Laboratory high-temperature electrochemical testing device capable of quantitatively regulating and controlling temperature gradient

Abstract

The invention discloses a laboratory high-temperature electrochemical testing device capable of quantitatively regulating and controlling temperature gradient. The laboratory high-temperature electrochemical testing device comprises a simulated flue gas input module, a circulating water module, a system control module, a high-temperature tube furnace and a tail gas treatment module, an electrochemical and temperature measuring module is arranged in the high-temperature tube furnace and is used for electrochemically measuring corrosion and reading the temperature of a metal wall surface through a thermocouple embedded in the heat exchange coil pipe; the weightlessness module is used for obtaining metal sample weightlessness information of a time scale by setting a sampling interval through a metal test piece, so that the instantaneous corrosion rate is obtained in real time, and the average corrosion rate in a long time scale is effectively evaluated; the system control module controls the water flow and the gas content in the heat exchange coil pipe through the PID controller and is used for conducting dynamic adjustment and atmosphere regulation and control on the temperature of the metal wall face. The regulation and control of the temperature gradient and the simulation of the atmosphere components can truly reproduce the corrosion environment in the combustion process of the high-chlorine fuel, and the comprehensive evaluation of the corrosion rate is realized through the combination of the electrochemical online monitoring module and the weightlessness module.

Description

Technical Field

[0001] The present invention relates to a laboratory electrochemical testing device, and particularly to a laboratory high-temperature electrochemical testing device for quantitatively regulating temperature gradient. Background Art

[0002] High-chlorine fuel high-temperature corrosion is a key research topic in the fields of energy, materials science, etc. Especially in the applications of fuel cells, combustion systems, and high-temperature power equipment, the reaction of chlorine element with the metal surface will cause serious corrosion, thus affecting the durability and safety of the equipment. In order to deeply understand the high-temperature corrosion mechanism caused by high-chlorine fuel, researchers usually use experimental means to simulate different corrosion environments and explore the main influencing factors during the corrosion process.

[0003] Currently, the gravimetric method (weight gain method or weight loss method) is one of the most commonly used methods in corrosion kinetics research. This method evaluates the corrosion rate by measuring the change in the mass of the sample before and after exposure to the corrosion environment. Although the gravimetric method has certain application value, it has significant limitations. First, the gravimetric method requires a long experimental time to measure the change in the mass of the material, which makes the experimental cycle long and the efficiency low. Second, the gravimetric method can only provide a rough estimate of the overall mass loss of the sample, unable to capture the subtle changes during the corrosion process, nor can it provide in-depth quantitative analysis for the corrosion mechanism. In addition, the handling of corrosion products and the accuracy of sample measurement before and after also limit its reliability.

[0004] Existing experimental methods often cannot effectively decouple the various influencing factors in high-temperature corrosion. The high-temperature corrosion process is affected by the combined action of multiple factors, such as temperature, chlorine source concentration, atmosphere, etc. These factors often change simultaneously in traditional experimental designs. Since it is difficult to separate and analyze each factor individually, it is very difficult for researchers to clearly distinguish the independent role of each factor in the corrosion process, which makes the understanding of the corrosion mechanism still have great uncertainty. Therefore, the existing corrosion research methods limit the in-depth development of high-temperature corrosion research in decoupling the effects of different factors. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a high-temperature electrochemical testing device for quantitatively regulating temperature gradient, realizing the independent control of temperature and atmosphere during the corrosion process, reproducing the corrosion conditions of the actual combustion environment in the laboratory, and obtaining accurate corrosion data.

[0006] Technical Solution: A laboratory high-temperature electrochemical testing device for quantitatively regulating temperature gradient according to the present invention, the device includes a simulated flue gas input module, a circulating water module, a system control module, and a high-temperature tube furnace;

[0007] The simulated flue gas input module includes a gas storage tank and a premixing tank;

[0008] The high-temperature tube furnace is internally provided with a temperature gradient corrosion probe. The temperature gradient corrosion probe includes a ceramic substrate, on which there are an electrochemistry and temperature measurement module and a weight loss module. The ceramic substrate is internally provided with a heat exchange coil and nickel wires. The electrochemistry and temperature measurement module is used for electrochemically measuring the metal corrosion rate and real-time reading of the metal wall temperature through a thermocouple embedded in the heat exchange coil. The weight loss module obtains the weight loss information of the metal specimen on the time scale by setting a sampling interval through metal specimens placed in parallel on the ceramic substrate;

[0009] The system control module controls the opening of the mass flowmeter through a PID controller, and thus controls the water flow rate and gas content in the heat exchange coil, for dynamically adjusting the metal wall temperature and atmosphere regulation.

[0010] Preferably, the PID controller controls the water flow rate in the heat exchange coil to dynamically adjust the metal wall temperature, and the temperature is controlled between 300 °C and 800 °C.

[0011] Preferably, the high-temperature tube furnace controls the external flue gas temperature, and the thermocouple for simulating the flue gas side real-time reads the actual simulated flue gas temperature, and the temperature is controlled between 750 and 1200 °C.

[0012] Preferably, the gases in the simulated flue gas input module include but are not limited to nitrogen, oxygen, and carbon dioxide. The gas content is dynamically set by a computer, and the total gas flow rate is controlled by a mass flowmeter after the gases are mixed in a premixing tank.

[0013] Preferably, each sampling point of the weight loss module includes four parallel metal specimens, where three metal specimens are used to obtain the measurement data at each time point, and one metal specimen is used for characterization and analysis.

[0014] Preferably, the electrochemistry and temperature measurement module uses linear polarization method, electrochemical impedance spectroscopy method, and electrochemical noise method for measurement. The sampling time of the linear polarization method is 40 seconds, the sampling time of the electrochemical impedance spectroscopy method is 3 minutes, and the sampling time of the electrochemical noise method is 1 second.

[0015] Preferably, the electrochemistry on-line monitoring module combines with the weight loss method to obtain the instantaneous corrosion rate, and calculates the average corrosion rate by measuring the mass loss of the metal sample.

[0016] Preferably, the device further includes a tail gas treatment module for treating the tail gas in the experiment.

[0017] Preferably, the linear polarization method determines the degree of metal corrosion through the change of current density. The electrochemical impedance method identifies the electrochemical reaction mechanism during the metal corrosion process by analyzing the electrochemical characteristics of the metal surface reaction. The electrochemical noise method captures the corrosion changes on the metal surface by obtaining data points.

[0018] Preferably, the circulating water module includes a steam generator for controlling the vapor content in the combustion environment.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages: The high-temperature electrochemical test device of the present invention can effectively decouple various corrosion factors in the high-chlorine fuel combustion environment and provide more accurate experimental conditions; by quantitatively regulating the temperature gradient, atmosphere, and chlorine source concentration, the experiment can independently analyze the effects of each corrosion factor, which helps to deeply understand the corrosion mechanism of high-chlorine fuel on metal materials; the electrochemical on-line monitoring method realizes the real-time monitoring of the corrosion process, obtains the real-time corrosion rate of the metal every 20 seconds, significantly improves the efficiency and accuracy of the experiment. Combining the electrochemical impedance method and the electrochemical noise method, the present invention can obtain more comprehensive corrosion kinetic information and reveal the electrochemical reaction mechanism of metals in different corrosion environments. Description of the Drawings

[0020] Figure 1 It is the structure diagram of the device described in the present invention.

[0021] Figure 2 It is the internal structure diagram of the temperature gradient corrosion probe of the present invention.

[0022] Figure 3 It is the structure diagram of the heat exchange coil.

[0023] Figure 4 It is the structure diagram of the ceramic substrate.

[0024] Figure 5 It is the structure diagram of the electrochemistry and temperature measurement module.

[0025] Figure 6 It is the structure diagram of the weight loss module. Detailed Embodiments

[0026] The technical solution of the present invention will be further described below with reference to the drawings.

[0027] As Figure 1 shown, a laboratory high-temperature electrochemical test device for quantitatively regulating the temperature gradient, the device includes a simulated flue gas input module 1, a circulating water module 2, a system control module 3, a high-temperature tube furnace 4, a tail gas treatment module 5, and a temperature gradient corrosion probe 6.

[0028] The simulated flue gas input module 1 includes a gas storage tank and a premixing tank. The simulated flue gas input module 1 is connected to the high-temperature tubular furnace 4 and is used to provide the atmosphere environment required for corrosion.

[0029] As Figure 2 shown, the high-temperature tubular furnace 4 is internally provided with a temperature gradient corrosion probe 6. The temperature gradient corrosion probe 6 includes a ceramic substrate 11. As Figure 4 shown, the ceramic substrate 11 includes an electrochemistry and temperature measurement module 7 and a weight loss module 8. The ceramic substrate 11 is internally provided with a nickel wire 10 and a heat exchange coil 9 as Figure 3 shown. As Figure 5 shown, the electrochemistry and temperature measurement module 7 is used to perform electrochemical measurement on the metal corrosion rate. By simultaneously measuring the linear polarization method, the electrochemical impedance method, and the electrochemical noise method, the real-time corrosion rate and corrosion mode information of the metal are obtained. The sampling time of the linear polarization method is 40 seconds, the sampling time of the electrochemical impedance method is 3 minutes, and the sampling interval of the electrochemical noise method is 1 second. Combining with the weight loss method, comprehensive metal corrosion kinetics information is obtained. The electrochemistry and temperature measurement module 7 also reads the metal wall temperature in real time through the thermocouple embedded in the heat exchange coil 9.

[0030] As Figure 6 shown, the weight loss module 8 obtains the weight loss information of the metal specimen on the time scale by setting the sampling interval through the metal specimens placed in parallel on the ceramic substrate 11; the weight loss module 8 provides high-precision corrosion mass loss data through the parallel metal specimens and obtains the weight loss information of the metal specimen on the relevant time scale by setting the sampling interval by itself. Among them, there are three parallel specimens at each sampling point for error analysis, and there is also one specimen for characterization analysis to ensure the accuracy of error analysis and improve the reliability of experimental data.

[0031] The circulating water module 2 includes a steam generator and is used to provide water flow to adjust the temperature of the heat exchange coil 9.

[0032] The system control module 3 controls the opening of the mass flowmeter through a PID controller, thereby controlling the flow rate of the heat exchange coil to dynamically adjust the metal wall temperature. The temperature range can be controlled between 300°C and 800°C. The external flue gas temperature is uniformly set by the tubular furnace and controlled between 750°C and 1200°C. The thermocouple on the simulated flue gas side reads the actual simulated flue gas temperature in real time. And according to the dynamic setting of the computer, the contents of gases such as nitrogen, oxygen, carbon dioxide, hydrogen chloride, sulfur dioxide, and hydrogen sulfide in the atmosphere are set. After being fully mixed in the premixing tank, the total gas flow rate is controlled by the mass flowmeter.

[0033] Among them, the tail gas treatment module 5 is used for tail gas treatment in the experiment.

[0034] This device realizes the quantitative control of the experimental atmosphere through a computer system. The simulated flue gas input module 1 can simulate the contents of dry flue gas components, moisture (such as water vapor), and alkali metal vapor in a real combustion environment. The system control module 3 adjusts the gas flow rate and atmosphere composition in real time, precisely setting the concentration of each gas, so as to simulate the corrosion environment under different working conditions. Especially for the precise control of chlorine source gas and water vapor, the experiment can better reproduce the dynamic changes of the atmosphere during the combustion of high-chlorine fuels, meeting the research needs of the influence of different corrosion factors on metal materials.

[0035] This device adopts a tube furnace design and sets the flue gas temperature according to the experimental requirements. By the user inputting the target temperature on the computer terminal, the system automatically adjusts the water flow rate through the PID control algorithm, precisely controlling the heating process to ensure that the temperature of the metal sample reaches the set value. To ensure the stability of the metal sample at different corrosion stages, the system is equipped with a temperature measurement unit to monitor the metal wall temperature in real time. If the metal temperature deviates from the set value, the water flow rate will be automatically adjusted to avoid too high or too low surface temperature of the metal, ensuring the accuracy and reproducibility of the experiment.

[0036] This device integrates linear polarization method, electrochemical impedance spectroscopy (EIS), and electrochemical noise method (ECN) for on-line monitoring of electrochemical corrosion, and can conduct multiple electrochemical tests simultaneously, providing comprehensive real-time data support for metal corrosion kinetics.

[0037] Among them, the linear polarization method can measure the corrosion rate of metals in real time within 20 seconds, and evaluate the degree of corrosion through the change of current density, which is suitable for quickly obtaining metal corrosion rate data.

[0038] The scanning frequency range of the electrochemical impedance spectroscopy (EIS) is from 0.1 Hz to 100,000 Hz, which can analyze the electrochemical characteristics of the metal surface reaction, helping to identify the electrochemical reaction mechanism during the corrosion process. EIS can provide in-depth understanding of the corrosion process, such as corrosion rate, reaction kinetics, surface state and other information.

[0039] The electrochemical noise method (ECN) can capture the changes in microscopic corrosion on the metal surface by obtaining one data point per second, helping to analyze the corrosion mode and the dynamic process of corrosion development.

[0040] By combining the three electrochemical test methods, this device can obtain the instantaneous corrosion rate of metals in a short time, comprehensively analyze the corrosion mode of metals in different corrosion environments, and provide more accurate corrosion kinetics data.

[0041] To correct and calibrate the results of the electrochemistry online monitoring method, the device includes a weight loss method module. The weight loss method calculates the average corrosion rate by measuring the mass loss of the metal sample and is used as the calibration standard for the electrochemistry online monitoring results. This method can effectively complement the deficiencies of electrochemistry tests and provide more accurate quantitative data for the metal corrosion process.

[0042] By combining the electrochemistry online monitoring method and the weight loss method, the system can comprehensively analyze the metal corrosion kinetics. The electrochemistry method can capture the instantaneous changes during the corrosion process in real time and sensitively, while the weight loss method provides the average corrosion rate over a long period. The combination of the two can better correct and verify the corrosion rate data, effectively decouple the influence of corrosion factors such as temperature, atmosphere, and chlorine source, provide comprehensive corrosion kinetics information for researchers, and thus promote the in-depth exploration of the high-temperature corrosion mechanism and the research and development of corrosion-resistant materials.

Claims

1. A laboratory high-temperature electrochemical test device for quantitatively regulating temperature gradient, characterized in that, The device includes a simulated flue gas input module (1), a circulating water module (2), a system control module (3), and a high-temperature tubular furnace (4); The simulated flue gas input module (1) includes a gas storage tank and a premixing tank; The high-temperature tubular furnace (4) is internally provided with a temperature gradient corrosion probe (6). The temperature gradient corrosion probe (6) includes a ceramic substrate (11). The ceramic substrate (11) includes an electrochemistry and temperature measurement module (7) and a weight loss module (8). The ceramic substrate (11) is internally provided with a heat exchange coil (9) and a nickel wire (10). The electrochemistry and temperature measurement module (7) is used to electrochemically measure the metal corrosion rate and real-time read the metal wall temperature through a thermocouple embedded in the heat exchange coil (9). The weight loss module (8) obtains the weight loss information of the metal specimen on the time scale by setting the sampling interval through metal specimens placed in parallel on the ceramic substrate (11); The system control module (3) controls the opening degree of the mass flowmeter through a PID controller, and further controls the water flow rate and gas content in the heat exchange coil, and is used for dynamically adjusting the metal wall temperature and atmosphere control.

2. The laboratory high-temperature electrochemical testing device for quantitatively regulating temperature gradient according to claim 1, characterized in that, The PID controller controls the water flow rate in the heat exchange coil (9) to dynamically adjust the metal wall temperature, and the temperature is controlled between 300°C and 800°C.

3. A laboratory high-temperature electrochemical testing device for quantitatively regulating a temperature gradient according to claim 1, characterized in that, The high-temperature tubular furnace (4) controls the external flue gas temperature, and the thermocouple on the simulated flue gas side real-time reads the actual simulated flue gas temperature, and the temperature is controlled between 750 and 1200°C.

4. A laboratory high-temperature electrochemical test device for quantitatively regulating temperature gradient according to claim 1, characterized in that, The gases in the simulated flue gas input module (1) include but are not limited to nitrogen, oxygen, and carbon dioxide. The gas content is dynamically set by a computer, and the total gas flow rate is controlled by a mass flowmeter after the gases are mixed in the premixing tank.

5. A laboratory high-temperature electrochemical test device for quantitatively regulating temperature gradient according to claim 1, characterized in that, Each sampling point of the weight loss module (8) includes four parallel metal specimens, where three metal specimens are used to obtain the measurement data at each time point, and one metal specimen is used for characterization and analysis.

6. The laboratory high-temperature electrochemical test device for quantitatively regulating the temperature gradient according to claim 1, wherein, The electrochemistry and temperature measurement module (7) performs measurements using the linear polarization method, electrochemical impedance spectroscopy, and electrochemical noise method. The sampling time of the linear polarization method is 40 seconds, the sampling time of the electrochemical impedance spectroscopy is 3 minutes, and the sampling time of the electrochemical noise method is 1 second.

7. A laboratory high-temperature electrochemical test device for quantitatively regulating temperature gradient according to claim 1, characterized in that, The electrochemistry online monitoring module combines the weight loss method to obtain the instantaneous corrosion rate, and calculates the average corrosion rate by measuring the mass loss of the metal sample.

8. A laboratory high-temperature electrochemical test device for quantitatively regulating temperature gradient according to claim 1, characterized in that, The device further includes an exhaust gas treatment module (5) for treating the exhaust gas in the experiment.

9. A laboratory high-temperature electrochemical test device for quantitatively regulating temperature gradient according to claim 6, characterized in that, The linear polarization method judges the degree of metal corrosion through the change of the current density. The electrochemical impedance spectroscopy identifies the electrochemical reaction mechanism during the metal corrosion process by analyzing the electrochemical characteristics of the metal surface reaction. The electrochemical noise method captures the corrosion change on the metal surface by acquiring data points.

10. The laboratory high-temperature electrochemical test device for quantitatively regulating the temperature gradient according to claim 1, wherein, The circulating water module (2) includes a steam generator for controlling the steam content in the combustion environment.

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