The arrangement of electrolyte inlet in the copper electro-refining(ER)cell has a great influence on the local flow field,which affects the distribution of electrical current density in consequence.In order to understand the complicated phenomena ofelectrolyte flow behavior in vertical counter electrodes in full-scale copper ER cell,the three-dimensional computational fluiddynamics(CFD)models with four different arrangements of electrolyte inlets,i.e.,single inlet(SI),central bottom inlets(CBI),topside interlaced inlets(TII),and bottom side interlaced inlets(BII),were established to simulate the flow behavior.Simulation resultshave revealed that the parallel injection devices help to improve the electrolyte velocity between electrodes,and while the relativerange of electrolyte velocity in CBI exceeds that of TII and BII,which is more than4times,indicating its severer unequal flowdistribution.Meanwhile,the average velocity of electrolyte in BII is4times larger than that of SI due to its higher turbulenceintensity.Generally,one of the efficient ways to supply fresh copper solution rapidly and uniformly into the inter-electrode space is toadapt the arrangement of BII.By utilizing such an arrangement,the electro-refining under high electrical current density is possible,and the productivity can be increased in sequence.
To investigate the differences and the development trends of the 400 kA aluminum reduction cell, four representative cells were deeply analyzed. By using numerical simulation methods in ANSYS software, the structure parameters were firstly compared, and then three-dimensional models of electric-magnetic-flow field were built and solved with finite element method(FEM). The comparison of the structures reveals that the cell bodies are similar while the current flow path and distribution ratio of bus bars are different. It appears that most of the current(70%-80%) in side A are used as the magnetic field compensation current and flow through two ends. The numerical simulation results indicate that the distributions of magnetic fields are different but all satisfy with the magnetohydrodynamics(MHD) stabilization, and the flow patterns are all two or multi vortexes with appropriate velocities. The comparison shows that all studied cells can satisfy with the physical field requirement, and the commercial applications also verify that the 400 kA cells have become the product of the mature and world's leading technology.
针对传统的ε-不敏感支持向量回归机(ε-insensitive support vector regression,ε-SVR)未充分考虑局部支持向量对回归预测结果的影响,不利于提高回归预测精度的问题,提出了一种ε-SVR预测误差校正方法。该方法以期望预测值与ε-SVR回归预测值及局部支持向量间的欧氏距离和最小为目标函数,以ε不敏感损失带(ε-tube)宽度为约束条件,通过利用高维特征空间中ε-tube边界上和边界外的局部支持向量对ε-SVR的回归预测值进行误差校正。利用人工产生的不同分布数据集和UCI数据集进行的仿真结果表明,与传统的ε-SVR相比,该文方法具有更高的预测精度和更强的泛化能力。
This paper focuses on the distributed parameter modeling of the zinc electrowinning process(ZEWP)to reveal the spatiotemporal distribution of concentration of zinc ions(CZI)and sulfuric acid(CSA)in the electrolyte.Considering the inverse diffusion of such ions in the electrolyte,the dynamic distribution of ions is described by the axial dispersion model.A parameter estimation strategy based on orthogonal approximation has been proposed to estimate the unknown parameters in the process model.Different industrial data sets are used to test the effectiveness of the spatiotemporal distribution model and the proposed parameter estimation approach.The results demonstrate that the analytical model can effectively capture the trends of the electrolysis reaction in time and thus has the potential to implement further optimization and control in the ZEWP.
In genetic regulatory networks,a stable configuration can represent the evolutionary behavior of cell death or unregulated growth in genes.We present analytical investigations on output feedback stabilizer design of Boolean networks(BNs)to achieve global stabilization via the semi-tensor product method.Based on network structure information describing coupling connections among nodes,an output feedback stabilizer is designed to achieve global stabilization.Compared with the traditional pinning control design,the output feedback stabilizer design is not based on the state transition matrix of BNs,which can efficiently determine pinning control nodes and reduce computational complexity.Our proposed method is efficient in that the calculation of the state transition matrix with dimension 2^n×2^n is avoided;here n is the number of nodes in a BN.Finally,a signal transduction network and a D.melanogaster segmentation polarity gene network are presented to show the efficiency of the proposed method.Results are shown to be simple and concise,compared with traditional pinning control for BNs.
