Research And Development Of Liquid Lead-bismuth Alloy Oxygen Concentration Measuring Instrument

As a candidate material for accelerator-driven sub-critical system(ADS)spallation target and coolant for the fourth generation of lead-cooled fast reactor(LFR),liquid lead-bismuth eutectic alloys have gradually become a research hotspot in the field of energy and materials in recent years.Despite many excellent physical and chemical properties,the serious corrosion of structural materials and the easy congestion of oxide impurities in pipelines have seriously hindered the practical application and development of LBE.The research shows that controlling dissolved oxygen in LBE in a certain concentration range can protect structural materials from corrosion without forming redundant oxides blocking the circuit.Therefore,how to accurately measure dissolved oxygen concentration in LBE has become the basis and key of relevant research.In this paper,through the design of the reference electrode test platform,the existing oxygen sensor is improved and the performance test is carried out on the solid oxygen control experimental platform.The corresponding experimental data and laws are obtained.The main research results are as follows:(1)A reference electrode test platform was built for different reference electrodes to simplify the traditional experimental procedure,and can be used for Bi/Bi2O3,Cu/Cu2O,Fe/Fe3O4 without the need to assemble a complete oxygen sensor.The performance of all aspects of the electrode was evaluated and judged.(2)A step-type cooling experiment was designed.By analyzing the data in different experimental sections of heat preservation and cooling,quantitative analysis and evaluation of the accuracy,stability and responsiveness of the oxygen sensor can be made.(3)Among the three types of oxygen sensors,Bi/Bi2O3,Cu/Cu2O and Fe/Fe3O4,Bi/Bi2O3 and Cu/Cu2O have good accuracy,and the measured electromotive force error is within ± 10%,and the Fe/Fe3O4 type error Larger,up to 50%,need to continue to improve its analysis.(4)The Bi/Bi2O3 type oxygen sensor that works in the LBE environment for a long time has a constant electromotive force response trend with the new oxygen sensor,but the numerical deviation becomes larger,and the probability of signal fluctuation increases.(5)The change of the reference electrode ratio does not affect the electromotive force and temperature change trend,but causes a small proportional bias to the electromotive force.The experimental results provide a new idea and direction for the development and improvement of oxygen practical oxygen sensor,and provide reference for the establishment of domestic oxygen sensor technical standards and the improvement of related databases.