Intelligent identification of the flow regimes of two-component particles in a fluidized bed with the optimized fuzzy c-means clustering algorithm

Zhaoping Zhong,Heng Wang,Xiaoyi Wang,Feihong Guo 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.5

Flow regime identification is important in the application of fluidized beds. This paper provides a method for deciding flow regime number by objective criterion. The optimized fuzzy c-means clustering algorithm was used to cluster the flow regime classification of two-component particles in a fluidized bed. The genetic algorithm was applied to optimize the initial center clusters of fuzzy c-means clustering. Hilbert-Huang transform was applied to analyze pressure fluctuation signals and extract the characteristic parameters. Three clusters were found and respectively ascribed to three flow regimes: bubbling bed, slugging bed, and turbulent bed. A multilayer neural network was used to train and test the identification system of the flow regimes. The identification accuracies of bubbling bed, slugging bed, and turbulent bed can reach 91.67%, 92.85%, and 91.30%, respectively.

Simulation of large biomass pellets in fluidized bed by DEM-CFD

Zhaoping Zhong,Lingli Zhu,Heng Wang,Zeyu Wang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.10

An improved numerical model was proposed to solve the problem that the traditional DEM-CFD (Discrete element method-computational fluid dynamics) method was not suitable for the flow simulation of large particles. In the improved model, the large particle was regarded as an agglomerate of many small fictitious spheres. Herein, the drag force between gas and large pellets was assumed as a combined effect of that between gas and fictitious spheres by volume penalty method. Based on the proposed model, the flow of the mixtures of large biomass pellets and quartz sands in fluidized bed was simulated. It shows that the existence of the biomass pellets has a great impact on the flow field. The flow patterns and pressure drops under different working conditions in simulation results have a good agreement with that in experimental results partially, which also tests the proposed model.

Experimental study of the influence of sodium salts as additive to NOxOUT process

Zhaoping Zhong,Xiujin Liang,Baosheng Jin,Xiaolin Chen,Weiling Li,Hongge Wei,Houkun Guo 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.5

An experimental study of the SNCR process with urea as reducing agent and sodium salts as additive has been carried out, and detailed analysis of the reaction mechanism has been given here. In the temperature range of 800-975 oC, NO concentration decreases at first and then increases while the concentration of N2O increases at first and then decreases with the increasing of temperature, and the turning point is 900 oC. With increasing of normalized stoichiometric ratio of reduction nitrogen to NOx (NSR), NO removal efficiency increases, while the concentration of N2O also increases, which decreases overall NOx removal efficiency. With sodium salts as additive, the concentration of N2O decreases with increasing of sodium salts addition at all temperatures, while the concentration of NO decreases at first and then increases at low-temperature side of the temperature window and increases at high-temperature side with additional increasing, whose changing extent is smaller than N2O. Since sodium salts as additive can remove N2O effectively and have no large influence on the removal of NO, the effect of sodium salts as additive is the combined effect of the production of active radicals and the removal of HNCO produced by the decomposition of urea through neutralization reactions, which is more important. To achieve the same effect under each condition, the needed addition of NaOH and CH3COONa is less than that of Na2CO3 counting as Na atom. For the decomposition of CH3COONa can produce CH3COO, its addition can promote the reduction of NO more obviously at the lower temperature than Na2CO3 or NaOH. Overall NOx removal efficiency at 900 oC with NSR=1.5 had been improved from about 30% to 70.45% through the addition of sodium salts. Sodium salts as additive caused the flue gas to become alkaline gas, but it was not serious for sodium salts existing as NaNCO.

Sliding Mode Control for Nonlinear Discrete Networked Cascade Control Systems With Uncertain Delay

Zhaoping Du,Zhilin Zou,Hui Ye,Jianzhen Li 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

In this paper, the problems of modeling and sliding mode control for a class of nonlinear discrete networked cascade control systems (NCCSs) are studied. Firstly, a class of discrete networked cascade control systems with nonlinear disturbance is considered, the sliding mode control is introduced and the model of the system is established. Based on this model and the Lyapunov functional method, the state feedback primary controller and the sliding mode secondary controller for this system are co-designed. Finally, an example of a thermal power plant is given to illustrate the effectiveness of the proposed co-design method. The main advantages are that the sliding mode control is introduced into cascade control system (CCS) and the design method of sliding mode controller for this system is proposed for the first time. On the premise of ensuring the stability of the system, it can be driven to the sliding mode surface in a limited time, and remain on the sliding mode surface in all subsequent times. The method can achieve better results and be applied to the corresponding industrial system with networked cascade control structure.

Calreticulin protects the HT22 hippocampal neurons from injury induced by hypoxia

Zhaoping Wang,Mei Yang,Jian Xue,Yanjun Chong 대한독성 유전단백체 학회 2018 Molecular & cellular toxicology Vol.14 No.1

The purpose of this study was to evaluate the role of calreticulin (CRT) in the hypoxia-induced injury of HT22 cells through over-expression and knockdown of CRT. Cells were transfected with pcDNA3.1, pcDNA3.1 carrying full length CRT (pcDNA-CRT), small interfering RNA targeting CRT (si-CRT) or its negative control (siNC). Then, cell viability and apoptosis were respectively detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to evaluate mRNA expression level of CRT. Western blotting was performed to determine the protein expression levels of CRT and apoptosis related proteins. Results showed CRT was successfully overexpressed by transfection of pcDNA-CRT (P<0.05) and silenced by transfection of si-CRT(P<0.05). CRT over-expression could promote the HT22 cell proliferation (P<0.01 or P<0.001) and inhibit hypoxia-induced apoptosis(P<0.05). Western blotting illustrated up-regulation of CRT increased the expression of Bcl2 (P<0.01) but decreased the expressions of cytochrome c (P<0.01), active caspase 3 (P<0.001) and active caspase 9 (P<0.05) under hypoxia treatment. The effect of CRT knockdown was opposite to CRT over-expression. We speculated that CRT might regulate the expression of apoptosis related factors such as cytochrome-c, caspase 3, caspase 9 and Bcl-2, protecting the HT22 cells from hypoxia-induced injury. These results will provide the theory basis for the clinical treatment of cerebral hypoxia-induced injury.

Influence of the roof lithological characteristics on rock burst: a case study in Tangshan colliery, China

Jienan, Pan,Zhaoping, Meng,Quanlin, Hou,Yiwen, Ju,Guofu, Li Techno-Press 2009 Geomechanics & engineering Vol.1 No.2

Many factors influence occurrences of rock burst in coal mines, such as mining methods, control methods of the coal roof, lithological characteristics of the roof and floor, tectonic stress, groundwater and so on. Among those factors, lithological characteristics in the roof are the intrinsic controlling factors that affect rock burst during coal mining. Tangshan colliery is one of the coal mines that have suffered seriously from rock bursts in China. In this paper, based on the investigating the lithological characteristics of coal roofs and occurrence of rock bursts in Tangshan colliery, a numerical method is used to study the influence of roof lithological characteristics on rock burst potential. The results show that the lithological characteristics in the roof have an important impact on the distributions of stresses and elastic strain energy in coal seams and their surrounding rocks. Occurrences of rock bursts in this colliery have a close correlation with the thick-bedded, medium- to fine-grained sandstones in the roof. Such strata can easily cause severe stress concentration and accumulate enough energy to trigger rock bursts in the working face during mining operations.

An overlay-based service architecture for distributed video surveillance system

Xuesong Cao,Zhaoping Wang,Ruimin Hu Jun Chen 보안공학연구지원센터 2008 International Journal of Software Engineering and Vol.2 No.2

In this paper, a service architecture based on overlay network was presented. The architecture was designed to build a novel distributed video surveillance system, called as Etouch. In the model, the system is divided into three layers: underlying network layer (UNL) , overlay service network layer (OSNL) and application layer (AL). OSNL is composed of many intelligent overlay nodes mapped by underlying network layer. Overlay nodes provide all kinds of media service for surveillance application in AL. OSNL allows media service composition of distributed stream processing applications dynamically. And a load balance of QoS-aware service composition algorithm (LBQSC) is employed to satisfy their end-to-end QoS demands. Large-scale experimental results demonstrate the scalability, efficiency and performance of the E-touch system.

Estimation of the Glass Forming Ability of the Fe-based Bulk Metallic Glass Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 that Contains Non-metallic Inclusions

Hongxiang Li,Zhaoping Lu,이승훈 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.1

For the mass production of bulk metallic glasses, the use of industrial raw materials that contain certain amounts of inclusions is inevitable. The glass-forming ability of bulk metallic glasses, i.e., the critical cooling rate for glass formation upon solidification, is closely related to the nature of heterogeneous nucleation offered by inclusions during the solidification process. Significantly different effects of various types of inclusions on the glass forming ability of the alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 are demonstrated in this study. The origins of the effects of different inclusions on the glass forming ability are analyzed through thermodynamic, crystallographic and classical heterogeneous nucleation kinetic theories. For the mass production of bulk metallic glasses, the use of industrial raw materials that contain certain amounts of inclusions is inevitable. The glass-forming ability of bulk metallic glasses, i.e., the critical cooling rate for glass formation upon solidification, is closely related to the nature of heterogeneous nucleation offered by inclusions during the solidification process. Significantly different effects of various types of inclusions on the glass forming ability of the alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 are demonstrated in this study. The origins of the effects of different inclusions on the glass forming ability are analyzed through thermodynamic, crystallographic and classical heterogeneous nucleation kinetic theories.

Application of Hilbert-Huang transformation in fluidized bed with two-component (biomass particles and quartz sands) mixing flow

Xiaoyi Wang,Zhaoping Zhong,Heng Wang,Zeyu Wang 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Hilbert-Huang transformation was used to investigate the nonlinear characteristics of two-component (bio-mass particles and quartz sand) mixing flow by analyzing the pressure fluctuation signals in fluidized bed. Based onempirical mode decomposition (EMD), the Hilbert-Huang spectra in bubbling and slugging flow patterns were ob-tained and analyzed. In bubbling flow pattern, compared with one-component (quartz sand) flow, the energy of two-component mixing flow is lower in 0-5 Hz and higher in 40-50 Hz. In slugging flow pattern, the energy in pressurefluctuation mainly lies in 0-5 Hz. and the effect of biomass particles on the Hilbert-Huang spectrum is not very obvi-ous. Compared with traditional power spectral density (PSD), HHT is much more suitable for investigating pressurefluctuation signals in fluidized beds.

Performance of fluidized bed electrode in a molten carbonate fuel cell anode

Jubing Zhang,Zhaoping Zhong,Jianmin Xiao,Zongming Fu,Jinxiao Zhao,Weiling Li,Min Yang 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.8

A fluidized bed electrode could lower concentration polarization and activation polarization because of its high mass and heat transfer coefficient. The polarization characteristics of the fluidized bed electrode are systematically investigated in a molten carbonate fuel cell anode with an O_2/CO_2/gold reference electrode. The results show that polarization performance of the anode is improved by selecting proper flow rates of H_2, O_2 and CO_2, choosing suitable nickel particle content together with appropriate O_2/CO_2 ratio, and increasing reaction temperature as well as the area of the current collector. Limiting current density of 115.56 mA·cm^(−2) is achieved under optimum performance as follows:a cylindrically curved nickel plate current collector, nickel particle content of 7.89%, the reaction temperature of 923 K,H_2 flow rate of 275 mL·min^(−1), O_2/CO_2 flow rate of 10/20 mL·min−1 and O_2/CO_2 ratio of 1 : 2.