Tank body drilling and pouring maintenance method

Abstract

The invention discloses a tank body drilling and pouring maintenance method, and relates to the technical field of storage tank maintenance, and the method comprises the following steps: S1, damage positioning and pretreatment: determining a damage area through nondestructive testing, and cleaning surface rust and impurities of the damage area of a tank body; s2, drilling design, wherein a plurality of miniature flow guide holes are evenly formed in the damaged edge of the tank body; s3, pouring repair is conducted, specifically, a corrosion-resistant polymer composite material is injected through the micro flow guide holes formed in the step S2, and the material is made to permeate into damaged internal pores through pressure equipment; s4, repairing and curing are conducted, specifically, the repaired position is cured in a segmented heating mode, and ultraviolet auxiliary crosslinking is combined, so that the repairing material forms a repairing layer tightly combined with the tank body; and S5, hole sealing and surface treatment. The repairing strength reaches 90% or above of that of raw materials, the pressure resistance is improved by 20%-30%, the construction time is shortened by 50%, the method is suitable for online maintenance, materials are environmentally friendly and non-toxic, and the requirements of food-grade storage tanks are met.

Description

Technical Field

[0001] The present invention relates to a method for repairing a tank body, and particularly to a method for repairing a tank body by drilling and perfusion. Background Art

[0002] During long-term use, storage tanks are prone to local damage due to corrosion, mechanical collision, or stress concentration. Traditional repair methods (such as welding and patch repair) have the following defects:

[0003] 1. Welding may cause material deformation or the risk of secondary corrosion;

[0004] 2. External patching cannot repair internal structural damage and has insufficient sealing performance;

[0005] 3. For complex damage, the storage tank needs to be shut down, resulting in a long repair cycle and high cost. Summary of the Invention

[0006] The purpose of the present invention is to provide a non-destructive, fast, and durable tank body repair solution to solve the problems raised in the above background art.

[0007] To achieve the above purpose, the present invention provides the following technical solution: A method for repairing a tank body by drilling and perfusion, comprising the following steps:

[0008] S1. Damage location and pretreatment: Determine the damage area through non-destructive testing, and clean the rust and impurities on the surface of the damaged area of the tank body;

[0009] S2. Drilling design: Uniformly open a plurality of micro diversion holes along the edge of the damaged part of the tank body;

[0010] S3. Perfusion repair: Inject a corrosion-resistant polymer composite material through the micro diversion holes opened in step S2, and use a pressure device to make the material penetrate into the internal pores of the damage;

[0011] S4. Repair and curing: Cure the repaired part by means of segmented heating, combined with ultraviolet-assisted crosslinking, so that the repair material forms a repair layer that tightly binds to the tank body;

[0012] S5. Hole sealing and surface treatment: Remove the diversion tube, seal the drilled holes and polish the surface of the repaired part.

[0013] As a preferred technical solution of the present invention, ultrasonic testing is used for the non-destructive testing in step S1.

[0014] As a preferred technical solution of the present invention, in step S2, the micro-guiding hole adopts a stepped aperture design, and the micro-guiding hole is divided into an outer hole section and an inner hole section with different diameters. When drilling, a three-dimensional modeling of the damaged area is performed based on finite element analysis software (such as ANSYS), and the tank material parameters (elastic modulus, Poisson's ratio) and load conditions (internal pressure, external bending moment) are input to calculate the maximum principal stress direction and stress concentration factor, simulate the stress distribution of the damaged area of ​​the tank, optimize the drilling position and angle, and make the micro-guiding hole tilted 30°-45° along the maximum principal stress direction to enhance the shear resistance of the repair layer;

[0015] The outer hole section diameter of the micro-diversion hole is 8mm, the depth is 40% of the tank wall thickness, the inner wall is processed with a spiral guide groove (spiral 2mm, groove depth 0.3mm), the inner hole section diameter is 5mm, extending to the edge of the damaged area, the hole mouth chamfer is 0.2*45° to reduce stress concentration, a nylon diversion tube (outer diameter 7.8mm, inner diameter 4.8mm) is pre-embedded in the micro-diversion hole, and a barb-shaped protrusion (height 0.5mm, spacing 3mm) is set on the outer surface of the diversion tube. It is embedded in the spiral guide groove of the outer hole section through hot pressing assembly to form a one-way diversion channel to prevent backflow.

[0016] As a preferred technical solution of the present invention, the corrosion-resistant polymer composite material in step S3 contains 0.1%-0.5% by mass of graphene nanosheets and 2%-5% by mass of alumina particles to form a conductive-enhanced dual-functional composite material.

[0017] As a preferred technical solution of the present invention, the pressure equipment for pouring the corrosion-resistant polymer composite material in step S3 is an electric grouting pump equipped with a PLC.

[0018] As a preferred technical solution of the present invention, the segmented heating curing in step S4 includes an initial curing at 50°C-60°C and a final curing at 80°C-100°C.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The repair strength of the present invention reaches more than 90% of the raw material, the pressure resistance is improved by 20%-30%, and the construction time is reduced by 50%. It is suitable for online maintenance. The material is environmentally friendly and non-toxic and meets the requirements of food-grade storage tanks. DETAILED DESCRIPTION

[0021] The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention provides a technical solution for a tank body drilling and pouring maintenance method, comprising the following steps:

[0023] S1. Damage location and pretreatment: determine the damaged area through non-destructive testing, and clean the surface rust and impurities in the damaged area of ​​the tank;

[0024] S2. Drilling design: multiple micro diversion holes are evenly opened along the damaged edge of the tank;

[0025] S3, perfusion repair: inject the corrosion-resistant polymer composite material through the micro-guiding holes opened in step S2, and use pressure equipment to make the material penetrate into the damaged internal pores;

[0026] S4, repair curing: the repaired part is cured by segmented heating, combined with ultraviolet assisted cross-linking, so that the repair material forms a repair layer that is closely combined with the tank body;

[0027] S5. Sealing and surface treatment: Remove the guide tube, seal the drilled hole and polish the surface of the repaired part.

[0028] The non-destructive testing in step S1 adopts ultrasonic testing.

[0029] In step S2, the micro-guiding holes are designed with stepped apertures, and the micro-guiding holes are divided into outer hole sections and inner hole sections with different diameters. When drilling, three-dimensional modeling of the damaged area is performed based on finite element analysis software (such as ANSYS), and the tank material parameters (elastic modulus, Poisson's ratio) and load conditions (internal pressure, external bending moment) are input to calculate the maximum principal stress direction and stress concentration factor, simulate the stress distribution in the damaged area of ​​the tank, optimize the drilling position and angle, and make the micro-guiding holes tilted by 30°-45° along the maximum principal stress direction to enhance the shear resistance of the repair layer;

[0030] The outer hole section diameter of the micro-diversion hole is 8mm, the depth is 40% of the tank wall thickness, the inner wall is processed with a spiral guide groove (spiral 2mm, groove depth 0.3mm), the inner hole section diameter is 5mm, extending to the edge of the damaged area, the hole mouth chamfer is 0.2*45° to reduce stress concentration, a nylon diversion tube (outer diameter 7.8mm, inner diameter 4.8mm) is pre-embedded in the micro-diversion hole, and a barb-shaped protrusion (height 0.5mm, spacing 3mm) is set on the outer surface of the diversion tube. It is embedded in the spiral guide groove of the outer hole section through hot pressing assembly to form a one-way diversion channel to prevent backflow.

[0031] The corrosion-resistant polymer composite material in step S3 contains 0.1%-0.5% by mass of graphene nanosheets and 2%-5% by mass of aluminum oxide particles to form a conductive-enhanced dual-functional composite material.

[0032] The pressure equipment for pouring the corrosion-resistant polymer composite material in step S3 is an electric grouting pump equipped with a PLC.

[0033] The segmented heating curing in step S4 includes an initial curing at 50°C-60°C and a final curing at 80°C-100°C.

[0034] Example 1 (taking the corrosion perforation repair of chemical storage tanks as an example):

[0035] (1) First, use ultrasonic testing equipment to perform non-destructive testing on the tank to be repaired to determine the damaged area, and clean the surface rust and impurities in the damaged area of ​​the tank;

[0036] (2) Based on the ultrasonic testing results, a three-dimensional model of the damaged area is constructed using finite element analysis software (such as ANSYS). The tank material parameters (elastic modulus, Poisson's ratio) and load conditions (internal pressure, external bending moment) are input, the maximum principal stress direction and stress concentration factor are calculated, and the stress distribution in the damaged area of ​​the tank is simulated. The drilling position and angle are optimized so that the micro-guiding holes are inclined by 30°-45° along the maximum principal stress direction to enhance the shear resistance of the repair layer. According to the simulation results, at least 6 micro-guiding holes are drilled around the damaged area, and the micro-guiding holes are drilled at a minimum of 10° and 20°. The outer hole section diameter of the type diversion hole is 8mm, the depth is 40% of the tank wall thickness, the inner wall is processed with a spiral guide groove (spiral 2mm, groove depth 0.3mm), the inner hole section diameter is 5mm, extending to the edge of the damaged area, the hole chamfer is 0.2*45° to reduce stress concentration, a nylon diversion tube (outer diameter 7.8mm, inner diameter 4.8mm) is pre-embedded in the micro diversion hole, and a barb-shaped protrusion (height 0.5mm, spacing 3mm) is set on the outer surface of the diversion tube, which is embedded in the spiral guide groove of the outer hole section through hot pressing assembly to form a one-way diversion channel to prevent backflow;

[0037] (3) When pouring the corrosion-resistant polymer composite material into the micro-guide hole, an electric grouting pump (flow range 0-500ml / min, pressure accuracy ±0.02MPa) is used, integrated with a PT100 temperature sensor and a Coriolis mass flowmeter. The data is processed in real time by a PLC (Siemens S7-1200), and an FBG sensor array (wavelength 1525-1565nm, grid length 10mm) is buried in the repair layer and distributed in a 10mm*10mm grid. During the pouring process, the strain of the repair layer is monitored in real time by the distributed FBG sensors.

[0038] (4) After the repair material is poured, the temperature of the repaired part of the tank is raised to 60°C by infrared heating (heating rate 5°C / min), and kept warm for 2 hours for preliminary curing. Then the temperature of the repaired part of the tank is raised to 100°C (heating rate 3°C / min), and kept warm for 1 hour to complete the final curing. In addition, ultraviolet light is used to assist crosslinking (wavelength 365nm, intensity 50mW / cm 2 );

[0039] After the repair material is cured and the hole is sealed, remove the diversion tube, seal the drill hole and polish the surface of the repaired part. Then, after the hole is sealed, it can pass the 48-hour pressure test without leakage.

[0040] Example 2 (pressure repair in low-temperature environment):

[0041] (1) Drill 8 stepped holes (outer hole 8 mm / inner hole 5 mm) inclined at 40° at the crack of the -25 °C liquefied natural gas storage tank;

[0042] (2) Raise the temperature around the hole to 15 °C by electromagnetic induction heating, and inject low-temperature modified epoxy resin containing graphene (curing temperature -10 °C);

[0043] (3) Use a two-way seal diversion valve to complete the repair at a pressure of 0.6 MPa inside the tank. After the repair, the helium mass spectrometry leak rate ≤ 1×10 -9 Pa·m 3 / s.

[0044] Example 3 (intelligent monitoring of the repair layer):

[0045] (1) Arrange 32 FBG sensors in a grid pattern on the repair layer;

[0046] (2) After the material is cured, monitor the strain distribution under operating conditions through a fiber Bragg grating demodulator (sampling rate 1 kHz);

[0047] (3) Establish a digital twin model, and trigger the warning system when the local strain exceeds 2000 με.

[0048] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for repairing a tank body by drilling and pouring, characterized in that It includes the following steps: S1. Damage location and pretreatment: Determine the damage area through non-destructive testing, and clean the rust and impurities on the surface of the damaged area of the tank body; S2. Drilling design: Uniformly open a plurality of micro diversion holes along the edge of the damage of the tank body; S3. Injection repair: Inject a corrosion-resistant polymer composite material through the micro diversion holes opened in step S2, and use a pressure device to make the material penetrate into the internal pores of the damage; S4. Repair and curing: Cure the repaired part by means of segmented heating, combined with ultraviolet-assisted crosslinking, so that the repair material forms a repair layer tightly combined with the tank body; S5. Hole sealing and surface treatment: Remove the diversion pipe, seal the drilled holes and polish the surface of the repaired part.

2. A method for repairing a tank body by drilling and pouring according to claim 1, characterized in that: In step S1, ultrasonic testing is used for non-destructive testing.

3. A method for repairing a tank body by drilling and pouring according to claim 1, characterized in that: In step S2, the micro diversion holes adopt a stepped hole diameter design, and the micro diversion holes are divided into an outer hole section and an inner hole section with different diameters.

4. A method for repairing a tank body by drilling and pouring according to claim 1, characterized in that: In step S3, the corrosion-resistant polymer composite material contains graphene nanosheets and alumina particles to form a conductive-enhanced bifunctional composite material.

5. A method for repairing a tank body by drilling and pouring according to claim 1, characterized in that: In step S3, the pressure device for injecting the corrosion-resistant polymer composite material is an electric grouting pump equipped with a PLC.

6. A method for repairing a tank body by drilling and pouring according to claim 1, characterized in that: The segmented heating and curing in step S4 includes initial curing at 50°C - 60°C and final curing at 80°C - 100°C.