Advanced Materials Research Vols. 960-961

Abstract: The potential hazard effects of Endocrine Disruptors (EDCs) are drawing growing attention from the public,and the traditional sewage water treat process works in an unstable way in the removal of EDCs and can be influenced by many factors.The membrane technology shows good interception efficiency of EDCs,and the photocatalytic oxidation,with its wide application range of different types of polluted water,can thoroughly convert EDCs to inorganic materials.The combination process of nanofiltration and photocatalytic oxidation can easily extract EDCs from the water at first step,and decompose the EDCs in the concentrated polluted water and the back fluch water collected at the second step.The combination process is a reliable,practical and effective methods for EDCs removal.

Abstract: Fusion reactors require high-speed pumping of helium, deuterium and tritium while maintaining the inventory of tritium in the pumps at a low level. Cryopumping is potentially the most attractive method for this task. Cryosorption pump using rare-gas as sorbent is a good choice to satisfy the reactors for its special characters. Although a large number of works have been published in recent years on the properties of cryosorption pump using rare-gas as sorbent, it is hard to understand the behavior of fluid in a frost layer due to expensive and strict experiment conditions. Molecular modeling provides a convenient way to understand the principle of adsorption procedure in microscopic view. This paper applies the Grand Canonical Monte Carlo (GCMC) simulation method to study the adsorption behavior of Helium in argon frost. The HFD-B (HE) Aziz potential is used for the description of the interaction between two helium molecules. The adsorption behavior of helium in slit pore at T=4.3 K, 5 K, 6 K and 7 K is simulated. The simulation results show that the adsorption capacity increased rapidly as the bulk pressure smaller than 0.01 Pa, and the slop becomes slowly as pressure raised. The adsorption capacity is over 50% higher at lower temperature. The adsorption behavior agrees very well with experimental data in the public literature. The results show in this paper could be a guide for cryogenic workers to design cryosorption pump system. It is also provided a convenient method to predict the real adsorption procedure.

Abstract: This paper presents a numerical study on laminar flow and convective heat transfer of nanofluids in a circular tube under constant wall heat flux boundary condition. Single phase model is used for simulating the heat transfer and flow behaviors of three different nanofluids. The effects of nanoparticle concentrations, nanoparticle diameter, nanoparticle material and Reynolds number on the Nusselt number and wall shear stress of nanofluids are determined and discussed in details. The comparison of Nusselt number of CuO-EG/water, SiO₂-EG/water and Al₂O₃-EG/water nanofluids are presented. The results show that Nusselt number clearly increases with an increase in the nanoparticle concentration and flow Reynolds number, while the nanoparticle diameter has an opposite effect on the Nusselt number. Compared to SiO₂-EG/water and Al₂O₃-EG/water nanofluids, CuO-EG/water nanofluids give higher Nusselt number with the same nanoparticle concentrations. The results also show that wall shear stress increases with increasing nanoparticle volume concentration.

Abstract: A Cu-Ni thin film heat flux sensor had been fabricated on a 0.05mm thick polyimide film substrate by vacuum coating technology. The overall dimension of the sensor was 8 mm long and 4 mm wide. A thermopile and a thermocouple were arranged on the substrate to measure both heat flux and surface temperature. The thermopile had 18 thermocouple junctions which formed 9 pairs of differential thermocouples and were covered by two different thickness of thermal resistance layers. This research carried out static and dynamic tests of the thin film heat flux sensor. Seebeck coefficient of thermocouple is 19.3761μV/(°C). Sensitivity of the thermopile is 0.010121μV/(W/m²). Steady-state tests of the thermopile and the thermocouple were taken separately. Time constant of the thermocouple is about 0.26s, which is faster than the thermopile of 1.57s.

Abstract: Hydrocarbon fuel synthesis with renewable energy and captured CO₂ is a promising option for CCU and an important approach to sustainable energy. Like photosynthesis of plants, the technology of CO₂ direct captured from atmosphere with CO₂ utilization would close the carbon cycle thoroughly. Because of the dilute CO₂ in the atmosphere, the air capture process faces the challenge of high energy penalty. However, integrated with fuel synthesis process, the air capture process can take advantage of the waste heat produced by syngas production process and the transportation of CO₂ can also be avoided. In this study, a thermodynamic model of the fuel synthesis system is built through energy and exergy analysis. The thermodynamic contribution of three typical CO₂ capture technologies, moisture swing air capture, high-temperature swing air capture and traditional amine-based flue gas capture, is studied using the model built. Furthermore, by the sensitivity analysis of the critical parameters of the capture, electrolysis and heat exchange process, the influence of each process on the performance of fuel synthesis system is examined and the approach to improve the efficiency of the total system is proposed.

Abstract: This article mainly makes a brief introduction about Microencapsulated Phase Change Material Slurries(MEPCMS) and its preparations ，the research status and several correlations of heat transfer in turbulent flow of MEPCMS is also listed.The influencing factors of turbulent heat transfer are mainly the degree of turbulence, the mass fraction and wall heating rate,particle size effects weakly. Several heat transfer correlations under different degrees of turbulence are also presented.

Abstract: This paper studied the methane/moist air combustion characteristics in smooth microtube and microtubes with five different shape grooves and proposed the microtube groove dimensionless shape factor F=4πS/L2. The results show that the appearance of five grooves make combustion components and velocity occur jumping change and the vortex flow appears. The highest methane conversion rate is for the microtube with triangle grooves, which also indicates that the smaller shape factor is more in favor of methane conversion.

Abstract: In order to solve the problem of that the boiler burns inferior coal but cannot guarantee the combustion stability, the rich-lean burner divides primary wind pulverized coal airflow into two stocks of airflows containing different amounts of pulverized coal and sends the airflows into coal-fired furnace for improving the ignition characteristics. By the numerical simulation of the pulverized coal flow characteristics in an elbow bias-oriented rich-lean burner, regarding the “concentration ratio” and “speed difference” as the standard of evaluating the separation characteristic of the burner, considering the influence of the partition plate length, bias current stopper height and primary wind velocity to the separation effect of pulverized coal so as to provide technical assistances for the elbow bias-oriented rich-lean burner’s practical application and improvement.

Abstract: Fuel evaporation and ignition process on the high-temperature hot surface are difficult to be predicted accurately. The rule of fuel evaporation and ignition delay that various with hot wall temperature have been obtained by utilizing the simulated experiment to study the evaporation and ignition process of aviation fuel on hot surface. This study complements the related content of the fuel ignition mechanism on hot wall,at the same, reference method for fuel fire engineering practice has been provided.

Abstract: Silicon-on-insulator (SOI) transistors have been widely used in the micro-electronic devices. The Lattice Boltzmann method (LBM) is employed to simulate the heat conductions of hotspots appeared in a SOI transistor. The results show that a thermal wave effect is appeared in micro-region, and it can not be found in Fourier prediction. Comparing the results obtained by the Fourier law and LBM, we find that the LBM solution shows approximately 22% higher energy density than the Fourier prediction. When two thermal waves form different hotspots meet together, a significant energy enhancement will be appeared.