Dynamic control method for autonomous deployment and recovery of ocean platform

Abstract

The invention relates to the technical field of floating and sinking control of submarine equipment, in particular to a dynamic control method for autonomous deployment and recovery of an ocean platform. Comprising the following steps: connecting seabed equipment with a floating and sinking control mechanism, lowering the seabed equipment until the seabed equipment completely enters water, and enabling the seabed equipment to be in a floating state through the floating and sinking control mechanism; the seabed equipment is released, the floating and sinking control mechanism is deflated, and the seabed equipment sinks to the seabed at the safe speed after the seabed equipment is accelerated to sink to the safe speed; after the seabed equipment completes operation at the seabed, the seabed equipment is in a floating state through the floating and sinking control mechanism; the floating and sinking control mechanism drives the seabed equipment to rise in an accelerated mode, and when the seabed equipment is accelerated to the safe speed, the seabed equipment floats to the sea surface at the safe speed. The device is widely applicable to most of submarine equipment, and can smoothly realize automatic sinking and floating of the submarine equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of seabed equipment floating and sinking control, and in particular to a dynamic control method for autonomous deployment and recovery of an ocean platform. Background Art

[0002] The stable lowering and recovery of subsea equipment is crucial for the success of underwater operations, especially for deep-sea equipment, which demands a higher level of technology and reliability. Currently, subsea equipment can be categorized as either cabled or cableless, depending on the deployment method. Cabled subsea equipment primarily relies on cables and work vessels, requiring calculations that consider parameters such as the cable's strength and stiffness, as well as the vessel's energy storage capacity and size. This requires significant computational effort and coordination between the cable and work vessel, often resulting in a certain amount of excess resources.

[0003] In comparison, the data calculation for cable-free subsea equipment is simpler. At present, the bottom recovery technology of cable-free subsea equipment usually uses its own weight or U-shaped warehouse to exhaust and let in water to achieve sinking: its floating process needs to rely on controlling the U-shaped warehouse to complete. When it is impossible to float in an emergency, it is usually completed by discarding the load block. Although only the data of the subsea equipment itself needs to be calculated, the calculation for the U-shaped warehouse is very complicated, and the emergency floating method of discarding the load block also needs to be customized and selected according to the subsea equipment itself. Therefore, in actual use, a large number of calculations need to be performed separately for each type of subsea equipment, which cannot be widely applied to most subsea equipment. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and propose a dynamic control method for autonomous deployment and recovery of marine platforms, which is widely applicable to most submarine equipment and can smoothly realize the automatic sinking and floating of submarine equipment.

[0005] The technical solution of the present invention is: a dynamic control method for autonomous deployment and recovery of an offshore platform, which includes the following steps:

[0006] S1. Connect the subsea equipment to the buoyancy control mechanism, lower the subsea equipment until it is completely submerged in water, and place the subsea equipment in a floating state using the buoyancy control mechanism. The buoyancy control mechanism includes an airbag mechanism, which includes three airbag units, a first airbag unit, a second airbag unit, and a third airbag unit, arranged sequentially from bottom to top. Each airbag unit includes an airbag, each airbag is equipped with a self-monitoring air release valve, and the connecting pipes between adjacent airbags are equipped with an automatic switching valve.

[0007] Open the automatic switch valve between the first layer airbag unit and the second layer airbag unit, and fill the first layer airbag unit and the second layer airbag unit of the airbag mechanism with a constant pressure value of P1 = 0.75P m+P0 gas, P m The maximum pressure that the airbag can bear;

[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 submarine equipment is in a floating state;

[0009] S2. Release the submarine equipment and deflate the buoyancy control mechanism, accelerating the submarine equipment to sink to a safe speed. The submarine equipment then sinks to the seabed at a safe speed.

[0010] Close the automatic switch valve between the first and second airbag units, open the self-monitoring pressure relief valve on the second airbag, and deflate the second airbag. During the deflation process, the submarine equipment sinks faster. When the second airbag is emptied, the submarine equipment accelerates to a safe speed v a , then the submarine equipment moves at a safe speed v a Sinking to the seabed at a constant speed;

[0011] During the release of the submarine equipment, the airbag mechanism is always supplied with gas at a pressure of P2.

[0012]

[0013] in, It represents the actual latitude of the submarine equipment in the water, and z represents the depth of the equipment in the water;

[0014] S3. After the submarine equipment completes its operation on the seabed, the submarine equipment is placed in a floating state through the floating and sinking control mechanism;

[0015] When the submarine equipment needs to float up, the automatic switch valve between the first and second airbags is opened, and pressurized gas with a constant pressure value of P3 is injected into the first and second airbags of the airbag mechanism through the booster mechanism.

[0016]

[0017] Among them, z m Indicates the depth of the seabed where the submarine equipment works;

[0018] After the first and second airbags are filled with gas, the entire device is in a floating state;

[0019] S4. The buoyancy control mechanism drives the submarine equipment to accelerate upward. When the submarine equipment accelerates to a safe speed, the submarine equipment floats to the sea surface at a safe speed.

[0020] Open the automatic switch valve between the second layer airbag unit and the third layer airbag unit, and inject gas with a pressure of P4 into the airbag unit.

[0021]

[0022] During the injection process, the submarine equipment accelerates to float up. When the third layer of airbag is filled with gas, the submarine equipment accelerates to float up to a safe speed v b , stop injecting gas into the airbag unit.

[0023] The buoyancy control mechanism also includes:

[0024] The shell has a bottom connected to the lower seabed equipment through a connecting claw;

[0025] An airbag mechanism is arranged on the top outer side of the shell;

[0026] The boost mechanism is disposed in a cavity inside the housing and includes a boost cylinder unit and a turbocharger unit; the boost cylinder unit includes a boost cylinder, a transmission motor, and a push block slidably disposed in the boost cylinder, one side of the push block being connected to the output shaft of the transmission motor, and the other side of the push block and the boost cylinder forming a boost chamber;

[0027] The turbocharger unit includes a first boost chamber and a pressurized chamber. The inlet of the first boost chamber is connected to the air tank, the outlet of the first boost chamber is connected to the inlet of the boost chamber through a first one-way valve, the inlet of the pressurized chamber is connected to the outlet of the boost chamber through a second one-way valve, and the outlet of the pressurized chamber is connected to the airbag mechanism through an automatic decompression valve. Turbines are respectively provided in the first boost chamber and the pressurized chamber, and the turbines are fixedly connected by a turbine connecting rod.

[0028] The outer side of the annular lower part of the airbag is covered with an airbag reel, one end of the airbag reel is fixedly connected to the airbag, and the other end of the airbag reel is connected to a reel controller, which is fixed on the airbag. The reel controller is used to adjust the length of the airbag reel covered on the outside of the airbag to adjust the inflation amount in the airbag.

[0029] In step S1,

[0030] When the submarine equipment is completely submerged in water, the 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 submarine equipment is released. When the second layer of airbags is emptied, the opening volume of the airbag mechanism is:

[0034]

[0035] Where ρ(z) represents the seawater density value that changes with the seawater depth, and g(z) represents the gravitational acceleration value that changes with the seawater depth;

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

[0037]

[0038] Where M represents the molar mass of the gas currently filled, ρ represents the density of the gas currently filled, R represents the molar gas constant, T represents the temperature inside the airbag in Kelvin, k is expressed as f(ρ(z),A), A represents the maximum cross-sectional area of the device, and ρ(z) represents the seawater density function that changes with the depth of the seawater.

[0039] ρ(z)=ρ0+4.80×10 -6 z,

[0040] Among them, ρ0=1.0278.

[0041] In step S3,

[0042] 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:

[0043]

[0044] In step S4,

[0045] The boost mechanism stops and the subsea equipment then moves at a safe speed v b It rises to the sea surface at a constant speed. During this process, the deflation of the self-monitoring pressure relief valve of the third-layer airbag unit ensures the safe use of the airbag mechanism.

[0046] The volume V1 of the first layer of airbags in the first layer of airbag units is

[0047]

[0048] The volume V2 of the second layer of airbags in the second layer of airbag units is

[0049]

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

[0051]

[0052] The beneficial effect of the present invention is that the present application can pressurize 5MPa gas to 40-50MPa high-pressure gas through a boosting mechanism. Therefore, during the process of raising and lowering the submarine equipment, it is only necessary to control the boosting mechanism to fill the airbag mechanism with high-pressure gas or to deflate the airbag mechanism according to the pressure of the external seawater to achieve automatic sinking and floating of the submarine equipment. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0054] Figure 2 It is a structural diagram of the floating and sinking control mechanism;

[0055] Figure 3 It is a structural diagram of the supercharging mechanism;

[0056] Figure 4 It is a structural diagram of the boost cylinder unit;

[0057] Figure 5 It is a structural diagram of a turbocharger unit;

[0058] In the figure: shell 1, airbag mechanism 2, boosting mechanism 3, connecting claw 4, first layer airbag unit 5, second layer airbag unit 6, third layer airbag unit 7, self-monitoring deflation valve 8, airbag reel 9, reel controller 10, boosting cylinder 11, transmission motor 12, push block 13, boosting chamber 14, crank block 15, push rod 16, turbine 17, turbine connecting rod 18, first boosting chamber 19, pressurized chamber 20, air storage tank 21, first one-way valve 22, second one-way valve 23, automatic decompression valve 24. DETAILED DESCRIPTION

[0059] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0060] The following description sets forth specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art will be able to make similar generalizations without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0061] The method for dynamic control of autonomous deployment and recovery of an offshore platform according to the present invention comprises the following steps. The working principle diagram of the three-layer airbag structure in the process is shown in FIG. Figure 1 shown.

[0062] In the first step, the seabed equipment is connected to the floating and sinking control mechanism, and the seabed equipment is lowered until it is completely immersed in the water. The floating and sinking control mechanism is used to put the seabed equipment in a floating state.

[0063] like Figure 2As shown, the buoyancy control mechanism includes a housing 1, an airbag mechanism 2, and a pressurizing mechanism 3. The pressurizing mechanism is fixed within the cavity of the housing 1. The airbag mechanism 2 is located on the top and outside of the housing 1. The pressurizing mechanism 3 is connected to the airbag mechanism 2 and provides high-pressure gas to the airbag mechanism through the pressurizing mechanism. A connecting claw 4 is provided at the bottom of the housing to connect the buoyancy control mechanism to the subsea equipment below.

[0064] The airbag mechanism comprises three airbag units, arranged sequentially from bottom to top: first-layer airbag unit 5, second-layer airbag unit 6, and third-layer 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 differential within the airbag in real time. When the valve detects that the pressure differential has reached a certain value, it automatically opens, deflating the airbag and ensuring it remains under a safe pressure. Furthermore, the deflation of the airbag by the self-monitoring deflation valve accelerates the sinking of subsea equipment.

[0065] An airbag reel 9 is also located outside the annular lower portion of the airbag, wrapping around the outer ring. One end of the reel is fixedly connected to the outer surface of the airbag, while the other end is housed within a reel controller 10, which is located on the outer surface of the airbag. The reel controller 10 adjusts the length of the reel 9, located outside the annular shape of the airbag, thereby adjusting the maximum inflation volume of the airbag.

[0066] Two adjacent airbags are connected by a connecting pipe, and an automatic switching valve is provided on the connecting pipe. The inflation control of each airbag is achieved through the automatic switching valve.

[0067] like Figures 3 to 5 As shown, the boost mechanism comprises a boost cylinder unit and a turbocharger unit. The boost cylinder unit includes a boost cylinder 11 and a transmission motor 12, which operates the boost cylinder. The boost cylinder 11 and the housing of the transmission motor 12 form a closed chamber. A push block 13 slides within the boost cylinder 11. One side of the push block 13 is connected to the output shaft of the transmission motor 12, while the other side of the push block 13 forms a boost chamber 14 with the cylinder body of the boost cylinder 11.

[0068] The output shaft of the transmission motor 12 is fixedly connected to one end of the crank block 15. The other end of the crank block 15 is hingedly connected to one end of a push rod 16, and the other end of the push rod 16 is hingedly connected to the side of the push block 13. Therefore, during the operation of the transmission motor 12, its output shaft rotates, which in turn drives the push block 13 through the crank block 15 and push rod 16 to reciprocate within the boost cylinder 11. The crank block 15 and push rod 16 convert the rotation of the output shaft into linear motion of the push block 13. As the push block 13 moves within the boost cylinder, it compresses the gas within the boost chamber 14, thereby increasing the pressure of the gas within the boost 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 disposed within a sealed boost chamber, which is independent and disconnected from each other. In this embodiment, the boost chambers are a first boost chamber 19 and a pressurized chamber 20. The inlet of the first boost chamber 19 is connected to a gas storage tank 21, and the outlet of the first boost chamber 19 is connected to the inlet of the boost chamber 14. A first one-way valve 22 is provided on the connecting pipe between the first boost chamber 19 and the boost chamber 14. This first one-way valve 22 ensures that gas within the first boost chamber 19 can only flow into the boost chamber 14. The inlet of the pressurized chamber is connected to the inlet of the boost chamber, and the outlet of the pressurized chamber is connected to the airbag mechanism. A second one-way valve 23 is provided on the connecting pipe between the pressurized chamber 20 and the boost chamber 14. This second one-way valve 23 ensures that gas within the boost chamber 14 can only flow into the pressurized chamber 20. An automatic pressure reducing valve 24 is provided on the connecting pipeline between the pressurizing chamber 20 and the airbag mechanism, and the pressure of the high-pressure gas outputted from the pressurizing chamber 20 is precisely adjusted by the automatic pressure reducing valve 24 .

[0070] Connect the buoyancy control mechanism to the subsea equipment below via the connecting claws 4 at its bottom, and drag the subsea equipment with the buoyancy control mechanism until it is completely submerged in the water. At this point, the automatic on-off valve between the first and second airbag units opens, and the pressurizing mechanism activates, 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 boosting mechanism, the gas tank 21 provides gas to the first boosting chamber 19, and the pressurized gas in the gas tank 21 directly rushes into the first boosting chamber 19. After the gas in the first boosting chamber 19 passes through the first one-way valve 22 and enters the boosting chamber 14 in the boosting cylinder 11, the transmission motor 12 is activated, and its output shaft rotates, and in turn drives the push block 13 to reciprocate in the boosting cylinder 11 through the crank block 15 and the push rod 16. During the reciprocating movement, the push block compresses the gas in the boosting chamber 14, thereby realizing the first pressurization of the gas.

[0072] After the gas after the first pressurization passes through the second one-way valve 23 and enters the pressurization chamber 20, 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 accelerate its rotation, thereby realizing the first pressurization of the gas entering the first pressurization chamber.

[0073] After the gas that has undergone the first boosting passes through the first one-way valve 22 and enters the boosting chamber 14 in the boosting cylinder 11, during the operation of the transmission motor 12 and the rotation of the output shaft of the transmission motor 12, the push block 13 is driven to reciprocate in the boosting cylinder 11 through the crank block 15 and the push rod 16 in sequence. During the reciprocating movement, the push block compresses the gas in the boosting chamber 14, thereby achieving the second boosting of the gas.

[0074] After the second boost, the gas passes through the second one-way valve 23 and enters the pressurized chamber 20. The pressurized gas drives the turbine in the pressurized chamber 20 to accelerate, which in turn drives the turbine in the first boost chamber to accelerate, thereby continuously boosting the gas entering the first boost chamber. After the gas in the first boost chamber enters the boost cylinder 11, the transmission motor 12 pushes the push block, causing the gas in the boost chamber 14 to be boosted a second time, thereby maintaining the continuous secondary boosting process of the gas entering the boost mechanism. After this secondary boosting process, the gas in the gas storage tank at a pressure of 5 MPa can be boosted to 45-50 MPa.

[0075] The high-pressure gas after secondary pressurization is reduced in pressure by the automatic pressure reducing valve and then supplied to the airbag mechanism and filled with gas with a constant pressure value of P1.

[0076] P1=0.75P m +P0,

[0077] After the first and second airbags are filled with gas, the entire device is in a floating state. In this application, the standard for the airbag to be full is when the pressure difference between the gas pressure inside the airbag detected by the self-monitoring deflation valve on the airbag and the external seawater pressure of the airbag reaches 0.75P m When P m The maximum pressure that the airbag can bear.

[0078] When the submarine equipment is completely submerged in water, the 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 is to release the subsea device while the second airbag slowly deflates. This process accelerates the entire device's descent, increasing its overall sinking speed. Once the second airbag is completely deflated, the device's sinking speed accelerates to a safe speed. The entire device then sinks steadily and evenly to the seafloor at a safe speed.

[0082] During the process of releasing the submarine equipment, the automatic switching valve between the first layer of airbags and the second layer of airbags is closed, and the self-monitoring pressure relief valve on the second layer of airbags is opened to deflate the second layer of airbags.

[0083] During the deflation process, the overall gravity on the device is greater than the buoyancy, and the device moves downward at an accelerated rate. The water resistance it encounters will also continue to increase as the sinking speed increases.

[0084] The water resistance of the entire device will continue to catch up with the difference between buoyancy and gravity, approaching a state of equilibrium. Since the overall buoyancy of the device is certain after deflation is completed, the difference between the overall buoyancy of the device and gravity after deflation is completed is also certain.

[0085] As the sinking speed of the submarine equipment increases, the water resistance of the equipment also increases. 阻 The formula is as follows:

[0086] F 阻 =kv1 2 ,

[0087] Where v1 represents the sinking speed of the submarine equipment underwater, k is expressed as f(ρ(z),A), A represents the maximum cross-sectional area of the equipment, and ρ(z) represents the seawater density function that changes with the depth of the seawater.

[0088] ρ(z)=ρ0+4.80×10 -6 z,

[0089] Among them, ρ0=1.0278.

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

[0091] F 阻 =f[ρ(z),A])v1 2 ,

[0092] As the water resistance increases, the entire device will eventually reach a limit speed, so that the water resistance, buoyancy and gravity of the device as a whole are balanced, that is:

[0093] F 浮 =GF 阻 .

[0094] The safe speed of sinking of submarine equipment is expressed as va. In this application, let v a = 0.8~1.2m / s. When the submarine equipment sinks steadily, the water resistance it encounters is:

[0095] F 阻 =f[ρ(z),A])v a 2 ,

[0096] When the water resistance, buoyancy and gravity of the device as a whole are in balance, the buoyancy provided by the buoyancy control mechanism is:

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

[0098] Among them, g(z) represents the value of gravity acceleration that changes with the depth of sea water,

[0099] g(z)=g0+2.40×10 -6 z.

[0100] Therefore, when the second layer of airbags 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 maximum magnitude of change of ρ(z) and g(z) is 10 -2 , compared to the values of ρ0 and g0, the change is very small. In addition, the airbag itself has a certain elasticity, so k can be expressed as a function constant f(ρ(z),A). Therefore, when the maximum cross-sectional area A of the device is determined, k is a fixed value. At this time, V 排2 Can be simplified to:

[0103]

[0104] During the deflation of the second layer of airbag, the self-monitoring deflation valve of this layer monitors the deflation volume. When the deflation volume detected by the self-monitoring deflation valve is zero, it means that the second layer of airbag is completely deflated. At this time, the submarine equipment accelerates to a safe speed v a , then the submarine equipment moves at a safe speed v a Sinking to the seabed at a constant speed.

[0105] Compared with the airbag deployment volume in the first step, the airbag deployment volume is reduced by

[0106]

[0107] From this we can get the volume V2 of the second layer airbag unit:

[0108]

[0109] Correspondingly, the volume V1 of the first layer of airbag unit can be obtained as

[0110]

[0111] During the release of the submarine equipment, as the water depth increases, the water pressure on the airbag mechanism gradually increases, and the gas pressure provided by the booster mechanism to the airbag mechanism should be increasingly greater. In this step, the gas pressure P2 provided by the booster mechanism to the airbag mechanism is:

[0112]

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

[0114] That is, during the release of the submarine equipment, the booster mechanism continuously inflates the airbag mechanism. As the submarine equipment sinks and the depth z of the submarine equipment in the water increases, the pressure of the air inflated by the booster mechanism into the airbag mechanism gradually increases.

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

[0116]

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

[0118] The inflation must reach the above flow rate to meet the condition that the gas pressure in the first layer of airbag is greater than the external seawater pressure on the airbag.

[0119] In the third step, after the subsea equipment has landed on the seabed and completed its operations, when it needs to surface, the automatic valve between the first and second airbags is opened, and pressurized gas at a constant pressure of P3 is supplied through the booster mechanism and injected into the airbag mechanism. Once the first and second airbags are filled with gas, the entire equipment is in a floating state.

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

[0121]

[0122] Among them, z m Indicates the deepest point of the submarine equipment, that is, the depth of the equipment's working seabed.

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

[0124]

[0125] Compared with the airbag opening volume of the airbag mechanism in the second step, the airbag opening volume in this step is increased by

[0126]

[0127] The fourth step is to open the automatic switch valve between the second-layer airbag unit and the third-layer airbag unit, slowly fill the third-layer airbag with gas, and provide pressurized gas with a pressure of P4 to the airbag mechanism through the booster mechanism. During the process of inflating the airbag mechanism, the submarine equipment as a whole continues to accelerate and float up, that is, the ascent speed of the submarine equipment gradually increases.

[0128] During the inflation process, the buoyancy of the device as a whole is greater than the gravity, and the device as a whole accelerates upward. The water resistance it encounters will also continue to increase as the upward speed increases.

[0129] The water resistance of the device as a whole will continue to catch up with the difference between buoyancy and gravity, approaching a state of equilibrium. Because the buoyancy after inflation is certain, the difference between the overall buoyancy and gravity of the device after inflation is also certain.

[0130] The inflation speed or flow rate will only affect the time to reach the above difference, and will not affect the set certain difference, so it is only necessary to ensure the safety of the airbag by not inflating too fast.

[0131] When the third layer of airbags is fully inflated, the subsea equipment's ascent speed accelerates to a safe speed. The subsea equipment then gradually and steadily ascends to the surface at a safe speed, achieving automatic recovery of the subsea equipment.

[0132] During the ascent of the submarine equipment, the booster 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 injected by the booster mechanism into the airbag mechanism gradually decreases. The gas pressure P4 provided by the booster mechanism to the airbag mechanism is:

[0133] As the overall floating speed of the submarine equipment increases, the water resistance of the equipment as a whole will also become greater and greater. The water resistance F 阻 The formula is as follows:

[0134] F 阻 '=kv2 2 ,

[0135] v2 represents the rising speed of the submarine equipment underwater, k is expressed as f(ρ(z),A), A represents the maximum cross-sectional area of the equipment, ρ(z) represents the seawater density function value that changes with the depth of the seawater. Therefore, when the maximum cross-sectional area A of the equipment is determined, k is a function of the depth z. Therefore,

[0136] F 阻 =f[ρ(z),A])v2 2 ,

[0137] As the water resistance increases, the entire device will eventually reach a limit speed, so that the water resistance, buoyancy and gravity of the device as a whole are balanced, that is:

[0138] F 浮 =G+F 阻 ,

[0139] The safe speed of the submarine equipment rising to the surface is expressed as v b In this application, let v b = 0.8~1.2m / s, so when the submarine equipment floats steadily, the water resistance it encounters is:

[0140] F 阻 =f[ρ(z),A])v b 2 ,

[0141] When the water resistance, buoyancy and gravity of the device as a whole are in balance, 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 layer of airbags is fully filled, 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 maximum magnitude of change of ρ(z) and g(z) is 10 -2 , compared to the values of ρ0 and g0, the change is very small. In addition, the airbag itself has a certain elasticity, so k can be expressed as a function constant f(ρ(z),A). Therefore, when the maximum cross-sectional area A of the device is determined, k is a fixed value. At this time, V 排4 Can be simplified to:

[0146]

[0147] When the third layer of airbag is filled with gas, the submarine equipment accelerates to a safe speed v b , the booster stops working. During the overall buoyancy 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 , which will cause danger to the airbag mechanism. At this time, the self-monitoring deflation valve on the third layer of airbag is opened to deflate the airbag mechanism to ensure the safety of the airbag mechanism during the ascent. Since the purpose of deflation is to reduce the pressure inside the airbag mechanism, the deflation volume in this process is small, and the opening volume of the airbag mechanism does not change, so the submarine equipment can ascend at a safe speed v b Rise to the sea surface at a constant speed.

[0148] Compared with the airbag opening volume in the third step, the airbag opening volume in this step is increased by

[0149]

[0150] From this, the volume V3 of the third layer airbag unit can be obtained as

[0151]

[0152] The above is a detailed introduction to the dynamic control method for autonomous deployment and recovery of marine platforms provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The above description of the disclosed embodiments enables professionals in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dynamic control method for autonomous deployment and recovery of an offshore platform, characterized in that: The following steps are involved: S1. Connect the subsea equipment to the buoyancy control mechanism, lower the subsea equipment until it is completely submerged in water, and place the subsea equipment in a floating state using the buoyancy control mechanism. The buoyancy control mechanism includes an airbag mechanism, which includes three airbag units, a first airbag unit, a second airbag unit, and a third airbag unit, arranged sequentially from bottom to top. Each airbag unit includes an airbag, each airbag is equipped with a self-monitoring air release valve, and the connecting pipes between adjacent airbags are equipped with an automatic switching valve. Open the automatic switch valve between the first layer airbag unit and the second layer airbag unit, and fill the first layer airbag unit and the second layer airbag unit of the airbag mechanism with a constant pressure value of P1 = 0.75P m +P0 gas, P m The maximum pressure that the airbag can bear; After the first airbag of the first airbag unit and the second airbag of the second airbag unit are filled with gas, the entire submarine equipment is in a floating state; S2. Release the submarine equipment and deflate the buoyancy control mechanism, accelerating the submarine equipment to sink to a safe speed. The submarine equipment then sinks to the seabed at a safe speed. Close the automatic switch valve between the first and second airbag units, open the self-monitoring pressure relief valve on the second airbag, and deflate the second airbag. During the deflation process, the submarine equipment sinks faster. When the second airbag is emptied, the submarine equipment accelerates to a safe speed v a , then the submarine equipment moves at a safe speed v a Sinking to the seabed at a constant speed; During the release of the submarine equipment, the airbag mechanism is always supplied with gas at a pressure of P2. in, It represents the actual latitude of the submarine equipment in the water, and z represents the depth of the equipment in the water; S3. After the submarine equipment completes its operation on the seabed, the submarine equipment is placed in a floating state through the floating and sinking control mechanism; When the submarine equipment needs to float up, the automatic switch valve between the first and second airbags is opened, and pressurized gas with a constant pressure value of P3 is injected into the first and second airbags of the airbag mechanism through the booster mechanism. Among them, z m Indicates the depth of the seabed where the submarine equipment works; After the first and second airbags are filled with gas, the entire device is in a floating state; S4. The buoyancy control mechanism drives the submarine equipment to accelerate upward. When the submarine equipment accelerates to a safe speed, the submarine equipment floats to the sea surface at a safe speed. Open the automatic switch valve between the second layer airbag unit and the third layer airbag unit, and inject gas with a pressure of P4 into the airbag unit. During the injection process, the submarine equipment accelerates to float up. When the third layer of airbag is filled with gas, the submarine equipment accelerates to float up to a safe speed v b , stop injecting gas into the airbag unit.

2. The method for dynamic control of autonomous deployment and recovery of an offshore platform according to claim 1, characterized in that: The buoyancy control mechanism also includes: The shell has a bottom connected to the lower seabed equipment through a connecting claw; An airbag mechanism is arranged on the top outer side of the shell; The boost mechanism is disposed in a cavity inside the housing and includes a boost cylinder unit and a turbocharger unit; the boost cylinder unit includes a boost cylinder, a transmission motor, and a push block slidably disposed in the boost cylinder, one side of the push block being connected to the output shaft of the transmission motor, and the other side of the push block and the boost cylinder forming a boost chamber; The turbocharger unit includes a first boost chamber and a pressurized chamber. The inlet of the first boost chamber is connected to the air tank, the outlet of the first boost chamber is connected to the inlet of the boost chamber through a first one-way valve, the inlet of the pressurized chamber is connected to the outlet of the boost chamber through a second one-way valve, and the outlet of the pressurized chamber is connected to the airbag mechanism through an automatic decompression valve. Turbines are respectively provided in the first boost chamber and the pressurized chamber, and the turbines are fixedly connected by a turbine connecting rod.

3. The method for dynamic control of autonomous deployment and recovery of an offshore platform according to claim 2, characterized in that: The outer side of the annular lower part of the airbag is covered with an airbag reel, one end of the airbag reel is fixedly connected to the airbag, and the other end of the airbag reel is connected to a reel controller, which is fixed on the airbag. The reel controller is used to adjust the length of the airbag reel covered on the outside of the airbag to adjust the inflation amount of the airbag.

4. The method for dynamic control of autonomous deployment and recovery of an offshore platform according to claim 1, characterized in that: In step S1, when the submarine equipment is completely submerged in water, the volume of the airbag in the airbag mechanism is: Where m represents the total weight of the buoyancy control mechanism and the seabed equipment, and ρ0 represents the density of the seawater surface.

5. The method for dynamic control of autonomous deployment and recovery of an offshore platform according to claim 1, characterized in that: In step S2, the submarine equipment is released. When the second layer of airbags is emptied, the opening volume of the airbag mechanism is: Where ρ(z) represents the seawater density value that changes with the seawater depth, and g(z) represents the gravitational acceleration value that changes with the seawater depth; The inflation flow Q from the booster mechanism to the airbag mechanism is: Where M represents the molar mass of the gas currently filled, ρ represents the density of the gas currently filled, R represents the molar gas constant, T represents the temperature inside the airbag in Kelvin, k is expressed as f(ρ(z),A), A represents the maximum cross-sectional area of the device, and ρ(z) represents the seawater density function that changes with the depth of the seawater. ρ(z)=ρ0+4.80×10 -6 z, Among them, ρ0=1.0278.

6. The method for dynamic control of autonomous deployment and recovery of an offshore platform 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 method for dynamic control of autonomous deployment and recovery of an offshore platform according to claim 1, characterized in that: In step S4, the booster stops and the subsea equipment moves at a safe speed v b It rises to the sea surface at a constant speed. During this process, the deflation of the self-monitoring pressure relief valve of the third-layer airbag unit ensures the safe use of the airbag mechanism.

8. The method for dynamic control of autonomous deployment and recovery of an offshore platform according to claim 1, characterized in that: The volume V1 of the first layer of airbags in the first layer of airbag units is The volume V2 of the second layer of airbags in the second layer of airbag units is The volume V3 of the third layer airbag in the third layer airbag unit is

Images