Dynamic control method for autonomous deployment and recovery of offshore platform

Abstract

The present application relates to the technical field of subsea equipment float and sink control, and particularly relates to a dynamic control method for autonomous laying and recovering of an offshore platform. The method comprises the following steps: connecting a subsea equipment with a float and sink control mechanism, lowering the subsea equipment into water completely, and making the subsea equipment in a floating state through the float and sink control mechanism; releasing the subsea equipment, and making the subsea equipment accelerate to sink to a safe speed through the float and sink control mechanism, and then making the subsea equipment sink to the seabed at the safe speed; after the subsea equipment completes work at the seabed, making the subsea equipment in a floating state through the float and sink control mechanism; and making the subsea equipment accelerate to rise through the float and sink control mechanism, and then making the subsea equipment rise to the sea surface at a safe speed. The method is widely applicable to most subsea equipment, and can successfully realize automatic sinking and rising of the subsea equipment.

Description

Technical Field

[0001] This invention relates to the field of seabed equipment buoyancy control technology, and in particular to a dynamic control method for autonomous deployment and recovery of marine platforms. Background Technology

[0002] The successful deployment and retrieval of subsea equipment is crucial for the success of underwater engineering operations, especially for deep-sea equipment, which demands higher levels of technology and reliability. Currently, subsea equipment can be categorized into cabled and uncabled equipment based on its deployment method. Cabled subsea equipment relies primarily on cables and the work vessel for its operation. The process requires calculations considering parameters such as cable strength and stiffness, as well as the work vessel's energy storage capacity and size. This involves a significant amount of computation and necessitates close coordination between the cable and the work vessel, often resulting in a certain degree of resource overload.

[0003] In contrast, data calculations for untethered subsea equipment are much simpler. Currently, the recovery technology for untethered subsea equipment typically uses its own weight or a U-shaped hull for venting and water intake to achieve sinking; its ascent process relies on controlling the U-shaped hull, and in emergency situations where ascent is impossible, a weight is usually jettisoned to complete the ascent. Although only data about the subsea equipment itself needs to be calculated, the calculations for the U-shaped hull are very complex, and the emergency ascent method of jettisoning the weight also requires customized calculations based on the specific subsea equipment. Therefore, in practical use, extensive calculations are required for each type of subsea equipment, making it unsuitable for most subsea equipment. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects in the existing technology and to propose a dynamic control method for autonomous deployment and recovery of marine platforms. This method is widely applicable to most seabed equipment and can successfully realize the automatic sinking and floating of seabed equipment.

[0005] The technical solution of this invention is: a dynamic control method for autonomous deployment and recovery of marine platforms, comprising the following steps:

[0006] S1. Connect the subsea equipment to the buoyancy control mechanism, lower the subsea equipment until it is fully submerged in water, and use the buoyancy control mechanism to make the subsea equipment float. The buoyancy control mechanism includes an airbag mechanism, which includes three airbag units arranged from bottom to top: a first-layer airbag unit, a second-layer airbag unit, and a third-layer airbag unit. Each airbag unit includes an airbag, and the airbag is equipped with a self-monitoring deflation valve. Automatic switching valves are installed on the connecting pipes of adjacent airbags.

[0007] The automatic valve between the first and second airbag units is opened, inflating the first and second airbag units of the airbag mechanism with a constant pressure of P1 = 0.75P. m+P0 gas, P m This is the maximum pressure that the airbag can withstand;

[0008] After the first airbag of the first airbag unit and the second airbag of the second airbag unit are filled with gas, the entire underwater equipment is in a floating state.

[0009] S2. Release the seabed equipment, depress the buoyancy control mechanism to accelerate the seabed equipment to a safe speed, and then the seabed equipment sinks to the seabed at a safe speed.

[0010] The automatic valve between the first and second airbag units is closed, and the self-monitoring pressure relief valve on the second airbag is opened to deflate it. During the deflation process, the subsea equipment accelerates its descent. When the second airbag is completely depleted, the subsea equipment accelerates to a safe speed v. a Subsequently, the underwater equipment moved at a safe speed of v a It sank to the seabed at a constant speed;

[0011] During the deployment of the underwater equipment, gas at a pressure of P2 is continuously supplied to the airbag mechanism.

[0012]

[0013] in, The latitude of the subsea equipment in the water is represented by z, and the depth of the equipment in the water is represented by z.

[0014] S3. After completing its operations on the seabed, the subsea equipment is kept floating by a buoyancy control mechanism.

[0015] When the subsea equipment needs to surface, the automatic valve between the first and second airbags is activated, injecting pressurized gas at a constant pressure of P3 into the first and second airbags via a pressurization mechanism.

[0016]

[0017] Among them, z m This indicates the depth value of the seabed surface where the subsea equipment operates;

[0018] After the first and second airbags are filled with gas, the entire device floats.

[0019] S4. The buoyancy control mechanism drives the seabed equipment to accelerate upward. Once the seabed equipment accelerates to a safe speed, it rises to the surface at a safe speed.

[0020] Open the automatic valve between the second and third airbag units to inject gas at pressure P4 into the airbag units.

[0021]

[0022] During the injection process, the subsea equipment accelerates upwards. Once the third airbag is fully inflated, the equipment accelerates upwards to a safe speed v. b Stop injecting gas into the airbag unit.

[0023] The buoyancy control mechanism also includes:

[0024] The hull, whose bottom is connected to the subsea equipment below via connecting claws;

[0025] The airbag mechanism is located on the top outer side of the housing;

[0026] The boosting mechanism is located in a cavity inside the housing and includes a boosting cylinder unit and a turbo boosting unit. The boosting cylinder unit includes a boosting cylinder, a drive motor, and a push block that is slidably disposed in the boosting cylinder. One side of the push block is connected to the output shaft of the drive motor, and the other side of the push block and the boosting cylinder form a boosting chamber.

[0027] The turbocharger unit includes a first boost chamber and a pressurization chamber. The inlet of the first boost chamber is connected to the air tank, and the outlet of the first boost chamber is connected to the inlet of the boost chamber through a first check valve. The inlet of the pressurization chamber is connected to the outlet of the boost chamber through a second check valve, and the outlet of the pressurization chamber is connected to the airbag mechanism through an automatic pressure reducing valve. Turbines are respectively installed in the first boost chamber and the pressurization chamber, and the turbines are fixedly connected to each other through a turbine connecting rod.

[0028] The lower ring of the airbag is covered with an airbag roll. One end of the airbag roll is fixedly connected to the airbag, and the other end of the airbag roll is connected to a roll controller. The roll controller is fixed to the airbag. The length of the airbag roll covering the outside of the airbag is adjusted by adjusting the roll controller, thereby adjusting the inflation volume of the airbag.

[0029] In step S1,

[0030] When the entire submersible equipment is just fully submerged, the opening volume of the airbag in the airbag mechanism is:

[0031]

[0032] Where m represents the total weight of the buoyancy control mechanism and the seabed equipment, and ρ0 represents the density of the seawater surface.

[0033] In step S2, the underwater equipment is released. When the second airbag deflates, the opening volume of the airbag mechanism is:

[0034]

[0035] Where ρ(z) represents the seawater density as a function of seawater depth, and g(z) represents the gravitational acceleration as a function of seawater depth.

[0036] The inflation flow rate Q from the pressurization mechanism to the airbag mechanism is:

[0037]

[0038] Where M represents the molar mass of the gas currently being filled, ρ represents the density of the gas currently being filled, R represents the molar gas constant, T represents the temperature inside the gasbag in Kelvin, and k is represented as f(ρ(z),A), where A represents the maximum cross-sectional area of ​​the device, and ρ(z) represents the seawater density function as a function of seawater depth.

[0039] ρ(z)=ρ0+4.80×10 -6 z,

[0040] Wherein, ρ0 = 1.0278.

[0041] In step S3,

[0042] After the first and second airbags are filled with gas, the entire device floats. At this time, the airbag opening volume of the airbag mechanism is:

[0043]

[0044] In step S4,

[0045] The pressurization mechanism stopped operating, and then the subsea equipment resumed operation at a safe speed of v. b It rises to the sea surface at a constant speed. During this process, the airbag mechanism is made safe to use by using the self-monitoring pressure relief valve of the third airbag unit.

[0046] The volume V1 of the first airbag in the first airbag unit is

[0047]

[0048] The volume V2 of the second airbag in the second airbag unit is

[0049]

[0050] The volume V3 of the third airbag in the third airbag unit is

[0051]

[0052] The beneficial effects of this invention are: This application can pressurize 5MPa gas to 40-50MPa high-pressure gas through a pressurizing mechanism. Therefore, during the process of the underwater equipment rising and falling, it is only necessary to control the pressurizing mechanism to fill the airbag mechanism with high-pressure gas or to release the airbag mechanism according to the pressure of the external seawater to realize the automatic sinking and floating of the underwater equipment. Attached Figure Description

[0053] Figure 1 This is a diagram illustrating the operational principle of the three-layer airbag structure in this method.

[0054] Figure 2 This is a schematic diagram of the buoyancy control mechanism;

[0055] Figure 3 This is a schematic diagram of the booster mechanism;

[0056] Figure 4 This is a structural schematic diagram of the booster cylinder unit;

[0057] Figure 5 This is a schematic diagram of the turbocharger unit;

[0058] In the diagram: 1. Housing; 2. Airbag mechanism; 3. Pressurization mechanism; 4. Connecting claw; 5. First-layer airbag unit; 6. Second-layer airbag unit; 7. Third-layer airbag unit; 8. Self-monitoring deflation valve; 9. Airbag drum; 10. Drum controller; 11. Pressurization cylinder; 12. Drive motor; 13. Push block; 14. Pressurization chamber; 15. Crank block; 16. Push rod; 17. Turbine; 18. Turbine connecting rod; 19. First pressurization chamber; 20. Pressurization chamber; 21. Air tank; 22. First one-way valve; 23. Second one-way valve; 24. Automatic pressure reducing valve. Detailed Implementation

[0059] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0060] Specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0061] The autonomous deployment and recovery dynamic control method for marine platforms described in this invention includes the following steps, and the working principle diagram of the three-layer airbag structure in this process is shown in the figure below. Figure 1 As shown.

[0062] The first step is to connect the underwater equipment to the buoyancy control mechanism, lower the underwater equipment until it is fully submerged in the water, and then use the buoyancy control mechanism to keep the underwater equipment floating.

[0063] like Figure 2As shown, the buoyancy control mechanism includes a housing 1, an airbag mechanism 2, and a pressurization mechanism 3. The pressurization mechanism is fixed inside a cavity within the housing 1. The airbag mechanism 2 is located on the top outer side of the housing 1. The pressurization mechanism 3 is connected to the airbag mechanism 2 and provides high-pressure gas to the airbag mechanism through the pressurization mechanism. A connecting claw 4 is provided at the bottom of the housing, through which the buoyancy control mechanism can be connected to the seabed equipment below it.

[0064] The airbag mechanism comprises three airbag units arranged sequentially from bottom to top: the first airbag unit 5, the second airbag unit 6, and the third airbag unit 7. Each airbag unit includes an airbag equipped with a self-monitoring deflation valve 8. This valve monitors the internal and external pressure difference of the airbag in real time. When the valve detects that the pressure difference reaches a certain value, it automatically opens, deflating the airbag and ensuring it operates at a safe pressure. Furthermore, the deflation of the airbag via the self-monitoring valve can accelerate the descent of the submersible equipment.

[0065] Meanwhile, an airbag roll 9 is also provided on the outer side of the lower annular part of the airbag, covering the outer annular part of the airbag. One end of the airbag roll is fixedly connected to the outer surface of the airbag, and the other end of the airbag is set inside the roll controller 10. The roll controller 10 is set on the outer surface of the airbag. The length of the airbag roll 9 set on the outer annular part of the airbag is adjusted by the roll controller 10, thereby adjusting the maximum inflation volume of the airbag.

[0066] Adjacent airbags are connected by a connecting pipe, which is equipped with an automatic switching valve to control the inflation of each airbag.

[0067] like Figures 3 to 5 As shown, the boosting mechanism includes a booster cylinder unit and a turbocharger unit. The booster cylinder unit includes a booster cylinder 11 and a drive motor 12, which drives the booster cylinder. The booster cylinder 11 and the housing of the drive motor 12 form a closed cavity. A pusher block 13 is slidably disposed inside the booster cylinder 11. One side of the pusher block 13 is connected to the output shaft of the drive motor 12, and the other side of the pusher block 13 and the cylinder body of the booster cylinder 11 form a boosting chamber 14.

[0068] The output shaft of the drive motor 12 is fixedly connected to one end of the crank block 15, and the other end of the crank block 15 is hinged to one end of the push rod 16. The other end of the push rod 16 is hinged to the side of the push block 13. Therefore, during the operation of the drive motor 12, as its output shaft rotates, it sequentially drives the push block 13 to reciprocate within the booster cylinder 11 via the crank block 15 and the push rod 16. The crank block 15 and the push rod 16 convert the rotation of the output shaft into the linear motion of the push block 13. During the movement of the push block 13 within the booster cylinder, it can compress the gas in the booster chamber 14, thereby boosting the pressure of the gas within the booster chamber 14.

[0069] The turbocharger unit includes two turbines 17, which are fixedly connected by a turbine connecting rod 18. The two turbines 17 are respectively housed in sealed pressurization chambers, which are independent and not interconnected. In this embodiment, the pressurization chambers are a first pressurization chamber 19 and a pressurization chamber 20. The inlet of the first pressurization chamber 19 is connected to an air storage tank 21, and the outlet of the first pressurization chamber 19 is connected to the inlet of the pressurization chamber 14. A first one-way valve 22 is provided on the connecting pipeline between the first pressurization chamber 19 and the pressurization chamber 14, ensuring that gas in the first pressurization chamber 19 can only flow into the pressurization chamber 14. The inlet of the pressurization chamber is connected to the inlet of the pressurization chamber, and the outlet of the pressurization chamber is connected to the airbag mechanism. A second one-way valve 23 is provided on the connecting pipeline between the pressurization chamber 20 and the pressurization chamber 14, ensuring that gas in the pressurization chamber 14 can only flow into the pressurization chamber 20. An automatic pressure reducing valve 24 is installed on the connecting pipeline between the pressurization chamber 20 and the airbag mechanism. The pressure of the high-pressure gas output from the pressurization chamber 20 is precisely adjusted by the automatic pressure reducing valve 24.

[0070] The buoyancy control mechanism is connected to the seabed equipment below via its bottom connecting claw 4. The seabed equipment equipped with the buoyancy control mechanism is then towed until it is completely submerged in the water. At this time, the automatic switching valve between the first and second airbag units is opened, and the pressurization mechanism is activated, filling the first airbag of the first airbag unit and the second airbag of the second airbag unit with high-pressure gas.

[0071] During the operation of the pressurization mechanism, the gas storage tank 21 supplies gas to the first pressurization chamber 19. The pressurized gas in the gas storage tank 21 directly rushes into the first pressurization chamber 19. After the gas in the first pressurization chamber 19 enters the pressurization chamber 14 in the pressurization cylinder 11 through the first one-way valve 22, the drive motor 12 is activated, its output shaft rotates, and drives the push block 13 to reciprocate in the pressurization cylinder 11 in sequence through the crank block 15 and the push rod 16. During the reciprocating movement, the push block compresses the gas in the pressurization chamber 14, realizing the initial pressurization of the gas.

[0072] After the initial pressurization, the gas enters the pressurization chamber 20 through the second one-way valve 23. The pressurized gas drives the turbine in the pressurization chamber to rotate, and the turbine in the pressurization chamber drives the turbine in the first pressurization chamber 19 to rotate faster, thus realizing the first pressurization of the gas entering the first pressurization chamber.

[0073] After the gas has undergone the first pressurization, it enters the pressurization chamber 14 of the pressurization cylinder 11 through the first one-way valve 22. During the operation of the drive motor 12, the output shaft of the drive motor 12 rotates and drives the push block 13 to reciprocate within the pressurization cylinder 11 through the crank block 15 and the push rod 16 in sequence. During the reciprocating movement of the push block, the gas in the pressurization chamber 14 is compressed, thus achieving the second pressurization of the gas.

[0074] After being pressurized a second time, the gas enters the pressurization chamber 20 through the second one-way valve 23. The pressurized gas drives the turbine in the pressurization chamber 20 to rotate faster, which in turn drives the turbine in the first pressurization chamber to rotate faster, thus achieving continuous pressurization of the gas entering the first pressurization chamber. After the gas in the first pressurization chamber enters the pressurization cylinder 11, the pusher block is pushed by the drive motor 12 to pressurize the gas in the pressurization chamber 14 a second time, thereby maintaining a continuous secondary pressurization process for the gas entering the pressurization mechanism. After the above secondary pressurization process, the gas pressure in the gas storage tank can be increased from 5 MPa to 45-50 MPa.

[0075] After being pressurized twice, the high-pressure gas is reduced in pressure by an automatic pressure reducing valve and then supplied to the airbag mechanism to fill it with gas at a constant pressure of P1.

[0076] P1 = 0.75P m +P0,

[0077] After the first and second airbags are filled with gas, the entire device floats. In this application, the standard for filling the airbags is that the pressure difference between the gas pressure inside the airbag detected by the self-monitoring vent valve on the airbag and the external seawater pressure experienced by the airbag reaches 0.75P. m At this time, it indicates that the airbag is fully inflated. Among them, P... m This is the maximum pressure that the airbag can withstand.

[0078] When the entire submersible equipment is just fully submerged, the opening volume of the airbag in the airbag mechanism is:

[0079]

[0080] Where m represents the total weight of the buoyancy control mechanism and the seabed equipment, and ρ0 represents the density of the seawater surface.

[0081] The second step involves releasing the underwater equipment while the second airbag is slowly deflated. During this deflation process, the entire equipment accelerates its descent, meaning its overall descent speed continuously increases. Once the second airbag is completely deflated, the equipment's descent speed accelerates to a safe level. Subsequently, the entire equipment descends to the seabed at a safe, uniform, and stable speed.

[0082] During the release of the subsea equipment, the automatic switch valve between the first and second airbags is closed, and the self-monitoring pressure relief valve on the second airbag is opened to deflate the second airbag.

[0083] As the air is released, the overall weight of the equipment exceeds the buoyancy, causing the equipment to accelerate downwards. The water resistance also increases as the sinking speed increases.

[0084] The water resistance experienced by the equipment will continuously catch up with the difference between buoyancy and gravity, approaching a state of equilibrium. Since the buoyancy of the equipment is fixed after the deflation is completed, the difference between the buoyancy and gravity of the equipment is also fixed after the deflation is completed.

[0085] As the overall sinking speed of the underwater equipment increases, the water resistance experienced by the equipment also increases. Water resistance F 阻 The formula is as follows:

[0086] F 阻 =kv1 2 ,

[0087] Where v1 represents the sinking velocity of the underwater equipment, k is denoted as f(ρ(z),A), A represents the maximum cross-sectional area of ​​the equipment, and ρ(z) represents the seawater density function as a function of seawater depth.

[0088] ρ(z)=ρ0+4.80×10 -6 z,

[0089] Wherein, ρ0 = 1.0278.

[0090] Therefore, when the maximum cross-sectional area A of the equipment is determined, k is a function of the depth z, so...

[0091] F 阻 =f[ρ(z),A])v1 2 ,

[0092] As water resistance increases, the entire device will eventually reach a limit speed, at which point the water resistance, buoyancy, and the device's own weight will balance, i.e.:

[0093] F 浮 =GF 阻 .

[0094] The safe speed for the submersion of underwater equipment is denoted as va. In this application, let v be... a =0.8~1.2m / s. When the submersible equipment is steadily sinking, the water resistance it experiences is:

[0095] F 阻 =f[ρ(z),A])v a 2 ,

[0096] When the water resistance, buoyancy, and weight of the equipment are in equilibrium, the buoyancy provided by the buoyancy control mechanism is:

[0097] F 浮 =GF 阻 =mg(z)-f[ρ(z),A])v a 2 ,

[0098] Where g(z) represents the gravitational acceleration value as a function of seawater depth.

[0099] g(z) = g0 + 2.40 × 10 -6 z.

[0100] Therefore, after the second airbag is completely deflated, the theoretical calculated value of the airbag opening volume in the airbag unit is:

[0101]

[0102] Since ρ(z)=ρ0+4.80×10 -6 z, g(z) = g0 + 2.40 × 10 -6 When z varies between 0 and 10000, the magnitudes of change of ρ(z) and g(z) are at most 10. -2 Compared to the values ​​of ρ0 and g0 themselves, its change is very small. Furthermore, the airbag itself has a certain degree of elasticity, so k can be expressed as a constant function f(ρ(z), A). Therefore, when the maximum cross-sectional area A of the equipment is determined, k is a fixed value. At this time, V 排2 It can be simplified to:

[0103]

[0104] During the deflating of the second airbag, the self-monitoring deflation valve of this layer monitors the deflation rate. When the deflation rate detected by the self-monitoring deflation valve is zero, it means that the second airbag has been completely deflated. At this point, the subsea equipment accelerates to a safe speed v. a Subsequently, the underwater equipment moved at a safe speed of v a It sank to the seabed at a constant speed.

[0105] Compared to the airbag deployment volume in the first step, the airbag deployment volume has decreased.

[0106]

[0107] Therefore, the volume V2 of the second airbag unit can be obtained as follows:

[0108]

[0109] The corresponding volume V1 of the first airbag unit can be obtained as follows:

[0110]

[0111] During the deployment of the subsea equipment, as the water depth increases, the water pressure on the airbag mechanism gradually increases, and the gas pressure provided by the pressurization mechanism to the airbag mechanism should also increase. In this step, the gas pressure P2 provided by the pressurization mechanism to the airbag mechanism is:

[0112]

[0113] in, 'z' represents the actual latitude of the subsea equipment in the water, and 'z' represents the depth of the equipment in the water.

[0114] In other words, during the deployment of the underwater equipment, the pressurization mechanism continuously inflates the airbag mechanism. Furthermore, as the underwater equipment sinks and its depth (z) increases, the gas pressure injected into the airbag mechanism by the pressurization mechanism gradually increases.

[0115] The inflation flow rate Q from the pressurization mechanism to the first airbag of the airbag mechanism is:

[0116]

[0117] Where M represents the molar mass of the gas currently being filled, ρ represents the density of the gas currently being filled, R represents the molar gas constant, and T represents the temperature inside the airbag, with the unit being Kelvin.

[0118] The inflation must reach the above flow rate to ensure that the gas pressure inside the first airbag is greater than the external seawater pressure acting on the airbag.

[0119] Thirdly, after the underwater equipment has completed its operations on the seabed, when it needs to surface, the automatic valve between the first and second airbags is activated. A pressurization mechanism then injects pressurized gas at a constant pressure of P3 into the airbag system. Once the first and second airbags are full of gas, the entire equipment floats.

[0120] In this step, the pressure of the pressurized gas supplied by the pressurization mechanism to the airbag mechanism remains constant, and this pressure value is:

[0121]

[0122] Among them, z m This indicates the deepest point where the subsea equipment is located, i.e., the depth of the seabed where the equipment operates.

[0123] When the first and second airbags are filled with gas, the airbag opening volume of the airbag mechanism is:

[0124]

[0125] Compared to the airbag deployment volume in the second step, the airbag deployment volume in this step is increased.

[0126]

[0127] The fourth step involves opening the automatic valve between the second and third airbag units to slowly inflate the third airbag. The pressurization mechanism provides pressurized gas at a pressure of P4 to the airbag mechanism. During the inflation process, the entire underwater equipment continuously accelerates upward, meaning the ascent speed of the underwater equipment gradually increases.

[0128] As the equipment inflates, the buoyancy force on the entire device exceeds the gravity, causing the device to accelerate upwards. The water resistance also increases as the upward speed increases.

[0129] The water resistance experienced by the equipment will continuously catch up with the difference between buoyancy and gravity, approaching a state of equilibrium. Since the buoyancy after inflation is certain, the difference between the overall buoyancy and gravity of the equipment after inflation is also certain.

[0130] The inflation speed or flow rate only affects the time it takes to reach the above difference, and does not affect the set difference. Therefore, it is sufficient to ensure the safety of the airbag by not inflating too fast.

[0131] Once the third airbag is fully inflated, the underwater equipment accelerates to a safe buoyancy. Subsequently, the entire underwater equipment rises steadily and uniformly to the surface at a safe speed, thus achieving automatic recovery.

[0132] During the ascent of the subsea equipment, the pressurization mechanism continuously inflates the airbag mechanism. As the water depth z decreases, the water pressure on the airbag mechanism gradually decreases. To prevent the airbag from being damaged by excessive pressure, the gas pressure supplied by the pressurization mechanism to the airbag mechanism gradually decreases. The gas pressure P4 provided by the pressurization mechanism to the airbag mechanism is:

[0133] As the overall ascent speed of the underwater equipment increases, the water resistance experienced by the equipment also increases, with the water resistance F... 阻 The formula is as follows:

[0134] F 阻 =kv2 2 ,

[0135] v2 represents the buoyancy of the submersible equipment underwater, and k is denoted as f(ρ(z),A), where A represents the maximum cross-sectional area of ​​the equipment, and ρ(z) represents the seawater density function value as a function of seawater depth. Therefore, when the maximum cross-sectional area A of the equipment is determined, k is a function of depth z.

[0136] F 阻 =f[ρ(z),A])v2 2 ,

[0137] As water resistance increases, the entire device will eventually reach a limit speed, at which point the water resistance, buoyancy, and the device's own weight will balance, i.e.:

[0138] F 浮 =G+F 阻 ,

[0139] The safe speed for underwater equipment to surface is expressed as v. b In this application, let v b =0.8~1.2m / s, so when the underwater equipment is stably rising, the water resistance it experiences is:

[0140] F 阻 =f[ρ(z),A])v b 2 ,

[0141] When the water resistance, buoyancy, and weight of the equipment are in equilibrium, the buoyancy provided by the buoyancy control mechanism is:

[0142] F 浮 =G+F 阻 =mg(z)+f[ρ(z),A])v b 2 ,

[0143] Therefore, when the third airbag is fully inflated, the theoretical calculated value of the airbag opening volume in the airbag unit is:

[0144]

[0145] Since ρ(z)=ρ0+4.80×10 -6 z, g(z) = g0 + 2.40 × 10 -6When z varies between 0 and 10000, the magnitudes of change of ρ(z) and g(z) are at most 10. -2 Compared to the values ​​of ρ0 and g0 themselves, its change is very small. Furthermore, the airbag itself has a certain degree of elasticity, so k can be expressed as a constant function f(ρ(z), A). Therefore, when the maximum cross-sectional area A of the equipment is determined, k is a fixed value. At this time, V 排4 It can be simplified to:

[0146]

[0147] Once the third airbag is fully inflated, the underwater equipment accelerates to a safe speed v. b The pressurization mechanism stops operating. During the overall ascent of the equipment, as the external water pressure gradually decreases, the difference between the gas pressure inside the airbag mechanism and the external water pressure gradually increases. If the difference reaches P... m This could pose a danger to the airbag mechanism. At this point, the self-monitoring deflation valve on the third airbag is opened to release air and ensure the safety of the airbag mechanism during ascent. Since the purpose of deflation is to reduce the pressure inside the airbag mechanism, the amount of air released during this process is small, and the opening volume of the airbag mechanism does not change. Therefore, the subsea equipment can proceed at a safe speed v. b It rises to the surface of the sea at a constant speed.

[0148] Compared to the airbag deployment volume in step three, the airbag deployment volume in this step is larger.

[0149]

[0150] Therefore, the volume V3 of the third airbag unit can be obtained as follows:

[0151]

[0152] The above provides a detailed description of the autonomous deployment and recovery dynamic control method for marine platforms provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dynamic control method for autonomous deployment and recovery of marine platforms, characterized in that, Includes the following steps: S1. Connect the subsea equipment to the buoyancy control mechanism, lower the subsea equipment until it is fully submerged in water, and use the buoyancy control mechanism to make the subsea equipment float. The buoyancy control mechanism includes an airbag mechanism, which includes three airbag units arranged from bottom to top: a first-layer airbag unit, a second-layer airbag unit, and a third-layer airbag unit. Each airbag unit includes an airbag, and the airbag is equipped with a self-monitoring deflation valve. Automatic switching valves are installed on the connecting pipes of adjacent airbags. The automatic valve between the first and second airbag units is opened, allowing a constant pressure to be injected into the first and second airbag units of the airbag mechanism. gas, This is the maximum pressure that the airbag can withstand; After the first airbag of the first airbag unit and the second airbag of the second airbag unit are filled with gas, the entire underwater equipment is in a floating state. S2. Release the seabed equipment, depress the buoyancy control mechanism to accelerate the seabed equipment to a safe speed, and then the seabed equipment sinks to the seabed at a safe speed. As the overall sinking speed of the underwater equipment increases, the water resistance experienced by the equipment also increases. The formula is as follows: ， in, This indicates the sinking speed of the underwater equipment. Represented as A represents the maximum cross-sectional area of ​​the equipment; The automatic valve between the first and second airbag units is closed, and the self-monitoring pressure relief valve on the second airbag is opened to deflate it. During the deflation process, the subsea equipment accelerates its descent. When the second airbag is completely depleted, the subsea equipment accelerates to a safe speed. The underwater equipment then proceeded at a safe speed. It sank to the seabed at a constant speed; During the deployment of the underwater equipment, a pressure of [pressure value] is continuously supplied to the airbag mechanism. gas, ， in, The latitude of the subsea equipment in the water is represented by z, and the depth of the equipment in the water is represented by z. S3. After completing its operations on the seabed, the subsea equipment is kept floating by a buoyancy control mechanism. When the subsea equipment needs to surface, the automatic valve between the first and second airbags is activated, and a constant pressure is injected into the first and second airbags of the airbag mechanism through the pressurization mechanism. pressurized gas, ， in, This indicates the depth value of the seabed surface where the subsea equipment operates; After the first and second airbags are filled with gas, the entire device floats. S4. The buoyancy control mechanism drives the seabed equipment to accelerate upward. Once the seabed equipment accelerates to a safe speed, it rises to the surface at a safe speed. The automatic valve between the second and third airbag units is opened, injecting pressure into the airbag units to a pressure of [pressure value missing]. gas, ， During the injection process, the underwater equipment accelerates upwards. Once the third airbag is fully inflated, the equipment accelerates upwards to a safe speed. Stop injecting gas into the airbag unit.

2. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 1, characterized in that, The buoyancy control mechanism also includes: The hull, whose bottom is connected to the subsea equipment below via connecting claws; The airbag mechanism is located on the top outer side of the housing; The boosting mechanism is located in a cavity inside the housing and includes a boosting cylinder unit and a turbo boosting unit. The boosting cylinder unit includes a boosting cylinder, a drive motor, and a push block that is slidably disposed in the boosting cylinder. One side of the push block is connected to the output shaft of the drive motor, and the other side of the push block and the boosting cylinder form a boosting chamber. The turbocharger unit includes a first boost chamber and a pressurization chamber. The inlet of the first boost chamber is connected to the air tank, and the outlet of the first boost chamber is connected to the inlet of the boost chamber through a first check valve. The inlet of the pressurization chamber is connected to the outlet of the boost chamber through a second check valve, and the outlet of the pressurization chamber is connected to the airbag mechanism through an automatic pressure reducing valve. Turbines are respectively installed in the first boost chamber and the pressurization chamber, and the turbines are fixedly connected to each other through a turbine connecting rod.

3. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 2, characterized in that, The lower ring of the airbag is covered with an airbag roll. One end of the airbag roll is fixedly connected to the airbag, and the other end of the airbag roll is connected to a roll controller. The roll controller is fixed to the airbag. The inflation volume of the airbag is adjusted by adjusting the length of the airbag roll covering the outside of the airbag through the roll controller.

4. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 1, characterized in that, In step S1, when the entire underwater equipment is just fully submerged, the opening volume of the airbag in the airbag mechanism is: ， Where m represents the total weight of the buoyancy control mechanism and the seabed equipment. This indicates the density of the seawater surface.

5. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 1, characterized in that, In step S2, the underwater equipment is released. When the second airbag deflates, the opening volume of the airbag mechanism is: ， in, This represents the seawater density value as a function of seawater depth. This represents the value of gravitational acceleration as a function of seawater depth. The inflation flow rate Q from the pressurization mechanism to the airbag mechanism is: , Where M represents the molar mass of the gas currently being introduced. The density of the gas currently being filled is represented by R, the molar gas constant by R, and the temperature inside the airbag by T, both in Kelvin. Represented as A represents the maximum cross-sectional area of ​​the equipment. This represents a function of seawater density that varies with seawater depth. ， in, .

6. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 1, characterized in that, In step S3, after the first and second airbags are filled with gas, the entire device is in a floating state. At this time, the airbag opening volume of the airbag mechanism is: 。 7. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 1, characterized in that, In step S4, the pressurization mechanism stops operating, and then the subsea equipment resumes operation at a safe speed. It rises to the sea surface at a constant speed. During this process, the airbag mechanism is made safe to use by using the self-monitoring pressure relief valve of the third airbag unit.

8. The dynamic control method for autonomous deployment and recovery of marine platforms according to claim 1, characterized in that, The volume of the first airbag in the first airbag unit for ； The volume of the second airbag in the second airbag unit for ； The volume of the third airbag in the third airbag unit for 。

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