volume-09-Issue 2 (2015)
IJTEE, volume-09, Issue 2 (2015) , PP 117 - 126
Published: 13 Jul 2015
by K. Bala Showry, P. Ravinder Reddy, A.V. Sita Rama Raj from DRK Institute of Science and Technology, Hyderabad, India, 500090 Mechanical Engineering Department, CBIT Hyderabad, India, 500075 Mechanical Engineering Department, JNTUH Hyderabad, India, 500085
Abstract: In order to meet the stringent emission standards, significant efforts have been imparted to the research and development of cleaner IC engines. Diesel combustion and the formation of pollutants are directly influenced by the spatial and temporal distribution of the fuel injected. The development and validation of computational fluid dynamics (CFD) models for diesel engine combustion and emissions is described. The complexity of diesel combustion requires simulation with many complex interacting sub-models in order to have success in improving the performance and to reduce the emissions. In the present work, an attempt has been made to develop a multidimensional ax-symmetric model for CI engine combustion and emissions. Later simulations have been carried out using split injection for single, double, and three pulses (split injection) for which commercial validation tool FLUENT was used for simulation. The tool solves basic governing equations of fluid flow that are continuity, momentum, species transport, and energy equation. Using the finite volume method turbulence was modeled by using the RNG K-ɛ model. The injection was modeled using the La Grangian approach and the reaction was modeled using non-premixed combustion which considers the effects of turbulence and detailed chemical mechanism into account to model the reaction rates. The specific heats were approximated using piecewise polynomials. Subsequently, the simulated results have been validated with the existing experimental values. The peak pressure obtained by simulation for single and double is 10% higher than that of the experimental value. Whereas for triple injections 5% higher than that of the experimental value. For quadruple injection, the pressure has been decreased by 10% when compared to triple injection.NOX has been decreased in simulation for single, double, and triple injections by 15%, 28%, and 20%. For quadruple injection NOX was reduced in quadruple injection by 20% to that of triple injection. The simulated value of soot for single, double, and triple injections are 12%, 22%, and 12% lesser than the experimental values. For quadruple injection, the soot levels were almost negligible. The simulated heat release rates for single, double, and triple were reduced by 12%, 18%, and 11%. For quadruple injection, heat release is reduced the same as that of triple injection read more... read less...
Keywords: Split injection, Computational Fluid Dynamics, Start of injection, Duration of injection
EnergyEfficiency Improvements through Optimization of Low Grade Industrial Waste Heat Recovery Organic Rankine Cycle by usingGeneticAlgorithms and Taguchi s Method
IJTEE, volume-09, Issue 2 (2015) , PP 107 - 115
Published: 04 Jul 2015
by Umesh Kumar, Munawar N. Karimi from Department of Mechanical Engineering, Jamia Millia Islamia, New Delhi, India
Abstract: Present work focuses on thermodynamic optimization of Organic Rankine Cycle (ORC) used for waste heat recovery from industries. The effect of variation in operating parameters is studied for three different working fluids. Parameters of the ORC are optimized with thermal efficiency, net work output and exergy destruction rate as the objective functions using genetic algorithm in MATLAB. Optimization of ORC performed by genetic algorithms is compared with that done by Taguchi’s method for the similar set of performance parameters and the same waste heat source. Both the methods revealed results in accordance with each other. ORC shows the optimized thermal efficiency with R-245fa and optimized net work output for R-134a. It is found that performance parameters have significant effect on the performance of ORC. By genetic algorithm the optimum performance can be predicted with good accuracy. read more... read less...
Keywords: Organic Rankine Cycle, Energy Efficiency, waste heat, Genetic algorithms
Design, Construction and Operation of Solar Dryer for Granules and Micros Chips of Manihot esculenta crantz Tuberous Roots
IJTEE, volume-09, Issue 2 (2015) , PP 99 - 105
Published: 05 Jun 2015
by P. Bokungu Efoto, L. Efoto Eale, S. Lukombo Singi and Mahungu Nzola Meso from Department of Physics, Faculty of sciences, University of Kinshasa, Kinshasa, D.R. Congo Scientific Committee for the Research and Development of Biodiversity (CSB), Faculty of sciences, University of Kinshasa, Kinshasa, D.R. Congo International Institute of Tropical Agriculture (IITA), 4163, Av. Haut-Congo, Gombe, Kinshasa, D.R. Congo
Abstract: This study presents the design details and the performance analyses carried out with Eloumah 1, the solar drier of cassava tuberous roots reduced in granules and microchips. Eloumah 1 is composed by a solar collector, a drying chamber and a box of rectangular section that joins the two previous components. In this solar drier the wet agricultural products are dried on the basis of the heat flux buoyancy that is induced by the difference in temperature and humidity in its compartments. Analyses of masses evaporated water of zizila and Obama (TME 419) granules and microchips tuberous roots varieties have been carried out in order to estimate the drying performance of Eloumah 1 and to know the natural laws of the drying process. The results show that Eloumah 1 is able to dry granules and microchips and to reduce their moisture contain to less than 10%. Moreover, it can be established that the drying process is a logistic process because in wet control samples, moisture contain has limited value. Therefore, the drying process cannot extract the free water beyond this limit value. The logistic function adjusts well these data based on the correlation coefficient (R2) and chi square coefficient (χ2). read more... read less...
Keywords: Manihot esculenta crantz, drying process, logistics process, drying speed function
IJTEE, volume-09, Issue 2 (2015) , PP 91 - 97
Published: 05 Jun 2015
by M.R. Guechi, P. Desevaux, P. Baucour, C. Espanet, R. Brunel and M. Poirot from University of Franche-Comté, FEMTO-ST-UMR CNRS 6174, Dept Energy, Belfort F-90000, France INSA Lyon, IMP-UMR CNRS 5223, Villeurbanne F-69621, France
Abstract: The objective of this work is the improvement of the heat dissipation and the cooling of electric motors intended for the traction of vehicles. Two ways of improvement are proposed. The first one consists in replacing the air surrounding the stator windings by resins of higher thermal conductivity. The second way consists in using the spray cooling technique to cool the hottest parts of electric motor, i.e. coil windings. The two solutions are tested independently and simultaneously. Results show that filling the coil windings with resin enables better heat dissipation in the case of basic cooling by free air convection. On the contrary, the lowest temperatures are obtained with traditional coil winding without resin and by using spray cooling. In that case, the liquid part of the spray may infiltrate inside the coil and the evaporation takes place at the hottest point. read more... read less...
Keywords: Electric motor, Thermal performance, Heat dissipation, Windings impregnation, Spray cooling
Turning to Service, Preliminary Study of a Wood Conventional Semi Industrial Dryer and Cost Price of the Wood Drying in the African Tropical Context
IJTEE, volume-09, Issue 2 (2015) , PP 83 - 90
Published: 31 May 2015
by Merlin Simo Tagne, Romain Rémond, Yann Rogaume, André Zoulalian, Eric Mougel from Douala Higher Institute of Technology, PO Box 1623, Douala-Cameroon Association for Research and Promotion of Sustainable Energy in Central Africa (ARPEDAC) University of Lorraine, LERMaB, PO Box 1041-88051, Epinal- France
Abstract: As all apparatus used permanently or not, dryers of wood require a regular maintenance in other that the entry orders are effectively operated in the dryer and these components: interior air, interior wall and wood during the drying. This maintenance also permits to obtain the real values of the measured orders to following very well the drying operation. In this paper, we present the equipment and the calibration of wood semi industrial dryer of the National Higher College of Wood Technologies and Industries (ENSTIB) of the University of Lorraine situated at Epinal-France. These actions are much importance to use this dryer for the serious scientific studies. Then, the results that we have obtained in this dryer are analyzed and validated. Ayous wood (Triplochiton Scleroxylon) is used, because desorption isotherms are well-know and desorption energy is deducted very easily. We have also estimated the appropriated wood waste to bring the energy needed by combustion. An estimation of the cost price of the drying of wood is doing in order to motivate the workers of the domain. read more... read less...
Keywords: Wood dryer, calibration, drying kinetic, enthalpy, cost price, ayous, tropical woods.
IJTEE, volume-09, Issue 2 (2015) , PP 75 - 82
Published: 31 May 2015
by Sunil J. Kulkarni, Jayant P. Kaware from Department of Chemical Engineering, Datta Meghe College of Engineering, Airoli, Navi Mumbai, India, 400708 Bhonsala College of Engineering and Research, Akola, Maharashtra, India, 444001
Abstract: Packed bed adsorption of various pollutants from effluents is efficient and cost effects method. Various factors affecting the removal percentage are initial concentration, flow rate, pH and bed height. Various models can be used to explain the packed bed adsorption. In the current work, the experimental data obtained for packed bed is fitted in the two model equations. Thomas model and Yoon Nelson model were used and the kinetic parameters were computed. Also effect of the factors like initial concentration, flow rate, pH and bed height on these kinetic parameters was studied. It was observed that these factors moderately influence the kinetic parameters. The experimental data was well described by these two models. read more... read less...
Keywords: kinetic model, parameters, capacity, concentration, saturation.
IJTEE, volume-09, Issue 2 (2015) , PP 67 - 74
Published: 02 May 2015
by Mazen Abualtayef, Reem Elghossain, Mahmoud Shatat, Israa Abushaban from Environmental Engineering Department, the Islamic University of Gaza, Gaza, Palestine, Institute of Sustainable Energy Technology – University of Nottingham, Nottingham, NG7 2RD – UK
Abstract: Sustainable energy supply is one of the main challenges that people will face over the coming decades. Biomass can make a substantial contribution to supplying future energy demand in a sustainable way. Currently it is the largest global contributor of renewable energy, and has significant potential to expand the production of heat, electricity and fuels for transport. Municipal solid waste is an enormous renewable resource that has high energy capacity because it contains a high proportion of biomass materials. This kind of sustainable waste management typically called waste-to-energy is critical for reducing the reliance on fossil fuels and non-renewable materials. Waste-to-energy is a reliable and alternative form of energy that has become the basis for many of the most successful solid waste management systems in many countries. Energy recovery from waste is the conversion of waste materials into useable heat, electricity, or fuel through a variety of processes. This study assesses the potential contribution of waste-to-energy facilities to total Gaza peak power demand up to the year 2040 based on three scenarios: incineration, anaerobic digestion and landfill gas recovery. Three dumping sites are distributed along the Gaza Strip, Johr El-deek, Deir El-balah and Rafah. The analysis shows a potential to produce about 1100 MWh per day based on the anaerobic digestion scenario, about 580 MWh per day based on incineration of municipal solid waste scenario, and about 130 MWh per day based on landfill gas recovery scenario. These values accounts to 275%, 145% and 33% of the year 2014 peak electricity demand of 400 megawatt from the three scenarios, respectively. The forecasted results of the three scenarios can be used to design future waste-to- energy facilities in the main cities of the Gaza Strip. The production cost of energy was 7¢/kWh, 5¢/kWh and 17¢/kWhfor incineration, anaerobic digestion and landfill gas recovery scenarios, respectively. read more... read less...
Keywords: Municipal solid waste, Biomass, Waste-to-Energy, Cost.
Study of the Effect of pH and Supersaturation on the Kinetics and Rate of Solid Layer Formation at External Sides of Thermal Heat Transfer Tubes
IJTEE, volume-09, Issue 2 (2015) , PP 61 - 66
Published: 07 Apr 2015
by Waid S. Omar from Chemical Engineering Department, College of Engineering, King Faisal University, Al-Hofuf, Al-Ahsaa 31982, Saudi Arabia
Abstract: The formation of scale layers at the external sides of heated tubes at situations comparable with a Multi Effect Distiller (MED) desalination processes is experimentally studied. The growth of scale layer was measured at different temperatures, pH levels and salinities. The measured scale deposition rate data were correlated to the calcium carbonate supersaturation according to a power low kinetics. It was found that the growth rate order (n) with respect to supersaturation is strongly temperature dependent. It decreases with increasing temperature. The calculated value of activation energy of scale layer growth is Ea = 33360 J/mol. The scale layer growth was found to be strongly dependent on pH. It increases in the basic medium. The salinity was found to be significant in determining the growth rate of scale layer. The scale layer composition is affected by temperature. It was found that calcium carbonate is dominant at high temperatures (80 °C). calcium sulfate deposited besides calcium carbonate at lower temperatures (60-70 °C). read more... read less...
Keywords: scale layer, outer tubes, MED, kinetics, growth, pH, Temperature, activation energy, tubes.
IJTEE, volume-09, Issue 2 (2015) , PP 53 - 60
Published: 07 Apr 2015
by Md S. Opu from Oorja Fuel Cells, Fremont, California, USA, 949
Abstract: In this fundamental research investigation, the simple fundamental experimental design with two platinum wire as anode/cathode electrode and KOH solution as electrolyte were used throughout the experiments. The effect of electrolyte volume and concentration, electrode location and submerged length into the electrolyte, distance between two electrode and operating temperature on efficiency of water electrolysis was investigated. The results showed that the performance of alkaline water electrolysis is significantly affected by distance between electrode, electrolyte concentration and operating temperature. Higher rate of hydrogen production can be possible at smaller gap between electrodes with higher concentration of electrolyte operating at higher temperature. read more... read less...
Keywords: electrolyte, anode/cathode electrode, electrode location