Applied Mechanics and Materials Vol. 700

Abstract: With the coal energy reduction and human concern for global environmental issues,briquette development imperative. Its coal utilization, environmental pollution, etc. is becoming a hot research by many scholars at home and abroad. The key lies in one of briquette binder choice, directly to biomass as a binder, not only to meet the basic requirements of briquette, such as reducing coal ignition point,but also the prospects for the full application of biomass development.

Abstract: This paper describes the study and analysis of different techniques for online solar irradiance prediction algorithms to properly estimate over the 24 hours of the next day in the “Universidad Militar Nueva Granada” (UMNG) campus at Cajicá, Colombia, in order to use predictions for a model predicted control of a DC-micro grid. These models were designed and tested using MATLAB® software. The performance of models were evaluated and compared among them to determine the best forecasting approach for Cajicá. The absence of seasons and the noisy solar irradiance time series caused by cloudy covering as perturbation are the main particularity of the Cajicá’s climate behavior. A meteorological database from 2010 to 2014 was used to estimate or train the model of prediction ARMAX and NNF, NAR, NARX as Artificial Neural Networks (ANNs), which were compared with error criteria such as square and absolute error criteria.

Abstract: This paper presents a single axis tracking solar photovoltaic system,the system has the advantages of simple structure, high control accuracy, low cost. The tracking system be composed of sunlight sensor, controller, barrel ,motor. It can freely achieve to rotate in the space within the range from 0°to 180°. The sunshine vertical irradiation bias in the solar panel is not more than 0.3°. Compared with the fixed photovoltaic system,it can effectively improve the utilization efficiency of solar energy.

Abstract: An analyzing software was developed for studying the solar irradiance on the Universidad Militar Nueva Granada (UMNG) Campus, as well as for sizing a stand-alone photovoltaic (PV) system in terms of power generation and energy storage, which is intended to be part of an hybrid DC smart grid with several energy sources, including not only solar but additional renewable. This software has a two stage sequential structure: First, it let to calculate the total solar energy resource and define the average irradiance and its variability for several user-defined periods, i.e. daily, monthly, annual and even multiannual. Simultaneously, the software gives the user a graphical data variation, where irradiance in hours of bright sunlight (at Standard Test Conditions - STC: 1 kWh/m2) and variability are organized in a period range (hours, days or months). The sizing stage let to define the system architecture in terms of modules and batteries, i.e. estimate PV network and battery bank. Finally, after providing load, voltage level and autonomy, it proceeds to calculations, considering factors of safety.

Abstract: This work seeks to analyze the feasibility to integrate a renewable hybrid energy resource in the DC smart grid for the campus of Universidad Militar Nueva Granada (UMNG), which is located in Cajica - Cundinamarca. Taking the wind energy as the selected renewable resource, we developed software in Matlab® in order to do the analysis of meteorological data based on the Weibull’s probabilistic distribution model and the Betz’s efficient energy use method. The software shows the wind speed and power analysis based on its data input (atmospheric pressure, temperature, wind speed and direction, etc.) of the study site. The software also allows the simultaneous and differential power analysis of different types of commercial wind turbines, which is characterized and implemented into the software, for the appropriate selection. Moreover, the user is able to upload its own meteorological files or use a data base from any weather station, such as those installed by the Regional Autonomous Corporation (CAR).

Abstract: The work is devoted to solve allocation task problem in the distributed energy way in multi agents systems with multi-objective genetic algorithms. The paper shows the main advantages of genetic algorithms and the way to apply a new genetic operator using the solution information of the other agents for saving energy in the search of expand the solution of the optimal distribution.

Abstract: A passive control method is proposed for the performance enhancement of a 2D wind turbine blade using the aeroelastic coupling of locally flexible structure (LFS). An aeroelastic model of LFS airfoil is presented using the theory of shallow arch with large deformation. After the verification of numerical algorithm, the interaction between flow and LFS airfoil on the performance is studied with various elastic stiffness. The results show that the unsteady interaction between fluid and structure has a great potential to improve the aerodynamic performance of the airfoil. The lift-drag ratio of the airfoil is enhanced significantly at proper structural parameters, compared with the rigid airfoil. The idea for locally flexible structure can be considered as a smart structure for enhancing the aerodynamic performance of the wind turbine blade.

Abstract: The main circuit structure of single-phase wind power system, grid inverter model with modeling, and the design of the filters are introduced. Comparing two control strateies between several common control strategies with using Matlab/simulation tools. The results show that quasi-PR control has better performance.

Abstract: This paper discusses the importance of per-cooling vegetable and fruit, establishes a mathematical model of the solar adsorption refrigeration system collector bed. It applies activated carbon - methanol as working pairs, takes solar vacuum tube－water cooled collector bed for refrigerating, adsorption temperature and adsorption rate versus time are calculated , draw the corresponding curve figure. Analyses solar adsorption refrigeration system performance and puts forward the improvement direction.