Moonpool system for a vessel and method of installation

Abstract

The application discloses a moon pool system of a ship, the ship comprising a ship ballast device, the moon pool system comprising: a moon pool comprising a moon pool ballast device and a guide device; a moon pool bottom cover, the moon pool bottom cover draining water when the moon pool bottom cover is installed through the moon pool ballast device, the moon pool bottom cover comprising: a bottom cover air permeation device, the bottom cover air permeation device controlling water injection of the moon pool bottom cover; a bottom cover ballast device, the bottom cover ballast device controlling water injection of the moon pool bottom cover to adjust the barycentre and the centre of buoyancy position of the moon pool bottom cover; a bottom cover ballast device, the bottom cover ballast device draining water of the moon pool bottom cover after installation through the ship ballast device; a hoisting device, the hoisting device being arranged on a deck of the ship, the hoisting device installing the moon pool bottom cover to the bottom of the moon pool through the guide device. The application also discloses a method for installing a moon pool bottom cover of a moon pool system of a ship.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ships, in particular to a moon pool system of a ship. BACKGROUND

[0002] When a ship is working in water, a channel penetrating the ship body is often needed. For example, when a J-lay vessel carrying a J-lay system arranges a J-tower in the ship, a moon pool needs to be provided on the ship. Although the moon pool facilitates the laying of a submarine pipeline, it also brings a series of problems such as loss of working area of the open deck, loss of ship displacement, increase of the risk of sea wave impact on the equipment in the moon pool, and reduction of the sailing resistance.

[0003] Chinese patent CN215706926U discloses a moon pool retracting system with a watertight bottom cover, which is arranged on a ship with a moon pool. The moon pool includes a moon pool well and a moon pool workshop. The moon pool retracting system includes a watertight bottom cover including a watertight cover plate and an opening and closing actuator. The retracting system includes a winch, a steel wire rope, a trolley, a movable guide rail and a fixed guide rail. The movable guide rail is installed in the moon pool workshop, and the fixed guide rail is installed in the moon pool well. The movable guide rail can be extended downward to be connected with the fixed guide rail to form a complete guide rail penetrating the moon pool workshop and the moon pool well, which is used for the trolley to move back and forth along the guide rail between the moon pool workshop and the moon pool well. The trolley moves up and down along the guide rail by retracting and releasing the steel wire rope by the winch.

[0004] Although the above-mentioned moon pool retracting system with a watertight bottom cover ensures the efficiency of the operation and increases the safety of the equipment and the operating personnel. However, in actual use, it is found that the above-mentioned moon pool retracting system with a watertight bottom cover adopts an opening and closing and locking device, which has a high sealing requirement for the locking device. Moreover, the opening and closing device is prone to failure under the erosion of seawater and the like, which reduces the efficiency of the ship operation. Furthermore, the opening and closing machine locking device is only suitable for relatively small moon pools and moon pool covers, and cannot be applied to large engineering ships. SUMMARY

[0005] To solve the above-mentioned problems, the purpose of the present application is to provide a moon pool system of a ship, which can be conveniently installed on water and improve the sealing performance by the moon pool bottom cover and the buoyancy of the moon pool itself against the water surface, close the bottom of the ship body, reduce the impact of sea waves on the equipment in the moon pool, and reduce the resistance of the ship.

[0006] The present application provides a moon pool system of a ship, the ship including a ship ballast device, the moon pool system including:

[0007] a moon pool, the moon pool being arranged on the ship, the moon pool including a moon pool ballast device and a guide device;

[0008] A moon pool bottom cover, the moon pool bottom cover is drained by the moon pool draining device, the moon pool bottom cover is pressed against the bottom of the moon pool by buoyancy, the moon pool bottom cover reduces the sailing resistance of the ship, the moon pool bottom cover comprises:

[0009] A moon pool bottom cover ventilation device, the moon pool bottom cover ventilation device controls the water inflow of the moon pool bottom cover;

[0010] A moon pool bottom cover ballast device, the moon pool bottom cover ballast device controls the water injection of the moon pool bottom cover to adjust the barycenter and the center of buoyancy of the moon pool bottom cover;

[0011] A moon pool bottom cover draining device, the moon pool bottom cover draining device drains the water inflow of the moon pool bottom cover after installation by the ship ballast device;

[0012] A lifting device, the lifting device is arranged on the deck of the ship, the lifting device installs the moon pool bottom cover to the bottom of the moon pool through the guide device.

[0013] Further, the moon pool system of the ship further comprises a moon pool top cover, the moon pool top cover is arranged on the top of the moon pool, the moon pool top cover is provided with a moon pool top cover fixing limiting device, the moon pool top cover is connected with the ship through the moon pool top cover fixing limiting device, and the moon pool top cover increases the deck operation area of the ship.

[0014] Further, the moon pool system of the ship, the moon pool top cover further comprises a top cover hoisting lug plate, and the lifting device installs the moon pool top cover through the top cover hoisting lug plate.

[0015] Further, the moon pool system of the ship, the moon pool system further comprises an isolation cabin, the isolation cabin is arranged around the moon pool, and the isolation cabin increases the hull strength.

[0016] Further, the moon pool system of the ship, the lifting device comprises a crane and a lifting winch, the crane hoists the moon pool bottom cover to the water surface, and the lifting winch pulls the moon pool bottom cover to the bottom of the moon pool through the guide device.

[0017] Further, the moon pool system of the ship, the moon pool bottom cover further comprises a moon pool bottom cover locking device, the moon pool bottom cover locking device is connected with the moon pool, and the moon pool bottom cover locking device locks the moon pool bottom cover and the moon pool.

[0018] Further, the moon pool system of the ship, the guide device is a guide wheel.

[0019] Further, the moon pool system of the ship, the moon pool bottom cover draining device is connected with the ship ballast device through a hose.

[0020] The embodiment of the present application also provides a method for installing a moon pool system of a ship, using the moon pool system of the ship as described above, comprising the following steps:

[0021] Step 1, turning on the moon pool bottom cover air permeation device and the moon pool bottom cover ballast device;

[0022] Step 2, hoisting the moon pool bottom cover to the water surface;

[0023] Step 3, after filling the specified ballast tank of the moon pool bottom cover with water by using the moon pool bottom cover ballast device, sinking the moon pool bottom cover into the water;

[0024] Step 4, connecting the moon pool bottom cover with the steel wire rope of the lifting winch and tightening the steel wire rope to pull the moon pool bottom cover to the position below the moon pool;

[0025] Step 5, continuing to tighten the steel wire rope to make the moon pool bottom cover closely adhere to the ship;

[0026] Step 6, turning on the moon pool ballast discharge device to discharge the seawater in the moon pool;

[0027] Step 7, checking whether there is water seepage in the moon pool, and if there is water seepage, connecting the moon pool bottom cover ballast discharge device with the ship ballast device to further discharge the water in the moon pool bottom cover to increase the buoyancy;

[0028] Step 8, locking the moon pool bottom cover locking device, and completing the installation.

[0029] Further, the method for installing the moon pool system further comprises the step of using an underwater robot to connect the moon pool bottom cover with the steel wire rope of the lifting winch and tighten the steel wire rope to pull the moon pool bottom cover to the position below the moon pool.

[0030] The technical scheme provided by the embodiment of the present application has the following advantages:

[0031] 1. Since the moon pool bottom cover air permeation device, the ballast device and the ballast discharge device are adopted, the installation and dismounting of the moon pool bottom cover are facilitated;

[0032] 2. Since the crane and the lifting winch are cooperated to install the moon pool bottom cover, the risk of equipment damage is reduced, and the cost is lowered. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The side view of the preferred moon pool system of the ship in the embodiment of the present application;

[0034] Figure 2 The side view of the preferred moon pool in the embodiment of the present application;

[0035] Figure 3 The layout view of the preferred moon pool top cover in the embodiment of the present application;

[0036] Figure 4 A preferred moon pool bottom cover arrangement for embodiments of the present application;

[0037] Figure 5 A preferred moon pool bottom cover moon pool bottom cover guide and seal arrangement for embodiments of the present application;

[0038] Figure 6 A preferred moon pool bottom cover ballast and de-ballast arrangement for embodiments of the present application;

[0039] Figure 7 A preferred moon pool bottom cover installation for embodiments of the present application;

[0040] Figure 8 A preferred moon pool system installation method flow chart for embodiments of the present application.

[0041] Reference numerals:

[0042] Ship - 100;

[0043] Ship ballast - 110;

[0044] Moon pool system - 200;

[0045] Moon pool - 210;

[0046] Moon pool de-ballast - 211; Moon pool sea gate - 2111;

[0047] Guide - 212;

[0048] Moon pool bottom cover guide - 213;

[0049] Moon pool bottom cover - 220;

[0050] Bottom cover vent - 221;

[0051] Bottom cover ballast - 222;

[0052] Bottom cover de-ballast - 223;

[0053] Moon pool bottom cover lifting ear - 224;

[0054] Moon pool bottom cover hoisting ear - 225;

[0055] Moon pool bottom cover locking device - 226A, 226B;

[0056] Moon pool bottom cover horizontal locking device - 226A;

[0057] Moon pool bottom cover vertical locking device - 226B;

[0058] Pressure resisting block - 227;

[0059] Sealing strip - 228

[0060] Hoisting device - 230A, 230B

[0061] Crane - 230A

[0062] Hoist winch - 230B

[0063] Moon pool cover - 240

[0064] Moon pool cover fixing stopper - 241

[0065] Cover hoisting lug - 242

[0066] Isolation cabin - 250

[0067] Underwater robot - 260

[0068] J-type tower - A

[0069] Hose - B DETAILED DESCRIPTION

[0070] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application. In the drawings, the same or similar notations represent the same or similar elements or elements having the same or similar functions. The described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0071] In addition, it also needs to be explained that, unless explicitly specified and limited, the "installation", "connection", "connection" and the like similar words used in the description of the present application should be understood in a broad sense, for example, the connection can be fixed connection, or detachable connection, or integrally connected; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements, those skilled in the art can understand the specific meaning of the present application according to the specific circumstances.

[0072] Figure 1 The side view of the moon pool system of the preferred ship of the embodiments of the present application. Figure 2 The side view of the moon pool of the preferred ship of the embodiments of the present application. Figure 3 The moon pool cover arrangement of the preferred ship of the embodiments of the present application. Figure 4 The moon pool bottom cover arrangement of the preferred ship of the embodiments of the present application. Figure 5A moon-pool bottom cover guiding and sealing device of a moon-pool bottom cover preferred by the embodiment of the present application is shown in the schematic diagram. Figure 6 A moon-pool bottom cover ballast device and a moon-pool bottom cover unballast device preferred by the embodiment of the present application are shown in the schematic diagram. Figure 7 A moon-pool bottom cover installation schematic diagram preferred by the embodiment of the present application is shown in the schematic diagram. Figures 1-7 As shown in the schematic diagram, a ship 100 includes a ship ballast device 110, and a moon-pool system 200 includes a moon-pool 210 disposed on the ship 100. In the preferred embodiment, the moon-pool 210 is disposed on the right side of the middle of the ship 100. The moon-pool 210 includes a moon-pool unballast device 211 and a guiding device 212. A moon-pool bottom cover 220 is installed by the moon-pool unballast device 211 to discharge water entered into the moon-pool bottom cover 220 during installation. It is worth noting that only the pipeline of the moon-pool unballast device 211 is shown in the schematic diagram. The moon-pool bottom cover 220 is compressed against the bottom of the moon-pool 210 by buoyancy. The moon-pool bottom cover 220 can reduce the resistance of the ship 100 during sailing. The moon-pool bottom cover 220 includes a bottom cover air-permeable device 221 for controlling the water entered into the moon-pool bottom cover 220, a bottom cover ballast device 222 for controlling the water filled into the moon-pool bottom cover 220 to adjust the position of the center of gravity and the center of buoyancy of the moon-pool bottom cover 220, and a bottom cover unballast device 223 for discharging the water entered into the moon-pool bottom cover 220 after installation by the ship ballast device 110. The bottom cover air-permeable device 221 and the bottom cover unballast device 223 cooperate to control the water filled into the moon-pool bottom cover 220 to adjust the overall weight, the center of gravity, and the position of the center of buoyancy of the moon-pool bottom cover 220. Hoisting devices 230A and 230B are disposed on the deck of the ship 100, and the hoisting devices 230A and 230B install the moon-pool bottom cover 220 to the bottom of the moon-pool 210 through the guiding device 212. In the preferred embodiment, the guiding device 212 is a guiding wheel.

[0073] In the preferred embodiment, the pipeline of the moon-pool unballast device 211 is connected to the moon-pool bottom cover unballast device 223 through, for example, a hose to discharge the water of the moon-pool bottom cover 220.

[0074] Preferably, the lifting device 230A, 230B comprises a crane 230A and a hoist winch 230B. The crane 230A lifts the moon pool bottom cover 220 to the water surface, and the hoist winch 230B pulls the moon pool bottom cover 220 to the bottom of the moon pool 210 through the guide device 212 arranged in the moon pool 210. Preferably, the moon pool bottom cover 220 is provided with a moon pool bottom cover lifting lug 225 and a moon pool bottom cover hoisting lug 224, and the crane 230A lifts the moon pool bottom cover 220 to the water surface through the wire rope and the moon pool bottom cover lifting lug 225. Then the wire rope of the hoist winch 230B is tied to the moon pool bottom cover hoisting lug 224 on the moon pool bottom cover 220 by the underwater robot 260 or manually, and the wire rope of the crane 230A is untied. The hoist winch 230B pulls the moon pool bottom cover 220 to the bottom of the moon pool 210 through the guide device 212 arranged in the moon pool 210.

[0075] Preferably, the moon pool bottom cover 220 further comprises moon pool bottom cover locking devices 226A, 226B, which can be connected with the moon pool 210 to lock the moon pool bottom cover 220 with the moon pool 210. Preferably, the moon pool bottom cover locking devices comprise moon pool bottom cover horizontal locking devices 226A for horizontal locking of the moon pool bottom cover 220 with the moon pool 210, and moon pool bottom cover vertical locking devices 226B for vertical locking of the moon pool bottom cover 220 with the moon pool 210.

[0076] Preferably, the moon pool bottom cover 220 is further provided with pressure resisting blocks 227 and sealing strips 228, which are arranged at the connection between the moon pool bottom cover 220 and the ship 100. Under the cooperation of the pressure resisting blocks 227 and the sealing strips 228, the inside of the moon pool 210 can be isolated from seawater.

[0077] The moon pool bottom cover 220 can close the hull bottom of the ship 100 during navigation and other non-operation, reduce the impact of sea waves on the equipment in the moon pool 210, and reduce the resistance of the ship 100. Preferably, the moon pool bottom cover 220 is a watertight structure, which can be divided into a plurality of liquid compartments and air compartments for leveling and controlling the overall weight of the moon pool bottom cover 220.

[0078] Preferably, the moon pool 210 is further provided with a moon pool bottom cover guide device 213, which can install the moon pool bottom cover 220 at a designated position of the ship 100 when the moon pool bottom cover 220 is installed, and better fit the ship 100.

[0079] Preferably, the moon pool discharge device 211 of the moon pool 210 further comprises a moon pool sea gate 2111, and the moon pool discharge device 211 discharges seawater in the moon pool 210 through the moon pool sea gate 2111 to better press the moon pool bottom cover 220 against the ship 100.

[0080] Preferably, the moon pool system 200 further comprises a moon pool top cover 240, which can be provided in plurality, and is connected to the ship 100 through a moon pool top cover fixing and limiting device 241 provided on the moon pool top cover 240. In the preferred embodiment, the plurality of moon pool top covers 240 are locked to each other through the moon pool top cover fixing and limiting device 241. The moon pool top cover 240 can cover the deck surface above the moon pool 210 when the ship is performing J-type pipe laying operation and after the J-type tower A is fixed at an angle, or during other operations, thereby increasing the operation area of the open deck of the ship 100.

[0081] Preferably, the moon pool top cover 240 further comprises a top cover hoisting lug plate 242, through which the hoisting device 230 installs the moon pool top cover 240.

[0082] In the preferred embodiment, the moon pool top cover 240 is in a sheet structure, and a total of 5 sheets are provided, and 1-5 sheets can be installed according to actual use, thereby reducing the operation area of the deck loss.

[0083] Preferably, the moon pool system 200 further comprises an isolation cabin 250. The isolation cabin 250 is arranged around the moon pool 210, and the isolation cabin 250 increases the strength of the ship 100 and protects the space inside the cabin.

[0084] Preferably, the bottom cover load discharging device 223 is connected to the ship ballast device 110 through a hose B.

[0085] Preferably, the moon pool 210 is vertically penetrated through the ship 100. The rear wall of the moon pool 210 is appropriately inclined, so as to reduce the influence of water flow on the ship 100, and at the same time, the inclination angle range of the ship 100 carrying the J-type tower A can be increased.

[0086] Figure 8 The flow chart of the installation method of the moon pool system of the preferred ship of the present application is shown in FIG. 1. Figure 8 As shown in FIG. 1, the installation method of the moon pool system of the ship uses the above-mentioned moon pool system of the ship, and comprises the following steps:

[0087] Step 1, opening the bottom cover air permeation device 221 and the bottom cover ballast device 222 of the moon pool bottom cover 220.

[0088] Specifically, the bottom cover air permeation device 221 and the bottom cover ballast device 222 of the moon pool bottom cover 220 are opened.

[0089] Step 2, hoisting the moon pool bottom cover 220 to the water surface.

[0090] Specifically, the moon pool bottom cover hoisting lug plate 225 installed on the moon pool bottom cover 220 is connected through the crane 230A installed on the ship 100, and the moon pool bottom cover 220 is hoisted to the water surface.

[0091] Step 3, fill the designated ballast tank of moon pool bottom cover 220 with water using the bottom cover ballast device 222 of moon pool bottom cover 220, and then sink moon pool bottom cover 220 underwater.

[0092] Specifically, after filling the designated ballast tank of moon pool bottom cover 220 with water using the bottom cover ballast device 222 of moon pool bottom cover 220, the steel wire rope of the hoist 230A is lowered, and the moon pool bottom cover 220 is sunk underwater.

[0093] Step 4, connect the moon pool bottom cover 220 with the steel wire rope of the hoist winch 230B and tighten the steel wire rope to pull the moon pool bottom cover 220 under the moon pool 210.

[0094] Specifically, after the steel wire rope of the hoist winch 230B on the main deck of the ship 100 is tied to the moon pool bottom cover lifting lug 224 on the moon pool bottom cover 220 using the underwater robot 260, the hook of the hoist 230A is released, the steel wire rope of the hoist winch 230B is tightened, and the moon pool bottom cover 220 is pulled to the bottom of the moon pool 210 through the guide device 212 on the side wall.

[0095] Step 5, continue to tighten the steel wire rope to make the moon pool bottom cover tightly fit the ship.

[0096] Specifically, the steel wire rope of the hoist winch 230B is continuously tightened, and the moon pool bottom cover 220 is lifted to tightly fit the ship 100 with the help of the moon pool bottom cover guide device 213.

[0097] Step 6, open the moon pool ballast device 211 to empty the seawater in the moon pool 210;

[0098] Specifically, the moon pool ballast device 211 is opened, the seawater in the moon pool 210 is emptied through the moon pool sea gate 2111 on the moon pool 210, and the moon pool bottom cover 220 is pressed more and more tightly on the ship 100 under the action of buoyancy, and the moon pool 210 is isolated from seawater under the cooperation of the pressure-resistant block 227 and the sealing strip 228.

[0099] Step 7, check whether there is water seepage in the moon pool 210, if there is water seepage, connect the moon pool bottom cover ballast device 223 of the moon pool bottom cover 220 with the ship ballast device 110 to further empty the water in the moon pool bottom cover 220 to increase the buoyancy.

[0100] Specifically, if there is water seepage in the moon pool 210, the moon pool bottom cover ballast device 223 of the moon pool bottom cover 220 can be connected with the ship ballast device 110 through the hose B after the moon pool bottom cover ballast system 222 of the moon pool bottom cover 220 is closed, and the water in the moon pool bottom cover 220 is further emptied to increase the buoyancy, so that the moon pool 210 is no longer seeped.

[0101] Step 8, lock the moon pool bottom cover locking device 226A, 226B, complete the installation.

[0102] Specifically, after connecting the moon pool bottom cover horizontal locking device 226A and the moon pool bottom cover vertical locking device 226B on the moon pool bottom cover 220, the installation of the moon pool bottom cover 220 is completed.

[0103] It is worth noting that the removal process of the moon pool bottom cover 220 only needs to operate in the reverse process of the above installation method.

[0104] The present application can be used for J-type pipe laying or other marine engineering operations by opening a moon pool 210 in the right middle of the ship 100. The bottom configuration moon pool bottom cover 220 can close the ship bottom when sailing and other non-J-type pipe laying operations, reduce the impact of sea waves on the moon pool equipment, and reduce the ship resistance. The moon pool top cover 240 is configured on the top of the ship body, which covers the deck surface above the moon pool 210 after the J-type tower A is fixed at an angle or other operations, and increases the operation area of the open deck.

[0105] The moon pool 210 is installed with lifting winches 230B on the deck surface around it, and the moon pool bottom cover locking device 226A, 226B is provided on the cabin wall around it. The moon pool bottom cover 220 is provided with an ear plate, a sealing strip and the like for convenient installation of the moon pool bottom cover 220. The ballast and cleaning system installed in the ship can empty the seawater in the moon pool after the moon pool bottom cover is installed, so that the moon pool bottom cover is pressed on the ship bottom by buoyancy. The moon pool bottom cover is provided with a bottom cover air permeation device 221, a bottom cover ballast device 222, and a bottom cover ballast device 223, which can realize the functions of moon pool bottom cover drainage and water injection.

[0106] The above embodiments are provided to those skilled in the art to implement or use the present application, and those skilled in the art can make various modifications or changes to the above embodiments without departing from the application idea of the present application, so the protection scope of the present application is not limited by the above embodiments, but should be the maximum scope meeting the innovative features mentioned in the claims.

Claims

1. A moonpool system of a vessel, the vessel comprising a vessel ballast device, characterized in that, The moon pool system comprises: a moon pool arranged on the ship, the moon pool comprising a moon pool ballast device and a guide device; a moon pool bottom cover, the moon pool bottom cover draining water when installed by the moon pool ballast device, the moon pool bottom cover being pressed against the bottom of the moon pool by buoyancy, the moon pool bottom cover reducing the sailing resistance of the ship, the moon pool bottom cover comprising: a bottom cover air passage device, the bottom cover air passage device controlling the water intake of the moon pool bottom cover; a bottom cover ballast device, the bottom cover ballast device controlling the water injection of the moon pool bottom cover to adjust the barycenter and the center of buoyancy of the moon pool bottom cover; a bottom cover ballast device, the bottom cover ballast device draining water after the installation of the moon pool bottom cover by the ballast device of the ship; a lifting device arranged on the deck of the ship, the lifting device installing the moon pool bottom cover to the bottom of the moon pool through the guide device; wherein the moon pool system further comprises a moon pool top cover arranged on the top of the moon pool, the moon pool top cover being provided with a moon pool top cover fixing limiting device, the moon pool top cover being connected with the ship through the moon pool top cover fixing limiting device, the moon pool top cover increasing the deck operation area of the ship; the moon pool top cover further comprising a top cover hoisting lug plate, the lifting device installing the moon pool top cover through the top cover hoisting lug plate; the moon pool system further comprising an isolation cabin arranged around the moon pool, the isolation cabin increasing the hull strength.

2. A moon pool system of a vessel according to claim 1, characterized in that the lifting device comprising a crane and a lifting winch, the crane hoisting the moon pool bottom cover to the water surface, the lifting winch pulling the moon pool bottom cover to the bottom of the moon pool through the guide device.

3. A moon pool system of a vessel according to claim 1, characterized in that, the moon pool bottom cover further comprising a moon pool bottom cover locking device, the moon pool bottom cover locking device being connected with the moon pool, the moon pool bottom cover locking device locking the moon pool bottom cover and the moon pool.

4. The moon pool system of a vessel according to claim 1, characterized in that, the guide device being a guide wheel.

5. The moon pool system of a vessel according to claim 1, characterized in that, the bottom cover ballast device being connected with the ballast device of the ship through a hose.

6. A method of installing a moonpool system of a vessel using a moonpool system of a vessel according to any one of claims 1-5, characterized in that, comprising the following steps: step 1, opening the bottom cover air passage device and the bottom cover ballast device of the moon pool bottom cover; step 2, hoisting the moon pool bottom cover to the water surface; step 3, filling the designated ballast tank of the moon pool bottom cover with water using the bottom cover ballast device of the moon pool bottom cover, and then sinking the moon pool bottom cover under water; step 4, connecting the moon pool bottom cover with the steel wire rope of the lifting winch and tightening the steel wire rope to pull the moon pool bottom cover under the moon pool; step 5, continuing to tighten the steel wire rope to make the moon pool bottom cover closely adhere to the ship; step 6, opening the moon pool ballast device to drain the seawater in the moon pool; step 7, checking whether there is water seepage in the moon pool, if there is water seepage, connecting the bottom cover ballast device of the moon pool bottom cover with the ballast device of the ship to further drain the water in the moon pool bottom cover to increase the buoyancy; step 8, locking the moon pool bottom cover locking device, and completing the installation.

7. A method of installing a moon pool system according to claim 6, characterised in that, the step 4 further comprising using an underwater robot to connect the moon pool bottom cover with the steel wire rope of the lifting winch and tighten the steel wire rope to pull the moon pool bottom cover under the moon pool.

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