| Hydrogen energy has been recognized as one of the most promising green energy sources,and hydrogen storage technology has become an essential component of large-scale hydrogen energy engineering applications.The solid-state hydrogen storage based on hydrogen storage materials has significant advantages in safety and volume storage density,and has become a research hotspot of advanced hydrogen storage technology,which raises the requirements for hydrogen storage performance testing technology and promotes the development of volumetric apparatus for measuring the absorption/desorbtion properties of hydrogen storage materials.Among the commonly used methods for quantitatively evaluating the hydrogen storage properties of hydrogen storage materials,the volumetric technique is widely favored because it is relatively simple,affordable and flexible.Although volumetric devices have been developed to a sufficient level,there is still a lot of room for improvement,especially in terms of the accuracy,efficiency,and automation of testing.Motivated by the above,this thesis focuses on how to improve the test performance of a volumetric instrument.First,the module design and part selection of the apparatus were performed,and the device structure was optimized using SolidWorks software.The equipment entity was carefully constructed based on a 3D virtual structure drawing.Comparisons with foreign equipments indicate that the device is compact and lightweight.In order to improve the test accuracy of the volumetric apparatus,the principle of the volumetric apparatus was investigated.The high-precision Leachman gas equation of state was chosen,a dynamic calculation of the dead volume of the sample cell was presented,the governing equations of the device were derived from the point of view of mass conservation,and the conversion relationship between the atom ratio of hydrogen-to-materials host and the well-known gravimetric storage capacity was presented.Accurate volume calibration of the device chamber is crucial for accurate testing.To address the problems of low accuracy,low efficiency and high cost in current calibration techniques,a novel online accurate volume calibration method for chambers was proposed.Mathematical models of the method were developed and the instrument volume calibration process was automated using Lab VIEW software.A Dynamic Volumes of Sample cell and Tube(DVST)method was proposed to overcome the influence of temperature gradient on test accuracy.Finally,a series of validation experiments were performed to demonstrate the rationality and accuracy of the calibration method and DVST method.In order to measure Pressure-Composition-Temperature(PCT)isotherm tests of hydrogen storage materials efficiently,completely automatically and without human intervention,a novel efficient automatic dosing method was developed.A mathematical model of the method was developed and a specific implementation process was also presented.The efficiency and practicality of the proposed method were verified by performing some automated PCT tests on different materials.Based on serial communication,an ultra-efficient cycle-based automated PCT test method of variable temperature was proposed and validated to achieve genuinely high-efficiency automated PCT testing.Aiming at the problems of low efficiency and data redundancy of cycle life measurements,a composite method of cycle life test was presented and its high efficiency was validated.For the accuracy and safety of tests,the influence of the temperature holding time of the sample cell on temperature measurements was investigated.The influence of various factors on temperature measurements was researched and correction methods were presented.An abnormal phenomenon of hydrogen absorption during activation was analyzed theoretically and verified experimentally,and the cause of the phenomenon was identified.Finally,a number of guidance recommendations were introduced for the design and test of the unit. |
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