Dynamic sealing connection system of glass fiber reinforced plastic pipeline for ship

Abstract

The invention relates to the technical field of ship pipeline connection, in particular to a dynamic sealing connection system of a glass fiber reinforced plastic pipeline for a ship, which comprises the following modules: a connection main body module, a dynamic sealing module, a vibration buffer module, a load regulation module, a corrosion protection module and a state monitoring module, the dynamic sealing performance is excellent, the axial displacement is adapted to + / -5 mm, the radial vibration is adapted to + / -2 mm, the angular displacement is adapted to + / -3 degrees, the sealing leakage rate is smaller than or equal to 1 * 10 <-6 > m < 3 > / s (3 times higher than the GB / T21238-2020 standard), the seawater-resistant service life of a sealing piece is longer than or equal to 5 years, a metal insert is not rusted after being tested for 1000 hours through a salt spray test, and the service life is prolonged by more than two times compared with a traditional structure.

Description

Technical Field

[0001] This invention relates to the field of marine pipeline connection technology, specifically a dynamic sealing connection system for fiberglass pipes used in ships. Background Technology

[0002] In marine engineering, fiberglass reinforced plastic (FRP) pipes are widely used in seawater cooling systems, sewage discharge systems, and other applications due to their advantages such as corrosion resistance and light weight. However, existing shipboard FRP pipe connection technologies suffer from the following core problems:

[0003] Dynamic seal failure risk: When a ship is in operation, the pipeline is affected by dynamic loads such as hull vibration, thermal expansion and contraction, and mechanical impact. The static sealing structure of traditional flange connection (such as rubber sealing ring) is prone to fatigue cracks, which can lead to seawater and fuel leakage. The probability of seal failure increases significantly, especially in high salt spray and high humidity environments.

[0004] Insufficient vibration damping capacity: The existing connection structure lacks professional vibration damping design and cannot effectively absorb the high-frequency vibration (10-50Hz, amplitude 0.5-2mm) transmitted from the hull to the pipeline. Long-term vibration leads to accelerated wear of the seals, loosening of the connecting bolts, and even pipeline breakage accidents.

[0005] Corrosion protection deficiencies: Electrochemical corrosion between fiberglass and metal flanges (potential difference ≥ 0.3V), and insufficient seawater corrosion resistance of sealing materials (e.g., the lifespan of ordinary nitrile rubber in seawater is < 2 years) make the connection points vulnerable to corrosion in the pipeline system.

[0006] Lack of condition monitoring: Existing systems cannot monitor key parameters such as the wear degree of seals, changes in the torque of connecting bolts, and local corrosion rates in real time, making it difficult to provide early warnings of seal failure risks and resulting in high maintenance costs (average annual maintenance costs account for 15%-20% of the total cost of the pipeline system). Therefore, a dynamic sealing connection system for fiberglass pipes used in ships is proposed. Summary of the Invention

[0007] In view of this, the present invention provides a dynamic sealing connection system for fiberglass pipes for ships, in order to solve or alleviate the technical problems existing in the prior art, and at least provide a beneficial alternative.

[0008] The technical solution of the present invention is implemented as follows: a dynamic sealing connection system for fiberglass pipes for ships, comprising the following modules: a connection body module, a dynamic sealing module, a vibration buffer module, a load adjustment module, a corrosion protection module, and a condition monitoring module.

[0009] More preferably, the connecting main module adopts a double-flange connecting cylinder, including a left flange, a right flange, and a middle flexible connecting cylinder. The left / right flanges are integrally formed with the FRP pipe through a glass fiber winding process, with a surface roughness Ra≤1.6μm. The middle flexible connecting cylinder adopts a composite structure of FRP reinforcement layer (inner layer) + nitrile rubber elastic layer (middle layer) + polytetrafluoroethylene wear-resistant layer (outer layer), with a thickness ratio of 3:2:1. It can withstand axial tensile load ≥50kN and radial compressive load ≥30kN. The flange substrate is glass fiber reinforced unsaturated polyester resin (tensile strength ≥300MPa, seawater corrosion rate ≤0.01mm / year). The metal inserts (around the bolt holes) are made of titanium alloy (TA2) to avoid electrochemical corrosion with FRP (potential difference <0.1V).

[0010] Further preferably, the dynamic sealing module includes a sealing ring made of hydrogenated nitrile butadiene rubber (HNBR) with a Shore hardness of 85±5A and a modified Ω-shaped cross-section. The inner side has three annular raised ribs (2mm high, 5mm spacing) to increase the sealing contact area (40% higher than traditional O-rings), adapting to dynamic contact of the sealing surface during radial vibration. A sealing groove (5mm deep, 60° angle) is provided on one side of the left / right flange for installing the sealing ring. The groove has drainage holes (2mm diameter, 20mm spacing) at the bottom to promptly drain condensate and corrosive media from the sealing surface, preventing aging of the seal due to localized liquid accumulation (aging rate reduced by 60%).

[0011] In a further preferred embodiment, the vibration buffer module has four sets of magnetorheological dampers on the outside of the flexible connecting cylinder, with Fe3O4 magnetorheological fluid inside. The damping force (0-50N) is adjusted by current to suppress radial vibration amplitude ≤0.5mm (70% reduction compared to traditional structures).

[0012] Further preferably, the load adjustment module uses shape memory alloy bolts (SMA bolts) made of Ti-Ni alloy with a preload temperature compensation coefficient of 0.8 N / ℃. It can automatically adjust the preload (range 5-15 kN) according to the ambient temperature (-20℃~60℃) to avoid bolt loosening caused by temperature changes (traditional bolt loosening rate ≥10% / year, this system ≤2% / year). Piezoelectric ceramic plates (402) are set around the bolt holes to monitor bolt torque changes in real time (accuracy ±0.5 N·m) and transmit the data to the ship monitoring system via a wireless module (403).

[0013] More preferably, the corrosion protection module has a graphene-modified epoxy resin coating (50 μm thick) on the surface of the flange metal insert, which shows no rust after 1000 hours of salt spray testing (NSS), and a zinc alloy sacrificial anode (204) is embedded in the sealing ring groove with a potential of -1.1V (vsSCE), and a protection area of ​​1.5m². 2The anode life is ≥3 years, and the outer polytetrafluoroethylene layer (0.5mm thick) of the flexible connecting cylinder has a seawater permeability of ≤0.01kg / (m³). 2 ·d), the main sealing ring made of HNBR material has a seawater swelling rate of ≤5% (after immersion in seawater at 70℃ for 1000 hours).

[0014] In a further preferred embodiment, the condition monitoring module has a corrosion rate sensor installed inside the flexible connecting cylinder, employing linear polarized resistor (LPR) technology to measure the localized corrosion current density in real time (accuracy ±0.1 μA / cm). 2 An early warning is triggered when the corrosion rate is greater than 0.02 mm / year.

[0015] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions:

[0016] I. This invention exhibits excellent dynamic sealing performance: it adapts to axial displacement ±5mm, radial vibration ±2mm, and angular displacement ±3°, with a sealing leakage rate ≤1×10⁻⁶. -6 m 3 / s (3 times higher than GB / T21238-2020 standard), the seals have a seawater resistance life of ≥5 years, and the metal inserts show no corrosion after 1000 hours of salt spray testing, which is more than twice the life of traditional structures.

[0017] II. This invention provides real-time feedback of sealing status parameters, with an early warning accuracy rate of ≥95%, reduces the frequency of unplanned maintenance by more than 40%, has a vibration energy absorption rate of ≥85%, automatically compensates for bolt preload, and is adaptable to all ship operating conditions (including severe vibrations under harsh sea conditions).

[0018] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a system diagram of the present invention;

[0021] Figure 2 This is a structural diagram of the present invention. Detailed Implementation

[0022] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] like Figure 1-2 As shown, this embodiment of the invention provides a dynamic sealing connection system for fiberglass pipes used in ships, including the following modules: a connection body module, a dynamic sealing module, a vibration buffer module, a load adjustment module, a corrosion protection module, and a status monitoring module.

[0025] In one embodiment, the main connecting module adopts a double-flange connecting cylinder, including a left flange, a right flange, and a middle flexible connecting cylinder. The left / right flanges are integrally formed with the fiberglass pipe through a fiberglass winding process, with a surface roughness Ra≤1.6μm. The middle flexible connecting cylinder adopts a composite structure of fiberglass reinforcement layer (inner layer) + nitrile rubber elastic layer (middle layer) + polytetrafluoroethylene wear-resistant layer (outer layer), with a thickness ratio of 3:2:1. It can withstand axial tensile load ≥50kN and radial compressive load ≥30kN. The flange substrate is fiberglass reinforced unsaturated polyester resin (tensile strength ≥300MPa, seawater corrosion rate ≤0.01mm / year). The metal inserts (around the bolt holes) are made of titanium alloy (TA2) to avoid electrochemical corrosion with fiberglass (potential difference <0.1V).

[0026] In one embodiment, the dynamic sealing module includes a sealing ring made of hydrogenated nitrile butadiene rubber (HNBR) with a Shore hardness of 85±5A and a modified Ω-shaped cross-section. The inner side has three annular raised ribs (2mm high, 5mm spacing) to increase the sealing contact area (40% higher than traditional O-rings), adapting to dynamic contact of the sealing surface during radial vibration. A sealing groove (5mm deep, 60° angle) is provided on one side of the left / right flange for installing the sealing ring. The groove has drainage holes (2mm diameter, 20mm spacing) at the bottom to promptly drain condensate and corrosive media from the sealing surface, preventing aging of the seal due to localized liquid accumulation (aging rate reduced by 60%).

[0027] In one embodiment, the vibration buffer module has four sets of magnetorheological dampers on the outside of the flexible connecting cylinder, with Fe3O4 magnetorheological fluid inside. The damping force (0-50N) is adjusted by current to suppress radial vibration amplitude ≤0.5mm (70% reduction compared to traditional structures).

[0028] In one embodiment, the load adjustment module uses shape memory alloy bolts (SMA bolts) made of Ti-Ni alloy with a preload temperature compensation coefficient of 0.8 N / ℃. It can automatically adjust the preload (range 5-15 kN) according to the ambient temperature (-20℃~60℃) to avoid bolt loosening caused by temperature changes (traditional bolt loosening rate ≥10% / year, this system ≤2% / year). Piezoelectric ceramic plates (402) are installed around the bolt holes to monitor bolt torque changes in real time (accuracy ±0.5 N·m) and transmit the data to the ship monitoring system via a wireless module (403).

[0029] In one embodiment, the corrosion protection module has a flange metal insert surface coated with a graphene-modified epoxy resin coating (50 μm thick), which shows no rust after 1000 hours of salt spray testing (NSS). A zinc alloy sacrificial anode (204) is embedded in the sealing ring groove, with a potential of -1.1V (vsSCE), and a protection area of ​​1.5 m². 2 The anode life is ≥3 years, and the outer polytetrafluoroethylene layer (0.5mm thick) of the flexible connecting cylinder has a seawater permeability of ≤0.01kg / (m³). 2 ·d), the main sealing ring made of HNBR material has a seawater swelling rate of ≤5% (after immersion in seawater at 70℃ for 1000 hours).

[0030] In one embodiment, the condition monitoring module has a corrosion rate sensor installed inside the flexible connecting cylinder, employing linear polarized resistor (LPR) technology to measure the local corrosion current density in real time (accuracy ±0.1 μA / cm). 2 An early warning is triggered when the corrosion rate is greater than 0.02 mm / year.

[0031] In operation, this invention involves: cutting the end face of the fiberglass pipe to a roughness of Ra≤1.6μm; installing titanium alloy metal inserts; and integrally forming the flange and pipe through fiberglass winding. During pipe operation, the HNBR sealing ring adapts to radial vibration through elastic deformation. When the temperature changes, the SMA bolts automatically adjust the preload to ensure stable sealing pressure (fluctuation ≤±5%). The magnetorheological damper suppresses radial vibration, the ball joint allows angular displacement, and the sensor group monitors the wear, corrosion rate, and vibration parameters of the seal in real time. The control unit dynamically adjusts the damper current and bolt preload to achieve preventive maintenance.

[0032] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A dynamic sealing connection system for fiberglass pipes used in ships, characterized in that: It includes the following modules: main body connection module, dynamic sealing module, vibration buffer module, load adjustment module, corrosion protection module and condition monitoring module.

2. The dynamic sealing connection system for fiberglass pipes for ships according to claim 1, characterized in that: The main connecting module adopts a double-flange connecting cylinder, including a left flange, a right flange, and a middle flexible connecting cylinder. The left / right flanges are integrally formed with the fiberglass pipe through a fiberglass winding process, with a surface roughness Ra≤1.6μm. The middle flexible connecting cylinder adopts a composite structure of fiberglass reinforcement layer (inner layer) + nitrile rubber elastic layer (middle layer) + polytetrafluoroethylene wear-resistant layer (outer layer), with a thickness ratio of 3:2:

1. It can withstand axial tensile load ≥50kN and radial compressive load ≥30kN. The flange substrate is fiberglass reinforced unsaturated polyester resin (tensile strength ≥300MPa, seawater corrosion rate ≤0.01mm / year). The metal inserts (around the bolt holes) are made of titanium alloy (TA2) to avoid electrochemical corrosion with fiberglass (potential difference <0.1V).

3. The dynamic sealing connection system for marine fiberglass pipes according to claim 1, characterized in that: The dynamic sealing module includes a sealing ring made of hydrogenated nitrile butadiene rubber (HNBR) with a Shore hardness of 85±5A. The ring has a modified Ω-shaped cross-section and three annular ridges (2mm high, 5mm spacing) on ​​the inner side to increase the sealing contact area (40% larger than traditional O-rings). This allows for dynamic contact of the sealing surface during radial vibration. A sealing groove (5mm deep, 60° angle) is provided on one side of the left / right flange for installing the sealing ring. The groove has drainage holes (2mm diameter, 20mm spacing) at the bottom to promptly drain condensate and corrosive media from the sealing surface, preventing localized liquid accumulation that could lead to seal aging (reducing the aging rate by 60%).

4. The dynamic sealing connection system for fiberglass pipes for ships according to claim 1, characterized in that: The vibration buffer module has four sets of magnetorheological dampers on the outside of the flexible connecting cylinder, with Fe3O4 magnetorheological fluid inside. The damping force (0-50N) is adjusted by current to suppress radial vibration amplitude ≤0.5mm (70% reduction compared to traditional structures).

5. The dynamic sealing connection system for marine fiberglass pipes according to claim 1, characterized in that: The load adjustment module uses shape memory alloy bolts (SMA bolts) made of Ti-Ni alloy with a preload temperature compensation coefficient of 0.8 N / ℃. It can automatically adjust the preload (range 5-15 kN) according to the ambient temperature (-20℃~60℃) to avoid bolt loosening caused by temperature changes (traditional bolt loosening rate ≥10% / year, this system ≤2% / year). Piezoelectric ceramic plates (402) are installed around the bolt holes to monitor bolt torque changes in real time (accuracy ±0.5 N·m) and transmit the data to the ship monitoring system via a wireless module (403).

6. The dynamic sealing connection system for marine fiberglass pipes according to claim 1, characterized in that: The corrosion protection module features a 50μm thick graphene-modified epoxy resin coating on the surface of the flange metal insert, which showed no rust after 1000 hours of salt spray testing (NSS). A zinc alloy sacrificial anode (204) is embedded in the sealing ring groove, with a potential of -1.1V (vsSCE), and a protection area of ​​1.5m². 2 The anode life is ≥3 years, and the outer polytetrafluoroethylene layer (0.5mm thick) of the flexible connecting cylinder has a seawater permeability of ≤0.01kg / (m³). 2 ·d), the main sealing ring made of HNBR material has a seawater swelling rate of ≤5% (after immersion in seawater at 70℃ for 1000 hours).

7. A dynamic sealing connection system for fiberglass pipes for ships according to claim 1, characterized in that: The condition monitoring module has a corrosion rate sensor installed inside the flexible connecting cylinder. It employs linear polarized resistance (LPR) technology to measure the localized corrosion current density in real time (accuracy ±0.1 μA / cm²). 2 An early warning is triggered when the corrosion rate is greater than 0.02 mm / year.

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