Pressure chamber experimental device
Technical Field
The utility model belongs to loading testing arrangement relates to steel pipe external pressure testing arrangement, especially relates to a pressure chamber experimental apparatus, is a deep sea corrodes steel pipe test piece bucking unstability testing arrangement.
Background
Submarine pipelines are used as the main artery for offshore oil and gas transportation and play an increasingly important role in offshore oil and gas development. The submarine pipeline is generally made of steel pipes, the corrosion resistance is poor, and corrosion failure is the main failure form of the submarine pipeline. The production of oil and gas fields is stopped due to the damage of submarine pipelines caused by corrosion, and large-area pollution in sea areas occurs sometimes, so that not only is great loss caused to economy, but also the caused environmental pollution is more concerned in the world. The deep sea pipeline is easy to induce buckling instability of the pipeline at a corrosion defect part under a deep sea high-pressure environment, and the buckling instability can be propagated along the axial direction, so that the pipeline is damaged by long-distance instability, and huge economic loss and serious environmental disasters can be caused. The deep sea pipeline is complex in stress, diversified in corrosion defect form, reasonable in description of defect geometry purchase and sale, and large in challenge of buckling instability mechanism and ultimate bearing capacity research. The existing foreign standards are only suitable for predicting the burst pressure of the pipeline with the internal pressure as the load control and the thin-wall corrosion defect on the land and shallow sea, but lack a reasonable and accurate evaluation method for the ultimate bearing capacity of the pipeline with the external pressure as the load control and the deep sea. A deep sea pressure chamber proportion model test is necessary to verify the feasibility of the proposed theoretical model, and a theoretical basis is laid for establishing an effective evaluation method.
Disclosure of Invention
For solving the problem that the existing loading device does not have the forming and can be used for testing the steel pipe with corrosion defects, the utility model aims to provide a pressure chamber experimental device which is based on a manual water pressure testing device.
The utility model discloses the device is by the pressure cabin body, the flat lid, pressure sensor, the relief port, the inlet outlet, the force (forcing) pump, flourishing water container, the electronic scale, the steel pipe, the end cap, defects, the drainage pipe constitutes, pressure cabin body total length 2m, internal diameter 200mm, pressure cabin body tip is fixed with the flat lid, be close to and set up the relief port on the flat lid edge, the flat lid intermediate position sets up pressure sensor, and pass through female connection with the flat lid, the force (forcing) pump applys internal pressure through the inlet outlet on the tip flat lid, the inlet outlet has a valve (for showing in the picture), place the pressure cabin internally in the steel pipe, the steel pipe both sides tip has welded the metal end cap, the defect is a sunkenly, be located the steel pipe middle part, one side metal end cap is connected the drainage pipe and is.
The utility model discloses the test steel pipe adopts SS304 stainless steel pipe, adopts the digit control machine tool processing, and the precision is high, and the low alloy 16Mn steel is chooseed for use to the pressure cabin material, and the flat lid adopts the level four forging, with the pressure cabin for the body nut fastening screw and soft aluminium gasket sealing connection. The booster pump is a hand-operated plunger type, and the nut and the plunger are pushed to move linearly by rotating the handle, so that water is pressed in or discharged, and pressure control is facilitated.
Before the test is started, the steel pipe and the drainage guide pipe are filled with water through the pressure pump, along with the increase of pressure, when the steel pipe is bent and deformed, the water in the steel pipe is drained to the water container through the drainage guide pipe, the weight change of the water container is measured through the electronic scale, and the volume change of the steel pipe is indirectly measured.
The utility model relates to a deep sea pipeline external pressure loading device, structural design is reasonable, and structural style is simple, and whole rigidity is good, can realize the bucking unstability pressure and the deformation form that have different corrosion defect shape steel pipe test pieces, provides important verification data for nonlinear buckling unstability theoretical model analysis and numerical simulation, is an accurate test, the reliable high-level experimental technique platform of data.
Drawings
FIG. 1 is a test chart of the external pressure buckling test of the steel pipe by the device, and the right circular ring is a sectional view of the cabin 1.
Detailed Description
The invention is further described with reference to the following figures and examples.
Example 1
Referring to fig. 1, the utility model relates to a pressure chamber experimental device, which comprises a pressure chamber body 1, a flat cover 2, a pressure sensor 3, a relief port 4, a water inlet and outlet 5, a pressure pump 6, a water container 7, an electronic scale 8, a steel pipe 9, a plug 10, a defect 11 and a drainage conduit 12, wherein the total length of the pressure chamber body 1 is 2m, the inner diameter is 200mm, the end part of the pressure chamber body 1 is fixed with the flat cover 2 by a fastening nut, the relief port 4 is arranged on the edge of the flat cover 2, the pressure sensor 3 is arranged in the middle of the flat cover 2 and is connected with the flat cover 2 through an internal thread, the pressure pump 6 applies internal pressure through the water inlet and outlet 5 on the flat cover 2, the water inlet and outlet 5 is provided with a valve (shown in the figure), the steel pipe 9 is arranged in the pressure chamber body 1, the end parts on both sides of the steel pipe 9 are welded with metal plugs 10, the defect 11 is a depression and is, the water container 7 is arranged on the electronic scale 8. The flat cover 2 is connected with the end part of the pressure cabin body 1 in a sealing way through a nut fastening screw and a soft aluminum gasket.
Example 2
Installing the steel pipe 9, connecting experimental devices and equipment, filling water into the steel pipe 9 and the drainage guide pipe 12 through the pressure pump 6 before the test starts, discharging gas in the pressure cabin body 1 through the pressure pump 6 after the water is filled, closing the valve of the inlet and the outlet 5 after the water gushes out from the inlet and the outlet 5, observing that the pressure starts to rise and maintains the internal decline for a period of time, indicating that the water is continuously pumped into the deep sea pressure cabin body 1, and observing that the pressure starts to rise and maintains the internal decline for a period of time, indicating that the sealing performance of the cabin body is good. When the pressure in the deep sea pressure cabin body 1 rises to a certain critical pressure value, the cabin generates brittle sound, the critical pressure is the local buckling instability pressure of the steel pipe 9, the reading of the pressure sensor 3 at the moment is recorded, the valve of the inlet and the outlet 5 is opened slowly, the pressure in the pressure cabin body 1 is released, the flat cover 2 is removed, the steel pipe 9 is taken out, and the buckling instability form is observed. The test can be used for measuring the buckling instability pressure and the deformation form of steel pipe test pieces with different corrosion defect shapes and defect geometric sizes and single corrosion defects or multiple corrosion defects, and provides important verification data for nonlinear buckling instability theoretical model analysis and finite element numerical simulation.