Experiments were carried out to investigate condensation of ethanol-water vapor mixtures on a vertical mini-tube with outer diameter of 1.032 *** length,inter diameter of the tube was 110 mm,0.727 mm,*** tests were pe...
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Experiments were carried out to investigate condensation of ethanol-water vapor mixtures on a vertical mini-tube with outer diameter of 1.032 *** length,inter diameter of the tube was 110 mm,0.727 mm,*** tests were performed at a wide range of ethanol concentrations(Cv=0%,1%,2%,5%) and varied velocity of vapor(Uv=2m/s,4m/s,6m/s) and pressure(Pv=31.2kPa,47.4kPa,84.5kPa).With the change of the vapor-to-surface temperature difference,the heat transfer coefficients revealed nonlinear characteristics with the peak values under all ethanol mass fractions of *** heat transfer coefficients decreased with increasing ethanol mass fraction of vapor.
In the current study simultaneous reactions of hydrodesulfurization(HDS) of dibenzothiophene(DBT) and reforming of methanol in a micro-autoclave reactor were studied over bi-metallic(Co-Mo/Al2O3 and Ni-Mo/Al2O3) and t...
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In the current study simultaneous reactions of hydrodesulfurization(HDS) of dibenzothiophene(DBT) and reforming of methanol in a micro-autoclave reactor were studied over bi-metallic(Co-Mo/Al2O3 and Ni-Mo/Al2O3) and tri-metallic(Pd-Co-Mo/Al2O3 and Pd-Ni-Mo/Al2O3) catalyst systems which were prepared by incipient impregnation *** situ hydrogen utilization and low Pd loadings were the major targets of this *** comparison purpose,catalytic activity was separately determined for both the methanol reforming and HDS of DBT reactions as *** based catalysts were confirmed with better activity than Co ones for both the reactions with Pd promoted ones ranking at the top ***-Ni-Mo/Al2O3 > Ni-Mo/Al2O3 > Pd-Co-Mo/Al2O3 > Co-Mo/Al2O3 where Pd-Ni-Mo/Al2O3 showed 91% DBT conversion at 380 ℃ and 12 h reaction *** of the selected organic additives on catalytic activity were tested for their effect toward HDS reaction which was unique with close relation to their chemical *** products were quantitatively and qualitatively analyzed via HPLC and GC-MS techniques respectively which helped in elucidating reaction mechanism.
A simplified cooling device consisting of two parallel channels is used to simulate the regeneratively cooled structure of hypersonic vehicles. A concept of "static flow instability (SFI)" is proposed in thi...
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Droplet evaporation is one of the important physical processes in liquid spray. Various models have been formulated in literature to compute the mass flow rate of droplet evaporation. It is found that all these models...
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Droplet evaporation is one of the important physical processes in liquid spray. Various models have been formulated in literature to compute the mass flow rate of droplet evaporation. It is found that all these models can be written in a single formulation, with various models represented by different expressions in the driving force HM, which can be classified into three kinds, namely, classical model, mass analogy model and drift-flux model. In this paper, we perform an analysis of the assumptions involved in the derivation of the three kinds of models, and find that the drift-flux model, which takes into account the effects of Stefan flow and corrective mass transfer, is the correct expression, while the classical model ignores Stefan flow effect and the mass analogy model ignores transient effect. Then the influence of mass driving force HM on droplet evaporation is analyzed, and it is concluded that both the classical model and the mass analogy model underestimate the effect of evaporation especially at high evaporate rates.
Due to their negligible volatility,reasonable thermal stability,strong dissolubility,wide liquid range and tunability of structure and property,ionic liquids have been regarded as emerging candidate reagents for CO2 c...
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Due to their negligible volatility,reasonable thermal stability,strong dissolubility,wide liquid range and tunability of structure and property,ionic liquids have been regarded as emerging candidate reagents for CO2 cap-ture from industries *** this review,the research progresses in CO2 capture using conventional ionic liquids,functionalized ionic liquids,supported ionic-liquids membranes,polymerized ionic liquids and mixtures of ionic liquids with some molecular solvents were investigated and *** of relevant research fields was presented and the future developments were suggested.
Lewis acidic 1-allyl-3-methylimidazolium chloroaluminate ionic liquids were used as promising elec-trolytes in the low-temperature electrodeposition of *** studies on deposition process have been performed by cyclic v...
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Lewis acidic 1-allyl-3-methylimidazolium chloroaluminate ionic liquids were used as promising elec-trolytes in the low-temperature electrodeposition of *** studies on deposition process have been performed by cyclic voltammetry and *** surface morphology and X-ray diffraction(XRD) patterns of deposits prepared at different experimental conditions were also *** was shown that the nu-cleation density and growth rate of crystallites had a great effect on the structure of aluminium *** crys-tallographic orientation of deposits was mainly influenced by temperature and current ***,dense and well adherent aluminium coatings were obtained on copper substrates at 10-25 mA?cm?2 and 313.2-353.2 ***-over,the current efficiency of deposition and purity of aluminium have been significantly improved,demonstrating that the ionic liquids tested have a prospectful potential in electroplating and electrorefining of aluminium.
The multiphase reactive flow in process equipments, e.g., fluidized beds, involves complex coupling among flow, heat/mass transfer and reaction kinetics over scales ranging from molecules, sub-particle eddies up to eq...
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ISBN:
(纸本)8190171437
The multiphase reactive flow in process equipments, e.g., fluidized beds, involves complex coupling among flow, heat/mass transfer and reaction kinetics over scales ranging from molecules, sub-particle eddies up to equipments. Conventional two-fluid model (TFM) ignores the effects of meso-scale structures, and hence is not suitable for describing the intrinsically multi-scale heterogeneity within multiphase systems. To be consistent with the meso-scale structures, we proposed a structure-dependent multi-fluid model (SFM), and closed its drag force by invoking the stability condition defined in the energy-minimization multi-scale (EMMS) model. The SFM reduces to the conventional TFM if homogeneous distribution is assumed within each grid, and reverts to the original EMMS model if it is used to describe steady state, global behavior of a fluidized bed. The multi-scale computational fluid dynamics (CFD), which is characterized by coupling of TFM and EMMS drag coefficient, can then be viewed as a simplified solution of the SFM. We demonstrate that the SFM significantly improves the accuracy and at the same time enables higher efficiency by allowing for much coarser grid used than in TFM. Recent application of it in 3D, full-loop, transient simulation of industrial processes, e.g., fluid catalytic cracking, coal combustion, gasification, kaolinite clay calcinations, shows its advantages in helping design and troubleshoot multiphase process equipments.
A comprehensive performance evaluation index that reflects the heat transfer capacity of the metal hydrides reactor was introduced, and some advantages of this index were discussed. A mathematical model of hydrogen ad...
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A comprehensive performance evaluation index that reflects the heat transfer capacity of the metal hydrides reactor was introduced, and some advantages of this index were discussed. A mathematical model of hydrogen adsorption and desorption was set up, and the validity of the model was confirmed by experimental data reported in literatures. Numerical simulations about working processes of two types of classical reactors (tubular and disc reactor) were performed. The results of comparative study show that the new index can be used in a quantitative evaluation of the reactor performance, and it is more reasonable than traditional ones.
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