The descriptors of polarizability effect index(PEI),the number of effective carbon(N_C,eff),the differences in PEI and N_C,eff between the branching chain and straight chain isomers,δPEI and δN_C,eff,are derived from molecular structure.The quantitative structure-property relationships(QSPRs)between these descriptors and boiling points of 520 aliphatic alcohols,ethers,aldehydes,ketones,acids,and esters were obtained separately.The QSPRs between these descriptors and boiling points were developed for 520 aliphatic oxygen-containing organic compounds by best subsets regression method.For the training set,the correlation coefficient R² is 0.9946 and the standard deviation(s)is 6.70 K.For the test set,R² is 0.9857 and s is 6.10 K.The average relative error is 1.19%.According to the regression equation,the influences of the number of effective carbon of alkyl,the role of functional groups and their interaction on the boiling point were analyzed.These results showed a good correlation between the boiling points of organic compounds and these descriptors derived from PEI for aliphatic alcohols,ethers,aldehydes,ketones,acids,and esters.

The gasification efficiency of a novel two-stage gasifier was studied and analyzed by numerical simulation.In this model the coal-water slurry(CWS)gasification process was divided into several sub-models:water droplet evaporation,coal pyrolysis,gas homogeneous reaction and gas-solid heterogeneous reaction.Turbulent flow mixing and chemical reaction were considered in the rate of gas phase reaction.The unreacted-core shrinking model was used to describe the rate of gas-solid heterogeneous reaction.The realizable k-ε turbulence model was used for the gas phase flow,and coal-water slurry particles were tracked by the Random-Trajectory model.The CWS gasification model was verified based on the model subject of a pilot-scale opposed multi-burner(OMB)gasifier.The simulation result showed that effective gas composition of the novel two-stage gasifier was 85.91%,and cold gas efficiency was 76.42%.

Continuous siphon vacuum pump driven by tidal energy(TEVP),with its experimentally-proved suction capacity over 2?10^-5 kg gas?(kg sea water)^-1 employing 3.5 m tidal height margin under 7.5 kPa(abs.)suction pressure,showed the potential of industrial application based on reliable theoretical principles.Sea water could be used as working fluid for vacuum suction prior to performing as cooling medium for a coastal plant.In a 900 MW pressurized water reactor nuclear power station,a 132 kW mechanical vacuum pump with 61.4 kg穐^-1 of suction capacity under the pressure of 7.5 kPa(abs.)was expected to be replaced by a TEVP employing sea water with a flow rate of 3070 t穐^-1.The suction capacity would be increased along with the increase of suction pressure,which was constrained by the rate of momentum transfer between gas and liquid phases,or the maximum of momentum flow rate of the gas phase.In order to avoid siphon break-off,the velocity of sea water in the siphon pipe should be greater than the velocity under the maximum momentum flow rate of the gas phase.The ideal suction efficiency could reach 0.6 when involving a smooth pipe model for calculation and ignoring local flow resistance,but it would sharply decrease taking into consideration the local flow resistance loss caused by valves and other pipe fittings.Therefore it was a basic principle to avoid flow resistance caused by pipe fittings regarding the gas/liquid two-phase flow for a TEVP to ensure its performance in high efficiency region.

The field synergy principle for convective mass transfer indicates that Sherwood number depends not only on Reynolds number and the Schmidt number but also on the synergy of concentration field and velocity field.The numerical simulations are performed for laminar convective mass transfer and fluid flow characteristics in the straight tube,and the results show that concentration gradient in radial direction is 2 orders of magnitude larger than that in axial direction when Sc is 1.2,which means that the synergy of concentration field and velocity field is not good.In order to strengthen the mass transfer,the angle of velocity and concentration gradient should be decreased,in another word,the radial flow of fluid should be generated.From the observation and quantitative calculation of the velocity field and concentration field in the helical tube,it is found that the secondary flow crosses the equi-concentration line,and the presence of secondary flows improves the synergy of the two fields.For the same Re,the secondary flow is more intense,the effect of mass transfer is more significant.For the same helical structure,the secondary flow increases with Re.The secondary flows promote the synergy of concentration and velocity fields,which is the reason for helical tube to improve the mass transfer.The maximum of area-average secondary velocity reaches 6.5%-6.8% of bulk velocity,and Sh increases 4.99-6.43 folds when Re=1000-2400 for helical structure in the paper.It is shown that the field synergy principle well explains the mechanism of mass transfer enhancement in the helical tube.

The traditional liquid-level detection method for storage tank by using thermal infrared imager is mainly digital image processing,so the measurement accuracy is not high.In this paper,a mathematical model of heat transfer in storage tank is built and the temperature distribution of external surface of the tank is solved by finite volume method.An inverse heat transfer algorithm for quantitative identification of liquid-level in storage tank is proposed based on the temperature distribution of external surface of the tank and the effects of initial guess,measurement error(σ)and maximum surface temperature difference on the level detection results are investigated.The results show that within the range of acceptable measurement error in engineering applications(σ=2℃),the inversion liquid-level has a high accuracy,with relative error less than 2%.It provides a new thought and a way for the liquid-level detection for storage tank.

Heat storage systems are used to reduce the mismatch between heat supply and heat demand. Compared to sensible and latent heat storage,thermochemical heat storage has two major advantages:high heat storage density and long-period storage capability at ambient temperature without extra thermal insulation.In this study,the thermal behavior of Mg/MgH₂ thermochemical heat storage system is numerically investigated.A mathematical model for considering the exothermic process of heat storage is developed,and the influence of different boundary conditions is examined.The results indicate that heat transfer plays a key role in overall thermochemical heat storage efficiency,and an optimum reaction temperature exists which leads to a maximum discharging power for a given heat transfer coefficient.When the boundary condition is constant wall temperature,the system has a maximum discharging power 0.79 kW?(kg Mg)^-1.

In order to suppress vortex shedding and reduce drag,an active control is implemented by two symmetrical affiliated cylinders with fixed rotation,which are located right behind the main cylinder. Numerical study on this active control is employed for the two-dimensional unsteady flow around the cylinder.Numerical simulations are performed in a range of rotation speed α and different directions of rotation at Reynolds number of 200.The numerical simulation result indicates that when the upper small cylinder spins clockwise and the bottom cylinder spins counterclockwise,the purpose can be achieved. When α equals to 2.4,vortex shedding of wake fluid of the main cylinder is suppressed completely. When the rotation directions of two affiliated cylinders are different,the vorticity is reinforced and the drag and lift coefficients are increased.

Dilute aqueous solutions of alcohols with large number of carbon atoms,due to their properties associated to an anomalous dependency of the surface tension with temperature,can be prepared as self-rewetting fluids.In this study,experimental investigation was conducted to explore heat transport capability of heat pipe working with self-rewetting fluid[0.1%(mass) heptanol aqueous solution].Under different heat loads and different orientations(vertical and horizontal orientation),the heat transport capabilities of heat pipe with the self-rewetting fluid and water were compared.The results show that with the increase of heating power,the heat transport capability of heat pipe is enhanced by using the self-rewetting fluid.In the horizontal heating mode,without the influence of gravity,the enhancement of heat transfer is more evident.Compared with water,the self-rewetting fluid presents significantly better heat transport capability.

This paper presents an experimental investigation on nucleate pool boiling of saturated deionized water from uncoated and self-made sintered coated porous tubes with the heat flux from 0.1 to 160 kW·m^-2.The influences of the orientation(vertical and horizontal)and diameter(20,25 and 32 mm)of the heating tube and the coating particle size(between 30 and 105 μm)on the nucleate pool boiling were investigated.The results show that the sintered porous coatings can lower the incipient boiling superheat and enhance nucleate boiling heat transfer coefficient compared with smooth surfaces.The incipient boiling superheat of deionized water drops from 4-5 K with the smooth tubes to 1-2.5 K with the porous coated tubes.And the nucleate heat transfer coefficient on porous coating tubes are 3-4.5 times those of smooth tubes.It is found that,at high heat flux,the horizontal tube presents better boiling performance than the vertical tube due to the decrease in bubble slug formation on the tube surface and easy access of liquid to the surface.In addition,the influence of tube orientation on boiling performance is smaller for the porous tube than for smooth tubes.The heat transfer coefficients on smooth tubes and porous tubes decrease as the tube diameter increases.The data for different porous coatings suggest that small particle has slight effect on boiling heat transfer and greater enhancement is found with larger particle size.

A two-dimensional physical and mathematical transient heat transfer model for the pipeline with irregular inner geometry boundary is built.The identification problem of pipeline inner boundary is solved by using finite element method and conjugate gradient method(CGM)-based inverse algorithm.The differences of sensitivities of the transient and steady pipeline outer surface temperature to the inner boundary change are analyzed and certified by a series of numerical simulation experiments,in which the influences of temperature measurement errors and initial inner boundary guesses are tested.It is found that the temperature measurement errors and initial inner boundary guesses have no obvious effect on the pipeline inner boundary identification results when the infrared inspection is carried out in the transient heat transfer state,while the accuracy of the boundary identification results is poor with temperature measurement errors when the infrared inspection is carried out in the steady heat transfer state.Therefore,in the engineering application,in order to identify the inner geometry boundary accurately,the infrared inspection in the transient heat transfer state is more appropriate than that in steady heat transfer state.

Characteristics of interface distribution in air-water two-phase bubbly flow in a vertical pipe was experimentally investigated by using the measurement method of optical fiber probes.The inner diameter of the circular pipe was 100 mm,and superficial gas and liquid velocities ranged from 0 to 0.1 m穝^-1 and from 0 to 1.0 m穝^-1,respectively.Local distributions of the interfacial area concentration(IAC),void fraction and bubble diameter were obtained.By analyzing the forces on a bubble,it was found that lift force and turbulent dispersion force determined the radial motion of bubbles,and the former dominated the radial profile of IAC.When the bubble diameter exceeded the critical size of 5.7 mm,the distribution of IAC would change from wall peak to core peak resulting from the lift force pointing to the pipe center due to lift force coefficient changing from positive to negative.

The gas-solids two-phase flow in the superfine classifier with two different feeding types was studied by numerical simulation.The pressure difference,air velocity and solids concentration distribution were analyzed.The performance superfine classifier with two feeding types was studied by experiments,and the characteristic particle size and size distribution of fine powder of under and upper feeding type were compared and analyzed.The results showed that compared with the under feeding type,the pressure drop between inlet and outlet of the superfine classifier of the upper feeding type was bigger due to adding the mechanical spreading plate.For the upper feeding type,the tangential and radial velocities of cylindrical surface along the rotor were distributed more uniformly,which helped to reduce the fluctuation of classification size and obtain fine powder with narrow particle size distribution.Particle concentration was distributed uniformly with the upper feeding type,but was affected heavily by rotor speed.According to the experiment,both under feeding and upper feeding types could obtain good classification performance.After classification,the size of fine powder was small,with narrow distribution,mainly in the range of 1-30 μm.The percentage of particle less than 30 μm of fine powder was above 90%.The study results could provide guidance to designing the feeding type and optimizing the geometry of the superfine classifier.

The paper analyzes the flow mechanism,shape characteristics and inner velocity distribution of gas-liquid slug flow in a horizontal pipe,and develops a physical model for the horizontal pipe.In a steady slug unit,lift velocity is always equal to shedding velocity,so the slug can keep an established shape.The model divides the slug into two parts:liquid-slug and film/bubble zone.For the liquid-slug zone,mass conservation and momentum conservation equations are built up to compute the local liquid-holdup and pressure-drop.For the film area,the model takes film height variation into consideration,assuming the height is only varying along the flow direction but not in the radial direction.The paper deduces a film height variation expression by building local control equations,and then develops a film height via liquid-holdup function and a film height via wet-diameter function.By comparing with test data and some other models,this model presents more accurate prediction results of liquid-holdup and pressure-drop.

Particles exist in many areas,their characterization measurement and monitoring are of great importance.With the development of technology,digital image processing technique as a direct-viewing and non-contact measurement method has been widely used.However,in the optical imaging system,the depth of field is limited.In order to increase the measurement range,the defocus images should be processed. Defocus image of spherical particles were studied from simulation and experiment. It was proven that the gradient of image transition area and the defocus distance were related,and the difference of two maximum gradients along the radial direction was the particle diameter in image.

Taking the fluid flow uniformity and pressure drop as the evaluation indexes,the real 3D solid numerical model is adopted to investigate the influence of geometrical structure parameters of the tapered flow distributor on flow uniformity and flow resistance.The corresponding relation charts of flow status in entrance region of shell side and key structure parameters L,θ,and H are obtained,where L is the distance between the inner surface of jacket and the exine of internal liner barrel,θ is the inclination angle of inlet section where fluid enter the draft-tube,and H is the distance from the high end of the internal liner barrel to the tube plate. By adjusting the above structure parameters in proper ranges,the flow uniformity at the entrance section of the shell side can be improved and the pressure drop in the shell side is decreased effectively.The ranges of L,θ,and H values recommended are:L=50-70 mm,θ=7°-12.5°,H=50-100 mm for the optimum design.

According to the requirement of middle and low temperature air conditioning,the solar-powered air-cooled two-staged ejector cooling system with rated cooling capacity of 10 kW is designed,using water,ammonia,R290 and R600a as working fluids separately.The performance is analyzed.At certain cooling capacity and indoor temperature,the water system is the most material-saving system,followed by the ammonia and R290 ones with equivalent consumption,and the R600a system is the most material-consuming one.The four systems have relatively perfect off-design performance and their cooling capacities are almost the same on comprehensive consideration of the influences of ambient temperature and solar irradiance.Among the four systems,the water system presents higher COP value,the effect of which is more obvious under weaker solar irradiance,followed by ammonia system,R290 and R600a systems. A solar-powered air-cooled ejector refrigeration system with water as working fluid is more suitable for use in the regions with relatively weak solar irradiance.

A numerical simulation for frost formation and growth on the surface of finned-tube vaporizer was carried out based on the diffusion limited aggregation model of fractal theory,and images of frost formation and growth at different stages were obtained by experimental observations.For the frost layer profile on the surface of vaporizer,fractal dimension of pore area distribution and fractal porosity were calculated.The simulation results are in good agreement with experiments.Then the fractal model for heat conduction through the frost layer was established and the thermal resistance method was used to get an expression for thermal conductivity of frost layer.The result shows that the calculated thermal conductivity of frost layer falls in the range of measured data.Compared with other thermal conductivity models,the introduction of profile area distribution fractal dimension into the thermal conductivity model is appropriate,which is a new method for the theoretical study for thermal conductivity of frost layer.

Using water as working medium,an experimental investigation on heat transfer performance of the nickel foam wick heat pipe and the mesh wick heat pipe was conducted under the conditions of natural cooling and water cooling.The wall temperature distribution and isothermal characteristic of the two heat pipes were discussed.The variation of the evaporation and condensation heat transfer coefficients in the nickel foam wick heat pipe with the heat flux with natural cooling were obtained.In a certain range,the evaporation and condensation heat transfer coefficients increased with the increase of the heat flux.Under the conditions of water cooling,the evaporation heat transfer coefficients in the nickel foam wick heat pipe first increased and then decreased with the increase of the heat flux when the cooling water flow rate was 0.01 m³穐^-1.The experimental results indicate that the nickel foam wick heat pipe has a good start-up performance,and the mesh wick heat pipe is easier to reach the heat transfer limit than the nickel foam wick heat pipe.

Experiments of gas mixing between two half-beds were performed in a dual-leg circulating fluidized bed(DL-CFB)240 mm in width,40 mm in depth and 2000 mm in height by using glass beads with diameter of 0.25-0.28 mm as bed material.SO₂ and CO as the gas tracers entering the left and right distributors separately were used to simulate the gas mixing between the two legs.MSD(mean square displacement)model was adopted to calculate the gas dispersion coefficient(D_w)which was used to investigate the effect of fluidization velocity and bed material inventory on gas mixing in the DL-CFB.The experimental results showed that D_w was about 50-300 cm²穝^-1 at different fluidization velocities and bed material inventories.A higher fluidization velocity benefited particles exchange between two half-beds,which intensified the gas-solids interactions at the region with higher solids volume fraction.The gas mixing in the lower region of the DL-CFB was stronger than that in the upper region of the bed.A higher bed inventory was helpful to gas mixing at a lower fluidization velocity,while a higher fluidization velocity weakened gas mixing because of higher solids concentration in the center of the bed that prevented gas mixing.

A series of metal-modified heteropolyacid salt catalysts(M_XH_3-2XPW₁₂O₄₀,M=Zn,Cu,Cs,Ag)were prepared,and the solid heteropolyacid salt Ag₃W₁₂O₄₀ was used in hydrolysis of glucose to produce levulinic acid.The surface structures of different heteropolyacid salt catalysts were characterized by means of FTIR,XRD.The surface structures and element relative mass content change of the fresh and used Ag₃W₁₂O₄₀ catalyst were also analyzed by means of FTIR,XRD,SEM and EPMA.The effects of such factors as reaction temperature,reaction time,amount of catalyst and glucose concentration on the yield of levulinic acid were investigated.Experimental results showed that the M_XH_3-2XPW₁₂O₄₀ heteropolyacid salt catalysts kept primary Keggin structure,and Ag₃W₁₂O₄₀ catalyst had the structure of Keggin after reuse for several times.It was found that the highest yield of levulinic acid was 81.61%(mole) under the conditions of reaction temperature 200℃,reaction time 2 h,Ag₃PW₁₂O₄₀ catalyst dosage 0.7 g and glucose concentration 40 g·L^-1.The catalyst could be used repeatedly.

To improve dechlorination effectiveness of 4-chlorophenol,palladium-modified lanthanum-nickel electrode(Pd/LaNi₅ electrode)was prepared by chemical deposition,and characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and linear sweep voltammetry(LSV).The measurement results of electrocatalytic activity show that the dechlorination efficiency is higher for Pd/LaNi₅ electrode than for LaNi₅ and Pd/Ni electrode.At conditions of 4-CP initial concentration 0.1 mmol稬^-1,apparent current density 10 mA穋m^-2,pH 4.0 and Pd loading 1.8 mg穋m^-2,the dechlorination efficiency was 77.3%,and corresponding current efficiency 0.14%. Based on the physico-chemical characterization,the conclusion is that better hydrogen-storage property of LaNi₅ is responsible for the enhancement of electrochemical dechlorination process.

Conversion of methanol to propylene(MTP)was comparatively studied over four zeolites with different topologies,em.e.SAPO-34,ZSM-48,ZSM-5 and beta at atmospheric pressure,450℃ and WHSV=1.5 h^-1.The correlations between product selectivity,catalyst stability and zeolite topology were investigated.Besides,coking behavior of the four zeolite catalysts during the reaction was also discussed.Among the studied catalysts,SAPO-34 with narrow 8-member ring openings showed the highest selectivity to light olefins(ethylene and propylene).However,it seems that the high density of acid site and the large cages of SAPO-34 resulted in an extremely fast coking deactivation.Beta zeolite with wide pore structure exhibited high propylene/ethylene(P/E)ratio,but the propylene selectivity was somewhat low due to the product distribution shifting towards heavier hydrocarbons.In contrast,ZSM-48 and ZSM-5 zeolite with 10-member ring openings gave higher propylene selectivity,but their deactivation rates were quite different.ZSM-48 zeolite with symmetrical straight channels underwent fast deactivation after a few hours on stream,while ZSM-5 zeolite with intersecting channel system presented superior resistance to coke deactivation.The significant difference in catalytic performance of the four zeolites could be mainly ascribed to the combined effect of shape selectivity for intermediates and products controlled by zeolites topology.

Catalytic cracking upgrading of coal pyrolysis oil and gas products was conducted in a dual-stage reactor using char and Co-impregnated char(Co-char)as the catalyst.The tested coal was Fugu coal,and the upper stage of the dual-stage reactor was used for pyrolysis.During catalytic cracking of coal pyrolysis products,tar yield decreased,and gas yield and also light oil fraction content of(boiling points<360℃) the tar increased,while the yield of light tar remained constant or increased slightly.For the pyrolysis with secondary cracking at 600℃ over a char layer of 20% the tested coal,its gas yield and light tar content increased respectively by 31.2%(vol)and 25%(mass)in comparison with the direct pyrolysis of coal at 600℃,whereas light tar yield varied little.When Co-char was used as the catalyst,cracking at 500℃ over the catalyst of 5% coal mass increased light oil yield and light oil content in the tar by 8.8%(mass),and 28.8%(mass),respectively.The corresponding increase in gas yield was 21.5%(vol).Catalytic secondary cracking in coal pyrolysis worked mainly to convert heavy oil components into light oil and pyrolysis gas.

Aiming at the incomplete utilization of chemical energy of reducing gas in a shaft furnace like Midrex for direct reduced iron production,oxygen blowing into the upper part of the furnace was proposed to transform the excessive chemical energy into thermal energy.In this way,the proportioning and balancing between chemical and thermal energies of reducing gas in the furnace could be realized,and their maximum utilization and thus gas consumption reduction could be expected.A mass and heat balances model was developed to analyze the gas consumption of both traditional and newly proposed processes.A one-dimensional kinetic model was developed to calculate the composition and temperature profiles of both gas and solid phases in the furnace.The distribution of thermodynamic excess,i.e.the excessive chemical energy of reducing gas was also obtained.The results showed that with oxygen blowing into the upper part of the furnace,the temperatures of both gas and solid phases increased and the concentrations of CO and H₂ decreased,and thus gas utilization was increased significantly.In the case of 536.40 m³穐^-1 oxygen blowing at the furnace height of 6.5m,gas consumption decreased by 25.94% and off-gas reduction potential decreased by 53.69%.

The composite polydimethylsiloxane(PDMS)/polysulfone(PSf)and PDMS/polyvinylidenefluoride(PVDF)hollow fiber membranes were prepared by dip-coating modification for the distillation of isopropanol(IPA)/water solution.Compared with the PVDF and PSf hollow fiber membrane contactors,the distillate concentration of membrane contactors packed with PDMS/PVDF and PDMS/PSf hollow fibers was increased by 20% and decreased by 3%~10%,respectively.The height of mass transfer unit of modified packing could be less than 20 cm and the minimum is 5 cm.Mass transfer time was generally less than 10 s.All contactors can be operated normally without considering the flooding and loading limits of conventional packings,which presents great advantages in both hydraulic performance and separation efficiency.

This study aims at the enhancement in nanofiltration process of aqueous solutions of inorganic salts and provides reference values for industrial application.Gas-sparged nanofiltration experiments with aqueous solution of MgSO₄ were performed using a DK2540F element spiral nanofilitration membrane module.The permeate flux and the enhancement from gas sparging were measured in the following operation ranges:temperature 28-36℃,feed concentration 20-50 g·L^-1,transmembrane pressure 0.4-0.7 MPa,air/liquid ratio 1.0-3.5,and air velocity 1.0-3.5 m·s^-1.The effects of different conditions on the permeate flux,rejection and increment rate of permeate flux of nanofiltration membrane were investigated.The experimental results show that gas sparging can significantly increase the permeate flux and rejection of MgSO₄ aqueous solution,appropriate temperature is between 30℃ and 40℃ and feed concentration,transmembrane pressure,and air/liquid have profound effects on the permeate flux and rejection rate of MgSO₄ aqueous solution,and the flux enhancement is more significant at higher feed concentration,lower transmembrane pressure,and higher air/liquid.

The growth of particle dendrites on a single fiber during fibrous filtration was simulated by the Monte Carlo stochastic simulation and Kuwabara cell model.With the interactions between particles in the dendrites considered,the drag force contribution from each individual particle was calculated and analyzed.The results indicate that two steps may be distinguished in evolution of the pressure drop with deposit aspect for all filtration conditions studied.The variation of pressure drop is strongly depended upon filtration velocity,particle size and particle dendrite structure.However,in the range of fiber diameter concerned,there is no influence on the evolution of pressure drop.A new theoretical model for estimation of the pressure drop across the fibrous filter during clogging was developed with the understanding of the evolution of pressure drop for a dust-loaded fiber with deposit aspect.The model test shows that the calculated values are in good agreement with the experimental data for the filtration velocity from 0.01 m穝^-1 to 0.3 m穝^-1.It can be used for the prediction of pressure drop during fibrous filter clogging.

A hydrogen network is usually optimized based on lowering the hydrogen concentration of each hydrogen sink to the lowest limit in order to obtain possibly the largest hydrogen saving.However,it may reduce the operating flexibility.During reducing the hydrogen sink concentration,the pinch location may change which leads to the slope reduction of hydrogen saving amount-hydrogen sink concentration curve.Based on such analysis as well as the other economic factors,a method to determine the optimal hydrogen concentration to optimize the system is proposed,in which way,good hydrogen saving with a marginally lower concentration in hydrogen sinks can be obtained.A case study is used to show the method,for which the optimal hydrogen concentration of a key hydrogen sink is found based on the relationship between the concentration of the key hydrogen sink and the hydrogen saving amount.The hydrogen saving amount is 42.81 mol穝^-1 which accounts for 21.58% of the current fresh hydrogen consumption.The results show that this method could achieve a good effect of hydrogen saving in the case of that the hydrogen sink concentration reduces lower.

The presence of gross errors can corrupt a model’s performance,giving undesirable results.A novel weighted least square support vector machine regression(WLS-SVM)is proposed,which combines gross error detection and adaptive weight value for the training sample.First,the 3δ principle is applied to detect the gross error.Second,the initial weight is obtained according to the fitting error of each sample.Then,an adaptive immune algorithm(AIGA)is applied to obtain the optimal parameters of the WLS-SVM.To illustrate the performance of the WLS-SVM,simulation experiment is designed to produce the training sample.The results showed that the predicting performance of AIGA-WLS-SVM is the best. Furthermore,the AIGA-WLS-SVM method was applied to estimate the rate constants of an industrial p-xylene oxidation model,and the satisfactory result was obtained.

Coal-water slurry gasification is a very important technology in developing clean and efficient use of coal.Gasifier furnace temperature is one of the key variables which is closely related to the process safety,stability and long-term operation of the gasification.Thermocouple elements are easily ruined under complex industrial condition with high temperature,high pressure and high flow erosion.Thus it is difficult to maintain a long period of work.In this paper,aiming at an opposed multi-burner coal-water slurry gasification process,adopting fuzzy C-means clustering based multi-modeling method and least square support vector machines,a gasifier temperature soft sensor model is established.The actual operation’s validation results show that the predictive temperature of the furnace based on this soft sensor model has a pretty good predictive precision and generalization ability.

Three-dimensional axial compressor model is established by using the method of mesh in Gambit and the different boundary of compressed N-S equation is evaluated.Based on the turbulent model of standard model k-ε of double equation,diversified through the finite volume method and calculated by that the characteristic curve of compressor is plotted with the data of Fluent algorithm and classic formula algorithm.Then through the simulation validates the reliability of the three-dimensional numerical simulation,analysis the instability process of compressor under different rotating speed in the rotating stall and surge characteristics and recovery calculation process after instability.Finally,imported the active actuator close coupled valve(CCV),compressor characteristic curve of non-dimensional flow and pressure is changed because of the different CCV opening.It reduces the least flow of compressor in other words,the result of importing CCV is that the characteristic curve of compressor moves to the left,and expands the steady operating areas of compressor greatly.It is important for avoiding instability.

Industrial processes usually contain complex nonlinearities.For example,the control of pH neutralization processes is a challenging problem in the chemical process industry because of their inherent strong nonlinearity.In this paper,the model predictive control(MPC)strategy is extended to a nonlinear process using Hammerstein model that consists of a static nonlinear polynomial function followed in series by a linear difference equation dynamic element.The calculation strategy of optimal control output based on the static nonlinear polynomial function of the Hammerstein model is presented in detail.Thus a new nonlinear Hammerstein predictive control strategy(NLHPC)is developed.Simulation and control experiments of a pH neutralization process show that NLHPC gives better control performance than the commonly used industrial nonlinear PID(NL-PID)controller.

With the goals of optimal performance,energy conservation and cost effectiveness of process operations in industry,controller performance assessment of process control have received great attention in both academia and industry.Controller performance monitoring and assessment are necessary to assure effectiveness of model predictive control systems and consequently safe and profitable plant operation. Taking region constraint properties of model predictive control(MPC)into consideration,a novel approach based on the weighted point statistics is developed for the performance assessment of region control(RC)problems in this study.All controlled variables are grouped into two categories:constrained variables(CVs)and quality variables(QVs),according to the importance of the controlled variables in MPC systems.By introducing the weighted points for all controlled variables,the performance index is calculated based on the statistics analysis of closed-loop data sets,which can be used to assess the performance of an MPC control system.The important advantage of the proposed approach is that just the routine closed-loop operation data of the system and constrained region of each CV are required,which is convenient for the industrial applications.Simulation example and industrial case study illustrate the applicability of the proposed approach.

A new working condition-based optimization framework for operational patterns was proposed. The framework is composed of three components which are data preprocessing,the creation of library of optimized operational patterns and real-time optimization based on working conditions.On the basis of optimization and control framework,the application of online operational optimization for the dry-point temperature of FCCU was focused.Base on the FCCU properties,a two-step optimization approach for operational patterns which combines SVM and AdaBoost was proposed.Experimental results show that the new approach has higher prediction performance.

A parallel multi-families genetic algorithm (PMOGA) is proposed to reduce computing burden which is incurred in the solution of the multi-objective optimization problem in chemical process when combining the single genetic algorithm (GA) with the process simulator.A master-slave node distributed computing strategy is employed in the proposed algorithm.Based on the idea of decomposition-coordination, the Pareto curve is divided into multi-sections, and then the calculation task of each sub-section is assigned to single computer in LAN to reduce the computing time.The proposed method has been tested on two practical chemical examples.The results show that PMOGA is superior to single GA in both uniformity and comprehensiveness of the Pareto solutions.

The near-infrared spectroscopy(NIRS)with GA-BP neural network model was used for rapid prediction of gross calorific value of coal.The prediction model was non-linear,so the classical linear principal component analysis(LPCA)method was not applicable for processing spectral data.The nonlinear polynomial kernel principal component analysis(P-KPCA)method was proposed for extracting spectral feature and filtering abnormal samples in this paper.The extracted principal components had high feature concentration,obvious dimension reduction effect,and good correlation with output variable.After eliminating the abnormal spectra,prediction accuracy was greatly improved.The results showed that P-KPCA provided effectively processed spectral data for the rapid prediction model.

A new immune cultural algorithm(ICA)based on immune clone selection was proposed.In ICA,immune clone machine was used for training and testing sampling data from SRT-Ⅲ furnace.One selection was taken as population space of cultural algorithm.In belief space,the knowledge extraction,expression,storage,update methods were proposed according to their evolutionary characteristics. Communication function was improved at the same time which in turn improved the capacity of algorithm evolution.The test results showed that compared with genetic algorithm(GA)and chemotactic differential evolution algorithm(CDEA),immune cultural algorithm had much improvement in search precision and convergence speed.The algorithm was applied to the support vector machine parameter optimization for solving fault diagnosis of ethylene cracking furnace.Multi-class classifier was made by support vector machine.Compared with fault classification using the parameters optimized by genetic algorithm,the simulation results showed that the proposed algorithm achieved good result in classification accuracy,20 percentage points higher than the method without using immune cultural algorithms.

The coating of Ni-P/Ni-Cu-P on the surface of Kevlar fiber was achieved by electroless plating. The surface appearance and composition of original sample,coarsened sample,plated sample and spalled coating were investigated and compared by means of SEM,EDS and XRD.In addition,the formation mechanism and spalling reason of the coating was studied.The results showed that the Kevlar fiber specific surface area,hydrophilicity and activity increased after chemical pretreatment.After chemical Ni-P/Ni-Cu-P plating,the content of Ni in Ni-P coating decreased,however,the content of P increased,Ni was transformed into Ni₃P and a little Cu was discovered in Ni-P coating.The atomic proportions of Ni,Cu,P in overall coating were 8.54:3.66:5.59,the phase of the coating mostly consisted of Cu,Cu₃P and Ni₃P.Because the stress of coating distributed unequally and P gathered partly in Ni-P/Ni-Cu-P phase interface,the interface bonding strength was weakened and local stress concentration occurred,which appeared to be the reason for spalling of the coating.The chemical Cu plating relied on the catalytic action of nickel ions,which helped deposition of copper ions to form the coating.

A novel Fe-based oxygen carrier/coal ash was proposed for CO oxidation in CLC system in this paper.Its activity and thermal stability as well as the synergistic effect between oxygen carrier and coal ash were studied by TGA and combustion experiments in a small fluidized bed and density functional theory calculations also performed.It is found that the novel oxygen carrier is more active for CO oxidation in CLC system,because of greater porosity and synergistic effect between them.At 850℃ and with 10.0%(mass) foamer,the maximum conversion is much higher for the novel Fe-based ash oxygen carrier(84.9%)than for Fe₂O₃/Al₂O₃(54.3%),and the former is of preferable thermal stability in 30 cycles test.The activity of novel oxygen carrier is influenced significantly by the content of foamer and reaction conditions.Suitable foamer content(about 10%(mass))is favorable,whereas high reaction temperature causes its sintering. Furthermore,the effect of interfacial interaction and electronic properties related to the synergistic effect between them on CO oxidation were studied by density functional theory(DFT).The calculation results indicate that total charge population in the Fe₂O₃ particles is positive due to interfacial charge transfer between coal ash and Fe₂O₃,which could be favorable for reaction of CO and oxygen carrier.Synergistic effect between coal ash and Fe₂O₃ could cause a decrease of their frontier orbital energy difference,hence promote reactions between CO and Fe₂O₃.

The composite flocculant was prepared by polymerizing CPAM(a cationic flocculant P:acrylamide-methacryloxyethyltrimethyl ammonium chloride-acryloxyethyltrimethyl ammonium chloride)and PFAS(polymeric aluminum ferric sulfate).The morphological distribution of Fe and Al was studied by using Ferron analysis,and the morphology of the copolymer was observed using scan electron microscopy.The Box-Behnken mathematical relational model between COD_Cr removal rate and affecting factors was established,and the technique composing PAFS-CPAM was optimized.The optimum synthesis conditions were: react temperature 61℃,react time 74 min,and Fe/CPAM mass ratio 28,respectively.At these optimized conditions and using 50 mg·L^-1 PAFS-CPAM flocculant prepared,COD_Cr removal and turbidity removal rates were 80.86% and 97.50%,respectively.

Influence of various additives on pyrolysis-debromination of resin in non-metal components(NMFs)in wasted printed circuit boards(WPCB)was investigated.The results show that urea additive can effectively promote removal of Br-containing flame retardant and the formation of gas phase HBr,bromomethane and bromoethane,increase amount of phenol and its derivative in pyrolysis-residue oil; and reduce amount of Br content in solid residue C.However,for DDM(4,4'-diaminodiphenylmethane)additive,although it can promote formation of phenol and its derivative,decrease gas products and increases liquid and solid products,it can not remove Br in NMFs resin of WPCB.For hexamethylenetetramine,in spite of removing Br-containing flame retardant and forming gas phase products such as HBr,methyl bromide,and ethyl bromide,decreases obviously liquid products such as phenol and its derivative,but find large amount of N-methylacetamide and N,N-dimethylformamide in liquid products.Besides,hexamethylenetetramine makes amount of liquid and solid products increase and that of gas products decrease.

In order to study the effect of different carbon sources on the phosphorus release,PHA transform,population of the phosphate accumulating organisms(PAOs),and the anaerobic stoichiometry of PHA and glycogen,three enhanced biological phosphorus removal(EBPR)reactors were operated for a long term in the sequencing batch reactor(SBR)fed with acetate/propionate,glucose,or domestic wastewater.The result showed that three systems acquired stable phosphorus removal efficiency from the 182nd day,and FISH results showed that PAOs accounted for 89%?3%,55%?3%,45%?4% of total biomass.Polyhydroxybutyrate and polyhydroxyvalerate were synthesized by PAOs when fed with acetate,glucose,or domestic wastewater as carbon source,only polyhydroxyvalerate was synthesized when fed with propionate as carbon source,and no poly-3-hydroxy-2- methylvalerate(PH2MV)was detected.Stoichiometry research showed that 1.15 C-mol of PHB and 0.15 C-mol of PHV were synthesized per C-mol acetate,meanwhile 0.47 C-mol of glycogen was degraded.0.44 C-mol of PHV was synthesized and 0.271 C-mol of glycogen was degraded when fed with 1 C-mol propionate.0.16 C-mol of PHV was synthesized and 0.16 C-mol of glycogen was degraded when fed with one C-mol glucose,while very few of PHB was synthesized during this process.The proportions of PHB/COD and PHV/COD were 0.98 and 0.13 respectively when fed with domestic wastewater.Release of phosphorus reached the maximum 134 mg稬^-1 and release rate was 23.80 mg P?(g VSS)^-1穐^-1 with acetate as sole carbon source.With propionate or glucose as carbon source,phosphorus release rate was similar,while with domestic wastewater as carbon source phosphorus release rate was the smallest.

Electrochemistry(electro-assisted)was introduced to the microbial reduction of PCP in order to resolve the lack of electron donor and the slow reduction rate.It was found that the PCP degradation efficiency of 97% in the electro-assisted microbial system was higher than the sum of that of 62% in the microbial system and that of 26% in the electrochemical system by about 10%.The cyclic voltammetry(CV)curves of the PCP reduction degradation in the electro-assisted microbial system and in the electrochemical system were compared.There were obvious redox peaks in the cyclic voltammetry curves of the electro-assisted microbial system and the electron transfer rate was 0.856 m穝^-1,the electron transfer coefficient was 2.024 in a two-electron transfer process,which conformed to the biodegradation characteristics.The electron given by the electric field did accelerate the electron transfer during the microbial respiration.There was reverse electronic transfer between the electrodes,cytochrome c,cty穊c1,NAD and pollutants in the electro-assisted microbial system and the long-range electron transfer processes of multiphase interface between the electrode,microorganisms and pollutants were implemented. The study provides a new concept of electrochemical synergy with microbial reduction for environmental pollution control.

A two-step nitrification model was built by simplifying the standard activated sludge model No.1,and dynamic dissolved oxygen(DO)simulation can be done for aerobic nitrification process in a sequencing batch reactor(SBR)with constant aeration intensity.The parameters in the model could be distinguished into two groups by model identification:in a group parameter values can be directly obtained,including yield coefficient,DO saturation coefficient(or substrate coefficient),and in other group parameter values needed to be estimated by optimization algorithm.Adopting the parameter values recommended by literatures,dynamic processes were simulated for important process variables,which revealed multi-DO levels and fitted well with the real response trend in SBR operation.Optimal experimental design method was employed for obtaining dynamic DO data of aerobic nitrification process in the SBR with typical aeration intensity,from which the values of K_La and S_O^eq could be determined by theoretical analysis and second order differential treatment of these data.Then,further parameter estimation could be optimal based on the model identification and K_La determination.

Coke gasification,CaSO₄ chemical-looping combustion and CaCO₃ decomposition were integrated into a CaO regeneration reactor in the simulation performed with Aspen Plus.The effects of temperature(700-1200℃),pressure(0.1-4 MPa)on the required minimum H₂O flow,coke flow,equilibrium product yields,pollution gas emissions,heat transfer between reactors and solids circulation rate were investigated.The minimum H₂O flow and coke flow reduced with increasing temperature and the declining pressure.The percentages of H₂S in product gases without H₂O decreased with increasing temperature and declining pressure,while the percentage of SO₂ had a reverse trend.The percentage of H₂S+SO₂ decreased first then increased with increasing temperature.H₂S was the main gas pollutant at a lower temperature and was replaced by SO₂ as temperature increased,which was explained by the side reactions of CaSO₄.The heat and recycled solids between the reactors decreased while solids circulation rate increased with increasing temperature,but the heat and recycled solids between the reactors increased while solids circulation rate decreased with increasing pressure.

Two-stage oxygen delignification(O₁/O₂)and chlorine dioxide-based bleaching sequence(D₀ED₁P,where D was chlorine dioxide bleaching,E alkaline extraction and P hydrogen peroxide bleaching)was employed to bleach pre-hydrolyzed larch kraft pulp.The dosage effect of sodium hydroxide(NaOH)in O₁ stage,chlorine dioxide(ClO₂)in D₀ one and hydrogen peroxide(H₂O₂)in P one on pulp properties was investigated.The results showed that high efficiency of oxygen delignification can be achieved in two-stage delignification,and the Kappa reduction of 76.4% was gained at optimal amount 2.5% and 0.5% NaOH in O₁ and in O₂ stages respectively.The dissolving pulp with alpha cellulose 94.1%,pentosan 2.86%,polymerization degree 511 and ISO brightness 87.2% can be prepared by D₀ED₁P bleaching for the oxygen-delignification pulp at optimal chemicals dosage.It has been proved that the bleaching technology proposed in this paper is reliable.The clean bleaching sequence could be used to remake the traditional CEHP bleaching(C chlorine,E alkaline extraction,H hypochlorite and P hydrogen peroxide bleaching)with the advantage of investment saving due to reuse of original apparatus and pipelines.In addition,the content of absorbable organic halides(AOX)generated during bleaching was just 0.96 kg?(t pulp)^-1,only about ten percent of the AOX generated in traditional CEHP bleaching,giving better environmental benefit.

The corncob was microwave-assistedly modified by KMnO₄ and used for adsorption of U(Ⅵ)ions from aqueous solution.The kinetics and thermodynamics of their adsorption were measured using batch experiments.The results show that the kinetics of adsorption follows well the pseudo-second order equation,indicating that the uranium adsorption by the modified corncob is mainly chemisorption. The Langmuir,Freundlich and D-R isothermal adsorption models were used to relate the equilibrium data,finding that Langmuir isotherm of monolayer adsorption is better fitting them,pointing out that the adsorption mainly occurs on surface active sites of modified corncob.The values of apparent activation energy E_a and average adsorption energy E_s support also the suggestion that adsorption of U(Ⅵ) on modified corncob is mainly chemisorption,although some physical adsorption can not be got rid of.The thermodynamic parameters(ΔH,ΔS and ΔG)calculated from the adsorption isotherms at various temperatures indicated that the adsorption of U(Ⅵ)on modified corncob is an endothermic,spontaneous process and more favorable at higher temperature.

In this paper,a model of technological process is to be constructed for Huadian-type oil shale retorting system using Aspen Plus software,and the physical parameters in the model came from oil shale samples of Gonglangtou mine in Jilin province.The overall thermal efficiency and power consumption of the main auxiliary device of this system were analyzed by calculating the mass balance and thermal balance of the simulated oil shale retorting system and by simulating different heating temperature conditions of two-stage heater.The results show increase of heating temperature for semi-coke combustion furnace can reduce consumption of fuel gas in gas combustion furnace.Furthermore,rise of heating temperature for gas combustion furnace can cut down flow of hot circulating gas and reduce loss of condensation heat for retorting gas and oil vapor.So,the overall thermal efficiency of whole retorting system can be improved by simultaneous increase of heating temperature in the two-stage combustion furnace,and its economic benefit can be enhanced by increase of foreign supply amount of gas and semicoke.

Magnetic Fe-containing ordered mesoporous carbons(Fe/OMCs)with high surface area and large pore volume provide an easy and effective way for the treatment of dye in waste water.Fe/OMCs were synthesized by the soft-template route,wherein phenolic resin was used as a carbon precursor,triblock copolymer F127 as a template agent,tetraethylorsilicate(TEOS)as a silica precursor and hydrated iron nitrate as an iron source.The effects of Fe(NO₃)₃?9H₂O loading on the morphology,structural parameters,and magnetic properties of the Fe/OMCs were evaluated by X-ray diffraction(XRD),N₂ sorption analysis,transmission electron microscopy(TEM)and physical property measurements.By using methylene blue(MB)as model dye,the adsorption of MB on the obtained Fe/OMCs was investigated.The experimental results showed that the ordering,specific surface area and total pore volume decreased with the increase of Fe(NO₃)₃?9H₂O loading.The Fe/OMCs had fast adsorption ability for MB.The adsorption of MB on the obtained Fe/OMCs followed the Sips adsorption equation and the corresponding parameters were obtained.

To obtain magnetic nanoparticles (NPs) with good water dispersibility, Fe₃O₄ nanoparticles were synthesized by thermal decomposition of the iron(Ⅲ) acetylacetonate (Fe(acac)₃) in poly(ethylene glycol) (PEG) containing poly(vinyl pyrrolidone) (PVP) of different molecular weight as modifying agents.The samples were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), superconductivity quantum interference device (SQUID), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and particles & zeta potential analyser.The stability of Fe₃O₄ nanoparticles dispersed in physiological saline and physiological buffers was investigated.The prepared Fe₃O₄ nanoparticles had high crystallinity, and showed superparamagnetic behavior at 300 K with higher saturate magnetization.The surfaces of Fe₃O₄ nanoparticles were modified by PEG and PVP which provided good water dispersibility.The Fe₃O₄ nanoparticles revealed high dissolubility and stability in physiological saline and physiological buffers.The surfaces of Fe₃O₄ nanoparticles were electrically neutral in water, and steric hindrance effect of the surface modified layer might be the main reason for high dispersion stability of the prepared nanoparticles in aqueous solution.

In order to study the influence of water and weak acid on the thermal hazard of cumene hydroperoxide(CHP),the thermal decomposition of CHP and CHP mixtures with different contents of water and weak acid and different pH of weak acid in the air was studied by C600 calorimeter.The corresponding kinetic and thermodynamic parameters based on experimental data were obtained,and the Semenov model was used to calculate the self accelerating decomposition temperature (SADT).The results show that small amounts of water and weak acid reduce the initial exothermic temperature,peak exothermic temperature and activation energy.The pH of weak acid also affects thermal hazard of CHP.As the pH of weak acid decreases,it is easier for the CHP decomposition reaction to occur.Calculated SADT of CHP is 84℃.The comparison on the calculated SADT results indicates that small amounts of water and weak acid reduce the SADT of CHP,and at lower pH of weak acid,the SADT also decreases.