CN114459818B - Active liquid accurate compensation device and method for deep sea pressure maintaining sampler - Google Patents

Abstract

The present invention relates to pressure compensation technology for pressure-maintaining sampling, and aims to provide an active liquid precision compensation device and method for a deep-sea pressure-maintaining sampler. The device includes a mechanical transmission system, a hydraulic system and a control system; the mechanical transmission system includes at least three sets of driving mechanisms, which are composed of motors, reduction gearboxes and screw nut assemblies. The hydraulic system includes a number matching the screw nut assemblies. A piston boosting cylinder, and the pistons in each boosting cylinder have different radial sizes; one side of the piston is connected to seawater, and the other side is connected to the sampler cavity through a pressure tube to maintain pressure; the control system includes a single-chip microcomputer and Pressure Sensor. The invention solves the problems of slow compensation speed, low accuracy and poor safety using the gas accumulator pressure compensation method, and can provide a reference basis for the design of the pressure compensation device method of the deep-sea pressure maintaining sampler, and is used for various pressure compensation in different environments. Design and in-depth research on pressure compensation methods for similar vessels.

Description

Active liquid precision compensation device and method for deep sea pressure maintaining sampler

Technical field

The invention relates to pressure compensation technology for pressure-maintaining sampling, and in particular to an active liquid accurate compensation device and method for a pressure-maintaining sampler in a deep-sea high-pressure environment.

Background technique

During the recovery process of the sampler from the deep sea, the internal pressure of the sampler will decrease due to pressure difference changes, temperature changes, sample leakage and other reasons. Pressure changes may cause deep-sea organisms to become inactivated or even damaged due to drastic changes in their living environment. Therefore, pressure-maintaining sampling technology is an indispensable technology in seabed sampling technology.

In current sampling devices, passive or active pressure compensation technology in which gas accumulators are precharged with high-pressure gas is usually used. However, the extremely high pressure of the deep sea environment will reduce the available fluid volume of the gas, resulting in a slow compensation speed. The process of pressure compensation is difficult to control, has low accuracy, and reduces safety.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide an active liquid precision compensation device and method for a deep-sea pressure-maintaining sampler.

In order to solve the technical problem, the solution of the present invention is:

Provide an active liquid precision compensation device for a deep-sea pressure-maintaining sampler, including a mechanical transmission system, a hydraulic system and a control system; wherein the mechanical transmission system includes at least three sets of driving mechanisms, and the driving mechanism consists of a motor, a reduction gearbox and a wire The rod nut assembly is used to convert the rotation of the motor into the axial displacement of the screw; the hydraulic system includes a number of booster cylinders matching the screw nut assembly; a piston is provided in the chamber of the booster cylinder. And the pistons in each booster cylinder have different radial sizes; one end of the piston is equipped with a piston rod, which is connected to the corresponding screw rod; there is a clearance fit between the piston rod and the cylinder body of the booster cylinder, and seawater can enter the piston. The chamber on one side of the rod; the other side of the piston is a closed chamber, which is connected to the sampler cavity through a pressure tube to maintain pressure; the control system includes a single-chip microcomputer and a pressure sensor, and the pressure sensor is located on the sampler cavity It is used to detect its internal pressure. The microcontroller connects the pressure sensor and each motor in the mechanical transmission system through signal lines to achieve control; the power supply is connected to the microcontroller and each motor in the mechanical transmission system through cables to achieve power supply.

As a preferred solution of the present invention, the mechanical transmission system, hydraulic system and single-chip microcomputer are packaged in a pressure-maintaining sealed cavity, and a watertight plug-in interface is provided on the cavity; the cable connecting to the power supply and the signal line connecting the pressure sensor , respectively connected to the pressure-maintaining sealing chamber through watertight connectors.

As a preferred solution of the present invention, the device further includes a remote computer or a local start switch connected to the microcontroller through a signal line.

As a preferred solution of the present invention, the power source is a battery provided locally in the sampling device, or a power supply equipment provided on the mother ship.

As a preferred solution of the present invention, the motor has a power interface and a speed controller, the former is connected to the power supply through a cable, and the latter is connected to the microcontroller through a signal line.

As a preferred solution of the present invention, there are three booster cylinders, and the radial dimensions of their pistons are 40mm, 30mm, and 20mm respectively.

As a preferred solution of the present invention, the measurement range of the pressure sensor is 0-120MPa, and the pressure measurement accuracy is 0.01MPa.

As a preferred solution of the present invention, the microcontroller is an STM32 microcontroller.

As a preferred solution of the present invention, the boosting cylinder includes a cylinder body, a cylinder head and a piston; the piston is installed in the cylinder body with openings at both ends, and the end of its piston rod is fixedly connected to the end of the screw rod in the driving mechanism. The cylinder head is screwed to the end of the cylinder opposite the piston rod; annular grooves are set on the side walls of the piston and cylinder head, and O-rings are embedded in the grooves to achieve sealing; the cylinder head is screwed The pipe joint is fixedly installed in the connection method, and is provided with a through hole that penetrates the pipe joint and the cylinder head; one end of the pressure tube is connected to the sampler cavity, and the other end is connected to the pipe joint, and is connected to the pipe joint through the through hole on the cylinder head. The cylinders are connected.

The present invention further provides a method for realizing active liquid precision compensation of a deep-sea pressure-maintaining sampler based on the aforementioned device, which includes the following steps:

(1) Use an underwater robot to lower the sampler to a deep-sea sampling point with a specified water depth, and perform the sampling operation according to the regular process; after the sampling is completed, the sampler cavity and the pressurized cylinder cavity on the side of the piston rod are filled with high-pressure seawater, so that The pressure on both sides of the piston remains balanced;

(2) Before recovering the sampler, use a remote computer or a local start switch to activate the microcontroller; use a pressure sensor to measure the in-situ pressure value of the sampling point, transmit the data to the microcontroller and record it as the reference pressure _Pref ;

(3) During the sampler recovery process, the pressure sensor continuously detects the real-time pressure value P of the sampler cavity and transmits it to the microcontroller; the microcontroller calculates the difference PP _ref between the real-time pressure value and the reference pressure, and activates it according to the difference. Different levels of boosting cylinders; when the difference is large, it is preferred to use a boosting cylinder with a larger piston radial size to reduce the pressure difference as quickly as possible; when the difference is small, it is preferred to use a boosting cylinder with a small piston radial size to achieve precise adjustment;

(4) During the adjustment process, the microcontroller performs PID control based on the difference between the real-time pressure value and the reference pressure to obtain the motor speed based on the current difference; the selected motor drives the screw nut assembly to drive the corresponding piston for linear displacement movement , driving the high-pressure liquid on the other side of the piston to move into the sampler cavity through the pressure tube, so that the pressure loss in the sampler cavity due to the increase in water depth is compensated;

(5) Repeat steps (3) and (4) during the process of recovering the sampler, so that the pressure in the sampler cavity is always maintained near the reference pressure.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention proposes an active liquid precision compensation device and method for a deep-sea pressure maintaining sampler, which solves the problems of slow compensation speed, low accuracy, and poor safety using a gas accumulator pressure compensation method, and can achieve deep-sea maintenance. Provide a reference basis for the method design of the pressure compensation device of the pressure sampler.

(2) The active liquid precise pressure compensation method provided by the present invention specifically includes the acquisition of pressure difference, the setting of multi-stage boosting cylinders and the setting of the hydraulic rod movement speed; therefore, it can be used to control various types of pressure in different environments. Design and in-depth study of vessel pressure compensation methods.

Description of the drawings

Figure 1 is a schematic diagram of the present invention;

Figure 2 is the mechanical structure diagram of a single booster cylinder;

Figure 3 is a mechanical structural diagram of a multi-stage booster cylinder.

In the picture: 1 remote computer; 2 power supply; 3 motor; 4 reduction gearbox; 5 screw nut assembly; 6 third-stage booster cylinder; 7 second-stage booster cylinder; 8 first-stage booster cylinder; 9 sampler Cavity; 10 pressure sensor; 11 microcontroller; 12 pressure tube; 13 pipe joint; 14 cylinder head; 15 first O-ring seal; 16 cylinder block; 17 second O-ring seal; 18 piston rod; 19 annular concave Groove; 20 booster cylinder cavity; 21 first threaded hole; 22 second threaded hole.

Detailed ways

The following examples can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way.

The serial numbers assigned to components in this application, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The terms "connection" and "connection" mentioned in this application include direct and indirect connections (connections) unless otherwise specified. In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", The orientations or positional relationships indicated by "bottom", "inside", "outer", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. , rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be construed as a limitation on the present application.

In this application, unless otherwise expressly stated and limited, a first feature being "on" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. touch. Furthermore, the terms "above", "above" and "above" the first feature is above the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "below" and "beneath" the first feature to the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

In the present invention, the power supply, control computer, motor, reduction gearbox, screw nut driving mechanism, O-ring seal, pressure sensor, STM32 microcontroller, pressure tube, and pipe joints can be purchased from commercially available products. Components such as the three-stage booster cylinder can be processed according to actual needs.

As shown in the figure, the active liquid precision compensation device used in the deep sea pressure maintaining sampler in the present invention includes a mechanical transmission system, a hydraulic system and a control system; wherein,

The mechanical transmission system includes three sets of driving mechanisms. The driving mechanism is composed of a motor 3, a reduction box 4 and a screw nut assembly 5. It is used to convert the rotation of the motor 3 into the axial displacement of the screw; the motor 11 has a power interface and Speed controller, the former is connected to the power supply 2 through a cable, and the latter is connected to the microcontroller 11 through a signal line.

The hydraulic system includes a number of boosting cylinders matching the screw nut assembly 5; a piston is provided in the chamber of the boosting cylinder, and the pistons in each boosting cylinder have different radial sizes, as shown in Figure 1, The radial dimensions of the pistons in the third-stage boosting cylinder 6, the second-stage boosting cylinder 7, and the first-stage boosting cylinder 8 are successively reduced. A piston rod 18 is provided at one end of the piston, and the piston rod 18 is connected to the corresponding screw rod; there is a clearance fit between the piston rod 18 and the cylinder 16 of the booster cylinder, and it is ensured that seawater can enter the chamber on one side of the piston rod 18; The other side of the piston is a closed chamber, which is connected to the sampler chamber 9 through a pressure tube for maintaining pressure. The boosting cylinder includes a cylinder 16, a cylinder head 14 and a piston; the piston is installed in the cylinder 16 with openings at both ends, the end of the piston rod is fixedly connected to the end of the screw rod in the driving mechanism, and the cylinder head 14 is screwed Fixed on one end of the cylinder 16 opposite to the piston rod 18; an annular groove is provided on the side wall of the piston and the cylinder head 14, and an O-ring is embedded in the groove to achieve sealing; screwed on the cylinder head 14 The pipe joint 13 is fixedly installed, and is provided with a through hole that penetrates the pipe joint 13 and the cylinder head 14; one end of the pressure pipe 12 is connected to the sampler cavity 9, and the other end is connected to the pipe joint 13, and passes through the cylinder head 14 The through hole is connected with the cylinder 16.

The control system includes a single-chip computer 11 and a pressure sensor 10. The pressure sensor 10 is installed on the sampler cavity 9 to detect its internal pressure. The single-chip computer 11 connects the pressure sensor 10 and each motor 3 in the mechanical transmission system through signal lines to achieve control; The microcontroller 11 is also connected to the remote computer 1 or the local start switch provided on the sampling device through a signal line.

The power supply 2 is connected to the microcontroller 11 and each motor 3 in the mechanical transmission system through cables to achieve power supply. The power supply 1 may be a battery located locally on the sampling device, or a power supply equipment located on the mother ship.

In order to adapt to the deep sea high-pressure environment, the mechanical transmission system, hydraulic system and single-chip microcomputer 11 are packaged in a pressure-maintaining sealed cavity, and a watertight plug-in interface is provided on the cavity; the cable connected to the power supply 2 and the signal line connected to the pressure sensor 10 are respectively It is connected to the pressure-maintaining sealing chamber through a watertight plug-in connector. The remote computer 1 can be installed on the mother ship and connected to the pressure-maintaining sealed chamber through a submarine cable; the local start switch can be directly embedded on the outer wall of the pressure-maintaining sealed chamber, and can be opened and closed by the manipulator touch of the underwater robot.

The method of using this device to achieve active liquid precision compensation of a deep-sea pressure-maintaining sampler includes the following steps:

(1) Use an underwater robot to lower the sampler to a deep-sea sampling point with a specified water depth, and perform the sampling operation according to the regular process; after the sampling is completed, the sampler cavity 9 and the pressurized cylinder cavity on the side of the piston rod 18 are filled with high-pressure seawater , to keep the pressure on both sides of the piston balanced;

(2) Before recovering the sampler, use the remote computer 1 or the local start switch to activate the microcontroller 11; use the pressure sensor 10 to measure the in-situ pressure value of the sampling point, transmit the data to the microcontroller 11 and record it as the reference pressure _Pref ;

(3) During the sampler recovery process, the pressure sensor 10 continuously detects the real-time pressure value P of the sampler cavity 9 and transmits it to the single-chip computer 11; the single-chip computer 11 calculates the difference PP _ref between the real-time pressure value and the reference pressure, and calculates the difference based on the difference. Different levels of boosting cylinders are activated for different values; when the difference is large, it is preferred to activate a boosting cylinder with a larger piston radial size to reduce the pressure difference as quickly as possible; when the difference is small, it is preferred to activate a boosting cylinder with a small piston radial size to reduce the pressure difference as quickly as possible; when the difference is small, it is preferred to activate a boosting cylinder with a small piston radial size Achieve precise adjustment;

(4) During the adjustment process, the microcontroller 11 performs PID control based on the difference between the real-time pressure value and the reference pressure to obtain the motor speed based on the current difference; the selected motor 3 drives the screw nut assembly 5 to drive the corresponding piston. The linear displacement movement drives the high-pressure liquid on the other side of the piston to move into the sampler cavity 9 through the pressure tube 12, so that the pressure loss in the sampler cavity 9 due to the reduction of water depth is compensated;

(5) Repeat steps (3) and (4) during the process of recovering the sampler, so that the pressure in the sampler cavity 9 is always maintained near the reference pressure.

A more detailed implementation example is described below:

As shown in Figures 1 to 3, the screw nut driving mechanism 5 includes three sets of driving mechanisms, the radial dimensions of the pistons in the third-stage boosting cylinder 6, the second-stage boosting cylinder 7, and the first-stage boosting cylinder 8. They are 40mm, 30mm and 20mm respectively. The measurement range of the pressure sensor 10 is 0-120MPa, and the measurement accuracy is 0.01MPa. The optional single-chip microcomputer 11 is STM32-F103 series models and above. Annular grooves are provided on the side walls of the cylinder head and the piston, and the first O-ring sealing ring 15 and the second O-ring sealing ring 17 are respectively nested.

The active liquid precise compensation method for deep sea sampling tubes includes the following steps:

(1) Use external equipment to place the sampler to the specified depth. At this time, the sampler cavity 9 and the booster cylinder cavity 20 are filled with high-pressure liquid. Use the pressure sensor 10 to measure the in-situ pressure of the sampling depth, and the microcontroller 11 records The in-situ pressure value is used as the reference pressure _Pref ; after completing the sampling operation, close the sampler and start recovering it.

(2) During the recovery process, the pressure sensor 10 is used to measure the real-time pressure value P in the sampler cavity 9 in real time, and the real-time pressure value is transmitted to the single-chip computer 11, and the single-chip computer 11 calculates the difference between the real-time pressure value and the reference pressure ( PP _ref ). Different levels of boosting cylinders are enabled for different differences; if PP _ref ≥5MPa, three-stage boosting cylinder 6 is enabled; if 1MPa <PP _ref <5MPa, two-stage boosting cylinder 7 is enabled; if PP _ref ≤1MPa, two-stage boosting cylinder 7 is enabled One-stage booster cylinder 8.

(3) Use the microcontroller 11 to perform PID control on the difference between the real-time pressure value and the reference pressure, and calculate the motor speed value n based on the current difference. The motor 3 drives the screw nut assembly 5 and drives the piston rod 18 to perform linear displacement motion. So that the piston rod 18 obtains a movement speed v toward the cavity 20;

(4) The movement speed v of the piston rod 18 is used to cause the high-pressure liquid in the booster cylinder cavity 20 to move into the sampler cavity 9 through the pressure tube 12. The sampler cavity 9 loses pressure due to the pressure of the high-pressure liquid. be compensated;

(5) Repeat steps (2) to (4) during the recovery process of the sampler cavity 9 so that the pressure in the sampler cavity 9 is maintained at a value near the reference pressure.

Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many modifications are possible. By adjusting the number of booster cylinders, adjusting the inner diameter of booster cylinders at all levels, changing the control algorithm, etc., it is possible to achieve accurate compensation for the pressure in the sampling cylinder under different environments. All modifications that a person of ordinary skill in the art can directly derive or associate from the disclosure of the present invention should be considered to be within the protection scope of the present invention.

Claims (10)

1. An active liquid accurate compensation device for a deep sea pressure maintaining sampler comprises a mechanical transmission system, a hydraulic system and a control system; wherein,

the mechanical transmission system comprises at least three groups of driving mechanisms, wherein the driving mechanisms consist of a motor, a reduction gearbox and a screw-nut assembly and are used for converting the rotation motion of the motor into the axial displacement motion of the screw rod;

the hydraulic system comprises a pressurizing cylinder with the number matched with that of the screw nut component; the piston is arranged in the cavity of each pressurizing cylinder, and the pistons in the pressurizing cylinders have different radial sizes; one end of the piston is provided with a piston rod which is connected with a corresponding screw rod; the piston rod is in clearance fit with the cylinder body of the pressurizing cylinder, and seawater can enter a cavity at one side of the piston rod; the other side of the piston is a closed cavity, and is connected with the cavity of the sampler through a pressure guiding pipe for maintaining pressure;

the control system comprises a singlechip and a pressure sensor, wherein the pressure sensor is arranged on the cavity of the sampler and used for detecting the internal pressure of the sampler, and the singlechip is connected with the pressure sensor and each motor in the mechanical transmission system through a signal wire so as to realize control;

the power supply is connected with the single chip microcomputer and each motor in the mechanical transmission system respectively through cables so as to realize power supply;

before the sampler is recovered from the deep sea sampling point, a remote computer or a local start switch is utilized to activate the singlechip; the pressure sensor is used for measuring the in-situ pressure value of the sampling point, and the data is transmitted to the singlechip and recorded as the reference pressure P _ref The method comprises the steps of carrying out a first treatment on the surface of the In the recovery process of the sampler, the pressure sensor continuously detects a real-time pressure value P of the sampler cavity and transmits the real-time pressure value P to the singlechip; the singlechip calculates the difference P-P between the real-time pressure value and the reference pressure _ref And starting the pressurizing cylinders of different levels according to the difference values; when the difference is large, firstly starting a booster cylinder with large radial size of the piston to reduce the pressure difference as soon as possible; and when the difference value is small, a pressure cylinder with small radial size of the piston is started to realize accurate adjustment.

2. The device according to claim 1, wherein the mechanical transmission system, the hydraulic system and the single-chip microcomputer are packaged in a pressure-keeping sealing cavity, and a watertight plug is arranged on the cavity of the pressure-keeping sealing cavity; the cable connected with the power supply and the signal wire connected with the pressure sensor are respectively connected to the pressure-maintaining sealing cavity through watertight connectors.

3. The device of claim 1, further comprising a remote computer or local start switch connected to the single-chip microcomputer via a signal line.

4. The device of claim 1, wherein the power source is a battery located locally to the sampling device or is a power supply located on a parent ship.

5. The device of claim 1, wherein the motor has a power interface and a speed controller, the former is connected to a power source through a cable, and the latter is connected to the single chip microcomputer through a signal line.

6. The device according to claim 1, wherein the number of the pressurizing cylinders is three, and the radial sizes of the pistons are 40mm, 30mm and 20mm respectively.

7. The device according to claim 1, wherein the pressure sensor has a measurement range of 0-120MPa and a pressure measurement accuracy of 0.01MPa.

8. The apparatus of claim 1, wherein the single-chip microcomputer is an STM32 single-chip microcomputer.

9. The apparatus of claim 1, wherein the booster cylinder comprises a cylinder block, a cylinder head, and a piston; the piston is arranged in a cylinder body with openings at two ends, the end part of a piston rod of the piston is fixedly connected with the end part of a screw rod in the driving mechanism, and the cylinder cover is fixed at one end of the cylinder body opposite to the piston rod in a threaded manner; annular grooves are formed in the side walls of the piston and the cylinder cover, and O-shaped sealing rings are embedded in the grooves to realize sealing; the cylinder cover is fixedly provided with a pipe joint in a screw connection mode, and is provided with a through hole penetrating through the pipe joint and the cylinder cover; one end of the pressure guiding pipe is connected to the cavity of the sampler, and the other end is connected to the pipe joint and connected with the cylinder body through the through hole on the cylinder cover.

10. Method for achieving an active liquid accurate compensation of a deep sea pressure maintaining sampler using the device according to any one of claims 1 to 9, characterized in that it comprises the following steps:

(1) Lowering the sampler to a deep sea sampling point with a designated water depth by using an underwater robot, and executing sampling operation according to a conventional flow; after sampling is completed, the cavity of the sampler and the cavity of the pressurizing cylinder at one side of the piston rod are filled with high-pressure seawater, so that the pressure at two sides of the piston is kept balanced;

(2) Before the sampler is recovered, a remote computer or a local start switch is utilized to activate the singlechip; the pressure sensor is used for measuring the in-situ pressure value of the sampling point, and the data is transmitted to the singlechip and recorded as the reference pressure P _ref ；

(3) In the recovery process of the sampler, the pressure sensor continuously detects a real-time pressure value P of the sampler cavity and transmits the real-time pressure value P to the singlechip; the singlechip calculates the difference P-P between the real-time pressure value and the reference pressure _ref And starting the pressurizing cylinders of different levels according to the difference values; when the difference is large, firstly starting a booster cylinder with large radial size of the piston to reduce the pressure difference as soon as possible; when the difference value is small, a pressurizing cylinder with small radial size of the piston is started to realize accurate adjustment;

(4) In the adjusting process, the singlechip performs PID control according to the difference value between the real-time pressure value and the reference pressure to obtain the motor rotating speed based on the current difference value; the selected motor drives the screw rod nut component to drive the corresponding piston to perform linear displacement movement, and drives high-pressure liquid at the other side of the piston to move into the cavity of the sampler through the pressure guiding pipe, so that the pressure lost due to the increase of the water depth in the cavity of the sampler is compensated;

(5) And (3) and (4) are repeated continuously in the process of recycling the sampler, so that the pressure in the cavity of the sampler is always kept near the reference pressure.