Parametric optimization of packed bed for activated coal fly ash waste heat recovery using CFD techniques

Coal fly ash is an industrial solid waste generated from coal preparation during the processing and cleaning of coal for electric power generation. Comprehensive investigation on the reutilization of waste heat of activated coal fly ash is of great economic significance. The method of recovering the waste heat, proposed in this study,is the transfer of heat from activated coal fly ash to gas with the movement of air using the packed bed, providing valuable energy sources for preheating the raw coal fly ash to reduce the overall energy consumption. The investigation is carried on the heat transfer characteristics of gas–solid(activated coal fly ash) phases and air temperature fields of the packed bed under some key conditions via computational fluid dynamics. A two dimensional geometry is utilized to represent key parts of packed bed. The distribution mechanism of the temperature field for gas phase is analyzed based on the transient temperature contours at different times. The results show that the obtained rule of gas–solid heat transfer can effectively evaluate the influences of operating parameters on the air temperature in the packed bed. Simultaneously, it is found that no temperature differences exist in the hot air at the outlet of the packed bed. The investigation provides guidance for the design and optimization of other similar energy recovery apparatuses in industries.     

Theoretical calculation simulation studies of ABV nuclear reactor coupled with desalination system

In this paper, research has been conducted on the floating type nuclear power plant named as ABV reactor which is designed for district heating, power, and sea water desalination by OKBM facility at Russia. This reactor was tested under different thermal loads during the designing phase, and three modules have been investigated. Theoretical calculations and simulation studies have been performed on these three modules having specifications as ABV‐6M with 47MW_th, ABV‐6 with 38MW_th, and ABV‐3 with 18MW_th.The results obtained from these modules have been calculated mathematically and verified by simulation. We have compared the originally derived data of ABV desalination system with our theoretical and simulation analysis. The results from two desalination techniques including RO and RO + MED have been calculated and are presented in this paper with details. The results obtained from both analysis show that the efficiency of ABV nuclear reactor desalination system increases with the decrease in corresponding water cost ratio. Copyright © 2015 John Wiley & Sons, Ltd.     

Space charge limitation on the response time of organic photodiodes

The dynamic response of an organic bulk heterojunction photodiode to small changes in applied bias or light intensity is investigated as function of the intensity of a constant background illumination by means of photoimpedance and transient photocurrent measurements. For bias voltages close to the open circuit voltage we find that the response timescale with the square root of the light intensity. The results can be quantitatively explained in terms of a space charge limitation on the photocurrent as predicted by Goodman and Rose (J. Appl. Phys. 42, 2823 (1971)). The relaxation time of the diode at open circuit corresponds to the lifetime of the slowest charge carrier in the diode. This relaxation time is determined by the dielectric constant and the smallest of the two carrier mobilities in the bulk heterojunction. This illustrates the importance of balanced carrier mobilities for obtaining diodes with fast response time at low bias for e.g. imaging arrays.     

Physics‐based model of lithium‐ion batteries running on a circuit simulator

The authors developed a physics‐based equivalent circuit model of a lithium‐ion battery (LIB) whose parameters are continually updated, reflecting the theoretical calculation results of the Butler‐Volmer equation, diffusion equations of the lithium‐ion and lithium, and Nernst equations of the liquid and solid phases. The developed model was applied to the charge/discharge simulations of an LIB, and the experimental and simulated results of constant current discharges and pulsed‐charge/discharge were found to be in excellent agreement. In particular, using the developed model, analyzing transient responses of the LIB derived from the transition of the electric double layer charging to the electrode reaction is possible. These results demonstrate that the electrochemical performance of an LIB can be calculated on a circuit simulator using the developed model.     

Physicochemical and environmental characteristics of alkali leaching residue of wolframite and process for valuable metals recovery

Physicochemical and mineralogical characteristics of an alkali leaching residue of wolframite were studied by XRD, SEM?EDS, chemical phase analysis, mineral liberation analyzer (MLA), and TG?DSC methods. Batch leaching tests, toxicity characteristic leaching procedure (TCLP) tests and Chinese standard leaching tests (CSLT) were conducted to determine the environmental mobility of toxic elements. The results show that, due to the high contents of W, Fe, Mn, Sn, and Nb, the residue is with high resource value, but the content of a toxic element, As, is also high. The existing minerals of the investigated elements mainly occur as monomer particles, but it is difficult to extract these valuable metals by conventional acid leaching due to their mineral properties. The release of As increases over time in acidic environment. The leaching concentration of all investigated harmful elements through TCLP is within the limiting value, while the leaching concentration of As through CSLT exceeds the limiting value by more than 4 times, so the residue is classified as hazardous solid waste based on the Chinese standard. A process for valuable metals recovery from this residue was proposed. Preliminary experimental results indicated that the main valuable metals could be extracted effectively.     

甘二酯对油脂中抗氧化剂活性的影响

研究sn-1,3-棕榈酸甘二酯对纯净菜籽油氧化稳定性的影响,以期探明其作用机理,为油脂加工和储存提供科学的依据。通过柱层析的方法制备仅含甘三酯成分的纯净菜籽油,测定DAG在菜籽油中形成反相胶束的临界浓度,并在反相胶束体系中,研究DAG及与天然抗氧化剂γ-生育酚及合成抗氧化剂(TBHQ、BHA、BHT)联合作用对纯净菜籽油氧化稳定性的影响。结果表明:DAG在菜籽油中的临界胶束浓度为0.5%;在反相胶束体系中,DAG的添加促进了纯净菜籽油的氧化,DAG对不同种类的抗氧化剂活性的影响存在差异,DAG增强了弱极性抗氧化剂γ-生育酚、BHT的活性,但是减弱了极性较强的抗氧化剂TBHQ、BHA的活性。     

The functionality of woven fabric from air-jet yarn from the mixture of CO/PA and CO/PES fibres in the weft direction

The purpose of presented research is to find out the influence of air-jet yarn from the mixture of CO/PA (50/50) and CO/PES (67/33) fibres on functionality of woven fabric in the plain weave.The first part of the study is directed to the mechanical and physical properties of air-jet yarns (16.7 tex) from CO/PA and CO/PES fibres, while the second part of the study focuses on permeability properties of fabrics with air-jet yarns in the weft. The results show that air-jet yarn in the weft direction influences on the water vapor transmission and thermal conduction increase and air permeability decrease.Incorporation of air-jet yarn in the weft direction also improves breaking extension level.The results of presented research also show that the incorporation of air-jet yarn in the weft has statistical important influence on thermal conduction, water-vapor and air permeability changes.     

仓泵技术应用于电石粉尘回收装置的探讨

根据陕西金泰氯碱化工有限公司新建的电石粉尘回收装置的运行情况,探讨了仓泵技术的应用及仓泵在运行过程中的异常情况。指出装置运行后降低了电石消耗,每年可产生约400万元的经济效益,同时也降低了企业的安全风险,改善了乙炔生产现场环境。     

Co-optimization of CO2 sequestration and enhanced oil recovery in extra-low permeability reservoir in Shanbei

This article put forward a theoretical system, which is used to analyze co-optimization of CO₂ sequestration and enhanced oil recovery by using the methods or theories including the design of experiments, numerical simulation, net present value, and the response surface methods. A CO₂ flooding operation in an immiscible water-alternating-gas process of Shanbei extra-low permeability reservoir was estimated preliminarily by using the methods proposed in this article. The result shows that optimized values obtained from predicted values were in good agreement with the values obtained from the simulation model and it is possible to optimize a coupled CO₂ sequestration and enhanced oil recovery project.