A simulation testing device for scour corrosion of hydraulic steel gate under cathodic protection condition

Abstract

A kind of simulation test device of hydraulic steel gate scouring corrosion under cathodic protection condition, it mainly includes corrosion medium circulating system, flow control module, experimental tank, test piece clamping table, test piece transmission system, impressed current cathodic protection system and rack.Corrosion medium circulating system is used for the storage and circulating delivery of corrosion medium;Flow control module is used for controlling the linear velocity of water flow in experimental tank;Experimental tank is used for scouring corrosion test;Test piece clamping table is used for installing and fixing test piece;Test piece transmission system is used for controlling the vertical opening of test piece and its impact angle with corrosion medium;Impressed current cathodic protection system is used for inhibiting corrosion factors of test piece in scouring corrosion test.The scouring corrosion simulation test device of the present application has simple structure, effectively simulates the scouring corrosion working condition of sand-containing water flow to flat steel gate and arc steel gate under different opening degrees and different impact angles, can simultaneously carry out scouring corrosion test of multiple test pieces, and can apply impressed current cathodic protection to inhibit corrosion factors and realize pure scouring test.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of scouring corrosion test equipment, in particular to a scouring corrosion simulation test device for hydraulic steel gate under cathodic protection condition. BACKGROUND

[0002] Hydraulic steel gate is an important metal structure to ensure the safe operation of water gate, hydropower station, reservoir and other hydraulic structures, which usually serves in underwater immersion or frequent wet-dry alternating environment, and is subjected to the complex coupling of corrosion factors such as water, silt and ice for a long time, and corrosion damage is inevitable. Especially for water areas with high silt content, silt-laden water flow continuously impacts the steel gate at a certain angle and speed, which can aggravate the damage of the gate surface coating and the scouring corrosion of the gate body.

[0003] Under the interaction of mechanical damage and corrosion, the total weight loss of metal material caused by scouring corrosion includes four parts: pure corrosion, pure scouring, the influence of corrosion on scouring and the influence of scouring on corrosion. At present, the test devices for studying scouring corrosion mainly include three types: rotating type, spraying type and pipe flow type.

[0004] Chinese patent application 202211102869.8 discloses a seawater-ice crystal two-phase flow rotating scouring corrosion test device, which drives the working electrode to rotate at high speed in the test solution through a rotating disc, simulating the different flow characteristics and scouring corrosion conditions of seawater / ice crystal liquid-solid two-phase flow in the ship cooling system.

[0005] Chinese patent 201620780097.7 discloses a multiphase flow erosion cavitation and corrosion comprehensive experimental bench data acquisition and control device, which sprays the slurry at high speed to the surface of the test piece through a high-pressure slurry pump to form a scouring action.

[0006] Chinese patent 202310046623.1 discloses a pipe segment type seawater pipeline corrosion test device aiming at the scouring corrosion of the flowing medium on the inner wall of the pipeline. The above-mentioned test devices usually have a constant speed relative motion between the fluid and the test piece, producing a parallel scouring shear action on the surface of the test piece. However, during the opening and closing process of the hydraulic steel gate, the surface of the gate is subjected to the vertical impact of water flow and the parallel scouring shear action at the same time, and the flow state at the bottom edge of the gate is complex and the flow velocity is not constant at different opening degrees. Especially for the arc-shaped gate, there is a continuous change of the impact angle during the opening and closing process.

[0007] Therefore, the traditional test device has great limitations in simulating the complex scouring corrosion working condition of the hydraulic steel gate, and no related technology has been reported at present. In addition, in order to determine the dominant damage mechanism in the scouring corrosion process, the weight loss data of pure corrosion, pure scouring and total scouring corrosion need to be measured respectively. The scouring corrosion test device reported at present can be used to evaluate the total weight loss of the scouring corrosion material, but the corrosion is not inhibited in the test, and the test of the scouring single factor cannot be realized. SUMMARY

[0008] In view of the problems in the prior art, the purpose of the present application is to provide a scouring corrosion simulation test device for a hydraulic steel gate under cathodic protection conditions, which can form a stable outgoing water flow by using a rotating stirring device, a circulating pump and a flow control module, change the water flow velocity and the impact angle of the test piece by using an opening degree and angle control device, effectively simulate the scouring corrosion condition of the hydraulic steel gate during operation, and accurately test the pure scouring weight loss of the test piece under the condition of an impressed current cathodic protection.

[0009] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a scouring corrosion simulation test device for a hydraulic steel gate under cathodic protection conditions, which comprises a corrosion medium circulating system, a flow control module, an experimental tank, a test piece clamping table, a test piece transmission system, an impressed current cathodic protection system and a rack. The corrosion medium circulating system is a corrosion medium storage, recovery and circulating device for driving the corrosion medium to circulate and convey. The flow control module is used to realize the impact of the corrosion medium on the test piece at different flow velocities. The experimental tank is used to obtain a stable linear water flow velocity and perform a scouring corrosion test. The test piece clamping table is used to install and fix the test piece. The test piece transmission system is used to drive the test piece to lift and rotate, control the opening degree of the test piece and the impact angle of the test piece with the corrosion medium. The impressed current cathodic protection system is used to inhibit the corrosion of the test piece in the scouring corrosion test.

[0010] Further, the rack is a steel frame structure, the corrosion medium circulating system is installed below the rack, and the corrosion medium circulating system comprises a corrosion medium storage container and a circulating pump which are connected in sequence by a pipeline. The pipeline is made of non-metallic material and is fixed on the rack by a U-shaped pipe clamp. A rotating blade is installed at the bottom of the corrosion medium recovery container, and the rotating shaft of the rotating blade is rotated by an alternating current motor.

[0011] The flow control module is an electromagnetic flowmeter which is connected with the pipeline through a flange at one end and is fastened with the experimental tank at the other end. The experimental tank is a rectangular open tank, the base of which is fixed on the rack, and one end of the bottom is provided with an opening to collect the water flow into the corrosion medium recovery container.

[0012] Further, the flow rate control range of the electromagnetic flowmeter is 2 m / s-10 m / s.

[0013] The experimental tank is made of non-metal materials such as organic glass or quartz glass, so as to avoid affecting the cathodic protection current efficiency.

[0014] The test piece transmission system comprises a lifting and translation table and a rotation angle table; the water-facing surface and the bottom end surface of the test piece clamping table are provided with grooves, and are fixed on the sliding block of the lifting and translation table by using non-metal screws; the lifting and translation table is fixed on the rotation angle table by a connecting piece; the sliding block is controlled to slide up and down along the linear sliding rail by a ball screw; the opening height is controlled by the scale rulers on the two sides of the lifting and translation table; the rotation angle table is fixed on the inner side of the side wall of the experimental tank by screws; the worm and gear mechanism is controlled by a manual knob; and the test piece clamping table is driven to rotate to a set angle along the direction of the water flow.

[0015] Further, the water-facing surface and the bottom end surface of the test piece clamping table are provided with grooves, and two positioning threaded holes are arranged in each groove; the vertical test piece and the horizontal test piece, which are also provided with two holes, are fixed in the grooves of the water-facing surface and the bottom end surface of the test piece clamping table by using non-metal screws.

[0016] The impressed current cathodic protection system comprises a constant potential instrument, an auxiliary anode, a reference electrode and connecting wires; the positive terminal of the constant potential instrument is connected with the auxiliary anode by a wire; the negative terminal is connected with the vertical test piece and the horizontal test piece by wires; and the reference electrode terminal is connected with the reference electrode by a wire; the auxiliary anode is a mixed metal oxide anode, which is fixed on the inner side of the side wall of the experimental tank by a plastic insulating fastener; the reference electrode is a copper / saturated copper sulfate reference electrode or a silver / silver chloride reference electrode, which is fixed on the surface of the test piece clamping table by a plastic insulating fastener; the vertical test piece and the horizontal test piece are cuboid test pieces with the same size, and the test surfaces of the test pieces are provided with two positioning through holes, and the test pieces are fixed on the test piece clamping table by non-metal screws passing through the positioning through holes; one threaded hole is arranged at the center position of the opposite surface of the test surface of the vertical test piece and the long side adjacent side of the test surface of the horizontal test piece, and a threaded terminal can be screwed into the threaded hole for leading out the wire and connecting with the negative terminal of the constant potential instrument.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] (1) The water conservancy steel gate scouring corrosion simulation test device under cathodic protection conditions provided by the present application can control the linear water flow velocity of the water-facing surface of the test piece by using an electromagnetic flowmeter, can adjust the lifting opening degree of the test piece, can obtain different flow velocities at the bottom edge, and can continuously adjust the impact angle of the water flow and the test piece by rotating the test piece, so as to effectively simulate the scouring corrosion working conditions of the sand-containing water flow on the flat steel gate and the arc-shaped steel gate.

[0019] (2) The device can apply cathodic protection to the test piece in the experiment, inhibit the occurrence of test piece corrosion, and make more accurate and actual test of pure scouring weight loss. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic diagram of a hydraulic steel gate scouring corrosion simulation test device under cathodic protection provided by the present application.

[0021] Figure 2 A schematic diagram of the structure of the test piece clamping table and test piece transmission system of the scouring corrosion simulation test device. Figure 1 A partial enlarged view thereof.

[0022] Figure 3 A schematic diagram of the structure assembly of the test piece clamping table, lifting translation table and rotation angle table of the scouring corrosion simulation test device. Figure 2 A right view thereof.

[0023] Figure 4 A schematic diagram of the clamping position of the test piece and reference electrode of the scouring corrosion simulation test device.

[0024] Figure 5 A three-dimensional schematic diagram of the vertical test piece of the scouring corrosion simulation test device.

[0025] Figure 6 A three-dimensional schematic diagram of the horizontal test piece of the scouring corrosion simulation test device.

[0026] In the figure, 1 is a rack, 2 is an AC motor access end, 3 is an AC motor, 4 is a transmission belt, 5 is a corrosion medium storage container, 6 is an experimental tank drainage hole, 7 is a stirring blade, 8 is a rotating shaft, 9 is a drainage hole, 10 is a pipeline, 11 is an impressed current cathodic protection system, 12 is a circulating pump, 13 is an AC circulating pump access end, 14 is a U-shaped pipe clamp, 15 is a flow control module, 16 is a water inlet, 17 is an experimental tank, 18 is an auxiliary anode fastener, 19 is an auxiliary anode, 20 is a reference electrode, 21 is a reference electrode fastener, 22 is a vertical test piece, 23 is a horizontal test piece, 24 is a test piece clamping table, 25 is a sliding block, 26 is a ball screw, 27 is a screw knob, 28 is a lifting translation table, 29 is a scale ruler, 30 is a connecting piece, 31 is a worm knob, 32 is a rotation angle table, 33 is an annular disc, 34 is a test piece transmission system, 35 is a vertical test piece terminal post, 36 is a horizontal test piece terminal post, 37 is a vertical test piece positioning through hole, 38 is a vertical test piece threaded hole, 39 is a horizontal test piece positioning through hole, and 40 is a horizontal test piece threaded hole. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings and examples.

[0028] As shown in the drawings, Figures 1-6 The present application provides a simulation test device for scouring corrosion of hydraulic steel gate under cathodic protection condition, which mainly comprises a rack 1, a corrosion medium storage container 5, a circulating pump 12, a flow control module 15, an experimental tank 17, a test piece clamping table 24, a test piece transmission system 34, an impressed current cathodic protection system 11, and the like, and the specific structure is as follows:

[0029] The corrosion medium storage container 5 is cylindrical with an open top and is placed directly below the drainage hole 6 of the experimental tank. A drainage hole 9 is provided on the side wall of the container near the bottom, and the flange of the pipe 10 of the circulating pump 12 is connected to the drainage hole 9. A stirring blade 7 is provided on the bottom plate of the corrosion medium storage container 5, and the rotating shaft 8 of the stirring blade 7 is driven to rotate by the transmission belt wheel driven by the alternating current motor 3 through the transmission belt 4. The alternating current motor 3 is connected to the power supply through the alternating current motor connection end 2.

[0030] The pipe 10 at one end of the circulating pump 12 is connected to the drainage hole 9 at the bottom of the side of the corrosion medium storage container 5, and the pipe at the other end is fixed to the side of the rack 1 through the U-shaped pipe clamp 14, and the end of the pipe is connected to the flange of one side of the flow control module 15. After the alternating current connection end 13 of the circulating pump is connected to the power supply, the corrosion medium in the corrosion medium storage container 5 is transported to the flow control module 15 through the pipe 10 of the circulating pump 12, and after the flow is adjusted by the flow control module 15, the corrosion medium is transported into the experimental tank 17 through the pipe and the water inlet hole 16 at one end of the experimental tank 17 for scouring experiment.

[0031] The experimental tank 17 made of non-metallic material is a rectangular open tank fixed to the top of the rack 1. The experimental tank 17 is provided with a water inlet hole 16 near the bottom plate at one end and a drainage hole 6 on the bottom plate. The bottom plate of the experimental tank 17 has a variable cross-sectional thickness, with different thicknesses at both ends and a connection through a circular arc section in the middle. The circular arc section and the annular disc 33 of the rotating angle table 32 are concentric arcs, which can realize the rotation of the vertical test piece 22 and the horizontal test piece 23 in the experimental tank 17.

[0032] The rotating angle table 32 of the test piece transmission system 34 is fixed inside the side wall of the experimental tank 17, and a rotating angle scale is arranged along the outer diameter of the annular disc 33. The annular disc 33 can be controlled to rotate counterclockwise by the worm knob 31, so that the vertical test piece 22 and the water flow angle of attack change from 90° to 0°. The lifting translation table 28 is fixed on the surface of the annular disc 33 of the rotating angle table 32 by the connecting piece 30, and the bottom end is flush with the bottom end of the rotating angle table 32. The sliding block 25 can slide up and down along the linear sliding rail by controlling the screw knob 27 of the ball screw 26, and the opening height can be controlled by the scale scale 29 on both sides of the lifting translation table 28. When the sliding block 25 is at the lowest point of the lifting translation table 28, the bottom end surface of the test piece clamping table 24 is closed to the upper surface of the bottom plate of the experimental tank 17, simulating the completely closed state of the gate. The test piece clamping table 24 is fixed on the sliding block 25 of the lifting translation table 28 by a non-metal screw. The water-facing surface and the bottom end surface of the test piece clamping table 24 are provided with grooves, and each groove is provided with two positioning threaded holes. The vertical test piece 22 is fixed in the water-facing groove of the test piece clamping table 24 by a non-metal screw through the vertical test piece positioning hole 37, and the horizontal test piece 23 is fixed in the bottom end groove by a non-metal screw through the horizontal test piece positioning hole 39. The test surface of the test piece is required to be flush with the top surface of the groove, and the erosion experiment in two directions of vertical water flow and parallel water flow can be carried out at the same time. A vertical test piece threaded hole 38 is arranged at the center position of the opposite surface of the test surface of the vertical test piece 22, and a horizontal test piece threaded hole 40 is arranged at the center position of the long side adjacent surface of the test surface of the horizontal test piece 23. The vertical test piece terminal post 35 and the horizontal test piece terminal post 36 can be screwed in, respectively, and are connected with the negative terminal of the constant potential instrument by wires when the external current cathodic protection is applied.

[0033] The constant potential instrument of the impressed current cathodic protection system 11 is fixed in the frame structure of the rack 1, and is provided with a positive terminal, a negative terminal and a reference electrode terminal. The auxiliary anode 19 and the reference electrode 20 are connected with the positive terminal and the reference electrode terminal of the constant potential instrument by wires, respectively. The vertical test piece 22 and the horizontal test piece 23 are connected with the negative terminal of the constant potential instrument by wires in parallel, and the input current can be adjusted by the constant potential instrument to provide cathodic protection for the vertical test piece 22 and the horizontal test piece 23, so as to avoid corrosion. The auxiliary anode 19 is a mixed metal oxide anode, which is fixed on the inner side of the side wall of the experimental tank 17 by an auxiliary anode fastener 18 made of insulating material. The reference electrode 20 is a copper / saturated copper sulfate reference electrode or a silver / silver chloride reference electrode, which is fixed on the water-facing surface of the test piece clamping table 24 by a reference electrode fastener 21 made of insulating material. The requirement is that the ceramic core end of the reference electrode 20 is close to the surface of the test piece.

[0034] The working process of the device is as follows:

[0035] After the experimental device is installed, the treated vertical test piece 22 and horizontal test piece 23 are weighed and then installed on the test piece clamping table 24. The rotation angle table 32 is adjusted so that the water-facing surface of the test piece clamping table 24 is perpendicular to the water flow, simulating the operating condition of the flat steel gate. The lifting translation table 28 is controlled to adjust the test piece to the highest point. The AC motor 3 is started to rotate the stirring blade 7 to uniformly stir the corrosion medium used in the experiment. The parameters of the flow control module 15 are set, and the circulating pump 12 is started to deliver the corrosion medium into the experimental tank 17. After a stable water flow is formed in the experimental tank 17, the lifting translation table 28 is controlled to lower the vertical test piece 22 to just immerse in the water flow and stop. At this time, the potentiostat of the impressed current cathodic protection system 11 is started, and the constant output current value is set to polarize the vertical test piece 22 and horizontal test piece 23. At the same time, the lifting translation table 28 is controlled to lower to the test opening, and the scouring corrosion experiment test is started. After the test is completed, the machine is stopped, and the test piece is sampled and weighed to calculate the weight loss and analyze the surface morphology change of the material. According to the experimental needs, the rotation angle table 32 can be adjusted before the test to rotate the test piece counterclockwise to the set angle, and the scouring corrosion damage performance of the test piece at different attack angles can be tested.

[0036] The above only describes the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A simulation testing device for erosion corrosion of hydraulic steel gates under cathodic protection conditions, characterized in that: The test chamber includes a frame (1), a corrosive medium circulation system, a flow control module (15), an experimental tank (17), a specimen clamping platform (24), a specimen transmission system (34), and an impressed current cathodic protection system (11). The corrosive medium circulation system is located inside the frame (1) and is used to drive the circulation and delivery of the corrosive medium. The corrosive medium circulation system delivers the corrosive medium to the experimental tank (17) through the flow control module (15). The flow control module (15) is used to realize the impact of the corrosive medium on the specimen at different flow velocities. The test tank (17) is used to obtain a stable linear water flow velocity and to conduct scouring corrosion tests. The test specimen clamping platform (24) and the test specimen transmission system (34) are set in the test tank (17). The test specimen clamping platform (24) is used to install and fix the test specimen. The test specimen transmission system (34) is used to drive the test specimen to rise, fall and rotate, and control the opening of the test specimen and its impact angle with the corrosive medium. The impressed current cathodic protection system (11) is set inside the frame (1) to suppress the corrosion of the test specimen in the scouring corrosion test. The rotating angle stage (32) of the specimen transmission system (34) is fixed on the inner side of the side wall of the experimental tank (17). A rotating angle scale is provided along the outer diameter of the annular disk (33). The annular disk (33) is rotated counterclockwise by the worm gear knob (31). The lifting and translating stage (28) is fixed on the surface of the annular disk (33) of the rotating angle stage (32) by the connecting piece (30). The bottom end is flush with the bottom end of the rotating angle stage (32). The slider (25) is controlled to slide up and down along the linear slide rail by the screw knob (27) of the ball screw (26). The opening height is controlled by the scale (29) on both sides of the lifting and translating stage (28). When the slider (25) is at the lowest point of the lifting and translating stage (28), the bottom end face of the specimen clamping stage (24) is closed with the upper surface of the bottom plate of the experimental tank (17), simulating the state of the gate being completely closed. The specimen clamping platform (24) is fixed to the slider (25) of the lifting and translating platform (28) with non-metallic screws. The specimen clamping platform (24) has grooves on the water-facing side and the bottom side. Each groove has two positioning threaded holes. The vertical specimen (22) is fixed in the groove on the water-facing side of the specimen clamping platform (24) with non-metallic screws through the vertical specimen positioning through hole (37). The horizontal specimen (23) is fixed in the groove on the bottom side through the horizontal specimen positioning through hole (39). The test surface of the specimen is flush with the top surface of the groove, which can simultaneously carry out scouring corrosion experiments in two directions: vertical water flow and parallel water flow. The vertical test specimen (22) has a vertical test specimen threaded hole (38) at the center of the test surface opposite the test surface, and the horizontal test specimen (23) has a horizontal test specimen threaded hole (40) at the center of the long side adjacent to the test surface. The vertical test specimen terminal (35) and the horizontal test specimen terminal (36) can be screwed into them respectively. When applying the applied current cathodic protection, they are connected to the negative terminal of the potentiostat by a wire.

2. The simulation test device for erosion corrosion of hydraulic steel gates under cathodic protection conditions according to claim 1, characterized in that: The corrosive medium circulation system includes a corrosive medium storage container (5) and a circulation pump (12) connected in sequence by pipes. The corrosive medium storage container (5) is cylindrical with an open top and is placed directly below the drain hole (6) of the experimental tank. A drain hole (9) is provided at the bottom of one side of the cylindrical wall and is connected to the flange of the pipe (10) of the circulation pump (12). A stirring blade (7) is provided on the bottom plate of the corrosive medium storage container (5). The rotating shaft (8) of the stirring blade (7) is driven by an AC motor (3) through a transmission belt (4) to rotate the pulley. The AC motor (3) is connected to the mains power supply through the AC motor input terminal (2). One end of the circulation pump (12) is connected to the drain hole (9) through the pipe (10), and the other end of the pipe is fixed to the side of the frame (1) through a U-shaped pipe clamp (14). The end of the pipe is connected to the flange on one side of the flow control module (15). The circulation pump (12) is connected to the mains power through the AC power input terminal (13) of the circulation pump.

3. The simulation test device for erosion corrosion of hydraulic steel gates under cathodic protection conditions according to claim 1, characterized in that: The experimental tank (17) is a rectangular open tank, fixed to the top of the frame (1); a water inlet (16) is provided at one end of the experimental tank (17) near the bottom plate, and a drain hole (6) is provided on the bottom plate; the bottom plate of the experimental tank (17) adopts a variable cross-sectional thickness, with different thicknesses at both ends, and is connected in the middle by a circular arc cross-section, and the circular arc cross-section and the annular disk (33) of the rotating angle stage (32) are concentric circular arcs, which can realize the rotation of the vertical specimen (22) and the horizontal specimen (23) in the experimental tank (17).

4. The simulation test device for erosion corrosion of hydraulic steel gates under cathodic protection conditions according to claim 1, characterized in that: The potentiostat of the impressed current cathodic protection system (11) is fixed in the frame structure of the frame (1). It is equipped with a positive terminal, a negative terminal and a reference electrode terminal. The auxiliary anode (19) and the reference electrode (20) are connected to the positive terminal and the reference electrode terminal of the potentiostat respectively through wires. The vertical test piece (22) and the horizontal test piece (23) are connected to the negative terminal of the potentiostat through wires. The input current is adjusted by the potentiostat to provide cathodic protection for the vertical test piece (22) and the horizontal test piece (23) to prevent them from corroding.

5. The simulation test device for erosion corrosion of hydraulic steel gates under cathodic protection conditions according to claim 4, characterized in that: The auxiliary anode (19) is a mixed metal oxide anode, which is fixed to the inner side of the experimental tank (17) with an insulating auxiliary anode fastener (18); the reference electrode (20) is a copper / saturated copper sulfate reference electrode or a silver / silver chloride reference electrode, which is fixed to the water-facing side of the specimen clamping platform (24) with an insulating reference electrode fastener (21), and the ceramic core end of the reference electrode (20) is close to the surface of the specimen.

6. The simulation test device for erosion corrosion of hydraulic steel gates under cathodic protection conditions according to claim 1, characterized in that: The flow control module (15) is an electromagnetic flow meter, and the flow rate control range of the electromagnetic flow meter is 2m / s~10m / s.

7. The simulation test device for erosion corrosion of hydraulic steel gates under cathodic protection conditions according to claim 1, characterized in that: The frame (1) is a steel frame structure; the experimental tank (17) is made of non-metallic materials, including plexiglass or quartz glass, to avoid affecting the efficiency of the cathodic protection current.

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