Advanced Materials Research Vols. 860-863

Abstract: Phase change materials (PCM) have recently received considerable attention in the field of thermal energy storage, due to their intrinsic properties. Phase change material slurry is a novel medium of heat storage and transfer, its apparent specific heat and heat transfer capacity is better than water.PCM slurries are being investigated for active thermal energy storage or as alternatives to conventional single phase fluids because they are pumpable and have advanced heat transport performance with phase change. This review mainly presents the information on PCM emulsions and microencapsulated PCM slurries (mPCM slurries).

Abstract: Coated Al₂O₃ thin film on the surface of the carbon sulfur composite material by liquid phase impregnation method, then made physical and chemical properties and electrochemical performance analysis on the coated carbon sulfur composite materials.Al₂O₃ reduce the direct contact of the carbon sulfur composite materials and electrolyte, reducing the erosion of electrolyte on cathode materials, improve the cycle performance of carbon sulfur composite material. 0.1C in the 2.1~3.2v cycle 20 to 100 times. The capacity retention rate increased from 70% to 90% after coating.

Abstract: The High Potential Material Lini_0.5Mn_1.5O₄ was Synthesized via Solid-State Reaction.The Surface Morphology and Particle Size of the Sample were Observed by Scanning Electron Microscope(SEM).The Crystal Structure of the Sample was Collected and Analyzed through X-Ray Diffractometry(XRD).The Sample was Charaterized by Charge-Discharge Tests.Results Indicated that the Cycling Retention Rate was about 80%,after being Charge-Diacharged at a Rate of 0.1C in a Voltage of 3.45-4.77V for 10 Times.Compared with Limn₂O₄,LiNi_0.5Mn_1.5O₄ has good cycle performance.Both of LiNi_0.5Mn_1.5O₄ structure were space group of Fd3m.

Abstract: Lots of basic analyses carried on YJOS (Yaojie oil shale) and LKOS (Longkou oil shale) consist of proximate analysis, ultimate analysis, XRF analysis and shale oil yield in aluminum retort. Besides, TGA are used on YJOS, LKOS and shale oil, gas chromatographic analysis is used on retorting gas. The results show that LKOS and YJOS have the same hydrogen-to-carbon ratio, but LKOS has higher volatile component and its oil yield in aluminum retort is much higher than YJOS. Ca content in LKOS is much higher than YJOS, however, Al and Fe content in LKOS are lower than YJOS. Two kinds of shale oil after destructive distillation have similar composition and relative content, in addition, they all produce more low boiling point distillates, combustible component of their destructive distillation gas are H₂ and CH₄, the second are CO and C₂H₆. Aluminium retort experimental findings, The carbonization temperature is the main influence factor on oil shale destructive distillation process in aluminum retort. Residence time has small influence on shale oil yield but need to choose appropriate heating rate and particle size. Best carbonization parameters of LKOS in aluminum retort: Temperature 500~550°C, heating rate 5°C/min, particle size 2~4mm, Residence time 10~20min;the best parameters of YJOS: Temperature 500~550°C, heating rate 5°C/min, particle size0.2~0.9mm, residence time 10~20min.

Abstract: The high temperature creep tests of standard specimen and double U-type notch specimen of T92 steel were carried out under different stresses at 650 °C. Then optical microscopy and scanning electron microscopy were used to observe the fracture morphology and microstructure. The results show that the multiaxial stress state leads to the creep fracture cracking initiation in notch. Under multiaxial stress state, the failure mode of T92 steel is transgranular and dimple plastic fracture, and is more obvious with the increase of creep life. Compared with under uniaxial stress state, the precipitates under multiaxial stress state are larger in size and quantity, and are much coarser.

Abstract: Taking the P92 steel as the object,Creep-Fatigue (CF) tests of P92 steel at 873K under stress-controlled were carried out with GWT2504 equipment to investigate the CF life prediction. The life prediction model based on Applied Mechanical Work Density (AMWD) was developed in this study,and introduce the effective coefficient ƞ to modify the former. To verify the prediction capability of the AMWD-based and the modified model, comparisons of the models predicted lives with the experimental data of CF tests on P92 steel at 873K were made, it is found out that the AMWD-based model predictions for CF are in agreement with the experimental lives with the factors of 0.9013 and 1.0600, which verifies the model has a good predictability, and the Modified model with the factors of 0.9558 and 1.0469.

Abstract: In order to find out the migration rules of radon transport in porous aquifer medium,transport process of radon in natural groundwater environment was simulated by laboratory seepage sand box experiment.This paper made in-depth discussions on the migration rules of radon in groundwater and soil and revealed the behaviours of radon in the environment.The experimental results indicated that convection dominated on the movement of radon in porous aquifer medium.The lateral migration of radon was due to not only diffusion but also carrying of groundwater, adsorption of porous medium, decay and volatilization. The lateral migration played an important part in the movement of radon.The cluster theory and microbubble theory in the existing research results were not the the principal migration mechanism of radon transport in porous aquifer medium. Release and accumulation, volatilization, decay, adsorption and convection should be the result of different periods of peak during the process of radon movement. The findings provided the scientific evidence for quantitative study of migration behaviours of radon in the underground environment and further support for the theory that the application of radon in oil and gas exploration, detection of ground fissures, earthquake monitoring and prediction and so on.

Abstract: A comprehensive molecular simulation study on heterogeneous reaction mechanisms of NO with nitrogen-containing char is carried out using density functional theory. NO chemisorption and subsequent possible reaction pathways are proposed. Geometries of reactants, products, stable intermediates and transition states are optimized at B3LYP/6-31G(d) level. It is found that NO molecule chemisorption with its bond axis parallel to the edge line of nitrogen-containing char is a weakly exothermic process. The N-O bond in NO molecule tends to dissociate after chemisorption. N₂ and CO are desorbed when NO molecules are chemisorbed with the formation of N-N bond. N₂ desorption is exothermic, while CO desorption is endothermic. So we conclude that N₂ is the dominant product from interaction between NO and nitrogen-containing char.

Abstract: Though the power molding of Yaojie oil shale, the optimum binder and proportion are confirmed. Hot strength,cold strength and oil yield of oil shale ball produced by power molding are measured. The results show that: Ⅰ , Ⅱ are suitable binders for power molding, besides, the hot strength and cold strength of oil shale ball produced by Ⅰ and Ⅱ are higher than 200N and 400N respectively. It can be found that from SEM, binders filling between particles of oil shale become gel or crystal after mixing with water. All that gel or crystal make particles connected closely and form net structure. The reason of low oil yield may be that the larger diameter of oil shale ball hinder the escaping of shale gas, and during escaping, shale gas is pyrolyzed because of long heating time, in addition, binders may absorb some shale gas.

Abstract: The impurity of benzothiophthene can be removed by extractive distillation in the crude naphthalene purification process. A process simulation has been studied on the crude naphthalene purification. In the case of ensuring each fraction's naphthalene concentration, a sensitivity analysis is made to determine the optimal conditions by varying extractive distillation parameters such as the feed stage, the reflux ratio and the distillate rate. Besides controlling of the sensitive plate for the recovery section is also discussed.