WO2022116823A1 - Semi-submersible lifting and disassembly platform and control method therefor - Google Patents

Abstract

A semi-submersible lifting and disassembly platform and a control method therefor. The platform comprises a larboard floating body (102), a starboard floating body (101), two larboard poles (202), two starboard poles (201), and a deck box (3); both the larboard floating body (102) and the starboard floating body (101) are provided with several normal ballast tanks (15) and several fast ballast tanks (14); the tops of the fast ballast tanks (14) are in communication with a compressed air ballast system; each of the larboard poles (202) and the starboard poles (201) is provided with a pole-side ballast tank (13); the tops of the pole-side ballast tanks (13) are in communication with the compressed air ballast system; and each of the normal ballast tanks (15), the fast ballast tanks (14), and the pole-side ballast tanks (13) is provided with a water pump ballast system.

Description

A semi-submersible lifting and dismantling platform and its control method technical field

The invention relates to the field of marine engineering equipment, in particular to a semi-submersible lifting and dismantling platform and a control method thereof.

Background technique

With the continuous implementation of my country's strategy of marine power, the development of marine resources has become more and more in-depth, and various large-scale marine structures are more and more needed to cope with the harsh sea conditions of deep-sea oceans. Solution recycling.

CN201220358429.4 and CN201120024196.X hoisting operation platforms have a symmetrical layout structure, and the center of gravity cranes used for hoisting operations are also symmetrically arranged on the platform deck, but when lifting and dismantling large and heavy structural parts, the platform stability cannot be guaranteed. The semi-submersible lifting and dismantling platform, as a professional offshore lifting and dismantling equipment, has the wave response adjustment ability unmatched by the conventional lifting platform (ship), and has a larger operating range and stronger operating capacity. The semi-submersible lifting platform described in CN201110196551.6 patent is a semi-submersible lifting platform with asymmetric structure, which has a certain effect on improving the stability of the platform, but does not involve the stability control strategy and emergency response of the platform operation. Response handling method.

In addition, most of the conventional crane ships balance the hull while working, and lack the estimation and planning for the stability of the platform, and the safety of the operation is very worrying. At the same time, such platforms often operate in the ocean, where the ocean conditions are harsh and are prone to sudden failures such as collisions and damages. A complete set of emergency response measures also needs to be established urgently.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a semi-submersible lifting and dismantling platform and a control method thereof. The technical scheme adopted in the present invention is:

A semi-submersible lifting and dismantling platform is characterized in that: it includes a floating box, a column and a deck box arranged from bottom to top, the floating box is provided with a power system and a positioning control system, and the floating box includes a port side The floating body and the starboard floating body, the column includes two port column and two starboard columns, the port floating body is connected to the deck box through the two port column, and the starboard floating body is connected to the deck box through the two starboard columns, and the bottom of the floating box is provided with full rotation Propeller, the top of the deck box is a platform deck, and at least one full-rotation heavy-duty crane and a retractable trestle are arranged on the platform deck. The port floating body and the starboard floating body are independent of each other, and the port floating body and the starboard floating body are arranged in both There are ordinary ballast water tanks and fast ballast water tanks. The top of the fast ballast water tank is connected to the compressed air ballast system through a pipeline with a first control valve. The volume of the starboard float is at least 1.5 times that of the port float. The total volume of the fast ballast water tanks in the starboard floating body is more than 1.5 times the total volume of the fast ballast water tanks in the port floating body. The column side ballast water tank is respectively set in the column and the starboard side column, and the top of the column side ballast water tank is connected with the compressed air ballast system through a pipeline with a second control valve. Both the tank and the column side ballast water tank are equipped with a water pump ballast system. The water pump ballast system includes a water inlet and outlet pipeline with a water pump. The bottom of the water-carrying tank and the ballast water tank at the column side is provided with a discharge pipeline with a drain valve leading to the sea.

There are two port side uprights and two starboard side uprights, and the volume of the starboard side uprights is larger than that of the port side uprights.

The transition arc surface connecting the column, the floating box and the deck box is a single-leaf hyperboloid arc plate transition, which is composed of a hyperbola.

, a>0, b>0, rotated around the axis of symmetry, and satisfies the following surface equation:

The length of the real long axis of the hyperbola is 2a, the focal length of the hyperbola is 2c; the length of the imaginary axis of the hyperbola is 2b; b ² =c ² -a ² .

Two parking pads are arranged on the port side of the bow and the stern on the platform deck; davits and a plurality of lifeboats are arranged on the platform deck in the middle of the bow and stern; and one apron is arranged on the port side of the platform deck. Small crane; with living quarters at the bow of the platform deck.

20 ordinary ballast water tanks are evenly arranged in the port and starboard floating bodies, 2 fast ballast water tanks are arranged in the port side floating body, and 4 fast ballast water tanks are arranged in the starboard floating body.

The lower parts of each fast ballast water tank in the port side floating body are connected in turn by passages with normally open valves, and the lower parts of each fast ballast water tank in the starboard side floating body are sequentially connected by passages with normally open valves.

There is a ballast pipeline with a discharge valve between the left column side ballast tank and the left side corresponding fast ballast water tank, and the right side column side ballast tank and the right side corresponding fast ballast water tank Ballast pipes with relief valves are arranged between the tanks.

The ballast pipes are all provided with reverse exhaust check valves.

A kind of control method of semi-submersible lifting and dismantling platform, it is characterized in that: comprise the following steps:

Step 1: Carry out platform stability analysis: design the operation form, establish a hydrostatic model, analyze the wind tilt moment, set the stability criterion, and obtain the stability criterion of the semi-submersible platform of the present invention in the global sea area, that is, set The allowable vertical center of gravity (AVCG) curve of the semi-submersible platform under different operating conditions and different drafts;

Step 2: Pre-analysis of lifting operation:

Step 2-1: Analyze platform load and center of gravity: the loads on the semi-submersible platform of the present invention mainly include fixed loads and variable loads. The load mainly includes deck load and fluid level change. The specific load types are as follows:

(1) Light ship load: the mass M ₀ , the longitudinal center of gravity LCG ₀ , the transverse center of gravity TCG ₀ , and the vertical center of gravity VCG ₀ are obtained according to the ship’s factory inspection report;

(2) Deck load: according to the actual ship condition, the external load including hoisting,

The fluid in the platform piping system, the temporarily stacked cargo and consumables, the anchor and the anchor chain, and the deck load information of the helicopter are evaluated to obtain the mass M ₁ , the longitudinal center of gravity LCG ₁ , the transverse center of gravity TCG ₁ , and the vertical center of gravity VCG ₁ ;

(3) Tank weight and free surface moment: The tank mainly includes fuel oil tank, lubricating oil tank, fresh water tank and ballast water tank, and each tank is equipped with liquid level transmitter and blower. Gas-type liquid level gauge, two liquid level measurement methods, both of which are redundant with each other, and measure the liquid level in the tank in real time; the calibration density of various fluids in each tank is recorded as ρ _2i , before each operation The density of the tank actually measured by the staff is recorded as ρ _i , in which the seawater salinity in different sea areas is measured by the seawater salinity meter; after obtaining the fluid filling ratio or water level in the tank, the volume V of the fluid in each tank is obtained. _i , the longitudinal center of gravity LCG _2i , the transverse center of gravity TCG _2i , the vertical center of gravity VCG _2i , the longitudinal free surface moment TSML _2i and the free surface transverse moment FSMT _2i of the fluid in the tank are calculated by linear interpolation;

Weight in tank: M _2i =V _i ρ _i , where i = {fuel oil, lubricating oil, fresh water, sea water...};

Actual free surface transverse moment of tank: FSMT _i ＝FSMT _2i ÷ρ _0i ×ρ _i ;

Actual free surface longitudinal moment of tank: FSML _i = FSML _2i ÷ρ _0i ×ρ _i ;

(4) Calculated moment: The moment of the load of each component of the semi-submersible platform of the present invention is calculated in the following way, where j={0,1,2}:

Longitudinal moment: LMT _j =M _j ×LCG _j ;

Transverse moment: TMT _j =M _j ×LCG _j ;

Vertical moment: VMT _j =M _j ×LCG _j ;

(5) Calculate the total weight, center of gravity and free surface correction:

Total mass: M=∑M _j , where j={0,1,2};

Total longitudinal center of gravity: LCG＝∑LMT _j ÷M;

Total transverse center of gravity: TCG=∑TMT _j ÷M;

Total vertical center of gravity: VCG＝∑VMT _j ÷M;

Total vertical center of gravity-transverse moment correction: VT=VCG+∑FSMT _i ÷M;

Total vertical center of gravity-longitudinal moment correction: VL=VCG+∑FSML _i ÷M;

Step 2-2: Analyze draft and transverse and trim angles:

(1) Draft depth: according to the seawater salinity ρ _seawater in the region where the measurement is obtained in step 2-1(3), and the calculation in step 2-1(5), the total mass M obtained can be solved by using the linear interpolation method The vertical center of buoyancy LCB, the horizontal center of buoyancy TCB, the vertical center of buoyancy VCB, the vertical center of buoyancy KML, the horizontal center of stability KMT and the draft D;

(2) Heel angle and pitch angle:

Heel angle: θ=arctan[(TCG-TCB)/(KMT-VT)];

Pitch angle: α=arctan[(LCG-LCB)/(KML-VL)];

Step 2-3: Verify the allowable vertical center of gravity: According to the platform draught D obtained in step 2-2(1), bring the allowable vertical center of gravity curve of the semi-submersible platform in the global sea area obtained in step 1 to obtain the current The allowable vertical center of gravity value AVCG0 of the platform under the sea area, the current working condition and the current draft, and verify it; if VT < AVCG ₀ and VL < AVCG ₀ , it means that the current loading and stress conditions meet the platform's safe operation conditions, otherwise, re-adjust the deck load arrangement in step 2-1(2) and the fluid distribution of the main tank in step 2-1(3), that is, the ballast water tank, until the aforementioned comparison conditions are met, the platform can not be used. continue the work operation;

Step 3: Platform hoisting operation: After passing the verification in step 2, the platform begins to formally carry out hoisting operation;

First of all, the drain valves of the two column-side ballast water tanks located in the starboard column are opened, and the compressed air ballast system and the water pump ballast system of the two column-side ballast water tanks in the starboard column are drained, and the starboard side is drained. The ballast water of the column-side ballast water tank is discharged into the sea; while the two column-side ballast water tanks in the port side column start the water pump ballast system, and the column-side ballast water tank of the port side column is filled with water, which makes the whole platform quickly Complete the initial tilt to the left;

Then, the water discharge valve of the fast ballast water tank in the starboard floating body is opened, and the compressed air ballast system and the water pump ballast system of the fast ballast water tank in the starboard floating body perform drainage work, and the starboard fast ballast water tank is drained. The ballast water is discharged into the sea; while the port fast ballast water tank starts the water pump ballast system, and the port fast ballast water tank enters water, which drains the starboard floating body ballast tank and the port floating body ballast tank respectively. tilt;

Finally, the ordinary ballast water tanks in the port and starboard floating bodies complete the final fine-tuning through the water pump ballast system; For the change of the liquid level of the ballast water tank, repeat step 2 in real time to ensure that the VT and VL of the platform meet the requirements of the allowable vertical center of gravity of the platform, so that the platform meets the conditions for safe operation;

During the hoisting operation of the platform, according to the requirements of the aforementioned allowable vertical center of gravity, the distribution of the platform's ballast water is adjusted through the compressed air ballast system, the ballast system of each water pump, and the switch of the drain valve on the discharge pipeline to ensure that the platform is in the whole process. During the hoisting operation, the corresponding stability criteria have been met to ensure the safety of the platform.

The operation process of the lifting operation of the platform includes the following steps:

Step 1: According to the technical and maritime requirements of the towing device, use the tugboat to tow the platform to the target waters;

Step 2: According to the position of the target module to be lifted, move the platform to the service radius under the corresponding sea conditions;

Step 3: According to different working conditions and hoisting weight, use the ballast system to adjust the draft of the platform to within 22 to 26.4 meters of the crane design service draft;

Step 4: Mount the trestle on the opposite module or platform, and the service personnel will withdraw the trestle after reaching the operation area through the trestle to complete the hoisting preparation;

Step 5: Adjust the offshore crane to the working position, that is, within the service radius of the crane, and do a good job in the connection and inspection of the rigging and spreader;

Step 6: Start the crane to smoothly lift the module to the platform deck, and place the module;

Step 7: After the module is placed, remove the offshore crane from the module, reset the crane to the rest arm and fix it;

Step 8: The process of lifting a module is completed, repeat steps 2-8;

Step 9: After all dismantling tasks are completed, the platform will leave the working waters.

The advantages of the present invention: the platform is equipped with an azimuth heavy-duty crane, which has excellent lifting capacity and expands the operating capacity of the platform; the platform is equipped with an azimuth propeller, which has superior dynamic positioning and motion performance and high control accuracy; The vertical service angle and axial service distance are calculated. There is a large-capacity living and living area at the bow of the platform, which provides a comfortable and safe living and living environment for the staff; the reinforced deck box design improves the deck bearing capacity and the linear load of the bulkhead, providing conditions for the shipment of large modules; The invention adopts the combination of water pump ballast and compressed air ballast systems, and has several fast ballast tanks and ordinary ballast tanks, which ensures fast anti-tilt load adjustment during lifting operations, and meets platform stability and crane operation. Safety requirements; at the same time, in the event of an emergency in the lifting operation, such as the sudden loss of the lifting load, the use of compressed air to quickly empty the ballast water for anti-tilt load regulation in the column to reduce the tilt angle of the platform and further improve the safety of the platform operation Through the monitoring and control of the dual-machine-machine connection, the accurate lifting positioning under complex sea conditions is guaranteed. When combined with the ballast monitoring system for joint monitoring, rapid ballast deployment and real-time adjustment can be effectively performed to ensure the safety and stability of the platform; According to the design and use requirements of the platform, the stability criteria for the platform's global sea area operations are established, and the platform's load conditions are pre-analyzed to ensure that the platform can meet the stability of safe operations when operating in different sea areas, different draughts, and different loads. requirements, to ensure the safety of the platform and staff to a great extent; an emergency response system has been established, including an emergency control center, emergency action team and emergency operation procedures, to ensure that the platform encounters sudden failures in overseas operations. The platform operation command is smooth in real time, the emergency rescue is fast and accurate, and the staff responds in an orderly and safe manner.

Description of drawings

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Fig. 1 is the front view of the semi-submersible lifting and dismantling platform of the present invention;

Fig. 2 is the bow view of the semi-submersible lifting and dismantling platform of the present invention;

3 is a step diagram of a control method of the semi-submersible lifting and dismantling platform of the present invention during operation;

FIG. 4 is a flow chart of the operation control of the hoisting operation of the semi-submersible hoisting and dismantling platform of the present invention.

Among them: 1. pontoon; 101, starboard floating body; 102, port floating body; 2. column; 201, starboard column; 202, port column; 3. deck box; 4. apron; , small crane; 7, platform deck; 8, living area; 9, retractable trestle; 10, davit; 11, lifeboat; 12, azimuth thruster; 13, column side ballast water tank; 14, Fast ballast water tank; 15. Ordinary ballast water tank.

Detailed ways

As shown in Figure 1-4, a semi-submersible lifting and dismantling platform includes a floating box 1, a column 2 and a deck box 3 arranged from bottom to top. The floating box 1 is provided with a power system and a positioning control system. The pontoon 1 includes a port side pontoon 102 and a starboard side pontoon 101 , the column 2 includes two port side columns 202 and two starboard side columns 201 , the port side pontoon 102 is connected to the deck box 3 through the two port side columns 202 , and the starboard pontoon 101 passes through two starboard side columns 201 The deck box 3 is connected, the bottom of the pontoon 1 is provided with an azimuth thruster 12, the top of the deck box 3 is a platform deck 7, and the platform deck 7 is provided with at least one azimuth heavy crane 5, a retractable trestle 9, and a port floating body 102 It is independent from the starboard floating body 101. Both the port floating body 102 and the starboard floating body 101 are provided with ordinary ballast water tanks 15 and fast ballast water tanks 14. The top of the fast ballast water tank 14 is connected to the water tank through a pipeline with a first control valve. The compressed air ballast system is connected, the volume of the starboard floating body 101 is at least 1.5 times the volume of the port floating body 102, and the total volume of the fast ballast water tank 14 in the starboard floating body 101 is the total volume of the fast ballast water tank 14 in the port floating body 102. 1.5 times or more, all the full-rotation heavy-duty cranes 5 are placed on the side of the platform deck 7 corresponding to the port floating body 102. The port column 202 and the starboard column 201 are respectively provided with column-side ballast water tanks 13 and column-side ballast water tanks 13 The top is connected to the compressed air ballast system through a pipeline with a second control valve. The ordinary ballast water tank 15, the fast ballast water tank 14 and the column side ballast water tank 13 are all provided with a water pump ballast system. The system includes water inlet and outlet pipes with pumps, the inlet and outlet of the water inlet and outlet pipes are located in seawater, and the inlet and outlet pipes are provided with subsea valves, and the bottom of the fast ballast water tank 14 and the column side ballast water tank 13 are provided with belts leading to the sea. Drain valve discharge pipe.

There are two port side uprights 202 and two starboard side uprights 201 , and the volume of the starboard side uprights 201 is larger than the volume of the port side uprights 202 .

The transition arcs connecting the column 2 to the pontoon 1 and the deck box 3 are all single-leaf hyperboloid arc plate transitions.

a>0, b>0, rotated around the axis of symmetry, and satisfies the following surface equation:

The length of the real long axis of the hyperbola is 2a, the focal length of the hyperbola is 2c; the length of the imaginary axis of the hyperbola is 2b; b ² =c ² -a ² .

Two parking pads 4 are arranged on the platform deck 7 at the bow and the port side of the stern; on the platform deck 7, the middle of the bow and stern are arranged with davits 10 and a plurality of lifeboats 11; on the port side of the platform deck 7 A small crane 6 is arranged on it; there is a living area 8 on the bow of the platform deck 7 .

There are 20 ordinary ballast water tanks 15 evenly arranged in the port and starboard floating bodies, two fast ballast water tanks 14 are arranged in the port side floating body 102, and four fast ballast water tanks 14 are arranged in the starboard floating body 101.

The lower parts of the fast ballast tanks 14 in the port side buoy 102 are connected in turn by channels with normally open valves, and the lower parts of the fast ballast tanks 14 in the starboard buoy 101 are connected in turn by channels with normally open valves.

A ballast pipeline with a relief valve is provided between the column-side ballast tank 13 on the left side and the corresponding rapid ballast water tank 14 on the left side, and the column-side ballast tank 13 on the right side is provided with the corresponding rapid ballast water tank on the right side. Ballast pipes with discharge valves are provided between the water tanks 14 .

All ballast pipes are provided with reverse exhaust check valves.

A control method for a semi-submersible lifting and dismantling platform, comprising the following steps:

Step 1: Carry out platform stability analysis: design the operation form, establish a hydrostatic model, analyze the wind tilt moment, set the stability criterion, and obtain the stability criterion of the semi-submersible platform of the present invention in the global sea area, that is, set The allowable vertical center of gravity (AVCG) curve of the semi-submersible platform under different operating conditions and different drafts;

Step 2: Pre-analysis of lifting operation:

Step 2-1: Analyze platform load and center of gravity: the loads on the semi-submersible platform of the present invention mainly include fixed loads and variable loads. The load mainly includes deck load and fluid level change. The specific load types are as follows:

(1) Light ship load: the mass M ₀ , the longitudinal center of gravity LCG ₀ , the transverse center of gravity TCG ₀ , and the vertical center of gravity VCG ₀ are obtained according to the ship’s factory inspection report;

(2) Deck load: according to the actual ship condition, the external load including hoisting,

The fluid in the platform piping system, the temporarily stacked cargo and consumables, the anchor and the anchor chain, and the deck load information of the helicopter are evaluated to obtain the mass M ₁ , the longitudinal center of gravity LCG ₁ , the transverse center of gravity TCG ₁ , and the vertical center of gravity VCG ₁ ;

(3) Tank weight and free surface moment: The tank mainly includes fuel oil tank, lubricating oil tank, fresh water tank and ballast water tank, and each tank is equipped with liquid level transmitter and blower. Gas-type liquid level gauge, two liquid level measurement methods, both of which are redundant with each other, and measure the liquid level in the tank in real time; the calibration density of various fluids in each tank is recorded as ρ _2i , before each operation The density of the tank actually measured by the staff is recorded as ρ _i , in which the seawater salinity in different sea areas is measured by the seawater salinity meter; after obtaining the fluid filling ratio or water level in the tank, the volume V of the fluid in each tank is obtained. _i , the longitudinal center of gravity LCG _2i , the transverse center of gravity TCG _2i , the vertical center of gravity VCG _2i , the longitudinal free surface moment TSML _2i and the free surface transverse moment FSMT _2i of the fluid in the tank are calculated by linear interpolation;

Weight in tank: M _2i =V _i ρ _i , where i = {fuel oil, lubricating oil, fresh water, sea water...};

Actual free surface transverse moment of tank: FSMT _i ＝FSMT _2i ÷ρ _0i ×ρ _i ;

Actual free surface longitudinal moment of tank: FSMT _i ＝FSMT _2i ÷ρ _0i ×ρ _i ;

(4) Calculated moment: The moment of the load of each component of the semi-submersible platform of the present invention is calculated in the following way, where j={0,1,2}:

Longitudinal moment: LMT _j =M _j ×LCG _j ;

Transverse moment: LMT _j =M _j ×LCG _j ;

Vertical moment: VMT _j =M _j ×LCG _j ;

(5) Calculate the total weight, center of gravity and free surface correction:

Total mass: M=∑M _j , where j={0,1,2};

Total longitudinal center of gravity: LCG＝∑LMT _j ÷M;

Total transverse center of gravity: TCG=∑TMT _j ÷M;

Total vertical center of gravity: VCG＝∑VMT _j ÷M;

Total vertical center of gravity-transverse moment correction: VT=VCG+∑FSMT _i ÷M;

Total vertical center of gravity-longitudinal moment correction: VL=VCG+∑FSML _i ÷M;

Step 2-2: Analyze draft and transverse and trim angles:

(1) Draft depth: according to the seawater salinity ρ _seawater in the region where the measurement is obtained in step 2-1(3), and the calculation in step 2-1(5), the total mass M obtained can be solved by using the linear interpolation method The vertical center of buoyancy LCB, the horizontal center of buoyancy TCB, the vertical center of buoyancy VCB, the vertical center of buoyancy KML, the horizontal center of stability KMT and the draft D;

(2) Heel angle and pitch angle:

Heel angle: θ=arctan[(TCG-TCB)/(KMT-VT)];

Pitch angle: α=arctan[(LCG-LCB)/(KML-VL)];

Step 2-3: Verify the allowable vertical center of gravity: According to the platform draught D obtained in step 2-2(1), bring the allowable vertical center of gravity curve of the semi-submersible platform in the global sea area obtained in step 1 to obtain the current The allowable vertical center of gravity value AVCG0 of the platform under the sea area, the current working condition and the current draft, and verify it; if VT < AVCG ₀ and VL < AVCG ₀ , it means that the current loading and stress conditions meet the platform's safe operation conditions, otherwise, re-adjust the deck load arrangement in step 2-1(2) and the fluid distribution of the main tank in step 2-1(3), that is, the ballast water tank, until the aforementioned comparison conditions are met, the platform can not be used. continue the work operation;

Step 3: Platform hoisting operation: After passing the verification in step 2, the platform begins to formally carry out hoisting operation;

First of all, the drain valves of the two column-side ballast water tanks located in the starboard column are opened, and the compressed air ballast system and the water pump ballast system of the two column-side ballast water tanks in the starboard column are drained, and the starboard side is drained. The ballast water of the column-side ballast water tank is discharged into the sea; while the two column-side ballast water tanks in the port side column start the water pump ballast system, and the column-side ballast water tank of the port side column is filled with water, which makes the whole platform quickly Complete the initial tilt to the left;

Then, the water discharge valve of the fast ballast water tank in the starboard floating body is opened, and the compressed air ballast system and the water pump ballast system of the fast ballast water tank in the starboard floating body perform drainage work, and the starboard fast ballast water tank is drained. The ballast water is discharged into the sea; while the port fast ballast water tank starts the water pump ballast system, and the port fast ballast water tank enters water, which drains the starboard floating body ballast tank and the port floating body ballast tank respectively. tilt;

Finally, the ordinary ballast water tanks in the port and starboard floating bodies complete the final fine-tuning through the water pump ballast system; For the change of the liquid level of the ballast water tank, repeat step 2 in real time to ensure that the VT and VL of the platform meet the requirements of the allowable vertical center of gravity of the platform, so that the platform meets the conditions for safe operation;

During the hoisting operation of the platform, according to the requirements of the aforementioned allowable vertical center of gravity, the distribution of the platform's ballast water is adjusted through the compressed air ballast system, the ballast system of each water pump, and the switch of the drain valve on the discharge pipeline to ensure that the platform is in the whole process. During the hoisting operation, the corresponding stability criteria have been met to ensure the safety of the platform.

The operation process of the lifting operation of the platform includes the following steps:

Step 1: According to the technical and maritime requirements of the towing device, use the tugboat to tow the platform to the target waters;

Step 2: According to the position of the target module to be lifted, move the platform to the service radius under the corresponding sea conditions;

Step 3: According to different working conditions and hoisting weight, use the ballast system to adjust the draft of the platform to within 22 to 26.4 meters of the crane design service draft;

Step 4: Mount the trestle on the opposite module or platform, and the service personnel will withdraw the trestle after reaching the operation area through the trestle to complete the hoisting preparation;

Step 5: Adjust the offshore crane to the working position, that is, within the service radius of the crane, and do a good job in the connection and inspection of the rigging and spreader;

Step 6: Start the crane to smoothly lift the module to the platform deck, and place the module;

Step 7: After the module is placed, remove the offshore crane from the module, reset the crane to the rest arm and fix it;

Step 8: The process of lifting a module is completed, repeat steps 2-8;

Step 9: After all dismantling tasks are completed, the platform will leave the working waters.

The platform of the invention is equipped with an azimuth heavy-duty crane, which has excellent lifting capacity and expands the operating capacity of the platform; the platform is equipped with an azimuth propeller, which has superior dynamic positioning and motion performance and high control accuracy; Angular and axial service distance. There is a large-capacity living and living area at the bow of the platform, which provides a comfortable and safe living and living environment for the staff; the reinforced deck box design improves the deck bearing capacity and the linear load of the bulkhead, providing conditions for the shipment of large modules; The invention adopts the combination of water pump ballast and compressed air ballast systems, and has several fast ballast tanks and ordinary ballast tanks, which ensures fast anti-tilt load adjustment during lifting operations, and meets platform stability and crane operation. Safety requirements; at the same time, in the event of an emergency in the lifting operation, such as the sudden loss of the lifting load, the use of compressed air to quickly empty the ballast water for anti-tilt load regulation in the column to reduce the tilt angle of the platform and further improve the safety of the platform operation Through the monitoring and control of the dual-machine-machine connection, the accurate lifting positioning under complex sea conditions is guaranteed. When combined with the ballast monitoring system for joint monitoring, rapid ballast deployment and real-time adjustment can be effectively performed to ensure the safety and stability of the platform; According to the design and use requirements of the platform, the stability criteria for the platform's global sea area operations are established, and the platform's load conditions are pre-analyzed to ensure that the platform can meet the stability of safe operations when operating in different sea areas, different draughts, and different loads. requirements, to ensure the safety of the platform and staff to a great extent; an emergency response system has been established, including an emergency control center, emergency action team and emergency operation procedures, to ensure that the platform encounters sudden failures in overseas operations. The platform operation command is smooth in real time, the emergency rescue is fast and accurate, and the staff responds in an orderly and safe manner.

The above-mentioned embodiments are only to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, those skilled in the art can make various modifications to the technical solutions of the present invention. Variations and improvements should be included within the scope of protection determined by the claims of the present invention.

Claims (10)

1. A semi-submersible lifting and dismantling platform is characterized in that: it includes a floating box, a column and a deck box arranged from bottom to top, the floating box is provided with a power system and a positioning control system, and the floating box includes a port side The floating body and the starboard floating body, the column includes two port column and two starboard columns, the port floating body is connected to the deck box through the two port column, and the starboard floating body is connected to the deck box through the two starboard columns, and the bottom of the floating box is provided with full rotation Propeller, the top of the deck box is a platform deck, and at least one full-rotation heavy-duty crane and a retractable trestle are arranged on the platform deck. The port floating body and the starboard floating body are independent of each other, and the port floating body and the starboard floating body are arranged in both There are ordinary ballast water tanks and fast ballast water tanks. The top of the fast ballast water tank is connected to the compressed air ballast system through a pipeline with a first control valve. The volume of the starboard float is at least 1.5 times that of the port float. The total volume of the fast ballast water tanks in the starboard floating body is more than 1.5 times the total volume of the fast ballast water tanks in the port floating body. The column side ballast water tank is respectively set in the column and the starboard side column, and the top of the column side ballast water tank is connected with the compressed air ballast system through a pipeline with a second control valve. Both the tank and the column side ballast water tank are equipped with a water pump ballast system. The water pump ballast system includes a water inlet and outlet pipeline with a water pump. The bottom of the water-carrying tank and the column-side ballast water tank is provided with a discharge pipeline with a drain valve leading into the sea.
2. The semi-submersible lifting and dismantling platform according to claim 1, wherein there are two port side uprights and two starboard side uprights, and the volume of the starboard side uprights is larger than that of the port side uprights.
3. The semi-submersible lifting and dismantling platform according to claim 1, characterized in that: the transition arc surfaces connecting the column, the floating box and the deck box are all single-leaf hyperboloid arc plate transitions, which are composed of hyperbolic arcs.

   

   a>0, b>0, rotated around the axis of symmetry, and satisfies the following surface equation:

   

   The length of the real long axis of the hyperbola is 2a, the focal length of the hyperbola is 2c; the length of the imaginary axis of the hyperbola is 2b; b ² =c ² -a ² .
4. A semi-submersible lifting and dismantling platform according to claim 1, characterized in that: two parking pads are arranged on the platform deck at the bow and the port side of the stern; There are davits and several lifeboats arranged in the middle of the platform; a small crane is arranged on the port side of the platform deck; there is a living area at the bow of the platform deck.
5. The semi-submersible lifting and dismantling platform according to claim 1, wherein 20 ordinary ballast water tanks are evenly arranged in the port and starboard buoys, and 2 fast ballast tanks are arranged in the port buoys Ballast water tank, four fast ballast water tanks are arranged in the starboard floating body.
6. A semi-submersible lifting and dismantling platform according to claim 5, characterized in that: the lower parts of the fast ballast tanks in the port floating body are connected in sequence by passages with normally open valves, and the The lower parts of the fast ballast water tanks are connected in sequence by passages with normally open valves.
7. A semi-submersible lifting and dismantling platform according to claim 1 or 5, characterized in that: between the column side ballast tank on the left side and the corresponding fast ballast water tank on the left side, there is a set For the ballast pipeline of the relief valve, there is a ballast pipe with a relief valve between the column-side ballast tank on the right side and the corresponding fast ballast water tank on the right side.
8. The semi-submersible lifting and dismantling platform according to claim 7, wherein a reverse exhaust check valve is provided on each of the ballast pipes.
9. The control method of a semi-submersible lifting and dismantling platform according to any one of claims 1-8, characterized in that: comprising the following steps:

   Step 1: Carry out platform stability analysis: design the operation form, establish a hydrostatic model, analyze the wind tilt moment, set the stability criterion, and obtain the stability criterion of the semi-submersible platform of the present invention in the global sea area, that is, set The allowable vertical center of gravity (AVCG) curve of the semi-submersible platform under different operating conditions and different drafts;

   Step 2: Pre-analysis of lifting operation:

   Step 2-1: Analyze platform load and center of gravity: the loads on the semi-submersible platform of the present invention mainly include fixed loads and variable loads. The load mainly includes deck load and fluid level change. The specific load types are as follows:

   (1) Light ship load: the mass M ₀ , the longitudinal center of gravity LCG ₀ , the transverse center of gravity TCG ₀ , and the vertical center of gravity VCG ₀ are obtained according to the ship’s factory inspection report;

   (2) Deck load: according to the actual ship condition, the external load including hoisting,

   The fluid in the platform piping system, the temporarily stacked cargo and consumables, the anchor and the anchor chain, and the deck load information of the helicopter are evaluated to obtain the mass M ₁ , the longitudinal center of gravity LCG ₁ , the transverse center of gravity TCG ₁ , and the vertical center of gravity VCG ₁ ;

   (3) Tank weight and free surface moment: The tank mainly includes fuel oil tank, lubricating oil tank, fresh water tank and ballast water tank, and each tank is equipped with liquid level transmitter and blower. Gas-type liquid level gauge, two liquid level measurement methods, both of which are redundant with each other, and measure the liquid level in the tank in real time; the calibration density of various fluids in each tank is recorded as ρ _2i , before each operation The density of the tank actually measured by the staff is recorded as ρ _i , in which the seawater salinity in different sea areas is measured by the seawater salinity meter; after obtaining the fluid filling ratio or water level in the tank, the volume V of the fluid in each tank is obtained. _i , the longitudinal center of gravity LCG _2i , the transverse center of gravity TCG _2i , the vertical center of gravity VCG _2i , the longitudinal free surface moment TSML _2i and the free surface transverse moment FSMT _2i of the fluid in the tank are calculated by linear interpolation;

   Weight in tank: M _2i =V _i ρ _i , where i = {fuel oil, lubricating oil, fresh water, sea water...};

   Actual free surface transverse moment of tank: FSMT _i ＝FSMT _2i ÷ρ _0i ×ρ _i ;

   Actual free surface longitudinal moment of tank: FSML _i = FSML _2i ÷ρ _0i ×ρ _i ;

   (4) Calculated moment: The moment of the load of each component of the semi-submersible platform of the present invention is calculated in the following way, where j={0,1,2}:

   Longitudinal moment: LMT _j =M _j ×LCG _j ;

   Transverse moment: TMT _j =M _j ×LCG _j ;

   Vertical moment: VMT _j =M _j ×LCG _j ;

   (5) Calculate the total weight, center of gravity and free surface correction:

   Total mass: M=ΣM _j , where j={0,1,2};

   Total longitudinal center of gravity: LCG＝ΣLMT _j ÷M;

   Total transverse center of gravity: TCG＝ΣTMT _j ÷M;

   Total vertical center of gravity: VCG＝ΣVMT _j ÷M;

   Total vertical center of gravity-transverse moment correction: VT=VCG+ΣFSMT _i ÷M;

   Total vertical center of gravity-longitudinal moment correction: VL=VCG+ΣFSML _i ÷M;

   Step 2-2: Analyze the draft and transverse and trim angles:

   (1) Draft depth: according to the seawater salinity ρ _seawater in the region where the measurement is obtained in step 2-1(3), and the calculation in step 2-1(5), the total mass M obtained can be solved by using the linear interpolation method The vertical center of buoyancy LCB, the horizontal center of buoyancy TCB, the vertical center of buoyancy VCB, the vertical center of buoyancy KML, the horizontal center of stability KMT and the draft D;

   (2) Heel angle and pitch angle:

   Heel angle: θ=arctan[(TCG-TCB)/(KMT-VT)];

   Pitch angle: α=arctan[(LCG-LCB)/(KML-VL)];

   Step 2-3: Verify the allowable vertical center of gravity: According to the platform draught D obtained in step 2-2(1), bring the allowable vertical center of gravity curve of the semi-submersible platform in the global sea area obtained in step 1 to obtain the current The allowable vertical center of gravity value AVCG0 of the platform under the sea area, the current working condition and the current draft, and verify it; if VT < AVCG ₀ and VL < AVCG ₀ , it means that the current loading and stress conditions meet the platform's safe operation conditions, otherwise, re-adjust the deck load arrangement in step 2-1(2) and the fluid distribution of the main tank in step 2-1(3), that is, the ballast water tank, until the aforementioned comparison conditions are met, the platform can not be used. continue the work operation;

   Step 3: Platform hoisting operation: After passing the verification in step 2, the platform begins to formally carry out hoisting operation;

   First of all, the drain valves of the two column-side ballast water tanks located in the starboard column are opened, and the compressed air ballast system and the water pump ballast system of the two column-side ballast water tanks in the starboard column are drained, and the starboard side is drained. The ballast water of the column side ballast water tank is discharged into the sea; while the two column side ballast water tanks in the port side column start the water pump ballast system, and the column side ballast water tank of the port side column is filled with water, which makes the whole platform quickly Complete the initial tilt to the left;

   Then, the water discharge valve of the fast ballast water tank in the starboard floating body is opened, and the compressed air ballast system and the water pump ballast system of the fast ballast water tank in the starboard floating body perform drainage work, and the starboard fast ballast water tank is drained. The ballast water is discharged into the sea; while the port fast ballast water tank starts the water pump ballast system, and the port fast ballast water tank enters water, which drains the starboard floating body ballast tank and the port floating body ballast tank respectively. tilt;

   Finally, the ordinary ballast water tanks in the port and starboard floating bodies complete the final fine-tuning through the water pump ballast system; For the change of the liquid level of the ballast water tank, repeat step 2 in real time to ensure that the VT and VL of the platform meet the requirements of the allowable vertical center of gravity of the platform, so that the platform meets the conditions for safe operation;

   During the hoisting operation of the platform, according to the requirements of the aforementioned allowable vertical center of gravity, the distribution of the platform's ballast water is adjusted through the compressed air ballast system, the ballast system of each water pump, and the switch of the drain valve on the discharge pipeline to ensure that the platform is in the whole process. During the hoisting operation, the corresponding stability criteria have been met to ensure the safety of the platform.
10. The method for controlling a semi-submersible hoisting and disassembling platform according to claim 9, wherein the hoisting operation process of the platform comprises the following steps:

    Step 1: According to the technical and maritime requirements of the towing device, use the tugboat to tow the platform to the target waters;

    Step 2: According to the position of the target module to be lifted, move the platform to the service radius under the corresponding sea conditions;

    Step 3: According to different working conditions and lifting weight, use the ballast system to adjust the draft of the platform to within 22 to 26.4 meters of the crane design service draft;

    Step 4: Mount the trestle on the opposite module or platform, and the service personnel will withdraw the trestle after reaching the operation area through the trestle to complete the hoisting preparation;

    Step 5: Adjust the offshore crane to the working position, that is, within the service radius of the crane, and do the connection and inspection of the rigging and spreader;

    Step 6: Start the crane to smoothly lift the module to the platform deck, and place the module;

    Step 7: After the module is placed, remove the offshore crane from the module, reset the crane to the rest arm and fix it;

    Step 8: The process of lifting a module is completed, repeat steps 2-8;

    Step 9: After all dismantling tasks are completed, the platform will leave the working waters.

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