Advanced Materials Research Vol. 827

Abstract: This paper is aimed to show that oil gas dispersion model of underground fuel depot are useful for predicting hazardous areas and choosing emergency response strategy. For this purpose, the factors affecting the dispersion process in the long narrow underground fuel depot are analyzed and the simulation model is put forward. The simulation results agree well with the experimental data and show the effects of oil gas flow rate and concentration on the hazardous areas.

Abstract: Currently, the primary method for developing extra heavy oil is the steam assisted gravity drainage (SAGD) characterized by high recovery factor and gas-oil ratio. However, in the course of application of this technology, because the whole reservoir needs to be heated to a very high temperature, too much steam is needed, and simultaneously, the loss of heat of reservoir is also increased. For the purpose of exploiting the extra heavy oil more economically, a SAGP technique, the steam and gas push, is put forward in the oil industry world. This paper takes the adding of nitrogen as an example, conducts reservoir engineering theory analysis, numerical simulation study and physical modeling study, and concludes that when adopting SAGP technique, it is unnecessary to increase the temperature of the whole reservoir to a very high value; compared with SAGD, although the cumulative production of SAGP declines to some extent, the steam injection volume is only 68% of that of SAGD, which indicates that SAGP exploitation technique can save steam and thus reduce the production cost compared with SAGD.

Abstract: The production of a multilateral horizontal well is higher than the production of a vertical well, even than that of a unilateral horizontal well. Nonetheless, the stimulation effect is significantly influenced by the branch parameters, and the impacts of branch parameters on the productivity of a multilateral horizontal well are rather complex. In this paper, the factors which affect the productivity of multilateral horizontal wells are preliminarily analyzed with the laboratory method of physical simulation. Then, a semi-analytical coupling model of wellbore flow and reservoir flow is built, and the multilateral horizontal wells are simulated to investigate the impacts of branch parameters on the stimulation effect of multilateral horizontal wells.

Abstract: In the development of bottom water sandstone reservoir, the utilization of horizontal wells is economical and reliable but also can delay the bottom water coning and it has the advantages over the conventional vertical wells .The methods adopted in the past have methodological errors. This paper regards the reservoir flow and wellbore flow of horizontal well as a interactional system which considers the fluid friction, momentum change, the mixed interference of wellbore wall inflows and other complex factors and obtains Laplace space solution by using the Laplace transform to establish the coupled model of wellbore pressure drop calculation. It can provide more advanced means for reservoir engineering studies, well completion and production engineering design of horizontal wells on the conditions of bottom water reservoir.

Abstract: This paper provides three types of modern bio-fuels transformation approach, and the corresponding products as well as their world-wide production and application situation. The paper also analyses the advantage and disadvantage of Marine biological fuel and current challenges. Developing bio-fuels should not simply consider energy exploitation, but should concern setting up matched production system and multi-functional frameworks, highly integrating environmental, social, and economic resources, so as to achieve goal of long-term sustainable development.

Abstract: Experiments found that the thickness of the cesium carbonate modified layer of the processing solution will affect the performance of the polymer solar cells. We dissolved cesium carbonate in an organic solvent 2-ethoxyethanol, and prepared cesium carbonate modified layer of different thickness at different rotational speed. When the rotationing speed was at 2000 r/min, the efficiency of the device was preferably 2.28%, which indicated that the thickness prepared at this speed was most advantageous to the enhancement of the performance of the device. In addition, by annealing cesium carbonate modified layer at 130°C and 150°C, we found that the performance degradation of the annealing device at higher temperature was due to the fact that too much of the energy destroyed the micro-structure of the formed active layer.

Abstract: Under the different experimental condition of ignition energy, the variations of gas explosive limit were obtained. The explosive limit ranges from 4.86% to 16.72%, under the condition of high ignition energy of 450 J. The result is quite different from the theoretical explosion limit range from 5% to 16%, thus providing a new basis to effectively prevent the gas explosion accidents.

Abstract: In the light of low efficiency of photovoltaic power generation and the problems of air source heat pumps application in the cold regions, this paper developed a composite evaporator and designed a new type of solar-air composite heat pump system, which was comprised of independently developed solar photovoltaic-thermal collector based on flat plate micro heat pipe and air source heat pump. The performances of heat pump system were studied experimentally, including water temperature of the heating tank, suction and discharge pressure, and performance of heat pump. When 73L water in the heating tank was heated by 1 HP heat pump from 15°C to 50°C at the ambient temperature of 5°C, the running time of dual heat source operation conditions was 5.14% shorter than that of separate air heat source operation conditions. Meanwhile, COP increased by 5.99%.

Abstract: With the rapid development of wind power in recent years, the wind power industry has gradually shifted from infrastructure construction to equipment operation and maintenance. The importance of the operation and maintenance of the wind turbine is increasingly apparent. A new vibration monitoring mode of wind turbine, called distribution acquisition-Centralized analysis, has been established by full investigation and study. This mode involves information technology, electronics technology and automation control technology. It is based on the mechanical movement principle and the principles of mechanics analysis. Throughout the one-year application of this vibration monitoring mode in wind farms, it is obseraved that: this model can grasp the operational status of the key equipment of the wind turbine, and effectively identify potential failures in a timely manner. This mode reduces costs of maintenance, improves equipment reliability and extends equipments operation time.

Abstract: Based on the DC-link voltage-to-shoot-through duty ratio control problem of non-minimum phase in Z-source inverter, the photovoltaic system has been taken as an example, according to the nonlinear characteristics and switching state equation of Z-source inverter, the affine nonlinear model was set, based on the differential geometric, the proper coordinate transformation was constructed. In order to simplify the controller, and ensure the internal dynamic system stability, the zero-dynamic design was used for controlling DC-link voltage of Z-source inverter. Simulation results show that when the change of the output power of photovoltaic cells occurs, this method has better dynamic characteristics.