Variable ammonia-alcohol-hydrogen environment multi-type corrosion testing device and testing method

Abstract

The invention relates to the field of material mechanical property testing device development, in particular to a variable ammonia-alcohol-hydrogen environment multi-type corrosion testing device and a variable ammonia-alcohol-hydrogen environment multi-type corrosion testing method.The variable ammonia-alcohol-hydrogen environment multi-type corrosion testing device comprises a first reaction kettle, a second reaction kettle and a third reaction kettle, the second reaction kettle is a constant displacement stress corrosion device, and the third reaction kettle is an electrochemical corrosion test device; the first reaction kettle, the second reaction kettle and the third reaction kettle are respectively connected with a gas distribution device for supplying gas and a tail gas recovery device for recovering tail gas through pipelines; the first reaction kettle, the second reaction kettle and the third reaction kettle are connected with the stepless pressure regulating device through pipelines; and the first reaction kettle, the second reaction kettle and the third reaction kettle are respectively connected with a water bath circulating temperature control device through water jackets. According to the device and the method, actual working conditions can be accurately simulated, and a constant-load tensile stress corrosion test, a constant-displacement stress corrosion test and an electrochemical corrosion test of ammonia-alcohol-hydrogen in different corrosion environments can be synchronously or asynchronously realized.

Description

Technical Field

[0001] This invention relates to the field of developing testing devices for the mechanical properties of materials, and in particular to a testing device and method for multi-type corrosion testing in a variable ammonia-hydrogen environment. Background Technology

[0002] Hydrogen is produced by electrolyzing water, and then combined with nitrogen, carbon dioxide, and other substances to synthesize ammonia and methanol, replacing fossil fuels and driving deep decarbonization across multiple industries. This integrated "hydrogen → ammonia, methanol → end-use" model has become a key solution for energy and industrial transformation under the dual-carbon goals.

[0003] Hydrogen, as the "ultimate energy source" of the 21st century, boasts advantages such as high energy density (39.72 kWh / kg), zero carbon emissions, diverse sources, and wide application range. Hydrogen can achieve large-scale, long-term energy storage, absorb intermittent renewable energy sources such as wind and solar power, replace traditional fossil fuels, and significantly reduce carbon emissions. Hydrogen provides a new option for the energy system's transition to a clean and low-carbon future.

[0004] Ammonia, as a hydrogen storage medium, has advantages such as high hydrogen content (17.7% by mass), low storage and transportation costs, zero carbon emissions at the end, and high safety. The zero-carbon circular economy route using ammonia as a hydrogen storage carrier—"efficient synthesis → safe storage and transportation → carbon-free ammonia hydrogen utilization"—provides a new method for achieving rapid energy structure adjustment and accelerating the carbon neutrality process.

[0005] Methanol boasts advantages such as high energy density, convenient storage and transportation, and green and safe operation. Its synthesis process fixes carbon dioxide, and the carbon dioxide released during use can re-enter the biological cycle, achieving a closed-loop carbon cycle. Methanol provides a new pathway for promoting deep decarbonization of energy and the resource utilization of carbon dioxide.

[0006] Currently, hydrogen, ammonia, and alcohols in China are mainly transported via tank trucks and trailers. With the rapid growth in market demand for "hydrogen-ammonia-alcohol" systems, large-diameter, high-pressure pipelines will become the primary means of safe transportation in China's future. It is worth noting that hydrogen embrittlement can lead to fatigue cracking in hydrogen pipelines, especially in long-distance pipelines where large temperature variations further exacerbate the risk of brittle fracture. Ammonia readily interacts with media such as air and water, causing pipeline failure due to corrosion during long-term service. Methanol readily reacts with media such as oxygen, and the moisture in it forms electrolytes, leading to electrochemical corrosion of the pipelines. Therefore, a systematic evaluation of the corrosion resistance of pipeline materials under variable hydrogen, ammonia, and alcohol environments and various corrosion types is of significant engineering importance, clarifying the corrosion resistance characteristics of pipeline materials under different complex operating conditions.

[0007] Research on testing devices and methods still has significant shortcomings and urgently needs further investigation. Therefore, this invention aims to develop a device and method capable of synchronously or asynchronously testing various environments and types of corrosion samples, in order to accurately simulate and reproduce material corrosion behavior under actual working conditions. Summary of the Invention

[0008] The purpose of this invention is to provide a variable ammonia-hydrogen environment multi-type corrosion testing device and testing method, which can accurately simulate actual working conditions. By changing the temperature and pressure and the composition of ammonia-hydrogen gas, constant load tensile stress corrosion testing, constant displacement stress corrosion testing and electrochemical corrosion testing can be carried out synchronously or asynchronously under different ammonia-hydrogen corrosion environments.

[0009] The technical solution of this invention is as follows: a variable ammonia-ethanol-hydrogen environment multi-type corrosion testing device, comprising a first reaction vessel, a second reaction vessel, and a third reaction vessel. Both the first and second reaction vessels have a perforated base plate fixed inside. The base plate in the first reaction vessel is used to fix the bottom of the test sample. Multiple test samples are connected to the same lever outside the first reaction vessel with different lever arms, each bearing a weight. The base plate in the second reaction vessel supports C-ring samples and T-WOL samples. A resistance probe corrosion detector is externally connected to the second reaction vessel. An electrode group is provided inside the third reaction vessel, and the electrode group is connected to an external electrochemical workstation. The first, second, and third reaction vessels are respectively connected via pipelines to a gas supply device and to a tail gas recovery device. All three reaction vessels are connected to a stepless pressure regulating device. Furthermore, each of the three reaction vessels is also connected to a water bath circulating temperature control device.

[0010] Furthermore, the gas delivery device includes multiple gas pipelines, one end of each gas pipeline is connected to a gas cylinder via a fully enclosed safety valve, each gas pipeline is equipped with a flow meter electrically connected to the control panel, and the other end of each gas pipeline is connected to a connecting valve. The upper ends of the first reaction vessel, the second reaction vessel, and the third reaction vessel are respectively equipped with a gas line interface, and each gas line interface is connected to the connecting valve via a pipe.

[0011] Furthermore, a fully enclosed safety valve II controlled by a DC motor is provided on the output end side of the connecting valve, and the DC motor is controlled by the control panel; a fully enclosed safety valve III is provided on the air circuit interface I.

[0012] Furthermore, the tail gas recovery device includes a distillation separation tower. The upper ends of the first reaction vessel, the second reaction vessel, and the third reaction vessel are respectively provided with gas path interface two. The gas path interface two is connected to the distillation separation tower via pipelines. The liquid phase output end of the distillation separation tower is transported to the main body area of ​​the waste liquid storage tank for storage via a drain pipeline. The gas phase output end of the distillation separation tower is introduced into the upper space of the waste liquid storage tank via an exhaust pipeline. The waste liquid storage tank is connected to a waste gas absorption tower.

[0013] Furthermore, the stepless pressure regulating device includes reactor pressure regulating cylinders respectively disposed in the first reactor, the second reactor, and the third reactor. Each reactor pressure regulating cylinder has a pressure regulating piston. The reactor pressure regulating cylinders are respectively connected to a pressurized constant flow pump via pipelines. The pressurized constant flow pump is connected to a hydraulic oil storage tank.

[0014] Furthermore, the upper ends of the first, second, and third reaction vessels are all equipped with safety valves and pressure sensors; the electrochemical workstation and the resistance probe corrosion detector are all connected to a computer.

[0015] Furthermore, the water bath circulating temperature control device includes a water bath circulating temperature control box with a temperature control panel. The first reaction vessel, the second reaction vessel, and the third reaction vessel are all provided with water jackets on their sides. The outlet of the water bath circulating temperature control box is connected to the inlet of the water jacket via a circulating pump and a solenoid valve. The inlet of the water bath circulating temperature control box is connected to the outlet of the water jacket.

[0016] A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, comprising a device for testing multiple types of corrosion in a variable ammonia-hydrogen environment, and the steps are as follows: (I) Preparation and installation: Suspend multiple test samples in the first reaction vessel, fix the bottom of the sample to the base plate, and connect multiple samples to a lever with weights attached by different lever arms to ensure that the samples are subjected to constant load tensile tests under different loads in the environment of ammonia-ethanol hydrogen stress corrosion. (ii) Loading operation: Apply load by adding weights to the other side of the lever connected to the test sample, measure the deformation of the sample, and then determine the actual load applied to the sample according to the pre-calibrated "deformation-load" relationship. (III) Environment and Monitoring: Place the test sample in the target environment, keep the environmental conditions stable during the process, and monitor the state of the sample. (iv) Results recording: Observe the occurrence of cracks, crack propagation or fracture of the sample, record the corresponding time, stress changes and other data, complete the test, and finally summarize the corrosion resistance of the sample in the ammonia / alcohol / hydrogen environment.

[0017] A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, comprising a device for testing multiple types of corrosion in a variable ammonia-hydrogen environment, and the steps are as follows: (I) Preparation and stress application: Measure the dimensions of the C-ring specimen and calculate the change in the outer diameter of the C-ring specimen; (II) Sample preparation and loading: Clean the C-ring sample, and then place the C-ring sample on the bottom plate of the second reactor; purge nitrogen into the second reactor at a certain speed, and repeat this operation three times. (III) Liquid ammonia filling and environmental control: The second reactor is cooled to below the specified temperature using a water bath circulating temperature control device. Ammonia gas is slowly introduced at a certain flow rate to liquefy it, and the gas injection volume is measured. The pressure inside the second reactor is adjusted to be higher than the saturated vapor pressure of liquid ammonia at the corresponding temperature, and then adjusted to the test temperature using a water bath circulating temperature control device. (iv) Stress corrosion test: Under the set temperature and pressure conditions, the C-ring sample is subjected to liquid ammonia corrosion test at continuous intervals of a specified number of days to ensure that only the corrosive medium contacts the key stress area and surface of the C-ring sample, and to avoid contact stress arcs such as the hollow base plate. (V) End of test and sample removal: Slowly release the liquid ammonia containing impurities to normal pressure, and discharge the gas after neutralization by the tail gas recovery device; after confirming no leakage with an ammonia detector, open the second reaction vessel under ventilation conditions and remove the C-ring sample at the same time. (vi) Corrosion rate calculation: Weigh the C-ring sample before and after corrosion, and use the weight gain method combined with the formula CR=(W1-W0)*87600 / (A•T•D) to calculate the corrosion rate in mm / a. In the formula, W0 is the weight before corrosion, W1 is the weight after corrosion, A is the sample surface area, T is the test duration, and D is the material density.

[0018] A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, comprising a device for testing multiple types of corrosion in a variable ammonia-hydrogen environment, and the steps are as follows: (I) Sample preparation: Take the steel pipe of the required material, cut it into the required size and specifications by wire cutting, coarse grinding with metallographic sandpaper and fine grinding with wet sandpaper to the specified thickness, clean and dry it for later use. (II) Equipment and Environment Preparation: Set up an electrode group and prepare an ammonia solution of a certain concentration as an electrolyte; after passing nitrogen gas for a period of time, purge the oxygen from the solution, and then use a mass flow controller to pass oxygen into the solution to the specified pressure. Use a water bath circulation temperature control device to control the third reaction vessel to the specified temperature. (III) Open circuit potential measurement: Place the electrode group into the electrolyte with the parameters adjusted, connect it to the electrochemical workstation, monitor the open circuit potential until it stabilizes, and record the stable value; (iv) Potential dynamic polarization test: Based on the stable open circuit potential, scan from the cathode to the anode within the specified range and at the specified rate, record the polarization curve, and use Tafel fitting to calculate the corrosion current density and corrosion potential; (V) Post-treatment and characterization: The sample was washed and dried successively with an acidic slow-release solution containing hexamethylenetetramine and anhydrous ethanol. The surface morphology was observed by scanning electron microscopy, and the corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction.

[0019] Compared with the prior art, the present invention has the following advantages: 1. The testing device and method can accurately prepare a variable ammonia-hydrogen environment to adapt to corrosion testing requirements under different pressures and temperatures, and supports synchronous or asynchronous testing of multiple environments, multi-level pressure regulation, multiple samples, and multiple corrosion modes.

[0020] 2. This testing apparatus consists of three reaction vessels, capable of simultaneously or asynchronously performing constant-load tensile stress corrosion tests, constant-displacement stress corrosion tests, and electrochemical corrosion tests under different corrosion environments of ammonia, alcohol, and hydrogen. The first reaction vessel has a lever with external weights to ensure that the sample 27 bears stable stress during the tensile test. Multiple samples 27 bear different loads through different lever arms, completing stress corrosion tests under different loads in the same environment. The second reaction vessel is connected to a resistance probe corrosion detector to monitor the corrosion rate of the C-ring in real time. The electrode group of the third reaction vessel is connected to an external electrochemical workstation, employing a three-electrode system to investigate the electrochemical corrosion behavior of materials in ammonia / alcohol solutions under different temperatures and pressures. It is noteworthy that during the reaction process, the gas introduced into the first and second reaction vessels can be ammonia, hydrogen, or methanol, while the gas introduced into the third reaction vessel should be ammonia or methanol. That is, the environment for the constant-load tensile stress corrosion test and the constant-displacement stress corrosion test is an ammonia, alcohol, or hydrogen environment, while the environment for the electrochemical corrosion test should be an ammonia or alcohol environment.

[0021] The gas delivery device achieves consistent and stable volumetric flow rate from the source to the receiver, accurately establishes the reaction environment, ensures the repeatability of subsequent corrosion tests, and realizes data acquisition and feedback closed-loop control of DC motor to control valve opening to improve test accuracy.

[0022] The water bath circulating temperature control device enables temperature control of the reactor and corrosive environment. The device includes a water bath circulating temperature control chamber, a circulating pump, and a water jacket. These components work together to achieve precise temperature control: the water bath circulating temperature control chamber's performance can accurately match the corrosion testing requirements under different temperature conditions, providing a stable temperature environment for testing; the circulating pump effectively accelerates the circulation rate of the water bath medium, improving circulation efficiency and thus achieving efficient heat exchange, ensuring the effectiveness of internal temperature control; the water jacket, through its structure design that fits tightly against the equipment wall, improves heat transfer efficiency.

[0023] The exhaust gas recovery device achieves efficient recovery of exhaust gas and safe disposal of waste liquid. The obtained test waste liquid is condensed and separated in a distillation separation tower, and then discharged into the main body of the waste liquid storage tank. The test exhaust gas is then converted into the corresponding liquid using the temperature difference of the gas-liquid phase transition and stored in the waste liquid storage tank for secondary use, ensuring accurate recovery of the test waste liquid. Finally, the residual test exhaust gas and the hazardous gases volatilized from the waste liquid storage tank are uniformly introduced into the exhaust gas absorption tower through a dedicated emission pipeline for centralized treatment using chemical absorption and other methods to achieve harmless disposal.

[0024] The stepless pressure regulating device can achieve stepless pressure variation during corrosion, and drive the pressure regulating piston to achieve corrosion environments under different pressure conditions. It can efficiently simulate the actual storage and transportation conditions of ammonia, alcohol and hydrogen, and study the corrosion resistance of materials.

[0025] This variable ammonia-hydrogen environment and multi-type corrosion testing device can accurately prepare a variable ammonia-hydrogen environment to adapt to corrosion testing needs under different pressures and temperatures. It also supports simultaneous or asynchronous testing of multiple environments, multi-level pressure regulation, multiple samples, and multiple corrosion methods, which greatly enhances the testing capabilities of the device. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the corrosion testing device of the present invention; Figure 2 This is a schematic diagram of the first reaction vessel structure of the present invention. Figure 3 This is a schematic diagram of the second reaction vessel structure of the present invention; Figure 4 This is a schematic diagram of the third reaction vessel structure of the present invention; Figure 5 This is a schematic diagram of the hollow base plate structure of the present invention; Figure 6 These are schematic diagrams of various specimens used for corrosion testing in this invention; In the diagram: 1-Flow meter, 2-Control panel, 3-DC motor, 4-First reaction vessel, 5-Second reaction vessel, 6-Third reaction vessel, 7-Computer, 8-Electrochemical workstation, 9A-Fully enclosed safety valve 1, 9B-Fully enclosed safety valve 2, 9C-Fully enclosed safety valve 3, 9D-Fully enclosed safety valve 4, 9E-Fully enclosed safety valve 5, 9F-Fully enclosed safety valve 6, 10-Ammonia storage tank, 11-Connecting valve, 12-Lever, 13-Distillation separation tower, 14-Waste liquid storage tank, 15-Waste gas absorption tower, 16-Circulating pump, 17-Solenoid valve, 18-Outlet, 19-Inlet, 20-Water bath circulating temperature control box, 21-Temperature control panel, 22-Hydraulic oil storage tank, 2 3-Pressure constant flow pump, 24-Safety valve, 25-Pressure sensor, 26A-Gas interface one, 26B-Gas interface two, 27-Sample, 28-Piston container, 29-C-ring sample, 30-T-WOL sample, 31-Perforated base plate, 32-Resistance probe corrosion detector, 33-Electrode group, 34-Water jacket, 35-Reaction vessel pressure regulating cylinder, 36-Pressure regulating piston, 37-Universal wheel, 38-Hydrogen cylinder, 39-Nitrogen cylinder, 40-Support frame, 41-Methanol storage tank. Detailed Implementation

[0027] To make the above features and advantages of the present invention more readily understood, specific embodiments are described below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

[0028] refer to Figures 1 to 6 A variable ammonia-ethanol-hydrogen environment multi-type corrosion testing device includes a first reaction vessel 4, a second reaction vessel 5, and a third reaction vessel 6. The first reaction vessel 4 is a constant load tensile stress corrosion device, the second reaction vessel 5 is a constant displacement stress corrosion device, and the third reaction vessel 6 is an electrochemical corrosion testing device. Gas inlets 26A at the upper ends of the first reaction vessel 4, second reaction vessel 5, and third reaction vessel 6 are connected via pipelines to a gas distribution device for gas supply, and gas inlets 26B are connected via pipelines to a tail gas recovery device for tail gas recovery. The first reaction vessel 4, second reaction vessel 5, and third reaction vessel 6 are all connected via pipelines to a stepless pressure regulating device to adjust the pressure inside them. Water jackets 34 are respectively installed on the outer walls of the first reaction vessel 4, second reaction vessel 5, and third reaction vessel 6, and are connected via the water jackets 34 to a water bath circulation temperature control device to control the temperature inside them. This allows for simultaneous or asynchronous constant load tensile stress corrosion test, constant displacement stress corrosion test, and electrochemical corrosion test under different ammonia-ethanol-hydrogen environments using three reaction vessels.

[0029] In this embodiment, the first reactor 4, the second reactor 5, and the third reactor 6 are all disposed in piston-type containers 28 located inside the reactor body. The reactor bodies of the first reactor 4, the second reactor 5, and the third reactor 6 are respectively mounted on support frame 40. Universal wheels 37 are installed at the bottom of support frame 40, which helps to overcome the disadvantages of the reactor being relatively bulky and difficult to transport, and realizes the free movement of the reactor.

[0030] In this embodiment, both the piston-type containers 28 of the first reactor 4 and the second reactor 5 are welded with perforated bottom plates 31. The bottom plate 31 in the first reactor 4 is used to fix the bottom of multiple test samples 27. The multiple test samples 27 are connected to the same lever 12 with weights hanging on it outside the first reactor 4 with different lever arms, so as to achieve constant load conditions. Specifically, the reactor body is provided with a mounting hole for the pull rod to pass through. An O-ring dynamic sealing assembly is provided between the mounting hole and the pull rod so that the pull rod can slide up and down while maintaining a sealed state. The lower end of the pull rod is connected to the test sample (27). The lever (12) is provided with a through hole for the pull rod to pass through. The upper end of the pull rod is engaged with the lever (12) through a double spherical washer to adaptively absorb the angle error caused by the lever deflection, ensuring that the pull rod only moves up and down in a straight line, so that the sample is subjected to a vertical tensile load (the friction force generated by the dynamic seal can be offset by the weight force compensation; since the tensile displacement of the sample is short, lateral movement is not considered).

[0031] In this embodiment, the perforated bottom plate 31 inside the second reactor 5 is used to support the C-ring sample 29, and to place several T-WOL samples 30 (T-type Wedge-Opening Loading Specimen, T-WOL) placed on the bottom plate 31 in the middle of the C-ring sample 29 to achieve full contact with the medium. A resistance probe corrosion detector 32 is externally connected to the second reactor 5 to monitor the corrosion rate of the C-ring sample 29 inside the second reactor 5 in real time.

[0032] In this embodiment, the third reaction vessel 6 is equipped with an electrode group 33, which consists of a working electrode WE, a reference electrode RE, and an auxiliary electrode CE. The electrode group 33 is connected to an external electrochemical workstation 8, and the electrochemical workstation 8 and the resistance probe corrosion detector 32 are connected to the same computer 7. The computer 7 monitors the liquid ammonia corrosion testing process inside the second reaction vessel 5 and the third reaction vessel 6 to improve the accuracy of the test results.

[0033] Regarding specimen type, plate-shaped specimens, rod-shaped specimens, C-ring specimens, T-WOL specimens, etc., can be selected. Different specimen fixing methods and different specimen types can be chosen according to actual test requirements.

[0034] In this embodiment, the gas delivery device includes multiple gas pipelines. One end of each gas pipeline is connected to a gas cylinder via a fully enclosed safety valve 9A. The gas cylinders are a hydrogen cylinder 38, a methanol storage tank 41, a nitrogen cylinder 39, and an ammonia storage tank 10. Each gas pipeline is equipped with a flow meter 1, which is electrically connected to a control panel 2 to transmit flow data to the control panel. The other end of each gas pipeline is connected to a connecting valve 11. The upper ends of the first reaction vessel 4, the second reaction vessel 5, and the third reaction vessel 6 are respectively equipped with gas inlets 26A. Each gas inlet 26A is equipped with a fully enclosed safety valve 9C. Each gas inlet 26A is connected to the connecting valve 11 via a pipe. The output end of the connecting valve 11 is equipped with a fully enclosed safety valve 9B controlled by a DC motor 3, which is controlled by the control panel 2.

[0035] Flow meter 1 monitors and regulates the flow in real time. During the test, nitrogen is first circulated to purge the gas, and then gas is supplied according to the set ratio under the control of valve group and control panel 2, achieving synchronous or asynchronous gas mixing. The first reaction vessel 4 and the second reaction vessel 5 are in an ammonia / alcohol / hydrogen environment, and the third reaction vessel 6 is in an ammonia and alcohol environment. Control panel 2 and DC motor 3 are in closed-loop control and collect feedback data to improve test accuracy. Before the test, the air in each reaction vessel can be purged with nitrogen, and ammonia is introduced after all impurities have been removed.

[0036] In this embodiment, in order to regulate the pressure inside the reactor, the stepless pressure regulating device includes reactor pressure regulating cylinders 35 respectively disposed in the lower chambers of the first reactor 4, the second reactor 5, and the third reactor 6. The reactor pressure regulating cylinders 35 are tightly fitted with the reactor bodies. Each reactor pressure regulating cylinder 35 has a pressure regulating piston 36. Each reactor pressure regulating cylinder 35 is connected to a branch pipe with a fully enclosed safety valve 9D. The branch pipe is connected to a pressurized constant flow pump 23 via a main pipe with a fully enclosed safety valve 9E. The pressurized constant flow pump 23 is connected to a hydraulic oil storage tank 22.

[0037] In this embodiment, the upper ends of the first reaction vessel 4, the second reaction vessel 5, and the third reaction vessel 6 are all connected to safety valves 24 and pressure sensors 25, which ensure that the pressure can be released in time when it is too high during the reaction process to ensure the safety of the reaction, and that the pressure inside the container can be measured in real time to understand the pressure changes inside the device.

[0038] When the stepless pressure regulating device is in operation, the pressurizing constant flow pump 23 pushes the pressure regulating piston 36 of the pressure regulating cylinder 35 of the reactor upward through the pump pipeline, thereby pressurizing the liquid inside the cylinder. When the pressure of the corrosive medium reaches the expected value, the pressure sensor 25 transmits a signal to the pressurizing constant flow pump 23, stopping the push of the pressure regulating piston 36. The reciprocating motion of the pressure regulating piston 36 allows the pressure inside the reactor to be changed arbitrarily according to the requirements.

[0039] In this embodiment, the water bath circulation temperature control device includes a water bath circulation temperature control box 20 with a temperature control panel 21. Water jackets 34 are provided on the sides of the first reactor 4, the second reactor 5, and the third reactor 6. The water jackets 34 fit tightly against the reactor walls, enabling uniform heat transfer. The outlet 18 of the water bath circulation temperature control box 20 is connected to the inlet of the water jacket 34 via a circulation pump 16 and a solenoid valve 17. The inlet 19 of the water bath circulation temperature control box 20 is connected to the outlet of the water jacket 34. The water jacket 34 and the reactor walls save on traditional cooling time. Water bath circulation temperature control via the water jacket 34 ensures stable temperature during the reaction process, allowing the reaction inside the reactor to proceed stably for an extended period.

[0040] After the experiment is started, the temperature sensor of the water bath circulation temperature control device provides real-time feedback on the water temperature in the temperature control chamber 20. The target temperature is set via the temperature setting key: refrigeration is achieved by starting the compressor, with refrigerant R404A absorbing heat through phase change; heating is achieved by starting the electric heating element. Once the preset temperature is reached, the temperature control system reduces its power, the circulation pump 16 starts, and the solenoid valve 17 opens. The circulating water in the temperature control chamber 20 flows into the water jacket 34 of the reactor through the outlet 18, and then flows back to the temperature control chamber 20 through the inlet 19, completing the water bath circulation and reactor temperature control.

[0041] In this embodiment, to ensure the experiment is conducted in a green and environmentally friendly manner, the exhaust gas recovery device includes a distillation separation tower 13. The upper ends of the first reaction vessel 4, the second reaction vessel 5, and the third reaction vessel 6 are each equipped with a gas path interface 26B. Each gas path interface 26B is fitted with a fully enclosed safety valve 9F and connected to the distillation separation tower 13 via a pipeline. During the experiment, the low-temperature discharged experimental waste liquid is first introduced into the distillation separation tower 13. The liquid phase component after distillation separation is transported to the main area of ​​the waste liquid storage tank 14 via a drain pipe for storage. The gas phase component is introduced into the upper space of the waste liquid storage tank 14 via an exhaust pipe at the top of the distillation separation tower 13. The condensable waste gas undergoes a liquefaction reaction due to the temperature difference between the gas and liquid phase transitions and is collected in the waste liquid storage tank 14, achieving secondary utilization of the waste gas resources. For the experimental waste gas that fails to liquefy and the hazardous gases volatilized during the operation of the waste liquid storage tank 14, they are uniformly transported to the waste gas absorption tower 15 via a dedicated discharge pipeline for centralized treatment using methods such as chemical absorption to achieve harmless disposal.

[0042] A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, employing the aforementioned test apparatus for multiple types of corrosion in a variable ammonia-hydrogen environment. The steps for the constant load tensile specimen test in the first reaction vessel 4 are as follows: (I) Preparation and installation: First, suspend multiple test samples 27 in the piston-type container 28 of the reactor. The bottom of the sample 27 is fixed to the hollow bottom plate 31. Multiple samples 27 are connected to a lever 12 with weights hanging on it through different lever arms to ensure that the sample 27 is subjected to constant load tensile test under different loads in the environment of ammonia-ethanol hydrogen stress corrosion. (ii) Loading operation: Apply load by adding weights to the other side of the lever 12 connected to the test sample 27, and at the same time measure the deformation of the sample 27 with tools such as dial indicator. Then, determine the actual load applied to the sample 27 according to the pre-calibrated "deformation-load" relationship. (III) Environment and monitoring: The test sample 27 was placed in the target environment, and the environmental conditions were kept stable during the process, while the state of the sample 27 was monitored. (iv) Result recording: Observe the occurrence of cracks, crack propagation or fracture of sample 27, record the corresponding time, stress change and other data, complete the test, and finally summarize the corrosion resistance of sample 27 in ammonia / alcohol / hydrogen environment.

[0043] A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment is provided, employing the aforementioned device for testing such corrosion. The corrosion test method for the C-ring sample in the second reaction 5 is as follows (taking an ammonia environment as an example): (I) Preparation and Stress Application: Measure the dimensions of the C-ring specimen 29 and calculate the change in its outer diameter. Apply stress to the predetermined change in outer diameter by tightening the bolt device, which consists of a stud and a nut. Each stud has a nut on one side, and the nuts are tightly fitted against the outer wall of the C-ring. Stress is applied to the C-ring by tightening the nuts on both sides. When measuring the change in outer diameter of the C-ring specimen 29, the measurement must be taken along the center line of the bolt device. Alternatively, the measurement can be taken at the center of the outer diameter, inner diameter, or wall thickness. Consistency of measurement points is essential. If the change in outer diameter of the C-ring specimen 29 exceeds the requirement, the test must be conducted at a higher change or the specimen must be scrapped. (II) Sample preparation and loading: Clean the C-ring sample 29, and then place the C-ring sample 29 on the hollow bottom plate 31; Nitrogen cylinder 39 introduces nitrogen into the second reaction vessel 5 at a certain speed, and repeats this operation three times to purge the impurity gas in the second reaction vessel 5. (III) Liquid ammonia filling and environmental control: The reaction vessel is cooled to below the specified temperature using a water bath circulating temperature control device. Ammonia gas is slowly introduced at a certain flow rate to liquefy it. The filling amount is measured by a high-precision electronic platform scale and the gas is injected through flow meter 1. The pressure in the second reaction vessel 5 is adjusted to be higher than the saturated vapor pressure of liquid ammonia at the corresponding temperature. The temperature is adjusted to the test temperature using a water bath circulating temperature control device. Coatings or insulating bushings are used to prevent galvanic corrosion or crevice corrosion from occurring on the C-ring sample 29, bolts, hollow base plate 31 and between them. (iv) Stress corrosion test: Under the set temperature and pressure conditions, the C-ring sample 29 is subjected to liquid ammonia corrosion test at a continuous interval of a specified number of days to ensure that only the corrosive medium contacts the key stress area and surface of the C-ring sample 29, and avoids contact stress arcs such as the hollow base plate 31. (V) End of test and sample removal: Slowly release the liquid ammonia containing impurities to normal pressure through the liquid ammonia circulation pipeline. The gas is neutralized by the tail gas recovery device and then discharged. The operator wears anti-freeze gloves, goggles and other protective equipment. After confirming that there is no leakage with the ammonia detector, the second reaction vessel 5 is opened under ventilation conditions, and the C-ring sample 29 is taken out at the same time. (vi) Corrosion rate calculation: Weigh the C-ring sample 29 before and after corrosion. Use the weight gain method combined with the formula CR=(W1-W0)*87600 / (A•T•D) to calculate the corrosion rate in mm / a. In the formula, W0 is the weight before corrosion, W1 is the weight after corrosion, A is the sample surface area, T is the test duration, and D is the material density.

[0044] A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment is provided, employing the aforementioned device for testing such corrosion. Specifically, the corrosion test method for T-WOL sample 30 in the second reaction vessel 5 is as follows: (I) Sample preparation: T-WOL samples were prepared at specific locations on the pipe and circumferential weld to meet the requirements for thickness, width and other dimensions. After machining and electrical discharge machining of the notches, fatigue cracks were pre-induced in the laboratory air environment and the samples were prepared for use after surface treatment. (II) Test apparatus and environment: Fix the sample with an electrical insulation clamp to ensure that the liquid ammonia medium immerses the notch of the sample; (III) Test loading and monitoring: After cleaning the specimen according to the specifications, load it to the initial stress intensity factor in constant displacement mode, carry out one test cycle, measure the crack length once every specified number of days, calculate the propagation rate, and record the change of opening displacement; (iv) K ISCC Determination and Result Reporting: After crack propagation stops or the specimen fractures, determine the effective crack length and calculate K. ISCC After verifying the effectiveness of the test, the material information, test conditions, crack data, etc. are compiled into a report.

[0045] A method for testing multiple types of corrosion in a variable ammonia-ethanol-hydrogen environment is provided, employing the aforementioned device for testing such corrosion. Specifically, the electrochemical corrosion test method for the third reaction vessel 6 is as follows (taking an ammonia environment as an example): (I) Sample preparation: Take the steel pipe of the required material, cut it into the required size and specifications by wire cutting, coarse grinding with metallographic sandpaper and fine grinding with wet sandpaper to the specified thickness, clean and dry it for later use. (II) Equipment and Environment Preparation: Electrode group 33 is set up. Specifically, electrode group 33 is a three-electrode system (working electrode is a steel tube sample, reference electrode is a saturated calomel electrode, and auxiliary electrode is a platinum electrode). Ammonia solution of a certain concentration is prepared as electrolyte. After purging nitrogen for a period of time, the oxygen in the solution is purged. Then, oxygen is introduced to the specified pressure using a mass flow controller (MFC). The water bath circulating temperature control box 20 controls the third reaction vessel 6 to the specified temperature. (III) Open Circuit Potential (OCP) Measurement: Place the three electrodes in the electrolyte with the parameters adjusted, connect to the electrochemical workstation 8, monitor the OCP until it stabilizes, and record the stable value; (iv) Potential dynamic polarization test: Based on the stable OCP, scan from the cathode to the anode within the specified range and at the specified rate, record the polarization curve, and use Tafel fitting to calculate the corrosion current density and corrosion potential; (V) Post-treatment and characterization: The sample was washed and dried successively with an acidic slow-release solution containing hexamethylenetetramine and anhydrous ethanol. The surface morphology was observed by scanning electron microscopy, and the corrosion products were analyzed by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD).

[0046] The above description is only a preferred embodiment of the present invention. For those skilled in the art, designing different forms of variable ammonia-hydrogen environment multi-type corrosion testing devices and methods according to the teachings of the present invention does not require creative labor. All equivalent changes, modifications, substitutions and variations made in accordance with the scope of the patent application of the present invention without departing from the principles and spirit of the present invention shall be covered by the present invention.

Claims

1. A variable ammonia-ethanol-hydrogen environment multi-type corrosion testing device, comprising a first reaction vessel (4), a second reaction vessel (5), and a third reaction vessel (6), characterized in that, Both the first reactor (4) and the second reactor (5) have a perforated bottom plate (31) fixed inside. The bottom plate (31) inside the first reactor (4) is used to fix the test sample (27) below. Multiple test samples (27) are connected to the same lever (12) with weights hanging outside the first reactor (4) with different lever arms. The bottom plate (31) inside the second reactor (5) is used to support the C-ring sample (29) and the T-WOL sample (30). A resistance probe corrosion detector (32) is externally connected to the second reactor (5). The third reactor... An electrode group (33) is provided inside the vessel (6), and the electrode group (33) is connected to an external electrochemical workstation (8); the first reaction vessel (4), the second reaction vessel (5), and the third reaction vessel (6) are respectively connected to a gas distribution device for gas supply and to a tail gas recovery device via pipelines; the first reaction vessel (4), the second reaction vessel (5), and the third reaction vessel (6) are respectively connected to a stepless pressure regulating device; the first reaction vessel (4), the second reaction vessel (5), and the third reaction vessel (6) are also respectively connected to a water bath circulating temperature control device.

2. The variable ammonia-hydrogen environment multi-type corrosion testing device according to claim 1, characterized in that, The gas delivery device includes multiple gas pipelines. One end of each gas pipeline is connected to a gas cylinder via a fully enclosed safety valve (9A). Each gas pipeline is equipped with a flow meter (1) that is electrically connected to the control panel (2). The other end of each gas pipeline is connected to a connecting valve (11). The upper ends of the first reactor (4), the second reactor (5), and the third reactor (6) are respectively equipped with gas interface (26A). Each gas interface (26A) is connected to the connecting valve (11) via a pipe.

3. The variable ammonia-hydrogen environment multi-type corrosion testing device according to claim 2, characterized in that, The output end of the connecting valve (11) is provided with a fully enclosed safety valve two (9B) controlled by a DC motor (3), and the DC motor (3) is controlled by the control panel (2); the air passage interface one (26A) is provided with a fully enclosed safety valve three (9C).

4. A variable ammonia-hydrogen environment multi-type corrosion testing device according to claim 1, 2 or 3, characterized in that, The tail gas recovery device includes a distillation separation tower (13). The upper ends of the first reaction vessel (4), the second reaction vessel (5), and the third reaction vessel (6) are respectively provided with gas path interface two (26B). The gas path interface two (26B) is connected to the distillation separation tower (13) via pipelines. The liquid phase output end of the distillation separation tower (13) is transported to the main area of ​​the waste liquid storage tank (14) via the drain pipeline for storage. The gas phase output end of the distillation separation tower (13) is introduced into the upper space of the waste liquid storage tank (14) via the exhaust pipeline. The waste liquid storage tank (14) is connected to a waste gas absorption tower (15).

5. The variable ammonia-hydrogen environment multi-type corrosion testing device according to claim 1, characterized in that, The stepless pressure regulating device includes reactor pressure regulating cylinders (35) respectively installed in the first reactor (4), the second reactor (5), and the third reactor (6). Each reactor pressure regulating cylinder (35) has a pressure regulating piston (36). Each reactor pressure regulating cylinder (35) is connected to a pressurized constant flow pump (23) via a pipeline. The pressurized constant flow pump (23) is connected to a hydraulic oil storage tank (22).

6. A variable ammonia-hydrogen environment multi-type corrosion testing device according to claim 1, 2, 3, 4 or 5, characterized in that, The upper ends of the first reactor (4), the second reactor (5), and the third reactor (6) are all connected to a safety valve (24) and a pressure sensor (25); the electrochemical workstation (8) and the resistance probe corrosion detector (32) are all connected to the computer (7).

7. The variable ammonia-hydrogen environment multi-type corrosion testing device according to claim 1, characterized in that, The water bath circulating temperature control device includes a water bath circulating temperature control box (20) with a temperature control panel (21). The first reaction vessel (4), the second reaction vessel (5), and the third reaction vessel (6) are all provided with water jackets (34) on their sides. The outlet (18) of the water bath circulating temperature control box (20) is connected to the inlet of the water jacket (34) via a circulating pump (16) and a solenoid valve (17). The inlet (19) of the water bath circulating temperature control box (20) is connected to the outlet of the water jacket (34).

8. A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, comprising the multi-type corrosion testing apparatus for a variable ammonia-hydrogen environment as described in any one of claims 1-7, characterized in that, The steps are as follows: (I) Preparation and installation: Suspend multiple test samples (27) in the first reaction vessel (4). The sample (27) is fixed to the bottom plate (31). Multiple samples (27) are connected to a lever (12) with weights attached by different lever arms to ensure that the sample (27) is subjected to constant load tensile test under different loads in the environment of ammonia-ethanol hydrogen stress corrosion. (ii) Loading operation: Apply load by adding weights to the other side of the lever (12) connected to the test sample (27), measure the deformation of the sample (27), and then determine the actual load applied to the sample (27) according to the pre-calibrated "deformation-load" relationship. (III) Environment and monitoring: The test sample (27) was placed in the target environment, and the environmental conditions were kept stable during the process. The state of the sample (27) was monitored at the same time. (iv) Results recording: Observe the occurrence of cracks, crack propagation or fracture of the sample (27), record the corresponding time, stress change and other data, complete the test, and finally summarize the corrosion resistance of the sample (27) in the ammonia / alcohol / hydrogen environment.

9. A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, comprising the multi-type corrosion testing apparatus for a variable ammonia-hydrogen environment as described in any one of claims 1-7, characterized in that, The steps are as follows: (I) Preparation and stress application: Measure the dimensions of the C-ring specimen (29) and calculate the change in the outer diameter of the C-ring specimen (29); (ii) Sample preparation and loading: Clean the C-ring sample (29), and then place the C-ring sample (29) on the bottom plate (31) of the second reactor (5); purge nitrogen into the second reactor (5) at a certain speed, and repeat the operation three times; (III) Liquid ammonia filling and environmental control: The second reactor (5) is cooled to below the specified temperature using a water bath circulating temperature control device, and ammonia gas is slowly introduced at a certain flow rate to liquefy it, and the gas injection amount is measured; the pressure inside the second reactor (5) is adjusted to be higher than the saturated vapor pressure of liquid ammonia at the corresponding temperature, and adjusted to the test temperature using a water bath circulating temperature control device; (iv) Stress corrosion test: Under the set temperature and pressure conditions, the C-ring sample (29) is subjected to liquid ammonia corrosion test at a continuous interval of a specified number of days to ensure that only the corrosive medium contacts the key stress area and surface of the C-ring sample (29) and avoids contact stress arcs such as the hollow base plate (31). (V) End of test and sample removal: Slowly release the liquid ammonia containing impurities to normal pressure, and discharge the gas after neutralization by the tail gas recovery device; after confirming no leakage with an ammonia detector, open the second reaction vessel (5) under ventilation conditions, and at the same time remove the C-ring sample (29). (vi) Corrosion rate calculation: Weigh the C-ring sample (29) before and after corrosion, and use the weight gain method combined with the formula CR=(W1-W0)*87600 / (A•T•D) to calculate the corrosion rate mm / a. In the formula, W0 is the weight before corrosion, W1 is the weight after corrosion, A is the sample surface area, T is the test duration, and D is the material density.

10. A method for testing multiple types of corrosion in a variable ammonia-hydrogen environment, comprising the multi-type corrosion testing apparatus for a variable ammonia-hydrogen environment as described in any one of claims 1-7, characterized in that, The steps are as follows: (I) Sample preparation: Take the steel pipe of the required material, cut it into the required size and specifications by wire cutting, coarse grinding with metallographic sandpaper and fine grinding with wet sandpaper to the specified thickness, clean and dry it for later use. (II) Equipment and Environment Preparation: Set up an electrode group (33), prepare an ammonia solution of a certain concentration as an electrolyte; after passing nitrogen gas for a period of time, vent the oxygen in the solution, and then use a mass flow controller to pass oxygen into the solution to the specified pressure. Use a water bath circulating temperature control device to control the third reactor (6) to the specified temperature. (III) Open circuit potential measurement: Place the electrode group (33) into the electrolyte with adjusted parameters, connect it to the electrochemical workstation (8), monitor the open circuit potential until it stabilizes, and record the stable value; (iv) Potential dynamic polarization test: Based on the stable open circuit potential, scan from the cathode to the anode within the specified range and at the specified rate, record the polarization curve, and use Tafel fitting to calculate the corrosion current density and corrosion potential; (V) Post-treatment and characterization: The sample was washed and dried successively with an acidic slow-release solution containing hexamethylenetetramine and anhydrous ethanol. The surface morphology was observed by scanning electron microscopy, and the corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction.

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