A molecular thermodynamic model for the chain-like Yukawa fluid is derived by using statistical mechanics of chemical association. The Helmholtz function contains two terms, a reference term arising from the hard-core Yukawa fluid, and a bonding term due to the bonding of hard-core Yukawa segments. The cavity correlation function is obtained from the Monte Carlo simulation data of compressibility factors of dimer Yukawa fluids. Using this cavity correlation function the equation of state of chain-like Yukawa fluid is expressed analytically.The predicted results of compressibility factors are in excellent agreement with computer simulation of 4-mer and 8-mer chain-like Yukawa fluid for λ=1.8 and λ=3.0.The results are better than that of Wang and Chiew. Meanwhile the equation of state is simpler than SAFT-VR.

A program for mixing calculation was developed based on the commercial CFD code CFX4.It was used in the numerical study of mixing process of a single Rushton turbine in the stirred tank. Coupled and segregated solutions of momentum and mass equation were adopted. The calculated concentration response curve was consistent with the literature data. Both solutions predicted the same change of mixing time,but the value of mixing time from coupled solution was shorter than that from segregated solution.Coupled solution needed much more computational efforts than segregated solution.The mixing process relied on the flow field used for mixing calculation. The value of mixing time was dependent on the position of detection and feeding.When the tracer was fed near the impeller, the mixing time was the shortest.When it was fed near the bottom of the tank, the mixing time was the longest.

Numerical modeling is performed to investigate the mixing effects of flow in pipes consisting of bends with same or different curvatures.The mixing at the transition area between different bends will cause disturb ance in fluid flow. Flow rate (case change of Reynolds number) and curvatures of the bends (case change of Dean number) will take different effects in the development of secondary flow. The results show that a change in Dean number created in varying curvature bends cause significant influence on the flow.

The finite-volume method for radiative transfer is applied to two-dimensional rectangular enclosures.The results are compared with those obtained by the existing solutions.It shows that the result obtained by finite-volume software is reliable.According to the analysis，different phase function and scattering albedo have effects on the temperature profile.Meanwhile, the temperature distributions in the two-dimensional rectangular media with linear anisotropic scattering and isotropic scattering phase function are calculated respectively.The results show that there is a definite zone for the different extinction coefficient and scattering albedo,which satisfies the given precision.Therefore, when the two parameters are chosen in this zone, the anisotropic scattering media can be simplified to isotropic scattering media, and it makes the model easier.

Micron size mechanical devices are becoming more prevalent, both in commercial and in scientific applications,such as in the area of micro heat exchangers, micro sensors, micro actuators, Micro-Electro-Mechanical System(MEMS) and so on. Computational modeling can provide effective predictive capability for momentum transfer in mocrodevice before hardware fabrication.In this paper a theoretical analysis for laminar flow in the microchannels of [HJ*4/9]arbitrary shape in slip flow regime is presented. The momentum equation with the one-order slip boundary conditions is solved by using a computation-oriented method of the orthonormal function analysis for the fully developed laminar flow of the incompressible fluid in the microchannels. The dimensionless velocity profiles and the friction factors in the microchannels are obtained. As an example, the flow performance is calculated with the rectangle microchannel and compared with the experimental results. The agreement between analytic solutions and existing experimental results shows that in a definite extension of Knudsen number the traditional Navier-Stokes equations with the slip boundary conditions can govern the gaseous flow mechanisms in microchannels, and the orthonormal function method is available to study the slip flow characteristics in the microchannel of arbitrary shape.Slip flow occurs at the wall of the microchannel in the slip flow regime.The slip velocity of fluid on the channel wall increases as the Kn number increases,and the friction coefficient is substantially reduced for slip flow compared with the no-slip flow. The aspect affects the dimensionless drag coefficient at a fixed Kn number in the rectangle microchannel.

The longitudinal wall heat conduction, the nonuniformity of temperature field and fluid flow distribution could be coupled and could cause the deterioration of heat exchanger efficiency, especially for the compact heat exchanger. The effect of fluid flow nonuniformity on heat exchanger efficiency is the most important one among the three because it can intensify longitudinal wall heat conduction and the maldistribution of interior temperature. The complicated interior structure and many other factors can cause fluid flow nonuniformity in the plate-fin heat exchanger. The objective of this paper is to investigate the effect of different header configuration on the fluid flow distribution in the plate-fin heat exchanger. It is found that the effect of header configuration on flow maldistribution in the plate-fin heat exchanger is mainly shown in the vertical direction of gross flow passage. To change header configuration can make the flow distribution more uniform in the vertical direction of gross flow passage. Optimized configuration of header can effectively improve the flow distribution in the plate-fin heat exchanger.

The phenomenon of condensation of low-pressure vapor in a horizontal tube was studied.The interactions between heat flux density,vapor pressure,vapor velocity and the coefficient of heat transfer for filmwise condensation in the tube,the overall coefficient of heat transfer were investigated.The relationships between heat flux density and the overall temperature difference,the difference in temperature and pressure drop at the entrance and the exit of the vapor were investigated as well.Analytical relationships were obtained for calculation of the coefficient of heat transfer for filmwise condensation in the tube.The deviation between the experimental value and the calculated value was lower than ±15%.

On the basis of combination of droplet population,by taking the initial location as marginal distribution,the velocity and the diameter as conditional ones, a probability model describing the motion characteristics of droplets in cross rotating packed bed was proposed,and a three dimensional droplet motion model was developed. The calculated result from the model was verified by experimental measurements.

In this paper a totally new microwave-assisted extraction apparatus is designed to develop the new technique——microwave extraction.The cylinder-shaped extractor has a concentric inner partition,which forms an annular space for the fluid to receive microwave energy from the inside of the concentric partition. In order to know whether it is fit for the demand of continuous production,the LDA (Laser Doppler Anemometer) method is used to measure axial velocity and tangential velocity of the fluid in the apparatus. The axial velocity and tangential velocity of different layers in the annular space are obtained, as well as the axial velocity at different rotation degrees θ. The effect of flow rate is also discussed. 2-D and 3-D figures are drawn by software Matlab to illustrate the data measured by Dual PDA. Another software PHOENICS is used to simulate and analyze the flow field in the microwave extractor. Compared with the experimental data, the result of PHOENICS is reliable.Improvement of flow field is achieved by revising the apparatus design with a conical inner partition.

Referring to the specificities of the flow field with anisotropic property,the group theory of particles is used and the general constitutive equation of Reynolds stress proposed by Shih is introduced to build a realizable algebraic stress model. The diffusion theory of vortex is also used in the model to set up the diffusion equation of gas, and the barrier caused by the variation of flow patterns inside the flow field is resolved. With the numerical model, the characteristics of the “cold state” flow field in the quench chamber of coal slurry gasifier are predicted. The relations of the maximum descending depth and void ratio of gas with outlet momentum are further discussed.

A new computation method of Kolmogorov entropy based on the concept of general entropy was used to extract the complexity of time series in order to characterize the oil/water two phase flow patterns,and was proved reliable by an example of the Mackey-Glass Equation.The characterization results of Kolmogorov entropy for the experimental fluctuating signals of conductance are analyzed, and the sensitivity of the Kolmogorov entropy to flow pattern variations is confirmed. Also the results correspond to the complex power spectrum characteristics and characterization results of the fractal and chaos which was presented in the authors’ previous study. It shows that Kolmogorov entropy is a sensitive “indicator” of oil/water two phase flow pattern variations.

The ferrite catalyst synthesized under magnetic field has a crystalline structure of spinel type Fe_xO,with 0.75≤x≤0.85.The magnetic field can impel more Fe²⁺ to occupy the octahedral site,so Fe/O atom ratio, the residual magnetron and the crystal defects are increased.As a result,the spinel ferrite catalyst can increase the catalytic redox reaction rate such as decomposition of H₂O₂.

In this paper, a novel experimental technique for gas-liquid-solid reaction was developed to study kinetics of p-xylene oxidation under the condition of high temperature and pressure. Methyl and aldehyed oxidation during the p-xylene oxidation process was studied according to radical reaction mechanism and recycling of the cobalt-manganese-bromide catalyst. The coupling effect between catalysts and radical reactions was analyzed in detail, and a kinetic model was developed based on the proposed mechanism.Model parameters were determined by data fitting.The model agreed well with the experiments.

Based on the population balance model and ΔL law, a crystal growth rate equation was deduced, and an apparatus was built up and used to measure the on-line dynamic transmittance and concentration for the batch cooling crystallization process. The KNO3 in water was tested and its linear growth rate was also calculated with dynamic transmittance and concentration. When crystal growth was dominant in the later stage of crystallization, the KNO3 crystal growth kinetic parameters (kg and g) in the empirical model were obtained by correlating its linear growth rate with the relative supersaturation,and agreed well with those in the literature.For the spontaneous crystallization process, the nucleation and crystal growth stages could be identified qualitatively with the dynamic transmittance, supersaturation and the deduced linear growth rate equation. The growth rate equation and its solution in this paper would be further used for mechanism demonstrations and/or applications of the batch crystallization.

The bubble dispersion behavior in the liquid on a sieve tray is studied on the basis of Kolmogoroff’s isotropic turbulence theory.The bubble breakage rate model is derived from the mechanism of deformation of bubbles bombarded by the turbulent eddies and the probability of bubble breakup,and the bubble coalescence rate model is developed through comparison between the contact time of bubbles and the time required for bubble coalescence.The dynamic bubble population balance model is established on the basis of comprehensive analysis of the effect of breakage and coalescence on bubble size distribution in the bubbling liquid,and is solved numerically to give bubble population density which is analogous to the lognormal distribution function and is in agreement with the experimental results.The population balance model has been proved to be useful for predicting the gas-liquid interfacial area,which is important to the design of distillation tray and optimization of distillation operation.So it has good prospects for the accurate simulation of the dispersion characteristic of the multiphase turbulent system in processing engineerinng.

Four rules of retrofit of heat exchanger networks (HENs) are proposed through qualitative analysis of HENs：①The controlled variables (CVs)are sensitive to the manipulated variables (MVs)；②The number of the selected MVs should be less than or equal to the number of the CVs；③A set of the controlled variables possess a set of the manipulated variables, and the changes in the CVs induced by the changes of disturbance variables (DVs) can be adjusted and their increments are equal to zero at the end by the adjustment of the selected MVs；④If the existing HEN is optimal in normal operating condition, and the minimum change of the existing HEN during retrofit makes the HEN suitable for present or multi-period operating conditions, then the retrofit cost may [HJ]be the minimum, so the retrofitted HEN may be optimal. The mathematical models and solving method of retrofit and control of HENs are established based on the rules and sensitivity analysis of HENs. The procedure of the retrofit of HENs is given. It is established by the calculation of the examples and practical use that the method is correct and available.

This paper deals with the formulation and solution of a class of mixed-integer nonlinear programming (MINLP) problems, applied to optimal process synthesis in a modular environment. The proposed algorithm avoids doing a lot of calculation of the model equations. It makes the size of MINLP small. The MINLP algorithm consists of solving alternation sequences of MILP master problem and NLP subproblems, whose sizes are remarkably reduced. The NLP subproblem provides the linearization information of the nonlinear constraints that relate the output variables to input variables specified explicitly. The HDA process is taken as a case study of the capabilities of the process synthesizer. It proves that the proposed solution deals with complex MINLP problems satisfactory.

A theoretical model for hollow-fiber membrane partition chromatography of amino acid was established by taking into account the dissociation of amino acid and mass transfer in the stationary phase immobilized in the membrane. With all the parameters determined independently, the model simulated very well the experimental chromatograms of a model amino acid, L-tryptophan, indicating the applicability of the model. Theoretical analysis also revealed the dependence of mobile phase pH on local amino acid concentration. In addition, the experimental and simulation results showed that mobile phase ionic strength had significant effect on the retention and peak shape of amino acid. Using a gradient elution mode can improve the peak shape and increase the column efficiency.

The microstructure change in the dynamic calcination and sintering of carbide slag is studied at a high temperature of 1200℃ on a tubular electric furnace with X-ray powder diffractometer,mercury intrusion porosimeter and scanning electronic microscope(SEM). It is found that the main crystal composition of raw carbide slag, Ca (OH)₂, turns to CaO after calcination at a high temperature. The mean pore diameter of carbide slag increases and the specific surface area decreases all along with increasing experimental time, while the total pore volume firstly increases and then decreases. After intense sintering, the surface of carbide slag is composed of many swelled dumbbell-like CaO particles,similar in particle diameters and arrayed in order.

The combustion behavior of petroleum coke is investigated by using a pulse-differential fix bed reactor in order to understand the combustion kinetics of petroleum coke.Two representative petroleum cokes are examined with particle sizes of 150—280μm and 60—70μm between 800℃ and 950℃ burning in pure oxygen and air. The results show that the combustion is very unstable and can be divided into three stages (Ⅰstage,Ⅱstage and difficult-combustion stage) because of the complexity of petroleum cokes compositions. For particular features, petroleum coke is very difficult to burn off. Through tests, the effective exhausting rates of the two types of coke at different temperatures are obtained. In this paper, the reaction order(n)is assumed to be 1, and the combustion kinetics parameters, the molar ratio of CO/CO₂ in the flue gas of different stages are obtained.

To evaluate the hydrogen adsorption performance of the typical carbon based adsorbents from the aspect of adsorption heat, nonlocal density functional theory（NDFT）,Carnahan-Starling, MBWR equations of state and the mean-field theory are used to determine the bulk density and density profiles of hydrogen molecules within the adsorption space.The adsorption density is obtained from the weighted average of the density profile calculated with NDFT in the width (or radial) direction of adsorption space. The maximum physical adsorption capacities of hydrogen molecules in the close-packing state are used to calculate the isosteric heat of adsorption. The adsorption isotherms at 77—297K with a step of 10K and 1—10MPa with a step of 1kPa are first determined,then,the isosteric heat of adsorption on three typical carbon based adsorbents are ascertained by the adsorbed phase volume and the bulk gas volume in thermodynamic equilibrium during the adsorption process.From the comparisons among the results from the NDFT calculation and experimental data,not only the isotherms of hydrogen adsorption on carbon [HJ]nanotubes have similar figure to those of activated carbon,but also the values of isosteric heat of adsorption on these adsorbents are within the same range.Finally,the measure that the accurate hydrogen adsorption experiments on pure carbon nanotubes should be carried out to verify their physical adsorption performance,and the effective measures for the management of adsorption heat should also be emphasized while considering the cryogenic adsorption of hydrogen in carbon nanotubes.

Using a synthetic method designed and installed with computer monitor on line, the solubility values of melamine in water were determined and were in good agreement with traditional analytic method data. The solubilities of melamine in alcohol and dimethyl sulfoxide were also determined with this method. The experimental data were correlated with Apelblat equation.

Numerical analyses were made for combined heat and mass transfer by natural convection on a vertical surface. Both boundary layer equations and full equations of momentum,energy and mass were solved by using a control-volume formulation, and the results were compared in detail for velocity, temperature, concentration, Nusselt and Sherwood number profiles. The discrepancies of boundary layer analysis from full equations under different values of buoyancy ratio B were systematically investigated for Pr/Sc>1,Pr/Sc<1 and Pr/Sc=1. The value of buoyancy ratio B_min predicted by boundary layer equations at the minimum heat and mass transfer rates was consistent with that of full equations solutions. The boundary layer analysis did not predict the velocity, temperature and concentration profiles accurately at Pr/Sc≠1 in the region near B_min. The maximum deviations of Nusselt and Sherwood numbers occurred near B=-1, and they were 40 percent and 21 percent respectively for Pr/Sc=3.18, and 40 percent and 35 percent respectively for Pr/Sc=0.14. The boundary layer equations might predict the heat and mass transfer rates rather accurately except the region near B_min, however, the deviation tends to increase with increasing ｜B｜.

The characteristics of pressure drop and heat transfer of air across the corrugated tubes with three values of row number were investigated experimentally by measuring the average heat transfer coefficients and friction factors. The results were compared with that of the corresponding same row number smooth tube bundles.The corresponding correlation for the Nusselt numbers and Euler numbers vs the Reynolds numbers for the corrugated tubes were obtained. It was found that the corrugated tube bundles will reach the developed state at a smaller row number compared with the smooth tube bundles. Within the range of Reynolds numbers of the present work, the heat transfer coefficients and the friction factors of the corrugated tube bundles were 13.6%—29.2% and 3.2%—60.0% higher than those of the smooth tube bundles respectively.

p-Xylene liquid phase oxidation at different temperatures of 186—197℃ was carried out to investigate the temperature effect. The kinetics model developed in Part（Ⅰ） was used to fit the data.The rate constants obtained can be well represented by the Arrhenius relationship.The obtained activation energy of different reaction steps ranged from 54 kJ&#8226;mol^-1 to 93kJ&#8226;mol^-1, among them the activation energy of p-toluic acid to 4-carboxybenzaldehyde step was the highest (92.8kJ&#8226;mol^-1) and that of 4-carboxybenzaldehyde to terephthalic acid step was the second(84.9kJ&#8226;mol^-1).They are remarkably higher than the values of the other steps (54.94—67.53kJ&#8226;mol^-1). This fact showed that oxidation of the second methyl group of p-xylene was more sensitive to the temperature variation than the first one.

Extraction of p-aminophenol by D2EHPA, Alamine336 and their mixture were studied under various initial pH ranging 3—10.Both extractants extracted neutral form of p-aminophenol. When the pH value was between pK_a1and pK_a2,a maximum distribution ratio appeared. This pH dependence can be explained by varying the molar fraction of neutral PAP with pH value. The mixed solvent of D2EHPA and Alamine336 had a higher distribution ratio than either Alamine336 or D2EHPA alone, i.e.,the extraction of p-aminophenol with the mixed solvent showed the synergistic effect,and the molar concentration ratio of D2EHPA to Alamine336 at 1∶1.5 was the synergistic point.

A genetic recombinant hEGF producer E.coli JM101 was immobilized in polyurethane foam matrix and a three-phase fluidized-bed bioreactor was used to produce human epidermal growth factor (hEGF).The results indicated that polyurethane foam is an adequate immobilization material. With the addition of polyurethane foam matrix, the free cell density, plasmid stability and hEGF productivity were higher than those without the foam matrix, respectively. The two-stage culture of the immobilized cells was further carried out, in which, the first stage was performed in a three-phase fluidized-bed bioreactor for cell growth and the second stage was performed in bubbling bed for product expression. At a dilution rate of 0.2h^-1, after continuous cultivation for more than 60h, the free cell density and product expression were maintained relatively stable. The hEGF productivity was still higher than 140mg&#8226;L^-1 and the fraction of plasmid-carrying was more than 27%. The hEGF productivity in two-stage process was higher than the batch process.

In this paper, methyl 2-(6-methoxy-2naphthyl)propionate（naproxen）was asymmetrically hydrolyzed by candida rugosa lipase in pseudo-eutectic and organic solvent systems. The result showed that S-(+)-naproxen with enantiomeric excess more than 95% could be obtained with commercially available candida rugosa lipase in both systems. In organic solvent system, 24.1% reaction conversion of naproxen methylester could be obtained after 96 hours, while in pseudo-eutectic systems, the conversion was 40.1% after 72 h. Furthermore,only one fifth organic solvent volume was used in pseudo-eutectic systems.Compared to organic solvent systems, the effects of lipase concentration, substrate and water concentration, and several different kinds of adjuncts on reaction conversion were studied in pseudo-eutectic system. Also,under the optimium pseudo-eutectic enzymatic reaction conditions, the reaction conversion was 45.8%.

Preliminary experimental studies on evaporation of Gengnian’an liquid extract of traditional Chinese medicine(TCM)with vapor-liquid-solid flow boiling technique were carried out in a transparent natual circulating three-phase evaporator. The height of the heating tube is 2.5m with an inner diameter of 0.038m and an outer diameter of 0.045m. The cylindrical solid particles with a diameter of 0.0025m and a length of 0.0025 m is made of a kind of inert material that does not interact with the liquid of Gengnian’an. The heat energy for the evaporator was supplied by the electric heating system. It was shown that the presence of the solid particles could enhance the process of heat transfer since the heat transfer coefficients in vapor-liquid-solid boiling system was about 1.5—2.0 times that of the vapor-liquid boiling system when the heat flux was constant. On the other hand,fouling prevention and a lower wall temperature were also seen when the solid particles were present. The quality of concentrated liquid of TCM would be improved.

Petroleum coke has high nitrogen and high sulfur.Its combustion will cause pollution to atmosphere. This paper studies the characteristics of SO₂ emission and NO_x emission during the combustion of petroleum coke and desulfuration processes and discusses the effect of limestone on NOx emission. Considering desulfuration, denitration and operating costs of boilers, there is an appropriate Ca/S mole ratio for the combustion and desulfuration of petroleum coke. It provides a practical basis for industrial utilization of petroleum coke.