Advanced Materials Research Vols. 347-353

Abstract: The use of solar photovoltaic (PV) in residential electricity generation is encouraged by Australian governments incentive. However, what extent of residents benefit from installing a grid-connected PV system is not fully understood yet. The purpose of this study is to investigate and optimize the economic, technical and environmental performance of grid-connected PV system in Queensland, Australia. Using the price of PV devices and accessories, grid electricity tariff and sale-back tariff as economic analysis inputs, and global solar irradiation as solar energy resource data, the system is simulated and optimized by HOMER software. The optimized system not only satisfies the typical residential load of 23 kWh per day but also meet the requirement of minimizing the total costs of system investment and electricity consumption during the system life (20 years). It is found that under the weather conditions of the eleven main cities of Queensland, a PV system is an effective way to reducing electricity bills and mitigating carbon dioxide emission.

Abstract: The behavior of a foundation built on normally consolidated soft soil reinforced with stone columns (SC) and deep mixing columns (DMC) is studied using a finite element analysis program, Phase2D. The numerical predictions are analyzed in terms of absolute vertical displacement, absolute horizontal displacement, mean stresses, volumetric strain, maximum shear strain and strength reduction factor. Firstly, the effectiveness of the use of stone columns, the first composite ground, is studied. Afterwards, because load bearing capacity is less than 160 kPa designed, the effectiveness analysis reinforced with DMC, the second composite ground, is performed to study the influence on the soil-columns system of the foundation and columns.

Abstract: Nano-Sn0.25Ti0.75O2 was prepared with hydrothermal method using tetrabutyl titanate as one of the primary raw materials. The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn4+-doped nano-TiO2 is rutile, and the nanoparticles diameter was 14.49nm. Photocatalytic treatment the machining wastewater containing cadmium ions with the UV excitation by Nano-Sn0.25Ti0.75O2 was investigated. The experimental results show that Nano-Sn0.25Ti0.75O2 can be used as photocatalyst to removal Cd2+ from the wastewater effectively with the UV excitation. The wastewater pH value, the initial concentration of Cd2+, the amount of catalyst，the reaction time and other factors affect the efficiency of photocatalytic treatment significantly. The optimization experimental conditions for photocatalytic treatment wastewater containing cadmium ions are as follows, when the concentration of Cd2+ in the wastewater is 20mg/L, amount of Sn0.25Ti0.75O2 is 2g/L, pH in wastewater is 7 and the photocatalytic reaction time is 2h, the removal rate of Cd2+ from the wastewater is up to 98.4%.

Abstract: Copper(II) mixed-valence complex, [Cu(II)Cu(I)(R)3(RH)2L4].CH3COCH3 (R = C6H5COO; L = CH3COCH2C(OH)(CH3)2) (1), is a potential photovoltaic material with low bandgap It is formed as a black solid from a facile carbon-carbon bond-forming reaction involving [Cu2(C6H4COO)4(C2H5OH)2] (2) and CH3COCH3 under acidic condition. The complex was soluble in most common organic solvents, but insoluble in water. Its formula was deduced from FTIR, UV-vis, and 1H-NMR spectroscopies, TGA and GCMS. Its effective magnetic moment was 1.33 B.M. at 298 K, suggesting strong antiferromagnetic coupling between the two Cu centres. Cyclic voltammetry shows an anodic peak at +0.70 V and two cathodic peaks at +0.53 V and -1.0 V. The HOMO and LUMO energy levels are 4.9 eV and 3.7 eV respectively, and hence the bandgap energy is 1.2 eV.

Abstract: In this paper, sequential 12 months’ wind data was used which is obtained from professional observing towers and meteorological stations in Chongqing. Wind energy source was calculated and analyzed. The results of calculation and analysis based on stereo monitoring data to wind resource in Chongqing showed as following: (1) Data of meteorological stations can be used to accurately evaluate wind energy source in Chongqing; (2) There are developable wind energy source at present technology level in Chongqing; (3) Vertical profile of wind speed fitted power exponent relationship.

Abstract: Design and develop a new type of parallel hybrid electric vehicle with ISG motor, super capacitor and electric dual-clutch, based on the former automobile chassis. Look profoundly into the structure and the control strategy of the hybrid power system. The driving mode of the vehicle has been divided strictly into five modes and the torque of engine and ISG motor has been distributed rationally. The control model of the system has been built by Simulink, and the control parameters for each driving mode have been optimized through a lot of experiments. At last, the validity of control strategy has been proved and verified by the simulation platform of Matlab/Simulink and hub experiments.

Abstract: This article introduces examples of solar cities, such as the Sutton Beddington Community in United Kingdom and the Abu Dhabi City in United Arab Emirates. Meanwhile, the spate of solar city is described in detail. The most important, we point out the confusion of China's solar cities development.

Abstract: In the traditional single-phase grid-connected photovoltaic(PV) system, the output grid-current has the shortcomings of high harmonic distortion rate and slow dynamic response. In order to solve these problems, an improved method on the inverter is proposed. The inverter consists of full-bridge circuit and auxiliary circuit. With the multi-carrier PWM, the inverter produces output voltages in five levels, which can reduce the THD of the grid current. At the same time , this paper presents the power feed-forward algorithm based on traditional control method. The output power of PV array is added to the reference of current close-loop as power feed-forward, which improves the dynamic response to the input power changes. At last, the simulation results show the effectiveness of the proposed method.

Abstract: In the middle and small scale diesel engine, the interaction between the spray wall-impingement and air motion plays a fundamental role on the mixture formation process, it also greatly influences the combustion process and the exhaust emissions. An experimental setup for spray impingement visualization has been made in this paper, the influences of common rail pressure and variable inclination angles on spray impingement are investigated. The experimental results show that the splashing volume increases according to the increasing common rail pressure, and the better atomization is achieved. As for variable inclination angle of spray, the upstream of impingement spray decreases and the downstream increases with the increase of inclination of the wall, the change of entrainment is hardly detected, but the overall splashing volume increases slightly.

Abstract: This paper optimizes the running strategy of residential cogeneration system, through discussing the introduction effect of a hypothetical cogeneration system for a detached house. Based on the seasonally electricity and thermal load characteristics, several annual running strategies were set considering the cogeneration equipment’s efficiency (electricity generation and thermal recover efficiencies). By simulating hourly operation condition, the yearly energy consumption, CO2 emission and energy cost were discussed. Then, the effect of running strategy were evaluated in the view of energy saving, energy cost and environmental effects. Analysis results is that the optimal running strategy is different for different co-generation equipment’s efficiency, and then the running strategy design should considering not only energy demand but also the equipment’s efficiency performance for residential cogeneration system.