Aiming at the direct calculation of two-dimensional model of effectiveness factor for a cylindrical catalyst pellet，this paper presents the construction of approximate analytical method and the corresponding accuracy test．A polynomial form is chosen to correlate the relationship between effectiveness factor and Thiele modulus(φ),where (1／tanhφ-1／φ）／φ is the element considering the features of two-dimensional problem.The needed values of parameters in calculation are provided by solving two-dimensional diffusion-reaction equations under extreme conditions.The accuracy is tested by first-order reversible reaction,steam-shift reaction and methanol decomposition reaction,and the results show that the approximate analytical method is not only simple but also has the same accuracy as the finite-element method or orthogonal collocation method.Further,it can be used in the problem of surface poisoned catalyst pellets．

To solve the problem of large system energy integration,which can not be solved by traditional algorithms,a new algorithm named IGA/SA(improved genetic algorithm/simulated algorithm)is Presented in this paper.General genetic algorithm is improved by using OCX and EC factors.Moreover,the improved genetic algorithm is combined with simulated annealing effectively to avoid the common defect of early convergence.IGA/SA was used to solve a 110 stream problem.Good result was achieved to help the total process retrofit.

The crystal structure and stability of H type gas hydrate were studied by using molecular dynamics simulation method for the first time.Site-site pair radial distribution functions for H type gas hydrate were determined The influence of temperature and guest molecule on the stability of crystal structure was investigated by computation of translational mean square displacement,orientational mean square displacement and orientational autocorrelation function for water molecules. It is found that the stability of hydrate crystal depends upon the guest molecule enclathrated in the cavities.On the other hand，the influence of temperature on the stability of crystal structure is insensitive.

The problem of process monitoring was defined by using the principle of pattem recognition.After the analysis of time-frequency character of discrete wavelet transform,a means to extract the features of frequency band in real process measurement siwgnals based on discrete wavelet transform was stru ied．Meanwhile a new pattem classification algorithm was proposed to induce the relationship of the extracted features and corresponding process conditions.The induction result was applied to process monitoring,which verified the feasibility and effectiveness of the method.

The paper deals with the experimental study on the effect of maldistribution on the break through in a technical column of activated carbon.The effect of maldistribution are described with a 2D model．The result shows that the effect of maldistrbution can not be neglected even when Db/dp=90．The difference of breakthrough between the wall-near zone and the center of the fixed bed can be 4 hours.The calculated results are in good agreement with the experimental ones.

The effect of polymeric additives PAM on the time-correlation structure of turbulence in the cenerline region of a rectangular pipe was investigated experimentally with a 2-dimensional laser Doppler velocimeter.It was found under the condition of drag reduction that the time-correlation charactenristics of turbulent fluctuating velocities showed obvious changes.At the same Rynolds number,all the time scales of longitudinal autocorrelation,transversal autocorrelation and cross-correlation increased with the additive concentration. This trend of change is consistent with that of drag reduction ratio.A new phenomenon,the time-effect of cross-correlation coefficient at the centreline,is reported for the first time．These results provide further theoretical investigation with new experimental facts,and support the role of viscoelasticity in the mechanism of drag reduction.

Stability analysis of fluid catalytic cracking units(FCCU)is an important part of operation analysis,process design and process control.For the FCCU with a highly efficient regenerator,the regenerator is composed of two stages that are characteristic of a fast fluidized bed and a bubble fluidized bed.Regenerated catalyst from the second stage of the regenerator circulates into the bottom of the first stage as well as the bottom of the riser reactor.The influence of the reactor and the regenerator on each other should be considened together in the stability analysis.Because of the complexity of the unit,the conventional technique of stability analysis such as heat generation and removal rates analysis for the CSTR with exothermic reaction is not suitable．After linearization of the dynamic mechanistic model of the FCCU with a highly efficient regenerator,stability theory is applied to the linear state space models obtained．Under the control of the inventories of the stripper and the second stage of the regenerator,the FCCU’s reactor/regenerator section is stable with in a wide range of operation conditions,because all the real component of eigenvalues of linear state space models are negative.

Experimental research is made on compound heat transfer enhancement by combination of inlet axial vane swirlers with left spirally corrugated tube,right spirally corrugated tube and symmetrical cross spirally corrugated tube,respectively.The experimental results of the tube side friction and heat transfer are given,and the corresponding friction and heat transfer dimensionless correlations which reflect the in fluence of the compound attack angle are obtained.Moreover,the thermodynamical performance curves are presented to show that given the same pump power and heat transfer area,the heat transfer rate Q of the combination in the opposite spiral direction is always higher than that of the combination in the same spiral direction,and within the experimental range,the value of Q can be increased by 90%,compared to the smooth tube．

A general strategy is developed for controlling the chaos in the distributed parameter sysytems without underlying model equations．The Karhunen-Loeve procedure is utilized to decompose the spatiotemporal pattems in the system and identify the dominant spatial modes with the first return mapping in the Poincare section to obtain the setpoint.The linear feedback on the deviation of dominant spatial structure between the setpoint and the measured one is used to stabilize the system.A non-isothermal catalytic reactor undergoing period-doubling and an isothermal bioreactor undergoing quasiperiod-doubling are taken as two examples and the performance of the proposed strategy is demonstrated via numerical simulation.The simulation results illustrate that this methodology works satisfactorily and the system can be stabilized into period-one.The controlled dynamics is indeed the embedding unstable periodone orbit for the period-doubling chaotic system while some offsets between the controlled dynamics and setpoint are existing for the quasiperiod-doubling chaotic system.

In order to afford an insight into the problem of bubble mass transfer,this paper experimentally and theoretically deals with the effective factors of near-interfacial mass transfer of a single bubble.The micro real-time holographic interference results showed that near-interfacial concentration is a stable value of dynamic mass transfer.It was affected by relative velocity,bubble dianmeter,temperature,pressure,etc.The thermodynamic analysis of the bubble mass transfer got the same result as experiment.Nunerical simulation of the near-interfacial concentration field of a single CO_2 bubble absorbed in alcohol was made.

The complexity of the dynamic characteristics of plate-fin heat exchangers is the existence of fin conduction between channels.The steady-state and unsteady-state conduction of fins was analyzed,and a general dynamic model of multi-fluid plate-fin heat exchangers including separator sheet’s heat-capacity was developed.The mathematical model,in partial differential equations,can also be expressed by the form of dynamic thermal resistance network of plate-fin heat exchangers.By the transformation of the dynamic thermal resistance network,the model was represented by algebraic equations of a tridiagonal matrix which can be solved easily and quickly.By using this model,the dynamic responses of both two-stream plate-fin heat exchanger and four-stream plate-fin heat exchanger were preeicted for fluid flow,or inlet tempeatue petubations.The calculated results were in good agreement with test data．

The vapor-liquid data were measured for the isotherm of binary systems of aldehydeethylidene diacetate,acetic acid-ethylidene diacetate,aldehyde-acetic anhydride,vinyl acetate ethylidene diacetate and vinyl acetate-acetic anhydride,with a self-suction equilibrium still.The“chemical theory”was used to correct the nonideality of the vapor phase with associated molecules.UNIQUAC equation was used to calculate liquid activity coefficient.The calculated results of the thermodynamic model show good agreement with experimental data.

Monte Carlo simulation techniques were used to study the microscopic structure of supercritical binary mixtures of methanol-hexane of different solution densitise.The TIP potential energy parameters developed by Jorgensen were applied to model the methanol-methanol,hexane-hexane and methanol-hexane interaction.The stochastic boundary condition was adopted in near-critical region,and compared with the results of periodic boundary condition.The results showed that significant aggregation at near-critical density was not only limited to methanol molecules that one would expect to have specific hydrogen bonding,but also to nonpolar hexane molecules.

The specific heat capacities of HFC152a/HFC32(92%/8% wt) mixture in liquid phase used in the refrigerator as an alternative for CFC12 are determined and 32 values of heat capacity are reported in this paper.The purities of HFC152a and HFC32 are all 99.95%.The flow apparatus for measuring heat capacities of liquid phase compounds and their mixtures under the pressure up to 12 MPa,and at temperatures from 26OK to 47OK was built by the authors.

A novel surface deposition modified ceramic m embrane was developed to decrease the membrane pore size.Accordingly r-alumina supported membranes modified by calcium carbonate were prepared.Pore size distribution determination and SEM photographs of membranes mdicated that this modi fied membrane can reduce pore size effectively and improve the membrane separation property obviously.Comparisons of vapor permeation separation of ethanol/water mixtures between alumina membranes unmodified and those modified by CaCO_3 also supported the improvement.

Mathematical equations on distribution of permeability and flow resistance of woven filter medium were deduced,and the permeability and resistance to fluid-flow of four woven filter media were calculated.The results show that the pores in a yam of plain weave filter media and among uarns of twill weave ones are very important for fluid-flow through these two kinds of filter media and the resistance to fluid-flow of woven filter media is below the smaller resistance these two kinds of pores in filter media.

An improved RBFN algorithm is proposed.Its training algorithm includes K-mean cluster algorithm and improved recursive method with discounted measurements.The former is used in on-line leaming network centers,and the latter is used to adjust netword weights.Simulation results about estimating the catalyst activity in an industrial fixed-bed reactor show that the training algorithm provides simple structure,good track performance,fast learning speed.

The turbulence structure control by adding component parts similar to the large eddy break up device and riblets in the hydrocyclone was investigated by studying the characteristics of the turbulent pressure field,and the relationship between turbulence structure variation and energy consumption reduction was also studied. The results showed that all the time-averaged characteristics of turbulenyt pressure distribution,pressure fluctuation,relative pressure fluctuation and the probability density distribution characteristics of fluctuating pressure in the hydrocyclone were controlled effectively by adding a winged core and adopting a spiral type cone,and the energy consunmption in the hydrocyclone separation process was reduced remarkably.The winged core is very effective in controlling the trubulence structure and reduceing the energy consumption in the hydrocyclone.

Using the new model for flow boiling heat transfer derived by vector means and combining with the mass transfer revision factor proposed by Palen,the write tested the adaptability of the new model to a mixture flow boiling system.The result showed that with the help of Palen revision in mass transfer,the new model could be used to predict the heat transfer coefficient of mixture flow boiling heat transfer.