Tensioning hydraulic cylinder assembly of marine riser tensioner and marine riser tensioner

Abstract

The tensioning hydraulic cylinder assembly comprises a hydraulic cylinder and an energy accumulator, an oil port in the lower end of the hydraulic cylinder is communicated with a liquid port in the lower end of the energy accumulator, the hydraulic cylinder and the energy accumulator are fixed together, the hydraulic cylinder is a plunger hydraulic cylinder with the double-acting characteristic, the energy accumulator is a piston-free type energy accumulator, and the energy accumulator is a piston-free type energy accumulator. And a bubble reduction structure is detachably connected in the energy accumulator and is used for reducing gas dissolved in the hydraulic oil so as to reduce cavitation of the gas to the hydraulic element. The hydraulic cylinder is a plunger hydraulic cylinder with the double-acting characteristic, the advantages of stability and sealing reliability of the double-acting hydraulic cylinder are kept, the hydraulic cylinder has the advantages of the plunger hydraulic cylinder, and multiple problems of an existing tensioning hydraulic cylinder assembly in selection of the plunger hydraulic cylinder and the double-acting hydraulic cylinder are solved; according to the tensioning hydraulic cylinder assembly, the bubble reduction structure is arranged in the energy accumulator, so that the problem of air cavitation existing in an existing tensioning hydraulic cylinder assembly is solved, and cavitation of components is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of offshore oil drilling equipment, and in particular relates to a tensioning cylinder assembly of a riser tensioner and a riser tensioner. Background Art

[0002] The riser string is a key equipment to ensure that floating drilling vessels can smoothly carry out offshore oil and gas drilling operations. Due to the combined effects of the ship's heave and sinking movements and the waves and ocean currents, the riser string will be impacted by external irregular loads for a long time. If it is not controlled, its service life will be seriously affected. For this reason, in engineering, multiple sets of riser tensioners are often used to apply a constant tension on the top of the riser. This tension value is sufficient to overcome the underwater wet weight of the riser string itself and form an overlift force, so that the entire section of the riser string from the water surface to the wellhead is in a tensile state. In this state, the vibration of the riser string caused by the impact of external loads will be greatly reduced, the working stability of the riser string will be improved, and the service life will be effectively extended. Therefore, the riser tensioner is an important equipment to ensure the safe operation of the riser string.

[0003] The most widely used and most mature tensioner type at present is the wire rope type riser tensioner. It uses a hydraulic cylinder, an accumulator and a gas cylinder to form a "liquid-gas spring". The movable and fixed pulleys at the upper and lower ends of the hydraulic cylinder are used to wind the wire rope, so that the thrust of the hydraulic cylinder is transmitted to the wire rope. At the same time, the 2×3 rope system composed of the movable and fixed pulleys can achieve a 4:1 relationship between the heave displacement of the ship and the stroke of the hydraulic cylinder. The wire rope is guided by the guide pulley at the bottom of the moon pool and then connected to the tensioning ring of the riser string, thereby achieving the purpose of applying tension on the top of the riser. Due to the characteristics of the hydraulic spring, the applied top tension fluctuates slightly during the movement of the hydraulic cylinder and remains basically constant.

[0004] The hydraulic cylinders used in the wire rope type watertightening tensioners currently in service are usually plunger hydraulic cylinders and double-acting hydraulic cylinders. The plunger hydraulic cylinder does not need to add a low-pressure protective gas cylinder at one end of the rod chamber, which can reduce the complexity of the system and the weight control of the equipment. It is the best choice for the hydraulic cylinder of the watertightening tensioner that is under pressure for a long time. However, compared with the double-acting hydraulic cylinder, the plunger hydraulic cylinder has many disadvantages: First, to ensure the same tension, the overall size and weight are larger than the double-acting hydraulic cylinder. Secondly, the plunger hydraulic cylinder has no piston. For the tensioner that bears the partial load for a long time, in order to ensure the stability of its pressure rod, the hydraulic cylinder design is more complicated than the double-acting hydraulic cylinder, and the wear of the hydraulic cylinder piston rod is also greater. Thirdly, since the end of the cylinder needs to be sealed by the sealing assembly, and the sealing assembly contains a large number of sealing and guiding parts, its service life is relatively short, and the seal is frequently replaced. Finally, the plunger hydraulic cylinder often uses a complex annular spring to solve the buffering problem of the hydraulic cylinder. The spring will gradually rust after being immersed in the water-based hydraulic oil in the hydraulic cylinder for a long time, further affecting the cleanliness of the system oil. In general, the two current types of hydraulic cylinders are not well suited to the tensioner's requirements for durability and ease of use, and further optimization is needed.

[0005] The accumulators used in the wire rope type riser tensioner currently in service are divided into two types: pistonless and piston-equipped. The pistonless accumulator is also called high-pressure oil and gas storage, that is, the hydraulic oil and air are in direct contact. The piston accumulator adds a piston to the accumulator to isolate the hydraulic oil and air. Both have their advantages and disadvantages. The pistonless accumulator has no moving parts, which eliminates the problem of regular replacement of piston seals. However, the oil and air are in direct contact, and the air will penetrate into the hydraulic oil in the form of bubbles. After passing through the throttling element, cavitation will be formed, affecting the life of the components. The piston accumulator is completely isolated from the oil and gas, and the use conditions of the oil and hydraulic components are better, but the gas-liquid seals on the piston will inevitably leak during use; if air enters the hydraulic oil, it may cause the cylinder to creep and move, resulting in the synchronization of multiple cylinders being affected; if the oil enters the air, the total amount of hydraulic oil in the cylinder will gradually decrease, and there is a risk of the piston punching the cylinder. At the same time, the oil cannot be discharged well after entering the gas pipeline. Therefore, there is still room for further optimization in the design of accumulators for tensioners at this stage.

[0006] The tensioner body consists of an upper and lower pulley assembly, a hydraulic cylinder, an accumulator, and attached pipe valves. Traditional tensioners are often designed with a large number of hydraulic cylinder and accumulator fixed structures. The hydraulic cylinder to accumulator and accumulator to gas line interfaces are often realized by forged elbows or welded pipelines, which ultimately leads to the difficulty of processing and manufacturing the entire tensioner and inconvenient use and maintenance. If the upper and lower pulley assemblies are left aside, the hydraulic cylinder, accumulator, and pipe valves of the tensioner are integrated to form a compact tensioning hydraulic cylinder assembly, which is a good design idea for reducing the overall weight of the tensioner and reducing the complexity of the equipment.

[0007] With the intensification of offshore oil and gas exploration and development, it is particularly urgent to solve the problems existing in the design, manufacturing and use of key components of existing tensioners, to design and develop compact tensioning cylinder assemblies, and to propose innovative problem-solving methods and design ideas. Summary of the invention

[0008] In order to solve all or part of the above problems, the purpose of the present invention is to provide a tensioning cylinder assembly and a riser tensioner for a watertight pipe tensioner. The cylinder of the present invention solves many problems faced by the existing tensioning cylinder assembly in the selection of plunger cylinders and double-acting cylinders; the accumulator of the present invention is a pistonless accumulator, thereby eliminating the daily maintenance process of replacing piston seals.

[0009] According to one aspect of the present invention, there is provided a tensioning cylinder assembly of a riser tensioner, comprising a cylinder and an accumulator, wherein the oil port at the lower end of the cylinder is connected to the liquid port at the lower end of the accumulator, and wherein the cylinder and the accumulator are fixed together, the cylinder is a double-acting plunger cylinder, the accumulator is a pistonless accumulator, and a bubble reduction structure is detachably connected inside the accumulator, and the bubble reduction structure is used to reduce gas dissolved in hydraulic oil to reduce cavitation of hydraulic components by gas.

[0010] Furthermore, an anti-recoil valve group is connected between the oil port at the lower end of the hydraulic cylinder and the liquid port at the lower end of the accumulator, and the anti-recoil valve group is in a normally open state to connect the oil port of the hydraulic cylinder and the liquid port of the accumulator; ball valves are respectively installed at the bottom of the hydraulic cylinder and the bottom of the accumulator, and the ball valves are in a normally closed state, and can be used to charge and discharge hydraulic oil after opening;

[0011] The upper end of the accumulator is threadedly connected with a liquid level probe, and one end of the liquid level probe extending outside the accumulator is connected with a filling needle valve, the filling needle valve is in a normally closed state, and after the filling needle valve is opened during the filling process, the filling condition of the accumulator can be guided by the cooperation of the liquid level probe and the filling needle valve; a safety valve is installed at the upper end of the accumulator;

[0012] The accumulator is fixed together with the hydraulic cylinder through an accumulator fixing frame, the accumulator fixing frame is divided into two groups, and the outside of the accumulator and the hydraulic cylinder are both provided with grooves matched with the accumulator fixing frame.

[0013] Furthermore, the upper end of the accumulator is connected to a gas end stop valve group, which is in a normally closed state and can connect the internal space of the accumulator and the main gas circuit of the ship when the gas end stop valve group is opened.

[0014] Further, the gas end stop valve group includes a valve block body, the valve block body is sealed and fixedly connected to the upper end of the accumulator, the valve block body is sealed and fixedly connected to a face-mounted ball valve, the face-mounted ball valve is sealed and fixedly connected to a flange head, the flange head is used to be sealed and fixedly connected to the main gas circuit of the ship, the valve block body, the face-mounted ball valve and the flange head are provided with flow channels that are connected in sequence, and the face-mounted ball valve is in a normally closed state;

[0015] A discharge port, a bypass port and a pressure measuring port are provided on the flow channel of the valve block body. A pressure relief needle valve is installed at the discharge port. The pressure relief needle valve is in a normally closed state and can relieve pressure from the accumulator after opening. The bypass port is fixedly connected to one end of the bypass needle valve. The other end of the bypass needle valve is communicated with the flow channel on the flange head. The bypass ball valve is in a normally closed state. A pressure gauge needle valve is installed at the pressure measuring port, and the pressure gauge needle valve is connected to a pressure gauge.

[0016] Furthermore, the bubble reduction structure includes a filter screen, which is a cylindrical structure with an opening at one end, and filter holes are arranged on the side wall and the bottom wall of the cylindrical structure, and the open end of the filter screen is fixedly connected to a filter screen mounting block, and an external thread structure is arranged on the outer circumference of the filter screen mounting block. The filter screen mounting block is detachably connected to the accumulator via the external thread structure on its outer circumference, and a liquid channel is arranged in the filter screen mounting block.

[0017] Further, the accumulator comprises an accumulator cylinder, the lower end of the accumulator cylinder is detachably sealed and connected to the accumulator lower end cover, the upper end of the accumulator cylinder is detachably sealed and connected to the accumulator upper end cover, the accumulator lower end cover is provided with an internal threaded liquid port, the filter screen mounting block is threadedly connected to the internal threaded liquid port, a polygonal connecting block is fixedly connected between the filter screen mounting block and the filter screen, and the polygonal connecting block is used to cooperate with a wrench to connect the filter screen to the accumulator lower end cover;

[0018] The filter is made of stainless steel plate that is punched and then cold-bent and welded. The polygonal connecting block is provided with flow holes. The holes on the filter, the flow holes on the polygonal connecting block, the liquid channel on the filter mounting block and the internal threaded liquid port are connected in sequence. The internal threaded liquid port is connected to the oil port at the lower end of the liquid cylinder. The polygonal connecting block is a polygonal stainless steel plate with a flow hole in the middle. The filter mounting block is a stainless steel pipe with an external threaded structure on the outer circumference.

[0019] Furthermore, the hydraulic cylinder comprises a hydraulic cylinder barrel and a hydraulic cylinder piston rod, the bottom of the hydraulic cylinder barrel is used to be fixedly connected to the fixed pulley block of the watertight pipe tensioner, and the hydraulic cylinder piston rod is used to be fixedly connected to the movable pulley block of the watertight pipe tensioner;

[0020] The cylinder barrel of the hydraulic cylinder comprises a cylinder barrel body, the upper end and the lower end of the cylinder barrel body are respectively fixedly connected with a cylinder barrel end head and a cylinder barrel lower end cover, the hydraulic cylinder piston rod comprises a piston head and a piston rod body that are fixedly connected, the piston head and the cylinder barrel body are sealed and connected to divide the space in the cylinder barrel body into a plug chamber and a rod chamber, a plurality of guide holes are arranged on the piston head between the sealing part of the piston head and the cylinder barrel body and the piston rod body, a connecting hole is opened on the piston head, one end of the connecting hole is connected with the plurality of the guide holes, and the other end of the connecting hole extends to an end close to the cylinder barrel lower end cover to pass through the piston head, and the plug chamber and the rod chamber are connected through the guide hole and the connecting hole;

[0021] A main flow channel and a discharge flow channel hole are opened in the lower end cover of the cylinder, and the main flow channel is connected to the liquid port at the lower end of the accumulator. The end of the cylinder is connected to a sealing dustproof structure, and the sealing dustproof structure cooperates with the piston rod body to seal the rod cavity and prevent dust from entering the rod cavity.

[0022] Furthermore, an oil outlet flange is connected in the main flow channel, the oil outlet flange is communicated with the liquid port at the lower end of the accumulator, the oil outlet flange is welded by a flange with a seal and a straight pipe, and the straight pipe of the oil outlet flange is fixed in the main flow channel of the lower end cover of the cylinder barrel by sink welding;

[0023] The piston rod body is fixedly connected to a connecting end at one end away from the piston head, and a step is provided on the connecting end, and the step is used to cooperate with the mounting frame of the movable pulley block;

[0024] The sealing and dustproof structure includes a second upper end cover and a sealing and dustproof assembly. The second upper end cover is fixedly connected to the first upper end cover. The sealing and dustproof assembly is arranged in the second upper end cover. The first upper end cover is fixedly connected to the cylinder end. The first upper end cover is installed with a guide sleeve and a wear-resistant ring that cooperate with the piston rod body.

[0025] Further, the piston head includes a piston head body, the guide hole and the communicating hole are both arranged on the piston head body, the piston head body and the piston rod body are fixedly connected, a sealing mounting ring and a buffer ring are threadedly connected to the piston head body, a sealing ring is sleeved on the sealing mounting ring, the piston head and the cylinder body are sealed and connected via the sealing ring, and the side of the sealing mounting ring away from the buffer ring is limited by a limiting ring and a fastening screw;

[0026] Both ends of the cylinder barrel are respectively fixedly connected with lifting ears, and a cylinder lateral fixing seat is fixedly connected to the cylinder barrel. The cylinder lateral fixing seat is used to cooperate with the cylinder support frame of the watertight pipe tensioner to fix the upper end of the tensioning cylinder assembly.

[0027] Furthermore, a stroke measuring device is fixed to the outside of the hydraulic cylinder or the accumulator, and the stroke measuring device is used to cooperate with the movable pulley block of the watertight pipe tensioner to measure the stroke of the hydraulic cylinder.

[0028] Furthermore, the stroke measuring device is a pull-rope type displacement sensor, the body of the pull-rope type displacement sensor is fixed on a mounting plate, the mounting plate is fixed on the outside of the hydraulic cylinder or the accumulator, a protective shell is connected to the mounting plate, the body of the pull-rope type displacement sensor is located in the protective shell, and the rope end of the pull-rope type displacement sensor passes through the protective shell and is fixed on the movable pulley block.

[0029] Furthermore, a pressure measuring device is fixedly installed at the bottom of the liquid cylinder, and the pressure measuring device is used to measure the pressure inside the liquid cylinder.

[0030] Furthermore, the pressure measuring device includes a pressure sensor and a pressure measuring lead-out pipeline. A flow channel hole is opened at the bottom of the liquid cylinder. The pressure measuring lead-out pipeline is located in the flow channel hole. One end of the pressure measuring lead-out pipeline extending out of the flow channel hole is connected to the pressure sensor. A sensor needle valve is arranged on the pressure measuring lead-out pipeline, and the sensor needle valve is in a normally open state.

[0031] An embodiment of the present invention further provides a riser tensioner, comprising a tensioning cylinder assembly of the riser tensioner as described in any one of the above.

[0032] It can be seen from the above technical solution that the tensioning cylinder assembly of a riser tensioner and the riser tensioner provided by the present invention have the following beneficial effects:

[0033] The cylinder of the present invention is a double-acting plunger cylinder, which maintains the advantages of stability and sealing reliability of the double-acting cylinder and has the advantages of the plunger cylinder, solving many problems faced by the existing tensioning cylinder assembly in the selection of the plunger cylinder and the double-acting cylinder.

[0034] The accumulator of the present invention is a pistonless accumulator, thereby eliminating the daily maintenance process of replacing the piston seal, and the present embodiment provides a bubble reduction structure in the accumulator, thereby solving the problem of air cavitation existing in the existing tensioning cylinder assembly, and greatly reducing the cavitation of components;

[0035] The accumulator of the present invention is detachably connected to the bubble reduction structure, thereby facilitating maintenance of the bubble reduction structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of a riser tensioner according to an embodiment of the present invention;

[0037] Figure 2It is a front view of a riser tensioner according to an embodiment of the present invention;

[0038] Figure 3 A side view of a riser tensioner according to an embodiment of the present invention;

[0039] Figure 4 A front view of a tensioning cylinder assembly of a riser tensioner according to an embodiment of the present invention;

[0040] Figure 5 A bottom view of a tensioning cylinder assembly of a riser tensioner according to an embodiment of the present invention;

[0041] Figure 6 A side view of a tensioning cylinder assembly of a riser tensioner according to an embodiment of the present invention;

[0042] Figure 7 for Figure 6 Sectional view along AA direction;

[0043] Figure 8 for Figure 4 A partial enlarged view of point B in the middle;

[0044] Fig. 9 for Figure 4 A partial enlarged view of point C in the middle;

[0045] Fig.10 It is the front view of the cylinder;

[0046] Fig.11 It is a bottom view of the cylinder;

[0047] Fig.12 It is the left view of the cylinder;

[0048] Fig.13 It is the right side view of the cylinder;

[0049] Fig.14 for Fig.12 Cross-sectional view along the DD direction;

[0050] Fig.15 for Fig.14 A partial enlarged view of point E in the middle;

[0051] Fig.16 for Fig.14 A partial enlarged view of the F in the middle;

[0052] Fig.17 is a cross-sectional view of a piston head according to an embodiment of the present invention;

[0053] Fig.18 This is a schematic structural diagram of a piston head according to an embodiment of the present invention;

[0054] Fig.19 It is the front view of the accumulator;

[0055] Fig. 20 for Fig.19 Sectional view along the GG axis;

[0056] Fig.21 It is the front view of the bubble reduction structure;

[0057] Fig. 22 It is a structural schematic diagram of the bubble reduction structure;

[0058] Fig.23 This is the main view of the gas end stop valve group;

[0059] Fig.24 This is the right view of the gas end stop valve group;

[0060] Fig.25 This is the left view of the gas end stop valve group;

[0061] Fig.26 for Fig.25 Cross-sectional view along the mid-HH direction;

[0062] Fig. 27 It is a structural diagram of the gas end stop valve group;

[0063] Fig.28 is a front view of the stroke measuring device;

[0064] Fig.29 It is a structural schematic diagram of the stroke measuring device. DETAILED DESCRIPTION

[0065] In order to better understand the purpose, structure and function of the present invention, the tensioning cylinder assembly and the watertight pipe tensioner of the watertight pipe tensioner of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0066] like Figure 4 , Figure 5 and Fig. 20 As shown, it shows a tensioning cylinder assembly of a watertight pipe tensioner according to an embodiment of the present invention, including a cylinder 11 and an accumulator 12. The oil port at the lower end of the cylinder 11 is connected to the liquid port at the lower end of the accumulator 12. The cylinder 11 and the accumulator 12 are fixed together. The cylinder 11 is a plunger cylinder with double-acting characteristics, and the accumulator 12 is a pistonless accumulator. A bubble reduction structure 124 is detachably connected to the accumulator 12. The bubble reduction structure 124 is used to reduce the gas dissolved in the hydraulic oil to reduce the cavitation of the hydraulic components by the gas.

[0067] The liquid cylinder 11 of this embodiment is a double-acting plunger liquid cylinder, which maintains the stability and sealing reliability of the double-acting liquid cylinder, and has the advantages of the plunger liquid cylinder, solving the multiple problems faced by the existing tensioning liquid cylinder assembly in the selection of the plunger liquid cylinder and the double-acting liquid cylinder. The accumulator 12 of this embodiment is a pistonless accumulator, thereby eliminating the daily maintenance process of replacing the piston seal, and the present embodiment is provided with a bubble reduction structure 124 in the accumulator 12, thereby solving the problem of air cavitation existing in the existing tensioning liquid cylinder assembly, and greatly reducing the cavitation of components. Again, the accumulator 12 of this embodiment is detachably connected to the bubble reduction structure 124, thereby facilitating the maintenance of the bubble reduction structure 124.

[0068] The accumulator 12 is fixed together with the liquid cylinder 11 through the accumulator fixing frame 15. There are two sets of accumulator fixing frames 15. Each set of accumulator fixing frames 15 is a combination of a pad and a U-bolt 162. The outside of the accumulator 12 and the liquid cylinder 11 are provided with grooves that match the accumulator fixing frames 15. This embodiment adopts two sets of accumulator fixing frames 15, and grooves are respectively formed on the outside of the cylinder barrels of the accumulator 12 and the liquid cylinder 11, which can ensure that the accumulator 12 is reliably bound to the liquid cylinder 11.

[0069] The embodiment of the present invention adopts an integrated design concept, such as Figure 7 As shown, the hydraulic cylinder 11, the accumulator 12 and the anti-recoil valve group 13 are integrated, wherein the anti-recoil valve group 13 is connected between the oil port of the hydraulic cylinder 11 and the liquid port of the lower end (i.e., the liquid end) of the accumulator. The configuration of this embodiment enables the oil port of the hydraulic cylinder 11 to be directly connected to the anti-recoil valve group 13, and the anti-recoil valve group 13 is directly installed at the liquid end of the accumulator 12. The hydraulic channels between the hydraulic cylinder 11 and the anti-recoil valve group 13, and between the anti-recoil valve group 13 and the accumulator 12 are directly connected, sealed with a seal, and fastened with bolts, which saves pipes, bends, and other components compared with the prior art. The installation and design of the head; the anti-recoil valve group 13 of the embodiment of the present invention is a standard configuration of the tensioner and is a set of safety equipment. Under normal circumstances, the anti-recoil valve group 13 is in a normally open state to connect the oil port of the hydraulic cylinder 11 and the liquid port of the accumulator 12. The hydraulic oil in the hydraulic cylinder 11 and the accumulator 12 passes through the valve almost without resistance. When the wire rope breaks or an emergency detachment occurs, the opening of the internal flow channel of the anti-recoil valve group 13 is controlled automatically by hydraulic pressure or a preset program, thereby realizing the control of the speed of the hydraulic cylinder 11 and ensuring the safety of the entire system.

[0070] Among them, Figure 7As shown, ball valves 18 are installed at the bottom of the cylinder 11 and the bottom of the accumulator 12. A flow hole is provided at the bottom of the cylinder 11, and a ball valve 18 is installed at the flow hole; two flow holes are provided at the liquid end of the accumulator 12, and a ball valve 18 is installed in each flow hole. The ball valve 18 of this embodiment is in a normally closed state, and can be used to charge and discharge hydraulic oil after the ball valve 18 is opened.

[0071] Among them, Figure 7 As shown, the upper end (i.e., the gas end) of the accumulator 12 is connected to a gas end stop valve group 14. The gas end stop valve group 14 of this embodiment is directly installed at the gas end of the accumulator 12. The gas pressure channel between the gas end stop valve group 14 and the accumulator 12 of this embodiment adopts a direct connection, a seal, and a bolt fastening method, which eliminates the installation and design of pipes and elbows. The gas end stop valve group 14 is in a normally closed state, and the gas end stop valve group 14 can connect the internal space of the accumulator 12 and the main gas path of the ship when it is opened.

[0072] The hydraulic and pneumatic channels of this embodiment are directly connected, sealed with seals, and fastened with bolts, eliminating the installation and design of pipes and elbows, thereby greatly reducing the design of pipelines and mounting brackets, improving the integration of the tensioner, and effectively controlling the weight and size of the equipment.

[0073] Among them, Fig. 9 As shown, a safety valve 19 is installed at the upper end of the accumulator 12. Specifically, a flow channel hole is opened at the upper end of the accumulator 12, and the safety valve 19 is installed in the flow channel hole. The setting of the safety valve 19 can prevent the accumulator 12 from overpressure.

[0074] Among them, Fig.23 , Fig.24 , Fig.25 , Fig.26 and Fig. 27 As shown, the gas-end stop valve group 14 includes a valve block body 141, which is sealed and fixedly connected to the upper end of the accumulator 12, and the valve block body 141 is sealed and fixedly connected to a face-mounted ball valve 142, and the face-mounted ball valve 142 is sealed and fixedly connected to a flange head 143, which is used for sealing and fixedly connecting to the main gas circuit of the ship, and the valve block body 141, the face-mounted ball valve 142 and the flange head 143 are provided with flow channels connected in sequence, and the face-mounted ball valve 142 is in a normally closed state.

[0075] In this embodiment, the gas end stop valve group 14 includes a valve block body 141, a face-mounted ball valve 142 and a flange head 143. Among the three, the valve block body 141 and the face-mounted ball valve 142 are fixedly connected by bolts, and the face-mounted ball valve 142 and the flange head 143 are fixedly connected by bolts. The corresponding valve block body 141 is designed with a screw countersunk hole. Among them, the valve block body 141 and the gas end of the accumulator 12, the valve block body 141 and the face-mounted ball valve 142 are connected through end face seals, and the flange head 143 is welded and connected to the main gas pipeline of the ship. The valve block body 141, the face-mounted ball valve 142 and the flange head 143 are provided with flow channels that are connected in sequence, and the flow channels are 90° flow channels. The face-mounted ball valve 142 of this embodiment is in a normally closed state, so that the accumulator 12 cannot be connected to the main gas path of the ship through the aforementioned 90° flow channel under normal conditions. When the two need to be connected, the face-mounted ball valve 142 can be opened.

[0076] Among them, a discharge port, a bypass port and a pressure measuring port are opened on the flow channel of the valve block body 141. A pressure relief needle valve 144 is installed at the discharge port. The pressure relief needle valve 144 is in a normally closed state, and the pressure relief needle valve 144 can relieve pressure for the accumulator 12 after opening. The bypass port is fixedly connected to one end of a bypass needle valve 145, and the other end of the bypass needle valve 145 is connected to the flow channel on the flange head 143. The bypass ball valve 18 is in a normally closed state. A pressure gauge needle valve 147 is installed at the pressure measuring port, and the pressure gauge needle valve 147 is connected to a pressure gauge 146.

[0077] The bypass needle valve 145 of this embodiment is used to enable the face-mounted ball valve 142 to be opened smoothly. Specifically, when the pressure difference between the two ends of the face-mounted ball valve 142 is too large, the operator will not be able to overcome the opening torque of the face-mounted ball valve 142 to operate the face-mounted ball valve 142. At this time, the bypass needle valve 145 is opened to balance the pressure at both ends of the face-mounted ball valve 142. After the pressure at both ends of the face-mounted ball valve 142 is balanced, the opening torque of the face-mounted ball valve 142 will be greatly reduced, so that the operator can smoothly open the face-mounted ball valve 142. The pressure relief needle valve 144 of this embodiment is used to quickly relieve pressure for the tensioning cylinder assembly; the settings of the pressure gauge needle valve 147 and the pressure gauge 146 facilitate the operator to observe the pressure inside the accumulator 12 at any time to ensure safe operation.

[0078] Among them, Fig. 9 , Fig. 20 As shown, the upper end of the accumulator 12 is threadedly connected with a liquid level probe 125, and one end of the liquid level probe 125 extending outside the accumulator 12 is connected with a filling needle valve 20, the filling needle valve 20 is in a normally closed state, and after the filling needle valve 20 is opened during the filling process, the filling condition of the accumulator 12 can be guided by the cooperation of the liquid level probe 125 and the filling needle valve 20.

[0079] In specific use, when it is necessary to fill the tensioning cylinder assembly, first retract the cylinder 11 completely, open the filling needle valve 20 at the gas end of the accumulator 12, close the face-type ball valve 142 at the same time, pass low-pressure air through the discharge needle valve, and use the accumulator 12 or any ball valve 18 at the bottom of the cylinder 11 to fill. Observe the outflow of the filling needle valve 20 at regular intervals. If the liquid level in the accumulator 12 does not reach the height of the liquid level probe 125, the medium flowing out of the filling needle valve 20 is air. If the liquid level reaches the height of the liquid level probe 125, the medium flowing out of the filling needle valve 20 is hydraulic oil. When the medium flowing out of the filling needle valve 20 is hydraulic oil, the liquid level has reached the use requirement, stop filling, and close the discharge needle valve.

[0080] The liquid level probe 125 at the top of the accumulator 12 of this embodiment is mainly used to guide the filling of the liquid. The liquid level probe 125 is connected to the accumulator 12 through a thread, and then connected to the filling needle valve 20. The length of the liquid level probe 125 represents the maximum value of the internal liquid level of the accumulator 12 after the tensioning cylinder assembly is fully retracted. Under normal circumstances, the amount of liquid filled in the tensioning cylinder assembly should be greater than the sum of the oil volumes when the accumulator 12 and the cylinder 11 are in the middle position, so as to prevent the oil from being sucked out.

[0081] like Fig.21 , Fig. 22 As shown, the bubble reduction structure 124 includes a filter 1241, which is a cylindrical structure with an opening at one end. Filter holes are arranged on the side wall and the bottom wall of the cylindrical structure, and a filter mounting block 1243 is fixedly connected to the open end of the filter 1241. An external thread structure is arranged on the outer circumference of the filter mounting block 1243. The filter mounting block 1243 is detachably connected to the accumulator 12 through the external thread structure on its outer circumference, and a liquid channel is arranged in the filter mounting block 1243.

[0082] During specific use, under the drive of the tensioning cylinder assembly, the oil in the accumulator 12 is exchanged with the oil in the cylinder 11 through the filter holes on the filter screen 1241 and the liquid channel of the filter screen mounting block 1243. To ensure the continuity of the flow channel and the minimum flow resistance, the inner diameter of the cylindrical structure of the filter screen 1241 and the inner diameter of the liquid channel of the filter screen mounting block 1243 should be consistent. Due to the obstruction of the filter screen 1241, the bubbles in the oil burst after passing through the holes, and the cavitation effect will be concentrated on the filter screen 1241, thereby avoiding the influence of cavitation on other hydraulic components in the tensioning cylinder assembly. At the same time, large-diameter impurities in the oil can also be blocked by the filter screen 1241, thereby avoiding the wear and blockage of components after entering the tensioning cylinder assembly. Since the cavitation effect is concentrated on the filter 1241, the filter 1241 is vulnerable. In this embodiment, the filter 1241 is fastened to the accumulator 12 through the external thread structure on the filter mounting block 1243, so that the filter 1241 can be regularly removed and replaced to continuously protect the interior of the tensioning cylinder assembly.

[0083] like Fig.19 , Fig. 20 As shown, the accumulator 12 includes an accumulator cylinder 121, the lower end of the accumulator cylinder 121 is detachably sealed and connected to an accumulator lower end cover 122, the upper end of the accumulator cylinder 121 is detachably sealed and connected to an accumulator upper end cover 123, an internal threaded liquid port is provided on the accumulator lower end cover 122, a filter mounting block 1243 is threadedly connected to the internal threaded liquid port, a polygonal connecting block 1242 is fixedly connected between the filter mounting block 1243 and the filter 1241, and the polygonal connecting block 1242 is used to cooperate with a wrench to connect the filter 1241 to the accumulator lower end cover 122.

[0084] In this embodiment, the filter screen mounting block 1243 is threadedly connected to the lower end cover 122 of the accumulator, so the lower end cover 122 of the accumulator can be removed regularly and the filter screen 1241 can be replaced. The filter screen 1241, the polygonal connection block 1242 and the filter screen mounting block 1243 are fixedly connected in sequence, wherein the filter screen 1241 is formed by cold bending and welding after punching a stainless steel plate, and the polygonal connection block 1242 is a polygonal stainless steel plate with a flow channel hole in the middle; the filter screen mounting block 1243 is a stainless steel pipe with an external thread structure on the outer circumference, and the polygonal connection block 1242 is, for example, a hexagonal shape. The polygonal connection block 1242 is provided with a flow channel hole, and the hole on the filter screen 1241, the flow channel hole on the polygonal connection block 1242, the liquid channel on the filter screen mounting block 1243 and the internal thread liquid port are connected in sequence, and the liquid port at the lower end of the accumulator 12 is the internal thread liquid port, which is connected to the oil port at the lower end of the liquid cylinder 11 through the anti-recoil valve group 13. In order to ensure the continuity of the flow channel and minimize the flow resistance, the inner diameter of the flow channel hole on the polygonal connecting block 1242 and the inner diameter of the liquid channel of the filter installation block 1243 should be consistent.

[0085] The accumulator cylinder 121 and the accumulator lower end cover 122, and the accumulator cylinder 121 and the accumulator upper end cover 123 are respectively spliced ​​by screws, and multiple seals are designed between the accumulator cylinder 121 and the accumulator lower end cover 122, and between the accumulator cylinder 121 and the accumulator upper end cover 123, so as to avoid leakage of the working medium through multiple seals. The accumulator lower end cover 122 is the liquid end, and the upper end cover is the gas end. The upper end cover is connected to the valve block body 141 of the gas end stop valve group 14, and the accumulator lower end cover 122 is connected to the anti-recoil valve group 13. The liquid level probe 125 is threadedly connected to the accumulator upper end cover 123.

[0086] The accumulator 12 in the embodiment of the present invention is a pistonless accumulator, and the hydraulic oil and air are in direct contact. Since the accumulator 12 is installed vertically and the lower end cover 122 of the accumulator faces downward, the hydraulic oil and air in the accumulator will be stratified internally, and the liquid level will change under the drive of the hydraulic cylinder 11. Since there is no piston, air molecules will dissolve in the hydraulic oil in the form of bubbles under the action of pressure. If not controlled, the cavitation of the bubbles at the throttling point will affect the life of the hydraulic components. In the embodiment of the present invention, a bubble reduction structure 124 is provided on the lower end cover 122 of the accumulator. The filter holes on the filter screen 1241 of the bubble reduction structure 124 can reduce cavitation and prevent pollutants. At the same time, the design of the detachable connection between the lower end cover 122 of the accumulator and the bubble reduction structure 124 is convenient for later maintenance and replacement.

[0087] Among them, Fig.10 As shown, the hydraulic cylinder 11 includes a hydraulic cylinder barrel 111 and a hydraulic cylinder piston rod 112. The bottom of the hydraulic cylinder barrel 111 is used to be fixedly connected to the fixed pulley block of the watertight pipe tensioner, and the hydraulic cylinder piston rod 112 is used to be fixedly connected to the movable pulley block of the watertight pipe tensioner. Specifically, the bottom of the hydraulic cylinder barrel 111 is provided with a mounting hole along the circumferential direction, and the end of the hydraulic cylinder piston rod 112 is provided with a threaded hole along the circumferential direction. The tensioner hydraulic cylinder assembly is fastened to the fixed pulley block at the bottom by bolt connection through the mounting hole, and the tensioner hydraulic cylinder assembly is fastened to the movable pulley block at the top by bolt connection through the threaded hole.

[0088] like Fig.14 As shown, the cylinder barrel 111 includes a cylinder body 1111, and the upper and lower ends of the cylinder body 1111 are respectively fixedly connected with a cylinder head 1112 and a cylinder lower end cover 1115. In specific implementation, the cylinder body 1111 and the cylinder head 1112, the cylinder body 1111 and the cylinder lower end cover 1115 are connected together by full penetration welding, so that the reliability of the cylinder barrel 111 is guaranteed. The cylinder lower end cover 1115 should be designed to have sufficient strength in structure to support the loads of the tensioning cylinder assembly in all directions.

[0089] like Fig.14 , Fig.15, Fig.17 , Fig.18 As shown, the cylinder piston rod 112 is located in the cylinder body 1111, and the cylinder piston rod 112 includes a piston head 1121 and a piston rod body 1122 that are fixedly connected. The piston head 1121 and the cylinder body 1111 are sealed and connected to divide the space in the cylinder body 1111 into a plug chamber and a rod chamber. A plurality of guide holes 11212 are arranged on the piston head 1121 between the sealing part between the piston head 1121 and the cylinder body 1111 and the piston rod body 1122. A connecting hole is opened on the piston head 1121, one end of the connecting hole is connected with the plurality of guide holes 11212, and the other end of the connecting hole extends toward the end close to the lower end cover 1115 of the cylinder to pass through the piston head 1121, and the plug chamber and the rod chamber are connected through the guide hole 11212 and the connecting hole.

[0090] The piston head 1121 and the cylinder body 1111 of this embodiment are sealed and connected, which serves the purpose of isolating the plug cavity and the rod cavity. The piston head 1121 can also be installed with components such as guide sleeves and wear-resistant rings as needed to guide the cylinder piston rod 112. The guide hole 11212 is set on the piston head 1121 between the sealing part and the piston rod body 1122, and the guide hole 11212 is connected to the connecting hole. The setting of the guide hole 11212 and the connecting hole in this embodiment realizes the connection between the plug cavity and the rod cavity, so that the cylinder 11 of this embodiment becomes a plunger cylinder with the characteristics of a double-acting cylinder.

[0091] Among them, the cylinder end 1112 is connected to a sealing dustproof structure, and the sealing dustproof structure and the piston rod body 1122 cooperate to seal the rod cavity and prevent dust from entering the rod cavity.

[0092] Among them, the main flow channel and the discharge flow channel hole are opened in the lower end cover 1115 of the cylinder, and the main flow channel is connected with the liquid port at the lower end of the accumulator through the anti-recoil valve group 13. The main flow channel is connected with the liquid port at the lower end of the accumulator to realize the circulation of liquid; the discharge flow channel hole is used for sewage discharge.

[0093] Among them, an oil outlet flange is connected in the main channel, and the oil outlet flange is connected to the liquid port at the lower end of the accumulator through an anti-recoil valve group 13. The oil outlet flange port 1116 is welded by a flange with a seal and a straight pipe. The straight pipe of the oil outlet flange port 1116 is fixed in the main channel of the lower end cover 1115 of the cylinder barrel by sinking welding.

[0094] The piston rod body 1122 is fixedly connected to a connecting end 1123 at one end away from the piston head 1121. The connecting end 1123 is provided with a step, which is used to cooperate with the mounting frame of the movable pulley block, that is, the step is used to limit the mounting frame of the movable pulley block to prevent the movable pulley block from loosening after installation. The piston head 1121 and the piston rod body 1122, the piston rod body 1122 and the connecting end 1123 are formed into the cylinder piston rod 112 through full penetration welding.

[0095] like Fig.16 As shown, the sealing and dustproof structure includes a second upper end cover 1114 and a sealing and dustproof assembly. The second upper end cover 1114 is fixedly connected to the first upper end cover 1113. The sealing and dustproof assembly is arranged in the second upper end cover 1114. The first upper end cover 1113 is fixedly connected to the cylinder end 1112. The first upper end cover 1113 is installed with a guide sleeve and a wear-resistant ring that cooperate with the piston rod body 1122.

[0096] That is, the cylinder barrel 111 of the present embodiment is composed of a cylinder barrel body 1111, a cylinder barrel end 1112, a first upper end cover 1113, a second upper end cover 1114, a cylinder barrel lower end cover 1115 and an oil outlet flange 1116. The first upper end cover 1113 is mainly used to install the guide sleeve, wear-resistant ring and other components of the cylinder piston rod 112, and plays the role of cylinder guidance and anti-eccentric wear. The first upper end cover 1113 is installed on the cylinder barrel end 1112 by screws arranged along the circumferential direction. The second upper end cover 1114 is mainly used to install the sealing and dustproof components of the cylinder piston rod 112, and plays the role of sealing the rod cavity and preventing dust from entering the rod cavity. The second upper end cover 1114 is installed on the first upper end cover 1113 by screws arranged along the circumferential direction.

[0097] The design of the two layers of end covers, namely the first upper end cover 1113 and the second upper end cover 1114, in this embodiment is based on the consideration of service life and maintenance convenience. Normally, the service life of the guide sleeve, the wear-resistant ring and the sealing and dustproof components are all different. By adopting a layered design, the sealing and dustproof component with the shortest service life is designed on the second upper end cover 1114 which is easiest to replace, and the guide sleeve and the wear-resistant ring with relatively long service life are designed on the first upper end cover 1113 of the lower layer. The convenience of on-site maintenance will be greatly improved.

[0098] like Fig.17 , Fig.18 As shown, the piston head 1121 includes a piston head body 11211, the guide hole 11212 and the connecting hole are both arranged on the piston head body 11211, the piston head body 11211 and the piston rod body 1122 are fixedly connected, the piston head body 11211 is threaded with a sealing mounting ring 11213 and a buffer ring 11215, the sealing mounting ring 11213 is sleeved with a sealing ring, the piston head 1121 and the cylinder body 1111 are sealed and connected via the sealing ring, and the side of the sealing mounting ring 11213 away from the buffer ring 11215 is limited by a limiting ring 11216 and a fastening screw 11214.

[0099] The piston head 1121 of this embodiment is assembled from a piston head body 11211, a sealing mounting ring 11213 and a buffer ring 11215. The sealing mounting ring 11213 and the buffer ring 11215 are both provided with internal threads, and are screwed in with the external threads on the piston head body 11211 for installation, and the fastening screws 11214 cooperate with the limiting ring 11216 to securely install the sealing mounting ring 11213 and the buffer ring 11215. The buffer ring 11215 replaces the annular spring of the plunger cylinder in the prior art to play a buffering role. The buffer ring 11215 of this embodiment is made of non-metallic materials and will not rust, so it will not affect the cleanliness of the system oil.

[0100] The guide hole 11212 is provided on the piston head body 11211. The flow channel formed by the guide hole 11212 and the connecting hole connects the plug cavity and the rod cavity of the cylinder. The guide hole 11212 is the key feature of the cylinder changing from a double-acting cylinder to a plunger cylinder. In specific implementation, for example, the guide holes 11212 are set to 6.

[0101] The hydraulic cylinder of the embodiment of the present invention is divided into two chambers, a plug chamber and a rod chamber. The plug chamber and the rod chamber are connected, and the action surface of the hydraulic cylinder output is only the cross-section of the piston rod. A guide and sealing component is designed between the hydraulic cylinder barrel 111 and the piston head 1121, and the stability and life of the hydraulic cylinder are guaranteed. A hydraulic throttling buffer can be designed on the first upper end cover 1113 of the hydraulic cylinder barrel 111, which simplifies the spring buffer design of the traditional plunger type hydraulic cylinder.

[0102] Among them, Fig.11 , Fig.12 As shown, the two ends of the cylinder barrel 111 are respectively fixedly connected with lifting ears 113, and the cylinder barrel 111 is fixedly connected with a cylinder lateral fixing seat 114, which is used to cooperate with the cylinder support frame of the watertightening pipe tensioner to fix the upper end of the tensioning cylinder assembly.

[0103] The arrangement of the lifting lugs 113 facilitates the lifting of the cylinder. In a specific implementation, for example, four lifting lugs 113 are respectively installed at both ends of the cylinder barrel 111. The cylinder lateral fixing seat 114 is a forging. The cylinder lateral fixing seat 114 and the cylinder barrel 111 are welded and fixed. When in use, threaded holes are opened at the bottom of the cylinder lateral fixing seat 114 and the cylinder support frame are used to ensure that the upper end of the tensioning cylinder assembly is firmly fixed. The angle between the cylinder lateral fixing seat 114 and the center line of the cylinder is determined by the installation and fixing method of the accumulator, such as Figure 6 As shown, the angle between the plane where the axis of the accumulator and the axis of the cylinder are located and the vertical plane where the axis of the cylinder is located is 45°. Fig.13 As shown, the angle between the cylinder lateral fixing seat 114 and the vertical plane where the axis of the cylinder is located is also 45°.

[0104] like Figure 4 As shown, a stroke measuring device 16 is fixed to the outside of the hydraulic cylinder or the accumulator, and the stroke measuring device 16 is used to cooperate with the movable pulley block of the watertight pipe tensioner to measure the stroke of the hydraulic cylinder.

[0105] like Fig.28 , Fig.29 As shown, the stroke measuring device 16 is a draw-rope displacement sensor, the body 164 of the draw-rope displacement sensor is fixed on a mounting plate 161, the mounting plate 161 is fixed to the outside of the hydraulic cylinder or the accumulator by a UU-type bolt 162, a protective shell 163 is connected to the mounting plate 161, the body 164 of the draw-rope displacement sensor is located in the protective shell 163, and the rope head 167 of the draw-rope displacement sensor passes through the protective shell 163 and is fixed on the movable pulley block.

[0106] The stroke measuring device 16 of this embodiment is fixed on the outside of the hydraulic cylinder or the accumulator. The main component of the stroke measuring device 16 of this embodiment is a pull-rope displacement sensor, which has a spring self-reset structure for realizing the self-reset of the pull-rope rope head. When in use, the extension and retraction of the hydraulic cylinder piston rod 112 will drive the top movable pulley block to move, and the movable pulley block moves, and the rope head 167 of the pull-rope displacement sensor moves accordingly, so that the output signal of the body 164 of the pull-rope displacement sensor changes, and the stroke of the hydraulic cylinder is measured.

[0107] In order to facilitate the installation and protection of the rope-pull type displacement sensor, a mounting plate 161 and a UU-type bolt 162 are designed, and the mounting plate 161 and the UU-type bolt 162 are used to install the rope-pull type displacement sensor on the cylinder barrel 111; the body 164 of the rope-pull type displacement sensor is located in the protective shell 163, and the protective shell 163 is waterproof and explosion-proof, which can effectively protect the body 164 of the rope-pull type displacement sensor from the external salt spray environment or mechanical collision, thereby extending its service life; the protective shell 163 is also installed with wiring terminals 165, terminal guides 166 and related accessories for electrical wiring of the body 164 of the rope-pull type displacement sensor.

[0108] like Figure 4 ,like Figure 8 As shown, a pressure measuring device 17 is fixedly installed at the bottom of the cylinder through a fixed sleeve 173, and the pressure measuring device 17 is used to measure the pressure inside the cylinder. Specifically, the pressure measuring device 17 includes a pressure sensor 171 and a pressure measuring lead-out pipeline 174. A flow channel hole is opened at the bottom of the cylinder, and the pressure measuring lead-out pipeline 174 is located in the flow channel hole. One end of the pressure measuring lead-out pipeline 174 extending out of the flow channel hole is connected to the pressure sensor 171. A sensor needle valve 172 is provided on the pressure measuring lead-out pipeline 174, and the sensor needle valve 172 is in a normally open state.

[0109] The pressure measuring device 17 includes a pressure sensor 171 and a pressure measuring lead-out line 174. The pressure measuring lead-out line 174 is used to lead the internal pressure of the liquid cylinder to the pressure sensor 171, and then the actual pressure inside the liquid cylinder can be measured by the pressure sensor 171. The sensor needle valve 172 is used when replacing the sensor. The sensor needle valve 172 is in a normally open state. When necessary, the sensor needle valve 172 can be closed to replace the pressure sensor 171. The fixing sleeve 173 is used to fix the pressure measuring device 17 reliably.

[0110] The tensioning cylinder assembly of the embodiment of the present invention has the following advantages:

[0111] Longer service life of the equipment: The double-acting hydraulic cylinder design concept is adopted. The piston rod is designed with guide and sealing elements at the piston head and the cylinder end. The local eccentric load on the piston rod is smaller, and the service life of the piston rod body and seals is longer;

[0112] The anti-fouling and anti-cavitation bubble reduction structure design inside the accumulator reduces the cavitation and pollution of the internal hydraulic components during the exchange of oil between the cylinder and the accumulator, ensuring the operation of the equipment.

[0113] High integration: The main body of the tensioner's "liquid-gas spring" actuator is designed in an integrated manner. The accumulator is directly bundled with the hydraulic cylinder. The anti-recoil valve group is directly connected to the accumulator liquid end, and the gas end stop valve group is also integrated. The whole set of equipment is highly compact and has fewer pipelines.

[0114] Convenient maintenance and use: The hydraulic cylinder adopts a double-layer end cover design of the first upper end cover and the second upper end cover, which is convenient for on-site replacement of sealing, wear-resistant, guiding and other components;

[0115] There is no piston inside the accumulator, which avoids the influence of air on the tensioner itself and saves the daily maintenance process of replacing the piston seal. At the same time, a liquid level probe is designed inside the accumulator to facilitate on-site filling. The equipment is highly integrated, with fewer leakage points and is more convenient for maintenance.

[0116] The embodiment of the present invention further provides a watertightening device, such as Figure 1 , Figure 2 and Figure 3 As shown, the tensioning cylinder assembly 1 of the watertight pipe tensioner including any one of the above items also includes a fixed pulley block 2, a movable pulley block 3, a cylinder support frame 4, a tensioning wire rope 5, etc. During normal use, a vertical installation method is adopted, and the fixed pulley block 2 and the cylinder support frame 4 are connected to the platform steel structure mounting seat. One end of the tensioning wire rope 5 is fixed on the fixed pulley block 2, and the other end is connected to the watertight pipe string after passing through the wheel train composed of the movable pulley block 3 and the fixed pulley block 2. Due to the movement of the ship, the tensioning cylinder assembly 1 will drive the movable pulley block 3 to move, and the force acting on the tensioning wire rope remains basically stable.

[0117] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0118] In addition, the terms "one", "two", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0119] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A tensioning cylinder assembly of a riser tensioner, comprising a cylinder and an accumulator, wherein the oil port at the lower end of the cylinder is connected to the liquid port at the lower end of the accumulator, and characterized in that: The hydraulic cylinder and the accumulator are fixed together, the hydraulic cylinder is a double-acting plunger hydraulic cylinder, the accumulator is a pistonless accumulator, and a bubble reduction structure is detachably connected inside the accumulator, and the bubble reduction structure is used to reduce the gas dissolved in the hydraulic oil to reduce the cavitation of the hydraulic components by the gas.

2. The tensioning cylinder assembly of the riser tensioner according to claim 1, characterized in that: An anti-recoil valve group is connected between the oil port at the lower end of the hydraulic cylinder and the liquid port at the lower end of the accumulator, and the anti-recoil valve group is in a normally open state to connect the oil port of the hydraulic cylinder and the liquid port of the accumulator; ball valves are respectively installed at the bottom of the hydraulic cylinder and the bottom of the accumulator, and the ball valves are in a normally closed state, and can be used to charge and discharge hydraulic oil after opening; The upper end of the accumulator is threadedly connected with a liquid level probe, and one end of the liquid level probe extending outside the accumulator is connected with a filling needle valve, the filling needle valve is in a normally closed state, and after the filling needle valve is opened during the filling process, the filling condition of the accumulator can be guided by the cooperation of the liquid level probe and the filling needle valve; a safety valve is installed at the upper end of the accumulator; The accumulator is fixed together with the hydraulic cylinder through an accumulator fixing frame, the accumulator fixing frame is divided into two groups, and the outside of the accumulator and the hydraulic cylinder are both provided with grooves matched with the accumulator fixing frame.

3. The tensioning cylinder assembly of the riser tensioner according to claim 1, characterized in that: The upper end of the accumulator is connected to a gas end stop valve group, which is in a normally closed state and can connect the internal space of the accumulator with the main gas path of the ship when the gas end stop valve group is opened.

4. The tensioning cylinder assembly of the riser tensioner according to claim 3, characterized in that: The gas end stop valve group comprises a valve block body, the valve block body is sealed and fixedly connected to the upper end of the accumulator, the valve block body is sealed and fixedly connected to a face-mounted ball valve, the face-mounted ball valve is sealed and fixedly connected to a flange head, the flange head is used to be sealed and fixedly connected to the main gas circuit of the ship, the valve block body, the face-mounted ball valve and the flange head are provided with flow channels connected in sequence, and the face-mounted ball valve is in a normally closed state; A discharge port, a bypass port and a pressure measuring port are provided on the flow channel of the valve block body. A pressure relief needle valve is installed at the discharge port. The pressure relief needle valve is in a normally closed state and can relieve pressure from the accumulator after opening. The bypass port is fixedly connected to one end of the bypass needle valve. The other end of the bypass needle valve is communicated with the flow channel on the flange head. The bypass ball valve is in a normally closed state. A pressure gauge needle valve is installed at the pressure measuring port, and the pressure gauge needle valve is connected to a pressure gauge.

5. The tensioning cylinder assembly of the riser tensioner according to claim 1, characterized in that: The bubble reduction structure includes a filter screen, which is a cylindrical structure with an opening at one end. Filter holes are arranged on the side wall and the bottom wall of the cylindrical structure, and a filter screen mounting block is fixedly connected to the open end of the filter screen. An external thread structure is arranged on the outer circumference of the filter screen mounting block. The filter screen mounting block is detachably connected to the accumulator through the external thread structure on its outer circumference, and a liquid channel is arranged in the filter screen mounting block.

6. The tensioning cylinder assembly of the riser tensioner according to claim 5, characterized in that: The accumulator comprises an accumulator cylinder, the lower end of the accumulator cylinder is detachably sealed and connected to the accumulator lower end cover, the upper end of the accumulator cylinder is detachably sealed and connected to the accumulator upper end cover, the accumulator lower end cover is provided with an internal threaded liquid port, the filter screen mounting block is threadedly connected to the internal threaded liquid port, a polygonal connecting block is fixedly connected between the filter screen mounting block and the filter screen, and the polygonal connecting block is used to cooperate with a wrench to connect the filter screen to the accumulator lower end cover; The filter is made of stainless steel plate that is punched and then cold-bent and welded. The polygonal connecting block is provided with flow holes. The holes on the filter, the flow holes on the polygonal connecting block, the liquid channel on the filter mounting block and the internal threaded liquid port are connected in sequence. The internal threaded liquid port is connected to the oil port at the lower end of the liquid cylinder. The polygonal connecting block is a polygonal stainless steel plate with a flow hole in the middle. The filter mounting block is a stainless steel pipe with an external threaded structure on the outer circumference.

7. The tensioning cylinder assembly of the riser tensioner according to claim 1, characterized in that: The hydraulic cylinder comprises a hydraulic cylinder barrel and a hydraulic cylinder piston rod, the bottom of the hydraulic cylinder barrel is used to be fixedly connected to the fixed pulley block of the watertight pipe tensioner, and the hydraulic cylinder piston rod is used to be fixedly connected to the movable pulley block of the watertight pipe tensioner; The cylinder barrel of the hydraulic cylinder comprises a cylinder barrel body, the upper end and the lower end of the cylinder barrel body are respectively fixedly connected with a cylinder barrel end head and a cylinder barrel lower end cover, the hydraulic cylinder piston rod comprises a piston head and a piston rod body that are fixedly connected, the piston head and the cylinder barrel body are sealed and connected to divide the space in the cylinder barrel body into a plug chamber and a rod chamber, a plurality of guide holes are arranged on the piston head between the sealing part of the piston head and the cylinder barrel body and the piston rod body, a connecting hole is opened on the piston head, one end of the connecting hole is connected with the plurality of the guide holes, and the other end of the connecting hole extends to an end close to the cylinder barrel lower end cover to pass through the piston head, and the plug chamber and the rod chamber are connected through the guide hole and the connecting hole; A main flow channel and a discharge flow channel hole are opened in the lower end cover of the cylinder, and the main flow channel is connected to the liquid port at the lower end of the accumulator. The end of the cylinder is connected to a sealing dustproof structure, and the sealing dustproof structure cooperates with the piston rod body to seal the rod cavity and prevent dust from entering the rod cavity.

8. The tensioning cylinder assembly of the riser tensioner according to claim 7, characterized in that: An oil outlet flange is connected in the main channel, and the oil outlet flange is communicated with the liquid port at the lower end of the accumulator. The oil outlet flange is welded by a flange with a seal and a straight pipe, and the straight pipe of the oil outlet flange is fixed in the main channel of the lower end cover of the cylinder barrel by sink welding; The piston rod body is fixedly connected to a connecting end at one end away from the piston head, and a step is provided on the connecting end, and the step is used to cooperate with the mounting frame of the movable pulley block; The sealing and dustproof structure includes a second upper end cover and a sealing and dustproof assembly. The second upper end cover is fixedly connected to the first upper end cover. The sealing and dustproof assembly is arranged in the second upper end cover. The first upper end cover is fixedly connected to the cylinder end. The first upper end cover is installed with a guide sleeve and a wear-resistant ring that cooperate with the piston rod body.

9. The tensioning cylinder assembly of the riser tensioner according to claim 7, characterized in that: The piston head comprises a piston head body, the guide hole and the communicating hole are both arranged on the piston head body, the piston head body and the piston rod body are fixedly connected, a sealing mounting ring and a buffer ring are threadedly connected to the piston head body, a sealing ring is sleeved on the sealing mounting ring, the piston head and the cylinder body are sealed and connected via the sealing ring, and the side of the sealing mounting ring away from the buffer ring is limited by a limiting ring and a fastening screw; Both ends of the cylinder barrel are respectively fixedly connected with lifting ears, and a cylinder lateral fixing seat is fixedly connected to the cylinder barrel. The cylinder lateral fixing seat is used to cooperate with the cylinder support frame of the watertight pipe tensioner to fix the upper end of the tensioning cylinder assembly.

10. The tensioning cylinder assembly of the riser tensioner according to claim 1, characterized in that: A stroke measuring device is fixed to the outside of the hydraulic cylinder or the accumulator, and the stroke measuring device is used to cooperate with the movable pulley block of the watertight pipe tensioner to measure the stroke of the hydraulic cylinder.

11. The tensioning cylinder assembly of the riser tensioner according to claim 10, characterized in that: The stroke measuring device is a pull-rope displacement sensor, the body of the pull-rope displacement sensor is fixed on a mounting plate, the mounting plate is fixed on the outside of the hydraulic cylinder or the accumulator, a protective shell is connected to the mounting plate, the body of the pull-rope displacement sensor is located in the protective shell, and the rope end of the pull-rope displacement sensor passes through the protective shell and is fixed on the movable pulley block.

12. The tensioning cylinder assembly of the riser tensioner according to claim 1, characterized in that: A pressure measuring device is fixedly installed at the bottom of the liquid cylinder, and the pressure measuring device is used to measure the pressure inside the liquid cylinder.

13. The tensioning cylinder assembly of the riser tensioner according to claim 12, characterized in that: The pressure measuring device includes a pressure sensor and a pressure measuring lead-out pipeline. A flow channel hole is opened at the bottom of the liquid cylinder. The pressure measuring lead-out pipeline is located in the flow channel hole. One end of the pressure measuring lead-out pipeline extending out of the flow channel hole is connected to the pressure sensor. A sensor needle valve is arranged on the pressure measuring lead-out pipeline, and the sensor needle valve is in a normally open state.

14. A riser tensioner, characterized in that: A tensioning cylinder assembly comprising a riser tensioner as described in any one of claims 1-13.

Images