Research On Mathematical Model Of Hydrogen Absorption Process In NdFeB Hydrogen Decrepitation

As one of the important process of the NdFeB magnetic materials production,Hydrogen Decrepitation has been paid more and more attention in recent years. With therapid development of NdFeB industry, traditional relatively simple production process hasbeen unable to meet the increasing demands on quality of products in the market. How tomake Hydrogen Decrepitation process have shorter production cycle, higher economicefficiency and better performance become a serious problem to be solved. It makes afurther request in the Hydrogen Decrepitation process control optimization. Therefore, it isparticularly important to establish an accurate model for the Hydrogen Decrepitationprocess control system.Due to the hydrogen absorption process in NdFeB Hydrogen Decrepitation hascharacteristics of nonlinear, time-varying parameters and coupling, and the smash degreeof the alloy can not be detected online in the hydrogen absorption process. It brings greatdifficulties to determine the alloy’s exact state in hydrogen-absorbing process, andtherefore the problem of Hydrogen Decrepitation process optimization control is still in theexploratory stage. Since Hydrogen absorption process is the key process of the NdFeBHydrogen Decrepitation, this study focused on the dynamic mechanism model of thehydrogen absorption process. This paper analyzed the hydrogen absorbing mechanism ofNdFeB Decrepitation process in depth. Under certain assumptions, using the mass balance,energy balance, the ideal gas equation and reaction kinetics theory, first proposed a statespace modeling method to describe the dynamic mechanism model of hydrogen absorptionprocess. the Nd-rich phase hydrogen absorption capacity, the main phase hydrogenabsorption capacity, the furnace temperature and the furnace pressure was selected as thestate variables, and the heating amount and filling amount of hydrogen as the inputvariables. Then listed every state variable’s differential equation, determined the modelstructure and parameters through theoretical derivation and calculating. After that, in thispaper, the measured data from the Yun Shen magnetic company production filed andlaboratory were used to test and verify the accuracy of the mechanism model. Comparisonof the simulation results show that the model error is within the allowable range, which indicates that the simulation model can reflect the actual dynamic absorbing hydrogendecrepitation process approximatively.Considering that the established mechanism modelwill be finally used in the actual production, in this study, a NdFeB hydrogen decrepitationfurnace computer control system design was put forward，and a brief introduction of PCmonitoring center and lower machine control system design was given.