Advanced Materials Research Vols. 724-725

Abstract: With the growing tension of the energy resources, energy risk has become the core of common concern. In this paper, the definition and the cause of energy risk analysis, combined with the analytic hierarchy process (AHP) construct the comprehensive risk-based energy industry index system. According to the viewpoint of information theory, the entropy method to calculate the objective factors, to measure the information content of the Beijing Energy Risk indicators inexact. By visual comparison of each indicator entropy, research the impact of various indicators of system.

Abstract: The paper aims to investigate the energy separation effect of gases such as natural gas to vortex tube. Energy separation phenomena of different gases were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of natural gas, air, nitrogen, et al were simulated. The main factors that affect the energy separation were found. With cold mass fraction being 0.7 and pressure drop ratio being 3.90, the results show the effect can be divided into three intervals in terms of the freedom degrees. The first interval is filled with monatomic gas at 50°C to 60°C; the second diatomic gas at40°C to 50°C; and the third polyatomic gas at 0°C to 40°C. In monatomic gas and diatomic gas, the smaller the gas specific heat capacity is, the better effect will be. However, in polyatomic gas, bigger specific heat capacity ensures better energy separation.

Abstract: This manuscript developed two methodologies of mapping energy flows of coal utilization in the form of Sankey diagrams: one was energy allocation diagram without illustrating any energy losses and the other was energy efficiency diagram illustrating main energy losses. Based on the methodologies, energy flow diagrams of China's coal utilization in the year 2005 and 2010 were presented. The two diagrams divided coal utilization into four stages from raw coal supply, by coal products supply and coal conversion, to energy end-use. Comparing with previous studies, some technical details were further introduced into the mapping, including coal preparation and the distribution of end-use energy such as electricity, heat and coke etc. Based on the results, the main characteristics of coal utilization in China and its main changes from 2005 to 2010 were discussed.

Abstract: Ocean thermal energy (OTE) is a kind of ocean energy with a large development potential. In this paper, a new method making direct use of OTE for desalination was put forward and its principles and working process were also expounded. Firstly, this paper established the relevant process model of OTE desalination system. The system used OTE to maintain a vacuum and seawater could be evaporated at a much lower temperature and with less energy than conventional technique. Secondly, a parametric study was carried out quantitatively. It analyzed the influence on the system’s operation of three main parameters (temperature, mass flow and energy consumption). Finally, this paper improved the energy efficiency of the system. The lowest unit energy consumption could reach 4.54kWh/m3. The results indicate the feasibility of OTE used for desalination and its competitiveness against common solar desalination method.

Abstract: Fuel injection pumps of Diesel engine are lubricated primarily by the fuel itself, so the fuel should have lubricity. It has been proved that diesel engine has some extraordinary virtues when fueled with dimethyl ether (DME), but the precision pairs (plunger and needle valve pairs) of the fuel system will wear badly when pure DME is used. As well known, some vegetable oil contains fatty acid, which possess polar-headed and long straight chain in molecular, so vegetable oils should be good boundary lubrication additives. In this paper, the lubricity of pure DME and DME added with castor oil and rap oil as lubrication additive were detected. The endurance test for each kind of fuel was carried out for 160 hours. The results show that, By adding 2% castor oil or 6% rap oil into DME, the surface of plunger is no obvious wear,the maximum supply pressure of pump declines less than 6 MPa and 3MPa correspondingly, the decompression time of delivery valve decrease less than 10 seconds and 5 seconds respectively. The results demonstrate that the lubrication performance of dimethyl ether will be improved greatly by adding right amount of certain vegetable oil.

Abstract: Chemical looping hydrogen production (CLH) has become a promising technology for hydrogen production with inherent separation of carbon dioxide. This paper simulated the three reactors of CLH process of coal as solid fuel using Aspen Plus. The effects of temperature, oxygen carrier/coal ratio, steam/coal ratio, and the air/coal ratio on the gas composition in specific reactor were discussed. Simulation results showed that the temperature had a great effect on the reactor performance. The optimized OC/coal ratio in the OC/coal ratio in this paper was 19.1. The CO₂ fraction in the flue gas of FR reached 87.5% when the vapor was condensed at the temperature of 950 °C. The fraction of dry-based H₂ in the SR was almost 100% when the SR temperature was 815 °C and the steam/coal ratio was 18.8. The simulation confirmed that the CLH process showed high potential in hydrogen production and the carbon capture.

Abstract: Diesel combustion dust was analyzed by accelerated solvent extraction-high performance liquid chromatography (ASE-HPLC) in this article. The optimum extraction conditions was that N-hexane was the optimum extraction solvent, extraction time was 30min, temperature was 140°C and the pressure was 120Mpa. it could be a promising technique for the confirmation of the diesel combustion dusts.

Abstract: High energy import rates (over 90% per year) make both countries (Taiwan R.O.C. and Slovak Republic), viably engaged in research on renewable resources, also green planning policy has been proposed. Population is concentrated in the major cities which are facing energy deficiency issues; the unregulated development of micro-urban areas is underestimated in both cases so are the energy issues bound with them. Centralized energy sources require long distance wires to support remote areas; hydro energy is so far the most common, stable and efficient renewable resource in use. Water turbine’s efficiency has gone up to 96%; a proposed new multi-purpose small hydro type is one of the preliminary small scale systems that could be precisely tailored to micro-urban demands. It could stand by for direct use if needed and also use various types of working mediums (e.g. compressed gas, steam, water).

Abstract: Hanjiang River Basin Development is an important strategy in China. Xiangyang is one of the core cities on the verge of Hanjiang, occupying important place in the development in Hanjing River basin.The thesis analyze the present situation of Green energy development and utilization in Xiangyang, and then summarize main problems from utilization level, support policies, difficulties in grid-connected systems and consumption shortage and put forward some development measures at last.

Abstract: Severe corrosion phenomenon appeared in an expansion joint of blast furnace gas (BFG) pipeline after booster fan in a power plant. The sediment adhered to the inner wall of the expansion joint was analyzed by ion chromatography. The corrosion site of expansion joint was examined by scanning electron microscope (SEM), and the behavior of electrochemical corrosion of stainless steel electrode was discussed through electrochemical impedance spectroscopy (EIS) and polarization curve. The results reveal that the leaching solution of the sediment is a kind of strong electrolyte solution. Along with the increase of immersion period, the impedance of stainless steel electrode decreases dramatically, the impedance spectroscopy experiences such a procedure that a single capacitive reactance arc gradually develops into the contraction of inductive reactance and then tends to be two capacitive reactance arc, which indicates that pitting corrosion transfers from induction period to evolution period until metastable pitting translates into stable pitting. There exists no passive area in polarization curves of stainless steel and shows the characteristics of active dissolution. In conclusion, the failure of the expansion joint stainless steel shows typical pitting characteristic.