Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 7 Articles
Compared with front engine vehicle, the windward side�s flow field in cooling model of rear engine\nbus is complicated and it can�t be calculated by means of 1D model. For this problem, this paper\nhas used Star-CCM to build a 3D simulation model of cooling system, engine compartment and\ncomplete vehicle. Then, it had a 1D/3D coupling calculation on cooling system with Kuli software.\nIt could be helpful in the optimization design of the flow field of rear engine compartment and optimization\nmatch of cooling system....
To accelerate the pace of research and the use of alternative energy strategies Gas Hydrate, on the\nbasis of previous studies, this paper analyzes the composition characteristics of Gas Hydrate\nproduced gas. It provides technical support for our research and the use of Gas Hydrate. This eases\nthe supply and demand of energy and reduces pollution of the atmospheric environment....
External mixture formation (PFI) of a diesel fuel aerosol has employed to investigate the diesel\nHCCI engine combustion and emissions characteristics. The key to the external mixture formation\nwith diesel fuel is the proper fuel/air mixture preparation. A proposed intake diesel fuel aerosol\nsystem mainly consists of a small chamber, in which the diesel fuel is fully vaporized by means of\nfuel cavitation inside the diesel injector nozzle. Nozzle cavitation is mainly affected by the injection\npressure and the fuel system temperature. Results obtained reveal that the proposed method\ndetermines the possibility of producing a complete homogeneous fuel/air mixture, which can be\napplied to the diesel HCCI engine. With this method, the combustion and emission behavior were\nentirely optimized and the engine is capable of running in HCCI combustion mode with nearly\nideal mixture preparation. In the present investigation, a methodology for the HCCI combustion\nmode of the diesel aerosol/air mixtures based on the fuel cavitation inside the injector nozzle parameters\n(such as the injection pressure and the fuel system temperature where fuel premixed\nratio, NOx, CO, CO2, and HC emissions) have analyzed. Based on the engine performance and emissions\ncharacteristics the fuel injection pressure and the fuel system temperature have optimized\nto produce a suitable fuel premixed ratio and the perfect fuel/air mixture homogeneity at different\nengine operating conditions. The optimal injection pressure ranges between 150 - 200 bars,\nwhile the fuel system temperature lies within 175C - 200C. Loops of exhaust gas recirculation\n(EGR) are used to extend the engine load by controlling the combustion phasing....
In Middle East region, where there are plentiful amounts of solar radiation and great desert areas,\nsolar energy can play a potential role in replacing conventional fuel-operated electricity generation\nmethods with a cost-effective, sustainable solution. This paper presents a feasibility study of a\nlow-cost solar energy steam generator for rural areas electrification. The proposed system is\nbased on the use of trough concentrator which converts solar radiation into thermal energy in its\nfocal line (where a receiver pipe is installed with a fluid flowing in its interior). The aim of the paper\nis to predict the feasibility and potential for steam generation using a stand-alone solar concentrator\nwith a small dimension for domestic and small-scale electricity generation. The study\npresented here is based on modelling of the system to determine the points at which the system is\nexpected to produce sufficient steam energy at the tube outlet to drive a steam engine for producing\nelectricity. Results are presented in graphical forms to show the operating points and the effect\nof changing selected input parameters on the behavior of the system in order to set some limits\n(boundaries) for such parameters. Results show that among the three input design parameters\nselected, the tube diameter is the most dominant parameter that influences steam energy, then\nthe tube length and finally the flow rate of the water passing through the tube. The results of this\npaper can provide a useful guideline for future simulation and/or physical implementation of the\nsystem....
This paper presents sputtered-deposited Ag nanoparticles (NPs) on the encapsulant material\n(ethylene vinyl acetate, EVA) with the variation of annealing condition on crystalline silicon solar\ncell to enhance the light intensity, and a conventional solar cell is also performed for comparison.\nIt was found that an increase in the transmittance at the wavelength of 500 - 800 nm was detected\nin the Ag nanoparticle solar cells. And red-light enhancement of around 2% was measured in the\nAg-sputtered solar module under annealing condition of 700C for 3 min from incident photon to\nconverted electron (IPCE) profile. The photovoltaic performance of solar modules was characterized\nby a flasher system in AAA class (temporal instability, spectral match, and irradiance nonuniformity).\nThe IV curve showed a current enhancement with Ag-EVA sample, and thus a high\npower output around 0.250 W was observed. A high fill factor of 73.63% also implied a high performance\nin series and shunt resistance. Surface plasmonic resonance effects of Ag nanoparticles\ndeposited on the surface of solar cell were examined and discussed. This paper not only illustrated\nthe performance of the surface plasmonic resonance of a solar device but also verified the application\nin the industrial production....
This paper discusses and presents figures about the future power consumption in the world and,\nespecially in Brazil, based on the current world and Brazilian�s energy scenarios. Emphasis is given\nto the scenarios of nuclear power and uranium resources demand. A discussion on the future\nroles of thorium and uranium fuels in the replacement of the traditional resources like oil and gas\nis also presented, as it is the role of the new nuclear power plants, planned to be built in a short\nterm time horizon. This paper considers two different indexes for future projections, and the results\nobtained indicated a strong dependence on them. The time horizon for the analysis was fixed\non the time estimated for Brazil to reach its maximum in population, and parameters evaluated\nwere taken from the Brazilian�s governmental and world data on the population growth, energy\nconsumption and energy consumption per capita. Calculations show that the power consumption\nprojections for Brazil, for the adopted time horizon and working with global indexes, become\noverestimated, when compared with the results considering the national indexes. According to\nour approach, power consumption estimates using global indexes becomes approximately 4.5\ntimes higher than the estimates presented by the Brazilian indexes. This was the motivation to the\ndiscussion between the Brazilian and world energy demand scenarios, and also the roles of nuclear\nenergy in the future transition from the current conventional to alternative sources....
In recent 20 years, energy saving has been done in many projects. However, in pneumatic system,\nit is not easy to determine or measure the air power flow because of the compressibility of pneumatic\nsystem. In this paper, we used air power meter (APM) to measure the energy consumption\nof flow in pneumatic cylinder actuator system. Meter-in circuit and meter-out circuit of speed\ncontrol system are used in this research. The model of cylinder system is based on four equations:\nstate equation of air, energy equation, motion equation and flow equation. The model estimates\nthe pressure change in charge and discharge side of cylinder, and also the displacement and velocity\nof the piston. Furthermore, energy consumption could theoretically be calculated when the\nchange of air state is regarded as isothermal change. Lastly, some data of these two circuits are\nshown, and the consumption of energy is discussed....
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