Advanced Materials Research Vols. 512-515

Abstract: LiFePO4 has attracted broad attention as a promising cathode material for lithium ion batteries. The key issues related to LiFePO₄ performance lie on the intrinsic characteristic of poor diffusion of lithium ions through an interface between LiFePO₄ and FePO₄. To explore the effect of polyaniline on performances, LiFePO₄/C cathode materials were prepared via hydrothermal method, using glucose as a carbon source and polyaniline as a modifier. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), galvanostatic charge–discharge test and cyclicvoltammetry (CV). The results show that the olivine-type phase of LiFePO₄/C is not changed by polyanilines and LiFePO₄/C is composed of relatively large particles of about 400nm and some nano-sized polyaniline particles, which favor the electronic conductivity. The LiFePO₄/C cathode material modified by 10% polyaniline has the highest uniformity. It delivers the capacity of 167.9mAh/g at 0.1C, and has good reversibility and high capacity retention.

Abstract: With unique advantages, salt cavern gas storage was got more and more attention in the field of oil industry in the world. It is a complicated system engineering to build an underground dissolved cavity to store gas with a certain shape in salt layer. Combined with the characteristics on the gas storage construction in salt layer, and based on the cavity destination and implementation process of cavity construction, cavity construction technology of salt cavern gas storage was conducted a comprehensive exposition. Through analyzing the formation process of gas storage cavity, well-types of cavity construction, water recycle modes, steps of dissolving cavity, adjustment modes of two wells distance, shape control method, roof protection technology, sealing detection, cavity stability and many other techniques were put forward on the respect of cavity construction process, cavity control and detection method. And the column combination modes of cavity construction, the methods of determining water injection flow and the measures of protecting cavity stability were recommended. It is meaningful for the design and construction of the cavity construction of salt cavern gas storage.

Abstract: It is very important to monitor and estimate thermal stability of the power battery because that the thermal runaway will happen at some high temperature. Therefore, this study was focused on thermal stability estimation of the power battery thermal stability. The thermal stability estimation model consists of collect module, judge module, cusp catastrophe estimation module and control module. The important module is cusp catastrophe estimation module which was established based on cusp catastrophe theory. The experimental results show that thermal stability estimation model of the power battery works well. Therefore, thermal stability estimation model of the power battery is helpful to monitor and estimate the safety and reliability of power battery on line.

Abstract: This article proposes a multistage cool storage system of natural coldness resource storage joint operation with refrigeration unit cool storage using heat pipe as heat transfer components. This system can realize both cold energy stored in winter used in summer which is called “Seasonal storage of cold energy” and cold energy stored at night used in the day which is called “cool storage day by day”. When the user needs cooling, it will choose different cycle way to release cold energy to the cooling user according to the temperature grade of the cool storage medium and the cooling load of the user. This system can achieve the purpose of energy conservation and environment protection.

Abstract: Cascaded hydro-thermal scheduling has many constraints increasing the difficulty of the scheduling. Furthermore, the limited energy storage capability of water reservoirs, along with the stochastic nature of their availability, make its solution a more difficult job. A multi-objective cascaded hydro-thermal scheduling model considering energy saving, emission reduction and cascade energy storage is presented. Every objective function is converted to fuzzy numbers, then it is reformulated into a single objective. Genetic algorithm is used to solve it. The simulation results show that this model increases generation benefits of hydroelectric power plants, reduces operation costs of thermal power plants, advances comprehensive benefits of power systems

Abstract: Coal as the world's most widely used fossil fuels, during the combustion process large amounts of greenhouse gas emission, which has a huge impact on global climate warming. However, coal is a nonrenewable resource, and the energy conservation is imperative. This paper, through analyzed the essential of coal combustion, and the feasibility and means for coal saving by using chemical intervention combustion. After tested the practical effects of chemical intervention coal combustion catalyst, which provided by Guangzhou Fenfang Environmental Protection Technology Co., Ltd. The results shown, the as received basis net calorific value at constant volume of the selected coal sample improved 8% which was tested by an oxygen bomb calorimeter, almost 1/6 sulfur was fixed in the cinder and the practical application coal saving effects in new dry rotary kilns and thermal power plants were more than 6%. Therefore, the chemical intervention combustion method has important significance in research and practical for coal saving and reducing emissions of pollutants.

Abstract: A model for predicting annual electricity consumption based on the combination of neural network and partial least square method was proposed. The factors affecting the annual electricity consumption are analyzed by means of partial least square method to extract the most important components so that not only the problem of multi-correlation among variables can be solves but also the amount of input dimensions of the neural network can be reduced. Besides, the application of neural network helps to solve the problem of non-linearity of the model. The application example shows that the proposed model has high precision.

Abstract: A remotely controlled energy saving combustion control system is developed in this paper. The system includes three parts: upper computer, communication program between upper and lower computer, lower computer control program. Friendly human-machine interface is designed by Labview, which realizes the remote control of PLC; With Visual C, a standard dynamic link library is designed and debugged, by which the serial communication between PC and PLC can be realized; According to the scheme of air-fuel ratio, the control programs are achieved by PLC, which realizes energy saving combustion. The results of experiment in PLC experimental platform shows that the PC can effectively control the PLC .The scheme of air-fuel ratio is similar with the actual situation.

Abstract: The decomposition of sulfur hexafluoride (SF6) in overheated electric equipment at different temperature and humidity was simulated in the study. SF6 is significantly decomposed at 350°C. SF6 is more easily decomposed in high humidity than in low humidity. The concentrations of SF6 byproducts, such as sulfur dioxide (SO2), sulfureted hydrogen (H2S) and hydrofluoric acid (HF), in high humidity are much higher than those in low humidity. Moisture in electric equipment accelerates the decomposition of SF6. In order to insure the safety operation of electric equipment, moisture in the equipment should be strictly controlled. SF6 will be decomposed to format HF. The concentration of HF will decrease when its concentration increases up to a certain concentration. It may be because that HF was strongly corrosive and its corrosion to inner equipment made the concentration of HF decreasing.

Abstract: Analyze economically and make evaluation of several investment projects of ground-source heat pump combining relevant economic evaluation methods. Compare this system with other conventional air conditioning systems in economic input to provide suggestions for applying and promoting the ground-source heat pump air-conditioning system.