For improving the correctness rate of dynamic fault diagnosis, a new artificial neuralnetwork——wavelet-sigmoidal function based neural network(WSNN) is proposed after introducing wavelet transforms, and is successfully applied to dynamic process fault diagnosis. The training algorithm is also presented based on its error surface properties. In this paper, WSNN is compared with the traditional sigmoidal function based neural network (SBFN) in terms of the correctness rate of fault diagnosis.

Limits of superheat of binary liquid mixtures of n - pentane etc. under different pressures and several compositions were measured. Theoretical analysis and predictions on the basis of thermodynamics and kinetics were made. Methods of concise calculation were proposed.

In this paper, the turbulent heat transfer in the horizontal helical coil is investigated in detail in a wide range of experimental parameters. The experiment shows that the enhancement of heat transfer in the coil results from the effect of turbulent flow and secondary flow. If the Reynolds number becomes larger, the secondary flow gives less contribution to the enhancement heat transfer, and then the average heat transfer coefficient of the coil is closer to that in straight tubes under the same condition. The cocal heat transfer coefficients on the cross section of the coil are not uniformly-distributed. The cocal heat transfer coefficient on the outside is three or four times period which is half of the average heat transfer coefficient. A correlation is proposed to calculate the heat transfer coefficient distribution on the cross section. The average heat transfer coefficients on the cross section change period along the direction of the fluid flow.

This paper develops an equation of state method to predict vapor-liquid equilibria (VLE)of mixtures using only pure component parameters. Based on the mixing rule combined with excess Gibbs free energy gE, a model of infinite dilution activity coefficients MOSCED is used to predict the interaction parameters of the activity coefficients equation which calculates the gE. This makes the cubic equation of state into a predictive one for the VLE calculations over a wide temperature and pressure range. Like the UNIFAC group-contribution equation of state, it performs satisfactorily in the VLE prediction of systems containing polar components , including VLE under high pressures.

Due to hydrogen bond, strong association exists in the hydrogen fluoride vapor which causes the thermodynamic properties deviate largely from ideal gas behavior. A thermodynamic model was proposed for systems containing strongly associated hydrogen fluoride. This model considers both chemical and physical interactions between monomer and oligomers. SRK equation of state was modified to describe the phase behavior of systems containing hydrogen fluoride.

This paper presents an improved mixed integer nonlinear programming (MINLP) model for heat integration of simultaneous synthesis of heat exchanger network with the process. The model can deal with nonconvex nonlinear objective and constraints which can be solved with genetic algorithm for MINLP problems. A heat integration synthesis example of a distillation sequence with a heat exhanger network is given to illustrate the capabilities of the improved simultaneous model which can be more realistically formulated as an MINLP problem.

In this paper, a soft-sensor model of the membrane efficiency is given by using the mixed modelling method based on artificial neural networks. Based on this soft-sensor model, the complex method is used to calculate the membrane efficiency on-line under some constraints. Some problems in the application of artificial neural networks and the complex method are also discussed.

The problem of column simulation and optimization is studied in this paper. Equations for column simulation are derived based on strict thermodynamic properties calculations. Three kinds of optimization problem formulations are constructed and the reduced version of simultaneous method which takes advantage of the specialized structure of mathematical model for column simulation is preferred. Nonlinear constrained optimization is implemented with sequential quadratic programming codes. It is emphasized that the open structure of the simultaneous method is suitable for all simulation, and optimization problems. The differences lie only in the definitions of free variables and equality constraints. Example calculations show the performance and flexibili-ty of the proposed method.

Based on classify analysis and conclusive comments about various kinds of drying model , a rigorously formulated and quite comprehensive theoretical model has been established to describe heat and mass transfer during constant rate and falling rate periods in convective drying of porous media. The concept of iterative correction is introduced and the corresponding numerical method is developed for the moving boundary problem in numerical simulation of drying process. The calculation results for drying of bricks show that the present model is more precise than other models.

Fractal dimension scaling relationship of desorption was deduced according to the balance of the Gibbs free energy. The results show that the relationship is accordingly from the conditions of fractal existence, and it avoids some invalidates of traditional adsorption fractal BET relationships. It has been proved that the relationship is reliable and suitable for samples not only with small surface area but also with large surface area. The method of data processing is convenient.

The study on hydrodynamics and mass transfer performance is carried out in a 25 mm diameter continuous countercurrent supercritical fluid extraction spray column. The range of experimental pressure is from 8 to 14 MPa and the temperature is 35℃. The testing systems arecarbon dioxide-isopropanol-water and carbon dioxide-ethanol-water. A model for describing two-phase flow in the supercritical fluid extraction spray column is obtained. A new model based on two film theory for calculating overall volumetric mass transfer coefficient is developed. Both of the two models match experimental data well.

Hydrodynamics and mass transfers are discussed both within the dimpled liquid film and along the gas liquid interface between two bubbles, and a model of coalescence is developed, in which the effects of London-van der Waals forces and electric double layer forces are taken into account.The predicted results of the present model match previous experimental data well.

Two assumptions were put forward as a result of analysis of the flow curves of hy-drolyzed polyacrylamide-salt solution. Based on these, the relationships between the constantsγ1/2 and Pα in Meter s equation and zero-shear viscosity η0 were established, and therefore a universal Meters equation relating apparent viscosity ηa with shear rate γ was deduced. The equationand the MHS equation in part ( Ⅰ ) and the equation (4) in part ( Ⅱ ) can be used to simulate theapparent viscosity for the system and good results were obtained.

Sulfur dioxide oxidation catalyzed by activated carbon in a slurry reactor (at room temperature and atmospheric pressure) was studied . The postulated reaction mechanism was indirectly tested by varying the composition of oxygen and sulfur dioxide in inlet gas and by measuring the volume-averaged oxidation rate of sulfur dioxide of small particles (the resistance of mass transfer is of minor importance), and furthermore, the model parameters were evaluated by varying the concentrations of slurries of activated carbon , the sizes of particle as well as the reaction temperature.

The kinetic performance of isothermal piston flow desulfurization bed was studied on basis of the Equivalent Grain Model suggested by the authors that was used to discribing apparent kinetics of desulfurization with zinc oxide particles. The representation of both sulfur distribution curve and break-through curve was given. The effect of temperature, flow rate and concentration of sulfur compound on these curves was analyzed. After analysis of results obtained in a commercial scale desulfurizing bed of metal oxides, like zimc oxide, iron oxide, it was verified that the Equivalent Grain Model could be preferably used to describing the desulfurization process of metal oxides.

Kinetics of single-substrate enzyme-catalyzed reactions in batch reactor (BR) using thermokinetic method were investigated , and the influence of product competitive inhibition on these models was discussed in details. Catalase-catalyzed decomposition of H2O2 and arginase-catalyzed hydrolysis of L-arginine were studied by microcalorimetry, and the reliability of this thermokinetic method applied to the study of kinetics of single-substrate enzyme-catalyzed reactions in BR has been verified by the experimental data.

The morphological change of Penicillium chysogenum during the penicillin fermentation cycle was studied. The shear environment in the fermentor was found to influence microbial morphology and to be closely related to the mean pellet diameter and effective length of mycelium during the middle and late periods of fermentation. Based on flow field test results in laboratory-scale stirred vessels, a number of parameters for describing the total shear environment in the fermentor were evaluated for their reliability, with the morphological change of P. chrysogenum being used as contrast. It was found that the morphological response to high shear environment exhibit an "impression-attenuation" mechanism, from which a concept of characteristic shear power can be deduced. An appropriately high shear environment is required for penicillin fermentation. With the concept of characteristic shear power, the design and operation of hydrofoil impeller can be implemented to provide a proper shear environment for microbial growth and metabolism for synthesis of the object product.

Isobaric VLE data of three binary systems (benzene-lsopropylbenzene,isopropyl-benzene-diisopropylbenzene and benzene-diisopropylbenzene) under 0.053MPa were determined with the modified Dvorak-Boublik still and were correlated by using Wilson equation. Thermody-namic consistency test indicated that the experimental data were reliable.

A new type of rotary hydrocyclone for oil-water separation was presented. Its performance was studied by using blend oil-water and kerosene-water systems. The results showed that this rotary hydrocyclone was superior to the static one. Its maximum efficiency was raised significantly. Its operating range was 2 times of that of the static one. Its overflow rate at maximum efficiency was about 1.25-2 times of that of the static one.

The 3-D flow field with a central air core in a hydrocyclone is simulated by K-ε. turbulent model in the present paper. The model constants C1, C2, and Cμ are modified because ofthe anisotropic character of turbulent viscosity in the hydrocyclone. The numerical prediction has been tested against the LDA measurement results and has been found to perform well. Based on the prediction, the flow field and the pressure field as well as the distribution of the dissipation rate of the turbulent energy are discussed. The study shows that an important approach to reduce energy dissipation in the hydrocyclone is to improve the flow pattern in the cylindrical section.