Liquid metal oxygen sensor reference electrode system and method considering precision and safety

Abstract

The invention relates to a liquid metal oxygen sensor reference electrode system and method with both precision and safety, which can provide stable oxygen partial pressure when a probe works normally and actively prevent harmful substances from leaking when the probe is damaged, so that the measurement precision of a liquid metal oxygen sensor is ensured, and the safety and the reliability are improved at the same time. Comprising a sensor, a gas micro-flow controller, a reference gas cylinder, an inert gas cylinder, a gas fan and a waste gas treatment system, the sensor is connected with a signal measuring instrument through a cable; the sensor is connected with a reference gas cylinder and an inert gas cylinder through a gas supply pipeline; the sensor is sequentially connected with a back pressure valve, a pressure measuring instrument, a gas component measuring instrument, a gas fan, a check valve and a waste gas treatment system through an exhaust pipeline. The long-term measurement accuracy and stability can be improved, and the system misoperation probability is reduced; meanwhile, the safety of the reference electrode powder is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid metal coolant, in particular to a liquid metal oxygen sensor reference electrode system and method considering precision and safety. BACKGROUND

[0002] Liquid metal cooled reactor is one of the fourth generation advanced reactor types, which has the advantages of high inherent safety and high economy. However, the liquid metal coolant has a serious corrosive effect on structural materials. Controlling the dissolved oxygen concentration in the liquid metal within a certain range can not only effectively prevent the formation of lead oxides to block the pipeline, but also form a protective oxide film on the surface of the structural material to inhibit corrosion. The real-time monitoring of the dissolved oxygen concentration at key positions in the system by using a liquid metal oxygen sensor is crucial to the safe operation of the liquid metal system.

[0003] The measurement of the dissolved oxygen concentration in liquid metal mainly uses a concentration cell type oxygen sensor with yttria-stabilized zirconia solid electrolyte as a probe. The concentration cell potential is generated based on the difference in oxygen partial pressure on both sides of the solid electrolyte, so that the oxygen content is determined by the current signal generated by the electrode. According to the reference electrode material, the oxygen sensor can be divided into air reference electrode type and coexisting phase reference electrode type. The coexisting phase reference electrode (Cu / Cu2O, Bi / Bi2O3, etc.) has problems such as element interdiffusion and phase decomposition at high temperatures for a long time, which leads to reference potential drift and reduces measurement accuracy. The latest research shows that some air reference electrode (LSM / Air, LSCF / Air, etc.) oxygen sensors exhibit good performance in the temperature range of 200-550℃, especially in terms of accuracy and stability, which are superior to coexisting phase reference electrodes (Cu / Cu2O, Bi / Bi2O3, etc.). However, the air reference electrode oxygen sensor directly uses air as the reference gas. During measurement, the reference electrode chamber in the probe needs to be connected with the atmosphere to obtain a stable air oxygen partial pressure. If the sensor probe is damaged, harmful substances such as liquid metal vapor and fission products with radioactivity and chemical toxicity in the reactor may leak directly into the environment through the reference gas path, causing serious nuclear safety and radiation safety problems. Therefore, the existing technology cannot guarantee long-term measurement accuracy while meeting the high safety requirements under extreme working conditions.

[0004] This paper proposes a liquid metal oxygen sensor reference electrode system and method considering precision and safety. The system can provide stable reference gas without drift when the probe is working normally, and actively prevent reference gas from entering the reactor to cause oxidation of liquid metal and leakage of harmful substances in the reactor when the probe is damaged, which not only guarantees the measurement accuracy of the liquid metal oxygen sensor, but also improves the safety and reliability. SUMMARY

[0005] The present application aims to provide a liquid metal oxygen sensor reference electrode system and method which takes into account the accuracy and safety, the system can provide stable oxygen partial pressure when the probe is working normally, and actively prevent harmful substance leakage when the probe is damaged, which ensures the measurement accuracy of the liquid metal oxygen sensor, and improves the safety and reliability.

[0006] The technical solution of the present application is as follows: a liquid metal oxygen sensor reference electrode system which takes into account the accuracy and safety, comprising a sensor, a gas micro-flow controller, a reference gas cylinder, an inert gas cylinder, a gas fan, and a waste gas treatment system; the sensor is connected to a signal measuring instrument through a cable; the sensor is connected to the reference gas cylinder and the inert gas cylinder through a gas supply pipeline; the sensor is connected to a back pressure valve, a pressure measuring instrument, a gas component measuring instrument, a gas fan, a check valve, and a waste gas treatment system in sequence through an exhaust pipeline.

[0007] The sensor comprises a probe, a shell, and a terminal, the probe is encapsulated in the shell through a sealing structure, which is an elongated tube with one end closed and an open top, the inner cavity constitutes a reference electrode chamber, the bottom of the reference electrode chamber is filled with reference electrode material to form a reference electrode powder bed; a reference electrode lead wire penetrates the center of the reference electrode chamber, one end is deeply inserted and buried in the reference electrode powder bed at the bottom, and the other end extends upward, penetrates the entire reference electrode chamber, and is reliably connected to the terminal arranged at the top of the sensor, and is connected to the signal measuring instrument through a cable.

[0008] A hole is opened on the shell at a position above the open top of the probe, and is connected to the gas supply pipeline and the exhaust pipeline respectively, the gas supply pipeline extends to the reference electrode chamber through a gas guide pipe, and the outlet end of the gas guide pipe is located above the reference electrode powder bed; a valve, a pressure measuring instrument, and a gas micro-flow controller are arranged on the gas supply pipeline.

[0009] The outlet of the gas guide pipe is kept a distance from the surface of the reference electrode powder bed.

[0010] The outlet end of the gas guide pipe is a bevel, forming an inclined angle of 30-60 degrees.

[0011] The reference gas cylinder contains a reference gas with a fixed oxygen component, and the oxygen component ranges from 1vol% to 20vol%, and the inert gas cylinder contains a protective inert gas.

[0012] The exhaust pipeline is led out from the outlet on the shell.

[0013] The sensor electrical signal from the signal measuring instrument, the exhaust pipeline pressure signal from the pressure measuring instrument, and the exhaust pipeline gas component signal from the gas component measuring instrument are analyzed, when all three signals indicate abnormalities at the same time, it is determined that the probe is damaged, and the normal working mode is immediately switched to a safety protection mode.

[0014] A method for using a liquid metal oxygen sensor reference electrode system that balances accuracy and safety: In normal operating mode, the reference gas cylinder is connected to the gas supply line. The flow rate of the reference electrode gas is controlled at an extremely low first preset flow rate by a gas micro-flow controller, and the back pressure valve on the exhaust line is adjusted to establish a micro-positive pressure environment in the reference electrode chamber. At this time, the gas fan is in the off state. After the reference gas enters from the gas supply line, it is transported to the gas phase space above the reference electrode powder bed through the gas guide pipe, and comes into contact with the reference electrode powder, so that the sensor can perform measurements.

[0015] When the probe is accidentally damaged, close the outlet valve of the reference gas cylinder and open the outlet valve of the inert gas cylinder; control the gas micro-flow controller to increase the gas flow to the higher second preset flow, switch the back pressure valve on the exhaust line to the fully open state, and start the gas blower. The gas blower establishes an effective directional negative pressure flow field in the exhaust line.

[0016] The first preset flow rate is 1-10 mL / min, and the second preset flow rate is 50-200 mL / min.

[0017] The slightly positive pressure environment is 50 Pa higher than the ambient pressure.

[0018] After equilibration, the stale gas is discharged from bottom to top through the exhaust pipe in the reference electrode chamber.

[0019] A method for calculating the concentration of liquid metal oxygen includes the following steps:

[0020] S1: The volume percentage of oxygen (V) on the reference electrode side of the reference gas cylinder. o2,gas The reference electrode side air pressure P is obtained by measuring the pressure on the air supply pipeline and the pressure measuring instrument. gas Substituting into formula (3), we obtain the oxygen partial pressure p on the reference electrode side of the sensor. o2 ,ref;

[0021]

[0022] p o2,gas —Oxygen partial pressure on the reference electrode side;

[0023] p 0 —Reference pressure, p 0 =1 bar;

[0024] V o2,gas —Oxygen volume percentage on the reference electrode side;

[0025] P gas —Reference electrode side air pressure.

[0026] S2: p o2 Substituting ref into formula (1) yields the oxygen partial pressure p in the liquid metal.o2 ;

[0027]

[0028] In the formula:

[0029] E—sensor output voltage, collected by the measuring instrument 20;

[0030] R—molar gas constant;

[0031] F—Faraday constant;

[0032] p o2 —oxygen partial pressure in liquid metal;

[0033] S3: Obtain real-time liquid metal oxygen concentration c by formula (2) o ;

[0034]

[0035] T—liquid metal temperature.

[0036] The significant effect of the present application is:

[0037] (1) The reference gas with fixed components is adopted to provide stable oxygen partial pressure, eliminate the root cause of reference signal drift, and improve long-term measurement accuracy and stability;

[0038] (2) The inclined surface guide pipe is set, and the gas micro-flow controller and the back pressure valve opening degree are adjusted in cooperation to realize effective distribution and atmosphere stability of the reference gas, and ensure the safety of the reference electrode powder;

[0039] (3) In the event of probe damage, the linkage control system quickly switches from normal working mode to safety protection mode: by cutting off and replacing the oxygen-containing reference gas, the oxidation of liquid metal caused by the entry of oxygen-containing reference gas into the reactor is effectively prevented, and by establishing strong negative pressure exhaust through the fan, the leakage of harmful substances in the reactor to the environment is reliably prevented, realizing bidirectional protection;

[0040] (4) Multiple redundant diagnostic strategies are adopted to reliably identify probe damage, greatly reducing the probability of system malfunction. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a process schematic diagram of a liquid metal oxygen sensor reference electrode system considering accuracy and safety;

[0042] Figure 1 The marks in the drawings and the corresponding names of the parts are as follows:

[0043] 1 - probe, 2 - reference electrode powder bed, 3 - reference electrode chamber, 4 - reference electrode lead, 5 - gas duct, 6 - housing, 7 - gas supply line, 8 - gas microflow controller, 9 - reference gas cylinder, 10 - inert gas cylinder, 11 - back pressure valve, 12 - pressure measuring instrument, 13 - gas component measuring instrument, 14 - exhaust line, 15 - gas blower, 16 - check valve, 17 - exhaust gas treatment system, 18 - terminal, 19 - cable, 20 - signal measuring instrument. DETAILED DESCRIPTION

[0044] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced without the specific details, or with an equivalent arrangement, and that the present application can include other implementations. Thus, the present application is not limited to the specific implementations disclosed in the following description.

[0045] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of one or more embodiments of the present application. As used in this disclosure and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0046] It will be understood that, although the terms first, second, etc. can be used herein to describe various information, these terms are not intended to denote a temporal or chronological order. Rather, these terms are used solely to distinguish one from another only. For example, a first item could be termed a second item, and, similarly, a second item could be termed a first item without departing from the scope of one or more embodiments of the present application.

[0047] The technical content of the present application will be described below with reference to the accompanying drawings;

[0048] A liquid metal oxygen sensor reference electrode system that takes into account both accuracy and safety, including a sensor, a gas microflow controller 8, a reference gas cylinder 9, an inert gas cylinder 10, a gas blower 15, and an exhaust gas treatment system 17.

[0049] The sensor comprises a probe 1, a shell 6, and a terminal 18. The probe 1 is encapsulated in the shell 6 through a sealing structure. The shell 6 is an elongated tube with a closed end and an open top. The inner cavity of the shell 6 forms a reference electrode chamber 3. The bottom of the reference electrode chamber 3 is filled with solid powder reference electrode material, forming a reference electrode powder bed 2. A reference electrode lead 4 penetrates the center of the reference electrode chamber 3. One end of the reference electrode lead 4 is deeply inserted into the reference electrode powder bed 2 at the bottom to establish reliable electrochemical contact. The other end of the reference electrode lead 4 extends upward and passes through the entire reference electrode chamber 3 to reliably connect with the terminal 18 arranged at the top of the sensor. Thus, the sensor electrical signal is led out to the signal measuring instrument 20 through the cable 19.

[0050] A hole is opened on the shell 6 above the open top of the probe 1. The hole is connected with a gas supply line 7 and an exhaust line 14, respectively. The gas supply line 7 extends to the reference electrode chamber 3 through a gas guide pipe 5. The outlet end of the gas guide pipe 5 is located above the reference electrode powder bed 2 and maintains a small distance from the surface of the reference electrode powder bed 2. The outlet end of the gas guide pipe 5 is beveled to form a 30-60 degree angle. The outflow direction of the gas is basically parallel to the surface of the reference electrode powder bed 2, which greatly reduces the direct impact and is beneficial to the uniform mixing of the gas in the upper space.

[0051] The dissolved oxygen equilibrium system in the liquid metal forms a working electrode. The working electrode lead is provided by the shell 6. The reference electrode powder bed 2, the reference electrode chamber 3, and the reference gas form a reference electrode. The inside of the probe 1 is the reference electrode, and the outside is the working electrode.

[0052] The gas supply line 7 is connected with a reference gas cylinder 9 and an inert gas cylinder 10 at the gas inlet end. The reference gas cylinder 9 contains a reference gas with a fixed oxygen component. The oxygen component ranges from 1 vol% to 20 vol%. The inert gas cylinder 10 contains a protective inert gas, such as high-purity argon (≥99.999%). Valves, pressure measuring instruments, and a gas micro-flow controller 8 are arranged on the gas supply line 7.

[0053] The exhaust line 14 is connected with a back pressure valve 11, a pressure measuring instrument 12, a gas component measuring instrument 13, a gas fan 15, and a check valve 16 in sequence. The exhaust line 14 is finally connected with a waste gas treatment system 17.

[0054] A multiple redundant diagnostic strategy is adopted to reliably identify probe damage and greatly reduce the probability of system malfunction. The sensor electrical signal from the signal measuring instrument 20, the exhaust line pressure signal from the pressure measuring instrument 12, and the exhaust line gas component signal from the gas component measuring instrument 13 are comprehensively analyzed. When all three signals indicate abnormalities at the same time, it is determined that the probe is damaged, and the normal working mode is immediately switched to a safety protection model.

[0055] In normal operation mode, the reference gas cylinder 9 is connected to the gas supply line 7, the flow of reference electrode gas is controlled at a very low first preset flow rate (e.g. 1-10 mL / min) by the gas micro-flow controller 8, and the back pressure valve 11 on the exhaust line 14 is adjusted to establish a stable micro-positive pressure environment (e.g. 50 Pa higher than ambient pressure) in the reference electrode chamber 3, in which the gas blower 15 is in the off state. After the reference gas enters from the gas supply line 7, it is transported to the gas phase space above the reference electrode powder bed 2 through the gas guide pipe 5, and penetrates into the pores of the loose reference electrode powder at the bottom through diffusion, fully contacts the surface of the powder particles, and establishes a stable electrochemical equilibrium. The very low flow rate makes the gas uniformly update the gas phase environment above the reference electrode powder bed 2 by diffusion, and effectively prevents impact and entrainment on the reference electrode powder bed 2. The stale gas after diffusion balance is discharged from the bottom to the top in the reference electrode chamber 3 through the exhaust line 14, relying on the stable and gentle pressure gradient in the reference electrode chamber 3. In this state, the reference electrode obtains a constant oxygen partial pressure, and the sensor performs high-precision measurement.

[0056] When the probe 1 is accidentally damaged, the sensor electrical signal of the signal measuring instrument 20, the exhaust line pressure signal of the pressure measuring instrument 12, and the exhaust line gas component signal of the gas component measuring instrument 13 simultaneously indicate an abnormality, at which time the system switches to a safety protection mode, and the following operations are performed: the outlet valve of the reference gas cylinder 9 is closed, and the outlet valve of the inert gas cylinder 10 is opened; the gas micro-flow controller 8 is controlled to increase the gas flow to a higher second preset flow rate (e.g. 50-200 mL / min), which provides sufficient inert gas to effectively displace and purge the oxygen-containing reference gas and leakage while cutting off the oxygen source, and avoids violent splashing of a small amount of liquid metal that may enter the reference electrode chamber 3. Synchronously, the back pressure valve 11 on the exhaust line 14 is switched to the fully open state, and the gas blower 15 is started, which maximally reduces the flow resistance of the exhaust line 14, ensures that the gas blower 15 establishes an effective directional negative pressure flow field in the exhaust line 14, and efficiently captures and forcibly transports the displaced oxygen-containing reference gas and harmful substances leaked from the damaged opening to the waste gas treatment system.

[0057] For the reference gas with a fixed oxygen component, the calculation formula of the liquid metal oxygen sensor is as follows:

[0058] The relationship between the output voltage of the liquid metal oxygen sensor and the oxygen partial pressure on both sides of the solid electrolyte of the sensor obeys the Nernst equation (the theoretical equation of concentration cell):

[0059]

[0060] In the formula:

[0061] E - sensor output voltage, V;

[0062] R - molar gas constant, R = 8.3145 J-mol -1 ·k -1 ;

[0063] F - Faraday constant, F = 96485.31 C-mol -1 ;

[0064] p o2 ,ref - oxygen partial pressure at the sensor reference electrode side, bar;

[0065] p o2 - oxygen partial pressure at the sensor working electrode side, i.e. in the liquid metal, bar.

[0066] wherein the oxygen partial pressure in the liquid metal is calculated according to the following formula:

[0067]

[0068] c o - oxygen concentration in the liquid metal, wt%;

[0069] T - liquid metal temperature, K.

[0070] The relationship of the oxygen partial pressure at the sensor reference electrode side is given by:

[0071]

[0072] p o2,gas - oxygen partial pressure at the reference electrode side;

[0073] p 0 - reference pressure, p 0 = 1 bar;

[0074] V o2,gas - oxygen gas volume percentage at the reference electrode side;

[0075] P gas - gas pressure at the reference electrode side.

[0076] The voltage signal E output by the liquid metal oxygen sensor is collected by the measuring instrument 20; the oxygen gas volume percentage V o2,gas at the reference electrode side in the reference gas cylinder 9 and the gas pressure P gas at the reference electrode side obtained by the pressure measuring instrument on the gas supply line 7 are brought into formula (3) to obtain the oxygen partial pressure p o2 ,ref at the sensor reference electrode side, which is substituted into formula (1) to obtain the working electrode oxygen partial pressure p o2 , and finally the real-time liquid metal oxygen concentration c o is obtained by formula (2).

[0077] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0078] It should be noted that, for the foregoing method embodiments, for the convenience of description, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0079] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0080] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The alternative embodiments do not describe all the details and limit the present application to the specific embodiments described. Obviously, according to the content of the present application, many modifications and changes can be made. The present application selects and describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application.

Claims

1. A reference electrode system for a liquid metal-oxygen sensor that balances accuracy and safety, characterized in that: Includes a sensor, a gas microflow controller (8), a reference gas cylinder (9), an inert gas cylinder (10), a gas blower (15), and an exhaust gas treatment system (17); the sensor is connected to a signal measuring instrument (20) via a cable (19); the sensor is connected to the reference gas cylinder (9) and the inert gas cylinder (10) via a gas supply line (7); the sensor is connected to a back pressure valve (11), a pressure measuring instrument (12), a gas component measuring instrument (13), a gas blower (15), a check valve (16), and the exhaust gas treatment system (17) in sequence via an exhaust line (14).

2. The reference electrode system for a liquid metal oxygen sensor that balances accuracy and safety according to claim 1, characterized in that: The sensor includes a probe (1), a housing (6), and a terminal block (18). The probe (1) is encapsulated in the housing (6) by a sealed structure. It is a long and thin tube with one end closed and the top open. The inner cavity forms a reference electrode chamber (3). The bottom of the reference electrode chamber (3) is filled with reference electrode material to form a reference electrode powder bed (2). The reference electrode lead (4) runs through the center of the reference electrode chamber (3). One end is deeply inserted and buried in the reference electrode powder bed (2) at the bottom, and the other end extends upward, passes through the entire reference electrode chamber (3), and is reliably connected to the terminal block (18) set on the top of the sensor. It is also connected to the signal measuring instrument (20) through a cable (19).

3. The reference electrode system for a liquid metal oxygen sensor that balances accuracy and safety according to claim 2, characterized in that: A hole is made in the housing (6) above the top opening of the probe (1) to connect to the gas supply line (7) and the exhaust line (14) respectively. The gas supply line (7) extends into the reference electrode chamber (3) through the gas guide pipe (5). The outlet end of the gas guide pipe (5) is located above the reference electrode powder bed (2). Valves, pressure measuring instruments and gas microflow controllers (8) are arranged on the gas supply line (7).

4. The reference electrode system for a liquid metal oxygen sensor that balances accuracy and safety according to claim 3, characterized in that: The outlet of the gas duct (5) is kept at a distance from the surface of the reference electrode powder bed (2).

5. The reference electrode system for a liquid metal-oxygen sensor that balances accuracy and safety according to claim 3, characterized in that: The outlet end of the air duct (5) is a beveled surface, forming a bevel angle of 30-60 degrees.

6. The reference electrode system for a liquid metal oxygen sensor that balances accuracy and safety according to claim 3, characterized in that: The reference gas cylinder (9) contains a reference gas with a fixed oxygen composition, the oxygen composition range being 1 vol% to 20 vol%. The inert gas cylinder (10) contains a protective inert gas.

7. The reference electrode system for a liquid metal oxygen sensor that balances accuracy and safety according to claim 3, characterized in that: The exhaust line (14) is led out from the outlet on the housing (6).

8. The reference electrode system for a liquid metal-oxygen sensor that balances accuracy and safety according to claim 3, characterized in that: The sensor electrical signal from the signal measuring instrument (20), the exhaust pipeline pressure signal from the pressure measuring instrument (12), and the exhaust pipeline gas component signal from the gas component measuring instrument (13) are acquired and analyzed. When all three signals indicate an abnormality at the same time, it is determined that the probe is damaged and the normal working mode is immediately switched to the safety protection mode.

9. A method for using a liquid metal oxygen sensor reference electrode system that balances accuracy and safety, employing the system as described in claim 6, characterized in that: In normal working mode, the reference gas cylinder (9) is connected to the gas supply line (7). The flow rate of the reference electrode gas is controlled at an extremely low first preset flow rate by the gas micro flow controller (8), and the back pressure valve (11) on the exhaust line (14) is adjusted to establish a micro positive pressure environment in the reference electrode chamber (3). At this time, the gas fan (15) is in the off state. After the reference gas enters from the gas supply line (7), it is transported to the gas phase space above the reference electrode powder bed (2) through the gas guide pipe (5) and comes into contact with the reference electrode powder. The sensor performs measurement. When the probe (1) is accidentally damaged, close the outlet valve of the reference gas cylinder (9) and open the outlet valve of the inert gas cylinder (10); control the gas micro-flow controller (8) to increase the gas flow rate to a higher second preset flow rate, switch the back pressure valve (11) on the exhaust pipeline (14) to the fully open state, and start the gas blower (15). The gas blower (15) establishes an effective directional negative pressure flow field in the exhaust pipeline (14).

10. The method of using a liquid metal oxygen sensor reference electrode system that balances accuracy and safety according to claim 9, characterized in that: The first preset flow rate is 1-10 mL / min, and the second preset flow rate is 50-200 mL / min.

11. The method of using a liquid metal oxygen sensor reference electrode system that balances accuracy and safety according to claim 9, characterized in that: The slightly positive pressure environment is 50 Pa higher than the ambient pressure.

12. The method of using a liquid metal oxygen sensor reference electrode system that balances accuracy and safety according to claim 9, characterized in that: After balancing, the stale gas is discharged from bottom to top in the reference electrode chamber (3) through the exhaust line (14).

13. A method for calculating the concentration of liquid metal oxygen, using the system as described in claim 6, characterized in that: Includes the following steps: S1: The volume percentage of oxygen (V) on the reference electrode side of reference gas cylinder 9. o2,gas The reference electrode side air pressure P is obtained by measuring the pressure on the gas supply pipeline (7) and the pressure measuring instrument. gas Substituting into formula (3), we obtain the oxygen partial pressure p on the reference electrode side of the sensor. o2 ,ref; p o2,gas —Oxygen partial pressure on the reference electrode side; p 0 —Reference pressure, p 0 =1 bar; V o2,gas —Oxygen volume percentage on the reference electrode side; P gas —Reference electrode side air pressure; S2: p o2 Substituting ref into formula (1) yields the oxygen partial pressure p in the liquid metal. o2 ; In the formula: E—Sensor output voltage, acquired by measuring instrument 20; R—molar gas constant; F—Faraday constant; p o2 —Oxygen partial pressure in liquid metal; S3: The real-time liquid metal oxygen concentration c can be obtained through formula (2). o ; T—Liquid metal temperature.

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