CN118794482A - A method for deploying and recovering a deep-sea bottom-mounted long-term in-situ monitoring device - Google Patents

Abstract

The invention relates to the technical field of deployment and recovery of a deep-sea bottom-sitting long-term in-situ monitoring device, in particular to a deployment and recovery method of the deep-sea bottom-sitting long-term in-situ monitoring device, which comprises the following steps: s100: determining the number of floating balls and the weight of the balancing weights in the arrangement and recovery device; s200: performing geophysical measurements on a target area; s300: the ship hoisting device and the winch steel cable are utilized to place the placing and recovering device on the water surface along with the monitoring device, and the unhooking device is utilized to disconnect the placing and recovering device from the winch steel cable; s400: the monitoring device starts monitoring; s500: after monitoring is completed, the vessel transmits an acoustic signal: the monitoring device disconnects the communication cable, discards the balancing weight, and the communication cable floats up to the water surface under the action of the floating force of the floating ball; s600, when the smoke and fire module at the lower end of the floating ball floats on the water surface, the smoke and fire module releases and emits smoke and fire for the ship to pursue the smoke and fire; s700: the ship determines the position of the monitoring device by means of the pyrotechnic signal and carries out recovery.

Description

A method for deploying and recovering a deep-sea bottom-mounted long-term in-situ monitoring device

Technical Field

The present invention relates to the technical field of deployment and recovery of a deep-sea bottom-mounted long-term in-situ monitoring device, and in particular to a deployment and recovery method of a deep-sea bottom-mounted long-term in-situ monitoring device.

Background Art

Deep-sea mining is the mining of mineral resources at the bottom of the deep sea. Due to the global population growth and accelerated industrialization, the demand for important metals such as copper, iron, manganese, and rare earth elements has increased dramatically. The depletion of terrestrial mineral resources and the increase in mining costs have prompted people to turn to the deep sea as a new source of resource supply. However, since the deep-sea ecosystem is one of the least known and most fragile ecosystems on Earth, deep-sea mining activities may have irreversible effects on these ecosystems, so long-term in-situ observations of the seabed environment of deep-sea mining are indispensable.

The deep-sea ecosystem in existing technologies is very complex and responds slowly. Long-term in-situ monitoring helps to understand the impact of mining activities on biodiversity, ecological structure and function, thereby tracking environmental changes and trends, reducing negative impacts on the environment, and achieving sustainable use of deep-sea resources. Long-term in-situ monitoring data collected before mining activities begin can serve as a benchmark for assessing mining impacts and become an important basis for whether mining activities can be carried out reasonably.

Before conducting long-term in-situ observations, it is necessary to consider how to reasonably deploy and recover in-situ monitoring devices. However, the current methods of deploying and recovering devices have certain defects and limitations. First, traditional deployment methods require crew members to perform more manual operations, including physically connecting and disconnecting devices, which not only increases the complexity and risk of operations, but also means higher labor costs; second, relying on manual marking (buoy markers) to recover devices may be limited by weather conditions and sea conditions, resulting in reduced recovery efficiency, especially in bad weather or at night; third, the lack of detailed topographic and geological assessments of the deployment area may result in the deployment of devices in inappropriate locations.

These problems will have a great impact on the deployment and recovery of long-term in-situ monitoring equipment, thereby increasing the risk of device damage and affecting the accuracy and reliability of data. Therefore, a new deployment and recovery device and method suitable for deep-sea mining bottom monitoring platforms are urgently needed to overcome the above problems and achieve higher accuracy, safety and efficiency in-situ monitoring.

Summary of the invention

One of the purposes of the present invention is to provide a method for deploying and recovering a deep-sea bottom-mounted long-term in-situ monitoring device to achieve in-situ monitoring with higher accuracy, safety and efficiency.

The technical solution of the present invention is as follows:

A method for deploying and recovering a deep-sea bottom-mounted long-term in-situ monitoring device comprises the following steps:

S100: Determine the number of floating balls and the weight of the counterweight in the deployment and recovery device;

S200: geophysical survey of the target area;

S300: placing the deployment and recovery device on the water surface along with the monitoring device using the lifting device and the winch cable of the vessel, and disconnecting the deployment and recovery device from the winch cable using the unhooking device;

S400: The monitoring device starts monitoring;

S500: After completing the monitoring, the vessel sends an acoustic signal: the monitoring device disconnects from the communication cable, discards the counterweight, and the communication cable floats up to the water surface under the buoyancy of the buoyant ball;

S600: The pyrotechnic module at the lower end of the buoy is disconnected when floating on the water surface, and the pyrotechnic module releases fireworks for the vessel to follow the fireworks;

S700: The vessel determines the location of the monitoring device through pyrotechnic signals and recovers it.

Furthermore, step S100 includes:

S110: Calculate the total weight _Gz of the monitoring device in water;

Including determining the length L of the communication cable and its underwater weight _Gt , the underwater weight _Gfz of the buoy, the number _N2 of cable clamps and their underwater weight _Gl , and the underwater weight Gx of all sensors, batteries, communication equipment, etc.;

S120: Calculate the required weight G _p of the counterweight in water, determine the expected sinking velocity V based on the total weight of the device in water and the anti-seismic requirements of the device when sitting on the bottom, and calculate the weight m _x of the counterweight that must be added;

S130: Determine the number of floating balls. According to the total weight of the device plus the counterweight, the buoyancy F _f of a single floating ball, calculate how much buoyancy is needed to make the device float back to the surface after releasing the counterweight, and determine the number of floating balls N ₁ ;

S140: Perform a water tank test, under controlled conditions, using actual floats and weights to test the sinking and floating of the device in a water tank or similar environment according to the calculated values;

Adjust the number of floats and the weight of the counterweight until the device sinks to the bottom as expected and returns to the surface after the counterweight is released, and re-determine the number of floats N _1-1 and the minimum counterweight mass m _x-1 .

S150: Safety factors are added during calculation and testing to account for possible uncertainties under actual conditions, such as changes in seawater density and the effects of deep-sea pressure.

Furthermore, the calculation formula for the number of floats _N1 in step S130 is:

N ₁ = F _fz /F _f ;

Where, F _fz is the total buoyancy of the floating ball (N);

_Ff is the buoyancy of a single float (N).

Furthermore, the calculation formula of the communication cable length L in step S110 is:

Where H is the vertical distance from the bottom when the equipment is deployed (m);

X is the estimated movement and distance of the vessel when deploying the equipment (m).

Furthermore, the calculation formula of the weight _Gp of the ballast block in water and the weight _{mx that} must be added in step S120 is:

Where, f is the resistance of the monitoring device (N);

G _z is the total weight of the monitoring device in water (N);

F is the buoyancy of the monitoring device in water (N);

A is the resistance area (m2);

V is the settling velocity of the monitoring device in water (m/s);

_Fp is the buoyancy of the weight in water (N);

Empirical values: c=0.85, ρ=1020kg/m3, g=9.8 (N/kg).

Furthermore, step S500 includes:

S510: Sending acoustic signals: After the monitoring mission is completed, the vessel sends acoustic signals through dedicated equipment to trigger the recovery procedure of the monitoring device.

S520: The releaser module responds. After receiving the acoustic release command, the releaser module opens the mechanism connected to the communication cable or the counterweight, disconnects the communication cable and discards the counterweight.

S530: Cable clamp falls off: As the counterweight is detached from the communication cable, the fuses in the cable clamp that originally fixed the communication cable are disconnected in sequence according to the command after receiving the signal, and the cable clamp falls off or unlocks in sequence from top to bottom and from right to left, thereby releasing the communication cable.

S540: The buoy rises. After losing the restraint of the counterweight, the buoy connected to one end of the communication cable drives the communication cable and the monitoring device to float from underwater to the surface with the help of its own buoyancy.

Furthermore, the deployment and recovery device includes a float, an ultra-short baseline beacon, a communication cable, a pyrotechnic module, an acoustic releaser and a counterweight;

The pyrotechnic module and the ultra-short baseline beacon are installed on the lower side of the floating ball, and the two ends of the communication cable are respectively connected to the floating ball and the monitoring device. The monitoring device includes a releaser module, and the releaser module is connected to the counterweight block.

Further, the communication cable includes an electric wire and a Kevlar cable, and the Kevlar cable is located outside the electric wire;

The communication cable is wound into an "S"-shaped structure and is fixed by a cable clamp with an electrically controlled release function for the communication cable.

The working principle and beneficial effects of the present invention are:

Compared with the prior art, the present invention improves the efficiency and reliability of long-term in-situ monitoring tasks through the reasonable deployment and recovery of deep-sea mining equipment, thus making up for the shortcomings of existing deployment and recovery methods. Starting from determining the counterweight block and the float, the present invention establishes a deployment and recovery device and method suitable for the bottom monitoring platform of deep-sea mining by performing geophysical measurement, deployment, and recovery of the target area. It is worth noting that this method not only improves the accuracy and safety of the equipment deployment position, but also makes the recovery of the equipment simpler and more reliable. The establishment of the present invention will provide more accurate ideas and methods for the deployment and recovery of deep-sea mining in-situ devices. .

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG1 is an overall schematic diagram of a deployment and recovery device in this embodiment;

FIG2 is a schematic diagram of the process of deploying the monitoring device in this embodiment;

FIG3 is a schematic diagram of a process for recovering the monitoring device in this embodiment;

FIG4 is a schematic diagram of the structure of the fireworks module in this embodiment;

FIG5 is a schematic diagram of the circuit breaking process of the pyrotechnic module in this embodiment;

FIG. 6 is a schematic structural diagram of the cable clamp in this embodiment.

In the figure: 1. Float; 2. Ultra-short baseline beacon; 3. Fireworks module; 4. Communication cable; 5. Monitoring device; 6. Cable clamp.

DETAILED DESCRIPTION

The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

As shown in FIG1 , a method for deploying and recovering a deep-sea bottom-mounted long-term in-situ monitoring device 5 comprises the following steps:

S100: Determine the number of floating balls 1 and the weight of the counterweight in the deployment and recovery device in the laboratory. The weight of the counterweight should be sufficient to ensure that the monitoring device 5 can sink to the bottom of the sea as a whole. The number of floating balls 1 should be sufficient to ensure that after the releaser module discards the counterweight, the floating balls 1 can float to the surface when connected to the monitoring device 5;

Specifically, step S100 includes:

S110: Calculate the total weight _Gz of the monitoring device 5 in water;

Including determining the length L and underwater weight _Gt of the communication cable 4, the underwater weight _Gfz of the float 1, the number _N2 of cable clamps 6 and their underwater weight _Gl , and the underwater weight Gx of all sensors, batteries, communication equipment, etc.;

The calculation formula of the length L of the communication cable 4 in step S110 is:

Where H is the vertical distance from the bottom when the equipment is deployed (m);

X is the estimated movement and distance of the vessel when deploying the equipment (m).

The above formula determines the length L of the communication cable, which can ensure that the device can be quickly and reasonably deployed and recovered and avoid waste of resources.

S120: Calculate the required weight G _p of the ballast block in water, determine the expected sinking speed V based on the total weight of the device in water and the anti-seismic requirements of the device when sitting on the bottom, and calculate the weight m _x that must be added to ensure that the device can overcome the buoyancy of water and sink to the seabed;

The calculation formula for the weight _Gp of the counterweight block in water and the required counterweight _mx in step S120 is:

The calculation formula is based on the falling speed V of the object in water and the resistance f:

Obtain the total weight _Gz of the monitoring device in water:

Obtain the weight _Gp of the counterweight in water, the total weight _Gz of the monitoring device in water minus the weight _Gt , _Gfz , _Gl and _Gx of the communication cable, float, cable clamp and other equipment in water except the counterweight:

To obtain the required counterweight m _x, the following conditions must be met:

Where, f is the resistance of the monitoring device 5 (N);

G _z is the total weight of the monitoring device 5 in water (N);

F is the buoyancy of the monitoring device 5 in water (N);

A is the resistance area (m ² );

V is the settling velocity of the monitoring device 5 in water (m/s);

_Fp is the buoyancy of the weight in water (N);

Empirical values: c=0.85, ρ=1020kg/m3, g=9.8 (N/kg).

The above formula determines the weight _Gp of the ballast block in water and the ballast weight _{mx that} must be added to ensure that the monitoring device can safely sit on the bottom.

S130: Determine the number of floating balls 1, and calculate the buoyancy F _f of a single floating ball 1 according to the total weight of the device plus the counterweight block, and the buoyancy required to make the device float back to the water surface after releasing the counterweight block, and determine the number N ₁ of the floating balls 1;

The calculation formula of the number of float balls _N1 in step S130 is:

N ₁ = F _fz /F _f ;

Where, F _fz is the total buoyancy of the floating ball (N);

_Ff is the buoyancy of a single float (N).

The above formula determines the number of floating balls N ₁ to ensure that when the monitoring device is recovered, the floating balls can pull the monitoring device to the water surface through buoyancy.

S140: Perform a water pool test, under controlled conditions, use the actual float 1 and the counterweight block to test the sinking and floating of the device in a water pool or similar environment according to the calculated values;

Adjust the number of floats 1 and the weight of the counterweight until the device can sink to the bottom as expected and return to the water surface after the counterweight is released, and determine the number of floats 1 N _1-1 and the minimum counterweight mass m _x-1 again.

S150: Safety factors are added during calculation and testing to account for possible uncertainties under actual conditions, such as changes in seawater density and the effects of deep-sea pressure.

S200: Conduct geophysical surveys of the target area to ensure that the deployment can be carried out at locations with flat terrain, uniform bottom and stable strata;

S300: placing the deployment and recovery device on the water surface along with the monitoring device 5 by using the lifting device and the winch cable of the vessel, and disconnecting the deployment and recovery device from the winch cable by using the unhooking device;

The monitoring device 5 falls slowly as a whole until it touches the bottom, and the communication cable 4 should be in a vertical state under the action of the float 1.

S400: The monitoring device 5 starts monitoring;

S500: After the monitoring is completed, the ship sends an acoustic signal: after receiving the release command, the releaser module disconnects from the communication cable 4, thereby discarding the counterweight, and the monitoring device 5 floats up to the water surface along with the communication cable 4 under the buoyancy of the buoy 1;

At the same time, after receiving the signal, the cable clamps 6 fall off from top to bottom in sequence.

Specifically, step S500 includes:

S510: Sending an acoustic signal: After the monitoring task is completed, the vessel sends an acoustic signal through a dedicated device, and after the acoustic receiving module on the monitoring device 5 receives the acoustic signal, the recovery procedure of the monitoring device 5 is triggered.

S520: The releaser module responds. After receiving the acoustic release command, the releaser module responds to open the mechanism connected to the communication cable 4 or the counterweight (such as an electrically controlled underwater automatic unhooking device, a clamp, or other electrically controlled connecting devices), disconnects from the communication cable 4, and discards the counterweight.

In this embodiment, the electric control connection device is installed on the counterweight by default, and then connected to the connection piece (such as a connection ring) on the communication cable 4.

S530: The cable clamp 6 falls off: As the counterweight block detaches from the communication cable 4, the fuse in the cable clamp 6 that originally fixed the communication cable 4 is disconnected in sequence according to the instruction after receiving the signal, and the cable clamp 6 falls off or unlocks in sequence from top to bottom and from right to left, thereby releasing the wound communication cable 4.

The cable clamp 6 in this embodiment can adopt a structure of two clamps to clamp the wound communication cable 4. The two clamps can be bound by a fuse, and then the fuse is electrically connected to the fuse circuit. When the clamps need to be disconnected, the fuse is directly blown by an electrical signal. Or other electric control clamping devices that can be used underwater can be used to clamp and fix the communication cable 4, which will not be described in detail in this embodiment. The number of clamps of the cable clamp 6 can be set according to needs.

S540: The buoy 1 floats up. After losing the restraint of the counterweight, the buoy 1 connected to one end of the communication cable 4 drives the communication cable 4 and the monitoring device 5 to float up from underwater to the surface of the water by virtue of its own buoyancy.

S600: The pyrotechnic module 3 at the lower end of the buoy 1 is disconnected when the buoy 1 floats to the surface of the water, and the pyrotechnic module 3 releases fireworks toward the water surface for the vessel to follow the fireworks;

S700: The ship determines and tracks the location of the monitoring device 5 through fireworks signals, connects one end of the communication cable 4 connected to the buoy 1 to the ship, and uses a lifting device to recover the monitoring device.

In addition, in order to cooperate with the above method, the deployment and recovery device in this embodiment should at least include a floating ball 1, an ultra-short baseline beacon 2, a communication cable 4, a pyrotechnic module 3, an acoustic releaser and a counterweight;

The pyrotechnic module 3 and the ultra-short baseline beacon 2 (which can be electrically connected to the monitoring device 5) are installed on the lower side or side of the float 1. The pyrotechnic module 3 can be controlled and release fireworks by the monitoring device 5 through wired or wireless communication. It can also be closed underwater through its own circuit design, disconnected when the float 1 comes out of water, and then release fireworks. This embodiment will not be repeated here.

The two ends of the communication cable 4 are respectively connected to the float 1 and the monitoring device 5 (or it can be understood that the monitoring device 5 is fixed on the communication cable 4). The monitoring device 5 includes a releaser module for connecting or disconnecting the counterweight.

Since the communication cable 4 is separated from the counterweight in this embodiment, it is mainly to allow the communication cable 4 to float and straighten under the drive of the float 1. In order to facilitate the recovery of the counterweight, one end of the communication cable 4 can be always connected to the counterweight. The releaser module is mainly used to prevent the communication cable 4 from being stretched and floating. Therefore, the releaser module is fixed in the middle of the communication cable 4, and moves to the lower part to connect with the counterweight through the winding of the communication cable 4. After the releaser module releases the counterweight, it does not affect the connection between the end of the communication cable 4 and the counterweight.

The communication cable 4 includes electric wires and Kevlar cables. The Kevlar cables are high in strength and corrosion-resistant. They are located outside the electric wires and can protect the electric wires underwater. They are also lightweight and easy to carry.

In addition, in this embodiment, the communication cable 4 is wound into an "S"-shaped structure, which can reduce the length of the communication cable 4 during deployment to facilitate deployment, and then is fixed by a cable clamp 6 with an electrically controlled release function of the communication cable 4. When it is recovered, it is easy to release the communication cable 4, allowing the communication cable 4 to stretch and the buoy 1 to float to the surface.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. The deployment and recovery method of the deep sea bottom-sitting long-term in-situ monitoring device (5) is characterized by comprising the following steps:

S100: determining the number of floating balls (1) and the weight of the balancing weights in the arrangement and recovery device;

s200: performing geophysical measurements on a target area;

s300: the ship hoisting device and the winch steel cable are utilized to place the placing and recovering device on the water surface along with the monitoring device (5), and the unhooking device is utilized to disconnect the placing and recovering device from the winch steel cable;

s400: the monitoring device (5) starts monitoring;

s500: after monitoring is completed, the vessel transmits an acoustic signal: the monitoring device (5) disconnects the communication cable (4), discards the balancing weight, and the communication cable (4) floats up to the water surface under the action of the floating force of the floating ball (1);

S600, when the smoke and fire module (3) at the lower end of the floating ball (1) floats on the water surface, the smoke and fire module (3) releases and emits smoke and fire, so that a ship can track the smoke and fire;

S700: the ship determines the position of the monitoring device (5) by means of pyrotechnic signals and carries out recovery.

2. A deployment and retrieval method of a deep sea bottoming long term in situ monitoring device (5) according to claim 1, wherein step S100 comprises:

s110: calculating the total weight G _z of the monitoring device (5) in water;

the method comprises the steps of determining the length L of a communication cable (4) and the weight G _t in water, the weight G _fz in water of a floating ball (1), the number N ₂ of cable clamps (6) and the weight G _l in water, and the weight Gx in water of all sensors, batteries, communication equipment and the like;

S120: calculating the required weight G _p in the water of the balancing weight, determining the expected sedimentation velocity V based on the total weight of the device in the water and the anti-seismic requirement of the bottom of the device, and calculating the weight m _x which needs to be added;

s130: determining the number of floating balls (1), and according to the total weight of the device and the balancing weight, calculating the buoyancy force F _f of a single floating ball (1) to enable the device to float to a water surface after releasing the balancing weight, and determining the number N ₁ of the floating balls (1);

s140: under the control condition, carrying out sink and float tests on the device in a pool or similar environment by using an actual floating ball (1) and a balancing weight according to the calculated value;

The number of floating balls (1) and the weight of the balancing weights are adjusted until the device can sink to the bottom as expected and return to the water surface after the balancing weights are released, and the number N _1-1 of the floating balls (1) and the minimum weight m _x-1 of the balancing weights are determined again.

S150: safety factors are added in the calculation and test processes to cope with uncertainties which can occur under practical conditions, such as sea water density change and deep sea pressure influence.

3. The deployment and recovery method of the deep sea bottom-sitting long-term in-situ monitoring device (5) according to claim 2, wherein the calculation formula of the number of floating balls N ₁ in step S130 is as follows:

N₁＝F_fz/F_f；

Wherein F _fz is the total floating force (N) of the floating ball;

f _f is the single float upward buoyancy (N).

4. The deployment and retrieval method of the deep sea bottoming long-term in-situ monitoring device (5) according to claim 2, wherein the calculation formula of the length L of the communication cable (4) in step S110:

Wherein H is the vertical distance (m) from the bottom when the equipment starts to be placed;

X is the expected movement and distance (m) of the vessel when the device is deployed.

5. The deployment and recovery method of the deep sea bottom-supported long-term in-situ monitoring device (5) according to claim 2, wherein the calculation formula of the weight G _p of the balancing weight in water and the weight m _x to be added in step S120 is as follows:

Wherein f is the resistance (N) of the monitoring device (5);

G _z is the total weight (N) of the monitoring device (5) in water;

F is the buoyancy (N) of the monitoring device (5) in the water;

A is the resistance area (m 2);

v is the sedimentation velocity (m/s) of the monitoring device (5) in water;

f _p is the buoyancy (N) of the balancing weight in water;

empirical values: c=0.85, ρ=1020 kg/m3, g=9.8 (N/kg).

6. The deployment and retrieval method of a deep sea bottoming long term in situ monitoring device (5) according to claim 1, wherein step S500 comprises:

s510: transmitting an acoustic signal: after the monitoring task is completed, the ship sends an acoustic signal through a special device to trigger the recovery procedure of the monitoring device (5).

S520: and the releaser module responds to the mechanism for connecting the communication cable (4) or the balancing weight is opened after receiving the acoustic release instruction, the connection with the communication cable (4) is disconnected, and the balancing weight is discarded.

S530: the cable clamp (6) falls off: along with the balancing weight separating from the communication cable (4), the fusible link in the cable clamp (6) originally fixing the communication cable (4) is sequentially disconnected according to the instruction after receiving the signal, and the cable clamp (6) is sequentially separated or unlocked from top to bottom and from right to left, so that the communication cable (4) is released.

S540: the floating ball (1) floats upwards, and after the constraint of the balancing weight is lost, the floating ball (1) connected with one end of the communication cable (4) drives the communication cable (4) and the monitoring device (5) to float to the water surface from the water under the action of the self buoyancy.

7. The deployment and retrieval method of a deep sea bottoming long-term in-situ monitoring device (5) according to claim 1, wherein the deployment and retrieval device comprises a floating ball (1), an ultra-short baseline beacon (2), a communication cable (4), a pyrotechnic module (3), an acoustic releaser and a counterweight;

The smoke and fire module (3) and the ultrashort baseline beacon (2) are arranged on the lower side of the floating ball (1), the two ends of the communication cable (4) are respectively connected with the floating ball (1) and the monitoring device (5), the monitoring device (5) comprises a releaser module, and the releaser module is connected with the balancing weight.

8. The deployment and retrieval method of a deep sea bottoming long-term in-situ monitoring device (5) according to claim 7, wherein the communication cable (4) comprises an electric wire and a kevlar cable, and the kevlar cable is positioned outside the electric wire;

And the communication cable (4) is wound into an S-shaped structure and is fixed by a cable clamp (6) with the function of electrically releasing the communication cable (4).