Seawater filter corrosion detection test device

Abstract

The invention belongs to the technical field of ship seawater filter corrosion evaluation, and relates to a seawater filter corrosion detection test device, a main body structure comprises a seawater circulation system and a data acquisition and analysis system which are respectively connected with a corrosion test system, and the corrosion test system is connected with the data acquisition and analysis system through a built-in sensor module. The device is used for simulating a corrosive medium environment of the seawater filter, investigating marine environment factors such as temperature, dissolved oxygen content, salinity and sediment content, and comprehensively evaluating the corrosion behavior and corrosion resistance of the seawater filter serving in a complex marine environment through electrochemical, weightlessness, microstructure and other methods. Thoughts, guidance and schemes are provided for material selection design of a seawater filter, material selection of components such as a filter screen, anti-corrosion maintenance measures and ship navigation safety guarantee, cost and energy consumption of a ship and an ocean platform can be reduced, potential safety hazards are reduced, and the cost is reduced. And the method has guiding significance in prolonging the test life of the ship seawater filter, selecting materials and designing the seawater filter and daily maintenance and repair.

Description

Technical Field:

[0001] The present invention belongs to the technical field of corrosion evaluation of ship seawater filters, and particularly relates to a corrosion detection test device for seawater filters, which is used to comprehensively evaluate the corrosion behavior and corrosion resistance of seawater filters serving in complex marine environments, and provide guidance and solutions for the material selection design of seawater filters and the safety guarantee of ship navigation. Background Art:

[0002] The seawater filter is used to filter seawater impurities such as sediment entering the ship's cooling system to ensure the safe operation of machinery and equipment in the ship system. It serves in a harsh and complex marine environment and is affected by corrosion of high-salinity seawater, erosion by scouring, and biofouling. After long-term service, problems such as corrosion failure and decreased working efficiency may occur, and even serious safety accidents such as blockage of the cooling and heat exchange system may be triggered. At present, static immersion or simple dynamic circulation tests are mostly used for the corrosion tests of seawater filters, which are difficult to truly simulate the complex corrosion environment under actual working conditions. For example, a simulation device for the corrosion test of metals in a dynamic environment disclosed in Chinese Patent No. 201820649525.1 includes a main frame. A first motor is provided on one side of the main frame. The output shaft of the first motor is fixedly connected to one end of a lead screw. A cavity is provided inside the main frame. The lead screw is sleeved through the cavity. A lead screw nut is sleeved on the lead screw in a driving manner. The lower end of the lead screw nut is fixedly connected to the upper end of a second motor through a connecting block. One end of the output shaft of the second motor is fixedly connected to the upper end of a support rod through a coupling. A clamp is provided at the lower end of the support rod. A bottom plate is provided below the main frame. A spraying area is provided above the bottom plate. A pipeline is provided on the side wall of one side of the spraying area. A spray head is provided at one end of the pipeline. The upper end of the spraying area is a lower cross plate. A third chute is provided on the lower cross plate. Above the lower cross plate is an isolation area. Above the isolation area is an upper cross plate. A second chute is provided on the upper cross plate. Symmetrical notches are provided on the side walls of both sides of the isolation area. The support rods are respectively inserted and movably clamped in the second chute, the notches, and the third chute. A scanner body is provided above one end of the bottom plate. One end of the lead screw is axially connected to one side of the cavity through a bushing. The lead screw nut is slidably clamped in the cavity. A first chute communicating with the cavity is provided at the lower end of the main frame. The connecting block is slidably sleeved through the first chute. The spray heads are provided on both sides of the clamp. The pipeline is communicated with an external water pump. Cabinet doors are symmetrically provided on the side walls of both sides of the spraying area. The two groups of cabinet doors are respectively provided below the two ends of the third chute. The upper cross plate and the lower cross plate have the same shape and size. The widths of the second chute, the notches, and the third chute are all the same as the cross-sectional diameter of the support rod. The lower part of the main frame is fixedly connected to the upper side of the upper cross plate through a support rod. It can simulate the working environment of metal materials, but is not suitable for studying the corrosion behavior of seawater filters under complex service environments such as corrosion, scouring, and microbial attachment.A corrosion test device based on dynamic simulation disclosed in Chinese Patent No. 202310270677.6 includes a spiral lifting rod and a guide rod fixedly arranged vertically side by side on a base. A fixed block is jointly installed at the lower parts of the spiral lifting rod and the guide rod. The fixed block is horizontally fixedly connected to a reaction kettle. An lifting block is slidably installed at the upper parts of the spiral lifting rod and the guide rod. The lifting block is in transmission connection with a spiral turbine mechanism. The lifting block is horizontally fixedly connected to a cover plate. An electric heating tape is wrapped around the outer circumferential surface of the reaction kettle body. A drain pipe is communicated with the bottom plate of the reaction kettle. An upper magnetic rotor is installed on the upper surface of the axis of the cover plate. The upper magnetic rotor is in transmission connection with a frequency conversion motor. A lower magnetic rotor is installed on the lower surface of the axis of the cover plate. A hanging rack is hung downward from the lower magnetic rotor. The hanging rack is connected with a plurality of test pieces through insulating gaskets. The cover plate is provided with a plurality of vertical through holes. A temperature sensor, a pressure sensor, a pressure gauge, an air inlet pipe, a pressure relief safety valve and an exhaust pipe are respectively installed in each through hole. The temperature sensor, the pressure sensor and the frequency conversion motor are all in signal connection with a controller. The cover plate is a sealed flange structure. A plurality of sealing bolts are installed on the cover plate. Each sealing bolt is downwardly correspondingly connected to a sealing screw hole in the mouth edge of the reaction kettle. The reaction kettle is in a cylindrical shape and is made of a corrosion-resistant alloy material. The reaction kettle and the cover plate are connected through the sealing bolts. A sealing gasket is arranged in the flange mouth edge groove of the reaction kettle. The hanging rack is made of a corrosion-resistant alloy material. The hanging rack is provided with three hanging positions and is evenly arranged at an angle of 120 degrees in the circumferential direction. The test pieces are made in the shape of a flat cuboid. Each test piece is provided with double ear holes at the upper part. It takes into account the relative speed between the corrosion test solution and the test sample, and improves the accuracy of test data. A dynamic corrosion experiment simulation device disclosed in Chinese Patent No. 201610096668.X is composed of three parts: a refrigeration area, a water pump area and a test area. The main working part of the refrigeration area is a condenser, whose function is to refrigerate and keep the water temperature constant, and the temperature change can be adjusted within a certain range. The water tank in the water pump area is used to store seawater. The water pump provides power for the seawater to wash the surface of the sample at a certain speed. The test area is used for the installation of the sample, electrochemical testing, the change of the test surface angle of the sample and the transmission of the mechanical vibration device. The condenser used in the refrigeration area is based on the physical refrigeration principle of Freon. The vaporization and liquefaction of Freon can efficiently cool down and realize recycling, with a fast refrigeration speed and high efficiency. The water tank material is stainless steel, with good corrosion resistance and impact resistance. The water pump in the water pump area is a submersible pump placed in water to achieve a higher impact speed under high pressure. The upper surface of the water tank is sealed with an acrylic transparent cover. An acrylic transparent cover handle is installed to facilitate relevant operations on the internal components of the box when the experiment stops. The water level in the water tank can be controlled by increasing or decreasing the number of stainless steel baffles between the water pump area and the test area. The relative angle between the sample surface and the water flow can be changed by rotating the fixture. The relative angle between the sample surface and the water flow can be accurately obtained by measuring the rotation angle corresponding to the rotation of the fixture. The position of the sample fixture in different directions can be adjusted to adapt to different sample sizes.Through an electrochemical method, it explores the corrosion behavior of ships in seawater from four aspects: temperature, seawater velocity, erosion angle, and ship vibration frequency. However, the above two patent documents do not consider the differences in seawater salinity, dissolved oxygen content, and sediment content in different sea areas and at different service depths. Moreover, the targeting of the specimens is not high enough to meet the test requirements for local corrosion sites. Therefore, it is of great significance to develop and design a corrosion detection test device for seawater filters to simulate the corrosion medium environment of seawater filters and investigate marine environmental factors such as temperature, dissolved oxygen content, salinity, and sediment content. Summary of the Invention:

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art, develop and design a corrosion detection test device for seawater filters, provide ideas for the structural design of seawater filters, material selection for components such as filter meshes, and anti-corrosion maintenance measures, so as to ensure the safe and reliable operation of seawater filters in application environments such as ships and reduce the risk of sudden accidents.

[0004] To achieve the above purpose, a corrosion detection test device for seawater filters involved in the present invention can set the sampling time and test frequency, periodically collect and analyze the corrosion behavior of the filter, and conduct efficient monitoring and comprehensive analysis of the corrosion behavior of the seawater filter. Its main structure includes a seawater circulation system and a data acquisition and analysis system respectively connected to the corrosion test system. The corrosion test system is connected to the data acquisition and analysis system through a built-in sensor module to real-time monitor the temperature, salinity, and dissolved oxygen content of the corrosion test system, so as to simulate the real service environment of the seawater filter and meet the requirements of various test conditions; specifically:

[0005] (1) Corrosion Test System

[0006] The corrosion test system includes a corrosion test chamber with a housing made of polycarbonate material, as well as an erosion simulation module and an electrochemical test module, which is convenient for observing the test process in real time.

[0007] The corrosion test chamber is provided with a liquid inlet and a liquid outlet, which are connected to a regulator for simulating environmental factors. The regulator includes but is not limited to a temperature regulator, a salinity regulator, a dissolved oxygen regulator, and a sediment content regulator:

[0008] The temperature controller includes a heater and a cooler, and adjusts the temperature according to the characteristics of the filter service sea area and time;

[0009] The salinity regulator adjusts the seawater salinity range by adding or diluting brine;

[0010] The dissolved oxygen regulator uses a sensor to real-time monitor and adjust the dissolved oxygen concentration to simulate different seawater conditions;

[0011] The sediment content regulator changes the sediment content by adding sediment or diluting the corrosion medium.

[0012] (a) Scouring simulation module

[0013] The scouring simulation module includes a rotating blade and a pressure controller.

[0014] The rotating blade is driven by an external motor, and the scouring effect of seawater flow with different intensities on the seawater filter is simulated by changing the rotation speed.

[0015] The high-pressure nozzle of the pressure controller is made of corrosion-resistant ceramic material. By adjusting the injection angle and pressure, the requirements of seawater flow rate are met, and the scouring environment of flowing high-pressure seawater is simulated.

[0016] (b) Electrochemical test module

[0017] The electrochemical test module is used for electrochemical tests such as open circuit, electrochemical impedance, and potentiodynamic polarization curve, and includes an electrochemical workstation and a reference electrode, an auxiliary electrode, and a test clamp respectively connected thereto.

[0018] The reference electrode and the auxiliary electrode are pre-welded with matching screws and placed in the electrode grooves at the bottom of the corrosion test chamber. The reference electrode is a columnar saturated calomel electrode, and the auxiliary electrode is a platinum electrode.

[0019] The test clamp is welded to both sides of the inner wall of the corrosion test chamber and is used to fix the seawater filter specimen.

[0020] (2) Seawater circulation system

[0021] The seawater circulation system includes a circulation pipeline and a water pump and a flow regulating valve provided thereon.

[0022] The circulation pipeline introduces seawater into the seawater circulation system and then inputs it into the corrosion test system to ensure the stable flow of seawater in the test device.

[0023] The water pump ensures the seawater flow by pumping and transporting seawater, maintains the normal operation of the test device, and maintains the cooling effect and the stability of the test device.

[0024] The flow regulating valve is used to precisely control the seawater flow rate and has digital display and automatic control functions.

[0025] (3) Data acquisition and analysis system

[0026] The data acquisition and analysis system includes a sensor module, a data acquisition module, and data analysis software, and is used to record and analyze data such as temperature, salinity, dissolved oxygen, corrosion current, and corrosion potential.

[0027] The sensor module includes a temperature sensor, a salinity sensor, a dissolved oxygen sensor, and a flow sensor, and is used to collect test data in real time.

[0028] The data acquisition module is connected to the sensor module for multi-channel data acquisition. It has a built-in program that supports long-term continuous real-time data recording by controlling the corrosion test time and acquisition frequency. The acquisition frequency is set to 1 Hz.

[0029] The data analysis software is equipped with calculation models for corrosion current, corrosion potential, corrosion rate, etc. According to requirements, data can be viewed in the form of tables or graphs.

[0030] Compared with the prior art, the present invention is used to simulate the corrosion medium environment of seawater filters, investigate marine environmental factors such as temperature, dissolved oxygen content, salinity, and sediment content, and comprehensively evaluate the corrosion behavior and corrosion resistance of seawater filters serving in complex marine environments through methods such as electrochemistry, weight loss, and microscopic morphology. It provides ideas, guidance, and solutions for the material selection design of seawater filters, the material selection of components such as filter meshes, anti-corrosion maintenance measures, and the safety guarantee of ship navigation, helps reduce the costs and energy consumption of ships and offshore platforms, reduces potential safety hazards, and has guiding significance for extending the test life of ship seawater filters, the material selection and design of seawater filters, and daily maintenance and repair; its structure is simple, and it can dynamically adjust temperature, dissolved oxygen content, sediment content, and salinity to simulate a complex and changeable service environment of high pressure and high flow rate. By synchronously and real-time recording data on environmental factors such as temperature, dissolved oxygen content, and sediment content and corrosion electrochemistry test data, multi-dimensional corrosion behavior analysis is adopted to meet the comprehensive test requirements. Brief Description of the Drawings:

[0031] Figure 1 It is a schematic diagram of the main structure principle of the present invention.

[0032] Figure 2 It is a schematic diagram of the main structure of the corrosion test chamber related to the present invention.

[0033] Figure 3 It is a partial microscopic corrosion morphology diagram of the filter sample after the corrosion test related to the present invention. Detailed Embodiments:

[0034] The following further illustrates the present invention through embodiments in conjunction with the drawings.

[0035] Embodiment 1:

[0036] The main structure of the seawater filter corrosion detection test device related to this embodiment includes a corrosion test chamber 1, a circulation pipeline 2, an electrochemical workstation 3, a controller 4, and a regulator 5; the corrosion test chamber 1 is respectively connected to the circulation pipeline 2, the electrochemical workstation 3, the controller 4, and the regulator 5, as Figure 1 shown;

[0037] The corrosion test chamber 1 has a liquid inlet 11 and a liquid outlet 12, and is internally provided with a rotating blade 13, a test clamp 14, and a high-pressure nozzle 15, as Figure 2As shown, the vertical height of the liquid inlet 11 is higher than that of the liquid outlet 12. The rotating blade 13 is arranged on the side wall. The test clips 14 are arranged in pairs and increased accordingly according to the number of specimens. The high-pressure nozzle 15 is arranged on the top.

[0038] A water pump 21 and a flow regulating valve 22 are arranged on the circulation pipeline 2. The water pump 21 is located in front of the flow regulating valve 22 (in the seawater flow direction).

[0039] The reference electrode 31 and the auxiliary electrode 32 arranged on the electrochemical workstation 3 are placed in the corrosion test chamber 1. Both the reference electrode 31 and the auxiliary electrode 32 are arranged at the bottom of the corrosion test chamber 1 through screws 33.

[0040] The sensor module 41 arranged on the controller 4 is placed in the corrosion test chamber 1.

[0041] The regulator 5 is connected to the controller 4 to share data.

[0042] The seawater filter corrosion detection test device involved in this embodiment is used to simulate the service environment of the seawater filter and test the corrosion behavior of a certain type of stainless steel marine seawater filter under different conditions. The corrosion medium is the natural seawater of Aoshan Bay. The test process is as follows:

[0043] First, fix the seawater filter specimen in the corrosion test chamber 1 through the test clip 15, and screw the platinum electrode and the saturated calomel electrode with pre-welded screws 33 into the electrode slots at the bottom of the corrosion test chamber 1 respectively.

[0044] Then, adjust the water pump 21 to pump seawater into the corrosion test chamber 1.

[0045] Check the sensors and regulators such as temperature, salinity, and flow rate built in the corrosion test chamber 1.

[0046] Adjust the rotation speed of the rotating impeller 13 and the pressure of the high-pressure nozzle 14 to simulate the seawater scouring service environment with different high pressures and different rotation speeds.

[0047] Through the controller 4, adjust the temperature to 25 °C, the dissolved oxygen content to 7 mg / L, and the salinity to 35‰ to test the corrosion data of the seawater filter specimen at different flow rates.

[0048] Finally, start the electrochemical workstation 3, set the program, and monitor the open circuit potential, electrochemical impedance, and potentiodynamic polarization curve.

[0049] After 60 days, the test ends. Take out the seawater filter specimen from the corrosion test chamber 1. The microscopic morphology is as Figure 3 shown. The monitoring data exported from the data analysis software is shown in Table 1:

[0050] Flow velocity (m / s) 1 2 5 Corrosion rate (mm / a) 0.0798 0.1224 0.1456

[0051] It can be seen that the corrosion rate gradually increases with the increase of the flow rate.

[0052] The law of the corrosion rate changing with the flow rate is calculated by the weight loss test method, which is consistent with the conclusion obtained in this embodiment.

Claims

1. A seawater filter corrosion detection test device, characterized in that: The main structure includes a seawater circulation system and a data acquisition and analysis system which are respectively connected to the corrosion test system. The corrosion test system is connected to the data acquisition and analysis system through a built-in sensor module to monitor the temperature, salinity and dissolved oxygen content of the corrosion test system in real time.

2. A seawater filter corrosion detection test device according to claim 1, characterized in that: The corrosion test system includes a corrosion test chamber whose shell is made of polycarbonate material, an erosion simulation module and an electrochemical test module; The corrosion test chamber is provided with a liquid inlet and a liquid outlet, which are connected to the regulators simulating environmental factors, including a temperature regulator, a salinity regulator, a dissolved oxygen regulator, and a sediment content regulator; The scour simulation module includes rotating blades and pressure controller; The electrochemical test module is used for electrochemical testing, and includes an electrochemical workstation and a reference electrode, an auxiliary electrode and a test clamp respectively connected thereto.

3. A seawater filter corrosion detection test device according to claim 2, characterized in that: The seawater circulation system comprises a circulation pipeline and a water pump and a flow regulating valve arranged thereon.

4. A seawater filter corrosion detection test device according to claim 3, characterized in that: The data acquisition and analysis system includes a sensor module, a data acquisition module and data analysis software.

5. A seawater filter corrosion detection test device according to claim 4, characterized in that: The temperature controller includes a heater and a cooler to adjust the temperature according to the service area and time characteristics of the filter; The salinity regulator adjusts the salinity range of seawater by adding or diluting salt water; The dissolved oxygen regulator uses sensors to monitor and adjust the dissolved oxygen concentration in real time to simulate different seawater conditions; The sediment content regulator changes the sediment content by adding sediment or diluting the corrosive medium.

6. A seawater filter corrosion detection test device according to claim 5, characterized in that: The rotating blades simulate the scouring effect of seawater flows of different intensities on the seawater filter by changing the rotation speed; The high-pressure nozzle of the pressure controller is made of corrosion-resistant ceramic material. By adjusting the spray angle and pressure, it simulates the flushing environment of flowing high-pressure seawater. The reference electrode and the auxiliary electrode are welded with matching screws in advance and set in the electrode slot at the bottom of the corrosion test chamber. The reference electrode is a columnar saturated calomel electrode, and the auxiliary electrode is a platinum electrode. The test clamps are welded to both sides of the inner wall of the corrosion test chamber and are used to fix the seawater filter specimens.

7. A seawater filter corrosion detection test device according to claim 4, characterized in that: The sensor module includes temperature sensor, salinity sensor, dissolved oxygen sensor and flow sensor to collect test data in real time; The data acquisition module is connected to the sensor module for multi-channel data acquisition. The built-in program supports long-term continuous real-time data recording by controlling the corrosion test time and acquisition frequency. The acquisition frequency is set to 1Hz. The data analysis software is equipped with a computational model.

8. A seawater filter corrosion detection test device according to claim 1, characterized in that: The main structure includes a corrosion test chamber, a circulation pipeline, an electrochemical workstation, a controller and a regulator; the corrosion test chamber is connected to the circulation pipeline, the electrochemical workstation, the controller and the regulator respectively; The corrosion test chamber has a liquid inlet and a liquid outlet, and is internally provided with rotating blades, a test clamp and a high-pressure nozzle; The circulation pipeline is provided with a water pump and a flow regulating valve; The reference electrode and auxiliary electrode set on the electrochemical workstation are placed in the corrosion test chamber; The sensor module installed on the controller is placed in the corrosion test chamber; The regulator is connected to the controller.

9. A seawater filter corrosion detection test device according to claim 8, characterized in that: It is used to simulate the service environment of seawater filters and test the corrosion behavior of marine seawater filters under different conditions. The test process is as follows: First, the seawater filter sample is fixed in the corrosion test chamber, and the reference electrode and the auxiliary electrode welded with screws are fixed in the corrosion test chamber; Then, seawater is pumped into the corrosion test chamber; Adjust the speed of the rotating impeller and the pressure of the high-pressure nozzle to simulate the service environment of seawater flushing at different high pressures and speeds; Through the controller, the temperature, dissolved oxygen content and salinity are adjusted; Finally, the electrochemical workstation was started to monitor the open circuit potential, electrochemical impedance and potentiodynamic polarization curve.

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