main deck area via distribution pipe S1, proportioner P2 is connected to the engine room bottom area via distribution pipe S2, and proportioner P3 is connected to the fuel preparation area via distribution pipe S3. The diameters of injection pipes F1, F2, and F3 are DN50, DN32, and DN25.

[0006] The main seawater pipeline is divided into DN250 pipeline and DN80 pipeline. The DN250 pipeline is connected to proportioner P1, and the DN80 pipeline is connected to proportioner P2 and proportioner P3 respectively through two branch pipelines.

[0007] There are 8 foam cannons in the main deck area, 2 of which are located on deck C, above the methanol day tank at the highest point of the open deck area.

[0008] Furthermore, the aforementioned combined methanol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC further includes a foam tank with a volume of 2m³. 3 .

[0009] Furthermore, the aforementioned combined methanol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC further includes two foam cannons connected in parallel on the C deck, which are then sequentially connected to the remaining six foam cannons, with the six foam cannons arranged in zones along the length of the ship.

[0010] Furthermore, the aforementioned combined methanol-resistant foam fire extinguishing system for methanol dual-fuel VLCCs is further equipped with a manual isolation valve and a fire isolation valve for each foam cannon.

[0011] Furthermore, the aforementioned combined methanol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC is equipped with an electric injection valve at the inlet of the F1 injection pipe, the inlet of the F2 injection pipe, and the inlet of the F3 injection pipe.

[0012] Furthermore, the aforementioned combined methanol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC is further equipped with an automatic release valve P1V on the S2 distribution line and an automatic release valve P3V on the S3 distribution line.

[0013] Furthermore, the aforementioned combined methanol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC further includes a foam liquid injection pipe installed at the top of the foam tank.

[0014] This invention changes the traditional 3% concentration to 1% and the volume of the foam tank from the original 6m³. 3 Reduced to 2m 3 This design facilitates the layout of system equipment. Combining two independent systems into a single integrated system saves on the need for a separate foam tank and pump unit, and can meet the fire protection requirements of different areas. To more accurately control the foam liquid injection ratio in each protected area, the foam pump unit is equipped with three proportioning mixers and release pipelines. Different foam extinguishing system control modes are used according to different protected areas, making it suitable for the fire protection requirements of different areas.

[0015] To meet the needs of routine testing of the fire protection system, spectacle flanges (normally open) are installed in the automatically release distribution lines S2 and S3. Pressure gauges, relief valves, and test branch pipe and hose connection valves (located outdoors) are installed before these flanges. If system testing is required, the spectacle flanges are closed, the test connection valves are connected to the hoses, and the release button for that area is activated. The mixed foam solution can then be discharged through the hoses connected outdoors, thus not affecting the fire control station environment while meeting the testing requirements. Attached Figure Description

[0016] Figure 1 This is a system schematic diagram of the present invention;

[0017] Among them, 1-foam cannon, 2-foam cannon isolation valve, 3-fire isolation valve, 4-methanol daily use cabinet, 5-fuel preparation room. Detailed Implementation

[0018] The invention will be further described with reference to the accompanying drawings.

[0019] A combined anti-methanol foam fire extinguishing system for methanol dual-fuel VLCCs is provided. When the fuel tanks are located on an open deck, the foam fire extinguishing system needs to cover the maximum deck area affected by a fuel tank leak. Anti-methanol foam liquid is used. In order to cover all fuel tanks (methanol day tank and methanol fuel tank), two of the foam cannons are positioned on the C deck, above the highest methanol day tank in the open deck area, to meet the coverage requirements.

[0020] To reduce the number of foam fire suppression systems, this invention integrates the alcohol-resistant foam systems required for the engine room floor and fuel preparation area into the deck alcohol-resistant foam system. Sharing a single foam tank unit with the deck alcohol-resistant foam system, this project optimizes the foam concentrate selection for the deck alcohol-resistant foam system, changing the concentration from the traditional 3% to 1%, and reducing the required foam tank volume from the original 6m³. 3 Reduced to 2m 3 This makes it easier to arrange system equipment.

[0021] To match the different discharge requirements of the three protected areas and to more precisely control the foam liquid injection ratio in each area, the foam pump unit is equipped with three proportioning mixers: P1 for the main deck area, P2 for the engine room bottom area, and P3 for the fuel preparation room bottom area. The 1% concentrated foam liquid from the foam tank is divided into three lines (DN50 F1 injection pipe, DN32 F2 injection pipe, and DN25 F3 injection pipe), each connected to one of the three proportioning mixers. The main seawater pipeline from the engine room fire pump and the bilge pump splits into two lines at the foam tank unit inlet: one DN250 line connects to the proportioning mixer P1 of the system's largest user—the deck anti-alcohol foam system; the other DN80 seawater line splits into two branches, DN80 and DN40, before connecting to P2 / P3.

[0022] The mixed fire-fighting foam solution, after passing through the proportioner, is delivered to three protected areas via three pipelines. Different operations are performed under different conditions:

[0023] State 1: The piping in the main deck area is S1. At regular intervals along the piping, a set of manually operated fire isolation valves and foam cannons are installed. The isolation valves are normally open. If a fire occurs in this area, the corresponding isolation valve (M2V in the diagram) is closed to isolate the fire extinguishing agent in the piping. Simultaneously, by activating the "Deck Foam" release button on the control panel, the system automatically starts the engine room main fire pump and the bilge main pump, activates the foam pump and the electric injection valve F1V on the F1 injection pipeline, automatically releasing the mixed foam liquid. The main deck foam isolation valve M1V at the fire control station is manually opened, and the foam cannon FM1 in front of the main deck isolation valve is manually operated to spray foam liquid for fire extinguishing.

[0024] Status 2: The piping in the engine room bottom area is S2, and an automatic mixture release valve P2V is installed in the piping. If a fire occurs in this area, clicking the "Engine Room Bottom Area" release button on the control box panel of the fire control station will automatically start the engine room main fire pump, activate the foam pump and the electric injection valve F2V on the F2 injection line and P2V in the S2 line. The system will automatically release the mixed foam mixture, which will then cover the flame surface through foam nozzles located in the protected area to extinguish the fire.

[0025] Status 3: The piping in the bilge area of ​​the fuel preparation room is S3, and an automatic release valve P3V for the mixed liquid is installed in the piping. If a fire occurs in this area, clicking the release button for the bilge area of ​​the fuel preparation room on the control box panel of the fire control station will automatically start the main fire pump in the engine room, activate the foam pump and the electric injection valve F3V on the F3 injection line and P3V on the S3 line, and the system will automatically release the mixed foam liquid, which will then cover the flame surface through foam nozzles located in the protected area to extinguish the fire.

Claims

1. A combined alcohol resistant foam fire extinguishing system for a methanol dual fuel VLCC, characterized in that, The fuel tank is arranged on the open deck, the ship forms three protection areas, which are the main deck area, the engine room inner bottom area and the fuel preparation room area, the system is provided with a foam tank and a foam pump unit, the foam tank is filled with 1% concentration of concentrated anti-alcohol foam liquid, the foam pump unit is connected with the proportional mixer P1 through the F1 injection pipe, connected with the proportional mixer P2 through the F2 injection pipe, and connected with the proportional mixer P3 through the F3 injection pipe, the proportional mixer P1 is connected with the main deck area through the S1 distribution pipeline, the proportional mixer P2 is connected with the engine room inner bottom area through the S2 distribution pipeline, and the proportional mixer P3 is connected with the fuel preparation room area through the S3 distribution pipeline, the caliber of the F1 injection pipe is DN50; The seawater main pipeline is divided into a DN250 pipeline and a DN80 pipeline, the DN250 pipeline is connected with the proportional mixer P1, and the DN80 pipeline is connected with the proportional mixer P2 and the proportional mixer P3 through two branch pipelines. The main deck area is provided with eight foam cannons, two of which are located on the C deck and are higher than the methanol daily use cabinet at the highest part of the open deck area.

2. A combined alcohol resistant foam extinguishing system for a methanol dual fuel VLCC as claimed in claim 1, wherein, The volume of the foam can is 2 m 3 .

3. A combined alcohol resistant foam extinguishing system for a methanol dual fuel VLCC as claimed in claim 1, wherein, The two foam cannons on the C deck are connected in parallel, and the two parallel foam cannons are sequentially connected with the remaining six foam cannons, and the six foam cannons are arranged in areas along the length direction of the ship.

4. A combined anti-alcohol foam extinguishing system for a methanol dual fuel VLCC as claimed in claim 3, wherein, Each foam cannon is provided with a manual isolation valve and a fire isolation valve.

5. A combined alcohol resistant foam extinguishing system for a methanol dual fuel VLCC as claimed in claim 1, wherein, The inlet of the F1 injection pipe, the inlet of the F2 injection pipe and the inlet of the F3 injection pipe are all provided with an electric injection valve.

6. A combined alcohol resistant foam extinguishing system for a methanol dual fuel VLCC as claimed in claim 1, wherein, The S2 distribution pipeline is provided with an automatic release valve P1V, and the S3 distribution pipeline is provided with an automatic release valve P3V.

7. A combined alcohol resistant foam extinguishing system for a methanol dual fuel VLCC as claimed in claim 1, wherein, The top of the foam tank is provided with a foam liquid injection pipe.

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