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

Abstract

A methanol dual-fuel VLCC combined type alcohol-resistant foam fire extinguishing system is characterized in that a fuel cabin is arranged on an open deck, a ship forms a main deck area, an engine room inner bottom area and a fuel preparation room area respectively, a foam tank of the system is filled with concentrated alcohol-resistant foam liquid with the concentration of 1%, a foam pump unit is connected with a proportioning mixer P1 through an F1 injection pipe, and the proportioning mixer P1 is connected with a fuel pump unit through an F2 injection pipe; the proportional mixer P1 is connected with the proportional mixer P2 through an F2 injection pipe and connected with the proportional mixer P3 through an F3 injection pipe, the proportional mixer P1 is connected with a main deck area through an S1 distribution pipeline, the proportional mixer P2 is connected with a cabin inner bottom area through an S2 distribution pipeline, and the proportional mixer P3 is connected with a fuel preparation room area through an S3 distribution pipeline. The traditional concentration of 3% is changed into the concentration of 1%, the volume of the foam tank is reduced to 2m < 3 > from the original 6m < 3 >, and arrangement of system equipment is facilitated. And two independent systems are combined into an integral system, so that a set of foam tank and pump unit is saved, and the fireproof requirements of different areas can be met.

Description

Technical Field

[0001] The invention belongs to the field of marine ship design and construction, and in particular relates to a combined alcohol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC. Background Art

[0002] The fire extinguishing system for open decks of methanol dual-fuel VLCC ships must meet the following two requirements: 1) When the fuel tank is arranged on the open deck, the ship should be equipped with a fixed foam fire extinguishing system with alcohol-resistant fire extinguishing agent, and the foam fire extinguishing system should be able to cover the maximum deck area spread after the fuel tank leaks. 2) An approved alcohol-resistant foam system should be installed for Class A machinery spaces / important machinery spaces and fuel preparation rooms containing methanol / ethanol, and the foam system should cover the inner bottom plate and the bottom area under the bottom plate.

[0003] Methanol dual-fuel VLCC ships are equipped with methanol fuel tanks and methanol daily cabinets, of which the methanol fuel tank is set in the cargo hold area, in the front of the fourth cargo hold, and the methanol daily cabinet is arranged in the open area at the rear of the main deck cargo hold. Currently, there are only deck foam fire extinguishing systems covering the entire cargo hold deck area and local alcohol-resistant foam fire extinguishing systems covering the bottom of the engine room containing the methanol main engine and the fuel preparation room, but there is no combined alcohol-resistant foam fire extinguishing system that can meet all the above requirements. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC, and the technical solution adopted is: A combined alcohol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC, wherein a fuel tank is arranged on an open deck, and the ship forms three protection areas, namely, a main deck area, an engine room inner bottom area, and a fuel preparation room area. The system is provided with a foam tank and a foam pump unit, wherein the foam tank is filled with a concentrated alcohol-resistant foam liquid with a concentration of 1%, and the foam pump unit is respectively connected to a proportioning mixer P1 through an F1 injection pipe, connected to a proportioning mixer P2 through an F2 injection pipe, and connected to a proportioning mixer P3 through an F3 injection pipe. The proportioning mixer P1 is connected to the main deck area through an S1 distribution pipeline, the proportioning mixer P2 is connected to the engine room inner bottom area through an S2 distribution pipeline, and the proportioning mixer P3 is connected to the fuel preparation room area through an S3 distribution pipeline. The diameter of the F1 injection pipe is DN50, the diameter of the F1 injection pipe is DN32, and the diameter of the F1 injection pipe is DN25.

[0005] The main seawater pipeline is divided into a DN250 pipeline and a DN80 pipeline. The DN250 pipeline is connected to the proportioning mixer P1, and the DN80 pipeline is connected to the proportioning mixer P2 and the proportioning mixer P3 through two branch pipelines.

[0006] There are 8 foam monitors installed in the main deck area, 2 of which are located on C deck, higher than the methanol daily tank at the highest point of the open deck area.

[0007] The above-mentioned methanol dual-fuel VLCC combined alcohol-resistant foam fire extinguishing system, further, the volume of the foam tank is 2m 3 .

[0008] The combined alcohol-resistant foam fire extinguishing system of the methanol dual-fuel VLCC mentioned above further comprises two foam cannons located on the C deck connected in parallel, the two parallel foam cannons are connected in sequence with the remaining six foam cannons, and the six foam cannons are arranged in different areas along the length of the ship.

[0009] The above-mentioned combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC, further, each foam monitor is provided with a manual isolation valve and a fire isolation valve.

[0010] The combined alcohol-resistant foam fire extinguishing system of the methanol dual-fuel VLCC mentioned above, further, is provided with electric injection valves at the inlet of the F1 injection pipe, the inlet of the F2 injection pipe, and the inlet of the F3 injection pipe.

[0011] The above-mentioned combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC further comprises an automatic release valve P1V on the S2 distribution pipeline and an automatic release valve P3V on the S3 distribution pipeline.

[0012] The above-mentioned combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC further comprises a foam liquid injection pipe provided on the top of the foam tank.

[0013] The present invention changes the traditional 3% concentration to 1% concentration, and the volume of the foam tank is increased from the original 6m 3 Reduced to 2m 3 , which is more convenient for the layout of system equipment. Combining two independent systems into an integrated system saves one set of foam tanks and pump units, which can meet the fire protection requirements of different areas. In order to more accurately control the foam liquid injection ratio of each protection area, a total of 3 sets of proportion mixers and release pipelines are set in the foam pump unit. Different foam fire extinguishing system control modes are used according to different protection areas to meet the fire protection requirements of different areas.

[0014] Considering the needs of routine testing of the fire protection system, spectacles flanges (normally open) are set in the distribution pipelines S2 and S3 that can be automatically released, and pressure gauges and discharge valves as well as test branches and hose connector valves (arranged outdoors) are set in front of the spectacles flanges. If system testing is required, close the spectacles flanges, connect the test connector valve to the hose, and activate the release button in this area. The mixed foam mixture can be discharged from the hose connected outdoors, which does not affect the environment of the fire control station and also meets the testing requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a system schematic diagram of the present invention; Among them, 1-foam monitor, 2-foam monitor isolation valve, 3-fire isolation valve, methanol daily cabinet, 5-fuel preparation room. DETAILED DESCRIPTION

[0016] The present invention will be further described in conjunction with the accompanying drawings.

[0017] A combined alcohol-resistant foam fire extinguishing system for a methanol dual-fuel VLCC. When the fuel tank is arranged on the open deck, the foam fire extinguishing system needs to cover the maximum deck area spread after the fuel tank leaks. Alcohol-resistant foam liquid is used. At the same time, in order to cover all fuel tanks (methanol daily tanks and methanol fuel tanks), the layout positions of two foam monitors are raised to C deck, higher than the methanol daily tank at the highest point of the open deck area, to meet the coverage requirements.

[0018] In order to reduce the number of foam fire extinguishing systems, the present invention combines the alcohol-resistant foam system required for the bottom of the cabin and the fuel preparation room into the deck alcohol-resistant foam system. Sharing a foam tank unit with the deck alcohol-resistant foam system, this project optimizes the foam liquid selection scheme of the deck alcohol-resistant foam system, changing the concentration from the traditional 3% to 1%, and the volume of the required foam tank is reduced from the original 6m 3 Reduced to 2m 3 , making it more convenient to arrange the system equipment.

[0019] In order to match the different displacement requirements of the three protection areas and to more accurately control the foam liquid injection ratio of each protection area, the foam pump unit is equipped with 3 sets of proportion mixers, namely, mixer P1 for the main deck area, proportion mixer P2 for the bottom area of ​​the engine room, and proportion mixer P3 for the bottom area of ​​the fuel preparation room. The 1% concentrated foam liquid from the foam tank is divided into three routes (F1 injection pipe with a diameter of DN50, F2 injection pipe with a diameter of DN32, and F3 injection pipe with a diameter of DN25), which are connected to the three proportion mixers respectively. The main seawater pipeline from the engine room fire pump and the bilge pump is divided into two routes when connected to the inlet of the foam tank unit. One route is a DN250 pipeline, which is connected to the proportion mixer P1 of the deck alcohol-resistant foam system, the largest user of the system. In order to save pipeline layout, the other DN80 seawater pipeline is divided into two branches DN80 and DN40 before connecting to P2 / P3.

[0020] After passing through the proportioning mixer, the mixed fire foam liquid is sent to three protection areas through three pipelines. Different operations are performed in different states: State 1: The pipeline in the main deck area is S1. A set of manually operated fire isolation valves and foam monitors are set at regular intervals in the pipeline, and the isolation valves are normally open. If a fire occurs in this area, close the corresponding isolation valve (M2V in the figure) to isolate the fire extinguishing agent in the pipeline here. At the same time, start the "deck foam" release button in the control box panel, and the system will automatically start the engine room fire pump and the bilge pump, start the foam pump and the electric injection valve F1V on the F1 injection pipeline, automatically release the mixed foam mixture, manually open the deck foam main isolation valve M1V of the fire control station, and manually operate the foam monitor FM1 in front of the main deck isolation valve to spray foam liquid for fire extinguishing.

[0021] State 2: The pipeline in the bottom area of ​​the cabin is S2, and the pipeline is equipped with an automatic release valve for mixed liquid P2V. If a fire occurs in this area, click the "cabin bottom area" release button in the control box panel of the fire control station, and the system will automatically start the cabin fire fighting pump, the foam pump and the electric injection valve F2V on the F2 injection pipeline and P2V in the S2 pipeline. The system automatically releases the mixed foam mixture, which is covered on the flame surface through the foam nozzle arranged in the protection area to extinguish the fire.

[0022] State 3: The pipeline in the bilge area of ​​the fuel preparation room is S3, and an automatic release valve for the mixed liquid P3V is installed in the pipeline. If a fire occurs in this area, click the release button for the bilge area of ​​the fuel preparation room in the control box panel of the fire control station, and the system will automatically start the engine room fire fighting pump, the electric injection valve F3V on the F3 injection pipeline, and the P3V in the S3 pipeline. The system will automatically release the mixed foam mixture, which will cover the flame surface through the foam nozzles arranged in the protection area to extinguish the fire.

Claims

1. A combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC, characterized in that: The fuel tank is set on the open deck, and the ship forms three protection areas, namely the main deck area, the bottom area of ​​the engine room, and the fuel preparation room area. The system is equipped with a foam tank and a foam pump unit. The foam tank is filled with 1% concentrated anti-alcohol foam liquid. The foam pump unit is connected to the proportioning mixer P1 through the F1 injection pipe, connected to the proportioning mixer P2 through the F2 injection pipe, and connected to the proportioning mixer P3 through the F3 injection pipe. The proportioning mixer P1 is connected to the main deck area through the S1 distribution pipeline, the proportioning mixer P2 is connected to the bottom area of ​​the engine room through the S2 distribution pipeline, and the proportioning mixer P3 is connected to the fuel preparation room area through the S3 distribution pipeline. The diameter of the F1 injection pipe is DN50, the diameter of the F1 injection pipe is DN32, and the diameter of the F1 injection pipe is DN25; The main seawater pipeline is divided into a DN250 pipeline and a DN80 pipeline. The DN250 pipeline is connected to the proportion mixer P1, and the DN80 pipeline is connected to the proportion mixer P2 and the proportion mixer P3 through two branch pipelines respectively. There are 8 foam monitors installed in the main deck area, 2 of which are located on C deck, higher than the methanol daily tank at the highest point of the open deck area.

2. A combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC according to claim 1, characterized in that: The volume of the foam tank is 2m 3 .

3. A combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC according to claim 1, characterized in that: Two foam monitors located on C deck are connected in parallel, and the two parallel foam monitors are connected in sequence with the remaining six foam monitors. The six foam monitors are arranged in different areas along the length of the ship.

4. A combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC according to claim 3, characterized in that: Each foam monitor is equipped with a manual isolation valve and a fire isolation valve.

5. The combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC according to claim 1 is characterized in that: Electric injection valves are provided at the inlet of the F1 injection pipe, the inlet of the F2 injection pipe, and the inlet of the F3 injection pipe.

6. A combined alcohol-resistant foam fire extinguishing system for methanol dual-fuel VLCC according to claim 1, characterized in that: 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 fire extinguishing system for methanol dual-fuel VLCC according to claim 1, characterized in that: A foam liquid injection pipe is arranged on the top of the foam tank.

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