Current research status on methane conversion under low temperature plasma is reviewed. Both advances and prospects of techniques, reactors and reaction mechanisms of methane conversion under low temperature plasma are described.

Suction line heat exchanger is used for inner heat recovery with which heat is exchanged between condensed refrigerant liquid and evaporated refrigerant gas. In a general refrigeration system,inner heat recovery is helpful to increase cooling output, but it may lower the performance of vapor compressing refrigeration system sometimes also. In adsorption refrigeration cycle, inner heat recovery is beneficial to improve the cycle performance in terms of quantitative thermodynamic analysis. Although inner heat recovery decreases the cooling effect to adsorbent from evaporated gas,this does not offset the tendency of increasing cooling output. Some experimental data also verify that the precooler recovers some heat from the evaporated gas and help the evaporator to provide much more cooling capacity. Therefore, in adsorption refrigeration system, the precooler for inner heat recovery is an effective element to improve its performance,especially in the situation that condensing temperature is far higher than evaporating temperature.

The heat transfer enhancement and flow resistance characteristics of non-decaying swirl flow formed by a spiral fin tube is investigated experimentally in this paper. The effects of non-decaying swirl flow, decaying swirl flow and non-swirl flow on heat transfer and resistance characteristics are also compared and analyzed. The experimental results indicate that heat transfer coefficient of non-decaying swirl flow increases by 60%～80% compared with non-swirl flow and by 49% compared with decaying swirl flow, but the pressure drop of non-decaying swirl flow is obviously higher than that of decaying swirl flow and non-swirl flow. The analysis results show that the comprehensive thermal property of non-decaying swirl flow is better than that of decaying swirl flow at a low Re, when Re is larger than a critical value (Re=1.8×10⁴ in this experiment) the decaying swirl flow is better.

Numerical simulation and theoretical investigation of fluid flow and heat transfer in porous media/fluid coupled areas have been widely studied in recent years. Few researches are focused on compressible gas flow in porous media/fluid coupled areas.The unified governing equations for the fluid and porous media are used to describe the compressible flow in porous media/fluid coupled areas. A method to decide the source terms for flow in porous media is also presented. As an example, a detailed numerical simulation of compressible gas flow in a straight round pipe with porous media/fluid coupled areas and backward-facing and forward-facing steps are carried out and the computational results coincide with the experimental data.

To investigate the effects of micro-fin geometry and operating conditions on flow evaporation performance of micro-fin tubes, tests were conducted on four micro-fin tubes having different micro-fin geometries and one smooth tube having 9.52mm outside diameter (OD). Two of the micro-fin tubes had 9.52mm OD and the remaining two had 7.0mm OD.The refrigerant used was R22. The experiments were carried out for 90—400kg•m^-2•s^-1 refrigerant mass fluxes at 7℃ evaporation temperature, 15%—20% inlet vapor quality, 5—6℃ outlet superheat degrees. The variations of evaporation performance of micro-fin tubes with refrigerant mass flux were obtained. The effects of micro-fin geometry and tube diameter on performance were discussed. The two 9.52mm OD micro-fin tubes yielded 130% and 180% greater heat transfer coefficients than the smooth tube, while the inside surface areas of the two micro-fin tubes were only 40% and 70% greater than that of the smooth tube.

The electric field enhancement of natural convection and pool boiling heat transfer of ethyl acetate on plate surface was investigated. The comparison and analysis for the experimental results were performed. The experimental data indicated that electric field has a strong enhancement effect for natural convection and pool boiling heat transfer of ethyl acetate. The enhancement effect of electric field for ethyl acetate natural convection heat transfer is larger than the effect for pool boiling heat transfer. At the same voltage, the enhancement factor，f，decreases gradually with further increasing heat fluxes. When the heat flux is larger than 4kW•m^-2, the variations in enhancement effect of electric field for natural convection heat transfer are much less with further increasing of heat flux.At the same heat flux, the enhancement factor increases gradually with increasing voltage of the applied electric field. Since ethyl acetate is a strong polar organic dielectric, it has intense response to the electric field applied. In the experimental condition, the enhancement factor of electric field for natural convection heat transfer reaches 6—7. For pool boiling heat transfer, the enhancement factor reaches 4—5.

The forces affecting the motion of particle clusters near the wall of a Circulating Fluidized Bed (CFB) were analyzed to determine the contact time of particle clusters and to develop a theoretical model for the particle-gas convection heat transfer coefficient. The results compare well to prior experimental data,suggesting that this theory accurately reflects the convection heat transfer in a CFB.

The characteristics of power law fluid governing equation was elaborated and the effect of viscosity and flow exponent on two-phase flow was studied. With increasing flow exponent, the velocity of power law fluid near the pipe center decreased, and the velocity of particle near the pipe center increased but decreased near the pipe wall. With increasing viscosity, the velocities of power law fluid and particle showed the same trend. It was found be compared the two-phase flow of power law fluid-solid with that of liquid-solid that the fluid velocity of power law fluid-solid was bigger than that of liquid-solid and the particle velocity distribution of power law fluid-solid was flatter than that of liquid-solid.

In a pilot scale reverse flow reactor with a liter of catalyst, catalytic combustion of typical industrial waste gas contaminated with volatile aromatic compounds (VOC) was systematically investigated, and the “temperature run-away”in the case of too high feed concentration and the “extinction of reactor” in the case of low feed concentration were observed. More attention was paid to determining the range of feed concentration in which through adjusting operation parameters,such as the periodic time,the reactor could achieve a high conversion of VOCs and meanwhile maintain a stable ignited state,i.e neither “temperature run-away” nor “extinction”.

A kind of CWAO catalyst, RuO₂/γ-Al₂O₃, was prepared by dipping Al₂O₃ into aqueous solution composed of RuCl₃. Taking phenol as organic substrate,the influences of the initial pH of the feed solution and degradation temperatures on the stability and the activity of RuO₂/γ-Al₂O₃ catalyst were investigated. Results showed that leaching of Ru and Al existed in the process of CWAO of phenol and the amount of leached Ru and Al increased with decreasing initial pH of the feed solution, but phenol removal was higher in the acidic feed solution than that in the alkaline feed solution. The amount of leached Ru and Al decreased and phenol removal was higher with increasing degradation temperature. The influences of Ce and Zr added to RuO₂/γ-Al₂O₃ catalyst on the stability and the activity of the catalyst were also studied. The result showed that doping of Ce and Zr into RuO₂/γ-Al₂O₃ catalyst can promote the stability and activity of the catalyst prepared.

Thermally Coupled Distillation Columns are more efficient than conventional sequences. Because of the difficulties of proper design, their applications are restricted. In this paper, a new approach using genetic algorithm and artificial neural network for the optimization of thermally coupled distillation is presented. Mathematical model constructed with artificial neural network based on the simulation results with ASPEN PLUS. The Comparison of ANN prediction results and ASPEN PLUS simulation results shows that the model can simulate thermally coupled distillation rightly. Modified genetic algorithm is used to optimize the artificial neural network model. With the proposed model and optimization algorithm, the decision variables and the target value can be solved automatically and quickly. The convergence curve proves the efficiency of the genetic algorithm. A practical example is used to demonstrate the algorithm.

Batch processes are widely used in producing many high-value chemical products for its good flexibility. However, the production and costeffectiveness of batch plants mostly depend on short-term scheduling. The construction of traditional models for batch scheduling relies on the definition of time slots or time events, which lead to the result that many binary variables are involved in the models and it takes much time to solve the problems with the branch and bound method.A new kind of model for scheduling of multi-product batch plants is presented. The new model uses a continuous-time domain representation that does not rely on the definition of time slots or time events. The symmetrical and complemental feature of binary variables is also considered to simplify the model. As a result, the number of binary variables of the new model is successfully reduced to no more than half of the traditional ones. A medium-scale example is presented to prove that the new model quickly solve and reach the global optimal result. Comparisons with traditional model are also provided with large-scale problems. Moreover, the principle of the new model can be not only used in the multi-product problem,but also easily applied in other aspects such as multi-purpose batch scheduling and so on.

Direct separation and purification of hemoglobin from fresh bovine hemolysate were studied with expanded bed adsorption. Ionic strength, pH and temperature had great influence on the formation of methemoglobin in the process. The purity and recovery of the product were also influenced by these factors. The conditions for adsorption and elution were optimized. The best performance was obtained by using 10mmol•L^-1 phosphate buffer solution, pH6.6. Eluting at pH 7.2 was carried out at low ionic strength and the final recovery of hemoglobin was more than 80%. A low temperature of 4℃ in the process was necessary for prevention of methemoglobin formation. Under optimized conditions, natural bovine hemoglobin of electrophoretical purity could be obtained by only one step of operation, and the dynamic adsorption capacity was between 70—75mg•ml^-1. HPLC result suggested that the purity of the product was about 99%.Methemoglobin was kept as low as 5.4%. Compared with the traditional process of membrane filtration followed by chromatography, the expanded bed adsorption has the advantages of short processing time, high recovery, and high product activity. The method was simple, efficient and potential scale-up to commercial production.

Oxidation and absorption of nitric oxide can be achieved by using cobalt(Ⅱ) in aqueous ammonia solution. Nitric oxide is oxidized to soluble nitric dioxide in liquid phase. The Co(NH₃)²⁺₆ produced by cobalt(Ⅱ) ions complexing with ammonia acts as the catalyst. The oxidant is the oxygen in flue gas. Oxidation and absorption of nitric oxide proceed simultaneously. A stirred vessel with a plane gas-liquid interface was used to measure the chemical absorption rates of nitric oxide into Co(NH3)2+6 solutions. The reaction of NO with Co(NH₃)²⁺₆ can be considered as instantaneous. The gas-liquid reaction becomes gas film controlling as Co(NH₃)²⁺₆ concentration exceeds 20mmol•L^-1. Oxygen in the gas phase is favorable to the absorption of nitric oxide, but the effect is less significant at oxygen concentration above 5.2%. The NO absorption rate decreases with increasing temperature. The kinetic equation of NO absorption into Co(NH₃)²⁺₆ solutions in the presence of oxygen is presented.

The effects of some factors on degradation of 4-chlorophenol in waste water with pulsed high-voltage discharge plasma were studied. Furthermore,the kinetics of degradation of 4-chlorophenol was also studied. The degradation efficiency of 4-chlorophenol could be raised considerably by increasing peak voltage, bubbling rate of gas and by decreasing electric conductivity of waste water. The presence of alcohol would decrease the degradation efficiency of 4-chlorophenol. The degradation of 4-chlorophenol in waste water with pulsed high-voltage plasma was a first-order reaction. The correlation between degradation rate constant k and reaction temperature T could be expressed by Arrhenius equation. At initial pH 7.0, electric conductivity of waste water 80μS•cm^-1,peak voltage 30kV,discharge frequency 60Hz,the diameter of discharge electrode 0.6mm,and discharge distance were 3.0cm, A was 1.365×10^-2min^-1 and experimental activation energy E_a was 5.129kJ•mol^-1. The degradation rate constant k could also be expressed.

A simplified Solomon pyrolysis model for simulating HCN release in NO formation during coal combustion is proposed. A full two-fluid model together with the k-ε-k_p two-phase turbulence model, the EBU-Arrhenius combustion model, the six-flux radiation model, and two different HCN release models are used to simulate gas-particle flows, coal combustion, HCN release and NO formation in a swirl burner. Comparison of predictions with experimental results taken from references indicates that the HCN release model based on the simplified Solomon pyrolysis model is better than the original HCN release model based on the two-equation pyrolysis model.

A novel desulfurization method for petroleum products by gamma rays radiation is put forward and investigated in this paper. The n-dodecanethiol (DCT) dissolved in n－dodecane was used as the simulated petroleum product. The results showed that the degradation efficiency of DCT was proportional to the radiation dose of gamma rays, and a lower dose rate seemed to correspond to higher degradation efficiency at the same dose. Degradation occurred under both circumstances with and without oxygen, while the demanded dose for the degradation efficiency of 90% was 250kGy and 700kGy, which implied that the degradation process was improved greatly by oxygen. Part of the end product of DCT degradation was sulphate with oxygen, and hydrogen sulfide was detected under the condition without oxygen.

A research framework of application-oriented ceramic membrane design was proposed. The effects of membrane pore size distribution and particle size distribution of suspension on filtration were analyzed. In this work a blocking factor(k) was given to describe membrane fouling and a new crossflow microfiltration model of particle suspensions was built. This model discovers the correlation between membrane permeability and microscopic material structure, by which the variation of permeate flux with filtration time would be obtained and the influences of membrane structure parameters on permeate flux could be predicted.The model calculation showed good agreement with the experimental results.

Based on the established model of microfiltration for separating particle suspensions, which described the relation between membrane structure parameters and its permeability, the influences of membrane structure parameters such as pore size, thickness and porosity on its performance were theoretically predicted and discussed under the ideal conditions that membrane pore size and particle size distribution are normal. The simulated results showed that there was an optimum pore size in the filtration of suspensions which maximized permeate flux, and the optimum pore size was influenced by the size and size distribution of the particulates.

On the basis of the developed microfiltration model, membrane pore size was optimized to filter the particle suspensions of titanium pigment. The optimized Al₂O₃ ceramic membrane was prepared by state particle sintering method and characterized by SEM and the gas bubble pressure method. The prepared membrane was superior to commercial membranes and the model calculation showed good agreement with the experimental results. The method of application-oriented ceramic membranes design was basically completed.

The kinetic model of vulcanization of liquid silicone rubber was established by experiment, and the conversion rate of the reactants was calculated. The fundamental control equation for calculating the temperature field accompanied by reaction heat was derived, and two types of thermal boundary conditions were analyzed. The implementation procedures of the numerical simulation were described in detail. The simulation software of hot vulcanization process of moldable silicone rubber was designed. Finally, the rationality of the simulation theory and algorithm was verified by one typical engineering example and its hardness test as well as its engineering application.

It has been acknowledged that a dilute-phase/dense-cluster two-phase micro flow structure exists in the riser. The particle velocity signals from Laser Doppler Velocimeter are analyzed and the velocity and turbulent velocity of particles in the dilute phase are obtained. The radial velocity distribution of particles in the dilute phase is similar to a parabola. A correlation, similar to the 1/n power law of gas velocity in turbulent state, is given to describe the velocity distribution quantitatively. The cross-sectional average velocity of particles in the dilute phase is nearly equal to the superficial gas velocity, which indicates that the particles in the dilute phase exist in individual particle state. A maximum value exists at the radial position r/R=0.5—0.8 for the turbulent velocity of particles in the dilute phase. This radial position may correspond to the boundary between the dilute phase controlled region and the dense cluster controlled region.

It is significant for the development of multidimensional two-phase models to study the measurement technology and distribution characteristics of local parameters in two-phase flow. The radial distribution of a rising bubble in stagnant liquid is investigated through the radial measurement in a vertical tube using the dual-sensor optical probe. The analyses of probe signals show that optical probe is very sensitive to the bubble signals and satisfactory measurement results can be obtained. Besides, the effect of the up-stream sensor on the down-stream one is studied in this paper.

Photo-catalytic TiO₂ was prepared from tetraisopropyl titanate (TPT) in supercritical ethanol. It was found that TPT in supercritical ethanol could be effectively converted into the anatase-form of TiO₂ crystallites. The anatase-form of TiO₂ as a photo-catalyst was evaluated for its adsorptivity and subsequent photo-catalytic activities on formaldehyde, one of the harmful air pollutants in the environment. As a result, the supercritically treated TiO₂ had a high decomposing ability. Under the same condition, the experiment was repeated for 5 times,and photocatalysis of the samples did not decrease. This indicated that the supercritical treatment was effective to prepare photo-catalytic TiO₂, which was feature by stability, longevity and high photo-catalytic decomposition of formaldehyde for environmental cleaning. Meanwhile, unlike conventional chemical reaction, which is complex and time-consuming, supercritical treatment is easy to operate, saving both time and labor.

This paper presents artificial neural network (ANN) modeling of heat transfer performance for a pulsating heat pipe (PHP). The investigated PHP is a vertical closed loop copper/ethanol PHP. Fully connected multi-layer feed forward network is adopted and back propagation momentum algorithm, sigmoid node function are used. In the network, two input nodes correspond to heat load and fill rate and the output is a single node for thermal resistance. The matching of the ANN test output data and the experimental data is satisfying. It can be inferred that the ANN model can be applied to accurately model PHP performance.

The corrosion inhibition of a kind of green scale inhibitor, polyepoxysuccinic acid (PESA) was studied based on dynamic experiments. In addition, the synergistic effect among PESA, Zn²⁺ and sodium gluconate was also investigated. According to the experimental data, when only PESA is used, it had fairly good effect on steel. The synergy between PESA and Zn²⁺ or sodium gluconate was poor. However, the synergistic effect of PESA, Zn²⁺ and sodium gluconate is very good. Further experiments show that the corrosion inhibition of PESA is mainly affected by oxygen atom inserted.

In this paper Singular Decompositon Value (SVD) formula and modified Chi-square solution are provided, and the modified Chi-square is combined with FT-IR instrument to control biochemical reaction process. Using the modified Chi-square technique, the unknown concentration of reactants and products in test samples withdrawn from the process is determined. The technique avoids the need for the spectral data to conform to Beer’s Law and the best spectral range is determined automatically.

A new method of regenerating ion exchange resin was brought forward aiming at the improving of regeneration techniques used at present. Experimental study was made by adopting a single stage of three compartments regeneration device. Under the experimental conditions, electric regeneration of ion exchange resin in the packed electrodialysis bed was not effective. The most suitable way is to make acid and base from water electrodialysis with bipolar membrane electrodialysis.

The air drawing model of polymer in melt blowing process is established by considering the effects of the variation of density and specific heat capacity at constant pressure of polymer melt with polymer temperature. The model is solved by introducing the numerical computation results of air jet flow field of the dual slot die, and model predictions of fiber diameter show good agreement with the experimental data. The effects of the processing parameters and die design parameters on fiber diameter are studied. It is found that lower polymer flow rate, higher initial polymer temperature, higher initial air velocity, smaller angle between the slot and the die axis, smaller width of the die head and larger width of the slot can all yield finer fibers.