Thermal contact resistance (TCR) has been a hot topic in electronics cooling and cryogenic superconducting thin films etc. In this paper, the fundamental research method, metrology macro- and nanotechnology and the diminishing method of TCR were discussed. The reported research suggests that in order to investigate the mechanism of TCR, the scattering and radiation of phonon and electron should be considered besides the quantitative analysis in macro. In the experiment, the current measurement accuracy is not perfect enough, the experimental work remains to be further improved. For reducing the contact resistance, in addition to the commonly used methods, producing new high-performance thermal conductivity materials (such as carbon nano-tubes) on the contact surface is a useful way. Based on summarizing the reported studies, the future research directions are pointed out.

A method is presented to predict the vapor-liquid equilibria (VLE) for binary and ternary HFC/HC mixtures using PR equation of state and van der Waals (vdW) mixing rule. The binary interaction parameters kij is predicted by the difference-correlation model, which is assumed to be the difference between the mixing factors ki of the pure components. The values of ki of 10 HFCs and 3 HCs have been obtained according to VLE correlation for 39 binary mixtures in authors' previous works. In this work, this prediction method is further verified with 11 new binary systems (HFC236ea / HC290、HFC152a / HC600、HFC125 / HC600a、HFC143a / HC600、HFC227ea / HC600、HFC152 / HC290、HFC125 / HC227ea、HFC125 / HC290、HFC134a / HC290、HFC134 / HC290、HFC134 / HC600a), and then extended to predict VLE properties of ternary HFC/HC mixtures, which are HFC32 / HFC125 / HFC134a, HC290 / HC600a / HFC32, HFC125 / HFC143a / HFC134a, HFC32 / HC290 / HFC227ea and HFC32/HFC125/HC290. The predicted results are compared with the experimental data reported in literatures. The overall deviations of pressure and vapor composition are 2.23% and 0.0086 for the HFC32 / HFC125 / HFC134a system, 8.33% and 0.014 for the HC290 / HC600a / HFC32 system, 1.43% and 0.0054 for the HFC125 / HFC143a / HFC134a system, 0.40% and 0.0071 for the HFC32 / HC290 / HFC227ea system, and 1.71% and 0.0089 for the HFC32 / HFC125 / HC290 system, respectively. The comparison shows very good agreement between predicted and experimental results, validating the feasibility of the method to predict VLE properties for binary and ternary HFC/HC mixtures.

In this work, the equation of state for Methyl tert-butyl ether (MTBE) has been developed based on the published experimental data using the Helmholtz energy as the fundamental property with independent variables of density and temperature. Overall, the uncertainty of the equation of state is 1.0% in vapor pressure bellow 430 K, and increases as the temperature increases due to a lack of experimental data. The uncertainty in density ranges from 0.1% in the liquid region to 1.0% elsewhere, including the critical and vapor regions. The uncertainties in the properties related to energy (such as heat capacity and sound speed) are estimated to be 0.5%. In the critical region, the uncertainties are higher for all properties except vapor pressure. The behavior of the equation of state is reasonable within the region of validity and at higher and lower temperatures and pressures. A detailed analysis has been performed in the article.

Experimental solubilities of terephthalic acid and 1,4-carboxybenzaldehyde in mixed solvent of acetic acid and water were measured at the temperature range from 420K to 505K. It is shown that solubility of terephthalic acid is the most sensitive to temperature under the condition of 70% of acetic acid concentration, and reduces with increased concentration of acetic acid. When temperature is below 470K , solubility of terephthalic acid in water is lower than that of terephthalic acid in acetic acid. However, it is above 470K that the solubility significantly increased the sensitivity to temperature. The solubility of 1,4-carboxybenzaldehyde is the most sensitive to temperature under the condition of 40% of acetic acid concentration, and increases with increased concentration of acetic acid. The solubility data of terephthalic acid and 1,4-carboxybenzaldehyde in mixed solvent of acetic acid and water were correlated by modified Apelblat equation, which gave good agreement with all experimental data.

The staged oxygen entrained flow coal-slurry gasifier has advantages such as higher carbon conversion rate, stronger turbulent mixing inside gasifier and lower temperature near coal slurry nozzle. In this article, effects of the secondary oxygen mass flow rate on gasification performance were numerically investigated through CFD simulation. The characteristics of the gasification flames were analyzed as well as the flow field under different secondary oxygen mass flow rate in the staged gasifier. As the mass flow rate of the secondary oxidizer decreases, the secondary gasification flame curves up with the backflow near the wall. At the same time, dome wall temperature increases as well. When the mass flow rate of the secondary oxidizer is less than 8% of the total oxidizer mass flow rate, the effect of the secondary oxidizer is too weak to change the macro flow field.

Liquid mixing behaviors inside micro-droplets in the microchannels were visualized by μ-LIF technique. These measurement results were adopted to validate the numerical simulations by a newly developed multi-phase, multi-component Lattice Boltzmann Method (LBM), especially to determine a key parameter in the LBM model. The results showed that the simulation can successfully reveal the detailed mixing phenomena inside the droplets. It was discovered that the droplet deformation along its movement in the microchannels can significantly shorten the distance of mass transfer, and thereafter intensify the mixing process. The wetting property of the dispersed phase had strong influence on the flow pattern when the droplet passed through the complex geometry of the micro-channels. In summary, this work provided a solid foundation for the theoretical investigation of complex flows in micro-reactors.

In this paper, equilibrium molecular dynamics simulation and the Green–Kubo method for the systems of from fully occupied to vacant occupied sI methane hydrate have been performed to estimate the Influence of guest molecules number on methane hydrate thermal performance. Results indicate that the thermal conduction of methane hydrate is determined by framework of cage which constitutes the hydrate lattices. In addition, as the cage occupancy ratio become greater after more guest molecules enclosed the cage, the density increases and the impact of guest molecules scattering becomes more significant. This process results that the poor thermal conduction from methane hydrate improves.

Screen is one of the simplest resistance internals for improving velocity profile in a bubble column. In this paper axial liquid velocity and gas hold up distributions along the radial of ?500×5000 bubble column with multi-layer screens were measured by Pavlov tube and conductivity probe respectively. The experimental observations showed that the lateral screen internals can remarkably reduce the ascending liquid velocity in the core region, resulted in an improvement of flow profiles. The smaller the screen hole is, the more remarkable the resistance effect will be, and the higher the average gas hold up is. A one dimensional CFD model similar to that applied to pipe bundle internals was developed, and the damping effect of screen internals on the liquid was regarded as volumetric sources of momentum, turbulent kinetic energy and dissipation. The value of parameters appeared in turbulent energy dissipation equation were different form the model of pipe bundle internals, and they were estimated as c3=1.0，c4=1.3 by comparison with experimental data. The calculated results agreed well with the experimental data. The present model provided a effective tool in simulation of damping effect of multi-layer screens internals in bubble columns.

Abstract：An experimental study was undertaken on dense gas-particles swirling jet with disturbance of air source by using high-speed camera. The effects of swirl number and disturbance of air source on the characteristics of particle flow were investigated. The result showed that gas phase had a characteristic frequency which was identical to the natural frequency of fan. The characteristic frequency remained after the introduction of swirl. Remarkable periodic bubbles were formed under the influence of disturbance of air source. When ug＜4.42 m?s-1, disturbance of air source played a central role in the formation of bubbles, and the bubbling frequency was approximately equal to the characteristic frequency of gas phase. In addition, more rapidly dispersion of the particles and larger dispersion angle were achieved with disturbance of air source and strongly swirl.

In the present study, a conservative compressible numerical model coupling with dynamic model for non-equilibrium phase change and Virial Equations of steam, was developed and used to predict the spontaneous condensation phenomenon with homogenous nucleation in the supersonic steam flow. In order to capture the transient characteristics of the supersonic flow and the condensation shock effect, the improved high resolution Roe-FDS scheme was used. The influence of inlet steam temperature on the homogenous nucleation and the condensation shock was revealed, and the impact of temperature change on the thermodynamic characteristic was investigated. In the research, it is found that the inlet temperature has a significant influence on the non-equilibrium phase change in the supersonic steam flow. With a lower inlet temperature, the non-equilibrium homogenous nucleation occurs more early and the radius of droplets is bigger. When the inlet temperature decreases, the onset of the non-equilibrium condensation will move to the outlet of the nozzle, and the temperature will decrease rapidly to make the expansion steam achieve a higher Mach number, saturation ratio and supercooling temperature, and then the non-equilibrium condensation will occur eventually with a higher nucleation rate.

A numerical investigation of the heat transfer characteristics and the self-sustained oscillations flow is conducted in a grooved channel with periodic mounted different structure. Control of low Reynolds number range(400-1600), two-dimensional, unsteady laminar flow was analyzed.Three structures of using oblique plate and two curve vanes with different direction was considered to induce the self-sustained oscillations flow. A comparison among different channels was made for streamlines,isothermal,Nusselt number(Nu) and friction factor. The research found that the critical Reynolds number was low, the value is 620,480,400,respectively. And in the channel with the lower critical Reynolds number, the oscillation was drastic. The corresponding performance was strong vortices movement in the groove areas, to create better heat transfer. For the same Reynolds number ,the oscillation period of three kinds of channel were roughly equal, but the self-sustained oscillations characteristics were different.The friction factor had different change trend because of the different vortex in the channel. When Reynolds number was over 800,the value of friction coefficient of the GCCV1 and GCCV2 channel was averagely three times as the value of friction coefficient of GCOP channel,while the same trend was also presented in the heat transfer of the three channels.

Fick’s law of diffusion is only valid for the description of an ideal binary diffusion without external force, while Maxwell-Stefan (MS) equation can be applied to multicomponent mass transfer under the influence of external field. The physical meaning of MS equation was clearly explained, and the generalized expression of MS equation was rewritten to a form which is simpler and easier for use. The expressions of the external forces which could be used in the equation were given. Fick’s law of diffusion is the special form of MS equation to the mass diffusion in ideal binary fluid without external force. The application results of MS equation to the centrifugal separation and the electrolyte diffusion are consistent with that of traditional descriptions, but more comprehensive. In this paper, application of MS equation to electric conduction leading to Ohm’s law was carried out, which provides a new method to get diffusivity through the measurement of conductivity. The characteristic of mass transfer in spherical particles enhanced by electric field was investigated with MS equation, and this investigation showed that MS equation could effectively describe the mass transfer enhanced by external field. MS equation provides an effective theoretical method to study the mass transfer enhanced by external fields.

Gas-solid two-phase flow of the quick-contact cyclone reactor was simulated with the Eulerian model, especially the volume fraction of solid in the mixing cavity was researched. The results show that tangential gas admission accelerates the gas speed in the mixing cavity, it has a great impact on shortening gas-solid residence time and ensuring short contact reaction effect. For two mixing cavity structures, the second reactor (tangential intake pipes were fixed at the top of the mixing cavity) has a shorter residence time in the same inlet velocity, it is more likely to achieve the short contact requirement. Solid particles of the first reactor (tangential intake pipes were fixed at the bottom of the mixing cavity) spread outward in the mixing cavity from the bottom of the feed inlet, nearly no particle moves to the centre space, the concentration gradient is obvious, then under the action of the tangential flow, solid spread evenly, tangential flow has a beneficial effect on the spreading of solid. In the second reactor, axial feeding contacts with the tangential flow in the mixing cavity at once, under the action of the tangential flow, solid particles are evenly distributed, enhancing the contact effect of gas-solid two-phase. The flow state of gas-solid in the separation cavity of two different structures has no difference, particles gather on the wall of the reactor because of the centrifugal force, and then flow down around a spiral. In a word, turbulent diffusion of tangential gas admission increase turbulent intensity, it has a great beneficial effect on spreading the catalyst particles effectively, enhancing gas-solid contact effect. Due to tangential gas admission, the second reactor is better to FCC reaction because of the solid particles spreading more evenly. The comparison of the numerical results and the experimental results show that the present model is available to describe the flow pattern in the reactor. This work could offer a base for the structure optimization of the quick-contact reactor and improve its efficiency.

The flowability of Yangchangwan, Beisu, and Tianba coal powders with different particle sizes were investigated using five methods including Angle of repose, Hausner ratio, Carr flow index, Jenike theory and mass flow rate. The methods were compared and analyzed systematically. Experimental results showed that, the flowability of the coal powders could be improved obviously by increasing the particle size, especially for those smaller than 75μm approximately. Flowability of the three coal powders in similar sizes could be distinguished by Angle of repose, Hausner ratio and Carr flow index, and Beisu Coal behaved the poorest flowability. The methods had a good agreement in describing the trend of flowability. However, at preconsolidation stress of 40kPa, the ffc was beyond the traditional relationship between it and the flowability.

The heat transfer and flow characteristics of 85% glycerin in smooth tubes bundle supported by evenly spaced twisted tapes was studied and compared with the thermal performance of smooth tubes bundle by numerical simulation. Meanwhile, slowly changing effective heat transfer temperature difference characteristic of heat transfer replacement method of highly viscous fluid was also discussed. The results indicated smooth tubes bundle supported by evenly spaced twisted tapes has a better integrated performance than single smooth tubes bundle under laminar flow and smaller twist ratio and bigger angle of twisted tapes was more efficient to improve integrated performance. Furthermore, in the containing evenly spaced twisted tapes segments of smooth tubes bundle supported by evenly spaced twisted tapes，the heat transfer rate can be improved by both enhancement of heat transfer coefficient and increasement of effective heat transfer temperature difference, and slowly changing effective heat transfer temperature difference can be employed to continue to improve heat transfer rate in downstream of twisted tapes, which indicated a novel way to enhance heat transfer of avoiding more fluid replacement frequency and saving more fluid transporting power.

In order to distribute pulp more uniform in headbox, the design methods of the rectangular tapered distributor were analysed in this paper.A new distributor was put forward based on nonuniformity of pulp mass flow rate out of the manifold in the rectangular tapered distributor which is designed by the Baines method or the methods derived from it. Then, the mechanism of pulp distribution in the new distributor was analysed and the structure of the new distributor was designed. The new distributor was composed of same two rectangular tapered heads which were symmetrically put together one on top of another.The distribution trends of mass flow rate in manifold tubes of two rectangular tapered heads were just inverse.So the pulp out of manifold tubes was mixed complementarily in the mixing chamber and pulp distribution out of the mixing chamber was closer to the expected value than the old one. Finally the method of numerical simulation was adopted to research the flow characteristic of pulp in the new distributor. The results show that pulp out of manifold tubes of two rectangular tapered heads was mixed complementarily and plenty in the mixing chamber.The nonuniformity of pulp flow out of two rectangular tapered heads was effectively eliminated.So the trend of mass flow rate of pulp out of the mixed chamber was closer to the theory curve and expected value curve than one of old model.In comparison of pulp distribution in models, the new model was obvious better than others and the deviation to expected value in new model was minimum.To the new distributor, the analysis of distributing mechanism and the structure design were reasonable and the distribution of pulp was more uniform and satisfied.

The mathematical model describing combustion, fluid flow and heat transfer in combustion and carbonization chambers of coke oven was established to describe coupled transport phenomena in complex structures of chambers. Since it is time-consuming and difficult to converge for coupling numerical simulation, two different decoupling numerical methods were proposed and performed. It turned out that two decoupling simulation methods are less time-consuming, easier to be carried out with a good accuracy and a faster convergence compared with coupling method. The second decoupling method is preferred to the first one because of its results’ better match of the actual condition, although it is more time-consuming. It is expected that these two decoupling numerical methods could supply alternative ways for numerical simulation of transport phenomena in combustion and carbonization chambers of coke oven, and be helpful for other similar simulations of complicated transport processes.

Sintered nickel capillary wicks with controlled porosity, pore size distribution and high strength were prepared by salt-leaching pore forming method. The influences of different soluble salt addition and particle size on the capillary pumping performance were investigated. The results showed that the porosity of sintered nickel wicks was increased linearly with the increasing of soluble salt amount. When the amount of soluble salt was up to 40 wt%，the nickel wicks porosity reached to 73 % with high strength. Changing the particle size of soluble salt can influence the pore size distribution of the wicks，but the porosity didn’t change obviously. The experimental research on the capillary pumping performance showed that the capillary pumping performance of the wicks was controlled not only by the porosity, but also the pore size distribution. With the same porosity, wicks with smaller pore size and more centralized pore size distribution showed more excellent capillary pumping performance.

Due to the problem in available numerical simulations of flow patterns in dense pneumatic conveying, a new mathematical model, which uses solidphase volume concentration of local space and kinematic characteristics of clusters to describe the interactions between particles, was proposed in this paperThis model was first used to numerically simulate the dense pneumatic conveying (even for the packing of particles), and then used to numerically study the flow behavior of dense phase pneumatic conveying in horizontal pipe at high pressures, in which the separation and sedimentation between gas phase and solid phase in the conveying process were investigatedThe simulation results also illustrated the evolving characteristics of flow patterns such as dune flow and plug flow, which are consistent with the experimental phenomenaMoreover, some rules of flow patterns were revealed by qualitatively analyzing the distribution of solidphase flow patterns at different superficial gas velocitiesThe results show that the new model is appropriate and can be used to study the dense pneumatic conveying.

We make an experiment with five double-impeller underwater aeration machines which have different powers for reducing the consumption of energy and avoiding excessive aeration, and we test the aeration speed of every aeration machine and the dissolved oxygen concentrations of three of them. when they have different rotate speed; According to the experimental data, on the mathematical statistics of linear regression analysis method, we can analyse the relationship of Aeration speed, Rotate speed, and oxygen utilization coefficient, still further conduct the relationship of Rotate speed and Oxygenate speed, compare with the experiment data.. It turned out that: although it has deviation between the mathematical model of the relationship of oxygen utilization coefficient and rotate speed and the variation tendency comes from the experiment, but from the calculation value ,when it meetings 800≤n≤1450,it can be discovered that the most relative bias between the calculation value and the value comes from experiment δmax＜0.082 through calculation. We can conclude that the relational expression between the Rotate speed conducted and Oxygenate speed could exactly response the relationship between the Rotate speed and the oxygenate speed, and it can be the theoretical basis and foundation of the control for the aeration machine.

A molecular kinetic model for catalytic pyrolysis process of FCC gasoline in a pulsating reactionchromatograph equipment was developed by the structureoriented lumping (SOL)method combined with Monte Carlo (MC)simulationSOL was applied here to describe the structure of hydrocarbons and establish reaction networkSeven structure vectors were designed to construct the hydrocarbon molecules that existed in gasolineNinetytwo kinds of hydrocarbons covering most in FCC gasoline were generated as fundamental molecules and 2000 molecules were drawn out as a whole to represent the composition of FCC gasoline from those 92 kinds whose numbers were determined by mole fractionsBy integral calculating each molecule reaction probability using the MC method, the product distribution could be obtainedEleven typical hydrocarbons involved basically in pyrolysis reactions were chosen as model compoundsThe rules of their reactions were studied, and a reaction framework was established and reaction rate constants were calculated on the basis of such rulesThe results showed that the simulation method of combining SOL and MC for constructing molecular kinetic model was advisableThe simulated product yields fitted well with the experimental resultsRelative errors of most product yields were less than 10%This model also had an ability to predict product yields when prolonging the reaction time.

Abstract: The yields of aromatics, C1-C4 paraffins and ethylene at varying space time and at methanol partial pressure of 20 kPa in co-reaction of methanol and butene, pentene or hexene were investigated over H-ZSM-5 catalyst in an isotherm fixed-bed reactor at 460℃. For each feed, the CH2 mass ratio of alkenes to methanol was 4. It was found that each yield of aromatics and individual C2-C4 paraffins showed liner dependence on space time while ethylene yield increased slowly with space time up to thermodynamic equilibrium. It was also found that at constant space time each yield of aromatics, individual C2-C4 paraffins and ethylene did not rely on the feed composition. Only slight dependence of mass fraction on the feed composition was observed for propylene, C4, C5 and C6, respectively. These results indicate that in co-reaction of methanol and butene, pentene or hexene, a mixture of C3=-C6= with relatively steady distribution is first formed through the methylation of C4=-C6= followed by the cracking of C6= and C7=. Ethylene is formed subsequently through oligomerization and cracking of the C3=-C6= mixture to reach thermodynamic equilibrium composition. Aromatic products, mainly toluene, xylenes and tri-methylbenzenes, are suggested to be formed through aromatization of C7 and C8 olefins along with the formation of paraffins through hydrogen transfer reactions.

Polyvinylidine fluoride (PVDF) hollow fiber membrane contactors were applied to the separation of carbon dioxide (CO2) from flue gas using water (H2O), sodium hydroxide (NaOH), potassium glycine (GLY) and potassium glycine-piperazine (GLY-PZ) solution as dedicated absorption liquid. Effects of flow mode, flow rate of feed gas and absorbent solution, absorbent concentration and temperature, feed gas concentration and packing density on the removal rate and total mass transfer coefficient were investigated in detail. Results showed that the lumen side process with two phases flowing countercurrently had the highest separation efficiency. The absorption performances of four kinds of absorbents were in the sequence of NaOH> GLY-PZ> GLY> H2O. The effect of temperature on various absorbent was different. The separation efficiency of CO2 can be enhanced by increasing of the packing density, concentration and flow rate of absorbent solutions while weakened with increasing of the concentration and flow rate of flue gas.

Considering the low separating efficiency of conventional gas-liquid separator for small liquid drops, a new type of gas-liquid separator was proposed, which is available in a Mechanical Vapor Recompression (MVR) evaporation system, and its separation characterization was analyzed based on the research approach of a numerical simulation combined experiment verification in this study. Firstly, the numerical simulation method was employed to locate the most effective separation position through analyzing flow field and pressure distribution of the conventional gas-liquid separator, and the 3/4 circular baffle was installed there to construct a new type of gas-liquid separator. Secondly, separation characteristics of the proposed separator and influence rule of the number of 3/4 circular baffles were analyzed. Finally, the new separator structure was built and experimented to verify the simulation results and separation effect. The study results showed the separator with 3/4 circular baffle could improve the separation efficiency of small liquid drops significantly, with a little pressure loss. The circular body affected the separator characteristics significantly. With 3/4 circular baffle installed, the effective length of tangible movement could be increased and the radial velocity could be decreased, which plays a good role for increased separation efficiency with little pressure loss. Also, the separation efficiency and pressure loss are all increased with the number of 3/4 circular baffles. In this study, the separation efficiency of liquid drops with diameters less than 3 μm of the new separator structure could be increased by 15%, and pressure loss is only increased 200Pa .Combining the separation efficiency and pressure loss comprehensively, gas-liquid separators with two 3/4 circular baffles could achieve the most separation characteristics.

A general model is proposed for optimal operation of heat exchanger network(HEN), aiming to achieve two goals: 1) all controlled temperatures are kept at their targets; 2) operating cost is minimized. The model is formulated as non-linear program(NLP), which consists of exchanger model, splitter model, mixer model, by-pass model and relation model between unit models. The HEN structure is represented with stage-wise superstructure presented by Yee and Grossmann(1990), which is developed for considering non-constant film coefficient. A solution strategy based on particle swarm optimization algorithm is developed for NLP problem, which promises simple, fast and robust searching procedure. The proposed method is applied to four benchmark problems reported by published literatures, and the optimal results prove that the method is more effective to optimal operation problem of HEN.

In a refinery accurately extracting data of heat exchanger network has intimate influences on schemes of heat integration and performances of optimal operation. For data reconciliation of nonlinear state parameters of a heat exchanger, a lumped parameter heat transfer model, which features partitioning the heat exchanger with piecewise linear sub-models, was proposed to overcome the difficulty of nonlinear state space equations induced by nonlinear change of stream properties in the heat exchanger. A set of state space equations on the basis of piecewise linear Kalman filtering was established. A method of data reconciliation for nonlinear state parameters of heat exchangers was proposed. The procedure of the proposed approach and its behaviors were exemplified by data reconciliation for a high pressure heat exchanger in a wax oil hydrotreating unit. The results show that the convergence of the proposed model is strongly dependent upon numbers of partitioning segments for a heat exchanger. The state parameters of heat exchanger tend to be convergent to a constant as the numbers of partitioning segments increase. And numbers of partitioning segments should be determined by trial-and-error according to requirements of computational precise in practice. When the inlet temperatures of heat exchanger are measured, the outlet temperatures can be rectified using the proposed method. And data reconciliation on the inlet and outlet temperatures of the heat exchanger can be performed iteratively. The proposed method can be effectively used for data reconciliation of nonlinear state parameters of heat exchangers. The proposed approach has higher accuracy for data reconciliation of larger difference between inlet and outlet temperatures or dramatic changes of physical properties of streams in heat exchangers.

During the operation of Heat exchanger network (HEN), for operating conditions are always varied, the bypass optimal control is considered as an effective method to adjust the temperatures and saving energy. However, locations of bypasses are derived without the verification by the control theory. Therefore, it is very necessary to analysis the structural characteristics of heat exchanger networks. Firstly, based on the topology theory, the structural states configuration and array are presented by using the structural model of the HEN. Then, the HEN structural controllability, the structural control intension and redundancy degree are analyzed. The results indicate that the bypass on downstream is less controllability than that on upstream; structural control intension is affected by the corresponding bypass location; and the using of the coupling channel may affect the redundancy degree and the controllability significantly. The analysis of case study demonstrated this method can be used to testify the controllability of the HEN with bypass optimal control, and significantly reduce the analysis complication on complex structural controllability analysis. This method also indicated a novel idea for applying control theory on engineering process.

In terms of the thermodynamic characteristics of conventional reactive distillation columns, an externally heat-integrated reactive distillation system (EHIRDS) is proposed and studied. It is comprised of a high-pressure reactive column and a low-pressure separation column, with external heat integration between the rectifying section of the former and the stripping section of the latter. A hypothetical quaternary ideal exothermic reaction A + B ? C + D is chosen to evaluate the EHIRDS with an objective function of minimization of total annual cost (TAC) and reduction in operating cost is acquired. The simplification of the EHIRDS with three heat exchangers (i.e., S-EHIRDS) can lead to a further reduction in capital investment and operating cost. These simulation results confirm preliminarily the great potentials of the EHIRDS.

Centrifugal pumps are widely used in chemical production. Cavitation happened in pumps is one of the major causes which leading to the reduction of efficiency. A diagnostic method of inception cavitation is put forward based on low frequency and high frequency characteristics of pump inlet pressure fluctuation signals. The marginal spectrum is getted through empirical mode decomposition (EMD) of experimental data and Hilbert-Huang transform (HHT). By qualitative analysis root-mean-square and marginal spectrum band energy of each intrinsic mode function can be used for cavitation recognition. But it takes too much time to recognize when the characteristic dimension is high, therefore it is necessary to quantitatively analyze to simplify characters. A four-dimensional feature vector was put into the back propagation neural (BP) networks for training and simulation , with the first and the second level root-mean-square energy value of intrinsic mode function get through EMD as high frequency feature and the 0 to 20 Hz and 20 to 40 Hz band energy values of marginal spectrum as low frequency feature. The method mentioned above has increased the recognition rate by 7.26% and 3.59% with simulation time decreasing by 77.72% when contrasting with wavelet analysis method and EMD energy entropy method. It has a strong influence on the training of networks that 3 to 9 level energy entropy of experimental data EMD varies little with cavitation conditions. So EMD energy entropy method takes much time of simulation with low recognition rate. Removing the redundant characteristics recognition rate increased by 3.59, simulation time decreased by 77.72% . During wavelet analysis characteristic vector selected varies much with flow rate, therefore recognition rate is high for the same flow rate and is low for different flow rate. For characteristic value in this paper varies not much and similarly with flow rate, recognition rate raises by 7.26% .

Dry gas seals with T-grooves onto its faces have been widely used in axial seal of a centrifugal compressor in petro-refinery and chemical process. The failures of such seals cannot be diagnosed correctly due to the lack of the theory of such seal geometric construction. In this paper, a finite element analysis was used to resolve Reynolds equation for the gas flow between the two faces of a non-contacting T-groove dry gas seal based on gas lubrication theory. The maximum value of gas film stiffness was selected as the optimization object for T-grooved face geometric parameters. The diversification law of opening force, leakage rate and gas film stiffness varied with geometric parameters of T-grooves in the different rotational speeds or sealed medium pressures was analyzed. The results showed that the rotational speed has great effect on the optimization values of T-groove geometric parameters, such as arc ratio α1, groove width ratio α2 and groove depth hg, but he effect of rotational speed on the optimization value of radial ratio β1 and groove length ratio β2 can be ignored. The higher the rotational speed, the greater the optimization values of α1 and hg, but the lower the optimization value of α2. The effect of the sealed medium pressure on the optimization values of α1, β1 and hg was great to a certain degree, but to the optimization values of α2 and β2, the effect could be ignored. The sensitivity of opening force, leakage rate and film stiffness to the above five geometric parameter values of T-groove would be lower when the sealed medium pressure was higher. The optimization values of α1 and hg would be lower when the sealed medium pressure became higher, but the optimization value of β1 would be higher. The results would provide the theoretical support for the practical utilization under the condition of different operational parameters of a T-groove dry gas seal.

Nanocrystalline metal Cr is prepared by mechanical alloying through hot-pressing processes and its corrosion mechanism and corrosion resistances in media containing chloride ions is also investigated as compared with corresponding coarse-grained alloy. Results show that with the increment of chloride ion concentrations, the corrosion current densities increase and therefore corrosion rates become faster. After the grain size is refined, the corrosion current densities of nanocrystalline Cr are bigger than those of the corresponding coarse grained materials. This indicates that the corrosion resistances decrease when the grain size is refined. Two kinds of grain size metal Cr produce passivating phenomena, but they become weaker initially and afterwards stronger alternately with the increment of chloride ion concentrations. These results indicate that chloride ions act on destroying and restoration. The electrochemical impedance spectroscopy (EIS) of the two alloys in media containing chloride ions is composed of single capacitive loop, therefore corrosion process is controlled by electrochemical reaction.

Tetrabenazine was approved by Food and Drug Administration (FDA) in US as the first drug to treat chorea associated with Huntington’s disease in 2008. A convenient two-step method for synthesis of tetrabenazine with water as reaction medium was proposed. The process was started with 5-methyl-2-hexanone via Mannich reaction to afford 3-dimethylaminomethyl-5-methyl-hexan-2-one. The intermediate was reacted further with 6,7-Dimethoxy-3,4-dihydroisoquinoline hydrochloride at 90℃ catalyzed by triethylbenzylammonium chloride(TEBAC) in water to form the target compound. The influences of various reaction conditions on the yield were investigated. The optimal reaction conditions (temperature, time, molar yield) were as follows: Mannich reaction, reflux for 5 h, 55 %; amine exchange, 90 ℃ for 4 h, 68 %. The chemical structure of the target product with 98 % HPLC purity was characterized by 1H NMR, IR, MS and elemental analyses. The process is much of industrial value because of cheap and available materials, milder conditions, shorter reaction time, simple operations and environmental friendliness.

The angle between high pressure port and middle pressure port is one of the most important structure parameters for gas wave ejector. In this study, the influence of this angle on the performance of gas wave ejector is analyzed by numerical simulation and experiment. The prediction method for the optimal angle is proposed. For any given conditions, there is an optimal angle ψopt. When the angle is greater than the optimal one, a reflected shock wave is generated and the isentropic efficiency of gas wave ejector decreases significantly; While the angle is less than the optimal one, the efficiency declines slightly for the case of lower middle pressure. However, if the middle pressure is higher than pM-extra, the pressure inside the channel after a cycle is lower than that at the middle pressure outlet. A compression wave is produced when the channel is exposed to the outlet, so the efficiency drops sharply as the port angle decreases. The calculation results agree well with the experiment data, so the model could predict the optimal angel effectively. When the temperature and pressure of the inflows are constant, the optimal angels at different middle pressure are almost the same, but increase linearly with the rotation speed. The above conclusions provide guidance for gas wave ejector design and optimization.

Combinations of chlorine dioxide and chlorine by mechanically mixing are finding potential applications in drinking water and urban reuse disinfection to achieve maximum disinfection and minimum toxicity simultaneously. However, transportation and reservation of chlorine dioxide and chlorine may threat to environmental safety. Therefore, site preparation methods are necessary for field use. At present, preparation methods of associated chlorine dioxide-free chlorine disinfectant include chemical reduction of sodium chlorate and electrolysis of sodium chloride. And the content of chlorine dioxide is usually below 30%. To extend the preparation method of associated chlorine dioxide-free chlorine disinfectant, the electrolysis of sodium chloride (NaCl) was followed by chemical oxidation of sodium chlorite(NaClO2) with membrane-free plate electrode reactor. The content of ClO2 in the compound disinfectants can be controlled. The effect of current density(A), mass ratio of NaClO2:NaCl(B), electrolysis time(C) on concentration and mass percentage of ClO2, free chlorine, ClO2- and ClO3- was investigated systematically. With the current density of 41.67~83.33A.m-2，mass ratio of NaClO2 and NaCl at 1:3~3:3，reaction time at 5~15min, the mass percentage of chlorine dioxide(ClO2) and free chlorine reached 70% and 20% in the compound solution. The free chlorine yield was mainly affected by factors C and A, the ClO2 was significantly influenced by factors C and B, and the by-products of ClO2- and ClO3- were greatly impacted by factor A. The total coliforms of urban sewage reached 105 ~ 108 cfu.L-1 after secondary treatment and before disinfection. The disinfected effluent after 30min contact time with ClO2 dosage of 4mg.L-1 and free chlorine of 1.20mg.L-1 above, complied with water quality standard for urban miscellaneous consumption GB / T18920-2002. In addition, the use of disinfectants was reduced, as well as the generation of ClO2-. Some fundamental insights into the preparation of associated chlorine dioxide-free chlorine disinfectants support its further application in safe urban reuse.

Ash formation during coal gasification was investigated based on benchscale OMB gasifier Particle size and composition of the initial minerals and the resulting fly ash were measured by SEM, XRF, XRD and Malvern Laser Particle Size AnalyzerThe results showed that particle size distribution and composition of fly ash were significantly different between fly ash at impinging zone and fly ash at gasifier outletParticle size distribution of fly ash at impinging zone was slightly finer than that of raw coal, composition of fly ash at impinging zone was quartz, calcite and FeSParticle size distribution of fly ash at gasifier outlet dramatically decreased compared to that of fly ash at impinging zone, and composition of fly ash at gasifier outlet was quartz, calcite, FeS, mullite, anorthite, gehlenite and calcium oxideAsh formation mechanisms at different gasification stages were also differentPart of fixed carbon combustion and excluded mineral transformation were the mechanisms of ash formation at the combustion stage, char fragmentation and included mineral liberation and transformation were the mechanisms of ash formation at the char gasification stage.

The energy flow is densitive and the parasitic energy is high for the CO2 capture process with MEA (monoethanolamine) method in power plant. The energy saving based on process integration is important. The characteristics of the grand composite curve justifies the nature of high energy consumption of the CO2 capture process. The pinch analysis of heat exchange net shows the heat transfer across the pinch point. The heat exchange net is optimized and the energy saving projects are: (1) Above the pinch point, the high temperature heat energy from the MEA lean solvent is recovered for the heating of regeneration gas from the pre-absorption tower; (2) Below the pinch point, an ammonia absorption refrigerator driven by the heat of the wet CO2 mixture from the MEA stripper, and the original cold utility for the CO2 liquification is reduced by 43.4%. The energy saving projects based on process integration can reduce the steam consumption and cooling water by 21% and 17.2%, respectively.

Sweet sorghum bagasse（SSB）was hydrolyzed with liquid hot water in a flowthrough reactor with the objective of achieving complete saccharification of hemicellulose of SSB and understanding the hydrolysis mechanismThe effect of reaction temperature (155—235℃)and flow rate (5—30 ml·min-1)on the concentration of xylose, glucose, arabinose, their total sugars and their degradation products (furfural, 5HMF, acetic acid, glucuronic acid, formic acid and glycolic acid)in the liquid fractions was investigatedThe experimental results indicated that xylose was more sensitive to temperature and flow rate than arabinose and glucoseThe concentration of total xylose including xylose monomer and xylose oligomer dropped dramatically when temperature was higher than 195℃A lower flow rate (5 ml·min-1）resulted in a higher furfural yield due to longer residence time for xylose in the reactorIn contrast, a higher flow rate (30 ml·min-1）would reduce the thickness of stagnant fluid layer surrounding the solid particles and lower resistance to penetration of water into the solids for hydrolysis and diffusion of oligomers into solutionIt was hypothesized that the major xylan in SSB hemicellulose was O-acetyl4-O-methylglucuronoarabinoxylanXylose, arabinose, glucose and their oligosaccharides could be considered as the primary productsGlucuronic acid and acetic acid were produced from the decomposition of glucuronic and Oacetyl groups in the branched chain of hemicelluloseFurfural and 5hydroxymethyl2-furaldehyde (5-HMF)were the direct degradation products of sugarsMoreover, glucuronic acid would be further oxidatively degraded into glycolic acidLow molecular weight organic acids, such as formic acid were the further degradation products.

The CaO/FA sorbents sorbents were prepared by calcination reaction and hydration reaction using calcium hydroxide and fly ash from Coal-fired power plant waste. The CO2 adsorption capacity of CaO/FA sorbents was investigated in a fix-bed reactor within the temperature range of 350~650℃. The effect of different mass ratio of CaO and fly ash were investigated. The morphological properties of those sorbents before and after the carbonation reaction were characterized by using XRD, SEM and N2 adsorption-desorption. And the deactivation model was used to analysis the experimental breakthrough data. The results indicated that, the sorbents have high BET surface area and large pore volume after hydration reaction, with the rise of carbonation reaction temperature, the CO2 adsorption capacities of CaO/FA sorbents also on the increased. All of CaO/FA sorbents have the minimum of CO2 adsorption capacity when the carbonation temperature at 350℃. When the reaction temperature is within the range of 450~650℃, the CO2 adsorption capacity of those sorbents increased but not obviously. It was found that, CaO/FA sorbents showed a higher CO2 adsorption capacity when the mass ratio of CaO and fly ash was 3:1 and the reaction temperature reach to 650℃, the maximum CO2 adsorption amount reached 227.13mg/g. The CaO/FA sorbents have high and stable adsorption capacity after 9 cycles. In addition, the CO2 breakthrough curves of CaO/FA sorbents are well predicted with the deactivation model, and obtained good adsorption and deactivation rate constants.

A model of oil shale retort furnace with gas heat carrier was developed using Aspen Plus, which mainly integrated the process operations of drying/preheating and pyrolisis of oil shale feedstock. Components in oil shale feedstock were divided into moisture, organic substance, and minerals, which were defined as conventional stream, non-conventional stream and conventional inertia stream respectively. According to the mechanism of oil shale pyrolisis and the kinetic equation of overall first reaction, the mass of organic matter and its pyrolysis products including shale oil, pyrolysis gases and semi-coke have been calculated and analyzed at normal operating temperature of the retort. They were also calculated and analyzed at different temperatures. The simulation results agreed well with design and operation parameters of the retort, and it was convenient to predict the mass of pyrolisis products at different temperatures.

Two-sludge technology is a representative of denitrifying phosphorus removal technologies and has potential advantage in treating municipal wastewater with low carbon source. There have a large number of reports about the technology, but few concerned with the modeling of it. So this paper was aim to develop a mathematical model which can be used to simulate the processes of Two-sludge system. A series of kinetic models which were simplified to linear form basing on some assumption and referencing to ASM2D were adopted to represent the main biochemical processes including phosphorus release（organic storing under anaerobic condition）, nitrating, aerobic biodegradability of organic and denitrifying phosphorus uptake. Then the model of Two-sludge technology was developed on the base of material balance and the principal components of the model were a set of linear equations. The input variables of the model include water quality parameters,HRT of each reactor,MLSS of anaerobic tank, MLSS of nitrifying tank, reflux ratio and transfluence ratio.The kinetic parameters and stoichiometry parameter of the model can be estimated base on experiment data. In this paper, the values of the reaction rate constants of organic storing under anaerobic condition, aerobic biodegradability of organic in nitrifying tank, nitrating in nitrifying tank, aerobic biodegradability of organic in postpositional aeration tank and phosphorus uptake in postpositional aeration tank were estimated from the run datum of a Two-sludge system pilot and the values were respectively 0.29 L/(g.h), 0.26 L/(g.h), 0.64 L/(g.h), 0.31 L/(g.h), 0.20 L/(g.h), 2.326 L/(g.h).The stoichiometry parameters were also estimated from experiment. The stoichiometry relation between the organic consumption and denitrification is 10.03g(COD)/g(N), the stoichiometry relation between phosphorus release and organic storing is 0.2g(P)/g(COD) and that between denitrification and phosphorus uptake is 0.98g(N)/g(P).It is worthy of special mention that, the reaction rate denitrifying phosphorus uptake is expressed as the product of the duration of the phosphorus uptake and the average rate of denitrifying phosphorus uptake per MLSS（ KP-upt） reflect the effect of phosphorus release on denitrifying phosphorus uptake because it was shown by the former experiment that the value of KP-upt is related with the amount of phosphorus release per MLSS and duration of the phosphorus uptake. The value of KP-upt can be got from a table which reflect the KP-upt relation of , the amount of phosphorus release per MLSS and duration of the phosphorus uptake. The table can be drawn from denitrifying phosphorus uptake. But not as other parameters, the value of KP-upt can’t be ascertained before the model being solved ,for the amount of phosphorus release is unknown, so the solution of the model can’t be obtained by solving linear equations in on time. For that problem, trial balance method was adopted. The model was verified by experiment, and it was proved that the model can simulate the variation of the concentration of each kind of pollutant of every unit of Two-sludge system well, but the high accuracy was possibly benefit from the mutual offset of difference partially，So further study is still needed.

The K2Ti6O13 macroporous ceramics were prepared by dry pressing method with raw materials of K2Ti6O13 whiskers, K2CO3 and TiO2 powers, and the pore structure was controlled by changing the length of K2Ti6O13 whiskers and using the accumulation of whiskers with different size. The relationship among the particle size, the ratios of whiskers with different particle size and the properties of permeability and bending strength of porous K2Ti6O13 ceramics were investigated. Results show that the bulk density and bending strength of K2Ti6O13 porous ceramics increase with the decrease of the particle size of K2Ti6O13 whiskers, contrary to the behaviors of the porosity and the permeability. When K2Ti6O13 porous ceramics were prepared using the accumulation of K2Ti6O13 whiskers with different size which the length was D50=7.50 μm and 1.60 μm, the corresponding mass ratio was 3:1, the framework of K2Ti6O13 ceramic were connected with the long whiskers and the medium or small particles. This K2Ti6O13 ceramic exhibits optimal properties as follows: a bending strength of 42.8±0.2 MPa, a pure water flux of 2366 L.m-2.h-1.MPa-1 and its open porosity is 36.4%, respectively. The performance of K2Ti6O13 porous ceramic prepared from whiskers with different size was better than that of ceramic with uniform whiskers on permeability and bending strength. This material shows excellent potential in the area of molecular sieve membrane.

In this paper, organic-coated Co metallic soft-magnetic microspheres with the average diameter at around 5 μm have been prepared by solvothermal method. We got several kinds of products by using different reducing agents in various conditions. The results of XRD(X-Ray Powder Diffraction), FT-IR(FT-IR Spectromete), SEM(Scanning Electron Microscope), TEM(Transmission Electron Microscope)showthe material structure and surface characteristics of prepared samples. The size of the sample was about 5 μm, and it is obvious that there is organic package layer on the cobalt surface.The package was made by situ parcel method successfully. After 3 months, Co was not oxygenated by the result of XRD. Furthermore, We found the samples have outstanding thermal stability at 450 oC and soft-magnetic properties by using TG-DTA(Thermogravimetry-Differential thermal analysis)and VSM(Vibrating Sample Magnetometer) test. The Bs/Hc can respectively reach to as high/low as 169 emu/g /50 Oe as well as the Br less that 10 emu/g. Additionally, there is some positive connect between the formation and property of final products and the key experimental conditions, such as amounts of surfactant P123 or solvent.

A series of Ag-deposited anatase TiO2 nanobelts with different Ag content were prepared using ultraviolet-light reduction or/and seeding growth proceeding. The structure, morphology, Ag-deposition and SERS properties of the products were measured by various techniques. The measurement results show that the Ag nanoparticles reduced by ultraviolet-light, mainly in a diameter range of 10-50 nm, were deposited completely on the surface of TiO2 nanobelts, and the Ag content slowly enhances with the increase of reduction times. Based on the product, the nanocomposite with much more Ag content and coverage above 80 % was further obtained through seeding growth of Ag nanoparticles. The products remarkably exhibit surface-enhanced Raman scattering (SERS) activities using pyridine as a probe molecule, and the more Ag nanoparticles are, the stronger SERS signal is.

The aqueous two-phase copolymerization of acrylamide(AM) and methacryloyloxyethyl trimethyl ammonium chloride(DMC) with the initiator 2,2’-azobis[2-(2-imidazolin-2-yl)propane]-dihydrochloride in aqueous poly(ethylene glycol)(PEG) solution was studied. In order to determine the phase separation point where the transmittance declined suddenly, the spectrophotometer was employed to detect the transmittance of the reaction solution on-line. The effect of various parameters on the critical conversion of the reaction solution with total mass 50.0g was measured by improved bromating method. The critical conversion kept at about 37~38% as the initiator amount increased from 0.005g to 0.025g and the temperature increased from 45℃ to 65℃. And it decreased sharply as the monomers amount increased from 2.5g to 12.5g, decreased little with PEG amount increased from 2.5g to 12.5g, and also decreased with PEG molecular weight increased from 600 to 20000. But it increased with the mole fraction of DMC increased from zero to 20%. The critical molecular weight was also investigated by gel permeation chromatogram(GPC). When the initiator amount increased or temperature rose, the critical molecular weight both decreased linearly. When the overall monomers amount or PEG amount increased, the critical molecular weight increased firstly, and then decreased. The highest critical molecular weight was 3.64×105 and 7.59×105, respectively. As the mole fraction of DMC increased, the critical molecular weight decreased linearly. But when PEG molecular weight increased, it increased accordingly. The results showed that the effects of PEG molecular weight and mole fraction of DMC were most remarkable, the effects of overall monomers amount and PEG amount were little smaller, and the effects of initiator amount and temperature were smallest. Therefore, in order to bring about effective phase separation of the aqueous two-phase copolymerization system, the reaction parameters should be controlled in the suitable range. That is, initiator amount 0.005~0.025g, temperature 45~65℃, overall monomers amount 5.0~12.5g, PEG amount 7.5~12.5g, PEG molecular weight 10000~20000, mole fraction of DMC 5~10%, respectively.

A flame retardant waterborne polyurethane(PU)was prepared by using N,N-bis(2-hydroxymethyl)aminoethyl phosphonic acid dimethyl ester and toluene diisocynateThe performance of the PU was studied with oxygen index (LOI), thermogravimetric analysis (TG), scanning electron microscopy (SEM)and differential scanning calorimetry (DSC).The results showed that with 15% flame retardant in the PU, the LOI of the PU reached 302%, making the polyurethane from flammable level reduced to flame retardant levelCompared with unmodified waterborne polyurethane, the thermodecomposition temperature of the PU was reduced, but the maximum decomposition rate dropped by 389% and the amount of carbon residue increased by 1075%The surface of carbon residue was compact and smooth without holes, which would be good for separating oxygen and heatPhase separation with increasing flame retardant content showed regular changesWith increasing content of flame retardant, tensile strength increased and elongation at break decreased

Taking NaOH as raw material, zinc oxide ore was treated by roasting method. ZnO, SiO2 and PbO reacted with alkali first and then went into solution after digestion process. In this paper, orthogonal experiment method was used to optimize technological conditions for extraction of ZnO from zinc oxide ore when roasted with alkali. The optimized conditions are mass ratio of ore and alkali 1:6, holding temperature 400℃, holding time 4h. Under these conditions, the extraction rate of ZnO is 82.4%. The essential components of zinc extracted slag are stishovite, Na2ZnSiO4, whose generation impedes the extraction of ZnO, and so on. The morphology of slag is irregular, the size of particles is nonuniform.