Advanced Materials Research Vols. 347-353

Abstract: In order to avoid spontaneous combustion of coal, reduce cost and improve the effect of fire prevention and extinction, this essay brings about the technology and related device to prevent and control the spontaneous combustion of coal based on the properties of fire prevention and extinction of the liquid CO₂ toward fire area, such as: asphyxiation oxygen, cooling down and inerting. The technical difficulties such as the safety packing, transportation and perfusion to the fire area underground of liquid CO₂ are solved. The liquid CO₂ is transported safely to the fire area underground and are infused to fire area in the form of liquid. The on site operation and test proved that the fire-fighting technology and device has the following advantages: high speed, simple operation, adjusted continuously, stable operation, and significant and reliable fire prevention effect. It accords with the actual application and has great practical value.

Abstract: In order to investigate the nutritive and ensiling characteristics of banana stems and leaves, the chemical compositions of banana stems and leaves were analyzed and the effects of additives on fermentation quality were measured. The research results showed: Banana stems and leaves had high fiber content (stem>58% DM, leaf >72% DM), nitrogen free extract content (>50% DM), and water soluble carbohydrate contents (WSC>5% DM), with certain nutritive value. Tannins of banana stem and leaf were 0.11% DM and 0.24% DM. There were lactic acid bacteria (>105cfu/g FM) in the banana stems and leaves; they might be well preserved with some treatments.

Abstract: Import and export from China’s environmental and economic systems are analyzed to study current resources utilization by emergy anaysis. Domistic resource, purchased energy, materials input and outputs in environment and human society were identified. The emergy contrastive analysis between import and export from 1985 to 2005 reveals that the majority of resource depletion has been brought about by China’s internal booming development, China’s economy has benefited from recent international trade, and China makes great contributions to the world economy. However, increasing resource depletion impels China into exploiting indigenous resources and depending increasingly on international resource markets. The amount of waste generated as the main byproduct of resource depletion grows continuously every year, so domestic increasingly rigorous ecological and environmental problems is unavoidable.

Abstract: Deformation of slope for all section is almost the same while the width of slope along the strike is large enough, that is plane deformation. If the width is small, then cannot analyze according to the plane problem. According to above method, slope deformation of concave base is 3D problem if excavates a limited width concave conveyor belt alone the slope dip in open-pit mine. In this article, the relation between excavation width and deformation is analyzed by 3D numerical simulation method, on the basis of some mine actual geological occurrence conditions, meanwhile, calculative equation among deformation geometry and limit equilibrium is established to evaluate concave base slope stability. Concave base slope for conveyor belt is 32% for deformation of plane mode slope in light of numerous simulation result, and the stability coefficient can be improved by 0.5 through case studies analysis. So, the safety of belt transport system is ensured.

Abstract: This paper presents experimental work that quantifies the effect of water-alternating-gas (WAG) variables on the immiscible N2 flooding process for low permeability reservoir of Ordos Basin. Many experiments were done with the sand-packed model under the formation condition. The results may be used to determine such parameters as injection pattern, WAG radio, and the number of WAG slugs. Analysis of the relative efficiency of each WAG slug is discussed.

Abstract: The Volume calculation model of big channels is established based on percolation echanics theory. The permeability calculation model of big channels is on the basis of high-speed non-Darcy fluid flowing in big channels. Big channels inunconsolidated sandstone reservoirs exist in incomplete developed form and complete development form. And the percolation indexes vary in different stages of development. Research results show that permeability of big channels when percolation index is 0.5 differs from permeability of big channels calculated according to linear Darcy flow with a ifference of 15.8 times. Confirming the percolation index n accurately is the premise of calculating permeability in big channels and the average radius.

Abstract: The effects of Na⁺, Ca²⁺, and Mg²⁺ on hydrophobically associating water-soluble polymers (HAWP) were studied in this paper.Their decreased viscosity in aqueous solution at different salt concentrations were measured and the corresponding microstructure by Atomic Force Microscopy (AFM) were determined. The results show that the destructive microstrucure was the intrinsic reason for the decresed viscosity. Among the three salt aqueous solutins, CaCl₂ has the highest strong destructive capability to the microstucute of HAWP.

Abstract: Modular HTGR nuclear power plant because of inherent safety and high thermal efficiency shows good prospects for development. The current high-temperature reactor demonstration power plant (HTR-PM) using two thermal power of 250MW of modular HTGR with an electric power 211MWe turbine unit. As one development goals of multi-reactor with one turbine unit, millions of kilowatt nuclear power plant will use more reactor module and steam generator module more like demonstration power plant (HTR-PM) with 1000MWe supercritical turbine generator unit. spiral-style super-critical steam generator design, modeling is a key factor. Analyzing the structure and the characteristic of moderate spiral coil steam generator which is used in Modular HTGR demonstration power plant, from the mechanism of equipments, based on the law of quality conservation, energy conservation, momentum conservation, authors build up the full scope real time simulation mathematical model of super critical steam generator. The dynamic experiments of feed water disturbance, power disturbance, Helium flux disturbance are made on the basis of the model. The experiments show that the model of super critical steam generator has excellent dynamic characteristics.

Abstract: The thesis analyses and compares the traditional tea polysaccharide extracting technology, goes on the experimental research of the supercritical extraction technology in tea polysaccharide extracting, and confirms the best technical parameters of the supercritical extraction in tea polysaccharide extracting.，at the condition of the grain size was 380um、20% anhydrous ethanol、extracting pressure 35Mpa、extracting temperature45°C、extracting time2h, the extraction rate of TPS could reach 92.5%.Compared with other methods, Supercritical CO2 extraction technology can keep tea polysaccharide activity better,and it has a good application prospect.

Abstract: Carbon dioxide flooding is an important way to exploit heavy oil reservoir. Considering the Zheng411 super heavy oil reservoir in Shengli Oil Field, the solubility of supercritical carbon dioxide in super heavy oil, and the effect of supercritical carbon dioxide on the volume factor, viscosity, component content and oil/water emulsification of super heavy oil are researched. The result shows: the solubility of carbon dioxide in super heavy oil increases with the increasing pressure, but the increasing extent declines gradually, when the pressure is below 28MPa, the solubility of carbon dioxide decreases with the rising temperature under the same saturation pressure; the volume factor increases linearly with the increase of supercritical carbon dioxide solubility; under the condition of unsaturation, the supercritical carbon dioxide is able to reduce the density of super heavy oil substantially, whereas it has little impact on the chemical properties of oil; Demulsification and visbreaking can be realized through dissolving supercritical carbon dioxide in super heavy oil that contains water, and the viscosity reduction capacity of carbon dioxide is hardly affected by water.