Hydraulic system of active and passive fusion heave compensation lifting appliance

Abstract

The active and passive fusion heave compensation lifting appliance hydraulic system comprises an active compensation hydraulic module and a passive compensation hydraulic module, the active compensation hydraulic module comprises an active compensation hydraulic cylinder I (251) and an active compensation hydraulic cylinder II (252), and the passive compensation hydraulic module comprises a passive compensation hydraulic cylinder (26). And a triangular stable supporting structure is formed by piston rod end hinge points of the active compensation hydraulic cylinder I (251), the active compensation hydraulic cylinder II (252) and the passive compensation hydraulic cylinder (26) through a steel frame. According to the invention, the synchronous lag caused by mechanical clearance and installation error in the traditional multi-cylinder compensation is eliminated, and the synchronous operation of three oil cylinders is realized; in cooperation with closed-loop feedback control of the stay wire sensor, advanced dynamic compensation is realized; the buffering effect of the passive module is combined with accurate adjustment of the active module, load fluctuation is effectively restrained, and therefore the operation stability under the complex ocean working condition is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of wave compensation hydraulics, and in particular to a hydraulic system of an active and passive wave compensation spreader used in offshore lifting operations. Background Art

[0002] In marine operations, heave compensation, a key component of wave compensation, is crucial for ensuring operational safety and precision. Crane vessels, transport ships, and floating structures are all subject to heave motion due to wind, waves, and currents. This not only reduces operational accuracy but can also lead to damage and capsizing. The core function of a heave compensation system is to decouple the load from the vessel's heave motion, ensuring that the load's vertical motion is unaffected by the vessel's influence, stabilizing cable tension, and ensuring the safety of equipment and personnel.

[0003] In practical applications of wave compensation, hydraulic systems are often used as compensating power devices. Current heave compensation systems are primarily categorized into three types, passive, active, and semi-active, based on the compensation method. Passive compensation often uses accumulators to provide energy. For example, some offshore crane wave compensation systems utilize a combination of hydraulic cylinders, accumulators, and solenoid valves to achieve passive and constant tension compensation, mitigating the effects of heave. Passive systems require no external energy input and rely on mechanical structures for open-loop operation. While simple, they are less effective against high-frequency, large heave movements. Active compensation employs a complex closed-loop architecture, leveraging sensors to monitor the vessel's status in real time and control systems to drive actuators to actively adjust loads. This effectively offsets heave effects, but it faces challenges such as high cost, high energy consumption, and limited reliability and response speed, posing numerous challenges in practical application. Semi-active compensation combines the advantages of both passive and active systems, absorbing some energy through mechanical structures while also achieving fine-tuning through active control. This theoretically offers improved compensation effectiveness and stability, but existing semi-active systems still have room for improvement in compensation accuracy.

[0004] The invention patent with publication number CN119370286B discloses a pump-controlled semi-active ship heave compensation hydraulic system and its control method. The system includes: an active compensation hydraulic module, a passive compensation hydraulic module, a sensor module, a controller and a motion sensor; the passive compensation hydraulic module includes a nitrogen bottle unit, an accumulator unit, a gas-liquid converter, a seventh electromagnetic reversing valve, a fourth electromagnetic reversing valve and a passive compensation asymmetric hydraulic cylinder; the active compensation hydraulic module includes a third accumulator, a servo motor, a bidirectional quantitative hydraulic pump, a first one-way valve, a second one-way valve, an active compensation asymmetric hydraulic cylinder, a first electromagnetic reversing valve, a second electromagnetic reversing valve and a third electromagnetic reversing valve. This invention combines passive compensation and active compensation. Although it improves the compensation efficiency, since the piston rod ends of the passive compensation asymmetric hydraulic cylinder and the active compensation asymmetric hydraulic cylinder cannot form a stable support structure, synchronization lag problems caused by mechanical clearance and installation errors are prone to occur during compensation. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to solve the deficiencies in the prior art and to provide a hydraulic system for a main and auxiliary fused heave compensation spreader.

[0006] Technical solution: A hydraulic system for a main and passive integrated heave compensation sling, including an active compensation hydraulic module and a passive compensation hydraulic module. The active compensation hydraulic module includes an active compensation hydraulic cylinder 1 and an active compensation hydraulic cylinder 2. The rod chamber 1 of the active compensation hydraulic cylinder 1 is connected to the rod chamber 2 of the active compensation hydraulic cylinder 2, and the rodless chamber 1 of the active compensation hydraulic cylinder 1 is connected to the rodless chamber 2 of the active compensation hydraulic cylinder 2; the passive compensation hydraulic module includes a passive compensation hydraulic oil cylinder, the rod chamber 3 of the passive compensation hydraulic oil cylinder is connected to the electromagnetic on-off valve 4, the oil end of the accumulator 3, the oil end of the accumulator 4, and the electromagnetic on-off valve 3 through an oil circuit, the gas end of the accumulator 3, the gas end of the accumulator 4, the gas end of the accumulator 5, the electromagnetic on-off valve 6, the high-pressure nitrogen cylinder, the stop valve, and the safety valve through an air circuit, and the piston rod end hinges of the active compensation hydraulic cylinder 1, the active compensation hydraulic cylinder 2 and the passive compensation hydraulic cylinder form a triangular stable support structure through a steel frame.

[0007] A further improvement of the present invention is that the cylinder bodies of the active compensating hydraulic cylinder 1 and the active compensating hydraulic cylinder 2 are rigidly fixedly connected to the cylinder body of the passive compensating hydraulic cylinder, the rod chamber 1, the rod chamber 2, the servo electromagnetic reversing valve, the accumulator 1, and the electromagnetic on-off valve 1 are connected to the variable hydraulic pump through an oil circuit, and the rodless chamber 1 and the rodless chamber 2 are connected to the throttling speed control valve, the accumulator 2, and the electromagnetic on-off valve 2 through an oil circuit.

[0008] A further improvement of the present invention is that the rod chamber 1 and the rodless chamber 1 of the active compensating hydraulic cylinder 1 are isolated by piston 1, and the rod chamber 2 and the rodless chamber 2 of the active compensating hydraulic cylinder 2 are isolated by piston 2. The accumulator 2 is used to recover gravitational potential energy, that is, to absorb the high-pressure oil discharged from the rodless chamber 1 and the rodless chamber 2 when the load rises, and the throttling control valve is used to accurately control the return oil speed of the rodless chamber 1 and the rodless chamber 2.

[0009] A further improvement of the present invention is that the variable hydraulic pump is connected to an oil tank, and the oil tank is connected to the air filter element, the radiator, the oil return filter, and the sewage ball valve through an oil circuit or a flange.

[0010] A further improvement of the present invention is that the variable hydraulic pump is coaxially connected to the electric motor through a coupling, and the variable hydraulic pump is connected to the second oil inlet of the electromagnetic on-off valve, the first oil inlet of the electromagnetic on-off valve, the oil inlet of the servo electromagnetic reversing valve, and the third oil inlet of the electromagnetic on-off valve through an oil circuit.

[0011] A further improvement of the present invention is that the active compensating hydraulic cylinder 1, the active compensating hydraulic cylinder 2 and the passive compensating hydraulic cylinder are equipped with wire sensors.

[0012] A further improvement of the present invention is that a one-way valve 1 and a relief valve 1 are installed between the variable hydraulic pump and the return oil filter, a pressure relay 5 is installed above the electromagnetic on-off valve 3, an relief valve 5 is installed on the right side of the electromagnetic on-off valve 3, and the electromagnetic on-off valve 6 is connected to the pressure relay 6.

[0013] A further improvement of the present invention is that electromagnetic on-off valve 1 is equipped with overflow valve 2, electromagnetic on-off valve 2 is equipped with overflow valve 3, valve block 1 is connected between rodless chamber 1 and rodless chamber 2, and valve block 1 is installed with pressure relay 3 and one-way valve 2; valve block 2 is connected between rod chamber 1 and rod chamber 2, and valve block 2 is installed with pressure relay 4.

[0014] A further improvement of the present invention is that accumulator 1 is connected to pressure relay 1, accumulator 2 is connected to pressure relay 2, and the servo electromagnetic reversing valve is equipped with overflow valve 4 and check valve 3.

[0015] Compared with the prior art, the hydraulic system of the main and auxiliary heave compensation spreader provided by the present invention achieves at least the following beneficial effects: 1. Significantly improved energy efficiency: The passive compensation module bears the static load, while the active compensation module only needs to deal with dynamic loads, significantly reducing the power demand of the active compensation hydraulic module and reducing system energy consumption. In addition, the active compensation hydraulic cylinder's rodless chamber works in conjunction with the accumulator, which absorbs or releases energy, reducing the continuous output flow of the variable hydraulic pump and further improving energy conservation.

[0016] 2. Optimized cylinder adjustment method: The rodless chamber of the active compensation hydraulic cylinder is linked with the accumulator and throttling speed control valve, breaking through the traditional active compensation mode that relies solely on pump control or valve control. The passive energy storage characteristics assist the cylinder expansion and contraction adjustment, which not only simplifies the complexity of active control but also improves the dynamic response speed, providing a novel structural type for similar heave compensation systems.

[0017] 3. Reduced overall system cost: On the one hand, the passive compensation module stores and releases energy through nitrogen cylinders and accumulators, reducing dependence on high-power motors and hydraulic pumps and lowering the selection cost of core components. On the other hand, the coordinated control of the active and passive fusion reduces the throttling loss of the valve control system, which can extend the service life of the equipment and reduce operation and maintenance costs.

[0018] 4. Improved compensation accuracy and stability: The dual active and passive compensation hydraulic cylinders are rigidly fixed, and the piston rod end hinges form a triangular stable support structure through a steel frame. This eliminates the synchronization lag caused by mechanical clearance and installation errors in traditional multi-cylinder compensation, enabling synchronous operation of the three cylinders. Combined with the closed-loop feedback control of the cable sensor, advanced dynamic compensation is achieved. At the same time, the buffering effect of the passive module is combined with the precise adjustment of the active module to effectively suppress load fluctuations, thereby ensuring operational stability in complex marine conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural schematic diagram of a hydraulic system of a main and quilted fusion heave compensation spreader of the present invention; Figure 2 This is a schematic diagram showing the piston rods of the active compensation hydraulic cylinder and the passive compensation hydraulic cylinder being fully retracted; Figure 3 This is a schematic diagram of the piston rods of the active compensation hydraulic cylinder and the passive compensation hydraulic cylinder being fully extended.

[0020] Figure 1: Oil tank, air filter, motor, coupling, variable hydraulic pump, one check valve, overflow valve, servo electromagnetic reversing valve, electromagnetic on-off valve, pressure relay, pressure relay, pressure relay, valve block, valve, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic reversing valve, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic reversing valve, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic reversing valve, servo electromagnetic on-off valve, pressure relay ... on-off valve, pressure relay, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic on-off valve, pressure relay, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic on-off valve, pressure relay, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic on-off valve, pressure relay, pressure relay, valve block, valve, check valve, overflow valve, servo electromagnetic on-off valve, pressure relay, pressure relay, valve block, check valve, overflow valve, servo electromagnetic on-off valve, pressure relay, pressure relay, valve block, check valve, overflow valve, servo electromagnetic on-off valve, pressure relay, pressure relay, Block 2, 24-pressure relay 4, 251-active compensation hydraulic cylinder 1, 252-active compensation hydraulic cylinder 2, 26-passive compensation hydraulic cylinder, 27-electromagnetic on-off valve 3, 28-overflow valve 5, 29-pressure relay 5, 30-electromagnetic on-off valve 4, 311-accumulator 3, 312-accumulator 4, 321-electromagnetic on-off valve 5, 322-electromagnetic on-off valve 6, 33-pressure relay 6, 34-high-pressure nitrogen cylinder, 35-stop valve, 36-safety valve, 37-return oil filter, 38-radiator, 39-drain ball valve. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and values ​​set forth in these embodiments do not limit the scope of the present invention. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0022] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0023] See Figure 1 A hydraulic system for a main and passive fusion heave compensation spreader includes an oil tank, a control unit, a motion reference unit, an active compensation hydraulic module and a passive compensation hydraulic module. The active compensation hydraulic module includes an active compensation hydraulic cylinder 1 251 and an active compensation hydraulic cylinder 2 252. The rod cavity 1 of the active compensation hydraulic cylinder 1 251 is connected to the rod cavity 2 of the active compensation hydraulic cylinder 252, and the rodless cavity 1 of the active compensation hydraulic cylinder 1 251 is connected to the rodless cavity 2 of the active compensation hydraulic cylinder 252; the passive compensation hydraulic module includes a passive compensation hydraulic oil cylinder 26. The rod chamber three of the active compensation hydraulic cylinder 26 is connected to the electromagnetic on-off valve four 30, the oil end of the accumulator three 311, the oil end of the accumulator four 312, and the electromagnetic on-off valve three 27 through an oil circuit. The gas end of the accumulator three 311, the gas end of the accumulator four 312, the electromagnetic on-off valve five 321, the electromagnetic on-off valve six 322, the high-pressure nitrogen cylinder 34, the stop valve 35, and the safety valve 36 through an air circuit. The piston rod end hinge points of the active compensation hydraulic cylinder one 251, the active compensation hydraulic cylinder two 252 and the passive compensation hydraulic cylinder 26 form a triangular stable support structure through a steel frame.

[0024] A further improvement of the present invention is that the cylinder bodies of the active compensating hydraulic cylinder 1 251 and the active compensating hydraulic cylinder 2 252 are rigidly fixedly connected to the cylinder body of the passive compensating hydraulic cylinder 26, the rod chamber 1, the rod chamber 2, the servo electromagnetic reversing valve 8, the accumulator 1 14, and the electromagnetic on-off valve 1 9 are connected to the variable hydraulic pump 5 through an oil circuit, and the rodless chamber 1 and the rodless chamber 2 are connected to the throttling speed regulating valve 17, the accumulator 2 16, and the electromagnetic on-off valve 2 10 through an oil circuit. The throttling speed regulating valve 17 accurately controls the return oil speed of the rodless chamber, avoiding energy waste and impact vibration caused by the traditional rodless chamber directly returning to the oil tank. The two work together to provide passive auxiliary power for active compensation.

[0025] A further improvement of the present invention is that the rod chamber 1 and the rodless chamber 1 of the active compensating hydraulic cylinder 1 251 are isolated by piston 1, and the rod chamber 2 and the rodless chamber 2 of the active compensating hydraulic cylinder 2 252 are isolated by piston 2. The accumulator 2 16 is used to recover gravitational potential energy, that is, to absorb the high-pressure oil discharged from the rodless chamber 1 and the rodless chamber 2 when the load rises, and the throttling control valve 17 is used to accurately control the return oil speed of the rodless chamber 1 and the rodless chamber 2.

[0026] A further improvement of the present invention is that the variable hydraulic pump 5 is connected to the oil tank 1, and the oil tank 1 is connected to the air filter 2, the radiator 38, the return oil filter 37, and the drain ball valve 39 through oil circuits or flanges to effectively prevent oil leakage.

[0027] A further improvement of the present invention is that the variable hydraulic pump 5 is coaxially connected to the motor 3 through a coupling 4, and the variable hydraulic pump 5 is connected to the oil inlet 10 of the electromagnetic on-off valve 2, the oil inlet 9 of the electromagnetic on-off valve 1, the oil inlet of the servo electromagnetic reversing valve 8, and the oil inlet 27 of the electromagnetic on-off valve 3 through an oil circuit.

[0028] A further improvement of the present invention is that the active compensation hydraulic cylinder 1 251, the active compensation hydraulic cylinder 2 252 and the passive compensation hydraulic cylinder 26 are equipped with pull-wire sensors. The pull-wire sensors adopt the principle of magnetic sensitivity effect, have high measurement accuracy, and provide real-time feedback of piston rod position information, supporting the closed-loop control system to achieve high-precision positioning.

[0029] A further improvement of the present invention is that a one-way valve 6 and a relief valve 7 are installed between the variable hydraulic pump 5 and the return oil filter 37, a pressure relay 5 29 is installed above the electromagnetic on-off valve 3 27, a relief valve 5 28 is installed on the right side of the electromagnetic on-off valve 3 27, and the electromagnetic on-off valve 6 322 is connected to the pressure relay 6 33.

[0030] A further improvement of the present invention is that the electromagnetic on-off valve 19 is equipped with an overflow valve 2 11, the electromagnetic on-off valve 2 10 is equipped with an overflow valve 3 12, a valve block 19 is connected between the rodless chamber 1 and the rodless chamber 2, and the valve block 1 19 is installed with a pressure relay 3 18 and a one-way valve 2 20; a valve block 23 is connected between the rod chamber 1 and the rod chamber 2, and the valve block 2 23 is installed with a pressure relay 4 24. The valve blocks 19 and 23 integrate multiple hydraulic valves and pipelines to replace complex pipeline connections, reduce leakage points and save space.

[0031] A further improvement of the present invention is that accumulator 1 14 is connected to pressure relay 1 13, and accumulator 2 16 is connected to pressure relay 2 15. Pressure relay 13 and pressure relay 2 15 convert the pressure signal of the hydraulic system into an electrical signal to achieve automatic control. The servo electromagnetic reversing valve 8 is equipped with a relief valve 4 21 and a check valve 3 22. The relief valve 4 21 limits the maximum pressure of the system to prevent overload, and the check valve 3 22 only allows the fluid to flow in one direction and prevents reverse flow.

[0032] During operation, the motion reference unit monitors the ship's motion posture signal in real time and transmits it to the control unit. After analysis and calculation by the control unit, it generates precise instructions to drive the executive components of the active compensation hydraulic module and the passive compensation hydraulic module to implement advanced dynamic heave compensation.

[0033] Initial state: Figure 2As shown, the piston rods of the active compensating hydraulic cylinder 1 251, the active compensating hydraulic cylinder 2 252 and the passive compensating hydraulic cylinder 26 are all retracted; the motor 3 is started, the oil circuit builds up pressure, the electromagnetic on-off valve 2 10, the electromagnetic on-off valve 1 9, and the electromagnetic on-off valve 3 27 are opened, and the accumulator 2 16, the accumulator 1 14, the accumulator 3 311, and the accumulator 4 312 are pre-filled with oil. After the oil pressure reaches the preset value, the electromagnetic on-off valve 2 10, the electromagnetic on-off valve 1 9, and the electromagnetic on-off valve 3 27 are closed.

[0034] Preparation conditions: Figure 3 As shown, the hydraulic system of the active and passive heave-compensating spreader, under the influence of the load's gravity, extends active compensating hydraulic cylinder 1 251, active compensating hydraulic cylinder 2 252, and passive compensating hydraulic cylinder 26. At this point, passive compensating hydraulic cylinder 26 resists the load's own weight and adjusts the compressed nitrogen pressure in accumulator 3 311 and accumulator 4 312 by adjusting electromagnetic on-off valve 5 321, electromagnetic on-off valve 6 322, and high-pressure nitrogen cylinder 34. This adjusts the oil pressure in accumulator 3 311 and accumulator 4 312. Accumulator 3 311, accumulator 4 312, electromagnetic on-off valve 4 30, and passive compensating hydraulic cylinder 26 are connected, maintaining load balance when the piston rod reaches the neutral position. The passive compensating hydraulic module dynamically adjusts the static load-bearing ratio based on the load weight, while the active compensating hydraulic module only needs to compensate for the remaining dynamic fluctuations. This solves the problem of excessive energy consumption in the active module under light loads and insufficient support in the passive module under heavy loads, which is caused by the fixed division of labor between the active and passive modules in traditional systems.

[0035] Active compensation working condition: Active compensation hydraulic cylinder 1 251 and active compensation hydraulic cylinder 2 252 are arranged on both sides of the passive compensation hydraulic cylinder 26 to achieve active and passive fusion. Wave compensation is achieved by receiving control system commands.

[0036] Load Lifting and Acceleration: When the load is at its lowest position, it is lifted upward. Gravity and inertia are both downward. Active Compensation Cylinder 1 251 and Active Compensation Cylinder 2 252 provide an upward pull, accelerating the load upward. Deceleration: When the load is decelerating from its mid-position to its highest position, gravity and inertia are both downward. Active Compensation Cylinder 1 251 and Active Compensation Cylinder 2 252 provide a downward thrust, decelerating the load upward.

[0037] Valve group control: The variable hydraulic pump 5 continuously replenishes oil to the system, opens the electromagnetic on-off valve 9, and the servo electromagnetic reversing valve 8 works in the right position. It opens to a certain degree according to the control signal to realize the lifting acceleration and deceleration action of the main and auxiliary heave compensation spreader. The wire sensor feeds back the cylinder stroke and cylinder operating speed to the servo system to realize closed-loop control.

[0038] The load descends in an accelerated motion. From the highest position, the load falls due to gravity, with gravity acting downward and inertia acting upward. Active compensating hydraulic cylinder 1 251 and active compensating hydraulic cylinder 2 252 provide downward thrust, accelerating the load as it descends. Deceleration: From the middle position to the lowest position, the load decelerates. With gravity acting downward and inertia acting downward, active compensating hydraulic cylinder 1 251 and active compensating hydraulic cylinder 2 252 provide upward pulling, decelerating the load as it descends.

[0039] Valve group control: The variable hydraulic pump 5 continuously replenishes oil to the system, closes the electromagnetic on-off valve 9, and the servo electromagnetic reversing valve 8 works in the left position. It opens to a certain degree according to the control signal. At this time, the servo electromagnetic reversing valve 8 controls the oil return speed of the system, realizing the acceleration and deceleration of the main and auxiliary heave compensation spreader. The wire sensor feeds back the cylinder stroke and cylinder operating speed to the servo system to realize closed-loop control.

[0040] To sum up, the hydraulic system of a main and passive integrated heave compensation sling of the present invention belongs to a semi-active system. The passive compensation module provides the static load force to overcome the load. After the passive compensation hydraulic cylinder overcomes the static load force of the load, the energy consumption of the active compensation hydraulic cylinder is greatly reduced; the active compensation module provides the active force to overcome the dynamic load force of the load. At the same time, a passive compensation accumulator is arranged in the rodless cavity of the active compensation hydraulic cylinder to further reduce energy consumption. The active hydraulic module and the passive hydraulic module act synchronously to achieve the active compensation adjustment function. The hinge point of the piston rod end forms a triangular stable support structure through the steel frame, which eliminates the synchronization lag caused by mechanical clearance and installation error in traditional multi-cylinder compensation. The variable hydraulic pump is combined with the servo electromagnetic reversing valve to achieve precise control of the active compensation hydraulic cylinder. The servo electromagnetic reversing valve is used to control the amount of oil in and out of the rod cavity to achieve precise speed control. At the same time, the rodless cavity utilizes the characteristics of the accumulator to achieve shock absorption and energy dissipation, provide descending kinetic energy, and thus reduce energy consumption.

[0041] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A hydraulic system for a main and submerged heave compensation spreader, characterized in that: The invention comprises an active compensating hydraulic module and a passive compensating hydraulic module, wherein the active compensating hydraulic module comprises an active compensating hydraulic cylinder 1 (251) and an active compensating hydraulic cylinder 2 (252), wherein the rod chamber 1 of the active compensating hydraulic cylinder 1 (251) is connected to the rod chamber 2 of the active compensating hydraulic cylinder 2 (252), and the rodless chamber 1 of the active compensating hydraulic cylinder 1 (251) is connected to the rodless chamber 2 of the active compensating hydraulic cylinder 2 (252); the passive compensating hydraulic module comprises a passive compensating hydraulic oil cylinder (26), wherein the rod chamber 3 of the passive compensating hydraulic oil cylinder (26) is connected to the electromagnetic on-off valve. Four (30), the oil end of accumulator three (311), the oil end of accumulator four (312), and electromagnetic on-off valve three (27) are connected through an oil circuit, and the gas end of accumulator three (311), the gas end of accumulator four (312) and electromagnetic on-off valve five (321), electromagnetic on-off valve six (322), high-pressure nitrogen cylinder (34), stop valve (35), and safety valve (36) are connected through a gas circuit, and the piston rod end hinge points of active compensation hydraulic cylinder one (251), active compensation hydraulic cylinder two (252) and passive compensation hydraulic oil cylinder (26) form a triangular stable support structure through a steel frame.

2. A hydraulic system for main and submerged heave compensation spreaders according to claim 1, characterized in that: The cylinder bodies of the active compensating hydraulic cylinder 1 (251) and the active compensating hydraulic cylinder 2 (252) are rigidly fixedly connected to the cylinder body of the passive compensating hydraulic cylinder (26); the rod chamber 1, the rod chamber 2, the servo electromagnetic reversing valve (8), the accumulator 1 (14), and the electromagnetic on-off valve 1 (9) are connected to the variable hydraulic pump (5) through an oil circuit; the rodless chamber 1, the rodless chamber 2, the throttling speed regulating valve (17), the accumulator 2 (16), and the electromagnetic on-off valve 2 (10) are connected to the oil circuit.

3. The hydraulic system of a main and submerged heave compensation spreader according to claim 1, characterized in that: The rod chamber 1 and the rodless chamber 1 of the active compensating hydraulic cylinder 1 (251) are isolated by piston 1, and the rod chamber 2 and the rodless chamber 2 of the active compensating hydraulic cylinder 2 (252) are isolated by piston 2. The accumulator 2 (16) is used to recover gravitational potential energy, that is, to absorb the high-pressure oil discharged from the rodless chamber 1 and the rodless chamber 2 when the load rises. The throttling control valve (17) is used to accurately control the return oil speed of the rodless chamber 1 and the rodless chamber 2.

4. The hydraulic system of a main and submerged heave compensation spreader according to claim 2, characterized in that: The variable hydraulic pump (5) is connected to an oil tank (1), and the oil tank (1) is connected to an air filter element (2), a radiator (38), an oil return filter (37), and a sewage ball valve (39) through an oil circuit or a flange.

5. The hydraulic system of a main and submerged heave compensation spreader according to claim 2, characterized in that: The variable hydraulic pump (5) is coaxially connected to the motor (3) via a coupling (4), and the variable hydraulic pump (5) is connected to the oil inlet of the electromagnetic on-off valve 2 (10), the oil inlet of the electromagnetic on-off valve 1 (9), the oil inlet of the servo electromagnetic reversing valve (8), and the oil inlet of the electromagnetic on-off valve 3 (27) via an oil circuit.

6. The hydraulic system of a main and submerged heave compensation spreader according to claim 1, characterized in that: The active compensating hydraulic cylinder 1 (251), the active compensating hydraulic cylinder 2 (252) and the passive compensating hydraulic cylinder (26) are equipped with wire sensors.

7. The hydraulic system of a main and submerged heave compensation spreader according to claim 4, characterized in that: A one-way valve (6) and a relief valve (7) are installed between the variable hydraulic pump (5) and the return oil filter (37). A pressure relay (29) is installed above the electromagnetic on-off valve (27). A relief valve (28) is installed on the right side of the electromagnetic on-off valve (27). The electromagnetic on-off valve (322) is connected to a pressure relay (33).

8. The hydraulic system of a main and submerged heave compensation spreader according to claim 2, characterized in that: The electromagnetic on-off valve 1 (9) is equipped with an overflow valve 2 (11), and the electromagnetic on-off valve 2 (10) is equipped with an overflow valve 3 (12). A valve block 1 (19) is connected between the rodless chamber 1 and the rodless chamber 2, and the valve block 1 (19) is installed with a pressure relay 3 (18) and a one-way valve 2 (20); a valve block 2 (23) is connected between the rod chamber 1 and the rod chamber 2, and the valve block 2 (23) is installed with a pressure relay 4 (24).

9. The hydraulic system of a main and submerged heave compensation spreader according to claim 2, characterized in that: The accumulator 1 (14) is connected to the pressure relay 1 (13), the accumulator 2 (16) is connected to the pressure relay 2 (15), and the servo electromagnetic reversing valve (8) is equipped with an overflow valve 4 (21) and a one-way valve 3 (22).

Images