Papers by Keyword: Load

Abstract: The thermal contact resistance (TCR) between similar and dissimilar materials (copper, aluminium, brass and type 304 stainless steel) was assessed. Copper foil, aluminium foil, lead and Sn-9Zn lead free solder were selected as thermal interface materials (TIMs). The interfacial contact pressure was varied by application of load on materials in contact. The interfacial heat flux was estimated by solving the inverse heat conduction problem (IHCP). At higher load, the temporal variation of thermal contact resistance showed early occurrence of peak and lower values of TCR. The use of thermal interface materials reduced the contact resistance between the hot source and cold sink materials. Among the interface materials used, Sn-9Zn lead free solder showed the lowest contact resistance. This was attributed to the solid to liquid phase transformation at higher temperatures and the conformance of the interface material to surfaces in contact. Factorial experiments were carried out to determine the significance of experimental variables on TCR. The analysis showed that the effect of applied load on TCR was significant compared to other parameters.

Abstract: Micro-Grid is a small system consisting of micro-power source and the load, which provide electricity and heat for the user. Micro-grid concept proposed mainly to solve large-scale, distributed power and network diversity technically and issues on the market and policy in order to play the advantages of distributed generation technologies in the economic, energy and the environment. It can maximize acceptance of distributed power, and better meet the electricity users’ requirements of power reliability and power quality. Therefore, the research and development of micro-network is an inevitable choice for a large number of distributed generation connected to the grid. This paper briefly discusses evolution of Micro-Grid development, including the difference from conventional power system, the characteristics of Micro-Grid, the present research status, and the key technologies of Smart Grid.

Abstract: In this paper, an 1000MW ultra-supercritical boiler unit was taken as the research case. The neural network, RBF, was used to build the model for the 1000MW ultra supercritical unit based on Matlab. The inputs of the model include fuel amount, feedwater flow,turbine valve opening demand. The outputs include unit load, main steam pressure and intermediate point temperature. The simulation results proved the validity of the model. The model can be used to improve the response rate of the unit load and optimize the coordinating control with certain practical engineering significance.

Abstract: With the appliances increasing on campus, illegal appliances caused a great security risk to the campus grid security. For malignant load of illegal appliances, we design intelligent detection system of load to solve the problem. First, this paper analyzes the forecasting method for campus electricity load, and does statistical analysis of the amount of college electricity load for 24 hours; followed by the overall design of intelligent detection system of malignant load, describing its features and performance indicators; finally, the system’s part implementation and source code. This

Abstract: With the large-scale EV(electric vehicle) integrating into the power system, new challenges has been brought to the planning as well as the security of the network. There will be a great impact on the system if the system operator ignores the vast quantity of EV charging at the same. Thus, taking measures, e.g. the multiple tariff, is of vital importance to give the guidance to the EV owners to charging wisely to save the daily cost on charging, as well as reduce the gap between peak load and valley load. A model for TOU has been presented in this paper. In the model , an objective function is declared to describe the purpose of TOU, and the optimal solution is gained according to the response of EV when the price of electricity changes. Finally , a case based on the daily load curve of a certain place is calculated with the model in this paper.

Abstract: Evaporative cooling is able to generate the cooling medium at a temperature approaching to the ambient wet bulb temperature. In this paper, a low-energy air-conditioning strategy is proposed, which is a combination of cooled ceiling (CC),microencapsulated phase change material (MPCM) slurry storage and evaporative cooling technologies. The assessment of evaporative cooling availability and utilization is done for five representative climatic cities, including Hong Kong, Shanghai, Beijing, Lanzhou and Urumqi in China, and the energy saving potential of the proposed air-conditioning system is analyzed by using a well validated building simulation code. The results indicate that the new system offers energy saving potential up to 80% under northwestern Chinese climate and up to 10% under southeastern Chinese climate. The optimal design method of the slurry storage tank is also proposed based on the slurry cooling storage behaviors and cooling demand variations of the ceiling panels.

Abstract: Loading and unloading material is inevitable in actual production,but the process is fussy and human injury is often happened.In this paper, a kind of four freedom pneumatic manipulator which designed can provide a convenient, comfortable, safety operation for workman. The paper will proceed the overall design , introduce the composition and basic principle ,expound the design thought .These will provide a reliable theoretical for manipulator production.

Abstract: Soil mechanics is based on mechanics, researching characteristics of soil. It include the calculation of deformation and stability of soil. The consolidation experiment is an important method for the determination of resistance to deformation and strength of foundation soil. We can know the compressibility and compression modulus of the soil by the experiment. In order to ensure the economy and safe of the structure, we calculate the final settlement using the elastic theory method and foundation specification method. Base on the experimental teaching platform of geotechnical experiment microcomputer data acquisition system, student can master steps of consolidation experiment. Besides, it can mobilize students’ seeking knowledge desire and profound understanding value of course.

Abstract: The study tested the short-term bending creep curves of Eucalyptus Plantation Wood under different loads, moisture contents and temperatures, analyzed the influence of load, moisture content and temperature on creep of Eucalyptus. Guided by the rheological theory, the study adopted the Burger rheological model to do the curve fitting and solved the model parameters. A defect found from Burger model in simulating long-term creep properties of wood was preliminary discussed and remedied. The equivalence of creep test and relaxation one was discussed.

Abstract: The forecast of natural gas load is a comprehensive and difficult job. In this paper, the gas load forecasting with analysis of environmental resources based on gray model is discussed. The load data of some city from 2002 to 2011 is considered. The different experiments are finished to validate the method. From the experiments, it can be conclude that the gray forecasting model is suitable to short term forecasting. In addition, it can also be found that the oldest data has little influence on the future forecasting data.